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1

c-Myc Mediates a Hypoxia-Induced Decrease in Acetylated Histone H4  

UK PubMed Central (United Kingdom)

Global acetylation of histone H4 is a mark of gene transcriptional activation. The c-Myc transcription factor binds to specific DNA sites in cellular chromatin and induces the acetylation of...Full Text Available

2009-10-01

2

Structural Basis for Acetylated Histone H4 Recognition by the Human BRD2 Bromodomain*  

UK PubMed Central (United Kingdom)

Recognition of acetylated chromatin by the bromodomains and extra-terminal domain (BET) family proteins is a hallmark for transcriptional activation and anchoring viral genomes to mitotic chromosomes...Full Text Available

2010-03-05

3

Gene silencing induced by oxidative DNA base damage: association with local decrease of histone H4 acetylation in the promoter region  

UK PubMed Central (United Kingdom)

Oxidized DNA bases, particularly 7,8-dihydro-8-oxoguanine (8-oxoG), are endogenously generated in cells, being a cause of carcinogenic mutations and possibly interfering with gene expression. We found...Full Text Available

2010-07-01

4

The Caenorhabditis elegans Elongator Complex Regulates Neuronal ?-tubulin Acetylation  

UK PubMed Central (United Kingdom)

Although acetylated α-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate α-tubulin acetylation are, to date, largely unknown. Therefore,...Full Text Available

2010-01-01

5

Evaluation of gels obtained from acetylation of chitosan in heterogeneous medium  

International Nuclear Information System (INIS)

Chitosan was acetylated during 2, 5 and 10 h and physical gels were obtained at different polymer concentrations in N,N-dimethylacetamide containing 5% of LiCl. Acetylation was confirmed by infrared spectroscopy and "1"3C NMR, and degrees of acetylation in the range of 0.82-0.91 were determined by NMR. The O-acetylation degree (0.12-0.15) was exclusively determined by a volumetric method. Rheological studies showed that the storage modulus values were smaller for the more acetylated samples and increased with the temperature and the polymer concentration. All the gels presented storage modulus superior to loss modulus, evidencing more elastic than viscous characteristics. The results obtained in this work suggest a gelation process based on a balance between O and N-acetylation and intermolecular bonds. (author)

6

The recruitment of acetylated and unacetylated tropomyosin to distinct actin polymers permits the discrete regulation of specific myosins in fission yeast  

UK PubMed Central (United Kingdom)

Tropomyosin (Tm) is a conserved dimeric coiled-coil protein, which forms polymers that curl around actin filaments in order to regulate actomyosin function. Acetylation of the Tm N-terminal...Full Text Available

2010-10-01

7

N-acetyltransferase 2 slow acetylator genotype associated with adverse effects of sulfasalazine in the treatment of inflammatory bowel disease  

UK PubMed Central (United Kingdom)

AIM:N-acetyltransferase 2 (NAT2) is an important enzyme catalyzing N-acetylation of sulfasalazine (SASP). The aim of the present study was to investigate...Full Text Available

2007-03-01

8

Changes in N-acetyl-B-D-glucosaminidase and B-glucuronidase activities in milk during bovine mastitis.  

UK PubMed Central (United Kingdom)

To determine the N-acetyl-B-D-glucosaminidase (NAGase) and B-glucuronidase (B-Gase) activities in mastitic milk, basic enzyme assay conditions, distribution of NAGase and B-Gase, comparison of their...Full Text Available

1987-01-01

9

Asymmetric Distribution of Glucose and Indole-3-Acetyl-myo-Inositol in Geostimulated Zea mays Seedlings 1  

UK PubMed Central (United Kingdom)

Indole-3-acetyl-myo-inositol occurs in both the kernel and vegetative shoot of germinating Zea mays seedlings. The effect of a gravitational stimulus on the transport...Full Text Available

1988-07-01

10

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

UK PubMed Central (United Kingdom)

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

11

The photoaffinity ligand [3,5-"3H] 4-azidoclonidine. Synthesis and characterization details  

International Nuclear Information System (INIS)

[3,5-"3H] 4-Azidoclonidine 6 was prepared from [3,5-"3H] 4-aminoclonidine 4 and has emerged as a valuable tool to study the alpha-2-adrenergic receptor. (author)

2004-07-01

13

Cellulose and cellulignin from sugarcane bagasse reinforced polypropylene composites: Effect of acetylation on mechanical and thermal properties  

British Library Electronic Table of Contents (United Kingdom)

This current work is concerned with the development of polypropylene composites reinforced with cellulose and cellulignin fibers attained from sugarcane bagasse. Moreover, the fibers were chemically modified by acetylating process and its effects on the fiber/matrix interaction were also evaluated. The chemical modification efficiency was verified by FTIR analysis and the fibers morphological aspects of fibers by SEM. Likewise, the influence of modified fibers content in the composites was studied by mechanical (tensile, shear and flexural tests) and thermal analyses (TGA and DSC). After the chemical modification, the FTIR results showed the appearance of acetyl groups and reduction of OH bonds for all fibers. Together with, SEM characterization showed that the acetylation changed the morp...

2008-01-01

14

Expression and fine structure of the gene encoding N epsilon-(indole-3-acetyl)-L-lysine synthetase from Pseudomonas savastanoi.  

UK PubMed Central (United Kingdom)

The gene encoding N epsilon-(indole-3-acetyl)-L-lysine synthetase, iaaL, from Pseudomonas savastanoi was localized within a 4.25-kilobase EcoRI fragment derived from pIAA1 of oleander strain EW 2009....Full Text Available

1990-08-01

15

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

UK PubMed Central (United Kingdom)

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

16

Structure of the Taz2 domain of p300: insights into ligand binding  

UK PubMed Central (United Kingdom)

CBP and its paralog p300 are histone acetyl transferases that regulate gene expression by interacting with multiple transcription factors via specialized domains. The structure...Full Text Available

2009-12-01

17

Role of TRAIL and the pro-apoptotic Bcl-2 homolog Bim in acetaminophen-induced liver damage  

UK PubMed Central (United Kingdom)

Acetaminophen (N-acetyl-para-aminophenol (APAP), paracetamol) is a commonly used analgesic and antipyretic agent. Although considered safe at therapeutic doses, accidental or intentional...Full Text Available

2011-06-01

18

Reaction of human albumin with aspirin in vitro: mass spectrometric identification of acetylated lysines 199, 402, 519, and 545  

UK PubMed Central (United Kingdom)

The aspirin esterase activity of human plasma is due to butyrylcholinesterase and albumin. Our goal was to identify the amino acid residues involved in the aspirin esterase activity of albumin....Full Text Available

2010-03-01

19

Mammalian Sirt1: insights on its biological functions  

UK PubMed Central (United Kingdom)

Sirt1 (member of the sirtuin family) is a nicotinamide adenosine dinucleotide (NAD)-dependent deacetylase that removes acetyl groups from various proteins. Sirt1 performs a wide variety of functions...Full Text Available

20

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

UK PubMed Central (United Kingdom)

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

 
 
 
 
21

Chronic Cocaine-Induced H3 Acetylation and Transcriptional Activation of CaMKII? in the Nucleus Accumbens Is Critical for Motivation for Drug Reinforcement  

UK PubMed Central (United Kingdom)

The regulation of gene expression in the brain reward regions is known to contribute to the pathogenesis and persistence of drug addiction. Increasing evidence suggests that the regulation of gene transcription...Full Text Available

2010-03-01

22

Cd36, a class B scavenger receptor, functions as a monomer to bind acetylated and oxidized low-density lipoproteins  

UK PubMed Central (United Kingdom)

Cd36 is a small-molecular-weight integral membrane protein expressed in a diverse, but select, range of cell types. It has an equally diverse range of ligands and physiological functions, which has...Full Text Available

2007-11-01

23

Application of the histone deacetylase inhibitors for the treatment of endometriosis: histone modifications as pathogenesis and novel therapeutic target.  

Science.gov (United States)

BACKGROUND Accumulating evidence suggests that various epigenetic aberrations play definite roles in the pathogenesis of endometriosis. We investigated the histone acetylation status in endometriosis and the application of the histone deacetylase inhibitors (HDACIs) for the treatment of endometriosis. METHODS The levels of acetylated histones in the endometriotic cyst stromal cells (ECSCs) and normal endometrial stromal cells (NESCs) were evaluated. The effects of the HDACIs on cell proliferation, the cell cycle, apoptosis of ECSCs and NESCs, and the expression of genes related to these cellular events were investigated. The effects of HDACIs on histone acetylation in chromatin of the promoter region of the cell cycle regulatory genes in ECSCs were also investigated. RESULTS The acetylated histone levels were significantly lower in ECSCs than in NESCs (P endometriosis and that HDACIs reactivated ...

2011-06-29

24

Acetylation of Histones and Transcription-Related Factors  

UK PubMed Central (United Kingdom)

The state of chromatin (the packaging of DNA in eukaryotes) has long been recognized to have major effects on levels of gene expression, and numerous chromatin-altering strategies—including...Full Text Available

2000-06-01

25

A simplified assay for the arylamine N-acetyltransferase 2 polymorphism validated by phenotyping with isoniazid.  

UK PubMed Central (United Kingdom)

Human arylamine N-acetyltransferase (NAT) activity is determined by two distinct genes, NAT1 and NAT2, and the classical acetylation polymorphism in NAT2 has been associated with a variety of disorders,...Full Text Available

1997-09-01

26

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

International Nuclear Information System (INIS)

["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 ...

27

N"v"a"r"-"e"p"s"i"l"o"n-acetyl-#beta#-lysine: An osmolyte synthesized by mothanogenic archaebacteria  

International Nuclear Information System (INIS)

Methanosarcina thermophila, a nonmarine methanogenic archaebacterium, can grow in a range of saline concentrations. At less than 0.4 M NaCl, Ms. thermophila accumulated glutamate in response to increasing osmotic stress. At greater than 0.4 M NaCl, this organism synthesized a modified #beta#-amino acid that was identified as N"v"a"r"-"e"p"s"i"l"o"n-acetyl-#beta#-lysine by NMR spectroscopy and ion-exchange HPLC. This #beta#-amino acid derivative accumulated to high intracellular concentrations (up to 0.6 M) in Ms. thermophila and in another methanogen examined - Methanogenium cariaci, a marine species. The compound has features that are characteristic of a compatible solute: it is neutrally charged at physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological pH and it is highly soluble. When the cells were grown in the presence of exogenous glycine betaine, a physiological compatible solute, ...

28

Synthesis and biodistribution of "9"9"mTc-peptides conjugated adenine as tumor imaging agents  

International Nuclear Information System (INIS)

Two peptide ligands conjugated adenine, [9-N-(tritylmercapto acetyl diglycyl aminoethyl) adenine, Tr-MAG_2-Ade] and [9-N-(tritylmercapto acetyl triglycyl aminoethyl) adenine, Tr-MAG3-Ade], are synthesized and labeled with "9"9"mTc by directly labeling method. The stability of "9"9"mTc-MAG_2- adenine and "9"9"mTc-MAG_3-adenine in vitro is measured. The uptake radios of tumor to muscle at 3h post-injection are 5.70 and 4.92, respectively. The biodistribution and scintigraphic imaging studies show that the two complexes have high localization in tumor and high contrasted tumor images can be obtained, which suggest their potential utility as tumor imaging agents. But the high radioactivity of abdomen could prevent the tumor imaging in this area. (author)

2007-07-01

29

Interaction of iodine-containing acids with o-methylacetanilide in aqueous solutions  

International Nuclear Information System (INIS)

The systems CH_3COHNC_6H_4CH_3-HI-H_2O, CH_3CONHC_6H_4CH_3-HIO_3-H_2O, CH_3CONHC_6H_4CH_3-H_5IO_6-H_2O have been studied by the solubility method. It has been ascertained that the systems containing periodic and iodic acids are referred to systems of simple eutonic type. Formation of compound of o-methylacetanilide with iodic acid of equimolecular composition has been proved. Concentrational boundaries of its existence in solutions have been established, its certain physicochemical characteristics being determined.

