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61.
62.
Gottardo R Polettini A Sorio D Pascali JP Bortolotti F Liotta E Tagliaro F 《Electrophoresis》2008,29(19):4078-4087
A new method for the determination of illicit and abused drugs in blood by capillary zone electrophoresis-electrospray ionization-time-of-flight mass spectrometry is proposed, in view of its application in clinical and forensic toxicology. The analytes (methamphetamine, methylenedioxyamphetamine, methylenedioxyethylamphetamine, methylenedioxymethamphetamine, methadone, cocaine, morphine, codeine, 6-acethylmorphine, benzoylecgonine) were separated with capillary zone electrophoresis by applying 15 kV within 25 min, in an uncoated fused-silica capillary (75 microm x 100 cm) using a 25 mM ammonium formate electrolyte solution (pH 9.5). The capillary electropherograph was coupled to time-of-flight mass spectrometry through an orthogonal electrospray ionization source, with a coaxial sheath liquid interface. The sheath liquid was composed of isopropanol-water (1:1 v/v) containing 0.5% formic acid delivered at 4 microL/min. Forensic drugs were identified by exact mass determination (mass accuracy typically < or =5 ppm) and by matching of the isotopic pattern. Under optimized conditions, linearity was assessed in the range 10-2000 ng/mL, with correlation coefficients between 0.9744 and 0.9982 for all the analytes. LODs were in the range of 2-10 ng/mL (S/N > or =3) and LOQs of 10-30 ng/mL. The CVs (tested at 40 and 800 ng/mL in biological matrix) were below 2.97% for migration times and below 14.61% for peak area ratios (analyte/internal standard). Blood samples were extracted by using a liquid-liquid extraction procedure and injected under field-amplified sample stacking conditions. The method was successfully applied to real cases. 相似文献
63.
Gohres JL Shukla CL Popov AV Hernandez R Liotta CL Eckert CA 《The journal of physical chemistry. B》2008,112(47):14993-14998
Solvation of heterocyclic amines in CO(2)-expanded methanol (MeOH) has been explored with UV/vis spectroscopy and molecular dynamics (MD) simulations. A synergistic study of experiments and simulations allows exploration of solute and solvent effects on solvation and the molecular interactions that affect absorption. MeOH-nitrogen hydrogen bonds hinder the n-pi* transition; however, CO(2) addition causes a blue shift relative to MeOH because of Lewis acid/base interactions with nitrogen. Effects of solute structure are considered, and very different absorption spectra are obtained as nitrogen positions change. MD simulations provide detailed solvent clustering behavior around the solute molecules and show that the local solvent environment and ultimately the spectra are sensitive to the solute structure. This work demonstrates the importance of atomic-level information in determining the structure-property relationships between solute structure, local salvation, and solvatochromism. 相似文献
64.
A conformationally restrained epothilone A analogue (3) with a short bridge between methyl groups at C6 and C8 was designed and synthesized. Preliminary biological evaluation indicates 3 to be only weakly active (IC50 = 8.5 microM) against the A2780 human ovarian cancer cell line. 相似文献
65.
Richard Li Erica F. Antunes Estelle Kalfon‐Cohen Akira Kudo Luiz Acauan Wei‐Chang D. Yang Canhui Wang Kehang Cui Andrew H. Liotta Ananth Govind Rajan Jules Gardener David C. Bell Michael S. Strano J. Alexander Liddle Renu Sharma Brian L. Wardle 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(27):9302-9307
Synthesis of low‐dimensional carbon nanomaterials such as carbon nanotubes (CNTs) is a key driver for achieving advances in energy storage, computing, and multifunctional composites, among other applications. Here, we report high‐yield thermal chemical vapor deposition (CVD) synthesis of CNTs catalyzed by reagent‐grade common sodium‐containing compounds, including NaCl, NaHCO3, Na2CO3, and NaOH, found in table salt, baking soda, and detergents, respectively. Coupled with an oxidative dehydrogenation reaction to crack acetylene at reduced temperatures, Na‐based nanoparticles have been observed to catalyze CNT growth at temperatures below 400 °C. Ex situ and in situ transmission electron microscopy (TEM) reveal unique CNT morphologies and growth characteristics, including a vaporizing Na catalyst phenomenon that we leverage to create CNTs without residual catalyst particles for applications that require metal‐free CNTs. Na is shown to synthesize CNTs on numerous substrates, and as the first alkali group metal catalyst demonstrated for CNT growth, holds great promise for expanding the understanding of nanocarbon synthesis. 相似文献
66.
Kevin Swiss Woo-Baeg Choi Julie Mohan Christopher Barnum Manohar Saindane George Zima Dennis Liotta 《Heteroatom Chemistry》1990,1(2):141-149
When lithium enolates are allowed to react with selenium metal, selenolate (selenide) ions are formed. Alkylation of these selenolate ions produces the corresponding α-alkylselenenyl carbonyl derivatives. These derivatives can then be converted to their unsaturated counterparts using the same type of protocols that are employed with arylselenenyl derivatives. 相似文献
67.
L.F. Liotta A. Macaluso G. Pantaleo A. Longo A. Martorana G. Deganello G. Marcì S. Gialanella 《Journal of Sol-Gel Science and Technology》2003,26(1-3):235-240
Ceria-zirconia mixed oxides of nominal composition Ce0.6Zr0.4O2 were prepared by sol-gel method. The structural and morphological modifications of these materials due to calcination and redox treatments up to 1000°C were studied by X-ray diffraction (XRD) and Rietveld refinements, specific surface area measurements (BET), oxygen storage capacity (OSC), TEM and SEM analyses. The materials maintain high OSC after several hours of treatments at 1000°C in oxidizing and reducing atmosphere, showing good resistance to the thermal ageing. An improvement of the OSC is manifested after repetitive redox cycles, even though textural characterization shows that reduction/oxidation processes induce sintering of the crystallites. 相似文献
68.
An evaluation of two-particle resonances in the complex energy plane is presented. The representation used in the method consists of bound and antibound single-particle states, Gamow resonances and scattering waves on the complex energy plane. Within this representation the structure of halo nuclei is studied. 相似文献
69.
70.
Conditions which must be fulfilled by clusters of nucleons to qualify as elementary modes of excitation are analysed in terms of simple criteria involving experimental binding energies. It is found that the most complex possible mode is the α-like cluster. 相似文献