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51.
Casey L. Sayre Mandi Hopkins Jody K. Takemoto Neal M. Davies 《Biomedical chromatography : BMC》2013,27(3):404-406
Pharmacometric characterization studies of liquiritigenin have historically overlooked its chiral nature. To achieve complete characterization, an analytical method enabling the detection and quantification of the individual enantiomers of racemic (±) liquiritigenin is necessary. Resolution of the enantiomers of liquiritigenin was achieved using a simple high‐performance liquid chromatographic method. A Chiralpak® ADRH column was employed to perform baseline separation with UV detection at 210 nm.The standard curves were linear ranging from 0.5 to 100 µg/mL for each enantiomer. Limit of quantification was 0.5 µg/mL. The assay was applied successfully to stereoselective serum disposition of liquiritigenin enantiomers in rats. Liquiritigenin enantiomers were detected in serum as both aglycones and glucuronidated conjugates. Both unconjugated enantiomers had a serum half‐life of ~15 min in rats. The volume of distribution (Vd) for S‐ and R‐liquiritigenin was 1.49 and 2.21 L/kg, respectively. Total clearance (Cltotal) was 5.12 L/h/kg for S‐liquiritigenin and 4.79 L/h/kg for R‐liquiritigenin, and area under the curve (AUC0‐inf) was 3.95 µg h/mL for S‐liquiritigenin and 4.23 µg h/mL for R‐liquiritigenin. The large volume of distribution coupled with the short serum half‐life suggests extensive distribution of liquiritigenin into tissues. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
52.
Kenji Ichimura Hiroyuki Nakano Masanao Takashima 《Molecular Crystals and Liquid Crystals》2013,570(2):111-117
Abstract In the MxPS3 and M1?xM'xPS3 systems, the P2S6 cluster contributes to the poor electrical conductivity for the compounds in which the energy level of the metal 3d orbital is deeper than those of the P, S 3p orbitals. For the compounds in which metal 3d orbital is closed to P and S 3p orbitals and has mixed valency, the induced mixed valency of P2S6, cluster and/or hopping mechanism contribute to the electrical conductivity. In the organic electron donor intercalation into MxPS3 and M1?xM'xPS3 compounds, the new intercalation reaction is discovered, in which formation of tris-complexes of metal ions with guest molecules occurs in the host interlayer. 相似文献
53.
In this study, Higgs and Z boson associated production with subsequent decay is attempted in the framework of alternative left-right model, which is motivated by superstring-inspired E_6 model at CEPC and future linear colliders. We systematically analyze each decay channel of Higgs with theoretical constraints and latest experimental methods. Due to the mixing of scalars in the Higgs sector, charged Higgs bosons can play an essential role in the phenomenological analysis of this process. Even though the predictions of this model for the signal strengths of this process are close to the standard model expectations, it can be distinct under high luminosity. 相似文献
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55.
M. Zeeman C. M. Auer R. G. Clements J. V. Nabholz R. S. Boethling 《SAR and QSAR in environmental research》2013,24(3):179-201
Abstract As testing is not required, ecotoxicity or fate data are available for ≈ 5% of the approximately 2,300 new chemicals/year (26,000 + total) submitted to the US-EPA. The EPA's Office of Pollution Prevention and Toxics (OPPT) regulatory program was forced to develop and rely upon QSARs to estimate the ecotoxicity and fate of most of the new chemicals evaluated for hazard and risk assessment. QSAR methods routinely result in ecotoxicity estimations of acute and chronic toxicity to fish, aquatic invertebrates, and algae, and in fate estimations of physical/chemical properties, degradation, and bioconcentration. The EPA's Toxic Substances Control Act (TSCA) Inventory of existing chemicals currently lists over 72,000 chemicals. Most existing chemicals also appear to have little or no ecotoxicity or fate data available and the OPPT new chemical QSAR methods now provide predictions and cross-checks of test data for the regulation of existing chemicals. Examples include the Toxics Release Inventory (TRI), the Design for the Environment (DfE), and the OECD/SIDS/HPV Programs. QSAR screening of the TSCA Inventory has prioritized thousands of existing chemicals for possible regulatory testing of: 1) persistent bioaccumulative chemicals, and 2) the high ecotoxicity of specific discrete organic chemicals. 相似文献
56.
You Wei 《Journal of Dispersion Science and Technology》2013,34(12):1785-1794
57.
This letter describes an original freezing process that yields homogeneous solid films at ambient temperature with preservation of the layered structure of the chiral smectic phase. One of the most remarkable features of the process is its ability to provide complexly bent films with arbitrary three-dimensional shapes. Their optical homogeneity is observed in the planar as well as in the bent films. The method is very simple. After forming the films by spreading the liquid crystal above a hole in a glass slice placed over a hot stage, the film is heated from below. The hot film is exposed to ambient temperature. Then, a solid object at room temperature with a specifically adapted shape is immersed in the liquid film. The mechanical constraints imposed by the object curves the film and stabilises various solid two- and three-dimensional structures. Their homogeneous optical properties are due to long-range organisation of the molecular orientation (tilt), which combines with a complex helical arrangement of the frozen smectic layers. 相似文献
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59.
A. M. Al-Sabagh N. G. Kandile N. M. Nasser M. R. Mishrif 《Journal of Dispersion Science and Technology》2014,35(10):1361-1368
This study mainly concentrates on the synthesis of three novel demulsifiers and the investigation of their demulsification efficiency. The demulsifiers were derived from 1,3,5-triethanolhexahydro-1,3,5-triazine, which was prepared by the reaction of monoethanol amine with formaldehyde. The 1,3,5-triethanolhexahydro-1,3,5-triazine was ethoxylated by introducing 20 units of ethylene oxide and then esterified at different molar ratios with oleic acid (1, 2, and 3) to give three demulsifiers, namely, E20TO, E20TO2, and E20TO3. The chemical structures of the prepared demulsifiers were confirmed by 1H NMR and FTIR spectrum. The demulsification efficiency of these demulsifiers was tested on the natural water-in-oil (w/o) emulsions (50% water content). From the obtained results, it has been found that the investigated demulsifiers have a great potential to break the w/o emulsions. The trioleat ester (E20TO3) exhibited the maximum demulsification efficiency (96%) after 120 minutes at 55°C. 相似文献
60.