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941.
Determination of ecliptasaponin A in rat plasma and tissues by liquid chromatography‐tandem mass spectrometry 下载免费PDF全文
Jing Zhao Erwei Liu Lifeng Han Linlin Wang Yi Zhang Tao Wang Shiming Fang Xiumei Gao 《Biomedical chromatography : BMC》2016,30(6):846-851
A sensitive, rapid and specific high‐performance liquid chromatography tandem mass spectrometry method (HPLC‐MS/MS) was developed to determine ecliptasaponin A in rat plasma and tissues after oral administration. Ginsenoside Rg1 was used as the internal standard (IS). The plasma and tissues samples were prepared by liquid‐liquid extraction with ethyl acetate and separated on an Eclipse Plus C18 column (2.1 mm × 150 mm, 5 µm) at a flow rate of 0.4 mL/min using acetonitrile and water (containing 0.05% acetic acid) as the mobile phase. The tandem mass detection was carried out with eletrospray ionization in negative mode. Quantification was performed by using multiple reaction monitoring (MRM), which monitored the fragmentation of m/z 633.4→587.2 for ecliptasaponin A and m/z 859.4→637.4 for the IS. The calibration curves obtained were linear in different matrices, and the lower limit of quantification (LLOQ) achieved was 0.5 ng/mL both for rat plasma and tissues. The intra‐ and inter‐day precisions were below 15%. This method was successfully applied to pharmacokinetic study of ecliptasaponin A in rat plasma and tissues after oral administration. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
942.
Yang Li Xin Peng Di Zhao Shengjie Shi Changcheng He Huiliang Wang 《Journal of Polymer Science.Polymer Physics》2016,54(23):2432-2441
A very simple yet novel strategy to significantly enhance the mechanical properties of hydrogels is reported. Poly(acrylic acid) (PAA) hydrogels with aligned macroporous channels are immersed in the aqueous solutions of poly(dimethyl diallyl ammonium chloride) (PDMDAAC). Strong electrostatic interactions are formed between the anionic PAA and cationic PDMDAAC chains. In the resultant PAA/PDMDAAC hybrid hydrogels, the mass ratio of PDMDAAC to PAA is about 0.2 and PDMDAAC is uniformly distributed throughout the gels. The mechanical properties of the formed hybrid hydrogels are largely enhanced in comparison with the original PAA hydrogels. The hybrid hydrogels exhibit high tensile strengths (0.38–1.73 MPa), elastic moduli (0.21–1.59 MPa) and toughness (up to 3.0 MJ/m3), about several to more than 10 times those of the corresponding PAA hydrogels. In addition, the PAA/PDMDAAC hydrogels also show excellent and very rapid shape recovery ability in both air and deionized water. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2432–2441 相似文献
943.
944.
The enhanced biological activities of three Zn (II) complexes based on different 1,2,4‐triazole fungicides 下载免费PDF全文
Guo‐yu Ren Jie Li Xu‐zhan Wei Jin‐hua Zhou Biao Yan Zhao‐qi Guo Ying‐hui Ren Xiao‐hong Sun Hai‐xia Ma 《应用有机金属化学》2018,32(9)
In order to screen effective fungicides, three Zn (II) complexes, [Zn L 1 4 (NO3)2]·2H2O·2EtOH ( 1 ), [Zn L 2 4 (NO3)2] ( 2 ), and [Zn L 3 4 (DMF)2](NO3)2 ( 3 ), ( L 1 = paclobutrazol, L 2 = diniconazole, and L 3 = hexaconazole), were synthesized and characterized by elemental analysis, FT‐IR spectroscopy, and single‐crystal XRD. The antifungal activities of these complexes were then evaluated against four selected fungi using the mycelial growth rate method. The resulting data indicate that all the complexes show the enhanced antifungal activities than the corresponding ligand and mixtures. And, the interactions between the metal salt and ligands in the three complexes seem to be synergistic. According to the study of the influence of the structures on the activity, complex 2 with C=C linkage and 2,4‐dichlorophenyl moieties enhances the bioactivity significantly, especially against Wheat gibberellic ( II ). Density functional theory (DFT) calculations were carried out to help explain the enhanced bioactivity of the Zn (II) complexes. Meanwhile, all complexes are excellent grow‐regulators, especially complex 3 . The resulting data show that the complexes based on triazole fungicides have the potential applications in agriculture. 相似文献
945.
946.
947.
In this note, it is proved for n ≤ 5 that if Q is a finite quantale with |Q| ≥ n, then there are at least n subquantales of Q. However, the result does not hold when |Q| ≥ 6. Also, an example is given of a sequence of quantales of cardinality p + 2 for p prime, each of which have exactly 5 subquantales. 相似文献
948.
Bin Zhao 《Journal of Thermal Analysis and Calorimetry》2012,107(1):387-393
In order to study the temperature changing rule of the crude oil in the storage tank, the wavelet finite element method, the
traditional finite element method and the test were used to carry out the numerical simulation. Firstly, the thermal wavelet
finite element was put forward established based on thermal finite element theory and the wavelet theory. And the computational
model and three boundary conditions were established. And then the temperature changing rule of the crude oil in the storage
tank in 24 h for three boundary conditions was obtained by using three methods, and the results showed that the wavelet finite
element method had advantages in the numerical analysis of the temperature changing rule of the crude oil in the storage.
And then the temperature distribution rule of the crude oil in the storage tank under different conditions in 5 h was obtained.
And the temperature changing mechanism of the crude oil was summarized finally. 相似文献
949.
Inside Cover: High‐Nuclear Organometallic Copper(I)–Alkynide Clusters: Thermochromic Near‐Infrared Luminescence and Solution Stability (Chem. Eur. J. 49/2016) 下载免费PDF全文
950.
Photoisomerization Mechanism of Ruthenium Sulfoxide Complexes: Role of the Metal‐Centered Excited State in the Bond Rupture and Bond Construction Processes 下载免费PDF全文
Dr. Huifang Li Lisheng Zhang lvyin Zheng Dr. Xun Li Dr. Xiaolin Fan Dr. Yi Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(40):14285-14292
Phototriggered intramolecular isomerization in a series of ruthenium sulfoxide complexes, [Ru(L)(tpy)(DMSO)]n+ (where tpy=2,2’:6’,2’’‐terpyridine; DMSO=dimethyl sulfoxide; L=2,2’‐bipyridine (bpy), n=2; N,N,N’,N’‐tetramethylethylenediamine (tmen) n=2; picolinate (pic), n=1; acetylacetonate (acac), n=1; oxalate (ox), n=0; malonate (mal), n=0), was investigated theoretically. It is observed that the metal‐centered ligand field (3MC) state plays an important role in the excited state S→O isomerization of the coordinated DMSO ligand. If the population of 3MCS state is thermally accessible and no 3MCO can be populated from this state, photoisomerization will be turned off because the 3MCS excited state is expected to lead to fast radiationless decay back to the original 1GSS ground state or photodecomposition along the Ru2+?S stretching coordinate. On the contrary, if the population of 3MCS (or 3MCO) state is inaccessible, photoinduced S→O isomerization can proceed adiabatically on the potential energy surface of the metal‐to‐ligand charge transfer excited states (3MLCTS→3MLCTO). It is hoped that these results can provide valuable information for the excited state isomerization in photochromic d6 transition‐metal complexes, which is both experimentally and intellectually challenging as a field of study. 相似文献