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431.
432.
Zhengxiang Xia Lei Lv Xuemei Di Jiyang Xue Zhen Gao Guoqing Zhang Hai Zhang 《Biomedical chromatography : BMC》2019,33(5)
Ermiao Pill (EMW), a traditional Chines medicine (TCM), composed of a two‐herb pair, Phellodendri Cortex (PC) and Atractylodis Rhizome (AR), is used for the treatment of pelvic inflammatory disease and inflammatory‐related diseases. However, the underlying mechanism is still unknown. Compatibility plays a crucial role in the complex drugs such as those used in traditional Chinese medicine. We propose a compositive strategy, which integrated pharmacokinetics and network pharmacology to explore the compatibility in EMW. Firstly, a simple, rapid, and selective method based on UPLC–MS/MS was established and validated for simultaneous qualification of six alkaloids in rat plasma, which was used for a comparative pharmacokinetic study of EMW and its constituent herb PC. The concentration–time profiles suggested that AR might reduce the toxicity of some alkaloids in EMW. Secondly, network pharmacology analysis showed that the key protein PTGS2 was targeted by four alkaloids, and that the competition among them might be allevited by AR. Thirdly, molecular docking exhibited interactions between the alkaloids and PTGS2 through H and π–π bonds, and the same residue formed interactions with different alkaloids, which account for the toxicity of these alkaloids, and these were confirmed by the cell viability assay. The combination of pharmacokinetics and network pharmacology clarified the compatibility in EMW. 相似文献
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An improvement for multidimensional characteristic‐based scheme by using different selected waves 下载免费PDF全文
In this study, an improved multidimensional characteristic‐based (MCB) scheme, used for calculation of incompressible flows via artificial compressibility method, is presented. The new idea uses four different waves instead of traditional waves, which were used in the original MCB scheme corresponding to coordinate axes. In the new selection of waves, the number of compatibility relations is increased to eight, and therefore, more information reaches to each face in order to estimate convective fluxes. Numerical tests show that the new improved MCB scheme is faster in terms of convergence and demonstrates the same accuracy by the older one. Also, it needs less CPU time in comparison with traditional MCB scheme for running the computer code at the same conditions. The new scheme is able to use higher CFL numbers compared with the old MCB scheme. Results obtained by the new proposed method are in good agreement with the benchmark solutions at the wide range of Reynolds numbers. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
438.
N. Hernandez‐Montero Jone M. Ugartemendia Hegoi Amestoy J. R. Sarasua 《Journal of Polymer Science.Polymer Physics》2014,52(2):111-121
A miscibility and phase behavior study was conducted on poly(ethylene glycol) (PEG)/poly(l ‐lactide‐ε‐caprolactone) (PLA‐co‐CL) blends. A single glass transition evolution was determined by differential scanning calorimetry initially suggesting a miscible system; however, the unusual Tg bias and subsequent morphological study conducted by polarized light optical microscopy (PLOM) and atomic force microscopy (AFM) evidenced a phase separated system for the whole range of blend compositions. PEG spherulites were found in all blends except for the PEG/PLA‐co‐CL 20/80 composition, with no interference of the comonomer in the melting point of PEG (Tm = 64 °C) and only a small one in crystallinity fraction (Xc = 80% vs. 70%). However, a clear continuous decrease in PEG spherulites growth rate (G) with increasing PLA‐co‐CL content was determined in the blends isothermally crystallized at 37 °C, G being 37 µm/min for the neat PEG and 12 µm/min for the 20 wt % PLA‐co‐CL blend. The kinetics interference in crystal growth rate of PEG suggests a diluting effect of the PLA‐co‐CL in the blends; further, PLOM and AFM provided unequivocal evidence of the interfering effect of PLA‐co‐CL on PEG crystal morphology, demonstrating imperfect crystallization in blends with interfibrillar location of the diluting amorphous component. Significantly, AFM images provided also evidence of amorphous phase separation between PEG and PLA‐co‐CL. A true Tg vs. composition diagram is proposed on the basis of the AFM analysis for phase separated PEG/PLA‐co‐CL blends revealing the existence of a second PLA‐co‐CL rich phase. According to the partial miscibility established by AFM analysis, PEG and PLA‐co‐CL rich phases, depending on blend composition, contain respectively an amount of the minority component leading to a system presenting, for every composition, two Tg's that are different of those of pure components. © 2013 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014 , 52, 111–121 相似文献
439.
T. A. Medina-Tejeda 《Mathematische Nachrichten》2023,296(2):732-756
In this paper, we prove a similar result to the fundamental theorem of regular surfaces in classical differential geometry, which extends the classical theorem to the entire class of singular surfaces in Euclidean 3-space known as frontals. Also, we characterize in a simple way these singular surfaces and its fundamental forms with local properties in the differential of its parametrization and decompositions in the matrices associated to the fundamental forms. In particular, we introduce new types of curvatures that can be used to characterize wave fronts. The only restriction on the parametrizations that is assumed in several occasions is that the singular set has empty interior. 相似文献
440.
Xiaorong Guo Jiangtao Geng Bin Sun Qi Xu Yibo Li Shiwei Xie Yuanyuan Xue Hong Yan 《先进技术聚合物》2021,32(1):41-53
Modified intumescent flame retardants (MIFRs) and polysiloxane (APID) have been used in combination to enhance the flame retardancy of polypropylene (PP). The IFR system was composed of melamine (MEL), ammonium polyphosphate (APP) and pentaerythritol (PER). Aimed to improve the thermal stability of the IFR and its dispersivity in PP, titanate coupling agent NDZ‐201 was used to modify the IFRs via ball milling. MIFRs and APID have a cooperative effect on the flame retardant properties of PP. With 25 wt.% of MIFR and APID, the flame retardant sample (PPMA) was rated V0 for UL‐94, the LOI value was 34.3%, and the peak heat release rate (PHRR) was reduced by 80% in cone calorimeter test. In addition, APID could improve the compatibility of MIFR with the PP matrix, thereby increasing the mechanical properties of PP blends. The flame retardant effect of APID and MIFR in PP was presented in the condensed phase resulting in a rigid, thermally stable and expanded carbon layer due to different char structures. 相似文献