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91.
Bertin Diarra Fana Tangara 《P-Adic Numbers, Ultrametric Analysis, and Applications》2009,1(2):128-135
Let q be a principal unit of the ring of valuation of a complete valued field K, extension of the field of p-adic numbers. Generalizing Mahler basis, K. Conrad has constructed orthonormal basis, depending on q, of the space of continuous functions on the ring of p-adic integers with values in K. Attached to q there are two models of the quantum plane and a model of the quantum Weyl algebra, as algebras of bounded linear operators
on the space of p-adic continuous functions. For q not a root of unit, interesting orthonormal (orthogonal) families of these algebras are exhibited and providing p-adic completion of quantum plane and quantum Weyl algebras.
The text was submitted by the authors in English. 相似文献
92.
Bertin PA Gibbs JM Shen CK Thaxton CS Russin WA Mirkin CA Nguyen ST 《Journal of the American Chemical Society》2006,128(13):4168-4169
We present a rational approach for assembling diverse bioactive agents, such as DNA, proteins, and drug molecules, into core-shell multifunctional polymeric nanoparticles (PNPs) that can be internalized in human breast cancer cells. Using ring-opening metathesis polymerization (ROMP), block copolymers containing small-molecule drug segments (>50% w/w) and tosylated hexaethylene glycol segments were prepared and assembled into PNPs that allowed for the surface conjugation of single-stranded DNA sequences and/or tumor-targeting antibodies. The resulting antibody-functionalized particles were readily uptaken by breast cancer cells that overexpressed the corresponding antigens. 相似文献
93.
Assayag N Rivé K Ader M Jézéquel D Agrinier P 《Rapid communications in mass spectrometry : RCM》2006,20(15):2243-2251
We present here an improved and reliable method for measuring the concentration of dissolved inorganic carbon (DIC) and its isotope composition (delta(13)C(DIC)) in natural water samples. Our apparatus, a gas chromatograph coupled to an isotope ratio mass spectrometer (GCIRMS), runs in a quasi-automated mode and is able to analyze about 50 water samples per day. The whole procedure (sample preparation, CO(2(g))-CO(2(aq)) equilibration time and GCIRMS analysis) requires 2 days. It consists of injecting an aliquot of water into a H(3)PO(4)-loaded and He-flushed 12 mL glass tube. The H(3)PO(4) reacts with the water and converts the DIC into aqueous and gaseous CO(2). After a CO(2(g))-CO(2(aq)) equilibration time of between 15 and 24 h, a portion of the headspace gas (mainly CO(2)+He) is introduced into the GCIRMS, to measure the carbon isotope ratio of the released CO(2(g)), from which the delta(13)C(DIC) is determined via a calibration procedure. For standard solutions with DIC concentrations ranging from 1 to 25 mmol . L(-1) and solution volume of 1 mL (high DIC concentration samples) or 5 mL (low DIC concentration samples), delta(13)C(DIC) values are determined with a precision (1sigma) better than 0.1 per thousand. Compared with previously published headspace equilibration methods, the major improvement presented here is the development of a calibration procedure which takes the carbon isotope fractionation associated with the CO(2(g))-CO(2(aq)) partition into account: the set of standard solutions and samples has to be prepared and analyzed with the same 'gas/liquid' and 'H(3)PO(4)/water' volume ratios. A set of natural water samples (lake, river and hydrothermal springs) was analyzed to demonstrate the utility of this new method. 相似文献
94.
Bouvet D Michalowicz A Crauste-Manciet S Brossard D Provost K 《Inorganic chemistry》2006,45(8):3393-3398
Platinum compounds constitute a discrete class of DNA-damaging anticancer drug agents, including cisplatin, carboplatin, and oxaliplatin. The toxicity of such drugs raises the problem of waste detoxification. Diethyl dithiocarbamate (DDTC) is recommended by the World Heath Organization (WHO) for the destruction of cisplatin, but the degradation product has not been structurally characterized. This paper deals with the extended X-ray absorption fine structure (EXAFS) and IR structural study of the reaction products of DDTC with cisplatin, carboplatin, and oxaliplatin. Cisplatin and carboplatin give the same reaction product: Pt(DDTC)2. In the case of oxaliplatin, we observed the formation of [(diaminocyclohexane)(DDTC)Pt(II)]. In all cases, the replacement of labile ligands by strong ligands should lead to inactive compounds. Our results suggest that the WHO inactivation protocol might be extended to carboplatin and oxaliplatin. Nevertheless, this should be validated by toxicity tests of the degradation products. 相似文献
95.
Silva AA Haraguchi SK Cellet TS Schuquel IT Sarragiotto MH Vidotti GJ de Melo JO Bersani-Amado CA Zanoli K Nakamura CV 《Natural product research》2012,26(9):865-868
A phytochemical study of the ethyl acetate fractions from the partition of seeds and roots methanol extracts of Cenchrus echinatus L. led to the isolation of three resveratrol-derived stilbenoids: pallidol (1), carasiphenol C (2) and nepalensinol B (3). The results of a topic anti-inflammatory evaluation, DPPH assay and antiproliferative activity against adenocarcinoma cells (Caco 2) are described. 相似文献
96.
