The O-nucleophilicity of basic anthranilic acid salts was documented, analyzed, and utilized in synthesis. Specifically substitutions leading to esters instead of secondary amines, and formation of anthranilic acid anhydrides were studied. 相似文献
In rock grouting, idealized 2D-radial laminar flow of yield stress fluids (YSF) is a fundamental flow configuration that is used for cement grout spread estimation. A limited amount of works have presented analytical and numerical solutions on the radial velocity profiles between parallel disks. However, to the best of our knowledge, there has been no experimental work that has presented measured velocity profiles for this geometry. In this paper, we present velocity profiles of Carbopol (a simple YSF), measured by pulsed ultrasound velocimetry within a radial flow model. We describe the design of the physical model and then present the measured velocity profiles while highlighting the plug-flow region and slip effects observed for three different apertures and volumetric flow rates. Although the measured velocity profiles exhibited wall slip, there was a reasonably good agreement with the analytical solution. We then discuss the major implications of our work on radial flow.
Ultra performance liquid chromatography (UPLC) using small sub-2 ??m particles and high performance liquid chromatography (HPLC) were compared for separation and determination of the most common dietary folates; 5-methyltetrahydrofolate, tetrahydrofolate, 5-formyltetrahydrofolate, 10-formylfolic acid and folic acid. Two UPLC columns??Acquity BEH C18 and Acquity HSS T3, and two HPLC columns with similar surface chemistry??Xbridge C18 and Atlantis d18 were tested. When using UPLC, the signal-to-noise ratio could be improved by a factor of 2?C50 for different folate derivatives and the run time could be reduced fourfold without sacrificing separation efficiency. The applicability of UPLC to real food samples was demonstrated. 相似文献
Manipulation of biological cells by acoustic radiation forces is often motivated by its improved biocompatibility relative to alternative available methods. On the other hand, it is well known that acoustic exposure is capable of causing damage to tissue or cells, primarily due to heating or cavitation effects. Therefore, it is important to define safety guidelines for the design and operation of the utilized devices. This tutorial discusses the biocompatibility of devices designed for acoustic manipulation of mammalian cells, and different methods for quantifying the cell viability in such devices. 相似文献
The title compound, [CuCl2(C6H7NO)2], was synthesized during a study of conformationally chiral square‐planar coordination compounds. The coordination geometry deviates from the square‐planar geometry generally adopted by copper(II) chloride complexes with pyridine ligands towards a tetrahedral arrangement of ligands. The complex is conformationally chiral but crystallizes in a centrosymmetric space group with both enantiomers present in the unit cell. 相似文献
Ultrasonic radiation forces can be used for non-intrusive manipulation and concentration of suspended micrometer-sized particles. For bioanalytical purposes, standing-wave ultrasound has long been used for rapid immuno-agglutination of functionalized latex beads. More recently, detection methods based on laser-scanning fluorometry and single-step homogeneous bead-based assays show promise for fast, easy and sensitive biochemical analysis. If such methods are combined with ultrasonic enhancement, detection limits in the femtomolar region are feasible. In this paper, we review the development of standing-wave ultrasonic manipulation for bioanalysis, with special emphasis on miniaturization and ultrasensitive bead-based immunoassays. 相似文献
By addition of organometallic reagents to 2-aminobenzonitriles followed by quenching with suitable electrophiles (acyl halides, aldehydes and ketones), several types of 6-membered benzofused aromatic and non-aromatic nitrogen heterocycles could be obtained. Rearrangements leading to 1,2-dihydro-3H-1,4-benzodiazepin-3-ones and preparation of various quinazolines are described. 相似文献