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1.
In this Note, we study a 2×2 system of evolution equations with some codimension 3 crossing. We derive two conditions of non-degeneracy. We focus on one of them and reduce our system to some Landau–Zener's type system. Using this reduction, we describe the energy transfer at the crossing by Landau–Zener formula for 2-scales semi-classical measures. To cite this article: C. Fermanian Kammerer, P. Gérard, C. R. Acad. Sci. Paris, Ser. I 335 (2002) 915–920. 相似文献
2.
Kammerer B Kahlich R Ufer M Laufer S Gleiter CH 《Rapid communications in mass spectrometry : RCM》2004,18(4):458-464
Phenprocoumon is a commonly used oral anticoagulant of the coumarin type, and has found extensive clinical use in the treatment of thrombophlebitis, pulmonary embolism and atrial fibrillation. In the course of a clinical study to investigate the influence of genetic polymorphisms of the CYP2C9 enzyme on phenprocoumon metabolism, we developed a new enantioselective liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/MS/MS) method to quantify (R)- and (S)-phenprocoumon in human plasma. HPLC separation of the enantiomers was achieved on a Chira-Grom-2 column under isocratic conditions using a water/acetonitrile/formic acid eluent. For detection and quantification a triple-quadrupole MS system was used in the selected reaction monitoring (SRM) mode. As an internal standard the structurally homologous compound warfarin was chosen. The detector response was linear with a correlation coefficient of 0.988-0.999 for (R)-phenprocoumon and 0.989-0.999 for (S)-phenprocoumon in the investigated concentration range between 62.5 and 1000 ng/mL (per enantiomer). The limit of detection (LOD) was 12.5 ng/mL. 相似文献
3.
Poignard Benjamin Fermanian Jean-David 《Annals of the Institute of Statistical Mathematics》2022,74(1):1-31
Annals of the Institute of Statistical Mathematics - We provide finite sample properties of general regularized statistical criteria in the presence of pseudo-observations. Under the restricted... 相似文献
4.
Liebich HM Müller-Hagedorn S Klaus F Meziane K Kim KR Frickenschmidt A Kammerer B 《Journal of chromatography. A》2005,1071(1-2):271-275
5.
The total flavonoids and saponins of the seeds of Glinus lotoides in the crude extracts and tablet formulation thereof were quantified by reversed-phase high-performance liquid chromatographic (RP-HPLC) methods with UV detection. The saponins were analyzed after acid hydrolysis in 3 M HCI at 100 degrees C for 1 h. Vicenin-2 and mollugogenol B were isolated and used as reference substances for the quantification of total flavonoids and saponins, respectively. The identity and purity (> 97%) of the standards were confirmed by spectroscopic (UV, MS, and NMR) and chromatographic (HPLC) methods. The flavonoids and saponins of the crude extract of the seeds and tablet formulation were separated by RP-HPLC (Nucleosil RP-18 column, 250 mm x 4.6 mm) using linear gradient elution systems of acetonitrile-water-0.1 M H3PO4 for flavonoids and methanol-water for saponins. Satisfactory separation of the compounds was obtained in less than 30 and 25 min, for the flavonoids and saponins, respectively. The methods were validated for linearity, repeatability, limits of detection (LOD) and limits of quantification (LOQ). Repeatability (inter- and intra-day, n = 6 and 9, respectively) showed less than 2% relative standard deviation (RSD). The LOD and LOQ were found to be 0.075 and 0.225 mg/mL, respectively, for vicenin-2 and 0.027 and 0.082 mg/100 mL, respectively, for mollugogenol B. The content of flavonoids and saponins of six single tablets was between 95 and 103% for flavonoids and 94-98% for saponins. The validated HPLC methods were employed to standardize a fingerprint of a laboratory produced purified extract, which could be used as a secondary standard for the routine quality control. Accordingly, the purified extract was found to contain 21.3% flavonoids (vicenin-2, 10%) and 25.4% saponins (glinuside G, 14.2%). 相似文献
6.