30

Crystal structure of Spot 14, a modulator of fatty acid synthesis  

Energy Technology Data Exchange (ETDEWEB)

Spot 14 (S14) is a protein that is abundantly expressed in lipogenic tissues and is regulated in a manner similar to other enzymes involved in fatty acid synthesis. Deletion of S14 in mice decreased lipid synthesis in lactating mammary tissue, but the mechanism of S14's action is unknown. Here we present the crystal structure of S14 to 2.65 {angstrom} and biochemical data showing that S14 can form heterodimers with MIG12. MIG12 modulates fatty acid synthesis by inducing the polymerization and activity of acetyl-CoA carboxylase, the first committed enzymatic reaction in the fatty acid synthesis pathway. Coexpression of S14 and MIG12 leads to heterodimers and reduced acetyl-CoA carboxylase polymerization and activity. The structure of S14 suggests a mechanism whereby heterodimer formation with MIG12 attenuates the ability of MIG12 to activate ACC.

2011-09-06

31

Role of Calcium in Serine Transport into Tobacco Cells  

UK PubMed Central (United Kingdom)

The transport of serine into tobacco (Nicotiana tabacum L. var. Xanthi) cells grown in liquid medium was studied. Serine transport was maximal below pH 4.0. A time-dependent stimulation...Full Text Available

1978-12-01

32

Magnetic moment measurements of gadolinium, holmium and ytterbium tartrate trihydrate crystals  

British Library Electronic Table of Contents (United Kingdom)

Magnetic moment and susceptibility of single crystals of rare earth tartrates of the type R(C4H4O6)(C4H5O6)3H2O (where R = Gd, Ho, and Yb), using a vibration sample magnetometer are reported. The experimental values of molar susceptibilities for Gd(C4H4O6)(C4H5O6)3H2O, Ho(C4H4O6)(C4H5O6)3H2O, and Yb(C4H4O6)(C4H5O6)3H2O are 2.58x10-2, 4.66x10-2, and 8.03x10-3 (in cgs em units), respectively. The calculated effective magnetic moments are in good agreement with the theoretical predictions on rare earth ions.

2008-01-01

33

N-(/sup 3/H)acetyl-labeling, a convenient method for radiolabeling of glycosaminoglycans  

Energy Technology Data Exchange (ETDEWEB)

A method for the introduction of N-(/sup 3/H)acetyl groups into glycosaminoglycans is described. The procedure is based on (/sup 3/H)acetylation of N-unsubstituted hexosamine residues by treating the polysaccharides with (/sup 3/H)acetic anhydride. Preparations of heparin and heparin sulfate were found to contain significant numbers of N-unsubstituted hexosamine residues, as isolates. In contrast, such units could not be detected in chondroitin sulfate, dermatan sulfate, or hyaluronic acid. These polysaccharides were therefore subjected to partial N-deacetylation by reaction with hydrazine in the presence of hydrazine sulfate. After treatment with (/sup 3/H)acetic anhydride, the specific activities of the resulting labeled polysaccharide preparations ranged between 0.1 X 10/sup 6/ and 0.6 X 10/sup 6/ cpm /sup 3/H/..mu..g of uronic acid. The /sup 3/H-labeled polysaccharide preparations did not differ significantly from the corresponding ...

1982-01-15

34

Synthesis of 3-O-sulphamoyl glucofuranose derivatives  

International Nuclear Information System (INIS)

The synthesis of 3-O-sulphamoyl derivatives of 1,2:5,6-di-O-isopropylidene-#alpha#-D-glucofuranose, 1,2-O-isopropylidene-#alpha#-D-glucofuranose, and 5,6-di-O-acetyl-1,2-O-isopropylidene-#alpha#-D-glucofuranose is described. A study of the reactions of carbohydrate chlorosulphates with azide has demonstrated the relative case with which certain chlorosulphonyloxy groups may be converted into azidosulphates. These azidosulphates could have potential synthetic value if a facile method for their conversion into sulphamoyl (aminosulphate) derivatives were available, since some sulphamoyl carbohydrates have been shown to possess antibiotic and antitrypanosomal activity. This report deals with the application of sodium borohydride and platinum oxide-hydrogen to the reduction of some 3-O-azidosulphate glucofuranose derivatives. "1H-n.m.r. spectra and infrared spectra were used.

35

Pharmacokinetic and pharmacodynamic properties of an oral formulation of the histone deacetylase inhibitor Belinostat (PXD101)  

British Library Electronic Table of Contents (United Kingdom)

Purpose The primary objective of this sub-study, undertaken as an extension to the previously reported phase-I study, was to explore the feasibility, tolerability and pharmacokinetics (PK) of belinostat when administered by the oral route. Preliminary pharmacodynamic (PD) studies were also performed to enable comparison of the biological effects of the oral and intravenous formulations. Patients and methods Oral belinostat was administered in a range of doses and schedules (once, twice or thrice daily), on either day 1 or days 1?5, of the second or a subsequent treatment cycle in 15 patients who were included in the phase-I trial of intravenous belinostat. Serial blood samples were collected for PK and PD (histone acetylation) analyses, and the results compared with corresponding analyses ...

2011-01-01

36

Neurochemical deficits in the cerebellar vermis in child offspring of parents with bipolar disorder  

British Library Electronic Table of Contents (United Kingdom)

Singh MK, Spielman D, Libby A, Adams E, Acquaye T, Howe M, Kelley R, Reiss A, Chang KD. Neurochemical deficits in the cerebellar vermis in child offspring of parents with bipolar disorder.-Bipolar Disord 2011: 13: 189-197. 2011 The Authors.-Journal compilation 2011 John Wiley & Sons A/S. Objectives:- We aimed to compare concentrations of N-acetyl aspartate, myo-inositol, and other neurometabolites in the cerebellar vermis of offspring at risk for bipolar disorder (BD) and healthy controls to examine whether changes in these neuronal metabolite concentrations occur in at-risk offspring prior to the onset of mania. Methods:- A total of 22 children and adolescents aged 9-17-years with a familial risk for bipolar I or II disorder [at-risk offspring with non-bipolar I disorder mood symptoms (AR...

2011-01-01

37

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

38

Analysis by high-performance liquid chromatography of radioactively labeled carbohydrate components of proteoglycans  

Energy Technology Data Exchange (ETDEWEB)

Methods were developed for the separation of radioactively labeled carbohydrate components of proteoglycans by isocratic ion-moderated partition HPLC. Neutral sugars were separated after hydrolysis in trifluoroacetic acid with baseline separation between glucose, xylose, galactose, fucose, and mannose. N-Acetylneuraminic acid, N-acetylated hexosamines, glucose, galactose, and xylitol were likewise well separated from each other under isocratic elution conditions. Glucuronic acid, iduronic acid, and their lactones were separated after hydrolysis in formic acid and sulfuric acid. Glucosamine, galactosamine, galactosaminitol, and glucosaminitol were separated by HPLC on a cation exchanger with neutral buffer after hydrolysis in hydrochloric acid. THe separation techniques also proved useful in fractionation of exoglycosidase digests of O- and N-linked oligosaccharides. Separations of aldoses, hexosamines, and uronic acids were adapted to sensitive photometric ...

1986-04-01

39

Synthesis of novel tellurium containing analogues of choline and acetylcholine and their quantitation by pyrolysis-gas chromatography-mass spectrometry.  

Science.gov (United States)

Methods for the synthesis and quantitation of the novel choline analogues, telluronium choline and acetyltelluronium choline, are described. An assay procedure utilizing pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) with cold trapping was developed with [2H4]telluronium choline and [2H4]acetyltelluronium choline as internal standards. The telluronium compounds were ion-pair extracted from tissue with dipicrylamine, washed with 2-butanone, and pyrolyzed prior to GC-MS analysis. The compounds were monitored using selected ion monitoring at m/z 232 and m/z 190 for acetyltelluronium and telluronium choline, respectively, and at m/z 236 and m/z 194 for the analogous deuterated internal standards. The assay was linear over a range of 20 pmol-20 nmol of compound taken through the assay. PMID:8130881

1993-12-31

40

Separation of lithium and calcium isotopes during chemical isotopic exchange in extraction systems with phosphoryl-containing podands  

International Nuclear Information System (INIS)

A study was made on extraction of a series of lithium and calcium salts by monopodands L with common formula R-C_6H_4-O-(CH_2CH_2O)_n-C_6H_4-R, where R - CH_2P(O)Ph_2, n 1-3. Extraction-chromatographic separation of lithium and calcium isotopes in systems of metal aquacomplex-solvatocomplex with L in organic phase was conducted. It was established that separation coefficients of "6Li/"7Li isotopes ranged between 1.003 #+-#0.001 and 1.017 #+-#0.002 at the maximal separation degree equal to 1.60. Separation of "4"0Ca/"4"4Ca isotopes was not fixed. 12 refs., 4 figs., 1 tab.

 
 
 
 
41

Lead, copper and zinc biosorption from bicomponent systems modelled by empirical Freundlich isotherm  

Energy Technology Data Exchange (ETDEWEB)

The biosorption of lead, copper and zinc ions on Rhizopus arrhizus has been studied for three single-component and two binary systems. The equilibrium data have been analysed using the Freundlich adsorption model. The characteristic parameters for the Freundlich adsorption model have been determined and the competition coefficients for the competitive biosorption of Pb(II)-Cu(II) at pH 4.0 and 5.0, and Pb(II)-Zn(II) at pH 5.0 have been calcualted. For the individual single-component isotherms, lead has the highest biosorption capacity followed by copper, then zinc. The capacity of lead in the two binary systems is always significantly greater than those of the other metal ions, in agreement with the single-component data. Only a partial selectivity for copper ions has been obtained at pH 4.0. (orig.)

2000-07-01

42

Detection of glycoproteins in the Acanthamoeba plasma membrane  

International Nuclear Information System (INIS)

In the present study the authors have shown that glycoproteins are present in the plasma membrane of Acanthamoeba castellanii by utilizing different radioactive labeling techniques. Plasma membrane proteins in the amoeba were iodinated by "1"2"5I-lactoperoxidase labeling and the solubilized radiolabeled glycoproteins were separated by lectin-Sepharose affinity chromatography followed by polyacrylamide gel electrophoresis. The periodate/NaB"3H_4 and galactose oxidase/NaB"3H_4 labeling techniques were used for labeling of surface carbohydrates in the amoeba. Several surface-labeled glycoproteins were observed in addition to a diffusely labeled region with M_r of 55,000-75,000 seen on electrophoresis, which could represent glycolipids. The presence of glycoproteins in the plasma membrane of Acanthamoeba castellanii was confirmed by metabolic labeling with ["3"5S]methionine followed by lectin-Sepharose ...

43

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

Energy Technology Data Exchange (ETDEWEB)

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 ...

1985-01-17

44

Gene Repressive Activity of RIP140 Through Direct Interaction with CDK8.  

Science.gov (United States)

Receptor interacting protein 140 (RIP140) is a coregulator for numerous nuclear receptors and transcription factors and primarily exerts gene-repressive activities on various target genes. We previously identified a spectrum of posttranslational modifications on RIP140 that augment its property and biological activity. In T(3)-triggered biphasic regulation of cellular retinoic acid binding protein 1 (Crabp1) gene along the course of fibroblast-adipocyte differentiation, we found TRAP220(MED1) critical for T(3)-activated chromatin remodeling whereas RIP140 essential for T(3)-repressive chromatin remodeling of this gene promoter. In this current study, we aim to examine whether and how RIP140 replaces TRAP220(MED1) on the CrabpI promoter in differentiating adipocyte cultures. We find increasing recruitment of RIP140 to this promoter, with corresponding reduction in TRAP220(MED1) recruitment during the T(3)-repressive phase. We also uncover direct interaction of RIP140 with ...

2011-08-25

45

Energetics and kinetics of anaerobic aromatic and fatty acid degradation  

Science.gov (United States)

The kinetics of benzoate degradation by the anaerobic syntrophic bacterium, Syntrophus buswellii, was studied in coculture with Desulfovibrio strain G11. The threshold value for benzoate degradation was dependent on the acetate concentration with benzoate threshold values ranging from 2.4 [mu]M at 20 mM acetate to 30.0 [mu]M at 65 mM acetate. Increasing acetate concentrations also inhibited the rate of benzoate degradation with a apparent K[sub i] for acetate inhibition of 7.0 mM. Lower threshold values were obtained when nitrate rather than sulfate was the terminal electron acceptor. These data are consistent with a thermodynamic explanation for the threshold, and suggest that there is a minimum Gibbs free energy value required for the degradation of benzoate. An acetoacetyl-CoA thiolase has been isolated from Syntrophomonas wolfei; it is apparently a key enzyme controlling the synthesis of poly-B-hydroxyalkanoate from acetyl-CoA in this organism. Kinetic ...

