Catalytic Stereoinversion of L-Alanine to Deuterated D-Alanine.

Science.gov (United States)

Moozeh, Kimia; So, Soon Mog; Chin, Jik

2015-08-03

A combination of an achiral pyridoxal analogue and a chiral base has been developed for catalytic deuteration of L-alanine with inversion of stereochemistry to give deuterated D-alanine under mild conditions (neutral pD and 25 °C) without the use of any protecting groups. This system can also be used for catalytic deuteration of D-alanine with retention of stereochemistry to give deuterated D-alanine. Thus a racemic mixture of alanine can be catalytically deuterated to give an enantiomeric excess of deuterated D-alanine. While catalytic deracemization of alanine is forbidden by the second law of thermodynamics, this system can be used for catalytic deracemization of alanine with deuteration. Such green and biomimetic approach to catalytic stereocontrol provides insights into efficient amino acid transformations. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Deuterium labelling of tryptamine, serotonin and their N-methylated metabolites using solvent exchange reactions

Energy Technology Data Exchange (ETDEWEB)

Raeisaenen, M; Kaerkkaeinen, J [Helsinki Univ. (Finland). Dept. of Medical Chemistry

1979-01-01

Technically uncomplicated methods based on catalytic isotope exchange in deuterated solvents are described for the deuteration of tryptamine, serotonin and their N-methylated metabolites. Heterogeneous platinum catalysis, homogeneous acid catalysis and their combination have been employed. The properties of the labelled derivatives prepared with each technique as well as their use in mass spectrometric work are discussed.

Deuterium labelling of tryptamine, serotonin and their N-methylated metabolites using solvent exchange reactions

International Nuclear Information System (INIS)

Raeisaenen, M.; Kaerkkaeinen, J.

1979-01-01

Technically uncomplicated methods based on catalytic isotope exchange in deuterated solvents are described for the deuteration of tryptamine, serotonin and their N-methylated metabolites. Heterogeneous platinum catalysis, homogeneous acid catalysis and their combination have been employed. The properties of the labelled derivatives prepared with each technique as well as their use in mass spectrometric work are discussed. (author)

Selective deuteration illuminates the importance of tunneling in the unimolecular decay of Criegee intermediates to hydroxyl radical products.

Science.gov (United States)

Green, Amy M; Barber, Victoria P; Fang, Yi; Klippenstein, Stephen J; Lester, Marsha I

2017-11-21

Ozonolysis of alkenes, an important nonphotolytic source of hydroxyl (OH) radicals in the atmosphere, proceeds through unimolecular decay of Criegee intermediates. Here, we report a large kinetic isotope effect associated with the rate-limiting hydrogen-transfer step that releases OH radicals for a prototypical Criegee intermediate, CH 3 CHOO. IR excitation of selectively deuterated syn -CD 3 CHOO is shown to result in deuterium atom transfer and release OD radical products. Vibrational activation of syn -CD 3 CHOO is coupled with direct time-resolved detection of OD products to measure a 10-fold slower rate of unimolecular decay upon deuteration in the vicinity of the transition state barrier, which is confirmed by microcanonical statistical theory that incorporates quantum mechanical tunneling. The corresponding kinetic isotope effect of ∼10 is attributed primarily to the decreased probability of D-atom vs. H-atom transfer arising from tunneling. Master equation modeling is utilized to compute the thermal unimolecular decay rates for selectively and fully deuterated syn methyl-substituted Criegee intermediates under atmospheric conditions. At 298 K (1 atm), tunneling is predicted to enhance the thermal decay rate of syn -CH 3 CHOO compared with the deuterated species, giving rise to a significant kinetic isotope effect of ∼50.

Urinary excretion of deuterated metabolites in patients with tyrosinemia type I after oral loading with deuterated L-tyrosine

International Nuclear Information System (INIS)

Wadman, S.K.; Duran, M.; Ketting, D.; Bruinvis, L.; Sprang, F.J. van; Berger, R.; Smit, G.P.A.; Divry, P.; Farriaux, J.P.; Cartigny, B.

1983-01-01

The metabolic fate of orally given deuterated L-tyrosine, 50 mg/kg body weight, was investigated in seven patients with tyrosinemia type I in order to obtain evidence that the primary defect is at the level of fumarylacetoacetase. The absence of fumarylacetoacetase could be proved in liver biopsy specimens obtained from four patients. All patients excreted deuterated succinylacetoacetate and deuterated succinylacetone was detected in six out of seven. The total amount of these compounds was rather low; maximal 8.3% of the dose. The peak of the excretion occurred 3-6 h after loading, indicating an endogenous formation of the metabolites. All patients excreted deuterated 4-hydroxyphenyl acids, probably reflecting secondary 4-hydroxyphenylpyruvate dioxygenase deficiency connected with liver damage. 5. No evidence for other secondary routes of tyrosine metabolism was found. (Auth.)

Agonists and partial agonists of rhodopsin: retinal polyene methylation affects receptor activation.

Science.gov (United States)

Vogel, Reiner; Lüdeke, Steffen; Siebert, Friedrich; Sakmar, Thomas P; Hirshfeld, Amiram; Sheves, Mordechai

2006-02-14

Using Fourier transform infrared (FTIR) difference spectroscopy, we have studied the impact of sites and extent of methylation of the retinal polyene with respect to position and thermodynamic parameters of the conformational equilibrium between the Meta I and Meta II photoproducts of rhodopsin. Deletion of methyl groups to form 9-demethyl and 13-demethyl analogues, as well as addition of a methyl group at C10 or C12, shifted the Meta I/Meta II equilibrium toward Meta I, such that the retinal analogues behaved like partial agonists. This equilibrium shift resulted from an apparent reduction of the entropy gain of the transition of up to 65%, which was only partially offset by a concomitant reduction of the enthalpy increase. The analogues produced Meta II photoproducts with relatively small alterations, while their Meta I states were significantly altered, which accounted for the aberrant transitions to Meta II. Addition of a methyl group at C14 influenced the thermodynamic parameters but had little impact on the position of the Meta I/Meta II equilibrium. Neutralization of the residue 134 in the E134Q opsin mutant increased the Meta II content of the 13-demethyl analogue, but not of the 9-demethyl analogue, indicating a severe impairment of the allosteric coupling between the conserved cytoplasmic ERY motif involved in proton uptake and the Schiff base/Glu 113 microdomain in the 9-demethyl analogue. The 9-methyl group appears therefore essential for the correct positioning of retinal to link protonation of the cytoplasmic motif with protonation of Glu 113 during receptor activation.

Synthesis and properties of deuterated polystyrene

International Nuclear Information System (INIS)

Liu Chang; Jin Rong; Xu Yewei; Zhang Lin; Yan Hongwei; Du Kai; Wei Chengfu

2012-01-01

Deuterated poly(vinylcyclohexane) (D-PVCH, C 8 H 8 D 6 ) was successfully prepared via deuterated catalytic technology of polystyrene (PS). The structure of D-PVCH was characterized by FT-IR and 1 HNMR spectroscopy, and the results show good agreement with the proposed structure and the deuterated ratio is 41.5%. DSC and TG analyses of the D-PVCH show that D-PVCH possesses good thermal stability (glass transition temperature of 125 ℃, 5% weight loss temperature of 403 ℃). Additionally, D-PVCH dissolves in common solvents such as petroleum ether, cyclohexane and toluene at room temperature. Compared with PS, D-PVCH possesses better thermal stability and improved solubility. (authors)

Deuteration of benzen derivatives and condensed aromatics

International Nuclear Information System (INIS)

Ichikawa, Masaru.

1970-01-01

A process for the deuteration of aromatic compounds (benzene derivatives having one or more cyano, halogeno, nitro or other electron attractive groups, and condensed ring aromatics) is provided. The process comprises reducing said aromatic compound with an alkali metal (preferably K, Rb or Cs) in a solvent (dimethoxyethane, tetrahydrofuran, etc.) to provide an electron-acceptor-donor complex, which is followed by introducing gaseous deuterium into the solution. The deuteration takes place selectively at the position of highest electron density in accordance with nature of the substituent, regardless of steric hindrance. The process is applicable to a wide variety of aromatics to give deuterated compounds in high yields. In one example, 5x10 -3 mole of anthracene (An) was reacted with 2g of metallic potassium in 80cc of dimethoxyethane in a N 2 atmosphere. Into the resulting solution of An=2K + was introduced D 2 gas (30 cmHg) at 25 0 C. After decomposition with air and washing with alcohol, the precipitate was recrystallized from benzene. Yield of recovered AN: more than 90%. Yield of deuteration: 100%. Position of deuteration: 9 and 10 (revealed by NMR and mass spectroscopy). (Kaichi, S.)

Deuterated drugs; updates and obviousness analysis.

Science.gov (United States)

Timmins, Graham S

2017-12-01

The pharmacokinetics and/or toxicity of many known drugs can be modified by selective deuteration, an area of significant commercial interest and scientific and regulatory progress. Areas covered: This review firstly discusses recent developments in deuterated drugs including the FDA approval of deutetrabenazine. Secondly, it discusses 35 U.S.C. §103 'obviousness' as it relates to recent patent prosecution, and also to Inter Partes Review (IPR). IPR is a new post-award review of patentability under §102 or §103, two IPR petitions upon deuterated drugs have been instituted and included §103 arguments. Finally, an extended analysis of §103 obviousness based upon the practices of major pharmaceutical companies is provided, that supports rather late priority dates, while §102 is also discussed. Expert opinion: The total value of transactions involving deuterated drugs is close to $5 billion. While the importance of §103 'obviousness' rejections remains in patent applications under current prosecution, IPR of issued patents is developing and will affect likely affect §103 interpretations in this area. However, patents are still issuing with later priority dates, and further litigation will likely occur.

Multilayer Formation and Evaporation of Deuterated Ices in Prestellar and Protostellar Cores

Science.gov (United States)

Taquet, Vianney; Charnley, Steven B.; Sipilä, Olli

2014-08-01

Extremely large deuteration of several molecules has been observed toward prestellar cores and low-mass protostars for a decade. New observations performed toward low-mass protostars suggest that water presents a lower deuteration in the warm inner gas than in the cold external envelope. We coupled a gas-grain astrochemical model with a one-dimensional model of a collapsing core to properly follow the formation and the deuteration of interstellar ices as well as their subsequent evaporation in the low-mass protostellar envelopes with the aim of interpreting the spatial and temporal evolutions of their deuteration. The astrochemical model follows the formation and the evaporation of ices with a multilayer approach and also includes a state-of-the-art deuterated chemical network by taking the spin states of H2 and light ions into account. Because of their slow formation, interstellar ices are chemically heterogeneous and show an increase of their deuterium fractionation toward the surface. The differentiation of the deuteration in ices induces an evolution of the deuteration within protostellar envelopes. The warm inner region is poorly deuterated because it includes the whole molecular content of ices, while the deuteration predicted in the cold external envelope scales with the highly deuterated surface of ices. We are able to reproduce the observed evolution of water deuteration within protostellar envelopes, but we are still unable to predict the super-high deuteration observed for formaldehyde and methanol. Finally, the extension of this study to the deuteration of complex organics, important for the prebiotic chemistry, shows good agreement with the observations, suggesting that we can use the deuteration to retrace their mechanisms and their moments of formation.

Multilayer formation and evaporation of deuterated ices in prestellar and protostellar cores

International Nuclear Information System (INIS)

Taquet, Vianney; Charnley, Steven B.; Sipilä, Olli

2014-01-01

Extremely large deuteration of several molecules has been observed toward prestellar cores and low-mass protostars for a decade. New observations performed toward low-mass protostars suggest that water presents a lower deuteration in the warm inner gas than in the cold external envelope. We coupled a gas-grain astrochemical model with a one-dimensional model of a collapsing core to properly follow the formation and the deuteration of interstellar ices as well as their subsequent evaporation in the low-mass protostellar envelopes with the aim of interpreting the spatial and temporal evolutions of their deuteration. The astrochemical model follows the formation and the evaporation of ices with a multilayer approach and also includes a state-of-the-art deuterated chemical network by taking the spin states of H 2 and light ions into account. Because of their slow formation, interstellar ices are chemically heterogeneous and show an increase of their deuterium fractionation toward the surface. The differentiation of the deuteration in ices induces an evolution of the deuteration within protostellar envelopes. The warm inner region is poorly deuterated because it includes the whole molecular content of ices, while the deuteration predicted in the cold external envelope scales with the highly deuterated surface of ices. We are able to reproduce the observed evolution of water deuteration within protostellar envelopes, but we are still unable to predict the super-high deuteration observed for formaldehyde and methanol. Finally, the extension of this study to the deuteration of complex organics, important for the prebiotic chemistry, shows good agreement with the observations, suggesting that we can use the deuteration to retrace their mechanisms and their moments of formation.

Multilayer formation and evaporation of deuterated ices in prestellar and protostellar cores

Energy Technology Data Exchange (ETDEWEB)

Taquet, Vianney; Charnley, Steven B. [Astrochemistry Laboratory and The Goddard Center for Astrobiology, Mailstop 691, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20770 (United States); Sipilä, Olli [Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki (Finland)

2014-08-10

Extremely large deuteration of several molecules has been observed toward prestellar cores and low-mass protostars for a decade. New observations performed toward low-mass protostars suggest that water presents a lower deuteration in the warm inner gas than in the cold external envelope. We coupled a gas-grain astrochemical model with a one-dimensional model of a collapsing core to properly follow the formation and the deuteration of interstellar ices as well as their subsequent evaporation in the low-mass protostellar envelopes with the aim of interpreting the spatial and temporal evolutions of their deuteration. The astrochemical model follows the formation and the evaporation of ices with a multilayer approach and also includes a state-of-the-art deuterated chemical network by taking the spin states of H{sub 2} and light ions into account. Because of their slow formation, interstellar ices are chemically heterogeneous and show an increase of their deuterium fractionation toward the surface. The differentiation of the deuteration in ices induces an evolution of the deuteration within protostellar envelopes. The warm inner region is poorly deuterated because it includes the whole molecular content of ices, while the deuteration predicted in the cold external envelope scales with the highly deuterated surface of ices. We are able to reproduce the observed evolution of water deuteration within protostellar envelopes, but we are still unable to predict the super-high deuteration observed for formaldehyde and methanol. Finally, the extension of this study to the deuteration of complex organics, important for the prebiotic chemistry, shows good agreement with the observations, suggesting that we can use the deuteration to retrace their mechanisms and their moments of formation.

State of mixing of deuterated and non-deuterated block polymer chains

International Nuclear Information System (INIS)

Hasegawa, Hirokazu; Hashimoto, Takeji

1984-01-01

Prior to the small-angle neutron scattering study on the conformation of block polymer chains in the domain space, the state of mixing of two block polymers, an ordinary polystyrene-polyisoprene diblock polymer and a poly(deuterated styrene)-polyisoprene diblock polymer with a different molecular weight and composition, was investigated by a small-angle X-ray scattering (SAXS) technique. Only one kind of domain structure was observed for each blend, and the domain spacings obtained by SAXS were proportional to the two-thirds power of the number-average molecular weight of the blends (reduced to non-deuterated block polymer). The volume fractions of polystyrene domain in the blends evaluated by computer simulation of SAXS profiles well agreed with the values estimated from blend composition. All these facts suggest the molecular mixing of the two block polymers in the domain space. (author)

A novel method for the biosynthesis of deuterated proteins with selective protonation at the aromatic rings of Phe, Tyr and Trp

International Nuclear Information System (INIS)

Rajesh, Sundaresan; Nietlispach, Daniel; Nakayama, Hiroshi; Takio, Koji; Laue, Ernest D.; Shibata, Takehiko; Ito, Yutaka

2003-01-01

A novel biosynthetic strategy is described for the preparation of deuterated proteins containing protons at the ring carbons of Phe, Tyr and Trp, using the aromatic amino acid precursor shikimic acid. Specific protonation at aromatic side chains, with complete deuteration at C α/β positions was achieved in proteins overexpressed in bacteria grown in shikimate-supplemented D 2 O medium. Co-expression of a shikimate transporter in prototrophic bacteria resulted in protonation levels of 62-79%, whereas complete labeling was accomplished using shikimate auxotrophic bacteria. Our labeling protocol permits the measurement of important aromatic side chain derived distance restraints in perdeuterated proteins that could be utilized to enhance the accuracy of NMR structures calculated using low densities of NOEs from methyl selectively protonated samples

Deuteration kinetics of the graphene

Energy Technology Data Exchange (ETDEWEB)

Nefedov, Alexei; Woell, Christof [KIT, Leopoldshafen (Germany); Paris, Alessio; Calliari, Lucia [FBK-CMM, Trento (Italy); Verbitskiy, Nikolay [MSU, Moscow (Russian Federation); University of Vienna, Vienna (Austria); Wang, Ying; Irle, Stephan [Nagoya University, Nagoya (Japan); Fedorov, Alexander [IFW Dresden, Dresden (Germany); St. Petersburg University, St. Petersburg (Russian Federation); Haberer, Danny; Knupfer, Martin; Buechner, Bernd [IFW Dresden, Dresden (Germany); Oetzelt, Martin [BESSY II, Berlin (Germany); Petaccia, Luca [Elettra, Trieste (Italy); Usachov, Dmitry [St. Petersburg University, St. Petersburg (Russian Federation); Vyalikh, Denis [St. Petersburg University, St. Petersburg (Russian Federation); TU Dresden, Dresden (Germany); Sagdev, Hermann [MPI fuer Polymerforschung, Mainz (Germany); Yashina, Lada [MSU, Moscow (Russian Federation); Grueneis, Alexander [IFW Dresden, Dresden (Germany); University of Vienna, Vienna (Austria)

2013-07-01

The kinetics of the hydrogenation/deuteration reaction of graphene was studied by time-dependent x-ray photoemission spectroscopy (XPS). The graphene layer was then exposed to hydrogen or deuterium atomic gas beams, obtained by thermal cracking in a tungsten capillary at T=3000 K. After each step XPS of the C1s line was performed in order to measure H/C and D/C ratios. We have observed a strong kinetic isotope effect for the hydrogenation/deuteration reaction leading to substantially faster adsorption and higher maximum D/C ratios as compared to H/C (D/C 35% vs. H/C 25%).

Synthesis, purification and physico-chemical characterization of the deuterized chloroform

International Nuclear Information System (INIS)

Mihaila, Vasile; Chiper, Diana

1999-01-01

This work refers to deuterized chloroform synthesis and purification methods. Three preparation methods of deuterized chloroform are presented. In the first method the direct chlorination of methane (CH 4 + 3Cl 2 ) in the presence of light and in an oxygen-free atmosphere results in CHCl 3 + 3HCl. The method's drawback is that the resulting product is impure, being obtained also secondary chlorinated compounds, such as CHCl, CH 2 Cl 2 and CCl 4 . The second method consists in chlorination of acetaldehyde or acetone, in basic catalysis and in halogen excess (α substitution with direct synthesis of trihalogen compound), followed by a haloform reaction (hydrolytic splitting) in the presence of chlorinated lime. This method makes use of decarbolyzing of trichlor acetate acid (as a sodium salt), what results in CL 3 CH + NaHCO 3 . This method is the most suitable for the deuterized chloroform synthesis, since the reaction takes place in absence of other hydrogen atoms (protons) and in deuterized water of 99.87% purity, according to the following reaction: Cl 3 C-COONa → (D 2 O) → Cl 2 CD + NaDCO 3 . Another advantage is that this method avoids the synthesis of secondary products, which could entail additional purifications (distillations, rectification, a.s.o.). The deuterized chloroform is separated from the deuterized sodium bicarbonate aqueous solution by washing with deuterized water, in a liquid to liquid separating funnel. After separation, deuterized chloroform is dried in nitrogen atmosphere. The characterization of the final product is carried out by nuclear magnetic resonance spectrometry. (authors)

Effects of deuteration on hematopoiesis in the mouse

International Nuclear Information System (INIS)

Adams, W.H.; Adams, D.G.

1988-01-01

Mice ingesting 30 to 50% D 2 O (heavy water, deuterium oxide) developed a dose-dependent depression of formed peripheral blood elements in 4 to 9 days. The principal mechanism of anemia and thrombocytopenia is impaired hematopoiesis. Despite pancytopenia in the peripheral blood, bone marrow cellularity and morphology remained normal. Upon replacement of D 2 O with tap water, platelet and neutrophil concentrations returned to normal within 48 to 72 hr. In contrast, blood lymphocyte concentrations remained low for several weeks. B-lymphocytes may be more affected by deuteration than other lymphocyte subsets. In vivo reticuloendothelial cell function, as assessed by 51 Cr-labeled sheep erythrocyte clearance, was unaffected by D 2 O. Although a dose-dependent decrease in fluid intake occurred during deuteration, hematocytopenia was not a consequence of dehydration. In view of the known kinetics of D 2 O in biological systems, the rapid response of myeloid elements to deuteration must be due primarily to the solvent (nonmetabolic) isotope effect. Prolonged deuteration has proven toxic when included in regimens for treatment of neoplasia, including leukemia, in animal models. The present study shows that modulation of hematopoiesis by D 2 O is possible without invoking the toxicities associated with prolonged deuteration

Deuteration of acetanilides and other substituted aromatics using [Ir(COD)(Cy3P)(Py)]PF6 as catalyst

International Nuclear Information System (INIS)

Hesk, D.; Das, P.R.; Evans, B.

1995-01-01

Deuterium exchange labelling using [Ir(COD)(Cy 3 P)(Py)]PF 6 as catalyst and deuterium gas was studied on a number of substituted acetanilides. In most cases products containing deuterium ortho to the anilide group were obtained with a high degree of enrichment. With one exception no evidence for meta, para or anilide methyl labelling was seen. The catalyst was also effective in the ortho deuteration of acetophenone, benzophenone and the β-lactam containing compound Sch 48461. (Author)

DNA methylation dynamics in the rat EGF gene promoter after partial hepatectomy

Directory of Open Access Journals (Sweden)

Deming Li

2014-06-01

Full Text Available Epidermal growth factor (EGF, a multifunctional growth factor, is a regulator in a wide variety of physiological processes. EGF plays an important role in the regulation of liver regeneration. This study was aimed at investigating the methylation level of EGF gene throughout liver regeneration. DNA of liver tissue from control rats and partial hepatectomy (PH rats at 10 time points was extracted and a 354 bp fragment including 10 CpG sites from the transcription start was amplified after DNA was modified by sodium bisulfate. The result of sequencing suggested that methylation ratio of four CpG sites was found to be significantly changed when PH group was compared to control group, in particular two of them were extremely striking. mRNA expression of EGF was down-regulated in total during liver regeneration. We think that the rat EGF promoter region is regulated by variation in DNA methylation during liver regeneration.

Synthesis, purification and physico-chemical characterization of the deuterized chloroform

International Nuclear Information System (INIS)

Mihaila, V.; Olteanu-Chiper, D.

1999-01-01

This work refers to deuterized chloroform synthesis and purification methods. Three methods for obtaining deuterized chloroform are presented. 1. The direct chlorination of methane, in presence of light and in oxygen-free atmosphere: CH 4 + 3 Cl 2 + ℎν→ CHCl 3 + 3 HCl. The method's drawback is that the product obtained is impure, as other chlorinated compounds such as CH 3 Cl, CH 2 Cl 2 , CCl 4 also result. 2. Chlorination of acetaldehyde or acetone, in basic catalysis and in halogen excess (α substitution with direct synthesis of trihalogen compound), followed by a haloform reaction (hydrolytic splitting) in presence of chlorinated lime: CH 3 CHO (Cl 2 /HO - )/(-HCl)Cl 3 C-CHO (CaCl 2 /HOH)/(-(HCOO) 2 Ca) CHCl 3 and CH 3 -CO-CH 3 (Cl 2 /HO)/(-HCl) Cl 3 C-CO-CH 3 (NaOH)/(-CH 3 COONa) CHCl 3 . 3. Decarboxylizing of trichloroacetate acid (as sodium salt): Cl 3 C-COONa (t deg C)/(H 2 O) Cl 3 CH + NaHCO 3 . This method is the most suitable for the deuterized chloroform synthesis since the reaction takes place in absence of other hydrogen atoms (protons) and in deuterized water 99,87% purity, according to the following reaction: Cl 3 C-COONa (t deg C)/(D 2 O) Cl 3 CD + NaDCO 3 . Another advantage is that this method avoids the synthesis of secondary products which could entail additional purifications (distillations, rectifications, a.s.o.). The deuterized chloroform is separated from the deuterized sodium bicarbonate aqueous solution by washing with deuterized water, in a liquid-to-liquid separating funnel. After separation, the deuterized chloroform is dried in nitrogen atmosphere. The characterization of the final product is carried out through Nuclear Magnetic Resonance Spectrometry. (authors)

Boronization on NSTX using Deuterated Trimethylboron

International Nuclear Information System (INIS)

Blanchard, W.R.; Gernhardt, R.C.; Kugel, H.W.; LaMarche, P.H.

2002-01-01

Boronization on the National Spherical Torus Experiment (NSTX) has proved to be quite beneficial with increases in confinement and density, and decreases in impurities observed in the plasma. The boron has been applied to the interior surfaces of NSTX, about every 2 to 3 weeks of plasma operation, by producing a glow discharge in the vacuum vessel using deuterated trimethylboron (TMB) in a 10% mixture with helium. Special NSTX requirements restricted the selection of the candidate boronization method to the use of deuterated boron compounds. Deuterated TMB met these requirements, but is a hazardous gas and special care in the execution of the boronization process is required. This paper describes the existing GDC, Gas Injection, and Torus Vacuum Pumping System hardware used for this process, the glow discharge process, and the automated control system that allows for remote operation to maximize both the safety and efficacy of applying the boron coating. The administrative requirements and the detailed procedure for the setup, operation and shutdown of the process are also described

Hydrogen/deuterium exchange of cross-linkable alpha-amino acid derivatives in deuterated triflic acid

OpenAIRE

Wang, Lei; Murai, Yuta; Yoshida, Takuma; Okamoto, Masashi; Masuda, Katsuyoshi; Sakihama, Yasuko; Hashidoko, Yasuyuki; Hatanaka, Yasumaru; Hashimoto, Makoto

2014-01-01

In this paper we report here a hydrogen/deuterium exchange (H/D exchange) of cross-linkable alpha-amino acid derivatives with deuterated trifluoromethanesulfonic acid (TfOD). H/D exchange with TfOD was easily applied to o-catechol containing phenylalanine (DOPA) within an hour. A partial H/D exchange was observed for trifluoromethyldiazirinyl (TFMD) phenylalanine derivatives. N-Acetyl-protected natural aromatic alpha-amino acids (Tyr and Trp) were more effective in H/D exchange than unprotect...

Deuteration of lidocaine

International Nuclear Information System (INIS)

Haedener, A.

1988-01-01

Stepwise deuteration of the acidic methylene group of lidocaine on a large scale using a moderate excess of 2 H 2 O in triethylamine/pyridine at 200 0 is described. The efficient and economical preparation of bideuterated lidocaine facilitates the use of this compound as an excellent internal standard in lidocaine determination or as a tracer in lidocaine pharmacokinetics. (author)

Deuteration of lidocaine

Energy Technology Data Exchange (ETDEWEB)

Haedener, A.

1988-01-01

Stepwise deuteration of the acidic methylene group of lidocaine on a large scale using a moderate excess of /sup 2/H/sub 2/O in triethylaminepyridine at 200/sup 0/ is described. The efficient and economical preparation of bideuterated lidocaine facilitates the use of this compound as an excellent internal standard in lidocaine determination or as a tracer in lidocaine pharmacokinetics.

Synthesis of deuterated 1-phenylpropenols

International Nuclear Information System (INIS)

Denhez, J.P.; Girault, G.; Dizabo, P.

1981-01-01

The synthesis of deuterated 1-phenylpropenols is reported. The methods involve either Grignard reactions or selective reduction of α, β unsaturated ketones. These ketones are obtained by degradation of ammonium salts of the Mannich bases. (author)

X-ray structure determination and deuteration of nattokinase

International Nuclear Information System (INIS)

Yanagisawa, Yasuhide; Chatake, Toshiyuki; Naito, Sawa; Ohsugi, Tadanori; Yatagai, Chieko; Sumi, Hiroyuki; Kawaguchi, Akio; Chiba-Kamosida, Kaori; Ogawa, Megumi; Adachi, Tatsumi; Morimoto, Yukio

2013-01-01

X-ray structure determination and deuteration of nattokinase were performed to facilitate neutron crystallographic analysis. Nattokinase (NK) is a strong fibrinolytic enzyme, which is produced in abundance by Bacillus subtilis natto. Although NK is a member of the subtilisin family, it displays different substrate specificity when compared with other subtilisins. The results of molecular simulations predict that hydrogen arrangements around Ser221 at the active site probably account for the substrate specificity of NK. Therefore, neutron crystallographic analysis should provide valuable information that reveals the enzymatic mechanism of NK. In this report, the X-ray structure of the non-hydrogen form of undeuterated NK was determined, and the preparation of deuterated NK was successfully achieved. The non-hydrogen NK structure was determined at 1.74 Å resolution. The three-dimensional structures of NK and subtilisin E from Bacillus subtilis DB104 are near identical. Deuteration of NK was carried out by cultivating Bacillus subtilis natto in deuterated medium. The D 2 O resistant strain of Bacillus subtilis natto was obtained by successive cultivation rounds, in which the concentration of D 2 O in the medium was gradually increased. NK was purified from the culture medium and its activity was confirmed by the fibrin plate method. The results lay the framework for neutron protein crystallography analysis

Deuterated-xylene (xylene-d{sub 10}; EJ301D): A new, improved deuterated liquid scintillator for neutron energy measurements without time-of-flight

Energy Technology Data Exchange (ETDEWEB)

Becchetti, F.D.; Raymond, R.S.; Torres-Isea, R.O. [Department of Physics, University of Michigan, Ann Arbor, MI 48109 (United States); Di Fulvio, A.; Clarke, S.D.; Pozzi, S.A. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Febbraro, M. [Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States)

2016-06-01

In conjunction with Eljen Technology, Inc. (Sweetwater,TX) we have designed, constructed, and evaluated a 3 in. ×3 in. deuterated-xylene organic liquid scintillator (C{sub 8}D{sub 10}; EJ301D) as a fast neutron detector. Similar to deuterated benzene (C{sub 6}D{sub 6}; NE230, BC537, and EJ315) this scintillator can provide good pulse-shape discrimination between neutrons and gamma rays, has good timing characteristics, and can provide a light spectrum with peaks corresponding to discrete neutron energy groups up to ca. 20 MeV. Unlike benzene-based detectors, deuterated xylene is less volatile, less toxic, is not known to be carcinogenic, has a higher flashpoint, and hence is much safer for many applications. In addition EJ301D can provide slightly more light output and better PSD than deuterated-benzene scintillators. We show that, as with deuterated-benzene scintillators, the light-response spectra can be unfolded to provide useable neutron energy spectra without need for time-of-flight (ToF). An array of these detectors arranged at many angles close to a reaction target can be much more effective (×10 to ×100 or more) than an array of long-path ToF detectors which must utilize a narrowly-bunched and pulse-selected beam. As we demonstrate using a small Van de Graaff accelerator, measurements can thus be performed when a bunched and pulse-selected beam (as needed for time-of-flight) is not available.

Infrared and Raman Spectra of Magnesium Ammonium Phosphate Hexahydrate (Struvite) and its Isomorphous Analogues. VIII. Spectra of Protiated and Partially Deuterated Magnesium Rubidium Phosphate Hexahydrate and Magnesium Thallium Phosphate Hexahydrate.

Science.gov (United States)

Soptrajanov, Bojan; Cahil, Adnan; Najdoski, Metodija; Koleva, Violeta; Stefov, Viktor

2011-09-01

The infrared and Raman spectra of magnesium rubidium phosphate hexahydrate MgRbPO4 • 6H2O and magnesium thallium phosphate hexahydrate, MgTlPO4 • 6H2O were recorded at room temperature (RT) and the boiling temperature of liquid nitrogen (LNT). To facilitate their analysis, also recorded were the spectra of partially deuterated analogues with varying content of deuterium. The effects of deuteration and those of lowering the temperature were the basis of the conclusions drawn regarding the origin of the observed bands which were assigned to vibrations which are predominantly localized in the water molecules (four crystallographically different types of such molecules exist in the structures) and those with PO43- character. It was concluded that in some cases coupling of phosphate and water vibrations is likely to take place. The appearance of the infrared spectra in the O-H stretching regions of the infrared spectra is explained as being the result of an extensive overlap of bands due to components of the fundamental stretching modes of the H2O units with a possible participation of bands due to second-order transitions. A broad band reminiscent of the B band of the well-known ABC trio characteristic of spectra of substances containing strong hydrogen bonds in their structure was found around 2400 cm-1 in the infrared spectra of the two studied compounds.

Estimating side-chain order in methyl-protonated, perdeuterated proteins via multiple-quantum relaxation violated coherence transfer NMR spectroscopy

International Nuclear Information System (INIS)

Sun Hechao; Godoy-Ruiz, Raquel; Tugarinov, Vitali

2012-01-01

Relaxation violated coherence transfer NMR spectroscopy (Tugarinov et al. in J Am Chem Soc 129:1743–1750, 2007) is an established experimental tool for quantitative estimation of the amplitudes of side-chain motions in methyl-protonated, highly deuterated proteins. Relaxation violated coherence transfer experiments monitor the build-up of methyl proton multiple-quantum coherences that can be created in magnetically equivalent spin-systems as long as their transverse magnetization components relax with substantially different rates. The rate of this build-up is a reporter of the methyl-bearing side-chain mobility. Although the build-up of multiple-quantum 1 H coherences is monitored in these experiments, the decay of the methyl signal during relaxation delays occurs when methyl proton magnetization is in a single-quantum state. We describe a relaxation violated coherence transfer approach where the relaxation of multiple-quantum 1 H– 13 C methyl coherences during the relaxation delay period is quantified. The NMR experiment and the associated fitting procedure that models the time-dependence of the signal build-up, are applicable to the characterization of side-chain order in [ 13 CH 3 ]-methyl-labeled, highly deuterated protein systems up to ∼100 kDa in molecular weight. The feasibility of extracting reliable measures of side-chain order is experimentally verified on methyl-protonated, perdeuterated samples of an 8.5-kDa ubiquitin at 10°C and an 82-kDa Malate Synthase G at 37°C.

X-ray structure determination and deuteration of nattokinase

Energy Technology Data Exchange (ETDEWEB)

Yanagisawa, Yasuhide [Chiba Institute of Science, 15-8 Shiomi-cho, Cho-shi, Chiba 288-025 (Japan); Chatake, Toshiyuki [Kyoto University, Asashironishi 2, Kumatori, Osaka 590-0494 (Japan); Naito, Sawa; Ohsugi, Tadanori; Yatagai, Chieko; Sumi, Hiroyuki [Kurashiki University of Science and the Arts, 2640 Nishinoura, Tsurajima-cho, Kurashiki, Okayama 712-8505 (Japan); Kawaguchi, Akio [Kyoto University, Asashironishi 2, Kumatori, Osaka 590-0494 (Japan); Chiba-Kamosida, Kaori [Nippon Advanced Technology Co. Ltd, J-PARC, 2-4 Shirane Shirakata, Tokai, Ibaraki 319-1195 (Japan); Ogawa, Megumi; Adachi, Tatsumi [Chiba Institute of Science, 15-8 Shiomi-cho, Cho-shi, Chiba 288-025 (Japan); Morimoto, Yukio [Kyoto University, Asashironishi 2, Kumatori, Osaka 590-0494 (Japan)

2013-11-01

X-ray structure determination and deuteration of nattokinase were performed to facilitate neutron crystallographic analysis. Nattokinase (NK) is a strong fibrinolytic enzyme, which is produced in abundance by Bacillus subtilis natto. Although NK is a member of the subtilisin family, it displays different substrate specificity when compared with other subtilisins. The results of molecular simulations predict that hydrogen arrangements around Ser221 at the active site probably account for the substrate specificity of NK. Therefore, neutron crystallographic analysis should provide valuable information that reveals the enzymatic mechanism of NK. In this report, the X-ray structure of the non-hydrogen form of undeuterated NK was determined, and the preparation of deuterated NK was successfully achieved. The non-hydrogen NK structure was determined at 1.74 Å resolution. The three-dimensional structures of NK and subtilisin E from Bacillus subtilis DB104 are near identical. Deuteration of NK was carried out by cultivating Bacillus subtilis natto in deuterated medium. The D{sub 2}O resistant strain of Bacillus subtilis natto was obtained by successive cultivation rounds, in which the concentration of D{sub 2}O in the medium was gradually increased. NK was purified from the culture medium and its activity was confirmed by the fibrin plate method. The results lay the framework for neutron protein crystallography analysis.

Uniform and selective deuteration in two-dimensional NMR of proteins

International Nuclear Information System (INIS)

LeMaster, D.M.

1990-01-01

This paper reports on the practicality of isotopic labeling, particularly deuteration, that has received considerable impetus from advances in molecular biology, which have allowed ready production of NMR quantities of labeled proteins. Protein expression in Escherichia coli allows use of the considerable metabolic genetics known for the organism in shaping the biosynthetic process to meet the labeling demands of the NMR experiments. In addition to deuteration's common use in spectral assignment problems, it also offers considerable potential for enhancing the quality of the nuclear Overhauser effect (NOE) distance and dihedral angle constraints used for solution structural analysis of proteins. Recent reviews emphasize the sample preparation and spectral benefits of protein deuteration

Deuterated scintillators and their application to neutron spectroscopy

International Nuclear Information System (INIS)

Febbraro, M.; Lawrence, C.C.; Zhu, H.; Pierson, B.; Torres-Isea, R.O; Becchetti, F.D.; Kolata, J.J.; Riggins, J.

2015-01-01

Deuterated scintillators have been used as a tool for neutron spectroscopy without Neutron Time-of-Flight (n-ToF) for more than 30 years. This article will provide a brief historical overview of the technique and current uses of deuterated scintillators in the UM-DSA and DESCANT arrays. Pulse-shape discrimination and spectrum unfolding with the maximum-likelihood expectation maximization algorithm will be discussed. Experimental unfolding and cross section results from measurements of (d,n), ( 3 He,n) and (α,n) reactions are shown

Discriminative stimulus properties of beta-phenylethylamine, deuterated beta-phenylethylamine, phenylethanolamine and some metabolites of phenylethylamine in rodents

Energy Technology Data Exchange (ETDEWEB)

Reid, D.; Goudie, A.J.

1986-06-01

The discriminative stimulus (cue) properties of phenylethylamine (PEA) were analysed in rodents in a conventional two lever FR10 operant drug discrimination task. Rats trained to discriminate phenylethylamine at 30 mg/kg showed complete dose-related generalization to PEA and to two potential PEA metabolites: phenylethanolamine (PEOH) and N-Methyl PEA (NMPEA). Only partial (50%) generalization was seen with N-Methylphenylethanolamine (NMPEOH), another potential PEA metabolite. The specificity of PEA's action as a discriminative stimulus was demonstrated by the finding that fenfluramine, a substituted phenylethylamine, failed to generalize to PEA even at high doses with marked behavioural effects which are known to have discriminative stimulus properties themselves. These data suggest that NMPEA and PEOH may be functionally important active metabolites of PEA, particularly if the major pathway of PEA metabolism to phenylacetic acid under the influence of MAO Type B is for any reason impaired. A long acting deuterium substituted form of PEA (alpha, alpha, d2 PEA), which is resistant to metabolism by MAO, produced complete dose-related generalization to the PEA cue but was more potent than PEA, due presumably to its resistance to metabolism by MAO. Deuterated PEA may therefore be a useful agent to use in future studies of the PEA cue, because the discriminability of PEA itself appears to be low due to its very rapid metabolism in vivo.

Crystal structures and phase transformation of deuterated lithium imide, Li2ND

International Nuclear Information System (INIS)

Balogh, Michael P.; Jones, Camille Y.; Herbst, J.F.; Hector, Louis G.; Kundrat, Matthew

2006-01-01

We have investigated the crystal structure of deuterated lithium imide, Li 2 ND, by means of neutron and X-ray diffraction. An order-disorder transition occurs near 360K. Below that temperature Li 2 ND can be described to the same level of accuracy as a disordered cubic (Fd3-bar m) structure with partially occupied Li 32e sites or as a fully occupied orthorhombic (Ima2 or Imm2) structure. The high temperature phase is best characterized as disordered cubic (Fm3-bar m) with D atoms randomized over the 192l sites. Density functional theory calculations complement and support the diffraction analyses. We compare our findings in detail with previous studies

Continuous-Flow Synthesis of Deuterium-Labeled Antidiabetic Chalcones: Studies towards the Selective Deuteration of the Alkynone Core

Directory of Open Access Journals (Sweden)

Sándor B. Ötvös

2016-03-01

Full Text Available Flow chemistry-based syntheses of deuterium-labeled analogs of important antidiabetic chalcones were achieved via highly controlled partial C≡C bond deuteration of the corresponding 1,3-diphenylalkynones. The benefits of a scalable continuous process in combination with on-demand electrolytic D2 gas generation were exploited to suppress undesired over-reactions and to maximize reaction rates simultaneously. The novel deuterium-containing chalcone derivatives may have interesting biological effects and improved metabolic properties as compared with the parent compounds.

DEUTERIUM FRACTIONATION DURING AMINO ACID FORMATION BY PHOTOLYSIS OF INTERSTELLAR ICE ANALOGS CONTAINING DEUTERATED METHANOL

Energy Technology Data Exchange (ETDEWEB)

Oba, Yasuhiro; Watanabe, Naoki; Kouchi, Akira [Institute of Low Temperature Science, Hokkaido University, N19W8, Kita-ku, Sapporo, Hokkaido 060-0819 (Japan); Takano, Yoshinori, E-mail: oba@lowtem.hokudai.ac.jp [Department of Biogeochemistry, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima, Yokosuka, Kanagawa 237-0061 (Japan)

2016-08-10

Deuterium (D) atoms in interstellar deuterated methanol might be distributed into complex organic molecules through molecular evolution by photochemical reactions in interstellar grains. In this study, we use a state-of-the-art high-resolution mass spectrometer coupled with a high-performance liquid chromatography system to quantitatively analyze amino acids and their deuterated isotopologues formed by the photolysis of interstellar ice analogs containing singly deuterated methanol CH{sub 2}DOH at 10 K. Five amino acids (glycine, α -alanine, β -alanine, sarcosine, and serine) and their deuterated isotopologues whose D atoms are bound to carbon atoms are detected in organic residues formed by photolysis followed by warming up to room temperature. The abundances of singly deuterated amino acids are in the range of 0.3–1.1 relative to each nondeuterated counterpart, and the relative abundances of doubly and triply deuterated species decrease with an increasing number of D atoms in a molecule. The abundances of amino acids increase by a factor of more than five upon the hydrolysis of the organic residues, leading to decreases in the relative abundances of deuterated species for α -alanine and β -alanine. On the other hand, the relative abundances of the deuterated isotopologues of the other three amino acids did not decrease upon hydrolysis, indicating different formation mechanisms of these two groups upon hydrolysis. The present study facilitates both qualitative and quantitative evaluations of D fractionation during molecular evolution in the interstellar medium.

DEUTERIUM FRACTIONATION DURING AMINO ACID FORMATION BY PHOTOLYSIS OF INTERSTELLAR ICE ANALOGS CONTAINING DEUTERATED METHANOL

International Nuclear Information System (INIS)

Oba, Yasuhiro; Watanabe, Naoki; Kouchi, Akira; Takano, Yoshinori

2016-01-01

Deuterium (D) atoms in interstellar deuterated methanol might be distributed into complex organic molecules through molecular evolution by photochemical reactions in interstellar grains. In this study, we use a state-of-the-art high-resolution mass spectrometer coupled with a high-performance liquid chromatography system to quantitatively analyze amino acids and their deuterated isotopologues formed by the photolysis of interstellar ice analogs containing singly deuterated methanol CH 2 DOH at 10 K. Five amino acids (glycine, α -alanine, β -alanine, sarcosine, and serine) and their deuterated isotopologues whose D atoms are bound to carbon atoms are detected in organic residues formed by photolysis followed by warming up to room temperature. The abundances of singly deuterated amino acids are in the range of 0.3–1.1 relative to each nondeuterated counterpart, and the relative abundances of doubly and triply deuterated species decrease with an increasing number of D atoms in a molecule. The abundances of amino acids increase by a factor of more than five upon the hydrolysis of the organic residues, leading to decreases in the relative abundances of deuterated species for α -alanine and β -alanine. On the other hand, the relative abundances of the deuterated isotopologues of the other three amino acids did not decrease upon hydrolysis, indicating different formation mechanisms of these two groups upon hydrolysis. The present study facilitates both qualitative and quantitative evaluations of D fractionation during molecular evolution in the interstellar medium.

Methyl labeling and TROSY NMR spectroscopy of proteins expressed in the eukaryote Pichia pastoris

International Nuclear Information System (INIS)

Clark, Lindsay; Zahm, Jacob A.; Ali, Rustam; Kukula, Maciej; Bian, Liangqiao; Patrie, Steven M.; Gardner, Kevin H.; Rosen, Michael K.; Rosenbaum, Daniel M.

2015-01-01

13 C Methyl TROSY NMR spectroscopy has emerged as a powerful method for studying the dynamics of large systems such as macromolecular assemblies and membrane proteins. Specific 13 C labeling of aliphatic methyl groups and perdeuteration has been limited primarily to proteins expressed in E. coli, preventing studies of many eukaryotic proteins of physiological and biomedical significance. We demonstrate the feasibility of efficient 13 C isoleucine δ1-methyl labeling in a deuterated background in an established eukaryotic expression host, Pichia pastoris, and show that this method can be used to label the eukaryotic protein actin, which cannot be expressed in bacteria. This approach will enable NMR studies of previously intractable targets

X-ray structure determination and deuteration of nattokinase.

Science.gov (United States)

Yanagisawa, Yasuhide; Chatake, Toshiyuki; Naito, Sawa; Ohsugi, Tadanori; Yatagai, Chieko; Sumi, Hiroyuki; Kawaguchi, Akio; Chiba-Kamosida, Kaori; Ogawa, Megumi; Adachi, Tatsumi; Morimoto, Yukio

2013-11-01

Nattokinase (NK) is a strong fibrinolytic enzyme, which is produced in abundance by Bacillus subtilis natto. Although NK is a member of the subtilisin family, it displays different substrate specificity when compared with other subtilisins. The results of molecular simulations predict that hydrogen arrangements around Ser221 at the active site probably account for the substrate specificity of NK. Therefore, neutron crystallographic analysis should provide valuable information that reveals the enzymatic mechanism of NK. In this report, the X-ray structure of the non-hydrogen form of undeuterated NK was determined, and the preparation of deuterated NK was successfully achieved. The non-hydrogen NK structure was determined at 1.74 Å resolution. The three-dimensional structures of NK and subtilisin E from Bacillus subtilis DB104 are near identical. Deuteration of NK was carried out by cultivating Bacillus subtilis natto in deuterated medium. The D2O resistant strain of Bacillus subtilis natto was obtained by successive cultivation rounds, in which the concentration of D2O in the medium was gradually increased. NK was purified from the culture medium and its activity was confirmed by the fibrin plate method. The results lay the framework for neutron protein crystallography analysis.

Development of a new neutron mirror made of deuterated Diamond-like carbon

International Nuclear Information System (INIS)

Sakurai, Dai; Chiba, Junsei; Shimizu, Hirohiko M; Nishimura, Daiki; Ino, Takashi; Kaneko, Naokatsu; Muto, Suguru; Kakusho, Nobunori; Seki, Yoshichika; Katayama, Ryo; Kitaguchi, Masaaki; Mishima, Kenji; Yamashita, Satoru; Ozeki, Kazuhide; Yoshioka, Tamaki

2014-01-01

We developed a new neutron mirror made of Diamond-like carbon (DLC). DLC is a film of amorphous carbon that has characteristics of both diamond and graphite. We produced DLC mirrors by ionization deposition method which is one of the chemical vapor deposition (CVD). Generally, DLC made by CVD contents a few tens of percentages of hydrogen. It decreases the Fermi potential of the DLC coating because hydrogen has negative Fermi potential. In order to increase the Fermi potential of the coating, we deuterated the DLC by using deuterated benzene for the source gas. The characteristics of the deuterated DLC(DDLC) coating was evaluated by RBS, ERDA, x-ray reflectivity, AFM. As a result, DDLC coating has 243 neV due to deuteration, which is the same level as Ni. The RMS of height of the DDLC was 0.6nm so that the DDLC coating can be applied for a focusing mirror or specular transportation of pulsed neutron. Besides, we also develop Hydrogen/Deuterium DLC multiple layer mirror. So far, 4 layers mirror has been succeeded.

Comprehensive physicochemical studies of a new hybrid material: 2-Amino-4-methyl-3-nitropyridinium hydrogen oxalate

Science.gov (United States)

Bryndal, I.; Kucharska, E.; Wandas, M.; Lorenc, J.; Hermanowicz, K.; Mączka, M.; Lis, T.; Marchewka, M.; Hanuza, J.

2014-01-01

A new organic-organic salt, 2-amino-4-methyl-3-nitropyridinium hydrogen oxalate (AMNPO), and its deuterium analogue have been synthesized and characterized by means of FT-IR, FT-Raman, DSC and single crystal X-ray studies. The DSC measurements and temperature dependence of the IR and Raman spectra in the range 4-295 K show that it undergoes a reversible phase transition at ∼240 K. At room temperature it crystallizes in noncentrosymmetric space group P21. The unit-cell is built of the 2-amino-4-methyl-3-nitropyridinium cations and oxalate monoanions which are connected via the Nsbnd H⋯O and Osbnd H⋯O hydrogen bonds. The geometrical and hydrogen bond parameters are similar for non-deuterated (at 120 and 293 K) and deuterated compounds (at 90 K). The phase transition is probably a consequence of order-disorder transition inside of hydrogen network. The 6-311G(2d,2p) basis set with B3LYP functional have been used to discuss the structure and vibrational spectra of the studied compound.

Catalytic hydrogenation of carbonyl group for deuterated compound production

International Nuclear Information System (INIS)

Gluhoi, C. Andreea; Marginean, P.; Lazar, Diana; Almasan, V.

1999-01-01

The total deuterated isopropyl alcohol can be produced starting from acetone. The developed technology comprises two steps: Deuteration of acetone by H/D isotopic exchange between acetone and heavy water in homogeneous catalysis. Reduction of the deuterated acetone with deuterium in presence of a metal/support catalyst. H/D isotopic exchange reaction of the H atoms from CH 3 groups is easy to occur because carbonyl group weakens C-H bond (ceto-enolyc tautomery). The big difference between boiling points of acetone and water permits an easy separation of acetone by distillation method. The reduction of acetone with deuterium was performed in a dynamic reactor by passing a deuterium flow saturated with acetone vapour through a supported nickel catalyst bed. The reaction products were analysed on-line using a flame ionisation detector. The supported nickel catalysts were checked for this reaction. By using nickel over different supports the selectivity for isopropyl alcohol was about 100%. The propane was detected only as traces. The catalytic activity depends strongly on the support nature: the Ni/SiO 2 is less active, while the Ni/TiO 2 presents the larger value for the intrinsic activity. (authors)

[2H26]-1-epi-Cubenol, a completely deuterated natural product from Streptomyces griseus

Directory of Open Access Journals (Sweden)

Christian A. Citron

2013-12-01

Full Text Available During growth on fully deuterated medium the volatile terpene [2H26]-1-epi-cubenol was released by the actinomycete Streptomyces griseus. This compound represents the first completely deuterated terpene obtained by fermentation. Despite a few previous reports in the literature the operability of this approach to fully deuterated compounds is still surprising, because the strong kinetic isotope effect of deuterium is known to slow down all metabolic processes in living organisms. Potential applications of completely labelled compounds from natural sources in structure elucidation, biosynthetic or pharmacokinetic investigations are discussed.

Highly selective deuteration of pharmaceutically relevant nitrogen-containing heterocycles: a flow chemistry approach.

Science.gov (United States)

Ötvös, Sándor B; Mándity, István M; Fülöp, Ferenc

2011-08-01

A simple and efficient flow-based technique is reported for the catalytic deuteration of several model nitrogen-containing heterocyclic compounds which are important building blocks of pharmacologically active materials. A continuous flow reactor was used in combination with on-demand pressure-controlled electrolytic D(2) production. The D(2) source was D(2)O, the consumption of which was very low. The experimental set-up allows the fine-tuning of pressure, temperature, and flow rate so as to determine the optimal conditions for the deuteration reactions. The described procedure lacks most of the drawbacks of the conventional batch deuteration techniques, and additionally is highly selective and reproducible.

Solubilization, partial purification, and reconstitution of glutamate- and N-methyl-D-aspartate-activated cation channels from brain synaptic membranes

International Nuclear Information System (INIS)

Ly, A.M.; Michaelis, E.K.

1991-01-01

L-Glutamate-activated cation channel proteins from rat brain synaptic membranes were solubilized, partially purified, and reconstituted into liposomes. Optimal conditions for solubilization and reconstitution included treatment of the membranes with nonionic detergents in the presence of neutral phospholipids plus glycerol. Quench-flow procedures were developed to characterize the rapid kinetics of ion flux induced by receptor agonists. [ 14 C]Methylamine, a cation that permeates through the open channel of both vertebrate and invertebrate glutamate receptors, was used to measure the activity of glutamate receptor-ion channel complexes in reconstituted liposomes. L-Glutamate caused an increase in the rate of [ 14 C]methylamine influx into liposomes reconstituted with either solubilized membrane proteins or partially purified glutamate-binding proteins. Of the major glutamate receptor agonists, only N-methyl-D-aspartate activated cation fluxes in liposomes reconstituted with glutamate-binding proteins. In liposomes reconstituted with glutamate-binding proteins, N-methyl-D-aspartate- or glutamate-induced influx of NA + led to a transient increase in the influx of the lipid-permeable anion probe S 14 CN - . These results indicate the functional reconstitution of N-methyl-D-aspartate-sensitive glutamate receptors and the role of the ∼69-kDa protein in the function of these ion channels

Gas Chromatographic Mass Spectrometric Determination of Myo-inositol in Humans Utilizing a Deuterated Internal Standard

DEFF Research Database (Denmark)

Andersen, Jan Rud; Larsen, Elfinn; Harbo, Helge

1982-01-01

The isotopic dilution technique was used for determining the content of myo-inositol in human urine, plasma and haemolysed erythrocyte samples. A deuterated myo-inositol, synthesized from inosose-2 by base-catalysed exchange of hydrogens by deuterium, followed by reduction of the inosose with 2H2......, was added as internal standard to the samples at an early stage in the analytical procedure. After separation and derivatization to the hexa-acetate, the gas chromatographic mass spectrometric analysis was carried out. A 25 m fused silica capillary column coated with methyl silicone was used, and the ions...... selected for monitoring were m/z 210 and m/z 214, which are characteristic and abundant fragment ions from unlabelled and hexadeuterated myo-inositolhexa-acetate, respectively. Calibration curves from water, urine, plasma and haemolysed erythrocytes show parallel, linear responses in the ratio between...

Methods for preparation of deuterated amino acids

International Nuclear Information System (INIS)

Pshenichnikova, A.B.; Karnaukhova, E.N.; Zvonkova, E.N.

1995-01-01

The current state and prospects for the use of amino acids labeled with stable isotopes are considered. Methods for the preparation of deuterated amino acids, including synthetic, chemicoenzymatic, and biosynthetic ones, and deuterium exchange reactions are summarized. Problems in the preparation of optically pure amino acids are discussed. 120 refs., 15 figs

Solid polystyrene and deuterated polystyrene light output response to fast neutrons

International Nuclear Information System (INIS)

Simpson, R.; Danly, C.; Merrill, F. E.; Volegov, P. L.; Wilde, C.; Glebov, V. Yu.; Hurlbut, C.

2016-01-01

The Neutron Imaging System has proven to be an important diagnostic in studying DT implosion characteristics at the National Ignition Facility. The current system depends on a polystyrene scintillating fiber array, which detects fusion neutrons born in the DT hotspot as well as neutrons that have scattered to lower energies in the surrounding cold fuel. Increasing neutron yields at NIF, as well as a desire to resolve three-dimensional information about the fuel assembly, have provided the impetus to build and install two additional next-generation neutron imaging systems. We are currently investigating a novel neutron imaging system that will utilize a deuterated polystyrene (CD) fiber array instead of standard hydrogen-based polystyrene (CH). Studies of deuterated xylene or deuterated benzene liquid scintillator show an improvement in imaging resolution by a factor of two [L. Disdier et al., Rev. Sci. Instrum. 75, 2134 (2004)], but also a reduction in light output [V. Bildstein et al., Nucl. Instrum. Methods Phys. Res., Sect. A 729, 188 (2013); M. I. Ojaruega, Ph.D. thesis, University of Michigan, 2009; M. T. Febbraro, Ph.D. thesis, University of Michigan, 2014] as compared to standard plastic. Tests of the relative light output of deuterated polystyrene and standard polystyrene were completed using 14 MeV fusion neutrons generated through implosions of deuterium-tritium filled capsules at the OMEGA laser facility. In addition, we collected data of the relative response of these two scintillators to a wide energy range of neutrons (1-800 MeV) at the Weapons Neutrons Research Facility. Results of these measurements are presented.

Solid polystyrene and deuterated polystyrene light output response to fast neutrons

Energy Technology Data Exchange (ETDEWEB)

Simpson, R., E-mail: raspberry@lanl.gov; Danly, C.; Merrill, F. E.; Volegov, P. L.; Wilde, C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Glebov, V. Yu. [Laboratory for Laser Energetics, Rochester, New York 14623 (United States); Hurlbut, C. [Eljen Technology, Sweetwater, Texas 79556 (United States)

2016-04-15

The Neutron Imaging System has proven to be an important diagnostic in studying DT implosion characteristics at the National Ignition Facility. The current system depends on a polystyrene scintillating fiber array, which detects fusion neutrons born in the DT hotspot as well as neutrons that have scattered to lower energies in the surrounding cold fuel. Increasing neutron yields at NIF, as well as a desire to resolve three-dimensional information about the fuel assembly, have provided the impetus to build and install two additional next-generation neutron imaging systems. We are currently investigating a novel neutron imaging system that will utilize a deuterated polystyrene (CD) fiber array instead of standard hydrogen-based polystyrene (CH). Studies of deuterated xylene or deuterated benzene liquid scintillator show an improvement in imaging resolution by a factor of two [L. Disdier et al., Rev. Sci. Instrum. 75, 2134 (2004)], but also a reduction in light output [V. Bildstein et al., Nucl. Instrum. Methods Phys. Res., Sect. A 729, 188 (2013); M. I. Ojaruega, Ph.D. thesis, University of Michigan, 2009; M. T. Febbraro, Ph.D. thesis, University of Michigan, 2014] as compared to standard plastic. Tests of the relative light output of deuterated polystyrene and standard polystyrene were completed using 14 MeV fusion neutrons generated through implosions of deuterium-tritium filled capsules at the OMEGA laser facility. In addition, we collected data of the relative response of these two scintillators to a wide energy range of neutrons (1-800 MeV) at the Weapons Neutrons Research Facility. Results of these measurements are presented.

Use of deuterated tyrosine and phenylalanine in the study of catecholamine and aromatic acid metabolism

International Nuclear Information System (INIS)

Curtius, H.C.; Redweik, U.; Steinmann, B.; Leimbacher, W.; Wegmann, H.

1975-01-01

Deuterated tyrosine and phenylalanine have been used for the study of their respective metabolism in patients with phenylketonuria (PKU) and in healthy persons. Urinary excretion of dopamine and its metabolites was studied by GC-MS after oral administration of deuterated L-tyrosine in 2 patients with PKU and in normal controls at low and high plasma phenylalanine levels. From these studies it seemed that the in vivo tyrosine 3-hydroxylase activity and thus the formation of L-dopa depend on the phenylalanine concentration in plasma and also in tissues. After loading 3 mentally retarded patients with 3,5-[ 2 H 2 ]-4-hydroxyphenylalanine, we found, among others, excretion of deuterated m-hydroxyphenyl-hydracrylic acid, p-hydroxymandelic acid, p-hydroxybenzoic acid, p-hydroxyhippuric acid, benzoic acid and hippuric acid. An intramolecular rearrangement is postulated. Deuterated phenylalanine was used to investigate phenylalanine and dopa metabolism in PKU. In addition, one untreated person with PKU of normal intelligence and normal excretion of catecholamines at high plasma phenylalanine concentration was investigated in order to see whether there exists an alternative metabolic pathway from phenylalanine to dopa formation

Deuteration effect on the rotary power of hydrogen bonded compounds

International Nuclear Information System (INIS)

Kolbe, A.; Kolbe, A.; Martin-Luther-Universitaet Halle-Wittenberg, Halle

1982-01-01

The variation of the rotatory power caused by deuteration in menthol, isopulegol, α-terpineol-(4), elemol, and diphenylacetyl-L-leucin has been investigated. The results and a brief discussion are given

Deuteration effect on the rotary power of hydrogen bonded compounds

Energy Technology Data Exchange (ETDEWEB)

Kolbe, A.; Kolbe, A. (Akademie der Wissenschaften der DDR, Halle/Saale. Inst. fuer Biochemie der Pflanzen; Martin-Luther-Universitaet Halle-Wittenberg, Halle (German Democratic Republic). Sektion Chemie)

1982-01-01

The variation of the rotatory power caused by deuteration in menthol, isopulegol, ..cap alpha..-terpineol-(4), elemol, and diphenylacetyl-L-leucin has been investigated. The results and a brief discussion are given.

Laboratory Measurements for H3+ Deuteration Reactions

Science.gov (United States)

Bowen, Kyle; Hillenbrand, Pierre-Michel; Urbain, Xavier; Savin, Daniel Wolf

2018-06-01

Deuterated molecules are important chemical tracers of protostellar cores. At the ~106 cm-3 particle densities and ~20 K temperatures typical for protostellar cores, most molecules freeze onto dust grains. A notable exception is H3+ and its isotopologues. These become important carriers of positive charge in the gas, can couple to any ambient magnetic field, and can thereby alter the cloud dynamics. Knowing the total abundance of H3+ and its isotopologues is important for studying the evolution of protostellar cores. However, H3+ and D3+ have no dipole moment. They lack a pure rotational spectrum and are not observable at protostellar core temperatures. Fortunately H2D+ and D2H+ have dipole moments and a pure rotational spectrum that can be excited in protostellar cores. Observations of these two molecules, combined with astrochemical models, provide information about the total abundance of H3+ and all its isotopologues. The inferred abundances, though, rely on accurate astrochemical data for the deuteration of H3+ and its isotopologues.Here we present laboratory measurements of the rate coefficients for three important deuterating reactions, namely D + H3+/H2D+/D2H+ → H + H2D+/ D2H+/D3+. Astrochemical models currently rely on rate coefficients from classical (Langevin) or semi-classical methods for these reactions, as fully quantum-mechanical calculations are beyond current computational capabilities. Laboratory studies are the most tractable means of providing the needed data. For our studies we used our novel dual-source, merged fast-beams apparatus, which enables us to study reactions of neutral atoms and molecular ions. Co-propagating beams allow us to measure experimental rate coefficients as a function of collision energy. We extract cross section data from these results, which we then convolve with a Maxwell-Boltzmann distribution to generate thermal rate coefficients. Here we present our results for these three reactions and discuss some implications.

Deuteration of ammonia in the starless core Ophiuchus/H-MM1

Science.gov (United States)

Harju, J.; Daniel, F.; Sipilä, O.; Caselli, P.; Pineda, J. E.; Friesen, R. K.; Punanova, A.; Güsten, R.; Wiesenfeld, L.; Myers, P. C.; Faure, A.; Hily-Blant, P.; Rist, C.; Rosolowsky, E.; Schlemmer, S.; Shirley, Y. L.

2017-04-01

Context. Ammonia and its deuterated isotopologues probe physical conditions in dense molecular cloud cores. The time-dependence of deuterium fractionation and the relative abundances of different nuclear spin modifications are supposed to provide a means of determining the evolutionary stages of these objects. Aims: We aim to test the current understanding of spin-state chemistry of deuterated species by determining the abundances and spin ratios of NH2D, NHD2 and ND3 in a quiescent, dense cloud. Methods: Spectral lines of NH3, NH2D, NHD2, ND3 and N2D+ were observed towards a dense, starless core in Ophiuchus with the APEX, GBT and IRAM 30-m telescopes. The observations were interpreted using a gas-grain chemistry model combined with radiative transfer calculations. The chemistry model distinguishes between the different nuclear spin states of light hydrogen molecules, ammonia and their deuterated forms. Different desorption schemes can be considered. Results: High deuterium fractionation ratios with NH2D/NH3 0.4, NHD2/ NH2D 0.2 and ND3/ NHD2 0.06 are found in the core. The observed ortho/para ratios of NH2D and NHD2 are close to the corresponding nuclear spin statistical weights. The chemistry model can approximately reproduce the observed abundances, but consistently predicts too low ortho/para-NH2D, and too large ortho/para-NHD2 ratios. The longevity of N2H+ and NH3 in dense gas, which is prerequisite to their strong deuteration, can be attributed to the chemical inertia of N2 on grain surfaces. Conclusions: The discrepancies between the chemistry model and the observations are likely to be caused by the fact that the model assumes complete scrambling in principal gas-phase deuteration reactions of ammonia, which means that all the nuclei are mixed in reactive collisions. If, instead, these reactions occur through proton hop/hydrogen abstraction processes, statistical spin ratios are to be expected. The present results suggest that while the deuteration of

THE L1157-B1 ASTROCHEMICAL LABORATORY: MEASURING THE TRUE FORMALDEHYDE DEUTERATION ON GRAIN MANTLES

International Nuclear Information System (INIS)

Fontani, F.; Codella, C.; Ceccarelli, C.; Lefloch, B.; Viti, S.; Benedettini, M.

2014-01-01

L1157 is a prototypical chemically active outflow driven by a low-mass class-0 protostar, and B1 is its brightest bow shock. Toward L1157-B1, several emission lines of deuterated molecules have been detected for the first time by Codella et al. The authors suggested that these were formed on grain mantles, and then released into the gas phase by the passage of the shock. In this Letter we report observations obtained at high angular resolution with the Plateau de Bure Interferometer of HDCO and CH 2 DOH. The emission of HDCO perfectly delineates the region of the interface between the fast jet and the slower ambient material, confirming the predictions of the previous work that deuterated species were formed on grain mantles and then released into the gas phase by the passage of the shock. CH 2 DOH emission is fainter and thus its emitting region is not well determined. The deuterated fraction HDCO/H 2 CO is ∼0.1 in the HDCO emitting region, an order of magnitude larger than the upper limit found in the surrounding material, probably dominated by warm-gas chemistry and less affected by grain evaporation. Our study represents the first clear evidence ever found of a deuterated molecule as shock tracer, and yields an indirect but ''clean'' measurement of the deuteration of the ices covering the dust grains during the cold pre-protostellar phase

Deuterated-decaborane using boronization on JT-60U

Energy Technology Data Exchange (ETDEWEB)

Yagyu, Jun-ichi; Arai, Takashi; Kaminaga, Atsushi; Miyata, Katsuyuki [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Arai, Masaru [Kaihatsu Denki Co., Ltd., Tokyo (Japan)

2001-03-01

In JT-60U, boronization using hydride-decaborane (B{sub 10}H{sub 14}) vaporization has been conducted for the first wall conditioning. Compared to other discharge cleaning (DC), boronization is claimed to be efficient in reduction of oxygen impurities and hydrogen recycling in plasma. However, there are some problems in reduction of hydrogen included in boron film and stabilization of DC glow discharge during the boronization. To solve these problems, a new boronization method using deuterated-decaborane (B{sub 10}D{sub 14}) was adopted instead of the conventional hydride-decaborane. As a result, hydrogen content in the boron film decreased clearly and discharge conditioning shots, for decreasing hydrogen content in plasmas, after the boronization were reduced to 1/10 in comparison to the conventional process. Furthermore, DC glow discharge became stable, with only helium carrier gas, and it was possible to save 30 hours in maximum of the time necessary to boronization. It is shown that the boronization using deuterated-decaborane is very efficient and effective method for the first wall conditioning. (author)

Low-temperature structural phase transition in deuterated and protonated lithium acetate dihydrate

Energy Technology Data Exchange (ETDEWEB)

Schroeder, F., E-mail: schroeder@kristall.uni-frankfurt.d [Goethe-Universitaet Frankfurt am Main, Institut fuer Geowissenschaften, Abt. Kristallographie, Altenhoeferallee 1, 60438 Frankfurt am Main (Germany); Winkler, B.; Haussuehl, E. [Goethe-Universitaet Frankfurt am Main, Institut fuer Geowissenschaften, Abt. Kristallographie, Altenhoeferallee 1, 60438 Frankfurt am Main (Germany); Cong, P.T.; Wolf, B. [Goethe-Universitaet Frankfurt am Main, Physikalisches Institut, Max-von-Laue-Strasse 1, 60438 Frankfurt am Main (Germany); Avalos-Borja, M. [Instituto Potosino de Investigacion Cientifica y Tecnologica, A.C. Camino a la Presa San Jose 2055, Col. Lomas 4 seccion CP 78216, San Luis Potosi (Mexico); Quilichini, M.; Hennion, B. [Laboratoire Leon Brillouin, CEN Saclay, 91191 Gif-sur-Yvette (France)

2010-08-15

Heat capacity measurements of protonated lithium acetate dihydrate show a structural phase transition at T = 12 K. This finding is in contrast to earlier work, where it was thought that only the deuterated compound undergoes a low temperature structural phase transition. This finding is confirmed by low temperature ultrasound spectroscopy, where the structural phase transition is associated with a velocity decrease of the ultrasonic waves, i.e. with an elastic softening. We compare the thermodynamic properties of the protonated and deuterated compounds and discuss two alternatives for the mechanism of the phase transition based on the thermal expansion measurements.