Guillaume Erbland Dr. Seifallah Abid Yohan Gisbert Nathalie Saffon-Merceron Yuichiro Hashimoto Leonardo Andreoni Théo Guérin Dr. Claire Kammerer Prof. Dr. Gwénaël Rapenne 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(71):16328-16339
The design and synthesis of two families of molecular-gear prototypes is reported, with the aim of assembling them into trains of gears on a surface and ultimately achieving controlled intermolecular gearing motion. These piano-stool ruthenium complexes incorporate a hydrotris(indazolyl)borate moiety as tripodal rotation axle and a pentaarylcyclopentadienyl ligand as star-shaped cogwheel, equipped with five teeth ranging from pseudo-1D aryl groups to large planar 2D paddles. A divergent synthetic approach was followed, starting from a pentakis(p-bromophenyl)cyclopentadienyl ruthenium(II) complex as key precursor or from its iodinated counterpart, obtained by copper-catalyzed aromatic Br/I exchange. Subsequent fivefold cross-coupling reactions with various partners allowed high structural diversity to be reached and yielded molecular-gear prototypes with aryl-, carbazole-, BODIPY- and porphyrin-derived teeth of increasing size and length. 相似文献
7.
Synthesis of Functionalized Mono‐, Bis‐, and Trisethynyltriptycenes for One‐Dimensional Self‐Assembly on Surfaces 下载免费PDF全文
Agnès M. Sirven Romain Garbage Yun Qiao Dr. Claire Kammerer Prof. Dr. Gwénaël Rapenne 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(42):15013-15019
This paper describes the synthesis of triptycene‐based building blocks that are able to interact through hydrogen bonds to form one‐dimensional self‐assembled motifs on surfaces. We designed 9,10‐diethynyltriptycene derivatives functionalized at the ethynyl end groups by a variety of hydrogen‐bonding groups for homomolecular recognition and complementary building blocks for heteromolecular recognition. We also present the synthesis of bis‐ and trisethynyltriptycenes with terminal alkyne functional groups available for on‐surface azide–alkyne cycloaddition reaction to expand the potential of the triptycene building block. 相似文献
8.
Bonnaffé-Moity M Ouadi A Mazan V Miroshnichenko S Ternova D Georg S Sypula M Gaillard C Billard I 《Dalton transactions (Cambridge, England : 2003)》2012,41(25):7526-7536
The extraction of uranyl from acidic (HNO(3)) aqueous solutions toward an ionic liquid phase, C(1)-C(4)-imTf(2)N (1-methyl,3-butylimidazolium Tf(2)N), has been investigated as a function of initial acid concentration and ligand concentration for two different extracting moieties: a classical malonamide, N,N'-dimethyl-N,N'-dibutylmalonamide (DMDBMA) and a functionalized IL composed of the Tf(2)N(-) anion and an imidazolium cation on which a malonamide pattern has been grafted (FIL-MA). The extraction mechanism, as demonstrated through the influence of added C(1)-C(4)-imCl or added LiTf(2)N in the aqueous phase, is slightly different between the DMDBMA and FIL-MA extracting agents. Modeling of the extraction data evidences a double extraction mechanism, with cation exchange of UO(2)(2+)versus 2 H(+) for DMDBMA or versus C(1)-C(4) -im(+) and H(+) for FIL-MA at low acidic values, and through anion exchange of [UO(2)(NO(3))(3)](-)versus Tf(2)N(-) for both ligands at high HNO(3) concentrations. The FIL-MA molecule is more efficient than its classical DMDBMA parent. 相似文献
9.
Kammerer D Carle R Schieber A 《Rapid communications in mass spectrometry : RCM》2003,17(21):2407-2412
Anthocyanins of black carrots (Daucus carota ssp. sativus var. atrorubens Alef.) were investigated by high-performance liquid chromatography/electrospray ionization mass spectrometry. Besides the main compounds which have already been characterized in detail as cyanidin glycosides, six anthocyanins with m/z 757, 565, 595, 903, 933 and 903 were detected and unambiguously characterized as peonidin and pelargonidin glycosides, based on their fragmentation patterns. Peonidin and pelargonidin were identified after acid hydrolysis by comparison of the fragmentation patterns and retention times of the released aglycones with those of standard compounds. To the best of our knowledge this is the first report on anthocyanins in black carrots consisting of aglycones other than cyanidin. 相似文献