1992-11-16

46

Hydrogenotrophic Methanogenesis by Moderately Acid-Tolerant Methanogens of a Methane-Emitting Acidic Peat  

UK PubMed Central (United Kingdom)

The emission of methane (1.3 mmol of CH4 m−2 day−1), precursors of methanogenesis, and the methanogenic microorganisms of acidic bog peat (pH 4.4) from...Full Text Available

2003-01-01

47

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  

Energy Technology Data Exchange (ETDEWEB)

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

48

Polycyclic Musks in Water, Sediment, and Fishes from the Upper Hudson River, New York, USA  

British Library Electronic Table of Contents (United Kingdom)

Synthetic musks are used in many consumer products for their pleasant odor and their binding affinity for fabrics. In the early 1990s, polycyclic musks were reported to occur in air, water, sediment, wildlife, and humans from many European countries. Concentrations of polycyclic musks, particularly 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta-[?]-2-benzopyr an (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronapthalene (AHTN), have been reported to increase over time in the environment. In this study, concentrations of musks in water, sediment, fish, and mussel were determined from three locations along the upper Hudson River. HHCB and AHTN were detected in water (n?=?5; 3.95?25.8 and 5.09?22.8?ng/L, respectively), sediment (n?=?3; 72.8?388 and 113?544?ng/g, dry weig...

2011-01-01

49

Genetic engineering of group 2 sigma factor SigE widely activates expressions of sugar catabolic genes in Synechocystis species PCC 6803.  

Science.gov (United States)

Metabolic engineering of photosynthetic organisms is required for utilization of light energy and for reducing carbon emissions.Control of transcriptional regulators is a powerful approach for changing cellular dynamics, because a set of genes is concomitantly regulated. Here, we show that overexpression of a group 2 ? factor, SigE, enhances the expressions of sugar catabolic genes in the unicellular cyanobacterium, Synechocystis sp. PCC 6803. Transcriptome analysis revealed that genes for the oxidative pentose phosphate pathway and glycogen catabolism are induced by overproduction of SigE. Immunoblotting showed that protein levels of sugar catabolic enzymes, such as glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, glycogen phosphorylase, and isoamylase, are increased. Glycogen levels are reduced in the SigE-overexpressing strain grown under light. Metabolome analysis revealed that metabolite levels of the TCA cycle and acetyl-CoA are ...

2011-07-11

50

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  

Energy Technology Data Exchange (ETDEWEB)

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

51

The initial potential and current distributions of the crevice corrosion process  

Energy Technology Data Exchange (ETDEWEB)

A computational model has been developed to calculate the potential and current distributions in the electrolyte phase and on the electrode surface for a system in which a part of the anode is passivated while the rest remains in the active dissolution state. The computation employs the finite element method allied with a boundary variation and a trial and error technique. From the obtained distributions, the location of the boundary between the active and passive regions on the anode can be predicted. In the case of a crevice, this means that a critical distance into the crevice exists beyond which active corrosion (crevice corrosion) takes place. In addition to the active/passive behavior of the material, solution conductivity, applied potential at the sample's outer surface, crevice gap and depth dimensions, and passive current density influence this critical distance to different degrees. The developed software package may also be used for (i) IR-induced crevice corrosion ...

1993-03-01

52

Sequential Voltammetric Determination of Ultratrace Osmium, Ruthenium and Iridium. Application to Superficial Water  

British Library Electronic Table of Contents (United Kingdom)

Abstract The present work, regarding the determination of ultratrace Os(VIII), Ru(III) and Ir(III) in superficial waters is an interesting example of the possibility to simultaneously, or better sequentially determine each single element in real samples by voltammetry. The method is based on the catalytic current of the Os(VIII)- and Ru(III)-bromate systems by square wave voltammetry and on the Ir(III) determination by square wave catalytic adsorptive stripping voltammetry. 0.5-mol-L-1 acetate buffer pH-4.9+7.710-2-mol-L-1 NaBrO3 and 0.5-mol-L-1 acetate buffer pH-4.9+7.710-2-mol-L-1 NaBrO3+2.310-5-mol-L-1 cetyltrimethylammonium bromide (CTAB) +0.2-mol-L-1 KCl were employed as the supporting electrolytes. The analytical procedure was verified by the analysis of the standard reference materi...

2011-01-01

53

Crystal-field excitations in uranium dioxide  

International Nuclear Information System (INIS)

The energy levels of the configuration f"2 in an eight-fold cubic crystal field (CF) have been calculated, and the results are used to explain the experimental spectrum of UO_2. The fourth-order CF potential turns out to be much smaller than usually assumed for this compound. This has an effect of reducing the J-mixing in the wavefunctions, particularly in the case of the ground state wavefunction. In spite of the strength of the CF, the ground state vertical stroke "3H_4T_2 right angle is found to be modified only slightly by the J-mixing effect; it consists of 89.4% "3He_4, and the remaining eleven components make up the rest. Very good correlation is obtained between the experimental and simulated energy-level schemes. The predominance of "3H_4 in the ground state consequently increases the value of the calculated effective magnetic moment. The results are compared with our previous predictions about ...

1998-04-01

54

Additional information from quantitative 24-hour sup 99m Tc-MDP bone scintigraphy in patients with prostatic carcinoma  

Energy Technology Data Exchange (ETDEWEB)

Quantitative bone scintigraphy was performed at 4 and 24 h after injection of {sup 99m}Tc-MDP. The lower thoracic and all the lumbar vertebrae were recorded in 37 patients with prostatic carcinoma before orchiectomy as well as two weeks, two and six months postoperatively. Fourteen patients had normal bone scintigrams. By means of the measured variation in the count rate between normal vertebrae, the criterion for a vertebra to be considered as abnormal was determined using the 4 h-uptake values. For patients with normal scintigrams the count rate at 24 h was below the 4 h level and the mean 24 h/4 h ratio was determined to be 0.85 {+-} 0.09 (1 SD). Normal vertebrae in patients with skeletal metastases had only slightly lower count rate values at 24 h than at 4 h. Abnormal vertebrae showed a higher count rate at 24 h, especially two weeks postoperatively, while a tendency towards lower values than at 4 h was seen after 6 months. If the 24 ...

1991-01-01

55

Additional information from quantitative 24-hour "9"9"mTc-MDP bone scintigraphy in patients with prostatic carcinoma  

International Nuclear Information System (INIS)

Quantitative bone scintigraphy was performed at 4 and 24 h after injection of "9"9"mTc-MDP. The lower thoracic and all the lumbar vertebrae were recorded in 37 patients with prostatic carcinoma before orchiectomy as well as two weeks, two and six months postoperatively. Fourteen patients had normal bone scintigrams. By means of the measured variation in the count rate between normal vertebrae, the criterion for a vertebra to be considered as abnormal was determined using the 4 h-uptake values. For patients with normal scintigrams the count rate at 24 h was below the 4 h level and the mean 24 h/4 h ratio was determined to be 0.85 #+-# 0.09 (1 SD). Normal vertebrae in patients with skeletal metastases had only slightly lower count rate values at 24 h than at 4 h. Abnormal vertebrae showed a higher count rate at 24 h, especially two weeks postoperatively, while a tendency towards lower values than at 4 h was seen after 6 months. If the 24 ...

56

Extraction of magnesium as the iodide by tributyl phosphate  

Science.gov (United States)

The extraction of magnesium by tributyl phosphate from KI solutions was investigated. With increasing KI and TBP concentrations, the extraction increased. The maximum extraction (82%) was attained at pH 4, and it did not decrease with a further pH increase. With decreasing pH, the extraction decreased because of HI extraction. The magnesium was extracted as the compound MgI/sub 2/ x 4TBP. Complexone III (at pH 3-4) does not affect the extraction of magnesium, which makes it possible to use it to mask other metals.

1987-08-20

57

Distribution of 6 q functions in nuclei and quark enhancement of hard processes with deuteron emission  

International Nuclear Information System (INIS)

"2H, "4He, "1"6O, "4"0Ca, "8"0Zr, "1"4"0Yb, "2"2"4112, "3"3"6168 nuclei are invesigated in terms of flucton model. Effective numbers of nuclear fluctons and deuterons are calculated. Values of complete effective numbers of low-radius deuterons and fluctons with S=1 spin and T=0 isospin are presented. Investigation results of inclusive reactions of quasi-elastic knock-out of deuterons by fast protons are discussed. 9 refs.; 1 fig.; 1 tab.

1988-06-14

58

Crystal field levels of Pr"3"+ in PrFeO_3 and PrGaO_3 determined by inelastic neutron scattering  

International Nuclear Information System (INIS)

The crystal field splitting of the "3H_4 ground state of the Pr ion in PrFeO_3 and PrGaO_3 has been investigated by inelastic scattering of the thermal neutrons. At several temperatures the transitions have been measured by TAS and TOF methods for polycrystalline PrFeO_3 and by the TOF method for polycrystalline PrGaO_3. Energy level schemes which are different for these materials are given. (author).

1975-01-01

59

Structural Studies of Electron Deficient Titanacyclobutanes  

British Library Electronic Table of Contents (United Kingdom)

Two 16 electron titanacyclobutanes of the formula Ti(C5H4R)2(?2-CH2)2C(CH3)(i-C3H7) (R=H, CH3) have been prepared from the reaction of Ti(C5H5)2(?2-CH2)(?2-Cl)Al(CH3)2 or Ti(C5H4CH3)2(?2-CH2)(?2-Cl)Al(CH3)2 with H2C=C(CH3)(i-C3H7). Structural parameters, most notably lengthened C?C bonds in the titanacyclobutane ring, for both complexes reveal the expected presence of (C?C)?Ti agostic interactions. The complexes are isomorphous, crystallizing in the monoclinic space group Cc. For Ti(C5H5)2(?2-CH2)2C(CH3)(i-C3H7), a?=?11.3459(3)??, b?=?16.2108(4)??, c?=?8.1646(2)??, ??=?105.5276(16)?, V?=?1446.87(6)?, Dcalc?=?1.268 at 150(1)?K. For Ti(C5H4CH3)2(?2-CH2)2C(CH3)(i-C3H7), a?=?12.6591(2)??, b?=?16.2795(4)??, c?=?8.2462(2)??, ??=?107.2421(14)?, V?=?1623.04(6)??3, Dcalc?=?1.245 at 150(1)?K. Graphi...

2011-01-01

60

Simple Methods for Determining Relative Stereochemistry of Kainoid Amino Acids by (1)H NMR Chemical Shifts.  

Science.gov (United States)

The kainoid amino acids are biologically important compounds because they show remarkable neuroexcitatory and excitotoxic activities. For exhibiting potent activity, the stereochemical relationship of the substituents on the pyrrolidine ring is crucial. We found simple methods for determining the relative stereochemistry of these compounds on the basis of the (1)H NMR chemical shifts of H-2 and H-4 in D(2)O solution. The signals of H-2 appear at fields higher than 4.2 ppm when the compounds have 2,3-trans stereochemistry whereas, in the 2,3-cis compounds, they appear lower than 4.2 ppm, irrespective of the C-4 substituent. This criterion holds when the solution is in the range of pD 3-8. Moreover, when an epimeric pair at C-2 is available and the spectra are recorded at the same or nearly equal pD, the H-2 chemical shift of the 2,3-trans isomer is higher than that of the corresponding 2,3-cis isomer. Similarly, the relative stereochemistry ...