Study of the deuterated albumin by FT-IR spectroscopy

International Nuclear Information System (INIS)

Stoenescu, Daniela; Sahini, V.E.

2000-01-01

The albumin is a protein from the soluble or corpuscular protein class, which exists in cells, in dissolved state or in form of a hydrated gel. Proteins are essential constituents beside water, inorganic salts, lipids, carbon hydrates, vitamins, enzymes. The albumin is also a protein soluble in water and in diluted electrolyte solutions (acids, bases and salts). The investigation of the vibration isotopic effect has a great importance both for the diatomic molecules and for the polyatomic molecules. This paper is the first from a series of works which are intended to study the physico-chemical properties of the deuterated albumin and of the albumin solutions in heavy water by an isotopic exchange method. To put in evidence H-D exchange, the FT-IR spectroscopy is used when the deuterated albumin has different layer thickness. It is also of interest to elucidate the isotopic exchange between the hydrogen and oxygen atoms in bovine serum albumin macromolecules. (authors)

ROTATIONAL SPECTRUM AND TENTATIVE DETECTION OF DCOOCH3-METHYL FORMATE IN ORION

International Nuclear Information System (INIS)

Margules, L.; Huet, T. R.; Demaison, J.; Carvajal, M.; Kleiner, I.; Moellendal, H.; Tercero, B.; Marcelino, N.; Cernicharo, J.

2010-01-01

New centimeter-wave (7-80 GHz) and submillimeter-wave (580-661 GHz) spectra of a deuterated species of methyl formate (DCOOCH 3 ) have been measured. Transitions with a maximum value of J = 64 and K = 36 have been assigned and fitted together with previous measurements. The internal rotation of this compound was treated using the so-called rho axis method. A total of 1703 transitions were fitted using this method. Only 24 parameters were employed in the final fit, which has an rms deviation of 94.2 kHz. The dipole moment and the nuclear quadrupole coupling constants of the deuterated specie have also been obtained. This new study has permitted a tentative detection of DCOOCH 3 in Orion with the IRAM 30 m telescope based on the observation of more than 100 spectral features with low blending effects among the 400 lines expected in the observed frequency domain (for which over 300 are heavily blended with other species). These 100 transitions are above noise and confusion limited without heavy blending and cannot be assigned to any other species. Moreover, none of the strongest unblended transitions is missing. The derived source-averaged total column density for DCOOCH 3 is 7.8 x 10 14 cm -2 and the DCOOCH 3 /HCOOCH 3 column density ratio varies between 0.02 and 0.06 in the different cloud components of Orion. This value is consistent with the deuteration enhancement found for other species in this cloud.

Methylation analysis of polysaccharides: Technical advice.

Science.gov (United States)

Sims, Ian M; Carnachan, Susan M; Bell, Tracey J; Hinkley, Simon F R

2018-05-15

Glycosyl linkage (methylation) analysis is used widely for the structural determination of oligo- and poly-saccharides. The procedure involves derivatisation of the individual component sugars of a polysaccharide to partially methylated alditol acetates which are analysed and quantified by gas chromatography-mass spectrometry. The linkage positions for each component sugar can be determined by correctly identifying the partially methylated alditol acetates. Although the methods are well established, there are many technical aspects to this procedure and both careful attention to detail and considerable experience are required to achieve a successful methylation analysis and to correctly interpret the data generated. The aim of this article is to provide the technical details and critical procedural steps necessary for a successful methylation analysis and to assist researchers (a) with interpreting data correctly and (b) in providing the comprehensive data required for reviewers to fully assess the work. Copyright © 2018 Elsevier Ltd. All rights reserved.

Stereoselective semi-hydrogenation and deuteration of a diacetylenic precursor of leukotriene B4 methyl ester

International Nuclear Information System (INIS)

Pontikis, R.; Le Merrer, Y.; Depezay, J.-C.; Petillot, Y.; Rousseau, B.; Beaucourt, J.P.

1990-01-01

[6,7,14,15- 2 H4]-Leukotriene B4 methyl ester was prepared by reduction with deuterium gas of a suitable precursor (deuterium incorporation > 90%). Several catalytic semi-hydrogenations were affected in order to determine the best conditions for the labeling step. (author)

Deuteration of metals through electric discharges

International Nuclear Information System (INIS)

Balderas G, L.M.

1995-01-01

In this work deuteration of titanium and a stainless steel through electrical discharges in a vacuum chamber was performed at different thermodynamic conditions. The samples were plates of 0.03 x 4.5 x 54 cm. The titanium sample was first cleaning with chloroform. The oxide layer was removed by cleaning the sample with a 1:1:1 mixture of water, nitric acid and sulphuric acid. Later was rinsed in water and dried with acetone. Finally, was treated with HCl to form an hydride layer on the surface. The stainless steel sample was only cleaned with soap and cleaning with acetone. The samples were cleaning at low pressure for several days with high temperature short cycles. The deuterium was loaded to the chamber at room temperature having absorption on the titanium samples at 10 3 at 10 1 mbar. Afterwards that the samples were heated up at 330 C and was observed the deuterium absorption in the same pressure range. Forced deuteration through electrical discharges between the sample and the chamber was tried obtaining absorption in the range of 10 3 at 10 2 mbar, however the deuterium absorption only was observed in specific cases. In order to detect neutron emission or released particles in this experiment were used alanine detectors and series of plastic CR-39 and borate films. No neutron were detected in the passive systems used in the experiments. (Author)

Fully deuterated microorganisms: Tools in magnetic resonance and neutron scattering

International Nuclear Information System (INIS)

Crespi, H.L.

1988-01-01

Current work at Argonne emphasizes the use of fully deuterated algae and cyanobacteria as tools in the study of photosynthesis and as a source of complex substrates for the culture of engineered overproducing bacteria. 17 refs., 1 fig., 1 tab

Methyl esters from vegetable oils with hydroxy fatty acids: Comparison of lesquerella and castor methyl esters

Science.gov (United States)

The search for alternative feedstocks for biodiesel as partial replacement for petrodiesel has recently extended to castor oil. In this work, the castor oil methyl esters were prepared and their properties determined in comparison to the methyl esters of lesquerella oil, which in turn is seen as alt...

Deuterated fibre Z-pinch on the S-300 generator

NARCIS (Netherlands)

Klir, D.; Kravarik, J.; Kubes, P.; Bakshaev, Yu L.; Blinov, P. I.; Chernenko, A. S.; Danko, S. A.; Korolev, V. D.; Ustroev, G. I.; Ivanov, M. I.; Cai, Hongchun

2006-01-01

Dense Z-pinch experiments were carried out on the S-300 generator (3.5 MA, 100 ns, 0.15 Omega) at the Kurchatov Institute in Moscow. The experiments were performed at a peak current of 2 MA with a rise time of about 100 ns. The Z-pinch was formed from a deuterated polyethylene fibre of 100 mu m

Deuteration of Dimethyl 4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphenyl-2,2'-dicarboxylate (BDD)

International Nuclear Information System (INIS)

Tong Qiang

1990-01-01

A new antihepatitic drug, BDD(I), which is very active and powerful especially in lowering elevated SGPT levels, has been previously discovered during the systematic study of Schisandra chinensis. In order to study the metabolism of this new antihepatitic drug, deuterated BDD was prepared according to the following method. BDD 1g, sodium chloroplatinate 193 mg, deuterium oxide 16 ml, acetic anhydride 30 ml, and acetyl chloride 0.4 ml were well mixed in a sealed ampoule and heated to 120-130 deg C for 12h. The mixture was then poured into water. The precipitate (0.86g) contained the deuterated acid (IIa, IIb) of BDD. After esterification with methanol, a mixture (m.p. 150 ∼ 153 deg C) of mono-and di-deuterated BDD was obtained. Molecular clustering, as determined by GC/MS, showed that the product consisted of mono-deutero-BDD(IIIa) (m/e419) and dideutero-BDD(IIIb) (m/e420) in the ratio of 1:1.3

Stereoselective semi-hydrogenation and deuteration of a diacetylenic precursor of leukotriene B sub 4 methyl ester

Energy Technology Data Exchange (ETDEWEB)

Pontikis, R.; Le Merrer, Y.; Depezay, J.-C. (U.D.C. CNRS-INSERM (URA 400), 75, Paris (France). Lab. de Chimie et Biochimie Pharamacologiques et Toxicologiques); Petillot, Y.; Rousseau, B.; Beaucourt, J.P. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Service des Molecules Marquees)

1990-10-01

(6,7,14,15-{sup 2}H4)-Leukotriene B4 methyl ester was prepared by reduction with deuterium gas of a suitable precursor (deuterium incorporation > 90%). Several catalytic semi-hydrogenations were affected in order to determine the best conditions for the labeling step. (author).

LIF excitation spectra for S 0 → S 1 transition of deuterated anthranilic acid COOD, ND 2 in supersonic-jet expansion

Science.gov (United States)

Kolek, Przemysław; Leśniewski, Sebastian; Andrzejak, Marcin; Góra, Maciej; Cias, Pawel; Weģrzynowicz, Adam; Najbar, Jan

2010-12-01

Laser induced fluorescence (LIF) excitation spectrum for the S 0 → S 1 transition of anthranilic acid molecules deuterated in the substituent groups (COOD, ND 2) was investigated. Analysis of the LIF spectrum allowed for the assignment of the six most prominent fundamental in-plane modes of frequencies up to ca. 850 cm. The experimental results show good correlation with the frequency changes upon deuteration computed with CIS (CI-Singles) and TD-DFT for the S 1 state. Deuteration induced red-shifts of the identified fundamental bands are used for examination of the alternative assignments proposed in earlier studies. Potential energy distributions (PED) and overlaps of the in-plane normal modes with frequencies below 850 cm indicate that the correspondence of the respective vibrations of the deuterated and non-deuterated molecule is very good. A blue-shift of the 00 transition due to the isotopic substitution, is equal to 47 cm. This relatively large value is caused primarily by a significant decrease of the N-H stretching frequency associated with the increase of strength of the intramolecular hydrogen bond upon the electronic excitation. The deuteration shift of the 00 band was interpreted in terms of the differences of the zero point energy (ZPE) between the S 0 and S 1 electronic states, computed with DFT and TD-DFT methods, respectively.

Infrared and Raman study of the fast internal motions of non-rigid molecules in condensed state: method of selective deuteration

International Nuclear Information System (INIS)

Lascombe, J.; Cavagnat, D.; Lassegues, J.C.; Rafilipomanana, C.

1983-01-01

The dynamical behaviour of non-rigid molecules in the gas state is now well known but very little information is available on these molecules in condensed state. The authors present a method of study based on the analysis of the infrared and Raman spectra of selectively deuterated molecules. It is applied to the nitromethane and cyclopentene molecules which provide respectively characteristic examples of methyl internal rotation and ring-puckering motion. In each case, an isolated -C0 or -CD oscillator is modulated by the internal motion and several γ(CH) or γ(CD) bands are observed as a result of the dependence of the vibrational frequency of the oscillator on its conformational situation. Moreover, in the case of crystalline nitromethane a detailed study of the temperature dependence of the band profiles allows the main mechanism of relaxation of the -CH oscillator to be deduced. (orig.)

Experimental Observations of Nuclear Activity in Deuterated Materials Subjected to a Low-Energy Photon Beam

Science.gov (United States)

Steinetz, Bruce M.; Benyo, Theresa L.; Pines, Vladimir; Pines, Marianna; Forsley, Lawrence P.; Westmeyer, Paul A.; Chait, Arnon; Becks, Michael D.; Martin, Richard E.; Hendricks, Robert C.;

Perdeuteration and methyl-selective 1H, 13C-labeling by using a Kluyveromyces lactis expression system

International Nuclear Information System (INIS)

Miyazawa-Onami, Mayumi; Takeuchi, Koh; Takano, Toshiaki; Sugiki, Toshihiko; Shimada, Ichio; Takahashi, Hideo

2013-01-01

The production of stable isotope-labeled proteins is critical in structural analyses of large molecular weight proteins using NMR. Although prokaryotic expression systems using Escherichia coli have been widely used for this purpose, yeast strains have also been useful for the expression of functional eukaryotic proteins. Recently, we reported a cost-effective stable isotope-labeled protein expression using the hemiascomycete yeast Kluyveromyces lactis (K. lactis), which allow us to express exogenous proteins at costs comparable to prokaryotic expression systems. Here, we report the successful production of highly deuterated (>90 %) protein in the K. lactis system. We also examined the methyl-selective 1 H, 13 C-labeling of Ile, Leu, and Val residues using commonly used amino acid precursors. The efficiency of 1 H- 13 C-incorporation varied significantly based on the amino acid. Although a high level of 1 H- 13 C-incorporation was observed for the Ile δ1 position, 1 H, 13 C-labeling rates of Val and Leu methyl groups were limited due to the mitochondrial localization of enzymes involved in amino acid biosynthesis and the lack of transporters for α-ketoisovalerate in the mitochondrial membrane. In line with this notion, the co-expression with branched-chain-amino-acid aminotransferase in the cytosol significantly improved the incorporation rates of amino acid precursors. Although it would be less cost-effective, addition of 13 C-labeled valine can circumvent problems associated with precursors and achieve high level 1 H, 13 C-labeling of Val and Leu. Taken together, the K. lactis system would be a good alternative for expressing large eukaryotic proteins that need deuteration and/or the methyl-selective 1 H, 13 C-labeling for the sensitive detection of NMR resonances

A Neutron Scattering Study of Phonons in Per-Deuterated S-Triazine

DEFF Research Database (Denmark)

Doue, M. T.; Heilmann, I. U.; Kjems, Jørgen

1983-01-01

The lattice dynamics of a fully-deuterated single crystal of s-triazine is investigated using the technique of coherent inelastic neutron scattering. Detailed measurements of the temperature dependence of the dispersion of the soft acoustic mode associated with the ferroelastic phase transition...

Methylation pattern of IFNG in periapical granulomas and radicular cysts.

Science.gov (United States)

Campos, Kelma; Gomes, Carolina Cavaliéri; de Fátima Correia-Silva, Jeane; Farias, Lucyana Conceição; Fonseca-Silva, Thiago; Bernardes, Vanessa Fátima; Pereira, Cláudia Maria; Gomez, Ricardo Santiago

2013-04-01

Interferon-γ plays an important role in the pathogenesis of periapical lesions, and the methylation of IFNG has been associated with transcriptional inactivation. The purpose of the present study was to investigate IFNG promoter methylation in association with gene transcription and protein levels in periapical granulomas and radicular cysts. Methylation-specific polymerase chain reaction was used to assess the DNA methylation pattern of the IFNG gene in 16 periapical granulomas and 13 radicular cyst samples. The transcription levels of IFNG mRNA were verified by quantitative real-time polymerase chain reaction, and protein expression was evaluated by immunohistochemistry. All the periapical lesion samples exhibited partial or total methylation of the IFNG gene. In addition, an increased methylation profile was found in radicular cysts compared with periapical granulomas. Increased IFNG mRNA expression was observed in the partially methylated periapical lesion samples relative to the samples that were completely methylated. The present study provides the first evidence of the possible impact of IFNG methylation on IFNG transcription in periapical lesions. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

{sup 15}N and {sup 13}C- SOFAST-HMQC editing enhances 3D-NOESY sensitivity in highly deuterated, selectively [{sup 1}H,{sup 13}C]-labeled proteins

Energy Technology Data Exchange (ETDEWEB)

Rossi, Paolo, E-mail: rossip@umn.edu; Xia, Youlin; Khanra, Nandish; Veglia, Gianluigi, E-mail: vegli001@umn.edu; Kalodimos, Charalampos G., E-mail: ckalodim@umn.edu [University of Minnesota, Department of Biochemistry, Molecular Biology and Biophysics (United States)

2016-12-15

The ongoing NMR method development effort strives for high quality multidimensional data with reduced collection time. Here, we apply ‘SOFAST-HMQC’ to frequency editing in 3D NOESY experiments and demonstrate the sensitivity benefits using highly deuterated and {sup 15}N, methyl labeled samples in H{sub 2}O. The experiments benefit from a combination of selective T{sub 1} relaxation (or L-optimized effect), from Ernst angle optimization and, in certain types of experiments, from using the mixing time for both NOE buildup and magnetization recovery. This effect enhances sensitivity by up to 2.4× at fast pulsing versus reference HMQC sequences of same overall length and water suppression characteristics. Representative experiments designed to address interesting protein NMR challenges are detailed. Editing capabilities are exploited with heteronuclear {sup 15}N,{sup 13}C-edited, or with diagonal-free {sup 13}C aromatic/methyl-resolved 3D-SOFAST-HMQC–NOESY–HMQC. The latter experiment is used here to elucidate the methyl-aromatic NOE network in the hydrophobic core of the 19 kDa FliT-FliJ flagellar protein complex. Incorporation of fast pulsing to reference experiments such as 3D-NOESY–HMQC boosts digital resolution, simplifies the process of NOE assignment and helps to automate protein structure determination.

Widespread deuteration across the IRDC G035.39-00.33

Science.gov (United States)

Barnes, A. T.; Kong, S.; Tan, J. C.; Henshaw, J. D.; Caselli, P.; Jiménez-Serra, I.; Fontani, F.

2016-05-01

Infrared Dark Clouds (IRDCs) are cold, dense regions that are usually found within Giant Molecular Clouds. Ongoing star formation within IRDCs is typically still deeply embedded within the surrounding molecular gas. Characterizing the properties of relatively quiescent IRDCs may therefore help us to understand the earliest phases of the star formation process. Studies of local molecular clouds have revealed that deuterated species are enhanced in the earliest phases of star formation. In this paper, we test this towards IRDC G035.39-00.33. We present an 80 arcsec by 140 arcsec map of the J = 2 → 1 transition of N2D+, obtained with the Institut de Radioastronomie Millimétrique 30 m telescope telescope. We find that N2D+ is widespread throughout G035.39-00.33. Complementary observations of N2H+ (1 - 0) are used to estimate the deuterium fraction, D_frac^N_2H^+ ≡ N(N2D+)/N(N2H+). We report a mean D_frac^N_2H^+ = 0.04 ± 0.01, with a maximum of D_frac^N_2H^+ = 0.09 ± 0.02. The mean deuterium fraction is ˜3 orders of magnitude greater than the interstellar [D]/[H] ratio. High angular resolution observations are required to exclude beam dilution effects of compact deuterated cores. Using chemical modelling, we find that the average observed values of D_frac^N_2H^+are in agreement with an equilibrium deuterium fraction, given the general properties of the cloud. This implies that the IRDC is at least ˜3 Myr old, which is ˜8 times longer than the mean free-fall time of the observed deuterated region.

Stereospecific assignments of glycine in proteins by stereospecific deuteration and {sup 15}N labeling

Energy Technology Data Exchange (ETDEWEB)

Hansen, A.P.; Curley, R.W. Jr.; Panigot, M.J.; Fesik, S.W. [Ohio State Univ., Columbus, OH (United States)

1994-12-01

Stereospecific assignments are important for accurately determining the three-dimensional structures of proteins through the use of multidimensional NMR techniques. It is especially important to stereospecifically assign the glycine {alpha}-protons in proteins because of the potential for different backbone conformations of this residue. These stereospecific assignments are critical for interpreting the {sup 3}J{sub NH,{alpha}H} coupling constants and NOEs involving the glycine {alpha}-protons that determine the conformation of this part of the protein. However, it is often difficult to unambiguously obtain the stereospecific assignments for glycine residues by using only NOE data. In this poster, we present a method for unambiguous, stereospecific assignment of the {alpha}-protons of glycine residues. This method involves synthesis of stereo-specifically deuterated and {sup 15}N-labeled Gly using a slightly modified procedure originally described by Woodard and coworkers for the stereoselective deuteration of glycine. The stereospecifically deuterated and {sup 15}N-labeled Gy has been incorporated into recombinant proteins expressed in both bacterial systems (FKBP) and mammalian cells (u-PA). Two- and three-dimensional isotope-filtered and isotope-edited NMR experiments were used to obtain the stereospecific assignments of the glycine {alpha}-protons for these proteins.

THE HERSCHEL AND IRAM CHESS SPECTRAL SURVEYS OF THE PROTOSTELLAR SHOCK L1157-B1: FOSSIL DEUTERATION

International Nuclear Information System (INIS)

Codella, C.; Fontani, F.; Vasta, M.; Ceccarelli, C.; Lefloch, B.; Kahane, C.; Taquet, V.; Wiesenfeld, L.; Busquet, G.; Caselli, P.; Lis, D.; Viti, S.

2012-01-01

We present the first study of deuteration toward the protostellar shock L1157-B1, based on spectral surveys performed with the Herschel-HIFI and IRAM 30 m telescopes. The L1157 outflow is driven by a low-mass Class 0 protostar and is considered the prototype of the so-called chemically active outflows. The young (2000 yr), bright blueshifted bow shock, B1, is an ideal laboratory for studying the gas chemically enriched by the release of dust mantles due to the passage of a shock. A total of 12 emission lines (up to E u = 63 K) of CH 2 DOH, HDCO, and DCN are detected. In addition, two lines of NH 2 D and HDO are tentatively reported. To estimate the deuteration, we also extracted from our spectral survey emission lines of non-deuterated isotopologues ( 13 CH 3 OH, H 2 13 CO, H 13 CN, H 2 13 CO, and NH 3 ). We infer higher deuteration fractions for CH 3 OH (D/H = 0.2-2 × 10 –2 ) and H 2 CO (5-8 × 10 –3 ) than for H 2 O (0.4-2 × 10 –3 ), HCN (∼10 –3 ), and ammonia (≤3 × 10 –2 ). The measurement of deuteration of water, formaldehyde, and methanol in L1157-B1 provides a fossil record of the gas before it was shocked by the jet driven by the protostar. A comparison with gas-grain models indicates that the gas passed through a low-density (≤10 3 cm –3 ) phase, during which the bulk of water ices formed, followed by a phase of increasing density, up to 3 × 10 4 cm –3 , during which formaldehyde and methanol ices formed.

Correlation between the structure and infra-red absorption characteristics of mono-deuterated compounds: contribution to the study of organo-magnesium compounds

International Nuclear Information System (INIS)

Paillous, A.

1965-10-01

The high sensitivity of the ν (C-D) vibration to the variations brought about by the substitution of the carbon attached to the deuterium is shown in the case of organic or organo-metallic mono-deuterated molecules. In particular, syntheses of various mono-deuterated organo-magnesium compounds have been carried out; results are given concerning an infra-red spectrometric examination of these compounds in the range 2100 - 2250 cm -1 . The results show the existence of only one type of deuterated carbon, which suggests that the same carbanion is involved in various ionic associations for the different magnesium-containing compounds. (authors) [fr

Molecular differences between deuterated and protonated polystyrenes using reversed-phase high-performance liquid chromatography.

Science.gov (United States)

Kayillo, Sindy; Gray, Michael J; Shalliker, R Andrew; Dennis, Gary R

2005-05-06

Isotopic substitution is a technique used to highlight particular bonds within a molecule for kinetic, spectroscopic and structure analysis. It is presumed that although some properties such as stretching frequencies will not be the same for substituted analogues, the chemical interactions will not vary appreciably as a function of labelling. Reversed-phase liquid chromatography has been used to demonstrate that there are significant differences between the chromatographic behaviour of a sequence of deuterated and protonated oligomeric polystyrenes. Two-dimensional reversed-phase liquid chromatography was used to show that even the diasteromers of the oligomers (n = 5) have retention mechanisms that are dependent on the subtle changes to the molecular conformation and electronic structure, which are a consequence of deuteration.

Labelling by deuteration and nitroxide radicals of mono-, oligo- and polysaccharides (cellulose and amylose)

Energy Technology Data Exchange (ETDEWEB)

Odier, L

1975-01-01

The application of NMR and deuteration labelling to the investigation of polysaccharides has led to considerable progress in recent years in the knowledge of these compounds. Although far more recent, the introduction of spin labelling techniques in the investigation of polymers, has given rise to interesting EPR studies of synthetic and natural macromolecules, but nothing appears to have been accomplished in the area of spin labelling of polysaccharides. This work was aimed at applying these two techniques to the study of glucose derivatives and of some of its oligomers (low molecular weight polymers): cellobiose, maltose and cyclodextrins; and its polymers: cellulose and amylose. Irrespective of the technique employed, the complexity of the polymers and problems connected with handling them always require the same procedure: an initial study of a model compound generally prepared from the monomer or an oligomer (dimer), followed by the oligomers, and finally the polymer. Part 1 is devoted to the deuteration labelling of mono- and oligosaccharides. Part 2 concerns spin labelling of cellulose acetate. In part 3, an attempt is made to apply the spin labelling technique to the determination of conformations of two disaccharides of different glycosidic configurations: cellobiose and maltose. Part 4 is devoted to spin and deuteration labelling of ..cap alpha.. and ..beta.. cyclodextrins.

Synthesis and spectroscopic stereospecificity assay of the deuterated quinolizidine alkaloids (2S)-[2H]- and (2R)-[2H]-sparteine

International Nuclear Information System (INIS)

Ebner, T.; Meese, C.O.; Rebell, J.

1989-01-01

Borohydride reduction of the (+)-1,2-dehydrosparteinium salts proceeds almost exclusively from the Si side, yielding, respectively, the stereoselectively (2S)(β)-deuterated (-)-sparteine and the (2R)(α)-deuterated (-)-sparteine. Stereo-chemistry and isotopic purity of the deuterium label (≥98%) are established unequivocally by 1 H, 2 H and 13 C NMR spectroscopy. (author)

The feasibility study of using deuterated gadolinium nitrate for moderator-poisoned shutdown and excess reactivity control in CANDU reactors

International Nuclear Information System (INIS)

Li, J.; Everatt, A.

2006-01-01

Gadolinium nitrate is used in CANDU stations as moderator poison for reactor shutdowns and excess reactivity control. The use of the light-water hydrate introduces significant quantities of light water into the moderator system, which must be removed from the moderator by periodically upgrading the moderator (isotopic maintenance). The benefit of using a deuterated gadolinium nitrate would be a higher moderator isotopic and/or a lesser isotopic maintenance requirement. This study evaluated the economics of using deuterated gadolinium nitrate, as opposed to the light-water hydrate, for moderator-poisoned shutdowns and excess reactivity control in CANDU-6 reactors. Normal gadolinium nitrate (i.e., the light-water hydrate) is available from suppliers at ∼125 $/kg. Supplier quotes for deuterated gadolinium nitrate ranged from 1900 to 4000 $/kg. To examine the possibility of producing deuterated gadolinium nitrate in-house at a lower cost than commercially available, a three-stage dissolution/evaporation manufacturing process was conceived and costed. Depending on the assumed demand for the product (i.e., the number of reactors adopting the use of the product) and the capital recovery period, the estimated unit cost for the dissolution/evaporation process ranged from 730 to 2500 $/kg. The determination of economic benefit from using deuterated gadolinium nitrate in existing CANDU stations was based on the cost savings resulting from a higher fuel burn-up (i.e., the higher moderator isotopic would give a higher fuel burn-up). The net benefit of using deuterated gadolinium nitrate for most CANDU stations was determined to be marginal (i.e., <20 k$/a). Only for those CANDU stations where the moderator isotopic was relatively low (e.g., 99.85 wt%) was there a potential significant benefit (20-100 k$/a). However, if the reason for the low moderator isotopic is a relatively high moderator light-water ingress rate from sources other than the use of the light-water hydrate

The rate of lactate production from glucose in hearts is not altered by per-deuteration of glucose

Science.gov (United States)

Funk, Alexander M.; Anderson, Brian L.; Wen, Xiaodong; Hever, Thomas; Khemtong, Chalermchai; Kovacs, Zoltan; Sherry, A. Dean; Malloy, Craig R.

2017-11-01

This study was designed to determine whether perdeuterated glucose experiences a kinetic isotope effect (KIE) as glucose passes through glycolysis and is further oxidized in the tricarboxylic acid (TCA) cycle. Metabolism of deuterated glucose was investigated in two groups of perfused rat hearts. The control group was supplied with a 1:1 mixture of [U-13C6]glucose and [1,6-13C2]glucose, while the experimental group received [U-13C6,U-2H7]glucose and [1,6-13C2]glucose. Tissue extracts were analyzed by 1H, 2H and proton-decoupled 13C NMR spectroscopy. Extensive 2H-13C scalar coupling plus chemical shift isotope effects were observed in the proton-decoupled 13C NMR spectra of lactate, alanine and glutamate. A small but measureable (∼8%) difference in the rate of conversion of [U-13C6]glucose vs. [1,6-13C2]glucose to lactate, likely reflecting rates of Csbnd C bond breakage in the aldolase reaction, but conversion of [U-13C6]glucose versus [U-13C6,U-2H7]glucose to lactate did not differ. This shows that the presence of deuterium in glucose does not alter glycolytic flux. However, there were two distinct effects of deuteration on metabolism of glucose to alanine and oxidation of glucose in the TCA. First, alanine undergoes extensive exchange of methyl deuterons with solvent protons in the alanine amino transferase reaction. Second, there is a substantial kinetic isotope effect in metabolism of [U-13C6,U-2H7]glucose to alanine and glutamate. In the presence of [U-13C6,U-2H7]glucose, alanine and lactate are not in rapid exchange with the same pool of pyruvate. These studies indicate that the appearance of hyperpolarized 13C-lactate from hyperpolarized [U-13C6,U-2H7]glucose is not substantially influenced by a deuterium kinetic isotope effect.

Preparation of α-deuterated L-amino acids using E.coli cells containing tryptophanase

International Nuclear Information System (INIS)

Faleev, N.G.; Ruvinov, S.B.; Saporovskaya, M.B.; Belikov, V.M.; Zakomyrdina, L.N.; Sakharova, I.S.; Torchinskij, Yu.M.

1989-01-01

Method for preparation of a series of α-deuterated L-amino acids of high optical purity with quantitative chemica yield, suing stereospecific isotopic exchange in D 2 O under the effect of E.coli cells with high tryptophanase activity was developed

THE HERSCHEL AND IRAM CHESS SPECTRAL SURVEYS OF THE PROTOSTELLAR SHOCK L1157-B1: FOSSIL DEUTERATION

Energy Technology Data Exchange (ETDEWEB)

Codella, C.; Fontani, F.; Vasta, M. [INAF, Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze (Italy); Ceccarelli, C.; Lefloch, B.; Kahane, C.; Taquet, V.; Wiesenfeld, L. [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041 (France); Busquet, G. [INAF - Istituto di Astrofisica e Planetologia Spaziali, via Fosso del Cavaliere 100, I-00133, Roma (Italy); Caselli, P. [School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT (United Kingdom); Lis, D. [California Institute of Technology, Cahill Center for Astronomy and Astrophysics 301-17, Pasadena, CA 91125 (United States); Viti, S., E-mail: codella@rcetri.astro.it [Department of Physics and Astronomy, University College London, London (United Kingdom)

2012-09-20

We present the first study of deuteration toward the protostellar shock L1157-B1, based on spectral surveys performed with the Herschel-HIFI and IRAM 30 m telescopes. The L1157 outflow is driven by a low-mass Class 0 protostar and is considered the prototype of the so-called chemically active outflows. The young (2000 yr), bright blueshifted bow shock, B1, is an ideal laboratory for studying the gas chemically enriched by the release of dust mantles due to the passage of a shock. A total of 12 emission lines (up to E{sub u} = 63 K) of CH{sub 2}DOH, HDCO, and DCN are detected. In addition, two lines of NH{sub 2}D and HDO are tentatively reported. To estimate the deuteration, we also extracted from our spectral survey emission lines of non-deuterated isotopologues ({sup 13}CH{sub 3}OH, H{sub 2} {sup 13}CO, H{sup 13}CN, H{sub 2} {sup 13}CO, and NH{sub 3}). We infer higher deuteration fractions for CH{sub 3}OH (D/H = 0.2-2 Multiplication-Sign 10{sup -2}) and H{sub 2}CO (5-8 Multiplication-Sign 10{sup -3}) than for H{sub 2}O (0.4-2 Multiplication-Sign 10{sup -3}), HCN ({approx}10{sup -3}), and ammonia ({<=}3 Multiplication-Sign 10{sup -2}). The measurement of deuteration of water, formaldehyde, and methanol in L1157-B1 provides a fossil record of the gas before it was shocked by the jet driven by the protostar. A comparison with gas-grain models indicates that the gas passed through a low-density ({<=}10{sup 3} cm{sup -3}) phase, during which the bulk of water ices formed, followed by a phase of increasing density, up to 3 Multiplication-Sign 10{sup 4} cm{sup -3}, during which formaldehyde and methanol ices formed.

Residue-specific membrane location of peptides and proteins using specifically and extensively deuterated lipids and {sup 13}C-{sup 2}H rotational-echo double-resonance solid-state NMR

Energy Technology Data Exchange (ETDEWEB)

Xie Li; Ghosh, Ujjayini; Schmick, Scott D.; Weliky, David P., E-mail: weliky@chemistry.msu.edu [Michigan State University, Department of Chemistry (United States)

2013-01-15

Residue-specific location of peptides in the hydrophobic core of membranes was examined using {sup 13}C-{sup 2}H REDOR and samples in which the lipids were selectively deuterated. The transmembrane topology of the KALP peptide was validated with this approach with substantial dephasing observed for deuteration in the bilayer center and reduced or no dephasing for deuteration closer to the headgroups. Insertion of {beta} sheet HIV and helical and {beta} sheet influenza virus fusion peptides into the hydrophobic core of the membrane was validated in samples with extensively deuterated lipids.

Some Routes in Forming C3Hn+ Ions and Deuterated Variants under Interstellar Conditions

International Nuclear Information System (INIS)

Savic, Igor; Gerlich, Dieter

2006-01-01

Laboratory experiments on hydrogenation and deuteration of C 3 + , C3H+ and C 3 H 2 + in collisions with H2 and HD have been performed from room temperature down to 15 K using a 22-pole ion-trap. At room temperature C 3 + reacts slowly with H2 but the reactivity increases with decreasing temperature. It has been shown that the association reaction C 3 + + H 2 → C 3 H 2 + + hν can compete with the exothermic reaction C 3 + + H 2 → C 3 H + + H. In collisions of C 3 + with HD, formation of C3D+ is slightly favored over C3H+ formation. A pronounced competition between various channels has been detected for deuterated variants of the C3H+ + H2 system. Most surprising is that formation of C3HD+ is over one hundred times faster then formation of C 3 H 2 + in collisions of C3H+ and HD. An tentative explanation is that the H-HD exchange takes place via an open-chain H2CCCH+ intermediate. Reactions of C 3 H 2 + and C 3 H 3 + with H2 are very slow. The formation of C3H2D+ or C 3 HD 2 + and finally C3HD via dissociative recombination has been discussed. The reaction C 3 H 3 + + HD → C 3 H 2 D + + H 2 can be ignored in astrochemical models since the reaction rate at 15 K is very small; however, quite efficient routes have been found starting from C 3 + and proceeding via deuterated C3H+ to C 3 H 2 + and C 3 H 3 + . The new reaction rate coefficients are recommended to be included in astrophysical databases. Nonetheless it is still unclear how to explain the large abundance of C3H2 and larger hydrocarbons and their deuterated variants observed in cold interstellar clouds

Biosynthetic preparation of selectively deuterated phosphatidylcholine in genetically modified Escherichia coli

DEFF Research Database (Denmark)

Maric, Selma; Thygesen, Mikkel Boas; Schiller, Jürgen

2015-01-01

Phosphatidylcholine (PC) is a major component of eukaryotic cell membranes and one of the most commonly used phospholipids for reconstitution of membrane proteins into carrier systems such as lipid vesicles, micelles and nanodiscs. Selectively deuterated versions of this lipid have many applicati...

Tritium aging effect of LaNi4.9Al0.1Dx on de-deuterating kinetics

International Nuclear Information System (INIS)

Xiong Yifu; Luo Deli; Li Rong

2002-01-01

Kinetics parameters are measured at different aging times of LaNi 4.9 Al 0.1 alloy. The influence of tritium aging on kinetic feature of LaNi 4.9 Al 0.1 alloy is assessed. The results show that reaction rate decreases with aging time, but tritium aging does not change de-deuterating reaction order. De-deuterating reaction orders a (with respect to deuterium pressure) and b (with respect to deuterium content) are 0.5 and 1, respectively. Activation energy (E) increases with aging time. After 1120 d, the reaction rate constant is decreased by two orders of magnitude, activation energy is increased by a factor of 0.3

The use of deuterated ethyl acetate in highly concentrated electrolyte as a low-cost solvent for in situ neutron diffraction measurements of Li-ion battery electrodes

International Nuclear Information System (INIS)

Petibon, R.; Li, Jing; Sharma, Neeraj; Pang, Wei Kong; Peterson, Vanessa K.; Dahn, J.R.

2015-01-01

A low-cost deuterated electrolyte suitable for in situ neutron diffraction measurements of normal and high voltage Li-ion battery electrodes is reported here. Li[Ni 0.4 Mn 0.4 Co 0.2 ]O 2 /graphite (NMC(442)/graphite) pouch cells filled with 1:0.1:2 (molar ratio) of lithium bis(fluorosulfonyl) imide (LiFSi):LiPF 6 : ethyl acetate (EA) and LiFSi:LiPF 6 :deuterated EA (d8-EA) electrolytes were successfully cycled between 2.8 V and 4.7 V at 40°C for 250 h without significant capacity loss, polarization growth, or gas production. The signal-to-noise ratio of neutron powder diffraction patterns taken on NMC(442) powder with a conventional deuterated organic carbonate-based electrolyte and filled with LiFSi:LiPF 6 :d8-EA electrolyte were virtually identical. Out of all the solvents widely available in deuterated form tested in highly-concentrated systems, EA was the only one providing a good balance between cost and charge-discharge capacity retention to 4.7 V. The use of such an electrolyte blend would half the cost of deuterated solvents needed for in situ neutron diffraction measurements of Li-ion batteries compared to conventional deuterated carbonate-based electrolytes

Fibronectin distribution in the extracellular matrix in the cells grown in deuterated media

International Nuclear Information System (INIS)

Buzgariu, Wanda; Caloianu, Maria; Moldovan, Lucia; Stefanescu, I.; Titescu, Gh.

2003-01-01

The aim of this work is the study of the influence of deuterated water upon the synthesis and organization of fibronectin (FN) in extracellular matrices. Changes were evidenced at the level of extracellular matrix in case of embryo fibroblast cultivation in media with different concentrations of heavy water (20%, 40% and 65%). FN was identified in the extracellular matrix by means of indirect immunocytochemical technique, using a secondary antibody coupled with peroxydase. In the presence of heavy water in culture medium, the arrangement and localization of cellular FN showed changes depending on the exposure time, D 2 O concentration in the medium and the FN polymerization step in the extra cellular matrix in correlation with the culture stage of the monolayer. The heavy water determined a strong reduction of the FN amount released by the cells. This reduction was most evident in the 65% D 2 O medium following a 5 day exposure. The FN distribution after 2 day exposure in an early stage with regards to the FN network formation in a the deuterated medium presented a FN pericellular distribution arranged in aggregates. The heavy water can act upon formation of FN fibrils immediately due to solvent role in the FN polymerization process but also indirectly through metabolic processes and so upon the protein synthesis and FN cellular secretion.The FN network arrangement in the cells cultivated in deuterated media as aggregates might be the effect of solvent role played by D 2 O while the quantitative reduction of FN results from perturbation of protein synthesis as well from biochemical synthesis reactions

TEM and EELS study of deuterated carbon: application to the fuel retention in tokamaks; Etude couplee MET-EELS du carbone deutere: application a la retention du combustible dans les tokamaks

Energy Technology Data Exchange (ETDEWEB)

Bernier, N

2007-12-15

We developed a methodology, based on the combination of TEM and EELS techniques, for a structural and chemical characterization, at a high spatial resolution, of a wide range of carbon materials. We i) optimized, in the framework of theoretical models, the sp2 fraction quantification from pure carbons by EELS ii) transferred this quantification to deuterated amorphous carbon layers iii) showed, from graphitized carbons, how the TEM-EELS combination allows to detect low concentrations of implanted D. Due to the accomplishment of these developments, we applied our approach to the study of D retention in composites C/C, which are the plasma-facing materials in TS. We showed that specific localized retention sites correspond to relatively large ({approx} 3 mm.) cracks between fibres and matrix; such cracks offer a simple and direct path for deuterated amorphous carbon. The particle balance performed in TS is discussed in the light of this trapping mechanism. (author)

A Deuteration Survey of Starless Clumps in GemOB1 and the First Quadrant

Science.gov (United States)

Henrici, Andrew; Shirley, Yancy L.; Svoboda, Brian

2018-01-01

One very strong chemical process in star-forming regions is the fractionation of deuterium in molecules, which results in an increase in the deuterium ratio many orders of magnitude over the ISM [D]/[H] ratio and provides a chemical probe of cold, dense regions. Recent maps of dust continuum emission at (sub)millimeter wavelengths have identified tens of thousands of dense clumps of gas and dust. By comparing these regions to infrared and radio surveys, we have identified starless clump candidates which have no evidence for embedded star formation. These objects represent the earliest phase of star formation throughout the Milky Way. One benefit of the Milky Way surveys is that it is also possible to study the chemistry of entire core and clump populations within a single cloud. We used the 10m Heinrich Hertz Submillimeter Telescope to survey starless clump candidates in the First Quadrant identified from the Bolocam Galactic Plane Survey 1.1 mm continuum in the deuterated molecular transitions of DCO+ 3-2 and N2D+ 3-2. We also survey the entire clump population of the Gemini OB1 molecular cloud. In both surveys, we compared detection statistics and compare deuteration fraction to physical properties of the clumps and their evolutionary stage. High resolution ALMA observations of 9 starless clump candidates of the same lines are used to analyze how the cold deuterated gas is spatially distributed in these clumps.

Synthesis of multiple deuterated N-n-propyl-norapomorphine N-(d/sub 7/) and derivatives

Energy Technology Data Exchange (ETDEWEB)

Gao, Yigong; Trainor, T.M.; Vouros, Paul; Neumeyer, J.L.

1988-03-01

Novapomorphine has been labelled using n-propyl iodide through alkylation of norcodeine followed by a multistep route which also affords the related deuterated analogs N-n-propylnorapocodeine, the prodrug 10,11-methylenedioxy-NPA and 10,11-dimethoxy-NPA.

Deuterated (d6)-dextromethorphan elicits antidepressant-like effects in mice.

Science.gov (United States)

Nguyen, Linda; Scandinaro, Anna L; Matsumoto, Rae R

2017-10-01

The over-the-counter antitussive dextromethorphan (DM) may have rapid antidepressant actions based on its overlapping pharmacology with ketamine, which has shown fast antidepressant effects but whose widespread use remains limited by problematic side effects. We have previously shown that DM produces antidepressant-like effects in the forced swim test (FST) and tail suspension test (TST) that are mediated in part through α-amino-3-hydroxy-5-methyl-4-isoxazole propionic (AMPA) and sigma-1 receptors, two protein targets associated with a faster onset of antidepressant efficacy. To utilize DM clinically, however, a major challenge that must be addressed is its rapid first-pass metabolism. Two strategies to inhibit metabolism of DM and maintain stable therapeutic blood levels are 1) chemically modifying DM and 2) adding quinidine, an inhibitor of the primary metabolizer of DM, the cytochrome P450 (CYP) 2D6 enzyme. The purpose of this study was to determine if modified DM (deuterated (d6)-DM) elicits antidepressant-like effects and if AMPA and sigma-1 receptors are involved. Furthermore, d6-DM was tested in conjunction with quinidine to determine if further slowing the metabolism of d6-DM affects its antidepressant-like actions. In the FST and TST, d6-DM produced antidepressant-like effects. Upon further investigation in the FST, the most validated animal model for predicting antidepressant efficacy, d6-DM produced antidepressant-like effects both in the absence and presence of quinidine. However, pretreatment with neither an AMPA receptor antagonist (NBQX) nor sigma-1 receptor antagonists (BD1063, BD1047) significantly attenuated the antidepressant-like effects. The data suggest d6-DM has antidepressant-like effects, though it may be recruiting different molecular targets and/or acting through a different mix or ratio of metabolites from regular DM. Copyright © 2017 Elsevier Inc. All rights reserved.

Isotopic fractionation of fentanyl and its deuterated analogues by capillary gas chromatography

International Nuclear Information System (INIS)

Sera, Shoji; Goromaru, Tsuyoshi

1997-01-01

Isotopic fractionation of fentanyl (FT) and its deuterated analogues by gas chromatography using capillary columns (CBP1 and CBP5) has been investigated. Seven kinds of analogues were labeled with 5 to 19 deuterium atoms at the anilino, propionyl and/or phenylethyl group of FT. The retention times of deuterated FT in CBP1 and CBP5 columns are inversely proportional to the number of labeled deuterium atoms in the molecule. The difference in free enegy changes (ΔΔG) had a linear relationship with the number of labeled deuterium atoms, except for labeling at anilino and phenylethyl group. The contribution of a deuterium atom to the ΔΔG value was estimated to be 1.13 cal/mol in CBP1 and 1.40 cal/mol in CBP5, respectively. While, its contribution in the propiony group was 2.84 cal/mol in CBP1 and 2.48 cal/mol in CBP5, respectively. An important factor in separation by GC may differences in interactions between the stationary phase of the column with the three dimensional protrusive moiety in the molecule. (author)

Isotopic fractionation of fentanyl and its deuterated analogues by capillary gas chromatography

Energy Technology Data Exchange (ETDEWEB)

Sera, Shoji; Goromaru, Tsuyoshi [Fukuyama Univ., Hiroshima (Japan)

1997-12-01

Isotopic fractionation of fentanyl (FT) and its deuterated analogues by gas chromatography using capillary columns (CBP1 and CBP5) has been investigated. Seven kinds of analogues were labeled with 5 to 19 deuterium atoms at the anilino, propionyl and/or phenylethyl group of FT. The retention times of deuterated FT in CBP1 and CBP5 columns are inversely proportional to the number of labeled deuterium atoms in the molecule. The difference in free enegy changes ({Delta}{Delta}G) had a linear relationship with the number of labeled deuterium atoms, except for labeling at anilino and phenylethyl group. The contribution of a deuterium atom to the {Delta}{Delta}G value was estimated to be 1.13 cal/mol in CBP1 and 1.40 cal/mol in CBP5, respectively. While, its contribution in the propiony group was 2.84 cal/mol in CBP1 and 2.48 cal/mol in CBP5, respectively. An important factor in separation by GC may differences in interactions between the stationary phase of the column with the three dimensional protrusive moiety in the molecule. (author)

Synthesis and spectroscopic stereospecificity assay of the deuterated quinolizidine alkaloids (2S)-( sup 2 H)- and (2R)-( sup 2 H)-sparteine

Energy Technology Data Exchange (ETDEWEB)

Ebner, T.; Meese, C.O. (Fischer-Bosch Inst. fuer Klinische Pharmakologie, Stuttgart (Germany, F.R.)); Rebell, J. (Stuttgart Univ. (Germany, F.R.). Inst. fuer Organische Chemie); Fischer, P. (Stuttgart Univ. (Germany, F.R.). Inst. fuer Organische Chemie Fischer-Bosch Inst. fuer Klinische Pharmakologie, Stuttgart (Germany, F.R.))

1989-04-01

Borohydride reduction of the (+)-1,2-dehydrosparteinium salts proceeds almost exclusively from the Si side, yielding, respectively, the stereoselectively (2S)({beta})-deuterated (-)-sparteine and the (2R)({alpha})-deuterated (-)-sparteine. Stereo-chemistry and isotopic purity of the deuterium label ({>=}98%) are established unequivocally by {sup 1}H, {sup 2}H and {sup 13}C NMR spectroscopy. (author).

Exploiting E. coli auxotrophs for leucine, valine, and threonine specific methyl labeling of large proteins for NMR applications

Energy Technology Data Exchange (ETDEWEB)

Monneau, Yoan R. [Rutgers University, Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology (United States); Ishida, Yojiro [Rutgers University, Center for Advanced Biotechnology and Medicine (United States); Rossi, Paolo; Saio, Tomohide; Tzeng, Shiou-Ru [Rutgers University, Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology (United States); Inouye, Masayori, E-mail: inouye@cabm.rutgers.edu [Rutgers University, Center for Advanced Biotechnology and Medicine (United States); Kalodimos, Charalampos G., E-mail: ckalodim@umn.edu [Rutgers University, Center for Integrative Proteomics Research and Department of Chemistry and Chemical Biology (United States)

2016-06-15

A simple and cost effective method to independently and stereo-specifically incorporate [{sup 1}H,{sup 13}C]-methyls in Leu and Val in proteins is presented. Recombinant proteins for NMR studies are produced using a tailored set of auxotrophic E. coli strains. NMR active isotopes are routed to either Leu or Val methyl groups from the commercially available and scrambling-free precursors α-ketoisovalerate and acetolactate. The engineered strains produce deuterated proteins with stereospecific [{sup 1}H,{sup 13}C]-methyl labeling separately at Leu or Val amino acids. This is the first method that achieves Leu-specific stereospecific [{sup 1}H,{sup 13}C]-methyl labeling of proteins and scramble-free Val-specific labeling. Use of auxotrophs drastically decreases the amount of labeled precursor required for expression without impacting the yield. The concept is extended to Thr methyl labeling by means of a Thr-specific auxotroph that provides enhanced efficiency for use with the costly L-[4-{sup 13}C,2,3-{sup 2}H{sub 2},{sup 15}N]-Thr reagent. The Thr-specific strain allows for the production of Thr-[{sup 13}CH{sub 3}]{sup γ2} labeled protein with an optimal isotope incorporation using up to 50 % less labeled Thr than the traditional E. coli strain without the need for {sup 2}H-glycine to prevent scrambling.

Effect of Isotopic Substitution on Elementary Processes in Dye-Sensitized Solar Cells: Deuterated Amino-Phenyl Acid Dyes on TiO2

Directory of Open Access Journals (Sweden)

Sergei Manzhos

2013-03-01

Full Text Available We present the first computational study of the effects of isotopic substitution on the operation of dye-sensitized solar cells. Ab initio molecular dynamics is used to study the effect of deuteration on light absorption, dye adsorption dynamics, the averaged over vibrations driving force to injection (∆Gi and regeneration (∆Gr, as well as on promotion of electron back-donation in dyes NK1 (2E,4E-2-cyano-5-(4-dimethylaminophenylpenta-2,4-dienoic acid and NK7 (2E,4E-2-cyano-5-(4-diphenylaminophenylpenta-2,4-dienoic acid adsorbed in monodentate molecular and bidentate bridging dissociative configurations on the anatase (101 surface of TiO2. Deuteration causes a red shift of the absorption spectrum of the dye/TiO2 complex by about 5% (dozens of nm, which can noticeably affect the overlap with the solar spectrum in real cells. The dynamics effect on the driving force to injection and recombination (the difference between the averaged <∆Gi,r> and ∆Gi,requil at the equilibrium configuration is strong, yet there is surprisingly little isotopic effect: the average driving force to injection <∆Gi> and to regeneration <∆Gr> changes by only about 10 meV upon deuteration. The nuclear dynamics enhance recombination to the dye ground state due to the approach of the electron-donating group to TiO2, yet this effect is similar for deuterated and non-deuterated dyes. We conclude that the nuclear dynamics of the C-H(D bonds, mostly affected by deuteration, might not be important for the operation of photoelectrochemical cells based on organic dyes. As the expectation value of the ground state energy is higher than its optimum geometry value (by up to 0.1 eV in the present case, nuclear motions will affect dye regeneration by recently proposed redox shuttle-dye combinations operating at low driving forces.

Neutron Compton scattering from selectively deuterated acetanilide

Science.gov (United States)

Wanderlingh, U. N.; Fielding, A. L.; Middendorf, H. D.

With the aim of developing the application of neutron Compton scattering (NCS) to molecular systems of biophysical interest, we are using the Compton spectrometer EVS at ISIS to characterize the momentum distribution of protons in peptide groups. In this contribution we present NCS measurements of the recoil peak (Compton profile) due to the amide proton in otherwise fully deuterated acetanilide (ACN), a widely studied model system for H-bonding and energy transfer in biomolecules. We obtain values for the average width of the potential well of the amide proton and its mean kinetic energy. Deviations from the Gaussian form of the Compton profile, analyzed on the basis of an expansion due to Sears, provide data relating to the Laplacian of the proton potential.

Static structure factor of polymerlike micelles: Overall dimension, flexibility, and local properties of lecithin reverse micelles in deuterated isooctane

DEFF Research Database (Denmark)

Jerke, G.; Pedersen, J.S.; Egelhaaf, S.U.

1997-01-01

We report a systematic investigation of the static structure factor S(q,c) of polymerlike reverse micelles formed by soybean lecithin and trace amounts of water in deuterated isooctane using small-angle neutron scattering and static light scattering. The experimental data for different concentrat......We report a systematic investigation of the static structure factor S(q,c) of polymerlike reverse micelles formed by soybean lecithin and trace amounts of water in deuterated isooctane using small-angle neutron scattering and static light scattering. The experimental data for different...

Three-dimensional cooling pattern of a granitic pluton 2. The study of deuteric sub-solidus reactions in the Toki granite, Central Japan

International Nuclear Information System (INIS)

Yuguchi, Takashi; Tsuruta, Tadahiko; Nishiyama, Tadao

2011-01-01

Petrographical studies examining the development and variations of sub-solidus reactions recorded in the Toki granite represent the three-dimensional cooling pattern of this zoned pluton in Central Japan. Samples collected from 19 boreholes in the Toki granite show characteristics indicative of spatial variations in the extent of the sub-solidus reactions. Exsolution coarsening has produced microperthite, including albite-rich lamellae, in this pluton, while deuteric coarsening has resulted in the formation of patchperthite, myrmekite, and the reaction rim. The extent of the deuteric coarsening reactions can be evaluated from the width and spacing of the albite-rich patch in patchperthite and from the thickness of myrmekite and the reaction rim. The width, spacing, and thickness of these textural features increase systematically with elevation; they also increase gradually in the horizontal inward direction in the western part of the pluton but not in the eastern part of the pluton. The systematic variations in textural development indicate that the Toki granite cooled effectively from the roof and from the western margin during the deuteric coarsening stage. The deuteric coarsening may have occurred at temperatures below 500°C, as indicated by ternary feldspar thermometry. (author)

Direct Detection of Hardly Detectable Hidden Chirality of Hydrocarbons and Deuterated Isotopomers by a Helical Polyacetylene through Chiral Amplification and Memory.

Science.gov (United States)

Maeda, Katsuhiro; Hirose, Daisuke; Okoshi, Natsuki; Shimomura, Kouhei; Wada, Yuya; Ikai, Tomoyuki; Kanoh, Shigeyoshi; Yashima, Eiji

2018-03-07

We report the first direct chirality sensing of a series of chiral hydrocarbons and isotopically chiral compounds (deuterated isotopomers), which are almost impossible to detect by conventional optical spectroscopic methods, by a stereoregular polyacetylene bearing 2,2'-biphenol-derived pendants. The polyacetylene showed a circular dichroism due to a preferred-handed helix formation in response to the hardly detectable hidden chirality of saturated tertiary or chiroptical quaternary hydrocarbons, and deuterated isotopomers. In sharp contrast to the previously reported sensory systems, the chirality detection by the polyacetylene relies on an excess one-handed helix formation induced by the chiral hydrocarbons and deuterated isotopomers via significant amplification of the chirality followed by its static memory, through which chiral information on the minute and hidden chirality can be stored as an excess of a single-handed helix memory for a long time.

Quantum mechanical alternative to Arrhenius equation in the interpretation of proton spin-lattice relaxation data for the methyl groups in solids

KAUST Repository

Bernatowicz, Piotr

2015-10-01

Theory of nuclear spin-lattice relaxation in methyl groups in solids has been a recurring problem in nuclear magnetic resonance (NMR) spectroscopy. The current view is that, except for extreme cases of low torsional barriers where special quantum effects are at stake, the relaxation behaviour of the nuclear spins in methyl groups is controlled by thermally activated classical jumps of the methyl group between its three orientations. The temperature effects on the relaxation rates can be modelled by Arrhenius behaviour of the correlation time of the jump process. The entire variety of relaxation effects in protonated methyl groups has recently been given a consistently quantum mechanical explanation not invoking the jump model regardless of the temperature range. It exploits the damped quantum rotation (DQR) theory originally developed to describe NMR line shape effects for hindered methyl groups. In the DQR model, the incoherent dynamics of the methyl group include two quantum rate, i.e., coherence-damping processes. For proton relaxation only one of these processes is relevant. In this paper, temperature-dependent proton spin-lattice relaxation data for the methyl groups in polycrystalline methyltriphenyl silane and methyltriphenyl germanium, both deuterated in aromatic positions, are reported and interpreted in terms of the DQR model. A comparison with the conventional approach exploiting the phenomenological Arrhenius equation is made. The present observations provide further indications that incoherent motions of molecular moieties in condensed phase can retain quantum character over much broad temperature range than is commonly thought.

Upper Bound for Neutron Emission from Sonoluminescing Bubbles in Deuterated Acetone

International Nuclear Information System (INIS)

Camara, C. G.; Putterman, S. J.; Hopkins, S. D.; Suslick, K. S.

2007-01-01

An experimental search for nuclear fusion inside imploding bubbles of degassed deuterated acetone at 0 degree sign C driven by a 15 atm sound field and seeded with a neutron generator reveals an upper bound that is a factor of 10 000 less than the signal reported by Taleyarkhan et al. The strength of our upper bound is limited by the weakness of sonoluminescence, which we ascribe to the relatively high vapor pressure of acetone

Deuteration of acetanilides

Energy Technology Data Exchange (ETDEWEB)

Chin, S.K.; Collier, R.; Hutchinson, D.W. (Warwick Univ., Coventry (UK). Dept. of Chemistry and Molecular Sciences)

1982-09-01

The base-catalysed exchange of a proton of the methyl groups in acetanilides can be used to incorporate deuterium into these amides. 4'-Hydroxyl-2(/sup 2/H)acetanilide (acetaminophen, paracetamol) can be prepared by the demethylation with boron tribromide of 4'-methoxy-2(/sup 2/H) acetamide obtained by this base-catalysed exchange.

Hexicon 2: automated processing of hydrogen-deuterium exchange mass spectrometry data with improved deuteration distribution estimation.

Science.gov (United States)

Lindner, Robert; Lou, Xinghua; Reinstein, Jochen; Shoeman, Robert L; Hamprecht, Fred A; Winkler, Andreas

2014-06-01

Hydrogen-deuterium exchange (HDX) experiments analyzed by mass spectrometry (MS) provide information about the dynamics and the solvent accessibility of protein backbone amide hydrogen atoms. Continuous improvement of MS instrumentation has contributed to the increasing popularity of this method; however, comprehensive automated data analysis is only beginning to mature. We present Hexicon 2, an automated pipeline for data analysis and visualization based on the previously published program Hexicon (Lou et al. 2010). Hexicon 2 employs the sensitive NITPICK peak detection algorithm of its predecessor in a divide-and-conquer strategy and adds new features, such as chromatogram alignment and improved peptide sequence assignment. The unique feature of deuteration distribution estimation was retained in Hexicon 2 and improved using an iterative deconvolution algorithm that is robust even to noisy data. In addition, Hexicon 2 provides a data browser that facilitates quality control and provides convenient access to common data visualization tasks. Analysis of a benchmark dataset demonstrates superior performance of Hexicon 2 compared with its predecessor in terms of deuteration centroid recovery and deuteration distribution estimation. Hexicon 2 greatly reduces data analysis time compared with manual analysis, whereas the increased number of peptides provides redundant coverage of the entire protein sequence. Hexicon 2 is a standalone application available free of charge under http://hx2.mpimf-heidelberg.mpg.de.

Hexicon 2: Automated Processing of Hydrogen-Deuterium Exchange Mass Spectrometry Data with Improved Deuteration Distribution Estimation

Science.gov (United States)

Lindner, Robert; Lou, Xinghua; Reinstein, Jochen; Shoeman, Robert L.; Hamprecht, Fred A.; Winkler, Andreas

2014-06-01

Hydrogen-deuterium exchange (HDX) experiments analyzed by mass spectrometry (MS) provide information about the dynamics and the solvent accessibility of protein backbone amide hydrogen atoms. Continuous improvement of MS instrumentation has contributed to the increasing popularity of this method; however, comprehensive automated data analysis is only beginning to mature. We present Hexicon 2, an automated pipeline for data analysis and visualization based on the previously published program Hexicon (Lou et al. 2010). Hexicon 2 employs the sensitive NITPICK peak detection algorithm of its predecessor in a divide-and-conquer strategy and adds new features, such as chromatogram alignment and improved peptide sequence assignment. The unique feature of deuteration distribution estimation was retained in Hexicon 2 and improved using an iterative deconvolution algorithm that is robust even to noisy data. In addition, Hexicon 2 provides a data browser that facilitates quality control and provides convenient access to common data visualization tasks. Analysis of a benchmark dataset demonstrates superior performance of Hexicon 2 compared with its predecessor in terms of deuteration centroid recovery and deuteration distribution estimation. Hexicon 2 greatly reduces data analysis time compared with manual analysis, whereas the increased number of peptides provides redundant coverage of the entire protein sequence. Hexicon 2 is a standalone application available free of charge under http://hx2.mpimf-heidelberg.mpg.de.

TEM and EELS study of deuterated carbon: application to the fuel retention in tokamaks

International Nuclear Information System (INIS)

Bernier, N.

2007-12-01

We developed a methodology, based on the combination of TEM and EELS techniques, for a structural and chemical characterization, at a high spatial resolution, of a wide range of carbon materials. We i) optimized, in the framework of theoretical models, the sp2 fraction quantification from pure carbons by EELS ii) transferred this quantification to deuterated amorphous carbon layers iii) showed, from graphitized carbons, how the TEM-EELS combination allows to detect low concentrations of implanted D. Due to the accomplishment of these developments, we applied our approach to the study of D retention in composites C/C, which are the plasma-facing materials in TS. We showed that specific localized retention sites correspond to relatively large (∼ 3 mm.) cracks between fibres and matrix; such cracks offer a simple and direct path for deuterated amorphous carbon. The particle balance performed in TS is discussed in the light of this trapping mechanism. (author)

Electron spin resonance and its implication on the maximum nuclear polarization of deuterated solid target materials

International Nuclear Information System (INIS)

Heckmann, J.; Meyer, W.; Radtke, E.; Reicherz, G.; Goertz, S.

2006-01-01

ESR spectroscopy is an important tool in polarized solid target material research, since it allows us to study the paramagnetic centers, which are used for the dynamic nuclear polarization (DNP). The polarization behavior of the different target materials is strongly affected by the properties of these centers, which are added to the diamagnetic materials by chemical doping or irradiation. In particular, the ESR linewidth of the paramagnetic centers is a very important parameter, especially concerning the deuterated target materials. In this paper, the results of the first precise ESR measurements of the deuterated target materials at a DNP-relevant magnetic field of 2.5 T are presented. Moreover, these results allowed us to experimentally study the correlation between ESR linewidth and maximum deuteron polarization, as given by the spin-temperature theory

A quantum mechanical alternative to the Arrhenius equation in the interpretation of proton spin-lattice relaxation data for the methyl groups in solids.

Science.gov (United States)

Bernatowicz, Piotr; Shkurenko, Aleksander; Osior, Agnieszka; Kamieński, Bohdan; Szymański, Sławomir

2015-11-21

The theory of nuclear spin-lattice relaxation in methyl groups in solids has been a recurring problem in nuclear magnetic resonance (NMR) spectroscopy. The current view is that, except for extreme cases of low torsional barriers where special quantum effects are at stake, the relaxation behaviour of the nuclear spins in methyl groups is controlled by thermally activated classical jumps of the methyl group between its three orientations. The temperature effects on the relaxation rates can be modelled by Arrhenius behaviour of the correlation time of the jump process. The entire variety of relaxation effects in protonated methyl groups have recently been given a consistent quantum mechanical explanation not invoking the jump model regardless of the temperature range. It exploits the damped quantum rotation (DQR) theory originally developed to describe NMR line shape effects for hindered methyl groups. In the DQR model, the incoherent dynamics of the methyl group include two quantum rate (i.e., coherence-damping) processes. For proton relaxation only one of these processes is relevant. In this paper, temperature-dependent proton spin-lattice relaxation data for the methyl groups in polycrystalline methyltriphenyl silane and methyltriphenyl germanium, both deuterated in aromatic positions, are reported and interpreted in terms of the DQR model. A comparison with the conventional approach exploiting the phenomenological Arrhenius equation is made. The present observations provide further indications that incoherent motions of molecular moieties in the condensed phase can retain quantum character over much broader temperature range than is commonly thought.

Neutron scattering on partially deuterated polybutadiene

CERN Document Server

Kahle, S; Monkenbusch, M; Richter, D; Arbe, A; Colmenero, J; Frick, B

2002-01-01

The molecular nature of the secondary relaxation (Johari-Goldstein relaxation) and its relationship with the alpha relaxation is in most cases still unknown. In order to access these processes on a molecular level, it is necessary to obtain spatial information of the relaxation. Through the momentum-transfer dependence of the dynamic structure factor S(Q,t), this information can be provided by quasielastic neutron scattering techniques. The large difference in scattering lengths between hydrogen and deuterium allows us to accentuate specific correlations between atoms in a polymer melt. Here, we report on recent results on a polybutadiene melt, where the double bond was hydrogeneous, while the methylene groups carried deuterons (d4h2-PB). In this way the correlations between the double bonds are emphasised. We will show that the double bond/double bond correlation function, generated in this way, shows the same temperature dependence as the viscosity at higher temperatures at the structure factor peak maximum...

Neutron diffraction study of crystal structures of deuterated glycinium phosphite in paraelectric and ferroelectric phases

International Nuclear Information System (INIS)

Machida, Mitsuo; Uchida, Hiroyuki; Ishibashi, Toku; Taniguchi, Hiroki; Komukae, Masaru; Osaka, Toshio; Koyano, Nobumitsu

2004-01-01

Crystal structure of deuterated glycinium phosphite was studied in the paraelectric (P) phase at 348 K and in the ferroelectric (F) phase at 223 K by means of the single crystal neutron diffraction. Deuteration rate is estimated to be 0.939 by the least-squares refinement. In the P phase, quasi-one-dimensional hydrogen bond chains are built by mutually linking the DPO 3 2- anions through two different types of hydrogen bonds with the bond angles of 179.2 and 171.6deg. Two independent deuterons within the hydrogen bonds forming the chains are disordered over two sites separated by 0.545 and 0.539A. In the F phase, they order at a position nearly equal to one of two sites related by the disorder in the P phase. With the ordering of the deuterons, the P-O bonds with covalently bonded deuteron elongate, and those without covalently bonded deuteron reduce their lengths to some extend from the values determined in the P phase. Two oxygens involved in the hydrogen bond with the bond angle 179.2deg exhibits especially large displacements in the F phase. This suggests strongly an importance of this hydrogen bond in the polarization appearance and in the ferroelectric transition. Comparison with results of non-deuterated salt indicates that only the hydrogen bonds forming the chains show significant isotope shift. In particular, the hydrogen bond with the bond angle 179.2deg exhibits the most pronounced shift on the angle parameter defined by the angle between the line connecting two sites of disordered proton or deuteron and the line connecting two oxygens involved in the hydrogen bond. (author)

Deuterium isotope effects on toluene metabolism. Product release as a rate-limiting step in cytochrome P-450 catalysis

International Nuclear Information System (INIS)

Ling, K.H.; Hanzlik, R.P.

1989-01-01

Liver microsomes from phenobarbital-induced rats oxidize toluene to a mixture of benzyl alcohol plus o-, m- and p-cresol (ca. 69:31). Stepwise deuteration of the methyl group causes stepwise decreases in the yield of benzyl alcohol relative to cresols (ca. 24:76 for toluene-d3). For benzyl alcohol formation from toluene-d3 DV = 1.92 and D(V/K) = 3.53. Surprisingly, however, stepwise deuteration induces stepwise increases in total oxidation, giving rise to an inverse isotope effect overall (DV = 0.67 for toluene-d3). Throughout the series (i.e. d0, d1, d2, d3) the ratios of cresol isomers remain constant. These results are interpreted in terms of product release for benzyl alcohol being slower than release of cresols (or their epoxide precursors), and slow enough to be partially rate-limiting in turnover. Thus metabolic switching to cresol formation causes a net acceleration of turnover

Experimental vapor pressures (from 1 Pa to 100 kPa) of six saturated Fatty Acid Methyl Esters (FAMEs): Methyl hexanoate, methyl octanoate, methyl decanoate, methyl dodecanoate, methyl tetradecanoate and methyl hexadecanoate

International Nuclear Information System (INIS)

Sahraoui, Lakhdar; Khimeche, Kamel; Dahmani, Abdallah; Mokbel, Ilham; Jose, Jacques

2016-01-01

Highlight: • Vapor-liquid equilibria, Enthalpy of Vaporization, saturated Fatty Acid Methyl Ester. - Abstract: Vapor pressures of six saturated Fatty Acid Methyl Esters (FAMEs), methyl hexanoate (or methyl caproate), methyl octanoate (or methyl caprylate), Methyl decanoate (or methyl caprate), methyl dodecanoate (or methyl laurate), methyl tetradecanoate (or methyl myristate), and methyl hexadecanoate (or methyl palmitate) were measured from 1 Pa to 100 kPa and at temperature range between 262 and 453 K using a static apparatus. The experimental data (P-T) were compared with the available literature data.

