n-nitro-l-arginine methyl ester: Topics by WorldWideScience.org

The effects of Al{sub 2}O{sub 3}-TiO{sub 2} coating in a diesel engine on performance and emission of corn oil methyl ester

An experimental investigation has been carried out to examine for the first time the performance and combustion noise of an indirect injection diesel engine running with new fuel derived from pure jojoba oil, jojoba methyl ester, and its blends with gas oil. A Ricardo E6 compression swirl diesel engine was fully instrumented for the measurement of combustion pressure and its rise rate and other operating parameters. Test parameters included the percentage of jojoba methyl ester in the blend, engine speed, load, injection timing and engine compression ratio. Results showed that the new fuel derived from jojoba is generally comparable and a good replacement to gas oil in diesel engine at most engine operating conditions, in terms of performance parameters and combustion noise produced. (author)

2003-07-01

3

Combustion of biodiesel fuel produced from hazelnut soapstock/waste sunflower oil mixture in a Diesel engine

Today, as a result of increase in oil prices, limited fossil fuel resources, environmental consideration and global warming, the methyl ester fuels have been focused on alternative fuels. Methyl ester fuels can be used more efficiently in low heat rejection engines (LHR), in which the temperature of combustion chamber is increased by creating a thermal barrier. In this study, the piston, cylinder head, exhaust and inlet valves of a diesel engine were coated with the ceramic material Al{sub 2}O{sub 3}-TiO{sub 2} by the plasma spray method. Thus, a thermal barrier was provided for the parts of the combustion chamber with these coatings. The effects of corn oil methyl ester that produced by the transesterification method, and No. D2 fuels' performance and exhaust emissions' rate were studied by using equal in every respect coated and uncoated ...

2010-10-15

4

Characterization and effect of using cotton methyl ester as fuel in a LHR diesel engine

Biodiesel is considered as an alternative fuel to Diesel fuel No. 2, which can be generally produced from different kinds of vegetable oils. Since the prices of edible vegetable oils are higher than that of Diesel fuel No. 2, waste vegetable oils and non-edible crude vegetable oils are preferred as potential low priced biodiesel sources. In addition, it is possible to use soapstock, a by-product of edible oil production, for cheap biodiesel production. In this study, a methyl ester biodiesel was produced from a hazelnut soapstock/waste sunflower oil mixture using methanol, sulphuric acid and sodium hydroxide in a two stage process. The effects of the methyl ester addition to Diesel No. 2 on the performance and emissions of a four cycle, four cylinder, turbocharged indirect injection (IDI) Diesel engine were examined at both full and partial loads. Experimental results showed that the hazelnut ...

2005-03-01

5

Ionically conductive thin polymer films prepared by plasma polymerization. Pt. 7. Preparation and characterization of solid polymer electrolyte having fixed carboxylic acid groups with single mobile species

In the present study, surfaces of cylinder head, piston, exhaust and inlet valve of a four-stroke, direct injection, single cylinder diesel engine were coated with molybdenum (Mo) by plasma spray method. Thus, thermal barrier characteristic was brought to these parts. Variances in performance and emission values of cotton methyl ester and 2D fuel mixtures were studied in the ceramic coated and uncoated engines under the same running conditions. Performance (6.0% for specific fuel consumption) and emission values (up to 18.0% for CO, 8.0% for smoke density) of the test fuel were improved in the coated engine compared with the uncoated engine. NO_x increase (4.5%) with the increased temperatures expected in the coated engine.

2011-01-01

6

Ionically conductive thin polymer films prepared by plasma polymerization

Ultra-thin, uniform, pinhole-free solid polymer electrolyte films having a fixed carboxylic ester group of approximately 1 {mu}m thickness were prepared by polymerization of methyl acrylate and tris(2-methoxyethoxy)vinylsilane in a glow discharge plasma. The carboxylic ester group of the plasma polymer were transformed to lithium carboxylate groups by treatment with lithium iodide. This process give a single lithium ion conductive film. These solid polymer electrolyte films showed ionic conductivities of the order of 10{sup -8} S cm{sup -1} (10{sup 4} {omega} cm{sup 2} resistance per unit area) at room temperature. (orig.).

1990-08-01

7

49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

Ultrathin solid polymer electrolyte membranes containing sulfonic ester groups were prepared by polymerization of methyl benzenesulfonate and octamethylcyclotetrasiloxane in a glow discharge plasma. The sulfonic ester groups of the plasma polymer were transformed to lithium sulfonate groups by treatment with lithium iodide. Hybridization of this plasma polymer containing the lithium sulfonate groups with poly(ethylene oxide) (average Mw 300) resulted in the formation of a single lithium ion conductive film. The hybrid polymer electrolyte films were about 1 #mu#m thick, pinhole-free, adherent to various substrates, and showed ionic conductivities at 60 degrees C of the order of 10"- "6 S cm"- "1 (10"2 #OMEGA# cm"2 resistance per unit area of as-prepared solid polymer electrolyte). This material shows promise for electrochemical applications such as all solid-state lithium batteries, sensors, and electrochemical display ...

8

Stereospecific ligands and their complexes. Part VII. Synthesis, characterization and in vitro antitumoral activity of platinum(II) complexes with O,Oprime-dialkyl esters of (S,S)-ethylenediamine-N,Nprime-di-2-(4-methyl)pentanoic acid

...false Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride...193 Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride...b) Bromoacetone, methyl bromide, chloropicrin and methyl bromide mixtures,...

2010-10-01

9

British Library Electronic Table of Contents (United Kingdom)

Platinum(II) complexes (1-4) with bidentate N,Nprime-ligands, O,Oprime-dialkyl esters (alkyl = ethyl, n-propyl, n-butyl and n-pentyl), of (S,S)-ethylenediamine-N,Nprime-di-2-(4-methyl)pentanoic acid were synthesized and characterized by IR, 1H NMR and 13C NMR spectroscopy and elemental analysis. DFT calculations were performed for the complexes and it was found that only one diastereoisomer could be formed. Cytotoxic activity of complexes 1-4 was determined against chronic lymphocytic leukemia cells (CLL) and compared to the activity of ligand precursors L12HCl-L42HCl and corresponding palladium(II) complexes, [PdCl2L] (L = L1-L4). The complexes were found to exhibit significantly higher antitumor activities than cisplatin on CLL cells. Cytotoxic effect of platinum(II) complexes on CLL cel...

2011-01-01

10

Synthetic enantiopure aziridinomitosenes: preparation, reactivity, and DNA alkylation studies.

Chemical constituents of Galianthe brasiliensis (Spreng.) E.L.Cabral and Bacigalupo (Rubiaceae)

An enantiocontrolled route to aziridinomitosenes had been developed from l-serine methyl ester hydrochloride. The tetracyclic target ring system was assembled by an internal azomethine ylide cycloaddition reaction based on silver ion-assisted intramolecular oxazole alkylation and cyanide-induced ylide generation via a labile oxazoline intermediate (62 to 66). Other key steps include reductive detritylation of 26, methylation of the N-H aziridine 56, oxidation of the sensitive cyclohexenedione 68 to quinone 70, and carbamoylation using Fmoc-NCO. Although the aziridinomitosene tetracycle is sensitive, a range of protecting group manipulations and redox chemistry can be performed if suitable precautions are taken. A study of DNA alkylation by the first C-6,C-7-unsubstituted aziridinomitosene 11a has been carried out, and evidence for DNA cross-link formation involving nucleophilic addition to the quinone subunit is described. ...

2003-12-24

11

Synthesis of 4,5,6,7 and 2,4,5,6,7 deuterium-labeled indole-3-acetic acid for use in mass spectrometric assays

This paper describes the chemical constituents isolated from aerial parts of the plant Galianthe brasiliensis. From a methanol extract, the iridoid glycosides asperuloside, deacetylasperuloside, mixture of Z- and E-6-O-p-coumaroylscandoside methyl ester, the triterpene ursolic acid and the steroids stigmasterol, campesterol, b-sitosterol and 3-O-b-glucopyranosyl sitosterol were isolated. The structures of the natural products were identified on the basis of spectral data, including 2D NMR experiments. The antiproliferative properties of the crude methanolic extract were investigated against a series of nine human cancer cell lines. (author)

12

Investigation of enzymatic biodiesel production using ionic liquid as a co-solvent

Syntheses are described for tetra and pentadeutero indole-3-acetic acid (IAA) labeled in positions 4,5,6,7 or 2,4,5,6,7 of the indole moiety. Polydeuterated IAA is proposed as an internal standard for gas chromatographic-mass spectrometric analysis of IAA by selected ion monitoring. Nanogram amounts of IAA may be assayed by monitoring the base peak of IAA at m/z = 130 (134 for d/sub 4/-IAA) and the molecular ion of the methyl ester of IAA at 189 (193 for d/sub 4/-IAA). Deuterium in positions 4,5,6, and 7 and, to only a slightly lesser extent, that in position 2 of IAA is retained during alkali treatment, thus permitting use of these compounds as internal standards for assay of IAA released by alkaline hydrolysis of ester and amide conjugates. The use of polydeutero internal standards separates the standards from the isotope cluster caused by the normal abundance of heavy isotopes and also permits use of reduced mass ...

1980-10-01

13

Structure-activity relationships of anthraquinone derivatives derived from bromaminic acid as inhibitors of ectonucleoside triphosphate diphosphohydrolases (E-NTPDases)

Ionic liquids can enhance the activity, selectivity, and stability of enzyme catalysts. Enzymes and ionic liquids as catalysts are seen as a more environmentally friendly technology than the use of traditional catalyst materials in biofuels production. This study investigated the lipase catalyzed esterification reaction for biodiesel production in the presence of the ionic liquid BMIM PF{sub 6}. Methyl acetate was used as the acyl acceptor. A titremetric assay was conducted to measure the activity of the lipase with various amounts of ionic liquid. Reaction parameters were investigated in order to determine their effects on biodiesel conversion. An 80 per cent overall methyl oleate biodiesel yield was successfully produced in the presence of the ionic liquid. The ionic liquid improved lipase activity as well as overall biodiesel yield. Results also showed that the addition of the ionic liquid facilitated the separation of ...

2010-04-15

14

British Library Electronic Table of Contents (United Kingdom)

Reactive blue 2 (RB-2) had been characterized as a relatively potent ectonucleoside triphosphate diphosphohydrolase (E-NTPDase) inhibitor with some selectivity for NTPDase3. In search for the pharmacophore and to analyze structure-activity relationships we synthesized a series of truncated derivatives and analogs of RB-2, including 1-amino-2-sulfo-4-ar(alk)ylaminoanthraquinones, 1-amino-2-methyl-4-arylaminoanthraquinones, 1-amino-4-bromoanthraquinone 2-sulfonic acid esters and sulfonamides, and bis-(1-amino-4-bromoanthraquinone) sulfonamides, and investigated them in preparations of rat NTPDase1, 2, and 3 using a capillary electrophoresis assay. Several 1-amino-2-sulfo-4-ar(alk)ylaminoanthraquinone derivatives inhibited E-NTPDases in a concentration-dependent manner. The 2-sulfonate group ...

2009-01-01

15

Estimation of dietary intake of ochratoxin A from liquorice confectionery

British Library Electronic Table of Contents (United Kingdom)

Ochratoxin A (OTA) was analyzed from 44 liquorice confectionery samples using immunoaffinity cleanup and liquid chromatography coupled with fluorescence detection. The presence of OTA was confirmed by methyl-ester derivatization. Liquorice confectionery samples were purchased from different retail outlets and supermarkets in Spain during 2007-2008, 16 of hard candies and 28 of soft candies. The incidence of OTA varied between 75% and 39% and mean ranged from 2.96 to 0.34mg/kg for hard and soft candies, respectively. Assuming a total mean value of 1.29mgOTA/kg sweet and a consumption of about 1.2g liquorice sweets per day, an OTA weekly uptake of 11ng was obtained, or, based on a total body weight of 30kg for a child consuming these sweets regularly, a weekly intake of 0.37ng/kg body weight...

2009-01-01

16

Chemical constituents of Galianthe brasiliensis (Spreng.) E.L.Cabral and Bacigalupo (Rubiaceae); Constituintes quimicos de Galianthe brasiliensis (Rubiaceae)

Ester-containing halopolyalkylenes

The paper describes the chemical constituents isolated from aerial parts of the plant Galianthe brasiliensis. From a methanol extract, the iridoid glycosides asperuloside, deacetylasperuloside, mixture of Z- and E-6-O-p-coumaroylscandoside methyl ester, the triterpene ursolic acid and the steroids stigmasterol, campesterol, b-sitosterol and 3-O-b-glucopyranosyl sitosterol were isolated. The structures of the natural products were identified on the basis of spectral data, including 2D NMR experiments. The antiproliferative properties of the crude methanolic extract were investigated against a series of nine human cancer cell lines. (author)

2006-05-15

17

Phorbol esters from croton oil chemical nature and biological activities

This invention relates to polyalkylenes which contain both halogen and ester groups, to the preparation thereof, and to the use thereof as pour depressants for fuel oils. This invention also relates to polyalkylene esters.

1985-11-19

18

Improving the performance of dual fuel engines running on natural gas/LPG by using pilot fuel derived from jojoba seeds

Not Available

1967-01-01

19

Esters useful as brain imaging agents

The use of jojoba methyl ester as a pilot fuel was investigated for almost the first time as a way to improve the performance of dual fuel engine running on natural gas or liquefied petroleum gas (LPG) at part load. The dual fuel engine used was Ricardo E6 variable compression diesel engine and it used either compressed natural gas (CNG) or LPG as the main fuel and jojoba methyl ester as a pilot fuel. Diesel fuel was used as a reference fuel for the dual fuel engine results. During the experimental tests, the following have been measured: engine efficiency in terms of specific fuel consumption, brake power output, combustion noise in terms of maximum pressure rise rate and maximum pressure, exhaust emissions in terms of carbon monoxide and hydrocarbons, knocking limits in terms of maximum torque at onset of knocking, and cyclic variability data of 100 engine cycles in terms of maximum pressure and its ...

2008-06-15

20

Esters useful as brain imaging agents

Certain radioiodine containing esters useful as brain imaging agents are disclosed. The formula of these compounds are presented.

1981-08-18

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

21

Effect of esters on lubricity of hydrotreated jet fuel

Certain radioiodine containing esters useful as brain imaging agents are disclosed. The formula of these compounds are presented.

22

Mechanism of trypsin inactivation by intact Hymenolepis diminuta (Cestoda)

The authors synthesized a number of esters of stearic acid with polyhydric alcohols and ran comparative tests on aliphatic alcohols to determine their effects on the antiwear properties of the fuel. They conclude that the differences in effectiveness in improving the lubricity by the use of aliphatic alcohols and the full and partial esters of polyhydric alcohols and stearic acid can be explained by the presence of hydroxyl and ester groups close to each other in partial esters. This is reflected in the higher polarity of the partial esters, a higher rate of adsorption, and a stronger bonding of the adsorbed layer to the metal surface.

1985-07-01

23

Investigation of novel organic n-type semiconductors in photovoltaic bulk heterojunction

The mechanism of trypsin inactivation by intact Hymenolepis diminuta has been investigated by biochemical and autoradiographic methods. Although worms inactivate trypsin and chymotrypsin in vitro, no inactivation of other endoproteases (subtilisin, pepsin and papain) could be demonstrated. Trypsin inactivation, as demonstrated by macromolecular substrates (azoalbumin, hemoglobin and casein), could not be detected using low molecular weight synthetic substrates such as N-p-benzoyl-DL-arginine-p-nitroanilide (BAPA) or N-p-tosyl-L-arginine methyl ester (TAME). In addition, the kinetic parameters (K/sub m/ and k_3) for H. diminuta-inactivated trypsin, using BAPA as the substrate, were not different from those of the native enzyme. The number of active sites for both native and inactivated trypsin were determined by titration with p-nitro-phenyl-p'-guanidinobenzoate. Absorbance values for both titrations were found to be identical. Dialysis, heating ...

1979-01-01

24

Exhaust emissions from a Diesel engine fueled with transesterified waste olive oil

Two novel organic n-type semiconductors are investigated due to their function as electron acceptor for applications in organic electronic devices to widen the knowledge of how molecule structure influences the excitation processes in organic electronics. Bispyrenylfullerene and Octadecyl-Capronacidesterfullerene are C{sub 60} derivates with sidechains more featured compared to the commonly used[6,6] phenyl-C{sub 61}-butyric acid methyl ester (PCBM). In bulk heterojunction devices regioregular poly(3-hexylthiophene) (P3HT) was used as donor. The materials, pristine and in blend, were studied in view of light absorption, their quenching abilities of the P3HT photoluminescence as well as excited states. Furthermore, the spin state of the excited states was determined by light-induced electron spin resonance. Combining these complimentary experimental techniques, we obtained information on the generation of excited states, their nature, and the ...

2009-07-01

25

Effects of Thermal Annealing Upon the Nanomorphology of Poly(3-hexylselenophene)-PCBM Blends

The exhaust emissions of a Diesel direct injection Perkins engine fueled with waste olive oil methyl ester were studied at several steady-state operating conditions. Emissions were characterized with neat biodiesel from used olive oil and conventional Diesel fuel. Results revealed that the use of biodiesel resulted in lower emissions of CO (up to 58.9%), CO{sub 2} (up to 8.6%, excepting a case which presented a 7.4% increase), NO (up to 37.5%), and SO{sub 2} (up to 57.7%), with increase in emissions of NO{sub 2} (up to 81%, excepting a case which presented a slight reduction). Biodiesel also presented a slight increase in brake-specific fuel consumption (lower than 8.5%) that may be tolerated due to the exhaust emission benefits. Combustion efficiency remained constant using either biodiesel or Diesel fuel. The proposed alternative for Diesel fuel could significantly decrease the enormous amount of waste frying oil, furthermore becoming less ...

2003-07-01

26

British Library Electronic Table of Contents (United Kingdom)

Abstract Grazing incidence X-ray diffraction (GI-XRD) is used to characterize the crystallographic dynamics of low molecular weight (LMW) and high molecular weight (HMW) poly(3-hexylselenophene) (P3HS) films and blend films of P3HS with [6-6-]-phenyl-C61-butyric acid methyl ester (PCBM) as a function of -step-by-step- thermal annealing, from room temperature to 250-C. The temperature-dependent GIXRD data show how the melting point of P3HS crystallites is decreased by the presence of PCBM. P3HS crystallite domain sizes dramatically increase upon annealing to the P3HS melting temperature. The formation of well-oriented HMW P3HS crystallites with the (100) plane parallel to the substrate (edge-on orientation), when cooled from melt, are observed. We compare the behaviour of P3HS pure and blen...

2011-01-01

27

Additive effects common to radiation grafting and wood plastic composite formation

Biodiesel development from high acid value polanga seed oil and performance evaluation in a CI engine

A range of additives has been developed for enhancing grafting yields in a variety of systems initiated by ionizing radiation. Cellulose has been adopted as the predominant naturally occurring model backbone polymer in these studies because of its structural relationship to wood which is the reference substrate for the work reported in the related second part of this paper concerning composites. Some experiments have been performed with the other major naturally occurring polymer, wool. For comparison purposes with synthetic materials, some studies have also been performed with polypropylene as trunk polymer. Styrene has been used as a predominant monomer in grafting with some experiments utilizing the acrulates like methyl methacrylate. The role of solvent in grafting has been evaluated. UV has been used as initiator to replace ionizing radiation for certain experiments. The additives used were mineral acids, lithium salts, multifunctional acrylates and their ...

1996-08-01

28

Determination of alcohols, esters and organic acids in irradiated sweet potato wine by capillary gas chromatography

Non-edible filtered high viscous (72 cSt at 40{sup o}C) and high acid value (44 mg KOH/gm) polanga (Calophyllum inophyllum L.) oil based mono esters (biodiesel) produced by triple stage transesterification process and blended with high speed diesel (HSD) were tested for their use as a substitute fuel of diesel in a single cylinder diesel engine. HSD and polanga oil methyl ester (POME) fuel blends (20%, 40%, 60%, 80%, and 100%) were used for conducting the short-term engine performance tests at varying loads (0%, 20%, 40%, 60%, 80%, and 100%). Tests were carried out over entire range of engine operation at varying conditions of speed and load. The brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) were calculated from the recorded data. The engine performance parameters such as fuel consumption, thermal efficiency, exhaust gas temperature and exhaust emissions (CO, CO{sub 2}, HC, NOx, and O{sub 2}) ...

2007-02-15

29

A Detailed Chemical Kinetic Reaction Mechanism for Oxidation of Four Small Alkyl Esters in Laminar Premixed Flames

This paper presents the analytical results of alcohols, esters and organic acids in sweet potato wine irradiated by #gamma#-rays. (author).

30

Sugar Ester Modified Lipase Catalyzed Esterification in Organic Media.

Abstract not provided

2008-07-14

31

British Library Electronic Table of Contents (United Kingdom)

The esterification reaction of a long-chain fatty acid and a fatty alcohol catalyzed by sugar ester-modified lipases in organic media was studied. The reaction activity was improved when the lipases were modified with sugar esters. Among four kinds of sugar esters and six kinds of lipases, lipase CES modified with sugar ester SE-7 showed the highest reaction activity. The pH, solvent and temperature on the reaction activity of SE-7 modified lipase CES were also studied. PMID:12142919

1999-01-01

32

Cleavable surfactants

The review covers the development within the field of cleavable surfactants since 2003. Cleavable surfactants are amphiphiles in which a weak linkage has been deliberately inserted, normally, but not always, between the hydrophobic tail and the polar headgroup. Alkali labile linkages that have been used for the purpose include normal ester bonds, betaine esters, and carbonates. Ketals and ortho esters are example of bonds that are susceptible to acid hydrolysis. Several investigations deal with cationic ester-containing surfactants, both monomeric and dimeric species, the latter being gemini surfactants. Ester, amide and carbonate containing surfactants have been investigated with respect to enzyme catalyzed hydrolysis. The main incentive for the development of novel cleavable surfactants ...

2007-01-01

33

METHOD FOR SYNTHESIZING [11C] METHYL HALIDE

J-STORE (Japan)

Full Text Available

2005-04-08

34

Some aspects of the pharmacology of an homologous series of choline esters of fatty acids

Method for inhibiting fouling of petrochemical processing equipment

The pharmacological effects of a series of fatty acid-choline esters have been studied on the isolated rabbit heart, the isolated guinea-pig ileum and the rat stomach. The effect changed with increasing...Full Text Available

1957-03-01

35

Comparison of estimation capabilities of response surface methodology (RSM) with artificial neural network (ANN) in lipase-catalyzed synthesis of palm-based wax ester

Method for inhibiting the formation of foulants on petrochemical equipment which involves adding to the petrochemical, during processing, a composition comprising a thiodipropionate and either a dialkyl acid phosphate ester or a dialkyl acid phosphite ester.

1980-10-07

36

["3H]Indole-3-acetyl-myo-inositol hydrolysis by extracts of Zea mays L. vegetative tissue

BackgroundWax esters are important ingredients in cosmetics, pharmaceuticals, lubricants and other chemical industries due to their excellent wetting property. Since the naturally...Full Text Available

37

Studies on dual fuel operation of rubber seed oil and its bio-diesel with hydrogen as the inducted fuel

["3H]Indole-3-acetyl-myo-inositol was hydrolyzed by buffered extracts of acetone powders prepared from 4 day shoots of dark grown Zea mays L. seedlings. The hydrolytic activity was proportional to the amount of extract added and was linear for up to 6 hours at 37"0C. Boiled or alcohol denatured extracts were inactive. Analysis of reaction mixtures by high performance liquid chromatography demonstrated that not all isomers of indole-3-acetyl-myo-inositol were hydrolyzed at the same rate. Buffered extracts of acetone powders were prepared from coleoptiles and mesocotyls. The rates of hydrolysis observed with coleoptile extracts were greater than those observed with mesocotyl extracts. Active extracts also catalyzed the hydrolysis of esterase substrates such as #alpha#-naphthyl acetate and the methyl esters of indoleacetic acid and naphthyleneacetic acid. Attempts to purify the indole-3-acetyl-myo-inositol hydrolyzing activity by chromatographic ...

38

Solution processable fluorenyl hexa-peri-hexabenzocoronenes in organic field-effect transistors and solar cells

The main problems with the use of neat vegetable oils in diesel engines are higher smoke levels and lower thermal efficiency as compared to diesel. The problem can be tackled by inducting a gaseous fuel in the intake manifold along with air. In this investigation, hydrogen is used as the inducted fuel and rubber seed oil (RSO), rubber seed oil methyl ester (RSOME) and diesel are used as main fuels in a dual fuel engine. A single cylinder diesel engine with rated output of 4.4 kW at 1500 rpm was converted to operate in the dual fuel mode. Dual fuel operation of varying hydrogen quantity with RSO and RSOME results in higher brake thermal efficiency and significant reduction in smoke levels at high outputs. The maximum brake thermal efficiency is 28.12%, 29.26% and 31.62% with RSO, RSOME and diesel at hydrogen energy share of 8.39%, 8.73% and 10.1%, respectively. Smoke is reduced from 5.5 to 3.5 BSU with RSOME and for RSO it is from 6.1 to 3.8 BSU ...

2008-11-15

39

Pathways for the degradation of organic photovoltaic P3HT:PCBM based devices

The organization of organic semiconductor molecules in the active layer of organic electronic devices has important consequences to overall device performance. This is due to the fact that molecular organization directly affects charge carrier mobility of the material. Organic field-effect transistor (OFET) performance is driven by high charge carrier mobility while bulk heterojunction (BHJ) solar cells require balanced hole and electron transport. By investigating the properties and device performance of three structural variations of the fluorenyl hexa-peri-hexabenzocoronene (FHBC) material, the importance of molecular organization to device performance was highlighted. It is clear from {sup 1}H NMR and 2D wide-angle X-ray scattering (2D WAXS) experiments that the sterically demanding 9,9-dioctylfluorene groups are preventing {pi}-{pi} intermolecular contact in the hexakis-substituted FHBC 4. For bis-substituted FHBC compounds 5 and 6, {pi}-{pi} intermolecular contact was observed in ...

2010-03-24

40

Synthesis of esters from lupeol isolated from Maytenus salicifolia (Celastraceae)

We report on studies of device degradation in organic photovoltaic devices based on blends of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM). Since delamination, oxidation, and chemical interactions at the metal electrode/organic interface have long been posited as degradation pathways in organic electronic devices, we first investigated the stability of a variety of electrodes for devices stored in an inert, dark environment. Second, a set of experiments was designed to separate the effects at the metal/organic interface from the degradation of the active layer or the hole extraction interface. To do this, Ca/Al electrodes were deposited to complete half of a substrate's devices, and samples were left both under constant illumination and 10% illumination (10% duty cycle of 1 sun illumination) in a glovebox environment. After more than 200 h of measurement, additional electrodes were deposited and ...

2008-07-15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

41

Thio Wax Ester Biosynthesis Utilizing the Unspecific Bifunctional Wax Ester Synthase/Acyl Coenzyme A:Diacylglycerol Acyltransferase of Acinetobacter sp. Strain ADP1

Portuguese 2009 1 p. Brazil Magalhaes, Cassia Goncalves Silva, Gracia

42

Power transmitting fluids containing esters of hydrocarbyl succinic acid or anhydride with thio-bis-alkanols

The bifunctional wax ester synthase/acyl coenzyme A (acyl-CoA):diacylglycerol acyltransferase (WS/DGAT) from Acinetobacter sp. strain ADP1 (formerly Acinetobacter calcoaceticus...Full Text Available

2005-02-01

43

UHRF1, a modular multi-domain protein, regulates replication-coupled crosstalk between DNA methylation and histone modifications

Mineral oil based power transmitting fluids, such as automatic transmission fluids, are disclosed which contain 0.05 to 2.0 weight percent of an ester of a thio-bis alkanol and a C/sub 12/-C/sub 50/ hydrocarbon succinic acid or anhydride, the ester being a multifunctional additive providing the properties of friction modification, corrosion inhibition, anti-wear, oxidation inhibition and extreme pressure properties to the fluids.

1987-10-27

44

Dissociation dynamics of methylal

Cytosine methylation in DNA is a major epigenetic signal, and plays a central role in propagating chromatin status during cell division. However the mechanistic links between DNA methylation...Full Text Available

2009-01-01

45

A new gene (alkB) of Escherichia coli that controls sensitivity to methyl methane sulfonate.

The dissociation of methylal is investigated using mass spectrometry, combined with a pyrolytic radical source and femtosecond pump probe experiments. Based on preliminary results two reaction paths of methylal dissociation are proposed and discussed. (author) 4 fig., 3 refs.

1999-08-01

46

Site-Specific Methylation of the Promoter Alters Deoxyribonucleic Acid-Protein Interactions and Prevents ...

Seven mutants of Escherichia coli were isolated that are sensitive to methyl methane sulfonate but not to UV light. They exhibited decreased host cell reactivation capacity for methyl methane sulfonate-treated...Full Text Available

1983-03-01

47

Methods in DNA methylation profiling

... and R. L. Momparler. DNA methylation of retinoic acid receptor beta in breast cancer and possible therapeutic role of ... ...

48

Production and use of biodiesel

Metastable and somatically heritable patterns of DNA methylation provide an important level of genomic regulation. In this article, we review methods for analyzing these genome-wide epigenetic...Full Text Available

2009-12-01

49

Preparation and Properties of New Ester-Linked Cleavable Gemini Surfactants

Biodiesel is produced from vegetable oils that have been chemically modified by esterification; an example is rapeseed oil methyl ester (RME), made by treating rapeseed oil with methanol. Biodiesel can be burned directly in diesel engines. Oil from the rapeseed variety known as 00 was the first type of vegetable oil used for transesterification to produce biodiesel. Many other oils have been used successfully as biodiesel feedstock including sunflower oil in Southern France and Italy, soybean oil in the USA, and palm oil in Malaysia. Biodiesel can be made from a wide range of feedstock and multi-feedstock blends. Compared to conventional diesel biodiesel has some environmentally friendly advantages, e.g. biodiesel is reported to release fewer solid particles. Potentially even more important is the low level of carbon dioxide generation associated with biodiesel, at a time when CO{sub 2} emissions are falling in every industrial sector except ...

2003-11-01

50

British Library Electronic Table of Contents (United Kingdom)

We have prepared a series of novel gemini surfactants having ester bonds in their structures. These surfactants possess two identical hydrophilic polyethylene glycol moieties, two hydrophobic alkyl group moieties, and an anionic spacer. The structures of these compounds were confirmed through infrared and nuclear magnetic resonance spectroscopic and elemental analyses. The novel gemini surfactants exhibit excellent surface activity in terms of their surface tension, low-foaming, wetting power, and fluorescence properties. The presence of the ester linkages made these structures cleavable surfactants.

2011-01-01

51

Free radicals in lysozyme reacted with peroxidizing methyl linoleate

Preparation of wood-plastic composites by impregnation with vinyl ester monomer combinations and polymerization with gamma radiation

... electron spin resonance gamma radiation lipids lyophilization lysozyme radicals

52

Analysis of Mammalian Carboxylesterase Inhibition by Trifluoromethylketone-Containing Compounds

(1972). Germany Garratt, PG Hoigne, J. INRESCOR AG, Schwarzenbach

1972-01-01

53

Phthalate esters used as plasticizers in packed red blood cell storage bags may lead to progressive toxin exposure and the release of pro-inflammatory cytokines

Carboxylesterases (CE) are ubiquitous enzymes that hydrolyze numerous ester-containing xenobiotics, including complex molecules, such as the anticancer drugs irinotecan (CPT-11) and capecitabine...Full Text Available

2007-03-01

54

ras gene alterations in invasive and non-invasive rat bladder carcinomas induced by N-methyl-N-nitrosourea.

Phthalate esters (PE's) are plasticizers used to soften PVC-based medical devices. PE's are the most abundant man-made pollutants and increase the risk of developing an allergic respiratory disease...Full Text Available

2009-07-01

55

The fission yeast gene pmt1+ encodes a DNA methyltransferase homologue.

We have established a reliable method to induce invasive and non-invasive carcinomas in the heterotopically transplanted urinary bladder of rats by repeated injection of N-methyl-N-nitrosourea (MNU),...Full Text Available

1991-07-01

56

Scintillation proximity assay for measurement of RNA methylation

DNA methylation of cytosine residues is a widespread phenomenon and has been implicated in a number of biological processes in both prokaryotes and eukaryotes. This methylation occurs at the 5-position...Full Text Available

1995-01-25

57

Practical, Stereoselective Synthesis of Cecropia Juvenile Hormone

Methylation of RNA by methyltransferases is a phylogenetically ubiquitous post-transcriptional modification that occurs most extensively in transfer RNA (tRNA) and ribosomal RNA (rRNA). Biochemical...Full Text Available

2009-03-01

58

Methanogen Diversity Evidenced by Molecular Characterization of Methyl Coenzyme M Reductase A (mcrA) Genes in Hydrothermal Sediments of the Guaymas Basin

The high-yield, stereoselective conversion of geraniol (3,7-dimethyl-trans-2,6-octadien-1-ol) to the insect juvenile hormone, methyl 12,14-dihomojuvenate (methyl cis-10-epoxy-3,11-dimethyl-7-ethyl-trans,...Full Text Available

1971-06-01

59

Induction of bladder cancer in rats by fractionated intravesicular doses of N-methyl-N-nitrosourea.

The methanogenic community in hydrothermally active sediments of Guaymas Basin (Gulf of California, Mexico) was analyzed by PCR amplification, cloning, and sequencing of methyl coenzyme M reductase...Full Text Available

2005-08-01

60

Identification of a Novel Inhibitor of Coactivator-associated Arginine Methyltransferase 1 (CARM1)-mediated Methylation of Histone H3 Arg-17*

Experiments were conducted to determine the dose response of rat bladder urothelium to a range of different single and fractionated intravesicular doses of the carcinogen, N-methyl-N-nitrosourea (MNU)....Full Text Available

1982-03-01

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61

Identification and Functional Relevance of de novo DNA Methylation in Cancerous B-Cell Populations

Methylation of the arginine residues of histones by methyltransferases has important consequences for chromatin structure and gene regulation; however, the molecular mechanism(s) of methyltransferase...Full Text Available

2010-03-05

62

An Arabidopsis thaliana methyltransferase capable of methylating farnesoic acid?

Epigenetic remodeling is a hallmark of cancer, with the frequent acquisition of de novo DNA methylation in CpG islands. However, the functional relevance of de novo...Full Text Available

2010-03-01

63

Intermediates to ethylene glycol: carbonylation of formaldehyde catalyzed by Nafion solid perfluorosulfonic acid resin

We previously reported the identification of a new family of plant methyltransferases (MTs), named the SABATH family, that use S-adenosyl-l-methionine (SAM) to methylate...Full Text Available

2006-04-15

64

A new zinc hydroxide nitrate heterogeneous catalyst for the esterification of free fatty acids and the transesterification of vegetable oils

Details of a series of reactions for the production of ethylene glycol using a catalyst of Nafion solid perfluorosulfonic acid resin was detailed. The reactions included the carbonylation of formaldehyde and esterification and then hydrogenation of the product of the carbonylation, glycolic acid. Other preparations included in the work included methyl glycolate, acetylglycolic acid, methyl acetylglycolate, and methyl methoxyacetate.

1983-01-01

65

British Library Electronic Table of Contents (United Kingdom)

A new heterogeneous catalyst for the esterification of free fatty acids and the transesterification of vegetable oils is reported. The layered compound zinc hydroxide nitrate (Zn5(OH)8(NO3)22H2O) was very effective in the alcoholysis of palm oil and the esterification of lauric acid with m(ethanol), even when hydrated ethanol was used. Over the range of 100-140degreeC, the ester yield was the highest at 140degreeC, while the catalyst concentration had a much greater effect on ester yields than the molar ratio of alcohol to acid did. Total ester contents above 95wt% were obtained in both reactions and 93.2wt% glycerin streams were recovered as a result of methanolysis.

2008-01-01

66

Antimalarial activity of selected Sudanese medicinal plants with emphasis to Maytenus senegalensis

Hypomethylation and induction of retinoic acid receptor beta 2 by concurrent action of adenosine analogues and natural compounds in breast cancer cells

The aim of the present study is to identify and characterize the antimalrial agents from traitional Sudanese medicinal plants. 49 plants parts representing 26 species from 15 families were extracted and screened for their in vitro antimalrial activity using P. falciparum strain 3D7 which is chloroquine sensitive and Dd2 strain which is chloroquine resistant and pyrimethamine sensitive.The plant species investigated exhibited diverse botanical families. They includes Annonaceae, Aristolochiaceae, Asteraceae, Balantiaceae, Caesalpiniceae, Celasteraceae, Cucurbitaceae, Fabaceae, Graminae, Meliaceae, Myrtaceae, Polygonaceae, Rubiaceae, Rutaceae, and simaroubaceae. The evaluation of these plants for their antimalarial activity and their effect on lymphocyte proliferation was carried out. 57 extracts were tested on the chloroquine sensitive strain (3D7). Where 34 extracts (59%) exhibited significant activity against 3D7 with IC_5_0 values #100 #mu# g/ml), where as Sonochous cornatus, ...

67

British Library Electronic Table of Contents (United Kingdom)

DNA methylation is considered as a potential cause of aberrations in regulation of gene expression during carcinogenesis. Therefore, changes in DNA methylation patterns may be targets for chemoprevention. In the present study, we investigated effects of all-trans retinoic acid (ATRA), vitamin D3, and resveratrol alone and in combination with adenosine analogues: 2-chloro-2'-deoxyadenosine (2CdA) and 9-beta-d-arabinosyl-2-fluoroadenine (F-ara-A), on methylation and expression of retinoic acid receptor beta 2 (RARbeta2) in MCF-7 and MDA-MB-231 breast cancer cell lines. Alterations in methylation and expression levels after treatment of cells with the tested compounds were evaluated by methylation-sensitive restriction analysis (MSRA) and real-time PCR, respectively. RARbeta2 promoter in the ...

2010-01-01

68

Headspace gas chromatographic method for determination of methyl bromide in food ingredients

Tyrosine-derived polycarbonate membrane in treating mandibular bone defects. An experimental study

A headspace gas chromatographic (GC) method, which can be automated, has been developed for determination of methyl bromide. This method has been applied to wheat, flour, cocoa, and peanuts. Samples to be analyzed are placed in headspace sample vials, water is added, and the vials are sealed with Teflon-lined septa. After an appropriate equilibration time at 32 degrees C, the samples are analyzed within 10 h. A sample of the headspace is withdrawn and analyzed on a gas chromatograph equipped with an electron capture detector (ECD). Methyl bromide levels were quantitated by comparison of peak area with a standard. The standard was generated by adding a known amount of methyl bromide to a portion of the matrix being analyzed and which was known to be methyl bromide free. The detection limit of the method was 0.4 ppb. The coefficient of variation (CV) was 6.5% for wheat, 8.3% for flour, 3.3% for cocoa, and ...

1985-11-01

69

Topical Application of 5-Aminolevulinic Acid Hexyl Ester and 5-Aminolevulinic Acid to Normal Nude Mouse Skin: ...

This study was designed to evaluate the suitability of a novel bioabsorbable material in treating bone defects. A poly(desaminotyrosyl-tyrosine-ethyl ester carbonate) (PDTE carbonate) membrane (thickness...Full Text Available

2006-10-22

70

Synthesis and characterization of a biotinylated organophosphorus ester for detection and affinity purification of a brain serine esterase: neuropathy target esterase.

... J. W. and R. A. de Zeeuw. 1990. Transdermal drug delivery: efficacy and potential applications of the penetration enhancer ... ...

71

Red Light-Regulated Growth ¹

We have synthesized a novel stable precursor, saligenin phosphorotrichloridate, which, on reaction with N-monobiotinyldiamines, generates a series of biotinylated covalent inhibitors of serine esterases....Full Text Available

1994-07-15

72

Protein thiolation and reversible protein-protein conjugation. N-Succinimidyl 3-(2-pyridyldithio)propionate, a new heterobifunctional reagent.

We examined the changes in the levels of indoleacetic acid (IAA), IAA esters, and a 22-kilodalton subunit auxin-binding protein (ABP1) in apical mesocotyl tissue of maize (Zea mays...Full Text Available

1991-09-01

73

Nasal retention of budesonide and fluticasone in man: Formation of airway mucosal budesonide-esters in vivo

A heterobifunctional reagent, N-succinimidyl 3-(2-pyridyldithio)propionate, was synthesized. Its N-hydroxysuccinimide ester group reacts with amino groups and the 2-pyridyl disulphide structure reacts...Full Text Available

1978-09-01

74

I. Cyclopeptide Alkaloids; II. Phycocyanobilipeptides.

AimsThe efficacy of topical glucocorticosteroids in rhinitis and asthma is likely to depend on drug retention in the airway mucosa. With fluticasone propionate, retention may be...Full Text Available

2001-02-01

75

Eugenol and isoeugenol, characteristic aromatic constituents of spices, are biosynthesized via reduction of a coniferyl alcohol ester

Several examples of the 14-membered, para-bridged ring system of the cyclopeptide alkaloids have been synthesized via an active ester cyclization. The yield of monomeric cyclopeptide varied from 1 to 33% and was affected by the amino acid substitution pat...