1996-07-12

 
 
 
 
61

Conductivity and Viscosity Measurements for Binary Lysozyme Chloride Aqueous Solution and Ternary Lysozyme-Salt-Water Solution  

CERN Document Server

We use the conductimetric method, adequate to electrolytes, to determine the lysozyme charge in lys-water and ternary lys-salt-water systems. We measured also the viscosities for the above binary and ternary systems in the same conditions at pH$=4.5$ and T$=298$ K, measurements that allow us to see any effect of viscosity on cations mobilities and implicitly on the lysozyme charge. The method is illustrated for the lysozyme chloride aqueous solution system at 25$^o$ C, using the data reported here for pH$=4.5$ at 0.15, 0.6, 0.8, 1., 1.5, 2., 2.5, 3., 3.5 mM (mg/mL) lysozyme chloride concentrations. The method was also applied to ternary lys-salt-water systems in the same conditions at pH$=4.5$ and T$=25^o$ C. Ternary conductivities are reported for a mean concentration 0.6 mM of lysozyme chloride in all systems and a mean concentration 0.01, 0.025, 0.05, 0.1, ...

2004-01-01

62

Tungsten Effects on Phosphate-Dependent Biochemical Pathways are Species and Liver Cell Line Dependent  

British Library Electronic Table of Contents (United Kingdom)

Tungsten, in the form of tungstate, polymerizes with phosphate, and as extensive polymerization occurs, cellular phosphorylation and dephosphorylation reactions may be disrupted, resulting in negative effects on cellular functions. A series of studies were conducted to evaluate the effect of tungsten on several phosphate-dependent intracellular functions, including energy cycling (ATP), regulation of enzyme activity (cytosolic protein tyrosine kinase [cytPTK] and tyrosine phosphatase), and intracellular secondary messengers (cyclic adenosine monophosphate [cAMP]). Rat noncancerous hepatocyte (Clone-9), rat cancerous hepatocyte (H4IIE), and human cancerous hepatocyte (HepG2) cells were exposed to 1-1000 mg/l tungsten (in the form of sodium tungstate) for 24 h, lysed, and analyzed for the ab...

2010-01-01

63

The mechanism of thorium biosorption by Rhizopus arrhizus  

Energy Technology Data Exchange (ETDEWEB)

Inactive cells of Rhizopus arrhizus have been documented to exhibit a high thorium biosorptive uptake (170 mg/g) from aqueous solutions. The mechanism of thorium sequestering by this biomass type was investigated following the same method as for the uranium biosorption emchanism. The thorium sequestering mechanism appeared somewhat different from that of uranium. Experimental evidence is presented which indicates that, at optimum biosorption pH (4), thorium coordinates with the nitroge of the chitin cell wall network and, in addition, more thorium is adsorbed by the external section of the fungal cell wall. At pH 2 the overall thorium uptake is reduced. The kinetic study of thorium biosorption revealed a very rapid rate of uptake. Unlike uranium at optimum solution pH, Fe/sup 2 +/ and Zn/sup 2 +/ did not interfere significantly with the thorium biosorptive uptake capacity of R. arrhizus.

1982-04-01

64

Production of carrier free 188Re radioisotope generator based on aluminum tungstate matrix  

British Library Electronic Table of Contents (United Kingdom)

Improved radionuclide generator include a substantially insoluble salt of a radioactive parent which may be directly packed in column for subsequent elution of the daughter radionuclide. An improved 188Re generator was prepared by reacting a radioactive tungsten (188W) as parent radionuclide incorporated with aluminum chloride to obtain an insoluble radioactive aluminum tungstate matrix. The investigated matrix was characterized on the basis of the chemical composition, IR, thermal analysis and mechanical stabilities. The factors affecting the elution performance were studied such as influence of pH, molar ratio and drying temperature. From the obtained data, the molar ratio W:Al was 1.5:1 at pH?=?4, the matrix dried at 105??C for 2 h. Chromatographic and multichannel analysis has been cur...

2010-01-01

65

On the interaction of vanadium (4) with derivatives 3,4,5-trihydroxy-isoxanthene  

International Nuclear Information System (INIS)

A study was made on interaction of vanadium (4) ions with dyes-pyrogallol red, brompyrogallol red and gallein- in the range of pH = 0-6. The maximal light absorption for gallein and brompyrogallol red is observed at pH=4 and #lambda#max = 545 nm and 560 nm respectively. The compound of vanadium (4) with pyrogalloe red is characterized by the maximal light absorption at pH=5 and #lambda#max=560 nm. Component ratio in all analyzed compounds is equal to 1:2. Molar extinction coefficients for compounds with gallein, pyrogallol red and brompyrogallol red are equal to 5000, 550 and 7400, and logarithms of stability constants - to 9.27, 13.17 and 13.25 respectively.

66

Interaction of rare earths with orthanyl K and its spectrophotometric determination in binary mixtures  

International Nuclear Information System (INIS)

A study has been made of the colour reaction involved in the interaction or rare-earth elements with the reagent orthanyl K, the optimum conditions for the reaction being: pH=4.0-4.5 and lambda=660-670 nm. The ratio of components in the complex is Me:R=1:2. Consideration of the relative optical density values of the complex solutions as a function of the serial number of the rare-earth elements made it possible to recommend orthanyl K as a selective reagent for determining La, Ce, Pr and Nb in a mixture of Tu, Yb, Lu and Y oxides. The molar extinction coefficients, the sensitivity of the reaction and the concentration limits where Beer's law applies were calculated. Lanthanum was determined in a binary mixture with thulium and yttrium. (author).

1975-01-01

67

Growth of ytterbium tartrate trihydrate crystals in silica and agar-agar gels and their characterization  

British Library Electronic Table of Contents (United Kingdom)

Single crystals of ytterbium tartrate trihydrate have been grown by gel method using silica and agar-agar gels as media of growth. The medium of growth influences the morphology of grown crystals, silica gel yielding single and polycrystalline in the form of spherulites whereas agar-agar gel leading to growth of single and twinned crystals. Materials grown as single crystals have been characterized by using optical and scanning electron microscopy (SEM), EDAX, XRD, FT-IR, CHN and thermogravimetric techniques. The stoichiometry of the grown single crystals is suggested to be Yb(C4H4O6) (C4H5O6).3H2O. The FT-IR spectrum shows the presence of singly as well as doubly ionized tartrate ligands. Results of thermal analysis indicate that the material is thermally stable up to a temperature of 200...

2006-01-01

68

Extraction of rare earths by carbonic acids melts  

Energy Technology Data Exchange (ETDEWEB)

Extraction of rare earths (La, Ce, Pr, Eu, Gd, Er, Yb) from nitrate solutions by melts of carboxylic acids of the C/sub 17/-C/sub 20/ fraction and stearic acid with paraffin, depending on the temperature (60-90 deg), phase contact time and their volume ratio (O:B from 1:5 up to 1:100), pH of the aqueous phase (2-6), rare earth concentration (10/sup -6/-10/sup -3/ m) is studied. It is shown that in the whole concentration range investigated rare earths are extracted quantitatively into the carboxylic acid melt of C/sub 17/-C/sub 20/ fraction at the equilibrium value of pH>=3.8, while into the melt of 0.1 M stearic acid in paraffin at pH>=4.5.

1980-10-01

69

Crystal structure of the human centromeric nucleosome containing CENP-A  

British Library Electronic Table of Contents (United Kingdom)

In eukaryotes, accurate chromosome segregation during mitosis and meiosis is coordinated by kinetochores, which are unique chromosomal sites for microtubule attachment. Centromeres specify the kinetochore formation sites on individual chromosomes, and are epigenetically marked by the assembly of nucleosomes containing the centromere-specific histone H3 variant, CENP-A. Although the underlying mechanism is unclear, centromere inheritance is probably dictated by the architecture of the centromeric nucleosome. Here we report the crystal structure of the human centromeric nucleosome containing CENP-A and its cognate ?-satellite DNA derivative (147 base pairs). In the human CENP-A nucleosome, the DNA is wrapped around the histone octamer, consisting of two each of histones H2A, H2B, H4 and CENP...

2011-01-01

70

Brown diamonds from an eclogite xenolith from Udachnaya kimberlite, Yakutia, Russia  

British Library Electronic Table of Contents (United Kingdom)

Abstract: We have performed petrographic and spectroscopic studies of brown diamonds from an eclogite xenolith from the Udachnaya pipe (Yakutia, Russia). Brown diamonds are randomly intermixed with colorless ones in the rock and often located at the grain boundaries of clinopyroxene and garnet. Brown diamonds can be characterized by a set of defects (H4, N2D and a line at 490.7nm) which are absent in colorless diamonds. This set of defects is typical for plastically deformed diamonds and indicates that diamonds were likely annealed for a relatively short period after deformation had occurred. Excitation of brown colored zones with a 632.8nm He-Ne laser produced the typical diamond band plus two additional bands at 1730cm^-^1 and 3350cm^-^1. These spectral features are not genuine Raman ban...

2011-01-01

71

Assembly of a water-insoluble strontium metal-organic framework with luminescent properties  

British Library Electronic Table of Contents (United Kingdom)

A new strontium metal-organic framework, [Sr2(BTEC)(H2O)4] 2H2O (1) (H4BTEC=benzene-1,2,4,5-tetracarboxylic acid), has been successfully synthesized by mixing the starting reagents. The single-crystal structure analysis showed that compound 1 displayed three-dimensional structures containing inorganic motifs with two-dimensional layers pillar-connected through organic linkers and forming water-coordinated neutral framework. Further studies revealed that compound 1 was insoluble in water and that it emitted strong luminescence at approximately 437nm after dehydration.

2011-01-01

72

Alcohol fermentation in olive oil extraction effluents  

Energy Technology Data Exchange (ETDEWEB)

Eight culture-collection yeast strains of various species and five newly isolated stains were tested for both growth in olive oil extraction effluents and fermentation of the sugars in the same media. The culture-collection yeast strains did not grow in an effluent containing 2.86% sugar (w/v), 8 g/litre phenolic substances, 4.58 g/litre titratable acidity and pH 4.96, whereas the newly isolated strains of Torulopsis sp. MK-1, Saccharomyces norbensis MC-1, S. oleaceus MC-2 and S. oleaginosus grew well and fermented the sugars. In the medium mentioned above, they produced alcohol in amounts of 1.63 to 1.38%, respectively. None of the yeasts grew in an olive oil extraction effluent vacuum-concentrated to over 13-14% of dry matter. The strain of T. sp. MK-1 showed a higher stability.

1989-01-01

73

The use of short-echo-time {sup 1}H MRS for childhood cerebellar tumours prior to histopathological diagnosis  

Energy Technology Data Exchange (ETDEWEB)

Proton magnetic resonance spectroscopy (MRS) measures concentrations of metabolites in vivo and provides a powerful method for identifying tumours. MRS has not entered routine clinical use partly due to the difficulty of analysing the spectra. To create a straightforward method for interpreting short-echo-time MRS of childhood cerebellar tumours. Single-voxel MRS (1.5-T Siemens Symphony NUM4, TR/TE 1,500/30 ms) was performed at presentation in 30 children with cerebellar tumours. The MRS results were analysed for comparison with histological diagnosis. Peak heights for N-acetyl aspartate (NAA), creatine (Cr), choline (Cho) and myo-inositol (mIns) were determined and receiver operator characteristic curves used to select ratios that best discriminated between the tumour types. The method was implemented by a group of clinicians and scientists, blinded to the results. A total of 27 MRS studies met the quality control criteria. NAA/Cr >4.0 distinguished all but ...

2007-11-15

74

Optical chemical sensors for atmospheric pollutants based on nano porous materials: application to the formaldehyde and the other carbonyl compounds; Capteurs chimiques a transduction optique de polluants atmospheriques a base de materiaux nanoporeux: application au formaldehyde et autres composes carbonyles  

Energy Technology Data Exchange (ETDEWEB)

Formaldehyde, a well-identified indoor pollutant, was recently classified as carcinogenic. New regulations for the air quality are expected and therefore there is a need for low-cost sensors, sensitive and selective with a fast response time for the detection of formaldehyde at ppb level. In the present work, we had developed a chemical sensor based on nano-porous matrices doped with Fluoral-P and optical methods of detection. The nano-porous matrices, elaborated via the Sol-Gel process, display nano-pores whose cavity is tailored for the trapping of the targeted pollutant. They provide a first selectivity with the discrimination of the pollutants by their size. A second selectivity is obtained with a molecular probe, Fluoral-P, which reacts specifically with formaldehyde leading to the 3,5- di-acetyl-1,4-dihydro-lutidine (DDL). The kinetics of formation of DDL was studied as function of many parameters such as the concentration of Fluoral-P in the matrix, the ...