The deuteration of acetanilides

International Nuclear Information System (INIS)

Chin, S.K.; Collier, R.; Hutchinson, D.W.

1982-01-01

The base-catalysed exchange of a proton of the methyl groups in acetanilides can be used to incorporate deuterium into these amides. 4'-Hydroxyl-2[ 2 H]acetanilide (acetaminophen, paracetamol) can be prepared by the demethylation with boron tribromide of 4'-methoxy-2[ 2 H] acetamide obtained by this base-catalysed exchange. (author)

Neutron total cross-section of hydrogenous and deuterated 1- and 2-propanol and n-butanol measured using the VESUVIO spectrometer

Science.gov (United States)

Rodríguez Palomino, L. A.; Dawidowski, J.; Márquez Damián, J. I.; Cuello, G. J.; Romanelli, G.; Krzystyniak, M.

2017-10-01

This work presents the total cross sections of a set of normal and deuterated alcohols (hydrogenous 1- and 2-propanol and n-butanol, 1-propanol(OD) and fully deuterated 2-propanol and n-butanol), measured at spectrometer VESUVIO (ISIS spallation neutron source, United Kingdom). Granada's Synthetic Model was applied to describe those systems and a satisfactory agreement with the measured total cross section was achieved in the range of energies from 10-3 to 100 eV. The input parameters of the model were determined from the essential features of the vibrational spectra of the atoms that compose the systems, which were studied using Molecular Dynamics.

Use of tobacco seed oil methyl ester in a turbocharged indirect injection diesel engine

International Nuclear Information System (INIS)

Usta, N.

2005-01-01

Vegetable oils and their methyl/ethyl esters are alternative renewable fuels for compression ignition engines. Different kinds of vegetable oils and their methyl/ethyl esters have been tested in diesel engines. However, tobacco seed oil and tobacco seed oil methyl ester have not been tested in diesel engines, yet. Tobacco seed oil is a non-edible vegetable oil and a by-product of tobacco leaves production. To the author's best knowledge, this is the first study on tobacco seed oil methyl ester as a fuel in diesel engines. In this study, potential tobacco seed production throughout the world, the oil extraction process from tobacco seed and the transesterification process for biodiesel production were examined. The produced tobacco seed oil methyl ester was characterized by exposing its major properties. The effects of tobacco seed oil methyl ester addition to diesel No. 2 on the performance and emissions of a four cycle, four cylinder turbocharged indirect injection (IDI) diesel engine were examined at both full and partial loads. Experimental results showed that tobacco seed oil methyl ester can be partially substituted for the diesel fuel at most operating conditions in terms of performance parameters and emissions without any engine modification and preheating of the blends. (Author)

Crystal Structure of the Sodium Cobaltate Deuterate Superconductor NaxCoO2o4xD2O (x=1/3)

OpenAIRE

Jorgensen, J. D.; Avdeev, M.; Hinks, D. G.; Burley, J. C.; Short, S.

2003-01-01

Neutron and x-ray powder diffraction have been used to investigate the crystal structures of a sample of the newly-discovered superconducting sodium cobaltate deuterate compound with composition Na0.31(3)CoO2o1.25(2)D2O and its anhydrous parent compound Na0.61(1)CoO2. The deuterate superconducting compound is formed by coordinating four D2O molecules (two above and two below) to each Na ion in a way that gives Na-O distances nearly equal to those in the parent compound. One deuteron of the D2...

Deuterated water in the solar-type protostars NGC 1333 IRAS 4A and IRAS 4B

NARCIS (Netherlands)

Coutens, A.; Vastel, C.; Cabrit, S.; Codella, C.; Kristensen, L. E.; Ceccarelli, C.; van Dishoeck, E. F.; Boogert, A. C. A.; Bottinelli, S.; Castets, A.; Caux, E.; Comito, C.; Demyk, K.; Herpin, F.; Lefloch, B.; McCoey, C.; Mottram, J. C.; Parise, B.; Taquet, V.; van der Tak, F. F. S.; Visser, R.; Yıldız, U. A.

2013-01-01

Context. The measure of the water deuterium fractionation is a relevant tool for understanding mechanisms of water formation and evolution from the prestellar phase to the formation of planets and comets. Aims: The aim of this paper is to study deuterated water in the solar-type protostars NGC 1333

Involvement of pectin methyl-esterase during the ripening of grape berries: partial cDNA isolation, transcript expression and changes in the degree of methyl-esterification of cell wall pectins.

Science.gov (United States)

Barnavon, L; Doco, T; Terrier, N; Ageorges, A; Romieu, C; Pellerin, P

2001-11-01

Grape berries (Vitis vinifera L., cv Ugni blanc) were harvested at 12 different weeks of development in 1996 and 1997. Ripening was induced at veraison, the crucial stage of berry softening, and was followed by a rapid accumulation of glucose and fructose and an increase of pH. Total RNAs, crude proteins and cell wall material were isolated from each developmental stage. A partial length cDNA (pme1, accession number AF159122, GenBank) encoding a pectin methyl-esterase (PME, EC 3.1.1.11) was cloned by RT-PCR with degenerate primers. Northern blots revealed that mRNAs coding for PME accumulate from one week before the onset of ripening until complete maturity, indicating that this transcript represents an early marker of veraison and could be involved in berry softening. However, PME activity was detected during all developmental stages. Total activity per berry increased, whereas "specific" activity, on a fresh weight basis, decreased during development. The amount of cell wall material (per berry and per g of berry) followed the same pattern as that of PME activity (total and "specific" respectively), indicating they were tightly correlated and that PME levels varied very little in the cell walls. Nevertheless, the degree of methyl-esterification of insoluble pectins decreased throughout the development from 68% in green stages to less than 20% for the ripe berries, and this observation is consistent with the induction of PME mRNAs during ripening. Relations between transcript expression, PME activity, the DE of insoluble pectic polysaccharides and their involvement in grape berry ripening are discussed.

Selectively deuterated liquid crystalline cyanoazobenzene side-chain polyesters. 3. Investigations of laser induced segmental mobility by Fourier transform infrared spectroscopy

DEFF Research Database (Denmark)

Kulinna, Christian; Hvilsted, Søren; Hendann, Claudia

1998-01-01

The laser-induced anisotropy in thin films of an extensive number of cyanoazobenzene sidechain liquid crystalline polytetradecanedioates, -dodecanedioates, and -adipates selectively deuterated at different positions have been investigated with polarized FTIR spectroscopy. The analysis of the segm......The laser-induced anisotropy in thin films of an extensive number of cyanoazobenzene sidechain liquid crystalline polytetradecanedioates, -dodecanedioates, and -adipates selectively deuterated at different positions have been investigated with polarized FTIR spectroscopy. The analysis...... of the segmental orientation based on dichroic ratios of characteristic absorption bands shows that, in polyesters with long main-chain spacing (tetradecanedioates and dodecanedioates), not only the light sensitive azo chromophore but also the main-chain methylene segment and to a smaller extent the flexible...

Study of adsorption properties of impregnated charcoal for airborne iodine and methyl iodide

International Nuclear Information System (INIS)

Qi-dong, L.; Sui-yuang, H.

1985-01-01

The adsorption characteristics of airborne radioiodine and methyl iodide on impregnated charcoal were investigated. The activated charcoal tested was made from home-made oil-palm shells, and KI and TEDA were used as impregnants. A new technique was used to plot the dynamic partial adsorption isotherm at challenge concentrations (concentration range of iodine: 1-20 ppm v/v). Some adsorption properties of the impregnated charcoal were estimated with the dynamic partial adsorption isotherm. The dependences of the adsorption capacity and penetration behavior for airborne iodine and methyl iodide on the ambient conditions (temperature, relative humidity, and superficial velocity) were studied

Effects of deuterated water upon specific activity of some marker enzymes for cytosol and plasmatic membrane

International Nuclear Information System (INIS)

Buzgariu, Wanda; Coroiu, Viorica; Moldovan, Lucia; Titescu, G.; Stefanescu, I.

2004-01-01

Recently, numerous studies were devoted to the effects of an increased environmental deuterium concentration on physiological characteristics of various biological systems, from monocellular organisms up to mammals. Within these preoccupations the experiments on enzyme activity and parameters are of special interest since they throw light upon the mechanisms in metabolic biochemical reactions (glycolysis, photosynthesis, transport across membranes, etc). The present work concerns the effects of heavy water upon the activity of some enzymes (dehydrogenase-LDH lactate and 5' nucleotidase) implied in different metabolic pathways, serving as functional indicators for some cellular compartments such as the cytosols and cellular membranes. Enzyme activity was determined by growing for 6 days the cells (Hep 2, CHO, fibroblasts) in deuterated culture media at different concentration levels (20%, 40%, 65% si 90%), as well as in a reaction medium deuterated at 99.96%. In case of the first experimental run the LDH activity was monitored for the three cellular lines (Hep 2, CHO, fibroblasts) for different time intervals (1 d, 3 d and 6 d). After the first 24 h of cells' exposure the activity values were similar regardless of the heavy water concentration in the medium. Exposing the cells for longer time (6 days) led to modifications of LDH activity. In contrast to the case of media with relatively moderate D 2 O content, cell growing in conditions of intense deuteration 65% and 90 % D 2 O) led to an increase of cytosolic enzyme activity of about 50%. In case of 5' nucleotidase after 6 days of cell cultivation in deuteration conditions the activity decreased to 50% and 70% from the value corresponding to normal conditions for cell growth. This diminution of the activity was characteristic for the media with 65% and 90% D 2 O. In the second experimental run the activities of dehydrogenase lactate and 5' nucleotidase from the cellular homogenate obtained from cells grown in

Syntheses of deuterated leu-enkephalins and their use as internal standards for the quantification of leu-enkephalin by fast atom bombardment mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Benfenati, E. (Istituto di Ricerche Farmacologiche Mario Negri, Bergamo (Italy) Istituto di Ricerche Farmacologiche Mario Negri, Milan (Italy)); Icardi, G.; Chen, S. (Istituto di Ricerche Farmacologiche Mario Negri, Bergamo (Italy)); Fanelli, R. (Istituto di Ricerche Farmacologiche Mario Negri, Milan (Italy))

1990-04-01

We have developed a synthetic method for the preparation of di- and pentadeuterated leu-enkephalin (LE), Tyr-Gly-Gly-Phe-Leu, by proton-deuterium exchange using CF[sub 3]COOO[sup 2]H. Four to six deuterium atoms are introduced using a reaction temperature of 120[sup o]C and if 5% of [sup 2]H[sub 2]O is added the di-deuterated LE is obtained. These deuterated compounds are used as internal standards to plot calibration curves of LE using fast atom bombardment mass spectrometry. (author).

Effect of hydrostatic pressure on the antiferroelectric phase transitions in ammonium dihydrogen arsenate NH4H2AsO4 and deuterated analogue

International Nuclear Information System (INIS)

Gesi, Kazuo; Ozawa, Kunio

1984-01-01

Effect of hydrostatic pressure on the antiferroelectric phase transitions in NH 4 H 2 AsO 4 and deuterated analogue (deuterium concentration --80%) was studied by dielectric constant measurements at high pressures up to about 0.8GPa. The transition temperature linearly decreases with increasing pressure with the ratios of -19.7K GPa -1 and -14.5K GPa -1 for NH 4 H 2 AsO 4 and the deuterated compound, respectively. The pressure effect is compared with previously reported results of other KH 2 PO 4 -type ferro- and antiferroelectric crystals. (author)

Magnetic properties of nickel halide hydrates including deuteration effects

Energy Technology Data Exchange (ETDEWEB)

DeFotis, G.C., E-mail: gxdefo@wm.edu [Chemistry Department, College of William & Mary, Williamsburg, VA, 23187 United States (United States); Van Dongen, M.J.; Hampton, A.S.; Komatsu, C.H.; Trowell, K.T.; Havas, K.C.; Davis, C.M.; DeSanto, C.L. [Chemistry Department, College of William & Mary, Williamsburg, VA, 23187 United States (United States); Hays, K.; Wagner, M.J. [Chemistry Department, George Washington University, Washington, DC, 20052 United States (United States)

2017-01-01

Magnetic measurements on variously hydrated nickel chlorides and bromides, including deuterated forms, are reported. Results include locations and sizes of susceptibility maxima, T{sub max} and χ{sub max}, ordering temperatures T{sub c}, Curie constants and Weiss theta in the paramagnetic regime, and primary and secondary exchange interactions from analysis of low temperature data. For the latter a 2D Heisenberg model augmented by interlayer exchange in a mean-field approximation is applied. Magnetization data to 16 kG as a function of temperature show curvature and hysteresis characteristics quite system dependent. For four materials high field magnetization data to 70 kG at 2.00 K are also obtained. Comparison is made with theoretical relations for spin-1 models. Trends are apparent, primarily that T{sub max} of each bromide hydrate is less than for the corresponding chloride, and that for a given halide nD{sub 2}O (n=1 or 2) deuterates exhibit lesser T{sub max} than do nH{sub 2}O hydrates. A monoclinic unit cell determined from powder X-ray diffraction data on NiBr{sub 2}·2D{sub 2}O is different from and slightly larger than that of NiBr{sub 2}·2H{sub 2}O. This provides some rationale for the difference in magnetic properties between these. - Highlights: • The magnetism of Ni(II) chloride and bromide dihydrates and monohydrates is studied. • Effects of replacing H{sub 2}O by D{sub 2}O are examined for both hydration states and both halides. • Exchange interactions in bromides are weaker than in corresponding chlorides. • Exchange interactions are weaker in D{sub 2}O than in corresponding H{sub 2}O containing systems. • The unit cell of NiBr{sub 2}·2D{sub 2}O is different from and slightly larger than that of NiBr{sub 2}·2H{sub 2}O.

Spectroscopic and Quantum Mechanical Calculation Study of the Effect of Isotopic Substitution on NIR Spectra of Methanol.

Science.gov (United States)

Grabska, Justyna; Czarnecki, Mirosław A; Beć, Krzysztof B; Ozaki, Yukihiro

2017-10-19

In this work, we studied methanol and its deuterated derivatives (CH 3 OH, CH 3 OD, CD 3 OH, CD 3 OD) by NIR spectroscopy and anharmonic quantum chemical calculations. Vibrational bands corresponding to up to three quanta transitions (first and second overtones, binary and ternary combination modes) were predicted by the use of the VPT2 route. The accuracy of prediction of NIR modes was evaluated through density functional theory (DFT) with selected density functionals and basis sets. On the basis of the theoretical NIR spectra, detailed band assignments for all studied molecules were proposed. It was found that the pattern of bands in NIR spectra of deuterated methanols can be used for identification of isotopically equalized forms. Calculations of NIR spectra of all possible forms of CXXXOX (X = H, D) molecules demonstrated that the isotopic contamination can be identified due to a coexistence of bands specific to OH and OD groups. Also, bands from partially deuterated methyl groups can be distinguished in NIR spectra. Since the VPT2 framework is known to be sensitive to inaccuracy in the case of highly anharmonic modes, we obtained an independent insight by numerical solving of the time-independent Schrödinger equation corresponding to the O-X stretching mode scanned within -0.4 to 2.0 Å over a dense grid of 0.005 Å. This way the energies of vibrational levels of the CX1X2X3OX4 (X = H, D) isotopomers and the corresponding transition frequencies were obtained with high accuracy (<0.1 cm -1 ). The change in normal coordinate influences the reduced mass of the oscillator and thus its frequency. Our results lead to a conclusion that the effect of deuterization of the methyl group introduces a very specific and consistent frequency shift of the first overtone of the O-X stretching mode depending on the substitution of X1, X2, or X3 positions (<2 cm -1 ). However, the pattern of this shift is not reproduced accurately and is also largely overestimated by VPT2

Deuteration of metals through electric discharges; Deuteracion de metales bajo descargas electricas

Energy Technology Data Exchange (ETDEWEB)

Balderas G, L M

1996-12-31

In this work deuteration of titanium and a stainless steel through electrical discharges in a vacuum chamber was performed at different thermodynamic conditions. The samples were plates of 0.03 x 4.5 x 54 cm. The titanium sample was first cleaning with chloroform. The oxide layer was removed by cleaning the sample with a 1:1:1 mixture of water, nitric acid and sulphuric acid. Later was rinsed in water and dried with acetone. Finally, was treated with HCl to form an hydride layer on the surface. The stainless steel sample was only cleaned with soap and cleaning with acetone. The samples were cleaning at low pressure for several days with high temperature short cycles. The deuterium was loaded to the chamber at room temperature having absorption on the titanium samples at 10{sup 3} at 10{sup 1} mbar. Afterwards that the samples were heated up at 330 C and was observed the deuterium absorption in the same pressure range. Forced deuteration through electrical discharges between the sample and the chamber was tried obtaining absorption in the range of 10{sup 3} at 10{sup 2} mbar, however the deuterium absorption only was observed in specific cases. In order to detect neutron emission or released particles in this experiment were used alanine detectors and series of plastic CR-39 and borate films. No neutron were detected in the passive systems used in the experiments. (Author).

Study of deuterated water in the low-mass protostar IRAS16293-2422

Science.gov (United States)

Coutens, A.; Vastel, C.; Caux, E.; Ceccarelli, C.; Herschel Chess Team

2011-05-01

Observations of deuterated water are an important complement for studies of H2O, since they give strong constraints on the formation processes: grain surfaces versus gas-phase chemistry through energetic process as shocks. The CHESS (Chemical HErschel Surveys of Star forming regions) Key Program has allowed to detect a lot of transitions of HDO (8) and H2O (16) as well as its isotopes H_218O and H_217O towards the low-mass protostar IRAS16293-2422 thanks to the unbiaised spectral survey carried out with the HIFI instrument on board the Herschel Space Observatory. Complementary data of HDO from the ground-based telescopes IRAM and JCMT are also available, allowing a precise determination of the abundance of deuterated water through the protostar envelope. In order to reproduce the observed line profiles, we have performed a modeling of HDO from the hot corino through the envelope using the physical structure of the protostar (Crimier et al. 2010) and the spherical Monte Carlo radiative transfer code RATRAN, which takes also into account radiative pumping by continuum emission from dust. We have used new HDO collision rates with H_2, recently computed by Wiesenfeld, Scribano and Faure (2011, PCCP). The same method has been applied to model H_2O and its isotopes H_218O and H_217O. We will present the results of this analysis and discuss the determined abundances.

Electrical conductivity measurement on DKDP Crystals with different deuterated degrees

International Nuclear Information System (INIS)

Liu, Baoan; Yin, Xin; Xu, Mingxia; Ji, Shaohua; Zhu, Lili; Zhang, Lisong; Sun, Xun; Xu, Xinguang; Zhao, Minglei; Zhang, Qinghua

2012-01-01

Ten DKDP single crystals with deuterated degrees ranging from 0 to 90 % were grown by a rapid growth method. The electrical conductivities of these crystals were measured along a and c directions at room temperature. The electrical conductivity increases with the increase for deuterium content. Also, the electrical conductivities of certain crystals were measured at various temperatures ranging from 20 to 130 C. The values of activation energy decrease as the increase of deuterium content. The present study indicates that the deuterium tunneling frequency is smaller than that of hydrogen, which may be the reason why the variation of electrical conductivity happens after the substitution of hydrogen for deuterium in KDP crystal. (orig.)

Tweaking agonist efficacy at N-methyl-D-aspartate receptors by site-directed mutagenesis

DEFF Research Database (Denmark)

Hansen, Kasper B; Clausen, Rasmus P; Bjerrum, Esben J

2005-01-01

The structural basis for partial agonism at N-methyl-D-aspartate (NMDA) receptors is currently unresolved. We have characterized several partial agonists at the NR1/NR2B receptor and investigated the mechanisms underlying their reduced efficacy by introducing mutations in the glutamate binding site...

Identification of Methyl Halide-Utilizing Genes in the Methyl Bromide-Utilizing Bacterial Strain IMB-1 Suggests a High Degree of Conservation of Methyl Halide-Specific Genes in Gram-Negative Bacteria

Science.gov (United States)

Woodall, C.A.; Warner, K.L.; Oremland, R.S.; Murrell, J.C.; McDonald, I.R.

2001-01-01

Strain IMB-1, an aerobic methylotrophic member of the alpha subgroup of the Proteobacteria, can grow with methyl bromide as a sole carbon and energy source. A single cmu gene cluster was identified in IMB-1 that contained six open reading frames: cmuC, cmuA, orf146, paaE, hutI, and partial metF. CmuA from IMB-1 has high sequence homology to the methyltransferase CmuA from Methylobacterium chloromethanicum and Hyphomicrobium chloromethanicum and contains a C-terminal corrinoid-binding motif and an N-terminal methyl-transferase motif. However, cmuB, identified in M. chloromethanicum and H. chloromethanicum, was not detected in IMB-1.

Infiltrating leukocytes confound the detection of E-cadherin promoter methylation in tumors

International Nuclear Information System (INIS)

Lombaerts, Marcel; Middeldorp, Janneke W.; Weide, Esther van der; Philippo, Katja; Wezel, Tom van; Smit, Vincent T.H.B.M.; Cornelisse, Cees J.; Cleton-Jansen, Anne-Marie

2004-01-01

Promoter hypermethylation is known to result in transcriptional downregulation of many genes including the CDH1 gene. In this study we set out to determine CDH1 promoter methylation in breast tumors with decreased or absent E-cadherin protein expression and without CDH1 gene mutations by methylation-specific PCR (MSP). Interestingly, some tumor samples with normal E-cadherin expression yielded a methylation-specific PCR product. We hypothesized that other cells than tumor cells contribute to these products. Since in normal breast tissue no CDH1 promoter methylation is detected, infiltrating leukocytes, often present in tumors, might account for these methylation-specific fragments. Indeed, a methylation-specific fragment is found in all twelve leukocyte samples tested. Furthermore, activated T-cells also yielded a methylation-specific fragment. Sequencing of these fragments reveals two distinct methylation profiles. Leukocytes have only partial methylation of some CpGs, while the tumor-associated methylation profile shows complete methylation of most CpGs. Therefore, to assess whether CDH1 methylation is tumor associated, sequencing of MSP products is a prerequisite. Here we show that out of six lobular tumors lacking E-cadherin protein expression, three have tumor-associated CDH1 promoter methylation while in three other tumors no methylation is detected

Water deuteration in star-forming regions: Contribution of Herschel/HIFI spectroscopic data

International Nuclear Information System (INIS)

Coutens, Audrey

2012-01-01

Water (H_2O) is one of the most abundant molecules in the interstellar medium. In addition to being a primordial ingredient in the emergence of life, this species plays an essential role in the process of star formation through the cooling of warm gas. It also controls the chemistry for many species, either in the gas phase or on the grain surfaces. Studying its deuterated form HDO is a unique opportunity, through the estimation of the HDO/H_2O ratio, to constrain the mechanisms of water formation and to better understand the origin of water contained in terrestrial oceans. Indeed, recent results obtained with the Herschel satellite show that the HDO/H_2O ratio observed in comets is similar to the value measured in oceans (∼1.5 10"-"4), which suggests that comets could have brought a large fraction to Earth to form the oceans during heavy bombardments (Hartogh et al. 2011). In this thesis, I was interested in the study of deuterated water in the first stages of star formation, the Class 0 stage, which precede the formation of the protoplanetary disk leading to the birth of comets and planets. Through a 1D non-Local Thermodynamic Equilibrium radiative transfer modeling of the line profiles of the numerous HDO and H_2"1"8O transitions detected with the HIFI (Heterodyne Instrument for Far-Infrared) instrument onboard the Herschel Space Observatory and ground-based telescopes (IRAM, JCMT), I determined that the HDO/H_2O ratios of the solar-type protostar IRAS 16293-2422 was about 2% in the hot corino, the inner part of the protostellar envelope sufficiently warm (T ≥ 100 K) to desorb in gas phase the water molecules trapped in the icy grain mantles, and about 0.5% in the colder part of the envelope. This study (Coutens et al. 2012) also allowed me to show that an absorbing layer rich in water surrounds the protostar. This layer could be produced by the photo-desorption through the UV field of the water molecules frozen on the grains, on the edges of the molecular

Dispersion Relation for Skeletal Vibrations in Deuterated Polyethylene

Energy Technology Data Exchange (ETDEWEB)

Feldkamp, L. A.; Venkataraman, G.; King, J. S. [Department of Nuclear Engineering, University of Michigan, Ann Arbor, MI (United States)

1968-09-15

The low frequency vibrations in polyethylene have been studied previously, utilizing the incoherent scattering technique which yields an amplitude-weighted density of states. In the present work the dispersion relations have been obtained directly by observing the coherent scattering from a deuterated sample. This represents the first such measurement on a crystalline polymer. A target in which the molecular chain axes were approximately parallel was prepared by stretching polycrystalline material. The FWHM of the rocking curve for the (002) reflection was measured to be 9 Degree-Sign . Constant-Q and constant-E scans were made on the University of Michigan triple-axis spectrometer at room temperature to observe phonons propagating along the chain direction. The resulting dispersion curve for the v{sub 5} mode follows generally the calculated curve of Tasumi and Krimm with systematically lower frequencies. The maximum frequency of 1.36 x 10{sup 13} Hz agrees with the cut-off frequency determined previously from the incoherent scattering spectrum. (author)

Deuterated silicon nitride photonic devices for broadband optical frequency comb generation

Science.gov (United States)

Chiles, Jeff; Nader, Nima; Hickstein, Daniel D.; Yu, Su Peng; Briles, Travis Crain; Carlson, David; Jung, Hojoong; Shainline, Jeffrey M.; Diddams, Scott; Papp, Scott B.; Nam, Sae Woo; Mirin, Richard P.

2018-04-01

We report and characterize low-temperature, plasma-deposited deuterated silicon nitride thin films for nonlinear integrated photonics. With a peak processing temperature less than 300$^\\circ$C, it is back-end compatible with pre-processed CMOS substrates. We achieve microresonators with a quality factor of up to $1.6\\times 10^6 $ at 1552 nm, and $>1.2\\times 10^6$ throughout $\\lambda$ = 1510 -- 1600 nm, without annealing or stress management. We then demonstrate the immediate utility of this platform in nonlinear photonics by generating a 1 THz free spectral range, 900-nm-bandwidth modulation-instability microresonator Kerr comb and octave-spanning, supercontinuum-broadened spectra.

Insulin stimulation of phospholipid methylation in isolated rat adipocyte plasma membranes.

OpenAIRE

Kelly, K L; Kiechle, F L; Jarett, L

1984-01-01

Partially purified plasma membranes prepared from rat adipocytes contain N-methyltransferase(s) that utilize(s) S-adenosyl-L-methionine to synthesize phosphatidylcholine from phosphatidylethanolamine. The incorporation of [3H]methyl from S-adenosyl-L-[methyl-3H]methionine into plasma membrane phospholipids was linear with incubation time and plasma membrane protein concentration and was inhibited in a dose-dependent manner by both S-adenosyl-L-homocysteine and 3-deazadenosine. The addition of...

The Deuterator: software for the determination of backbone amide deuterium levels from H/D exchange MS data

Directory of Open Access Journals (Sweden)

Tsinoremas NF

2007-05-01

Full Text Available Abstract Background The combination of mass spectrometry and solution phase amide hydrogen/deuterium exchange (H/D exchange experiments is an effective method for characterizing protein dynamics, and protein-protein or protein-ligand interactions. Despite methodological advancements and improvements in instrumentation and automation, data analysis and display remains a tedious process. The factors that contribute to this bottleneck are the large number of data points produced in a typical experiment, each requiring manual curation and validation, and then calculation of the level of backbone amide exchange. Tools have become available that address some of these issues, but lack sufficient integration, functionality, and accessibility required to address the needs of the H/D exchange community. To date there is no software for the analysis of H/D exchange data that comprehensively addresses these issues. Results We have developed an integrated software system for the automated analysis and representation of H/D exchange data that has been titled "The Deuterator". Novel approaches have been implemented that enable high throughput analysis, automated determination of deuterium incorporation, and deconvolution of overlapping peptides. This has been achieved by using methods involving iterative theoretical envelope fitting, and consideration of peak data within expected m/z ranges. Existing common file formats have been leveraged to allow compatibility with the output from the myriad of MS instrument platforms and peptide sequence database search engines. A web-based interface is used to integrate the components of The Deuterator that are able to analyze and present mass spectral data from instruments with varying resolving powers. The results, if necessary, can then be confirmed, adjusted, re-calculated and saved. Additional tools synchronize the curated calculation parameters with replicate time points, increasing throughput. Saved results can then

Preliminary individualized chemotherapy for malignant astrocytomas based on O6-methylguanine-deoxyribonucleic acid methyltransferase methylation analysis.

Science.gov (United States)

Watanabe, Takao; Katayama, Yoichi; Ogino, Akiyoshi; Ohta, Takashi; Yoshino, Atsuo; Fukushima, Takao

2006-08-01

O(6)-methylguanine-deoxyribonucleic acid methyltransferase gene (MGMT) methylation is apparently correlated with responsiveness to nitrosourea chemotherapy, suggesting this alkylating agent should be effective against MGMT-methylated tumors. MGMT appears not to be linked to platinum resistance, so platinum chemotherapy should be used for MGMT-unmethylated tumors. This study was a preliminary trial of individualized chemotherapy based on MGMT methylation status in a total of 20 patients with newly diagnosed malignant astrocytomas (9 anaplastic astrocytomas and 11 glioblastomas multiforme). The procarbazine, 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-2(2-chloroethyl)-3-nitrosourea, and vincristine (PAV) regimen was administered to seven patients with MGMT-methylated tumors, and the carboplatin and etoposide (CE) regimen was administered to 13 patients with MGMT-unmethylated tumors. Objective response to the PAV therapy was noted in all three patients with measurable residual tumor (2 complete responses and 1 partial response). Five of the seven patients continued to be disease-free after initiation of the PAV therapy. Objective response to the CE therapy was seen in only one of seven patients with measurable residual tumor (1 partial response). Three of the 13 patients were free from progression, whereas the remaining 10 patients showed early progression. The PAV regimen is effective against MGMT-methylated malignant astrocytomas, but the CE regimen is not useful at the given dose and schedule in MGMT-unmethylated tumors.

Methyl-Analyzer--whole genome DNA methylation profiling.

Science.gov (United States)

Xin, Yurong; Ge, Yongchao; Haghighi, Fatemeh G

2011-08-15

Methyl-Analyzer is a python package that analyzes genome-wide DNA methylation data produced by the Methyl-MAPS (methylation mapping analysis by paired-end sequencing) method. Methyl-MAPS is an enzymatic-based method that uses both methylation-sensitive and -dependent enzymes covering >80% of CpG dinucleotides within mammalian genomes. It combines enzymatic-based approaches with high-throughput next-generation sequencing technology to provide whole genome DNA methylation profiles. Methyl-Analyzer processes and integrates sequencing reads from methylated and unmethylated compartments and estimates CpG methylation probabilities at single base resolution. Methyl-Analyzer is available at http://github.com/epigenomics/methylmaps. Sample dataset is available for download at http://epigenomicspub.columbia.edu/methylanalyzer_data.html. fgh3@columbia.edu Supplementary data are available at Bioinformatics online.

Effect of deuteration on the vibrational spectra of organic molecules

International Nuclear Information System (INIS)

Billes, Ferenc; Endredi, Henrietta; Varady, Balazs

2001-01-01

The stable isotope substitution of organic compounds deforms their vibrational spectra. The modifications of the spectra appear as band shifts and changes in intensities and shapes of the bands. The magnitude of the effect depends on the ratio of the masses of the new and old isotopes and on the atom active position. According to these mentioned reasons large effects can be observed only if hydrogen atoms are substituted. With the effect of the substitution we dealt already in a former lecture. In this lecture we concentrate on the effect of the change of hydrogen to deuterium. We investigate the changes both experimentally and theoretically. There are two possibilities: - the hydrogen atom is in an active position, its interaction with the environment is strong, either it can dissociate or move on the skeleton of the molecule (tautomerism, resonance) and it can build hydrogen bond, (e.g. it is connected to nitrogen and oxygen atoms); - the hydrogen atom is in an indifferent position in the molecule, its interaction with the environment is weak (e.g. it joins carbon atom). When building the hydrogen bond besides the hydrogen donors also acceptors exist, namely, oxygen and nitrogen atoms having non-bonded electron pairs. When comparing the experimental and theoretical (calculated) effects of this type of isotope changes one must take into account that the calculations refer to the isolated molecule while the experimental spectra characterize the compound. The hydrogen bond is a very strong intermolecular interaction and produces tremendous changes in the infrared spectrum of the molecule in comparison to the imagined theoretical spectrum of the molecule. Some bands disappear, appear, or shift and deform drastically. The H/D change diminishes these effects. Of course, these changes entail the shift of several bands. The Raman spectrum is less sensitive to the large dipole moment changes therefore the deuteration effect is there less dramatic. Deuteration of hydrogen

Phosphatidylcholine synthesis in the rat: The substrate for methylation and regulation by choline

International Nuclear Information System (INIS)

Datko, A.H.; Aksamit, R.R.; Mudd, S.H.

1990-01-01

Two lines of evidence led us to reexamine the possibility that methylation of phosphoethanolamine and its partially methylated derivatives, in addition to methylation of the corresponding phosphatidyl derivatives, plays a role in mammalian phosphatidylcholine biosynthesis: (a) Results obtained by Salerno and Beeler with rat appear to strongly support such a role for methylation of phosphobases; (b) Such reactions have recently been shown to play major roles in phosphatidylcholine synthesis by higher plants. We found that, following continuous labeling of rat liver with L-[methyl-3H]methionine for 10.4 min (intraperitoneal administration) or for 0.75 min (intraportal administration), virtually no 3H was detected in methylated derivatives of phosphoethanolamine, but readily detectable amounts of 3H were present in the base moiety of each methylated derivative of phosphatidylethanolamine. Thus, there was no indication that phospho-base methylation makes a significant contribution. Studies of cultured rat hepatoma cells showed definitively for the first time in a mammalian system that choline deprivation up-regulates the rate of flow of methyl groups originating in methionine into phosphatidylethanolamine and derivatives. Even under these conditions, methylation of phosphoethanolamine bases appeared to play a negligible role

Adsorption of methyl iodide on charcoal

International Nuclear Information System (INIS)

Hidajat, K.; Aracil, J.; Kenney, C.N.

1990-01-01

The adsorption of non-radioactive methyl iodide has been measured experimentally over a range of conditions of concentration, and temperature on an activated charcoal. This is of interest since methyl iodide is formed from iodine fission products in gas cooled nuclear reactors. A mathematical model has also been developed which describes the rate of adsorption, under isothermal and linear adsorption isotherm conditions in a recycle adsorber. This model takes into account the resistance to adsorption caused by the surface adsorption, as well as the external and internal mass transfer resistances. The solution to the model for the recycle adsorber was obtained using a semidiscretisation method to reduce the partial differential equations to a system of stiff ordinary differential equations, and the resulting differential equations solved by a standard numerical technique. (author)

In situ-observation of the vertical motion of soil waters by means of deuterated water using the gamma/neutron method: Laboratory and field

International Nuclear Information System (INIS)

Moutonnet, P.; Couchat, P.; Brissaud, F.; Puard, M.; Pappalardo, A.

1978-01-01

In order to study water movements in the field, the gamma/neutron method for measuring deuterated water was investigated. A laboratory device is presented which supplies measurements on 5 ml soil solution samples. A probe for in situ experiments is studied in all its performances: Background, calibration (count rate versus volumetric deuterated water content) and resolution. A dispersive transport of D 2 O pulses on soil column is presented and checked with a numerical simulation model. Then simultaneous measurement of soil water content and D 2 O concentration by neutron moisture gauge and gamma/neutron probe enable us to interpret the evolution of D 2 O pulse with an experimental field irrigation. (orig.) [de

Synthesis of 3 alpha-deuterated 7 alpha-hydroxy-DHEA and 7-oxo-DHEA and application in LC-MS/MS plasma analysis

Czech Academy of Sciences Publication Activity Database

Sosvorova, L.K.; Sarek, J.; Vitku, J.; Kvasnica, Miroslav

2016-01-01

Roč. 112, AUG (2016), s. 88-94 ISSN 0039-128X Institutional support: RVO:61389030 Keywords : 7 alpha-Hydroxy-DHEA * 7-Oxo-DHEA * Deuterated standard Subject RIV: CE - Biochemistry Impact factor: 2.282, year: 2016

Synthetic methyl hexagalacturonate hapten inhibitors of antihomogalacturonan monoclonal antibodies LM7, JIM5 and JIM7

DEFF Research Database (Denmark)

Clausen, Mads Hartvig; Willats, William George Tycho; Knox, J. Paul

2003-01-01

A range of synthetic methyl hexagalacturonates were used as potential hapten inhibitors in competitive-inhibition enzyme-linked immunosorbent assays (ELISAs) with anti-homogalacturonan monoclonal antibodies LM7, JIM5 and JIM7. The selective inhibition of these antibodies by different haptens...... provides insight into the structures of the partially methyl-esterified pectin epitopes of these widely used monoclonal antibodies....

Nucleophilic Substitution Reactions of N-Methyl α-Bromoacetanilides with Benzylamines in Dimethyl Sulfoxide

International Nuclear Information System (INIS)

Adhikary, Keshab Kumar; Lee, Hai Whang

2011-01-01

Kinetic studies of the reactions of N-methyl-Y-α-bromoacetanilides with substituted X-benzylamines have been carried out in dimethyl sulfoxide at 25.0 .deg. C. The Hammett plots for substituent X variations in the nucleophiles (log k N vs σ X ) are slightly biphasic concave upwards/downwards, while the Bronsted plots (log k N vs pK a ) are biphasic concave downwards with breakpoints at X = H. The Hammett plots for substituent Y variations in the substrates (log k N vs σ Y ) are biphasic concave upwards/downwards with breakpoints at Y = H. The cross-interaction constant ρ XY values are all negative: ρ XY = -0.32 for X = Y = electron-donating: -0.22 for X = electron-withdrawing and Y = electron-donating: -1.80 for X = electron-donating and Y = electronwithdrawing: -1.43 for X = Y = electron-withdrawing substituents. Deuterated kinetic isotope effects are primary normal (k H /k D > 1) for Y = electron-donating, while secondary inverse (k H /k D < 1) for Y = electronwithdrawing substituent. The proposed mechanisms of the benzylaminolyses of N-methyl-Y-α-bromoacetanilides are a concerted mechanism with a five membered ring TS involving hydrogen bonding between hydrogen (deuterium) atom in N-H(D) and oxygen atom in C = O for Y = electron-donating, while a concerted mechanism with an enolate-like TS in which the nucleophile attacks the α-carbon for Y = electronwithdrawing substituents

Inhibition of protein synthesis by N-methyl-N-nitrosourea in vivo

Science.gov (United States)

Kleihues, P.; Magee, P. N.

1973-01-01

1. The intraperitoneal injection of N-methyl-N-nitrosourea (100mg/kg) caused a partial inhibition of protein synthesis in several organs of the rat, the maximum effect occurring after 2–3h. 2. In the liver the inhibition of protein synthesis was paralleled by a marked disaggregation of polyribosomes and an increase in ribosome monomers and ribosomal subunits. No significant breakdown of polyribosomes was found in adult rat brains although N-methyl-N-nitrosourea inhibited cerebral and hepatic protein synthesis to a similar extent. In weanling rats N-methyl-N-nitrosourea caused a shift in the cerebral polyribosome profile similar to but less marked than that in rat liver. 3. Reaction of polyribosomal RNA with N-[14C]methyl-N-nitrosourea in vitro did not lead to a disaggregation of polyribosomes although the amounts of 7-methylguanine produced were up to twenty times higher than those found after administration of sublethal doses in vivo. 4. It was concluded that changes in the polyribosome profile induced by N-methyl-N-nitrosourea may reflect the mechanism of inhibition of protein synthesis rather than being a direct consequence of the methylation of polyribosomal mRNA. PMID:4774397

D/H isotope effects in π-complexes of deuterated hexamethylbenzenes with the nitrosonium cation

International Nuclear Information System (INIS)

Borodkin, G.I.; Elanov, I.R.; Shakirov, M.M.; Shubin, V.G.

1993-01-01

The isotope effects of deuterium, manifested in the 13 C NMR spectra of complexes of deuterated hexamethylbenzenes C 6 (CD 3 ) n ·(CH 3 ) 6-n with the nitrosonium cation, have been studied. The small values observed for the isotopic perturbation are evidence of π-bonding of the NO + group to the hexamethylbenzene molecule. The applicability of an additive scheme of calculation of isotope effects for the ring carbon atoms of the complexes, based on the increment of replacement of the CH 3 group by CD 3 in hexamethylbenzene, has been demonstrated

Microstructural characterization of a novel methyl acrylate-ethyl acrylate copolymer system

Energy Technology Data Exchange (ETDEWEB)

Olivares, M.; Castano, V.M. [Instituto de Fisica, UNAM, A.P. 1-1010, Queretaro, Mexico (Mexico); Molina, J.P.; Vazquez, F. [Facultad de Quimica UAEMex, Paseo Tollocan esq. Paseo Colon, Toluca, Estado de Mexico (Mexico)

1998-12-31

A number of different compositions of a novel methyl acrylate-ethyl acrylate copolymer were prepared by emulsion polymerization with potassium persulfate as initiator. The compositions synthesized were: 100/0, 75/25, 50/50, 25/75 and 0/100 on weight of methyl acrylate/ethyl acrylate at different temperatures and concentrations of initiators. The effect of other conditions were also studied. The samples were analyzed by Transmission Electron Microscopy. It was found that the size of aggregates and dispersion on sizes are controlled by the synthesis conditions, result partially supported by light scattering. (Author)

Microstructural characterization of a novel methyl acrylate-ethyl acrylate copolymer system

International Nuclear Information System (INIS)

Olivares, M.; Castano, V.M.; Molina, J.P.; Vazquez, F.

1998-01-01

A number of different compositions of a novel methyl acrylate-ethyl acrylate copolymer were prepared by emulsion polymerization with potassium persulfate as initiator. The compositions synthesized were: 100/0, 75/25, 50/50, 25/75 and 0/100 on weight of methyl acrylate/ethyl acrylate at different temperatures and concentrations of initiators. The effect of other conditions were also studied. The samples were analyzed by Transmission Electron Microscopy. It was found that the size of aggregates and dispersion on sizes are controlled by the synthesis conditions, result partially supported by light scattering. (Author)

Neutronic measurements on electrolytic cells with deuterated palladium in a submarine environment

International Nuclear Information System (INIS)

Granada, J.R.; Mayer, R.E.; Florido, P.C.; Gillette, V.H.; Gomez, S.E.

1990-01-01

Using a high efficiency system for the neutron thermal detection and a pulsed electrolytic current procedure, measurements were made on cells containing Pd cathodes and electrolytes at a D 2 O and H 2 O base. The peculiarity of these experiments is that they were carried out on board of the A.R.A. Santa Cruz submarine, at a depth of 50m under sea level, attaining ultra deep-down conditions in the measurements, corresponding to a reduction in a factor = 50 in relation to lab conditions. The mean level of the signal -obtained from counting combination of deuterated cathodes- results to be separated from the deep-down level by four standard deviations. (Author) [es

Promoter methylation of Wnt-antagonists in polypoid and nonpolypoid colorectal adenomas

International Nuclear Information System (INIS)

Voorham, Quirinus JM; Mulder, Chris JJ; Engeland, Manon van; Meijer, Gerrit A; Steenbergen, Renske DM; Carvalho, Beatriz; Janssen, Jerry; Tijssen, Marianne; Snellenberg, Suzanne; Mongera, Sandra; Grieken, Nicole CT van; Grabsch, Heike; Kliment, Martin; Rembacken, Bjorn J

2013-01-01

Nonpolypoid adenomas are a subgroup of colorectal adenomas that have been associated with a more aggressive clinical behaviour compared to their polypoid counterparts. A substantial proportion of nonpolypoid and polypoid adenomas lack APC mutations, APC methylation or chromosomal loss of the APC locus on chromosome 5q, suggesting the involvement of other Wnt-pathway genes. The present study investigated promoter methylation of several Wnt-pathway antagonists in both nonpolypoid and polypoid adenomas. Quantitative methylation-specific PCR (qMSP) was used to evaluate methylation of four Wnt-antagonists, SFRP2, WIF-1, DKK3 and SOX17 in 18 normal colorectal mucosa samples, 9 colorectal cancer cell lines, 18 carcinomas, 44 nonpolypoid and 44 polypoid adenomas. Results were integrated with previously obtained data on APC mutation, methylation and chromosome 5q status from the same samples. Increased methylation of all genes was found in the majority of cell lines, adenomas and carcinomas compared to normal controls. WIF-1 and DKK3 showed a significantly lower level of methylation in nonpolypoid compared to polypoid adenomas (p < 0.01). Combining both adenoma types, a positive trend between APC mutation and both WIF-1 and DKK3 methylation was observed (p < 0.05). Methylation of Wnt-pathway antagonists represents an additional mechanism of constitutive Wnt-pathway activation in colorectal adenomas. Current results further substantiate the existence of partially alternative Wnt-pathway disruption mechanisms in nonpolypoid compared to polypoid adenomas, in line with previous observations

Determining the mechanism of dehydration of primary, secondary, and tertiary alcohols by means of deuterium uptake on deuterated catalysts (BPO4, Ca3(PO4)2 and Sm2O3)

International Nuclear Information System (INIS)

Thomke, K.

1977-01-01

In order to gain insight into the mechanisms of dehydration (E1, E2, E1cB) of α- and β-substituted ethanols, the uptake of deuterium on deuterated catalysts [BPO 4 , Ca 3 (PO 4 ) 2 , Sm 2 O 3 ] into the alcohols and the thus formed olefines was measured. For that purpose microcatalytic and mass-spectrometric techniques were used. Most of the examined alcohols showed E1 on BPO 4 , E2 (sometimes mingled with E1) on Ca 3 (PO 4 ) 2 , and E1cB on Sm 2 O 3 . The common mechanism for ethanol on BPO 4 , for 2-propanol on Ca 3 (PO 4 ) 2 , and for 2-ethyl-2-propanol on Sm 2 O 3 was E2, i.e. that the OH-group and the β-proton were split off simultaneously. This can be explained by a decrease of the strength of the α-C-OH-bound caused by α-methyl-substitution on the one hand and by an increase of basicity of the catalyst on the other hand. (orig.) 891 HK [de

Neutron and soft X-ray emission from wire array Z-pinch imploding onto deuterated fiber

International Nuclear Information System (INIS)

Klir, D.; Kravarik, J.; Kubes, P.

2005-01-01

The implosion of a wire array Z-pinch onto a deuterated fiber was studied. The peak power of soft X-rays exceeded 200 GW and the total emitted energy was 2-8 kJ. The radiation was close to the radiation of the blackbody with the temperature of 40 eV. The neutron yield from the D-D reaction reached 2x10 8 per shot. The mean energy of neutrons determined in the axial direction was shifted from 2.45 MeV towards higher energies [ru

New method for the study of Amaryllidaceae alkaloid biosynthesis using biotransformation of deuterium-labeled precursor in tissue cultures

International Nuclear Information System (INIS)

Tahchy, A. E.; Boisbrun, M.; Chretien, F.; Henry, M.; Chapleur, Y.; Laurain-Mattar, D.; Ptak, A.; Dupire, F.

2010-01-01

Biotransformation of deuterated-4'-O-methylnorbelladine into alkaloids galanthamine and lycorine in tissue cultures of Leucojum aestivum was demonstrated using HPLC coupled to mass spectrometry. GC-MS screening was also carried to investigate other native and deuterated alkaloids. A total of six labeled alkaloids were identified indicating that 4'-O-methyl-d3-norbelladine is incorporated into three different groups of Amaryllidaceae alkaloids that are biosynthesized by three modes of intramolecular oxidative phenol coupling. (authors)

Production of deuterated switchgrass by hydroponic cultivation.

Science.gov (United States)

Evans, Barbara R; Bali, Garima; Foston, Marcus; Ragauskas, Arthur J; O'Neill, Hugh M; Shah, Riddhi; McGaughey, Joseph; Reeves, David; Rempe, Caroline S; Davison, Brian H

2015-07-01

The bioenergy crop switchgrass was grown hydroponically from tiller cuttings in 50 % D 2 O to obtain biomass with 34 % deuterium substitution and physicochemical properties similar to those of H 2 O-grown switchgrass controls. Deuterium enrichment of biological materials can potentially enable expanded experimental use of small angle neutron scattering (SANS) to investigate molecular structural transitions of complex systems such as plant cell walls. Two key advances have been made that facilitate cultivation of switchgrass, an important forage and biofuel crop, for controlled isotopic enrichment: (1) perfusion system with individual chambers and (2) hydroponic growth from tiller cuttings. Plants were grown and maintained for several months with periodic harvest. Photosynthetic activity was monitored by measurement of CO2 in outflow from the growth chambers. Plant morphology and composition appeared normal compared to matched controls grown with H2O. Using this improved method, gram quantities of switchgrass leaves and stems were produced by continuous hydroponic cultivation using growth medium consisting of basal mineral salts in 50 % D2O. Deuterium incorporation was confirmed by detection of the O-D and C-D stretching peaks with FTIR and quantified by (1)H- and (2)H-NMR. This capability to produce deuterated lignocellulosic biomass under controlled conditions will enhance investigation of cell wall structure and its deconstruction by neutron scattering and NMR techniques.

High-level expression and deuteration of sperm whale myoglobin: A study of its solvent structure by X-ray and neutron diffraction methods

Energy Technology Data Exchange (ETDEWEB)

Shu, F. [State Univ. of New York, Stony Brook, NY (United States); Ramakrishnan, V. [Brookhaven National Laboratory, Upton, NY (United States); Schoenborn, B.P. [Los Alamos National Laboratory, NM (United States)

1994-12-31

Neutron diffraction has become one of the best ways to study light atoms, such as hydrogens. Hydrogen however has a negative coherent scattering factor, and a large incoherent scattering factor, while deuterium has virtually no incoherent scattering, but a large positive coherent scattering factor. Beside causing high background due to its incoherent scattering, the negative coherent scattering of hydrogen tends to cancel out the positive contribution from other atoms in a neutron density map. Therefore a fully deuterated sample will yield better diffraction data with stronger density in the hydrogen position. On this basis, a sperm whale myoglobin gene modified to include part of the A cII protein gene has been cloned into the T7 expression system. Milligram amounts of fully deuterated holo-myoglobin have been obtained and used for crystallization. The synthetic sperm whale myoglobin crystallized in P2{sub 1} space group isomorphous with the native protein crystal. A complete X-ray diffraction dataset at 1.5{Angstrom} has been collected. This X-ray dataset, and a neutron data set collected previously on a protonated carbon-monoxymyoglobin crystal have been used for solvent structure studies. Both X-ray and neutron data have shown that there are ordered hydration layers around the protein surface. Solvent shell analysis on the neutron data further has shown that the first hydration layer behaves differently around polar and apolar regions of the protein surface. Finally, the structure of per-deuterated myoglobin has been refined using all reflections to a R factor of 17%.

High-level expression and deuteration of sperm whale myoglobin: A study of its solvent structure by X-ray and neutron diffraction methods

International Nuclear Information System (INIS)

Shu, F.; Ramakrishnan, V.; Schoenborn, B.P.

1994-01-01

Neutron diffraction has become one of the best ways to study light atoms, such as hydrogens. Hydrogen however has a negative coherent scattering factor, and a large incoherent scattering factor, while deuterium has virtually no incoherent scattering, but a large positive coherent scattering factor. Beside causing high background due to its incoherent scattering, the negative coherent scattering of hydrogen tends to cancel out the positive contribution from other atoms in a neutron density map. Therefore a fully deuterated sample will yield better diffraction data with stronger density in the hydrogen position. On this basis, a sperm whale myoglobin gene modified to include part of the A cII protein gene has been cloned into the T7 expression system. Milligram amounts of fully deuterated holo-myoglobin have been obtained and used for crystallization. The synthetic sperm whale myoglobin crystallized in P2 1 space group isomorphous with the native protein crystal. A complete X-ray diffraction dataset at 1.5 Angstrom has been collected. This X-ray dataset, and a neutron data set collected previously on a protonated carbon-monoxymyoglobin crystal have been used for solvent structure studies. Both X-ray and neutron data have shown that there are ordered hydration layers around the protein surface. Solvent shell analysis on the neutron data further has shown that the first hydration layer behaves differently around polar and apolar regions of the protein surface. Finally, the structure of per-deuterated myoglobin has been refined using all reflections to a R factor of 17%

Green chemistry perspectives of methane conversion via oxidative methylation of aromatics over zeolite catalysts

Energy Technology Data Exchange (ETDEWEB)

Adebajo, M.O. [University of Queensland, St Lucia, Qld. (Australia)

2007-06-15

This paper provides a general overview of the recent work that we and other researchers have done on the utilisation of methane for catalytic methylation of aromatic compounds and for direct coal liquefaction for the production of liquid hydrocarbons. In particular, the paper presents a detailed description of more recent substantial experimental evidence that we have provided for the requirement of oxygen as a stoichiometry reactant for benzene methylation with methane over moderately acidic zeolite catalysts. The reaction, which has been termed 'oxidative methylation', was thus postulated to involve a two-step mechanism involving intermediate methanol formation by methane partial oxidation, followed by benzene methylation with methanol in the second step. However, strongly acidic zeolites can cause cracking of benzene to yield methylated products in the absence of oxygen. The participation of methane and oxygen, and the effective use of zeolite catalysts in this methylation reaction definitely have some positive green chemistry implications. Thus, the results of these previous studies are also discussed in this review in light of the principles and tools of green chemistry. Various metrics were used to evaluate the greenness, cost-effectiveness, and material and energy efficiency of the oxidative methylation reaction.

Identification of Differentially Methylated Sites with Weak Methylation Effects

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Hong Tran

2018-02-01

Full Text Available Deoxyribonucleic acid (DNA methylation is an epigenetic alteration crucial for regulating stress responses. Identifying large-scale DNA methylation at single nucleotide resolution is made possible by whole genome bisulfite sequencing. An essential task following the generation of bisulfite sequencing data is to detect differentially methylated cytosines (DMCs among treatments. Most statistical methods for DMC detection do not consider the dependency of methylation patterns across the genome, thus possibly inflating type I error. Furthermore, small sample sizes and weak methylation effects among different phenotype categories make it difficult for these statistical methods to accurately detect DMCs. To address these issues, the wavelet-based functional mixed model (WFMM was introduced to detect DMCs. To further examine the performance of WFMM in detecting weak differential methylation events, we used both simulated and empirical data and compare WFMM performance to a popular DMC detection tool methylKit. Analyses of simulated data that replicated the effects of the herbicide glyphosate on DNA methylation in Arabidopsis thaliana show that WFMM results in higher sensitivity and specificity in detecting DMCs compared to methylKit, especially when the methylation differences among phenotype groups are small. Moreover, the performance of WFMM is robust with respect to small sample sizes, making it particularly attractive considering the current high costs of bisulfite sequencing. Analysis of empirical Arabidopsis thaliana data under varying glyphosate dosages, and the analysis of monozygotic (MZ twins who have different pain sensitivities—both datasets have weak methylation effects of <1%—show that WFMM can identify more relevant DMCs related to the phenotype of interest than methylKit. Differentially methylated regions (DMRs are genomic regions with different DNA methylation status across biological samples. DMRs and DMCs are essentially the same

To What Extent Does DNA Methylation Affect Phenotypic Variation in Cattle?

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Stephanie McKAY

2015-07-01

Full Text Available DNA methylation is an environmentally influenced epigenetic modification that regulates gene transcription and has the potential to influence variation in economically important phenotypes in agricultural species. We have utilized a novel approach to evaluate the relationship between genetic and epigenetic variation and downstream phenotypes. To begin with, we have integrated RNA-Seq and methyl binding domain sequencing (MBD-Seq data in order to determine the extent to which DNA methylation affects phenotypic variation in economically important traits of cattle. MBD-Seq is a technique that involves the sample enrichment of methylated genomic regions followed by their next-generation sequencing. This study utilized Illumina next generation sequencing technology to perform both RNA-Seq and MBD-Seq. NextGENe software (SoftGenetics, State College, PA was employed for quality trimming and aligning the sequence reads to the UMD3.1 bovine reference genome, generating counts of matched reads and methylated peak identification. Subsequently, we identified and quantified genome-wide methylated regions and characterized the extent of differential methylation and differential expression between two groups of animals with extreme phenotypes. The program edgeR from the R software package (version 3.0.1 was employed for identifying differentially methylated regions and regions of differential expression. Finally, Partial Correlation with Information Theory (PCIT was performed to identify transcripts and methylation events that exhibit differential hubbing. A differential hub is defined as a gene network hub that is more highly connected in one treatment group than the other. This analysis produced every possible pair-wise interaction that subsequently enabled us to look at network interactions of how methylation affects expression. (co-expression, co-methylation, methylation x expression. Genomic regions of interest derived from this analysis were then aligned

Intricate Conformational Tunneling in Carbonic Acid Monomethyl Ester.

Science.gov (United States)

Linden, Michael M; Wagner, J Philipp; Bernhardt, Bastian; Bartlett, Marcus A; Allen, Wesley D; Schreiner, Peter R

2018-04-05

Disentangling internal and external effects is a key requirement for understanding conformational tunneling processes. Here we report the s- trans/ s- cis tunneling rotamerization of carbonic acid monomethyl ester (1) under matrix isolation conditions and make comparisons to its parent carbonic acid (3). The observed tunneling rate of 1 is temperature-independent in the 3-20 K range and accelerates when using argon instead of neon as the matrix material. The methyl group increases the effective half life (τ eff ) of the energetically disfavored s- trans-conformer from 3-5 h for 3 to 11-13 h for 1. Methyl group deuteration slows the rotamerization further (τ eff ≈ 35 h). CCSD(T)/cc-pVQZ//MP2/aug-cc-pVTZ computations of the tunneling probability suggest that the rate should be almost unaffected by methyl substitution or its deuteration. Thus the observed relative rates are puzzling, and they disagree with previous explanations involving fast vibrational relaxation after the tunneling event facilitated by the alkyl rotor.

Pulse height model for deuterated scintillation detectors

International Nuclear Information System (INIS)

Wang, Haitang; Enqvist, Andreas

2015-01-01

An analytical model of light pulse height distribution for finite deuterated scintillation detectors is created using the impulse approximation. Particularly, the energy distribution of a scattered neutron is calculated based on an existing collision probability scheme for general cylindrical shaped detectors considering double differential cross-sections. The light pulse height distribution is analytically and numerically calculated by convoluting collision sequences with the light output function for an EJ-315 detector from our measurements completed at Ohio University. The model provides a good description of collision histories capturing transferred neutron energy in deuterium-based scintillation materials. The resulting light pulse height distribution details pulse compositions and their corresponding contributions. It shows that probabilities of neutron collision with carbon and deuterium nuclei are comparable, however the light pulse amplitude due to collisions with carbon nuclei is small and mainly located at the lower region of the light pulse distribution axis. The model can explore those neutron interaction events that generate pulses near or below a threshold that would be imposed in measurements. A comparison is made between the light pulse height distributions given by the analytical model and measurements. It reveals a significant probability of a neutron generating a small light pulse due to collisions with carbon nuclei when compared to larger light pulse generated by collisions involving deuterium nuclei. This model is beneficial to understand responses of scintillation materials and pulse compositions, as well as nuclei information extraction from recorded pulses.

Whole-genome methylation caller designed for methyl- DNA ...

African Journals Online (AJOL)

etchie

2013-02-20

Feb 20, 2013 ... Our method uses a single-CpG-resolution, whole-genome methylation ... Key words: Methyl-DNA immunoprecipitation, next-generation sequencing, ...... methylation is prevalent in embryonic stem cells andmaybe mediated.

Measurement of the response of the deuterated scintillators NE 232 and NE 230 to protons and deuterons

International Nuclear Information System (INIS)

Tornow, W.; Arnold, W.; Herdtweck, J.; Mertens, G.

1986-01-01

The response of the deuterated scintillators NE 232 and NE 230 to protons and deuterons has been measured via elastic neutron-proton and neutron-deuteron scattering using the two mixtures of C 6 H 12 /C 6 D 12 and C 6 H 6 /C 6 D 6 and ''pure'' scintillators. The energy range covered for protons and deuterons was about 1-16 MeV. The light output relation Lsub(p)(E)=(1/2)Lsub(d) (2E) has been observed. (orig.)

Small-angle neutron scattering from the reconstituted TF sub 1 of H sup + -ATPase from thermophilic bacterium PS3 with deuterated subunits

Energy Technology Data Exchange (ETDEWEB)

Ito, Yuji [Univ. of Tokyo (Japan) Brookhaven National Lab., Upton, NY (United States); Harada, Mitsuo [Univ. of Tokyo (Japan); Ohta, Shigeo; Kagawa, Yasuo; Aono, Osamu [Jichi Medical School, Tochigi (Japan); Schefer, J; Schoenborn, B P [Brookhaven National Lab., Upton (United States)

1990-01-01

Subunits {alpha}, {beta} and {gamma} of adenosine triphosphatase (H{sup +}-ATPase) from the thermophilic bacterium PS3 (TF{sub 1}) have been over-expressed in Escherichia coli. {alpha} and {beta} subunits deuterated to the level of 90% were obtained by culturing E. coli in {sup 2}H{sub 2}O medium. Both the subunits and the reconstituted {alpha}{beta}{gamma} complex, TF{sub 1}, which contain the deuterated components in various combinations, were studied in solution by small-angle neutron scattering. The individual shapes of the subunits and their organization in the {alpha}{beta}{gamma}-TF{sub 1} complex were examined using the techniques of selective deuteration and contrast variation. The {alpha} and {beta} subunits are well approximated as ellipsoids of revolution having minor semi-axes of 20{center dot}4({plus minus}0{center dot}4) and 20{center dot}0({plus minus}0{center dot}2) {angstrom}, and major semi-axes of 53{center dot}0({plus minus}1{center dot}4) and 55{center dot}8({plus minus}0{center dot}9) {angstrom}, respectively. In the TF{sub 1} complex, three {beta} subunits are aligned to form an equilateral triangle, with their major axes tilted by 35{degree} with respect to the 3-fold axis of the complex. The {beta}-{beta} distance is about 53 {angstrom}. Three {alpha} subunits are similarly arranged, positioned between the {beta} subunits, and with their direction of tilt opposite to that of the {beta} subunits. The centers of the {alpha} and {beta} subunits lie in the same plane, forming a hexagon. Adjacent subunits overlap in this model, suggesting that they are not simple ellipsoids of revolution.

Early Developmental and Evolutionary Origins of Gene Body DNA Methylation Patterns in Mammalian Placentas.

Directory of Open Access Journals (Sweden)

Diane I Schroeder

2015-08-01

Full Text Available Over the last 20-80 million years the mammalian placenta has taken on a variety of morphologies through both divergent and convergent evolution. Recently we have shown that the human placenta genome has a unique epigenetic pattern of large partially methylated domains (PMDs and highly methylated domains (HMDs with gene body DNA methylation positively correlating with level of gene expression. In order to determine the evolutionary conservation of DNA methylation patterns and transcriptional regulatory programs in the placenta, we performed a genome-wide methylome (MethylC-seq analysis of human, rhesus macaque, squirrel monkey, mouse, dog, horse, and cow placentas as well as opossum extraembryonic membrane. We found that, similar to human placenta, mammalian placentas and opossum extraembryonic membrane have globally lower levels of methylation compared to somatic tissues. Higher relative gene body methylation was the conserved feature across all mammalian placentas, despite differences in PMD/HMDs and absolute methylation levels. Specifically, higher methylation over the bodies of genes involved in mitosis, vesicle-mediated transport, protein phosphorylation, and chromatin modification was observed compared with the rest of the genome. As in human placenta, higher methylation is associated with higher gene expression and is predictive of genic location across species. Analysis of DNA methylation in oocytes and preimplantation embryos shows a conserved pattern of gene body methylation similar to the placenta. Intriguingly, mouse and cow oocytes and mouse early embryos have PMD/HMDs but their placentas do not, suggesting that PMD/HMDs are a feature of early preimplantation methylation patterns that become lost during placental development in some species and following implantation of the embryo.

Identification of endometrial cancer methylation features using combined methylation analysis methods.

Directory of Open Access Journals (Sweden)

Michael P Trimarchi

Full Text Available DNA methylation is a stable epigenetic mark that is frequently altered in tumors. DNA methylation features are attractive biomarkers for disease states given the stability of DNA methylation in living cells and in biologic specimens typically available for analysis. Widespread accumulation of methylation in regulatory elements in some cancers (specifically the CpG island methylator phenotype, CIMP can play an important role in tumorigenesis. High resolution assessment of CIMP for the entire genome, however, remains cost prohibitive and requires quantities of DNA not available for many tissue samples of interest. Genome-wide scans of methylation have been undertaken for large numbers of tumors, and higher resolution analyses for a limited number of cancer specimens. Methods for analyzing such large datasets and integrating findings from different studies continue to evolve. An approach for comparison of findings from a genome-wide assessment of the methylated component of tumor DNA and more widely applied methylation scans was developed.Methylomes for 76 primary endometrial cancer and 12 normal endometrial samples were generated using methylated fragment capture and second generation sequencing, MethylCap-seq. Publically available Infinium HumanMethylation 450 data from The Cancer Genome Atlas (TCGA were compared to MethylCap-seq data.Analysis of methylation in promoter CpG islands (CGIs identified a subset of tumors with a methylator phenotype. We used a two-stage approach to develop a 13-region methylation signature associated with a "hypermethylator state." High level methylation for the 13-region methylation signatures was associated with mismatch repair deficiency, high mutation rate, and low somatic copy number alteration in the TCGA test set. In addition, the signature devised showed good agreement with previously described methylation clusters devised by TCGA.We identified a methylation signature for a "hypermethylator phenotype" in

DNA methylation and temperature stress in an Antarctic polychaete, Spiophanes tcherniai.

Science.gov (United States)

Marsh, Adam G; Pasqualone, Annamarie A

2014-01-01

Epigenetic modifications of DNA and histones are a primary mechanism by which gene expression activities may be modified in response to environmental stimuli. Here we characterize patterns of methyl-cytosine composition in the marine polychaete Spiophanes tcherniai from McMurdo Sound, Antarctica. We cultured adult worms at two temperatures, -1.5°C (ambient control) and +4°C (warm treatment), for 4 weeks. We observed a rapid capacity for S. tcherniai organismal respiration rates and underlying catalytic rates of citrate synthase at +4°C to return to control levels in less than 4 weeks. We profiled changes in the methylation states of CpG sites in these treatments using an NGS strategy to computationally reconstruct and quantify methylation status across the genome. In our analysis we recovered 120,000 CpG sites in assembled contigs from both treatments. Of those, we were able to align 28,000 CpG sites in common between the two sample groups. In comparing these aligned sites between treatments, only 3000 (11%) evidenced a change in methylation state, but over 85% of changes involved a gain of a 5-methyl group on a CpG site (net increase in methyation). The ability to score CpG sites as partially methylated among gDNA copies in a sample opens up a new avenue for assessing DNA methylation responses to changing environments. By quantitatively distinguishing a "mixed" population of copies of one CpG site, we can begin to identify dynamic, non-binary, continuous-response reactions in DNA methylation intensity or density that previously may have been overlooked as noise.

DNA Methylation and Temperature Stress in an Antarctic Polychaete, Spiophanes tcherniai

Directory of Open Access Journals (Sweden)

Adam G. Marsh

2014-05-01

Full Text Available Epigenetic modifications of DNA and histones are a primary mechanism by which gene expression activities may be modified in response to environmental stimuli. Here we characterize patterns of methyl-cytosine composition in the marine polychaete emph{Spiophanes tcherniai} from McMurdo Sound, Antarctica. We cultured adult worms at two temperatures, -1.5 C (ambient control and +4 C (warm treatment, for four weeks. We observed a rapid capacity for emph{S. tcherniai} organismal respiration rates and underlying catalytic rates of citrate synthase to acclimate at +4 C and return to control levels. We profiled changes in the methylation states of CpG sites in these treatments using an NGS strategy to computationally reconstruct and quantify methylation status across the genome. In our analysis we recovered 120,000 CpG sites in assembled contigs from both treatments. Of those, we were able to align 28,000 CpG sites in common between the two sample groups. In comparing these aligned sites between treatments, only 3,000 (11% evidenced a change in methylation state, but over 85% of changes involved a gain of a 5-methyl group on a CpG site (net increase in methyation. The ability to score CpG sites as partially methylated among gDNA copies in a sample opens up a new avenue for assessing DNA methylation responses to changing environments. By quantitatively distinguishing a ``mixed'' population of copies of one CpG site, we can begin to identify dynamic, non-binary, continuous-response reactions in DNA methylation intensity or density that previously may have been overlooked as noise.

Modulation of the degree and pattern of methyl-esterification of pectic homogalacturonan in plant cell walls. Implications for pectin methyl esterase action, matrix properties, and cell adhesion.