1979-01-01

76

Chemical modification of soybean oil for lubricant

Phenylpropenes such as chavicol, t-anol, eugenol, and isoeugenol are produced by plants as defense compounds against animals and microorganisms and as floral attractants of pollinators....Full Text Available

2006-06-27

77

Changes in Amide-Linked and Ester Indole-3-Acetic Acid in Cotton Fruiting Forms during Their Development

This paper presents a series of structural modifications of soybean oils for lubricant. The reaction was monitored and products were confirmed by NMR and FTIR. The structural modification is carried out in four stages, (1) synthesis of soybean oil isooctyl ester from soybean oil; (2) synthesis of epoxy-soybean oil isooctyl ester from soybean oil isooctyl ester; (3) synthesis of hydroxylated products from epoxy soybean oil isooctyl ester with fatty acid; (4) esterification of the hydroxylated product with anhydride. Rheological behaviour of the products was measured. Pour points of the products (3) were observed as low as -24 C (lauric acid) and -15 C (isooctanoic acid) respectively. When the hydroxyl groups in the products were esterified with and acid anhydride, the pour points were became higher, which were -21 C (lauric acid) and -6 C (isooctanoic acid) without pour point depressant, and -27 C ...

2008-07-01

78

CID755673 enhances mitogenic signaling by phorbol esters, bombesin and EGF through a protein kinase D-independent pathway

The concentration of free indoleacetic acid (IAA) is high in cotton (Gossypium hirsutum L.) fruiting forms before anthesis, but is low at and for a few days after anthesis. Amide-linked...Full Text Available

1989-03-01

79

Biotransformation of Explosives by the Old Yellow Enzyme Family of Flavoproteins

Recently, CID755673 was reported to act as a highly selective inhibitor of protein kinase D (PKD). In the course of experiments using CID755673, we noticed that it exerted unexpected stimulatory...Full Text Available

2010-01-01

80

Alkyl acrylate adducts of polyamines, ether amines and ether polyamines

Several independent studies of bacterial degradation of nitrate ester explosives have demonstrated the involvement of flavin-dependent oxidoreductases related to the old yellow enzyme (OYE) of yeast....Full Text Available

2004-06-01

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81

UHRF1, a modular multi-domain protein, regulates replication-coupled crosstalk between DNA methylation and histone modifications

Disclosed are additives for hydrocarbon fuels which are the reaction products of a polyamine and an alkyl ester of acrylic or alkyl acrylic acid. A preferred composition is a mixture of the reaction product and oxygenated or non-oxygenated mono- or polyamines.

1980-12-23

82

6-Methyl-1,2,4-benzenetriol, a new intermediate in penicillic acid biosynthesis in Penicillium cyclopium

Cytosine methylation in DNA is a major epigenetic signal, and plays a central role in propagating chromatin status during cell division. However the mechanistic links between DNA methylation and histone methylation are poorly understood. A multi-domain protein UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1) is required for DNA CpG maintenance methylation at replication forks, and mouse UHRF1-null cells show enhanced susceptibility to DNA replication arrest and DNA damaging agents. Recent data demonstrated that the SET and RING associated (SRA) domain of UHRF1 binds hemimethylated CpG and flips 5-methylcytosine out of the DNA helix, whereas its tandom tudor domain and PHD domain bind the tail of histone H3 in a highly methylation sensitive manner. We hypothesize that UHRF1 brings the two components (histones and DNA) carrying appropriate markers (on the tails of H3 ...

2009-01-01

83

Reaction pathways of the dissociation of methylal: A DFT study

Penicillic acid-negative mutants were obtained from a color mutant derived from Penicillium cyclopium NRRL 1888 through N-methyl-N'-nitro-N-nitrosoguanidine treatment. One mutant (SK2N6) accumulated 6-methyl-1,2,4-benzenetriol, which was not previously known to be a metabolite of P. cyclopium, in addition to orsellinic acid and orcinol. The radioactivity of [1-"1"4C]acetic acid was rapidly incorporated into 6-methyl-1,2,4-benzenetriol in a culture of P. cyclopium SK2N6. Moreover, the radioactivity of ["1"4C]6-methyl-1,2,4-benzenetriol was efficiently incorporated into penicillic acid in a culture of P. cyclopium NRRL 1888. These data indicate that 6-methyl-1,2,4-benzenetriol is a precursor for penicillic acid biosynthesis. The results on the addition of 1,4-dihydroxy-6-methoxy-2-methylbenzene, 6-methoxy-2-methylbenzoquinone (1,4), and 1-O-methylorcinol to a culture of P. cyclopium ...

84

Addition of methyl cellulose enema to double-contrast barium imaging of sigmoid diverticulosis

Schemata for modelling combustion processes do not yet include reaction rates for oxygenated fuels like methylal (DMM) which is considered as an additive or replacement for diesel due to its low sooting propensity. Density functional theory (DFT) studies of the possible reaction pathways for different dissociation steps of methylal are presented. Cleavage of a hydrogen bond to the methoxy group or the central carbon atom were simulated at the BLYP/6-311++G{sup **} level of theory. The results are compared to the experiment when dissociating and/or ionising DMM with femtosecond pulses. (author) 1 fig., 1 tab., 1 ref.

1999-08-01

85

The Combined Influence of Molecular Weight and Temperature on the ...

Double-contrast barium enema has a reduced sensitivity in patients with severe sigmoid diverticulosis. Therefore a carboxy methyl cellulose enema was employed after the conventional double-contrast examination in 15 patients with sigmoid diverticulosis. A significant increase in lumen diameter and a superior removal of barium residue from the diverticulas facilitated the interpretation of the sigmoid loops. Conclusion: The addition of methyl cellulose enema to double-contrast barium imaging improves diagnostic imaging in diverticulosis by expanding the lumen and emptying the diverticulas. (orig.).

1997-01-01

86

Recycling of poly(methyl methacrylate) scrap in the styrene-methyl methacrylate copolymer cast sheet process

[12] Kusy, R. P. and Turner, D. T.: Influence of molecular-weight ofpoly(methyl methacrylate)on fracture morphology in notched tension, Polymer. ...

87

British Library Electronic Table of Contents (United Kingdom)

Poly(methyl methacrylate), PMMA, scrap generated during the casting process for PMMA cast sheet is an industrial waste stream, which has a high impact on the PMMA production cost and environment. This paper presents an alternative way to reduce the processing cost of PMMA cast sheet and decrease industrial waste by using styrene (S) as a co-monomer with methyl methacrylate (MMA) monomer, in conjunction with recycling of PMMA scrap in the S-MMA copolymer cast sheet process. The influence of factors, such as the concentrations of S and PMMA scrap, on the preparation of S-MMA copolymer cast sheet mixed with PMMA scrap was investigated. The characterization of basic copolymer composition, the physical, and the mechanical properties of the final products were examined. The results show that it ...

2009-01-01

88

2011 Critical Use Exemption Nominations from the Phaseout of...

The synthesis of 5-[1-"1"1C]ethyl barbiturates from labelled malonic esters

transmitted to the Ozone Secretariat of the United Nations Environment Programme (UNEP) its sixth nomination for a critical use exemption (CUE) from the phaseout of methyl...

2011-02-08

89

The oxygenation of [3-methyl-3H]desacetoxycephalosporin C [7beta-(5-D-aminadipamido)-3-methylceph-3-em-4-carboxylic acid] to [3-hydroxymethyl-3H]desacetylcephalosporin C by 2-oxoglutarate-linked dioxygenases from Acremonium chrysogenum and Streptomyces clavuligerus.

The synthesis of ["1"1C]phenobarbital, ["1"1C]pentobarbital and["1"1C]amobarbital labelled in the 5-[1-"1"1C]ethyl position is reported. The malonic esters R- CH(CO_2Et)_2 [R phenyl-, 1-methylbutyl-, and 3- methylbutyl- were alkylated with [1-"1"1C]ethyl iodide prepared from ["1"1C]carbon dioxide. Ring closure of the 2-[1-"1"1C]ethyl-labelled malonic esters with urea afforded 5-[1-"1"1C]ethyl-phenobarbital,-phenobarbital, -pentobarbital and -amobarbital synthesis times of 42-47 min, counted from ["1"1C] carbon dioxide. In typical syntheses starting with 3 GBq pentobarbitol and (81 mCi) ["1"1C]carbon dioxide, 150-215 MBq (4-6 mCi) were produced in 25-30% decay corrected -amobarbital radiochemical yields with radiochemical purities greater than 98%. (author).

90

Structural Chemistry of Human SET Domain Protein Methyltransferases

Cell-free extracts of Acremonium chrysogenum and Streptomyces clavuligerus oxidize the 3-methyl group of desacetoxycephalosporin C to a 3-hydroxymethyl group. The enzyme responsible for this reaction...Full Text Available

1978-09-01

91

Interaction of N-methyl-2-alkenyl-4-quinolones with ATP-dependent MurE ligase of Mycobacterium tuberculosis: antibacterial activity, molecular docking and inhibition kinetics

There are about fifty SET domain protein methyltransferases (PMTs) in the human genome, that transfer a methyl group from S-adenosyl-L-methionine (SAM) to substrate lysines on histone tails or other peptides. A number of structures in complex with cofactor, substrate, or inhibitors revealed the mechanisms of substrate recognition, methylation state specificity, and chemical inhibition. Based on these structures, we review the structural chemistry of SET domain PMTs, and propose general concepts towards the development of selective inhibitors.

2011-08-22

92

Insect-Induced Conifer Defense. White Pine Weevil and Methyl Jasmonate Induce Traumatic Resinosis, de Novo Formed Volatile Emissions, and Accumulation of Terpenoid Synthase and Putative Octadecanoid Pathway Transcripts in Sitka Spruce1[w

ObjectivesThe aim of this study was to comprehensively evaluate the antibacterial activity and MurE inhibition of a set of N-methyl-2-alkenyl-4-quinolones found...Full Text Available

2011-08-01

93

Genome-wide analysis of N¹-methyl-adenosine modification in human tRNAs

Stem-boring insects and methyl jasmonate (MeJA) are thought to induce similar complex chemical and anatomical defenses in conifers. To compare insect- and MeJA-induced terpenoid responses, we analyzed...Full Text Available

2005-01-01

94

A Role for Set1/MLL-Related Components in Epigenetic Regulation of the Caenorhabditis elegans Germ Line

The N¹-methyl-Adenosine (m¹A58) modification at the conserved nucleotide 58 in the TΨC loop is present in most eukaryotic tRNAs. In yeast, m¹A58 modification...Full Text Available

2010-07-01

95

Synthesis and biodistribution of a novel 99mTc-DMSA-metronidazole ester as a potential tumor hypoxia imaging agent

The methylation of lysine 4 of Histone H3 (H3K4me) is an important component of epigenetic regulation. H3K4 methylation is a consequence of transcriptional activity, but also has been shown to contribute...Full Text Available

2011-03-01

96

British Library Electronic Table of Contents (United Kingdom)

The dimercaptosuccinic acid metronidazole ester (DMSAMe) was synthesized and radiolabeled with 99mTc to form the 99mTc-DMSAMe complex in high yield. The radiochemical purity of the 99mTc-DMSAMe complex was over 90%, as measured by TLC and by HPLC, without any notable decomposition at room temperature over a period of 6?h. Its partition coefficient indicated that it was a lipophilic complex. The tumor cell experiment and the biodistribution in mice bearing S 180 tumor showed that the 99mTc-DMSAMe complex had a certain hypoxic selectivity and accumulated in the tumor with high uptake and good retention. The tumor/blood and tumor/muscle ratios increased with time, suggesting it would be a possible tumor hypoxia imaging agent.

2010-01-01

97

New [{sup 99m}Tc]-cytectrene amine compounds as specific brain imaging agents

New ["9"9"mTc]-cytectrene amine compounds as specific brain imaging agents

Lipophilic tertiary amines attached to cylcopentadienyl technetium-99m tricarbonyl (cytectrene) have been prepared with high radiochemical yield and purity. Biodistribution studies in mice showed that [{sup 99m}Tc]-cytectrenes, containing in their structure an N-methylpiperidine, were accumulated in the brain up to 2.8% of injected dose with high brain-to-blood ratios at 15 min p.i. They therefore indicate some potential as brain imaging agents. It has to be pointed out that the N-methylpiperidine ester showed similar biological behaviour as the keto derivatives. This indicates that the conversion to polar metabolite(s) via hydrolysis of the ester group - as described for [{sup 99m}Tc]-ECD -is not essential for brain retention. (Author).

1995-02-01

98

Mitochondrial sequestration of BCECF after ester loading in the giant alga Chara australis

Lipophilic tertiary amines attached to cylcopentadienyl technetium-99m tricarbonyl (cytectrene) have been prepared with high radiochemical yield and purity. Biodistribution studies in mice showed that ["9"9"mTc]-cytectrenes, containing in their structure an N-methylpiperidine, were accumulated in the brain up to 2.8% of injected dose with high brain-to-blood ratios at 15 min p.i. They therefore indicate some potential as brain imaging agents. It has to be pointed out that the N-methylpiperidine ester showed similar biological behaviour as the keto derivatives. This indicates that the conversion to polar metabolite(s) via hydrolysis of the ester group - as described for ["9"9"mTc]-ECD -is not essential for brain retention. (Author).

99

British Library Electronic Table of Contents (United Kingdom)

Summary. Ratiometric fluorescent dyes are often used to monitor free ion concentrations in vivo, especially in cells that are recalcitrant to transformation with genetically encoded fluorescent markers. Although intracellular dye distributions are often found to be cytosolic, dye localisation has often not been examined in detail. We began exploring the use of BCECF (2?,7?-bis(2-carboxyethyl)-5(6)-carboxyfluorescein) to monitor pH in the giant alga Chara australis and discovered that younger leaf cells could be loaded using the acetoxymethyl ester of BCECF. However, we were puzzled to find in microphotometric measurements that the fluorescence ratio appeared insensitive to manipulations affecting cytosolic pH. Confocal imaging of C. australis cells loaded with BCECF showed an accumulation ...

2007-01-01

100

Low-temperature oxidative degradation of PBX 9501 and its components determined via molecular weight analysis of the Poly[ester urethane] binder

British Library Electronic Table of Contents (United Kingdom)

The results of following the oxidative degradation of a plastic-bonded explosive (PBX 9501) are reported. Into over 1100 sealed containers were placed samples of PBX 9501 and combinations of its components and aged at relatively low temperatures to induce oxidative degradation of the samples. One of the components of the explosive is a poly(ester urethane) polymer and the oxidative degradation of the samples were following by measuring the molecular weight change of the polymer by gel permeation chromatography (coupled with both differential refractive index and multiangle laser light scattering detectors). Multiple temperatures between 40 and 64 degreeC were used to accelerate the aging of the samples. Interesting induction period behavior, along with both molecular weight increasing (cro...

2009-01-01

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101

Bisulfite genomic sequencing of DNA from dried blood spot microvolume samples.

Uragogin and blepharodin, unprecedented hetero-Diels-Alder adducts from Celastraceae species

DNA methylation is an important event in epigenetic changes in cells, and a fundamental regulator of gene transcription. Bisulfite genomic sequencing is a powerful technique used in studies of DNA methylation. However, the established procedures often require relatively large amounts of DNA. In everyday practice, samples submitted for analysis might contain very small amounts of poor quality material, as is often the case with forensic stain samples. In this study, we assess a modified, more efficient method of bisulfite genomic sequencing. Genomic DNA extracted from 3-mm dried blood spots using QIAamp micro kit was treated with sodium bisulfite (using EpiTect kit). Subsequent methylation-specific PCR (MSP) followed by DNA sequencing displayed the differentially methylated region of imprinted gene SNRPN. Our results show that this new combination of efficient DNA extraction and bisulfite treatment ...

2011-07-01

102

British Library Electronic Table of Contents (United Kingdom)

Uragogin and blepharodin were isolated from Crossopetalum uragoga and Maytenus magellanica, respectively. They represent the first examples of a triterpene-neolignan ester and a heptacyclic arylpropanoid-nor-triterpenephenol, hetero-Diels-Alder adducts built with dioxane bridges. Their proposed biosynthetic route is discussed.

2011-01-01

103

Study of complexing reactions and ligand exchange of zirconium and hafnium tetrachlorides with substituted derivative of O-naphthoquinonediazide

Study of complexing reactions and ligand exchange of zirconium and hafnium tetrachlorides with substituted derivative of O-naphthoquinonediazide

Using the PMR method the interaction of zirconium and hafnium tetrachlorides with tri.tet.butylphenyl ester of 1,2- naphthoquinonediazide (2)-5-sulfonic acid is studied. The formation of MCl/sub 4/xNQD complexes is established, the equilibrium constants and thermodynamic parameters of complexing reaction are determined. The presence of rapid ligand exchange, proceeding according to associative mechanism, is detected. The rate constants and activation energies of the exchange reaction are calculated.

1981-11-01

104

Sorption of heteropoly acids by polyurethane foam

Using the PMR method the interaction of zirconium and hafnium tetrachlorides with tri.tet.butylphenyl ester of 1,2- naphthoquinonediazide (2)-5-sulfonic acid is studied. The formation of MCl_4xNQD complexes is established, the equilibrium constants and thermodynamic parameters of complexing reaction are determined. The presence of rapid ligand exchange, proceeding according to associative mechanism, is detected. The rate constants and activation energies of the exchange reaction are calculated.

105

Reaction with glutathione. A possible mechanism involved in rodent brain retention of a "9"9"mTc SNS/S complex containing a pendant ester functionality

Sorption of oxidized and reduced forms of molybdosilicic, molybdophosphoric and molybdovanadophosphoric acids by polyurethane foam based on ethers and esters is studied. On the basis of sorption dependence on solution pH, polyurethane foam type and spectral characteristics of sorbates the suggestion has been made that in the polyurethane foam phase there are two main types of sorbent-sorbate interaction: electrostatic (ion-ion) and with hydrogen bond formation: and it is impossible to determine the contribution of every interaction

1997-12-01

106

Radiation-polymerizable mixture and recording material containing it

The synthesis, characterization of M"vO([CH_3CH_2N(CH_2CH_2S)_2](p-S-Ph-COOCH_2-CH_3)) (M:"9"9"mTc: I, Re: II) is presented in this work, where a pendant ester function is attached to the monothiolate ligand. Chemical structure of I is established after chromatographic comparison with II, synthesized in macroscopic amounts. Complex II is fully characterized by classical methods of analysis showing that the compound adopts a distorted trigonal bipyramidal configuration around the metal. The two sulfur atoms of the tridentate ligand and the oxo group form the basal plane, while the remaining nitrogen atom of the tridentate ligand and the sulfur atom of the monothiolate ligand occupy the apices of the bipyramid. In vitro challenge experiments with glutathione (GSH) in neutral aqueous medium demonstrate, that I suffers nucleophilic attack by GSH and thereby transformation to a more hydrophilic daughter metal compound. Formation of the latter depends on time and GSH ...

1998-08-01

107

Polybutylene terephthalate on metals: a density functional theory and cluster models investigation

Esters of dihydric alcohols with alkenylphosphonic or alkenylphosphinic acids which are polymerizable by free radicals are described. They are combined with polymer binders, in particular water-soluble polymers, and photoinitiators forming free radicals to give photopolymerizable mixtures which are suitable for the production of photoresists and printing plates. The mixtures display low heat-sensitivity and have long shelf lives. (author) 1 tab.

1991-01-01

108

Mo"5 and W"5 complexing with tri-tret-butyl phenyl ether of 1.2-naphthoquinonediazide-(2)-5-sulfochloride

The strength of adhesion of polybutylene terephthalate (PBT) on aluminium is investigated using density functional theory-based energy calculations. The aluminium atom is connected to a PBT monomer at different orientations, and total energies are calculated and compared to determine the most stable orientation. The binding is strongest when the Al is oriented at 180{sup 0} to the ester group of the monomer. Using this orientation as a basis, PBT adhesion on Ti, Ag, and Au is also investigated.

2006-02-01

109

Isomerization of 1-O-Indol-3-Ylacetyl-?-d-Glucose ¹

The complexing of paramagnetic salts of molybdenum and tungsten with tri-tert-butylphenyl ester of 1,2-naphthoquinone-diazide-(2)-5-sulfochloride is studied by PMR and EPR methods. From the changes of half-widths of lines in PMR spectra and analysis of g-factor in EPR spectra, the kinetic and thermodynamic parameters of the complexing are determined, and the composition of the complexes formed is established, and the schemes of their formation are suggested.

110

Hepatocellular carcinoma: recent advances in diagnosis with iodized oil

The first compound in the series of reactions leading to the ester conjugates of indole-3-acetic acid (IAA) in kernels of Zea mays sweet corn is the acyl alkyl acetal, 1-O-indol-3-ylacetyl-β-d-glucose...Full Text Available

1990-09-01

111

Enzymic Synthesis of Indole-3-Acetyl-1-O-?-d-Glucose ¹

This opinion presents an overview of recent developments in the diagnosis and treatment of hepatocellular carcinoma (HCC) in Japan. The use of Ethiodol (iodized ethyl ester of the fatty acid of poppyseed oil) for hepatic angiography in diagnosing and treating (combined with chemotherapeutic agents) HCC has been reported. Ethiodol has been found to localize in HCC and remain there for long periods. The implications of these findings are discussed.

1985-01-01

112

Cyclopeptide alkaloids. Synthesis of the ring system and its ion affinity

The first enzyme-catalyzed reaction leading from indole-3-acetic acid (IAA) to the myo-inositol esters of IAA is the synthesis of indole-3-acetyl-1-O-β-d-glucose...Full Text Available

1988-12-01

113

Corrosion inhibited alcohol motor fuel

Several examples of the 14-membered, para-bridged ring system of the cyclopeptide alkaloids have been synthesized via an active ester cyclization. The yield of monomeric cyclopeptide varied from 1 to 33% and was affected by the amino acid substitution pattern and amide conformation of the linear peptide precursors. Both the synthetic models and a naturally occurring cyclopeptide alkaloid, ceanothine B, bind monovalent (Li"+) and divalent (Ca"2"+, Mg"2"+) cations. 4 figures, 1 table.

114

Characterization of Auxin Conjugates in Arabidopsis. Low Steady-State Levels of Indole-3-Acetyl-Aspartate, Indole-3-Acetyl-Glutamate, and Indole-3-Acetyl-Glucose1

The addition of 0.0005-0.5 weight% linoleic acid trimer to synthetic motor fuels composed of 95.0-99.8% technical-grade alcohol (EtOH or MeOH) and 0.2-5.0% water inhibits the corrosion induced by the impurities, such as aliphatic acids 0.5-10.0, aliphatic aldehydes 0.5-10.0, and aliphatic esters 0.5-10 mg/100 ml alcohol.

1981-08-25

115

A nanoscale understanding of the adhesion of polybutylene terephthalate on aluminum

Amide-linked indole-3-acetic acid (IAA) conjugates constitute approximately 90% of the IAA pool in the dicot Arabidopsis, whereas ester-linked conjugates and free IAA account for approximately...Full Text Available

2000-06-01

116

British Library Electronic Table of Contents (United Kingdom)

The adhesion strength of polybutylene terephthalate (PBT) on aluminum was investigated using density functional theory-based total energy calculations. Aluminum atom was connected to a PBT monomer at different orientations and total energies were calculated in order to determine the most stable orientation. The energy differences showed that the Al oriented at 180degree with the ester group of the monomer bonded strongly. Using this orientation, the PBT monomer-adhesion on aluminum surface and the aluminum atom adhesion on PBT bulk were also investigated.

2007-01-01

117

Synthesis of C-11 iodoantipyrine for positron emission tomography

Extraction of hafnium by 1-phenyl-3-methyl-4-benzoyl-5-pyralozone from aqueous-alcoholic solutions

We have developed a method for the synthesis of C-11 iodoantipyrine. Carbon-11-labeled methyl iodide, prepared from /sup 11/CO2, was used to methylate 3-methyl-1-phenyl-2-pyrazolin-5-one to form C-11 antipyrine. Following silica-gel column chromatography and iodination, radiochemical purity of the C-11 iodoantipyrine was more than 99.5%, with a 10% yield and a specific activity of 30 mCi/mumol. Preliminary animal studies showed complete cerebral extraction and local cerebral blood-flow values that were within 4.6% of those obtained using C-14 iodoantipyrine. The C-11 analog, with positron emission tomography, will facilitate local cerebral blood-flow studies in human subjects.

1981-06-01

118

A study of methyl formate in astrochemical environments

Extraction of hafnium by 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HL) in benzene, toluene, chloroform and tetrachloromethane from aqueous-alcoholic solutions of the formal acidity of 2M-HClO_4 was studied. Methyl, ethyl, n- and isopropyl, tert-butyl and allyl alcohol as well as ethylene glycol monomethyl ether and propylene glycol were used as organic components of the mixed aqueous-organic phase. Their presence in some cases resulted in a synergic increase in the distribution ratio of hafnium. The increase is interpreted using the results of a slope analysis and measurements of the alcohol distribution and the relative permittivity of the organic phase. It is suggested that HfL_4 molecules were solvated by alcohol molecules in the organic phase. At high alcohol concentration synergism changed into antagonism. This was caused by changes in the distribution of HL and its interaction with the alcohol in the organic phase. (author).

119

CERN Document Server

Several complex organic molecules are routinely detected in high abundances towards hot cores and hot corinos. For many of them, their paths of formation in space are uncertain, as gas phase reactions alone seem to be insufficient. In this paper, we investigate a possible solid-phase route of formation for methyl formate (HCOOCH3). We use a chemical model updated with recent results from an experiment where simulated grain surfaces were irradiated with 200 keV protons at 16 K, to simulate the effects of cosmic ray irradiation on grain surfaces. We find that this model may be sufficient to reproduce the observed methyl formate in dark clouds, but not that found in hot cores and corinos.

2011-01-01

120

A quantum theoretical study of reactions of methyldiazonium ion with DNA base pairs

British Library Electronic Table of Contents (United Kingdom)

Methylation of the DNA bases in the Watson-Crick GC and AT base pairs by the methyldiazonium ion was investigated employing density functional and second order Moller-Plesset (MP2) perturbation theories. Methylation at the N3, N7 and O6 sites of guanine, N1, N3 and N7 sites of adenine, O2 and N3 sites of cytosine and the O2 and O4 sites of thymine were considered. The computed reactivities for methylation follow the order N7(guanine)>N3(adenine)>O6(guanine) which is in agreement with experiment. The base pairing in DNA is found to play a significant role with regard to reactivities of the different sites.

2011-01-01

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121

The biosynthesis of rubber from ?-hydroxy-?-methylglutaryl-coenzyme A in Hevea brasiliensis latex

Synergism among BIOLF-62, phosphonoformate, and other antiherpetic compounds.

1. β-Hydroxy-β-methyl[3-¹⁴C]glutaryl-CoA is efficiently incorporated into rubber on incubation with Hevea brasiliensis latex, and the incorporation is diminished...Full Text Available

1969-09-01

122

Surface structure recognized for covalent modification of the aspartate receptor in chemotaxis.

9-[[2-Hydroxy-1-(hydroxymethyl)ethoxy]methyl]guanine (BIOLF-62) is highly synergistic with either phosphonoformate or phosphonoacetate when used in combination against herpes simplex virus types 1 and...Full Text Available

1982-12-01

123

Stable Isotope-Coded Quaternization for Comparative Quantification of Estrogen Metabolites by High-Performance Liquid Chromatography-Electrospray Ionization Mass Spectrometry

The aspartate receptor involved in chemotaxis is modified by methyl esterification at four distinct glutamate residues during the adaptive response of this receptor. To explain the high degree of specificity...Full Text Available

1986-09-01

124

Role of histone methylation and demethylation in adipogenesis and obesity

A fast and sensitive LC-ESI-MS method is described for the comparative quantification of 16 estrogen metabolites based on the derivatization of estrogens with a novel derivatizing reagent, N-methyl-nicotinic...Full Text Available

2008-07-15

125

Removal of iodine species by concentrated nitric acid, (2)

Adipocyte differentiation is a complex developmental process that involves the coordinated interplay of numerous transcription factors. PPARγ has emerged as a master regulator of adipogenesis...Full Text Available

2010-01-01

126

Regulation and Function of Escherichia coli Sugar Efflux Transporter A (SetA) during Glucose-Phosphate Stress?

One of the most effective removing processes of iodine species is what is called ''Iodox Process'', which contains oxidation and absorption of iodine species by highly concentrated nitric acid. The result of fundamental test with bubble column in this process had been reported. Present paper describes the fundamental experiment by the use of packed column. This experiment has been carried out to clear the effect of feed gas flow rate, nitric acid flow rate, nitric acid concentration, and methyl iodide concentration on removal efficiency of methyl iodide. The following results were obtained. The decontamination factor of methyl iodide (DF) increases exponentially with nitric acid concentration, which agrees with the result obtained by using the bubble column. The factor is in inverse proportion to feed gas flow rate, and is also almost independent of nitric acid flow rate and methyl iodide concentration. ...

1978-07-01

127

Prenatal cocaine reduces AMPA receptor synaptic expression through hyperphosphorylation of the synaptic anchoring protein GRIP

Accumulation of certain nonmetabolizable sugar-phosphates (including α-methyl glucoside-6-phosphate) in Escherichia coli is growth inhibitory and elicits the glucose-phosphate...Full Text Available

2011-01-01

128

Personalized Epigenomic Signatures That Are Stable Over Time and Covary with Body Mass Index

Prenatal cocaine exposure produces sustained neurobehavioral and brain synaptic changes closely resembling those of animals with defective alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic...Full Text Available

2009-05-13

129

NOVEL EMBEDDED CERAMIC ELECTRODE SYSTEM TO ACTIVATE NANOSTRUCTURED TITANIUM DIOXIDE FOR DEGRADATION OF MTBE

The epigenome consists of non–sequence-based modifications, such as DNA methylation, that are heritable during cell division and that may affect normal phenotypes and predisposition...Full Text Available

2010-09-15

130

Methyl Jasmonate Induces Traumatic Resin Ducts, Terpenoid Resin Biosynthesis, and Terpenoid Accumulation in Developing Xylem of Norway Spruce Stems1

A novel reactor combining a flame-deposited nanostructured titanium dioxide film and a set of embedded ceramic electrodes was designed, developed and tested for degradation of methyl tert-butyl ether (MTBE) in water. On applying a voltage to the ceramic electrodes, a surface coro...

131

Isolation and identification of flavonoid (-)-4'-methyl-epigallocatechin of roots from Maytemus obtusifolia Mart. (Celastraceae)

Norway spruce (Picea abies L. Karst) produces an oleoresin characterized by a diverse array of terpenoids, monoterpenoids, sesquiterpenoids, and diterpene resin acids that can protect...Full Text Available

2002-07-01

132

Integrative Analysis of Epigenetic Modulation in Melanoma Cell Response to Decitabine: Clinical Implications

Portuguese ... Orig. Title Isolamento e identificacao do flavonoide (-)-4'-metil-epigalocatequina das raizes de Maytenus obtusifolia Mart. (Celastraceae)

2006-05-19

133

Inhibition of lymphocyte-mediated cytolysis by 3-deazaadenosine: Evidence for a methylation reaction essential to cytolysis

Decitabine, an epigenetic modifier that reactivates genes otherwise suppressed by DNA promoter methylation, is effective for some, but not all cancer patients, especially those with solid tumors. It...Full Text Available

134

Influence of murine leukemia proviral integrations on development of N-methyl-N-nitrosourea-induced thymic lymphomas in AKR mice.

3-Deazaadenosine (deazaAdo) inhibits lymphocyte-mediated cytolysis in vitro at micromolar concentrations and is potentiated markedly in this activity by L-homocysteine thiolactone....Full Text Available

1978-12-01

135

Identification of novel DNA repair proteins via primary sequence, secondary structure, and homology

The AKR mouse strain is characterized by a high incidence of spontaneous thymic lymphoma that appears in older animals (greater than 6 months of age) and is associated with novel provirus integrations...Full Text Available

1991-11-01

136

Effect of Inhibition of Acetoclastic Methanogenesis on Growth of Archaeal Populations in an Anoxic Model Environment

BackgroundDNA repair is the general term for the collection of critical mechanisms which repair many forms of DNA damage such as methylation or ionizing radiation. DNA repair has...Full Text Available

137

Dynamin-dependent NMDAR endocytosis during LTD and its dependence on synaptic state

Methyl fluoride is frequently used to specifically inhibit acetoclastic methanogenesis, thus allowing determination of the relative contribution of acetate versus H₂/CO₂ to total...Full Text Available

2006-01-01

138

Dual Beneficial Effects of (-)-Epigallocatechin-3-Gallate on Levodopa Methylation and Hippocampal Neurodegeneration: In Vitro and In Vivo Studies

BackgroundThe N-methyl-D-aspartate (NMDA)-type glutamate receptor expressed at excitatory glutamatergic synapses is required for learning and memory and is critical for normal brain...Full Text Available

139

DNA methylation and gene expression differences in children conceived in vitro or in vivo

BackgroundA combination of levodopa (L-DOPA) and carbidopa is the most commonly-used treatment for symptom management in Parkinson's disease. Studies have shown that concomitant...Full Text Available

140

Copy Number Alterations and Methylation in Ewing's Sarcoma

Epidemiological data indicate that children conceived in vitro have a greater relative risk of low birth-weight, major and minor birth defects, and rare disorders involving imprinted...Full Text Available

2009-10-15

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141

Coordination of PAD4 and HDAC2 in the regulation of p53 target gene expression

Ewing's sarcoma is the second most common bone malignancy affecting children and young adults. The prognosis is especially poor in metastatic or relapsed disease. The cell of origin remains elusive,...Full Text Available

2011-01-01

142

Cholinesterases from Plant Tissues

Histone Arg methylation and Lys acetylation have been found to cooperatively regulate the expression of p53 target genes. Peptidylarginine deiminase 4 (PAD4) is an enzyme that citrullinates...Full Text Available

2010-05-27

143

Calcium/Calmodulin-Dependent Protein Kinase II Mediates Hippocampal Glutamatergic Plasticity During Benzodiazepine Withdrawal

2-Isopropyl-4-dimethylamino-5-methylphenyl-1-piperidine carboxylate methyl chloride (AMO-1618) inhibits the activity of a cholinesterase isolated from mung bean (Phaseolus aureus) roots...Full Text Available

1973-09-01

144

Blood leukocyte DNA hypomethylation and gastric cancer risk in a high-risk Polish population

Benzodiazepine withdrawal anxiety is associated with potentiation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR) currents in hippocampal CA1 pyramidal...Full Text Available

2010-08-01

145

Antianxiety and antidepressant-like effects of AC-5216, a novel mitochondrial benzodiazepine receptor ligand

Global hypomethylation has been shown to increase genome instability potentially leading to increased cancer risk. We determined whether global methylation in blood leukocyte DNA was associated...Full Text Available

2010-10-15

146

Influence of wood extractives in the polymerization of methyl methacrylate by gamma irradiation

We investigated the ability of N-benzyl-N-ethyl-2-(7,8-dihydro-7-methyl-8-oxo-2-phenyl-9H-purin-9-yl)acetamide...Full Text Available

2004-08-01

147

Improved synthesis of (/sup 15/N) 16-Doxyl stearic acid

Those materials that can be extracted from pine or oak by ether, ethanol, methyl methacrylate (MMA), or benzene--alcohol all act as inhibitors in the #gamma# polymerization of MMA--wood composites. It was found that preirradiation of either the wood or of the wood--monomer combination reduces or eliminates the inhibitory effect. The most practical industrial solution to this problem is to increase the dose, thereby achieving high molecular polymer in the composite. However, the presence of a maximum in the molecular weight--dose curves means that each wood--monomer pair may have a different optimum dose.

1975-01-01

148

A comparative study on the carbon dioxide capture power between 30 wt% 2-amino-2-methyl-1-propanol and 30 wt% methyldiethanol amine aqueous solutions

An improved method for the synthesis of (/sup 15/N) 16-Doxyl stearate, a fatty-acid spin label, is reported. The method requires only one mole of (/sup 15/N) 2-amino-2-methyl propanol per mole of methyl keto stearate with an overall yield of about 50%. In contrast, the previous method produced only 1-3% yield. The great improvement in yield was achieved mainly through the reduction of reaction volume which increases the reaction rate by the law of mass action.

1987-10-01

149

Chemo-enzymatic epoxidation of olefins by carboxylic acid esters and hydrogen peroxide

A comparative study has been performed to compare the 30 wt% of 2-amino-2-methyl-1-propanol (AMP) aqueous solution and 30 wt% of methyldiethanol amine (MDEA) aqueous solution to capture carbon dioxide contained in the flue gas stream. The equilibrium constants for each electrolyte reactions have been used to estimate the carbon dioxide absorption process. Henry's constants for each binary pairs between solute gases and solvent have been used to estimate solubility of the gas components.

2009-05-15

150

Non-nitro radiation sensitizers

Ethylen and, recently, butadiene can be epoxidized directly with oxygen and for the epoxidation of propylene, the use of heterogeneous transition metals and organic peroxides (Halcon-Process) is the major player. But, beside from those notable exceptions, all other epoxidations, including large ones like the epoxidation of plant oils as PVC-stabilizers (about 200.000 t/year), are carried out with peroxy acids. Because mcpba is far to expensive for most applications, short chain peracids like peracetic acid are used. Being much less stable than mcpba and thus risky handled in large amounts and high concentrations, these peroxy acids were preferably prepared in-situ. However, conventional in-situ formation of peracids has the serious drawback, that a strong acid is necessary to catalyze peroxy acid formation from the carboxylic acid and hydrogen peroxide. The presence of a strong acid in the reaction mixture often results in decreased selectivity because of the formation of undesired ...

1998-12-31

151

Mechanism of the metal-mediated carbalkoxylation of vinyl electrophiles. 2. Preparation, molecular structure, and reductive couplings of {sigma}-alkoxycarbonyl {sigma}-vinyl platinum(II) complexes

This short communication aims to update the review of non-nitro radiation sensitizers (Shenoy and Singh 1985) and correct omissions. Work is mentioned and bibliography given for studied of cis-platinum, potassium permanganate, cobalt hexammine, sodium bromide, dimethylsulphoxide, zinc and copper ions, organic nitroxyl free radicals (TAN,TMPN and NPPN + PNAP), halogenated pyrimidines, organic and inorganic iodine containing compounds, diacetyl, acetone and acetophenone, rho-hydrobenzoic acid and its esters, pentobarbitone and secobarbitone, heparin and 9-anilinoacridines, dehydropiandosterone and paraquat. (U.K.).

152

Inhibitors of steel corrosion in hydrochloric acid at high temperature

The authors continued their efforts in studying the mechanism of carbalkoxylation of {sigma}-vinyls bound to platinum(II). In this work, the focus was specifically on the reductive elimination of {alpha},{beta}-unsaturated carboxylic esters form the carbonylated, alkoylated intermediates. Crystal structures of the carbonylated (12) and alkoxylated (13) intermediates were reported. Kinetic and NMR studies indicate that reductive elimination proceeds via a preequilibration involving phosphine dissociation, followed by a rate-determining trans-cis isomerization. 35 refs., 3 figs., 5 tabs.

1992-03-01

153

Oxidative stability of biodiesel from soybean oil fatty acid ethyl esters; Estabilidade oxidativa de biodiesel de esteres etilicos de acidos graxos de soja

A proposed inhibitor for steel corrosion in hydrochloric acid consists essentially of 0.5% of an inhibitor called BA-6, 0.25-0.5% of 1-hexynol-3, and about 0.02% of potassium iodide (calculated on the amount of acid). The inhibitor DA-6 is produced by condensing benzylamine with utrotropine. 1-Hexynol-3, secondary alcohol, is obtained from butyraldehyde and acetylene in the presence of caustic potash. The increase of potassium iodide concentration from 0.02-0.1% increases the protective action of the inhibitor. Hexynol, dipropargyl ester, and potassium iodide must be introduced in HC1 before injection of the latter into the well.

1965-01-07

154

Molar heat capacities for (2-methyl-2-butanol + heptane) mixtures and cyclopentanol at temperatures from (284 to 353) K

Biodiesel consists of long-chain fatty acid esters, derived from renewable sources such as vegetable oils, and its utilization is associated to the substitution of the diesel oil in engines. Depending on the raw material, bio diesel can contain more or less unsaturated fatty acids in its composition, which are susceptible to oxidation reactions accelerated by exposition to oxygen and high temperatures, being able to change into polymerized compounds. The objective of this work was to determine the oxidative stability of bio diesel produced by ethanolysis of neutralized, refined, soybean frying oil waste, and partially hydrogenated soybean frying oil waste. The evaluation was conducted by means of the Rancimat equipment, at temperatures of 100 and 105 deg C, with an air flow of 20 L h{sup -1}. The fatty acid composition was determined by GC and the iodine value was calculated. It was observed that even though the neutralized, refined and waste frying soybean oils ...

2005-06-01

155

Possible preparation of wood-plastic materials based on unsaturated polyester resins and methyl metacrylate, by radiation and chemical methods in combination

Isobaric specific heat capacities were measured for (2-methyl-2-butanol + heptane) mixtures and cyclopentanol within the temperature range from (284 to 353) K, and for 2-methyl-2-butanol in the (284 to 368) K temperature interval by means of a differential scanning calorimeter. The excess molar heat capacities were calculated from the experimental results. For the temperature range from (284 to 287) K, the excess molar heat capacity is S-shaped with negative values in the 2-methyl-2-butanol rich region and with small negative values at low alcohol concentrations at temperatures from (295 to 353) K. The excess molar heat capacities are positive for all compositions under test at temperatures from (288 to 294) K. The results are explained in terms of the influence of the molecular size and configuration of the alkanols on their self-association capability and of the change in molecular structure of the ...

