Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry最新文献_第3页

Dynamics of water and oil at the solid–liquid interface in macroporous media and reservoir rocks 大孔隙介质和储层岩石固液界面水、油动力学

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-11-01 DOI: 10.1016/S1387-1609(01)01331-7

Sophie Godefroy , Jean-Pierre Korb , Marc Fleury

引用次数: 3

Validity of permeability prediction from NMR measurements 核磁共振测量渗透率预测的有效性

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-11-01 DOI: 10.1016/S1387-1609(01)01343-3

Marc Fleury, Françoise Deflandre, Sophie Godefroy

引用次数: 31

Protein dynamics studies on a wheat type 2 lipid transfer protein 小麦2型脂转运蛋白的蛋白质动力学研究

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-11-01 DOI: 10.1016/S1387-1609(01)01298-1

Frédéric de Lamotte , Fabrice Vagner , Jean-Luc Pons , Marie-Françoise Gautier , Christian Roumestand , Marc-André Delsuc

引用次数: 3

Quantification of electric-field gradient in the supercage of Y zeolites with 131Xe (I = 3/2) NMR 用131Xe (I = 3/2)核磁共振定量Y型沸石超笼内电场梯度

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-11-01 DOI: 10.1016/S1387-1609(01)01346-9

Yannick Millot, Pascal P. Man, Marie-Anne Springuel-Huet, Jacques Fraissard

引用次数: 5

Intermolecular nuclear relaxation in paramagnetic solutions: from free radicals to rare earths 顺磁溶液中的分子间核弛豫:从自由基到稀土

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-11-01 DOI: 10.1016/S1387-1609(01)01332-9

Élie Belorizky , Pascal H. Fries , Sebastian Rast

{"title":"Intermolecular nuclear relaxation in paramagnetic solutions: from free radicals to rare earths","authors":"Élie Belorizky , Pascal H. Fries , Sebastian Rast","doi":"10.1016/S1387-1609(01)01332-9","DOIUrl":"https://doi.org/10.1016/S1387-1609(01)01332-9","url":null,"abstract":"<div>The principles of the intermolecular relaxation of a nuclear spin by its fluctuating magnetic dipolar interactions with the electronic spins of the paramagnetic surrounding species in solution are briefly recalled. It is shown that a very high dynamic nuclear polarization (DNP) of solvent protons is obtained by saturating allowed transitions of free radicals with a hyperfine structure, and that this effect can be used in efficient Earth field magnetometers. Recent work on trivalent lanthanide Ln3+ aqua complexes in heavy water solutions is discussed, including paramagnetic shift and relaxation rate measurements of the 1H NMR lines of probe solutes. This allows a determination of the effective electronic magnetic moments of the various Ln3+ ions in these complexes, and an estimation of their longitudinal and transverse electronic relaxation times T1e and T2e. Particular attention is given to Gd(III) hydrated chelates which can serve as contrast agents in magnetic resonance imaging (MRI). The full experimental electronic paramagnetic resonance (EPR) spectra of these complexes can be interpreted within the Redfield relaxation theory. Monte-Carlo simulations are used to explore situations beyond the validity of the Redfield approximation. For each Gd(III) complex, the EPR study leads to an accurate prediction of T1e, which can be also derived from an independent relaxation dispersion study of the protons of the probe solutes.</div>","PeriodicalId":100305,"journal":{"name":"Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry","volume":"4 11","pages":"Pages 825-832"},"PeriodicalIF":0.0,"publicationDate":"2001-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1387-1609(01)01332-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91717699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Diffusion macroscopique dans un tuffeau et un alginate, mesure IRM 在凝灰岩和海藻酸盐中的宏观扩散，mri测量

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-11-01 DOI: 10.1016/S1387-1609(01)01337-8

Michel Letellier , Barbara Brunet-Imbault , Sabrina Mariez , Simone Prigent

引用次数: 2

Mesures de la perfusion cérébrale chez le rat à l’aide de la RMN du 129Xe hyperpolarisé : étude de fluides biologiques vecteurs du 129Xe 用超极化129Xe nmr测量大鼠脑灌注:129Xe载体生物液体的研究

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-10-01 DOI: 10.1016/S1387-1609(01)01317-2

Guillaume Duhamel , Philippe Choquet , Emmanuelle Grillon , Jean-Louis Leviel , Anne Ziegler , André Constantinesco