Science.gov (United States)

Willats, W G; Orfila, C; Limberg, G; Buchholt, H C; van Alebeek, G J; Voragen, A G; Marcus, S E; Christensen, T M; Mikkelsen, J D; Murray, B S; Knox, J P

2001-06-01

Homogalacturonan (HG) is a multifunctional pectic polysaccharide of the primary cell wall matrix of all land plants. HG is thought to be deposited in cell walls in a highly methyl-esterified form but can be subsequently de-esterified by wall-based pectin methyl esterases (PMEs) that have the capacity to remove methyl ester groups from HG. Plant PMEs typically occur in multigene families/isoforms, but the precise details of the functions of PMEs are far from clear. Most are thought to act in a processive or blockwise fashion resulting in domains of contiguous de-esterified galacturonic acid residues. Such de-esterified blocks of HG can be cross-linked by calcium resulting in gel formation and can contribute to intercellular adhesion. We demonstrate that, in addition to blockwise de-esterification, HG with a non-blockwise distribution of methyl esters is also an abundant feature of HG in primary plant cell walls. A partially methyl-esterified epitope of HG that is generated in greatest abundance by non-blockwise de-esterification is spatially regulated within the cell wall matrix and occurs at points of cell separation at intercellular spaces in parenchymatous tissues of pea and other angiosperms. Analysis of the properties of calcium-mediated gels formed from pectins containing HG domains with differing degrees and patterns of methyl-esterification indicated that HG with a non-blockwise pattern of methyl ester group distribution is likely to contribute distinct mechanical and porosity properties to the cell wall matrix. These findings have important implications for our understanding of both the action of pectin methyl esterases on matrix properties and mechanisms of intercellular adhesion and its loss in plants.

Solubility comparison and partial molar volumes of 1,2-hexanediol before and after end-group modification by methyl oxalyl chloride and ethyl oxalyl monochloride in supercritical CO2

International Nuclear Information System (INIS)

Zhao, Lu; Yang, Hai-Jian; Cai, Zhuofu

2013-01-01

Highlights: ► Two new “CO 2 -philic” compounds were designed and synthesized. ► The tested solubility data were calculated and correlated with two models. ► Satisfactory agreements were obtained between the tested and calculated data. ► The partial molar volumes V ¯ 2 for three compounds were estimated. - Abstract: Bis(methoxy oxalic)-1,2-haxenediester and bis(ethoxy oxalic)-1,2-haxenediester were synthesized by modifying the end groups of 1,2-hexanediol with methyl oxalyl chloride and ethyl oxalyl monochloride. The solubilities of all three compounds in supercritical carbon dioxide were determined at different conditions of pressures (8.8 to 18.8) MPa and temperatures (313, 333, and 353) K. Then, the solubility data were correlated with the Bartle model and the Chrastil model. The average absolute relative deviation (AARD) for the Bartle model was in the range of (3.89 to 25.46)% which is within a good approximation. The Chrastil model also showed satisfactory agreement and the AARD was in the range of (3.70 to 16.92)%. Furthermore, the partial molar volumes of those compounds were estimated following the theory developed by Kumar and Johnston.

Straightforward synthesis of 2,2,4,4,5,7,7-d{sub 7}-cholestane: a new deuterated standard in petroleum analysis

Energy Technology Data Exchange (ETDEWEB)

Miranda, Maicon Guerra de; Albert, Andre Luis Mazzei; Cardoso, Jari Nobrega; Lopes, Rosangela Sabbatini Capella; Lopes, Claudio Cerqueira, E-mail: maicon_iq@yahoo.com [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica

2013-10-01

A short and efficient synthesis of heptadeuterated 2,2,4,4,5,7,7-d7-cholestane (1) from cholesterol (3) is described. The deuterated material will be useful for the analysis of different sources of petroleum in analytical geochemistry laboratories as internal standard for quantification of steranes via gas chromatography-mass spectrometry (GC-MS). (author)

Methylation of food commodities during fumigation with methyl bromide

International Nuclear Information System (INIS)

Starratt, A.N.; Bond, E.J.

1990-01-01

Sites of methylation in several commodities (wheat, oatmeal, peanuts, almonds, apples, oranges, maize, alfalfa and potatoes) during fumigation with 14 C-methyl bromide were studied. Differences were observed in levels of the major volatiles: methanol, dimethyl sulphide and methyl mercaptan, products of O- and S-methylation, resulting from treatment of the fumigated materials with 1N sodium hydroxide. In studies of maize and wheat, histidine was the amino acid which underwent the highest level of N-methylation. (author). 24 refs, 3 tabs

Crystal structure of the sodium cobaltate deuterate superconductor NaxCoO2ṡ4xD2O (x≈1/3)

Science.gov (United States)

Jorgensen, J. D.; Avdeev, M.; Hinks, D. G.; Burley, J. C.; Short, S.

2003-12-01

Neutron and x-ray powder diffraction have been used to investigate the crystal structures of a sample of the newly-discovered superconducting sodium cobaltate deuterate compound with composition Na0.31(3)CoO2ṡ1.25(2)D2O and its anhydrous parent compound Na0.61(1)CoO2. The anhydrous parent compound Na0.61(1)CoO2 has two partially occupied Na sites sandwiched, in the same plane, between CoO2 layers. When Na is removed to make the superconducting composition, the Na site that experiences the strongest Na Co repulsion is emptied while the occupancy of the other Na site is reduced to about one third. The deuterate superconducting compound is formed by coordinating four D2O molecules (two above and two below) to each remaining Na ion in a way that gives Na O distances nearly equal to those in the parent compound. One deuteron of the D2O molecule is hydrogen bonded to an oxygen atom in the CoO2 plane and the oxygen atom and the second deuteron of each D2O molecule lie approximately in a plane between the Na layer and the CoO2 layers. This coordination of Na by four D2O molecules leads in a straightforward way to ordering of the Na ions and D2O molecules consistent with the observation of additional shorter-range scattering features in the diffraction data. The sample studied here, which has Tc=4.5 K, has a refined composition of Na0.31(3)CoO2ṡ1.25(2)D2O, in agreement with the expected 1:4 ratio of Na to D2O. These results show that the optimal superconducting composition should be viewed as a specific hydrated compound, not a solid solution of Na and D2O (H2O) in NaxCoO2ṡD2O. The hydrated superconducting compound may be stable over a limited range of Na and D2O concentration, but studies of Tc and other physical properties vs Na or D2O composition should be viewed with caution until it is verified that the compound remains in the same phase over the composition range of the study.

Crystal structure of the sodium cobaltate deuterate superconductor NaxCoO2·4xD2O (x≅(1/3))

International Nuclear Information System (INIS)

Jorgensen, J.D.; Avdeev, M.; Hinks, D.G.; Burley, J.C.; Short, S.

2003-01-01

Neutron and x-ray powder diffraction have been used to investigate the crystal structures of a sample of the newly-discovered superconducting sodium cobaltate deuterate compound with composition Na 0.31(3) CoO 2 ·1.25(2)D 2 O and its anhydrous parent compound Na 0.61(1) CoO 2 . The anhydrous parent compound Na 0.61(1) CoO 2 has two partially occupied Na sites sandwiched, in the same plane, between CoO 2 layers. When Na is removed to make the superconducting composition, the Na site that experiences the strongest Na-Co repulsion is emptied while the occupancy of the other Na site is reduced to about one third. The deuterate superconducting compound is formed by coordinating four D 2 O molecules (two above and two below) to each remaining Na ion in a way that gives Na-O distances nearly equal to those in the parent compound. One deuteron of the D 2 O molecule is hydrogen bonded to an oxygen atom in the CoO 2 plane and the oxygen atom and the second deuteron of each D 2 O molecule lie approximately in a plane between the Na layer and the CoO 2 layers. This coordination of Na by four D 2 O molecules leads in a straightforward way to ordering of the Na ions and D 2 O molecules consistent with the observation of additional shorter-range scattering features in the diffraction data. The sample studied here, which has T c =4.5 K, has a refined composition of Na 0.31(3) CoO 2 ·1.25(2)D 2 O, in agreement with the expected 1:4 ratio of Na to D 2 O. These results show that the optimal superconducting composition should be viewed as a specific hydrated compound, not a solid solution of Na and D 2 O (H 2 O) in Na x CoO 2 ·D 2 O. The hydrated superconducting compound may be stable over a limited range of Na and D 2 O concentration, but studies of T c and other physical properties vs Na or D 2 O composition should be viewed with caution until it is verified that the compound remains in the same phase over the composition range of the study

The distribution of sorbed moisture within a partially crystalline cellulosic web of fibres (paper)

International Nuclear Information System (INIS)

Garvey, C.; Parker, I.H.; Simon, G.

1999-01-01

Full text: Paper is a hydrophilic web of partially crystalline cellulosic fibres. In conditions of changing humidity it will sorb/desorb moisture. It has been found by dielectric relaxation spectroscopy and two dimensional nuclear magnetic resonance spectroscopy that the sorption of water causes the activation of long range co-operative molecular motions by lowering the glass transition temperature into normal ambient range. Water therefore acts as a plasticiser. NMR also indicates that the water is not uniformly distributed within the paper matrix. Preliminary experiments have been performed using the AUSANS instrument to investigate the distribution of sorbed water with the eventual aim of understanding how sorbed water is mixed within the paper sheet. Samples of paper with varying polymer morphology have been selectively deuterated by allowing to equilibrate with known D 2 O humidities. The results are discussed within the context of the AUSANS instrument

Preparation of deuterated heterocyclic five-membered ring compounds (furan, thiophene, pyrrole, and derivatives) by base-catalyzed hydrogen isotope exchange with deuterium oxide

International Nuclear Information System (INIS)

Heinrich, K.H.; Herrmann, M.; Moebius, G.; Sprinz, H.

1984-01-01

Several deuterated heterocyclic compounds of the type of furan,thiophene and pyrrole were prepared by base-catalyzed proton exchange with deuterium oxide at temperatures above 423 K in a closed system. The determination of deuterium and its distribution within the molecules was carried out by mass spectrometry and 1 H nmr spectrometry. (author)

MIWI2 as an Effector of DNA Methylation and Gene Silencing in Embryonic Male Germ Cells

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Kanako Kojima-Kita

2016-09-01

Full Text Available During the development of mammalian embryonic germ cells, global demethylation and de novo DNA methylation take place. In mouse embryonic germ cells, two PIWI family proteins, MILI and MIWI2, are essential for the de novo DNA methylation of retrotransposons, presumably through PIWI-interacting RNAs (piRNAs. Although piRNA-associated MIWI2 has been reported to play critical roles in the process, its molecular mechanisms have remained unclear. To identify the mechanism, transgenic mice were produced; they contained a fusion protein of MIWI2 and a zinc finger (ZF that recognized the promoter region of a type A LINE-1 gene. The ZF-MIWI2 fusion protein brought about DNA methylation, suppression of the type A LINE-1 gene, and a partial rescue of the impaired spermatogenesis of MILI-null mice. In addition, ZF-MIWI2 was associated with the proteins involved in DNA methylation. These data indicate that MIWI2 functions as an effector of de novo DNA methylation of the retrotransposon.

An economical method for production of (2H, (13CH3-threonine for solution NMR studies of large protein complexes: application to the 670 kDa proteasome.

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Algirdas Velyvis

Full Text Available NMR studies of very high molecular weight protein complexes have been greatly facilitated through the development of labeling strategies whereby (13CH(3 methyl groups are introduced into highly deuterated proteins. Robust and cost-effective labeling methods are well established for all methyl containing amino acids with the exception of Thr. Here we describe an inexpensive biosynthetic strategy for the production of L-[α-(2H; β-(2H;γ-(13C]-Thr that can then be directly added during protein expression to produce highly deuterated proteins with Thr methyl group probes of structure and dynamics. These reporters are particularly valuable, because unlike other methyl containing amino acids, Thr residues are localized predominantly to the surfaces of proteins, have unique hydrogen bonding capabilities, have a higher propensity to be found at protein nucleic acid interfaces and can play important roles in signaling pathways through phosphorylation. The utility of the labeling methodology is demonstrated with an application to the 670 kDa proteasome core particle, where high quality Thr (13C,(1H correlation spectra are obtained that could not be generated from samples prepared with commercially available U-[(13C,(1H]-Thr.

Estimation of nitrogenase activity in the presence of ethylene biosynthesis by use of deuterated acetylene as a substrate

International Nuclear Information System (INIS)

Lin-Vien, D.; Fateley, W.G.; Davis, L.C.

1989-01-01

Nitrogenase reduces deuterated acetylene primarily to cis dideuterated ethylene. This can be distinguished from undeuterated ethylene by the use of Fourier transform infrared spectroscopy. Characteristic bands in the region from 800 to 3,500 cm-1 can be used to identify and quantitate levels of these products. This technique is applicable to field studies of nitrogen fixation where ethylene biosynthesis by plants or bacteria is occurring. We have verified the reaction stoichiometry by using Klebsiella pneumoniae and Bradyrhizobium japonicum in soybeans. The most useful bands for quantitation of substrate purity and product distribution are as follows: acetylene-d0, 3,374 cm-1; acetylene-d1, 2,584 cm-1; acetylene-d2, 2,439 cm-1; cis-ethylene-d2, 843 cm-1; trans-ethylene-d2, 988 cm-1; ethylene-d1, 943 cm-1; ethylene-d0, 949 cm-1. (The various deuterated ethylenes and acetylenes are designated by a lowercase d and subscript to indicate the number, but not the position, of deuterium atoms in the molecule.) Mass spectrometry coupled to a gas chromatograph system has been used to assist in quantitation of the substrate and product distributions. Significant amounts of trans-ethylene-d2 were produced by both wild-type and nifV mutant K. pneumoniae. Less of this product was observed with the soybean system

H19DMR methylation analysis in patients with Beckwith-Wiedemann syndrome and isolated hemihyperplasia

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Marcus Vinícius de Matos Gomes

2005-01-01

Full Text Available Beckwith-Wiedemann syndrome (BWS is a congenital overgrowth disorder of complex and heterogeneous etiology involving alterations in genomic imprinting. The cause of isolated hemihyperplasia (IHH is unknown but might be due to partial or incomplete expression of BWS because both these conditions share predisposition for the same types of neoplasias. We investigated the methylation pattern of the putative imprinting control region H19DMR using peripheral blood from 12 patients, six with clinical features of BWS and six with IHH. All the patients had normal karyotypes and paternal uniparental disomy (UPD was excluded in 10 informative cases. The normal H19DMR methylation pattern was found in eight informative patients, indicating that H19DMR methylation was not related to their condition. We suggest that the absence of neoplasias in the BWS and IHH patients studied might be related to the absence of UPD and to the presence of normal H19DMR methylation.

MethylMix 2.0: an R package for identifying DNA methylation genes.

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Cedoz, Pierre-Louis; Prunello, Marcos; Brennan, Kevin; Gevaert, Olivier

2018-04-14

DNA methylation is an important mechanism regulating gene transcription, and its role in carcinogenesis has been extensively studied. Hyper and hypomethylation of genes is a major mechanism of gene expression deregulation in a wide range of diseases. At the same time, high-throughput DNA methylation assays have been developed generating vast amounts of genome wide DNA methylation measurements. We developed MethylMix, an algorithm implemented in R to identify disease specific hyper and hypomethylated genes. Here we present a new version of MethylMix that automates the construction of DNA-methylation and gene expression datasets from The Cancer Genome Atlas (TCGA). More precisely, MethylMix 2.0 incorporates two major updates: the automated downloading of DNA methylation and gene expression datasets from TCGA and the automated preprocessing of such datasets: value imputation, batch correction and CpG sites clustering within each gene. The resulting datasets can subsequently be analyzed with MethylMix to identify transcriptionally predictive methylation states. We show that the Differential Methylation Values created by MethylMix can be used for cancer subtyping. olivier.gevaert@stanford.edu. https://bioconductor.org/packages/release/bioc/manuals/MethylMix/man/MethylMix.pdf. MethylMix 2.0 was implemented as an R package and is available in bioconductor.

Global DNA methylation analysis using methyl-sensitive amplification polymorphism (MSAP).

Science.gov (United States)

Yaish, Mahmoud W; Peng, Mingsheng; Rothstein, Steven J

2014-01-01

DNA methylation is a crucial epigenetic process which helps control gene transcription activity in eukaryotes. Information regarding the methylation status of a regulatory sequence of a particular gene provides important knowledge of this transcriptional control. DNA methylation can be detected using several methods, including sodium bisulfite sequencing and restriction digestion using methylation-sensitive endonucleases. Methyl-Sensitive Amplification Polymorphism (MSAP) is a technique used to study the global DNA methylation status of an organism and hence to distinguish between two individuals based on the DNA methylation status determined by the differential digestion pattern. Therefore, this technique is a useful method for DNA methylation mapping and positional cloning of differentially methylated genes. In this technique, genomic DNA is first digested with a methylation-sensitive restriction enzyme such as HpaII, and then the DNA fragments are ligated to adaptors in order to facilitate their amplification. Digestion using a methylation-insensitive isoschizomer of HpaII, MspI is used in a parallel digestion reaction as a loading control in the experiment. Subsequently, these fragments are selectively amplified by fluorescently labeled primers. PCR products from different individuals are compared, and once an interesting polymorphic locus is recognized, the desired DNA fragment can be isolated from a denaturing polyacrylamide gel, sequenced and identified based on DNA sequence similarity to other sequences available in the database. We will use analysis of met1, ddm1, and atmbd9 mutants and wild-type plants treated with a cytidine analogue, 5-azaC, or zebularine to demonstrate how to assess the genetic modulation of DNA methylation in Arabidopsis. It should be noted that despite the fact that MSAP is a reliable technique used to fish for polymorphic methylated loci, its power is limited to the restriction recognition sites of the enzymes used in the genomic

Methylation changes of H19 gene in sperms of X-irradiated mouse and maintenance in offspring

International Nuclear Information System (INIS)

Zhu Bin; Huang Xinghua; Chen Jindong; Lu Yachao; Chen Ying; Zhao Jingyong

2006-01-01

The nature of imprinting is just differential methylation of imprinted genes. Unlike the non-imprinted genes, the methylation pattern of imprinted genes established during the period of gametogenesis remains unchangeable after fertilization and during embryo development. It implies that gametogenesis is the key stage for methylation pattern of imprinted genes. The imprinting interfered by exogenous factors during this stage could be inherited to offspring and cause genetic effect. Now many studies have proved that ionizing irradiation could disturb DNA methylation. Here we choose BALB/c mice as a research model and X-ray as interfering source to further clarify it. We discovered that the whole-body irradiation of X-ray to male BALB/c mice could influence the methylation pattern of H 19 gene in sperms, which resulted in some cytosines of partial CpG islands in the imprinting control region could not transform to methylated cytosines. Furthermore, by copulating the interfered male mice with normal female, we analyzed the promoter methylation pattern of H 19 in offspring fetal liver and compared the same to the pattern of male parent in sperms. We found that the majority of methylation changes in offspring liver were related to the ones in their parent sperms. Our data proved that the changes of the H 19 gene methylation pattern interfered by X-ray irradiation could be transmitted and maintained in First-generation offspring

Oxidation of methyl heterocyclic compounds on vanadium oxide catalysts

International Nuclear Information System (INIS)

Shimanskaya, M.V.; Lejtis, L.A.; Iovel', I.G.; Gol'dberg, Yu.Sh.; Skolmejstere, R.A.; Golender, L.O.

1985-01-01

Data on vapor-phase oxidation of methyl derivatives of thiophene, Δ 2 - thiazo line, pyridine, pyrazine and pyramidine on oxide vanadium-molybdenum catalysts to corresponding heterylaldehydes are generalized. The dependence of catalytic properties of oxide vanadium-molybdenum systems in oxidation reactions of methylheterocyclic compounds on V:Mo ratio in the catalyst is revealed. It is shown that heterocyclic compounds are coordinated by a heteroatom on Lewis centres of V-Mo-O-catalyst primarily with partially reduced vanadium ions

Quantitative correlation between promoter methylation and messenger RNA levels of the reduced folate carrier

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Kheradpour Albert

2008-05-01

Full Text Available Abstract Background Methotrexate (MTX uptake is mediated by the reduced folate carrier (RFC. Defective drug uptake in association with decreased RFC expression is a common mechanism of MTX resistance in many tumor types. Heavy promoter methylation was previously identified as a basis for the complete silencing of RFC in MDA-MB-231 breast cancer cells, its role and prevalence in RFC transcription regulation are, however, not widely studied. Methods In the current study, RFC promoter methylation was assessed using methylation specific PCR in a panel of malignant cell lines (n = 8, including MDA-MB-231, and M805, a MTX resistant cell line directly established from the specimen of a patient with malignant fibrohistocytoma, whom received multiple doses of MTX. A quantitative approach of real-time PCR for measuring the extent of RFC promoter methylation was developed, and was validated by direct bisulfite genomic sequencing. RFC mRNA levels were determined by quantitative real-time RT-PCR and were related to the extent of promoter methylation in these cell lines. Results A partial promoter methylation and RFC mRNA down-regulation were observed in M805. Using the quantitative approach, a reverse correlation (correlation coefficient = -0.59, p Conclusion This study further suggests that promoter methylation is a potential basis for MTX resistance. The quantitative correlation identified in this study implies that promoter methylation is possibly a mechanism involved in the fine regulation of RFC transcription.

Hierarchical clustering of breast cancer methylomes revealed differentially methylated and expressed breast cancer genes.

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I-Hsuan Lin

Full Text Available Oncogenic transformation of normal cells often involves epigenetic alterations, including histone modification and DNA methylation. We conducted whole-genome bisulfite sequencing to determine the DNA methylomes of normal breast, fibroadenoma, invasive ductal carcinomas and MCF7. The emergence, disappearance, expansion and contraction of kilobase-sized hypomethylated regions (HMRs and the hypomethylation of the megabase-sized partially methylated domains (PMDs are the major forms of methylation changes observed in breast tumor samples. Hierarchical clustering of HMR revealed tumor-specific hypermethylated clusters and differential methylated enhancers specific to normal or breast cancer cell lines. Joint analysis of gene expression and DNA methylation data of normal breast and breast cancer cells identified differentially methylated and expressed genes associated with breast and/or ovarian cancers in cancer-specific HMR clusters. Furthermore, aberrant patterns of X-chromosome inactivation (XCI was found in breast cancer cell lines as well as breast tumor samples in the TCGA BRCA (breast invasive carcinoma dataset. They were characterized with differentially hypermethylated XIST promoter, reduced expression of XIST, and over-expression of hypomethylated X-linked genes. High expressions of these genes were significantly associated with lower survival rates in breast cancer patients. Comprehensive analysis of the normal and breast tumor methylomes suggests selective targeting of DNA methylation changes during breast cancer progression. The weak causal relationship between DNA methylation and gene expression observed in this study is evident of more complex role of DNA methylation in the regulation of gene expression in human epigenetics that deserves further investigation.

Systemic effects of chronically administered methyl prednisolonate and methyl 17-deoxyprednisolonate.

Science.gov (United States)

Olejniczak, E; Lee, H J

1984-06-01

The systemic activities of methyl prednisolonate and methyl 17-deoxyprednisolonate (1) were studied in rats. Methyl 17-deoxyprednisolonate produced significant changes in the amount of sodium ion (decreased) and potassium ion (increased) in urine; however, methyl prednisolonate had no effect on electrolyte balance. Both methyl prednisolonate and methyl 17-deoxyprednisolonate had no effect on liver glycogen content, plasma corticosterone level and relative adrenal weight. In contrast, the parent compound prednisolone caused a significant decrease in liver glycogen content, plasma corticosterone level and relative adrenal weight.

Lgr5 Methylation in Cancer Stem Cell Differentiation and Prognosis-Prediction in Colorectal Cancer.

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Shasha Su

Full Text Available Leucine-rich-repeat-containing G-protein-coupled receptor 5 (lgr5 is a candidate marker for colorectal cancer stem cells (CSC. In the current study, we investigated the methylation status within thelgr5 promoter and evaluated its relationship with CSC differentiation, prognosis for colorectal cancer, and its clinicopathological features.The methylation status within Lgr5 promoter was detected with a methylation-specific PCR in six colorectal cancer cell lines as well as 169 primary colorectal tumor tissues. Differentiation of CSC was examined with immunofluorescence and immunocytochemistry. Down-regulation of lgr5 was achieved with gene-specific siRNA. The associations between lgr5 methylation and the clinicopathological features as well as survival of patients were analyzed with statistical methods.The lgr5 promoter was methylated to different degrees for the six colorectal cell lines examined, with complete methylation observed in HCT116 cells in which the lgr5 expression was partially recovered following DAC treatment. The stem-cell sphere formation from HCT116 cells was accompanied by increasing methylation within the lgr5 promoter and decreasing expression of lgr5. Knocking down lgr5 by siRNA also led to stem-cell spheres formation. Among primary colorectal tumors, 40% (67/169 were positive for lgr5 methylation, while none of the normal colon tissues were positive for lgr5 methylation. Furthermore, lgr5 methylation significantly associated with higher tumor grade, and negative distant metastasis (p < 0.05, as well as better prognosis (p = 0.001 in patients with colorectal cancer.Our data suggests that lgr5 methylation, through the regulation of lgr5 expression and colorectal CSC differentiation, may constitute a novel prognostic marker for colorectal cancer patients.

Definitive difference among [DS-D2O], [DS-H2O] and [Bulk-D2O] cells in the deuterization and deuterium-reaction

International Nuclear Information System (INIS)

Arata, Yoshiaki; Zhang, Yue Chang

2000-01-01

We observed a new phenomena that the enormous amount of deuterium/hydrogen can be absorbed quickly as a 'solute-atom' into fine metal powders embedded inside a double-structure (DS) cathode in the electrolyses of D 2 O and H 2 O-electrolytes, respectively, but such highly deuterated powders can be produced only using DS-cathode immersed in D 2 O-electrolyte; [DS-D 2 O], and never generated in H 2 O-electrolyte even using the DS-cathode; [DS-H 2 O]. On the other hand, [Bulk-D 2 O] with bulk-cathode made by the bulk Pd metal never produces highly deuterated metal as mentioned above even though using D 2 O-electrolyte. In short, the deuterium-concentration generating in [Bulk-D 2 O] is found to be much lower than that in [DS-D 2 O]. As a result, because of reason mentioned above, in marked contrast to the case with the [DS-D 2 O], neither excess heat nor 4 He production are observed with both [DS-H 2 O] and [Bulk-D 2 O]. (author)

Preparation of. alpha. -deuterated L-amino acids using E. coli cells containing tryptophanase. Poluchenie. alpha. -dejterirovannykh L-aminokislot s ispol'zovaniem kletok E. coli, soderzhashchikh triptofanazy

Energy Technology Data Exchange (ETDEWEB)

Faleev, N G; Ruvinov, S B; Saporovskaya, M B; Belikov, V M; Zakomyrdina, L N; Sakharova, I S; Torchinskij, Yu M [AN SSSR, Moscow (USSR). Inst. Ehlementoorganicheskikh Soedinenij AN SSSR, Moscow (USSR). Inst. Molekulyarnoj Biologii AN SSSR, Moscow (USSR)

1989-10-01

Method for preparation of a series of {alpha}-deuterated L-amino acids of high optical purity with quantitative chemica yield, suing stereospecific isotopic exchange in D{sub 2}O under the effect of E.coli cells with high tryptophanase activity was developed.

Stress-related methylation of the catechol-O-methyltransferase Val 158 allele predicts human prefrontal cognition and activity.

Science.gov (United States)

Ursini, Gianluca; Bollati, Valentina; Fazio, Leonardo; Porcelli, Annamaria; Iacovelli, Luisa; Catalani, Assia; Sinibaldi, Lorenzo; Gelao, Barbara; Romano, Raffaella; Rampino, Antonio; Taurisano, Paolo; Mancini, Marina; Di Giorgio, Annabella; Popolizio, Teresa; Baccarelli, Andrea; De Blasi, Antonio; Blasi, Giuseppe; Bertolino, Alessandro

2011-05-04

DNA methylation at CpG dinucleotides is associated with gene silencing, stress, and memory. The catechol-O-methyltransferase (COMT) Val(158) allele in rs4680 is associated with differential enzyme activity, stress responsivity, and prefrontal activity during working memory (WM), and it creates a CpG dinucleotide. We report that methylation of the Val(158) allele measured from peripheral blood mononuclear cells (PBMCs) of Val/Val humans is associated negatively with lifetime stress and positively with WM performance; it interacts with stress to modulate prefrontal activity during WM, such that greater stress and lower methylation are related to reduced cortical efficiency; and it is inversely related to mRNA expression and protein levels, potentially explaining the in vivo effects. Finally, methylation of COMT in prefrontal cortex and that in PBMCs of rats are correlated. The relationship of methylation of the COMT Val(158) allele with stress, gene expression, WM performance, and related brain activity suggests that stress-related methylation is associated with silencing of the gene, which partially compensates the physiological role of the high-activity Val allele in prefrontal cognition and activity. Moreover, these results demonstrate how stress-related DNA methylation of specific functional alleles impacts directly on human brain physiology beyond sequence variation.

OD bands in the IR spectra of a deuterated soda-lime-silica glass

Energy Technology Data Exchange (ETDEWEB)

Peuker, C.; Brzezinka, K.W.; Gaber, M.; Kohl, A.; Geissler, H. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

2001-07-01

IR spectra of a deuterated glass of the composition (in mol%) 16 Na{sub 2}O . 10 CaO . 74 SiO{sub 2} complete earlier spectroscopic studies on water-poor soda-lime-silica glasses. The approved IR spectroscopic method of the deuterium exchange allows a reliable assignment of the hydroxyl bands also in the case of glasses. By spectra comparison the assignment of the IR bands at 3500 and 2800 cm{sup -1} to hydroxyl groups with different hydrogen bonding is verified. The IR band at about 4500 cm{sup -1} is interpreted as both a combination of the stretching vibrations {nu}O-H and {nu}Si-OH and a combination of the stretching vibration {nu}O-H and the deformation vibration {delta}SiOH. The bands at 1763 and 1602 cm{sup -1} are attributed to combination vibrations of the glass network. (orig.)

DNA methylation analysis reveals distinct methylation signatures in pediatric germ cell tumors

International Nuclear Information System (INIS)

Amatruda, James F; Frazier, A Lindsay; Poynter, Jenny N; Ross, Julie A; Christensen, Brock; Fustino, Nicholas J; Chen, Kenneth S; Hooten, Anthony J; Nelson, Heather; Kuriger, Jacquelyn K; Rakheja, Dinesh

2013-01-01

Aberrant DNA methylation is a prominent feature of many cancers, and may be especially relevant in germ cell tumors (GCTs) due to the extensive epigenetic reprogramming that occurs in the germ line during normal development. We used the Illumina GoldenGate Cancer Methylation Panel to compare DNA methylation in the three main histologic subtypes of pediatric GCTs (germinoma, teratoma and yolk sac tumor (YST); N = 51) and used recursively partitioned mixture models (RPMM) to test associations between methylation pattern and tumor and demographic characteristics. We identified genes and pathways that were differentially methylated using generalized linear models and Ingenuity Pathway Analysis. We also measured global DNA methylation at LINE1 elements and evaluated methylation at selected imprinted loci using pyrosequencing. Methylation patterns differed by tumor histology, with 18/19 YSTs forming a distinct methylation class. Four pathways showed significant enrichment for YSTs, including a human embryonic stem cell pluripotency pathway. We identified 190 CpG loci with significant methylation differences in mature and immature teratomas (q < 0.05), including a number of CpGs in stem cell and pluripotency-related pathways. Both YST and germinoma showed significantly lower methylation at LINE1 elements compared with normal adjacent tissue while there was no difference between teratoma (mature and immature) and normal tissue. DNA methylation at imprinted loci differed significantly by tumor histology and location. Understanding methylation patterns may identify the developmental stage at which the GCT arose and the at-risk period when environmental exposures could be most harmful. Further, identification of relevant genetic pathways could lead to the development of new targets for therapy

Deuterium isotope effects during formation of phenols by hepatic monoxygenases. Evidence for an alternative to the arene oxide pathway

International Nuclear Information System (INIS)

Tomaszewski, J.E.; Jerina, D.M.; Daly, J.W.

1975-01-01

The in vivo and in vitro metabolisms of normal and deuterated aromatic substrates have been investigated in rats. Significant isotope effects (k/ sub H//k/sub D/ equals 1.3-1.75) were associated with in vivo formation of meta-hydroxylated metabolites from 1:1 mixtures of normal and perdeuterio-(arylring) nitrobenzene, methyl phenyl sulfide, and methyl phenyl sulfone. Since isotope effects of this magnitude are incompatible with arene oxides as intermediates in the formation of phenols, the results provide evidence that multiple pathways are responsible for the formation of phenols in mammals. Significant isotope effects were not associated with the formation of the other phenolic isomers of nitrobenzene, methyl phenyl sulfone, or methyl phenyl sulfide or with the formation of phenolic products from anisole, bromobenzene, chlorobenzene, fluorobenzene, benzonitrile, naphthalene, zoxazolamine, acetanilide, biphenyl, diphenylhydantoin, benzene, o- and p-xylene, toluene, and mesitylene. Significant isotope effects might not be observable with the latter substrates if the kinetic parameters for oxidation of substrate change or if the arene oxide pathway greatly predominates. Furthermore, extensive in vivo metabolism of any substrate would make isotope effects unobservable by the procedure employed, namely the analysis of isotope content in metabolites formed from 1:1 mixtures of normal and deuterated substrates. (U.S.)

Detection of a deuterium isotope effect in di- and trisubstituted alkylphenylnitrosoureas. An SCE study in Chinese hamster V79-E cells

International Nuclear Information System (INIS)

Thust, R.; Mendel, J.; Bach, B.; Schwarz, H.

1985-01-01

The genotoxicity of 1-methyl-3-phenyl-1-nitrosourea (MPNU), 1-methyl-3-(p-chlorophenyl)-1-nitrosourea (C1-MPNU), 1-ethyl-3-phenyl-1-nitrosourea (EPNU), 1,3-dimethyl-3-phenyl-1-nitrosourea (DMPNU) and their derivatives substituted by deuterium in different positions was studied using sister chromatid exchange (SCE) induction in Chinese hamster V79-E cells. Deuterium substitution in the 1-methyl group of MPNU (MPNU-d3) and C1-MPNU (C1-MPNU-d3) diminished the SCE-inducing capacity by 20-30% and by 30-40% in DMPNU (DMPNU-d3B). There was no altered SCE activity detected when the phenyl group of MPNU (MPNU-d5) or the 3-methyl group of DMPNU (DMPNU-d3A) was deuterium labeled. No isotope effect was detected in deuterated EPNU derivatives, presumably due to the instability of these compounds. It is surmised that the easier delocalization of the positive charge in the deuterated alkyl diazonium ion causes a diminished reactivity and therefore influences the type and amount of DNA alkylation. Furthermore, the experiments with DMPNU and its derivatives revealed that, in contrast to mono- and disubstituted nitrosoureas, the biological activities of these very stable trisubstituted nitrosoureas are strongly influenced by a serum factor in the culture fluid

Detection of a deuterium isotope effect in di- and trisubstituted alkylphenylnitrosoureas. An SCE study in Chinese hamster V79-E cells.

Science.gov (United States)

Thust, R; Mendel, J; Bach, B; Schwarz, H

1985-06-01

The genotoxicity of 1-methyl-3-phenyl-1-nitrosourea (MPNU), 1-methyl-3-(p-chlorophenyl)-1-nitrosourea (C1-MPNU), 1-ethyl-3-phenyl-1-nitrosourea (EPNU), 1,3-dimethyl-3-phenyl-1-nitrosourea (DMPNU) and their derivatives substituted by deuterium in different positions was studied using sister chromatid exchange (SCE) induction in Chinese hamster V79-E cells. Deuterium substitution in the 1-methyl group of MPNU (MPNU-d3) and C1-MPNU (C1-MPNU-d3) diminished the SCE-inducing capacity by 20-30% and by 30-40% in DMPNU (DMPNU-d3B). There was no altered SCE activity detected when the phenyl group of MPNU (MPNU-d5) or the 3-methyl group of DMPNU (DMPNU-d3A) was deuterium labeled. No isotope effect was detected in deuterated EPNU derivatives, presumably due to the instability of these compounds. It is surmised that the easier delocalization of the positive charge in the deuterated alkyl diazonium ion causes a diminished reactivity and therefore influences the type and amount of DNA alkylation. Furthermore, the experiments with DMPNU and its derivatives revealed that, in contrast to mono- and disubstituted nitrosoureas, the biological activities of these very stable trisubstituted nitrosoureas are strongly influenced by a serum factor in the culture fluid.

Modeling of the oxidation of methyl esters—Validation for methyl hexanoate, methyl heptanoate, and methyl decanoate in a jet-stirred reactor

Science.gov (United States)

Glaude, Pierre Alexandre; Herbinet, Olivier; Bax, Sarah; Biet, Joffrey; Warth, Valérie; Battin-Leclerc, Frédérique

2013-01-01

The modeling of the oxidation of methyl esters was investigated and the specific chemistry, which is due to the presence of the ester group in this class of molecules, is described. New reactions and rate parameters were defined and included in the software EXGAS for the automatic generation of kinetic mechanisms. Models generated with EXGAS were successfully validated against data from the literature (oxidation of methyl hexanoate and methyl heptanoate in a jet-stirred reactor) and a new set of experimental results for methyl decanoate. The oxidation of this last species was investigated in a jet-stirred reactor at temperatures from 500 to 1100 K, including the negative temperature coefficient region, under stoichiometric conditions, at a pressure of 1.06 bar and for a residence time of 1.5 s: more than 30 reaction products, including olefins, unsaturated esters, and cyclic ethers, were quantified and successfully simulated. Flow rate analysis showed that reactions pathways for the oxidation of methyl esters in the low-temperature range are similar to that of alkanes. PMID:23710076

Modeling of the oxidation of methyl esters-Validation for methyl hexanoate, methyl heptanoate, and methyl decanoate in a jet-stirred reactor.

Science.gov (United States)

Glaude, Pierre Alexandre; Herbinet, Olivier; Bax, Sarah; Biet, Joffrey; Warth, Valérie; Battin-Leclerc, Frédérique

2010-11-01

The modeling of the oxidation of methyl esters was investigated and the specific chemistry, which is due to the presence of the ester group in this class of molecules, is described. New reactions and rate parameters were defined and included in the software EXGAS for the automatic generation of kinetic mechanisms. Models generated with EXGAS were successfully validated against data from the literature (oxidation of methyl hexanoate and methyl heptanoate in a jet-stirred reactor) and a new set of experimental results for methyl decanoate. The oxidation of this last species was investigated in a jet-stirred reactor at temperatures from 500 to 1100 K, including the negative temperature coefficient region, under stoichiometric conditions, at a pressure of 1.06 bar and for a residence time of 1.5 s: more than 30 reaction products, including olefins, unsaturated esters, and cyclic ethers, were quantified and successfully simulated. Flow rate analysis showed that reactions pathways for the oxidation of methyl esters in the low-temperature range are similar to that of alkanes.

Restoration of CpG Methylation in The Egf Promoter Region during Rat Liver Regeneration

Science.gov (United States)

Deming, Li; Ziwei, Li; Xueqiang, Guo; Cunshuan, Xu

2015-01-01

Epidermal growth factor (EGF) is an important factor for healing after tissue damage in diverse experimental models. It plays an important role in liver regeneration (LR). The objective of this experiment is to investigate the methylation variation of 10 CpG sites in the Egf promoter region and their relevance to Egf expression during rat liver regenera- tion. As a follow up of our previous study, rat liver tissue was collected after rat 2/3 partial hepatectomy (PH) during the re-organization phase (from days 14 to days 28). Liver DNA was extracted and modified by sodium bisulfate. The methylation status of 10 CpG sites in Egf promoter region was determined using bisulfite sequencing polymerase chain reaction (PCR), as BSP method. The results showed that 3 (sites 3, 4 and 9) out of 10 CpG sites have strikingly methylation changes during the re-organization phase compared to the regeneration phase (from 2 hours to 168 hours, P=0.002, 0.048 and 0.018, respectively). Our results showed that methylation modification of CpGs in the Egf promoter region could be restored to the status before PH operation and changes of methylation didn’t affect Egf mRNA expression during the re-organization phase. PMID:26464832

Henry's law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol

International Nuclear Information System (INIS)

Miyano, Yoshimori; Kobashi, Takahiro; Shinjo, Hiroshi; Kumada, Shinya; Watanabe, Yusuke; Niya, Wataru; Tateishi, Yoko

2006-01-01

Henry's law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol in the temperature range of 250 K to 330 K were measured by a gas stripping method and partial molar excess enthalpies were calculated from the activity coefficients. A rigorous formula for evaluating the Henry's law constants from the gas stripping measurements was used for the data reduction of these highly volatile mixtures. The uncertainty is about 2% for the Henry's law constants and 3% for the estimated infinite dilution activity coefficients. In the evaluation of the infinite dilution activity coefficients, the nonideality of the solute such as the fugacity coefficient and Poynting correction factor cannot be neglected, especially at higher temperatures. The estimated uncertainty of the infinite dilution activity coefficients includes 1% for nonideality

Differential methylation between ethnic sub-groups reflects the effect of genetic ancestry and environmental exposures

Science.gov (United States)

Galanter, Joshua M; Gignoux, Christopher R; Oh, Sam S; Torgerson, Dara; Pino-Yanes, Maria; Thakur, Neeta; Eng, Celeste; Hu, Donglei; Huntsman, Scott; Farber, Harold J; Avila, Pedro C; Brigino-Buenaventura, Emerita; LeNoir, Michael A; Meade, Kelly; Serebrisky, Denise; Rodríguez-Cintrón, William; Kumar, Rajesh; Rodríguez-Santana, Jose R; Seibold, Max A; Borrell, Luisa N; Burchard, Esteban G; Zaitlen, Noah

2017-01-01

Populations are often divided categorically into distinct racial/ethnic groups based on social rather than biological constructs. Genetic ancestry has been suggested as an alternative to this categorization. Herein, we typed over 450,000 CpG sites in whole blood of 573 individuals of diverse Hispanic origin who also had high-density genotype data. We found that both self-identified ethnicity and genetically determined ancestry were each significantly associated with methylation levels at 916 and 194 CpGs, respectively, and that shared genomic ancestry accounted for a median of 75.7% (IQR 45.8% to 92%) of the variance in methylation associated with ethnicity. There was a significant enrichment (p=4.2×10-64) of ethnicity-associated sites amongst loci previously associated environmental exposures, particularly maternal smoking during pregnancy. We conclude that differential methylation between ethnic groups is partially explained by the shared genetic ancestry but that environmental factors not captured by ancestry significantly contribute to variation in methylation. DOI: http://dx.doi.org/10.7554/eLife.20532.001 PMID:28044981

Methylation-sensitive linking libraries enhance gene-enriched sequencing of complex genomes and map DNA methylation domains

Directory of Open Access Journals (Sweden)

Bharti Arvind K

2008-12-01

Full Text Available Abstract Background Many plant genomes are resistant to whole-genome assembly due to an abundance of repetitive sequence, leading to the development of gene-rich sequencing techniques. Two such techniques are hypomethylated partial restriction (HMPR and methylation spanning linker libraries (MSLL. These libraries differ from other gene-rich datasets in having larger insert sizes, and the MSLL clones are designed to provide reads localized to "epigenetic boundaries" where methylation begins or ends. Results A large-scale study in maize generated 40,299 HMPR sequences and 80,723 MSLL sequences, including MSLL clones exceeding 100 kb. The paired end reads of MSLL and HMPR clones were shown to be effective in linking existing gene-rich sequences into scaffolds. In addition, it was shown that the MSLL clones can be used for anchoring these scaffolds to a BAC-based physical map. The MSLL end reads effectively identified epigenetic boundaries, as indicated by their preferential alignment to regions upstream and downstream from annotated genes. The ability to precisely map long stretches of fully methylated DNA sequence is a unique outcome of MSLL analysis, and was also shown to provide evidence for errors in gene identification. MSLL clones were observed to be significantly more repeat-rich in their interiors than in their end reads, confirming the correlation between methylation and retroelement content. Both MSLL and HMPR reads were found to be substantially gene-enriched, with the SalI MSLL libraries being the most highly enriched (31% align to an EST contig, while the HMPR clones exhibited exceptional depletion of repetitive DNA (to ~11%. These two techniques were compared with other gene-enrichment methods, and shown to be complementary. Conclusion MSLL technology provides an unparalleled approach for mapping the epigenetic status of repetitive blocks and for identifying sequences mis-identified as genes. Although the types and natures of

Characterization and relative quantification of phospholipids based on methylation and stable isotopic labeling[S

Science.gov (United States)

Cai, Tanxi; Shu, Qingbo; Liu, Peibin; Niu, Lili; Guo, Xiaojing; Ding, Xiang; Xue, Peng; Xie, Zhensheng; Wang, Jifeng; Zhu, Nali; Wu, Peng; Niu, Lili; Yang, Fuquan

2016-01-01

Phospholipids (PLs), one of the lipid categories, are not only the primary building blocks of cellular membranes, but also can be split to produce products that function as second messengers in signal transduction and play a pivotal role in numerous cellular processes, including cell growth, survival, and motility. Here, we present an integrated novel method that combines a fast and robust TMS-diazomethane-based phosphate derivatization and isotopic labeling strategy, which enables simultaneous profiling and relative quantification of PLs from biological samples. Our results showed that phosphate methylation allows fast and sensitive identification of the six major PL classes, including their lysophospholipid counterparts, under positive ionization mode. The isotopic labeling of endogenous PLs was achieved by deuterated diazomethane, which was generated through acid-catalyzed hydrogen/deuterium (H/D) exchange and methanolysis of TMS-diazomethane during the process of phosphate derivatization. The measured H/D ratios of unlabeled and labeled PLs, which were mixed in known proportions, indicated that the isotopic labeling strategy is capable of providing relative quantitation with adequate accuracy, reproducibility, and a coefficient of variation of 9.1%, on average. This novel method offers unique advantages over existing approaches and presents a powerful tool for research of PL metabolism and signaling. PMID:26733148

Automated sequence- and stereo-specific assignment of methyl-labeled proteins by paramagnetic relaxation and methyl-methyl nuclear overhauser enhancement spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Venditti, Vincenzo; Fawzi, Nicolas L.; Clore, G. Marius, E-mail: mariusc@mail.nih.gov [National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Laboratory of Chemical Physics (United States)

2011-11-15

Methyl-transverse relaxation optimized spectroscopy is rapidly becoming the preferred NMR technique for probing structure and dynamics of very large proteins up to {approx}1 MDa in molecular size. Data interpretation, however, necessitates assignment of methyl groups which still presents a very challenging and time-consuming process. Here we demonstrate that, in combination with a known 3D structure, paramagnetic relaxation enhancement (PRE), induced by nitroxide spin-labels incorporated at only a few surface-exposed engineered cysteines, provides fast, straightforward and robust access to methyl group resonance assignments, including stereoassignments for the methyl groups of leucine and valine. Neither prior assignments, including backbone assignments, for the protein, nor experiments that transfer magnetization between methyl groups and the protein backbone, are required. PRE-derived assignments are refined by 4D methyl-methyl nuclear Overhauser enhancement data, eliminating ambiguities and errors that may arise due to the high sensitivity of PREs to the potential presence of sparsely-populated transient states.

Acute and chronic gregarisation are associated with distinct DNA methylation fingerprints in desert locusts.

Science.gov (United States)

Mallon, Eamonn B; Amarasinghe, Harindra E; Ott, Swidbert R

2016-10-18

Desert locusts (Schistocerca gregaria) show a dramatic form of socially induced phenotypic plasticity known as phase polyphenism. In the absence of conspecifics, locusts occur in a shy and cryptic solitarious phase. Crowding with conspecifics drives a behavioural transformation towards gregariousness that occurs within hours and is followed by changes in physiology, colouration and morphology, resulting in the full gregarious phase syndrome. We analysed methylation-sensitive amplified fragment length polymorphisms (MS-AFLP) to compare the effect of acute and chronic crowding on DNA methylation in the central nervous system. We find that crowd-reared and solitary-reared locusts show markedly different neural MS-AFLP fingerprints. However, crowding for a day resulted in neural MS-AFLP fingerprints that were clearly distinct from both crowd-reared and uncrowded solitary-reared locusts. Our results indicate that changes in DNA methylation associated with behavioural gregarisation proceed through intermediate states that are not simply partial realisations of the endpoint states.

Ion acceleration and D-D nuclear fusion in laser-generated plasma from advanced deuterated polyethylene.

Science.gov (United States)

Torrisi, Lorenzo

2014-10-23

Deuterated polyethylene targets have been irradiated by means of a 1016 W/cm2 laser using 600 J pulse energy, 1315 nm wavelength, 300 ps pulse duration and 70 micron spot diameter. The plasma parameters were measured using on-line diagnostics based on ion collectors, SiC detectors and plastic scintillators, all employed in time-of-flight configuration. In addition, a Thomson parabola spectrometer, an X-ray streak camera, and calibrated neutron dosimeter bubble detectors were employed. Characteristic protons and neutrons at maximum energies of 3.0 MeV and 2.45 MeV, respectively, were detected, confirming that energy spectra of reaction products coming from deuterium-deuterium nuclear fusion occur. In thick advanced targets a fusion rate of the order of 2 × 108 fusions per laser shot was calculated.

Methylation diet and methyl group genetics in risk for adenomatous polyp occurrence

Directory of Open Access Journals (Sweden)

Mark Lucock

2015-06-01

Conclusion: A methylation diet influences methyl group synthesis in the regulation of blood homocysteine level, and is modulated by genetic interactions. Methylation-related nutrients also interact with key genes to modify risk of AP, a precursor of colorectal cancer. Independent of diet, two methylation-related genes (A2756G-MS and A66G-MSR were directly associated with AP occurrence.

Reactions of guanine with methyl chloride and methyl bromide: O6-methylation versus charge transfer complex formation

Science.gov (United States)

Shukla, P. K.; Mishra, P. C.; Suhai, S.

Density functional theory (DFT) at the B3LYP/6-31+G* and B3LYP/AUG-cc-pVDZ levels was employed to study O6-methylation of guanine due to its reactions with methyl chloride and methyl bromide and to obtain explanation as to why the methyl halides cause genotoxicity and possess mutagenic and carcinogenic properties. Geometries of the various isolated species involved in the reactions, reactant complexes (RCs), and product complexes (PCs) were optimized in gas phase. Transition states connecting the reactant complexes with the product complexes were also optimized in gas phase at the same levels of theory. The reactant complexes, product complexes, and transition states were solvated in aqueous media using the polarizable continuum model (PCM) of the self-consistent reaction field theory. Zero-point energy (ZPE) correction to total energy and the corresponding thermal energy correction to enthalpy were made in each case. The reactant complexes of the keto form of guanine with methyl chloride and methyl bromide in water are appreciably more stable than the corresponding complexes involving the enol form of guanine. The nature of binding in the product complexes was found to be of the charge transfer type (O6mG+ · X-, X dbond Cl, Br). Binding of HCl, HBr, and H2O molecules to the PCs obtained with the keto form of guanine did not alter the positions of the halide anions in the PCs, and the charge transfer character of the PCs was also not modified due to this binding. Further, the complexes obtained due to the binding of HCl, HBr, and H2O molecules to the PCs had greater stability than the isolated PCs. The reaction barriers involved in the formation of PCs were found to be quite high (?50 kcal/mol). Mechanisms of genotoxicity, mutagenesis and carcinogenesis caused by the methyl halides appear to involve charge transfer-type complex formation. Thus the mechanisms of these processes involving the methyl halides appear to be quite different from those that involve the

Trans-methylation reactions in plants: focus on the activated methyl cycle.

Science.gov (United States)

Rahikainen, Moona; Alegre, Sara; Trotta, Andrea; Pascual, Jesús; Kangasjärvi, Saijaliisa

2018-02-01

Trans-methylation reactions are vital in basic metabolism, epigenetic regulation, RNA metabolism, and posttranslational control of protein function and therefore fundamental in determining the physiological processes in all living organisms. The plant kingdom is additionally characterized by the production of secondary metabolites that undergo specific hydroxylation, oxidation and methylation reactions to obtain a wide array of different chemical structures. Increasing research efforts have started to reveal the enzymatic pathways underlying the biosynthesis of complex metabolites in plants. Further engineering of these enzymatic machineries offers significant possibilities in the development of bio-based technologies, but necessitates deep understanding of their potential metabolic and regulatory interactions. Trans-methylation reactions are tightly coupled with the so-called activated methyl cycle (AMC), an essential metabolic circuit that maintains the trans-methylation capacity in all living cells. Tight regulation of the AMC is crucial in ensuring accurate trans-methylation reactions in different subcellular compartments, cell types, developmental stages and environmental conditions. This review addresses the organization and posttranslational regulation of the AMC and elaborates its critical role in determining metabolic regulation through modulation of methyl utilization in stress-exposed plants. © 2017 Scandinavian Plant Physiology Society.

Effects of partial hydrogenation, epoxidation, and hydroxylation on the fuel properties of fatty acid methyl esters

Energy Technology Data Exchange (ETDEWEB)

Wadumesthrige, Kapila; Salley, Steven O.; Ng, K.Y. Simon [Department of Chemical Engineering and Materials Science, Wayne State University, 5050 Anthony Wayne Drive, Detroit, MI 48202 (United States)

2009-10-15

The properties of biodiesel depend on the chemical structure of individual fatty acid methyl esters (FAME). In this work the chemical structure of fatty acid chains was modified by catalytic hydrogenation, epoxidation and hydroxylation under controlled conditions. Hydrolysis of ester functionality or oxidation of fatty acid chain was not observed during these reactions. The properties of hydrogenated FAME strongly depend on the hydrogenation time. The total saturated fatty acid (SFA) percentage increased from 29.3% to 76.2% after 2 h of hydrogenation. This hydrogenated FAME showed higher oxidation stability and higher cetane number but poor cold flow properties. Formation of trans FAME was observed during hydrogenation. Both hydroxylation and epoxidation resulted in a decrease of unsaturated fatty acid methyl ester (UFA) fraction. The percentages of total unsaturated FAME decreased 39% in the epoxidation reaction and 44% in the hydroxylation reaction. The addition of hydroxyl groups to the unsaturated regions of the fatty acid chain yields biodiesel with better cold flow properties, increased lubricity and slightly increased oxidative stability. However, epoxy FAME shows some interesting properties such as higher oxidation stability, higher cetane number and acceptable cold flow properties, which met the limits of ASTM D6751 biodiesel specifications. (author)

21 CFR 177.2000 - Vinylidene chloride/methyl acrylate/methyl methacrylate polymers.

Science.gov (United States)

2010-04-01

... methacrylate polymers. 177.2000 Section 177.2000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.2000 Vinylidene chloride/methyl acrylate/methyl methacrylate polymers. The vinylidene chloride/methyl acrylate...

Synthesis and Characterization of Novel Dimeric Ionic Liquids by Conventional Approaches

Directory of Open Access Journals (Sweden)

Yatimah Alias

2008-07-01

Full Text Available The 1H-NMR shifts of the imidazolium protons of some novel dimeric ionic liquids were examined in various deuterated solvents. Interactions between the solvent and the imidazolium salt of butyl substituted ionic liquids were observed to give higher chemical shifts than methyl substitution.

Whole-genome methylation caller designed for methyl- DNA ...

African Journals Online (AJOL)

etchie

2013-02-20

Feb 20, 2013 ... Key words: Methyl-DNA immunoprecipitation, next-generation sequencing, Hidden ... its response to environmental cues. .... have a great potential to become the most cost-effective ... hg18 reference genome (set to 0 if not present in retrieved reads). ..... DNA methylation patterns and epigenetic memory.

DNA Methylation and Methylation Polymorphism in Genetically Stable In vitro Regenerates of Jatropha curcas L. Using Methylation-Sensitive AFLP Markers.

Science.gov (United States)

Rathore, Mangal S; Jha, Bhavanath

2016-03-01

The present investigation aimed to evaluate the degree and pattern of DNA methylation using methylation-sensitive AFLP (MS-AFLP) markers in genetically stable in vitro regenerates of Jatropha curcas L.. The genetically stable in vitro regenerates were raised through direct organogenesis via enhanced axillary shoot bud proliferation (Protocol-1) and in vitro-derived leaf regeneration (Protocol-2). Ten selective combinations of MS-AFLP primers produced 462 and 477 MS-AFLP bands in Protocol-1 (P-1) and Protocol-2 (P-2) regenerates, respectively. In P-1 regenerates, 15.8-31.17 % DNA was found methylated with an average of 25.24 %. In P-2 regenerates, 15.93-32.7 % DNA was found methylated with an average of 24.11 %. Using MS-AFLP in P-1 and P-2 regenerates, 11.52-25.53 % and 13.33-25.47 % polymorphism in methylated DNA was reported, respectively. Compared to the mother plant, P-1 regenerates showed hyper-methylation while P-2 showed hypo-methylation. The results clearly indicated alternation in degree and pattern of DNA methylation; hence, epigenetic instability in the genetically stable in vitro regenerates of J. curcas, developed so far using two different regeneration systems and explants of two different origins. The homologous nucleotide fragments in genomes of P-1 and P-2 regenerates showing methylation re-patterning might be involved in immediate adaptive responses and developmental processes through differential regulation of transcriptome under in vitro conditions.

Analysis of DNA methylation in Arabidopsis thaliana based on methylation-sensitive AFLP markers.

Science.gov (United States)

Cervera, M T; Ruiz-García, L; Martínez-Zapater, J M

2002-12-01

AFLP analysis using restriction enzyme isoschizomers that differ in their sensitivity to methylation of their recognition sites has been used to analyse the methylation state of anonymous CCGG sequences in Arabidopsis thaliana. The technique was modified to improve the quality of fingerprints and to visualise larger numbers of scorable fragments. Sequencing of amplified fragments indicated that detection was generally associated with non-methylation of the cytosine to which the isoschizomer is sensitive. Comparison of EcoRI/ HpaII and EcoRI/ MspI patterns in different ecotypes revealed that 35-43% of CCGG sites were differentially digested by the isoschizomers. Interestingly, the pattern of digestion among different plants belonging to the same ecotype is highly conserved, with the rate of intra-ecotype methylation-sensitive polymorphisms being less than 1%. However, pairwise comparisons of methylation patterns between samples belonging to different ecotypes revealed differences in up to 34% of the methylation-sensitive polymorphisms. The lack of correlation between inter-ecotype similarity matrices based on methylation-insensitive or methylation-sensitive polymorphisms suggests that whatever the mechanisms regulating methylation may be, they are not related to nucleotide sequence variation.

Thermo-Mechanical Properties of Semi-Degradable Poly(β-amino ester)-co-Methyl Methacrylate Networks under Simulated Physiological Conditions

Science.gov (United States)

Safranski, David L.; Crabtree, Jacob C.; Huq, Yameen R.; Gall, Ken

2011-01-01

Poly(β-amino ester) networks are being explored for biomedical applications, but they may lack the mechanical properties necessary for long term implantation. The objective of this study is to evaluate the effect of adding methyl methacrylate on networks' mechanical properties under simulated physiological conditions. The networks were synthesized in two parts: (1) a biodegradable crosslinker was formed from a diacrylate and amine, (2) and then varying concentrations of methyl methacrylate were added prior to photopolymerizing the network. Degradation rate, mechanical properties, and glass transition temperature were studied as a function of methyl methacrylate composition. The crosslinking density played a limited role on mechanical properties for these networks, but increasing methyl methacrylate concentration improved the toughness by several orders of magnitude. Under simulated physiological conditions, networks showed increasing toughness or sustained toughness as degradation occurred. This work establishes a method of creating degradable networks with tailorable toughness while undergoing partial degradation. PMID:21966028

The global DNA methylation surrogate LINE-1 methylation is correlated with MGMT promoter methylation and is a better prognostic factor for glioma.

Directory of Open Access Journals (Sweden)

Fumiharu Ohka

Full Text Available Gliomas are the most frequently occurring primary brain tumor in the central nervous system of adults. Glioblastoma multiformes (GBMs, WHO grade 4 have a dismal prognosis despite the use of the alkylating agent, temozolomide (TMZ, and even low grade gliomas (LGGs, WHO grade 2 eventually transform to malignant secondary GBMs. Although GBM patients benefit from promoter hypermethylation of the O(6-methylguanine-DNA methyltransferase (MGMT that is the main determinant of resistance to TMZ, recent studies suggested that MGMT promoter methylation is of prognostic as well as predictive significance for the efficacy of TMZ. Glioma-CpG island methylator phenotype (G-CIMP in the global genome was shown to be a significant predictor of improved survival in patients with GBM. Collectively, we hypothesized that MGMT promoter methylation might reflect global DNA methylation. Additionally in LGGs, the significance of MGMT promoter methylation is still undetermined. In the current study, we aimed to determine the correlation between clinical, genetic, and epigenetic profiles including LINE-1 and different cancer-related genes and the clinical outcome in newly diagnosed 57 LGG and 54 GBM patients. Here, we demonstrated that (1 IDH1/2 mutation is closely correlated with MGMT promoter methylation and 1p/19q codeletion in LGGs, (2 LINE-1 methylation levels in primary and secondary GBMs are lower than those in LGGs and normal brain tissues, (3 LINE-1 methylation is proportional to MGMT promoter methylation in gliomas, and (4 higher LINE-1 methylation is a favorable prognostic factor in primary GBMs, even compared to MGMT promoter methylation. As a global DNA methylation marker, LINE-1 may be a promising marker in gliomas.

Recognition of methylated DNA through methyl-CpG binding domain proteins

DEFF Research Database (Denmark)

Zou, Xueqing; Ma, Wen; Solov'yov, Ilia

2012-01-01

DNA methylation is a key regulatory control route in epigenetics, involving gene silencing and chromosome inactivation. It has been recognized that methyl-CpG binding domain (MBD) proteins play an important role in interpreting the genetic information encoded by methylated DNA (mDNA). Although...... the function of MBD proteins has attracted considerable attention and is well characterized, the mechanism underlying mDNA recognition by MBD proteins is still poorly understood. In this article, we demonstrate that the methyl-CpG dinucleotides are recognized at the MBD-mDNA interface by two MBD arginines...

[Mifepristone inhibites the migration of endometrial cancer cells through regulating H19 methylation].

Science.gov (United States)

Lu, Z Z; Yan, L; Zhang, H; Li, M J; Zhang, X H; Zhao, X X

2016-06-23

To investigate the effect and mechanism of mifepristone on the migration of human endometrial carcinoma cells. A human endometrial carcinoma cell line, Ishikawa cells, was cultured in vitro and treated with mifepristone at different concentrations. Wound healing assay was applied to detect the migration of Ishikawa cells. RT-PCR and methylation-specific PCR (MSP) were used to detect the levels of H19 mRNA and its DNA methylation. Western-blot was used to detect the expressions of HMGA2 and epithelial to mesenchymal transition (EMT) related proteins. When treated with different concentrations of mifepristone for 48 hours, the width of scratch of the the control group, the 5 mg/L and the 10 mg/L mifepristone treatment groups were (4.18±0.07)mm, (4.68±0.07)mm, and(4.99±0.07)mm, respectively (Pendometrial carcinoma cells partially through methylation-induced of transcriptional inhibition of H19, which results in the down-regulation of HMGA2 and vimentin and upregulation of E-cadherin.

Modulation of histone methylation and MLH1 gene silencing by hexavalent chromium

International Nuclear Information System (INIS)

Sun Hong; Zhou Xue; Chen Haobin; Li Qin; Costa, Max

2009-01-01

Hexavalent chromium [Cr(VI)] is a mutagen and carcinogen, and occupational exposure can lead to lung cancers and other adverse health effects. Genetic changes resulting from DNA damage have been proposed as an important mechanism that mediates chromate's carcinogenicity. Here we show that chromate exposure of human lung A549 cells increased global levels of di- and tri-methylated histone H3 lysine 9 (H3K9) and lysine 4 (H3K4) but decreased the levels of tri-methylated histone H3 lysine 27 (H3K27) and di-methylated histone H3 arginine 2 (H3R2). Most interestingly, H3K9 dimethylation was enriched in the human MLH1 gene promoter following chromate exposure and this was correlated with decreased MLH1 mRNA expression. Chromate exposure increased the protein as well as mRNA levels of G9a a histone methyltransferase that specifically methylates H3K9. This Cr(VI)-induced increase in G9a may account for the global elevation of H3K9 dimethylation. Furthermore, supplementation with ascorbate, the primary reductant of Cr(VI) and also an essential cofactor for the histone demethylase activity, partially reversed the H3K9 dimethylation induced by chromate. Thus our studies suggest that Cr(VI) may target histone methyltransferases and demethylases, which in turn affect both global and gene promoter specific histone methylation, leading to the silencing of specific tumor suppressor genes such as MLH1.

Dynamics of solid alanine by means of nuclear magnetic resonance relaxometry

Science.gov (United States)

Kubica-Misztal, A.; Rochowski, P.; Florek-Wojciechowska, M.; Kruk, D.

2017-04-01

1H nuclear magnetic resonance relaxometry was applied to investigate the dynamics of l-alanine in the solid phase (powder). The experimental studies were carried out in a very broad frequency range, covering four orders of magnitude—from 4 kHz to 40 MHz (referring to the 1H resonance frequency) in order to probe motional processes of much different time scales by a single experiment. To get access to the dynamics of different proton groups of alanine, the 1H spin-lattice relaxation measurements were performed for non-deuterated and partially deuterated alanine. The experiments were carried out in the temperature range of 293 K-370 K (non-deuterated alanine) and 318 K-370 K (partially deuterated alanine). As a result of a thorough theoretical analysis of the extensive set of experimental results, three motional processes occurring on different time scales are identified and quantitatively described. The slowest process occurs on a time scale of μs and it is attributed to the collective dynamics of a 3D hydrogen bond network of alanine, while the intermediate, attributed to the dynamics of the NH3 group, corresponds to the range of tenths of ns. The fast process describes the rotation of the CH3 group.

A neutron powder diffraction study of deuterated α-resorcinol: a test of profile refinement using TLS constraints

International Nuclear Information System (INIS)

Bacon, G.E.; Lisher, E.J.

1979-01-01

Constrained TL, TLX and TLS refinements have been used, with the powder-profile method, in the analysis of accurate neutron powder data for deuterated α-resorcinol at room temperature. There is good agreement between the translational and librational parameters derived from the TL refinement and those obtained from an equivalent analysis of accurate single-crystal neutron measurements. The fine details of the benzene ring are lost in the powder analysis, but the molecular orientation and the OH bond angles are in good agreement with the single-crystal values. No significant improvement could be found in the powder fit by applying the full TLS theory and, therefore, the approximate TLX model appears to be adequate for powder data. (Auth.)

USAGE OF METHYL ESTER PRODUCED FROM WASTE GRAPE AND MN ADDITIVE AS ALTERNATIVE DIESEL FUEL

Directory of Open Access Journals (Sweden)

Hanbey Hazar

2017-06-01

Full Text Available In this study, methyl ester was produced from waste grape pulp sources. The produced methyl ester was mixed with diesel in different proportions, and was tested for engine performance and emission. It was found that with increasing biodiesel content, the specific fuel consumption and exhaust temperature have increased partially, while the CO, HC and smoke emissions decreased significantly. Additionally, in the scope of this study, dodecanol, propylene glycol and Mn based additives were added to fuel B50 to improve the emission and engine performance values. With the presence of additives, an increase in the exhaust temperature was observed, while a decrease in the specific fuel consumption, CO, HC, and smoke emissions were detected.

The VA and VCD spectra of various isotopomers of L-alanine in aqueous solution

DEFF Research Database (Denmark)

Abdali, Salim; Jalkanen, Karl J.; Bohr, Henrik

2002-01-01

Density functional theory (DFT) at the Becke 3LYP level has been used to calculate the vibrational absorption (VA) and vibrational circular dichroism (VCD) spectra of various deuterated species Of L-alanine. The effect of replacing the methine hydrogen, CH1, the methyl group, CH3, and both...

A genome-wide methylation study on obesity Differential variability and differential methylation

NARCIS (Netherlands)

Xu, Xiaojing; Su, Shaoyong; Barnes, Vernon A.; De Miguel, Carmen; Pollock, Jennifer; Ownby, Dennis; Shi, Huidong; Zhu, Haidong; Snieder, Harold; Wang, Xiaoling

2013-01-01

Besides differential methylation, DNA methylation variation has recently been proposed and demonstrated to be a potential contributing factor to cancer risk. Here we aim to examine whether differential variability in methylation is also an important feature of obesity, a typical non-malignant common

Maternal intake of methyl-group donors affects DNA methylation of metabolic genes in infants.

Science.gov (United States)

Pauwels, Sara; Ghosh, Manosij; Duca, Radu Corneliu; Bekaert, Bram; Freson, Kathleen; Huybrechts, Inge; Langie, Sabine A S; Koppen, Gudrun; Devlieger, Roland; Godderis, Lode

2017-01-01

Maternal nutrition during pregnancy and infant nutrition in the early postnatal period (lactation) are critically involved in the development and health of the newborn infant. The Maternal Nutrition and Offspring's Epigenome (MANOE) study was set up to assess the effect of maternal methyl-group donor intake (choline, betaine, folate, methionine) on infant DNA methylation. Maternal intake of dietary methyl-group donors was assessed using a food-frequency questionnaire (FFQ). Before and during pregnancy, we evaluated maternal methyl-group donor intake through diet and supplementation (folic acid) in relation to gene-specific ( IGF2 DMR, DNMT1 , LEP , RXRA ) buccal epithelial cell DNA methylation in 6 months old infants ( n  = 114) via pyrosequencing. In the early postnatal period, we determined the effect of maternal choline intake during lactation (in mothers who breast-fed for at least 3 months) on gene-specific buccal DNA methylation ( n  = 65). Maternal dietary and supplemental intake of methyl-group donors (folate, betaine, folic acid), only in the periconception period, was associated with buccal cell DNA methylation in genes related to growth ( IGF2 DMR), metabolism ( RXRA ), and appetite control ( LEP ). A negative association was found between maternal folate and folic acid intake before pregnancy and infant LEP (slope = -1.233, 95% CI -2.342; -0.125, p  = 0.0298) and IGF2 DMR methylation (slope = -0.706, 95% CI -1.242; -0.107, p  = 0.0101), respectively. Positive associations were observed for maternal betaine (slope = 0.875, 95% CI 0.118; 1.633, p  = 0.0241) and folate (slope = 0.685, 95% CI 0.245; 1.125, p  = 0.0027) intake before pregnancy and RXRA methylation. Buccal DNMT1 methylation in the infant was negatively associated with maternal methyl-group donor intake in the first and second trimester of pregnancy and negatively in the third trimester. We found no clear association between maternal choline intake

Spectroscopic study on deuterated benzenes. I. Microwave spectra and molecular structure in the ground state

Energy Technology Data Exchange (ETDEWEB)

Kunishige, Sachi; Katori, Toshiharu; Baba, Masaaki, E-mail: baba@kuchem.kyoto-u.ac.jp [Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Nakajima, Masakazu; Endo, Yasuki [Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan)

2015-12-28

We observed microwave absorption spectra of some deuterated benzenes and accurately determined the rotational constants of all H/D isotopomers in the ground vibrational state. Using synthetic analysis assuming that all bond angles are 120°, the mean bond lengths were obtained to be r{sub 0}(C–C) = 1.3971 Å and r{sub 0}(C–H) = r{sub 0}(C–D) = 1.0805 Å. It has been concluded that the effect of deuterium substitution on the molecular structure is negligibly small and that the mean bond lengths of C–H and C–D are identical unlike small aliphatic hydrocarbons, in which r{sub 0}(C–D) is about 5 mÅ shorter than r{sub 0}(C–H). It is considered that anharmonicity is very small in the C–H stretching vibration of aromatic hydrocarbons.