2006-12-15

75

Ceramics based on SmCoO{sub 3-{delta}} prepared by combustion synthesis as catalysts in hydrocarbon partial oxidation  

Energy Technology Data Exchange (ETDEWEB)

Samarium cobaltite ceramic perovskites, with and without platinum particles dispersion, are possible candidates as electrode for electrochemical conversion of hydrocarbon and for intermediate temperature solid oxide fuel cells (ITSOFC). In this work, samarium cobaltites were synthesized by the combustion method using cobalt, and samarium nitrates as cation precursors and urea as fuel. For containing-platinum compositions Pt (II) acetyl acetonate was also employed as precursor. The effect of Sr on the phase formation and its electrical behavior is also studied. Specific surface area (BET), SEM-EDX, TEM and XRD analysis are used to characterize the powders obtained. Powders were pressed into pellets and sintered in air in the temperature range of 1200 -1400 C. Electrical impedance spectroscopy studies (EIS) are performed on sintered samples. The as-prepared powders showed an amorphous structure and by TEM a very small particle size ({proportional_to}10 nm) was ...

2002-07-01

76

Basic fibroblast growth factor binds to subendothelial extracellular matrix and is released by heparitinase and heparin-like molecules  

Energy Technology Data Exchange (ETDEWEB)

Basic fibroblast growth factor (bFGF) exhibits specific binding to the extracellular matrix (ECM) produced by cultured endothelial cells. Binding was saturable as a function both of time and of concentration of {sup 125}I-bFGF. Scatchard analysis of FGF binding revealed the presence of about 1.5 x 10{sup 12} binding sites/mm{sup 2} ECM with an apparent k{sub D} of 610 nM. FGF binds to heparan sulfate (HS) in ECM as evidenced by (i) inhibition of binding in the presence of heparin or HS at 0.1-1 {mu}g/mL, but not by chondroitin sulfate, keratan sulfate, or hyaluronic acid at 10 {mu}g/mL, (ii) lack of binding to ECM pretreated with heparitinase, but not with chondroitinase ABC, and (iii) rapid release of up to 90% of ECM-bound FGF by exposure to heparin, HS, or heparitinase, but not to chondroitin sulfate, keratan sulfate, hyaluronic acid, or chondroitinase ABC. Oligosaccharides derived from depolymerized heparin, and as small as the tetrasaccharide, released the ECM-bound FGF, but there ...

1989-02-21

77

Wetland treatment of oil and gas well wastewaters. Quarterly technical report, May 25, 1993-August 24, 1993  

Energy Technology Data Exchange (ETDEWEB)

In the third quarterly report adsorption of heavy metals ions such as Cu(II) and Cr(VI) onto soils drawn from the laboratory-type wetland was shown to be weak. Secondly, it was shown that modified-clays did adsorb Cr(VI) ions strongly at pH 4.5. Further, studies on the pH dependence of the adsorption of {beta}-naphthoic acid, (NA), a well-documented contaminant in many oil and gas well waste waters onto modified-clays were undertaken and it was shown that uptake of NA by modified-clays was of the high affinity type at pH 4.5 and 7.0, but weak at pH 9.0. Adsorption of heavy metal ions, Cu{sup 2+}, and Cr(VI) onto algae, a proposed wetland amendment, was carried out and the results were presented and discussed in the fourth quarterly report. Uptake of NA by the soil component of the laboratory-type wetland was monitored as a function of pH. This quarterly report presents results from studies on the uptake ...

1993-10-04

78

Weakly-bridged dimeric diorganotin(IV) compounds derived from pyruvic acid hydrazone Schiff base ligands: Synthesis, characterization and crystal structures  

British Library Electronic Table of Contents (United Kingdom)

We report the synthesis of four diorganotin(IV) compounds of Schiff base pyruvic acid hydrazone derivatives formulated as [R2SnLY]2, where L1 is 2-SC4H3CON2C(CH3)CO2 with Y = CH3CH2CH2CH2OH, R = n-Bu (1); L2 is C6H5CON2C(CH3)CO2 with Y = CH3CH2OH, R = p-F-Bz (2); L3 is 2-HOC6H4CON2C(CH3)CO2 with YH2O, R = p-CN-Bz (3); and L4 is 4-NO2-C6H4CON2C(CH3)CO2 with YCH3CH2OH, R = Bz (4). The structures of all compounds have been established by a combination of single-crystal X-ray diffraction analysis, 1H and 119Sn NMR spectroscopy, IR spectroscopy, and elemental analysis. Studies reveal that four ligands present the same coordination mode with tin center, which all present tridentate ONO donor Schiff bases and coordinate to the tin center in an enolic form. In compounds 1-4, each tin atom is seven...

2011-01-01

79

Effect of acidic fluoride solution on beta titanium alloy wire.  

Science.gov (United States)

The interaction between acidic fluoride solution and beta titanium alloy was investigated to explore the changes that occur in beta titanium alloy by fluoride-containing acetic acid solutions. For this, alloy crystal structure, tensile strength, and elements released from the alloy wires were determined using four solutions (0.05%/pH 6, 0.05%/pH 4, 0.2%/pH 6, and 0.2%/pH 4) for 1 or 3 days. The immersed wire did not form any identifiable new crystal structure compared with the as-received wire. The tensile strength of the immersed wires was significantly reduced compared to the as-received wires in the test solutions if the period of immersion increased from as-received to 3 days. The fractured area of the immersed wire was reduced compared to the as-received one. The dimple pattern at the inner part and a cup-cone morphology at the outer part of the fractured wires were similar in both as-received and ...

2005-05-01

80

Effect of PbO on the repassivation kinetics of alloy 690  

Energy Technology Data Exchange (ETDEWEB)

Effects of PbO on the repassivation kinetics of alloy 690TT were examined using the rapid scratching electrode technique under a potentiostatic condition to elucidate the influence of PbO on SCC resistance of the alloy. The repassivation kinetics of the alloy was analyzed in terms of the current density flowing from the scratch, i(t), as a function of the charge density that has flowed from the scratch, q(t). Repassivation on the scratched surface of the alloy occurred in two kinetically different processes; passive film initially nucleated and grew according to the place exchange model in which log i(t) is linearly proportional to q(t) with a slope of 1/K, and then grew according to the high field ion conduction model in which log i(t) is linearly proportional to 1/q(t) with a slope of cBV. 1/K and cBV are parameters representing the SCC susceptibility as well as repassivation rate of the alloy at an initial and an intermediated stages of repassivation respectively. The higher the ...

2000-07-01

 
 
 
 
81

Effect of PbO on the repassivation kinetics of alloy 690  

International Nuclear Information System (INIS)

Effects of PbO on the repassivation kinetics of alloy 690TT were examined using the rapid scratching electrode technique under a potentiostatic condition to elucidate the influence of PbO on SCC resistance of the alloy. The repassivation kinetics of the alloy was analyzed in terms of the current density flowing from the scratch, i(t), as a function of the charge density that has flowed from the scratch, q(t). Repassivation on the scratched surface of the alloy occurred in two kinetically different processes; passive film initially nucleated and grew according to the place exchange model in which log i(t) is linearly proportional to q(t) with a slope of 1/K, and then grew according to the high field ion conduction model in which log i(t) is linearly proportional to 1/q(t) with a slope of cBV. 1/K and cBV are parameters representing the SCC susceptibility as well as repassivation rate of the alloy at an initial and an intermediated stages of repassivation respectively. The higher the ...

2000-08-24

82

Crystal structure of ABPO_5 and optical study of Pr"3"+ embedded in these compounds  

International Nuclear Information System (INIS)

The crystal structure of borophosphates ABPO_5 (A = alkaline earth or Pb) was resolved on a polycrystalline sample using the Rietveld method. The x-ray diffraction patterns data show that ABPO_5 crystallize in a centrosymmetric space group P3_121 and their structure is related to the borogermanates REBGeO_5 with a stillwellite-type structure. Pr"3"+ ion was used as a local structural probe to corroborate the structural resolution results. Absorption and fluorescence spectra of A_1_-_xPr_xBP_1_-_xGe_xO_5 (A alkaline earth or Pb; x = 0.05) have been investigated at different temperatures. At 9 K the 3"H_4#->#"3P_0 transition of trivalent praseodymium ion (4f"2 configuration) is observed as a single line. This indicates a unique crystallographic site for the rare earth ion in these compounds replacing the divalent cation. Energy level schemes were deduced from the low-temperature spectroscopic measurements. Comparing the electronic level ...

2001-10-22

83

Cd(II), Pb(II) and Zn(II) removal from contaminated water by biosorption using activated sludge biomass  

Energy Technology Data Exchange (ETDEWEB)

Biosorption using activated sludge biomass (ASB) as a potentially sustainable technology for the treatment of wastewater containing different metal ions (Cd(II), Pb(II) and Zn(II)) was investigated. ASB metal uptake clearly competed with protons consumed by microbial biomass compared with control tests with non-activated sludge biomass. Biosorption tests confirmed maximum exchange between metal ions and protons at pH 2.0-4.5. It was revealed by the study that the amount of metal ions released from the biomass increased with biomass sludge concentration. The result showed that maximum absorption of metal ions was observed for Cd(II) at pH 3.5, Pb(II) at pH 4.0, and pH 4.5 for Zn(II) ions. The maximum absorption capacities of ASB for Cd(II), Pb(II) and Zn(II) were determined to be 59.3, 68.5 and 86.5%, respectively. The biosorption of heavy metals was directly proportional to ASB stabilization ...

2010-02-15

84

Pretargeted radioimmunotherapy in tumored mice using an in vivo {sup 212}Pb/{sup 212}Bi generator  

Energy Technology Data Exchange (ETDEWEB)

Objective: Pretargeting is the concept that combines optimal delivery of the antibody and rapid capture and elimination of the radioactivity. In this study, we evaluated the potential of antibody pretargeting to enable the tumor-targeting {sup 212}Pb for in vivo generation of {sup 212}Bi for {alpha} particle radiotherapy. Methods: The {sup 212}Pb/{sup 212}Bi chelate of DOTA-biotin, as well as their {gamma}-emitting analogues, {sup 203}Pb and {sup 205}Bi, was prepared and characterized. The radiolabeled compounds were injected in animals for evaluation of tumor targeting and normal tissue uptake and retention. In the pretargeting protocol, injection of 400 {mu}g of NR-LU-10 antibody-streptavidin conjugate was given at t=0 h, then 100 {mu}g of N-acetyl-galatosamine-biotin clearing agent was injected at t=20-24 h; finally, 1 {mu}g of {sup 212}Pb/{sup 212}Bi-DOTA-biotin was injected 6 h later. Results: Both {sup 203}Pb and {sup 205}Bi-DOTA-biotin were stable for at ...

2005-10-01

85

Uranium (VI)Bis(imido) chalcogenate complexes:synthesis and density functional theory analysis  

Energy Technology Data Exchange (ETDEWEB)

Bis(imido) uranium(VI) trans- and cis-dichalcogenate complexes with the general formula U(NtBu)2(EAr)2(OPPh3)2 (EAr = O-2-tBuC6H4, SPh, SePh, TePh) and U(NtBu)2(EAr)2(R2bpy) (EAr = SPh, SePh, TePh) (R2bpy = 4,4'-disubstituted-2,2'-bipyridyl, R = Me, tBu) have been prepared. This family of complexes includes the first reported monodentate selenolate and tellurolate complexes of uranium(VI). Density functional theory calculations show that covalent interactions in the U-E bond increase in the trans-dichalcogenate series U(NtBu)2(EAr)2(OPPh3)2 as the size of the chalcogenate donor increases and that both 5f and 6d orbital participation is important in the M-E bonds of U-S, U-Se, and U-Te complexes.