2009-03-01

156

Possible preparation of wood-plastic materials based on unsaturated polyester resins and methyl metacrylate, by radiation and chemical methods in combination

The preparation of wood-plastic combinations (WPC) using combined methods for curing intermediate products and final products is described. In the first step, impregnated wood was irradiated using doses of 1 to 10 kGy in the presence of chemical initiators of polymerization. Thereafter, curing of this partly cured impregnating mixture was accomplished in the wood at elevated temperatures with the aid of chemical initiators of polymerization. Impregnation mixtures based on unsaturated polyester resins and methyl methacrylate, and the wood species European Beech (Fagus silvatica) and Black Alder (Alnus glutinosa) were used. The results indicate that this method of preparing WPC allows substantially lower radiation doses to be used, i.e., doses in the range of 1 to 2.5 kGy. These doses gelatinate the impregnation mixture in the wood so that the subsequent curing by chemical polymerization initiators proceeds without the impregnation mixture flowing out of the wood, ...

1982-04-01

157

Oil palm empty fruit bunch (OPEFB) fiber reinforced PVC/ENR blend-electron beam irradiation

The preparation of wood-plastic combinations (WPC) using combined methods for curing intermediate products and final products is described. In the first step, impregnated wood was irradiated using doses of 1 to 10 kGy in the presence of chemical initiators of polymerization. Thereafter, curing of this partly cured impregnating mixture was accomplished in the wood at elevated temperatures with the aid of chemical initiators of polymerization. Impregnation mixtures based on unsaturated polyester resins and methyl methacrylate, and the wood species European Beech (Fagus silvatica) and Black Alder (Alnus glutinosa) were used. The results indicate that this method of preparing WPC allows substantially lower radiation doses to be used, i.e., doses in the range of 1 to 2.5 kGy. These doses gelatinate the impregnation mixture in the wood so that the subsequent curing by chemical polymerization initiators proceeds without the impregnation mixture flowing out of the wood, ...

1982-01-01

158

Modulation of gene expression in differentiating 3T3 - L1 preadipocytes

The effect of irradiation on the tensile properties of oil palm empty fruit bunch (OPEFB) fiber reinforced poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends were studied. The composites were prepared by mixing the fiber and the PVC/ENR blend using HAAKE Rheomixer at 150 deg. C. The composites were then irradiated by using a 3.0 MeV electron beam machine at doses ranging from 0 to 100 kGy in air and room temperature. The tensile strength, Young's modulus, elongation at break and gel fraction of the composites were measured. Comparative studies were also made by using poly(methyl acrylate) grafted OPEFB fiber in the similar blend system. An increase in tensile strength, Young's modulus and gel fraction, with a concurrent reduction in the elongation at break (Eb) of the PVC/ENR/OPEFB composites were observed upon electron beam irradiation. Studies revealed that grafting of the OPEFB fiber with methyl acrylate did ...

2007-12-15

159

Methyl bromide and methyl chloride fluxes from temperate forest litter

3T3 - L1 cells can be induced to differentiate by exposing cell culture to a medium containing 3-isobutyl-1-methyl-xanthine together with insulin and dexamethasone. They have observed that oxalomalate (OMA) which inhibits aconitase thus blocking the citric cycle, also favours differentiation to adipocytes leading to fatty acids accumulation and increased synthesis of specific proteins. They compared the effects of 3-isobutyl-1-methyl-xanthine-insulin-dexamethasone and OMA on the steady-state levels of mRNA of c / EBP, H-ferritin and aconitase / IRE-BP. OMA does not affect the steady-state mRNA amount of C / EBP, H-ferritin and aconitase / IRE-BP but the 3-isobutyl-1-methyl-xanthine-insulin-dexamethasone mixture is able to induce a five-fold increase of mRNA levels for aconitase / IRE-BP. This is the first finding correlating iron metabolism to adipocyte differentiation. Further studies will clarify a possible role for the ...

1997-12-31

160

British Library Electronic Table of Contents (United Kingdom)

Methyl halide fluxes were measured from fine (nonwoody) litter samples at a temperate deciduous forest site in Scotland on 16 occasions over more than a year and at a coniferous forest site. The resulting mean (+-1 sd) CH3Br and CH3Cl fluxes were 4.1 +- 3.7 ng kg-1 h-1 and 0.98 +- 0.62 mg kg-1 h-1, respectively, for dry mass leaf litter and 5.7 +- 6.3 ng kg-1 h-1 and 0.47 +- 0.14 mg kg-1 h-1 for dry mass needle litter. Temporal variations of net fluxes from leaf litter were significantly greater than spatial variations suggesting seasonality in the fluxes. The mean CH3Cl/CH3Br mass ratio of fluxes was 200 (to 1 sig. fig.), an order of magnitude larger than the ratio of their estimated global turnovers. Temperate forest litter may be a moderate net source of CH3Cl globally but a negligible ...

2011-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

161

Kinetic aspects of the photolysis of in-station airborne methyl iodide

Formation of methyl formate and other organic species in the warm-up phase of hot molecular cores

A method for converting organic iodides to elemental iodine would be advantageous in improving the performance of charcoal filters for the removal of radio iodines from reactor off gases. A photochemical method has been developed. The HAVCHM code was used to establish the relevant process time scales on a complete set of rate equations describing the primary and secondary reactions occurring in a plug-flow reactor containing low levels of elemental iodine and methyl iodide in air, which is irradiated by intense u.v. light. These simulations were used to justify the contraction of the complete set of reactions to the most significant elementary processes. The contracted set of rate equations are then solved analytically to render the concentration-time profiles of methyl iodide, total inorganic iodine and total oxidized organics, consistent with the achievement of a desirable radioiodine decontamination factor. For the short contact times ...

162

CERN Document Server

Aims: The production of saturated organic molecules in hot cores and corinos is not well understood. The standard approach is to assume that, as temperatures heat up during star formation, methanol and other species evaporate from grain surfaces and undergo a warm gas-phase chemistry at 100 K or greater to produce species such as methyl formate, dimethyl ether, and others. But a series of laboratory results shows that protonated ions, typical precursors to final products in ion-molecule schemes, tend to fragment upon dissociative recombination with electrons rather than just ejecting a hydrogen atom. Moreover, the specific proposed reaction to produce protonated methyl formate is now known not to occur at all. Methods: We utilize a gas-grain chemical network to probe the chemistry of the relatively ignored stage of hot core evolution during which the protostar switches on and the temperature of the surrounding gas and dust rises from 10 K to ...

2006-01-01

163

Effect of processing on pirimiphos-methyl residues in stored peanuts

Wood-polymer composites. Polymerization of methyl-metacrylate in Pinus strobus var. chiapensis wood by gamma radiation

Peanut grains (1500g) were placed in a jute sack which was sprayed with "1"4C- pirimiphos-methyl [0-2-diethylamino-6-methylpyrimidin-4-yl-O, O-dimethylphosphorothiate, "1"4C-labelled in the 2-position of the pyrimidine ring]; total dose 5.55 MBq + 22.5 mg cold insecticide. As in practice, the sack was stored under local conditions for 36 weeks. The grain was crushed, dried at 50 deg. C for 2 hours and soxhlet extracted with chloroform-methanol (1:1). The crude oil was then subjected to sequential processes of alkali treatment, bleaching and deodorization. The initial residue concentration in the crude oil (5.66 ppm) was reduced to 4.50 ppm through alkali treatment and declined further to 3.78 ppm after bleaching. Deodorization removed a substantial amount of "1"4C-residues leaving 1.35 ppm in the refined oil. It may be concluded that simulated commercial processing of crude oil were capable of removing 76% of pirimiphos-methyl and/or products. ...

1995-08-01

164

Use of lanthanide shift reagents together with silver trifluoroacetate for quantitative analysis of mixtures of aromatic hydrocarbons

To obtain Pinus wood-plastic composites, wood samples were impregnated with methyl methacrylate and polymerized by the use of gamma rays from a /sup 60/Co at different dose exposure and total dose. The best percentage of polymerization was obtained with the exposure of 2.0 MR of gamma radiation. It was found that the impregnation and polymerization, determined by the density values along the samples were uniform. The density became 2.6 times higher in relation to the control samples. The storage of the impregnated wood samples showed losses of the monomer, even when wrapped with aluminum or polyethylene film. It is recommended that the wood samples should be irradiated soon after impregnation.

1984-12-01

165

Spectroscopy and photophysics of mono methyl-substituted alloxazines

The shifts induced by equimolar mixture of typical lanthanide shift reagent such as 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5-octadionato europium with silver trifluoroacetate in /sup 1/H NMR spectra of aromatic hydrocarbons have been used for analytical purposes; the NMR determination of m- and p-xylenes in mixtures has been chosen as an example. The use has been made of the difference between induced shifts of methyl group signals in the /sup 1/H NMR spectra of m- and p-xylenes. The magnitude of induced shifts of methyl groups signal in m-xylene is always larger than that of p-isomer, irrespective of contents of m- and p-xylenes in mixture.

1980-01-01

166

Selective changes of retroelement expression in human prostate cancer

Singlet-singlet and triplet-triplet absorption spectra of a series of methyl-alloxazines were calculated using the time-dependent density-functional theory approach and compared to experimental results. The B3LYP functional provides good correlation between experimental and theoretical results, given that solvent effects are disregarded in the present calculations. Substituent and solvent dependences of the lowest, closely spaced, n,{pi}* and {pi},{pi}* excited state energies are discussed, their order being of consequence in determining the non-radiative decay rates and thus emission quantum yields and lifetimes. The high quantum yields of singlet oxygen formation indicate that the triplet state is formed by efficient intersystem crossing from the first singlet excited state.

2004-05-31

167

British Library Electronic Table of Contents (United Kingdom)

Retroelements constitute a large part of the human genome. These sequences are mostly silenced in normal cells, but genome-wide DNA hypomethylation in cancers might lead to their re-expression. Whether this re-expression really occurs in human cancers is largely unkown. We therefore investigated expression and DNA methylation of several classes of retroelements in human prostate cancer tissues and cell lines by quantitative reverse transcription-polymerase chain reaction and pyrosequencing, respectively. The most striking finding was strong and generalized increased expression of the HERV-K_22q11.23 provirus in cancers, including de novo expression of a spliced accessory Np9 transcript in some tumors. In parallel, DNA methylation in the long terminal repeat (LTR) decreased. Conversely, HER...

2011-01-01

168

Selected cardiovascular and central properties of three lidocaine analogs.

Process for filling tubular plates for lead batteries. Verfahren zum Fuellen von Rohrplatten fuer Bleiakkumulatoren

Three analogs of lidocaine (benzyl carbamyl, benzyl nitrile and methyl nitrile) were synthesized and examined for cardiovascular and central activity. The benzyl carbamyl analog was more potent than lidocaine in lowering blood pressure but possessed only slight local anesthetic, antiarrhythmic and CNS-depressant activity. At 40 mg/kg the benzyl nitrile derivative was superior to lidocaine in protecting against chloroform-induced arrhythmias. The methyl nitrile analog was less active than the benzyl nitrile analog in most parameters examined. The benzyl nitrile derivative and lidocaine had similar potencies on blood pressure depression, local anesthetic activity and ability to protect against calcium chloride-induced arrhythmias. Unlike the benzyl carbamyl derivative both lidocaine and the benzyl nitrile compounds appear to depress the cardiovascular system via a common mechanism. PMID:515167

1979-01-01

169

Molecular dynamics study of TiO2/poly(acrylic acid-co-methyl methacrylate) and Fe3O4/polystyrene composite latex particles prepared by heterocoagulation

The following method is proposed as a supplement to main patent 2419107, which deals with the filling of tubular plates surrounding the lead cores: the flat materials which are used to produce the jacket tubes are prepared before forming into jacket tubes by a film producing aqueous carboxy-methyl cellulose solution closing the pores. The preparation can be done by coating the flat material with a soluble foil. After pressing the paste in, the tubular plates are dried and after cooling are dipped into sulphuric acid with a specific gravity of 1.24 g/cm/sup 3/. The carboxy-methyl cellulose is dissolved and the permeability of the tube walls for electrolyte is restored after only 15 minutes.

1981-06-19

170

British Library Electronic Table of Contents (United Kingdom)

All-atom molecular dynamics simulations were used to study the morphology of polymer/inorganic composite particles prepared by heterocoagulation. The results were also compared to those of our previous study of the preparation of TiO2/poly(acrylic acid-co-methyl methacrylate) and Fe3O4/polystyrene composite particles. In the simulation system, polymer or inorganic particles were simulated by surface-charge-modified C60 or Na atoms. Through a combination of analysis of the radial distribution functions of charged atoms and snapshots of the equilibrated structure, three kinds of particle distributions were observed under different conditions. When the polymer and inorganic particles had opposite surface charges and their sizes were very different, the composite morphology showed a core-shell...

2010-01-01

171

Infrared spectroscopy of rovibrational transitions of methyl radicals (CH3, CD3) in solid parahydrogen

British Library Electronic Table of Contents (United Kingdom)

The n3 and n4 vibrational transitions of CH3 and CD3 isolated in solid parahydrogen were studied by high-resolution infrared spectroscopy. The radicals were produced by in situ UV photolysis of methyl iodides trapped in solid parahydrogen. The observed spectra showed clear rotational fine structures, which were subjected to further splitting due to the electrostatic field of solid parahydrogen. The molecular constants and crystal field parameters of the radicals in solid parahydrogen were determined by analyzing the spectral structures of the n3 and n4 transitions of CD3 by the crystal field theory. The rotational constants of the CD3 radical were found to be only a few percent smaller than those in the gas phase. The determined crystal field parameters indicated significant quantum effect...

2011-01-01

172

Hydrogen-atom attack on methyl viologen in aqueous solution studied by pulse radiolysis

Epigenetic regulation of Myc on retinoic acid receptor beta and PDLIM4 in RWPE1 cells

Using hydrogen at high pressures of up to 150 bar as an OH scavenger in aqueous MV"2"+ solutions (pH 1) it is possible to differentiate between two kinds of transient formed simultaneously by H-atom attack on methyl viologen. One of them is assigned to an H adduct on the N atom, MV"+H"+, with absorption bands identical to those of the radical cation, MV"+. The MV"+H"+ species deprotonates forming the long-lived radical cation, MV"+. The second type of transient produced is attributed to an H-adduct on the ring carbon, MV"2"+H, decaying by second-order kinetics. The formation of MV"+ by electron transfer from the propan-2-ol radical has been reinvestigated (pH 0 to 7); its absorption spectrum does not change in this pH range. Rate constants and molar extinction coefficients are presented. (U.K.).

1984-01-01

173

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND Hypermethylation of CpG islands is a common epigenetic alteration associated with cancer. Tumor suppressor genes retinoic acid receptor beta (RARb) and PDLIM4 are hypermethylated and silenced in prostate cancer (PCa) tissues and PCa cell lines compared to normal prostate cells. METHODS In this study, a benign prostate epithelial cell line RWPE1 was used as a model to study the epigenetic regulation of Myc on the RARb and PDLIM4 promoters. Forced Myc overexpression inhibited the RARb and PDLIM4 expression. RESULTS Pyrosequencing study showed that Myc overexpression increased methylation in several CpG sites of both promoters. A DNA methylation inhibitor 5-aza-2prime-deoxycytidine reversed the epigenetic alteration effect of Myc on both RARb and PDLIM4. CONCLUSION The epigenetic r...

2009-01-01

174

Enhancement of PVC/ENR blend properties by poly(methyl acrylate) grafted oil palm empty fruit bunch fiber

British Library Electronic Table of Contents (United Kingdom)

Effect of oil palm empty fruit bunch (OPEFB) fiber and poly(methyl acrylate) grafted OPEFB on several mechanical properties of poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends were studied. The composites were prepared by mixing the fiber and the PVC/ENR blends using HAKEE Rheomixer at the rotor speed of 50 rpm, mixing temperature 150degreeC, and mixing period of 20 min. The fiber loadings were varied from 0 to 30% and the effect of fiber content in the composites on their ultimate tensile strength (UTS), Youngs modulus, elongation at break, flexural modulus, hardness, and impact strength were determined. An increasing trend was observed in the Youngs modulus, flexural modulus, and hardness with the addition of grafted and ungrafted fiber to the PVC/ENR blends. However the i...

2008-01-01

175

Degradation of organophosphorus pesticides in wheat during cookie processing

British Library Electronic Table of Contents (United Kingdom)

For investigating carryover of some organophosphorus pesticide residues in the cereal food chain from grain to consumer, a study was set up on wheat bran, flour and cookies, with and without bran. Special emphasis was given to malathion and chlorpyrifos-methyl residues in cookies for better protection of consumers. Pesticide-free wheat was placed in a small-scale model of a commercial storage vessel and treated with these pesticides. The residue levels of insecticides were determined in wheat, as well as in bran, flour and cookies produced from stored wheat at various time intervals during storage. A multiresidue analysis was performed using GC-NPD and GC-MS. Malathion and chlorpyrifos-methyl residue levels were higher than the maximum residue limits (MRLs) in wheat after 240days of storag...

2009-01-01

176

Chemical cotton stalk destruction for maintenance of host-free periods for the control of overwintering boll weevil in tropical and subtropical climates

British Library Electronic Table of Contents (United Kingdom)

In the Lower Rio Grande Valley (LRGV) of Texas, cotton regrows and produces fruit from undestroyed stalks throughout the winter, and in spring weevils from such locations become a serious threat. The success of the boll weevil eradication program, which was reintroduced in the LRGV in 2005, will be dependent on thorough stalk destruction following harvest. However, adverse weather conditions and conservation tillage often impede immediate and complete stalk destruction using typical tool implements, and alternative stalk control methods are needed. This study provides an examination of the efficacy for cotton stalk destruction of different herbicides (thifensulfuron-methyl + tribenuron-methyl, dicamba-diolamine, 2,4-D-dimethylammonium, flumioxazin, 2,4-DB-dimethylammonium and carfentrazone...

2007-01-01

177

Blood gene expression markers to detect and distinguish target organ toxicity

British Library Electronic Table of Contents (United Kingdom)

The purpose of this study was to investigate whether the expression of specific genes in peripheral blood can be used as surrogate marker(s) to detect and distinguish target organ toxicity induced by chemicals in rats. Rats were intraperitoneally administered a single, acute dose of a well-established hepatotoxic (acetaminophen) or a neurotoxic (methyl parathion) chemical. Administration of acetaminophen (AP) in the rats resulted in hepatotoxicity as evidenced from elevated blood transaminase activities. Similarly, administration of methyl parathion (MP) resulted in neurotoxicity in the rats as evidenced from the inhibition of acetyl cholinesterase activity in their blood. Administration of either chemical also resulted in mild hematotoxicity in the rats. Microarray analysis of the global ...

2010-01-01

178

The tumor suppressor gene KCTD11^RENis regulated by Sp1 and methylation and its expression is reduced in tumors

Synthesis and properties of N,N-dialkyl-P-phenylphosphonamidous iodides

A hallmark of several human cancers is loss of heterozygosity (LOH) of chromosome 17p13. The same chromosomal region is also frequently hypermethylated in cancer. Although loss of 17p13 has been often...Full Text Available

179

Statistical mapping analysis of serotonin synthesis images generated in healthy volunteers using positron-emission tomography and alpha-[11C]methyl-L-tryptophan.

N,N-Dialkyl-P-phenylphosphonamidous iodides are formed in the reactions of phenylphosphonus diiodide with silylated secondary amines. N,N-Dialkyl-P-phenylphosphonamidous iodides react with electrophilic reagents (methyl iodide, benzenesulfonyl azide, and phenyl azide) by the usual schemes with the formation of alkylation and oxidative-imination products. Iodine catalyzes the disproportionation of morpholinophenylphosphinous iodide into dimorphomorpholinophenylphosphinous iodide with iodine are iododimorpholinophenylphosphonium triiodide and phenylphosphonous diiodide.

1987-01-20

180

Relationship between O6-alkylguanine-DNA alkyltransferase activity and N-methyl-N'-nitro-N-nitrosoguanidine-induced mutation, transformation, and cytotoxicity in C3H/10T1/2 cells expressing exogenous alkyltransferase genes.

OBJECTIVES: To assess the suitability of analyzing functional images of brain serotonin (5-HT) synthesis with statistical parametric mapping (SPM), and to investigate further possible sex-related regional...Full Text Available

2000-09-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

181

Preparation and radiolabeling of IBZM: a potential D-2 specific brain imaging agents for SPECT

While a great deal of evidence has directly implicated the importance of O6-alkylation of guanine in the mutagenicity of alkylating agents, evidence demonstrating the oncogenic potential of this lesion...Full Text Available

1992-12-01

182

NMR study of aluminium chloride and lithium tetrachloroaluminate solutions in a mixed solvent of thionylchloride-methylacetate

In developing new receptor-site specific brain imaging agents labeled with I-123 for single photon emission computed tomography (SPECT), an analog of raclopride, 3-["1"2"5I]-iodo-N-[(1-ethyl-2-pyrrolidinyl)-methyl]-2-hydroxy-6-me-thoxy benzamide (IBZM), was prepared using a method similar to that reported for raclopride and its derivatives. (author).

183

Lithium tetrachloroaluminate solutions in thionylchloride, methylacetate and their mixtures are studied by "7Li and "2"7Al NMR. It is found that introduction of methylacetate in the LiAlCl_4-SOCl_2 system results in a change of lithium tetrachloroaluminate formation constant. In the ternary system, Li"+ is solvated by methyl-acetate after complete destruction of tetrachloroaluminate anion. Refs. 9, figs. 2.

184

Methanol, MTBE suppliers will likely keep up with rising demand

Testicular germ cell tumours (TGCTs) of adolescents and adults morphologically mimic different stages of embryogenesis. Established cell lines of these cancers are used as informative models to study...Full Text Available

1997-01-01

185

Effects of alpha-deuterium substitution on the mutagenicity of 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK)

A primary and basic question prevails in the methanol industry - What will be the global demand for methanol, for the expanded production of methyl tertiary butyl ether (MTBE), during the next few years This article attempts to answer the question by discussing the global market; supply and demand factors; the market in North America, Western Europe, Far East and Asia, South America, and other regions; and the uncertainties that remain.

1993-03-29

186

Detection of acute myocardial infarction in spontaneously hypertensive rats by /sup 99m/Tc-Pyrrolidino methyl tetracycline

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a carcinogenic tobacco specific nitrosamine, can be converted to electrophilic diazohydroxide intermediates by metabolic hydroxylation of either the methylene carbon (carbon 4) or the methyl carbon attached to the nitrosamine group. To investigate the relative importance of these two processes in NNK mutagenesis, we synthesized 4,4-dideutero-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone((4,4,-D2)NNK) and 4-(trideuteromethylnitrosamino)-1-(3-pyridyl)-1-butanone ((CD3) NNK), and evaluated their mutagenic activities in Salmonella typhimurium tester strains. In the presence of Aroclor induced rat liver 9000 g supernatant, NNK and (4,4-D2)NNK had comparable mutagenic activities towards S. typhimurium TA 1535 and TA 100, but (CD3)NNK was inactive in both strains. These results suggest that hydroxylation of the methyl group of NNK is more important than hydroxylation of carbon 4 in its activation ...

1983-01-01

187

Coulomb Repulsion in Miniature Ion Mobility Spectrometry

The myocardial infarct induced by isoproterenol in spontaneously hypertensive rats accumulates higher activities of /sup 99/sup(m)Tc-PM tetracycline compared with the cardiac infarct in normotensive rats caused by the same method. The isoproterenol model of the myocardial necrosis was induced in intact rats without opening the thorax and is a convenient method for experimental radioisotope studies.

1983-01-01

188

Control of pyrethroid and DDT-resistant Anopheles gambiae by application of indoor residual spraying or mosquito nets treated with a long-lasting organophosphate insecticide, chlorpyrifos-methyl

We have undertaken a study of ion mobility resolution in a miniature ion mobility spectrometer with a drift channel 1.7 mm in diameter and 35 mm in length. The device attained a maximum resolution of 14 in separating ions of NO, O{sub 2}, and methyl iodine. The ions were generated by pulses from a frequency-quadrupled Nd:YAG laser. Broadening due to Coulomb repulsion was modeled theoretically and shown experimentally to have a major effect on the resolution of the miniature device.

1999-08-08

189

Characterization and properties of monoammine nitroimidazole complexes of platinum (PtCl sub 2 (NH sub 3 )(NO sub 2 Im)). Crystal and molecular structure of cis-Amminedichloro(1-((((2-hydroxyethyl)amino)carbonyl)methyl)-2-nitroimidazole)platinum(II)

BackgroundScaling up of long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) with support from the Global Fund and President's Malaria Initiative is providing...Full Text Available

190

A Facile One-Pot Expeditious Synthesis of Thiazolyl-pyrazolones

The characterization of monoammine(nitroimidazole)platinum(II) complexes of structure (PtCl{sub 2}(NH{sub 3})(NO{sub 2}Im)) (NO{sub 2}Im = 1-((((2-hydroxyethyl)amino)carbonyl)methyl)-2-nitroimidazole, Etanidazole (I), 1-(2-nitro-1-imidazolyl)-3-methoxy2-propanol, Misonidazole (II), and 1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole, Metronidazole (III)) is reported. Both is cis and trans isomers may be isolated for II and III. The crystal structure of cis-amminedichloro(1-((((2-hydroxyethyl)amino)carbonyl)methyl)-2-nitroimidazole)platinum(II) has been determined by X-ray diffraction. The crystals are orthorhombic, space group Pnab with cell dimensions a = 14.867 (7) {angstrom}, b = 9.915 (5) {angstrom}, c = 19.015 (9) {angstrom}, and Z = 8. The structure was refined to R = 0.062 and R{sub w} = 0.052. Platinum has the expected square-planar coordination. The Pt-Cl bond trans to the nitroimidazole ligand is shorter (2.269 (3) ...

1991-11-27

191

British Library Electronic Table of Contents (United Kingdom)

A novel, one-pot, multicomponent synthesis of 4-arylidene-3-methyl-1-(4-arylthiazol-2-yl)-1H-pyrazol-5(4H)-ones is described using phenacyl bromides, thiosemicarbazide, ethylacetoacetate, and aryl aldehydes. This synthesis involves simultaneous formation of two heterocycles like thiazole and pyrazolone along with condensation of active methylene group by aldehydes via Knoevenagel reaction. The methodology is mild, efficient, and high yielding. GRAPHICAL ABSTRACT[image omitted

2011-01-01

192

ent-Rosane and abietane diterpenoids as cancer chemopreventive agents

British Library Electronic Table of Contents (United Kingdom)

Two ent-rosane- (cuzcol, 1 and 6-dehydroxycuzcol, 2) and a abietatriene- (salvadoriol, 3) type diterpenoids have been isolated from Maytenus cuzcoina and Crossopetalum uragoga, respectively, along with five known diterpene compounds (4-8). Their stereostructures have been elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques, and computational data. The absolute configuration of cuzcol was determined by application of Riguera ester procedure. This is the first instance of isolation of ent-rosane diterpenoids from species of the Celastraceae. The isolated diterpenes were found to be potent anti-tumour-promoter agents, and carnosol (7) also showed a remarkable chemopreventive effect in an in vivo two-stage carcinogenesis model.

2011-01-01

193

Treatment of hepatocellular carcinoma (HCC) with radiolabeled Lipiodol: a preliminary report

Solvent effects on biocatalysis in organic systems: equilibrium position and rates of lipase catalyzed esterification.

Fatty acid esters such as Lipiodol or Ethiodol are known to selectively localize in vascular hepatocellular carcinomas (HCC), following intraarterial hepatic administration. Lipiodol was labeled with radioactive /sup 131/I and administered in 47 patients with HCC for both imaging and therapy. The short term preliminary results suggest radiolabeled Lipiodol is effective in eliminating ascites, shrinking the tumor by a high internal radiation dose, and in improving symptomatology of these tumors. In the future, /sup 90/Y, which is a stronger pure beta-emitter (maximum beta energy of 2.27 MeV, a half life of 64 h, and a maximum penetration or beta range of 11mm), than /sup 131/I will be used for more effective treatment of HCC.

1987-12-01

194

Reductive metabolism of the dinitrobenzamide mustard anticancer prodrug PR-104 in mice

Porcine pancreatic lipase immobilized on celite particles has been employed as a catalyst for the esterification of dodecanol and decanoic acid in a predominantly organic system. Solvent influence on the equilibrium position and on the catalyst activity has been studied using 20 solvents, including aliphatic and aromatic hydrocarbons, ethers, ketones, nitro- and halogenated hydrocarbons, and esters. The equilibrium constant for esterification correlates well with the solubility of water in the organic solvent, which in turn shows a good relationship with a function of Guttman's donor number and the electron pair acceptance index number of the solvent. This may be rationalized in terms of the requirements for solvation of water and of the reactants. The catalyst activity, measured as the initial rate of the esterification reaction, is best correlated as a function of both n-octanol-water partition coefficient (log P) and either the electron pair acceptance index or ...

1991-12-01

195

British Library Electronic Table of Contents (United Kingdom)

Purpose PR-104, a bioreductive prodrug in clinical trial, is a phosphate ester which is rapidly metabolized to the corresponding alcohol PR-104A. This dinitrobenzamide mustard is activated by reduction to hydroxylamine (PR-104H) and amine (PR-104M) metabolites selectively in hypoxic cells, and also independently of hypoxia by aldo-keto reductase (AKR) 1C3 in some tumors. Here, we evaluate reductive metabolism of PR-104A in mice and its significance for host toxicity. Methods The pharmacokinetics of PR-104, PR-104A and its reduced metabolites were investigated in plasma and tissues of mice (with and without SiHa or H460 tumor xenografts) and effects of potential oxidoreductase inhibitors were evaluated. Results Pharmacokinetic studies identified extensive non-tumor reduction of PR-104A to t...

2011-01-01

196

Radioiodinated phenoxyacetic acid derivatives as potential brain imaging agents, 2; Structure-biodistribution relationship

Phorbol esters, protein kinase C, and thyroxine 5 prime -deiodinase in brown adipocytes

In developing new brain imaging agents for single photon emission computed tomography (SPECT), we synthesized eleven radioiodinated phenoxyacetic acid derivatives and investigated the relationship between the chemical structure and in vivo characteristics. Biodistribution studies in mice revealed high initial brain uptake for all the compounds. Blood radioactivity level depended markedly upon the chemical stability of the compound. The alpha,alpha-dimethylester derivative, amide derivatives and diamine derivatives, which were stable to hydrolysis, showed low blood activity levels following intravenous administration. Disappearance of the ester and amide compounds from the brain was rapid. However, the diamine derivatives displayed improved retention in the brain. Compounds 3a and 4 possessed the best combination of high brain uptake and sufficient retention to be useful as potential brain imaging radiopharmaceuticals with SPECT devices.

1989-09-01

197

Optimization of extraction of high-ester pectin from passion fruit peel (Passiflora edulis flavicarpa) with citric acid by using response surface methodology

Protein kinase C activity has been identified in the rat brown adipocyte. About 60% of this activity is found in the cytosolic fraction under basal conditions, and 12-O-tetradecanoylphorbol 13-acetate (TPA) causes a rapid shift from the cytosol to the particulate fraction. Norepinephrine and phenylephrine causes a similar redistribution that can be blocked by prazosin but not by alprenolol. {alpha}{sub 1}-Adrenergic agonists cause three- to fivefold stimulation of type 2 iodothyronine 5{prime}-deiodinase activity in brown adipocytes. TPA has no effect on basal deiodinase activity and reduces the response of the enzyme to {alpha}{sub 1}-adrenergic agonists. These results suggest that the translocation of protein kinase C from cytosol to particulate fraction is not sufficient to increase deiodinase activity but can modulate the {alpha}{sub 1}-adrenergic agonist-mediated responses in these cells.

1988-03-01

198

British Library Electronic Table of Contents (United Kingdom)

A central composite design was employed to optimize the extraction of pectin with citric acid. The independent variables were citric acid concentration (0.086-2.91% w/v) and extraction time (17-102min). The combined effect of these variables on the degree of esterification was investigated. Results have shown that the generated regression models adequately explained the data variation and significantly represented the actual relationship between the independent variables and the responses. Besides that, the citric acid concentration was the most important factor to affect the degree of esterification, as it exerted a significant influence on the dependent variable. Lower citric acid concentration increased the pectin degree of esterification. The surface response showed the relationships b...

2008-01-01

199

New b-amino-a-trifluoromethyl alcohols and their exploration in the synthesis of trifluoromethylated imidazole derivatives

British Library Electronic Table of Contents (United Kingdom)

Racemic and enantiomerically pure b-amino-a-trifluoromethyl alcohols were obtained via sequential nucleophilic trifluoromethylation of selected a-imino ketones, derived from arylglyoxals, and subsequent removal of the MeO or Ph(Me)CH substituent, respectively, located at the N-atom. The obtained products, containing a primary amino group, were used for the synthesis of imidazole N-oxides bearing a trifluoromethyl group as a part of the N(1)-alkyl chain. Imidazole N-oxides with an electron-withdrawing ester group at C(4) underwent spontaneous isomerization under the reaction conditions, and the corresponding imidazol-2-ones derivatives were isolated as final products.

2011-01-01

200

Lipid composition of liver microsomes and mitochondria after acute and chronic {gamma}-irradiation of rats

Investigation of the preparation and physical properties of a novel semi-interpenetrating polymer network based on epoxised NR and PVA using maleic acid as the crosslinking agent

Acute {gamma}-irradiation of rats at doses of 100 and 270 Gy stimulates lipid synthesis and changes the lipid composition of liver cell organelles. The content of cholesterol and cholesterol esters in microsomes increased at 100 Gy and decreased at 270 Gy, with total phospholipid content remaining unchanged. The lipid content in mitochondria decreased considerably 1 h after irradiation at 270 Gy. This change was significantly less pronounced 47 h later. Under chronic {gamma}-irradiation (0.129 Gy/day), cholesterol and cardiolipin in mitochondria increased. The changes in lipid content caused by acute irradiation are presumed to be related to activated synthesis of lipids in the liver. The modification of the lipid content of mitochondria observed in chronically irradiated rats may indicate that energy-metabolizing liver cell systems are involved in the adaptation to irradiation.

1994-07-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

201

British Library Electronic Table of Contents (United Kingdom)

Natural rubber (NR) and its derivatives as renewable and biodegradable materials have attracted considerable attention because of the serious pollution problems caused by synthetic materials and a shortage of resources. A new semi-interpenetrating polymer network (semi-IPN) based on epoxidised natural rubber and polyvinyl alcohol containing maleic acid as a crosslinking reagent was synthesized and characterized by FTIR, XRD, SEM, swelling ratio in both distilled water and toluene, and mechanical properties. The curing time and dose of maleic acid were varied from 10 to 60min, and from 10 to 60% (w/w), respectively. An IR spectroscopic study indicated the presence of an ester linkage at 1730cm-1 in maleic acid crosslinked with PVA in semi-IPN films. In addition, the crystalline content of P...

2009-01-01

202

Global suppression of mitogen-activated ovine peripheral blood mononuclear cells by surface protein activity from Mycoplasma ovipneumoniae

British Library Electronic Table of Contents (United Kingdom)

Mycoplasma ovipneumoniae is associated with chronic non-progressive pneumonia of sheep and goats. As with many other mycoplasmas involved in animal diseases, protective immune responses have not been achieved with vaccines, even though antibody responses can be obtained. This study focuses on characterizing the interaction of M. ovipneumoniae with ovine PBMC using carboxy-fluorescein-succinimidyl-ester (CFSE) loading and flow cytometry to measure lymphoid cell division. M. ovipneumoniae induced a strong in vitro polyclonal suppression of CD4^+, CD8^+, and B blood lymphocyte subsets. The suppressive activity could be destroyed by heating to 60^oC, and partially impaired by formalin and binary ethyleneimine treatment that abolished its viability. The activity resided on the surface-exposed m...

2010-01-01

203

Equilibrium headspace analysis of volatile flavor compounds extracted from soursop (Annona muricata) using solid-phase microextraction

British Library Electronic Table of Contents (United Kingdom)

The influence of headspace solid-phase microextraction (HS-SPME) variables, namely, sample concentration, salt concentration and sample amount, on the equilibrium headspace analysis of the main volatile flavor compounds released from soursop was investigated. A total of 35 volatile compounds, comprising 19 esters, six alcohols, three terpenes, two acids, two aromatics, two ketones and an aldehyde, were identified. The results indicated that all response-surface models were significantly (p<0.05) fitted for 10 target volatile flavor compounds. The results further indicated that more than 65% of the variation in the equilibrium headspace concentrations of target volatile flavor compounds could be explained by the final reduced models, with high R2 values ranging from 0.658 to 0.944. Multiple...

2010-01-01

204

Degradation of a poly(ester urethane) elastomer. IV. Sorption and diffusion of water in PBX 9501 and its components

British Library Electronic Table of Contents (United Kingdom)

In preparation for studying the hydrolytic degradation of Estane 5703 in the plastic-bonded explosive PBX 9501, the sorption (solubility) and diffusion of water in PBX 9501 and each of its components are studied experimentally and modeled theoretically. Experiments are reported that measure the weight gain or loss due to a change in the relative humidity (RH). For all of the components, the equilibrium amount of water sorbed per gram of sample is linear in the RH at low relative humidities but curves upwards at higher relative humidities. This behavior is modeled with a water cluster model. Diffusion coefficients are determined by modeling the time dependence of the water concentrations assuming Fickian diffusion, and that fits the data for some of the materials. However, all the samples t...

2007-01-01

205

Part III. Direct enzymatic esterification of lactic acid with fatty acids.

New microwave assisted radiolabelling method and rat brain biodistribution study of two new "9"9"mTc-tricarbonyl complexes as potential brain imaging agents

Lipase catalyzed esterification reactions between lactic acid and several fatty acids have been studied. Difficulties arise in esterifying lactic acid because of the potential for this substance to act both as an acyl donor and as a nucleophile. These difficulties were minimized via strategies which greatly increased the yield of the desired ester. Use of the companion fatty acid in excess with respect to lactic acid in an apolar solvent (n-hexane) in which the lactic is not completely dissolved has been employed to minimize the potential for lactic acid to act as an acyl donor in a self-polymerization reaction.Beneficial and sinergistic effects of both silica gel and molecular sieves on conversion to the desired product are described. However, careful control of the amount of molecular sieves used is required. This fact is a consequence of two opposing effects of this material: i.e. adsorption of both lactic acid and water from the reaction mixture. For reaction ...

2001-07-01

206

Mitochondrial sequestration of BCECF after ester loading in the giant alga Chara australis.

Two new cyclopentadienyl piperidine derivatives, namely ferrocene carboxylic acid 1-ethyl-3-hydroxypiperidinyl ester and ferrocene carboxylic acid 4-hydroxypiperidinyl ester, were synthesized. The ligands were then radiolabelled with "9"9"mTc using two different approaches. The first method consisted of reacting the ligand precursor with Mn(CO)_5Br in pertechnetate "9"9"mTcO_4 - in normal saline and dimethyl formamide (DMF) at 150 "oC for 1 h. The yields were 70% and 90%, respectively. For the second method, the reactions mixtures were placed in a microwave oven for 2 min at 650 watt. The yields were higher than 90% for both "9"9"mTc complexes. Biodistribution studies showed that tricarbonyl[#eta#"5-[carboxy-3-hydroxy(N-ethyl)piperidine]cyclopentadienyl] technetium(I) had the highest brain uptake. The regional distribution in the brain also demonstrated relatively higher uptake of tricarbonyl [#eta#"5-[carboxy-3-hydroxy(N-ethyl) ...

207

Measurement of 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid and its metabolite 12-oxo-5Z,8E,10E-heptadecatrienoic acid in human plasma by gas chromatography/negative ion chemical ionization mass spectrometry

Ratiometric fluorescent dyes are often used to monitor free ion concentrations in vivo, especially in cells that are recalcitrant to transformation with genetically encoded fluorescent markers. Although intracellular dye distributions are often found to be cytosolic, dye localisation has often not been examined in detail. We began exploring the use of BCECF (2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein) to monitor pH in the giant alga Chara australis and discovered that younger leaf cells could be loaded using the acetoxymethyl ester of BCECF. However, we were puzzled to find in microphotometric measurements that the fluorescence ratio appeared insensitive to manipulations affecting cytosolic pH. Confocal imaging of C. australis cells loaded with BCECF showed an accumulation of the dye in two locations: (1) on the outside of the chloroplasts in irregularly shaped stationary bodies; (2) within 1-1.5 mum structures that moved rapidly with the pericellular ...

2007-12-19

208

The role and impact of rubber in poly(methyl methacrylate)/lithium triflate electrolyte

Thromboxane A2, the predominant product of arachidonic acid metabolism in the blood platelet, is a potent vasoconstrictor and platelet agonist. During its biosynthesis from cyclic endoperoxide, 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (HHT) is formed in equal amounts. The further metabolism of HHT, catalyzed by 15-hydroxyprostaglandin dehydrogenase, leads to 12-oxo-5Z,8E,10E-heptadecatrienoic acid (Oxo-HT). Sample workup procedures are described which allow for the sensitive and reproducible determination of these two arachidonic acid metabolites in human plasma by gas chromatography-mass spectrometry in the presence of deuterated analogues as internal standards. HHT is derivatized to the pentafluorobenzyl ester tert-butyldimethylsilyl ether. In order to enable quantification of low concentrations of about 10 pg/ml in nonstimulated human plasma, the samples have to be purified by HPLC. Oxo-HT is derivatized to the pentafluorobenzyl ester, ...