Kaaki K Hervé-Aubert K Chiper M Shkilnyy A Soucé M Benoit R Paillard A Dubois P Saboungi ML Chourpa I 《Langmuir : the ACS journal of surfaces and colloids》2012,28(2):1496-1505
We report the efficient one-step synthesis and detailed physicochemical evaluation of novel biocompatible nanosystems useful for cancer therapeutics and diagnostics (theranostics). These systems are the superparamagnetic iron oxide nanoparticles (SPIONs) carrying the anticancer drug doxorubicin and coated with the covalently bonded biocompatible polymer poly(ethylene glycol) (PEG), native and modified with the biological cancer targeting ligand folic acid (PEG-FA). These multifunctional nanoparticles (SPION-DOX-PEG-FA) are designed to rationally combine multilevel mechanisms of cancer cell targeting (magnetic and biological), bimodal cancer cell imaging (by means of MRI and fluorescence), and bimodal cancer treatment (by targeted drug delivery and by hyperthermia effect). Nevertheless, for these concepts to work together, the choice of ingredients and particle structure are critically important. Therefore, in the present work, a detailed physicochemical characterization of the organic coating of the hybrid nanoparticles is performed by several surface-specific instrumental methods, including surface-enhanced Raman scattering (SERS) spectroscopy, X-ray photoelectron spectrometry (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). We demonstrate that the anticancer drug doxorubicin is attached to the iron oxide surface and buried under the polymer layers, while folic acid is located on the extreme surface of the organic coating. Interestingly, the moderate presence of folic acid on the particle surface does not increase the particle surface potential, while it is sufficient to increase the particle uptake by MCF-7 cancer cells. All of these original results contribute to the better understanding of the structure-activity relationship for hybrid biocompatible nanosystems and are encouraging for the applications in cancer theranostics. 相似文献
97.
Messi BB Ndjoko-Ioset K Hertlein-Amslinger B Lannang AM Nkengfack AE Wolfender JL Hostettmann K Bringmann G 《Molecules (Basel, Switzerland)》2012,17(5):6114-6125
A new flavanone-chromone biflavonoid, preussianone (1), has been isolated from the leaves of Garcinia preussii, along with four known biflavonoids. The absolute stereostructures were elucidated by chemical, spectroscopic, and chiroptical methods. The biological properties of the new biflavonoid against several bacterial strains were evaluated. 相似文献
98.
Martin-Mingot A De Oliveira Vigier K Jérôme F Thibaudeau S 《Organic & biomolecular chemistry》2012,10(13):2521-2524
Herein, we show that after polyprotonation, superacid HF-SbF(5) is able to selectively depolymerise cellulose to water-soluble carbohydrates with 68 wt% yield of glucose. This process is efficient at low temperature, thus avoiding the formation of side products as commonly observed with conventional acids. 相似文献
99.
Sequestration of carbon dioxide in geological formations is an alternative way of managing extra carbon. Although there are
a number of mathematical modeling studies related to this subject, experimental studies are limited and most studies focus
on injection into sandstone reservoirs as opposed to carbonate ones. This study describes a fully coupled geochemical compositional
equation-of-state compositional simulator (STARS) for the simulation of CO2 storage in saline aquifers. STARS models physical phenomena including (1) thermodynamics of sub- and supercritical CO2, and PVT properties of mixtures of CO2 with other fluids, including (saline) water; (2) fluid mechanics of single and multiphase flow when CO2 is injected into aquifers; (3) coupled hydrochemical effects due to interactions between CO2, reservoir fluids, and primary mineral assemblages; and (4) coupled hydromechanical effects, such as porosity and permeability
change due to the aforementioned blocking of pores by carbonate particles and increased fluid pressures from CO2 injection. Matching computerized tomography monitored laboratory experiments showed the uses of the simulation model. In
the simulations dissolution and deposition of calcite as well as adsorption of CO2 that showed the migration of CO2 and the dissociation of CO2 into HCO3 and its subsequent conversion into carbonate minerals were considered. It was observed that solubility and hydrodynamic storage
of CO2 is larger compared to mineral trapping. 相似文献
100.
In this paper we study formal moduli for wildly ramified Galois covering. We prove a local-global principle. We then focus
on the infinitesimal deformations of the Z/p
Z-covers. We explicitly compute a deformation of an automorphism of order p which implies a universal obstruction for p>2. By deforming Artin-Schreier equations we obtain a lower bound on the dimension of the local versal deformation ring. At
last, by comparing the global versal deformation ring to the complete local ring in a point of a moduli space, we determine
the dimensions of the global and local versal deformation rings.
Oblatum 22-II-1999 & 15-XII-1999?Published online: 29 March 2000 相似文献
Déformations formelles des revêtements sauvagement ramifiés de courbes algébriques
Oblatum 22-II-1999 & 15-XII-1999?Published online: 29 March 2000 相似文献