2009-01-01

86

Studies on accumulation of uranium by fungus Lentinus sajor-caju  

Energy Technology Data Exchange (ETDEWEB)

The untreated, heat- and alkali-treated Lentinus sajor-caju mycelia were used for the recovery of uranium from aqueous solutions. The effect of pH, temperature, initial concentration of UO{sub 2} {sup 2+} ions and contact time parameters were investigated in a batch system. The particles sizes of the fungal mycelia were ranging from 100 to 200 {mu}m. Biosorption equilibriums were established in about 30 min and the correlation regression coefficients show that the adsorption process can be well defined by the Freundlich equation. The alkali treated form had a high biosorption capacity (378 mg/g) than those of the untreated (268 mg/g) and heat-treated fungal mycelia (342 mg/g). Optimum biosorption was observed at pH 4.5 for all the tested fungal preparations and was independent of temperature (5-35 deg. C). In addition, the polarity and surface energy of the fungal biomass film preparations were determined by contact angle measurement. The ...

2006-08-21

87

Structure and kinematics of edge-on galaxy discs - I. Observations of the stellar kinematics  

CERN Document Server

We present deep optical long-slit spectra of 17 edge-on spiral galaxies of intermediate to late morphological type, mostly parallel to their major axes and in a few cases parallel to the minor axes.The line-of-sight stellar kinematics are obtained from the stellar absorption lines using the improvedc ross-correlation technique. In general, the stellar kinematics are regular and can be traced well into the disc-dominated region. The mean stellar velocity curves are far from solid-body, indicating that the effect of dust extinction is not large. The line-of-sight stellar disc velocity dispersion correlates with the galaxy maximum rotational velocity, but detailed modeling is necessary to establish whether this represents a physical relation. In four spirals with a boxy- or peanut-shaped bulge we are able to detect asymmetric velocity distributions, having a common signature with projected radius in the mean line-of-sight velocity and the $h_{3}$ and ...

2004-01-01

88

Sorption of arsenite and arsenate on ferrihydrite: Effect of organic and inorganic ligands  

British Library Electronic Table of Contents (United Kingdom)

We studied the sorption of As(III) and As(V) onto ferrihydrite as affected by pH, nature and concentration of organic [oxalic (OX), malic (MAL), tartaric (TAR), and citric (CIT) acid] and inorganic [phosphate (PO4), sulphate (SO4), selenate (SeO4) and selenite (SeO3)] ligands, and the sequence of anion addition. The sorption capacity of As(III) was greater than that of As(V) in the range of pH 4.0-11.0. The capability of organic and inorganic ligands in preventing As sorption follows the sequence: SeO4~SO43 PO4. The efficiency of most of the competing ligands in preventing As(III) and As(V) sorption increased by decreasing pH, but PO4 whose efficiency increased by increasing pH. In acidic systems all the competing ligands inhibited the sorption of As(III) more than As(V), but in alkaline e...

2011-01-01

89

Preparation of a "6"2Zn-"6"2Cu generator and of "6"1Cu following alpha particle irradiation of a nickel target  

International Nuclear Information System (INIS)

The "6"2Zn-"6"2Cu generator system is one of the few which yield a pure positron emitting daughter. The authors have developed a method for the preparation of this generator system following 32 MeV #alpha# particle bombardment of nickel targets. The chemical processing involves two stages: first a hydrous zirconium oxide column is used at pH 4-5 to separate the zinc and copper activities produced in the target nickel, and secondly, a conventional anion exchange column is used to retain the "6"2Zn and remove all copper activities in 2M HCl. This column serves as the "6"2Cu generator which will yield pure "6"2Cu repeatedly, free from "6"2Zn and other impurities, in a mixture of HCl and NaCl. A method is outlined also to obtain a solution of "6"2Zn using the hydrous zirconium oxide (HZO) column. "6"1Cu can be prepared as a by-product in the above procedure, but a method for the preparation of "6"1Cu alone using an 18 MeV #alpha# particle beam on a ...

90

Molar extinction coefficients of some fatty acids  

International Nuclear Information System (INIS)

The attenuation of gamma rays in some fatty acids, viz. formic acid (CH_2O_2), acetic acid (C_2H_4O_2), propionic acid (C_3H_6O_2), butyric acid (C_4H_8O_2), n-hexanoic acid (C_6H_1_2O_2), n-caprylic acid (C_8H_1_6O_2), lauric acid (C_1_2H_2_4O_2), myristic acid (C_1_4H_2_8O_2), palmitic acid (C_1_6H_3_2O_2), oleic acid (C_1_8H_3_4O_2) and stearic acid (C_1_8H_3_6O_2), has been measured at the photon energies 81, 356, 511, 662, 1173 and 1332 keV. Experimental values for the molar extinction coefficient, the effective atomic number and the electron density have been derived and compared with theoretical calculations. There is good agreement between experiment and theory.

2002-10-01

91

Measurement of unpolarized semi-inclusive pi+ electroproduction off the proton  

Science.gov (United States)

Semi-inclusive pi+ electroproduction on protons has been measured with the CLAS detector at Jefferson Lab. The measurement was performed on a liquid-hydrogen target using a 5.75 GeV electron beam. The complete five-fold differential cross sections were measured over a wide kinematic range in Q2, x, z, and pT and over the complete range of azimuthal angles, phi, enabling us to separate the different structure functions, H2+eps*H1, H3 and H4. Our measurements of H2 at low-x were found to be in fairly good agreement with pQCD calculations, suggesting a precocious factorization of the process. Indeed, the conventional f(x)*D(z) term can account for almost all of the observed cross section, even at small z. The measured xF-distributions are in qualitative agreement with high energy data, which suggests a surprising numerical similarity between the spectator diquark fragmentation in the present reaction and the anti-quark fragmentation measured in ...

2008-01-01

92

Limits on Anomalous Trilinear Gauge Couplings in Zgamma Events from ppbar Collisions at sqrt{s} = 1.96 TeV  

CERN Document Server

Using Zgamma candidate events collected by the CDF detector at the Tevatron Collider, we search for potential anomalous (non-standard-model) couplings between the Z boson and the photon. At the hard scatter energies typical of the Tevatron, standard model Zgamma couplings are too weak to be detected by current experiments; hence any evidence of couplings indicates new physics. Measurements are performed using data corresponding to an integrated luminosity of 4.9 /fb in the Z -> nunubar decay channel and 5.1 /fb in the Z -> l^+l^- (l=mu, e) decay channels. The combination of these measurements provides the most stringent limits to date on Zgamma trilinear gauge couplings. Using an energy scale of Lambda = 1.5 TeV to allow for a direct comparison with previous measurements, we find limits on the CP-conserving parameters that describe Zgamma couplings to be |h_3^{\\gamma,Z}| < 0.017 and |h_4^{\\gamma,Z}| < 0.0006. These results are ...

2011-01-01

93

Influence of bias voltage on the formation and properties of iron-based nitrides produced by plasma nitriding  

Energy Technology Data Exchange (ETDEWEB)

A series of experiments have been conducted on AISI 5140 low alloy steel using a hollow cathode discharge-assisted plasma nitriding apparatus with the aim of elucidating the role of substrate bias voltages in plasma nitriding process. For comparison, some samples were nitrided with applied substrate bias (-50 V) while other samples were nitrided at floating potential. Treatments were carried out in NH{sub 3} atmosphere of 150 Pa at temperatures ranging from 450 {sup o}C to 550 {sup o}C for 2 h, 4 h, and 6 h. The nitrided samples were characterized by optical microscopy, X-ray diffraction and micro-hardness measurement. The corrosion behaviors were evaluated using anodic polarization tests in 3.5% NaCl solution. The results showed that the microstructure and phase constituents of the nitride layers were strongly influenced by the bias voltages. It was also demonstrated that the better corrosion resistance with a thicker nitrided layer was ...

2010-05-14

94

Influence of bias voltage on the formation and properties of iron-based nitrides produced by plasma nitriding  

International Nuclear Information System (INIS)

A series of experiments have been conducted on AISI 5140 low alloy steel using a hollow cathode discharge-assisted plasma nitriding apparatus with the aim of elucidating the role of substrate bias voltages in plasma nitriding process. For comparison, some samples were nitrided with applied substrate bias (-50 V) while other samples were nitrided at floating potential. Treatments were carried out in NH_3 atmosphere of 150 Pa at temperatures ranging from 450 "oC to 550 "oC for 2 h, 4 h, and 6 h. The nitrided samples were characterized by optical microscopy, X-ray diffraction and micro-hardness measurement. The corrosion behaviors were evaluated using anodic polarization tests in 3.5% NaCl solution. The results showed that the microstructure and phase constituents of the nitride layers were strongly influenced by the bias voltages. It was also demonstrated that the better corrosion resistance with a thicker nitrided layer was obtained on the ...

2010-05-14

95

Gas and stellar dynamics in NGC 1068. Probing the galactic gravitational potential  

CERN Document Server

We present Sauron 2D spectrography of the central 1.5 kpc of the nearby Sey2 galaxy NGC1068, encompassing the well-known NIR inner bar. We have successively disentangled the respective contributions of the ionized gas and stars, thus deriving their 2D distribution and kinematics. The [OIII] and Hbeta emission lines exhibit very different spatial distribution and kinematics, the latter following inner spiral arms with clumps associated with star formation. Strong inwards streaming motions are observed in both the Hbeta and [OIII] kinematics. The stellar kinematics also exhibit clear signatures of a non-axisymmetric tumbling potential, with a twist in both the velocity and h3 fields. We re-examined the long-slit data of Shapiro et al (2003) using pPXF: a strong decoupling of h3 is revealed, and the central decrease in h4 hinted in the Sauron data is confirmed. These data also suggest that NGC1068 is a good candidate for a so-called sigma-drop. We ...

2006-01-01

96

Emissions of nitrogen oxides from equatorial rain forest in central Africa: origin and regulation of NO emission from soils  

Energy Technology Data Exchange (ETDEWEB)

Emissions of nitric oxide from soils of equatorial rain forest were measured in the Dimonika Natural Park (4 degrees 30'S, 12 degrees 30'E) in the Mayombe Forest in Congo. Three research campaigns were carried out in June and July 1991 and in February 1992. Fluxes were measured by dynamic chamber techniques using a chemiluminescence instrument Scintrex LMA3. NO fluxes measured on natural soils are in between 5 and 17x10[sup 9] molecules cm[sup -2]s[sup -1]; they are of the same order of magnitude as those observed in similar tropical forest media. Soil treatment experiments show that the auto-decomposition of HNO[sub 2] in these acid soils (pH 4) (chemodenitrification) is a potentially important cause of nitric oxide production in this type of ecosystem. Nitrous acid comes from autotrophic nitrification all the year around, and also from biological denitrification, shown by N[sub 2]O emissions, during the rainy season. The ...

1994-09-01

97

Effects of soil pH on rhizoctonia damping-off of sugar beet and disease suppression induced by soil amendment with crop residues  

British Library Electronic Table of Contents (United Kingdom)

Effects of soil pH on damping-off of sugar beet by R. solani (AG2-2) and soil suppressiveness against the disease were studied by comparing disease incidences in pasteurized versus non-pasteurized, infested soils. Soil pH was correlated neither to disease incidence in five soils ranging from pH?4.5 to 7.2 nor to indigenous disease suppressiveness, the difference in disease incidences between non-treated soil and its pasteurized counterpart. When an alkaline soil was acidified with H2SO4, disease suppression markedly declined, increasing disease incidence in the non-pasteurized soil. Inversely, disease suppression was enhanced when an acidic soil was neutralized by adding Ca(OH)2. Soil amendment with dried peanut plant residue suppressed the disease in two pasteurized, near-neutral soils, l...

2011-01-01

98

Effect of chemical composition of SiOx films on rapid formation of Si nanocrystals induced by thermal plasma jet irradiation  

British Library Electronic Table of Contents (United Kingdom)

Si nanocrystal floating gate MOS capacitors were formed on p-Si (100) wafers by thermal plasma jet (TPJ) annealing of SiO2/SiOx /SiO2/Si(100) stacked structure. The chemical composition of SiOx layer was controlled by changing the SiH4, He, and O2 gas flow ratio during plasma enhanced chemical vapour deposition. The MOS capacitors showed clear hysteresis in capacitance-voltage (CV) characteristics after TPJ annealing. The hysteresis width shows maximum value when initial composition x =1.7, which shows the maximum photoluminescence (PL) intensity. The maximum hysteresis width of 6.8 V was observed with gate voltage swept between 20 and -20 V in x = 1.7 sample. The result means 7.4 x 1012 cm-2 carriers are injected to or emitted from Si nanocrystals. The duration of 1 V shift in flatband vo...