1990-01-01

209

British Library Electronic Table of Contents (United Kingdom)

In this research, new thin freestanding films of poly(methyl methacrylate) (PMMA)/50% epoxidised natural rubber (ENR 50) were doped with lithium triflate, LiCF3SO3 salt was prepared by a solvent casting method. The incorporation of ENR 50 is found to increase the conductivity of PMMA/LiCF3SO3 by two orders of magnitude at room temperature. The highest conductivity achieved was 5.09x10-5Scm-1 at room temperature when 60% of LiCF3SO3 salt was introduced into the PMMA blend containing 10% ENR 50. The formation of excessive hydrogen bonds and interchain crosslinking limit the performance of the blend at higher concentrations of ENR 50. The ionic conduction mechanisms in PMMA/ENR 50/LiCF3SO3 electrolytes obey the Arrhenius rule in which the ion transport in these materials is thermally assisted...

2006-01-01

210

Synthesis, crystal structure and spectroscopic studies of copper(II) complex of C-meso-1,5,8,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane

British Library Electronic Table of Contents (United Kingdom)

Copper(II) complex coordinated with cyclam-type macrocyclic tetramine, C-meso-1,5,8,12-tetramethyl-1,4,8,11-tetraazacyclotetradecane (2Cdmc) has been synthesized and characterized by single crystal X-ray crystallographic analysis and UV?Vis absorption spectra. Solved molecular structure of [Cu(2Cdmc)(H2O)]Cl2?2H2O (1) revealed that macrocyclic ligand 2Cdmc was in the most stable trans-III structure, but the C-methyl groups of 2Cdmc adopted energetically unfavorable axial configuration (C-axial). This complex 1 is the second example of complex of cyclam-type tetramine with only axially oriented C-methyl groups. This complex adopted five-coordinated square-pyramidal geometry with one water molecule occupying one of the two apical sites. Network of hydrogen bonds involving counter anions (Cl?...

2011-01-01

211

Synthesis of model compounds for coal liquefaction research. Quarterly report No. 1, June 21, 1990--September 20, 1990

Studies of initial stage in coal liquefaction. Effect of decomposition of oxygen-functional groups on coal liquefaction; Ekika hanno no shoki katei ni kansuru kenkyu. 3. Gansanso kannoki no bunkai kyodo to ekika hanno eno eikyo

The objectives of this project are to develop feasible synthetic routes to produce (1) 4(4`-hydroxy-5`,6`,7`,8`-tetrahydro-l`-naphthylmethyl )- 6-methyldibenzothiophene, and (2) a 1-hydroxynaphthalene-benzothiophene polymer. Our experimental work during this quarter concentrated on. As several possible synthetic routes to the target molecule, 4(4`-hydroxy-5`,6`,7`,8`-tetrahydro- l`-naphthylmethyl )-6-methyldibenzothiophene. We tried synthesizing the intermediates for our first method, in which we couple a metalated 4-methyldibenzothiophene with 4-formyl-5,6,7,8-tetrahydro-1-naphthol. We found that we could easily metalate dibenzothiophene, and then add a methyl group to the 4-position to give 4-methyldibenzothiophene in greater than 80% yield by using t-butyllithium in tetrahydropyran followed by dimethylsulfate. However, adding the second metal to the desired 4` position using the same method was more difficult, and instead the reaction occurred on the ...

1990-11-02

212

Radionuclear estimation with {sup 99m}Tc-N-pyridoxyl-5-methyl-tryptophan (PMT) scintigraphy of recurrent hepatocellular carcinoma after non-surgical treatment

Pretreatment of brown coal in oil was conducted using 1-methyl naphthalene or mixture of tetralin and 1-methyl naphthalene as solvent at temperatures ranging from 300 to 430{degree}C under nitrogen atmosphere. Effects of the solvent properties on the structural change of oxygen-functional groups (OFG) and coal liquefaction were investigated by means of quantitative analysis of OFG and solid state {sup 13}C-NMR measurement. When hydrogen transfer from solvent was insufficient, it was suggested that brown coal molecules loose their hydrogen to be aromatized. While, at lower temperatures ranging from 300 to 350{degree}C, hydrogen contained in brown coal molecules was consumed for the stabilization of pyrolytic radicals, and the deterioration of liquefaction was not observed. When hydrogen transfer from solvent was insufficient at higher temperatures above 400{degree}C in nitrogen atmosphere during pretreatment in oil, crosslinking like benzofuran ...

1996-10-28

213

Radiolytic stabilization of poly(methyl methacrylate) using commercial additives; Estabilizacao radiolitica do poli(metacrilato de metila) usando aditivos comerciais

{sup 99m}Tc-N-pyridoxyl-5-methyl-tryptophan (PMT) scintigraphy, which exhibits highly specific for the diagnosis of primary hepatocellular carcinoma (HCC), was performed for recurrent HCC following non-surgical treatment. Eighty-four patients (total 351 examinations) were selected for the study. The ability of PMT scintigraphy to diagnose recurrent HCC after treatment was compared with that of computed tomography, ultrasonography and angiography. The results showed that sixty-three (75%) of 84 cases demonstrated positive findings during our follow-up period, most of the tumors initially showing positive findings remained PMT positive when they recurred and PMT studies shortly after treatment demonstrated wider tracer uptake rather than the actual tumor area. In conclusion, PMT scintigraphy for patients with HCC after non-surgical treatment exhibited high accuracy in identifying viable HCC only for tumors indicating positive findings. (author)

1997-10-01

214

Production of bone cement composites: effect of fillers, co-monomer and particles properties

Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterelizable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its mechanical properties. Therefore, radiolytic of PMMA is important for it to become commercially radiosterizable. In this work some commercial additives, originally used in photo-and thermo-oxidate stabilization of polymers, were tested. Only two additives, type HALS (Hindered Amine Light Stabilizer), denoted Scavenger, showed a good protective quality. The investigation of radiation-induced main scissions was carried out by viscosimetric method. The most effective additive, added to the polymer system at 0.3 w/w%, promotes a great molecular radioprotection of 93%. That means a reduction of G-value (scissions/100 eV) from 0.611 to 0.053. In addition, the glassy transition temperature (T{sub ...

2000-04-01

215

Preparation of new proton exchange membrane based on self-assembly of poly(styrene-co-styrene sulfonic acid)-b-poly(methyl methacrylate)/poly(vinylidene fluoride) blend

Artificial bone cements (BCs) based on poly(methyl methacrylate) (PMMA) powders and methyl methacrylate (MMA) liquid monomer also present in their formulation small amounts of other substances, including a chemical initiator compound and radiopaque agents. Because inadequate mixing of the recipe components during the manufacture of the bone cement may compromise the mechanical properties of the final pieces, new techniques to incorporate the fillers into the BC and their effect upon the mechanical properties of BC pieces were investigated in the present study. PMMA powder composites were produced in situ in the reaction vessel by addition of X-ray contrasts to the reacting MMA mixture. It is shown that this can lead to much better mechanical properties of test pieces, when compared to standard bone cement formulations, because enhanced dispersion of the radiopaque agents can be achieved. Moreover, it is shown that the addition of hydroxyapatite ...

216

Preliminary study on the thermal conductivity and flammability of WPC based on some tropical woods

Amphiphilic block copolymers are synthesized by sulfonation of poly(styrene-b-methyl methacrylate) (PS-b-PMMA) using acetyl sulfate, and are blended with poly(vinylidene fluoride) (PVDF) to prepare a new proton exchange membrane, in which PMMA is miscible with PVDF. The morphology and the transport properties of the membranes are investigated as functions of the degree of sulfonation as well as the blend ratio. Notable transition of phase-separated morphology is observed as the PVDF content of the blend is increased. Both the proton conductivity and the ion-exchange capacity (IEC) of the membrane increase with increasing the degree of sulfonation of PS-b-PMMA, and they are also enhanced as the phase-separated domains of blend membrane are well-ordered. Unlike the Nafion membrane, the proton conductivity of the blend membrane increases up to 90 C, indicating the blend membrane shows better thermal stability than the Nafion membrane. (author)

2009-03-01

217

New Lactone and Xanthone Derivatives Produced by a Mangrove Endophytic Fungus Phoma sp. SK3RW1M from the South China Sea

Selected local woods and their wood-polymer combinations or composites (WPC) were tested for their thermal conductivity and their fire resistance. WPC were prepared by polymerizing monomers ''in situ'' in oven dried woods by gamma radiation. The monomers included acrylonitrile (AN), 60% styrene-40% acrylonitrile (STAN), methyl methacrylate (MMA), 95% methyl methacrylate-5% dioxane (MD), and vinylidene chloride (VDC). A reduction in thermal conductivity was exhibited by all the composites prepared. W-PAN showed the greatest reduction in thermal conductivity and W-PSTAN in general showed the least. An explanation is suggested for this behaviour. The polymers PMMA and PMD were found to enhance flammability of the woods while PVDC, PAN, and PSTAN imparted fire resistance to the woods. Of the six local woods studied, Ramin-and-Keruing-polymer composites showed the highest flammable tendencies obtained. The ...

1985-01-01

218

British Library Electronic Table of Contents (United Kingdom)

A new lactone, 1,8-dihydroxy-10-methoxy-3-methyldibenzo[b,e]oxepine-6,11-dione (1), and two new xanthones, 1-hydroxy-8-(hydroxymethyl)-6-methoxy-3-methyl-9H-xanthen-9-one (2) and 1-hydroxy-8-(hydroxymethyl)-3-methoxy-6-methyl-9H-xanthen-9-one (3), were isolated from a mangrove endophytic fungus Phoma sp. SK3RW1M collected from the South China Sea. This is the first report on xanthone derivatives isolated as secondary metabolites from Phoma species. Their structures were elucidated by spectroscopic methods, mainly 1D- and 2D-NMR techniques, and the structure of compound 2 was confirmed by X-ray crystallography. Cytotoxicity assays showed that compounds 1-3 were inactive against KB and KBv200 cells.

2010-01-01

219

Method for preparing drilling solutions that are resistant in Zechstein deposits

Manufacture of wood/plastic composites by radiation

The patent is for a method of preparing drilling muds that are notable for their chemical resistance to Zechstein deposits, especially to magnesium, carbonate and carboxylic acid ions. To achieve chemical resistance of the drilling mud to Zechstein deposits, it is suggested to saturate them with salt (the amount of added salt depends on the absorption properties of the solution), and then to process them with caustic soda or potassium oxide hydrate and lime in proportions that would cause filtrate alkalinity not to exceed 0.5. For example, to prepare drilling solution to bore through mediums containing magnesium salts, potassium salts, rock salt, anhydrate, dolomite, limestone, red salt clay: add 340 kg potassium chloride into 1 m/sup 3/ drilling solution with weighed bentonic clay, 10 kg. ferro-chromate lignosulfite, 7 kg. unslaked lime, 2 kg. sodium hydroxide, 5 kg. carboxy-methyl-cellulose, 5 kg. carboxy-methyl-hydroxylethyl-cellulose, 50 ...

1980-05-31

220

Epigenomic disruption: the effects of early developmental exposures.

The manufacture and use of wood/plastic composite (WPC) as an example of wood matrix and wood sawdust/plastic composites (SDP) as an example of plastic matrix are reviewed. The raw material for WPC are mostly vinyl monomers, particularly methyl methacrylate and styrene. The reaction in WPC polymerization is radical polymerization. Researches on the radiation sources mostly resulted in gamma-ray. Electron beam can be applied only to thin products. The future use of WPC may be for furnitures, sporting goods, decorative parts and the like. Vital study on the reduction of manufacturing costs is required, for example, the improvement of reaction and the adoption of continuous process must be considered. The raw materials for SDP are wood sawdust, vinyl monomer (mostly methyl methacrylate) and resins. Electron beam accelerators are the most preferable radiation source because of its high efficiency and safe operation. SDP shows good forming property. ...

1976-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

221

Endonuclease IV of Escherichia coli is induced by paraquat

Through DNA methylation, histone modifications, and small regulatory RNAs the epigenome systematically controls gene expression during development, both in utero and throughout life. The epigenome is also a very reactive system; its labile nature allows it to sense and respond to environmental perturbations to ensure survival during fetal growth. This pliability can lead to aberrant epigenetic modifications that persist into later life and induce numerous disease states. Endocrine-disrupting compounds (EDCs) are ubiquitous chemicals that interfere with growth and development. Several EDCs also interfere with epigenetic programming. The investigation of the epigenotoxic effects of bisphenol A (BPA), an EDC used in the production of plastics and resins, has further raised concern over the impact of EDCs on the epigenome. Using the Agouti viable yellow (A(vy)) mouse model, dietary BPA exposure was shown to hypomethylate both the A(vy) and the Cabp(IAP) metastable ...

2010-10-01

222

Dihydroxybenzene/benzoquinone-containing polymers: organic redox polymers

The addition of paraquat (methyl viologen) to a growing culture of Escherichia coli K-12 led within 1 hr to a 10- to 20-fold increase in the level of endonuclease IV, a DNase for apurinic/apyrimidinic sites. The induction was blocked by chloramphenicol. Increases of 3-fold or more were also seen with plumbagin, menadione, and phenazine methosulfate. H_2O_2 produced no more than a 2-fold increase in endonuclease IV activity. The following agents had no significant effect: streptonigrin, nitrofurantoin, tert-butyl hydroperoxide, #gamma# rays, 260-nm UV radiation, methyl methanesulfonate, mitomycin C, and ascorbate. Paraquat, plumbagin, menadione, and phenazine methosulfate are known to generate superoxide radical anions via redox cycling in vivo. A mutant lacking superoxide dismutase was unusually sensitive to induction by paraquat. In addition, endonuclease IV could be induced by merely growing the mutant in pure O_2. The levels of endonuclease ...

223

Cluster-assisted multiple ionization of methyl iodide by a nanosecond laser: Influence of laser intensity on the kinetic energy and peak profile of multicharged ions

Polymers containing hydroquinone, catechol or their corresponding benzoquinones are a special class of redox polymers. Three pathways of their syntheses are possible: condensation polymerization of suitable monomers, addition polymerization of vinyl monomers containing redox moiety, and chemical attachment of redox unit onto pre-made polymeric matrix. A range of functionalized matrices have been employed such as polyethers, polyesters, polycarbonates, polyurethanes, polyamides and others. Protection of their phenolic functionality has conducted to chemically interesting redox polymer precursors. The presence of a redox moiety coupled with the extant functionalization of the polymer matrix makes the materials very valuable, of wide properties and consequently of vast applicability. For instance, in the oil field, some polymers such as carboxy-methyl-cellulose (CMC) are often applied as to bring about a viscosity improvement and therefore to facilitate the oil ...

2000-08-01

224

Characterization of 3-["1"2"3I]iodo-L-#alpha#-methyl tyrosine (["1"2"3I]IMT) transport into human Ewing's sarcoma cells in vitro

The dependences of kinetic energies and peak profiles of multicharged ions of I "q"+ (q = 2-3) and C"2"+ on the laser intensity have been studied in detail by time-of-flight mass spectrometry, those multicharged ions are produced by irradiation of methyl iodide cluster beam with a nanosecond 532 nm Nd-YAG laser. Our experiments show that the kinetic energies released of multicharged ions increase linearly with the laser intensity in the range of 3 x 10"9-2 x 10"1"1 W/cm"2. The peaks of multicharged ions are split to forward ions and backward ions, and the ratio of the backward ions to forward ions decreases exponentially with laser intensity. The decreasing of backward ions is probably due to Coulomb scattering by the heavier I"+ ions when they turn around through the laser focus point. The linear dependence of kinetic energy of multicharged ions on laser intensity is interpreted by the ionization mechanism, in which the laser induced inverse bremsstrahlung heating ...

2006-03-20

225

Analysis of forward mutations induced by N-methyl-N'-nitro-N-nitrosoguanidine in the bacteriophage P22 mnt repressor gene

3-["1"2"3I]Iodo-L-#alpha#-methyl tyrosine (["1"2"3I]IMT) scintigraphy of extracranial malignant tumors has been described, but little is known about the transport systems involved in ["1"2"3I]IMT uptake into extracranial tumor cells. Here, the precise kinetics of ["1"2"3I]IMT transport into human Ewing's sarcoma cells (VH-64) was determined. The apparent Michaelis constant was of high affinity value (K_m=41.7#+-#3.9 #mu#M) and maximum transport velocity amounted to V_m_a_x=20.7#+-#0.6 nmol#centre dot#mg protein"-"1#centre dot#10 min"-"1. Inhibition experiments revealed the predominance of ["1"2"3I]IMT uptake via sodium-independent system L.

2001-02-01

226

An overview of PETC`s gas-to-liquids technology R&D Program

We describe the isolation and genetic characterization of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutations in the phage P22 mnt repressor gene cloned in plasmid pBR322. Mutations in the mnt repressor gene or its operator on this plasmid, pPY98, confer a tetracycline resistance phenotype, whereas the wild-type plasmid confers tetracycline sensitivity. Cells carrying pPY98 were briefly exposed to MNNG to give 20 to 40% survival and a 50- to 100-fold increase in tetracycline-resistant cells. DNA sequence analysis showed that 29 to 30 MNNG-induced mutations were GC-to-AT transitions and one was an AT-to-GC transition. About 80% of the mutations are in three hotspots. This mutation spectrum is consistent with the proposed mechanism of mutagenic action of MNNG, which involves mispairing of an alkylated base, O/sup 6/-methylguanine. The mnt gene may be a useful target for determining mutagenic specificity at the nucleotide level because (i) forward ...

1986-04-01

227

Wood-plastic composites with high toughness and dimensional stability

The overall goal of the Gas-to-Liquids Program at the U.S. Department of Energy`s Pittsburgh Energy Technology Center (PETC) is to develop technologies for the production of hydrocarbon fuels and premium chemicals from light alkane gases. PETC`s current Gas-to-Liquids Program comprises the development of four primary advanced conversion technologies, namely, partial oxidation, oxidative coupling, oxyhydrochlorination, and novel conversion processes. Based on the current state of development, it can be concluded that, in the near future, one or more of these technologies will reach proof-of-concept demonstration. Oxyhydrochlorination is the most advanced direct conversion technology, and the synthesis of lower cost methyl chloride from natural gas would impact several commercial technologies that utilize methyl chloride as an intermediate to high value products. Technology development for the partial oxidation of methane to synthesis gas using ...

1995-04-01

228

Two new paeciloxocins from a mangrove endophytic fungus Paecilomyces sp.

Using acrylic-group containing isocyanates together with methyl methacrylate as impregnating mixture and gamma rays for curing wood-plastic composites have been produced, which show high-dimensional stability and toughness (low brittleness) compared to commonly used wood-plastics. The syntheses of proper acrylic-group containing isocyanates are as well described as the properties of the produced composites, made from maple wood. Also the direct use of the initial compounds, necessary for the syntheses, resulted in products of similar properties. These wood-plastic composites are to be suggested for the production of high-class products, e.g. wood-wind instruments. (author).

1982-10-01

229

British Library Electronic Table of Contents (United Kingdom)

Paeciloxocins A and B (2-(1-hydroxy-3-methylbutyl)- and 2-(1-acetoxy-3-methylbutyl)- 11-hydroxy-9-methyl-1-methoxy-5H,7H-dibenzo[b,g]-1,5-dioxocin-5-ones), viz., two new metabolites, were isolated from the mangrove fungus Paecilomyces sp. collected from the Taiwan Strait. Their structures were elucidated by spectral methods. Paeciloxocin A exhibited strong cytotoxicity against the hepG2 cell line.

2010-01-01

230

Sound absorption of tropical woods and their radiation-induced composites

Resistance of radiation-induced tropical wood-polymer composites to fungal degradation

This is a preliminary study on the sound absorption properties of two tropical hardwoods, Light Red Meranti and Ramin, and their wood-polymer composites. Sound absorption is measured using a standing wave apparatus. The samples are of one thickness (7 mm) and cut longitudinally. Wood-polymer composites are made by impregnating the samples with methyl methacrylate which is polymerized in situ through #gamma#-irradiation. Both woods and their composites are better sound absorbers at higher sound frequencies. With partial impregnation, the absorption coefficients are improved upon particularly in the region between 1-3 kHz. (author).

1988-01-01

231

Microbuckling compression failure of a radiation-induced wood/polymer composite

The resistance of six tropical hardwoods to fungal degradation by two wild-type strains of Phanerochaete chrysosporium Burdsall was investigated using vermiculite burial and wood-block weight loss techniques. Radiation-induced wood-polymer composites (WPC), based on two hardwoods Ramin and Rubberwood with methyl methacrylate, were prepared, and samples were also exposed to the wood-rotting fungus. A significant improvement in resistance to fungal decay was observed in the WPC. Scanning-electron micrographs of the two woods and their composites after fungal degradation are presented and discussed.

1987-01-01

232

Microbuckling compression failure of a radiation-induced wood/polymer composite

A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45({plus minus}5)% and 90({plus minus}5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).

1990-01-01

233

Mechanism of biodegradation of paraquat by Lipomyces starkeyi

A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45(#+-#5)% and 90(#+-#5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).

1990-01-01

234

Mechanism of biodegradation of paraquat by Lipomyces starkeyi

The biodegradation of ring-/sup 14/C- and methyl-/sup 14/C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO/sub 2/. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.

1985-05-01

235

Long non-coding RNAs in nervous system function and disease

The biodegradation of ring-"1"4C- and methyl-"1"4C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO_2. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.

236

British Library Electronic Table of Contents (United Kingdom)

Central nervous system (CNS) development, homeostasis, stress responses, and plasticity are all mediated by epigenetic mechanisms that modulate gene expression and promote selective deployment of functional gene networks in response to complex profiles of interoceptive and environmental signals. Thus, not surprisingly, disruptions of these epigenetic processes are implicated in the pathogenesis of a spectrum of neurological and psychiatric diseases. Epigenetic mechanisms involve chromatin remodeling by relatively generic complexes that catalyze DNA methylation and various types of histone modifications. There is increasing evidence that these complexes are directed to their sites of action by long non-protein-coding RNAs (lncRNAs), of which there are tens if not hundreds of thousands speci...

2010-01-01

237

Effect of additives in the positive active mass of lead batteries. Zur Wirkung von Zusaetzen in der positiven Aktivmasse des Bleiakkumulators

Development of superconducting cryo-electron microscope and its applications

In order to improve the capacity and service life of cathodes, the effect of carboxy-methyl cellulose, soot, silica gel and fibres was examined. Structural tests and electrical and electro-chemical measurements are used for this. The additives can affect crystallization in the manufacturing stage of the electrodes and can increase the storage capacity for water and the electronic conductivity. They act to stabilize the mass in cyclic operation. Soot additive has little effect on the properties of the electrode, but the other substances increase the service life or the use of the mass. (LU).

1984-01-01

238

Complexing of ruthenium during sorption by a graft copolymer of a polyacrylonitrile fiber with poly-2-methvl-5-vinylpyridine (PAN-MVP)

Recently, a superconducting cryo-electron microscope in which specimens are cooled to the liquid helium temperature (4.2 K) has been developed. The main components and functional features of this new microscope are reported together with application data on polyethylene, poly (4-methyl-1-pentene), valonia cellulose, rock salt, ice crystallites and ceramic superconductor. The resistance to electron radiation damage, of beam-sensitive specimens including polymers has been increased more than ten times. Thus, the microscope has made it possible to take high resolution images and to analyze the crystal-structure of micro-areas. (orig.).

1988-01-01

239

Synthesis and PET imaging of the benzodiazepine receptor tracer [N-methyl-"1"1C]iomazenil

This paper studies the sorption of chlorine complexes of ruthenium (IV) on the graft copolymer of a polyacrylonitrile fiber with poly-2-methyl-5-vinylpyridine (PAN-MVP). The composition of the fiber is illustrated. It is shown that sorption of chlorine complexes of ruthenium (IV) from acid solutions by a pyridine fiber sorbent takes place according to an anion-exchange mechanism and is due to the formation of compounds of the diamine type (Ru(RPy)/sub 2/Cl/sub 4/).

1985-05-20

240

Methionine kinetics in adult men: effects of dietary betaine on L-[2H3-methyl-1-13C]methionine

The central benzodiazepine receptor tracer [N-methyl-"1"1C]iomazenil (Ro 16-0154) was synthesized by alkylation of the desmethyl precursor noriomazenil with ["1"1C]methyl iodide. The ["1"1C]CH_3I (prepared by reduction of ["1"1C]CO_2 with LiAlH_4 followed by reaction with HI) was reacted with noriomazenil inN,N -dimethylformamide and Bu_4N"+OH"- for 1 min at 80 deg. C and purified by HPLC (C_1_8, 34% CH_3CN/H_2O, 7 mL/min). The product was obtained with synthesis time 35 #+-# 5 min (mean #+-# SD, n = 7), radiochemical yield (EOB) 36 #+-# 16%, radiochemical purity 99 #+-# 1%, and specific activity 5100 #+-# 2800 mCi/#mu#mol. Absorbed radiation doses were calculated from previously acquired human biodistribution data. The urinary bladder wall received the highest dose (0.099 mGy/MBq) for 4.8 h voiding interval and the effective dose equivalent was 0.015 mSv/MBq. After i.v. injection of ["1"1C]iomazenil in an adult baboon or healthy human ...

1995-07-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

241

Isotope effects on the metabolism and pulmonary toxicity of butylated hydroxytoluene in mice by deuteration of the 4-methyl group

The effects of a daily 3-g supplement of betaine on kinetic aspects of L-[2H3-methyl-1-13C]methionine (MET) metabolism in healthy young adult men were explored. Four groups of four subjects each were given a control diet, based on an L-amino acid mixture supplying 29.5 and 21.9 mg.kg-1.d-1 of L-methionine and L-cystine for 4 d before the tracer study, conducted on day 5 during the fed state. Two groups received the control diet and two groups received the betaine supplement. Tracer was given intravenously (iv) or orally. The transmethylation rate of MET (TM), homocysteine remethylation (RM), and oxidation of methionine were estimated from plasma methionine labeling and 13C enrichment of expired air. RM tended to increase (P = 0.14) but the TM and methionine oxidation were significantly (P less than 0.05) higher after betaine supplementation when estimated with the oral tracer. No differences were detected with the intravenous tracer. Methionine concentration in ...

242

Fluoride complexes of Pt(II) as nucleophiles: activity of PtCl/sub 4//sup 2 -/, PtCl/sub 3/(H/sub 2/O)/sup -/, and PtCl/sub 3/(C/sub 2/H/sub 4/)/sup -/ anions in the oxidative addition of methyl iodide

A comparative test in mice for pulmonary toxicity between butylated hydroxytoluene (2,6-di-tert.-butyl-4-methylphenol, BHT) and 2,6-di-tert.-butyl-4-(alpha, alpha, alpha-2H3)methylphenol (BHT-d3) showed a significantly lower toxic potency of the latter. The rate of in vitro BHT metabolism to 2,6-di-tert.-butyl-4-methylene-2,5-cyclohexadienone (BHT-QM) was slowed by deuterating BHT in the 4-methyl group. On the other hand, the rate of in vitro metabolism to 2,6-di-tert.-butyl-4-hydroxy-4-methyl-2,5-cyclohexadienone (BHT-OH) was increased with the deuteration. A similar isotope effect of the deuterium substitution on the in vivo metabolic rates of BHT was observed. These observations support the concept that the lung damage caused by BHT is mediated by BHT-QM. The pulmonary toxicity of 2-tert.-butyl-4-ethylphenol (4-EP) and their deuterated analogs was also compared. 2-tert.-Butyl-4-(1,1-2H2)ethylphenol (4-EP-d2) showed a significantly lower ...

1983-06-30

243

Computerized tomography-guided neurolytic splanchnic nerve block

The kinetics of the oxidative addition of CH/sub 3/I to platinum(II) complexes in aqueous solutions of K/sub 2/PtCl/sub 4/ and KPtCl/sub 3/(C/sub 2/H/sub 4/) have been studied by PMR and GLC. The second-order rate constants for the PtCl/sub 3/(H/sub 2/O)/sup -/ and PtCl/sub 4//sup 2 -/ particles are equal to 400 exp(-2.7 x 10/sup 3//T) and 3.18 x 10/sup 10/ exp(-9.2 x 10/sup 3//T) mole/sup -1/ x liter x sec/sup -1/, respectively. The introduction of a ..pi..-acceptor ligand, viz. ethylene, into the coordination sphere of platinum(II) results in a sharp drop in the rate, probably due to a decrease in the electron density on the platinum atom. According to the PMR data, the product of the oxidative addition of CH/sub 3/I to Zeise's salt is a methyl complex of platinum(IV), is identical to the complex obtained by reacting methyl iodide with K/sub 2/PtCL/sub 4/, and does not contain an olefin.

1987-05-01

244

An Arabidopsis thaliana methyltransferase Capable of Methylating Farnesoic Acid

Computerized tomography-guided neurolytic splanchnic nerve block is a technique for relieving abdominal cancer pain; the goal is the alcoholic neurolytic interruption of the sensitive structures in retroperitoneal space. Computerized tomography yields accurate anatomical detailing and the course for needle placement and alcohol spread. January, 1993, to July, 1996, twenty-one bilateral splanchnic nerve blocks were performed through the posterior access. Forty-eight hours after alcoholism. 14 patients (66%) had complete pain regression; 52% of the patients needed no analgesics for 6 to 54 days and only 9 patients (42%) needed another low opioid therapy. Complications included hypotension and diarrhea in all cases. One had a cardiac arrest and diet 8 days after the procedure. There were no other complications. The whole procedure usually lasted 60 min (range: 45 to 90 min). Splanchnic nerve neurolysis is a useful treatment in the patients with severe chronic abdominal pain. It is used as ...

1997-01-01

245

3-Methyl-3-deazaadenine, a stable isostere of N3-methyl-adenine, is efficiently bypassed by replication in vivo and by transcription in vitro.

We previously reported the identification of a new family of plant methyltransferases (MTs), named the SABATH family, that use S-adenosyl-l-methionine (SAM) to methylate a carboxyl moiety or a nitrogen-containing functional group on a diverse array of plant compounds. The Arabidopsis genome alone contains 24 distinct SABATH genes. To identify the catalytic specificities of members of this protein family in Arabidopsis, we screened recombinantly expressed and purified enzymes with a large number of potential substrates. Here, we report that the Arabidopsis thaliana gene At3g44860 encodes a protein with high catalytic specificity towards farnesoic acid (FA). Under steady-state conditions, this farnesoic acid carboxyl methyltransferase (FAMT) exhibits K{sub M} values of 41 and 71 {mu}M for FA and SAM, respectively. A three-dimensional model of FAMT constructed based upon similarity to the experimentally determined structure of Clarkia breweri salicylic acid ...

2006-01-01

246

Vapor phase lubrication of a Ni-based superalloy

The goal of the present work was to determine the impact of N3-methyladenine (3-mA), an important lesion generated by many environmental agents and anticancer drugs, on in vivo DNA replication and in vitro RNA transcription. Due to 3-mA chemical instability, the stable isostere 3-methyl-3-deazaadenine (3-m-c(3)A) was site specifically positioned into an oligodeoxynucleotide. The oligomer was, then incorporated into a vector system that is rapidly converted to ssDNA inside yeast cells and requires DNA replication opposite the lesion for plasmid clonal selection. For control purposes, an adenine or a stable apurinic/apyrimidinic (AP)-lesion was placed at the same site. The presence of each lesion in the oligonucleotide was confirmed by MALDI-TOF analysis. Plasmids were then transfected into yeast cells. While the AP-site dramatically reduced plasmid replication in all strains, the 3-m-c(3)A had a slight effect in the rad30 background which significantly increased ...

2011-06-14

247

Unusual properties of crocodilian ovomacroglobulin shown in its methylamine treatment and sulfhydryl titration

In addition to ceramics, alloys such as tool steel and nickel- and iron-based superalloys are being considered for high temperature applications such as missile bearings and low heat rejection engines. Studies were made to lubricate a nickel-based superalloy at 500{degrees}C, by using a vaporized aryl phosphate ester, at a concentration of 0.1% in air. From deposition and wear studies it was found that it was impossible to form a good polymeric coating on the superalloy surface. Energy dispersive X-ray analyzer (EDXA) analysis showed that this was due to minute quantities of aluminum in the alloy segregating to the surface, upon being heated to 500{degrees}C, forming a passive oxide coating. It was necessary to activate the surface, in order to lubricate the material successfully. A method of activation by electrodepositing the surface with a layer of iron oxide was developed. Once activated, a good lubricous polymer was formed on the superalloy surface. Tests ...

1995-03-01

248

Thermodynamic prediction of distribution coefficients for the solvent extraction of the rare earth metals

The inhibitory activity of chicken and crocodilian ovomacroglobulins against trypsin was measured before and after their incubation with methylamine. The result for crocodilian ovomacroglobulin showed that methylamine treatment destroyed half of its activity, in unique contrast to human alpha 2-macroglobulin and chicken ovomacroglobulin for which methylamine either destroys the inhibitory activity of the former completely or does not affect that of the latter at all. Free sulfhydryl groups of chicken and crocodilian ovomacroglobulins were titrated with 5,5'-dithiobis(2-nitrobenzoic acid) before and after incubation with trypsin. Prior to the incubation with trypsin the chicken and crocodilian proteins respectively had 0 and 1 titratable sulfhydryl per molecule of Mr 720,000. After treatment with trypsin the crocodilian protein had 3.5-4 titratable sulfhydryls, whereas there were no titratable sulfhydryls in the chicken protein. After denaturation of the crocodilian protein in ...

1986-02-01

249

Radioiodinated phenoxyacetic acid derivatives as potential brain imaging agents, 2

A thermodynamic model for predicting the distribution coefficients has been developed by taking into account the extraction mechanism and the chloride complexation when Sm, Eu, Gd, Tb, Dy and Ho for single component systems are extracted from acidic chloride solutions by di-2-ethylhexyl ester in kerosene, respectively. The model equation includes two constants, of which one corresponds to the apparent extraction equilibrium constant and the other is due to the variation of the activity coefficients of organic species. These values are determined from a few experimental data by the curve fitting method. Then, the distribution coefficients under untried calculations, Bromley's formulation is used to estimate the activity coefficients of aqueous species and the interaction parameters for some rare earth chlorides are reported in terms of morality and molarity using data from Spedding et al. According to the authors the validity of this method has been confirmed by ...

250

Optimization of equilibrium headspace analysis of volatile flavor compounds of malaysian soursop (Annona muricata): Comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS)

In developing new brain imaging agents for single photon emission computed tomography (SPECT), we synthesized eleven radioiodinated phenoxyacetic acid derivatives and investigated the relationship between the chemical structure and in vivo characteristics. Biodistribution studies in mice revealed high initial brain uptake for all the compounds. Blood radioactivity level depended markedly upon the chemical stability of the compound. The #alpha#,#alpha#-dimethylester derivative (1e), amide derivatives (2a-c) and diamine derivatives (3a, b, 4), which were stable to hydrolysis, showed low blood activity levels following i.v. administration. Disappearance of the ester and amide compounds from the brain was rapid. However, the diamine derivatives displayed improved retention in the brain. Compounds 3a and 4 possessed the best combination of high brain uptake and sufficient retention to be useful as potential brain imaging radiopharmaceuticals with SPECT devices. ...

251

British Library Electronic Table of Contents (United Kingdom)

Headspace solid-phase microextraction (HS-SPME) coupled to comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) was applied for equilibrium headspace analysis of Malaysian soursop (Annona muricata) volatile flavor compounds. A two-level fractional factorial design (25-1) was used to determine the effect of SPME variables, namely, SPME fibers, adsorption temperature, extraction time, amount of salt, sample amount and sample concentration on the extraction efficiency of volatile flavor compounds. A total of 37 volatile compounds were identified, comprising 21 esters, 6 alcohols, 3 terpenes, 2 acids, 2 ketones, 2 aldehydes and an aromatic with different hydrophobicities (log P) ranging between -0.14 and 4.83. Extraction using 10g of diluted (5% w/w) ...

2011-01-01

252

Micropolarities of lipid bilayers and micelles. 3. Effect of monovalent ions on the dielectric constant of the water-membrane interface of unilamellar phosphatidylcholine vesicles

Lipase catalyzed esterification of glycidol in organic solvents

A study was undertaken of the effect of monovalent cations (Li/sup +/, Na/sup +/, K/sup +/) on the dielectric constant (epsilon) of the water-lipid interface of unilamellar phosphatidylcholine (PC) vesicles, i.e., the ester carbonyl oxygen region of the PC molecules or the neighborhood of the oxygen atoms of the phosphorylcholine moiety. epsilon was determined by reacting the free radical 1,1-diphenyl-2-picrylhydrazyl with ..cap alpha..-tocopherol incorporated in the lipid vesicles. The results are consistent with a decrease of epsilon (LiCl: 35.5 to 29.5; NaCl: 34 to 29; KCl: 33 to 29) as the concentration of the salts in the solvent media increases from 0.025 to 0.5 M. These effects can be rationalized in terms of dielectric saturation at the water-lipid interface brought about by ion-induced local electric fields. In the unilamellar PC vesicles the effect of the ions on epsilon follows the sequence K/sup +/ > Na/sup +/ > Li/sup +/ which contrasts ...

1986-02-27

253

Interaction of bovine serum albumin with some novel PEG-containing diblock copolymers

The authors studied the resolution of racemic glycidol through esterification with butyric acid catalyzed by porcine pancreatic lipase in organic media. A screening of seven solvents (log P values between 0.49 and 3.0, P being the n-octanol-water partition coefficient of the solvent) showed that neither log P nor the logarithm of the molar solubility of water in the solvent provides good correlations between enantioselectivity and the properties of the organic media. Chloroform was one of the best solvents as regards the enantiometic purity (e.p.) of the ester produced. In this solvent, the optimum temperature for the reaction was determined to be 35C. The enzyme exhibited maximum activity at a water content of 13 [plus minus] 2% (w/w). The enantiomeric purity obtained was 83 [plus minus] 2% of (S)-glycidol butyrate and did not depend on the alcohol concentration or the enzyme water content for values of these parameters up to 200 mM and 25% (w/w), respectively. ...

1993-08-05

254

British Library Electronic Table of Contents (United Kingdom)

A comparative study on the interaction of different PEG-containing diblock copolymers including SA400, SA600, SA1500 and OA1500 (stearyl and oleyl esters of polyethylene glycol with 400, 600 and 1500 molecular weights, respectively) with bovine serum albumin (BSA) was carried out using isothermal titration calorimetry (ITC), attenuated total reflectance Fourier transform infrared (ATR-FTIR), circular dichroism (CD), and fluorescence spectroscopies. ITC data show that SA400, SA600, SA1500 and OA1500 bind to BSA, with association constants of (14.5, 3.16, 50.7 and 17.6)x103M-1, respectively. Results also show that the binding is enthalpically driven, disfavored by conformational entropy. Quantitative analysis of the FTIR absorbance spectra at amide Iprime (1600-1700cm-1) as well as far UV ci...

2008-01-01

255

Increase in phorbol ester binding in liver microsomes after chronic administration of phenobarbital

GAS EVOLUTION FROM INSULATING MATERIALS FOR SUPERCONDUCTING COIL OF ITER BY GAMMA RAY IRRADIATION AT LIQUID NITROGEN TEMPERATURE

The effect of chronic administration of phenobarbital on the binding of phorbol-12,13-dibutyrate (({sup 3}H)PDBu), an activator of protein kinase C (PKC), was examined in rat liver microsomes. A significant increase in the number of binding sites was observed in microsomes of Fisher 344 rats. However, no change appeared in liver cytosol binding of PDBu. Consequently, a translocation process of PKC is unlikely. The increase in ({sup 3}H)PDBu binding in liver microsomes is significant 24 h. after one injection of phenobarbital and reaches its maximum in 2 days. In other strains of rats (ACI and lean Zucker), significant differences were found in the increase of ({sup 3}H)PDBu binding in microsomes. Fisher 344 were the most sensitive, lean Zucker rats, the least sensitive. Those results parallel the pentoxy-resorufin O demethylase activity in the microsomes of the same animals. EC{sub 50} values for inhibition of ({sup 3}H)PDBu binding by pentobarbital were determined in control ...

1991-03-15

256

Easy access to 6-membered iminoalditols - important glycosidase inhibitors

A laminated material composed of glass cloth/polyimide film/epoxy resin will be used as an insulating material for superconducting coil of International Thermonuclear Experimental Reactor (ITER). In order to keep safe and stable operation of the superconducting coil system, it is indispensable to evaluate radiation resistance of the material, because the material is exposed to severe environments such as high radiation field and low temperature of 4 K. Especially, it is important to estimate the amount of gases evolved from the insulating material by irradiation, because the gases affect on the purifying system of liquid helium in the superconducting coil system. In this work, the gas evolution from the laminated material by gamma ray irradiation at liquid nitrogen temperature (77 K) was investigated, and the difference of gas evolution behavior due to difference of composition in the epoxy resin was discussed. It was found that the main gases evolved from the laminated material by the ...