Protein methylation in pea chloroplasts

International Nuclear Information System (INIS)

Niemi, K.J.; Adler, J.; Selman, B.R.

1990-01-01

The methylation of chloroplast proteins has been investigated by incubating intact pea (Pisum sativum) chloroplasts with [ 3 H-methyl]-S-adenosylmethionine. Incubation in the light increases the amount of methylation in both the thylakoid and stromal fractions. Numerous thylakoid proteins serve as substrates for the methyltransfer reactions. Three of these thylakoid proteins are methylated to a significantly greater extent in the light than in the dark. The primary stromal polypeptide methylated is the large subunit of ribulose bisphosphate carboxylase/oxygenase. One other stromal polypeptide is also methylated much more in the light than in the dark. Two distinct types of protein methylation occur. One methylinkage is stable to basic conditions whereas a second type is base labile. The base-stable linkage is indicative of N-methylation of amino acid residues while base-lability is suggestive of carboxymethylation of amino acid residues. Labeling in the light increases the percentage of methylation that is base labile in the thylakoid fraction while no difference is observed in the amount of base-labile methylations in light-labeled and dark-labeled stromal proteins. Also suggestive of carboxymethylation is the detection of volatile [ 3 H]methyl radioactivity which increases during the labeling period and is greater in chloroplasts labeled in the light as opposed to being labeled in the dark; this implies in vivo turnover of the [ 3 H]methyl group

Retinal Biocompatibility of Brilliant Blue G with Deuterated Water for Chromovitrectomy

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Emmerson Badaró

2014-01-01

Full Text Available Purpose: To investigate the retinal biocompatibility of Brilliant Blue G with deuterated water (BBG-D2O as a vital dye for chromovitrectomy. Methods: In this animal study, 0.05 mL of 0.25 g/L Brilliant Blue G (BBG associated with 0.13 mL/mL of deuterium oxide (D2O was injected intravitreally in the right eye and the same amount of balanced salt solution (BSS was injected similarly in the left eye of rabbits. Clinical examination and histology with light microscopy were performed after seven days. Retinal cell layers were evaluated for morphologic alterations. Electroretinographic (ERG changes were also assessed at baseline and 7 days after the injections. Results: A total of 6 rabbits were included in the study. The gross histopathologic appearance of the retina, choroid, sclera and optic nerve was within normal limits without any sign of severe retinal necrosis or cystic degeneration. Light microscopy showed that BBG-D2O caused no substantial alterations in retinal layers as compared to control eyes. The injection of BBG-D2O did not induce considerable functional ERG alterations. Conclusion: Intravitreal injection of BBG-D2O 0.25 g/L seems to induce no retinal toxicity as documented by lack of functional and histological changes.

Genome-wide methylation analysis identified sexually dimorphic methylated regions in hybrid tilapia

Science.gov (United States)

Wan, Zi Yi; Xia, Jun Hong; Lin, Grace; Wang, Le; Lin, Valerie C. L.; Yue, Gen Hua

2016-01-01

Sexual dimorphism is an interesting biological phenomenon. Previous studies showed that DNA methylation might play a role in sexual dimorphism. However, the overall picture of the genome-wide methylation landscape in sexually dimorphic species remains unclear. We analyzed the DNA methylation landscape and transcriptome in hybrid tilapia (Oreochromis spp.) using whole genome bisulfite sequencing (WGBS) and RNA-sequencing (RNA-seq). We found 4,757 sexually dimorphic differentially methylated regions (DMRs), with significant clusters of DMRs located on chromosomal regions associated with sex determination. CpG methylation in promoter regions was negatively correlated with the gene expression level. MAPK/ERK pathway was upregulated in male tilapia. We also inferred active cis-regulatory regions (ACRs) in skeletal muscle tissues from WGBS datasets, revealing sexually dimorphic cis-regulatory regions. These results suggest that DNA methylation contribute to sex-specific phenotypes and serve as resources for further investigation to analyze the functions of these regions and their contributions towards sexual dimorphisms. PMID:27782217

Correlation between the structure and infra-red absorption characteristics of mono-deuterated compounds: contribution to the study of organo-magnesium compounds; Correlations entre structure et absorption infrarouge de composes monodeuteries; contribution a l'etude des composes organomagnesiens

Energy Technology Data Exchange (ETDEWEB)

Paillous, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-10-01

The high sensitivity of the {nu} (C-D) vibration to the variations brought about by the substitution of the carbon attached to the deuterium is shown in the case of organic or organo-metallic mono-deuterated molecules. In particular, syntheses of various mono-deuterated organo-magnesium compounds have been carried out; results are given concerning an infra-red spectrometric examination of these compounds in the range 2100 - 2250 cm{sup -1}. The results show the existence of only one type of deuterated carbon, which suggests that the same carbanion is involved in various ionic associations for the different magnesium-containing compounds. (authors) [French] La grande sensibilite de la vibration {nu} (C-D) aux variations apportees dans la substitution du carbone porteur du deuterium est mise en evidence pour des molecules organiques au organometalliques monodeuteriees. On a notamment realise la synthese de divers composes organomagnesiens monodeuteries; les observations auxquelles ils ont donne lieu en spectrometrie infrarouge, dons la zone 2100 - 2250 cm{sup -1}, sont rapportees; les resultats ne mettent en evidence qu'un seul type de carbone deuterie ce qui suggere I'intervention d'un meme carbanion dans des associations ioniques diverses pour les differents reactifs magnesiens. (auteur)

Transfer of human genes conferring resistance to methylating mutagens, but not to UV irradiation and cross-linking agents, into Chinese hamster ovary cells

International Nuclear Information System (INIS)

Kaina, B.; Van Zeeland, A.A.; Backendorf, C.; Thielmann, H.W.; Van de Putte, P.

1987-01-01

Chinese hamster ovary cells were transfected by human DNA ligated to the bacterial gpt (xanthine-guanine-phosphoribosyltransferase) gene which was used either in its native form or after partial inactivation with methylnitrosourea. The gpt+ transfectants were screened for resistance to high doses of N-methyl-N'-nitro-N-nitrosoguanidine. Using this approach, we showed that Chinese hamster ovary cells can acquire N-methyl-N'-nitro-N-nitrosoguanidine resistance upon transfection with DNA from diploid human fibroblasts, that this resistance is transferable by secondary transfection and is specific for methylating mutagens, and that it is not caused by increased removal of O6-methylguanine, 3-methyladenine, and 7-methylguanine from DNA

Aberrant TET1 Methylation Closely Associated with CpG Island Methylator Phenotype in Colorectal Cancer.

Science.gov (United States)

Ichimura, Norihisa; Shinjo, Keiko; An, Byonggu; Shimizu, Yasuhiro; Yamao, Kenji; Ohka, Fumiharu; Katsushima, Keisuke; Hatanaka, Akira; Tojo, Masayuki; Yamamoto, Eiichiro; Suzuki, Hiromu; Ueda, Minoru; Kondo, Yutaka

2015-08-01

Inactivation of methylcytosine dioxygenase, ten-eleven translocation (TET) is known to be associated with aberrant DNA methylation in cancers. Tumors with a CpG island methylator phenotype (CIMP), a distinct subgroup with extensive DNA methylation, show characteristic features in the case of colorectal cancer. The relationship between TET inactivation and CIMP in colorectal cancers is not well understood. The expression level of TET family genes was compared between CIMP-positive (CIMP-P) and CIMP-negative (CIMP-N) colorectal cancers. Furthermore, DNA methylation profiling, including assessment of the TET1 gene, was assessed in colorectal cancers, as well as colon polyps. The TET1 was silenced by DNA methylation in a subset of colorectal cancers as well as cell lines, expression of which was reactivated by demethylating agent. TET1 methylation was more frequent in CIMP-P (23/55, 42%) than CIMP-N (2/113, 2%, P CIMP-P, 16/40, 40%; CIMP-N, 2/24, 8%; P = 0.002), suggesting that TET1 methylation is an early event in CIMP tumorigenesis. TET1 methylation was significantly associated with BRAF mutation but not with hMLH1 methylation in the CIMP-P colorectal cancers. Colorectal cancers with TET1 methylation have a significantly greater number of DNA methylated genes and less pathological metastasis compared to those without TET1 methylation (P = 0.007 and 0.045, respectively). Our data suggest that TET1 methylation may contribute to the establishment of a unique pathway in respect to CIMP-mediated tumorigenesis, which may be incidental to hMLH1 methylation. In addition, our findings provide evidence that TET1 methylation may be a good biomarker for the prediction of metastasis in colorectal cancer. ©2015 American Association for Cancer Research.

Kinetics of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate in blood and of DEHP metabolites in urine of male volunteers after single ingestion of ring-deuterated DEHP

Energy Technology Data Exchange (ETDEWEB)

Kessler, Winfried, E-mail: kessler@helmholtz-muenchen.de [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Numtip, Wanwiwa [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Völkel, Wolfgang; Seckin, Elcim [Department of Chemical Safety and Toxicology, Bavarian Health and Food Safety Authority, Pfarrstrasse 3, D-80538 München (Germany); Csanády, György A. [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Institut für Toxikologie und Umwelthygiene, Technische Universität München, München (Germany); Pütz, Christian [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); and others

2012-10-15

The plasticizer di(2-ethylhexyl) phthalate (DEHP) is suspected to induce antiandrogenic effects in men via its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, there is only little information on the kinetic behavior of DEHP and its metabolites in humans. The toxikokinetics of DEHP was investigated in four male volunteers (28–61 y) who ingested a single dose (645 ± 20 μg/kg body weight) of ring-deuterated DEHP (DEHP-D{sub 4}). Concentrations of DEHP-D{sub 4}, of free ring-deuterated MEHP (MEHP-D{sub 4}), and the sum of free and glucuronidated MEHP-D{sub 4} were measured in blood for up to 24 h; amounts of the monoesters MEHP-D{sub 4}, ring-deuterated mono(2-ethyl-5-hydroxyhexyl) phthalate and ring-deuterated mono(2-ethyl-5-oxohexyl) phthalate were determined in urine for up to 46 h after ingestion. The bioavailability of DEHP-D{sub 4} was surprisingly high with an area under the concentration-time curve until 24 h (AUC) amounting to 50% of that of free MEHP-D{sub 4}. The AUC of free MEHP-D{sub 4} normalized to DEHP-D{sub 4} dose and body weight (AUC/D) was 2.1 and 8.1 times, that of DEHP-D{sub 4} even 50 and 100 times higher than the corresponding AUC/D values obtained earlier in rat and marmoset, respectively. Time courses of the compounds in blood and urine of the volunteers oscillated widely. Terminal elimination half-lives were short (4.3–6.6 h). Total amounts of metabolites in 22-h urine are correlated linearly with the AUC of free MEHP-D{sub 4} in blood, the parameter regarded as relevant for risk assessment. -- Highlights: ► After DEHP intake, DEHP and MEHP in blood show oscillating time courses. ► Dose-related blood levels of DEHP are 50 times higher in humans than in rats. ► Dose-related blood levels of free MEHP are 2 times higher in humans than in rats. ► Elimination of DEHP and its metabolites is short with half-lives of 4.3-6.6 h.

Evaluating genome-wide DNA methylation changes in mice by Methylation Specific Digital Karyotyping

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Maruoka Shuichiro

2008-12-01

Full Text Available Abstract Background The study of genome-wide DNA methylation changes has become more accessible with the development of various array-based technologies though when studying species other than human the choice of applications are limited and not always within reach. In this study, we adapted and tested the applicability of Methylation Specific Digital Karyotyping (MSDK, a non-array based method, for the prospective analysis of epigenetic changes after perinatal nutritional modifications in a mouse model of allergic airway disease. MSDK is a sequenced based method that allows a comprehensive and unbiased methylation profiling. The method generates 21 base pairs long sequence tags derived from specific locations in the genome. The resulting tag frequencies determine in a quantitative manner the methylation level of the corresponding loci. Results Genomic DNA from whole lung was isolated and subjected to MSDK analysis using the methylation-sensitive enzyme Not I as the mapping enzyme and Nla III as the fragmenting enzyme. In a pair wise comparison of the generated mouse MSDK libraries we identified 158 loci that are significantly differentially methylated (P-value = 0.05 after perinatal dietary changes in our mouse model. Quantitative methylation specific PCR and sequence analysis of bisulfate modified genomic DNA confirmed changes in methylation at specific loci. Differences in genomic MSDK tag counts for a selected set of genes, correlated well with changes in transcription levels as measured by real-time PCR. Furthermore serial analysis of gene expression profiling demonstrated a dramatic difference in expressed transcripts in mice exposed to perinatal nutritional changes. Conclusion The genome-wide methylation survey applied in this study allowed for an unbiased methylation profiling revealing subtle changes in DNA methylation in mice maternally exposed to dietary changes in methyl-donor content. The MSDK method is applicable for mouse models

Preparation and infrared spectra of differently deuterated tetramethyl-derivatives of the IV. main group

International Nuclear Information System (INIS)

Biedermann, S.

1972-01-01

19 different deuterated tetramethyl derivates of the type (CH 3 )sub(4-n)M(CH 3 )sub(n) of C, Si, Ge, Sn and Pb were prepared. Gas cuvettes with polyethylene, NaCl and KBr windows were used to absorb the infra-red spectra, the IR equipment Beckman IR 11 and IR 12 were used. The infra-red spectra of the above mentioned compounds were indicated from 33 to 4,000 cm -1 , the ground, upper and combination vibrations assigned, the PR separations of the partly well resolved rotation-vibration outlines determined and were compared with the calculated PR separations. The revision of the correlations performed by Graham for γsub(s)CH 3 and γsub(as)CH 3 in the race of vibration F 2 with Sn(CH 3 ) 4 and Pb(CH 3 ) 4 and the proposed one with C(CH 3 ) 4 , Si(CH 3 ) 4 and Ge(CH 3 ) 4 could be disproved by the new experimental results. (FW) [de

Intense deuterium nuclear fusion of pycnodeuterium-lumps coagulated locally within highly deuterated atom clusters

CERN Document Server

Yoshiaki, A; Zhang, Y C

2002-01-01

Embedded nano-Pd particles of 5 nm in size instantly abundant D-atoms more than 250% in the atomic ratio against Pd-atoms at room temperature when they are kept in D sub 2 gas pressurized to less than 10 atm. In such ultrahigh densities, 2-4 D-atoms can be coagulated inside each octahedral space of Pd lattice (pycnodeuterium-lump). When a stimulation energy such as latticequake causing by ultrasonic wave was supplied to those highly deuterated Pd particles, intense deuterium nuclear fusion (''solid fusion'') was generated there and both excess heat and sup 4 He gas were abundantly produced. Naturally, these facts can not be realized at all in bulk Pd. The results show that the nuclear fusion occurs without any hazardous rays in pycnodeuterium-lumps coagulated locally inside the each cell of the host metal lattice. These unit cells correspond to minimum unit of the solid fusion reactor as a ''Lattice Reactor''. (author)

Synthesis of leukotrienes labelled with deuterium: [11,12,14,15-2H4]-LTA4, -LTC4, -LTD4 and -LTE4

International Nuclear Information System (INIS)

Lellouche, J.P.; Aubert, F.; Noel, J.P.; Boullais, C.; Beaucourt, J.P.

1989-01-01

Semi-hydrogenation by D 2 gas on Lindlar catalyst of an acetylenic precursor led to [11,12,14,15- 2 H 4 ]-LTA 4 methyl ester. Nucleophilic opening of the epoxide ring by amino thioacids accorded, after saponification, the corresponding deuterated peptidoleukotrienes LTC 4 , LTD 4 and LTE 4 . (author)

Isocitrate dehydrogenase 1 and 2 genes mutations and MGMT methylation in gliomas

Directory of Open Access Journals (Sweden)

D. V. Tabakov

2017-01-01

Full Text Available Gliomas are the most common brain tumors. It is difficult to detect them at early stages of disease and there is a few available therapies providing significant improvement in survival. Mutations of isocitrate dehydrogenase 1 and 2 genes (IDH1 and IDH2 play significant role in gliomogenesis, diagnostics and selection of patient therapy. We tested the distribution of IDH1 and IDH2 mutations in gliomas of different histological types and grades of malignancy by DNA melting analysis using our protocol with a sensitivity of 5 %. The results of this assay were confirmed by conventional Sanger sequencing. IDH1/2 mutations were detected in 74 % of lower grade gliomas (II and III, World Health Organization and in 14 % of glioblastomas (IV, World Health Organization. Mutation rate in gliomas with oligodendroglioma component were significantly higher then in other glioma types (р = 0.014. The IDH1 mutations was the most common (79 % of general mutation number. IDH1/2 mutations can induce aberrant gene methylation. Detection of methylation rate of the gene encoding for O6-methylguanine-DNA-methyltransferase (MGMT, predictive biomarker for treatment of gliomas with the alkylating agents, has demonstrated a partial association with IDH1/2 mutations. In 73 % of IDH1/2-mutant tumors MGMT promoter methylation were observed. At the same time IDH1/2 mutations were not revealed in 67 % tumors with MGMT promoter methylation. These results indicate existence of another mechanism of MGMT methylation in gliomas. Our data strong support for necessity of both markers testing when patient therapy is selected.

Investigation of the utility of selective methyl protonation for determination of membrane protein structures

International Nuclear Information System (INIS)

Shih, Steve C. C.; Stoica, Ileana; Goto, Natalie K.

2008-01-01

Polytopic α-helical membrane proteins present one of the final frontiers for protein structural biology, with significant challenges causing severe under-representation in the protein structure databank. However, with the advent of hardware and methodology geared to the study of large molecular weight complexes, solution NMR is being increasingly considered as a tool for structural studies of these types of membrane proteins. One method that has the potential to facilitate these studies utilizes uniformly deuterated samples with protons reintroduced at one or two methyl groups of leucine, valine and isoleucine. In this work we demonstrate that in spite of the increased proportion of these amino acids in membrane proteins, the quality of structures that can be obtained from this strategy is similar to that obtained for all α-helical water soluble proteins. This is partly attributed to the observation that NOEs between residues within the transmembrane helix did not have an impact on structure quality. Instead the most important factors controlling structure accuracy were the strength of dihedral angle restraints imposed and the number of unique inter-helical pairs of residues constrained by NOEs. Overall these results suggest that the most accurate structures will arise from accurate identification of helical segments and utilization of inter-helical distance restraints from various sources to maximize the distribution of long-range restraints

MethylMeter(®): bisulfite-free quantitative and sensitive DNA methylation profiling and mutation detection in FFPE samples.

Science.gov (United States)

McCarthy, David; Pulverer, Walter; Weinhaeusel, Andreas; Diago, Oscar R; Hogan, Daniel J; Ostertag, Derek; Hanna, Michelle M

2016-06-01

Development of a sensitive method for DNA methylation profiling and associated mutation detection in clinical samples. Formalin-fixed and paraffin-embedded tumors received by clinical laboratories often contain insufficient DNA for analysis with bisulfite or methylation sensitive restriction enzymes-based methods. To increase sensitivity, methyl-CpG DNA capture and Coupled Abscription PCR Signaling detection were combined in a new assay, MethylMeter(®). Gliomas were analyzed for MGMT methylation, glioma CpG island methylator phenotype and IDH1 R132H. MethylMeter had 100% assay success rate measuring all five biomarkers in formalin-fixed and paraffin-embedded tissue. MGMT methylation results were supported by survival and mRNA expression data. MethylMeter is a sensitive and quantitative method for multitarget DNA methylation profiling and associated mutation detection. The MethylMeter-based GliomaSTRAT assay measures methylation of four targets and one mutation to simultaneously grade gliomas and predict their response to temozolomide. This information is clinically valuable in management of gliomas.

Role of mitochondrial dysfunction in neurotoxicity of MPP+: partial protection of PC12 cells by acetyl-L-carnitine.

Science.gov (United States)

Virmani, Ashraf; Gaetani, Franco; Binienda, Zbigniew; Xu, Alex; Duhart, Helen; Ali, Syed F

2004-10-01

The damage to the central nervous system that is observed after administration of either methamphetamine (METH) or 1-methyl-4-phenylpyridinium (MPP+), the neurotoxic metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), is known to be linked to dopamine (DA). The underlying neurotoxicity mechanism for both METH and MPP+ seem to involve free radical formation and impaired mitochondrial function. The MPP+ is thought to selectively kill nigrostriatal dopaminergic neurons by inhibiting mitochondrial complex I, with cell death being attributed to oxidative stress damage to these vulnerable DA neurons. In the present study, MPP+ was shown to significantly inhibit the response to MTT by cultured PC12 cells. This inhibitory action of MPP+ could be partially reversed by the co-incubation of the cells with the acetylated form of carnitine, acetyl-L-carnitine (ALC). Since at least part of the toxic action of MPP+ is related to mitochondrial inhibition, the partial reversal of the inhibition of MTT response by ALC could involve a partial restoration of mitochondrial function. The role carnitine derivatives, such as ALC, play in attenuating MPP+ and METH-evoked toxicity is still under investigation to elucidate the contribution of mitochondrial dysfunction in mechanisms of neurotoxicity.

Solid deuterated water in space: detection constraints from laboratory experiments

Science.gov (United States)

Urso, R. G.; Palumbo, M. E.; Baratta, G. A.; Scirè, C.; Strazzulla, G.

2018-06-01

The comparison between astronomical spectra and laboratory experiments is fundamental to spread light on the structure and composition of ices found in interstellar dense molecular clouds and in Solar System bodies. Water is among the most abundant solid-phase species observed in these environments, and several attempts have been made to investigate the presence of its solid-phase isotopologues. In particular, the detection of the O-D stretching mode band at 4.1 μm due to both D2O and HDO within icy grain mantles is still under debate, and no detection have been reported about the presence of these species within icy bodies in the Solar System yet. In the near future, an important contribution could derive from the data acquired in the O-D stretching mode spectral range by the sensitive instruments on board the James Webb Space Telescope. With this in mind, we performed several laboratory experiments to study the O-D stretching mode band in solid mixtures containing water and deuterated water deposited in the temperature range between 17 and 155 K, in order to simulate astrophysical relevant conditions. Furthermore, samples have been studied at various temperature and irradiated with energetic ions (200 keV H+) in order to study the effects induced by both thermal and energetic processing. Our results provide some constraints on the detection of the 4.1 μm band in astronomical environments.

Reactions of tritium atoms with amino acids, deuterated amino acids and mixtures of amino acids. Additivity property and isotope effect

International Nuclear Information System (INIS)

Badun, G.A.; Filatov, Eh.S.

1988-01-01

Interaction of tritium atoms with glycine (1) and leucine (2) amino acids, deuterated amino acids, their mixtures and glycylleucine (3) peptide in the 77-300 K temperature range is studied in isothermal and gradient regimes. Tagged amino acids were separated from targets after conducting the reaction. At T 150 K are associated with intermolecular transmission of free valence in the mixture of amino acids. Regularities of the reaction found for the mixture of amino acids are conserved for (3) as well, i.e. the peptide bond does not essentially affect the reaction of isotopic exchange conditioned by atomic tritium

The protection of different Italian marbles with two partially flourinated acrylic copolymers

Science.gov (United States)

Poli, T.; Toniolo, L.; Chiantore, O.

Committing stone protection to polymeric materials started in the sixties but the study and knowledge of the complex and multiple interactions between stone and polymers has only been carried out recently. It's important to note that, together with the factors related to the polymeric system itself, intrinsic properties of the stone substrate, like composition, porosity, and crystalline characteristics, play a relevant role. In this paper the issues related to protection of three different Italian marbles have been investigated: Candoglia marble, employed in the building of the Milan Cathedral, Carrara marble, widely used in sculpture and historical architecture, and S. Giuliano marble, used in the building of the Pisa Cathedral and its famous leaning tower. Specimens coming from blocks of the three quarried stones have been characterized, treated with two new partially fluorinated acrylic copolymers, 2,2,2-trifluoroethyl methacrylate/methyl acrylate (TFEMA/MA), and trifluoromethyl-2,2,2-trifluorethyl methacrylate/methyl acrylate (HFIMA/MA), and tested according to UNI-Normal Italian protocol. All the measurements including capillary water absorption, static contact angles, colour variation, water vapour permeability, and SEM morphological analysis have been carried out before and after the polymeric treatment. The aim of this work is to evaluate the protective efficacy of these two new partially fluorinated acrylic copolymers on the three different marbles, and to correlate the different behaviours with the polymers' properties and with the stone substrates characteristics.

CpG island methylator phenotype-low (CIMP-low) colorectal cancer shows not only few methylated CIMP-high-specific CpG islands, but also low-level methylation at individual loci.

Science.gov (United States)

Kawasaki, Takako; Ohnishi, Mutsuko; Nosho, Katsuhiko; Suemoto, Yuko; Kirkner, Gregory J; Meyerhardt, Jeffrey A; Fuchs, Charles S; Ogino, Shuji

2008-03-01

The CpG island methylator phenotype (CIMP or CIMP-high) with widespread promoter methylation is a distinct phenotype in colorectal cancer. However, the concept of CIMP-low with less extensive CpG island methylation is still evolving. Our aim is to examine whether density of methylation in individual CpG islands was different between CIMP-low and CIMP-high tumors. Utilizing MethyLight technology and 889 population-based colorectal cancers, we quantified DNA methylation (methylation index, percentage of methylated reference) at 14 CpG islands, including 8 CIMP-high-specific loci (CACNA1G, CDKN2A (p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3 and SOCS1). Methylation positivity in each locus was defined as methylation index>4. Low-level methylation (methylation index>0, CIMP-high-specific locus was significantly more common in 340 CIMP-low tumors (1/8-5/8 methylation-positive loci) than 133 CIMP-high tumors (> or =6/8 methylation-positive loci) and 416 CIMP-0 tumors (0/8 methylation-positive loci) (PCIMP-high, low-level methylation, was not persistently more prevalent in CIMP-low tumors. In conclusion, compared to CIMP-high and CIMP-0 tumors, CIMP-low colorectal cancers show not only few methylated CIMP-high-specific CpG islands, but also more frequent low-level methylation at individual loci. Our data may provide supporting evidence for a difference in pathogenesis of DNA methylation between CIMP-low and CIMP-high tumors.

Origin and fate of 4-methyl steroid hydrocarbons. I. Diagenesis of 4-methyl sterenes

Energy Technology Data Exchange (ETDEWEB)

Wolff, G.A.; Lamb, N.A.; Maxwell, J.R.

1986-03-01

Treatment of 4-methylcholest-4-ene under mild acid conditions at low temperatures gives chemical evidence for certain features seen in the distributions of sedimentary 4-methyl steroid hydrocarbons, and further indicates that many low temperature diagenetic reactions of steroids are explicable in terms of acid catalyzed rearrangements. Specifically, the results provide: (i) Indirect evidence that the 4-ene skeleton is a key intermediate in the dehydration of 4-methyl stanols in sediments. (ii) An explanation for the distribution of 4-methyl sterenes and A-nor sterenes in the lacustrine Messel shale (Eocene). (iii) An explanation for the presence of 4..beta..-methyl steranes in relatively immature sedimentary rocks, despite the precursor stanols having the 4..cap alpha..-methyl configuration. With increasing maturity in the Paris Basin shales (Lower Toarcian), the less stable 4..beta..-methyl steranes decrease gradually in abundance relative to their 4..cap alpha..-methyl counterparts, at a rate fairly similar to the change in pristane stereochemistry.

Analysis of DNA Cytosine Methylation Patterns Using Methylation-Sensitive Amplification Polymorphism (MSAP).

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Guevara, María Ángeles; de María, Nuria; Sáez-Laguna, Enrique; Vélez, María Dolores; Cervera, María Teresa; Cabezas, José Antonio

2017-01-01

Different molecular techniques have been developed to study either the global level of methylated cytosines or methylation at specific gene sequences. One of them is the methylation-sensitive amplified polymorphism technique (MSAP) which is a modification of amplified fragment length polymorphism (AFLP). It has been used to study methylation of anonymous CCGG sequences in different fungi, plants, and animal species. The main variation of this technique resides on the use of isoschizomers with different methylation sensitivity (such as HpaII and MspI) as a frequent-cutter restriction enzyme. For each sample, MSAP analysis is performed using both EcoRI/HpaII- and EcoRI/MspI-digested samples. A comparative analysis between EcoRI/HpaII and EcoRI/MspI fragment patterns allows the identification of two types of polymorphisms: (1) methylation-insensitive polymorphisms that show common EcoRI/HpaII and EcoRI/MspI patterns but are detected as polymorphic amplified fragments among samples and (2) methylation-sensitive polymorphisms which are associated with the amplified fragments that differ in their presence or absence or in their intensity between EcoRI/HpaII and EcoRI/MspI patterns. This chapter describes a detailed protocol of this technique and discusses the modifications that can be applied to adjust the technology to different species of interest.

Evidence for methyl group transfer between the methyl-accepting chemotaxis proteins in Bacillus subtilis

International Nuclear Information System (INIS)

Bedale, W.A.; Nettleton, D.O.; Sopata, C.S.; Thoelke, M.S.; Ordal, G.W.

1988-01-01

The authors present evidence for methyl (as methyl or methoxy) transfer from the methyl-accepting chemotaxis proteins H1 and possibly H3 of Bacillus subtilis to the methyl-accepting chemotaxis protein H2. This methyl transfer, which has been observed in vitro was strongly stimulated by the chemoattractant aspartate and thus may plan an important role in the sensory processing system of this organism. Although radiolabeling of H1 and H3 began at once after the addition of [ 3 H] methionine, radiolabeling of H2 showed a lag. Furthermore, the addition of excess nonradioactive methionine caused immediate exponential delabeling of H1 and H3 while labeling of H2 continued to increase. Methylation of H2 required the chemotactic methyltransferase, probably to first methylate H1 and H3. Aspartate caused increased labeling of H2 and strongly decreased labeling of H1 and H3 after the addition of nonradioactive methionine. Without the addition of nonradioactive methionine, aspartate caused demethylation of H1 and to a lesser extent H3, with an approximately equal increase of methylation of H2

[Analysis of genomic DNA methylation level in radish under cadmium stress by methylation-sensitive amplified polymorphism technique].

Science.gov (United States)

Yang, Jin-Lan; Liu, Li-Wang; Gong, Yi-Qin; Huang, Dan-Qiong; Wang, Feng; He, Ling-Li

2007-06-01

The level of cytosine methylation induced by cadmium in radish (Raphanus sativus L.) genome was analysed using the technique of methylation-sensitive amplified polymorphism (MSAP). The MSAP ratios in radish seedling exposed to cadmium chloride at the concentration of 50, 250 and 500 mg/L were 37%, 43% and 51%, respectively, and the control was 34%; the full methylation levels (C(m)CGG in double strands) were at 23%, 25% and 27%, respectively, while the control was 22%. The level of increase in MSAP and full methylation indicated that de novo methylation occurred in some 5'-CCGG sites under Cd stress. There was significant positive correlation between increase of total DNA methylation level and CdCl(2) concentration. Four types of MSAP patterns: de novo methylation, de-methylation, atypical pattern and no changes of methylation pattern were identified among CdCl(2) treatments and the control. DNA methylation alteration in plants treated with CdCl(2) was mainly through de novo methylation.

Quantitative analysis of deuterium using the isotopic effect on quaternary {sup 13}C NMR chemical shifts

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Darwish, Tamim A., E-mail: tamim.darwish@ansto.gov.au [National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Locked Bag 21, Kirrawee DC, NSW 2232 (Australia); Yepuri, Nageshwar Rao; Holden, Peter J. [National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Locked Bag 21, Kirrawee DC, NSW 2232 (Australia); James, Michael [Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168 (Australia)

2016-07-13

Quantitative analysis of specifically deuterated compounds can be achieved by a number of conventional methods, such as mass spectroscopy, or by quantifying the residual {sup 1}H NMR signals compared to signals from internal standards. However, site specific quantification using these methods becomes challenging when dealing with non-specifically or randomly deuterated compounds that are produced by metal catalyzed hydrothermal reactions in D{sub 2}O, one of the most convenient deuteration methods. In this study, deuterium-induced NMR isotope shifts of quaternary {sup 13}C resonances neighboring deuterated sites have been utilized to quantify the degree of isotope labeling of molecular sites in non-specifically deuterated molecules. By probing {sup 13}C NMR signals while decoupling both proton and deuterium nuclei, it is possible to resolve {sup 13}C resonances of the different isotopologues based on the isotopic shifts and the degree of deuteration of the carbon atoms. We demonstrate that in different isotopologues, the same quaternary carbon, neighboring partially deuterated carbon atoms, are affected to an equal extent by relaxation. Decoupling both nuclei ({sup 1}H, {sup 2}H) resolves closely separated quaternary {sup 13}C signals of the different isotopologues, and allows their accurate integration and quantification under short relaxation delays (D1 = 1 s) and hence fast accumulative spectral acquisition. We have performed a number of approaches to quantify the deuterium content at different specific sites to demonstrate a convenient and generic analysis method for use in randomly deuterated molecules, or in cases of specifically deuterated molecules where back-exchange processes may take place during work up. - Graphical abstract: The relative intensities of quaternary {sup 13}C {"1H,"2H} resonances are equal despite the different relaxation delays, allowing the relative abundance of the different deuterated isotopologues to be calculated using NMR fast

Reaction products from N-methyl-N-nitrosourea and deoxyribonucleic acid containing thymidine residues. Synthesis and identification of a new methylation product, O4-methyl-thymidine

Science.gov (United States)

Lawley, P. D.; Orr, D. J.; Shah, S. A.; Farmer, P. B.; Jarman, M.

1973-01-01

1. DNA was treated with N-methyl-N-nitrosourea at pH7–8, 37°C, degraded to yield 3- and 7-methylpurines and deoxyribonucleosides and the reaction products were separated by chromatography on ion-exchange resins. The following methods for identification and determination of products were used: with unlabelled N-methyl-N-nitrosourea, u.v. absorption; use of methyl-14C-labelled N-methyl-N-nitrosourea and use of [14C]thymine-labelled DNA. 2. The synthesis of O4-methylthymidine and its identification by u.v. and mass spectroscopy are reported. 3. 3-Methylthymidine and O4-methylthymidine were found as methylation products from N-methyl-N-nitrosourea with thymidine and with DNA, in relatively small yields. Unidentified products containing thymine were found in enzymic digests of N-methyl-N-nitrosourea-treated DNA, which may be phosphotriesters. 4. The possible role of formation of methylthymines in mutagenesis by N-methyl-N-nitrosourea is discussed. PMID:4798180

Methylation profiles of thirty four promoter-CpG islands and concordant methylation behaviours of sixteen genes that may contribute to carcinogenesis of astrocytoma

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Wang Yifei

2004-09-01

Full Text Available Abstract Background Astrocytoma is a common aggressive intracranial tumor and presents a formidable challenge in the clinic. Association of altered DNA methylation patterns of the promoter CpG islands with the expression profile of cancer-related genes, has been found in many human tumors. Therefore, DNA methylation status as such may serve as an epigenetic biomarker for both diagnosis and prognosis of human tumors, including astrocytoma. Methods We used the methylation specific PCR in conjunction with sequencing verification to establish the methylation profile of the promoter CpG island of thirty four genes in astrocytoma tissues from fifty three patients (The WHO grading:. I: 14, II: 15, III: 12 and IV: 12 cases, respectively. In addition, compatible tissues (normal tissues distant from lesion from three non-astrocytoma patients were included as the control. Results Seventeen genes (ABL, APC, APAF1, BRCA1, CSPG2, DAPK1, hMLH1, LKB1, PTEN, p14ARF, p15INK4b, p27KIP1, p57KIP2, RASSF1C, RB1, SURVIVIN, and VHL displayed a uniformly unmethylated pattern in all the astrocytoma and non-astrocytoma tissues examined. However, the MAGEA1 gene that was inactivated and hypermethylated in non-astrocytoma tissues, was partially demethylated in 24.5% of the astrocytoma tissues (co-existence of the hypermethylated and demethylated alleles. Of the astrocytoma associated hypermethylated genes, the methylation pattern of the CDH13, cyclin a1, DBCCR1, EPO, MYOD1, and p16INK4a genes changed in no more than 5.66% (3/53 of astrocytoma tissues compared to non-astrocytoma controls, while the RASSF1A, p73, AR, MGMT, CDH1, OCT6,, MT1A, WT1, and IRF7 genes were more frequently hypermethylated in 69.8%, 47.2%, 41.5%, 35.8%, 32%, 30.2%, 30.2%, 30.2% and 26.4% of astrocytoma tissues, respectively. Demethylation mediated inducible expression of the CDH13, MAGEA1, MGMT, p73 and RASSF1A genes was established in an astrocytoma cell line (U251, demonstrating that expression of

Effect of reaction conditions on methyl red degradation mediated by boron and nitrogen doped TiO2

International Nuclear Information System (INIS)

Galenda, A.; Crociani, L.; Habra, N. El; Favaro, M.; Natile, M.M.; Rossetto, G.

2014-01-01

Highlights: • Boron and/or nitrogen-doped TiO 2 for photocatalytic wastewater treatment. • Methyl red degradation/mineralisation as a function of pH, acids and dopants. • Adsorption time influence on photocatalytic process. • Recovery of worn-out catalyst. - Abstract: Nowadays the employment of renewable and sustainable energy sources, and solar light as main option, becomes an urgent need. Photocatalytic processes received great attention in wastewater treatment due to their cheapness, environmental compatibility and optimal performances. Despite the general low selectivity of the photocatalysts, an accurate optimisation of the operational parameters needs to be carried out in order to maximise the process yield. Because of this reason, the present contribution aims to deepen either the knowledge in boron and/or nitrogen doped TiO 2 -based systems and their employment in methyl red removal from aqueous solutions. The samples were obtained by coprecipitation and characterised by XRD, SEM, BET specific surface area, UV–vis and XPS techniques. The catalytic activity was for the first time carefully evaluated with respect to methyl red photodegradation in different conditions as a function of working pH, counter-ions and pre-adsorption time. An ad-hoc study was performed on the importance of the pre-adsorption of the dye, suggesting that an extended adsorption is useless for the catalyst photoactivity, while a partial coverage is preferable. The photocatalytic tests demonstrate the positive influence of boron doping in photo-activated reactions and the great importance of the operational parameters with respect to the simple methyl red bleaching rather than the overall pollutant mineralisation. It is proved, indeed, that different working pH, acidifying means and substrate pre-adsorption time can enhance or limit the catalyst performances with respect to the complete pollutant degradation rather than its partial breakage

Application of the deuterated retinol dilution technique to detect changes in hepatic retinol reserves in infants who receive high dose vitamin A supplements

International Nuclear Information System (INIS)

Penny, M.; Lanata, C.; Butron, B.; Haskell, M.; Brown, K.

1997-01-01

The purpose of this pilot study is to determine whether the deuterated retinol dilution technique can detect changes in hepatic vitamin A reserves in Peruvian infants in response to supplementation with vitamin A palmitate. Approximately 40 infants, 9 months of age, will be recruited for the study and randomly assigned to four treatment groups. Hepatic vitamin A reserves will be estimated using the deuterated retinol dilution technique before and after administration of a single supplement containing either 0, 7.5, 15, or 30 mg RE as retinyl palmitate in corn oil. Mean hepatic vitamin A reserves will be calculated based on the plasma isotopic ratio of d4-retinol:retinol as per Furr, et. al. Hepatic vitamin A reserves will be compared within groups before and after supplementation, and among the four groups. The mean change in hepatic vitamin A reserves across the four treatment groups will be examined in relation to the amount of vitamin A supplement administered, using regression analysis. The results of the pilot study will provide information on the size and variation of hepatic vitamin A reserves in 9-month old Peruvian infants. This information will be useful for calculating samples sizes to evaluate vitamin A intervention strategies by estimating changes in hepatic vitamin A stores in this age group, using the DRD technique. (author)

Application of the deuterated retinol dilution technique to detect changes in hepatic retinol reserves in infants who receive high dose vitamin A supplements

Energy Technology Data Exchange (ETDEWEB)

Penny, M; Lanata, C; Butron, B [Instituto de Investigacion Nutricional, Lima (Peru); Haskell, M; Brown, K [Programme in International Nutrition, Univ. of California, Davis, CA (United States)

1998-12-31

The purpose of this pilot study is to determine whether the deuterated retinol dilution technique can detect changes in hepatic vitamin A reserves in Peruvian infants in response to supplementation with vitamin A palmitate. Approximately 40 infants, 9 months of age, will be recruited for the study and randomly assigned to four treatment groups. Hepatic vitamin A reserves will be estimated using the deuterated retinol dilution technique before and after administration of a single supplement containing either 0, 7.5, 15, or 30 mg RE as retinyl palmitate in corn oil. Mean hepatic vitamin A reserves will be calculated based on the plasma isotopic ratio of d4-retinol:retinol as per Furr, et. al. Hepatic vitamin A reserves will be compared within groups before and after supplementation, and among the four groups. The mean change in hepatic vitamin A reserves across the four treatment groups will be examined in relation to the amount of vitamin A supplement administered, using regression analysis. The results of the pilot study will provide information on the size and variation of hepatic vitamin A reserves in 9-month old Peruvian infants. This information will be useful for calculating samples sizes to evaluate vitamin A intervention strategies by estimating changes in hepatic vitamin A stores in this age group, using the DRD technique. (author). 12 refs, 3 figs.

Etude par spectrometrie infrarouge et Raman de la triméthyl-4,5,6 pyrimidone-2 et de son chlorhydrate. Complexation par les halogenures de potassium

Science.gov (United States)

Lautié, Alain; Picquenard, Eric; Ratovelomanana, Nicole

The i.r. Raman spectra of crystalline 4,5,6-trimethyl 2-pyrimidone and seven deuterated derivatives have been investigated between 4000 and 180 cm -1. Aqueous and CHCl 3 solutions were also examined. An assignment for intramolecular fundamentals is given, as well as a distinction between the most characteristic of each methyl group. The methylation and protonation effects are discussed. Furthermore, a 1/1 adduct of this pyrimidone and potassium halides is observed and characterized; it contains a strong NH…X - hydrogen bond.

Synthesis of [methyl-14C]crotonobetaine from DL-[methyl-14C]carnitine

International Nuclear Information System (INIS)

Loester, H.; Seim, H.

1996-01-01

The causes of carnitine deficiency syndromes are not completely understood, but decomposition of L-carnitine in vivo is likely to be involved. Carnitine is metabolized to γ-butyrobetaine, and crotonobetaine is probably an intermediate in this pathway. To validate experimentally the precursor-product relationship between the three physiologically occuring γ-betaines - L-carnitine, crotonobetaine, γ-butyrobetaine - labelling with stable or radioactive isotopes became necessary. Methyl-labelled carnitine isomers (L(-)-, D(+)- or DL-) or γ-butyrobetaine can be easily synthesized by methylation of 4-amino-3-hydroxybutyric acid isomers or 4-aminobutyric acid, respectively. Because of problems with the 4-aminocrotonic acid, we synthesized labelled crotonbetaine from labelled carnitine. Thus, DL-[methyl- 14 C]carnitine was dehydrated by reaction with concentrated sulfuric acid. After removal of the latter the products were separated and purified by ion exchange chromatography on DOWEX 50 WX8 (200 - 400 mesh) and gradient elution with hydrochloric acid. In addition to the labelled main product [methyl- 14 C]crotonobetaine (yield about 50 %), [methyl- 14 C]glycine betaine and [methyl- 14 C]acetonyl-trimethylammonium (ATMA) were formed. The end products were identified by combined thin layer chromatography/autoradiography and quantified by liquid scintillation counting. (Author)

Cord blood buffy coat DNA methylation is comparable to whole cord blood methylation.

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Dou, John; Schmidt, Rebecca J; Benke, Kelly S; Newschaffer, Craig; Hertz-Picciotto, Irva; Croen, Lisa A; Iosif, Ana-Maria; LaSalle, Janine M; Fallin, M Daniele; Bakulski, Kelly M

2018-01-01

Cord blood DNA methylation is associated with numerous health outcomes and environmental exposures. Whole cord blood DNA reflects all nucleated blood cell types, while centrifuging whole blood separates red blood cells, generating a white blood cell buffy coat. Both sample types are used in DNA methylation studies. Cell types have unique methylation patterns and processing can impact cell distributions, which may influence comparability. We evaluated differences in cell composition and DNA methylation between cord blood buffy coat and whole cord blood samples. Cord blood DNA methylation was measured with the Infinium EPIC BeadChip (Illumina) in eight individuals, each contributing buffy coat and whole blood samples. We analyzed principal components (PC) of methylation, performed hierarchical clustering, and computed correlations of mean-centered methylation between pairs. We conducted moderated t-tests on single sites and estimated cell composition. DNA methylation PCs were associated with individual (P PC1 = 1.4 × 10 -9 ; P PC2 = 2.9 × 10 -5 ; P PC3 = 3.8 × 10 -5 ; P PC4 = 4.2 × 10 -6 ; P PC5 = 9.9 × 10 -13 , P PC6 = 1.3 × 10 -11 ) and not with sample type (P PC1-6 >0.7). Samples hierarchically clustered by individual. Pearson correlations of mean-centered methylation between paired samples ranged from r = 0.66 to r = 0.87. No individual site significantly differed between buffy coat and whole cord blood when adjusting for multiple comparisons (five sites had unadjusted Pcoat and whole cord blood are much lower than inter-individual variation, demonstrating that both sample preparation types can be analytically combined and compared.

Systematic study of (d,n) reactions at Ed = 16 MeV using a deuterated scintillator array

International Nuclear Information System (INIS)

Febbraro, M.; Becchetti, F.D.; Torres-Isea, R.O.; Riggins, A.; Lawrence, C.; Howard, A.M.; Kolata, J.J.

2014-01-01

We have developed a multi-element deuterated liquid scintillator array for the study of reactions involving neutrons utilizing high-speed digital signal processing. The liquid organic scintillators exhibit good digital pulse shape discrimination (DPSD). Typical configuration involves the detectors fixed to adjustable aluminium mounts, secured to an 80/20 aluminium frame. This allows for quick and adaptable configurations to be made for varying experimental conditions including measurements over a large angular range. A systematic study of (d,n) reactions at E d = 16 MeV on 9 Be, 11 B, 13 C, 14 N, 15 N, and 19 F has been conducted from 10 to 160 degrees (lab). In addition to previously unmeasured back-angle cross sections, this data can complement existing and future ( 3 He,d) measurements as an analog to (p,γ) for astrophysics applications

Methyl methacrylate oligomerically-modified clay and its poly(methyl methacrylate) nanocomposites

International Nuclear Information System (INIS)

Zheng Xiaoxia; Jiang, David D.; Wilkie, Charles A.

2005-01-01

A methyl methacrylate oligomerically-modified clay was used to prepare poly(methyl methacrylate) clay nanocomposites by melt blending and the effect of the clay loading level on the modified clay and corresponding nanocomposite was studied. These nanocomposites were characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis and cone calorimetry. The results show a mixed intercalated/delaminated morphology with good nanodispersion. The compatibility between the methylacrylate-subsituted clay and poly(methyl methacrylate) (PMMA) are greatly improved compared to other oligomerically-modified clays

Usability of human Infinium MethylationEPIC BeadChip for mouse DNA methylation studies.

Science.gov (United States)

Needhamsen, Maria; Ewing, Ewoud; Lund, Harald; Gomez-Cabrero, David; Harris, Robert Adam; Kular, Lara; Jagodic, Maja

2017-11-15

The advent of array-based genome-wide DNA methylation methods has enabled quantitative measurement of single CpG methylation status at relatively low cost and sample input. Whereas the use of Infinium Human Methylation BeadChips has shown great utility in clinical studies, no equivalent tool is available for rodent animal samples. We examined the feasibility of using the new Infinium MethylationEPIC BeadChip for studying DNA methylation in mouse. In silico, we identified 19,420 EPIC probes (referred as mEPIC probes), which align with a unique best alignment score to the bisulfite converted reference mouse genome mm10. Further annotation revealed that 85% of mEPIC probes overlapped with mm10.refSeq genes at different genomic features including promoters (TSS1500 and TSS200), 1st exons, 5'UTRs, 3'UTRs, CpG islands, shores, shelves, open seas and FANTOM5 enhancers. Hybridization of mouse samples to Infinium Human MethylationEPIC BeadChips showed successful measurement of mEPIC probes and reproducibility between inter-array biological replicates. Finally, we demonstrated the utility of mEPIC probes for data exploration such as hierarchical clustering. Given the absence of cost and labor convenient genome-wide technologies in the murine system, our findings show that the Infinium MethylationEPIC BeadChip platform is suitable for investigation of the mouse methylome. Furthermore, we provide the "mEPICmanifest" with genomic features, available to users of Infinium Human MethylationEPIC arrays for mouse samples.

A novel method to quantify local CpG methylation density by regional methylation elongation assay on microarray

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Qiao Yingjuan

2008-01-01

Full Text Available Abstract Background DNA methylation based techniques are important tools in both clinical diagnostics and therapeutics. But most of these methods only analyze a few CpG sites in a target region. Indeed, difference of site-specific methylation may also lead to a change of methylation density in many cases, and it has been found that the density of methylation is more important than methylation of single CpG site for gene silencing. Results We have developed a novel approach for quantitative analysis of CpG methylation density on the basis of microarray-based hybridization and incorporation of Cy5-dCTP into the Cy3 labeled target DNA by using Taq DNA Polymerase on microarray. The quantification is achieved by measuring Cy5/Cy3 signal ratio which is proportional to methylation density. This methylation-sensitive technique, termed RMEAM (regional methylation elongation assay on microarray, provides several advantages over existing methods used for methylation analysis. It can determine an exact methylation density of the given region, and has potential of high throughput. We demonstrate a use of this method in determining the methylation density of the promoter region of the tumor-related gene MLH1, TERT and MGMT in colorectal carcinoma patients. Conclusion This technique allows for quantitative analysis of regional methylation density, which is the representative of all allelic methylation patterns in the sample. The results show that this technique has the characteristics of simplicity, rapidness, specificity and high-throughput.

Maternal Methyl-Group Donor Intake and Global DNA (HydroxyMethylation before and during Pregnancy

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Sara Pauwels

2016-08-01

Full Text Available It is still unclear to which extent methyl-group intake during pregnancy can affect maternal global DNA (hydroxylmethylation. Pregnancy methylation profiling and its link with methyl-group intake in a healthy population could enhance our understanding of the development of pregnancy related disorders. One hundred forty-eight women were enrolled in the MANOE (MAternal Nutrition and Offspring’s Epigenome study. Thiry-four women were enrolled before pregnancy and 116 during the first trimester of pregnancy. Global DNA (hydroxymethylation in blood using LC-MS/MS and dietary methyl-group intake (methionine, folate, betaine, and choline using a food-frequency questionnaire were estimated pre-pregnancy, during each trimester, and at delivery. Global DNA (hydroxymethylation levels were highest pre-pregnancy and at weeks 18–22 of pregnancy. We observed a positive relation between folic acid and global DNA methylation (p = 0.04 and hydroxymethylation (p = 0.04. A high intake of methionine pre-pregnancy and in the first trimester showed lower (hydroxymethylation percentage in weeks 11–13 and weeks 18–22, respectively. Choline and betaine intake in the first weeks was negatively associated with hydroxymethylation. Women with a high intake of these three methyl groups in the second and third trimester showed higher hyrdoxymethylation/methylation levels in the third trimester. To conclude, a time trend in DNA (hydroxymethylation was found and women with higher methyl-group intake showed higher methylation in the third trimester, and not in earlier phases of pregnancy.

Dietary and supplemental maternal methyl-group donor intake and cord blood DNA methylation.

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Pauwels, Sara; Ghosh, Manosij; Duca, Radu Corneliu; Bekaert, Bram; Freson, Kathleen; Huybrechts, Inge; A S Langie, Sabine; Koppen, Gudrun; Devlieger, Roland; Godderis, Lode

2017-01-02

Maternal nutrition is critically involved in the development and health of the fetus. We evaluated maternal methyl-group donor intake through diet (methionine, betaine, choline, folate) and supplementation (folic acid) before and during pregnancy in relation to global DNA methylation and hydroxymethylation and gene specific (IGF2 DMR, DNMT1, LEP, RXRA) cord blood methylation. A total of 115 mother-infant pairs were enrolled in the MAternal Nutrition and Offspring's Epigenome (MANOE) study. The intake of methyl-group donors was assessed using a food-frequency questionnaire. LC-MS/MS and pyrosequencing were used to measure global and gene specific methylation, respectively. Dietary intake of methyl-groups before and during pregnancy was associated with changes in LEP, DNMT1, and RXRA cord blood methylation. Statistically significant higher cord blood LEP methylation was observed when mothers started folic acid supplementation more than 6 months before conception compared with 3-6 months before conception (34.6 ± 6.3% vs. 30.1 ± 3.6%, P = 0.011, LEP CpG1) or no folic acid used before conception (16.2 ± 4.4% vs. 13.9 ± 3%, P = 0.036 for LEP CpG3 and 24.5 ± 3.5% vs. 22.2 ± 3.5%, P = 0.045 for LEP mean CpG). Taking folic acid supplements during the entire pregnancy resulted in statistically significantly higher cord blood RXRA methylation as compared with stopping supplementation in the second trimester (12.3 ± 1.9% vs. 11.1 ± 2%, P = 0.008 for RXRA mean CpG). To conclude, long-term folic acid use before and during pregnancy was associated with higher LEP and RXRA cord blood methylation, respectively. To date, pregnant women are advised to take a folic acid supplement of 400 µg/day from 4 weeks before until 12 weeks of pregnancy. Our results suggest significant epigenetic modifications when taking a folic acid supplement beyond the current advice.

The mGluR5 antagonist AFQ056 does not affect methylation and transcription of the mutant FMR1 gene in vitro

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Tabolacci Elisabetta

2012-03-01

Full Text Available Abstract Background Fragile X syndrome (FXS, the leading cause of inherited mental retardation, is due to expansion and methylation of a CGG sequence in the FMR1 gene, which result in its silencing and consequent absence of FMRP protein. This absence causes loss of repression of metabotropic glutamate receptor 5 (mGluR5-mediated pathways resulting in the behavioral and cognitive impairments associated with FXS. In a randomized, double-blind trial it was recently demonstrated a beneficial effect of AFQ056, a selective inhibitor of metabotrobic glutamate receptor type 5 (mGluR5, on fully methylated FXS patients respect to partially methylated FXS ones. Methods To determine whether AFQ056 may have secondary effects on the methylation and transcription of FMR1, here we treated three FXS lymphoblastoid cell lines and one normal control male line. A quantitative RT-PCR was performed to assess transcriptional reactivation of the FMR1 gene. To assess the methylation status of the FMR1 gene promoter it was carried out a bisulphite sequencing analysis. Results Both FMR1-mRNA levels and DNA methylation were unmodified with respect to untreated controls. Conclusions These results demonstrate that the AFQ056 effect on fully methylated FXS patients is not due to a secondary effect on DNA methylation and consequent transcriptional activation of FMR1.

Detection of DNA methylation changes in micropropagated banana plants using methylation-sensitive amplification polymorphism (MSAP).

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Peraza-Echeverria, S; Herrera-Valencia, V A.; Kay, A -J.

2001-07-01

The extent of DNA methylation polymorphisms was evaluated in micropropagated banana (Musa AAA cv. 'Grand Naine') derived from either the vegetative apex of the sucker or the floral apex of the male inflorescence using the methylation-sensitive amplification polymorphism (MSAP) technique. In all, 465 fragments, each representing a recognition site cleaved by either or both of the isoschizomers were amplified using eight combinations of primers. A total of 107 sites (23%) were found to be methylated at cytosine in the genome of micropropagated banana plants. In plants micropropagated from the male inflorescence explant 14 (3%) DNA methylation events were polymorphic, while plants micropropagated from the sucker explant produced 8 (1.7%) polymorphisms. No DNA methylation polymorphisms were detected in conventionally propagated banana plants. These results demonstrated the usefulness of MSAP to detect DNA methylation events in micropropagated banana plants and indicate that DNA methylation polymorphisms are associated with micropropagation.

Methyl halide fluxes from tropical plants under controlled radiation and temperature regimes

Science.gov (United States)

Blei, Emanuel; Yokouchi, Yoko; Saito, Takuya; Nozoe, Susumu

2015-04-01

Methyl halides (CH3Cl, CH3Br, CH3I) contribute significantly to the halogen burden of the atmosphere and have the potential to influence the stratospheric ozone layer through their catalytic effect in the Chapman cycle. As such they have been studied over the years, and many plants and biota have been examined for their potential to act as a source of these gases. One of the potentially largest terrestrial sources identified was tropical vegetation such as tropical ferns and Dipterocarp trees. Most of these studies concentrated on the identification and quantification of such fluxes rather than their characteristics and often the chambers used in these studies were either opaque or only partially transparent to the full solar spectrum. Therefore it is not certain to which degree emissions of methyl halides are innate to the plants and how much they might vary due to radiation or temperature conditions inside the enclosures. In a separate development it had been proposed that UV-radiation could cause live plant materials to be become emitters of methane even under non-anoxic conditions. As methane is chemically very similar to methyl halides and had been proposed to be produced from methyl-groups ubiquitously found in plant cell material there is a relatively good chance that such a production mechanism would also apply to methyl halides. To test whether radiation can affect elevated emissions of methyl halides from plant materials and to distinguish this from temperature effects caused by heat build-up in chambers a set of controlled laboratory chamber enclosures under various radiation and temperature regimes was conducted on four different tropical plant species (Magnolia grandiflora, Cinnamonum camphora, Cyathea lepifera, Angiopteris lygodiifolia), the latter two of which had previously been identified as strong methyl halide emitters. Abscised leaf samples of these species were subjected to radiation treatments such UV-B, UV-A and broad spectrum radiation

A neutron diffraction study on deuterated Rochelle salt structure at - 195degC paraelectric phase

International Nuclear Information System (INIS)

Iwata, Yutaka; Mitani, Shigeshi; Fukui, Susumu; Shibuya, Iwao

1989-01-01

Neutron diffraction study on the low temperature paraelectric phase of Rochelle salt was performed using deuterated single crystal specimen. Large anisotropic thermal motions of atoms are found to be prevailing in the lower paraelectric phase. This indicates the disordering of atoms and the analysis by two-site split-atom method showed that a split atom model holds equally well with an ordinary non-split model. By connecting split positions selectively, a disordered paraelectric structure, which is composed of half-occupied units, was obtained. These units can be regarded as ones in the ferroelectric phase according to a deduction from an order-disorder phase transition scheme. A possibility of existence of the 'local disorder' of O(5)-H group in the tartrate molecule was examined by Fourier method and a result proved to be negative. Present disordered model gives better understanding to the phase transition scheme of Rochelle salt than the local disorder model case. (author)

DNA methylation

DEFF Research Database (Denmark)

Williams, Kristine; Christensen, Jesper; Helin, Kristian

2012-01-01

DNA methylation is involved in key cellular processes, including X-chromosome inactivation, imprinting and transcriptional silencing of specific genes and repetitive elements. DNA methylation patterns are frequently perturbed in human diseases such as imprinting disorders and cancer. The recent...... discovery that the three members of the TET protein family can convert 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) has provided a potential mechanism leading to DNA demethylation. Moreover, the demonstration that TET2 is frequently mutated in haematopoietic tumours suggests that the TET...... proteins are important regulators of cellular identity. Here, we review the current knowledge regarding the function of the TET proteins, and discuss various mechanisms by which they contribute to transcriptional control. We propose that the TET proteins have an important role in regulating DNA methylation...

Catalytic hydrodeoxygenation of methyl-substituted phenols: correlations of kinetic parameters with molecular properties.

Science.gov (United States)

Massoth, F E; Politzer, P; Concha, M C; Murray, J S; Jakowski, J; Simons, Jack

2006-07-27

The hydrodeoxygenation of methyl-substituted phenols was carried out in a flow microreactor at 300 degrees C and 2.85 MPa hydrogen pressure over a sulfided CoMo/Al(2)O(3) catalyst. The primary reaction products were methyl-substituted benzene, cyclohexene, cyclohexane, and H(2)O. Analysis of the results suggests that two independent reaction paths are operative, one leading to aromatics and the other to partially or completely hydrogenated cyclohexanes. The reaction data were analyzed using Langmuir-Hinshelwood kinetics to extract the values of the reactant-to-catalyst adsorption constant and of the rate constants characterizing the two reaction paths. The adsorption constant was found to be the same for both reactions, suggesting that a single catalytic site center is operative in both reactions. Ab initio electronic structure calculations were used to evaluate the electrostatic potentials and valence orbital ionization potentials for all of the substituted phenol reactants. Correlations were observed between (a) the adsorption constant and the two reaction rate constants measured for various methyl-substitutions and (b) certain moments of the electrostatic potentials and certain orbitals' ionization potentials of the isolated phenol molecules. On the basis of these correlations to intrinsic reactant-molecule properties, a reaction mechanism is proposed for each pathway, and it is suggested that the dependencies of adsorption and reaction rates upon methyl-group substitution are a result of the substituents' effects on the electrostatic potential and orbitals rather than geometric (steric) effects.

The origin and fate of 4-methyl steroid hydrocarbons. I. Diagenesis of 4-methyl sterenes

Science.gov (United States)

Wolff, George A.; Lamb, Neil A.; Maxwell, James R.

1986-03-01

Treatment of 4-methylcholest-4-ene under mild acid conditions at low temperatures gives chemical evidence for certain features seen in the distributions of sedimentary 4-methyl steroid hydrocarbons, and further indicates that many low temperature diagenetic reactions of steroids are explicable in terms of acid catalysed rearrangements. Specifically, the results provide: (i) Indirect evidence that the 4-ene skeleton is a key intermediate in the dehydration of 4-methyl stanols in sediments. (ii) An explanation for the distribution of 4-methyl sterenes and A-nor sterenes in the lacustrine Messel shale (Eocene). (iii) An explanation for the presence of 4β-methyl steranes in relatively immature sedimentary rocks, despite the precursor stanols having the 4α-methyl configuration. With increasing maturity in the Paris Basin shales (Lower Toarcian), the less stable 4β-methyl steranes decrease gradually in abundance relative to their 4α-methyl counterparts, at a rate fairly similar to the change in pristane stereochemistry.

A genome-wide methylation study on obesity: differential variability and differential methylation.

Science.gov (United States)

Xu, Xiaojing; Su, Shaoyong; Barnes, Vernon A; De Miguel, Carmen; Pollock, Jennifer; Ownby, Dennis; Shi, Hidong; Zhu, Haidong; Snieder, Harold; Wang, Xiaoling

2013-05-01

Besides differential methylation, DNA methylation variation has recently been proposed and demonstrated to be a potential contributing factor to cancer risk. Here we aim to examine whether differential variability in methylation is also an important feature of obesity, a typical non-malignant common complex disease. We analyzed genome-wide methylation profiles of over 470,000 CpGs in peripheral blood samples from 48 obese and 48 lean African-American youth aged 14-20 y old. A substantial number of differentially variable CpG sites (DVCs), using statistics based on variances, as well as a substantial number of differentially methylated CpG sites (DMCs), using statistics based on means, were identified. Similar to the findings in cancers, DVCs generally exhibited an outlier structure and were more variable in cases than in controls. By randomly splitting the current sample into a discovery and validation set, we observed that both the DVCs and DMCs identified from the first set could independently predict obesity status in the second set. Furthermore, both the genes harboring DMCs and the genes harboring DVCs showed significant enrichment of genes identified by genome-wide association studies on obesity and related diseases, such as hypertension, dyslipidemia, type 2 diabetes and certain types of cancers, supporting their roles in the etiology and pathogenesis of obesity. We generalized the recent finding on methylation variability in cancer research to obesity and demonstrated that differential variability is also an important feature of obesity-related methylation changes. Future studies on the epigenetics of obesity will benefit from both statistics based on means and statistics based on variances.

Correlation between the structure and infra-red absorption characteristics of mono-deuterated compounds: contribution to the study of organo-magnesium compounds; Correlations entre structure et absorption infrarouge de composes monodeuteries; contribution a l'etude des composes organomagnesiens

Energy Technology Data Exchange (ETDEWEB)

Paillous, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-10-01

The high sensitivity of the {nu} (C-D) vibration to the variations brought about by the substitution of the carbon attached to the deuterium is shown in the case of organic or organo-metallic mono-deuterated molecules. In particular, syntheses of various mono-deuterated organo-magnesium compounds have been carried out; results are given concerning an infra-red spectrometric examination of these compounds in the range 2100 - 2250 cm{sup -1}. The results show the existence of only one type of deuterated carbon, which suggests that the same carbanion is involved in various ionic associations for the different magnesium-containing compounds. (authors) [French] La grande sensibilite de la vibration {nu} (C-D) aux variations apportees dans la substitution du carbone porteur du deuterium est mise en evidence pour des molecules organiques au organometalliques monodeuteriees. On a notamment realise la synthese de divers composes organomagnesiens monodeuteries; les observations auxquelles ils ont donne lieu en spectrometrie infrarouge, dons la zone 2100 - 2250 cm{sup -1}, sont rapportees; les resultats ne mettent en evidence qu'un seul type de carbone deuterie ce qui suggere I'intervention d'un meme carbanion dans des associations ioniques diverses pour les differents reactifs magnesiens. (auteur)

Detection and discrimination of maintenance and de novo CpG methylation events using MethylBreak.

Science.gov (United States)

Hsu, William; Mercado, Augustus T; Hsiao, George; Yeh, Jui-Ming; Chen, Chung-Yung

2017-05-15

Understanding the principles governing the establishment and maintenance activities of DNA methyltransferases (DNMTs) can help in the development of predictive biomarkers associated with genetic disorders and diseases. A detection system was developed that distinguishes and quantifies methylation events using methylation-sensitive endonucleases and molecular beacon technology. MethylBreak (MB) is a 22-mer oligonucleotide with one hemimethylated and two unmethylated CpG sites, which are also recognition sites for Sau96I and SacII, and is attached to a fluorophore and a quencher. Maintenance methylation was quantified by fluorescence emission due to the digestion of SacII when the hemimethylated CpG site is methylated, which inhibits Sau96I cleavage. The signal difference between SacII digestion of both MB substrate and maintenance methylated MB corresponds to de novo methylation event. Our technology successfully discriminated and measured both methylation activities at different concentrations of MB and achieved a high correlation coefficient of R 2 =0.997. Additionally, MB was effectively applied to normal and cancer cell lines and in the analysis of enzymatic kinetics and RNA inhibition of recombinant human DNMT1. Copyright © 2017 Elsevier B.V. All rights reserved.

Mobility and molecular ions of dimethyl methyl phosphonate, methyl salicylate and acetone

Science.gov (United States)

Nowak, D. M.

1983-06-01

The mobilities of positive and negative reactant ions are reported for (H2O)nH(+); (H2O)2O2 and (H2O)2CO3(-) ion clusters. The formation of positive DMMP monomer and dimer is reported, and equilbria molecular reactions are reported. Acetone is reported as forming a dimer at 81 ppb with a reduced mobility (K sub o) of 1.82, Methyl salicylate is shown to form a protonated and hydrated positive monomer. Mixtures of DMMP and methyl salicylate with acetone showed a substantial change in DMMP ion clustering and little or no change in the methyl salicylate mobility spectra. Negative ions were not observed for DMMP, methyl salicylate, acetone and the mixtures under the conditions reported.

Evolution of DNA Methylation across Insects.