2010-01-01

99

Determination of principal and impurity components in monocrystals of erbium and yttrium formates grown on the basis of high-pure substances  

International Nuclear Information System (INIS)

Determination of principal and impurity components in monocrystals of erbium and yttrium formates grown on the basis of high-pure formates from oriental primers, using the method of isothermal evaporation of the salt aqueous solutions with pH 4.4 - 4.5, is described. Er and Y were determined complexonometrically by the titration of the complex with arsenazo 1 by EDTA solution, and formate-ion was determined iodometrically. Impurities were analyzed by atomic-absorption and titrimetric methods. The atomic-absorption method permits to determine in the monocrystal from 1 x 10"-"4 to 5 x 10"-"3 % Mg at relative standard deviation S_r = 0.05; from 1 x 10"-"3 to 2.5 x 10"-"2 % Ca at S_r = 0.07 and from 2 x 0"-"4 to 5 x 10"-"3 % Pb ar S_r = 0.08.

100

Catalytic-adsorptive stripping voltammetric determination of ultra-trace iridium(III). Application to fresh- and sea-water  

British Library Electronic Table of Contents (United Kingdom)

An extremely sensitive stripping voltammetric procedure for ultra-trace determination of iridium(III) is reported. The method is based on the interfacial accumulation of the iridium(III)-CTAB complex onto the glassy carbon electrode, followed by the catalytic reduction of the adsorbed complex in the presence of bromate. 0.3molL^-^1 acetate buffer pH 4.7+6.9x10^-^2molL^-^1 NaBrO3+2.7x10^-^5molL^-^1 cetyltrimethylammonium bromide (CTAB)+0.2molL^-^1 KCl was employed as the supporting electrolyte. The analytical procedure was verified by the analysis of the standard reference materials: Sea Water BCR-CRM 403 and Fresh Water NIST-SRM 1643d. The accuracy, expressed as relative error e%, was satisfactory, being lower than 6%, while precision as repeatability, expressed as relative standard deviat...

2011-01-01

 
 
 
 
101

Cadmium biosorption rate in protonated Sargassum biomass  

Energy Technology Data Exchange (ETDEWEB)

Biosorption of the heavy metal ion Cd{sup 2+} by protonated nonliving brown alga Sargassum fluitans biomass was accompanied by the release of hydrogen protons from the biomass. The uptake of cadmium and the release of proton matched each other throughout the biosorption process. The end-point titration methodology was used to maintain the constant pH 4.0 for developing the dynamic sorption rate. The sorption isotherm could be well represented by the Langmuir sorption model. A mass transfer model assuming the intraparticle diffusion in a one-dimensional thin plate as a controlling step was developed to describe the overall biosorption rate of cadmium ions in flat seaweed biomass particles. The overall biosorption mathematical model equations were solved numerically yielding the effective diffusion coefficient D{sub e} about 3.5 {times} 10{sup {minus}6} cm{sup 2}/s. This value matches that obtained for the desorption process and is approximately ...

1999-03-01

102

Apoferritin Templated Synthesis of Metal Phosphate Nanoparticle Labels for Electrochemical Immunoassay  

Energy Technology Data Exchange (ETDEWEB)

W have introduced template-synthesized metal phosphate nanoparticle labels for electrochemical immunoassay. Such use of an apoferritin template offers a simple and convenient route to prepare metallic nanoparticle labels for electrochemical immunoassays and avoid the complicated and time-consuming nanoparticle synthesis process (QD synthesis). Releasing metal ions from metal phosphate in an acetate buffer (pH 4.6) eliminates the harsh condition in the traditional metallic nanoparticle dissolution (e.g., strong acid dissolution of QDs and gold nanoparticles). This method is ultrasensitive and its DL is low to 77fM. The simultaneous detection of multiple protein targets is easily performed by using different metal phosphate nanoparticle labels (cadmium phosphate and lead phosphate). This approach can be extended to prepare multiple metal (such as zinc, lead, cadmium, copper, indium, gold, silver) phosphate nanoparticle labels or hybrid metal ...

2006-08-29

103

Analysis of S-adenosylmethionine and related sulfur metabolites in bacterial isolates of Pseudomonas aeruginosa (BAA-47) by liquid chromatography/electrospray ionization coupled to a hybrid linear quadrupole ion trap and Fourier transform ion cyclotron resonance mass spectrometry  

British Library Electronic Table of Contents (United Kingdom)

A comprehensive and highly selective method for detecting in bacterial supernatants a modified sulfur nucleoside, S-adenosyl-L-methionine (SAM), and its metabolites, i.e., S-adenosylhomocysteine (SAH), adenosine (Ado), 5prime-deoxy-5prime-methylthioadenosine (MTA), adenine (Ade), S-adenosyl-methioninamine (dcSAM), homocysteine (Hcy) and methionine (Met), was developed. The method is based on reversed-phase liquid chromatography with positive electrospray ionization (ESI+) coupled to a hybrid linear quadrupole ion trap (LTQ) and 7-T Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). A gradient elution was employed with a binary solvent of 0.05 M ammonium formate at pH 4 and acetonitrile. The assay involves a simultaneous cleanup of cell-free bacterial broths by solid-pha...

2009-01-01

104

Aggregation of silica nanoparticles directed by adsorption of lysozyme.  

Science.gov (United States)

The interaction of the globular protein lysozyme with silica nanoparticles of diameter 20 nm was studied in a pH range between the isoelectric points (IEPs) of silica and the protein (pH 3-11). The adsorption affinity and capacity of lysozyme on the silica particles is increasing progressively with pH, and the adsorbed protein induces bridging aggregation of the silica particles. Structural properties of the aggregates were studied as a function of pH at a fixed protein-to-silica concentration ratio which corresponds to a surface concentration of protein well below a complete monolayer in the complete-binding regime at pH > 6. Sedimentation studies indicate the presence of compact aggregates at pH 4-6 and a loose flocculated network at pH 7-9, followed by a sharp decrease of aggregate size near the IEP of lysozyme. The structure of the bridged silica aggregates was studied by cryo-transmission electron microscopy (cryo-TEM) and small-angle ...

2011-07-20

105

Ab initio and AIM studies on typical -type and pseudo--type halogen bonds: Comparison with hydrogen bonds  

British Library Electronic Table of Contents (United Kingdom)

Abstract Series of typical -type and pseudo--type halogen-bonded complexes BClY and BBrY and hydrogen-bonded complex BHY (B = C2H4, C2H2, and C3H6; Y = F, Cl, and Br) have been investigated using the MP2/aug-cc-pVDZ method. A striking parallelism was found in the geometries, vibrational frequencies, binding energies, and topological properties between BXY and BHY (X = Cl and Br). It has been found that the lengths of the weak bond d(X)/d(H), the frequencies of the weak bond (X)/(H), the frequency shifts (XY)/(HY), the electron densities at the bond critical point of the weak bonds c(X)/c(H), and the electron density changes c(XY)/c(HY) could be used as measures of the strengths of typical -type and pseudo--type halogen/hydrogen bonds. The typical -type and pseudo--type halogen bond and hyd...

2011-01-01

106

A comparison of the low cycle fatigue behavior of alloy 800 and alloy 800H  

International Nuclear Information System (INIS)

The low cycle fatigue testing was carried out to provide a basis for comparison of the behavior of the two kinds of Alloy 800 (low carbon Alloy 800 and high carbon Alloy 800H). The testing was done at temperatures of 500"0C and 650"0C either with or without hold. The results obtained were as follows: (1) At 650"0C, the low-cycle fatigue life was essentially the same for the two alloys on the basis of strain amplitude, but Alloy 800H had a longer life on the basis of stress amplitude. (2) At 500"0C, the two alloys exhibited longer lives than at 650"0C, with Alloy 800 exhibiting 2-3 times longer life than Alloy 800H when compared on the basis of plastic strain range. At this temperature the stress range showed the maximum for Alloy 800H. (3) When a creep effect was introduced either by way of a hold time or a reduced frequency, Alloy 800 exhibited a greater reduction in life than in Alloy 800H. (4) At lower temperature the strain aging phenomena ...

1979-06-01

107

Proposal to neutralize acid fluids from wells in the Los Humeros, Pue., geothermal field; Propuesta para la neutralizacion de fluidos acidos provenientes de pozos del campo geotermico de Los Humeros, Pue.  

Energy Technology Data Exchange (ETDEWEB)

Neutralizing an acidic fluid consists of adding a sodium hydroxide solution to neutralize the H group of acids, therefore increasing the pH. The injection of sodium hydroxide has to be continuous and at a proper depth inside the well to protect against the corrosion of casing and surface equipment. Neutralization is a common practice used in geothermal fields, such as at The Geysers in the US and Miravalles in Costa Rica-places where aggressive fluids cause problems for extracting and using geothermal fluids commercially. A zone surrounding wells H-4, H-16 and H-29 in the northern section of the Los Humeros, Pue., geothermal field, known as the Colapso Central, has shown evidence of aggressively acidic fluids. Several wells drilled in the area had to be repaired, thus plugging and isolating the deepest production zones. Well H-43 was drilled two years ago in the northern zone of the field, and even though it is not located in the ...

2009-07-15

108

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

International Nuclear Information System (INIS)

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

109

Studies on a Factor in Sweet Potato Root Which Agglutinates Spores of Ceratocystis fimbriata, Black Rot Fungus 1  

Science.gov (United States)

A factor which agglutinated the spores of Ceratocystis fimbriata in the presence of Ca2+ was purified from sweet potato (Ipomea batatas Lam cv. Norin[1]) root. Element composition of the purified factor was as follows; analysis found: C (29.8%), H (3.97%), O (65.34%), N (0.81%): calculated for C43H69O70N1: C (30.02%), H (4.01%), O (65.15%), N (0.81%). The factor was mainly composed of galacturonic acid (53% of dry weight) and contained arabinose, fucose, and unidentified component as minor components. The factor also agglutinated A-, B-, AB-, and O types of human erythrocytes to almost the same degree in the presence of Ca2+. The differential spore-agglutinating activity of the factor depended on the pH of the assay medium; it agglutinated similarly the germinated spores of sweet potato and coffee strains at pH 7.5 and 5.5, whereas it displayed a distinct differential agglutinating activity at pH 6.5. The factor was assayed for ...

1982-02-01

110

Separation and determination of cadmium and zinc as their thenoyltrifluoroacetone complexes with dibenzo-18-crown-6 by means of synergistic extraction and atomic absorption spectrometry  

Energy Technology Data Exchange (ETDEWEB)

A new method for the separation and determination of trace amounts of cadmium and zinc in water as their thenoyltrifluoroacetone (TTA) complexes with dibenzo-18-crown-6 (DB18C6) in o-dichlorobenzene has been established by means of synergistic extraction and back-extraction combined with atomic absorption spectrometry. The effect of various factors (synergism with TTA and DB18C6, shaking time, composition of the extracted species, and mutual separation etc.) on the extraction and back-extraction of cadmium and zinc has been in- vestigated. When the mixtures were extracted for 4 min at pH 4.9, only zinc was extracted quantitatively, whereas cadmium remained in the aqueous phase. After the phases were separated, cadmium was again extracted quantitatively at pH 7.5. Then, the two phases were each shaken with 0.05-0.1 mol/l HCl in order to back-extract cadmium and zinc from the organic phases; the ions were determined individually by atomic ...

1997-01-01

111

Quantitative bone scintigraphy. A study in patients with prostatic carcinoma  

International Nuclear Information System (INIS)

Quantitative bone scintigraphy was performed in patients with prostatic carcinoma before orchiectomy as well as two weeks, two and six months after operation. The count rate was recorded as serial gamma camera images over the lower thoracic and all lumbar vertebrae from 1 to 240 min and at 24 h after injection of "9"9"Tc"m-MDP. In almost all abnormal vertebrae an increased count rate was observed within one hour after injection. Most of the vertebrae which were considered normal at 4 h after injection, but had an increased 24h/4h ratio developed into abnormal vertebrae later in the study. The patients with normal bone scintigrams showed no change in "9"9Tc"m-MDP uptake during the study. The reproducibility of quantitative bone scintigraphy was found to be #+-# 7% (1 SD). In response to therapy, most of the patients with abnormal bone scintigrams showed an increase in count rate two weeks after operation followed by a decrease to the ...