2008-03-03

257

DEFF Research Database (Denmark)

Stereoselective methods for synthesising iminoalditols are still needed, as this class of compounds is known to contain strong glycosidase inhibitors. We have for some time investigated (1) the possibilities for using 2-amino-6-bromo-2,6-dideoxy-aldonolactones as starting materials for such compounds, since a substitution at C-6 by the 2-amino group should lead to the target molecules. We have found that treatment of mentioned 2-aminolacones with aqueous base gave 5- or 6-membered iminoalditols depending of the stereochemistry of the lactone, while under non aqueous conditions only formation of 6-membered iminoalditols were observed. The use of triethylamine in methanol thus gave methylesters of 6-membered iminouronic acids. Reduction of the ester group with sodium borohydride gave the target compounds. The mechanisms of the reactions will be discussed as well as specific results obtained. (1) Lundt, I. Top. Curr. Chem. 1997, 187, 117-156

258

Development and application of microbial selective plugging processes

Crystal structures of two novel sulfonylurea herbicides in complex with Arabidopsis thaliana acetohydroxyacid synthase

Phillips Petroleum Company recently completed a microbial selective plugging (MSP) pilot at the North Burbank Unit (NBU), Shidler, Oklahoma. Nutrients were selected for the pilot that could stimulate indigenous microflora in the reservoir brine to grow and produce exopolymer. It was found that soluble corn starch polymers (e.g., maltodextrins) stimulated the indigenous bacteria to produce exopolymer, whereas simple sugars (e.g., glucose and sucrose), as well as complex media (e.g., molasses and Nutrient Broth), did not. Injection of maltodextrin into rock cores in the presence of indigenous NBU bacteria resulted in stable permeability reductions (> 90%) across the entire length, while injection of glucose resulted only in face plugging. In addition, it was found that organic phosphate esters (OPE) served as a preferable source of phosphorus for the indigenous bacteria, since orthophosphates and condensed phosphates precipitated in NBU brine at reservoir ...

1995-12-31

259

Constituents of fruit pulp of Maytenus salicifolia and complete 1D/2D NMR data of 3?-hydroxy-D:B-friedo-olean-5-ene

Acetohydroxyacid synthase (AHAS; EC 2.2.1.6) is the first enzyme in the biosynthetic pathway of the branched-chain amino acids. It catalyzes the conversion of two molecules of pyruvate into 2-acetolactate or one molecule of pyruvate and one molecule of 2-ketobutyrate into 2-aceto-2-hydroxybutyrate. AHAS requires the cofactors thiamine diphosphate (ThDP), Mg{sup 2+} and FAD for activity. The herbicides that target this enzyme are effective in protecting a broad range of crops from weed species. However, resistance in the field is now a serious problem worldwide. To address this, two new sulfonylureas, monosulfuron and monosulfuron ester, have been developed as commercial herbicides in China. These molecules differ from the traditional sulfonylureas in that the heterocyclic ring attached to the nitrogen atom of the sulfonylurea bridge is monosubstituted rather than disubstituted. The structures of these compounds in complex with the catalytic subunit of Arabidopsis ...

2009-08-17

260

British Library Electronic Table of Contents (United Kingdom)

A mixture of long-chain hydrocarbons constituted by nonacosane (29C, 7.5%), hentriacontane (31C, 48.3%), and tritriacontane (33C, 30.1%), the ester 1?-acetyloxymethylpentacosa-20?-enyl 10-hydroxydecanoate (2), ?-amyrin (3), friedelin (4), and lupeol (5), and 3?-hydroxy-D:B-friedo-olean-5-ene (6) were identified as constituents of fruits of Maytenus salicifolia Reissek (Celastraceae). The structural formula and the stereochemistry of compound 6 were established by the data obtained through 1H and 13C NMR spectroscopy, including DEPT-135 and 2D (HMQC, HMBC, and NOESY) experiments. By analysis of the spectral data, it was possible to correct seven chemical shift assignments of compound 6, which were erroneous attributed and published in the scientific literature.

2010-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

261

A new kind of immobilized lipase in organic solvent and its structure model.

Solution conformations of CaCl sub 2 and Ca(NO sub 3 ) sub 2 complexes of chiral tetramethyl 18-crown-6 macrocycles: A 1D and 2D sup 1 H and sup 13 C NMR investigation

In this paper, we used Ca-alginate gel beads coated with polyetheneimine and glutaraldehyde to adsorb Expansum penicillium lipase. The immobilized lipase catalyzed esterification of 1-dodecanol with dodecanoic acid in benzene. The results show that when the concentration of Ca-alginate, polyetheneimine (PEI) and glutaraldehyde is 1%, 6% and 1%, respectively, the activity of the immobilized lipase and the amount of adsorbed protein are the highest. The immobilized lipase is better than the SDS-immobilized lipase. The activity of the immobilized lipase connected by glutaraldehyde is higher than the activity of that without glutaraldehyde. The initial rate of the immobilized lipase and lyophilized lipase powder is 5.9 x 10(2) nmol/min.mgpr and 2.8 x 10(1) nmol/min.mgpr, respectively. After the immobilized lipase catalyzed the esterification reaction at 37 degrees C for about 12 hours, 93.3% of 1-dodecanol was converted to ester, but for lyophilized lipase powder, only ...

1994-04-15

262

Developments of PET radioligands for NMDA receptors

One- and two-dimensional NMR techniques have been used to investigate the solution structures of (2S,6S,11S,15S)-2,6,11,15-tetramethyl-1,4,7,10,13,16-hexaoxacyclooctadecane (I) and (2R,3R,11R,12R)-2,3,11,12-tetramethyl-1,4,7,10,13,16-hexaoxyacyclooctadecane (II) macrocycle complexes of CaCl{sub 2} and Ca(NO{sub 3}){sub 2} in CDCl{sub 3}. Previous chiroptical studies of these and similar crown complexes by circularly polarized luminescence (CPL), total luminescence (TL), and circular dichroism (CD) spectroscopy have shown that the macrocycle asymmetric carbons in these complexes constrain the ring such that the sense of the ring twist in the S chiral ring complexes is opposite to that in the R chiral ring complexes. These studies have also shown that there is an added chirality element in the di- and trivalent (alkaline earth and lanthanide metal, respectively) nitrate complexes of I and II associated with the twist of the nitrate anions relative to one another as they sterically ...

1989-10-04

263

Two-step template-free route for synthesis of TiO2 hollow spheres

Aim: There has been a great demand for developments of the radioligands to visualize the N-methyl-D-aspartate (NMDA) receptors by PET/SPECT. We have recently synthesized two C-11 labeled antagonists for the glycine-binding site on NMDA receptors. The aim of this work is to examine for their in vitro and in vivo binding characteristics, and to evaluate their potentials as PET radioligands for the NMDA receptors. Materials and methods: Two C-11 labeled 4-hydroxy-2-quinolones (1 and 2) were synthesized by conventional methylation of the corresponding phenols with ["1"1C]methyl iodide. In vitro and ex vivo quantitative autoradiographs with imaging plate, as well as animal PET, were employed in order to evaluate their in vitro and in vivo binding to the NMDA receptors. Results: The compound 1 showed the specific binding to rat brain slices with higher localization in the hippocampus and cerebral cortex than in the cerebellum. ...

2002-09-01

264

British Library Electronic Table of Contents (United Kingdom)

The TiO2 hollow microspheres were prepared by microwave-assisted solvothermal treatment without template. The morphology and the phase of TiO2 hollow microspheres were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), and BET surface areas. The results show that the particles have hollow structures and the shell was covered by nanocrystals and have higher specific surface area. The possible formation mechanism of hollow TiO2 spherical structures has simply been proposed. The activity was evaluated by the photocatalytic degradation of methyl orange (MO). The results show that the particles having specific surface area show higher photocatalytic activity. It can be attribute to the doped ...

2011-01-01

265

Two dimensional NMR and NMR relaxation studies of coal structure

The separation of "2"0"3Pb from a thallium target

This report covers the progress made on the title project for the project period. Four major areas of inquiry are being pursued. Advanced solid state NMR methods are being developed to assay the distribution of the various important functional groups that determine the reactivity of coals. Special attention is being paid to methods that are compatible with the very high magic angle sample spinning rates needed for operation at the high magnetic field strengths available today. Polarization inversion methods utilizing the difference in heat capacities of small groups of spins are particularly promising. Methods combining proton-proton spin diffusion with [sup 13]C CPMAS readout are being developed to determine the connectivity of functional groups in coals in a high sensitivity relay type of experiment. Additional work is aimed at delineating the role of methyl group rotation in the proton NMR relaxation behavior of coals.

1992-11-25

266

Tertiary-Butanol: A toxicological review

"2"0"3Pb, an ideal radionuclide for toxicological studies, can be artificially produced by bombardment of a thallium target but due to the extreme toxicity of thallium the lead has to be separated completely from the thallium. A single step method is here described consisting of removing the thallium from a dilute acid chloride solution using a continuous ethyl ether extraction. Essentially all of the thallium and almost none of the lead is removed in a 3-hr extraction. Because the ether is recycled, only about 30 ml are needed. If other contaminants are introduced from the bombardment and its subsequent manipulations, an additional step is used in which the lead is extracted from an iodide solution with methyl isopropyl keton. (U.K.).

267

British Library Electronic Table of Contents (United Kingdom)

Tert-Butanol is an important intermediate in industrial chemical synthesis, particularly of fuel oxygenates. Human exposure to tert-butanol may occur following fuel oxygenate metabolism or biodegradation. It is poorly absorbed through skin, but is rapidly absorbed upon inhalation or ingestion and distributed to tissues throughout the body. Elimination from blood is slower and the half-life increases with dose. It is largely metabolised by oxidation via 2-methyl-1,2-propanediol to 2-hydroxyisobutyrate, the dominant urinary metabolites. Conjugations also occur and acetone may be found in urine at high doses. The single-dose systemic toxicity of tert-butanol is low, but it is irritant to skin and eyes; high oral doses produce ataxia and hypoactivity and repeated exposure can induce dependence...

2010-01-01

268

Targeting the kynurenine pathway as a potential strategy to prevent and treat Alzheimer's disease

British Library Electronic Table of Contents (United Kingdom)

Alzheimer's disease (AD) is a progressive neurodegenerative disorder of the elderly accounting for the vast majority of dementia. Recently, many studies have implicated the role of inflammatory response, especially neuroinflammatory response in the development and progression of AD. However, the underlying mechanism of how inflammatory response induces AD is unknown. Kynurenine pathway is a major route of the amino acid tryptophan catabolism, resulting in the production of nicotine adenine dinucleotide and other neuroactive intermediates: quinolinic acid (QA) and kynurenic acid (KA). QA exerts different toxic effects, including over-activation of N-methyl-d-aspartate (NMDA) receptor and excitotoxicity, synaptic dysfunction and neuronal death. On the other hand, KA is identified as the only...

2011-01-01

269

Synthesis of N-(3-azido-4-chlorophenyl)-N'-["3H-methyl] thiourea, an efficient photoaffinity probe for the urea carrier

Synthesis and characterization of conducting polymer composite (PAn/TiO{sup 2}) for cathode material in rechargeable battery

Starting from commercial 4-chloro-3-nitroaniline, through a 5 step synthesis, 3-azido-4-chlorophenylisothiocyanate was prepared and reacted with ["3H]-methylamine. The latter was obtained by three methods: (i) ["3H]-LiA1T_4 reduction of benzylcarbamate gave rise to ["3H]-methylamine (S.A.: > 70 Ci/mmol). (ii) Catalytic reduction of HCN with "3H_2 lead to ["3H]-CH_3NH_2 (S.A.: 0.7 Ci/mmol). (III) Schmidt rearrangement of ["3H]-sodium acetate gave ["3H]-CH_3NH_2 (S.A.: 29 Ci/mmol). (author).

270

Structure and antimicrobial activity relationship of quaternary N-alkyl chitosan derivatives against some plant pathogens

This paper deals with the preparation and characterization of polyaniline/TiO{sub 2} composite by XRD, UV-VIS spectra, TGA/DTA and FTIR. The composite is used as a cathode material for rechargeable battery comprising of zinc container as the anode, cellulose acetate as the separator and polyvinyl sulfate and carboxy methyl cellulose as the solid polymer electrolytes (SPE). By using the PAn/TiO{sub 2} composite as the cathode material, the cylindrical AA type rechargeable battery was fabricated and the following output was observed. The open circuit voltage (OCV) is 1.4 V and current is 250 mA to 1.0 A, 50 recharge cycles, power density is 350 A h/kg and power efficiency is 70%.

2003-02-01

271

British Library Electronic Table of Contents (United Kingdom)

In the present work, quaternary chitosans as water-soluble compounds were prepared based on three-step process. Schiff bases were firstly synthesized by the reaction between the amino groups of chitosan with aliphatic aldehydes followed by a reduction with sodium borohydride (NaBH4) to form N-(alkyl) chitosans. N,N,N-(dimethyl alkyl) chitosans were then obtained by a reaction of chitosan containing N-butyl, N-pentyl, N-hexyl, N-heptyl, and N-octyl substituents with methyl iodide. The compounds were characterized using IR and NMR spectroscopy. Subsequent experiments were conducted to test their antimicrobial activities against the most economic plant pathogenic bacteria of crown gall disease Agrobacterium tumefaciens, soft mold disease Erwinia carotovora, fungi of grey mold Botrytis cinerea...

2010-01-01

272

Silica Polyamine Composites: New Supramolecular Materials for Cation and Anion Recovery and Remediation

British Library Electronic Table of Contents (United Kingdom)

Summary: The surface coverage of amorphous silica gels used in the synthesis of silica polyamine composites has been investigated by 29Si NMR. By diluting the polyamine anchor silane, chloropropyl trichlorosilane, with methyl trichlorosilane it was found that surface coverage could be markedly improved for a range of amine polymers after grafting to the silica surface. The commensurate decrease in the number of anchor points and increase in the number of free amines results in an increase in metal capacity and/or an improvement in capture kinetics. Solid state CPMAS-13C NMR has been employed to investigate the structure and metal ion binding of a series of these composite materials. It is reported that the highly branched polymer, poly(ethyleneimine) (PEI) exhibits much broader 13C NMR res...

2006-01-01

273

Sheep prefer clean forage over forage contaminated with military explosives TNT, RDX and HMX

British Library Electronic Table of Contents (United Kingdom)

The common military explosives 2-methyl-1,3,5-trinitrobenzene (TNT), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) are distributed in many military training areas, and are thus encountered by grazing animals. The aim of this study was to examine small ruminant's intake of forage contaminated with explosives. An indoor, experimental setup was used to determine if contamination of forage by these compounds affected intake by sheep. The results clearly demonstrate that contamination by any of the three explosives reduced forage intake in sheep; in order of increasing avoidance: RDX

2011-01-01

274

Resonance Raman and photophysical studies of transition metal complexes in solution and entrapped in zeolites

Research on the preparation of coal water fuel (CWF) from Banko coal, south Sumatera

We have obtained convincing evidence for localization of the optical electron on a single-ring fragment of a chelated bipyridine-like'' ligand (ie., pyridylpyrazine or 4-Methyl-bipyridine). In addition we have completed studies of Ru(bipyrazine){sub 3}{sup 2+} in aqueous sulfuric acid (0--98% by weight) and find clear evidence for sequential addition of six-protons to the six peripheral nitrogen atoms. Studies of zeolite-entrapped complexes are continuing and a series of homo- and heteroleptic complexes have been prepared and characterized. Finally, the synthesis of zeolite-entrapped metallophthalocyanines has now been developed and the copper and cobalt analogues synthesized. The characterization of these materials is now in progress.

1992-03-31

275

Preparation and photocatalytic property of pyrochlore Bi2Ti2O7 and (Bi, La) 2Ti2O7 films

Studies of CWF preparation at laboratory scale have been carried out using the type and amount of additives and coal content as process variables. Other factors such as particle size, time and rate of stirring were kept constant. CWF with 45 wt% of dry solids, heating value of 5,475 BTU/lb, and stable without the evidence of sedimentation for 9 weeks have been obtained using carboxy methyl cellulose (CMC) as the additive. Low coal content and low heating value can be increased by hydrothermal process on the elevated temperature and pressure. By this process, CWF with dry solid of 55 wt% and a heating value of 7,125 BTU/lb could be obtained. 6 refs., 8 figs., 2 tabs.

1994-01-01

276

British Library Electronic Table of Contents (United Kingdom)

Dopant-free Bi2Ti2O7 thin films with pyrochlore structure and La-doped bismuth titanate thin films have been fabricated by means of chemical solution decomposition, and characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy and UV?Vis spectrophotometry in this study. Their photocatalytic activities have been evaluated by photodegrading methyl orange solution, and the optimum processing parameters for the highest photocatalytic activity have been found. Moreover, the effects of La-doping on the phase transformation and the photocalalytic activity have been studied. It has been deduced from the experiment result that substituted La3+ ions can act as a stabilizer of Aurivillus phase BLT and a grain?growth inhibitor in BLT thin films.

2008-01-01

277

Preparation and applications of wood-polyester composites

Preparation and applications of novel fluoroalkyl end-capped vinyltrimethoxysilane oligomer/hydroxyapatite nanocomposites

Optimum processing parameters were searched for the pilot-scale production of wood-polyester composites by irradiation of resin-impregnated wood material. The radiation initiation of the following systems were examined in wood and without wood matrix: methyl methacrylate, mixture of styrene and acrylonitryle, and their combination with unsaturated polyester. In the most cases the over-all rate of the complete polymerization process in wood matrix is proportional to the square root of the initiation rate. The parameters of the radiation technology of wood-polyester composites have been determined, using 260 TBq (7 kCi) "6"0Co radiation source. A pilot plant has been constructed using an underwater irradiation system of 1.85 PBq (50 kCi) "6"0Co. The successful production rate of 200 kg wood-polyester composite per day, as well as the application tests have demonstrated the technical feasibility of this new structural material. (author).

1982-01-01

278

British Library Electronic Table of Contents (United Kingdom)

Novel fluoroalkyl end-capped vinyltrimethoxysilane oligomer/hydroxyapatite (HAp) nanocomposites were prepared by the reaction of calcium nitrate tetrahydrate and phosphoric acid in the presence of the corresponding oligomer. These fluorinated oligomer/HAp composites thus obtained are nanometer size-controlled fine particles (83-173 nm), and were found to exhibit good dispersibility in methanol, ethanol, and isopropyl alcohol. These fluorinated HAp nanocomposites were applied to the surface modification of glass and poly(methyl methacrylate) (PMMA) to exhibit good hydro- and oleophobic characteristics imparted by fluorine on their surface. In addition, the surface structural changes of the modified polyethylene terephtalate and PMMA films treated with these fluorinated nanocomposites before...

2009-01-01

279

Possible preparation of wood-plastic composites based on unsaturated polyester resins and styrene by radiation and chemical methods in combination

Polymeric nanosponges as an alternative carrier for improved retention of econazole nitrate onto the skin through topical hydrogel formulation

Using the radiation chemical method it is possible to prepare wood-plastic composites using doses of 1 to 2.5 kGy. The impregnation mixture in the wood gelatinates and subsequent curing using chemical initiators takes place without outflow of the mixture from the wood and without formation of incrustations. The basic components of the impregnation mixtures used were unsaturated polyester resins; styrene or methyl methacrylate was used as the thinner. The proven initiator of polymerization was 2,2'-azobisisobutyronitrile. The technology is described of wood impregnation and radiation or chemical curing. The effects were monitored of viscosity, temperature, radiation dose and the concentrations of the individual components of the impregnation mixtures and initiators of polymerization on the process of the preparation of wood-plastic composites.

1983-06-01

280

British Library Electronic Table of Contents (United Kingdom)

The present study was carried out to exploit the feasibility of using polymeric nanosponges as an alternative carrier for targeting econazole nitrate (EN) to the skin through topical hydrogel formulation. Nanosponges prepared by emulsion solvent diffusion method were evaluated for various physicochemical parameters and in vitro drug release. The nanosponges of EN were discrete free flowing nanosized particles with perforated orange peel like morphology as visualized by SEM. The nanosponge formulated using PVA:EC (3:2) displayed highest in vitro release after 12 ?h in phosphate buffer (pH 6.8) that fitted matrix model. Selected nanosponge was formulated as Carbopol 934 NF hydrogel using varying concentrations of permeation enhancers propylene glycol and N-methyl-2-pyrrolidone. The EN nanosp...

2011-01-01

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281

Physical properties of wood-polymer composites prepared by an electron beam accelerator

Photoelectron resonance capture ionization mass spectrometry of fatty acids in olive oil

The dual characteristics in the performance of polymers in wood-polymer composites systems have been pursued with regard to the resolution of mechanical anisotropy of wood and the improvement in dimensional stability. The objective of the present study is to pursue the polymerization mechanism in wood under electron beam irradiation and the temperature dependence of polymer-wood interactions induced at various levels of higher order structure of wood in order to understand the polymer performance. Veneers used in the study were of rotary-cut beech (Fagus crenata Blume) 0.65 mm thick. All samples were oven-dried in vacuo at 80/sup 0/C for 30 hr. The monomers used in the study were methyl methacrylate, styrene, acrylic acid, acrylonitrile, and unsaturated polyester. Experimental details are given. Results are given and discussed.

1981-01-01

282

British Library Electronic Table of Contents (United Kingdom)

Photoelectron resonance capture ionization (PERCI) mass spectrometry has been developed for the direct online analysis of organics, including lipids. Analysis is conducted without the need for sample preparation or chemical derivatization such as methylation, foregoing the use of harmful or toxic chemicals. PERCI is currently being adapted towards the analysis of edible oils. Herein, as a proof of principle of the simplicity and potential utility of this method towards the analysis of edible oils, we present the analysis of the prevalent fatty acids (FA) in Tuscan extra-virgin olive oil along with triolein and linolenic acid (LNA) standards. Ionization of olive oil results in little fragmentation of the prevalent FA, which are measured as their molecular ions, [FA-H]-. The relative concent...

2006-01-01

283

One-electron redox reactions of pyrazolin-5-ones. A pulse radiolysis study of antipyrine and analogues

On synergism in inhibition of liquidphase oxidation of styrene and tetralin by organic phosphites and transition eleement acetylacetonates

One-electron oxidation of several derivatives of pyrazolin-5-one, including the drug antipyrine, were studied by pulse radiolysis of aqueous solutions. All the compounds were found to be oxidized by Br2 rapidly but considerably more slowly by weaker oxidants, such as peroxyl radicals. From redox equilibria using p-methoxyphenol and N,N,N',N'-tetramethyl-p-phenylenediamine as reference compounds, the one-electron oxidation potentials of the methyl-substituted 2-pyrazolin-5-ones were found to be in the range of 0.32-0.39 V versus normal hydrogen electrode. The relevance of these findings to the properties of the drug nafazatrom is discussed. Antipyrine was found to have a much higher oxidation potential, estimated as 1.2-1.5 V, which is rationalized on the basis of the phenyl substitution and lack of resonance stabilization of the radical cation.

1985-10-01

284

Molecular marks for epigenetic identification of developmental and cancer stem cells

Synergism has been observed during inhibiting initiated oxidation of styrene or tetralin by organic phosphites in the presence of complex compounds of some transition metals. The results are given of non-additive intensification of antioxidative activity of triphenylphosphite (TPP) and tri-(4-methyl-6-tert.-- butyl)-phenyl-phosphite (TMBP) in the process of initiated oxidation of styrene or tetralin with addition of acetylacetonates of cobalt and vanadyl. During styrene oxidation, inhibition of the reaction with chelate complex of vanadyl is weakened considerably when phosphite is added into the reaction system. During tetralin oxidation, postcatalytic (or branched) oxidation is observed only for large concentration of vanadyl complex. Addition of TPP to above complex sharply increases the induction period. When the induction period is completed, oxidation of tetralin follows the mechanism of usual, i.e. initiated, reaction.

285

British Library Electronic Table of Contents (United Kingdom)

Epigenetic regulations of genes by reversible methylation of DNA (at the carbon-5 of cytosine) and numerous reversible modifications of histones play important roles in normal physiology and development, and epigenetic deregulations are associated with developmental disorders and various disease states, including cancer. Stem cells have the capacity to self-renew indefinitely. Similar to stem cells, some malignant cells have the capacity to divide indefinitely and are referred to as cancer stem cells. In recent times, direct correlation between epigenetic modifications and reprogramming of stem cell and cancer stem cell is emerging. Major discoveries were made with investigations on reprogramming gene products, also known as master regulators of totipotency and inducer of pluoripotency, na...

2011-01-01

286

Jump in the air gasification rate of potassium-doped cellulosic chars

Imaging hypoxia in vivo by controlling the electrochemistry of copper radionuclide complexes

Chars prepared from potassium-exchanged carboxy methyl cellulose at several heat treatment temperatures (HTTs) were gasified in air isothermally at selected gasification temperatures (GTs) in the range 633-893 K to investigate the catalytic effectiveness of potassium species. The chars displayed a noticeable jump in gasification rate at a particular gasification temperature (called jump temperature, T{sub j}). The magnitude of jump was much less than that reported for copper and nickel catalysis, but comparable with that for calcium catalysis. Increase in HTT caused a decrease in the jump temperature of chars in contrast with the increase observed in copper, nickel and calcium catalysis; also the magnitude of jump did not decrease, but remained unaltered, on increasing HTT. The different behavior of potassium catalysis is correlated to a change in the chemical state of potassium at higher HTT. The results reveal the dependence of jump phenomenon on chemical state ...

2010-12-15

287

British Library Electronic Table of Contents (United Kingdom)

Tissue hypoxia is a feature of cancer, heart disease and stroke, and imaging it may become clinically important. Copper-ATSM (ATSMH2 = 2,3-butanedione bis(N-methyl)thiosemicarb-azone), labelled with 60Cu, 62Cu or 64Cu, is selectively taken up in hypoxic cells in vitro and in vivo by a bioreductive mechanism, and is a prototype hypoxia imaging agent amenable to improvement. In vitro studies with several differently alkylated analogues of CuATSM show that hypoxia selectivity is a general property of complexes with two alkyl groups at the diketone backbone, offering a range of pharmacokinetic properties while retaining hypoxia selectivity. This pharmacokinetic control affords a route to development of second-generation hypoxia imaging agents with optimized properties for different clinical ap...

2007-01-01

288

Hepatitis C virus core upregulates the methylation status of the RASSF1A promoter through regulation of SMYD3 in hilar cholangiocarcinoma cells

British Library Electronic Table of Contents (United Kingdom)

Increasing evidence has been accumulated indicating the important role of epigenetic regulation in tumor genesis. Previously, we observed that the transfection of hepatitis C virus core (HCVc) protein led to malignant transformation in normal biliary cells, and that tumor suppressor gene RASSF1A was downregulated in many hilar cholangiocarcinoma patients by hypermethylation in the promoter region. In the present study, we found SET and MYND domain-containing protein 3 (SMYD3), a novel histone methyltransferase, was overexpressed in cholangiocarcinoma patients especially in those with HCV infection. Transfection of HCVc into hilar cholangiocarcinoma cell lines QBC939 and FRH0201 could upregulate the expression of SMYD3 and promote cell growth, which was consistent with the results of our cl...

2011-01-01

289

Heat capacities of the mixtures of ionic liquids with acetonitrile

Green synthesis of iron nanoparticles and their application as a Fenton-like catalyst for the degradation of aqueous cationic and anionic dyes

Isobaric specific heat capacities were measured for {1-hexyl-3-methylimidazolium tetrafluoroborate (HMIMBF4) + acetonitrile (MeCN)} and {1-methyl-3-octylimidazolium tetrafluoroborate (OMIMBF4) + acetonitrile} within the whole range of composition and temperatures from (283.15 to 323.15) K. The excess molar heat capacities were calculated from the experimental results and satisfactorily fitted to Redlich-Kister type polynomials for several selected temperatures. Negative deviations from the additivity of molar heat capacities were observed within the whole composition range of (HMIBMF4 + MeCN) and (OMIMBF4 + MeCN). The results obtained have been interpreted in terms of interactions between ionic liquids and acetonitrile.

2010-02-01

290

British Library Electronic Table of Contents (United Kingdom)

Iron nanoparticles were produced using extracts of green tea leaves (GT-Fe NPs). The materials were characterized using TEM, SEM/EDX, XPS, XRD, and FTIR techniques and were shown to contain mainly iron oxide and iron oxohydroxide. The obtained nanoparticles were then utilized as a Fenton-like catalyst for decolorization of aqueous solutions containing methylene blue (MB) and methyl orange (MO) dyes. The related experiments investigated the removal kinetics and the effect of concentration for both MB and MO. The concentrations of dyes in aqueous solution were monitored using ultraviolet-visible (UV-vis) spectroscopy. The results indicated fast removal of the dyes with the kinetic data of MB following a second order removal rate, while those of MO were closer to a first order removal rate. T...

2011-01-01

291

Global status of commercialization of and developments on international trade in irradiated food

Flavonols and an oxychromonol from Piliostigma reticulatum

National and international organizations have paid particular attention to the use of food irradiation as a method to reduce postharvest food losses, to ensure hygienic quality of foods-especially those of animal origin, and to overcome certain non-tariff barriers to trade for the following reasons: (1) The increasingly strict standards for quality and quarantine in food trade. (2) The increasingly restrictions and prohibitions of fumigants of food for health or environmental reasons. (3) The increasing awareness of foodborne diseases in both advanced and developing countries. (4) The high postharvest losses of foods in developing countries. (5) The increase liberalization of food trade after GATT Uruguay Round, and the need to maintain or increase export of food and agricultural commodities and to be competitive in the world market. Irradiated foods have been commercialized since 1973 when the first potato irradiator was established at the Shihoro Agricultural Cooperative, Hokkaido, ...

1996-09-01

292

British Library Electronic Table of Contents (United Kingdom)

The leaf extract from the plant Piliostigma reticulatum was found to exhibit antimicrobial activity against some bacteria and fungi such as Staphylococcus aureus (NCTC 6571), Escherichia coli (NCTC 10418), Bacillus subtilis (NCTC 8236), Proteus vulgaris (NCTC 4175), Aspergillus niger (ATCC 10578) and Candida albicans (ATCC 10231). Upon investigation of the chemical constituents present in the leaf extract, a total of seven compounds were isolated and their structures were unambiguously established by spectroscopic methods including HR-MS and NMR spectrometry. Four of the isolated compounds were novel, namely 6-C-methyl-2-p-hydroxyphenyloxychromonol (piliostigmol), 1, 6,8-di-C-methylquercetin-3,3prime,7-trimethyl ether, 2, 6,8-di-C-methylquercetin-3,3prime-dimethyl ether, 3 and 3prime,6,8,-...

2008-01-01

293

Facilitated Proton Transfer by a Novel 2-Aminothiazole Derivative Across the Water/1,2-Dichloroethane Interface

British Library Electronic Table of Contents (United Kingdom)

The behavior of proton transfer facilitated by a novel thiazole derivative, N-methyl-4-(4-phenoxyphenyl)thiazol-2-amine (MPPT), across the water/1,2-dichloroethane (1,2-DCE) interface was investigated electrochemically. The ionic partition diagram for MPPT was obtained from interpretation of the cyclic voltammograms. The apparent partition coefficient of MPPT was evaluated by the shaking-flask method under experimental conditions, while that for the protonated form of MPPT was calculated from its transfer potential obtained from the ionic partition diagram. It was suggested that the mechanism for transfer of MPPT across the water/1,2-DCE) interface depends on the pH of the aqueous phase. The parameters of the facilitated proton transfer across the water/1,2-DCE interface were evaluated as ...

2011-01-01

294

Exploring the potential energy surface for proton transfer in acetylacetone

Excess and deviation properties for the binary mixtures of methylcyclohexane with benzene, toluene, p-xylene, mesitylene, and anisole at T = (298.15, 303.15, and 308.15) K

The portion of the potential energy surface (PES) of acetylacetone relevant for the intramolecular proton transfer reaction is studied using ab initio and DFT methods. The best estimate of the barrier governing proton transfer was found to be 3.4 kcal mol{sup -1} at the MP4(FC)/6-311 + G(2d,2p)//MP2(FC)/6-311 + G(2d,2p) level of theory. Six stationary points on the PES were characterized as well as the reaction paths connecting these points. Special attention paid to the pathway of intramolecular proton transfer reveals that the internal rotation of the methyl group adjacent to the carbonyl group and the proton transfer reaction are consecutive processes.

2004-11-15

295

Electrochemical impedance of electrolyte/electrode interfaces of lithium-ion rechargeable batteries

Experimental data on density, viscosity, and refractive index at T = (298.15, 303.15, and 308.15) K, while speed of sound values at T = 298.15 K are presented for the binary mixtures of (methylcyclohexane + benzene), methylbenzene (toluene), 1,4-dimethylbenzene (p-xylene), 1,3,5-trimethylbenzene (mesitylene), and methoxybenzene (anisole). From these data of density, viscosity, and refractive index, the excess molar volume, the deviations in viscosity, molar refraction, speed of sound, and isentropic compressibility have been calculated. The computed values have been fitted to Redlich-Kister polynomial equation to derive the coefficients and estimate the standard errors. Variations in the calculated excess quantities for these mixtures have been studied in terms of molecular interactions between the component liquids and the effects of methyl and methoxy group substitution on benzene ring.

2006-12-01

296

Electrochemical impedance of electrolyte/electrode interfaces of lithium-ion rechargeable batteries

It is well known that a protective film is formed on the graphite negative electrode in ethylene carbonate (EC) electrolyte solution. This film is lithium-ion conductive and protects the decomposition of the electrolyte solution. In the present paper, the electrode/electrolyte interfaces in lithium-ion rechargeable batteries were characterized by three-dimensional complex impedance plots, whose axes are real, imaginary parts and time. The film resistance R {sub sei} and charge transfer resistance R {sub ct} were determined for negative electrodes in EC/ethyl methyl carbonate (EMC) electrolyte solution, and the formation mechanisms of the interfacial film were discussed. Furthermore, the contributions of vinylene carbonate and ethylene sulfite, which are added into the electrolyte solution for the film formation, were investigated.

2006-01-20

297

Determination of some minor and trace elements in iron ores by ion exchange chromatography, spectrophotometry and atomic absorption spectrometry

It is well known that a protective film is formed on the graphite negative electrode in ethylene carbonate (EC) electrolyte solution. This film is lithium-ion conductive and protects the decomposition of the electrolyte solution. In the present paper, the electrode/electrolyte interfaces in lithium-ion rechargeable batteries were characterized by three-dimensional complex impedance plots, whose axes are real, imaginary parts and time. The film resistance R _s_e_i and charge transfer resistance R _c_t were determined for negative electrodes in EC/ethyl methyl carbonate (EMC) electrolyte solution, and the formation mechanisms of the interfacial film were discussed. Furthermore, the contributions of vinylene carbonate and ethylene sulfite, which are added into the electrolyte solution for the film formation, were investigated.

2006-01-20

298

Creep-characteristics of a tropical wood-polymer composite

A method is described for determination of aluminium, cadmium, cobalt, chromium, copper, calcium, magnesium, sodium, potassium, manganese, nickel, lead, strontium, zinc, titanium and vanadium in iron ore. After dissolution, a 1 gram sample of iron ore is applied to a column of AGI-X8 anion exchange resin (chloride form), in 100 ml of 7M HCl. Aluminium, chromium, calcium, magnesium, sodium, potassium, manganese, nickel, lead, strontium, titanium and vanadium are eluted with 7M HCl; iron, copper and cobalt are eluted with 0.5M HCl; cadmium and zinc are eluted with 2M HNO_3. Iron is subsequently removed from copper and cobalt by a solvent extraction with methyl isobutyl ketone. The elements are determined in the eluates by atomic absorption spectrometry, except for titanium and vanadium, which are determined spectrophotometrically.

299

Covalent modification of fused silica capillaries with quaternized polyamines to achieve robust and stable anodic electroosmotic flow

Wood polymer composite (WPC) specimens were produced by impregnating a tropical wood with methyl methacrylate and subsequently polymerised by ..gamma..-irradiation. Beam specimens of varying weight percentages of polymer were then subjected to a three point bend creep test under a constant load condition, for 250, 300 and 350 N. A Norton-Bailey (power law) mathematical model was used to describe the creep behavior, with the creep components determined by a nonlinear regression analysis. Significant creep improvements were obtained from the composite specimens as compared to the untreated wood specimens. Results indicated that maximum creep resistance is obtained when the amount of polymer loading exceeded 30%. An interfacial interaction between the polymer and the wood cell wall was used to account for the behavior of the increase in the creep resistance.

1987-01-01

300

British Library Electronic Table of Contents (United Kingdom)

Synthetic chemistry originally developed for the manufacture of chemically stable silica polyamine composites was adapted for the modification of fused silica capillaries for application in CE. Polyethyleneimine (PEI) and polyallylamine (PAA) were covalently bonded to the interior surface of fused silica capillaries utilizing 3-chloropropyltrichlorosilane (CPTCS) or 3-glycidoxypropyl-trimethoxysilane (GPTMS) to anchor the polymers to the surface. The surface-bound polymers were subsequently quaternized using methyl iodide (MeI). The resulting modified capillaries were studied using CE, and were shown to provide reproducible, stable, and robust anodic EOF throughout the pH range of 2-10. Surface modifications utilizing CPTCS could be rinsed with up to 6 M HCL or 1 M NaOH without significant...

2009-01-01

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301

Cleanliness of small precision swabs

Carnation Fusarium wilt suppression in four composts

Small swabs are often dampened with a solvent when used to clean surfaces. Cotton swabs of the type sold in drug stores contain stearic acid, probably used as a lubricant during manufacture of the swab. Such swabs, dampened with a solvent and used to clean a surface, will leave a film of stearic acid on the surface. Several kinds of swabs are sold for industrial use, and some are described as suitable for use in clean room manufacturing. Nine different swabs, some cotton and some urethane foam, were extracted with isopropyl alcohol, CFC 113 (Freon TF or Genesolv D), or mixture of CFC 113 and methyl alcohol. After evaporation of the solvent, from 0.5 to 3.8 mg of an oil or grease remained. For critical applications, swabs should be washed with solvent before use.

1992-02-01

302

British Library Electronic Table of Contents (United Kingdom)

Fusarium wilt is now a major disease of carnation crops worldwide. Methyl bromide, which is used to remedy it, is environmentally unsafe. An alternative approach integrated into biological control is to grow crops in suppressive media. Suppressiveness of seven plant growth media to Fusarium oxysporum f. sp. dianthi was evaluated in bioassays with carnation (Dianthus cariophyllus) cv. Medea. These media were: (1) grape marc compost, (2) cork compost, (3) olive oil husk + cotton gin trash composted and mixed with rice husk, (4) spent mushroom compost mixed with peat, (5) coir fibre, (6) light peat and (7) vermiculite. In order to look for carnation Fusarium wilt suppressiveness indicators, growth medium pH and ?-glucosidase activity were evaluated. Furthermore, F. oxysporum populations were ...

2009-01-01

303

Synthesis and spectral properties of diethyl organylchalcogenoalkyl(alkyl)malonates, RX(CH/sub 2/)/sub n/CR'(COOC/sub 2/H/sub 5/)/sub 2/, and 5-alkyl-5-(organylchalcogenoalkyl)barbiturates, RX(CH/sub 2/)/sub n/C(R')CONHC(Y)NHCO (X = Se, Te)

Radiolytic stabilization of industrial poly(methyl methacrylate); Estabilizacao radiolitica do poli(metacrilato de metila) industrial

Barbiturates substituted at the 5-position with organyltelluroalkyl or organylselenoalkyl groups were prepared by ring annulation of appropriately substituted diethyl malonates with urea or thiourea. The substituted diethyl malonates (phenyltellurobutyl(ethyl), i-propyltelluropropyl(ethyl), i-propyltelluropropyl(allyl), i-propyselenopropyl(ethyl), and phenylselenohexyl(methyl)) were prepared in 55-91% yield by reaction of diethyl omega-bromoalkyl(alkyl)malonates with organyltellurolates or selenolates (RXNa; X = Se, Te) in ethanol/benzene. The following barbiturates were obtained in 28-84% yield: phenyltellurobutyl(ethyl), m.p. 100/sup 0/C; i-propyltelluropropyl(ethyl), m.p. 119/sup 0/C; i-propylselenopropyl(ethyl), m.p. 137/sup 0/C; phenyl-selenohexyl(methyl), m.p. 124/sup 0/C. The 5-substituted thiobarbiturates i-propyltelluropropyl(ethyl)-(m.p. 75/sup 0/C) and i-propylselenopropyl(ethyl)thiobarbiturate (m.p. 83/sup 0/C) were isolated in 32 ...

1983-01-01

304

Quantum molecular dynamics and molecular interactions studied by NMR and INS[Nuclear magnetic resonance; Proton tunnelling; Hydrogen bond

Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterilisable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its physical properties. Therefore, radiolytic stabilization of PMMA is important for to become it commercially radio sterilisable. In this work we investigated the radiolytic stabilization of PMMA by using HALS (Hindered Amine Light Stabilizer) additive, commercially used for photo and thermo oxidative stabilization of polymers. The investigation of the radiation-induced main chain scissions was carried out by viscometric method. The additive added to the polymer system at 0.3 % w/w promotes a molecular radioprotection of 61%. That means a reduction of G value (scissions/100 eV) from 2.6 to 1.0. In addition, the glassy transition temperature (Tg) of PMMA (no additive), significantly changed ...

2005-03-15

305

Onium ions. 34. The methoxydiazonium ion: preparation, /sup 1/H, /sup 13/C, and /sup 15/N NMR and IR structural studies, theoretical calculations, and reaction with aromatics. Attempted preparation and the intermediacy of the hydroxydiazonium ion

The wavefunction of a particle extends into the classically forbidden barrier region of the potential energy surface. The consequence of this partial delocalisation is the phenomenon of quantum tunnelling, an effect which enables a particle to penetrate a potential barrier of magnitude greater than the energy of the particle. The tunnelling probability is an exponential function of the particle mass. The effect is therefore an important contribution to the behaviour of light atoms, in particular the proton. The hydrogen bond has long been appreciated to be an essential component of many biological and chemical systems, and the proton transfer reaction in the hydrogen bond is fundamental to many of these processes. The proton behaviour in the hydrogen bonds of benzoic acid, acetylacetone and calix-4-arene has been studied. A variety of techniques, both experimental and computational, were adopted for the study of the three hydrogen bonded systems. The complementary spectroscopic ...

