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51.
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Daquan Chen Xiaoyan Song Kaili Wang Chunjing Guo Yueming Yu Huaying Fan Feng Zhao 《Journal of nanoparticle research》2017,19(12):400
In this article, in order to enhance the bioavailiability and tumor targeting of curcumin (Cur), the oligosaccharides of hyaluronan conjugates, folic acid-oligosaccharides of hyaluronan-acetal-menthone 1,2-glycerol ketal (FA-oHA-Ace-MGK) carried oHA as a ligand to CD44 receptor, double-pH-sensitive Ace-MGK as hydrophobic moieties, and FA as the target of folate receptor. The structure characteristics of this smart response multifunctional dual-targeting nano-sized carrier was measured by fourier-transform infrared (FT-IR) and nuclear magnetic resonance (1H–NMR). Cur, an anticancer drug, was successfully loaded in FA-oHA-Ace-MGK micelles by self-assembly. The measurement results of transmission electron microscopy (TEM) presented that the Cur-loaded micelles were spherical in shape with the average size of 166.3?±?2.12 nm and zeta potential ??30.07 mV. Much more encapsulated Cur could be released at mildly acidic environments than at pH 7.4, from the Cur-FA-oHA-Ace-MGK micelles. Cytotoxicity assay indicated that non-Cur loaded micelles mostly had no cytotoxicity to MCF-7 cells and A549 cells, and Cur-loaded micelles had significantly lower survival rate than Cur suspension in the same concentration, which proved that the drug-loaded micelles can effectively inhibit tumor cell growth. The targeting of CD44 receptors and folate receptors was proved in vitro cellular uptake assay. These results showed the promising potential of FA-oHA-Ace-MGK as an effective nano-sized carrier for anti-tumor drug delivery. 相似文献
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介绍高选择性新试剂5-(2-羟基-5-磺酸基苯偶氮)罗丹宁(S-HBAR)与钯显色反应的研究与应用,建立了测定钯的新方法。在H_3PO_4介质中,在乳化剂OP存在下,S-HBAR与Pd(Ⅱ)形成稳定的红色配合物,最大吸收波长为500nm。钯浓度在0~70μg/25 mL范围内符合比耳定律。表观摩尔吸光系数ε=3.5×10~4 L/(mol·cm),选择性好。该方法无需加入掩蔽剂或其他分离手段,即可直接用于Pd-C催化剂和矿石中钯的测定。 相似文献
55.
Ding Zhou Qi Dong Kaili Liang Weilin Xu Yingshan Zhou Pu Xiao 《Journal of polymer science. Part A, Polymer chemistry》2019,57(18):1882-1889
Poly(vinyl alcohol) (PVA) hydrogels with high water content, good load‐bearing property, low frictional behavior as well as excellent biocompatibility have been considered as promising cartilage replacement materials. However, the lack of sufficient mechanical properties and cell adhesion are two critical barriers for their application as cartilage substitutes. To address these problems, herein, methacrylated PVA with low degree of substitution of methacryloyl group has been synthesized first. Then, methacrylated PVA‐glycidyl methacrylate/hydroxyapatite (PVA‐GMA/Hap) nanocomposite hydrogels have been developed by the photopolymerization approach subsequently. Markedly, both pure PVA‐GMA hydrogel and PVA‐GMA/Hap nanocomposite hydrogels exhibit excellent performance in compressive tests, and they are undamaged during compressive stress–strain tests. Moreover, compared to pure PVA‐GMA hydrogels, 8.5‐fold, 7.4‐fold, and 14.2‐fold increase in fracture stress, Young's modulus and toughness, respectively, can be obtained for PVA‐GMA/Hap nanocomposite hydrogels with 10 wt % Hap nanoparticles. These enhancements can be ascribed to the intrinsic property of PVA‐GMA and strong hydrogen bonding interactions between PVA‐GMA chain and Hap nanoparticles. More interestingly, significant improvement in the cell adhesion can also be successfully achieved by incorporation of Hap nanoparticles. These biocompatible nanocomposite hydrogels have great potential to be used as cartilage substitutes. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1882–1889 相似文献
56.