{"title":"Mesures de la perfusion cérébrale chez le rat à l’aide de la RMN du 129Xe hyperpolarisé : étude de fluides biologiques vecteurs du 129Xe","authors":"Guillaume Duhamel , Philippe Choquet , Emmanuelle Grillon , Jean-Louis Leviel , Anne Ziegler , André Constantinesco","doi":"10.1016/S1387-1609(01)01317-2","DOIUrl":"10.1016/S1387-1609(01)01317-2","url":null,"abstract":"<div>The high xenon solubility in blood and tissues makes hyperpolarized 129Xe a potential MR tracer for tissue perfusion studies. Two biocompatible fluids were studied with a view to be used as delivery media for hyperpolarized xenon injection: the carrier agents were 129Xe micro-bubbles in Echovist (2–3 μm in diameter), and Intralipid 129Xe suspension. Xenon chemical shifts and longitudinal relaxation time T1 were measured at 2.35 T in both fluids. Xenon chemical shift of the dissolved phase in Echovist was 204.1 ± 0.5 ppm from the micro-bubbles gas phase resonance data (0 ppm). Xenon T1 was 20.0 s in micro-bubbles in Echovist and 19.0 s for the dissolved phase. Xenon chemical shift in Intralipid was 194.6 ± 0.5 ppm. T1 was 15.2 ± 4.9 s (n = 5) in Intralipid 20 % and 20.9 ± 2.9 s (n = 4) in Intralipid 30 %. Using an intra-carotid injection of a small volume (0.15 mL) of hyperpolarized xenon dissolved in Intralipid 30 %, cerebral blood flow was measured in rats (160 ± 30 mL·(100 g)–1·min–1, n = 10). Rat brain xenon images were performed with 2-D projection–reconstruction pulse sequence, enabling regional blood flow measurements.</div>","PeriodicalId":100305,"journal":{"name":"Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry","volume":"4 10","pages":"Pages 789-794"},"PeriodicalIF":0.0,"publicationDate":"2001-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1387-1609(01)01317-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87006080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

1H NMR: a tool to study the fate of pollutants in the environment 1H NMR:一种研究环境中污染物命运的工具

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-10-01 DOI: 10.1016/S1387-1609(01)01322-6

Nicolas Haroune, Bruno Combourieu, Pascale Besse, Martine Sancelme, Anne-Marie Delort

引用次数: 10

Solution structure of the sheep prion PrP〚142-166〛: a possible site for the conformational conversion of prion protein 绵羊朊病毒PrP的溶液结构〚142-166:朊病毒蛋白构象转换的可能位点

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-10-01 DOI: 10.1016/S1387-1609(01)01308-1

Gildas Bertho , Sergei Kozin , Pascale Debey , Gaston Hui Bon Hoa , Jean-Pierre Girault

引用次数: 2

Le calcul du déplacement chimique, un outil de validation des structures d’acides nucléiques 化学位移计算，核酸结构验证工具

Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry Pub Date : 2001-10-01 DOI: 10.1016/S1387-1609(01)01309-3

Florent Barbault, Gérard Lancelot

{"title":"Le calcul du déplacement chimique, un outil de validation des structures d’acides nucléiques","authors":"Florent Barbault, Gérard Lancelot","doi":"10.1016/S1387-1609(01)01309-3","DOIUrl":"10.1016/S1387-1609(01)01309-3","url":null,"abstract":"<div>The large majority of analytical NMR methods in chemistry or biochemistry are based on the quality of the chemical shift dispersion. The purpose of this work is to show that theoretical chemical shift back calculation starting from structures can be used to select molecular modeling structures in order to differentiate several conformational possibilities. Here we report the result of the chemical shift calculation carried out on two original structures corresponding to two DNA ‘kissing complexes’. The 46 nucleotides sequence corresponds to the RNA deoxyribose analogous implied in the HIV-1Lai dimerization process. It is interesting to note that, even in cases we are very far from the classical helical structure (loop–loop interaction, AA base pairing, base stacking, misappariement...), the theoretical chemical shift is in very good agreement with the experimental chemical shift (±0.25 ppm). The satisfactory results obtained enable us to conclude that the comparison of the proton chemical shifts is an invaluable tool making it possible to select or to validate oligonucleotides structures.</div>","PeriodicalId":100305,"journal":{"name":"Comptes Rendus de l'Académie des Sciences - Series IIC - Chemistry","volume":"4 10","pages":"Pages 779-782"},"PeriodicalIF":0.0,"publicationDate":"2001-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1387-1609(01)01309-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85432973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0