Science.gov (United States)

Bewick, Adam J; Vogel, Kevin J; Moore, Allen J; Schmitz, Robert J

2017-03-01

DNA methylation contributes to gene and transcriptional regulation in eukaryotes, and therefore has been hypothesized to facilitate the evolution of plastic traits such as sociality in insects. However, DNA methylation is sparsely studied in insects. Therefore, we documented patterns of DNA methylation across a wide diversity of insects. We predicted that underlying enzymatic machinery is concordant with patterns of DNA methylation. Finally, given the suggestion that DNA methylation facilitated social evolution in Hymenoptera, we tested the hypothesis that the DNA methylation system will be associated with presence/absence of sociality among other insect orders. We found DNA methylation to be widespread, detected in all orders examined except Diptera (flies). Whole genome bisulfite sequencing showed that orders differed in levels of DNA methylation. Hymenopteran (ants, bees, wasps and sawflies) had some of the lowest levels, including several potential losses. Blattodea (cockroaches and termites) show all possible patterns, including a potential loss of DNA methylation in a eusocial species whereas solitary species had the highest levels. Species with DNA methylation do not always possess the typical enzymatic machinery. We identified a gene duplication event in the maintenance DNA methyltransferase 1 (DNMT1) that is shared by some Hymenoptera, and paralogs have experienced divergent, nonneutral evolution. This diversity and nonneutral evolution of underlying machinery suggests alternative DNA methylation pathways may exist. Phylogenetically corrected comparisons revealed no evidence that supports evolutionary association between sociality and DNA methylation. Future functional studies will be required to advance our understanding of DNA methylation in insects. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Assessment of global and gene-specific DNA methylation in rat liver and kidney in response to non-genotoxic carcinogen exposure

Energy Technology Data Exchange (ETDEWEB)

Ozden, Sibel, E-mail: stopuz@istanbul.edu.tr [Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Istanbul University, Istanbul (Turkey); Turgut Kara, Neslihan [Department of Molecular Biology and Genetics, Faculty of Science, Istanbul University, Istanbul (Turkey); Sezerman, Osman Ugur [Department of Biostatistics and Medical Informatics, Acibadem University, Istanbul (Turkey); Durasi, İlknur Melis [Biological Sciences and Bioengineering, Faculty of Engineering and Natural Sciences, Sabancı University, Istanbul (Turkey); Chen, Tao [Department of Toxicology, School of Public Health, Soochow University, Suzhou (China); Demirel, Goksun; Alpertunga, Buket [Department of Pharmaceutical Toxicology, Faculty of Pharmacy, Istanbul University, Istanbul (Turkey); Chipman, J. Kevin [School of Biosciences, The University of Birmingham, Birmingham (United Kingdom); Mally, Angela [Department of Toxicology, University of Würzburg, Würzburg (Germany)

2015-12-01

Altered expression of tumor suppressor genes and oncogenes, which is regulated in part at the level of DNA methylation, is an important event involved in non-genotoxic carcinogenesis. This may serve as a marker for early detection of non-genotoxic carcinogens. Therefore, we evaluated the effects of non-genotoxic hepatocarcinogens, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), hexachlorobenzene (HCB), methapyrilene (MPY) and male rat kidney carcinogens, d-limonene, p-dichlorobenzene (DCB), chloroform and ochratoxin A (OTA) on global and CpG island promoter methylation in their respective target tissues in rats. No significant dose-related effects on global DNA hypomethylation were observed in tissues of rats compared to vehicle controls using LC–MS/MS in response to short-term non-genotoxic carcinogen exposure. Initial experiments investigating gene-specific methylation using methylation-specific PCR and bisulfite sequencing, revealed partial methylation of p16 in the liver of rats treated with HCB and TCDD. However, no treatment related effects on the methylation status of Cx32, e-cadherin, VHL, c-myc, Igfbp2, and p15 were observed. We therefore applied genome-wide DNA methylation analysis using methylated DNA immunoprecipitation combined with microarrays to identify alterations in gene-specific methylation. Under the conditions of our study, some genes were differentially methylated in response to MPY and TCDD, whereas d-limonene, DCB and chloroform did not induce any methylation changes. 90-day OTA treatment revealed enrichment of several categories of genes important in protein kinase activity and mTOR cell signaling process which are related to OTA nephrocarcinogenicity. - Highlights: • Studied non-genotoxic carcinogens caused no change on global DNA hypomethylation. • d-Limonene, DCB and chloroform did not show any genome-wide methylation changes. • Some genes were differentially methylated in response to MPY, TCDD and OTA. • Protein kinase activity

Assessment of global and gene-specific DNA methylation in rat liver and kidney in response to non-genotoxic carcinogen exposure

International Nuclear Information System (INIS)

Ozden, Sibel; Turgut Kara, Neslihan; Sezerman, Osman Ugur; Durasi, İlknur Melis; Chen, Tao; Demirel, Goksun; Alpertunga, Buket; Chipman, J. Kevin; Mally, Angela

2015-01-01

Altered expression of tumor suppressor genes and oncogenes, which is regulated in part at the level of DNA methylation, is an important event involved in non-genotoxic carcinogenesis. This may serve as a marker for early detection of non-genotoxic carcinogens. Therefore, we evaluated the effects of non-genotoxic hepatocarcinogens, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), hexachlorobenzene (HCB), methapyrilene (MPY) and male rat kidney carcinogens, d-limonene, p-dichlorobenzene (DCB), chloroform and ochratoxin A (OTA) on global and CpG island promoter methylation in their respective target tissues in rats. No significant dose-related effects on global DNA hypomethylation were observed in tissues of rats compared to vehicle controls using LC–MS/MS in response to short-term non-genotoxic carcinogen exposure. Initial experiments investigating gene-specific methylation using methylation-specific PCR and bisulfite sequencing, revealed partial methylation of p16 in the liver of rats treated with HCB and TCDD. However, no treatment related effects on the methylation status of Cx32, e-cadherin, VHL, c-myc, Igfbp2, and p15 were observed. We therefore applied genome-wide DNA methylation analysis using methylated DNA immunoprecipitation combined with microarrays to identify alterations in gene-specific methylation. Under the conditions of our study, some genes were differentially methylated in response to MPY and TCDD, whereas d-limonene, DCB and chloroform did not induce any methylation changes. 90-day OTA treatment revealed enrichment of several categories of genes important in protein kinase activity and mTOR cell signaling process which are related to OTA nephrocarcinogenicity. - Highlights: • Studied non-genotoxic carcinogens caused no change on global DNA hypomethylation. • d-Limonene, DCB and chloroform did not show any genome-wide methylation changes. • Some genes were differentially methylated in response to MPY, TCDD and OTA. • Protein kinase activity

An experimental study on performance and exhaust emissions of a diesel engine fuelled with tobacco seed oil methyl ester

International Nuclear Information System (INIS)

Usta, N.

2005-01-01

Tobacco seeds are a by product of tobacco leaves production. To the author's best knowledge, unlike tobacco leaves, tobacco seeds are not collected from fields and are not commercial products. However, tobacco seeds contain significant amounts of oil. Although tobacco seed oil is a non-edible vegetable oil, it can be utilized for biodiesel production as a new renewable alternative diesel engine fuel. In this study, an experimental study on the performance and exhaust emissions of a turbocharged indirect injection diesel engine fuelled with tobacco seed oil methyl ester was performed at full and partial loads. The results showed that the addition of tobacco seed oil methyl ester to the diesel fuel reduced CO and SO 2 emissions while causing slightly higher NO x emissions. Meanwhile, it was found that the power and the efficiency increased slightly with the addition of tobacco seed oil methyl ester. (Author)

Acacia senegal and Prosopis chilensis-nodulating rhizobia Sinorhizobium arboris HAMBI 2361 and S. kostiense HAMBI 2362 produce tetra- and pentameric LCOs that are N-methylated, O-6-carbamoylated and partially sulfated.

Science.gov (United States)

Nowak, Petri; Soupas, Laura; Thomas-Oates, Jane; Lindström, Kristina

2004-04-28

Sinorhizobium arboris and S. kostiense are rhizobia that nodulate the tropical leguminous trees Acacia senegal and Prosopis chilensis. The lipochito-oligosaccharidic signalling molecules (LCOs) of S. arboris HAMBI 2361 and S. kostiense HAMBI 2362 were analyzed by mass spectrometry. The major LCOs produced by the strains were shown to be pentameric, acylated with common fatty acids, N-methylated, O-6-carbamoylated and partially sulfated, as are the LCOs characterized to date for other Acacia-nodulating rhizobia. Besides the major LCOs the two strains produced (i) tetrameric LCOs, (ii) LCOs acylated with fatty acids other than those commonly found, (iii) LCOs with only an acyl substituent and (iv) noncarbamoylated LCOs. Production of LCOs (i) to (iii) are novel among Acacia-nodulating rhizobia. The roles of the different structural characteristics of LCOs in the rhizobium-A. senegal symbiosis are discussed. Specific structural features of the LCOs are proposed to be important in the selection of effective nitrogen-fixing rhizobia by A. senegal.

Conformational and tautomeric eccentricities of 2-acetyl-1,8-dihydroxynaphthalenes

DEFF Research Database (Denmark)

Hansen, Poul Erik; Kamounah, Fadhil S.; Hansen, Bjarke Knud Vilster

2007-01-01

-range hydrogen-hydrogen coupling between the OH-1 and the OH-8 and by the isotope effects on 13C caused by deuteration at the CH3C=O methyl group. Compound 2 participates in a degenerate equilibrium between two equivalent nonsymmetrical rotamers (2A and 2B) , each having two intramolecular O...HO hydrogen bonds...

Relationship between methylation status of vitamin D-related genes, vitamin D levels, and methyl-donor biochemistry

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Emma Louise Beckett

2016-12-01

Full Text Available Vitamin D is known for its role in the regulation of gene expression via the vitamin D receptor, a nuclear transcription factor. More recently, a role for vitamin D in regulating DNA methylation has been identified as an additional mechanism of modulation of gene expression. How methylation status influences vitamin D metabolism and response pathways is not yet clear. Therefore, we aimed to assess the relationship between plasma 25-hydroxycholecalciferol (25(OHD and the methylation status of vitamin D metabolism enzyme genes (CYP2R1, CYP27B1 and CYP24A1 and the vitamin D receptor gene (VDR. This analysis was conducted in the context of dietary vitamin D, and background methyl donor related biochemistry, with adjustment for several dietary and lifestyle variables. Percentage methylation at CpG sites was assessed in peripheral blood cells using methylation sensitive and dependent enzymes and qPCR. Standard analytical techniques were used to determine plasma 25(OHD and homocysteine, and serum folate and B12, with the relationship to methylation status assessed using multi-variable regression analysis. CYP2R1 and VDR methylation were found to be independent predictors of plasma 25(OHD, when adjusted for vitamin D intake and other lifestyle variables. CYP24A1 was related to plasma 25(OHD directly, but not in the context of vitamin D intake. Methyl-group donor biochemistry was associated with the methylation status of some genes, but did not alter the relationship between methylation and plasma 25(OHD. Modulation of methylation status of CYP2R1, CYP24A1 and VDR in response to plasma 25(OHD may be part of feedback loops involved in maintaining vitamin D homeostasis, and may explain a portion of the variance in plasma 25(OHD levels in response to intake and sun exposure. Methyl-group donor biochemistry, while a potential independent modulator, did not alter this effect.

Methylation screening of the TGFBI promoter in human lung and prostate cancer by methylation-specific PCR

International Nuclear Information System (INIS)

Shah, Jinesh N; Shao, Genze; Hei, Tom K; Zhao, Yongliang

2008-01-01

Hypermethylation of the TGFBI promoter has been shown to correlate with decreased expression of this gene in human tumor cell lines. In this study, we optimized a methylation-specific polymerase chain reaction (MSP) method and investigated the methylation status of the TGFBI promoter in human lung and prostate cancer specimens. Methylation-specific primers were designed based on the methylation profiles of the TGFBI promoter in human tumor cell lines, and MSP conditions were optimized for accurate and efficient amplification. Genomic DNA was isolated from lung tumors and prostatectomy tissues of prostate cancer patients, bisulfite-converted, and analyzed by MSP. Among 50 lung cancer samples, 44.0% (22/50) harbored methylated CpG sites in the TGFBI promoter. An analysis correlating gene methylation status with clinicopathological cancer features revealed that dense methylation of the TGFBI promoter was associated with a metastatic phenotype, with 42.9% (6/14) of metastatic lung cancer samples demonstrating dense methylation vs. only 5.6% (2/36) of primary lung cancer samples (p < 0.05). Similar to these lung cancer results, 82.0% (41/50) of prostate cancer samples harbored methylated CpG sites in the TGFBI promoter, and dense methylation of the promoter was present in 38.9% (7/18) of prostate cancer samples with the feature of locoregional invasiveness vs. only 19.4% (6/31) of prostate cancer samples without locoregional invasiveness (p < 0.05). Furthermore, promoter hypermethylation correlated with highly reduced expression of the TGFBI gene in human lung and prostate tumor cell lines. We successfully optimized a MSP method for the precise and efficient screening of TGFBI promoter methylation status. Dense methylation of the TGFBI promoter correlated with the extent of TGFBI gene silencing in tumor cell lines and was related to invasiveness of prostate tumors and metastatic status of lung cancer tumors. Thus, TGFBI promoter methylation can be used as a potential

Palm H-FAME Production through Partially Hydrogenation using Nickel/Carbon Catalyst to Increase Oxidation Stability

Directory of Open Access Journals (Sweden)

Ramayeni Elsa

2018-01-01

Full Text Available One of the methods to improve the oxidation stability of palm biodiesel is through partially hydrogenation. The production using Nickel/Carbon catalyst to speed up the reaction rate. Product is called Palm H-FAME (Hydrogenated FAME. Partial hydrogenation breaks the unsaturated bond on FAME (Fatty Acid Methyl Ester, which is a key component of the determination of oxidative properties. Changes in FAME composition by partial hydrogenation are predicted to change the oxidation stability so it does not cause deposits that can damage the injection system of diesel engine, pump system, and storage tank. Partial hydrogenation is carried out under operating conditions of 120 °C and 6 bar with 100:1, 100:3, 100:5, 100:10 % wt catalyst in the stirred batch autoclave reactor. H-FAME synthesis with 100:5 % wt Ni/C catalyst can decrease the iodine number which is the empirical measure of the number of unsaturated bonds from 91.78 to 82.38 (g-I2/100 g with an increase of oxidation stability from 585 to 602 minutes.

A DNA methylation microarray-based study identifies ERG as a gene commonly methylated in prostate cancer.

Science.gov (United States)

Schwartzman, Jacob; Mongoue-Tchokote, Solange; Gibbs, Angela; Gao, Lina; Corless, Christopher L; Jin, Jennifer; Zarour, Luai; Higano, Celestia; True, Lawrence D; Vessella, Robert L; Wilmot, Beth; Bottomly, Daniel; McWeeney, Shannon K; Bova, G Steven; Partin, Alan W; Mori, Motomi; Alumkal, Joshi

2011-10-01

DNA methylation of promoter regions is a common event in prostate cancer, one of the most common cancers in men worldwide. Because prior reports demonstrating that DNA methylation is important in prostate cancer studied a limited number of genes, we systematically quantified the DNA methylation status of 1505 CpG dinucleotides for 807 genes in 78 paraffin-embedded prostate cancer samples and three normal prostate samples. The ERG gene, commonly repressed in prostate cells in the absence of an oncogenic fusion to the TMPRSS2 gene, was one of the most commonly methylated genes, occurring in 74% of prostate cancer specimens. In an independent group of patient samples, we confirmed that ERG DNA methylation was common, occurring in 57% of specimens, and cancer-specific. The ERG promoter is marked by repressive chromatin marks mediated by polycomb proteins in both normal prostate cells and prostate cancer cells, which may explain ERG's predisposition to DNA methylation and the fact that tumors with ERG DNA methylation were more methylated, in general. These results demonstrate that bead arrays offer a high-throughput method to discover novel genes with promoter DNA methylation such as ERG, whose measurement may improve our ability to more accurately detect prostate cancer.

DNA methylation and memory formation.

Science.gov (United States)

Day, Jeremy J; Sweatt, J David

2010-11-01

Memory formation and storage require long-lasting changes in memory-related neuronal circuits. Recent evidence indicates that DNA methylation may serve as a contributing mechanism in memory formation and storage. These emerging findings suggest a role for an epigenetic mechanism in learning and long-term memory maintenance and raise apparent conundrums and questions. For example, it is unclear how DNA methylation might be reversed during the formation of a memory, how changes in DNA methylation alter neuronal function to promote memory formation, and how DNA methylation patterns differ between neuronal structures to enable both consolidation and storage of memories. Here we evaluate the existing evidence supporting a role for DNA methylation in memory, discuss how DNA methylation may affect genetic and neuronal function to contribute to behavior, propose several future directions for the emerging subfield of neuroepigenetics, and begin to address some of the broader implications of this work.

DNA methylation in metabolic disorders

DEFF Research Database (Denmark)

Barres, Romain; Zierath, Juleen R

2011-01-01

DNA methylation is a major epigenetic modification that controls gene expression in physiologic and pathologic states. Metabolic diseases such as diabetes and obesity are associated with profound alterations in gene expression that are caused by genetic and environmental factors. Recent reports...... have provided evidence that environmental factors at all ages could modify DNA methylation in somatic tissues, which suggests that DNA methylation is a more dynamic process than previously appreciated. Because of the importance of lifestyle factors in metabolic disorders, DNA methylation provides...... a mechanism by which environmental factors, including diet and exercise, can modify genetic predisposition to disease. This article considers the current evidence that defines a role for DNA methylation in metabolic disorders....

Histone Lysine Methylation and Neurodevelopmental Disorders

Directory of Open Access Journals (Sweden)

Jeong-Hoon Kim

2017-06-01

Full Text Available Methylation of several lysine residues of histones is a crucial mechanism for relatively long-term regulation of genomic activity. Recent molecular biological studies have demonstrated that the function of histone methylation is more diverse and complex than previously thought. Moreover, studies using newly available genomics techniques, such as exome sequencing, have identified an increasing number of histone lysine methylation-related genes as intellectual disability-associated genes, which highlights the importance of accurate control of histone methylation during neurogenesis. However, given the functional diversity and complexity of histone methylation within the cell, the study of the molecular basis of histone methylation-related neurodevelopmental disorders is currently still in its infancy. Here, we review the latest studies that revealed the pathological implications of alterations in histone methylation status in the context of various neurodevelopmental disorders and propose possible therapeutic application of epigenetic compounds regulating histone methylation status for the treatment of these diseases.

Avocado and olive oil methyl esters

International Nuclear Information System (INIS)

Knothe, Gerhard

2013-01-01

Biodiesel, the mono-alkyl esters of vegetable oils, animal fats or other triacylglycerol-containing materials and an alternative to conventional petroleum-based diesel fuel, has been derived from a variety of feedstocks. Numerous feedstocks have been investigated as potential biodiesel sources, including commodity oils, however, the methyl esters of avocado and olive oil would likely be suitable as biodiesel fuel. In order to expand the database and comprehensive evaluation of the properties of vegetable oil esters, in this work the fuel-related properties of avocado and olive oil methyl esters, which exhibit similar fatty acid profiles including high oleic acid content, are determined. The cetane numbers of avocado oil methyl esters and olive oil methyl esters are relatively high, determined as 59.2 and 62.5, respectively, due to their elevated content of methyl oleate. Other properties are well within the ranges specified in biodiesel standards. The cloud points of both esters are slightly above 0 °C due to their content of saturated esters, especially methyl palmitate. Overall, avocado and olive oil yield methyl esters with fuel properties comparable to methyl esters from other commodity vegetable oils. The 1 H and 13 C NMR spectra of avocado and olive oil methyl esters are reported. -- Highlights: • Methyl esters of avocado and olive oil meet biodiesel fuel standards. • Provides comparison for methyl esters of other vegetable oils with high oleic content. • Discusses and compares present results with prior literature

The Role of DNA Methylation in the Development and Progression of Lung Adenocarcinoma

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Keith M. Kerr

2007-01-01

Full Text Available Lung cancer, caused by smoking in ∼87% of cases, is the leading cause of cancer death in the United States and Western Europe. Adenocarcinoma is now the most common type of lung cancer in men and women in the United States, and the histological subtype most frequently seen in never-smokers and former smokers. The increasing frequency of adenocarcinoma, which occurs more peripherally in the lung, is thought to be at least partially related to modifications in cigarette manufacturing that have led to a change in the depth of smoke inhalation. The rising incidence of lung adenocarcinoma and its lethal nature underline the importance of understanding the development and progression of this disease. Alterations in DNA methylation are recognized as key epigenetic changes in cancer, contributing to chromosomal instability through global hypomethylation, and aberrant gene expression through alterations in the methylation levels at promoter CpG islands. The identification of sequential changes in DNA methylation during progression and metastasis of lung adenocarcinoma, and the elucidation of their interplay with genetic changes, will broaden our molecular understanding of this disease, providing insights that may be applicable to the development of targeted drugs, as well as powerful markers for early detection and patient classification.

Partial demethylation of oligogalacturonides by pectin methyl esterase 1 is required for eliciting defence responses in wild strawberry (Fragaria vesca).

Science.gov (United States)

Osorio, Sonia; Castillejo, Cristina; Quesada, Miguel A; Medina-Escobar, Nieves; Brownsey, Geoff J; Suau, Rafael; Heredia, Antonio; Botella, Miguel A; Valpuesta, Victoriano

2008-04-01

In addition to the role of the cell wall as a physical barrier against pathogens, some of its constituents, such as pectin-derived oligogalacturonides (OGA), are essential components for elicitation of defence responses. To investigate how modifications of pectin alter defence responses, we expressed the fruit-specific Fragaria x ananassa pectin methyl esterase FaPE1 in the wild strawberry Fragaria vesca. Pectin from transgenic ripe fruits differed from the wild-type with regard to the degree and pattern of methyl esterification, as well as the average size of pectin polymers. Purified oligogalacturonides from the transgenic fruits showed a reduced degree of esterification compared to oligogalacturonides from wild-type fruits. This reduced esterification is necessary to elicit defence responses in strawberry. The transgenic F. vesca lines had constitutively activated pathogen defence responses, resulting in higher resistance to the necrotropic fungus Botrytis cinerea. Further studies in F. vesca and Nicotiana benthamiana leaves showed that the elicitation capacity of the oligogalacturonides is more specific than previously envisaged.

Methylated site display (MSD)-AFLP, a sensitive and affordable method for analysis of CpG methylation profiles.

Science.gov (United States)

Aiba, Toshiki; Saito, Toshiyuki; Hayashi, Akiko; Sato, Shinji; Yunokawa, Harunobu; Maruyama, Toru; Fujibuchi, Wataru; Kurita, Hisaka; Tohyama, Chiharu; Ohsako, Seiichiroh

2017-03-09

It has been pointed out that environmental factors or chemicals can cause diseases that are developmental in origin. To detect abnormal epigenetic alterations in DNA methylation, convenient and cost-effective methods are required for such research, in which multiple samples are processed simultaneously. We here present methylated site display (MSD), a unique technique for the preparation of DNA libraries. By combining it with amplified fragment length polymorphism (AFLP) analysis, we developed a new method, MSD-AFLP. Methylated site display libraries consist of only DNAs derived from DNA fragments that are CpG methylated at the 5' end in the original genomic DNA sample. To test the effectiveness of this method, CpG methylation levels in liver, kidney, and hippocampal tissues of mice were compared to examine if MSD-AFLP can detect subtle differences in the levels of tissue-specific differentially methylated CpGs. As a result, many CpG sites suspected to be tissue-specific differentially methylated were detected. Nucleotide sequences adjacent to these methyl-CpG sites were identified and we determined the methylation level by methylation-sensitive restriction endonuclease (MSRE)-PCR analysis to confirm the accuracy of AFLP analysis. The differences of the methylation level among tissues were almost identical among these methods. By MSD-AFLP analysis, we detected many CpGs showing less than 5% statistically significant tissue-specific difference and less than 10% degree of variability. Additionally, MSD-AFLP analysis could be used to identify CpG methylation sites in other organisms including humans. MSD-AFLP analysis can potentially be used to measure slight changes in CpG methylation level. Regarding the remarkable precision, sensitivity, and throughput of MSD-AFLP analysis studies, this method will be advantageous in a variety of epigenetics-based research.

Unraveling Additional O-Methylation Steps in Benzylisoquinoline Alkaloid Biosynthesis in California Poppy (Eschscholzia californica).

Science.gov (United States)

Purwanto, Ratmoyo; Hori, Kentaro; Yamada, Yasuyuki; Sato, Fumihiko

2017-09-01

California poppy (Eschscholzia californica), a member of the Papaveraceae family, produces many biologically active benzylisoquinoline alkaloids (BIAs), such as sanguinarine, macarpine and chelerythrine. Sanguinarine biosynthesis has been elucidated at the molecular level, and its biosynthetic genes have been isolated and used in synthetic biology approaches to produce BIAs in vitro. However, several genes involved in the biosynthesis of macarpine and chelerythrine have not yet been characterized. In this study, we report the isolation and characterization of a novel O-methyltransferase (OMT) involved in the biosynthesis of partially characterized BIAs, especially chelerythrine. A search of the RNA sequence database from NCBI and PhytoMetaSyn for the conserved OMT domain identified 68 new OMT-like sequences, of which the longest 22 sequences were selected based on sequence similarity. Based on their expression in cell lines with different macarpine/chelerythrine profiles, we selected three OMTs (G2, G3 and G11) for further characterization. G3 expression in Escherichia coli indicated O-methylation activity of the simple benzylisoquinolines, including reticuline and norreticuline, and the protoberberine scoulerine with dual regio-reactivities. G3 produced 7-O-methylated, 3'-O-methylated and dual O-methylated products from reticuline and norreticuline, and 9-O-methylated tetrahydrocolumbamine, 2-O-methylscoulerine and tetrahydropalmatine from scoulerine. Further enzymatic analyses suggested that G3 is a scoulerine-9-O-methyltransferase for the biosynthesis of chelerythrine in California poppy. In the present study, we discuss the physiological role of G3 in BIA biosynthesis. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Effect of D2O on growth properties and chemical structure of annual ryegrass (Lolium multiflorum)

Energy Technology Data Exchange (ETDEWEB)

Evans, Barbara R [ORNL; Bali, Garima [Georgia Institute of Technology, Atlanta; Reeves, David T [ORNL; O' Neill, Hugh Michael [ORNL; Sun, Qining [Georgia Institute of Technology, Atlanta; Shah, Riddhi S [ORNL; Ragauskas, Arthur [Georgia Institute of Technology, Atlanta

2014-01-01

In present paper, we report the production and detailed structural analysis of deuterium-enriched rye grass (Lolium multiflorum) for neutron scattering experiments. An efficient method to produce deuterated biomass was developed by designing hydroponic perfusion chambers. In preliminary studies, the partial deuterated rye samples were grown in increasing levels of D2O to study the seed germination and the level of deuterium incorporation as a function of D2O concentration. Solution NMR method indicated 36.9 % deuterium incorporation in 50 % D2O grown annual rye samples and further significant increase in the deuterium incorporation level was observed by germinating the rye seedlings in H2O and growing in 50 % D2O inside the perfusion chambers. Moreover, in an effort to compare the substrate characteristics related to enzymatic hydrolysis on deuterated and protiated version of biomass, annual rye grown in 50 % D2O was selected for detailed biomass characterization studies. The compositional analyses, degree of polymerization and cellulose crystallinity were compared with its protiated control. The cellulose molecular weight indicated slight variation with deuteration; however, hemicellulose molecular weights and cellulose crystallinity remain unaffected with the deuteration. Besides the minor differences in biomass components, the development of deuterated biomass for neutron scattering application is essential to understand the complex biomass conversion processes.

Stereospecific synthesis of specifically deuterated metoprolol enantiomers from chiral starting materials

Energy Technology Data Exchange (ETDEWEB)

Shetty, H.U.; Murthy, S.S.; Nelson, W.L. (Washington Univ., Seattle, WA (USA). Dept. of Medicinal Chemistry)

1989-10-01

Enantiomers of metoprolol (1) containing six deuterium atoms in the isopropyl methyl groups ((2R)), two deuterium atoms at C-2 and C-6 of the aromatic ring ((2S)), and two deuterium atoms at C-3 of the propanolamine side chain ((2S)) were prepared. Chiral 2,2-dimethyl-1,3-dioxolane-4-methanols ((4R) and (4S)) were key synthons. Sources of deuterium were ({sup 2}H{sub 6})-isopropyl-amine, 4-(2-methoxyethyl)-2,6-({sup 2}H{sub 2})-phenol, prepared by {sup 2}HCl/{sup 2}H{sub 2}O exchange, and (4S)-2,2-dimethyl-1,3-dioxolane-4-({sup 2}H{sub 2})-4-methanol, prepared by LiAl{sup 2}H{sub 4} reduction of (4S)-methyl 2,2-dimethyl-1,3-dioxolane-4-carboxylate. Enantiomeric excess was greater than 94% for each of the prepared enantiomers, as determined independently by {sup 1}H NMR spectroscopy on diastereomeric derivatives and by chiral column HPLC. (author).

Coenzyme Q10 quantification in muscle, fibroblasts and cerebrospinal fluid by liquid chromatography/tandem mass spectrometry using a novel deuterated internal standard.

Science.gov (United States)

Duberley, Kate E C; Hargreaves, Iain P; Chaiwatanasirikul, Korn-Anong; Heales, Simon J R; Land, John M; Rahman, Shamima; Mills, Kevin; Eaton, Simon

2013-05-15

Neurological dysfunction is common in primary coenzyme Q10 (2,3-dimethoxy, 5-methyl, 6-polyisoprene parabenzoquinone; CoQ10 ; ubiquinone) deficiencies, the most readily treatable subgroup of mitochondrial disorders. Therapeutic benefit from CoQ10 supplementation has also been noted in other neurodegenerative diseases. CoQ10 can be measured by high-performance liquid chromatography (HPLC) in plasma, muscle or leucocytes; however, there is no reliable method to quantify CoQ10 in cerebrospinal fluid (CSF). Additionally, many methods use CoQ9 , an endogenous ubiquinone in humans, as an internal standard. Deuterated CoQ10 (d6 -CoQ10 ) was synthesised by a novel, simple, method. Total CoQ10 was measured by liquid chromatography/tandem mass spectrometry (LC/MS/MS) using d6 -CoQ10 as internal standard and 5 mM methylamine as an ion-pairing reagent. Chromatography was performed using a Hypsersil GOLD C4 column (150 × 3 mm, 3 µm). CoQ10 levels were linear over a concentration range of 0-200 nM (R(2) = 0.9995). The lower limit of detection was 2 nM. The inter-assay coefficient of variation (CV) was 3.6% (10 nM) and 4.3% (20 nM), and intra-assay CV 3.4% (10 nM) and 3.6% (20 nM). Reference ranges were established for CoQ10 in CSF (5.7-8.7 nM; n = 17), fibroblasts (57.0-121.6 pmol/mg; n = 50) and muscle (187.3-430.1 pmol/mg; n = 15). Use of d6 -CoQ10 internal standard has enabled the development of a sensitive LC/MS/MS method to accurately determine total CoQ10 levels. Clinical applications of CSF CoQ10 determination include identification of patients with cerebral CoQ10 deficiency, and monitoring CSF CoQ10 levels following supplementation. Copyright © 2013 John Wiley & Sons, Ltd.

Methylation-sensitive amplified polymorphism-based genome-wide analysis of cytosine methylation profiles in Nicotiana tabacum cultivars.

Science.gov (United States)

Jiao, J; Wu, J; Lv, Z; Sun, C; Gao, L; Yan, X; Cui, L; Tang, Z; Yan, B; Jia, Y

2015-11-26

This study aimed to investigate cytosine methylation profiles in different tobacco (Nicotiana tabacum) cultivars grown in China. Methylation-sensitive amplified polymorphism was used to analyze genome-wide global methylation profiles in four tobacco cultivars (Yunyan 85, NC89, K326, and Yunyan 87). Amplicons with methylated C motifs were cloned by reamplified polymerase chain reaction, sequenced, and analyzed. The results show that geographical location had a greater effect on methylation patterns in the tobacco genome than did sampling time. Analysis of the CG dinucleotide distribution in methylation-sensitive polymorphic restriction fragments suggested that a CpG dinucleotide cluster-enriched area is a possible site of cytosine methylation in the tobacco genome. The sequence alignments of the Nia1 gene (that encodes nitrate reductase) in Yunyan 87 in different regions indicate that a C-T transition might be responsible for the tobacco phenotype. T-C nucleotide replacement might also be responsible for the tobacco phenotype and may be influenced by geographical location.

Spectroscopy and intramolecular relaxation of methyl salicylate in its first excited singlet state

Science.gov (United States)

Kuper, Jerry W.; Perry, David S.

1984-05-01

High resolution fluorescence excitation experiments are reported for the blue emitting rotamer of methyl salicylate in its first excited singlet state. These experiments employ moderate expansions of methyl salicylate seeded in argon ( P0D=5-8 Torr cm) to achieve rotational and vibrational cooling in a pulsed supersonic jet. The rotational contour of the electronic origin at 30 055.3 cm-1 is shown to be consistent with a geometrically distorted π-π* excited state, partially polarized along the A axis and with a rotational temperature of 5-7 K. A noticeable broadening of the spectral features beyond the rotational contour begins at 500 cm-1 above the origin and then increases rapidly above 900 cm-1 reaching a width of 12 cm-1 near 1200 cm-1. The constancy of fluorescence decay lifetimes in this region indicate that intramolecular vibrational relaxation in the S1 manifold is the broadening mechanism.

DNA methylation in sugarcane somaclonal variants assessed through methylation-sensitive amplified polymorphism.

Science.gov (United States)

Francischini, J H M B; Kemper, E L; Costa, J B; Manechini, J R V; Pinto, L R

2017-05-04

Micropropagation is an important tool for large-scale multiplication of plant superior genotypes. However, somaclonal variation is one of the drawbacks of this process. Changes in DNA methylation have been widely reported as one of the main causes of somaclonal variations in plants. In order to investigate the occurrence of changes in the methylation pattern of sugarcane somaclonal variants, the MSAP (methylation-sensitive amplified polymorphism) technique was applied to micro-propagated plantlets sampled at the third subculture phase. The mother plant, in vitro normal plantlets, and in vitro abnormal plantlets (somaclonal variants) of four sugarcane clones were screened against 16 MSAP selective primers for EcoRI/MspI and EcoRI/HpaII restriction enzymes. A total of 1005 and 1200 MSAP-derived markers with polymorphism percentages of 28.36 and 40.67 were obtained for EcoRI/HpaII and EcoRI/MspI restriction enzyme combinations, respectively. The genetic similarity between the mother plant and the somaclonal variants ranged from 0.877 to 0.911 (EcoRI/MspI) and from 0.928 to 0.955 (EcoRI/HpaII). Most of the MASPs among mother plant and micro-propagated plantlets were derived from EcoRI/MspI restriction enzymes suggesting alteration due to gain or loss of internal cytosine methylation. A higher rate of loss of methylation (hypomethylation) than gain of methylation (hypermethylation) was observed in the abnormal in vitro sugarcane plantlets. Although changes in the methylation pattern were also observed in the in vitro normal plantlets, they were lower than those observed for the in vitro abnormal plantlets. The MASP technique proved to be a promising tool to early assessment of genetic fidelity of micro-propagated sugarcane plants.

Genome-wide methylation analysis identifies differentially methylated CpG loci associated with severe obesity in childhood.

Science.gov (United States)

Huang, R C; Garratt, E S; Pan, H; Wu, Y; Davis, E A; Barton, S J; Burdge, G C; Godfrey, K M; Holbrook, J D; Lillycrop, K A

2015-01-01

Childhood obesity is a major public health issue. Here we investigated whether differential DNA methylation was associated with childhood obesity. We studied DNA methylation profiles in whole blood from 78 obese children (mean BMI Z-score: 2.6) and 71 age- and sex-matched controls (mean BMI Z-score: 0.1). DNA samples from obese and control groups were pooled and analyzed using the Infinium HumanMethylation450 BeadChip array. Comparison of the methylation profiles between obese and control subjects revealed 129 differentially methylated CpG (DMCpG) loci associated with 80 unique genes that had a greater than 10% difference in methylation (P-value obesity were validated using sodium bisulfite pyrosequencing across loci within the FYN, PIWIL4, and TAOK3 genes in individual subjects. Three CpG loci within FYN were hypermethylated in obese individuals (all P obesity was associated with lower methylation of CpG loci within PIWIL4 (P = 0.003) and TAOK3 (P = 0.001). After building logistic regression models, we determined that a 1% increase in methylation in TAOK3, multiplicatively decreased the odds of being obese by 0.91 (95% CI: 0.86 - 0.97), and an increase of 1% methylation in FYN CpG3, multiplicatively increased the odds of being obese by 1.03 (95% CI: 0.99 - 1.07). In conclusion, these findings provide evidence that childhood obesity is associated with specific DNA methylation changes in whole blood, which may have utility as biomarkers of obesity risk.

A DFT approach to discriminate the antagonist and partial agonist activity of ligands binding to the NMDA receptor

Science.gov (United States)

Haslak, Zeynep Pinar; Bozkurt, Esra; Dutagaci, Bercem; De Proft, Frank; Aviyente, Viktorya; De Vleeschouwer, Freija

2018-02-01

The activation of N-methyl-D-aspartate receptors is found to be intimately associated with neurodegenerative diseases which make them promising therapeutic targets. Despite the significantly increasing multidisciplinary interests centred on this ionotropic channel, design of new ligands with intended functional activity remains a great challenge. In this article, a computational study based on density functional theory is presented to understand the structural factors of ligands determining their function as antagonists and partial agonists. With this aim, the GluN1 subunit is chosen as being one of the essential components in the activation mechanism, and quantum chemical calculations are implemented for 30 antagonists and 30 partial agonists known to bind to this subunit with different binding affinities. Several quantum chemical descriptors are investigated which might unlock the difference between antagonists and partial agonists.

Analysis of RET promoter CpG island methylation using methylation-specific PCR (MSP), pyrosequencing, and methylation-sensitive high-resolution melting (MS-HRM): impact on stage II colon cancer patient outcome.

Science.gov (United States)

Draht, Muriel X G; Smits, Kim M; Jooste, Valérie; Tournier, Benjamin; Vervoort, Martijn; Ramaekers, Chantal; Chapusot, Caroline; Weijenberg, Matty P; van Engeland, Manon; Melotte, Veerle

2016-01-01

Already since the 1990s, promoter CpG island methylation markers have been considered promising diagnostic, prognostic, and predictive cancer biomarkers. However, so far, only a limited number of DNA methylation markers have been introduced into clinical practice. One reason why the vast majority of methylation markers do not translate into clinical applications is lack of independent validation of methylation markers, often caused by differences in methylation analysis techniques. We recently described RET promoter CpG island methylation as a potential prognostic marker in stage II colorectal cancer (CRC) patients of two independent series. In the current study, we analyzed the RET promoter CpG island methylation of 241 stage II colon cancer patients by direct methylation-specific PCR (MSP), nested-MSP, pyrosequencing, and methylation-sensitive high-resolution melting (MS-HRM). All primers were designed as close as possible to the same genomic region. In order to investigate the effect of different DNA methylation assays on patient outcome, we assessed the clinical sensitivity and specificity as well as the association of RET methylation with overall survival for three and five years of follow-up. Using direct-MSP and nested-MSP, 12.0 % (25/209) and 29.6 % (71/240) of the patients showed RET promoter CpG island methylation. Methylation frequencies detected by pyrosequencing were related to the threshold for positivity that defined RET methylation. Methylation frequencies obtained by pyrosequencing (threshold for positivity at 20 %) and MS-HRM were 13.3 % (32/240) and 13.8 % (33/239), respectively. The pyrosequencing threshold for positivity of 20 % showed the best correlation with MS-HRM and direct-MSP results. Nested-MSP detected RET promoter CpG island methylation in deceased patients with a higher sensitivity (33.1 %) compared to direct-MSP (10.7 %), pyrosequencing (14.4 %), and MS-HRM (15.4 %). While RET methylation frequencies detected by nested

Protection against de novo methylation is instrumental in maintaining parent-of-origin methylation inherited from the gametes.

Science.gov (United States)

Proudhon, Charlotte; Duffié, Rachel; Ajjan, Sophie; Cowley, Michael; Iranzo, Julian; Carbajosa, Guillermo; Saadeh, Heba; Holland, Michelle L; Oakey, Rebecca J; Rakyan, Vardhman K; Schulz, Reiner; Bourc'his, Déborah

2012-09-28

Identifying loci with parental differences in DNA methylation is key to unraveling parent-of-origin phenotypes. By conducting a MeDIP-Seq screen in maternal-methylation free postimplantation mouse embryos (Dnmt3L-/+), we demonstrate that maternal-specific methylation exists very scarcely at midgestation. We reveal two forms of oocyte-specific methylation inheritance: limited to preimplantation, or with longer duration, i.e. maternally imprinted loci. Transient and imprinted maternal germline DMRs (gDMRs) are indistinguishable in gametes and preimplantation embryos, however, de novo methylation of paternal alleles at implantation delineates their fates and acts as a major leveling factor of parent-inherited differences. We characterize two new imprinted gDMRs, at the Cdh15 and AK008011 loci, with tissue-specific imprinting loss, again by paternal methylation gain. Protection against demethylation after fertilization has been emphasized as instrumental in maintaining parent-of-origin methylation inherited from the gametes. Here we provide evidence that protection against de novo methylation acts as an equal major pivot, at implantation and throughout life. Copyright © 2012 Elsevier Inc. All rights reserved.

Deuteron NMR (Nuclear Magnetic Resonance) in relation to the glass transition in polymers

Science.gov (United States)

Roessler, E.; Sillescu, H.; Spiess, H. W.; Wallwitz, R.

1983-01-01

H-2NMR is introduced as a tool for investigating slow molecular motion in the glass transition region of amorphous polymers. In particular, we compare H-2 spin alignment echo spectra of chain deuterated polystyrene with model calculations for restricted rotational Brownian motion. Molecular motion in the polyztyrene-toluene system has been investigated by analyzing H-2NMR of partially deuterated polystyrene and toluene, respectively. The diluent mobility in the mixed glass has been decomposed into solid and liquid components where the respective average correlation times differ by more than 5 decades.

Structure, function and carcinogenicity of metabolites of methylated and non-methylated polycyclic aromatic hydrocarbons: a comprehensive review.

Science.gov (United States)

Flesher, James W; Lehner, Andreas F

2016-01-01

The Unified Theory of PAH Carcinogenicity accommodates the activities of methylated and non-methylated polycyclic aromatic hydrocarbons (PAHs) and states that substitution of methyl groups on meso-methyl substituted PAHs with hydroxy, acetoxy, chloride, bromide or sulfuric acid ester groups imparts potent cancer producing properties. It incorporates specific predictions from past researchers on the mechanism of carcinogenesis by methyl-substituted hydrocarbons, including (1) requirement for metabolism to an ArCH2X type structure where X is a good leaving group and (2) biological substitution of a meso-methyl group at the most reactive center in non-methylated hydrocarbons. The Theory incorporates strong inferences of Fieser: (1) The mechanism of carcinogenesis involves a specific metabolic substitution of a hydrocarbon at its most reactive center and (2) Metabolic elimination of a carcinogen is a detoxifying process competitive with that of carcinogenesis and occurring by a different mechanism. According to this outlook, chemical or biochemical substitution of a methyl group at the reactive meso-position of non-methylated hydrocarbons is the first step in the mechanism of carcinogenesis for most, if not all, PAHs and the most potent metabolites of PAHs are to be found among the meso methyl-substituted hydrocarbons. Some PAHs and their known or potential metabolites and closely related compounds have been tested in rats for production of sarcomas at the site of subcutaneous injection and the results strongly support the specific predictions of the Unified Theory.

Methylated genes as new cancer biomarkers.

LENUS (Irish Health Repository)

Duffy, M J

2012-02-01

Aberrant hypermethylation of promoter regions in specific genes is a key event in the formation and progression of cancer. In at least some situations, these aberrant alterations occur early in the formation of malignancy and appear to be tumour specific. Multiple reports have suggested that measurement of the methylation status of the promoter regions of specific genes can aid early detection of cancer, determine prognosis and predict therapy responses. Promising DNA methylation biomarkers include the use of methylated GSTP1 for aiding the early diagnosis of prostate cancer, methylated PITX2 for predicting outcome in lymph node-negative breast cancer patients and methylated MGMT in predicting benefit from alkylating agents in patients with glioblastomas. However, prior to clinical utilisation, these findings require validation in prospective clinical studies. Furthermore, assays for measuring gene methylation need to be standardised, simplified and evaluated in external quality assurance programmes. It is concluded that methylated genes have the potential to provide a new generation of cancer biomarkers.

Are clinicopathological features of colorectal cancers with methylation in half of CpG island methylator phenotype panel markers different from those of CpG island methylator phenotype-high colorectal cancers?

Science.gov (United States)

Bae, Jeong Mo; Rhee, Ye-Young; Kim, Kyung Ju; Wen, Xianyu; Song, Young Seok; Cho, Nam-Yun; Kim, Jung Ho; Kang, Gyeong Hoon

2016-01-01

CpG island methylator phenotype (CIMP)-high (CIMP-H) colorectal cancer (CRC) is defined when a tumor shows methylation at greater than or equal to 60% of CIMP panel markers. Although CRCs with methylation at 50% of panel markers are classified as CIMP-low/CIMP-0 tumors, little is known regarding the clinicopathological and molecular features of CRCs with methylation at 4/8 panel markers (4/8 methylated markers) and whether they are akin to CIMP-H or CIMP-low/CIMP-0 CRCs in terms of their clinicopathological or molecular features. A total of 1164 cases of surgically resected CRC were analyzed for their methylation status in 8 CIMP panel markers, and the frequencies of various clinicopathological and molecular features were compared between CRCs with 0/8, 1/8 to 3/8, 4/8, and 5/8 to 8/8 methylated markers. CRCs with 4/8 methylated markers were closer to CRCs with 5/8 to 8/8 methylated markers in terms of sex distribution, mucin production, serration, nodal metastasis, CK7 expression, CK20 loss, and CDX2 loss frequencies and overall survival rate. CRCs with methylation at 4/8 markers were closer to CRCs with 1/8 to 3/8 methylated markers in terms of less frequent right colon location and poor differentiation. CRCs with 4/8 methylated markers showed the shortest overall survival time compared with CRCs with 0/8, 1/8 to 3/8, 4/8, or 5/8 to 8/8 methylated markers. In terms of clinicopathological and molecular features, CRCs with 4/8 methylated markers appeared to be closer to CIMP-H than to CIMP-low/CIMP-0 and would thus be better classified as CIMP-H if the CRCs require classification into either CIMP-H or CIMP-low/CIMP-0. Copyright © 2015 Elsevier Inc. All rights reserved.

Pharmacokinetics of methadone during maintenance therapy: Pulse labeling with deuterated methadone in the steady state

International Nuclear Information System (INIS)

Aenggard, E.; Nilsson, M.I.; Holmstrand, J.; Gunne, L.M.; Uppsala Univ.; Karolinsky Institutet, Stockholm

1979-01-01

A technique is presented for study of steady state kinetics of methadone using pulse labeling with deuterated methadone (d 3 ) and mass fragmentography to measure both unlabeled and labeled methadone in blood. Seven subjects maintained on methadone for at least 10 months were admitted to a closed metabolic ward. The daily dose of unlabeled methadone (d 0 ) was substituted by one dose of methadone-d 3 and plasma levels of methadone-d 0 and methadone-d 3 were followed for 48 h using a precise (SD +- 5%) and sensitive (30 pmol/ml) mass fragmentographic technique. Plasma half-lives (tsub(1/2)) for both methadone-d 0 and methadone-d 3 were calculated from samples obtained 8-24 h following the dose of methadone-d 3 . The tsub(1/2) of oral methadone-d 3 was shorter (22 +- 2 h) than that of methadone-d 0 (52 +- 20 h). The same pattern was observed after intravenous administration. The results indicate multiple pools of methadone in the body. (orig.) 891 AJ/orig. 892 MKO [de

Development of new synthetic routes to bile pigments and synthesis of deuterated porphyrins

International Nuclear Information System (INIS)

Shim, Y.K.

1985-01-01

New synthetic routes to pyrromethanones using hydrogen peroxide/pyridine upon alpha-free pyrromethanes and a synthesis of mesobiliverdin are described. The pyrromethanones were applied to the synthesis of mesobiliverdin using 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) oxidation of mesourbilin, to give a high yield of the desired mesobiliverdin. New synthetic methodology to pyrrolinones using various oxidizing reagents were also described. Treatment of alpha-free pyrrole with thallium(III) trifluoroacetate (TTFA) gave a mixture of a pyrrolinone and a dimeric compound. The yield and the ratio of the two products were variable depending upon the solvents and the mole ratio of the TTFA used. Pyrrolinone syntheses using the other oxidizing reagents are also described. Syntheses of carbon-14 labelled biliverdins are also described. In addition, the preparation of biliverdin IX-BETA using b-bilene route is described. The second part of this study contains an introduction to porphyrins and syntheses of 6,7-bis(2-methoxycarbonyl-1,1-dideuteroethyl)-1,3,5,8-tetramethyl-2,4-divinylporphyrin. The latter is important in the study of heme protein reconstitution experiments. As a result of numerous synthetic approaches the desired product was obtained from the appropriately deuterated formylpyrrole using the a,c-biladiene route

ESR study of radiation damage in pyrimidines. Progress report, August 1, 1975--April 1, 1976

International Nuclear Information System (INIS)

Benson, B.W.

1976-04-01

The primary objective of this project is to develop general mechanisms for radiation damage to biomolecules using substituted pyrimidines as a model system. Results this year include a single crystal ESR study of 5-ethyl-5-isopropylbarbituric acid, development of the k-band microwave bridge, dose response measurements on methylated barbituric acid derivatives, and synthesis of several specifically deuterated uracil derivatives

How does methylation suppress the electron-induced decomposition of 1-methyl-nitroimidazoles?

Science.gov (United States)

Kossoski, F.; Varella, M. T. do N.

2017-10-01

The efficient decomposition of nitroimidazoles (NIs) by low energy electrons is believed to underlie their radiosensitizing properties. Recent dissociative electron attachment (DEA) measurements showed that methylation at the N1 site unexpectedly suppresses the electron-induced reactions in 4(5)-NI. We report theoretical results that provide a clear interpretation of that astounding finding. Around 1.5 eV, DEA reactions into several fragments are initiated by a π* resonance, not considered in previous studies. The autoionization lifetime of this anion state, which limits the predissociation dynamics, is considerably shorter in the methylated species, thereby suppressing the DEA signals. On the other hand, the lifetime of the π* resonance located around 3 eV is less affected by methylation, which explains why DEA is still observed at these energies. Our results demonstrate how even a simple methylation can significantly modify the probabilities for DEA reactions, which may be significant for NI-based cancer therapy.

Dissociation dynamics of methylal

Energy Technology Data Exchange (ETDEWEB)

Beaud, P; Frey, H -M; Gerber, T; Mischler, B; Radi, P P; Tzannis, A -P [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

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

Genomic DNA Methylation Signatures Enable Concurrent Diagnosis and Clinical Genetic Variant Classification in Neurodevelopmental Syndromes.

Science.gov (United States)

Aref-Eshghi, Erfan; Rodenhiser, David I; Schenkel, Laila C; Lin, Hanxin; Skinner, Cindy; Ainsworth, Peter; Paré, Guillaume; Hood, Rebecca L; Bulman, Dennis E; Kernohan, Kristin D; Boycott, Kym M; Campeau, Philippe M; Schwartz, Charles; Sadikovic, Bekim

2018-01-04

Pediatric developmental syndromes present with systemic, complex, and often overlapping clinical features that are not infrequently a consequence of Mendelian inheritance of mutations in genes involved in DNA methylation, establishment of histone modifications, and chromatin remodeling (the "epigenetic machinery"). The mechanistic cross-talk between histone modification and DNA methylation suggests that these syndromes might be expected to display specific DNA methylation signatures that are a reflection of those primary errors associated with chromatin dysregulation. Given the interrelated functions of these chromatin regulatory proteins, we sought to identify DNA methylation epi-signatures that could provide syndrome-specific biomarkers to complement standard clinical diagnostics. In the present study, we examined peripheral blood samples from a large cohort of individuals encompassing 14 Mendelian disorders displaying mutations in the genes encoding proteins of the epigenetic machinery. We demonstrated that specific but partially overlapping DNA methylation signatures are associated with many of these conditions. The degree of overlap among these epi-signatures is minimal, further suggesting that, consistent with the initial event, the downstream changes are unique to every syndrome. In addition, by combining these epi-signatures, we have demonstrated that a machine learning tool can be built to concurrently screen for multiple syndromes with high sensitivity and specificity, and we highlight the utility of this tool in solving ambiguous case subjects presenting with variants of unknown significance, along with its ability to generate accurate predictions for subjects presenting with the overlapping clinical and molecular features associated with the disruption of the epigenetic machinery. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

DNA methylation changes detected by methylation-sensitive amplified polymorphism in two contrasting rice genotypes under salt stress.

Science.gov (United States)

Wang, Wensheng; Zhao, Xiuqin; Pan, Yajiao; Zhu, Linghua; Fu, Binying; Li, Zhikang

2011-09-20

DNA methylation, one of the most important epigenetic phenomena, plays a vital role in tuning gene expression during plant development as well as in response to environmental stimuli. In the present study, a methylation-sensitive amplified polymorphism (MSAP) analysis was performed to profile DNA methylation changes in two contrasting rice genotypes under salt stress. Consistent with visibly different phenotypes in response to salt stress, epigenetic markers classified as stable inter-cultivar DNA methylation differences were determined between salt-tolerant FL478 and salt-sensitive IR29. In addition, most tissue-specific DNA methylation loci were conserved, while many of the growth stage-dependent DNA methylation loci were dynamic between the two genotypes. Strikingly, salt stress induced a decrease in DNA methylation specifically in roots at the seedling stage that was more profound in IR29 than in the FL478. This result may indicate that demethylation of genes is an active epigenetic response to salt stress in roots at the seedling stage, and helps to further elucidate the implications of DNA methylation in crop growth and development. Copyright © 2011. Published by Elsevier Ltd.

Study of methylation sites and factors in contaminated aquatic systems in the Amazon using an optimized radiochemical technique. Highlights and achievements

International Nuclear Information System (INIS)

Davee Guimaraes, Jean Remy

2002-01-01

Full text: Highlights and achievements: We confirmed that high methylation potentials (up to 22%) are found in roots of Paspalum repens and other floating macrophyte species such as Eichhomia crassipes and Ludwigia helmynthoryza during both phases of the hydrological cycle, with a tendency for higher values in the wet season, confirming findings of previous studies, and a strong intra and interlake variation. Hg methylation in macrophyte roots is carried out mainly in the root-associated periphyton a complex and variable assemblage of benthic microalgae, fungi, bacteria and organic and inorganic detritus. However, no significant correlation was found in the first campaign between Hg methylation in samples of Paspalum sp. roots and the amount of periphyton in these samples. We also verified that total plankton and phytoplankton are sites of a low 203 Hg; Basic infrastructure problems caused partial loss of samples in one of the campaigns. (author)

MTHFR methylation moderates the impact of smoking on DNA methylation at AHRR for African American young adults.

Science.gov (United States)

Beach, Steven R H; Lei, Man Kit; Ong, Mei Ling; Brody, Gene H; Dogan, Meeshanthini V; Philibert, Robert A

2017-09-01

Smoking has been shown to have a large, reliable, and rapid effect on demethylation of AHRR, particularly at cg05575921, suggesting that methylation may be used as an index of cigarette consumption. Because the availability of methyl donors may also influence the degree of demethylation in response to smoking, factors that affect the activity of methylene tetrahydrofolate reductase (MTHFR), a key regulator of methyl group availability, may be of interest. In the current investigation, we examined the extent to which individual differences in methylation of MTHFR moderated the association between smoking and demethylation at cg05575921 as well as at other loci on AHRR associated with a main effect of smoking. Using a discovery sample (AIM, N = 293), and a confirmatory sample (SHAPE, N = 368) of young adult African Americans, degree of methylation of loci in the first exon of MTHFR was associated with amplification of the association between smoking and AHRR demethylation at cg05575921. However, genetic variation at a commonly studied MTHFR variant, C677T, did not influence cg05575921 methylation. The significant interaction between MTHFR methylation and the smoking-induced response at cg05575921 suggests a role for individual differences in methyl cycle regulation in understanding the effects of cigarette consumption on genome wide DNA methylation. © 2017 Wiley Periodicals, Inc.

Synthesis of [methyl-{sup 14}C]crotonobetaine from DL-[methyl-{sup 14}C]carnitine

Energy Technology Data Exchange (ETDEWEB)

Loester, H.; Seim, H. [Leipzig Univ. (Germany). Inst. of Clinical Chemistry and Pathobiochemistry

1996-02-01

The causes of carnitine deficiency syndromes are not completely understood, but decomposition of L-carnitine in vivo is likely to be involved. Carnitine is metabolized to {gamma}-butyrobetaine, and crotonobetaine is probably an intermediate in this pathway. To validate experimentally the precursor-product relationship between the three physiologically occuring {gamma}-betaines - L-carnitine, crotonobetaine, {gamma}-butyrobetaine - labelling with stable or radioactive isotopes became necessary. Methyl-labelled carnitine isomers (L(-)-, D(+)- or DL-) or {gamma}-butyrobetaine can be easily synthesized by methylation of 4-amino-3-hydroxybutyric acid isomers or 4-aminobutyric acid, respectively. Because of problems with the 4-aminocrotonic acid, we synthesized labelled crotonbetaine from labelled carnitine. Thus, DL-[methyl-{sup 14}C]carnitine was dehydrated by reaction with concentrated sulfuric acid. After removal of the latter the products were separated and purified by ion exchange chromatography on DOWEX 50 WX8 (200 - 400 mesh) and gradient elution with hydrochloric acid. In addition to the labelled main product [methyl-{sup 14}C]crotonobetaine (yield about 50 %), [methyl-{sup 14}C]glycine betaine and [methyl-{sup 14}C]acetonyl-trimethylammonium (ATMA) were formed. The end products were identified by combined thin layer chromatography/autoradiography and quantified by liquid scintillation counting. (Author).

NMR characterization of HtpG, the E. coli Hsp90, using sparse labeling with 13C-methyl alanine.

Science.gov (United States)

Pederson, Kari; Chalmers, Gordon R; Gao, Qi; Elnatan, Daniel; Ramelot, Theresa A; Ma, Li-Chung; Montelione, Gaetano T; Kennedy, Michael A; Agard, David A; Prestegard, James H

2017-07-01

A strategy for acquiring structural information from sparsely isotopically labeled large proteins is illustrated with an application to the E. coli heat-shock protein, HtpG (high temperature protein G), a 145 kDa dimer. It uses 13 C-alanine methyl labeling in a perdeuterated background to take advantage of the sensitivity and resolution of Methyl-TROSY spectra, as well as the backbone-centered structural information from 1 H- 13 C residual dipolar couplings (RDCs) of alanine methyl groups. In all, 40 of the 47 expected crosspeaks were resolved and 36 gave RDC data. Assignments of crosspeaks were partially achieved by transferring assignments from those made on individual domains using triple resonance methods. However, these were incomplete and in many cases the transfer was ambiguous. A genetic algorithm search for consistency between predictions based on domain structures and measurements for chemical shifts and RDCs allowed 60% of the 40 resolved crosspeaks to be assigned with confidence. Chemical shift changes of these crosspeaks on adding an ATP analog to the apo-protein are shown to be consistent with structural changes expected on comparing previous crystal structures for apo- and complex- structures. RDCs collected on the assigned alanine methyl peaks are used to generate a new solution model for the apo-protein structure.

Process for the production of methyl methacrylate

NARCIS (Netherlands)

Eastham, G.R.; Johnson, D.W.; Straathof, A.J.J.; Fraaije, Marco; Winter, Remko

2015-01-01

A process of producing methyl methacrylate or derivatives thereof is described. The process includes the steps of; (i) converting 2-butanone to methyl propionate using a Baeyer-Villiger monooxygenase, and (ii) treating the methyl propionate produced to obtain methyl methacrylate or derivatives

Methylation patterns in marginal zone lymphoma.

Science.gov (United States)

Arribas, Alberto J; Bertoni, Francesco

Promoter DNA methylation is a major regulator of gene expression and transcription. The identification of methylation changes is important for understanding disease pathogenesis, for identifying prognostic markers and can drive novel therapeutic approaches. In this review we summarize the current knowledge regarding DNA methylation in MALT lymphoma, splenic marginal zone lymphoma, nodal marginal zone lymphoma. Despite important differences in the study design for different publications and the existence of a sole large and genome-wide methylation study for splenic marginal zone lymphoma, it is clear that DNA methylation plays an important role in marginal zone lymphomas, in which it contributes to the inactivation of tumor suppressors but also to the expression of genes sustaining tumor cell survival and proliferation. Existing preclinical data provide the rationale to target the methylation machinery in these disorders. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ketene as a Reaction Intermediate in the Carbonylation of Dimethyl Ether to Methyl Acetate over Mordenite

DEFF Research Database (Denmark)

Rasmussen, Dominik Bjørn; Christensen, Jakob Munkholt; Temel, Burcin

2015-01-01

Unprecedented insight into the carbonylation of dimethyl ether over Mordenite is provided through the identification of ketene (CH2CO) as a reaction intermediate. The formation of ketene is predicted by detailed DFT calculations and verified experimentally by the observation of doubly deuterated ...

DNA methylation-based variation between human populations.

Science.gov (United States)

Kader, Farzeen; Ghai, Meenu

2017-02-01

Several studies have proved that DNA methylation affects regulation of gene expression and development. Epigenome-wide studies have reported variation in methylation patterns between populations, including Caucasians, non-Caucasians (Blacks), Hispanics, Arabs, and numerous populations of the African continent. Not only has DNA methylation differences shown to impact externally visible characteristics, but is also a potential biomarker for underlying racial health disparities between human populations. Ethnicity-related methylation differences set their mark during early embryonic development. Genetic variations, such as single-nucleotide polymorphisms and environmental factors, such as age, dietary folate, socioeconomic status, and smoking, impacts DNA methylation levels, which reciprocally impacts expression of phenotypes. Studies show that it is necessary to address these external influences when attempting to differentiate between populations since the relative impacts of these factors on the human methylome remain uncertain. The present review summarises several reported attempts to establish the contribution of differential DNA methylation to natural human variation, and shows that DNA methylation could represent new opportunities for risk stratification and prevention of several diseases amongst populations world-wide. Variation of methylation patterns between human populations is an exciting prospect which inspires further valuable research to apply the concept in routine medical and forensic casework. However, trans-generational inheritance needs to be quantified to decipher the proportion of variation contributed by DNA methylation. The future holds thorough evaluation of the epigenome to understand quantification, heritability, and the effect of DNA methylation on phenotypes. In addition, methylation profiling of the same ethnic groups across geographical locations will shed light on conserved methylation differences in populations.

Cocoa Consumption Alters the Global DNA Methylation of Peripheral Leukocytes in Humans with Cardiovascular Disease Risk Factors: A Randomized Controlled Trial.

Science.gov (United States)

Crescenti, Anna; Solà, Rosa; Valls, Rosa M; Caimari, Antoni; Del Bas, Josep M; Anguera, Anna; Anglés, Neus; Arola, Lluís

2013-01-01

DNA methylation regulates gene expression and can be modified by different bioactive compounds in foods, such as polyphenols. Cocoa is a rich source of polyphenols, but its role in DNA methylation is still unknown. The objective was to assess the effect of cocoa consumption on DNA methylation and to determine whether the enzymes involved in the DNA methylation process participate in the mechanisms by which cocoa exerts these effects in humans. The global DNA methylation levels in the peripheral blood were evaluated in 214 volunteers who were pre-hypertensive, stage-1 hypertensive or hypercholesterolemic. The volunteers were divided into two groups: 110 subjects who consumed cocoa (6 g/d) for two weeks and 104 control subjects. In addition, the peripheral blood mononuclear cells (PBMCs) from six subjects were treated with a cocoa extract to analyze the mRNA levels of the DNA methyltransferases (DNMTs), methylenetetrahydrofolate reductase (MTHFR), and methionine synthase reductase (MTRR) genes. Cocoa consumption significantly reduced the DNA methylation levels (2.991±0.366 vs. 3.909±0.380, pcocoa effects on DNA methylation and three polymorphisms located in the MTHFR, MTRR, and DNMT3B genes. Furthermore, in PBMCs, the cocoa extract significantly lowered the mRNA levels of the DNMTs, MTHFR, and MTRR. Our study demonstrates for the first time that the consumption of cocoa decreases the global DNA methylation of peripheral leukocytes in humans with cardiovascular risk factors. In vitro experiments with PBMCs suggest that cocoa may exert this effect partially via the down-regulation of DNMTs, MTHFR and MTRR, which are key genes involved in this epigenetic process. Clinicaltrials.govNCT00511420 and NCT00502047.

DNA Methylation of MMP9 Is Associated with High Levels of MMP-9 Messenger RNA in Periapical Inflammatory Lesions.

Science.gov (United States)

Campos, Kelma; Gomes, Carolina Cavalieri; Farias, Lucyana Conceição; Silva, Renato Menezes; Letra, Ariadne; Gomez, Ricardo Santiago

2016-01-01

Matrix metalloproteinases (MMPs) are the major class of enzymes responsible for degradation of extracellular matrix components and participate in the pathogenesis of periapical inflammatory lesions. MMP expression may be regulated by DNA methylation. The purpose of the present investigation was to analyze the expression of MMP2 and MMP9 in periapical granulomas and radicular cysts and to test the hypothesis that, in these lesions, their transcription may be modulated by DNA methylation. Methylation-specific polymerase chain reaction was used to evaluate the DNA methylation pattern of the MMP2 gene in 13 fresh periapical granuloma samples and 10 fresh radicular cyst samples. Restriction enzyme digestion was used to assess methylation of the MMP9 gene in 12 fresh periapical granuloma samples and 10 fresh radicular cyst samples. MMP2 and MMP9 messenger RNA transcript levels were measured by quantitative real-time polymerase chain reaction. All periapical lesions and healthy mucosa samples showed partial methylation of the MMP2 gene; however, periapical granulomas showed higher MMP2 mRNA expression levels than healthy mucosa (P = .014). A higher unmethylated profile of the MMP9 gene was found in periapical granulomas and radicular cysts compared with healthy mucosa. In addition, higher MMP9 mRNA expression was observed in the periapical lesions compared with healthy tissues. The present study suggests that the unmethylated status of the MMP9 gene in periapical lesions may explain the observed up-regulation of messenger RNA transcription in these lesions. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Rapid analysis of heterogeneously methylated DNA using digital methylation-sensitive high resolution melting: application to the CDKN2B (p15) gene

DEFF Research Database (Denmark)

Candiloro, Ida Lm; Mikeska, Thomas; Hokland, Peter

2008-01-01

ABSTRACT: BACKGROUND: Methylation-sensitive high resolution melting (MS-HRM) methodology is able to recognise heterogeneously methylated sequences by their characteristic melting profiles. To further analyse heterogeneously methylated sequences, we adopted a digital approach to MS-HRM (dMS-HRM) t......ABSTRACT: BACKGROUND: Methylation-sensitive high resolution melting (MS-HRM) methodology is able to recognise heterogeneously methylated sequences by their characteristic melting profiles. To further analyse heterogeneously methylated sequences, we adopted a digital approach to MS-HRM (d......MS-HRM) that involves the amplification of single templates after limiting dilution to quantify and to determine the degree of methylation. We used this approach to study methylation of the CDKN2B (p15) cell cycle progression inhibitor gene which is inactivated by DNA methylation in haematological malignancies...... the methylated alleles and assess the degree of methylation. Direct sequencing of selected dMS-HRM products was used to determine the exact DNA methylation pattern and confirmed the degree of methylation estimated by dMS-HRM. CONCLUSION: dMS-HRM is a powerful technique for the analysis of methylation in CDKN2B...

Inductive effect of methyl group in a series of methylated indoles: A ...

Indian Academy of Sciences (India)

Vol. 125, No. 4, July 2013, pp. 905–912. c Indian Academy of Sciences. Inductive effect of methyl group in a series of methylated indoles: A graph theoretical analysis in the light of density functional theory and correlation with experimental charge transfer transition energies. AMIT S TIWARYa,∗ and ASOK K MUKHERJEEb.

Loss of ammonia during electron-transfer dissociation of deuterated peptides as an inherent gauge of gas-phase hydrogen scrambling

DEFF Research Database (Denmark)

Rand, Kasper D; Zehl, Martin; Jensen, Ole Nørregaard

2010-01-01

detected by a depletion of deuterium when deuterated ammonia is lost from peptides during ETD. This straightforward method requires no modifications to the experimental workflow and has the great advantage that the occurrence of hydrogen scrambling can be directly detected in the actual peptides analyzed......The application of electron-transfer dissociation (ETD) to obtain single-residue resolution in hydrogen exchange-mass spectrometry (HX-MS) experiments has recently been demonstrated. For such measurements, it is critical to ensure that the level of gas-phase hydrogen scrambling is negligible. Here...... we utilize the abundant loss of ammonia upon ETD of peptide ions as a universal reporter of positional randomization of the exchangeable hydrogens (hydrogen scrambling) during HX-ETD experiments. We show that the loss of ammonia from peptide ions proceeds without depletion of deuterium when employing...