1985-06-02

112

Oxidation and adsorption of Co(II) EDTA{sup 2-} complexes in subsurface materials with iron and manganese oxide grain coatings  

Science.gov (United States)

Batch interaction experiments were performed under aerobic conditions to characterize the adsorption behavior and valence speciation of CoEDTA complexes (equimolar at 10{sup -5} mol/L) in a series of Pliocene subsurface sediments containing various amounts of Fe and Mn oxides. The experiments were performed in 0.003 mol/L Ca(ClO{sub 4}){sub 2} with a solids concentration of 500 g/L at variable pH (4-9) and at the natural pH of the sediments (pH = 8.3). Three of these subaerial sediments (Ringold 1, 2, 3) contained significant quantities of extractable Fe and Mn, while the fourth (Ringold 4) was virtually devoid of sesquioxide precipates. Microscopic and mineralogic analyses of the most heavily encrusted material (Ringold 2) showed that the oxides existed as intergrain cements and contained crystalline goethite and rancieite/todorokite. Adsorption on a synthetic analog sorbent (0.6 mass% ferrihydrite-coated sand) over a range in pH showed that, ...

1995-11-01

113

Observation and simulation of the energy levels of the trivalent thulium ion in gadolinium oxychloride  

International Nuclear Information System (INIS)

The optical absorption of the Tm"3"+ ion in the gadolinium oxychloride (GdOCl) matrix in the UV, visible, and NIR range was studied at temperatures between 9 and 300 K. The visible luminescence of GdOCl:Tm"3"+ under Ar"+ ion laser and mercury lamp excitation was recorded at 9, 77, and 300 K, too. The crystal field (CF) splitting of the "3H_4_-_6, "3F_2_-_4, "1G_4, "1D_2, and "1I_6 levels of the Tm"3"+ ion deduced from the spectra was analysed according to the C_4_v point symmetry of the RE"3"+ site. The resulting energy level scheme, consisting of 39 levels (i.e. 55 Stark components) out of the total of 70 (91) for the whole 4f"1"2 configuration, was simulated with the aid of a phenomenological theory taking simultaneously into account both the free-ion and CF effects. The model included 13 adjustable parameters describing the electrostatic (the Racah parameters E_0_-_3) and the configuration interaction (the Trees parameters #alpha#, #beta#, ...

1995-06-26

114

In situ determination of the composition of surface films formed on Fe-Cr alloys  

Energy Technology Data Exchange (ETDEWEB)

A method for using in situ X-ray absorption near edge spectroscopy to determine the composition of passive, transpassive, and nonreducible thin oxide films is described. The method is demonstrated by determining the composition of the passive films formed in pH 4.5, 0.1 M acetate buffer, on 100 {angstrom} thick Fe-yCr alloys (y = 8.5, 15, 19, 23 atom %) at potentials: (1) low in the passive region ({minus}0.3 V vs. mercurous sulfate reference electrode, MSE); (2) high in the passive region; (3) in the transpassive region; and (4) in the cathodic region where the air-formed film is not fully reduced. The nonreducible film at {minus}1.2 V is entirely a Cr{sup 3+} oxide/hydroxide. This nonreducible film persists at anodic potentials. At {minus}0.3 V, the passive film on each alloy is significantly enriched in Cr. The film at {minus}0.3 V consists primarily of the nonreducible Cr{sup 3+} oxide/hydroxide plus a very small amount of additional ...

1998-06-01

115

Effects of pH and phosphate on metal distribution with emphasis on As speciation and mobilization in soils from a lead smelting site  

Energy Technology Data Exchange (ETDEWEB)

Arsenic in soils from the Asarco lead smelter in East Helena, Montana was characterized by X-ray absorption spectroscopy (XAS). Arsenic oxidation state and geochemical speciation were analyzed as a function of depth (two sampling sites) and surface distribution. These results were compared with intensive desorption/dissolution experiments performed in a pH stat reactor for samples from the site with the highest degree of As heterogeneity. The objectives of the study were to investigate the solid-phase geochemical As speciation, assess the speciation of As in solutions equilibrated with the solids under controlled pH (pH=4 or 6) and Eh (using hydrogen or air) environments, observe the effects of phosphate on the release of As into solution, and examine the effects of phosphate on metal mobility in the systems. Arsenic was predominantly found in the As(V) valence state, though there was evidence that As(III) and As(0) were present also. The ...

2005-06-01

116

Assessment of interference in biosorption of a heavy metal  

Energy Technology Data Exchange (ETDEWEB)

Biosorption of heavy metals by various biological materials has been studied extensively in the last decade due to its potential particularly in wastewater treatment. The presence of a large number of metals in industrial metal-bearing solutions makes it necessary to investigate their effect on the final metal uptake by individual biosorbent materials. Nonliving biomass of Sargassum, a brown marine alga, is capable of binding more than 10% of its dry weight in toxic cadmium ions. Although ubiquitous iron interferes with Cd uptake, only approximately 4.5% of it is sequestered (biomass dry weight). Biosorption of both metals at pH 4.5 could be described by Langmuir-type isotherms with b, the affinity-related coefficient (Cd: b = 0.015; Fe: b = 0.027). The interference of Fe with Cd uptake, and vice versa, was assessed by deriving three-dimensional equilibrium two-metal sorption isotherm surfaces, smoothed and cut to reveal the inhibition effect ...

1997-05-20

117

Oxidation and adsorption of Co(II)EDTA 2- complexes in subsurface materials with iron and manganese oxide grain coatings  

Science.gov (United States)

Batch interaction experiments were performed under aerobic conditions to characterize the adsorption behavior and valence speciation of CoEDTA complexes (equimolar at 10 -5 mol/L) in a series of Pliocene subsurface sediments containing various amounts of Fe and Mn oxides. The experiments were performed in 0.003 mol/L Ca(ClO 4 ) 2 with a solids concentration of 500 g/L at variable pH (4-9) and at the natural pH of the sediments (pH = 8.3). Three of these subaerial sediments (Ringold 1, 2, 3) contained significant quantities of extractable Fe and Mn, while the fourth (Ringold 4) was virtually devoid of sesquioxide precipitates. Microscopic and mineralogic analyses of the most heavily encrusted material (Ringold 2) showed that the oxides existed as intergrain cements and contained crystalline goethite and rancieite/todorokite. Adsorption on a synthetic analog sorbent (0.6 mass % ferrihydrite-coated sand) over a range in pH showed that, while ...

1995-11-01

118

Gallium-67 activated charcoal: a new method for preparation of radioactive capsules for colonic transit study  

Energy Technology Data Exchange (ETDEWEB)

Indium-111 is currently the radionuclide of choice for colonic transit study. However, it is expensive and not available in many hospitals. Technetium-99m has been proposed for colonic transit study but the short half-life has limited its use. Gallium-67 citrate is inexpensive and available in most countries. Most importantly, it has a suitable half-life for colonic transit study. Attempts have been made in some studies to use {sup 67}Ga citrate to label activated charcoal, but the results have not been good because of poor stability. In this study, we successfully labelled activated charcoal with {sup 67}Ga citrate by adding alcohol and 5% glucose solution. To evaluate the in vitro stability, the {sup 67}Ga-activated charcoal was incubated in a milieu mimicking the intestinal content, containing lipase, trypsin and glycochenodeoxycholate at different pH values (6.0, 7.0, 7.4 and 8.0) and for different durations (0 h, 24 h, 48 h, 72 h and 96 h). For the in vivo study, the {sup ...

2003-06-01

119

Extensions to the energy system GMM model: An overview  

International Nuclear Information System (INIS)

This report describes recent extensions to the energy-systems GMM (Global Multiregional MARKAL) model undertaken by the Energy Economics Group (EEG) of the Paul Scherrer Institute (PSI) in Switzerland (hereon referred to as PSI-EEG) in the context of the SAPIENTIA project sponsored by the European Commission (DG Research) and the Swiss National Centre for Competence in Research on Climate (NCCR-Climate). GMM is a multi-regional 'bottom-up' energy-systems optimization model that endogenizes technology learning. The model has been developed and is used at PSI-EEG. The main extensions undertaken here concern the incorporation of a clusters approach to technology learning, the introduction of an improved representation of the transportation sector with emphasis on the passenger sub-sector and the implementation of marginal abatement curves for CH4 and N2O, two main non-CO2 greenhouse gases. Also, a linear representation of the atmospheric concentration of CO2, CH4 and N2O has been ...

2005-06-12

120

310 nm irradiation of atmospherically relevant concentrated aqueous nitrate solutions: nitrite production and quantum yields.  

Science.gov (United States)

The heterogeneous processing of atmospheric aerosols by reaction with nitrogen oxides results in the formation of particulate and adsorbed nitrates. The water content of these hygroscopic nitrate aerosols and consequently the nitrate ion concentration depend on relative humidity, which can impact the physicochemical properties of these aerosols. This report focuses on the 310 nm photolysis of aqueous sodium and calcium nitrate solutions at pH 4 over a wide concentration range of nitrate ion concentrations representative of atmospheric aerosols. In particular, the quantum yield (phi) of nitrite formation was measured and found to significantly decrease at high concentrations of nitrate for Ca(NO(3))(2). In particular, phi for Ca(NO(3))(2) was found to have a maximum value of (7.8 +/- 0.1) x 10(-3) for nitrate ion solution concentrations near one molal, with the smallest quantum yield for the highest concentration solution above 14 m nitrate ion, ...

2008-12-25

 
 
 
 
121

/sup 18/O isotope effect in carbon-13 nuclear magnetic resonance spectroscopy. Part 8. Oxygen exchange of 2,4,6-trimethylpyrylium cation  

Energy Technology Data Exchange (ETDEWEB)

The rate of the oxygen-exchange reaction in an aqueous solution of a heterocyclic oxygen compound, 2,4,6-trimethylpyrylium perchlorate, was quantitated. The /sup 18/O isotope effect in /sup 13/C NMR spectroscopy affords a direct, continuous, and relatively simple analysis of the reaction and was used to obtain data on the incorporation of /sup 18/O from solvent H/sub 2//sup 18/O into the pyrylium salt. Due to the low solubility of this salt in aqueous solutions, 2,4,6-trimethyl(2-/sup 13/C)pyrylium perchlorate and 2,4,6-trimethyl(2,6-/sup 13/C/sub 2/)pyrylium perchlorate were synthesized to facilitate the acquisition of the data on an NTC-200 spectrometer operating at 50.31 MHz. Upon incorporation of /sup 18/O into the pyrylium salt, the /sup 13/C NMR signal of the directly bonded carbon atom is shifted upfield 0.038 ppm. A /sup 13/C isotope effect is also detected in the doubly /sup 13/C-enriched pyrylium salt where the /sup 13/C NMR signal for /sup 13/C-O-/sup 13/C appears 0.011 ppm ...

1984-12-12

122

Potential of sub-ablative pulsed CO{sub 2} laser irradiation on inhibition of artificial caries-like lesion progress in bovine dental enamel; Potencial de inibicao da progressao da carie artificial por irradiacao sub-ablativa com laser de CO{sub 2} pulsado em esmalte dental bovino  

Energy Technology Data Exchange (ETDEWEB)

The aim of this study was to investigate whether sub-ablative pulsed C0{sub 2} laser (1 0,6 {mu}m) irradiation is capable of reducing the susceptibility of the dental enamel to demineralization, and thus achieving a potential caries-protective effect. The crowns of 51 bovine front teeth, embedded in acrylic resin and polished until exposure of flat enamel surface, were used. The samples were cut in cubes of 10x10 mm, and totally coated with acid-resistant nail varnish, except for an enamel exposed window of 16 mm square. Three groups (n=17) were obtained: control group (CG) not irradiated; group laser A (LA) and group laser B (LB) where the samples were irradiated. The conditions were 60 mJ, 100 Hz, 0,3 J/cm{sup 2} for LA and 135 mJ, 10 Hz, 0,7 J/cm{sup 2} for LB. Two samples of each group were submitted to SEM analysis and fifteen to demineralization in 3 ml acetate buffer solution (0,1 mol/L) with pH 4,5 for 24h at 37 deg C, with regular ...

2005-07-01

123

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

International Nuclear Information System (INIS)

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, ...