2002-07-01

306

Molecular characterization of the Spirometra mansonoides genome: renaturation kinetics, methylation, and hybridization to human cDNA probes.

Nitrous oxide is methylated with CH/sub 3/F ..-->.. SbF/sub 5/F/sub 2/ or with CH/sub 3/O/sup +/SOClF in SO/sub 2/ClF to give the stable methoxydiazonium ion CH/sub 3/ON/sub 2//sup +/ (1), which was characterized by NMR (/sup 15/N, /sup 13/C, /sup 1/H) and FT IR spectroscopic studies. It is stable below -30 /sup 0/C, above which it decomposes, regenerating N/sub 2/O. When reacted with aromatics, such as toluene, 1 gives only methylation products and no methoxy derivatives are formed. Spectroscopic and chemical data indicate that the mesomeric form CH/sub 3/O-N=N/sup +/ is a significant contributor to the overall structure of 1. Consideration of computed charge distribution (4-31 G with full geometry optimization and 4-31 G*) also supports this conclusion. Independent generation of 1 was also studied by solvolysis of methylazoxy triflate and diazotization of methoxylamine with NO/sup +/BF/sub 4//sup -/. Preparation of the elusive ...

1986-04-16

307

Methionine kinetics and balance at the 1985 FAO/WHO/UNU intake requirement in adult men studied with L-[2H3-methyl-1-13C]methionine as a tracer

High molecular weight DNA from pleroceroid larvae of the tapeworm Spirometra mansonoides was purified from isolated nuclei by conventional techniques. The DNA so isolated has a melting temperature (Tm) of 87 degrees C and a guanine plus cytosine (G/C) content of 44%. 5-Methyl cytosine could not be detected in plerocercoid DNA by HPLC analysis of DNA hydrolysates, by radiolabeling 5'-termini of MspI digests with polynucleotide kinase, or by comparing restriction patterns generated by MspI and HpaII. Renaturation kinetics demonstrated that the genome of S. mansonoides contains repetitive as well as single copy sequences and has a genome size estimated at approx. 1.6 X 10(9) bp. Hybridization was carried out between plerocercoid DNA and cDNAs for human beta-actin, alpha-tubulin and growth hormone (hGH). Rationale for this analysis was based on known homologies among actin and tubulin genes in numerous species and on apparent similarities between hGH and a plerocercoid ...

1990-06-21

308

Lubricating composition for processing of flushing fluids

The upper range of the requirement for methionine plus cystine in healthy adults was proposed in 1985 by FAO/WHO/UNU to be 13 mg.kg body wt-1.d-1. To explore the validity of this estimate, five healthy, young adult men were given for 7 d a diet based on an L-amino acid mixture supplying 13 mg methionine.kg-1.d-1 (87 mumol.kg-1.d-1) without cystine. Constant intravenous infusions of L-[2H3-methyl-1-13C]methionine were given on days 5 and 7 while subjects were in the fed and postabsorptive states, respectively. Estimates were made of methionine oxidation, and daily methionine balance was derived from the intake-oxidation data. For the five subjects, methionine balances were -0.9, +0.7, +3.5, -3.1, and -3.8 mg kg-1.d-1, or -6, +5, +23, -21, and -26 mumol.kg-1.d-1. These findings lead to the conclusion that the upper range of the requirement for methionine plus cystine probably exceeds 13 mg.kg-1.d-1 in healthy young adults. The implications of this conclusion for ...

309

Incompatibility of metam sodium with halogenated fumigants.

Proposed is a lubricating composition for processing flushing fluids, which contains synthetic fatty acids of the fraction carbon 11-20, oxidized petrolatum, mineral oil, and additives. In order to increase the antiwear, anticorrosion, and antiscratching properties of the composition under conditions of polymineral corrosion with simultaneous decrease in the water loss of the flushing fluids as additives the composition contains stearic acid, polyoxyethylated methyl phenol, naptha soap, 1,5-dibenzoylnapthaline-4', 4''-dicarboxylic acid, calcined soda, secondary nonsaponifiables, obtained in the production of synthetic fatty acids by oxidation of paraffin, and polyfunctional oxygen-bearing compounds, obtained by oxidation of secondary nonsaponifiables by atmospheric oxygen, with the following ratio of components, wt%: 17.2-19.2% synthetic fatty acids of the carbon 17-20 fraction, 5.2-5.8% oxidized petrolatum, 3.5-3.7% polyoxyethylated ...

1981-03-15

310

Graft copolymers of methyl methacrylate and poly([R]-3-hydroxybutyrate) macromonomers as candidates for inclusion in acrylic bone cement formulations: Compression testing.

Metam sodium (metam) is a widely used soil fumigant. Combined application of metam and other available fumigants is intended to produce synergic pesticidal effects for a broad spectrum of pest control in soil fumigation. This study aimed to test the compatibility of metam with the halogenated fumigants 1,3-dichloropropene (1,3-D), chloropicrin, methyl bromide, methyl iodide and propargyl bromide. Halogenated fumigants and metam were spiked simultaneously into organic solvents, water and moist soils, and metam-induced degradation of these halogenated chemicals was evaluated. In all three media, the halogenated fumigants were incompatible with metam and degraded via rapid chemical reactions. The degradation rate varied with halogenated fumigant species and increased as the amount of metam present was increased. In moist soil, 15-95% of the halogenated fumigants were decomposed within 72 h by metam at a 1:1 molar ratio. Combined application of ...

2005-05-01

311

Further evaluation of a series of anti-inflammatory N-pyrrolylcarboxylic acids: effects on the nociception in rats.

Graft copolymers of methyl methacrylate and biodegradable, biocompatible bacterial poly([R]-3-hydroxybutyrate) (PHB) blocks were synthesized and evaluated as possible constituents in acrylic bone cements for use in orthopaedic applications. The copolymers were produced by conventional free radical copolymerization and incorporated in one commercially available acrylic bone cement brand, Antibiotic Simplex (AKZ). Cements with formulations containing 6.7 and 13.5 wt % of PMMA-graft-PHB were prepared. The morphology of the graft copolymer particles was suggested to influence the ability of the modified cement to be processed. Formulations containing more than about 20 wt % of the graft copolymer resulted in cement doughs that, both after first preparation and several hours later, were either sandy or soft spongy in texture and, thus, would be unacceptable for use in orthopaedic applications. The morphologies of the powders and the volumetric porosity (p) and ultimate ...

2006-04-01

312

FT-IR spectroscopic studies of tin-modified rhenium alumina-silica metathesis catalyst

The analgesic activity of nine substituted N-pyrrolylcarboxylic acids, previously reported as anti-inflammatory agents, has been evaluated. The effects on nociception were examined in male Wistar rats by the Randall-Selitto paw-pressure test. The compounds were administrated in doses 10, 20, and 40 mg/kg both i.p. and p.o. As a whole, the activities of 3-(N-pyrrolyl)propanoic acids 3e-3h and 2-[3-(ethoxycarbonyl)-2-methyl-5-phenyl-1H-1-pyrrolyl]-3-methylpentanoic acid 3i were comparable with or superior to that of metamizole used as a reference (200 mg/kg, i.p.), whereas only 3a from among the N-pyrrolyl-acetic acids 3a-3d showed analgesic activity on the inflamed paw. The compounds found most promising to increase the pain threshold significantly were the same ones with the higher anti-inflammatory activity registered in our previous study: 3-[3-(ethoxycarbonyl)-2-methyl-5-(3-nitrophenyl)-1H-1-pyrrolyl]propanoic acid 3e, together with its ...

2006-03-01

313

Development of methods of forecasting properties of polymer packaging materials which do not cause any changes in medicinal preparations during sterilization

FT-IR spectra of the products obtained in each step of the tetramethyltin (TMT)/3-wt.% Re_2O_7/Al_2O_3-SiO_2 and TMT/Al_2O_3-SiO_2 system preparation are presented and discussed. The obtained spectra show that TMT reacts with alumina-silica hydroxyl groups already at room temperature, yielding surface methyltin compounds; NH_4ReO_4 reacts with alumina-silica surface at temperatures up to 423 K, yielding rhenium surface species and ammonia, which is strongly bonded by acidic sites of the Broensted kind. FT-IR spectrum of the system (TMT)/3-wt.% Re_2O_7/Al_2O_3-SiO_2 indicated the absence of surface methyl tin compounds observed on the surface system TMT/Al_2O_3-SiO_2 , and the presence of physically adsorbed TMT; after 5 h of evacuation of the TMT/3-wt.% Re_2O_7/Al_2O_3-SiO_2 system, the FT-IR spectrum indicated the presence of only a single band at 2977 cm"-"1, which may be assigned to the C-H bond stretching of the methyl group in the surface ...

2000-01-01

314

Development of methods for forecasting properties of polymer packaging materials which do not cause any change in medicinal preparation during their sterilization

The authors present the results of an investigation of the effect of gamma radiation on the properties of low-molecular moulded polymethyl methacrylates (molecular weight distribution, physico-mechanical properties, resistance to the effects of aqueous media and physiological solution) in the form of copolymers of methyl methacrylate with methyl acrylate (MA) or butyl acrylate (BA) with the brand names Dacryl-4B, Dacryl-2M and Dacryl-4M (4% BA; 2 and 4% MA respectively) having a molecular weight of around 10"5. For comparison, block polymethyl methacrylate with a molecular weight of 3 x 10"6 was used. The results of experiments on the ageing of unirradiated and irradiated specimens in a heated store-room (t = 10 - 20"0C) and at high temperatures (90"0C) are also given. It is shown that irradiation with doses of 2.5 - 20 Mrad leads to radiolysis of the above copolymers, accompanied by destructive processes. Evidence of this is an increase in the ...

1974-12-09

315

Detailed Chemical Kinetic Reaction Mechanisms for Autoignition of Isomers of Heptane Under Rapid Compression

The authors present the results of an investigation of the effect of gamma radiation on the properties of low-molecular moulded polymethyl methacrylates (molecular weight distribution, physicomechanical properties, resistance to the effects of aqueous media and physiological solution) in the form of copolymers of methyl methacrylate with methyl (MA) or butyl acrylate (BA) with the brand names Dacryl-4B, Dacryl-2M and Dacryl-4M (4% BA; 2 and 4% MA respectively) having a molecular weight of around 10"5. For comparison, block polymethyl methacrylate with a molecular weight of 3 x 10"6 was used. The results of experiments on the ageing of unirradiated and irradiated specimens in a heated store-room (t = 10 - 20"0C) and at high temperatures (90"0C) are also given. It is shown that irradiation with doses of 2.5-20 Mrad leads to radiolysis of the above copolymers, accompanied by destructive processes. Evidence of this is an increase in the ...

1975-01-01

316

Combined photochemical-biological processes for treatment of unleaded gasoline oxygenates : MTBE, ETBE and TAME

Detailed chemical kinetic reaction mechanisms are developed for combustion of all nine isomers of heptane (C{sub 7}H{sub 16}), and these mechanisms are tested by simulating autoignition of each isomer under rapid compression machine conditions. The reaction mechanisms focus on the manner in which the molecular structure of each isomer determines the rates and product distributions of possible classes of reactions. The reaction pathways emphasize the importance of alkylperoxy radical isomerizations and addition reactions of molecular oxygen to alkyl and hydroperoxyalkyl radicals. A new reaction group has been added to past models, in which hydroperoxyalkyl radicals that originated with abstraction of an H atom from a tertiary site in the parent heptane molecule are assigned new reaction sequences involving additional internal H atom abstractions not previously allowed. This process accelerates autoignition in fuels with tertiary C-H bonds in the parent fuel. In addition, the rates of ...

2001-12-17

317

Combined photochemical-biological processes for treatment of unleaded gasoline oxygenates : MTBE, ETBE and TAME

A study was conducted to determine the feasibility and the opportunity of photochemical pretreatment on the biodegradation and detoxification of Methyl Tert Butyl Ether (MTBE), Ethyl Tert Butyl Ether (ETBE) and Tert Amyl Methyl Ether (TAME), the most common oxygenates used as octane enhancers in unleaded gasoline. The production, storage, uses and disposal of oxygenates result in an unknown amount of groundwater pollution. Because of their high solubility, MTBE, ETBE and TAME are detected in large portions in saturated zones of aquifers. The biodegradation of these oxygenates is difficult and slow, and information regarding their biodegradability is scarce. Photo-decomposition of oxidants under appropriate UV radiation has been shown to be very effective because the hydroxyl radicals produced possess high oxidation potential. In this study, the H{sub 2}O{sub 2}/UV process was used to generate hydroxyl radicals. Maximal oxygenates transformation ...

1998-10-01

318

Characterization of lithium electrode surface in lithium secondary batteries by in situ Raman spectroscopic methods. Final report, 1 September 1989-31 December 1992

A study was conducted to determine the feasibility and the opportunity of photochemical pretreatment on the biodegradation and detoxification of Methyl Tert Butyl Ether (MTBE), Ethyl Tert Butyl Ether (ETBE) and Tert Amyl Methyl Ether (TAME), the most common oxygenates used as octane enhancers in unleaded gasoline. The production, storage, uses and disposal of oxygenates result in an unknown amount of groundwater pollution. Because of their high solubility, MTBE, ETBE and TAME are detected in large portions in saturated zones of aquifers. The biodegradation of these oxygenates is difficult and slow, and information regarding their biodegradability is scarce. Photo-decomposition of oxidants under appropriate UV radiation has been shown to be very effective because the hydroxyl radicals produced possess high oxidation potential. In this study, the H_2O_2/UV process was used to generate hydroxyl radicals. Maximal oxygenates transformation was ...

1998-10-01

319

Attenuation by methyl mercury and mercuric sulfide of pentobarbital induced hypnotic tolerance in mice through inhibition of ATPase activities and nitric oxide production in cerebral cortex

Surface layers on lithium electrodes formed in several solvents including dimethyl carbonate (DMC), diethyl carbonate (DEC), polyethylene glycol 400 dimethyl ether (PEG400DME), and propylene carbonate (PC) have been studied by Raman spectroscopy. Both DMC and DEC were used singly, and also mixed with either methyl acetate or methyl formate. The Raman spectra showed that passive films formed on the Li surface in different solvents may have different chemical structures, which changed during the charging and discharging processes. A solid film of fullerene C6O, which could be used as a cathode in Li rechargeable batteries, was examined in the PEG400DME solution by both electrochemical and Raman spectroscopy. Cyclic voltammograms (CVs) showed five redox peaks which suggested the formation of C6O(-), C6O(2-), C6O(3-), C6O(4-), and C6O(5-). Raman spectra obtained from thin C6O film indicated that the thin fulleride film dissolved in the ...

1993-03-24

320

A zwitterionic silylene as reactive intermediate and its unusual dimerization to an N-heterobicyclic disilane.

This study is aimed at exploring the possible mechanism of hypnosis-enhancing effect of HgS or cinnabar (a traditional Chinese medicine containing more than 95% HgS) in mice treated with pentobarbital. We also examined whether the effect of HgS is different from that of the well-known methyl mercury (MeHg). After a short period (7 days) of oral administration to mice, a nontoxic dose (0.1 g/kg) of HgS not only significantly enhanced pentobarbital-induced hypnosis but also attenuated tolerance induction; while a higher dose (1 g/kg) of HgS or cinnabar exerted an almost irreversible enhancing effect on pentobarbital-hypnosis similar to that of MeHg (2 mg/kg) tested, which was still effective even after 10 or 35 days cessation of administration. To study comparatively the effects of different mercury forms from oral administration of MeHg and HgS on membrane ATPase activities of experimental mice, analysis of the Hg content in the cerebral cortex revealed that ...

2008-06-15

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

321

1,3-dipolar cyclo addition of benzyl aside to alpha-beta-unsaturated five-membered lactones

A way to synthesize the transient zwitterionic silylene L'Si: 8 {L'=CH[(C=CH(2))CMe(N(tBu))(2)]} and achieve its facile dimerization to the remarkable N-heterobicyclic disilane 8(2) is described. At first, employing the beta-diketiminate ligand L [L=CH(CMeN(tBu))(2)], both starting materials LH (2) and its N-lithium salt LLi (3) can react with SiBr(4) to yield the silylene precursor L'SiBr(2) (4) by silicon-induced C-H activation at an exocyclic methyl group on the backbone of the ligand. Compound 4 reacts with SiBr(4) above room temperature to afford the unexpected terminal CH(SiBr(3))-substituted dibromosilane 6 along with the unique tricyclic trisilane 7. Reduction of 4 with KC(8) at 0 degrees C furnishes the novel N-heterobicyclic disilane 8(2), which is a formal dimer of the desired zwitterionic silylene L'Si: (8). It has been reasoned that compound 8(2) may results from [4+1] cycloaddition of two molecules of 8 to give the transient dimer 8(2)', which ...

2009-08-01

322

Surface modification of functional self-assembled monolayers on 316L stainless steel via lipase catalysis.

The 1,3-dipolar cyclo addition reactions between benzyl azide and the alpha,beta-unsaturated lactones crotonolactone, alpha-methylenebutyrolactone and Beta-angelica lactone have been performed. The best yields of cycloadducts were obtained by working without solvent, at 60 degree centigree in a sealed tube under nitrogen atmosphere. (3aRS,6aSR)-1-Benzyl-3 a, 4,6,6a-tetrahydro-1H-furo[3,4-d]-1,2,3-triazol-4-one and 3-benzyl-7-oxa-1,2,3-triazaspiro[4.4] non-1-en-6-one have been isolated in 36% and 78% yield from the reactions of the two first lactones respectively. The second product is the first example of this heterocyclic system. The reaction with Beta-angelica lactone yielded the primary cycloadducts (3aR,S,6RS,6aSR)-and (3aRS,6SR,6aSR)-1-benzyl-3a,4,6,6a-tetrahydro-6-methyl-1H-furo[3,4-d]-1,1,3-triazol-4-one and the nitrogen elimination product 4-benzylamino-5-methyl 1-2(5H)-furanone in 44%, 11%, and 7% yield respectively. 26 refs.

1994-12-31

323

Surface activity at the planar interface in relation to the thermodynamics of intermolecular interactions in the ternary system: maltodextrin-small-molecule surfactant-legumin.

Lipase catalyzed esterification of therapeutic drugs to functional self-assembled monolayers (SAMs) on 316L stainless steel (SS) after assembly has been demonstrated. SAMs of 16-mercaptohexadecanoic acid (-COOH SAM) and 11-mercapto-1-undecanol (-OH SAM) were formed on 316L SS, and lipase catalysis was used to attach therapeutic drugs, perphenazine and ibuprofen, respectively, on these SAMs. The reaction was carried out in toluene at 60 degrees C for 5 h using Novozyme-435 as the biocatalyst. The FTIR spectra after surface modification of -OH SAMs showed the presence of the C=O stretching bands at 1745 cm(-1), which was absent in the FTIR spectra of -OH SAMs. Similarly, the FTIR spectra after the reaction of the -COOH SAM with perphenazine showed two peaks in the carbonyl region, a peak at 1764 cm(-1), which is the representative peak for the C=O stretching for esters. The second peak at 1681 cm(-1) is assigned to the C=O stretching of the remaining unreacted ...

2006-01-31

324

Solid/liquid lubrication of ceramics at elevated temperatures

We report on the effect of potato maltodextrins with variable dextrose equivalent (Paselli SA-2, SA-6 and SA-10) on the surface behavior at the air-water interface of the mixture: legumin+small-molecule surfactant. Distinct in nature small-molecule surfactants (model: sodium salt of capric acid, Na-caprate; and commercially important: a citric acid ester of monoglyceride, CITREM) have been under our consideration. The role of the structure of both of the maltodextrins and the small-molecule surfactants in the effect studied has been elucidated by measurements in a bulk aqueous medium of the enthalpy of their interaction from mixing calorimetry, value of weight average molecular weight of the maltodextrins and the thermodynamics of the pair maltodextrin-solvent and maltodextrin-protein interactions from laser static light scattering. The combined data of mixing calorimetry and light scattering suggest some complex formation between the small-molecule surfactants and ...

2001-07-01

325

Propolis derivatives inhibit the systemic inflammatory response and protect hepatic and neuronal cells in acute septic shock

This study investigates the effect of solid and liquid lubrication on friction and wear performance of silicon nitride (Si{sub 3}N{sub 4}) and cast iron. The solid lubricant was a thin silver film ({approx}2 {mu}m thick) produced on Si{sub 3}N{sub 4} by ion-beam-assisted deposition. A high-temperature polyol-ester-base synthetic oil served as the liquid lubricant. Friction and wear tests were performed with pin-on-disk and oscillating-slider wear test machines at temperatures up to 300{degrees}C. Without the silver films, the friction coefficients of Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4} test pairs were 0.05 to 0.14, and the average wear rates of Si{sub 3}N{sub 4} pins were {approx}5 x 10{sup -8} mm{sup 3} N{sup -1}. The friction coefficients of Si{sub 3}N{sub 4}/cast iron test pairs ranged from 0.08 to 0.11, depending on test temperature. The average specific wear rates of cast iron pins were {approx}3 x 10{sup -7} mm{sup 3} N{sup -1} m{sup -1}. However, ...

1996-04-01

326

Scientific Electronic Library Online (English)

Abstract in english BACKGROUND: Severe pathogenic infection triggers excessive release of cytokines as part of the massive inflammatory response associated with septic shock. OBJECTIVES: To investigate the protective effect of caffeic acid phenethye ester (CAPE) against lipopolysaccharide (LPS) induced endotoxemia, hepatic and neuronal damage and the associated systemic inflammatory response (SIR). METHODS: Fifty male Wister rats were divided into: control, LPS, and CAPE+LPS groups. Plasma c (more) oncentrations of various cytokines, including TNF-?, IL-1?, IL-1?, IL-6, IL-4, IL-10, and sICAM-1 were evaluated. In addition, the histopathological changes in the hepatic and neural cells were assessed. RESULTS: The LPS group showed high inflammatory cytokines and sICAM-1 levels reflecting the presence of SIR. Hepatocyte necrosis, apoptosis, extensive hemorrhage and inflammatory cellular infiltration together with brain astrocytes swelling, early neuron injury and ...

2011-08-01

327

Physical basis of the effect of hemoglobin on the "3"1P NMR chemical shifts of various phosphoryl compounds

Innovative clean gas introduction into new cooling tower packing; Innovative Reingaseinleitung in Kuehlturmneubauten

The marked difference between the intra- and extracellular "3"1P NMR chemical shifts of various phosphoryl compounds when added to a red cell suspension may be largely understood in terms of the effects of hemoglobin on the "3"1P NMR chemical shifts. The presence of [oxy- or (carbonmonoxy)-] hemoglobin inside the red cell causes the bulk magnetic susceptibility of the cell cytoplasm to be significantly less than that of the external solution. This difference is sufficient to account for the difference in the intra- and extracellular chemical shifts of the two phosphate esters trimethyl phosphate and triethyl phosphate. However, in the case of the compounds dimethyl methylphosphonate, diethyl methylphosphonate, and trimethylphosphine oxide as well as the hypophosphite, phenylphosphinate, and diphenylphosphinate ions, hemoglobin exerts an additional, much larger, effect, causing the "3"1P NMR resonances to shift to lower frequency in a manner that cannot be accounted ...

328

High oleic acid sun flower oil as raw material for the Oleochemistry; Hochoelsaeurehaltiges Sonnenblumenoel als Rohstoff fuer die Oleochemie

In 1991/1992, VEAG decided to convert its 500 MW plants at Jaenschwalde and Boxberg to the latest state of technology. This even included the discharge of the cleaned flue gas through the existing cooling towers. The site of the flue gas desulphurization plant and also the existing cooling tower shells required routeing of the clean gas lines similar to the routes in the existing plants of RWE. The positive experience accrued with the pipework material `glass-fibre reinforced vinyl ester resin` has also led to the selection of this material here. The universally positive experience gained from existing clean gas lines via cooling towers by very different power station operators induced VEAG and its partners also to equip new construction operations in the new Federal states with this technology. (orig.) [Deutsch] In den Jahren 1991/1992 entschloss sich die VEAG, ihre 500-MW-Anlagen Jaenschwalde und Boxberg auf den neuesten Stand der Technik umzuruesten. Hierzu ...

1997-06-01

329

Expression of Na(+)-H+ exchange and ATP-dependent proton extrusion in growing rat IMCD cells

High oleic acid sunflower oils have been commercially available for some years now. Due to their high content of monounsaturated fatty acids these oils have a number of potential applications in the oleochemical industry, especially where technical oleic acids and their derivatives are used. Whereas conventional sunflower oil contains approx. 68% linoleic acid (C{sub 1}8:2), it is now possible through breeding measures to obtain ''new sunflower oils'' (NSb oils) with oleic acid levels of 70-95% oleic acid (C{sub 1}8:1). The oil itself is of interest for technical applications: it is light-coloured, has a neutral odour and is relatively resistant to oxidation. Plant oils, especially those with a low content of polyunsaturated fatty acids, are increasingly gaining interest as ester oils in technical application areas, e.g. as lubricants. However, there are limits to the technical applicability of triglycerides due to their ...

2000-07-01

330

Electron-beam induced RAFT-graft polymerization of poly(acrylic acid) onto PVDF

As the last step of urinary acidification, the inner medullary collecting duct (IMCD) is thought to secrete protons into the tubular lumens by means of a H(+)-translocating adenosinetriphosphatase (H(+)-ATPase). However, recent studies have also shown the existence of Na(+)-H+ exchange activity in IMCD cells. Although the physiological function of the antiporter in IMCD cells is unknown, activation of Na(+)-H+ exchange in other cell-culture systems has been suggested to be closely associated with the process of cell growth. Thus presence of Na(+)-H+ exchange may relate to the growth phase of these cells. To examine intracellular pH (pHi) regulation in growing IMCD cells, we studied proton transport by Na(+)-dependent and Na(+)-independent mechanisms by microfluorimetry using the pHi-sensitive dye 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein acetoxymethyl ester (BCECF/AM). Actively growing cells, defined by (3H)thymidine incorporations, ...

1990-03-01

331

Cloning, chromosomal assignment, and regulation of the rat thyrotropin receptor: Expression of the gene is regulated by thyrotropin, agents that increase cAMP levels, and thyroid autoantibodies

This paper explores for the first time the post-radiation-induced-graft polymerization on solid substrate using reversible addition-fragmentation transfer (RAFT) mechanism. Radiation-induced graft polymerization onto polymers is a potentially interesting technique to create easily new materials from highly resistant polymers, e.g. surface graft polymerization of acrylic acid (AA) onto poly(vinylidene difluoride) (PVDF) improves its surface properties without losing its excellent mechanical properties. As a consequence of the radical nature of the polymerization processes it is difficult to control molecular weight of grafted chains, and therefore design and standardize the properties of the final product. RAFT polymerization is a suitable method to obtain monodisperse polymers. The ability of the RAFT agents to control the polymer chain length could be an interesting approach to improve the grafted polymers obtained by post-radiation-induced-graft polymerization technique. In this way, ...

2005-07-01

332

Chelation of intracellular calcium blocks insulin action in the adipocyte

A rat thyrotropin (thyroid-stimulating hormone, TSH) receptor cDNA was isolated that encoded a protein of 764 amino acids, M_r 86,528. Transfection of the cDNA caused COS-7 cells to develop a TSH-sensitive adenylate cyclase response and the ability to bind "1"2"5I-labeled TSH; both activities were similar to those of rat FRTL-5 thyroid cells and not duplicated by lutropin. The gene represented by the cDNA was assigned to mouse chromosome 12 and human chromosome 14. Northern analyses identified two species of mRNA, 5.6 and 3.3 kilobases, in FRTL-5 thyroid cells; the transcripts appeared to differ only in the extent of their 3' noncoding sequences. There were minimal amounts of the two mRNAs in rat ovary, and neither was detected in RNA preparations from rat testis, liver, lung, brain, spleen, and FRT thyroid cells, which do not have a functional TSH receptor. TSH decreased both mRNA species 3- to 4-fold within 8 hr in FRTL-5 thyroid cells; down-regulation was dependent on TSH ...

1990-01-01

333

Chelation of intracellular calcium blocks insulin action in the adipocyte

The hypothesis that intracellular Ca/sup 2 +/ is an essential component of the intracellular mechanism of insulin action in the adipocyte was evaluated. Cells were loaded with the Ca/sup 2 +/ chelator quin-2, by preincubating them with quin-2 AM, the tetrakis(acetoxymethyl) ester of quin-2. Quin-2 loading inhibited insulin-stimulated glucose transport without affecting basal activity. The ability of insulin to stimulate glucose uptake in quin-2-loaded cells could be partially restored by preincubating cells with buffer supplemented with 1.2 mM CaCl/sub 2/ and the Ca/sup 2 +/ ionophore A23187. These conditions had no effect on basal activity and omission of CaCl/sub 2/ from the buffer prevented the restoration of insulin-stimulated glucose uptake by A23187. Quin-2 loading also inhibited insulin-stimulated glucose oxidation and the ability of insulin to inhibit cAMP-stimulated lipolysis without affecting their basal activities. Incubation of cells with 100 ..mu..M ...

1987-02-01

334

Weed control and wheat (Triticum aestivum L.) yield under application of 2,4-D plus carfentrazone-ethyl and florasulam plus flumetsulam: Evaluation of the efficacy

The hypothesis that intracellular Ca"2"+ is an essential component of the intracellular mechanism of insulin action in the adipocyte was evaluated. Cells were loaded with the Ca"2"+ chelator quin-2, by preincubating them with quin-2 AM, the tetrakis(acetoxymethyl) ester of quin-2. Quin-2 loading inhibited insulin-stimulated glucose transport without affecting basal activity. The ability of insulin to stimulate glucose uptake in quin-2-loaded cells could be partially restored by preincubating cells with buffer supplemented with 1.2 mM CaCl_2 and the Ca"2"+ ionophore A23187. These conditions had no effect on basal activity and omission of CaCl_2 from the buffer prevented the restoration of insulin-stimulated glucose uptake by A23187. Quin-2 loading also inhibited insulin-stimulated glucose oxidation and the ability of insulin to inhibit cAMP-stimulated lipolysis without affecting their basal activities. Incubation of cells with 100 #mu#M quin-2 or quin-2 AM had no ...

335

British Library Electronic Table of Contents (United Kingdom)

Three field experiments were conducted at the research fields of Plant Protection Research Institute, Iran, at different locations in 2004-2005 to study the efficacy of different broadleaved herbicides to control weeds in wheat. Treatments were the full-season hand weeded and weed-infested controls, and post-emergence applications of florasulam plus flumetsulam at 8.75, 10.50, and 12.25ga.i./ha, 2,4-D plus carfentrazone-ethyl at 210, 245, 280, and 490ga.i./ha, bromoxynil plus MCPA at 75, 100, and 150ga.i./ha, 2,4-D at 560, 720, and 1120ga.i./ha, tribenuron methyl, and 2,4-D plus MCPA. Herbicides were applied at wheat tillering stage. Naturally occurring broadleaved weed populations were used in experiments. Results indicated that bromoxynil plus MCPA at 150ga.i./ha, 2,4-D plus MCPA, and 2,...

2007-01-01

336

Viscoelasticity of various gel films prepared from solvent-soluble constituents in coal; Sekitanchu no yobai kayoseibun kara sakuseishita shushu no gel maku no nendansei

Two dimensional NMR and NMR relaxation studies of coal structure. Progress report, July 1, 1992--September 30, 1992

Viscoelasticity of gel films prepared from solvent-soluble constituents without ash of coal using the mixed solvent of carbon disulfide and N-methyl-2-pyrrolidinone (CS2-NMP) was measured to study the network structure of the constituents. In experiment, Upper Freeport coal and Zao Zhuang coal were used as specimens. Viscoelasticity of various gels with different weight fractions of solvent was measured by creep measurement under a fixed load and stress-strain analysis under variable loads. In the 2nd and 3rd creep measurements, although no large changes in elastic strain and viscoelastic strain were found, viscous strain gradually decreased with an increase in viscosity. In the case of small weight fraction of solvent, small viscous strain and viscoelastic strain were found, while slightly large elastic strain was found. It was thus suggested that this elastic strain is derived from not only physical cross-linked networks by coal-solvent interaction but also those ...

1996-10-28

337

The toughness amplification map of poly(vinyl chloride) and its cellulose acetate-compatibilized starch alloys containing core/shell rubber particles: Possible transition to super-toughening

This report covers the progress made on the title project for the project period. Four major areas of inquiry are being pursued. Advanced solid state NMR methods are being developed to assay the distribution of the various important functional groups that determine the reactivity of coals. Special attention is being paid to methods that are compatible with the very high magic angle sample spinning rates needed for operation at the high magnetic field strengths available today. Polarization inversion methods utilizing the difference in heat capacities of small groups of spins are particularly promising. Methods combining proton-proton spin diffusion with {sup 13}C CPMAS readout are being developed to determine the connectivity of functional groups in coals in a high sensitivity relay type of experiment. Additional work is aimed at delineating the role of methyl group rotation in the proton NMR relaxation behavior of coals.

1992-11-25

338

British Library Electronic Table of Contents (United Kingdom)

Abstract Toughening amplification of the neat poly(vinyl chloride) (PVC) and its reinforced version containing 25 phr of the cellulose acetate (CA)-compatibilized starch using methyl methacrylate-butadiene-styrene (MBS) core-shell particles was studied. The room temperature measured impact strength of the PVC showed mild increase up to 10 wt % with the addition of MBS particles. Then, the toughness enhanced discontinuously to super-tough plateau regime. The room temperature measured impact strength of PVC containing 20 phr of MBS particles, however, was reduced by as much as 95% when it was filled with 25 phr of the CA-compatibilized starch. In addition, the brittle-ductile transition (BDT) of the toughened PVC increased from 0 to 60 C because of its reinforcement, even though the matrix n...

2011-01-01

339

The synthesis of (1',3'- sup 3 H)4-(4'-azido-5',6',7',8'-tetrahydro-5',5',8',8'-tetramethyl -2'-anthracenyl)benzoic acid as a probe of the retinoic acid receptor

Synthesis, structural activity-relationships, and biological evaluation of novel amide-based allosteric binding site antagonists in NR1A/NR2B N-methyl-d-aspartate receptors

The synthesis of (1',3'-{sup 3}H)4-(4'-azido-5',6',7',8'-tetrahydro-5'5'8',8'-tetramethyl-2'-anthracenyl)benzoic acid is described. This retinoid was designed as a photoaffinity probe of the receptor sites of cellular retinoic acid-binding protein and the nuclear retinoic acid receptor protein. The ({sup 3}H)azidoretinoid was prepared from 1,2,3,4-tetrahydro-1,1,4,4-tetra-methyl-7-(4-methylphenyl)-5-nitroanthracene in five steps in 15% yield (89% radiochemical purity by HPLC). {sup 1}H and {sup 3}H NMR was used to confirm the sites of {sup 3}H substitution on the ring. (author).

1990-01-01

340

British Library Electronic Table of Contents (United Kingdom)

The synthesis and structure-activity relationship analysis of a novel class of amide-based biaryl NR2B-selective NMDA receptor antagonists are presented. Some of the studied compounds are potent, selective, non-competitive, and voltage-independent antagonists of NR2B-containing NMDA receptors. Like the founding member of this class of antagonists (ifenprodil), several interesting compounds of the series bind to the amino terminal domain of the NR2B subunit to inhibit function. Analogue potency is modulated by linker length, flexibility, and hydrogen bonding opportunities. However, unlike previously described classes of NR2B-selective NMDA antagonists that exhibit off-target activity at a variety of monoamine receptors, the compounds described herein show much diminished effects against the...

2009-01-01

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341

Synthesis, luminescence quantum yields, and lifetimes of trischelated ruthenium(II) mixed-ligand complexes including 3,3'-dimethy1-2,2'-bipyridyl

Surface tension of a coal extract in an organic solvent; Sekitan chushutsu seibun no kaigo to hyomen choryoku

New five complexes of the type of [RuL sub(3-x)(dmby) sub(x)]X sub(2)(x = 1,2,3, L = 2,2'-bipyridyl or 1,10-phenanthroline, dmby = 3,3'-dimethy1-2,2'-bipyridyl, X = halide ion) have been synthesized in order to investigate the effects of two methyl groups of dmby on the absorption and emission spectra, luminescence quantum yields, and lifetimes. Values of the radiative and nonradiative rate constants have been calculated from these data at 77K. Although the absorption and emission maxima and the lifetimes are not much affected by the dmby ligand substitution, the molar extinction coefficients and emission quantum yields are decreased compared with trischelated complexes of the parent bipyridyl or phenanthroline ligands. At 25"0C the emission yields of the complexes containing dmby decrease by 3 - 4 orders of magnitude than at 77K. Possible causes of the decrease in the quantum yields are discussed. (author).

1982-01-01

342

Supplementation of pyruvate prevents palmitate-induced impairment of glucose uptake in C2 myotubes.

The behavior and properties of associated bodies were studied through measurement of surface tension considering acetone-soluble fraction relatively light among various solvent extracts of coal. In experiment, the acetone-soluble fraction was extracted from the substances extracted from Upper Freeport coal as standard specimen using the mixed solvent of carbon disulfide (CS2) and N-methyl-2-pyrrolidinone (NMP), and it was dissolved into NMP after drying. Surface tension was measured by Wilhelmy method. The experimental results are as follows. Equilibrium surface tension is equal to the surface tension of pure solvent in a low concentration range of solution, and decreases with an increase in concentration approaching a fixed value at 0 in log concentration, nearly showing an S curve. Adsorption of species with non-polar aromatic ring of the acetone-soluble fraction on a solution surface probably decreases surface tension. Change with time in surface tension is ...

1996-10-28

343

Steric Effects in Ionic Pairing and Polyelectrolyte Interdiffusion within Multilayered Films: A Neutron Reflectometry Study

Elevated fatty acid levels have been thought to contribute to insulin resistance. Repression of the glucose transporter 4 (GLUT4) gene as well as impaired GLUT4 translocation may be a mediator for fatty acid-induced insulin resistance. This study was initiated to determine whether palmitate treatment repressed GLUT4 expression, whether glucose/fatty acid metabolism influenced palmitate-induced GLUT4 gene repression (PIGR), and whether attempts to prevent PIGR restored palmitate-induced impairment of glucose uptake (PIIGU) in C2 myotubes. Not only stimulators of fatty acid oxidation, such as bezafibrate, AICAR, and TOFA, but also TCA cycle substrates, such as pyruvate, leucine/glutamine, and ?-ketoisocaproate/monomethyl succinate, significantly prevented PIGR. In particular, supplementing with pyruvate through methyl pyruvate resulted in nearly complete prevention of PIIGU, whereas palmitate treatment reduced the intracellular pyruvate level. These results suggest ...

2011-07-23

344

Silica Polyamine Composites: New Supramolecular Materials for Cation and Anion Recovery and Remediation

Using a series of polycations synthesized by atom transfer radical polymerization (ATRP), we investigate the effects of the polymer charge density and hydrophobicity on salt-induced interdiffusion of polymer layers within polyelectrolyte multilayer (PEM) films. Polycations with two distinct hydrophobicities and various quaternization degrees (QPDMA and QPDEA) were derived from parent polymers of matched molecular weights poly(2-(dimethylamino)ethyl methacrylate) (PDMA) and poly(2-(diethylamino)ethyl methacrylate) (PDEA) by quaternization with either methyl or ethyl sulfate. Multilayers of these polycations with polystyrene sulfonate (PSS) were assembled in low-salt conditions, and annealed in NaCl solutions to induce layer intermixing. As revealed by neutron reflectometry (NR), polycations with lower charge density resulted in a faster decay of film structure with distance from the substrate. Interestingly, when comparing polymer mobility in QPDEA/PSS and QPDMA/PSS ...

2011-01-01

345

Rubidium uptake by mouse pancreatic islets exposed to 6-hydroxydopamine, ninhydrin, or other generators of hydroxyl radicals

The surface coverage of amorphous silica gels used in the synthesis of silica polyamine composites has been investigated by 29Si NMR. By diluting the polyamine anchor silane, chloropropyl trichlorosilane, with methyl trichlorosilane it was found that surface coverage could be markedly improved for a range of amine polymers after grafting to the silica surface. The commensurate decrease in the number of anchor points and increase in the number of free amines results in an increase in metal capacity and/or an improvement in capture kinetics. Solid state CPMAS-13C NMR has been employed to investigate the structure and metal ion binding of a series of these composite materials. It is reported that the highly branched polymer, poly(ethyleneimine) (PEI) exhibits much broader 13C NMR resonances than the linear polymers poly(allylamine) (PAA) and poly(vinylamine) (PVA). These results are understood in terms of the low energy conformations calculated from molecular modeling ...

2006-03-01

346

Room-temperature cw operation of InGaP/InGaAlP visible light laser diodes on GaAs substrates grown by metalorganic chemical vapor deposition

The purpose was to study the toxicity of drugs known to generate free radicals on isolated pancreatic islets. The accumulattion of "8"6Rb"+ by mouse pancreatic islets was measured in vitro. Exposing the islets to 6-hydroxydopamine, minhydrin, or phenazine methosulphate + NADH inhibited the Rb"+ uptake, whereas paraquat or acetylphenylhydrazine had no effect. This effect of 6-hydroxydopamine was prevented by either of the hydroxyl radical scavengers, sodium benzoate and mannitol, but not by the non-scavenger,urea; ninhydrin was partially protected against by mannitol but not by benzoate. Protection against 6-hydroxydopamine was also afforded by D-glucose but not by L-glucose or 3-O-methyl-D-glucose; none of the sugars protected against ninhydrin. In damaging islet beta-cells and in being protected against by D-glucose, 6-hydroxydopamine closely resembles the diabetogenic drug, alloxan. It is suggested that protection against alloxan may involve both glucose ...