Helium (24He, 23He) within deuterated Pd-black

International Nuclear Information System (INIS)

Arata, Yoshiaki; Zhang, Yue-Chang

1997-01-01

Authors have clearly proven for the first time that deuterium nuclear reaction was continuously generated inside a highly deuterated solid by showing both of the excess energy and corresponding amount of helium as the reaction product generated simultaneously. Whenever there is a nuclear fusion reaction inside a metal, helium generated is unable to escape to the surroundings and is trapped in a frozen state inside that metal. The concentration of the helium within the metal will rise with increasing rate of reactions. Pd-black is under such state as the sample used and sealed within the 'closed QMS' developed by the authors (closed vessel including the Getter pump and the QMS). It is completely separated from the surroundings and the internal gases are removed to create super-vacuum. The reaction product released by the 'Sample-Heating' process (room temp. ↔ 1500(degC)) is thus the only matter which occupies the interior of the closed vessel and its detection by the QMS is assured. When the 'closed QMS' works under the above mentioned-state, it was clarified that the 'ash' or the reaction product of this fusion reaction within a solid is 2 4 He and 2 3 He and their ratio is 2 4 He/ 2 3 He ≅ 4. It can be concluded from the result that the main reaction product is 2 4 He and it is created directly as an inherent feature of the solid-state nuclear fusion. Authors think that the reaction process responsible for the creation of 2 3 He may be a different one from that created 2 4 He. One of which is the Rutherford reaction process and the other occurs based on the specific properties of solid, similar to the case of 2 4 He. The existence of 1 3 T will be required that the process is responsible for the generation of 2 3 He as the Rutherford reaction. The proof for the existence of 1 3 T within the 'closed QMS', however, was not obtained in this experiments. (author)

Methylation-Specific PCR Unraveled

Directory of Open Access Journals (Sweden)

Sarah Derks

2004-01-01

Full Text Available Methylation‐specific PCR (MSP is a simple, quick and cost‐effective method to analyze the DNA methylation status of virtually any group of CpG sites within a CpG island. The technique comprises two parts: (1 sodium bisulfite conversion of unmethylated cytosine's to uracil under conditions whereby methylated cytosines remains unchanged and (2 detection of the bisulfite induced sequence differences by PCR using specific primer sets for both unmethylated and methylated DNA. This review discusses the critical parameters of MSP and presents an overview of the available MSP variants and the (clinical applications.

Focal cortical dysplasia of the temporal lobe with late-onset partial epilepsy: serial quantitative MRI

Energy Technology Data Exchange (ETDEWEB)

Rademacher, J.; Seitz, R.J. [Department of Neurology, Heinrich-Heine University Duesseldorf (Germany); Aulich, A. [Department of Radiology, Heinrich-Heine University, Duesseldorf (Germany); Reifenberger, G. [Department of Neuropathology, Heinrich-Heine University, Duesseldorf (Germany); Kiwit, J.C.W. [Department of Neurosurgery, Heinrich-Heine University, Duesseldorf (Germany); Langen, K.J.; Schmidt, D. [Institute of Medicine, Research Center Juelich, Heinrich-Heine University, Duesseldorf (Germany)

2000-06-01

We describe serial studies of focal cortical dysplasia causing temporal lobe seizures and progressive aphasia in a 54-year-old woman. Initially, MRI volumetry of the temporal lobes showed significant left cortical thickening corresponding to an elevated aminoacid uptake in the left temporoparietal and inferior frontal cortex on SPECT using 3-[{sup 123}I]iodo-{alpha}-methyl-l-tyrosine (IMT). After 1 year there was severe shrinkage of the left temporal lobe, possibly the result of recurrent complex partial seizures. (orig.)

Focal cortical dysplasia of the temporal lobe with late-onset partial epilepsy: serial quantitative MRI

International Nuclear Information System (INIS)

Rademacher, J.; Seitz, R.J.; Aulich, A.; Reifenberger, G.; Kiwit, J.C.W.; Langen, K.J.; Schmidt, D.

2000-01-01

We describe serial studies of focal cortical dysplasia causing temporal lobe seizures and progressive aphasia in a 54-year-old woman. Initially, MRI volumetry of the temporal lobes showed significant left cortical thickening corresponding to an elevated aminoacid uptake in the left temporoparietal and inferior frontal cortex on SPECT using 3-[ 123 I]iodo-α-methyl-l-tyrosine (IMT). After 1 year there was severe shrinkage of the left temporal lobe, possibly the result of recurrent complex partial seizures. (orig.)

Synthesis of 14C-labelled α-methyl tyrosine

International Nuclear Information System (INIS)

Rajagopal, S.; Venkatachalam, T.K.; Conway, T.; Diksic, M.

1992-01-01

A new route for the preparation of radioactively labelled α-methyl L-tyrosine is described. The labelling at the α position has been successfully achieved with 14 C-, 11 C- (very preliminary, unpublished), and 3 H-labelled methyl iodide. A detailed report on 14 C-labelling at the α position and the hydrolysis of 4-methoxy α-methyl phenylalanine is presented. The alkylation proceeds via the methylation of the carbanion of N-benzylidene 4-methoxy phenylalanine methyl ester 2. Hydrolysis of 4-O methyl tyrosine to tyrosine by HBr and HI were analysed and used in the optimization of the hydrolysis conditions of 4. Enantiomeric purity of the isolated L-isomer has been found to be 99% as judged by HPLC. Pseudo first-order rate constant for the hydrolysis of 14 C-labelled α-methyl 4-methoxy phenyl alanine methyl ester was determined. Preliminary findings of the 3 H- and 11 C-radiolabelled α-methyl tyrosine (methyl labelled) are also mentioned. For the first time it was shown that α-methyl D,L-tyrosine can be separated into enantiomerically pure α-methyl D- and L-tyrosine using a CHIRALPAK WH column. (author)

Liberation of methyl acrylate from metallalactone complexes via M-O ring opening (M = Ni, Pd) with methylation agents

KAUST Repository

Lee, S. Y Tina; Ghani, Amylia Abdul; D'Elia, Valerio; Cokoja, Mirza; Herrmann, Wolfgang A.; Basset, Jean-Marie; Kü hn, Fritz

2013-01-01

Ring opening of various nickela- and palladalactones induced by the cleavage of the M-O bond by methyl trifluoromethanesulfonate (MeOTf) and methyl iodide (MeI) is examined. Experimental evidence supports the mechanism of ring opening by the alkylating agent followed by β-H elimination leading to methyl acrylate and a metal-hydride species. MeOTf shows by far higher efficiency in the lactone ring opening than any other methylating agent including the previously reported methyl iodide. © 2013 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.

Methylation pathways in schizophrenia

International Nuclear Information System (INIS)

Sargent, T.W. III.

1982-01-01

Research on the biochemical causes of human psychosis concentrates on investigating whether schizophremia is linked to abnormalities in the metabolism of methyl carbon groups in the body. The metabolism of C-14 labeled methyl groups in methionine is studied in animals, normal subjects and patient volunteers

Accurate Determination of Leucine and Valine Side-chain Conformations using U-[15N/13C/2H]/[1H-(methine/methyl)-Leu/Val] Isotope Labeling, NOE Pattern Recognition, and Methine Cγ-Hγ/Cβ-Hβ Residual Dipolar Couplings

International Nuclear Information System (INIS)

Tang, Chun; Iwahara, Junji; Clore, G. Marius

2005-01-01

An isotope labeling scheme is described in which specific protonation of methine and methyl protons of leucine and valine is obtained on a 15 N/ 13 C labeled background with uniform deuteration of all other non-exchangeable protons. The presence of a protonated methine group has little effect on the favorable relaxation properties of the methyl protons of Leu and Val. This labeling scheme permits the rotameric state of leucine side-chains to be readily determined by simple inspection of the pattern of Hγ(i)-H N (i) and Hγ(i)-H N (i+1) NOEs in a 3D 15 N-separated NOE spectrum free of complications arising from spectral overlap and spin-diffusion. In addition, one-bond residual dipolar couplings for the methine 13 C- 1 H bond vectors of Leu and Val can be accurately determined from an intensity J-modulated constant-time HCCH-COSY experiment and used to accurately orient the side-chains of Leu and Val. Incorporation of these data into structure refinement improves the accuracy with which the conformations of Leu and Val side-chains can be established. This is important to ensure optimal packing both within the protein core and at intermolecular interfaces. The impact of the method on protein structure determination is illustrated by application to enzyme IIA Chitobiose , a 34 kDa homotrimeric phosphotransferase protein

Simultaneous Determination of Salicylic Acid, Jasmonic Acid, Methyl Salicylate, and Methyl Jasmonate from Ulmus pumila Leaves by GC-MS

Directory of Open Access Journals (Sweden)

Zhi-hong Huang

2015-01-01

Full Text Available Salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate are important phytohormones and defensive signaling compounds, so it is of great importance to determine their levels rapidly and accurately. The study uses Ulmus pumila leaves infected by Tetraneura akinire Sasaki at different stages as materials; after extraction with 80% methanol and ethyl acetate and purification with primary secondary amine (PSA and graphitized carbon blacks (GCB, the contents of signal compounds salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate were determined by GC-MS. The results showed that the level of salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate increased remarkably in U. pumila once infected by T. akinire Sasaki, but the maximums of these four compounds occurred at different times. Salicylic acid level reached the highest at the early stage, and jasmonic acid level went to the maximum in the middle stage; by contrast, change of content of methyl salicylate and methyl jasmonate was the quite opposite.

Simultaneous Determination of Salicylic Acid, Jasmonic Acid, Methyl Salicylate, and Methyl Jasmonate from Ulmus pumila Leaves by GC-MS.

Science.gov (United States)

Huang, Zhi-Hong; Wang, Zhi-Li; Shi, Bao-Lin; Wei, Dong; Chen, Jian-Xin; Wang, Su-Li; Gao, Bao-Jia

2015-01-01

Salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate are important phytohormones and defensive signaling compounds, so it is of great importance to determine their levels rapidly and accurately. The study uses Ulmus pumila leaves infected by Tetraneura akinire Sasaki at different stages as materials; after extraction with 80% methanol and ethyl acetate and purification with primary secondary amine (PSA) and graphitized carbon blacks (GCB), the contents of signal compounds salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate were determined by GC-MS. The results showed that the level of salicylic acid, jasmonic acid, methyl salicylate, and methyl jasmonate increased remarkably in U. pumila once infected by T. akinire Sasaki, but the maximums of these four compounds occurred at different times. Salicylic acid level reached the highest at the early stage, and jasmonic acid level went to the maximum in the middle stage; by contrast, change of content of methyl salicylate and methyl jasmonate was the quite opposite.

Synthesis of DL-adrenaline (methyl C{sup 14}) (1961); Synthese de la DL-adrenaline (methyle {sup 14}C) (1961)

Energy Technology Data Exchange (ETDEWEB)

Pichat, L; Audinot, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The sodium derivative of 5-3-4 dibenzyl oxyphenyl 2-oxazolidinone reacted with methyl iodide {sup 14}C, in stoichiometric quantity, gives rise to the corresponding N-methyl {sup 14}C derivative. The oxazolidinone ring is opened by concentrated hydrochloric acid and the benzyl groups removed by catalytic hydrogenolysis. Adrenaline methyl {sup 14}C is then purified on Dowex 50 X-12 exchange resin. Overall-yield is 45 per cent based upon methyl iodide {sup 14}C. (author) [French] Le derive sode de la (dibenzyloxy-3-4-phenyl)-5 oxazolidinone-2 traite par l'iodure de methyle {sup 14}C, en proportion stoechiometrique, fournit le derive N-methyle {sup 14}C correspondant. Apres ouverture du cycle oxazolidinone par HCL concentre et debenzylation par hydrogenation catalytique, on purifie l'adrenaline (methyle {sup 14}C) par chromatographie sur resine echangeuse Dowex 50 X-12. Le rendement est de 45 pour cent par rapport a l'iodure de methyle {sup 14}C. (auteurs)

Synthesis of DL-adrenaline (methyl C{sup 14}) (1961); Synthese de la DL-adrenaline (methyle {sup 14}C) (1961)

Energy Technology Data Exchange (ETDEWEB)

Pichat, L.; Audinot, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The sodium derivative of 5-3-4 dibenzyl oxyphenyl 2-oxazolidinone reacted with methyl iodide {sup 14}C, in stoichiometric quantity, gives rise to the corresponding N-methyl {sup 14}C derivative. The oxazolidinone ring is opened by concentrated hydrochloric acid and the benzyl groups removed by catalytic hydrogenolysis. Adrenaline methyl {sup 14}C is then purified on Dowex 50 X-12 exchange resin. Overall-yield is 45 per cent based upon methyl iodide {sup 14}C. (author) [French] Le derive sode de la (dibenzyloxy-3-4-phenyl)-5 oxazolidinone-2 traite par l'iodure de methyle {sup 14}C, en proportion stoechiometrique, fournit le derive N-methyle {sup 14}C correspondant. Apres ouverture du cycle oxazolidinone par HCL concentre et debenzylation par hydrogenation catalytique, on purifie l'adrenaline (methyle {sup 14}C) par chromatographie sur resine echangeuse Dowex 50 X-12. Le rendement est de 45 pour cent par rapport a l'iodure de methyle {sup 14}C. (auteurs)

A novel multifunctional O-methyltransferase implicated in a dual methylation pathway associated with lignin biosynthesis in loblolly pine.

Science.gov (United States)

Li, L; Popko, J L; Zhang, X H; Osakabe, K; Tsai, C J; Joshi, C P; Chiang, V L

1997-05-13

S-adenosyl-L-methionine (SAM)-dependent O-methyltransferases (OMTs) catalyze the methylation of hydroxycinnamic acid derivatives for the synthesis of methylated plant polyphenolics, including lignin. The distinction in the extent of methylation of lignins in angiosperms and gymnosperms, mediated by substrate-specific OMTs, represents one of the fundamental differences in lignin biosynthesis between these two classes of plants. In angiosperms, two types of structurally and functionally distinct lignin pathway OMTs, caffeic acid 3-O-methyltransferases (CAOMTs) and caffeoyl CoA 3-O-methyltransferases (CCoAOMTs), have been reported and extensively studied. However, little is known about lignin pathway OMTs in gymnosperms. We report here the first cloning of a loblolly pine (Pinus taeda) xylem cDNA encoding a multifunctional enzyme, SAM:hydroxycinnamic Acids/hydroxycinnamoyl CoA Esters OMT (AEOMT). The deduced protein sequence of AEOMT is partially similar to, but clearly distinguishable from, that of CAOMTs and does not exhibit any significant similarity with CCoAOMT protein sequences. However, functionally, yeast-expressed AEOMT enzyme catalyzed the methylation of CAOMT substrates, caffeic and 5-hydroxyferulic acids, as well as CCoAOMT substrates, caffeoyl CoA and 5-hydroxyferuloyl CoA esters, with similar specific activities and was completely inactive with substrates associated with flavonoid synthesis. The lignin-related substrates were also efficiently methylated in crude extracts of loblolly pine secondary xylem. Our results support the notion that, in the context of amino acid sequence and biochemical function, AEOMT represents a novel SAM-dependent OMT, with both CAOMT and CCoAOMT activities and thus the potential to mediate a dual methylation pathway in lignin biosynthesis in loblolly pine xylem.

A novel multifunctional O-methyltransferase implicated in a dual methylation pathway associated with lignin biosynthesis in loblolly pine

Science.gov (United States)

Li, Laigeng; Popko, Jacqueline L.; Zhang, Xing-Hai; Osakabe, Keishi; Tsai, Chung-Jui; Joshi, Chandrashekhar P.; Chiang, Vincent L.

1997-01-01

S-adenosyl-l-methionine (SAM)-dependent O-methyltransferases (OMTs) catalyze the methylation of hydroxycinnamic acid derivatives for the synthesis of methylated plant polyphenolics, including lignin. The distinction in the extent of methylation of lignins in angiosperms and gymnosperms, mediated by substrate-specific OMTs, represents one of the fundamental differences in lignin biosynthesis between these two classes of plants. In angiosperms, two types of structurally and functionally distinct lignin pathway OMTs, caffeic acid 3-O-methyltransferases (CAOMTs) and caffeoyl CoA 3-O-methyltransferases (CCoAOMTs), have been reported and extensively studied. However, little is known about lignin pathway OMTs in gymnosperms. We report here the first cloning of a loblolly pine (Pinus taeda) xylem cDNA encoding a multifunctional enzyme, SAM:hydroxycinnamic Acids/hydroxycinnamoyl CoA Esters OMT (AEOMT). The deduced protein sequence of AEOMT is partially similar to, but clearly distinguishable from, that of CAOMTs and does not exhibit any significant similarity with CCoAOMT protein sequences. However, functionally, yeast-expressed AEOMT enzyme catalyzed the methylation of CAOMT substrates, caffeic and 5-hydroxyferulic acids, as well as CCoAOMT substrates, caffeoyl CoA and 5-hydroxyferuloyl CoA esters, with similar specific activities and was completely inactive with substrates associated with flavonoid synthesis. The lignin-related substrates were also efficiently methylated in crude extracts of loblolly pine secondary xylem. Our results support the notion that, in the context of amino acid sequence and biochemical function, AEOMT represents a novel SAM-dependent OMT, with both CAOMT and CCoAOMT activities and thus the potential to mediate a dual methylation pathway in lignin biosynthesis in loblolly pine xylem. PMID:9144260

Dual chromatin recognition by the histone deacetylase complex HCHC is required for proper DNA methylation in Neurospora crassa

Science.gov (United States)

Honda, Shinji; Bicocca, Vincent T.; Gessaman, Jordan D.; Rountree, Michael R.; Yokoyama, Ayumi; Yu, Eun Y.; Selker, Jeanne M. L.; Selker, Eric U.

2016-01-01

DNA methylation, heterochromatin protein 1 (HP1), histone H3 lysine 9 (H3K9) methylation, histone deacetylation, and highly repeated sequences are prototypical heterochromatic features, but their interrelationships are not fully understood. Prior work showed that H3K9 methylation directs DNA methylation and histone deacetylation via HP1 in Neurospora crassa and that the histone deacetylase complex HCHC is required for proper DNA methylation. The complex consists of the chromodomain proteins HP1 and chromodomain protein 2 (CDP-2), the histone deacetylase HDA-1, and the AT-hook motif protein CDP-2/HDA-1–associated protein (CHAP). We show that the complex is required for proper chromosome segregation, dissect its function, and characterize interactions among its components. Our analyses revealed the existence of an HP1-based DNA methylation pathway independent of its chromodomain. The pathway partially depends on CHAP but not on the CDP-2 chromodomain. CDP-2 serves as a bridge between the recognition of H3K9 trimethylation (H3K9me3) by HP1 and the histone deacetylase activity of HDA-1. CHAP is also critical for HDA-1 localization to heterochromatin. Specifically, the CHAP zinc finger interacts directly with the HDA-1 argonaute-binding protein 2 (Arb2) domain, and the CHAP AT-hook motifs recognize heterochromatic regions by binding to AT-rich DNA. Our data shed light on the interrelationships among the prototypical heterochromatic features and support a model in which dual recognition by the HP1 chromodomain and the CHAP AT-hooks are required for proper heterochromatin formation. PMID:27681634

Upper limits for the circular dichroism for the C 1s and O 1s core excitation of methyl oxirane

International Nuclear Information System (INIS)

Pruemper, G; Lischke, T; Fukuzawa, H; Reinkoester, A; Ueda, K

2007-01-01

The circular dichroism (CD) in the total and partial ion yields of methyl-oxirane C 3 H 6 O was measured at the C 1s and O 1s edges. The difference of the response of the chiral molecule to circularly polarized light with opposite handedness was found to be less than 0.2% for the total ion yield and less than 0.5% for the partial ion yield. Additionally we tried to find a dipole allowed molecular orientation CD effect by analysing the fragmentation in the forward and backward direction. For this effect we found an upper limit of 1-2% for all abundant ionic fragments

Transgenerational epigenetics: Inheritance of global cytosine methylation and methylation-related epigenetic markers in the shrub Lavandula latifolia.

Science.gov (United States)

Herrera, Carlos M; Alonso, Conchita; Medrano, Mónica; Pérez, Ricardo; Bazaga, Pilar

2018-04-01

The ecological and evolutionary significance of natural epigenetic variation (i.e., not based on DNA sequence variants) variation will depend critically on whether epigenetic states are transmitted from parents to offspring, but little is known on epigenetic inheritance in nonmodel plants. We present a quantitative analysis of transgenerational transmission of global DNA cytosine methylation (= proportion of all genomic cytosines that are methylated) and individual epigenetic markers (= methylation status of anonymous MSAP markers) in the shrub Lavandula latifolia. Methods based on parent-offspring correlations and parental variance component estimation were applied to epigenetic features of field-growing plants ('maternal parents') and greenhouse-grown progenies. Transmission of genetic markers (AFLP) was also assessed for reference. Maternal parents differed significantly in global DNA cytosine methylation (range = 21.7-36.7%). Greenhouse-grown maternal families differed significantly in global methylation, and their differences were significantly related to maternal origin. Methylation-sensitive amplified polymorphism (MSAP) markers exhibited significant transgenerational transmission, as denoted by significant maternal variance component of marker scores in greenhouse families and significant mother-offspring correlations of marker scores. Although transmission-related measurements for global methylation and MSAP markers were quantitatively lower than those for AFLP markers taken as reference, this study has revealed extensive transgenerational transmission of genome-wide global cytosine methylation and anonymous epigenetic markers in L. latifolia. Similarity of results for global cytosine methylation and epigenetic markers lends robustness to this conclusion, and stresses the value of considering both types of information in epigenetic studies of nonmodel plants. © 2018 Botanical Society of America.

Analysis of DNA methylation of perennial ryegrass under drought using the methylation-sensitive amplification polymorphism (MSAP) technique.

Science.gov (United States)

Tang, Xiao-Mei; Tao, Xiang; Wang, Yan; Ma, Dong-Wei; Li, Dan; Yang, Hong; Ma, Xin-Rong

2014-12-01

Perennial ryegrass (Lolium perenne), an excellent grass for forage and turf, is widespread in temperate regions. Drought is an important factor that limits its growth, distribution, and yield. DNA methylation affects gene expression and plays an important role in adaptation to adverse environments. In this study, the DNA methylation changes in perennial ryegrass under drought stress were assessed using methylation-sensitive amplified polymorphism (MSAP). After 15 days of drought stress treatment, the plant height was less than half of the control, and the leaves were smaller and darker. Genome-wide, a total of 652 CCGG sites were detected by MSAP. The total methylation level was 57.67 and 47.39 % in the control and drought treatment, respectively, indicating a decrease of 10.28 % due to drought exposure. Fifteen differentially displayed DNA fragments in MSAP profiles were cloned for sequencing analysis. The results showed that most of the genes involved in stress responses. The relative expression levels revealed that three demethylated fragments were up-regulated. The expression of a predicted retrotransposon increased significantly, changing from hypermethylation to non-methylation. Although the extent of methylation in two other genes decreased, the sites of methylation remained, and the expression increased only slightly. All of these results suggested that drought stress decreased the total DNA methylation level in perennial ryegrass and demethylation up-regulated related gene expressions and that the extent of methylation was negatively correlated with expression. Overall, the induced epigenetic changes in genome probably are an important regulatory mechanism for acclimating perennial ryegrass to drought and possibly other environmental stresses.

Microwave-assisted pyrolysis of methyl ricinoleate for continuous production of undecylenic acid methyl ester (UAME).

Science.gov (United States)

Nie, Yong; Duan, Ying; Gong, Ruchao; Yu, Shangzhi; Lu, Meizhen; Yu, Fengwen; Ji, Jianbing

2015-06-01

Undecylenic acid methyl ester (UAME) was continuously produced from methyl ricinoleate using a microwave-assisted pyrolysis system with atomization feeding. The UAME yield of 77 wt.% was obtained at 500°C using SiC as the microwave absorbent and heating medium. The methyl ricinoleate conversion and UAME yield from microwave-assisted pyrolysis process were higher than those from conventional pyrolysis. The effect of temperature on the pyrolysis process was also investigated. The methyl ricinoleate conversion increased but the cracking liquid yield decreased when the temperature increased from 460°C to 560°C. The maximum UAME yield was obtained at the temperature of 500°C. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sterol Methyl Oxidases Affect Embryo Development via Auxin-Associated Mechanisms1

Science.gov (United States)

Zhang, Xia; Sun, Shuangli; Nie, Xiang; Boutté, Yohann; Grison, Magali; Li, Panpan; Kuang, Susu

2016-01-01

Sterols are essential molecules for multiple biological processes, including embryogenesis, cell elongation, and endocytosis. The plant sterol biosynthetic pathway is unique in the involvement of two distinct sterol 4α-methyl oxidase (SMO) families, SMO1 and SMO2, which contain three and two isoforms, respectively, and are involved in sequential removal of the two methyl groups at C-4. In this study, we characterized the biological functions of members of the SMO2 gene family. SMO2-1 was strongly expressed in most tissues during Arabidopsis (Arabidopsis thaliana) development, whereas SMO2-2 showed a more specific expression pattern. Although single smo2 mutants displayed no obvious phenotype, the smo2-1 smo2-2 double mutant was embryonic lethal, and the smo2-1 smo2-2/+ mutant was dwarf, whereas the smo2-1/+ smo2-2 mutant exhibited a moderate phenotype. The phenotypes of the smo2 mutants resembled those of auxin-defective mutants. Indeed, the expression of DR5rev:GFP, an auxin-responsive reporter, was reduced and abnormal in smo2-1 smo2-2 embryos. Furthermore, the expression and subcellular localization of the PIN1 auxin efflux facilitator also were altered. Consistent with these observations, either the exogenous application of auxin or endogenous auxin overproduction (YUCCA9 overexpression) partially rescued the smo2-1 smo2-2 embryonic lethality. Surprisingly, the dwarf phenotype of smo2-1 smo2-2/+ was completely rescued by YUCCA9 overexpression. Gas chromatography-mass spectrometry analysis revealed a substantial accumulation of 4α-methylsterols, substrates of SMO2, in smo2 heterozygous double mutants. Together, our data suggest that SMO2s are important for correct sterol composition and function partially through effects on auxin accumulation, auxin response, and PIN1 expression to regulate Arabidopsis embryogenesis and postembryonic development. PMID:27006488

Quantitative DNA methylation analyses reveal stage dependent DNA methylation and association to clinico-pathological factors in breast tumors

International Nuclear Information System (INIS)

Klajic, Jovana; Tost, Jörg; Kristensen, Vessela N; Fleischer, Thomas; Dejeux, Emelyne; Edvardsen, Hege; Warnberg, Fredrik; Bukholm, Ida; Lønning, Per Eystein; Solvang, Hiroko; Børresen-Dale, Anne-Lise

2013-01-01

Aberrant DNA methylation of regulatory genes has frequently been found in human breast cancers and correlated to clinical outcome. In the present study we investigate stage specific changes in the DNA methylation patterns in order to identify valuable markers to understand how these changes affect breast cancer progression. Quantitative DNA methylation analyses of 12 candidate genes ABCB1, BRCCA1, CDKN2A, ESR1, GSTP1, IGF2, MGMT, HMLH1, PPP2R2B, PTEN, RASSF1A and FOXC1 was performed by pyrosequencing a series of 238 breast cancer tissue samples from DCIS to invasive tumors stage I to IV. Significant differences in methylation levels between the DCIS and invasive stage II tumors were observed for six genes RASSF1A, CDKN2A, MGMT, ABCB1, GSTP1 and FOXC1. RASSF1A, ABCB1 and GSTP1 showed significantly higher methylation levels in late stage compared to the early stage breast carcinoma. Z-score analysis revealed significantly lower methylation levels in DCIS and stage I tumors compared with stage II, III and IV tumors. Methylation levels of PTEN, PPP2R2B, FOXC1, ABCB1 and BRCA1 were lower in tumors harboring TP53 mutations then in tumors with wild type TP53. Z-score analysis showed that TP53 mutated tumors had significantly lower overall methylation levels compared to tumors with wild type TP53. Methylation levels of RASSF1A, PPP2R2B, GSTP1 and FOXC1 were higher in ER positive vs. ER negative tumors and methylation levels of PTEN and CDKN2A were higher in HER2 positive vs. HER2 negative tumors. Z-score analysis also showed that HER2 positive tumors had significantly higher z-scores of methylation compared to the HER2 negative tumors. Univariate survival analysis identifies methylation status of PPP2R2B as significant predictor of overall survival and breast cancer specific survival. In the present study we report that the level of aberrant DNA methylation is higher in late stage compared with early stage of invasive breast cancers and DCIS for genes mentioned above

The ectopic expression of a pectin methyl esterase inhibitor increases pectin methyl esterification and limits fungal diseases in wheat.

Science.gov (United States)

Volpi, Chiara; Janni, Michela; Lionetti, Vincenzo; Bellincampi, Daniela; Favaron, Francesco; D'Ovidio, Renato

2011-09-01

Cell wall pectin methyl esterification can influence plant resistance because highly methyl-esterified pectin can be less susceptible to the hydrolysis by pectic enzymes such as fungal endopolygalacturonases (PG). Pectin is secreted into the cell wall in a highly methyl-esterified form and, here, is de-methyl esterified by pectin methyl esterase (PME). The activity of PME is controlled by specific protein inhibitors called PMEI; consequently, an increased inhibition of PME by PMEI might modify the pectin methyl esterification. In order to test the possibility of improving wheat resistance by modifying the methyl esterification of pectin cell wall, we have produced durum wheat transgenic lines expressing the PMEI from Actinidia chinensis (AcPMEI). The expression of AcPMEI endows wheat with a reduced endogenous PME activity, and transgenic lines expressing a high level of the inhibitor showed a significant increase in the degree of methyl esterification. These lines showed a significant reduction of disease symptoms caused by the fungal pathogens Bipolaris sorokiniana or Fusarium graminearum. This increased resistance was related to the impaired ability of these fungal pathogens to grow on methyl-esterified pectin and to a reduced activity of the fungal PG to hydrolyze methyl-esterified pectin. In addition to their importance for wheat improvement, these results highlight the primary role of pectin despite its low content in the wheat cell wall.

The effect of O2 partial pressure on the structure and photocatalytic property of TiO2 films prepared by sputtering

International Nuclear Information System (INIS)

Liu Baoshun; Zhao Xiujian; Zhao Qingnan; Li Chunling; He Xin

2005-01-01

The TiO 2 films were prepared on slide substrates by dc reactive magnetron sputtering at different oxygen partial pressure, and were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and Fourier transform infrared spectrometry (FT-IR). The degradation of methyl orange aqueous solutions was used to evaluate the photocatalytic activity. The results show that all films show crystalline anatase structure irrespective of oxygen partial pressure. The surface oxygen element exists in three forms, the first one is TiO 2 , the second one is OH - and the last one is physical absorbed water. The films deposited at oxygen partial pressure of 0.035 and 0.040 mTorr present better photocatalytic activity, which shows clear tendency to increase with oxygen partial pressure. Such photocatalytic activity results are considered to correlate with the crystalline structure, grain sizes and the OH - concentration

Anomalous vibrational modes in acetanilide as studied by inelastic neutron scattering

Science.gov (United States)

Barthes, Mariette; Eckert, Juegen; Johnson, Susanna W.; Moret, Jacques; Swanson, Basil I.; Unkefer, Clifford J.

1992-10-01

A study of the anomalous modes in acetanilide and five deuterated derivatives by incoherent inelastic neutron scattering is reported. These data show that the dynamics of the amide and methyl groups influence each other. In addition, the anomalous temperature behaviour of the NH out-of-plane bending mode is confirmed. These observations suggest that the self-trapping mechanism in ACN may be more complex than hitherto assumed.

Genome-Wide DNA Methylation Profiling Reveals Epigenetic Adaptation of Stickleback to Marine and Freshwater Conditions.

Science.gov (United States)

Artemov, Artem V; Mugue, Nikolai S; Rastorguev, Sergey M; Zhenilo, Svetlana; Mazur, Alexander M; Tsygankova, Svetlana V; Boulygina, Eugenia S; Kaplun, Daria; Nedoluzhko, Artem V; Medvedeva, Yulia A; Prokhortchouk, Egor B

2017-09-01

The three-spined stickleback (Gasterosteus aculeatus) represents a convenient model to study microevolution-adaptation to a freshwater environment. Although genetic adaptations to freshwater environments are well-studied, epigenetic adaptations have attracted little attention. In this work, we investigated the role of DNA methylation in the adaptation of the marine stickleback population to freshwater conditions. DNA methylation profiling was performed in marine and freshwater populations of sticklebacks, as well as in marine sticklebacks placed into a freshwater environment and freshwater sticklebacks placed into seawater. We showed that the DNA methylation profile after placing a marine stickleback into fresh water partially converged to that of a freshwater stickleback. For six genes including ATP4A ion pump and NELL1, believed to be involved in skeletal ossification, we demonstrated similar changes in DNA methylation in both evolutionary and short-term adaptation. This suggested that an immediate epigenetic response to freshwater conditions can be maintained in freshwater population. Interestingly, we observed enhanced epigenetic plasticity in freshwater sticklebacks that may serve as a compensatory regulatory mechanism for the lack of genetic variation in the freshwater population. For the first time, we demonstrated that genes encoding ion channels KCND3, CACNA1FB, and ATP4A were differentially methylated between the marine and the freshwater populations. Other genes encoding ion channels were previously reported to be under selection in freshwater populations. Nevertheless, the genes that harbor genetic and epigenetic changes were not the same, suggesting that epigenetic adaptation is a complementary mechanism to selection of genetic variants favorable for freshwater environment. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Cytosine methylation at CpCpG sites triggers accumulation of non-CpG methylation in gene bodies

OpenAIRE

Zabet, NR; Catoni, Marco; Prischi, F; Paszkowski, Jerzy Waclaw

2017-01-01

Methylation of cytosine is an epigenetic mark involved in the regulation of transcription, usually associated with transcriptional repression. In mammals, methylated cytosines are found predominantly in CpGs but in plants non-CpG methylation (in the CpHpG or CpHpH contexts, where H is A, C or T) is also present and is associated with the transcriptional silencing of transposable elements. In addition, CpG methylation is found in coding regions of active genes. In the absence of the demethylas...

Temperature effect on life-time of electron-excited uranyl ion. III. Effect of deuteration of solvent

International Nuclear Information System (INIS)

Lotnik, S.V.; Khamidullina, L.A.; Kazakov, V.P.

2001-01-01

Effect of deuteration of solvent was detected. The effect appeared in significant difference of shape of curves of uranyl ion (UO 2 2+ )* life-time temperature dependences in electron-excited state (τ). The curves were plotted during heating of frozen up to 77 K H 2 SO 4 solutions in H 2 O and D 2 SO 4 solutions in D 2 O. It was shown that in the case of D 2 SO 4 τ value in glass-like solution was lower then in polycrystalline sample, whereas in frozen H 2 SO 4 solutions there was opposite picture. Detected isotope effect was explained just as different proceeding of phase transition in H 2 SO 4 and D 2 SO 4 solutions so significant decrease of probability of nonradiating deactivation of (UO 2 2+ )* absorbed on D 2 SO 4 ·4D 2 O crystallohydrate surface in comparison with (UO 2 2+ )* absorbed on H 2 SO 4 ·4H 2 O and H 2 SO 4 ·6.5H 2 O crystallohydrate surfaces [ru

miRNAting control of DNA methylation

Indian Academy of Sciences (India)

DNA methylation is a type of epigenetic modification where a methyl group is added to the cytosine or adenine residue of a given DNA sequence. It has been observed that DNA methylation is achieved by some collaborative agglomeration of certain proteins and non-coding RNAs. The assembly of IDN2 and its ...

Analysis of DNA Methylation of Gracilariopsis lemaneiformis Under Temperature Stress Using the Methylation Sensitive Amplification Polymorphism (MSAP) Technique

Science.gov (United States)

Peng, Chong; Sui, Zhenghong; Zhou, Wei; Hu, Yiyi; Mi, Ping; Jiang, Minjie; Li, Xiaodong; Ruan, Xudong

2018-06-01

Gracilariopsis lemaneiformis is an economically important agarophyte, which contains high quality gel and shows a high growth rate. Wild population of G. lemaneiformis displayed resident divergence, though with a low genetic diversity as was revealed by amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) analyses. In addition, different strains of G. lemaneiformis are diverse in morphology. The highly inconsistence between genetic background and physiological characteristics recommends strongly to the regulation at epigenetic level. In this study, the DNA methylation change in G. lemaneiformis among different generation branches and under different temperature stresses was assessed using methylation sensitive amplified polymorphism (MSAP) technique. It was shown that DNA methylation level among different generation branches was diverse. The full and total methylated DNA level was the lowest in the second generation branch and the highest in the third generation. The total methylation level was 61.11%, 60.88% and 64.12% at 15°C, 22°C and 26°C, respectively. Compared with the control group (22°C), the fully methylated and totally methylated ratios were increased in both experiment groups (15°C and 26°C). All of the cytosine methylation/demethylation transform (CMDT) was further analyzed. High temperature treatment could induce more CMDT than low temperature treatment did.

Cocoa Consumption Alters the Global DNA Methylation of Peripheral Leukocytes in Humans with Cardiovascular Disease Risk Factors: A Randomized Controlled Trial.

Directory of Open Access Journals (Sweden)

Anna Crescenti

Full Text Available DNA methylation regulates gene expression and can be modified by different bioactive compounds in foods, such as polyphenols. Cocoa is a rich source of polyphenols, but its role in DNA methylation is still unknown. The objective was to assess the effect of cocoa consumption on DNA methylation and to determine whether the enzymes involved in the DNA methylation process participate in the mechanisms by which cocoa exerts these effects in humans. The global DNA methylation levels in the peripheral blood were evaluated in 214 volunteers who were pre-hypertensive, stage-1 hypertensive or hypercholesterolemic. The volunteers were divided into two groups: 110 subjects who consumed cocoa (6 g/d for two weeks and 104 control subjects. In addition, the peripheral blood mononuclear cells (PBMCs from six subjects were treated with a cocoa extract to analyze the mRNA levels of the DNA methyltransferases (DNMTs, methylenetetrahydrofolate reductase (MTHFR, and methionine synthase reductase (MTRR genes. Cocoa consumption significantly reduced the DNA methylation levels (2.991±0.366 vs. 3.909±0.380, p<0.001. Additionally, we found an association between the cocoa effects on DNA methylation and three polymorphisms located in the MTHFR, MTRR, and DNMT3B genes. Furthermore, in PBMCs, the cocoa extract significantly lowered the mRNA levels of the DNMTs, MTHFR, and MTRR. Our study demonstrates for the first time that the consumption of cocoa decreases the global DNA methylation of peripheral leukocytes in humans with cardiovascular risk factors. In vitro experiments with PBMCs suggest that cocoa may exert this effect partially via the down-regulation of DNMTs, MTHFR and MTRR, which are key genes involved in this epigenetic process.Clinicaltrials.govNCT00511420 and NCT00502047.

Rotation and rotation-vibration spectroscopy of the 0+-0- inversion doublet in deuterated cyanamide.

Science.gov (United States)

Kisiel, Zbigniew; Kraśnicki, Adam; Jabs, Wolfgang; Herbst, Eric; Winnewisser, Brenda P; Winnewisser, Manfred

2013-10-03

The pure rotation spectrum of deuterated cyanamide was recorded at frequencies from 118 to 649 GHz, which was complemented by measurement of its high-resolution rotation-vibration spectrum at 8-350 cm(-1). For D2NCN the analysis revealed considerable perturbations between the lowest Ka rotational energy levels in the 0(+) and 0(-) substates of the lowest inversion doublet. The final data set for D2NCN exceeded 3000 measured transitions and was successfully fitted with a Hamiltonian accounting for the 0(+) ↔ 0(-) coupling. A smaller data set, consisting only of pure rotation and rotation-vibration lines observed with microwave techniques was obtained for HDNCN, and additional transitions of this type were also measured for H2NCN. The spectroscopic data for all three isotopic species were fitted with a unified, robust Hamiltonian allowing confident prediction of spectra well into the terahertz frequency region, which is of interest to contemporary radioastronomy. The isotopic dependence of the determined inversion splitting, ΔE = 16.4964789(8), 32.089173(3), and 49.567770(6) cm(-1), for D2NCN, HDNCN, and H2NCN, respectively, is found to be in good agreement with estimates from a simple reduced quartic-quadratic double minimum potential.

Colorectal Cancer "Methylator Phenotype": Fact or Artifact?

Directory of Open Access Journals (Sweden)

Charles Anacleto

2005-04-01

Full Text Available It has been proposed that human colorectal tumors can be classified into two groups: one in which methylation is rare, and another with methylation of several loci associated with a "CpG island methylated phenotype (CIMP," characterized by preferential proximal location in the colon, but otherwise poorly defined. There is considerable overlap between this putative methylator phenotype and the well-known mutator phenotype associated with microsatellite instability (MSI. We have examined hypermethylation of the promoter region of five genes (DAPK, MGMT, hMLH1, p16INK4a, and p14ARF in 106 primary colorectal cancers. A graph depicting the frequency of methylated loci in the series of tumors showed a continuous, monotonically decreasing distribution quite different from the previously claimed discontinuity. We observed a significant association between the presence of three or more methylated loci and the proximal location of the tumors. However, if we remove from analysis the tumors with hMLH1 methylation or those with MSI, the significance vanishes, suggesting that the association between multiple methylations and proximal location was indirect due to the correlation with MSI. Thus, our data do not support the independent existence of the so-called methylator phenotype and suggest that it rather may represent a statistical artifact caused by confounding of associations.

Molecular dynamics in conducting polyaniline protonated by camphor sulfonic acid as seen by quasielastic neutron scattering

International Nuclear Information System (INIS)

Djurado, D.; Combet, J.; Bee, M.; Rannou, P.; Dufour, B.; Pron, A.; Travers, J. P.

2002-01-01

Using incoherent quasielastic neutron scattering techniques, the molecular motions were investigated in fully hydrogenated and partially deuterated polyaniline protonated by camphor sulfonic acid (CSA) conducting samples. The obtained results show that on the 10 -9 -10 -12 s time scale the polymer chains do not exhibit any diffusive motions: the whole observed quasielastic scattering has accordingly to be attributed to motions of CSA ions. From our measurements two molecular movements could be differentiated. A rapid one has been attributed to the three-site rotation of methyl groups present on camphor moieties of CSA and a slower one that has been modeled as a rigid body motion of the whole CSA molecule. Due to the disordered character of the system, the methyl rotors appeared to be dynamically nonequivalent. Their dynamics was then described in terms of a log gaussian distribution of correlation times. This description allowed a good fitting of experimental data and gave an activation energy of 12.5 kJ mol-1. However, two different regimes in temperature could be distinguished. At high temperatures (T>280 K) the width of the distribution is nearly zero and thus, the methyl rotors are dynamically equivalent while it turned larger and larger when temperature is decreased below 250 K revealing that the rotors are more and more sensitive to their local environment. In the conducting samples the slowest motion clearly exists in the 280-330 K temperature range and is blocked at temperatures inferior to 250 K. This transition occurs in the temperature range in which the metal-insulator transition also happens

Synthesis of N-methyl and N-11C-methyl spiperone by phase transfer catalysis in anhydrous solvent

International Nuclear Information System (INIS)

Omokawa, Hiroyoshi; Tanaka, Akira; Iio, Mayumi; Nishihara, Yoshiaki; Inoue, Osamu; Yamazaki, Toshio.

1985-01-01

Spiperone, a butyrophenone neuroleptic drug, has been used in binding studies of dopamine receptors. Langstrom et al. developed N- 11 C-methyl spiperone, and, in cooperate with Wagner et al., made it possible to visualize the distribution of dopamine receptors in the human brain in vivo. In this paper, we independently developed another synthetic method of N- 11 C-methyl spiperone using the phase transfer catalyst in an anhydrous solvent. Separation of the product is feasible only by passing the reactant solution through a Millipore filter and injecting it onto high pressure liquid chromatography (HPLC). The time required for the synthesis and purification of N- 11 C-methyl spiperone from 11 C-methyl iodide and spiperone was 20 min. Radiochemical yield exceeded 35 % against 11 C-methyl iodide without correcting decay of the radioactivity. (author)

Differential Effects of Methyl-4-Phenylpyridinium Ion, Rotenone, and Paraquat on Differentiated SH-SY5Y Cells

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João Barbosa Martins

2013-01-01

Full Text Available Paraquat (PQ, a cationic nonselective bipyridyl herbicide, has been used as neurotoxicant to modulate Parkinson’s disease in laboratory settings. Other compounds like rotenone (ROT, a pesticide, and 1-methyl-4-phenylpyridinium ion (MPP+ have been widely used as neurotoxicants. We compared the toxicity of these three neurotoxicants using differentiated dopaminergic SH-SY5Y human cells, aiming to elucidate their differential effects. PQ-induced neurotoxicity was shown to be concentration and time dependent, being mitochondrial dysfunction followed by neuronal death. On the other hand, cells exposure to MPP+ induced mitochondrial dysfunction, but not cellular lyses. Meanwhile, ROT promoted both mitochondrial dysfunction and neuronal death, revealing a biphasic pattern. To further elucidate PQ neurotoxic mechanism, several protective agents were used. SH-SY5Y cells pretreatment with tiron (TIR and 2-hydroxybenzoic acid sodium salt (NaSAL, both antioxidants, and Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME, a nitric oxide synthase inhibitor, partially protected against PQ-induced cell injury. Additionally, 1-(2-[bis(4-fluorophenylmethoxy]ethyl-4-(3-phenyl-propylpiperazine (GBR 12909, a dopamine transporter inhibitor, and cycloheximide (CHX, a protein synthesis inhibitor, also partially protected against PQ-induced cell injury. In conclusion, we demonstrated that PQ, MPP+, and ROT exerted differential toxic effects on dopaminergic cells. PQ neurotoxicity occurred through exacerbated oxidative stress, with involvement of uptake through the dopamine transporter and protein synthesis.

Methylation profiling identified novel differentially methylated markers including OPCML and FLRT2 in prostate cancer.

Science.gov (United States)

Wu, Yu; Davison, Jerry; Qu, Xiaoyu; Morrissey, Colm; Storer, Barry; Brown, Lisha; Vessella, Robert; Nelson, Peter; Fang, Min

2016-04-02

To develop new methods to distinguish indolent from aggressive prostate cancers (PCa), we utilized comprehensive high-throughput array-based relative methylation (CHARM) assay to identify differentially methylated regions (DMRs) throughout the genome, including both CpG island (CGI) and non-CGI regions in PCa patients based on Gleason grade. Initially, 26 samples, including 8 each of low [Gleason score (GS) 6] and high (GS ≥7) grade PCa samples and 10 matched normal prostate tissues, were analyzed as a discovery cohort. We identified 3,567 DMRs between normal and cancer tissues, and 913 DMRs distinguishing low from high-grade cancers. Most of these DMRs were located at CGI shores. The top 5 candidate DMRs from the low vs. high Gleason comparison, including OPCML, ELAVL2, EXT1, IRX5, and FLRT2, were validated by pyrosequencing using the discovery cohort. OPCML and FLRT2 were further validated in an independent cohort consisting of 20 low-Gleason and 33 high-Gleason tissues. We then compared patients with biochemical recurrence (n=70) vs. those without (n=86) in a third cohort, and they showed no difference in methylation at these DMR loci. When GS 3+4 cases and GS 4+3 cases were compared, OPCML-DMR methylation showed a trend of lower methylation in the recurrence group (n=30) than in the no-recurrence (n=52) group. We conclude that whole-genome methylation profiling with CHARM revealed distinct patterns of differential DNA methylation between normal prostate and PCa tissues, as well as between different risk groups of PCa as defined by Gleason scores. A panel of selected DMRs may serve as novel surrogate biomarkers for Gleason score in PCa.

[Specific features of 2-methyl hydroxybenzene and 3-methyl hydroxybenzene distribution in the organism of warm-blooded animals].

Science.gov (United States)

Shormanov, B K; Grishenko, V K; Astashkina, A P; Elizarova, M K

2013-01-01

The present work was designed to study the specific features of 2-methyl hydroxybezene and 3-methyl hydroxybenzene distribution after intragastric administration of these toxicants to warm-blooded animals (rats). They were detected in the unmetabolized form in the internal organs and blood of the animals. The levels of 2-methyl hydroxybezene were especially high in the stomach and blood whereas the maximum content of 3-methyl hydroxybenzene was found in brain, blood, small intestines of the poisoned rats.

Genome-wide DNA methylation maps in follicular lymphoma cells determined by methylation-enriched bisulfite sequencing.

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Jeong-Hyeon Choi

Full Text Available BACKGROUND: Follicular lymphoma (FL is a form of non-Hodgkin's lymphoma (NHL that arises from germinal center (GC B-cells. Despite the significant advances in immunotherapy, FL is still not curable. Beyond transcriptional profiling and genomics datasets, there currently is no epigenome-scale dataset or integrative biology approach that can adequately model this disease and therefore identify novel mechanisms and targets for successful prevention and treatment of FL. METHODOLOGY/PRINCIPAL FINDINGS: We performed methylation-enriched genome-wide bisulfite sequencing of FL cells and normal CD19(+ B-cells using 454 sequencing technology. The methylated DNA fragments were enriched with methyl-binding proteins, treated with bisulfite, and sequenced using the Roche-454 GS FLX sequencer. The total number of bases covered in the human genome was 18.2 and 49.3 million including 726,003 and 1.3 million CpGs in FL and CD19(+ B-cells, respectively. 11,971 and 7,882 methylated regions of interest (MRIs were identified respectively. The genome-wide distribution of these MRIs displayed significant differences between FL and normal B-cells. A reverse trend in the distribution of MRIs between the promoter and the gene body was observed in FL and CD19(+ B-cells. The MRIs identified in FL cells also correlated well with transcriptomic data and ChIP-on-Chip analyses of genome-wide histone modifications such as tri-methyl-H3K27, and tri-methyl-H3K4, indicating a concerted epigenetic alteration in FL cells. CONCLUSIONS/SIGNIFICANCE: This study is the first to provide a large scale and comprehensive analysis of the DNA methylation sequence composition and distribution in the FL epigenome. These integrated approaches have led to the discovery of novel and frequent targets of aberrant epigenetic alterations. The genome-wide bisulfite sequencing approach developed here can be a useful tool for profiling DNA methylation in clinical samples.

Modeling spatiotemporal dynamics of DNA methylation

DEFF Research Database (Denmark)

Lövkvist, Cecilia Elisabet

into how epigenetic marks are distributed in the human genome. In the first part of the thesis, we investigate DNA methylation and maintenance of methylation patterns throughout cell division. We argue that collaborative models, those where the methylation of CpG sites depends on the methylation status...... into the game more explicitly in another type of model that speaks out the duality of the two aspects. Using statistical analysis of experimental data, this thesis further explores a link between DNA methylation and nucleosome occupancy. By comparing the patterns on promoters to regions with similar Cp...... division. The patterns of epigentic marks depend on enzymes that ensure their maintenance and introduction. Using theoretical models, this thesis proposes new mechanisms for how enzymes operate to maintain patterns of epigenetic marks. Through analysis of experimental data this work gives new insight...

Thermodynamics of poly(7-methoxy-2-acetylbenzofurane methyl methacrylate-co-styrene) and poly(2-acetylbenzofurane methyl methacrylate-co-styrene)-probe interactions at different temperatures by inverse gas chromatography

International Nuclear Information System (INIS)

İlter, Zülfiye; Demir, Abdullah; Kaya, İsmet

2016-01-01

Highlights: • Thermodynamic of methacrylate-co-styrene polymers were studied by the inverse gas chromatography. • The sorption parameters of polymer-solute systems were determined under glass transition temperature of polymers. • The solubility parameter (δ 2 ) of the polymer was obtained from the slope and intercepts. • Flory-Huggins interaction parameter (χ 12 ∞ ) were determined for polymer-solute systems. - Abstract: In this study, some thermodynamic properties of poly(7-methoxy-2-acetylbenzofurane methyl methacrylate-co-styrene) Poly(MABMM-co-St) and poly(2-acetylbenzofurane methyl methacrylate-co-styrene) Poly(ABMM-co-St) were studied by the inverse gas chromatography (IGC) technique. The retention times (t r ) of selected organic probes were determined from the interactions with Poly(MABMM-co-St) and Poly(ABMM-co-St) of four groups of solvents with different chemical natures and polarities. Then, specific volume (V g 0 ) values of probes were calculated at different column temperatures. The glass transition temperatures (T g ) of Poly(MABMM-co-St) and Poly(ABMM-co-St) were found as 393, 413 K from inverse gas chromatography measurements, respectively. Under the glass transition temperatures adsorption heat (ΔH a ) and above the glass transition molar heat (ΔH 1 S ), free energies (ΔG 1 S ) and entropies (ΔS 1 S ) belonging to sorption for every probe were calculated from inverse gas chromatography measurements. The partial molar heat (ΔH 1 ∞ ), partial molar free energy (ΔG 1 ∞ ), Flory-Huggins interaction parameter (χ 12 ∞ ) and weight fraction activity coefficient (a 1 /w 1 ) ∞ , values for infinite dilute solutions were calculated for polymer-probe systems. The solubility parameter (δ 2 ) of the polymer was obtained from the slope and intercepts of Flory-Huggins interaction parameter (χ 12 ∞ ) graphs with solubility parameters (δ 1 ) of probes.

Experimental and chemical kinetic modeling study of small methyl esters oxidation: Methyl (E)-2-butenoate and methyl butanoate

Energy Technology Data Exchange (ETDEWEB)

Gail, S.; Sarathy, S.M.; Thomson, M.J. [Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8 (Canada); Dievart, P.; Dagaut, P. [CNRS, 1C, Ave de la Recherche Scientifique, 45071 Orleans Cedex 2 (France)

2008-12-15

This study examines the effect of unsaturation on the combustion of fatty acid methyl esters (FAME). New experimental results were obtained for the oxidation of methyl (E)-2-butenoate (MC, unsaturated C{sub 4} FAME) and methyl butanoate (MB, saturated C{sub 4} FAME) in a jet-stirred reactor (JSR) at atmospheric pressure under dilute conditions over the temperature range 850-1400 K, and two equivalence ratios ({phi}=0.375,0.75) with a residence time of 0.07 s. The results consist of concentration profiles of the reactants, stable intermediates, and final products, measured by probe sampling followed by on-line and off-line gas chromatography analyses. The oxidation of MC and MB in the JSR and under counterflow diffusion flame conditions was modeled using a new detailed chemical kinetic reaction mechanism (301 species and 1516 reactions) derived from previous schemes proposed in the literature. The laminar counterflow flame and JSR (for {phi}=1.13) experimental results used were from a previous study on the comparison of the combustion of both compounds. Sensitivity analyses and reaction path analyses, based on rates of reaction, were used to interpret the results. The data and the model show that MC has reaction pathways analogous to that of MB under the present conditions. The model of MC oxidation provides a better understanding of the effect of the ester function on combustion, and the effect of unsaturation on the combustion of fatty acid methyl ester compounds typically found in biodiesel. (author)

Naturally occurring methyl salicylate glycosides.

Science.gov (United States)

Mao, Ping; Liu, Zizhen; Xie, Meng; Jiang, Rui; Liu, Weirui; Wang, Xiaohong; Meng, Shen; She, Gaimei

2014-01-01

As an important part of non steroids anti-inflammation drug (NSAIDs), salicylate has developed from natural substance salicylic acid to natrium salicylicum, to aspirin. Now, methyl salicylate glycoside, a new derivative of salicylic acid, is modified with a -COOH group integrated one methyl radical into formic ether, and a -OH linked with a monosaccharide, a disaccharide or a trisaccharide unit by glycosidic linkage. It has the similar pharmacological activities, anti-inflammatory, analgesic, antipyretic and antithrombotic as the previous salicylates' without resulting in serious side effects, particularly the gastrointestinal toxicity. Owing to the superiority of those significant bioactivities, methyl salicylate glycosides have became a hot research area in NSAIDs for several years. This paper compiles all 9 naturally occurring methyl salicylate glycosides, their distribution of the resource and pharmacological mechanism, which could contribute to the new drug discovery.

Protein methylation reactions in intact pea chloroplasts

International Nuclear Information System (INIS)

Niemi, K.J.

1989-01-01

Post-translational protein methylation was investigated in Pisum sativum chloroplasts. Intact pea chloroplasts were incubated with ( 3 H-methyl)-S-adenosylmethionine under various conditions. The chloroplasts were then separated into stromal and thylakoid fractions and analyzed for radioactivity transferred to protein. Light enhanced the magnitude of labeling in both fractions. One thylakoid polypeptide with an apparent molecular mass of 43 kDa was labeled only in the light. Several other thylakoid and stromal proteins were labeled in both light and dark-labeling conditions. Both base-labile methylation, carboxy-methylesters and base-stable groups, N-methylations were found. Further characterization of the methyl-transfer reactions will be presented

Molecular correlates with MGMT promoter methylation and silencing support CpG island methylator phenotype-low (CIMP-low) in colorectal cancer.

Science.gov (United States)

Ogino, Shuji; Kawasaki, Takako; Kirkner, Gregory J; Suemoto, Yuko; Meyerhardt, Jeffrey A; Fuchs, Charles S

2007-11-01

The CpG island methylator phenotype (CIMP or CIMP-high) with widespread promoter methylation is a distinct epigenetic phenotype in colorectal cancer. In contrast, a phenotype with less widespread promoter methylation (CIMP-low) has not been well characterised. O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation and silencing have been associated with G>A mutations and microsatellite instability-low (MSI-low). To examine molecular correlates with MGMT methylation/silencing in colorectal cancer. Utilising MethyLight technology, we quantified DNA methylation in MGMT and eight other markers (a CIMP-diagnostic panel; CACNA1G, CDKN2A (p16), CRABP1, IGF2, MLH1, NEUROG1, RUNX3 and SOCS1) in 920 population-based colorectal cancers. Tumours with both MGMT methylation and loss were correlated positively with MSI-low (p = 0.02), CIMP-high (>or=6/8 methylated CIMP markers, p = 0.005), CIMP-low (1/8-5/8 methylated CIMP markers, p = 0.002, compared to CIMP-0 with 0/8 methylated markers), KRAS G>A mutation (p = 0.02), and inversely with 18q loss of heterozygosity (p = 0.0002). Tumours were classified into nine MSI/CIMP subtypes. Among the CIMP-low group, tumours with both MGMT methylation and loss were far more frequent in MSI-low tumours (67%, 12/18) than MSI-high tumours (5.6%, 1/18; p = 0.0003) and microsatellite stable (MSS) tumours (33%, 52/160; p = 0.008). However, no such relationship was observed among the CIMP-high or CIMP-0 groups. The relationship between MGMT methylation/silencing and MSI-low is limited to only CIMP-low tumours, supporting the suggestion that CIMP-low in colorectal cancer may be a different molecular phenotype from CIMP-high and CIMP-0. Our data support a molecular difference between MSI-low and MSS in colorectal cancer, and a possible link between CIMP-low, MSI-low, MGMT methylation/loss and KRAS mutation.

The highly heterogeneous methylated genomes and diverse restriction-modification systems of bloom-forming Microcystis.

Science.gov (United States)

Zhao, Liang; Song, Yulong; Li, Lin; Gan, Nanqin; Brand, Jerry J; Song, Lirong

2018-05-01

The occurrence of harmful Microcystis blooms is increasing in frequency in a myriad of freshwater ecosystems. Despite considerable research pertaining to the cause and nature of these blooms, the molecular mechanisms behind the cosmopolitan distribution and phenotypic diversity in Microcystis are still unclear. We compared the patterns and extent of DNA methylation in three strains of Microcystis, PCC 7806SL, NIES-2549 and FACHB-1757, using Single Molecule Real-Time (SMRT) sequencing technology. Intact restriction-modification (R-M) systems were identified from the genomes of these strains, and from two previously sequenced strains of Microcystis, NIES-843 and TAIHU98. A large number of methylation motifs and R-M genes were identified in these strains, which differ substantially among different strains. Of the 35 motifs identified, eighteen had not previously been reported. Strain NIES-843 contains a larger number of total putative methyltransferase genes than have been reported previously from any bacterial genome. Genomic comparisons reveal that methyltransferases (some partial) may have been acquired from the environment through horizontal gene transfer. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of Methyl-Binding Domain Based Enrichment Approaches Revisited.

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Karolina A Aberg

Full Text Available Methyl-binding domain (MBD enrichment followed by deep sequencing (MBD-seq, is a robust and cost efficient approach for methylome-wide association studies (MWAS. MBD-seq has been demonstrated to be capable of identifying differentially methylated regions, detecting previously reported robust associations and producing findings that replicate with other technologies such as targeted pyrosequencing of bisulfite converted DNA. There are several kits commercially available that can be used for MBD enrichment. Our previous work has involved MethylMiner (Life Technologies, Foster City, CA, USA that we chose after careful investigation of its properties. However, in a recent evaluation of five commercially available MBD-enrichment kits the performance of the MethylMiner was deemed poor. Given our positive experience with MethylMiner, we were surprised by this report. In an attempt to reproduce these findings we here have performed a direct comparison of MethylMiner with MethylCap (Diagenode Inc, Denville, NJ, USA, the best performing kit in that study. We find that both MethylMiner and MethylCap are two well performing MBD-enrichment kits. However, MethylMiner shows somewhat better enrichment efficiency and lower levels of background "noise". In addition, for the purpose of MWAS where we want to investigate the majority of CpGs, we find MethylMiner to be superior as it allows tailoring the enrichment to the regions where most CpGs are located. Using targeted bisulfite sequencing we confirmed that sites where methylation was detected by either MethylMiner or by MethylCap indeed were methylated.

IGFBP3 Promoter Methylation in Colorectal Cancer: Relationship with Microsatellite Instability, CpG Island Methylator Phenotype, p53

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Takako Kawasaki

2007-12-01

Full Text Available Insulin-like growth factor binding protein 3 (IGFBP3, which is induced by wild-type p53, regulates IGF and interacts with the TGF-β pathway. IGFBP3 promoter methylation may occur in colorectal cancer with or without the CpG island methylator phenotype (CIMP, which is associated with microsatellite instability (MSI and TGFBR2 mutation. We examined the relationship between IGFBP3 methylation, p53 expression, CIMP and MSI in 902 population-based colorectal cancers. Utilizing real-time PCR (MethyLight, we quantified promoter methylation in IGFBP3 and eight other CIMP-high-specific promoters (CACNA1G, CDKN2A, CRABP1, IGF2, MLH1, NEUROG1, RUNX3, and SOCS1. IGFBP3 methylation was far more frequent in non-MSI-high CIMP-high tumors (85% = 35/41 than in MSI-high CIMPhigh (49% = 44/90, P < .0001, MSI-high non-CIMP-high (17% = 6/36, P < .0001, non-MSI-high non-CIMP-high tumors (22% = 152/680, P < .0001. Among CIMPhigh tumors, the inverse relationship between MSI and IGFBP3 methylation persisted in p53-negative tumors (P < .0001, but not in p53-positive tumors. IGFBP3 methylation was associated inversely with TGFBR2 mutation in MSI-high non-CIMP-high tumors (P = .02. In conclusion, IGFBP3 methylation is inversely associated with MSI in CIMP-high colorectal cancers, this relationship is limited to p53-negative tumors. Our data suggest complex relationship between global genomic/epigenomic phenomena (such as MSI/ CIMP, single molecular events (e.g., IGFBP3 methylation, TP53 mutation, TGFBR2 mutation, the related pathways.

High-excitation lines of deuterated formaldehyde (HDCO) in the Orion molecular cloud

International Nuclear Information System (INIS)

Loren, R.B.; Wootten, A.

1985-01-01

Five HDCO lines (up to 35 cm -1 ) have been detected in the narrow OMC-1 kinematic component. The best estimate of the [HDCO]/[H 2 CO] abundance ratio in OMC-1 is 0.01-0.03, at least an order of magnitude greater than the observed [DCO + ]/[HCO + ] abundance ratio. The [DCO + ]/[HCO + ] ratio greatly exceeds the [HDCO]/[H 2 CO] radio in cold clouds where the enhancement of both HDCO and DCO + abundances originates from H 2 D + . H 2 D + is abundant only at temperatures lower than found in OMC-1. The combination of a low [DCO + ]/[HCO + ] and high [HDCO]/[H 2 CO] abundance ratio in OMC-1 requires a different HDCO formation route at high temperature. This alternate HDCO formation path can occur because the exothermicity of the ion exchange reaction of HD and CH 3 + is greater than for the HD+H 3 + reaction. The CH 2 D + thus formed survives to higher temperatures than H 2 D + . Subsequent reactions with H 2 lead to CH 4 D + which by electronic recombination forms CH 2 D. The HDCO (H 2 CO) forms in the neutral-neutral reaction of CH 2 D (CH 3 ) and O. These reactions are not competitive in forming a variety of deuterated molecules at low temperatures since electronic recombination rapidly removes CH 2 D + and CH 4 D + ions while the abundant H 2 D + ion is slow to recombine, as reported by Smith and Adam in 1984

COSMOLOGICAL CONCORDANCE OR CHEMICAL COINCIDENCE? DEUTERATED MOLECULAR HYDROGEN ABUNDANCES AT HIGH REDSHIFT

International Nuclear Information System (INIS)

Tumlinson, J.; Malec, A. L.; Murphy, M. T.; Carswell, R. F.; Jorgenson, R. A.; Buning, R.; Ubachs, W.; Milutinovic, N.; Ellison, S. L.; Prochaska, J. X.; Wolfe, A. M.

2010-01-01

We report two detections of deuterated molecular hydrogen (HD) in QSO absorption-line systems at z>2. Toward J2123-0500, we find N(HD) =13.84 ± 0.2 for a sub-Damped Lyman Alpha system (DLA) with metallicity ≅0.5Z sun and N(H 2 ) = 17.64 ± 0.15 at z = 2.0594. Toward FJ0812+32, we find N(HD) =15.38 ± 0.3 for a solar-metallicity DLA with N(H 2 ) = 19.88 ± 0.2 at z = 2.6265. These systems have ratios of HD to H 2 above that observed in dense clouds within the Milky Way disk and apparently consistent with a simple conversion from the cosmological ratio of D/H. These ratios are not readily explained by any available model of HD chemistry, and there are no obvious trends with metallicity or molecular content. Taken together, these two systems and the two published z>2 HD-bearing DLAs indicate that HD is either less effectively dissociated or more efficiently produced in high-redshift interstellar gas, even at low molecular fraction and/or solar metallicity. It is puzzling that such diverse systems should show such consistent HD/H 2 ratios. Without clear knowledge of all the aspects of HD chemistry that may help determine the ratio HD/H 2 , we conclude that these systems are potentially more revealing of gas chemistry than of D/H itself and that it is premature to use such systems to constrain D/H at high redshift.

Osteoponin Promoter Controlled by DNA Methylation: Aberrant Methylation in Cloned Porcine Genome

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Chih-Jie Shen

2014-01-01

Full Text Available Cloned animals usually exhibited many defects in physical characteristics or aberrant epigenetic reprogramming, especially in some important organ development. Osteoponin (OPN is an extracellular-matrix protein involved in heart and bone development and diseases. In this study, we investigated the correlation between OPN mRNA and its promoter methylation changes by the 5-aza-dc treatment in fibroblast cell and promoter assay. Aberrant methylation of porcine OPN was frequently found in different tissues of somatic nuclear transferred cloning pigs, and bisulfite sequence data suggested that the OPN promoter region −2615 to −2239 nucleotides (nt may be a crucial regulation DNA element. In pig ear fibroblast cell culture study, the demethylation of OPN promoter was found in dose-dependent response of 5-aza-dc treatment and followed the OPN mRNA reexpression. In cloned pig study, discrepant expression pattern was identified in several cloned pig tissues, especially in brain, heart, and ear. Promoter assay data revealed that four methylated CpG sites presenting in the −2615 to −2239 nt region cause significant downregulation of OPN promoter activity. These data suggested that methylation in the OPN promoter plays a crucial role in the regulation of OPN expression that we found in cloned pigs genome.

Sterol Methyl Oxidases Affect Embryo Development via Auxin-Associated Mechanisms.

Science.gov (United States)

Zhang, Xia; Sun, Shuangli; Nie, Xiang; Boutté, Yohann; Grison, Magali; Li, Panpan; Kuang, Susu; Men, Shuzhen

2016-05-01

Sterols are essential molecules for multiple biological processes, including embryogenesis, cell elongation, and endocytosis. The plant sterol biosynthetic pathway is unique in the involvement of two distinct sterol 4α-methyl oxidase (SMO) families, SMO1 and SMO2, which contain three and two isoforms, respectively, and are involved in sequential removal of the two methyl groups at C-4. In this study, we characterized the biological functions of members of the SMO2 gene family. SMO2-1 was strongly expressed in most tissues during Arabidopsis (Arabidopsis thaliana) development, whereas SMO2-2 showed a more specific expression pattern. Although single smo2 mutants displayed no obvious phenotype, the smo2-1 smo2-2 double mutant was embryonic lethal, and the smo2-1 smo2-2/+ mutant was dwarf, whereas the smo2-1/+ smo2-2 mutant exhibited a moderate phenotype. The phenotypes of the smo2 mutants resembled those of auxin-defective mutants. Indeed, the expression of DR5rev:GFP, an auxin-responsive reporter, was reduced and abnormal in smo2-1 smo2-2 embryos. Furthermore, the expression and subcellular localization of the PIN1 auxin efflux facilitator also were altered. Consistent with these observations, either the exogenous application of auxin or endogenous auxin overproduction (YUCCA9 overexpression) partially rescued the smo2-1 smo2-2 embryonic lethality. Surprisingly, the dwarf phenotype of smo2-1 smo2-2/+ was completely rescued by YUCCA9 overexpression. Gas chromatography-mass spectrometry analysis revealed a substantial accumulation of 4α-methylsterols, substrates of SMO2, in smo2 heterozygous double mutants. Together, our data suggest that SMO2s are important for correct sterol composition and function partially through effects on auxin accumulation, auxin response, and PIN1 expression to regulate Arabidopsis embryogenesis and postembryonic development. © 2016 American Society of Plant Biologists. All Rights Reserved.

Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide

International Nuclear Information System (INIS)

Domanska, Urszula; Marciniak, Andrzej

2009-01-01

The activity coefficients at infinite dilution, γ 13 ∞ for 36 solutes: alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofuran, ethers, acetone, and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide [bmPY][NTf 2 ] were determined by gas-liquid chromatography at temperatures from 298.15 K to 368.15 K. The partial molar excess enthalpies at infinite dilution values ΔH 1 E,∞ were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The selectivity for different separation problems were calculated from the γ 13 ∞ and compared to the literature values for other ionic liquids, N-methyl-2-pyrrolidinone (NMP) and sulfolane.