Karin Kipper Kaili Anier Ivo Leito Juri Karjagin Kersti Oselin Koit Herodes 《Chromatographia》2009,70(9-10):1423-1427
A rapid and sensitive LC-UV method was developed and validated for the determination of meropenem, in human plasma and urine. Meropenem retention time was 4.8 min. Method development was based on comparative analysis of different extraction methods published as well as careful study of meropenem stability in biological samples under different conditions. Best results in plasma sample preparation were obtained from protein precipitation with methanol. LOQ was 0.1 µg mL?1 for plasma and 1 µg mL?1 for urine samples. Meropenem in plasma has low stability at room temperature (<20% of original content after 12 h), but had acceptable stability when the whole analysis procedure was designed to minimize the exposure of meropenem-containing samples and solutions to temperatures higher than 4 °C. The developed method was applied to a human pharmacokinetic study in patients with acute peritonitis. 相似文献
57.
设K_k(k=i,j)为欧氏平面R~2中面积为A_k,周长为P_k的域,它们的对称混合等周亏格(symmetric mixed isoperimetric deficit)为σ(K_i,K_j)=P_i~2P_j~2-16π~2A_iA_j.根据周家足,任德麟(2010)和Zhou,Yue(2009)中的思想,用积分几何方法,得到了两平面凸域的Bonnesen型对称混合不等式及对称混合等周不等式,给出了两域的对称混合等周亏格的一个上界估计.还得到了两平面凸域的离散Bonnesen型对称混合不等式及两凸域的对称混合等周亏格的一个上界估计,并应用这些对称混合(等周)不等式估计第二类完全椭圆积分. 相似文献
58.
Azafullerene C59N–Phthalocyanine Dyad: Synthesis,Characterisation and Photoinduced Electron Transfer
Dr. Georgios Rotas Dr. Jenni Ranta Prof. Alexander Efimov Dr. Marja Niemi Prof. Helge Lemmetyinen Prof. Nikolai Tkachenko Prof. Nikos Tagmatarchis 《Chemphyschem》2012,13(5):1246-1254
The synthesis of a new azafullerene C59N–phthalocyanine (Pc) dyad is described. The key step for the synthesis of the C59N–Pc dyad was the formation of the C59N‐based carboxylic acid, which was smoothly condensed with hydroxy‐modified Pc. The structure of the C59N–Pc dyad was verified by 1H and 13C NMR spectroscopy, IR spectroscopy, UV/Vis spectroscopy and MS measurements. The photophysical and electrochemical properties of the C59N–Pc dyad were investigated in both polar and non‐polar solvents by steady state and time‐resolved photoluminescence and absorption spectroscopy, as well as by cyclic voltammetry. Different relaxation pathways for the photoexcited C59N–Pc dyad, as a result of changing the solvent polarity, were found, thus giving rise to energy‐transfer phenomena in non‐polar toluene and charge‐transfer processes in polar benzonitrile. Finally, the detailed quenching mechanisms were evaluated and compared with that of a C60–Pc dyad, which revealed that the different excited‐state energies and reduction potentials of the two fullerene spheres (i.e. C59N vs. C60) strongly diverged in the deactivation pathways of the excited states of the corresponding phthalocyanine dyads. 相似文献
59.
Chamorovskiy A Rautiainen J Lyytikäinen J Ranta S Tavast M Sirbu A Kapon E Okhotnikov OG 《Optics letters》2010,35(20):3529-3531
A 1.6μm mode-locked Raman fiber laser pumped by a 1480nm semiconductor disk laser is demonstrated. Watt-level core pumping of the single-mode fiber Raman lasers with low-noise disk lasers together with semiconductor saturable absorber mirror mode locking represents a highly practical solution for short-pulse operation. 相似文献
60.
A Convenient Fluorescent Method to Simultaneously Determine the Enantiomeric Composition and Concentration of Functional Chiral Amines
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Zeng Huang Dr. Shanshan Yu Xue Zhao Kaili Wen Yimang Xu Prof. Dr. Xiaoqi Yu Yong Xu Prof. Dr. Lin Pu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(50):16458-16461
A 1,1′‐bi‐2‐naphthol (BINOL)‐based chiral aldehyde in combination with ZnII shows a highly enantioselective fluorescent response toward functional chiral amines at λ>500 nm. However, the combination of salicylaldehyde and ZnII gives the same fluorescent enhancement for both enantiomers of a functional chiral amine at λ=447 nm. By using the fluorescent responses of the combination of the BINOL‐based chiral aldehyde, salicylaldehyde and ZnII at the two emission wavelengths, both the concentration and enantiomeric composition of functional chiral amines such as amino alcohols, diamines, and amino acids can be simultaneously determined by a single fluorescent measurement. This work provides a simple and convenient method for chiral assay. 相似文献