347

Replacement of leucine-93 by alanine or threonine slows down the decay of the N and O intermediates in the photocycle of bacteriorhodopsin: Implications for proton uptake and 13-cis-retinal----all-trans-retinal reisomerization

Room-temperature cw operation for InGaP/InGaAlP double heterostructure (DH) laser diodes on GaAs substrates was achieved for the first time. The DH wafers were grown by low-pressure metalorganic chemical vapor deposition using methyl metalorganics. A lasing wavelength of 679 nm and a threshold current of 109 mA at 24C were obtained for an inner stripe structure laser diode with a 250- m-long and 7- m stripe geometry. The laser operated at up to 51C. The characteristic temperature T0 was 87 K at around room temperature. The lowest threshold current density, 5.0 kA/cmS, was obtained with a 20- m stripe width laser diode under room-temperature pulsed operation.

1986-01-20

348

Radiopharmaceuticals for the imaging of functional abnormalities of the developing brain

The authors report that the replacement of Leu-93 in bacteriorhodopsin by Ala (L93A) or Thr (L93T) slows down the photocycle by approximately 100-fold relative to wild-type bacteriorhodopsin. Time-resolved visible absorption spectroscopy and resonance Raman experiments, respectively, show the presence of long-lived O-like and N-like intermediates in the photocycles of the above mutants. We infer the existence of an equilibrium between the N and O intermediates in the photocycles of these mutants. The L93A and L93T mutants exhibit normal proton pumping under continuous illumination, suggesting that the decay of the N and/or O intermediate, and consequently, proton translocation, can be accelerated by the absorption of a second photon. Since the 13-cis----all-trans reisomerization of retinal is completed during the decay of the N and O intermediates, they conclude that the interaction of Leu-93 with retinal is important in this phase of the photocycle. This conclusion is supported by a ...

1991-08-01

349

Preservation of beech and spruce wood by allyl alcohol-based copolymers

The measurement of physiological parameters in man is possible with the help of positron emission tomography (PET) and radiopharmaceuticals labeled with short lived positron emitters as C 11, N 13, O 15 and F 18. With the use of this substances it is possible to make a tomographic map defining regional metabolic parameters in normal and diseased brain. This technique has therefore also be named 'in vivo autoradiography'. The possibility of applying C 11 or F 18 labeled deoxyglucose with PET for detecting regional and local changes in cerebral metabolic rate of glucose in brain development in children of 5 days to 1 year of age is discussed. Beyond this a relationship between cerebral metabolic rate of glucose, cerebral blood flow and cerebral metabolic rate of oxygen by use of this technique after inhalation of O 15 and C 11-labeled CO_2 is shown. Attention is drawn to the application of C 11-methyl-spiperone and PET to visualize dopamine receptor density in the ...

350

Preparation and photocatalytic property of pyrochlore Bi{sub 2}Ti{sub 2}O{sub 7} and (Bi, La) {sub 2}Ti{sub 2}O{sub 7} films

Allyl alcohol (AA), acrylonitrile (AN), methyl methacrylate (MMA), monomers and monomer mixtures AA+AN, AA+MMA were used to conserve and consolidate Beech and Spruce. After impregnation, copolymerisation and polymerisation were accomplished by gamma irradiation. The fine structure of wood+polymer(copolymer) composites was investigated by Scanning Electron Microscopy (SEM). It was observed that copolymer obtained from AA+MMA monomer mixture showed the optimum compatibility. The compressional strength and Brinell Hardness Numbers determined for untreated and treated wood samples indicated that the mechanical strength of wood+copolymer composites was increased. It was found that the mechanical strength of the wood samples containing the AA+MMA copolymer was higher than the others. In the presence of P(AA/MMA), at highest conversion, the compressive strength perpendicular to the fibres in Beech and Spruce increased approximately 100 times. The water uptake capacity of ...

1999-06-01

351

Pet's research at the SHFJ, Cea, one example: development and validation of a radioligand for the study of the cerebral dopaminergic system; La recherche en TEP au SHFJ, CEA. Un exemple: developpement et validation de radioligands pour l'etude du systeme dopaminergique

Dopant-free Bi{sub 2}Ti{sub 2}O{sub 7} thin films with pyrochlore structure and La-doped bismuth titanate thin films have been fabricated by means of chemical solution decomposition, and characterized by X-ray diffraction, atomic force microscopy, scanning electron microscopy and UV-Vis spectrophotometry in this study. Their photocatalytic activities have been evaluated by photodegrading methyl orange solution, and the optimum processing parameters for the highest photocatalytic activity have been found. Moreover, the effects of La-doping on the phase transformation and the photocalalytic activity have been studied. It has been deduced from the experiment result that substituted La{sup 3+} ions can act as a stabilizer of Aurivillus phase BLT and a grain-growth inhibitor in BLT thin films.

2008-11-28

352

Operation of a laboratory-scale tubular digester on pigery waste

The aim of this work is the evaluation of biodistribution and radiation dosimetry of a cocaine analog, the N-(3-iodo-prop-2E-enyl)-2beta-carbo-methoxy-3beta-(4-methyl-phenyl) nor-tropane (PE2I), labeled with carbon 11 ([{sup 11}C]PE2I). The [{sup 11}C]PE2I is a selective radioligand for imaging neuronal dopamine transporter (DAT) with positron emission tomography (PET). The DAT is a membrane-bound pre synaptically located protein that regulates the concentration of dopamine at nerve terminals. DAT radioligands are often used to evaluate the progression of Parkinson's disease or the efficiency of neuro-protective therapeutics and, typically, these studies required several successive PET scans. (author)

2005-10-15

353

Nuclear Targeting of Methyl-Recycling Enzymes in Arabidopsis thaliana Is Mediated by Specific Protein Interactions.

Three inclined tubular digesters of 13- to 15-litre volume were operated at temperatures between 20 and 30 degrees C with hydraulic retention times of 10-15 days on pig slurry of 10%, 5% and 2.5% Total Solids content. Tube inclination of 16-20 degrees gave no scumming problems. Solids were retained, giving improved gas yields when compared with literature values for conventional stirred digesters. Solids retention is affected by the size of the digester exit and appears to be greater with slurry of low solids content. There is a link between the movement of solids and gas along, and out of, the digester which can lead to unstable oscillating gas production. Tracer studies showed soluble components of the slurry mixed throughout the whole volume of the digester in 25% of the hydraulic retention time or less. Solids moved in well dispersed plug flow. Gas production (both intrinsic and after the addition of acetate) was most rapid in the central section of the digester. Extra-cellular ...

1986-01-01

354

Nitroimidazole conjugates of bis(thiosemicarbazonato)64Cu(II) - Potential combination agents for the PET imaging of hypoxia

Numerous transmethylation reactions are required for normal plant growth and development. S-adenosylhomocysteine hydrolase (SAHH) and adenosine kinase (ADK) act coordinately to recycle the by-product of these reactions, S-adenosylhomocysteine (SAH) that would otherwise competitively inhibit methyltransferase (MT) activities. Here, we report on investigations to understand how the SAH produced in the nucleus is metabolized by SAHH and ADK. Localization analyses using green fluorescent fusion proteins demonstrated that both enzymes are capable of localizing to the cytoplasm and the nucleus, although no obvious nuclear localization signal was found in their sequences. Deletion analysis revealed that a 41-amino-acid segment of SAHH (Gly(150)-Lys(190)) is required for nuclear targeting of this enzyme. This segment is surface exposed, shows unique sequence conservation patterns in plant SAHHs, and possesses additional features of protein-protein interaction motifs. ADK and SAHH interact in ...

2011-10-01

355

British Library Electronic Table of Contents (United Kingdom)

Combination agents comprising two different pharmacophores with the same biological target have the potential to show additive or synergistic activity. Bis(thiosemicarbazonato)copper(II) complexes (e.g. 64Cu-ATSM) and nitroimidazoles (e.g. 18F-MISO) are classes of tracer used for the delineation of tumor hypoxia by positron emission tomography (PET). Three nitroimidazole-bis(thiosemicarbazonato)copper(II) conjugates were produced in order to investigate their potential as combination hypoxia imaging agents. Two were derived from the known bifunctional bis(thiosemicarbazone) H2ATSM/A and the third from the new precursor diacetyl-2-(4-N-methyl-3-thiosemicarbazone)-3-(4-N-ethylamino-3-thiosem icarbazone) - H2ATSM/en. Oxygen-dependent uptake studies were performed using the 64Cu radiolabelled ...

2010-01-01

356

New Insights into the Design of Inhibitors of Human S-Adenosylmethionine Decarboxylase: Studies of Adenine C[superscript 8] Substitution in Structural Analogues of S-Adenosylmethionine

Monovalent cation-induced structure of telomeric DNA: The G-quartet model

S-Adenosylmethionine decarboxylase (AdoMetDC) is a critical enzyme in the polyamine biosynthetic pathway and depends on a pyruvoyl group for the decarboxylation process. The crystal structures of the enzyme with various inhibitors at the active site have shown that the adenine base of the ligands adopts an unusual syn conformation when bound to the enzyme. To determine whether compounds that favor the syn conformation in solution would be more potent AdoMetDC inhibitors, several series of AdoMet substrate analogues with a variety of substituents at the 8-position of adenine were synthesized and analyzed for their ability to inhibit hAdoMetDC. The biochemical analysis indicated that an 8-methyl substituent resulted in more potent inhibitors, yet most other 8-substitutions provided no benefit over the parent compound. To understand these results, we used computational modeling and X-ray crystallography to study C{sup 8}-substituted adenine analogues bound in the ...

2009-04-02

357

Microaerophilic growth and induction of the photosynthetic reaction center in Rhodopseudomonas viridis

We have investigated the structures formed by oligonucleotides composed of two or four repeats of the telomeric sequences from Oxytricha and Tetrahymena. The Oxytricha four-repeat molecule (d(T4G4)4 = Oxy-4) forms structures with increased electrophoretic mobility in nondenaturing gels containing Na+, K+, or Cs+, but not in gels containing Li+ or no added salt. Formation of the folded structure results in protection of a set of dG's from methylation by dimethyl sulfate. Efficient UV-induced cross-links are observed in Oxy-4 and the related sequence from Tetrahymena (d(T2G4)4 = Tet-4), and join thymidine residues in different repeats. Models proposed to account for these data involve G-quartets, hydrogen-bonded structures formed from four guanosine residues in a square-planar array. We propose that the G-quartet structure must be dealt with in vivo by the telomere replication machinery.

1989-12-01

358

Mechanism of biosorption of Heavy metals by mucor rouxii

Rhodopseudomonas viridis was grown in liquid culture at 30 degrees C anaerobically in light (generation time, 13 h) and under microaerophilic growth conditions in the dark (generation time, 24 h). The bacterium could be cloned at the same temperature anaerobically in light (1 week) and aerobically in the dark (3 to 4 weeks) if oxygen was limited to 0.1%. Oxygen could not be replaced by dimethyl sulfoxide, potassium nitrate, or sodium nitrite as a terminal electron acceptor. No growth was observed anaerobically in darkness or in the light when air was present. A variety of additional carbon sources were used to supplement the standard succinate medium, but enhanced stationary-phase cell density was observed only with glucose. Conditions for induction of the photosynthetic reaction center upon the change from microaerophilic to phototrophic growth conditions were investigated and optimized for a mutant functionally defective in phototrophic growth. R. viridis consumed about 20-fold its ...

1989-05-01

359

Iofetamine HCI {sup 123}I (IMP)

Fungi such as Aspergillus niger and Mucor rouxii are capable of removing heavy metals from aqueous solutions. The role various functional groups play in the cell wall of M. rouxii in metal biosorption of lead, cadmium, nickel and zinc was investigated in this paper. The biomass was chemically treated to modify the functional carboxyl, amino and phosphate groups. These modifications were examined by means of infrared spectroscopy. It was found that an esterification of the carboxyl groups and phosphate and a methylation of the amine groups significantly decreased the biosorption of the heavy metals studied. Thus, the carboxylate, amine and phosphate groups were recognized as important in the biosorption of metal ions by M. rouxii biomass. The role the lipids fraction play was not significant. The study showed that Na, K, Ca and Mg ions were released from the biomass after biosorption of Pb,Cd,Ni and Zn, indicating that ion exchange was a key mechanism in the ...

2008-08-15

360

Interaction of cis-diamminediaquoplatinum(II) with adenosylcobalamin and alkylcobalamins

Iofetamine HCI {sup 123}I is the generic name for the hydrochloride salt of N-isopropyl-p-iodoamphetamine labeled with {sup 123}I, commonly called IMP. Iofetamine HCI {sup 123}I is prepared by isotopic exchange with [{sup 123}I]Nal and is formulated in isotonic aqueous NaCl solution containing 1 mCi/ml iofetamine HCI I 123, 0.15 mg/ml iofetamine HCI carrier, and phosphate buffer for pH control. The radiochemical purity is >97%, and the product is stable for more than 24 hours; the commercial product distributed today is prepared with high purity {sup 123}I with >98% radionuclidic purity. Two radioiodinated agents have seen significant clinical application for functional brain imaging: iofetamine HCI (IMP) (1) and N,N,N{prime}-trimethyl-N{prime}-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine HIPDM (2). lofetamine HCI {sup 123}I is commercially available in the United States, Europe, and Japan. Although their primary use is for functional brain imaging, ...

1991-12-31

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361

Influence of potassium fluoride on the syntheses of methylpiperazine-modified poly(vinyl chloride)s for use as fixed-site proton carrier membranes.

The interaction of cis-diamminediaquoplatinum(II) nitrate with adenosylcobalamin and a series of alkylcobalamins was studied by carbon-13 nuclear magnetic resonance spectroscopy and by electronic spectroscopy. With these cobalamins cis-(Pt(NH/sub 3/)/sub 2/(OH/sub 2/)/sub 2/)/sup 2 +/ forms adducts in which N(3) of the 5,6-methylbenzimidazole moiety is co-ordinated to platinum(II) rather than to cobalt(III) of the corrin. The chemical shifts of the 5'-methylene carbon of adenosylcobalamin-platinum adduct and of the Co-methyl carbon of the methylcobalamin-platinum adduct are characteristic of these cobalamins in the base-off form. Furthermore, these cobalamin-platinum complexes have visible spectra identical to those of the cobalamins in acidic solution. The /sup 13/C NMR spectrum of the adenosylcobalamin-platinum complex suggests the presence of a second adduct in which platinum(II) complexes are co-ordinated to both the N(3) of the ...

1980-01-01

362

Induction of mutation in Trichoderma viride for conversion of natural cellulose into glucose

Aminated poly(vinyl chloride) (PVC) membranes were prepared that had a Nernstian response over a wide range of pH. The reaction between PVC and methyl-piperazine (MePIP) in dimethylformamide (DMF) was studied over a wide range of time and temperature, and in the presence of the catalyst, potassium fluoride (KF). Time, temperature, and KF increased the nitrogen (N) content of the resulting polymers, but sometimes at the expense of decreasing their specific viscosities (molecular weights). Activation energies of processes that occurred in different temperature ranges were estimated assuming an Arrhenius relationship. A Nernstian response occurred once the N content approached to about 0.3 w/w %, and was accelerated by the presence of KF at elevated temperatures. Increasing the N content above about 3% led to a loss of the Nernstian response either because of an increase in the double bond content and a subsequent decrease in polymer mobility, or because of a decrease ...

1998-03-15

363

In situ studies of imidazole and its derivatives as copper corrosion inhibitors. I. Activation energies and thermodynamics of adsorption

The production of cellulolytic enzymes from fungi has been extensively studied. Several mutants of Trichoderma reesei were selected. Most of the studies were carried out on T. reesei, T. viride, T. harzianum, Penicillium funiculosum, Altemaria alternata. Aspergillus phoenicis, A. ustus, A. tamarii, A. japonicus, and A. niger. T. koningii is one of the most active producers of the so-called C, factor, which is indispensable for the rapid and extensive attack on crystal-line cellulose. However, Trichodenna is known to excrete only small amounts of {beta}-glucosidase. Therefore, Trichoderma is supplemented with {beta}-glucosidase from Aspergillus to increase the saccharification rate of cellulose to glucose as the main sugar. Induction of mutations in Trichodenna spp. rather than T. viride as a tool for the enhancement of {beta}-glucosidase activity was reported. Unfortunately, T. reesei is a poor producer of {beta}-glucosidase. On the other hand, T. harzianum M{sub 5}, a mutant that was ...

1991-12-31

364

In situ and ex situ studies of imidazole and its derivatives as copper corrosion inhibitors. 2. AC impedance, XPS, and SIMS studies

The objective of this work was to investigate the efficiency of imidazole and its derivatives 4-methylimidazone, 4-methyl-5-hydroxymethylimidazone, 1-phenyl-4-methylimidazone, and 1-(p-tolyl)-4-methylimidazole for corrosion inhibition of copper in 0.5 M hydrochloric acid. Corrosion inhibition was studied using potentiodynamic methods. These studies have shown that 1-(p-tolyl)-4-methylimidazole has the best inhibitory efficiency. Activation energies were obtained by measuring the temperature dependence of the corrosion current. The activation energies in the presence of the various inhibitors are low (3--5 kJ/mol), with the best inhibitor showing the highest value. The adsorptive behavior of the imidazole derivatives on the copper electrode surface follows a Freundlich-type isotherm. The standard free energies of adsorption are also low (14--16 kJ/mol), indicating that imidazole and its derivatives physisorb on the copper surface. Possible mechanisms of corrosion ...

2000-02-01

365

Hexene catalytic cracking over 30% sapo-34 catalyst for propylene maximization: influence of reaction conditions and reaction pathway exploration

The objective of this work was to investigate the efficiency of imidazole derivatives for corrosion inhibition of copper in 0.5 M hydrochloric acid. Corrosion inhibition was studied using impedance spectroscopy. Imidazole and its derivatives 4-methylimida-zole, 4-methyl-5-hydroxymethylimidazole, 1-phenyl-4-methylimidazole, 1-(p-tolyl)-4-methylimidazole were investigated. These studies have shown that 1-(p-tolyl)-4-methylimidazole is the best inhibitor in this series and that it acts as mixed inhibitor. The nature of the chemical interaction between these molecules and the copper surface was investigated by Cu exposed to solutions having two very different pH values: 0.5 M HCl and unbuffered purified water. X-ray photoelectron spectroscopy and secondary ion mass spectrometry were used to explore the nature of the interaction. Possible mechanisms of corrosion inhibition for these molecules are discussed.

2000-03-01

366

Scientific Electronic Library Online (English)

Abstract in english Higher olefins are produced as a by product in a number of refinery processes and are one of the potential raw materials to produce propylene. In the present study, FCC model feed compound was considered to explore the olefin cracking features and options to enhance propylene using 30% SAPO-34 zeolite as catalyst in a micro-reactor. The superior selectivity of propylene (73 wt%) and higher total olefin selectivity was obtained over 30% SAPO-34 catalyst than over Y or ZSM- (more) 5 zeolite catalysts. The thermodynamical constraints were found to be relatively less serious in the case of 1-hexene conversion. Most of the 1-hexene follows a direct cracking pathway to give two propylene molecules, due to weak acid sites and better diffusion opportunities. The higher temperature and short residence time could also suppress the hydrogen transfer reactions. From OPE (olefins performance envelop) the products were classified as primary, secondary, or both. Iso-hexene ...

2009-12-01

367

Henry`s law gas-solid chromatography and correlations of virial coefficients for hydrocarbons, chlorofluorocarbons, ethers, and sulfur hexafluoride adsorbed onto carbon

Grafting of wood pulp with thermoplastic sidechains to make wood/plastic composites

Gas-solid chromatography was used to determine the Henry`s law second gas-solid virial coefficients within the temperature range of 314--615 K for ethane, propane, butane, isobutane, pentane, hexane, heptane, chloromethane, dichloromethane, trichloromethane, tetrachloromethane, trichlorofluoromethane (Freon 11), chlorodifluoromethane (Freon 22), dichlorodifluoromethane (Freon 12), methyl ether, ethyl ether, and sulfur hexafluoride with Carbopack B, a microporous carbon adsorbent. The temperature dependence of the second gas-solid virial coefficients of these adsorbates was used in conjunction with analyses based on a graphical method, a single-surface numeric integration method, a single-surface analytic expression method, and a two-surface analytic expression method to determine the gas-solid interaction energies and other parameters. The interaction energies were correlated with a ratio of the critical temperature divided by the square root of the critical ...

1995-07-01

368

Foam for combating mine fires

A method of grafting lignin-containing materials is now known which allows 1-phenylethylene or 4-methyl-2-oxy-3-oxopent-4-ene graft copolymers of wood to be quantitatively made. Graft copolymer is formed by conducting a free-radical polymerization with 1-phenylethene in nitrogen-saturated, organic or aqueous/organic solvent containing a lignin source, calcium chloride, and a hydroperoxide. Grafting changes solubility and surface properties of the wood. The lignin-containing materials grafted are unbleached wood pulps produced by chemical, thermal, and mechanical pulping. Grafting wood pulp produces a wood-reinforced, thermoplastic composite. When a particular plastic is to be blended with wood, we react the wood with the monomer used to make that plastic. This creates a hydrophobic surface of the plastic on the wood. This plastic coating can readily bond to the continuous plastic phase. The products of this grafting reaction are thermoplastic composites with ...

1995-12-01

369

Expression of ribosomal genes in pea cotyledons at the initial stages of germination

The application of foam in dealing with underground fire is well known due to its smothering action by cutting off air feed to burning fuel as well as acting as coolant. Besides plugging air feed to fire, water could be virtually reached to the fire affected areas much beyond the jet range as underground galleries with low roof restrict jet range of water. This method also enables a closer approach of a fire fighting team by isolating the toxic gases and smoke with a foam plug. The paper describes the development of high expansion foam composition and its application technology in order that foam plug method can be suitably utilized for combating mine fires in India. Three compositions were recommended for generation of high expansion foam: (a) 0.5% sodium/ammonium lauryl sulphate, 0.15 to 0.2% sodium carboxy methyl cellulose, 0.1% booster; (b) 0.5% sodium/ammonium lauryl sulfate, 0.12 to 0.15% alkaline solution of gum arabic, 0.1 to 0.2% ferrous gluconate; and (c) ...

1989-09-01

370

Evidence of minimal methanogenic numbers and activity in sediments collected from the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate production research well

The time of appearance of newly synthesized rRNAs and ribosomal proteins (r-proteins) in the ribosomes of pea cotyledons (Pisum sativum L.) during germination was investigated. The ribosomal fraction was isolated and analyzed according to the method of germination of the embryo in the presence of labeled precursors or after pulse labeling of the embryos at different stages of germination. For the identification of newly synthesized rRNAs in the ribosomes we estimated the relative stability of labeled RNAs to the action of RNase, the sedimentation rate, the ability to be methylated in vivo in the presence of (/sup 14/C)CH/sub 3/-methionine, and the localization in the subunits of dissociated ribosomes. The presence of newly synthesized r-proteins in the ribosomes was judged on the basis of the electrophoretic similarity in SDS-disc electrophoresis of labeled polypeptides of purified ribosome preparations and of genuine r-proteins, as well as according to the ...

1986-01-20

371

Evaluation of small-angle neutron scattering curves of unilamellar phosphatidylcholine liposomes using a multi shell model of bilayer neutron scattering length density

Gene analysis was used to determined the presence, abundance and phylogenetic affiliation of methanogens that exist in gas-hydrate-bearing sediment samples obtained from 23 drill cores from the JAPEX/JNOC/GSC et al. Mallik 5L-38 gas hydrate research well. Rates of methane production were examined using sediment-inoculated enrichments containing {sup 14}C-labeled carbon substrates, carbon dioxide and acetate. Archaeal 16S rDNA was only detected in 6 of the samples, resulting in 8 sequences with relationships to the Miscellaneous Crenarchaeotic Group (7 clones) and the Subsurface Euryarchaeotic Group (1 clone). The single Euryarchaeota sequence did not appear to be related to methanogens. Subsamples from the cores showed variable results upon DNA extraction and amplification. Methanogenic Coenzyme M (CoM) was detected in 13 of the 20 cores, but methanogenic methyl CoM reductase genes were not amplified from the samples when using a sensitive quantitative polymerase ...

2005-07-01

372

Enhancement of N-nitrosamine formation on granular-activated carbon from N-methylaniline and nitrite

Computer simulated small-angle neutron scattering curves of spherical poly disperse extruded unilamellar liposomes from saturated 1,2-diacylphosphatidylcholines in the aqueous phase are evaluated by using a multi shell model, which divides the lipid bilayer of liposomes into the polar head group region, and the nonpolar hydrocarbon region consisting of the chains of methylene groups and of the region of methyl groups. In the each of these regions, the coherent neutron scattering length density is supposed to by homogeneous. The evaluation is based on obtaining of radius of gyration from Kratky-Porod plot of small-angle neutron scattering data in the Guinier region of small scattering vector values. From radii of gyration obtained at several different molar fractions N_D_2_O/(N_D-2_O + N_H_2_O) in the aqueous phase (contrasts) and independent volumetric data, the lipid surface area A_L (or the bilayer thickness d_L) and the number of water molecules N_L penetrated ...

2000-12-15

373

Effects of the structural nature of the anionic additives on the rheological behavior of bentonite suspensions; Effets de la nature structurelle des additifs anioniques sur le comportement rheologique de suspensions de bentonite

Sterile aqueous N-methylaniline solutions were allowed to equilibrate at various nitrite, F-400 granular-activated carbon, and pH levels for 1 week. The aqueous and activated carbon phases were extracted and analyzed for nitrosamines relative to an added internal standard. Selected ion monitoring GC/MS, utilizing continuous monitoring of the NO/sup +/ ion (m/z 29.9980) characteristic of nitrosamines, at medium resolution (R = 2500-3000) was applied to quantitatively measure nitrosamines at picograms per microliter concentrations. This method selected for nitrosamine products only and eliminated interferences from non-nitrosamine reaction products. Results indicate that the pressure of granular-activated carbon significantly enhanced the formation of nitrosamine from N-methyl-aniline (F = 145, P< 0.0001). The amount of N-nitrosomethylaniline formed in the presence of activated carbon was 75 times more than that formed in the absence of activated carbon under the ...

1986-10-01

374

Effects of ionizing radiation on properties of monolayer and multilayer flexible food packaging materials

Different experimental measurements (Theology, granulometry, XRD) were carried out in order to study the main properties of bentonite suspensions in presence of anionic additives at different concentrations. These additives are: Sodium Dodecyl Sulfate (SDS) as surfactant, a flexible polymer (Sodium Carboxy Methyl Cellulose, CMC) and a semi-rigid polymer (Xanthan gum). It has been shown that the structural nature of anionic additive influences directly the mixtures viscoelastic and flow behavior. The steric effect of the surfactant modifies the Face-Edge interactions and yields changes of the mixtures rheological behavior at low deformation rates. Polymers act by coating each clay particle and prevent their agglomeration. Therefore, bentonite has no direct effect on the rheological behavior of the mixtures: the additives are responsible for the mechanisms of de-structuration and structure reorganization as well as the mixtures viscous and viscoelastic behavior. ...

2005-07-01

375

Effects of comonomer and two-step oxidation on production of polyacrylonitrile-based carbon fibers. Polyacrylonitrile kei tanso sen'i no seizo ni okeru sanka jikan ni oyobosu zenkutai sen'i no kyojugo seibun oyobi dankai sanka no koka

Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap technique and identified by combined gas chromatography-mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon irradiation. These products may affect organoleptic properties and thus shelf-life of prepackaged irradiated foods. ...

1999-05-01

376

Design, synthesis and evaluation of redox radiopharmaceuticals: a potential new approach for the development of brain imaging agents

The oxidation conditions were investigated for obtaining a higher productivity in the production of high strength carbon fiber from polyacrylonitrile (PAN). The effect of incorporation of 2 % comonomer such as methyl acrylate (MA), acrylate containing carboxylate (SA), acrylamide (AAm), and hydroxyethyl acrylate (HEA) on the oxidation conditions was also investigated. The measurement of DSC and bonded oxygen content revealed that the most effective comonomer for promoting the cyclization of nitril group and the bonding of oxygen was found to be SA, and the second best was AAm. The measurement of tensile strength of carbon fiber showed that the copolymer of SA, HEA, and MA gave a high strength fiber. It took a long time to oxidize the carbon fiber when it was oxidized at a temperature on which double layer structure was not formed. To shorten the production time, a method of combining the upper limit oxidation in which the double layer structure was not formed and ...

1994-06-10

377

Cellulose as a binding material in graphitic anodes for Li ion batteries: a performance and degradation study

The fabrication and complete evaluation are described of a dihydropyridine in equilibrium pyridinium salt type redox system for the delivery of radioiodinated agents to the brain. The pivotal intermediate, N-succinimidyl (1-methylpyridinium iodide)-3-carboxylate was prepared by condensation of nicotinic acid and N-hydroxysuccinimide in the presence of dicyclohexylcarbodimide, followed by quaternization of III with methyl iodide. Tissue distribution studies of "1"2"5I-labeled 4-iodoaniline and the redox agents were performed in rats. ["1"2"5I]Iodoaniline initially showed moderate (0.58% dose/gm) brain uptake with subsequent release of the radioactivity from the brain. ["1"2"5I]Iodoaniline, when coupled to a dihydropyridine carrier showed higher uptake and retention in the brain. The ["1"2"5I]iodophenylethyl analogue showed uptake and retention in the brain to be very similar. Apparently the lipophilic agents cross the blood-brain barrier and are oxidized ...

378

Bis(acetylacetonato)ruthenium Complexes of Noninnocent 1,2-Dioxolene Ligands: Qualitatively Different Bonding in Relation to Monoimino and Diimino Analogues

Four types of cellulose, in particular carboxy methyl cellulose (CMC), are tested as potential binding materials in graphitic anodes for lithium ion batteries. It is shown that a minimum content of a cellulose which gives acceptable anode properties (reversible capacity > 300 mA hg{sup -1} during the first 10 cycles, irreversible loss < 20%) is about 2 wt.%, which is less than in the case of conventional polymeric binders (5-10 wt.%). Kinetics of insertion-deinsertion and passivation processes seem not to be affected by the presence of cellulose. Explanation for the electrode failure at cellulose contents lower than 1 wt.% is given based on X-ray diffraction and microscopy investigations. Finally, the structure (distribution) of cellulose in the composite anode material is discussed and (indirectly) checked with a series of experiments. Most results are compared with the corresponding results obtained either with gelatin or conventional polymeric ...

2003-02-20

379

British Library Electronic Table of Contents (United Kingdom)

Abstract Coordination compounds [Ru(acac)2(Q)] (acac=acetylacetonate; Q=o-benzoquinone) were prepared as complexes 1 (Q=o-benzoquinone), 2 (Q=3-methoxy-o-benzoquinone), 3 (Q=4-methyl-o-benzoquinone), and 4 (Q=3,5-di-tert-butyl-o-benzoquinone). The structures of 1 and 2 were determined to reveal a RuIII/o-benzosemiquinone formulation, supported by analysis of experimental data (spectroscopy, magnetism of 1) and by DFT calculations. The S=1 ground state calculated for 1 stands in contrast to the spin-paired analogues with arylimino-o-benzosemiquinonato and diimino-o-benzoquinone ligands. The close contacts of about 5.3- possible between semiquinone O atoms of different molecules in the crystal allow for intermolecular spin-spin interactions and an overall complex magnetic behavior. One quasi...

2011-01-01

380

Binary copper(II) and uranyl(VI) complexes of glycocyamine, taurine and pyridoxal and ternary complexes involving 2,2'-bipyridine, 1,10-phenanthroline or nitrilotriacetic acid

Benzyl carbamyl analogue of lignocaine: vasodepressor mechanism of action.

Chelating tendencies of several biologically important compounds viz. glycocyamine (GCN: N-amidino-aminoethanoic acid) taurine (TRN: 2-aminoethanesulphonic acid) and pyridoxal [PDL: 3-hydroxy-5-(hydroxymethyl)-2-methyl-pyridine-4-carbaldehyde] have been examined by pH-metric titration technique in their binary complex formation with copper(II) and uranyl(VI) ions. The work has further been extended to investigating the ternary complex formation involving 2.2'-bipyridine. 1,10-phenanthroline or nitrilotriacetic acid as a primary and TRN and PDL as secondary ligands. All the experiments were carried out at 25"0C and at an ionic strength of 0.1M (NaCl0_4) in aqueous or 50% (v/v) aqueous-ethanol medium according to the suitability of the experimental conditions. Stabilities of ternary complexes as compared to those of the corresponding binary complexes of the secondary ligands have also been discussed. (author).

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

381

Atmospheric lifetimes and ozone depletion potentials of methyl bromide (CH3Br) and dibromomethane (CH2Br2)

1. The benzyl carbamyl analogue of lignocaine [2-(diethylaminoacetamido)-3-carbamyl-4-methyl-5-benzylpyrrole] at an intravenous dose of 4 mg/kg caused a blood pressure decrease of 54 mmHg. 2. A greater hypotensive effect was observed in hypertensive compared to normotensive animals. Anaesthesia magnified the vasodepressor effect in both groups. 3. The analogue did not possess centrally-mediated effects on blood pressure but exerted its hypotensive effect via a peripheral mechanism. 4. The analogue produced a relaxant effect on intestinal and vascular smooth muscle while exerting minimal effects on muscarinic, sympathetic, or ganglionic nicotinic receptors. 5. The analogue exhibited less cardiac depressant action on left ventricular rate (dp/dt) and force of contraction than lignocaine. 6. Lethal effects for the analogue were first observed at 16 mg/kg following intravenous administration and at 500 mg/kg following intraperitoneal administration. 7. In conclusion, ...

382

A phase 1 study of BMS-275183, a novel oral analogue of paclitaxel given on a daily schedule to patients with advanced malignancies

The rate coefficients for the reactions of OH radical with CH3Br and CH2Br2 were measured as functions of temperature using the laser photolysis - laser induced fluorescence method. This data was incorporated into a semiempirical model (Solomon et al., 1992) and a 2D model to calculate the steady-state ozone depletion potentials (ODP) and atmospheri lifetimes, tau, with greatly improved accuracy as compared to earlier studies. The calculated ODPs and tau are 0.65 and 1.7 years and 0.17 and 0.41 years for CH3Br and CH2Br2, respectively, using the semiempirical model. These lifetimes agree well with those calculated using a 2D model. This study better quantifies the ODPs and tau of these species which are needed inputs for discussion of possible regulation of human emissions currently under international considerations. 29 refs.

1992-10-01

383

British Library Electronic Table of Contents (United Kingdom)

Summary Purpose BMS-275183 is an oral C-4 methyl carbonate analogue of paclitaxel that has the same mechanism of action, stabilization of tubulin polymerization. The present study was designed to: (i) assess the safety and tolerability of BMS-275183, and (ii) determine a suitable Phase II dose of BMS-275183 when given on a continuous daily schedule to patients with advanced solid tumor(s). Methods This was a multi-institutional, open-label, Phase I, single-arm dose escalation study in which cohorts of eligible patients with advanced malignancies were treated with BMS-275183 orally on a continuous daily schedule. The starting dose level was 6?mg/m2/day administered once daily. Cohorts of 3 patients were treated at each dose level provided no dose-limiting toxicities (DLTs) were observed. Ea...

2011-01-01

384

A computational fluid dynamics investigation of fluid flow in a dense medium plasma reactor

3-["1"2"3I]Iodo-L-#alpha#-methyl tyrosine transport into human fibroblasts and comparison with Ewing's sarcoma cells

Computational fluid dynamics are applied to the study of three-dimensional fluid flow in a dense medium plasma reactor (DMPR) under different operating conditions. Reaction mechanisms and rates for the removal of methyl t-butyl ether (MTBE) in a DMPR are developed from experimental data to determine the plasma volume, the rate of interphase mass transfer and the photolysis rate of MTBE via UV emission from the plasma. The simulations utilize the plasma volume determined from the kinetic data to show that the volume of fluid in contact with the plasma in the DMPR only constitutes a maximum of approximately 10% of the fluid intended to be cycled through the plasma tubules. The simulations also predict appreciable pressure gradients on the surface of the pin electrodes, resulting in a small discharge area located away from the region in which the electric field strength is a maximum. This result has been confirmed indirectly through observation in that the pin ...

2007-01-21

385

Local chromatin structure of heterochromatin regulates repeatedDNA stability, nucleolus structure, and genome integrity

The cellular transport systems and the transport kinetics of ["1"2"3I]IMT uptake into non-malignant extracranial cells were characterized for the first time. Human fibroblasts were chosen as non-malignant extracranial cells as they are found ubiquitous in the body. ["1"2"3I]IMT is exclusively transported into fibroblasts via the sodium independent system L. An apparent Michaelis constant K_m=116.2#+-#18.9 #mu#M and a maximum transport velocity V_m_a_x=191.6#+-#13.9 pmol * (10"6 cells)"-"1 * min"-"1 were calculated for the sodium-independent transport. These results were compared with those determined in two malignantly transformed extracranial cell lines, the human Ewing's sarcoma cell lines VH-64 and CADO-ES-1.

2002-05-01

386

Fatty acid/poly(methyl methacrylate) (PMMA) blends as form-stable phase change materials for latent heat thermal energy storage

Heterochromatin constitutes a significant portion of the genome in higher eukaryotes; approximately 30% in Drosophila and human. Heterochromatin contains a high repeat DNA content and a low density of protein-encoding genes. In contrast, euchromatin is composed mostly of unique sequences and contains the majority of single-copy genes. Genetic and cytological studies demonstrated that heterochromatin exhibits regulatory roles in chromosome organization, centromere function and telomere protection. As an epigenetically regulated structure, heterochromatin formation is not defined by any DNA sequence consensus. Heterochromatin is characterized by its association with nucleosomes containing methylated-lysine 9 of histone H3 (H3K9me), heterochromatin protein 1 (HP1) that binds H3K9me, and Su(var)3-9, which methylates H3K9 and binds HP1. Heterochromatin formation and functions are influenced by HP1, Su(var)3-9, and the RNA interference (RNAi) ...

2007-05-05

387

Water in polymer membranes. 4. Raman scattering from cellulose acetate films

Fatty acids such as stearic acid (SA), palmitic acid (PA), myristic acid (MA), and lauric acid (LA) are promising phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications, but high cost is the most drawback which limits the utility area of them in thermal energy storage. The use of fatty acids as form-stable PCM will increase their feasibilities in practical LHTES applications due to reduced cost of the energy storage system. In this regard, a series of fatty acid/poly(methyl methacrylate) (PMMA) blends, SA/PMMA, PA/PMMA, MA/PMMA, and LA/PMMA were prepared as new kinds of form-stable PCMs by encapsulation of fatty acids into PMMA which acts as supporting material. The blends were prepared at different mass fractions of fatty acids (50, 60, 70, 80, and 90% w/w) to reach maximum encapsulation ratio. All blends were subjected to leakage test by heating the blends over the melting temperature of the PCM. The blends that do not allow ...

2008-02-15

388

Vitamins B2 and B6 and genetic polymorphisms related to one-carbon metabolism as risk factors for gastric adenocarcinoma in the European prospective investigation into cancer and nutrition

Raman scattering was observed from thin film optical waveguides of cellulose acetate exposed to water vapor from 0% to 100% relative humidity (RH), and from dilute solutions of water in methyl acetate. Spectra of cellulose acetate (CA398, 39.8% acetyl) at low RH and cellulose triacetate (CTA) at low and high RH are consistent with the presence of water monomers that are weakly hydrogen bonded to acetyl C=O groups. Differences between the spectra of water in CA398 and CTA at low RH are attributed to sequential hydrogen bonding involving OH groups in CA398. At high RH, CA398 and CTA (to a lesser extent) show bands attributed to water/water interactions that are similar to those found in sequentially hydrogen-bonded hydrates. CA398 films that are annealed at high temperatures exhibit decreased water/water interactions at high RH. Exposure of CA398 films to D/sub 2/O converts > 90% of all polymer OH groups to OD groups. This indicates that water is accessible to ...

1985-01-17

389

DEFF Research Database (Denmark)

B vitamins and polymorphisms in genes coding for enzymes involved in one-carbon metabolism may affect DNA synthesis and methylation and thereby be implicated in carcinogenesis. Previous data on vitamins B2 and B6 and genetic polymorphisms other than those involving MTHFR as risk factors for gastric cancer (GC) are sparse and inconsistent. In this case-control study nested within the European Prospective Investigation into Cancer and Nutrition cohort, cases (n = 235) and controls (n = 601) were matched for study center, age, sex, and time of blood sampling. B2 and B6 species were measured in plasma, and the sum of riboflavin and flavin mononucleotide was used as the main exposure variable for vitamin B2 status, whereas the sum of pyridoxal 5'-phosphate, pyridoxal, and 4-pyridoxic acid was used to define vitamin B6 status. In addition, we determined eight polymorphisms related to one-carbon metabolism. Relative risks for GC risk were calculated with conditional ...

