排序方式: 共有62条查询结果,搜索用时 62 毫秒
41.
Foad Mashayekhi Ricky Y. T. Chiu Alexander M. Le Felix C. Chao Benjamin M. Wu Daniel T. Kamei 《Analytical and bioanalytical chemistry》2010,398(7-8):2955-2961
Availability of a rapid, accurate, and reliable point-of-care (POC) device for detection of infectious agents and pandemic pathogens, such as swine-origin influenza A (H1N1) virus, is crucial for effective patient management and outbreak prevention. Due to its ease of use, rapid processing, and minimal power and laboratory equipment requirements, the lateral-flow (immuno)assay (LFA) has gained much attention in recent years as a possible solution. However, since the sensitivity of LFA has been shown to be inferior to that of the gold standards of pathogen detection, namely cell culture and real-time PCR, LFA remains an ineffective POC assay for preventing pandemic outbreaks. A practical solution for increasing the sensitivity of LFA is to concentrate the target agent in a solution prior to the detection step. In this study, an aqueous two-phase micellar system comprised of the nonionic surfactant Triton X-114 was investigated for concentrating a model virus, namely bacteriophage M13 (M13), prior to LFA. The volume ratio of the two coexisting micellar phases was manipulated to concentrate M13 in the top, micelle-poor phase. The concentration step effectively improved the M13 detection limit of the assay by tenfold from 5?×?108 plaque forming units (pfu)/mL to 5?×?107 pfu/mL. In the future, the volume ratio can be further manipulated to yield a greater concentration of a target virus and further decrease the detection limits of the LFA. Figure
A schematic representation of concentrating viruses with an aqueous two-phase micellar system containing Triton X-114 surfactant prior to the detection of the virus through the lateral-flow immunoassay 相似文献
42.
We present an approach based on the statistical associating fluids theory (SAFT) to predict the solubility of amino acids in aqueous and aqueous-electrolyte solutions. This approach can describe the association interactions and their effects on the solubility of amino acids. Using the experimental data of activity coefficients of amino acids in water, the parameters of SAFT model for amino acids are obtained. The solubility of several amino acids in the temperature range of 273.15–373.15 K is predicted. Results obtained from the model are in a good accordance with the experimental data. Also, we examine the effect of pH on the solubility of dl-methionine. Addition of an extra amino acid to the binary solution of amino acid + water makes the system more complex. To check the accuracy of model, we study the ternary solution of dl-serine + dl-alanine + water and dl-valine + dl-alanine + water. Predicted results depict that the proposed model has the ability to describe the ternary solution of amino acids, accurately. Finally, the solubility of amino acids in aqueous-electrolyte solutions is investigated. The long-range interactions caused by the presence of ions affects the solubility of amino acids, leading them to be salted in or out. To treat this kind of interaction, the restrictive primitive mean spherical approximation (RP-MSA) is coupled with the SAFT equation of state. The proposed model can accurately predict the solubility of amino acids in aqueous-electrolyte solutions. 相似文献
43.
Foad Kazemi Ali Reza Kiasat Began Mombaini 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6):1187-1191
Na2CO3/SOCl2 has been used for esterification of aliphatic and aromatic acids with isopropanol. This esterification method is compatible with a wide assortment of functional groups. 相似文献
44.
45.
In this report, synthesis of julolidines via one-pot cascade reaction of aniline derivatives with a mixture of styrene and formaldehyde in the presence of silica sulfuric acid as an efficient catalyst has been studied under aerobic condition. By presented method, various julolidines are obtained under mild and transition metal-free conditions. The reaction is proceeded with imine formation and followed by an Aza-Diels-Alder cycloaddition with styrene gave julolidine derivatives. The catalyst can be recycled and reused multiple times to catalyze the reaction. 相似文献
46.
Babak Kaboudin Ali Zangooei Foad Kazemi Tsutomu Yokomatsu 《Tetrahedron letters》2018,59(11):1046-1049
A simple method is reported for the synthesis of alkylaminophenols in moderate to good yields via a three-component, catalyst-free decarboxylative coupling of proline with salicylaldehyde and boronic acids. 相似文献
47.
Nidal A. Zatar Ali Z. Abu-zuhri Mohammad A. Al-nuri Foad M. Mahmoud Ahmad A. Abu-Obaid 《光谱学快报》2013,46(9):1203-1214
A method for simultaneous spectrophotometric determination of total iron, iron(II) and iron(III) in mixtures containing other metal ions has been described. The method is based on the complexation of iron with di-2-pyridyl ketone benzoylhydrazone (DPKBH) in 50% (v/v) ethanolic solution. Iron(II) complex with DPKBH exhibits two absorption maxima at 360 and 650 nm. meanwhile iron(II1) complex with DPKBH exhibits only one maximum at 360nm. Iron(II) and iron(III) complexes with DPKBH have similar behaviour at 360nm. Iron forms 1:2 complexes with the reagent. Beer's laws are obeyed over the ranges 0.1–2 μgml-1 and 0.4–5 μgrn1-l for iron(II) complexes at 360 and 650nm respectively. Iron(III) showed results similar to those obtained for iron(II) at 360nm. The effect of pH, effect of excess reagent. the stability of complexes. and the tolerance limit of many metal ions have been reported. The method is applied to the determination of total iron, iron(I1). and iron(II1) in synthetic solutions. 相似文献
48.
Mohammed Z. Kassaee Seyed M. Musavi Foad Buazar Mehdi Ghambarian 《Monatshefte für Chemie / Chemical Monthly》2006,137(11):1385-1400
Summary. DFT calculations predict the existence of three new triplet ground state silylenes: [(imino)-methylene]silylene, [(cyanoimino)methylene]silylene,
and [(methoxyimino)methylene]silylene, with CNSiX formula (X = H, CN, and OMe, respectively). Discrepancies are found between DFT and some ab initio results. 相似文献
49.
A variety of aromatic nitro compounds were chemoselectively reduced to the corresponding anilines using conveniently prepared nanosized CdS as a photocatalyst under the sunlight and blue LED irradiation. The results demonstrated that synthesized CdS nanostructures have the potential to provide a promising visible light driven photocatalyst for chemoselective reduction of nitro aromatics in the presence of nitrile and carbonyl groups to the corresponding amines under both sunlight and blue LED irradiation. Photoreduction of nitro aromatics by the prepared nanosized CdS with high surface area was faster than when using the commercially available CdS under both sunlight and LED irradiation. Nanosized CdS photocatalyst was prepared by a simple method without any capping agent. X-ray diffraction (XRD), energy dispersive spectrometry (EDAX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 absorption—desorption, diffuse reflectance spectroscopy (DRS), and flat band potential methods were employed for the characterization, which revealed that the prepared CdS nanoparticles have a well-resolved cubic structure with the size of around 10–30 nm and a band gap of 2.37 eV. 相似文献
50.
An efficient and simple procedure for conversion of different classes of aldehydes and ketones into the corresponding semicarbazones with semicarbazide hydrochloride using basic alumina is studied. 相似文献