Developmental differences in posttranslational calmodulin methylation in pea plants

International Nuclear Information System (INIS)

Oh, Sukheung; Roberts, D.M.

1990-01-01

A calmodulin-N-methyltransferase was used to analyze the degree of lysine-115 methylation of pea calmodulin. Calmodulin was isolated from segments of developing roots of young etiolated and green pea plants and was tested for its ability to be methylated by the calmodulin methyltransferase in the presence of 3 H-methyl-S-adenosylmethionine. Calmodulin methylation levels were lower in apical root segments and in the young lateral roots compared with the mature, differentiated root tissues. The methylation of these calmodulin samples occurs specifically at lysine 115 since site-directed mutants of calmodulin with substitutions at this position were not methylated and competitively inhibited methylation. The present findings, combined with previous data showing differences in NAD kinase activation by methylated and unmethylated calmodulins, raise the possibility that posttranslational methylation could affect calmodulin action

Thermal unimolecular decomposition of bicyclopropyl and deuterated analogues: infrared photoactivation as a diagnostic tool in mechanistic organic chemistry

International Nuclear Information System (INIS)

Farneth, W.E.; Thomsen, M.W.

1982-01-01

The infrared photochemistry of bicyclopropyl yields product mixtures that are not easily rationalized on the basis of the mechanistic scheme suggested by previous pyrolysis work. As a result of this inconsistency the thermal chemistry of bicyclopropyl and analogues deuterated specifically on one ring has been reexamined. A significant new reaction channel involving the chemically activated decomposition of cyclohexene to ethylene and butadiene has been demonstrated. Evidence for the involvement of chemically activated cyclohexene is as follows: (1) isotopic labeling studies implying a symmetric intermediate, (2) a pressure-dependent ratio of cyclohexene to butadiene and ethylene, (3) good agreement between experimental and calculated values for the unimolecular rate constant for retro-Diels-Alder decay of ''hot'' cyclohexene. A comprehensive mechanism for the unimolecular decay of bicyclopropyl is proposed. The important elements of this mechanism are a single first-formed 1,3 biradical common to all products and the intervention of chemical activation in the generation of several of the secondary products

Commensurately modulated 1/4 and 1/5 phases of deuterated betaine calcium chloride dihydrate: a neutron structural study

International Nuclear Information System (INIS)

Hernandez, O.; Cousson, A.; Kiat, J.M.; Ecole Centrale des Arts et Manufactures, 92 - Chatenay-Malabry; Paulus, W.; Technische Hochschule Aachen; Ezpeleta, J.M.; Zuniga, F.J.

1999-01-01

The structures of the commensurate 1/4 and 1/5 phases of the displacively modulated compound D-BCCD [deuterated betaine (trimethylammonioacetate) calcium chloride dihydrate, i.e. (CD 3 ) 3 NCD 2 COOCaCl 2 (D 2 O) 2 or CaCl 2 x C 5 D 11 NO 2 x 2D 2 O] have been determined by single-crystal neutron diffraction at 100 and 68 K, respectively. The structural model of the 1/4 phase is found to be quite different from that obtained previously from X-ray diffraction data of the hydrogenated compound. This discrepancy comes from the fact that X-ray irradiation induces in this compound an unusual time-dependent decrease of the intensity of high-order satellite diffraction peaks. As a consequence and due to the commensurate nature of the phases investigated, X-ray diffraction failed to detect the large anharmonicity of the structural modulation which is clearly present in the two structures determined by neutron diffraction. (orig.)

The respective N-hydroxypyrazole analogues of the classical glutamate receptor ligands ibotenic acid and (RS)-2-amino-2-(3-hydroxy-5-methyl-4-isoxazolyl)acetic acid

DEFF Research Database (Denmark)

Clausen, Rasmus P; Hansen, Kasper B; Calí, Patrizia

2004-01-01

We have determined the pharmacological activity of N-hydroxypyrazole analogues (3a and 4a) of the classical glutamate receptor ligands ibotenic acid and (RS)-2-amino-2-(3-hydroxy-5-methyl-4-isoxazolyl)acetic acid (AMAA), as well as substituted derivatives of these two compounds. The pharmacological...... partial agonism to antagonism with increasing substituent size, substitution abolishes affinity for mglu1 and mglu4 receptors. Ligand- and receptor-based modelling approaches assist in explaining these pharmacological trends among the metabotropic receptors and suggest a mechanism of partial agonism...

Improving the Accuracy of NMR Structures of Large Proteins Using Pseudocontact Shifts as Long-Range Restraints

Energy Technology Data Exchange (ETDEWEB)

Gaponenko, Vadim [National Cancer Institute, Structural Biophysics Laboratory (United States); Sarma, Siddhartha P. [Indian Institute of Science, Molecular Biophysics Unit (India); Altieri, Amanda S. [National Cancer Institute, Structural Biophysics Laboratory (United States); Horita, David A. [Wake Forest University School of Medicine, Department of Biochemistry (United States); Li, Jess; Byrd, R. Andrew [National Cancer Institute, Structural Biophysics Laboratory (United States)], E-mail: rabyrd@ncifcrf.gov

2004-03-15

We demonstrate improved accuracy in protein structure determination for large ({>=}30 kDa), deuterated proteins (e.g. STAT4{sub NT}) via the combination of pseudocontact shifts for amide and methyl protons with the available NOEs in methyl-protonated proteins. The improved accuracy is cross validated by Q-factors determined from residual dipolar couplings measured as a result of magnetic susceptibility alignment. The paramagnet is introduced via binding to thiol-reactive EDTA, and multiple sites can be serially engineered to obtain data from alternative orientations of the paramagnetic anisotropic susceptibility tensor. The technique is advantageous for systems where the target protein has strong interactions with known alignment media.

Selective bond cleavage in potassium collisions with pyrimidine bases of DNA.

Science.gov (United States)

Almeida, Diogo; Ferreira da Silva, Filipe; García, Gustavo; Limão-Vieira, Paulo

2013-01-11

Electron transfer in alkali-molecule collisions to gas phase thymine and uracil yielding H- formation is selectively controlled in the energy range between 5.3 and 66.1 eV. By tuning the collision energy, electron transfer from the alkali to partly deuterated thymine, methylated thymine at the N1 and methylated uracil at the N3 positions, H- loss proceeds not only through the breaking of the (C-H) against (N-H) bonds but also through N1 against N3 sites. Such selectivity, as far as bond and site are concerned, is here reported for the first time by electron transfer induced dissociation experiments in alkali-molecule collisions.

Patterns of cytosine methylation in an elite rice hybrid and its parental lines, detected by a methylation-sensitive amplification polymorphism technique.

Science.gov (United States)

Xiong, L Z; Xu, C G; Saghai Maroof, M A; Zhang, Q

1999-04-01

DNA methylation is known to play an important role in the regulation of gene expression in eukaryotes. In this study, we assessed the extent and pattern of cytosine methylation in the rice genome, using the technique of methylation-sensitive amplified polymorphism (MSAP), which is a modification of the amplified fragment length polymorphism (AFLP) method that makes use of the differential sensitivity of a pair of isoschizomers to cytosine methylation. The tissues assayed included seedlings and flag leaves of an elite rice hybrid, Shanyou 63, and the parental lines Zhenshan 97 and Minghui 63. In all, 1076 fragments, each representing a recognition site cleaved by either or both of the isoschizomers, were amplified using 16 pairs of selective primers. A total of 195 sites were found to be methylated at cytosines in one or both parents, and the two parents showed approximately the same overall degree of methylation (16.3%), as revealed by the incidence of differential digestion by the isoschizomers. Four classes of patterns were identified in a comparative assay of cytosine methylation in the parents and hybrid; increased methylation was detected in the hybrid compared to the parents at some of the recognition sites, while decreased methylation in the hybrid was detected at other sites. A small proportion of the sites was found to be differentially methylated in seedlings and flag leaves; DNA from young seedlings was methylated to a greater extent than that from flag leaves. Almost all of the methylation patterns detected by MSAP could be confirmed by Southern analysis using the isolated amplified fragments as probes. The results clearly demonstrate that the MSAP technique is highly efficient for large-scale detection of cytosine methylation in the rice genome. We believe that the technique can be adapted for use in other plant species.

Methylation sensitive amplified polymorphism (MSAP) reveals that ...

African Journals Online (AJOL)

ajl yemi

2011-12-19

Dec 19, 2011 ... Key words: Salt stress, alkali stress, Gossypium hirsutum L., DNA methylation, methylation sensitive amplified polymorphism (MSAP). INTRODUCTION. DNA methylation is one of the key epigenetic mecha- nisms among eukaryotes that can modulate gene expression without the changes of DNA sequence.

Thermal Decomposition of Potential Ester Biofuels. Part I: Methyl Acetate and Methyl Butanoate

Energy Technology Data Exchange (ETDEWEB)

Porterfield, Jessica P.; Bross, David H.; Ruscic, Branko; Thorpe, James H.; Nguyen, Thanh Lam; Baraban, Joshua H.; Stanton, John F.; Daily, John W.; Ellison, G. Barney

2017-06-09

Two methyl esters have been examined as models for the pyrolysis of biofuels. Dilute samples (0.06 - 0.13%) of methyl acetate (CH₃COOCH₃) and methyl butanoate (CH₃CH₂CH₂COOCH₃) were entrained in (He, Ar) carrier gas and decomposed in a set of flash-pyrolysis micro-reactors. The pyrolysis products resulting from the methyl esters were detected and identified by vacuum ultraviolet photoionization mass spectrometry. Complementary product identification was provided by matrix infrared absorption spectroscopy. Pyrolysis pressures in the pulsed micro-reactor were roughly 20 Torr and residence times through the reactors were approximately 25 - 150 µs. Reactor temperatures of 300 – 1600 K were explored. Decomposition of CH₃COOCH₃ commences at 1000 K and the initial products are (CH₂=C=O and CH₃OH). As the micro-reactor is heated to 1300 K, a mixture of (CH₂=C=O and CH₃OH, CH₃, CH₂=O, H, CO, CO₂) appears. The thermal cracking of CH₃CH₂CH₂COOCH₃ begins at 800 K with the formation of (CH₃CH₂CH=C=O, CH₃OH). By 1300 K, the pyrolysis of methyl butanoate yields a complex mixture of (CH₃CH₂CH=C=O, CH₃OH, CH₃, CH₂=O, CO, CO₂, CH₃CH=CH₂, CH₂CHCH₂, CH₂=C=CH₂, HCCCH₂, CH₂=C=C=O, CH₂=CH₂, HCΞCH, CH₂=C=O). Based on the results from the thermal cracking of methyl acetate and methyl butanoate, we predict several important decomposition channels for the pyrolysis of fatty acid methyl esters, R CH₂-COOCH₃. The lowest energy fragmentation will be a 4-center elimination of methanol to form the ketene, RCH=C=O. At higher temperatures, concerted

Electronic transport in methylated fragments of DNA

Energy Technology Data Exchange (ETDEWEB)

Almeida, M. L. de; Oliveira, J. I. N.; Lima Neto, J. X.; Gomes, C. E. M.; Fulco, U. L., E-mail: umbertofulco@gmail.com; Albuquerque, E. L. [Departamento de Biofísica e Farmacologia, Universidade Federal do Rio Grande do Norte, 59072-970 Natal-RN (Brazil); Freire, V. N. [Departamento de Física, Universidade Federal do Ceará, 60455-760 Fortaleza, CE (Brazil); Caetano, E. W. S. [Instituto Federal de Educação, Ciência e Tecnologia do Ceará, 60040-531 Fortaleza, CE (Brazil); Moura, F. A. B. F. de; Lyra, M. L. [Instituto de Física, Universidade Federal de Alagoas, 57072-900 Maceió-AL (Brazil)

2015-11-16

We investigate the electronic transport properties of methylated deoxyribonucleic-acid (DNA) strands, a biological system in which methyl groups are added to DNA (a major epigenetic modification in gene expression), sandwiched between two metallic platinum electrodes. Our theoretical simulations apply an effective Hamiltonian based on a tight-binding model to obtain current-voltage curves related to the non-methylated/methylated DNA strands. The results suggest potential applications in the development of novel biosensors for molecular diagnostics.

Electronic transport in methylated fragments of DNA

International Nuclear Information System (INIS)

Almeida, M. L. de; Oliveira, J. I. N.; Lima Neto, J. X.; Gomes, C. E. M.; Fulco, U. L.; Albuquerque, E. L.; Freire, V. N.; Caetano, E. W. S.; Moura, F. A. B. F. de; Lyra, M. L.

2015-01-01

We investigate the electronic transport properties of methylated deoxyribonucleic-acid (DNA) strands, a biological system in which methyl groups are added to DNA (a major epigenetic modification in gene expression), sandwiched between two metallic platinum electrodes. Our theoretical simulations apply an effective Hamiltonian based on a tight-binding model to obtain current-voltage curves related to the non-methylated/methylated DNA strands. The results suggest potential applications in the development of novel biosensors for molecular diagnostics

Current bonding systems for resin-bonded restorations and fixed partial dentures made of silver–palladium–copper–gold alloy

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Hideo Matsumura

2011-02-01

Full Text Available This review article describes about the bonding systems for noble metal alloys, bonding techniques of restorations and fixed partial dentures (FPDs made of Ag–Pd–Cu–Au alloys, and their clinical performance. Thione monomers, 6-(4-vinylbenzyl-n-propyl amino-1,3,5-triazine-2,4-dithione (VTD, 6-methacryloyloxyhexyl-2-thiouracil-5-carboxylate (MTU-6, and 10-methacryloxydecyl 6,8-dithiooctanoate (MDDT, has been proved effective for bonding noble metal alloys. An acrylic adhesive consists of the tri-n-butylborane (TBB initiator, methyl methacrylate (MMA monomer liquid with 5% 4-methacryloyloxyethyl trimellitate anhydride (4-META, and poly(methyl methacrylate (PMMA, is being used for bonding metallic restorations to abutment surfaces. Clinical performance of restorations and FPDs made of Ag–Pd–Cu–Au alloys is overall excellent when they are seated with the currently available noble metal bonding systems.

DNA Methylation Modulates Nociceptive Sensitization after Incision.

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Yuan Sun

Full Text Available DNA methylation is a key epigenetic mechanism controlling DNA accessibility and gene expression. Blockade of DNA methylation can significantly affect pain behaviors implicated in neuropathic and inflammatory pain. However, the role of DNA methylation with regard to postoperative pain has not yet been explored. In this study we sought to investigate the role of DNA methylation in modulating incisional pain and identify possible targets under DNA methylation and contributing to incisional pain. DNA methyltranferase (DNMT inhibitor 5-Aza-2'-deoxycytidine significantly reduced incision-induced mechanical allodynia and thermal sensitivity. Aza-2'-deoxycytidine also reduced hindpaw swelling after incision, suggesting an anti-inflammatory effect. Global DNA methylation and DNMT3b expression were increased in skin after incision, but none of DNMT1, DNMT3a or DNMT3b was altered in spinal cord or DRG. The expression of proopiomelanocortin Pomc encoding β-endorphin and Oprm1 encoding the mu-opioid receptor were upregulated peripherally after incision; moreover, Oprm1 expression was further increased under DNMT inhibitor treatment. Finally, local peripheral injection of the opioid receptor antagonist naloxone significantly exacerbated incision-induced mechanical hypersensitivity. These results suggest that DNA methylation is functionally relevant to incisional nociceptive sensitization, and that mu-opioid receptor signaling might be one methylation regulated pathway controlling sensitization after incision.

CpG island methylator phenotype (CIMP) of colorectal cancer is best characterised by quantitative DNA methylation analysis and prospective cohort studies.

Science.gov (United States)

Ogino, S; Cantor, M; Kawasaki, T; Brahmandam, M; Kirkner, G J; Weisenberger, D J; Campan, M; Laird, P W; Loda, M; Fuchs, C S

2006-07-01

The concept of CpG island methylator phenotype (CIMP) is not universally accepted. Even if specific clinicopathological features have been associated with CIMP, investigators often failed to demonstrate a bimodal distribution of the number of methylated markers, which would suggest CIMP as a distinct subtype of colorectal cancer. Previous studies primarily used methylation specific polymerase chain reaction which might detect biologically insignificant low levels of methylation. To demonstrate a distinct genetic profile of CIMP colorectal cancer using quantitative DNA methylation analysis that can distinguish high from low levels of DNA methylation. We developed quantitative real time polymerase chain reaction (MethyLight) assays and measured DNA methylation (percentage of methylated reference) of five carefully selected loci (promoters of CACNA1G, CDKN2A (p16), CRABP1, MLH1, and NEUROG1) in 460 colorectal cancers from large prospective cohorts. There was a clear bimodal distribution of 80 microsatellite instability-high (MSI-H) tumours according to the number of methylated promoters, with no tumours showing 3/5 methylated loci. Thus we defined CIMP as having >or=4/5 methylated loci, and 17% (78) of the 460 tumours were classified as CIMP. CIMP was significantly associated with female sex, MSI, BRAF mutations, and wild-type KRAS. Both CIMP MSI-H tumours and CIMP microsatellite stable (MSS) tumours showed much higher frequencies of BRAF mutations (63% and 54%) than non-CIMP counterparts (non-CIMP MSI-H (0%, pCIMP MSS tumours (6.6%, pCIMP is best characterised by quantitative DNA methylation analysis. CIMP is a distinct epigenotype of colorectal cancer and may be less frequent than previously reported.

Minimal methylation classifier (MIMIC): A novel method for derivation and rapid diagnostic detection of disease-associated DNA methylation signatures.

Science.gov (United States)

Schwalbe, E C; Hicks, D; Rafiee, G; Bashton, M; Gohlke, H; Enshaei, A; Potluri, S; Matthiesen, J; Mather, M; Taleongpong, P; Chaston, R; Silmon, A; Curtis, A; Lindsey, J C; Crosier, S; Smith, A J; Goschzik, T; Doz, F; Rutkowski, S; Lannering, B; Pietsch, T; Bailey, S; Williamson, D; Clifford, S C

2017-10-18

Rapid and reliable detection of disease-associated DNA methylation patterns has major potential to advance molecular diagnostics and underpin research investigations. We describe the development and validation of minimal methylation classifier (MIMIC), combining CpG signature design from genome-wide datasets, multiplex-PCR and detection by single-base extension and MALDI-TOF mass spectrometry, in a novel method to assess multi-locus DNA methylation profiles within routine clinically-applicable assays. We illustrate the application of MIMIC to successfully identify the methylation-dependent diagnostic molecular subgroups of medulloblastoma (the most common malignant childhood brain tumour), using scant/low-quality samples remaining from the most recently completed pan-European medulloblastoma clinical trial, refractory to analysis by conventional genome-wide DNA methylation analysis. Using this approach, we identify critical DNA methylation patterns from previously inaccessible cohorts, and reveal novel survival differences between the medulloblastoma disease subgroups with significant potential for clinical exploitation.

DNA damage, homology-directed repair, and DNA methylation.

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Concetta Cuozzo

2007-07-01

Full Text Available To explore the link between DNA damage and gene silencing, we induced a DNA double-strand break in the genome of Hela or mouse embryonic stem (ES cells using I-SceI restriction endonuclease. The I-SceI site lies within one copy of two inactivated tandem repeated green fluorescent protein (GFP genes (DR-GFP. A total of 2%-4% of the cells generated a functional GFP by homology-directed repair (HR and gene conversion. However, approximately 50% of these recombinants expressed GFP poorly. Silencing was rapid and associated with HR and DNA methylation of the recombinant gene, since it was prevented in Hela cells by 5-aza-2'-deoxycytidine. ES cells deficient in DNA methyl transferase 1 yielded as many recombinants as wild-type cells, but most of these recombinants expressed GFP robustly. Half of the HR DNA molecules were de novo methylated, principally downstream to the double-strand break, and half were undermethylated relative to the uncut DNA. Methylation of the repaired gene was independent of the methylation status of the converting template. The methylation pattern of recombinant molecules derived from pools of cells carrying DR-GFP at different loci, or from an individual clone carrying DR-GFP at a single locus, was comparable. ClustalW analysis of the sequenced GFP molecules in Hela and ES cells distinguished recombinant and nonrecombinant DNA solely on the basis of their methylation profile and indicated that HR superimposed novel methylation profiles on top of the old patterns. Chromatin immunoprecipitation and RNA analysis revealed that DNA methyl transferase 1 was bound specifically to HR GFP DNA and that methylation of the repaired segment contributed to the silencing of GFP expression. Taken together, our data support a mechanistic link between HR and DNA methylation and suggest that DNA methylation in eukaryotes marks homologous recombined segments.

Wp specific methylation of highly proliferated LCLs

International Nuclear Information System (INIS)

Park, Jung-Hoon; Jeon, Jae-Pil; Shim, Sung-Mi; Nam, Hye-Young; Kim, Joon-Woo; Han, Bok-Ghee; Lee, Suman

2007-01-01

The epigenetic regulation of viral genes may be important for the life cycle of EBV. We determined the methylation status of three viral promoters (Wp, Cp, Qp) from EBV B-lymphoblastoid cell lines (LCLs) by pyrosequencing. Our pyrosequencing data showed that the CpG region of Wp was methylated, but the others were not. Interestingly, Wp methylation was increased with proliferation of LCLs. Wp methylation was as high as 74.9% in late-passage LCLs, but 25.6% in early-passage LCLs. From two Burkitt's lymphoma cell lines, Wp specific hypermethylation was also found (>80%). Interestingly, the expression of EBNA2 gene which located directly next to Wp was associated with its methylation. Our data suggested that Wp specific methylation may be important for the indicator of the proliferation status of LCLs, and the epigenetic viral gene regulation of EBNA2 gene by Wp should be further defined possibly with other biological processes

DNA Methylation Biomarkers: Cancer and Beyond

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Thomas Mikeska

2014-09-01

Full Text Available Biomarkers are naturally-occurring characteristics by which a particular pathological process or disease can be identified or monitored. They can reflect past environmental exposures, predict disease onset or course, or determine a patient’s response to therapy. Epigenetic changes are such characteristics, with most epigenetic biomarkers discovered to date based on the epigenetic mark of DNA methylation. Many tissue types are suitable for the discovery of DNA methylation biomarkers including cell-based samples such as blood and tumor material and cell-free DNA samples such as plasma. DNA methylation biomarkers with diagnostic, prognostic and predictive power are already in clinical trials or in a clinical setting for cancer. Outside cancer, strong evidence that complex disease originates in early life is opening up exciting new avenues for the detection of DNA methylation biomarkers for adverse early life environment and for estimation of future disease risk. However, there are a number of limitations to overcome before such biomarkers reach the clinic. Nevertheless, DNA methylation biomarkers have great potential to contribute to personalized medicine throughout life. We review the current state of play for DNA methylation biomarkers, discuss the barriers that must be crossed on the way to implementation in a clinical setting, and predict their future use for human disease.

Subsets of microsatellite-unstable colorectal cancers exhibit discordance between the CpG island methylator phenotype and MLH1 methylation status.

Science.gov (United States)

Kim, Jung H; Rhee, Ye-Y; Bae, Jeong-M; Kwon, Hyeong-J; Cho, Nam-Y; Kim, Mi J; Kang, Gyeong H

2013-07-01

Although the presence of MLH1 methylation in microsatellite-unstable colorectal cancer generally indicates involvement of the CpG island methylator phenotype (CIMP) in the development of the tumor, these two conditions do not always correlate. A minority of microsatellite-unstable colorectal cancers exhibit discordance between CIMP and MLH1 methylation statuses. However, the clinicopathological features of such microsatellite-unstable colorectal cancers with discrepant MLH1 methylation and CIMP statuses remain poorly studied. Microsatellite-unstable colorectal cancers (n=220) were analyzed for CIMP and MLH1 methylation statuses using the MethyLight assay. Based on the combinatorial CIMP and MLH1 methylation statuses, the microsatellite-unstable colorectal cancers were grouped into four subtypes (CIMP-high (CIMP-H) MLH1 methylation-positive (MLH1m+), CIMP-H MLH1 methylation-negative, CIMP-low/0 (CIMP-L/0) MLH1m+, and CIMP-L/0 MLH1 methylation-negative), which were compared in terms of their associations with clinicopathological and molecular features. The CIMP-L/0 MLH1 methylation-negative and CIMP-H MLH1m+ subtypes were predominant, comprising 63.6 and 24.1% of total microsatellite-unstable colorectal cancers, respectively. The discordant subtypes, CIMP-H MLH1 methylation-negative and CIMP-L/0 MLH1m+, were found in 5 and 7% of microsatellite-unstable colorectal cancers, respectively. The CIMP-H MLH1 methylation-negative subtype exhibited elevated incidence rates in male patients and was associated with larger tumor size, more frequent loss of MSH2 expression, increased frequency of KRAS mutation, and advanced cancer stage. The CIMP-L/0 MLH1m+ subtype was associated with onset at an earlier age, a predominance of MLH1 loss, and earlier cancer stage. None of the CIMP-L/0 MLH1m+ subtype patients succumbed to death during the follow-up. Our findings suggest that the discordant subtypes of colorectal cancers exhibit distinct clinicopathological and molecular features

Production of Methyl Laurate from Coconut Cream through Fractionation of Methyl Ester

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Johnner P. Sitompul

2015-10-01

Full Text Available This paper concerns the production of methyl laurate from coconut cream through fractionation of methyl esters. Coconut oil was produced by wet processing of coconut cream. The esters were prepared by reacting coconut oil and methanol using homogeneous catalyst KOH in a batch reactor, followed by fractionation of fatty acid methyl esters (FAME at various reduced pressures applying differential batch vacuum distillation. Experimental data were compared with simulation of a batch distillation employing the simple Raoult’s model and modified Raoult’s model of phase equilibria. Activity coefficients (γi were determined by optimization to refine the models. The modified Rault’s model with activity coefficients gave better agreement with the experimental data, giving the value of γi between 0,56-0,73. For a given boiling temperature, lower operating pressure produced higher purity of C10 and C12 FAME for respective distillates.

Radiation effects on DNA methylation in mice

International Nuclear Information System (INIS)

Komura, J.; Kurishita, A.; Miyamura, Y.; Ono, T.; Tawa, R.; Sakurai, H.

1992-01-01

Effects of ionizing radiation on DNA methylation in liver, brain and spleen were examined by high performance liquid chromatography (HPLC). The total methylated cytosine level in the genome was reduced within 8 hours after 3.8 Gy of irradiation in liver of adult mice. But no appreciable effect was observed in brain and spleen. When mice were irradiated at newborn, liver DNA revealed no change in methylated cytosine level. Even though slight effects of radiation were detected in he methylation of the c-myc and c-fos genes, they were only temporary and no long-term effects were observed. These data suggest that the effect of radiation on DNA methylation in vivo is not prevailing a DNA damage, but rather influenced much through biological parameters. (author)

Methylation of ribonucleic acid by the carcinogens dimethyl sulphate, N-methyl-N-nitrosourea and N-methyl-N′-nitro-N-nitrosoguanidine. Comparisons of chemical analyses at the nucleoside and base levels

Science.gov (United States)

Lawley, P. D.; Shah, S. A.

1972-01-01

1. The following methods for hydrolysis of methyl-14C-labelled RNA, and for chromatographic isolation and determination of the products, were investigated: enzymic digestion to nucleosides at pH6 or 8; alkaline hydrolysis and conversion into nucleosides; hydrolysis by acid to pyrimidine nucleotides and purine bases, or completely to bases; chromatography on Dowex 50 (NH4+ form) at pH6 or 8.9, or on Dowex 50 (H+ form), or on Sephadex G-10. 2. The suitability of the various methods for determination of methylation products was assessed. The principal product, 7-methylguanosine, was unstable under the conditions used for determinations of nucleosides. 3- and 7-Methyladenine and 3- and 7-methylguanine are best determined as bases; 1-methyladenine and 3-methylcytosine can be isolated as either nucleosides or bases; O6-methylguanine is unstable under the acid hydrolysis conditions used and can be determined as the nucleoside; 3-methyluracil was detected, but may be derived from methylation of the ionized form of uracil. 3. Differences between the patterns of methylation of RNA and homopolyribonucleotides by the N-methyl-N-nitroso compounds and dimethyl sulphate were found: the nitroso compounds were able to methylate O-6 of guanine, were relatively more reactive at N-7 of adenine and probably at N-3 of guanine, but less reactive at N-1 of adenine, N-3 of cytosine and probably at N-3 of uridine. They probably reacted more with the ribose–phosphate chain, but no products from this were identified. 4. The possible influences of these differences on biological action of the methylating agents is discussed. Nitroso compounds may differ principally in their ability to induce miscoding in the Watson–Crick sense by reaction at O-6 of guanine. Both types of agent may induce miscoding to a lesser extent through methylation at N-3 of guanine; both can methylate N atoms, presumably preventing Watson–Crick hydrogen-bonding. N-Methyl-N-nitrosourea can degrade RNA, possibly

Methyl group turnover on methyl-accepting chemotaxis proteins during chemotaxis by Bacillus subtilis

International Nuclear Information System (INIS)

Thoelke, M.S.; Casper, J.M.; Ordal, G.W.

1990-01-01

The addition of attractant to Bacillus subtilis briefly exposed to radioactive methionine causes an increase of labeling of the methyl-accepting chemotaxis proteins. The addition of attractant to cells radiolabeled for longer times shows no change in the extent of methylation. Therefore, the increase in labeling for the briefly labeled cells is due to an increased turnover of methyl groups caused by attractant. All amino acids gave enhanced turnover. This turnover lasted for a prolonged time, probably spanning the period of smooth swimming caused by the attractant addition. Repellent did not affect the turnover when added alone or simultaneously with attractant. Thus, for amino acid attractants, the turnover is probably the excitatory signal, which is seen to extend long into or throughout the adaptation period, not just at the start of it

Transcription factors as readers and effectors of DNA methylation.

Science.gov (United States)

Zhu, Heng; Wang, Guohua; Qian, Jiang

2016-08-01

Recent technological advances have made it possible to decode DNA methylomes at single-base-pair resolution under various physiological conditions. Many aberrant or differentially methylated sites have been discovered, but the mechanisms by which changes in DNA methylation lead to observed phenotypes, such as cancer, remain elusive. The classical view of methylation-mediated protein-DNA interactions is that only proteins with a methyl-CpG binding domain (MBD) can interact with methylated DNA. However, evidence is emerging to suggest that transcription factors lacking a MBD can also interact with methylated DNA. The identification of these proteins and the elucidation of their characteristics and the biological consequences of methylation-dependent transcription factor-DNA interactions are important stepping stones towards a mechanistic understanding of methylation-mediated biological processes, which have crucial implications for human development and disease.

RlmCD-mediated U747 methylation promotes efficient G748 methylation by methyltransferase RlmAII in 23S rRNA in Streptococcus pneumoniae; interplay between two rRNA methylations responsible for telithromycin susceptibility.

Science.gov (United States)

Shoji, Tatsuma; Takaya, Akiko; Sato, Yoshiharu; Kimura, Satoshi; Suzuki, Tsutomu; Yamamoto, Tomoko

2015-10-15

Adenine at position 752 in a loop of helix 35 from positions 745 to 752 in domain II of 23S rRNA is involved in binding to the ribosome of telithromycin (TEL), a member of ketolides. Methylation of guanine at position 748 by the intrinsic methyltransferase RlmA(II) enhances binding of telithromycin (TEL) to A752 in Streptococcus pneumoniae. We have found that another intrinsic methylation of the adjacent uridine at position 747 enhances G748 methylation by RlmA(II), rendering TEL susceptibility. U747 and another nucleotide, U1939, were methylated by the dual-specific methyltransferase RlmCD encoded by SP_1029 in S. pneumoniae. Inactivation of RlmCD reduced N1-methylated level of G748 by RlmA(II) in vivo, leading to TEL resistance when the nucleotide A2058, located in domain V of 23S rRNA, was dimethylated by the dimethyltransferase Erm(B). In vitro methylation of rRNA showed that RlmA(II) activity was significantly enhanced by RlmCD-mediated pre-methylation of 23S rRNA. These results suggest that RlmCD-mediated U747 methylation promotes efficient G748 methylation by RlmA(II), thereby facilitating TEL binding to the ribosome. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Dynamic Alu Methylation during Normal Development, Aging, and Tumorigenesis

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Yanting Luo

2014-01-01

Full Text Available DNA methylation primarily occurs on CpG dinucleotides and plays an important role in transcriptional regulations during tissue development and cell differentiation. Over 25% of CpG dinucleotides in the human genome reside within Alu elements, the most abundant human repeats. The methylation of Alu elements is an important mechanism to suppress Alu transcription and subsequent retrotransposition. Decades of studies revealed that Alu methylation is highly dynamic during early development and aging. Recently, many environmental factors were shown to have a great impact on Alu methylation. In addition, aberrant Alu methylation has been documented to be an early event in many tumors and Alu methylation levels have been associated with tumor aggressiveness. The assessment of the Alu methylation has become an important approach for early diagnosis and/or prognosis of cancer. This review focuses on the dynamic Alu methylation during development, aging, and tumor genesis. The cause and consequence of Alu methylation changes will be discussed.

Organic Extractives from Mentha spp. Honey and the Bee-Stomach: Methyl Syringate, Vomifoliol, Terpenediol I, Hotrienol and Other Compounds

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Igor Jerković

2010-04-01

Full Text Available The GC and GC/MS analyses of the solvent organic extractive from the stomach of the bees, having collected Mentha spp. nectar, revealed the presence of methyl syringate (6.6%, terpendiol I (5.0% and vomifoliol (3.0% that can be attributed to the plant origin. Other major compounds from the bee-stomach were related to the composition of cuticular waxes and less to pheromones. Organic extractivesfrom Mentha spp. honey were obtained by solvent-free headspace solid-phase microextraction (HS-SPME and ultrasonic solvent extraction (USE and analyzed by GC and GC/MS. The major honey headspace compounds were hotrienol (31.1%–38.5%, 2-methoxy-4-methylphenol (0.5–6.0%, cis- and trans-linalool oxides (0.9–2.8%, linalool (1.0–3.1% and neroloxide (0.9–1.9%. Methyl syringate was the most abundant compound (38.3-56.2% in the honey solvent extractives followed by vomifoliol (7.0–26.6%. Comparison of the honey organic extractives with the corresponding bee-stomach extractive indicated that methyl syringate and vomofoliol were transferred to the honey while terpendiol I was partially transformed to hotrienol in ripened honey.

QSPR models of n-octanol/water partition coefficients and aqueous solubility of halogenated methyl-phenyl ethers by DFT method.

Science.gov (United States)

Zeng, Xiao-Lan; Wang, Hong-Jun; Wang, Yan

2012-02-01

The possible molecular geometries of 134 halogenated methyl-phenyl ethers were optimized at B3LYP/6-31G(*) level with Gaussian 98 program. The calculated structural parameters were taken as theoretical descriptors to establish two new novel QSPR models for predicting aqueous solubility (-lgS(w,l)) and n-octanol/water partition coefficient (lgK(ow)) of halogenated methyl-phenyl ethers. The two models achieved in this work both contain three variables: energy of the lowest unoccupied molecular orbital (E(LUMO)), most positive atomic partial charge in molecule (q(+)), and quadrupole moment (Q(yy) or Q(zz)), of which R values are 0.992 and 0.970 respectively, their standard errors of estimate in modeling (SD) are 0.132 and 0.178, respectively. The results of leave-one-out (LOO) cross-validation for training set and validation with external test sets both show that the models obtained exhibited optimum stability and good predictive power. We suggests that two QSPR models derived here can be used to predict S(w,l) and K(ow) accurately for non-tested halogenated methyl-phenyl ethers congeners. Copyright © 2011 Elsevier Ltd. All rights reserved.

Synthesis of specifically deuterated pregnanolone and pregnanediol sulphates for metabolic studies in pregant women

International Nuclear Information System (INIS)

Baillie, T.A.; Herz, J.E.; Anderson, R.A.; Sjovall, J.

1975-01-01

A series of specifically deuterated isomers of pregnanolone sulphate and pregnanediol mono- and disulphate have been synthesized for use in a study of the formation and metabolism of C 21 -steroid sulphates in the plasma of pregnant women. Hecogenin, the starting material for the synthesis, was equilibrated with NaO 2 H- 2 H 2 O and the resulting 11,11- 2 H 2 derivative converted directly to its tosylhydrazone. Reduction with sodium borohydride and degradation of the sapogenin side-chain gave 3β-hydroxy-5α-[11,11- 2 H 2 ] pregn-16-en-20-one (isotopic purity 91.6%). Further deuterium atoms were introduced in the 3α and 3α,20β positions by reductions with sodium borodeuteride and lithium aluminum deuteride, respectively. These reactions led to 3β-hydroxy-5α-[3α,11,11- 2 H 3 ] pregnan-20-one (isotopic purity 87.2%) and 5α-[3α,11,11,20β- 2 H 4 ] pregnane-3β,20α-diol (isotopic purity 83.9%). Steroids possessing the less readily accessible 3α-hydroxy-5α-[3β- 2 H] configuration were obtained, without loss of label, by epimerization of the 3β isomers. Pregnanolone sulphates and pregnanediol disulphates were prepared directly from the free alcohols, while the pregnanediol 3-monosulphates were synthesized from the appropriate pregnanediol 20-monoacetate derivatives

Small angle neutron scattering study of the micelle structure of amphiphilic block copolymers

International Nuclear Information System (INIS)

Yamaoka, H.; Matsuoka, H.; Sumaru, K.; Hanada, S.

1994-01-01

The amphiphilic block copolymers of vinyl ether were prepared by living cationic polymerization. The partially deuterated copolymers for SANS experiments were especially synthesized by introducing deuterated phenyl units in the hydrophobic chain. SANS measurements were performed for aqueous solutions of these copolymers by changing H 2 O/D 2 O ratios. The SANS profiles indicate that the micelles in the present system exhibit a core-shell structure and that the size and shape of micelles are largely dependent on the length of hydrophobic chain. The micelle of shorter hydrophobic chain was found to be nearly spherical, whereas the micelle of longer hydrophobic chain was confirmed to have an ellipsoidal shape

Annotating the genome by DNA methylation.

Science.gov (United States)

Cedar, Howard; Razin, Aharon

2017-01-01

DNA methylation plays a prominent role in setting up and stabilizing the molecular design of gene regulation and by understanding this process one gains profound insight into the underlying biology of mammals. In this article, we trace the discoveries that provided the foundations of this field, starting with the mapping of methyl groups in the genome and the experiments that helped clarify how methylation patterns are maintained through cell division. We then address the basic relationship between methyl groups and gene repression, as well as the molecular rules involved in controlling this process during development in vivo. Finally, we describe ongoing work aimed at defining the role of this modification in disease and deciphering how it may serve as a mechanism for sensing the environment.

Analysis of DNA methylation of maize in response to osmotic and salt stress based on methylation-sensitive amplified polymorphism.

Science.gov (United States)

Tan, Ming-pu

2010-01-01

Water stress is known to alter cytosine methylation, which generally represses transcription. However, little is known about the role of methylation alteration in maize under osmotic stress. Here, methylation-sensitive amplified polymorphism (MSAP) was used to screen PEG- or NaCl-induced methylation alteration in maize seedlings. The sequences of 25 differentially amplified fragments relevant to stress were successfully obtained. Two stress-specific fragments from leaves, LP166 and LPS911, shown to be homologous to retrotransposon Gag-Pol protein genes, suggested that osmotic stress-induced methylation of retrotransposons. Three MSAP fragments, representing drought-induced or salt-induced methylation in leaves, were homologous to a maize aluminum-induced transporter. Besides these, heat shock protein HSP82, Poly [ADP-ribose] polymerase 2, Lipoxygenase, casein kinase (CK2), and dehydration-responsive element-binding (DREB) factor were also homologs of MSAP sequences from salt-treated roots. One MSAP fragment amplified from salt-treated roots, designated RS39, was homologous to the first intron of maize protein phosphatase 2C (zmPP2C), whereas - LS103, absent from salt-treated leaves, was homologous to maize glutathione S-transferases (zmGST). Expression analysis showed that salt-induced intron methylation of root zmPP2C significantly downregulated its expression, while salt-induced demethylation of leaf zmGST weakly upregulated its expression. The results suggested that salinity-induced methylation downregulated zmPP2C expression, a negative regulator of the stress response, while salinity-induced demethylation upregulated zmGST expression, a positive effecter of the stress response. Altered methylation, in response to stress, might also be involved in stress acclimation. Copyright 2009 Elsevier Masson SAS. All rights reserved.

Analysis of Mammalian Cell Proliferation and Macromolecule Synthesis Using Deuterated Water and Gas Chromatography-Mass Spectrometry

Directory of Open Access Journals (Sweden)

Victoria C. Foletta

2016-10-01

Full Text Available Deuterated water (2H2O, a stable isotopic tracer, provides a convenient and reliable way to label multiple cellular biomass components (macromolecules, thus permitting the calculation of their synthesis rates. Here, we have combined 2H2O labelling, GC-MS analysis and a novel cell fractionation method to extract multiple biomass components (DNA, protein and lipids from the one biological sample, thus permitting the simultaneous measurement of DNA (cell proliferation, protein and lipid synthesis rates. We have used this approach to characterize the turnover rates and metabolism of a panel of mammalian cells in vitro (muscle C2C12 and colon cancer cell lines. Our data show that in actively-proliferating cells, biomass synthesis rates are strongly linked to the rate of cell division. Furthermore, in both proliferating and non-proliferating cells, it is the lipid pool that undergoes the most rapid turnover when compared to DNA and protein. Finally, our data in human colon cancer cell lines reveal a marked heterogeneity in the reliance on the de novo lipogenic pathway, with the cells being dependent on both ‘self-made’ and exogenously-derived fatty acid.

Ground-based Detection of Deuterated Water in Comet C/2014 Q2 (Lovejoy) at IR Wavelengths

Energy Technology Data Exchange (ETDEWEB)

Paganini, L.; Mumma, M. J.; Villanueva, G. L. [Goddard Center for Astrobiology, NASA Goddard Space Flight Center, Greenbelt, MD (United States); Gibb, E. L. [Department of Physics and Astronomy, University of Missouri, St. Louis, MO (United States)

2017-02-20

We conducted a deep search for deuterated water (HDO) in the Oort Cloud comet C/2014 Q2 (Lovejoy), through infrared (IR) spectroscopy with NIRSPEC at the Keck Observatory. In this Letter, we present our detections of HDO and water (H{sub 2}O) in comet Lovejoy on 2015 February 4 (post-perihelion) after 1 hr integration on source. The IR observations allowed simultaneous detection of H{sub 2}O and HDO, yielding production rates of 5.9 ± 0.13 × 10{sup 29} and 3.6 ± 1.0 × 10{sup 26} molecules s{sup −1}, respectively. The simultaneous detection permitted accurate determination of the isotopic ratio (D/H) in water of 3.02 ± 0.87 × 10{sup −4}, i.e., larger than the value for water in terrestrial oceans (or Vienna Standard Mean Ocean Water, VSMOW) by a factor of 1.94 ± 0.56. This D/H ratio in water exceeds the value obtained independently at millimeter wavelengths (0.89 ± 0.25 VSMOW; pre-perihelion). We discuss these parameters in the context of origins and emphasize the need for contemporaneous measurements of HDO and H{sub 2}O.

Ground-based Detection of Deuterated Water in Comet C/2014 Q2 (Lovejoy) at IR Wavelengths

International Nuclear Information System (INIS)

Paganini, L.; Mumma, M. J.; Villanueva, G. L.; Gibb, E. L.

2017-01-01

We conducted a deep search for deuterated water (HDO) in the Oort Cloud comet C/2014 Q2 (Lovejoy), through infrared (IR) spectroscopy with NIRSPEC at the Keck Observatory. In this Letter, we present our detections of HDO and water (H 2 O) in comet Lovejoy on 2015 February 4 (post-perihelion) after 1 hr integration on source. The IR observations allowed simultaneous detection of H 2 O and HDO, yielding production rates of 5.9 ± 0.13 × 10 29 and 3.6 ± 1.0 × 10 26 molecules s −1 , respectively. The simultaneous detection permitted accurate determination of the isotopic ratio (D/H) in water of 3.02 ± 0.87 × 10 −4 , i.e., larger than the value for water in terrestrial oceans (or Vienna Standard Mean Ocean Water, VSMOW) by a factor of 1.94 ± 0.56. This D/H ratio in water exceeds the value obtained independently at millimeter wavelengths (0.89 ± 0.25 VSMOW; pre-perihelion). We discuss these parameters in the context of origins and emphasize the need for contemporaneous measurements of HDO and H 2 O.

DNA methylation in obesity

Directory of Open Access Journals (Sweden)

Małgorzata Pokrywka

2014-11-01

Full Text Available The number of overweight and obese people is increasing at an alarming rate, especially in the developed and developing countries. Obesity is a major risk factor for diabetes, cardiovascular disease, and cancer, and in consequence for premature death. The development of obesity results from the interplay of both genetic and environmental factors, which include sedentary life style and abnormal eating habits. In the past few years a number of events accompanying obesity, affecting expression of genes which are not directly connected with the DNA base sequence (e.g. epigenetic changes, have been described. Epigenetic processes include DNA methylation, histone modifications such as acetylation, methylation, phosphorylation, ubiquitination, and sumoylation, as well as non-coding micro-RNA (miRNA synthesis. In this review, the known changes in the profile of DNA methylation as a factor affecting obesity and its complications are described.

Methylation-Sensitive High Resolution Melting (MS-HRM).

Science.gov (United States)

Hussmann, Dianna; Hansen, Lise Lotte

2018-01-01

Methylation-Sensitive High Resolution Melting (MS-HRM) is an in-tube, PCR-based method to detect methylation levels at specific loci of interest. A unique primer design facilitates a high sensitivity of the assays enabling detection of down to 0.1-1% methylated alleles in an unmethylated background.Primers for MS-HRM assays are designed to be complementary to the methylated allele, and a specific annealing temperature enables these primers to anneal both to the methylated and the unmethylated alleles thereby increasing the sensitivity of the assays. Bisulfite treatment of the DNA prior to performing MS-HRM ensures a different base composition between methylated and unmethylated DNA, which is used to separate the resulting amplicons by high resolution melting.The high sensitivity of MS-HRM has proven useful for detecting cancer biomarkers in a noninvasive manner in urine from bladder cancer patients, in stool from colorectal cancer patients, and in buccal mucosa from breast cancer patients. MS-HRM is a fast method to diagnose imprinted diseases and to clinically validate results from whole-epigenome studies. The ability to detect few copies of methylated DNA makes MS-HRM a key player in the quest for establishing links between environmental exposure, epigenetic changes, and disease.

Total body skeletal muscle mass: estimation by creatine (methyl-d3) dilution in humans

Science.gov (United States)

Walker, Ann C.; O'Connor-Semmes, Robin L.; Leonard, Michael S.; Miller, Ram R.; Stimpson, Stephen A.; Turner, Scott M.; Ravussin, Eric; Cefalu, William T.; Hellerstein, Marc K.; Evans, William J.

2014-01-01

Current methods for clinical estimation of total body skeletal muscle mass have significant limitations. We tested the hypothesis that creatine (methyl-d3) dilution (D3-creatine) measured by enrichment of urine D3-creatinine reveals total body creatine pool size, providing an accurate estimate of total body skeletal muscle mass. Healthy subjects with different muscle masses [n = 35: 20 men (19–30 yr, 70–84 yr), 15 postmenopausal women (51–62 yr, 70–84 yr)] were housed for 5 days. Optimal tracer dose was explored with single oral doses of 30, 60, or 100 mg D3-creatine given on day 1. Serial plasma samples were collected for D3-creatine pharmacokinetics. All urine was collected through day 5. Creatine and creatinine (deuterated and unlabeled) were measured by liquid chromatography mass spectrometry. Total body creatine pool size and muscle mass were calculated from D3-creatinine enrichment in urine. Muscle mass was also measured by magnetic resonance imaging (MRI), dual-energy x-ray absorptiometry (DXA), and traditional 24-h urine creatinine. D3-creatine was rapidly absorbed and cleared with variable urinary excretion. Isotopic steady-state of D3-creatinine enrichment in the urine was achieved by 30.7 ± 11.2 h. Mean steady-state enrichment in urine provided muscle mass estimates that correlated well with MRI estimates for all subjects (r = 0.868, P creatine dose determined by urine D3-creatinine enrichment provides an estimate of total body muscle mass strongly correlated with estimates from serial MRI with less bias than total lean body mass assessment by DXA. PMID:24764133

Effect of trimethylcolchicinic acid methyl ether d-tartrate (TMCA) on Hodgkin's and non-Hodgkin's lymphoma.

Science.gov (United States)

Stolinsky, D C; Jacobs, E M; Irwin, L E; Pajak, T F; Bateman, J R

1976-01-01

Trimethylcolchicinic acid methyl ether d-tartrate (TMCA; NSC-36351) was administered daily by mouth to 71 patients with malignant lymphomas. Partical (greater than 50%) responses were observed in eleven of 37 patients with Hodgkin's disesse, two of 22 patients with lymphocytic lymphoma, and one of two patients with mixed cell lymphoma. One complete and three partial responses were noted in nine patients with histiocytic lymphoma. Responses lasted from one to 91+ months (median: four months) and occurred in patients whose disease was resistant to alkylating agents, vinblastine, vincristine, procarbazine, prednisone or BCNU. Toxic effects included leukopenia, thrombocytopenia, nausea, diarrhea, stomatitis, alopecia and dermatitis.

Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils

International Nuclear Information System (INIS)

Gomez-Eyles, Jose L.; Collins, Chris D.; Hodson, Mark E.

2011-01-01

Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability. - Research highlights: → Isotope ratios can be used to evaluate chemical methods to predict bioavailability. → Chemical methods predicted bioavailability better than exhaustive extractions. → Bioavailability to earthworms was still far from that predicted by chemical methods. - A novel method using isotope ratios to assess the ability of chemical methods to predict PAH bioavailability to soil biota.

Using deuterated PAH amendments to validate chemical extraction methods to predict PAH bioavailability in soils

Energy Technology Data Exchange (ETDEWEB)

Gomez-Eyles, Jose L., E-mail: j.l.gomezeyles@reading.ac.uk [University of Reading, School of Human and Environmental Sciences, Soil Research Centre, Reading, RG6 6DW Berkshire (United Kingdom); Collins, Chris D.; Hodson, Mark E. [University of Reading, School of Human and Environmental Sciences, Soil Research Centre, Reading, RG6 6DW Berkshire (United Kingdom)

2011-04-15

Validating chemical methods to predict bioavailable fractions of polycyclic aromatic hydrocarbons (PAHs) by comparison with accumulation bioassays is problematic. Concentrations accumulated in soil organisms not only depend on the bioavailable fraction but also on contaminant properties. A historically contaminated soil was freshly spiked with deuterated PAHs (dPAHs). dPAHs have a similar fate to their respective undeuterated analogues, so chemical methods that give good indications of bioavailability should extract the fresh more readily available dPAHs and historic more recalcitrant PAHs in similar proportions to those in which they are accumulated in the tissues of test organisms. Cyclodextrin and butanol extractions predicted the bioavailable fraction for earthworms (Eisenia fetida) and plants (Lolium multiflorum) better than the exhaustive extraction. The PAHs accumulated by earthworms had a larger dPAH:PAH ratio than that predicted by chemical methods. The isotope ratio method described here provides an effective way of evaluating other chemical methods to predict bioavailability. - Research highlights: > Isotope ratios can be used to evaluate chemical methods to predict bioavailability. > Chemical methods predicted bioavailability better than exhaustive extractions. > Bioavailability to earthworms was still far from that predicted by chemical methods. - A novel method using isotope ratios to assess the ability of chemical methods to predict PAH bioavailability to soil biota.

The Morphology of Emulsion Polymerized Latex Particles

Science.gov (United States)

Wignall, G. D.; Ramakrishnan, V. R.; Linne, M. A.; Klein, A.; Sperling, L. H.; Wai, M. P.; Gelman, R. A.; Fatica, M. G.; Hoerl, R. H.; Fisher, L. W.

1987-11-01

Under monomer starved feed conditions, emulsion polymerization of perdeuterated methyl methacrylate and styrene in the presence of preformed polymethylmethacrylate latexes resulted in particles with a core-shell morphology, as determined by small-angle neutron scattering (SANS) analysis for a hollow sphere. The locus of polymerization of the added deuterated monomer is therefore at the particle surface. In similar measurements a statistical copolymer of styrene and methyl methacrylate was used as seed particles for further polymerization of trideuteromethyl methacrylate. The resulting polymer latex was again shown to have a core-shell morphological structure as determined by SANS. SANS experiments were also undertaken on polystyrene latexes polymerized by equilibrium swelling methods, with deuterated polymer forming the first or second step. The experiments covered a molecular weight range of 6 x 10{sup 4} 10{sup 6} the molecular weights are consistent with the experimental errors, indicating that the deuterium labeled molecules are randomly distributed in the latex. These results led to the finding that the polymer chains were constrained in the latex particles by factors of 2 to 4 from the relaxed coil dimensions. For M molecules. Several models were examined, including the possible development of core-shell structures at lower molecular weights.

Heterogeneity of DNA methylation in multifocal prostate cancer.

Science.gov (United States)

Serenaite, Inga; Daniunaite, Kristina; Jankevicius, Feliksas; Laurinavicius, Arvydas; Petroska, Donatas; Lazutka, Juozas R; Jarmalaite, Sonata

2015-01-01

Most prostate cancer (PCa) cases are multifocal, and separate foci display histological and molecular heterogeneity. DNA hypermethylation is a frequent alteration in PCa, but interfocal heterogeneity of these changes has not been extensively investigated. Ten pairs of foci from multifocal PCa and 15 benign prostatic hyperplasia (BPH) samples were obtained from prostatectomy specimens, resulting altogether in 35 samples. Methylation-specific PCR (MSP) was used to evaluate methylation status of nine tumor suppressor genes (TSGs), and a set of selected TSGs was quantitatively analyzed for methylation intensity by pyrosequencing. Promoter sequences of the RASSF1 and ESR1 genes were methylated in all paired PCa foci, and frequent (≥75 %) DNA methylation was detected in RARB, GSTP1, and ABCB1 genes. MSP revealed different methylation status of at least one gene in separate foci in 8 out of 10 multifocal tumors. The mean methylation level of ESR1, GSTP1, RASSF1, and RARB differed between the paired foci of all PCa cases. The intensity of DNA methylation in these TSGs was significantly higher in PCa cases than in BPH (p epigenetic profile of recurrent tumors can be inferred from our data.

Methylated genes as new cancer biomarkers

DEFF Research Database (Denmark)

Brunner, Nils; Duffy, M.J; Napieralski, R.

2009-01-01

Aberrant hypermethylation of promoter regions in specific genes is a key event in the formation and progression of cancer. In at least some situations, these aberrant alterations occur early in the formation of malignancy and appear to be tumour specific. Multiple reports have suggested that meas......Aberrant hypermethylation of promoter regions in specific genes is a key event in the formation and progression of cancer. In at least some situations, these aberrant alterations occur early in the formation of malignancy and appear to be tumour specific. Multiple reports have suggested...... that measurement of the methylation status of the promoter regions of specific genes can aid early detection of cancer, determine prognosis and predict therapy responses. Promising DNA methylation biomarkers include the use of methylated GSTP1 for aiding the early diagnosis of prostate cancer, methylated PITX2...... for predicting outcome in lymph node-negative breast cancer patients and methylated MGMT in predicting benefit from alkylating agents in patients with glioblastomas. However, prior to clinical utilisation, these findings require validation in prospective clinical studies. Furthermore, assays for measuring gene...

Aberrant Methylation and Reduced Expression of LHX9 in Malignant Gliomas of Childhood

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Valentina Vladimirova

2009-07-01

Full Text Available High-grade gliomas (HGGs of childhood represent approximately 7% of pediatric brain tumors. They are highly invasive tumors and respond poorly to conventional treatments in contrast to pilocytic astrocytomas, which usually are well demarcated and frequently can be cured by surgery. The molecular events for this clinical relevant finding are only partially understood. In the current study, to identify aberrantly methylated genes that may be involved in the tumorigenesis of pediatric HGGs, we performed a microarray-based differential methylation hybridization approach and found frequent hypermethylation of the LHX9 (human Lim-homebox 9 gene encoding a transcription factor involved in brain development. Bisulfite genomic sequencing and combined bisulfite restriction analysis showed that HGGs were frequently methylated at two CpG-rich LHX9 regions in comparison to benign, nondiffuse pilocytic astrocytomas and normal brain tissues. The LHX9 hypermethylation was associated with reduced messenger RNA expression in pediatric HGG samples and corresponding cell lines. This epigenetic modification was reversible by pharmacological inhibition (5-aza-2′-deoxycytidine, and reexpression of LHX9 transcript was induced in pediatric glioma cell lines. Exogenous expression of LHX9 in glioma cell lines did not directly affect cell proliferation and apoptosis but specifically inhibited glioma cell migration and invasion in vitro, suggesting a possible implication of LHX9 in the migratory phenotype of HGGs. Our results demonstrate that the LHX9 gene is frequently silenced in pediatric malignant astrocytomas by hypermethylation and that this epigenetic alteration is involved in glioma cell migration and invasiveness.

Methylated spirit burns: an ongoing problem.

Science.gov (United States)

Jansbeken, J R H; Vloemans, A F P M; Tempelman, F R H; Breederveld, R S

2012-09-01

Despite many educational campaigns we still see burns caused by methylated spirit every year. We undertook a retrospective study to analyse the impact of this problem. We retrospectively collected data of all patients with burns caused by methylated spirit over twelve years from 1996 to 2008. Our main endpoints were: incidence, age, mechanism of injury, total body surface area (TBSA) burned, burn depth, need for surgery and length of hospital stay. Ninety-seven patients with methylated spirit burns were included. During the study period there was no decrease in the number of patients annually admitted to the burn unit with methylated spirit burns. 28% of the patients (n=27) were younger than eighteen years old, 15% (n=15) were ten years old or younger. The most common cause of burns was carelessness in activities involving barbecues, campfires and fondues. Mean TBSA burned was 16% (SD 12.4). 70% (n=68) had full thickness burns. 66% (n=64) needed grafting. Mean length of hospital stay was 23 days (SD 24.7). The use of methylated spirit is an ongoing problem, which continues to cause severe burns in adults and children. Therefore methylated spirit should be banned in households. We suggest sale only in specialised shops, clear labelling and mandatory warnings. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

Absolute photoionization cross-section of the methyl radical.

Science.gov (United States)

Taatjes, Craig A; Osborn, David L; Selby, Talitha M; Meloni, Giovanni; Fan, Haiyan; Pratt, Stephen T

2008-10-02

The absolute photoionization cross-section of the methyl radical has been measured using two completely independent methods. The CH3 photoionization cross-section was determined relative to that of acetone and methyl vinyl ketone at photon energies of 10.2 and 11.0 eV by using a pulsed laser-photolysis/time-resolved synchrotron photoionization mass spectrometry method. The time-resolved depletion of the acetone or methyl vinyl ketone precursor and the production of methyl radicals following 193 nm photolysis are monitored simultaneously by using time-resolved synchrotron photoionization mass spectrometry. Comparison of the initial methyl signal with the decrease in precursor signal, in combination with previously measured absolute photoionization cross-sections of the precursors, yields the absolute photoionization cross-section of the methyl radical; sigma(CH3)(10.2 eV) = (5.7 +/- 0.9) x 10(-18) cm(2) and sigma(CH3)(11.0 eV) = (6.0 +/- 2.0) x 10(-18) cm(2). The photoionization cross-section for vinyl radical determined by photolysis of methyl vinyl ketone is in good agreement with previous measurements. The methyl radical photoionization cross-section was also independently measured relative to that of the iodine atom by comparison of ionization signals from CH3 and I fragments following 266 nm photolysis of methyl iodide in a molecular-beam ion-imaging apparatus. These measurements gave a cross-section of (5.4 +/- 2.0) x 10(-18) cm(2) at 10.460 eV, (5.5 +/- 2.0) x 10(-18) cm(2) at 10.466 eV, and (4.9 +/- 2.0) x 10(-18) cm(2) at 10.471 eV. The measurements allow relative photoionization efficiency spectra of methyl radical to be placed on an absolute scale and will facilitate quantitative measurements of methyl concentrations by photoionization mass spectrometry.

EG-13GENOME-WIDE METHYLATION ANALYSIS IDENTIFIES GENOMIC DNA DEMETHYLATION DURING MALIGNANT PROGRESSION OF GLIOMAS

Science.gov (United States)

Saito, Kuniaki; Mukasa, Akitake; Nagae, Genta; Aihara, Koki; Otani, Ryohei; Takayanagi, Shunsaku; Omata, Mayu; Tanaka, Shota; Shibahara, Junji; Takahashi, Miwako; Momose, Toshimitsu; Shimamura, Teppei; Miyano, Satoru; Narita, Yoshitaka; Ueki, Keisuke; Nishikawa, Ryo; Nagane, Motoo; Aburatani, Hiroyuki; Saito, Nobuhito

2014-01-01

Low-grade gliomas often undergo malignant progression, and these transformations are a leading cause of death in patients with low-grade gliomas. However, the molecular mechanisms underlying malignant tumor progression are still not well understood. Recent evidence indicates that epigenetic deregulation is an important cause of gliomagenesis; therefore, we examined the impact of epigenetic changes during malignant progression of low-grade gliomas. Specifically, we used the Illumina Infinium Human Methylation 450K BeadChip to perform genome-wide DNA methylation analysis of 120 gliomas and four normal brains. This study sample included 25 matched-pairs of initial low-grade gliomas and recurrent tumors (temporal heterogeneity) and 20 of the 25 recurring tumors recurred as malignant progressions, and one matched-pair of newly emerging malignant lesions and pre-existing lesions (spatial heterogeneity). Analyses of methylation profiles demonstrated that most low-grade gliomas in our sample (43/51; 84%) had a CpG island methylator phenotype (G-CIMP). Remarkably, approximately 50% of secondary glioblastomas that had progressed from low-grade tumors with the G-CIMP status exhibited a characteristic partial demethylation of genomic DNA during malignant progression, but other recurrent gliomas showed no apparent change in DNA methylation pattern. Interestingly, we found that most loci that were demethylated during malignant progression were located outside of CpG islands. The information of histone modifications patterns in normal human astrocytes and embryonal stem cells also showed that the ratio of active marks at the site corresponding to DNA demethylated loci in G-CIMP-demethylated tumors was significantly lower; this finding indicated that most demethylated loci in G-CIMP-demethylated tumors were likely transcriptionally inactive. A small number of the genes that were upregulated and had demethylated CpG islands were associated with cell cycle-related pathway. In

Theoretical modeling of deuteration-induced shifts of the 0-0 bands in absorption spectra of selected aromatic amines: the role of the double-well potential.

Science.gov (United States)

Andrzejak, Marcin; Kolek, Przemysław

2013-12-05

The harmonic approximation fails for inversion of the NH2 group in the ground state of aromatic amines as this vibration is characterized by a symmetric double-well potential with relatively small energy barrier. In such cases, the standard harmonic vibrational analysis is inapplicable: the inversion frequency calculated for the bottom of the potential well is strongly overestimated, while it attains imaginary values for the planar conformation of the molecule. The model calculations are discussed taking explicitly into account the presence of the double-well potential. The study is initially focused on reproduction of the deuteration-induced shifts of the 0-0 absorption band for anthranilic acid. The (incorrect) harmonic frequency of the NH2 inversion is replaced by a better one, obtained from numerical calculations employing a simple, quartic-quadratic model for the double-well potential, which is parametrized using just the harmonic frequency of the inversion and the height of the energy barrier. This operation brings theoretical results to qualitative agreement with experiment. A still better match is achieved with a modified version of the model that accounts for mixing of the NH2 inversion mode with other normal modes while retaining the initial simplicity of one-dimensional approach. The corrected results show surprisingly good accuracy, with deviations of the calculated shifts from the experimental values reduced to less than 5 cm(-1). In order to test the performance of the model for systems with higher energy barrier for the NH2 inversion, we have measured the LIF excitation spectra of three different amminobenzonitriles. Partial assignment of the 0-0 bands has been achieved based on their relative intensities for samples with different isotopic exchange ratios. Calculated shifts are in excellent agreement with experimental values for the identified bands. Theoretical predictions are used to complete the assignment of the 0-0 bands in the spectra of the

Methyl Iodide Decomposition at BWR Conditions

International Nuclear Information System (INIS)

Pop, Mike; Bell, Merl

2012-09-01

Based on favourable results from short-term testing of methanol addition to an operating BWR plant, AREVA has performed numerous studies in support of necessary Engineering and Plant Safety Evaluations prior to extended injection of methanol. The current paper presents data from a study intended to provide further understanding of the decomposition of methyl iodide as it affects the assessment of methyl iodide formation with the application of methanol at BWR Plants. This paper describes the results of the decomposition testing under UV-C light at laboratory conditions and its effect on the subject methyl iodide production evaluation. The study as to the formation and decomposition of methyl iodide as it is effected by methanol addition is one phase of a larger AREVA effort to provide a generic plant Safety Evaluation prior to long-term methanol injection to an operating BWR. Other testing phases have investigated the compatibility of methanol with fuel construction materials, plant structural materials, plant consumable materials (i.e. elastomers and coatings), and ion exchange resins. Methyl iodide is known to be very unstable, typically preserved with copper metal or other stabilizing materials when produced and stored. It is even more unstable when exposed to light, heat, radiation, and water. Additionally, it is known that methyl iodide will decompose radiolytically, and that this effect may be simulated using ultra-violet radiation (UV-C) [2]. In the tests described in this paper, the use of a UV-C light source provides activation energy for the formation of methyl iodide. Thus is similar to the effect expected from Cherenkov radiation present in a reactor core after shutdown. Based on the testing described in this paper, it is concluded that injection of methanol at concentrations below 2.5 ppm in BWR applications to mitigate IGSCC of internals is inconsequential to the accident conditions postulated in the FSAR as they are related to methyl iodide formation

Cast Partial Denture versus Acrylic Partial Denture for Replacement of Missing Teeth in Partially Edentulous Patients

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Pramita Suwal

2017-03-01

Full Text Available Aim: To compare the effects of cast partial denture with conventional all acrylic denture in respect to retention, stability, masticatory efficiency, comfort and periodontal health of abutments. Methods: 50 adult partially edentulous patient seeking for replacement of missing teeth having Kennedy class I and II arches with or without modification areas were selected for the study. Group-A was treated with cast partial denture and Group-B with acrylic partial denture. Data collected during follow-up visit of 3 months, 6 months, and 1 year by evaluating retention, stability, masticatory efficiency, comfort, periodontal health of abutment. Results: Chi-square test was applied to find out differences between the groups at 95% confidence interval where p = 0.05. One year comparison shows that cast partial denture maintained retention and stability better than acrylic partial denture (p< 0.05. The masticatory efficiency was significantly compromising from 3rd month to 1 year in all acrylic partial denture groups (p< 0.05. The comfort of patient with cast partial denture was maintained better during the observation period (p< 0.05. Periodontal health of abutment was gradually deteriorated in all acrylic denture group (p

Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide

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Domanska, Urszula [Physical Chemistry Department, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)], E-mail: ula@ch.pw.edu.pl; Marciniak, Andrzej [Physical Chemistry Department, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

2009-12-15

The activity coefficients at infinite dilution, {gamma}{sub 13}{sup {infinity}} for 36 solutes: alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofuran, ethers, acetone, and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide [bmPY][NTf{sub 2}] were determined by gas-liquid chromatography at temperatures from 298.15 K to 368.15 K. The partial molar excess enthalpies at infinite dilution values {delta}H{sub 1}{sup E,{infinity}} were calculated from the experimental {gamma}{sub 13}{sup {infinity}} values obtained over the temperature range. The selectivity for different separation problems were calculated from the {gamma}{sub 13}{sup {infinity}} and compared to the literature values for other ionic liquids, N-methyl-2-pyrrolidinone (NMP) and sulfolane.

Purification and general properties of pectin methyl esterase from Curvularia inaequalis NRRL 13884 in solid state culture using orange peels as an inducer.

Science.gov (United States)

Afifi, A F; Fawzi, E M; Foaad, M A

2002-01-01

Pectin methyl esterase (PME) [E.C.3. 1.1.11] production by Curvularia inaequalis (Shear) Boedijn NRRL 13884 was investigated using solid-state culture. The highest level of extracellular pectin methyl esterase was detected with orange peels as an inducing substrate and as a sole carbon source. The enzyme was partially purified using Sephadex G-100 and DEAE-Cellulose column chromatography. It was purified about 40 fold with optimum activity at pH 4.4 and 45 degrees C. The enzyme was activated by Co++, Mg++, Na+, whereas it was slightly activated in the presence of Cu++, K+, Mn++, Zn++. On the other hand Ag++, Ca++ and Hg++ inhibited the activity of the enzyme. The Km was calculated to be 0.52 mM.

Homogalacturonan methyl-esterification and plant development.

Science.gov (United States)

Wolf, Sebastian; Mouille, Grégory; Pelloux, Jérome

2009-09-01

The ability of a plant cell to expand is largely defined by the physical constraints imposed by its cell wall. Accordingly, cell wall properties have to be regulated during development. The pectic polysaccharide homogalacturonan is a major component of the plant primary walls. Biosynthesis and in muro modification of homogalacturonan have recently emerged as key determinants of plant development, controlling cell adhesion, organ development, and phyllotactic patterning. This review will focus on recent findings regarding impact of homogalacturonan content and methyl-esterification status of this polymer on plant life. De-methyl-esterification of homogalacturonan occurs through the action of the ubiquitous enzyme 'pectin methyl-esterase'. We here describe various strategies developed by the plant to finely tune the methyl-esterification status of homogalacturonan along key events of the plant lifecycle.