2010-01-01

390

Turnover of whole body proteins and myofibrillar proteins in middle-aged active men

Theoretical study on antitumor activity of palladium(II) and platinum(II) complexes with isoxazole and its derivatives

Endurance-trained older men have a higher proportion of lean tissue and greater muscle cell oxidative capacity, reversing age-related trends and suggesting major changes in protein metabolism. In this study, protein turnover was determined in 6 middle-aged (52+/-1 yr) men who were well trained (VO_2 max 55.2+/-5.0 ml O_2/kg.min) and lean (body fat 18.9+/-2.8%, muscle mass 36.6+/-0.6%). The maintained habitual exercise while consuming 0.6, 0.9 or 1.2 g protein/kg.day for 10-day periods. N flux was measured from "1"5N in urea after oral "1"5N-glycine administration. Myofibrillar protein breakdown was estimated from urinary 3-methyl-histidine. Dietary protein had no effect on turnover rates, even when N balance was negative. Whole body protein synthesis was 3.60+/-0.12 g/kg.day and breakdown was 3.40+/-0.14 g/kg.day for all N intakes. Whole body protein flux, synthesis and breakdown were similar to values reported for sedentary young (SY) or sedentary old (SO) men on ...

1986-04-13

391

The relationship of urinary metabolites of carbaryl/naphthalene and chlorpyrifos with human semen quality.

The palladium(II) and platinum(II)complexes(where, (M(L){sub 2}X{sub 2}), M=Pd(II), Pt(II); L=isoxazole (isox), 3, 5-dimethylisoxazole(3, 5-diMeisox), 3-methyl, 5-phenylisoxazole(3-Me, 5-Ph-isox), and 4-amino-3, 5-di-methylisoxazole (4-ADI); X=Cl, Br) with isoxazole and its derivatives were investigated on antitumor activity by MM2 and EHMO calculation. Because for all the complexes the {sigma}MO energy level (E{sub {sigma}}{sub (M-X)} between d{sub x}{sup 2}{sub -y}{sup 2} orbital of central metal and p{sub x} orbital of halogen atom is less than {sigma}MO energy level E{sub {sigma}}{sub (M-N)} between d{sub x}{sup 2}{sub -y}{sup 2} orbital of central metal and p{sub x} orbital of N atom, without exception. And judging, from the lower E{sub {sigma}}{sub (M-X)} value in trans, the bonding strength was found to be weaker in trans isomer than in cis. For the Pd(II) and Pt(II) complexes which have planar ligands, it was shown that for all the complexes dissociation of ...

1998-02-01

392

Synthesis, crystal structure, spectroscopic and photoluminescence studies of manganese(II), cobalt(II), cadmium(II), zinc(II) and copper(II) complexes with a pyrazole derived Schiff base ligand

Most of the general population is exposed to carbaryl and other contemporary-use insecticides at low levels. Studies of laboratory animals, in addition to limited human data, show an association between carbaryl exposure and decreased semen quality. In the present study we explored whether environmental exposures to 1-naphthol (1N), a metabolite of carbaryl and naphthalene, and 3,5,6-trichloro-2-pyridinol (TCPY), a metabolite of chlorpyrifos and chlorpyrifos-methyl, are associated with decreased semen quality in humans. Subjects (n=272) were recruited through a Massachusetts infertility clinic. Individual exposures were measured as spot urinary concentrations of 1N and TCPY adjusted using specific gravity. Semen quality was assessed as sperm concentration, percent motile sperm, and percent sperm with normal morphology, along with sperm motion parameters (straight-line velocity, curvilinear velocity, and linearity). Median TCPY and 1N concentrations were 3.22 and ...

2004-12-01

393

British Library Electronic Table of Contents (United Kingdom)

Varying coordination modes of the Schiff base ligand H"2L [5-methyl-1-H-pyrazole-3-carboxylic acid (1-pyridin-2-yl-ethylidene)-hydrazide] towards different metal centers are reported with the syntheses and characterization of four mononuclear Mn(II), Co(II), Cd(II) and Zn(II) complexes, [Mn(H"2L)(H"2O)"2](ClO"4)"2(MeOH) (1), [Co(H"2L)(NCS)"2] (2), [Cd(H"2L)(H"2O)"2](ClO"4)"2 (3) and [Zn(H"2L)(H"2O)"2](ClO"4)"2 (4), and a binuclear Cu(II) complex, [Cu"2(L)"2](ClO"4)"2 (5). In the complexes 1-4 the neutral ligand serves as a 3N,2O donor where the pyridine ring N, two azomethine N and two carbohydrazine oxygen atoms are coordinatively active, leaving the pyrazole-N atoms inactive. In the case of complex 5, each ligand molecule behaves as a 4N,O donor utilizing the pyridine N, one azomethine N...

2011-01-01

394

Synthesis, characterization, and evaluation of a novel bifunctional chelating agent for the lead isotopes {sup 203}Pb and {sup 212}Pb

Synthesis, characterization, and evaluation of a novel bifunctional chelating agent for the lead isotopes "2"0"3Pb and "2"1"2Pb

Radioisotopes of Pb(II) have been of some interest in radioimmunotherapy and radioimmunoimaging (RII). However, the absence of a kinetically stable bifunctional chelating agent for Pb(II) has hampered its use for these applications. {sup 203}Pb (T{sub 1/2}=52.02 h) has application potential in RII, with a {gamma}-emission that is ideal for single photon emission computerized tomography, whereas {sup 212}Pb (T{sub 1/2}=10 h) is a source of highly cytotoxic {alpha}-particles via its decay to its {sup 212}Bi (T{sub 1/2}=60 min) daughter. The synthesis of the novel bifunctional chelating agent 2-(4-isothiocyanotobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoyl methyl)-cyclododecane (4-NCS-Bz-TCMC) is reported herein. The Pb[TCMC]{sup 2+} complex was less labile to metal ion release than Pb[DOTA]{sup 2-} at pH 3.5 and below in isotopic exchange experiments. In addition to increased stability to Pb{sup 2+} ion release at low pH, the bifunctional TCMC ligand was ...

2000-01-01

395

Synthesis of c-axis preferred orientation ZnO:Al transparent conductive thin films using a novel solvent method

Radioisotopes of Pb(II) have been of some interest in radioimmunotherapy and radioimmunoimaging (RII). However, the absence of a kinetically stable bifunctional chelating agent for Pb(II) has hampered its use for these applications. "2"0"3Pb (T_1_/_2=52.02 h) has application potential in RII, with a #gamma#-emission that is ideal for single photon emission computerized tomography, whereas "2"1"2Pb (T_1_/_2=10 h) is a source of highly cytotoxic #alpha#-particles via its decay to its "2"1"2Bi (T_1_/_2=60 min) daughter. The synthesis of the novel bifunctional chelating agent 2-(4-isothiocyanotobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoyl methyl)-cyclododecane (4-NCS-Bz-TCMC) is reported herein. The Pb[TCMC]"2"+ complex was less labile to metal ion release than Pb[DOTA]"2"- at pH 3.5 and below in isotopic exchange experiments. In addition to increased stability to Pb"2"+ ion release at low pH, the bifunctional TCMC ligand was found to have many other ...

2000-01-01

396

Synthesis and tissue distribution of substituted [{sup 125}I]iodophenylamine derivatives: Possible brain imaging agents

Transparent aluminum doped zinc oxide (ZnO:Al, AZO) conducting thin films with a high-preferential c-axis orientation were synthesized using a new sol-gel formula. The films were deposited using a spin-coating route onto borosilicate glass substrates. We used propylene glycol methyl ether (PGME) as the solvent in place of ethylene glycol monomethyl ether (EGME), which is commonly used because it is easier to deposit onto the substrates. PGME is also superior in terms of health and safety. PGME solvent does not need to settle for several days before use and can be spin-coated as soon as the raw material and solvent are mixed. The effects of this novel solvent on the structural, morphological, electrical and optical properties are discussed using XRD, SEM, a four-point probe and UV-VIS spectrophotometry. It was found that the films produced with PGME showed a high-preferential c-axis orientation and compact microstructure in comparison films produced using EGME. The ...

2010-09-01

397

Synthesis and tissue distribution of substituted ["1"2"5I]iodophenylamine derivatives: Possible brain imaging agents

The synthesis and brain uptake in mice of the radioidinated derivatives of N,N-dimethyl-N'-(idodimethoxyphenyl)-1,3-propanediamine, as well as the N-substituted derivatives of (iodoalkylphenyl)isopropyl, iodoalkylphenylethylamine and 3,4-(methylenedioxy)phenyl-amphetamine (MDA) are described. These compounds contain structural features of both IMP and HIPDM, the cerebral perfusion agents currently in clinical use. The radiolabeled analogs were obtained via the [{sup 125}I]I exchange method, or by [{sup 125}I]NaI treatment of the iodo-free precursor in the presence of an oxidant. Following intravenous injection in mice, all compounds showed important radioactivity concentrations in the lungs and kidneys. The N-substituted (iodoalkylphenyl)isopropyl and iodoalkylphenyl-ethylamine derivatives displayed a high initial brain uptake (>10%IDg{sup -1}) followed by a rapid clearance phase, resulting in lower brain-to-blood ratios as those reported for IMP and HIPDM. In contrast, ...

1997-02-01

398

Surface modification of LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-films by zirconium alkoxide/PMMA composites and their effects on electrochemical properties

The synthesis and brain uptake in mice of the radioidinated derivatives of N,N-dimethyl-N'-(idodimethoxyphenyl)-1,3-propanediamine, as well as the N-substituted derivatives of (iodoalkylphenyl)isopropyl, iodoalkylphenylethylamine and 3,4-(methylenedioxy)phenyl-amphetamine (MDA) are described. These compounds contain structural features of both IMP and HIPDM, the cerebral perfusion agents currently in clinical use. The radiolabeled analogs were obtained via the ["1"2"5I]I exchange method, or by ["1"2"5I]NaI treatment of the iodo-free precursor in the presence of an oxidant. Following intravenous injection in mice, all compounds showed important radioactivity concentrations in the lungs and kidneys. The N-substituted (iodoalkylphenyl)isopropyl and iodoalkylphenyl-ethylamine derivatives displayed a high initial brain uptake (>10%IDg"-"1) followed by a rapid clearance phase, resulting in lower brain-to-blood ratios as those reported for IMP and HIPDM. In contrast, ...

1997-02-01

399

Study of multiphase flow useful to understand scaleup of coal liquefaction reactors. 1981-1984 final report

Three kinds of surface modifications were carried out on LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-films to improve the charge and discharge characteristics of LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} positive electrodes. Among them, Zr(OBu){sub 4}/poly(methyl methacrylate) (PMMA)-treated LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-film electrodes showed charge and discharge efficiency of 80-84% in the first cycle, which was much higher than that for an untreated LiNi{sub 1/2}Mn{sub 3/2}O{sub 4} thin-film electrode (73%). The values of the charge and discharge efficiency were still higher than that for an untreated electrode after the 30th cycle. The charge and discharge curves gave two plateaus at around 4.72 and 4.76 V, which were very similar to those for the untreated electrode. Ac impedance spectroscopy revealed that the surface film resistance should not increase by Zr(OBu){sub 4}/PMMA treatment. XPS measurements suggest that a composite layer should be formed on a LiNi{sub ...

2008-10-15

400

Steroidal hydrocarbons of the Kishenehn Formation, northwest Montana

Research over a three year time span involved the study of multiphase flow useful to understanding the scaleup of coal liquefaction reactors. We attempted to establish the flow patterns and their boundaries in which a direct coal liquefaction, large diameter, bubble column operates. A flow map has been proposed in which coal slurry properties can be input to determine the flow pattern boundaries at reactor operating conditions. Gas holdup and bubble diameters have been measured under different conditions of gas and liquid flow rate. These have been used to determine interfacial area in bubble columns. An equation for the estimation of interfacial area in the bubble-slug flow pattern has been proposed. It has also been established that gas holdup and thus interfacial area depends strongly on the gas distribution in the column. Porous plate gas distributors can yield gas holdups twice as large as sieve plate distributors. Measurements using aqueous solutions (carboxy ...

1984-09-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

401

Root-knot nematode management in double-cropped plasticulture vegetables.

The Oligocene Kishenehn Formation of northwest Montana and southeast British Columbia consists of fluvial and lacustrine sediments (marlstones, lignites and oil shales) deposited in an elongate, intermontane half-graben. The petroleum source rock potential and steroidal hydrocarbon distribution of selected shales of the Kishenehn Formation were examined. Several steroidal hydrocarbon series were documented, including 4-desmethylsteranes, 4-methylsteranes, sterenes, diasterenes, spirosterenes, C-ring monoaromatic steroids and B-ring monoaromatic anthrasteroids. Non-steroid hydrocarbons present include hopenes, ..beta beta..-hopanes, moretanes, perylene, botryococcane, a series of alkylcyclohexanes, and a fused-ring aromatic tentatively identified as a tetrahydrochrysene. Source rock analysis indicates that the Kishenehn Formation possesses excellent petroleum source potential. Conventional thermal maturity parameters, as well as maturity parameters derived from molecular parameters ...

1987-01-01

402

Purification of CH{sub 3}Cl from CH{sub 3}I using cold trap with sealed 2,2,4-trimethylpentane for {delta}{sup 37}Cl measurement

Combination treatments of chisel-injected fumigants (methyl bromide, 1,3-D, metam sodium, and chloropicrin) on a first crop, followed by drip-applied fumigants (metam sodium and 1,3-D +/- chloropicrin) on a second crop, with and without oxamyl drip applications were evaluated for control of Meloidogyne incognita in three different tests (2002 to 2004) in Tifton, GA. First crops were eggplant or tomato, and second crops were cantaloupe, squash, or jalapeno pepper. Double-cropped vegetables suffered much greater root-knot nematode (RKN) pressure than first crops, and almost-total yield loss occurred when second crops received no nematicide treatment. On a first crop of eggplant, all fumigants provided good nematode control and average yield increases of 10% to 15 %. On second crops, higher application rates and fumigant combinations (metam sodium and 1,3-D +/- chloropicrin) improved RKN control and increased yields on average by 20% to 35 % compared to the ...

2006-03-01

403

Production of Shiga-like toxins by Escherichia coli O157:H7 can be influenced by the neuroendocrine hormone norepinephrine.

A cryogenic separation method of chloromethane (CH{sub 3}Cl) from methyl iodide (CH{sub 3}I) for {delta}{sup 37}Cl measurement with isotope ratio mass spectrometer is described. A cold trap with sealed 2,2,4-trimethylpentane (TMP) as the cryogen is used in this method. CH{sub 3}Cl can be separated from CH{sub 3}I at the TMP melting point (-107 deg. C) based on the difference in the vapor pressure between CH{sub 3}Cl (322.6 Pa) and CH{sub 3}I (lower than 1.3 Pa) at -107 deg. C. After two-step separation processes, the yields of CH{sub 3}Cl purified from CH{sub 3}Cl-CH{sub 3}I mixture are 96-101%, and the difference between the {delta}{sup 37}Cl{sub original} and {delta}{sup 37}Cl{sub Afterseparation} is from -0.06 to +0.06 per mille (0.01 {+-} 0.04 per mille ). These results suggest that CH{sub 3}Cl is completely separated from CH{sub 3}I with no change of {delta}{sup 37}Cl value. This method using the cold trap with sealed TMP is very safe and not harmful, because ...

2006-01-05

404

Photooxidation of different organic dyes (RB, MO, TB, and BG) using Fe(III)-doped TiO{sub 2} nanophotocatalyst prepared by novel chemical method

To examine whether the neuroendocrine hormone norepinephrine may influence the production of the Shiga-like toxins (SLTs), several Escherichia coli O157:H7 clinical isolates were grown in the presence or absence of norepinephrine. An in vitro culture system consisting of low (<1500 colony-forming units/ml) initial concentrations of inocula into a serum-based medium was used to more closely approximate in vivo conditions. The growth of all isolates was increased several logs in the presence of norepinephrine, as compared with the growth in controls, during a 24-hour growth period. Controls included additional dextrose as well as the use of the norepinephrine metabolite normetanephrine, which contains one more methyl group than norepinephrine and hence would serve as a better energy source for growth if the effect were solely nutritionally mediated. During the 24 hours of growth, the production of cell-associated SLT-I on a protein-equivalent basis was shown to be ...

1996-10-01

405

Photoelectrocatalytic degradation of organic pollutants with TiO{sub 2} electrodes

The nano-structured Fe(III)-doped TiO{sub 2} photocatalysts with anatase phase have been developed for the oxidation of non-biodegradable different organic dyes like methyl orange (MO), rhodamine B (RB), thymol blue (TB) and bromocresol green (BG) using UV-Hg-lamp. The different compositions of Fe{sub x}Ti{sub 1-x}O{sub 2} (x = 0.005, 0.01, 0.05, and 0.1) nanocatalysts synthesized by chemical method (CM), have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectra, specific surface area (BET), transmission electronic microscopy (TEM) analysis, XPS, ESR and zeta potential. From XRD analysis, the results indicate that all the compositions of Fe(III) doped in TiO{sub 2} catalysts gives only anatase phase not rutile phase. For complete degradation of all the solutions of the dyes (MO, RB, TB, and BG), the composition with x = 0.005 is more photoactive compared all other compositions of Fe{sub x}Ti{sub 1-x}O{sub 2}, and degussa P25. The ...

2008-09-15

406

New technetium-99m radiopharmaceuticals for brain imaging

Photoelectrochemical oxidation is a potentially interesting method for destroying toxic organic materials. We have studied the photoelectrocatalytic activity of TiO{sub 2} films made by thermal oxidation of titanium, low pressure chemical vapour deposition (LPCVD), and anodisation of titanium. Two model organic compounds have been investigated for photooxidation: methyl phosphonic acid (MPA) which is a nerve gas analogue and 4-chlorophenol (4-CP) which is a chlorinated aromatic compound considered a standard for the evaluation of the TiO{sub 2} / UV processes. In addition to photoelectrochemical characterisation the films have been characterised by profilometry, XRD, AFM, photocurrent spectroscopy and Raman microscopy. Correlations have been made between the physical properties of the thin films and their catalytic activities. The most catalytic sample of thermally oxidised titanium was prepared at 400 deg C, and the presence of anatase was shown by XRD, MPA ...

2001-07-01

407

Natural gas conversion to higher hydrocarbons using plasma interactions with surfaces. Final report

Radiopharmaceuticals for brain imaging are used for the detection of ischemia, tumours and dementia associatied with disorders of the blood flow in the brain. The current radiopharmaceuticals for brain imaging have various limitations: 2-(F-18)fluoro-2-deoxyglucose (F-18-FDG) has a very short half-life. The physical properties of di-#beta#-(piperidinoethyl)-(Se-75)selenide (Se-75-PIPSE) and di-#beta#-(morpholinoethyl)-(Se-75)-selenide (Se-75-MOSE) are not ideal. Thallium-201 diethyldithricarbamate (T1-201-DDC) has unfavourable nuclidic characteristics, limited availability, a long half-life and high cost. I-123 in N-isopropyl-p-iodoamphetamine (I-123-IMP) and N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine (I-123-HIPDM) are not freely available and are expensive. N-13-labelled ammonia has a very short half-life. Technetium-99m hexamethylpropyleneamineoxime (Tc-99m-HM-PAO) is unstable both in vitro and in vivo and has a low brain-to-blood ...

1988-08-01

408

Molecular evolution and characterization of fungal indoleamine 2,3-dioxygenases.

Experiments are reported in which a methane plasma is created, and the methyl ions and hydrogen ions are accelerated within a microchannel array so that they interact with neutral methane molecules on the inside surfaces of the microchannels. No catalysts are used, and the device operates at room temperature. Impact energies of the ions are in the range of 10 eV to greater than 100 eV, and the energy delivered in the interaction at the surfaces causes the production of larger hydrocarbon molecules, such as C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, and C{sub 2}H{sub 6}, along with C{sub 3}, C{sub 4}, C{sub 5}m C{sub 6}, C{sub 7}m and C{sub 8} molecules. There is a decreasing percentage of larger molecules produced, in comparison with the C{sub 2} and C{sub 3} types. Conversion effectiveness is greater at higher pressure, due to the increased ionic activity. The yield of the higher hydrocarbons depends upon the external voltage used, and voltage can be used as a control ...

1993-12-01

409

Kinetics and product analysis of bromium-initiated gas-phase oxidation of {alpha}, {beta}-unsaturated carbonyls; Kinetik und Produktanalyse der brominitiierten Gasphasenoxidation von {alpha}, {beta}-ungesaettigten Carbonylen

Indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) are tryptophan-degrading enzymes. Mammalian IDO expression is induced by cytokines and has antimicrobial and immunomodulatory effects. A major role of mammalian TDO is to supply nicotinamide adenine dinucleotide (NAD(+)). In fungi, the IDO homologue is thought to be expressed constitutively and supply NAD(+), as TDO is absent from their genomes. Here, we reveal the distribution of IDO genes among fungal species and characterize their enzymatic activity. The yeast, Saccharomyces cerevisiae has only one IDO gene, whereas the koji-mold, Aspergillus oryzae has two genes, IDO? and IDO?. The A. oryzae IDO? showed more similar enzymatic properties to those of S. cerevisiae IDO than IDO?, suggesting that the A. oryzae IDO? is a functional homologue of the S. cerevisiae IDO. From the IDO? gene, two isoforms, IDO? and IDO?(+) could be generated by alternative splicing. The latter contained a 17 amino acids insertion which ...

2010-12-18

410

Involvement of a glutamergic mechanism in gamma-dendrotoxin-induced hippocampal neuronal cell loss in the rat.

The purpose of the present study was to examine reactions between bromium atoms with {alpha}, {beta}-unsaturated carbonyls. Acrolein, methacrolein, and methyl vinyl zetone were chosen as representatives of this family. The latter two compounds, beside formaldehyde, belong to the main products of atmospheric oxidation of isoprene and have been detected in the troposphere at concentrations of up to almost 1 ppb. It is known that alkenes react with bromium via addition to form an instable adduct. This product can either decompose again into its educts or react with molecular oxygen. The aim of the study was to determine the velocities of the reactions between the three {alpha}, {beta}-unsaturated carbonyls and bromium and to clarify the involved reaction mechanisms by means of kinetic experiments and product analyses. (orig./SR) [Deutsch] In dieser Arbeit wurde die Reaktion von Bromatomen mit {alpha}, {beta}-ungesaettigten Carbonylen untersucht. Ausgewaehlt wurden ...

1997-03-01

411

Investigation of the effect of laundering the ground crew chemical defense overgarment on toxic-free-area vapor transfer during shelter entry by initially contaminated personnel. Interim report, Oct 87-Jan 88

The epileptogenic and neurodegenerative effects of gamma-dendrotoxin, from Dendroaspis angusticeps, a specific blocker of a non-inactivating, voltage-sensitive K+ channel, were studied after focal injection into one dorsal hippocampus in rats pretreated with CGP040116, a N-methyl-D-aspartate (NMDA) receptor antagonist, and in rats bearing a monolateral surgical lesion of the Schaffer collaterals whose terminals originate from CA3 pyramids and release glutamate in the CA1 hippocampal area. Administration of 35 pmol gamma-dendrotoxin elicited in all of the treated animals (n=8) bilateral EEG discharges and damage to the hippocampal formation. Quantitation of the damage revealed significant bilateral neuronal cell loss in the CA1, CA3 and CA4 pyramidal cell layers. The lowest dose (0.35 pmol; n=4) of the toxin used did not affect EEG activity and failed to cause significant hippocampal cell loss whereas the 3.5 pmol (n=6) dose caused EEG seizures and hippocampal cell ...

2004-03-01

412

Influence of two changes in the composition of an acrylic bone cement on its handling, thermal, physical, and mechanical properties.

A study by the U.S. Air Force School of Aerospace Medicine, Brooks AFB, Texas, has compared the shelter processing transfer of chemical warfare agent simulant vapor for subjects wearing unwashed and laundered ground-crew chemical defense overgarments. Twice laundered and four times laundered protective garments were included in the assessment. Test subjects, wearing the unwashed and laundered protective garments were initially sprayed with liquid simulant (methyl salicylate) to a target density of 5 g m-2. They were then sequentially processed into and through the USAFSAM Collective Protection Shelter (SCPS-2B) test facility. Immediately upon entry to the Toxic-Free Area, the subjects were confined in individual off gassing booths for 2 h while offgassed simulant vapor concentration in the booths was recorded. The resulting mean maximum vapor concentrations recorded in the booths for subjects who had worn unwashed and laundered overgarments prior to booth entry ...

1990-12-01

413

Grazing incidence X-ray diffraction and neutron reflection studies of semi-crystalline polymer surfaces and interfaces[Polymers; Crystallisation behaviour

This study is a contribution to the growing body of work on the influence of changes in the composition of an acrylic bone cement on various properties of the curing and cured material. The focus is on one commercially-available acrylic bone cement brand, Surgical Simplex P, and three variants of it and a series of properties, namely, setting time, maximum exotherm temperature, activation energy and frequency factor for the polymerization reaction, diffusion coefficient for the uptake of phosphate buffered saline, at 37 degrees C, ultimate compressive strength (UCS), plane-strain fracture toughness, fatigue life (under fully-reversed tension-compression stress), hardness (H) and elastic modulus (both determined using quasi-static nanoindentation), and the variation of the storage and loss moduli with frequency of the applied force in a dynamic nanoindentation test. It was found that (a) a 68% reduction in the volume of the activator, N,N dimethyl-4-toluidine, relative to the total ...

2007-05-05

414

Gene expression profiles deciphering rice phenotypic variation between Nipponbare (Japonica) and 93-11 (Indica) during oxidative stress.

This thesis is concerned with the crystallisation behaviour of polymers near to a free surface or a buried interface. The properties of polymers are expected to differ significantly near to an interface (either with air or another polymer), due to the contributions of (a) chain configurations induced at the interface, and (b) different mobilities between interfacial regions and the bulk of the sample. For a semi-crystalline polymer, properties such as the degree of crystallinity and the crystallisation kinetics may be enhanced near to a free surface. Grazing incidence x--ray diffraction (GIXD) is used to investigate such effects in poly(ethylene terphthalate) (PET), showing that a lower crystallisation temperature is obtained at the surface, and the crystallisation kinetics are faster at the surface for all temperatures. It is proposed that in thin films of PET, this surface-induced ordering provides nucleation sites for crystallisation in the bulk. GIXD is also used to investigate the ...

2002-07-01

415

Focus ion beam preparation of transmission electron microscope sample in polymer clay nano composite

Rice is a very important food staple that feeds more than half the world's population. Two major Asian cultivated rice (Oryza sativa L.) subspecies, japonica and indica, show significant phenotypic variation in their stress responses. However, the molecular mechanisms underlying this phenotypic variation are still largely unknown. A common link among different stresses is that they produce an oxidative burst and result in an increase of reactive oxygen species (ROS). In this study, methyl viologen (MV) as a ROS agent was applied to investigate the rice oxidative stress response. We observed that 93-11 (indica) seedlings exhibited leaf senescence with severe lesions under MV treatment compared to Nipponbare (japonica). Whole-genome microarray experiments were conducted, and 1,062 probe sets were identified with gene expression level polymorphisms between the two rice cultivars in addition to differential expression under MV treatment, which were assigned as Core ...

2010-01-08

416

Effect of propylbenzilylcholine mustard on contraction and radioligand binding parameters of muscarinic receptors in guinea pig ileum

This paper deals with preparation of PE clay nano composite specimen for transmission electron microscopy (TEM) and studying the difference between dispersion of clay in low density polyethylene using poly(hydrogen methyl siloxane) (PHMS) as coupling agent and untreated one. Argon ion milling is the conventional means by which film sections are thinned to electron transparency for TEM analysis, but this technique exhibits significant problems. In particular, selective thinning and imaging of sub-micrometer inclusions during sample milling are highly problematic. We have achieved successful results using the focused ion beam (FIB) lift-out technique, which utilizes a 30 kV Ga"+ ion beam to extract electron transparent specimens with nanometer scale precision. Using this procedure, we have prepared a number of thin film materials representing a range of structures and compositions for TEM analysis. We believe that FIB milling will create major new opportunities in ...

2006-01-01

417

Development of food preservation and processing techniques by radiation

The receptor occupancy-biological effect relationship for muscarinic receptors in guinea pig ileal smooth muscle has been studied by comparison of radioligand binding and contractile response. Muscarinic receptors in homogenates of ileal smooth muscle were labeled with (/sub 3/H)-1-Quinuclidinyl benzilate. Treatment with propylbenzilylcholine mustard (PrBCM), to inactivate irreversibly muscarinic receptors, caused a large dose dependent rightward shift of the dose-response curve to three agonistic furtrethonium derivatives with a concomitant decrease in maximal response. Using those data, the fraction of receptors remaining unoccupied (q-values) and true affinity constants (-log K/sub A/-values) were calculated. Exposure to 20 or 60 nM PrBCM for 15 minutes resulted in a 39% and a 61% reduction in specific (/sup 3/H)-1-Quinuclidinyl benzilate binding sites respectively to be compared with a 62% and a 85% decrease expected from calculated q-values. K/sub A/-values for the ...

1987-10-26

418

Development of a Commercial Process for the Production of Silicon Carbide Fibrils

Development of food preservation and processing techniques by radiation was performed. Gamma irradiation at 2-10 kGy is considered to be an effective method to control pathogenic bacteria in species including Escherichia coli O157:H7. Gamma irradiation at 5 kGy completely eliminated pathogenic bacteria in beef. Gamma irradiation at such doses and subsequent storage at less than 4 deg C could ensure hygienic quality and prolong the microbiological shelf-life resulting from the reduction of spoilage microorganisms. Gamma irradiation on pre-rigor beef shortens the aging-period, improves tenderness and enhances the beef quality. And, a new beef processing method using gamma irradiation, such as in the low salt sausage and hygienic beef patty was developed. Safety tests of gamma-irradiated meats(beefs: 0-5 kGy; porks: 0-30 kGy) in areas such as genotoxicity, acute toxicity, four-week oral toxicity, rat hepato carcinogenesis and the anti oxidative defense system, were not affected by gamma ...

1988-04-18

419

Comparison of /sup 99/Tcsup(m) complexes (NEP-DADT, ME-NEP-DADT and HMPAO) with /sup 123/IAMP for brain SPECT imaging in dogs

The current work continues a project completed in 1999 by ReMaxCo Technologies in which a novel, microwave based, VLS Silicon Carbide Fibrils concept was verified. This project continues the process development of a pilot scale commercial reactor. Success will lead to sufficient quantities of fibrils to expand work by ORNL and others on heat exchanger tube development. A semicontinuous, microwave heated, vacuum reactor was designed, fabricated and tested in these experiments. Cylindrical aluminum oxide reaction boats are coated, on the inner surface, with a catalyst and placed into the reactor under a light vacuum. A series of reaction boats are then moved, one at a time, through the reactor. Each boat is first preheated with resistance heaters to 850 C to 900 C. Each reaction boat is then moved, in turn, to the microwave heated section. The catalyst is heated to the required temperature of 1200 C to 1300 C while a mixture of MTS (methyl trichlorosilane) and ...

2003-04-22

420

Characterization of tris(N-substituted-2-methyl-3-hydroxy-4-pyridinonato)technetium(IV) cations

In this study we have compared brain uptake and blood clearance of /sup 99/Tcsup(m)-N-ethylpiperi-dinediamino dithiol (/sup 99/Tcsup(m)-NEP DADT), its 4-methylated derivative (/sup 99/Tcsup(m)-Me-NEP-DADT) and /sup 99/Tcsup(m)-hexamethyl-propylene-amine-oxime (/sup 99/Tcsup(m)-HMPAO) with that of N-isopropyl(/sup 123/I)iodoamphetamine (/sup 123/IAMP) in two dogs. Single photon emission tomography (SPECT) was employed to measure brain accumulation and retention of the four radiopharmaceuticals. Cerebral uptake of the /sup 99/Tcsup(m) complexes was lower than that of /sup 123/IAMP. There was considerable extracerebral activity in the dog's head, especially in the olfactory and snout regions. Because of slow blood clearance, /sup 99/Tcsup(m)-HMPAO showed high uptake in these regions. Brain uptake of /sup 99/Tcsup(m)-HMPAO reached a plateau 5 to 10 min after intravenous injection and remained constant for the entire study period (1 h). /sup ...

1987-08-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

421

Characterization of tris(N-substituted-2-methyl-3-hydroxy-4-pyridinonato)technetium(IV) cations

A burgeoning interest in technetium coordination chemistry has been spurred by its widespread use in nuclear medicine. Recent focus has been on the design and preparation of new technetium complexes, the lipophilicity, polarity, and overall charge of which can be readily altered by simple substitutions in the molecular framework of the ligand in order to optimize the biodistribution and target specific organs. Examples are cationic (Cardiolite) and neutral (Ceretec) technetium complexes, used as myocardial and brain imaging agents, respectively. The authors have been pursuing a continuing study of tris(3-hydroxy-4-pyridinonato)gallium and -indium complexes that are water soluble, are hydrolytically stable, and are of varying lipophilicity and neutral charge. Studies of in vivo in rabbits and mice have revealed that several of these cationic complexes may be useful as morphologic kidney imaging agents, with [{sup 99m}Tc(pap){sub 3}]{sup +} showing elevated levels in the kidneys even ...

1994-11-23

422

Additives to lower and stabilize the viscosity of pyrolysis oils during storage

A burgeoning interest in technetium coordination chemistry has been spurred by its widespread use in nuclear medicine. Recent focus has been on the design and preparation of new technetium complexes, the lipophilicity, polarity, and overall charge of which can be readily altered by simple substitutions in the molecular framework of the ligand in order to optimize the biodistribution and target specific organs. Examples are cationic (Cardiolite) and neutral (Ceretec) technetium complexes, used as myocardial and brain imaging agents, respectively. The authors have been pursuing a continuing study of tris(3-hydroxy-4-pyridinonato)gallium and -indium complexes that are water soluble, are hydrolytically stable, and are of varying lipophilicity and neutral charge. Studies of in vivo in rabbits and mice have revealed that several of these cationic complexes may be useful as morphologic kidney imaging agents, with ["9"9"mTc(pap)_3]"+ showing elevated levels in the kidneys even after 24 h. In ...

423

ATRX ADD domain links an atypical histone methylation recognition mechanism to human mental-retardation syndrome

The initial development of additives to stabilize the viscosity of biocrude during long-term storage has produced dramatic results. The additives investigated were ethyl acetate, methyl isobuyl ketone and methanol, acetone, methanol, acetone and methanol, and ethanol. These additives represent three chemical families, which all demonstrated the ability to drastically reduce the aging rate of biocrude, as defined by the increase in viscosity with time. Accelerated aging tests were run at 90{degree}C to screen the additives. The additives not only lowered the initial viscosity at 40{degree}C by half but also reduced the aging rate of a hot gas filtered pyrolysis oil made from hybrid poplar (NREL run 175) by factors of 1-18 compared to the original pure oil. With the best additive, methanol, at a 10 wt% level in the pyrolysis oil, the modified biocrude was still a single-phase liquid and still met the ASTM no. 4 diesel fuel specification for viscosity even after 96 h ...

1997-09-01

424

Synthesis of polyester styrene resin beads as polymeric ionic exchangers by using chemical and irradiation techniques

ATR-X (alpha-thalassemia/mental retardation, X-linked) syndrome is a human congenital disorder that causes severe intellectual disabilities. Mutations in the ATRX gene, which encodes an ATP-dependent chromatin-remodeler, are responsible for the syndrome. Approximately 50% of the missense mutations in affected persons are clustered in a cysteine-rich domain termed ADD (ATRX-DNMT3-DNMT3L, ADD{sub ATRX}), whose function has remained elusive. Here we identify ADD{sub ATRX} as a previously unknown histone H3-binding module, whose binding is promoted by lysine 9 trimethylation (H3K9me3) but inhibited by lysine 4 trimethylation (H3K4me3). The cocrystal structure of ADD{sub ATRX} bound to H3{sub 1-15}K9me3 peptide reveals an atypical composite H3K9me3-binding pocket, which is distinct from the conventional trimethyllysine-binding aromatic cage. Notably, H3K9me3-pocket mutants and ATR-X syndrome mutants are defective in both H3K9me3 binding and localization at pericentromeric heterochromatin; ...

2011-07-19

425

Irradiation as an alternative post harvest treatment

The aim of the study is to prepare ionic exchangers using the polymerization of unsaturated polyster with monomeric styrene units in a ratio of 60%: 40% respectively. The type of method involved in this preparation, is called An Emulsion Polymerization. Such type of polymerization was carried out by two techniques: chemical and irradiation techniques. The first techniques requires the formation of free radical monomers by use of methyl Ethy Ketone Peroxide capable of decomposing into free radicals upon heating, while the other technique involves the use of gamma rays (using Co-60 source) capable of activating monomers towards free radical formations. A number of very effective chemical parameters and physical factors were used and investigated throughout the reactions such as: dispersant matrix, viscosity, rate of mixing, and irradiation dose. Besides, the study has included the study of the rate of Resin Beads Swelling which is thought to be another important part ...

3087-01-01

426

Investigation into {sup 64}Cu-labeled Bis(selenosemicarbazone) and Bis(thiosemicarbazone) complexes as hypoxia imaging agents

This current world population has significantly added to the pressures placed upon our finite resources and our resulting ability to feed ourselves. In order to cope with current and future demands, the two established lines of action, that is, reduced population growth and expansion of agricultural production, must be supplemented with the parallel activity of reducing food losses during and after harvest. For developing countries in particular, enormous post-harvest losses result from spillage, contamination, pests and physiological deterioration during storage. Studies in these countries indicate that post-harvest losses are enormous and amount to tens of millions of tons per year valued at billions of dollars. Programs to reduce post-harvest losses, if applied properly, can result in realistic yield increases between 10 and 30%, which can be directly converted into increased consumption for humans. Post-harvest losses vary greatly and are a function of the crop variety, pest ...

1997-10-27

427

Characterization of [[sup 123]I]IDAM as a novel single-photon emission tomography tracer for serotonin transporters

Background: Cu-diacetyl-bis(N{sup 4}-methylthiosemicarbazone) [Cu-ATSM], although excellent for oncology applications, may not be suitable for delineating cardiovascular or neurological hypoxia. For this reason, new Cu hypoxia positron emission tomography (PET) imaging agents are being examined to search for a higher selectivity for hypoxic or ischemic tissue at higher oxygen concentrations found in these tissues. Two approaches are to increase alkylation or to replace the sulfur atoms with selenium, resulting in the formation of selenosemicarbazones. Methods: Three {sup 64}Cu-labeled selenosemicarbazone complexes were synthesized and one was screened for hypoxia selectivity in vitro using EMT-6 mouse mammary carcinoma cells. Rodent biodistribution and small animal PET images were obtained from BALB/c mice implanted with EMT-6 tumors. One alkylated thiosemicarbazone was synthesized and examined. Results: Of the three bis(selenosemicarbazone) ligands synthesized and examined, only {sup ...

2005-02-01

428

Softwood forest thinning as a biomass source for ethanol production: A feasibility study for California

Development of selective serotonin transporter (SERT) tracers for single-photon emission tomography (SPET) is important for studying the underlying pharmacology and interaction of specific serotonin reuptake site inhibitors, commonly used antidepressants, at the SERT sites in the human brain. In search of a new tracer for imaging SERT, IDAM (5-iodo-2-[[2-2-[(dimethylamino)methyl]phenyl]thio]benzyl alcohol) was developed. In vitro characterization of IDAM was carried out with binding studies in cell lines and rat tissue homogenates. In vivo binding of [[sup 125]I]IDAM was evaluated in rats by comparing the uptakes in different brain regions through tissue dissections and ex vivo autoradiography. In vitro binding study showed that IDAM displayed an excellent affinity to SERT sites (K[sub i]=0.097 nM, using membrane preparations of LLC-PK[sub 1] cells expressing the specific transporter) and showed more than 1000-fold of selectivity for SERT over norepinehrine and ...

1999-08-01

429

Phytoremediation of Ionic and Methyl Mercury P

A plan has been put forth to strategically thin northern California forests to reduce fire danger and improve forest health. The resulting biomass residue, instead of being open burned, can be converted into ethanol that can be used as a fuel oxygenate or an octane enhancer. Economic potential for a biomass-to-ethanol facility using this softwood biomass was evaluated for two cases: Stand-alone and co-located. The co-located case refers to a specific site with an existing biomass power facility owned by Wheelabrator Environmental Systems Inc. near Martell, California. A two-stage dilute acid hydrolysis process is used for the production of ethanol from softwoods, and the residual lignin is used to generate steam and electricity. For a plant processing 800 dry tonnes per day of feedstock, the co-located case is an economically attractive concept. Total estimated capital investment is approximately $ 70 million for the co-located case. The resulting internal rate of return is about 24% ...

2000-07-01

430

In vitro and in vivo evaluation of novel ligands for radioimmunotherapy

Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and/or sequester toxic heavy metal pollutants as an environmentally friendly alternative to physical remediation methods. We have focused this phytoremediation research on soil and water-borne ionic and methylmercury. Mercury pollution is a serious world-wide problem affecting the health of human and wild-life populations. Methylmercury, produced by native bacteria at mercury-contaminated wetland sites, is a particularly serious problem due to its extreme toxicity and efficient biomagnification in the food chain. We engineered several plant species (e.g., Arabidopsis, tobacco, canola, yellow poplar, rice) to express the bacterial genes, merB and/or merA, under the control of plant regulatory sequences. These transgenic plants acquired remarkable properties for mercury remediation. (1) Transgenic plants expressing merB (organomercury lyase) extract methylmercury from their growth substrate and ...

1999-06-01

431