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941.
Gerald G. Miller Kevin Brown Ronald B. Moore Malcolm S. McPhee Zhenjun J. Diwu Jixiang Liu Liren Huang J. William Lown David A. Begg Vera Chlumecky John Tulip 《Photochemistry and photobiology》1995,61(6):632-638
Hypocrellins are naturally occurring compounds with photosensitizing properties in biological systems. We have prepared synthetic derivatives of hypocrellin B, which have promise as photosensitizers in the clinical application of photodynamic therapy. The intracellular localization and uptake kinetics of hypocrellin B and several selected hypocrellin congeners were determined semiquantitatively by fluorescence confocal microscopy in monolayer cultures of EMT6/Ed murine tumor cells. Each compound had unique uptake kinetics. Although no compound tested to date has demonstrated nuclear labeling, most could be detected in lysosomes, Golgi, endoplasmic reticulum and, to a minor extent, in cellular membranes. No two compounds gave identical labeling distributions. The differences are assumed to originate in physicochemical properties characteristic of each compound, which may ultimately impact upon the primary modality of phototoxicity. 相似文献
942.
Synthesis and characterization of segmented liquid crystal poly(azoxy polyester-co-polyoxypropylene)
Jaine-Ming Huang Jen-Feng Kuo Chuh-Yung Chen 《Journal of polymer science. Part A, Polymer chemistry》1995,33(1):165-173
In this study a series of a segmented copolyester, poly(4,4′-dioxy-2,2′-dimethyl-azoxybenzene dodecanedioyl) (PMABD)-co-polyoxypropylene 400 (POP), was prepared. The chain length of PMABD studied (n) was varied from 7.8-18.2, and that of POP was unchanged. The intrinsic viscosity of the segmented copolyesters was 1.04-1.30, and the number average molecular weight obtained was 2.53 × 104?3.49 × 104 g/mol. The mesophase texture and thermal properties of the segmented copolyesters were measured as functions of n. It was found that the insert of flexible POP between those liquid crystalline domains of PMABD did affect thermotropic properties of PMABD. As the n value was 9.0 and 7.8 (or 7.4 and 8.6% by weight POP) the texture appeared as cholesteric-like oily streaks. The effect could not be attained by simply copolymerizing a mesogenic moiety with a pair of spacers of different lengths. The fluidity and domain structure of the flexible dodecanedioyl-POP-dodcanedioyl segments are taken into account for the obtained results. © 1995 John Wiley & Sons, Inc. 相似文献
943.
Identification of a new flavone glycoside from <Emphasis Type="Italic">Codonopsis nervosa</Emphasis>
Xian-li Zhou Qiang Fan Shuai Huang Cui-juan Wang You-song Wang 《Chemistry of Natural Compounds》2012,47(6):888-890
A new flavone glycoside, luteolin 7-O-[(6″′-caffeoyl)-β-D-glucopyranosyl-(1 → 6)]-β-D-glucopyranoside (1), was isolated from Codonopsis nervosa, along with three other known compounds, luteolin 7-O-β-D-glucopyranoside (2), luteolin 7-O-gentiobioside (3), and tangshenoside VI (4). Their structures were determined on the basis of 1D and 2D NMR, IR, and HR-ESI-MS. 相似文献
944.
Synthesis and electrochemical properties of K-doped LiFePO4/C composite as cathode material for lithium-ion batteries 总被引:1,自引:0,他引:1
Xuesong Fang Jing Li Kelong Huang Suqin Liu Chenghuan Huang Shuxin Zhuang Jinbao Zhang 《Journal of Solid State Electrochemistry》2012,16(2):767-773
Li1 − x
K
x
FePO4/C (x = 0, 0.03, 0.05, and 0.07) composites were synthesized at 700 °C in an argon atmosphere by carbon thermal reduction method.
Based on X-ray diffraction, scanning electron microscopy, and transmission electron microscopy analysis, the composite was
ultrafine sphere-like particles with 100–300 nm size, and the lattice structure of LiFePO4 was not destroyed by K doping, while the lattice volume was enlarged. The electrochemical properties were investigated by
four-point probe conductivity measurements, galvanostatic charge and discharge tests, cyclic voltammetry and electrochemical
impedance spectroscopy. The results indicated that the capacity performance at high rate and cyclic stability were improved
by doping an appropriate amount of K, which might be ascribed to the fact that the doped K ion expands Li ion diffusion pathway.
Among the doped materials, the Li0.97K0.03FePO4/C samples exhibited the best electrochemical activity, with the initial discharge capacity of 153.7 mAh g−1 at 0.1 C and the capacity retention rate of about 92% after 50 cycles at above 1 C, 11% higher than undoped sample. Remarkably,
it still showed good cycle retention at a high current rate of 10 C. 相似文献
945.
Huang Q Xu T Wang GY Huang JF Xia H Yin R Tang A Fu WL 《Analytical and bioanalytical chemistry》2012,402(4):1625-1634
Ever since the emergence of bovine spongiform encephalopathy, the source of pharmaceutical heparin has been restricted to
porcine intestinal mucosa. In this project, two real-time fluorescent PCR methods were developed to assist with quality control
analysis. The first is a qualitative method which relies on SYBR Green I chemistry to confirm the porcine origin of industrial
crude porcine heparin (ICPH), identify any ruminant contaminants, and generally control purity. The second is based on TaqMan
chemistry and is able to quantitatively identify porcine, bovine, caprine, and ovine components and contaminants in ICPH.
By targeting mitochondrial DNA, both PCR systems showed a detection limit of 1 pg DNA and amplification efficiencies ranging
between 96% and 102%. Moreover, quantitative PCR showed a detection limit of 0.02 ppm in samples comprising porcine, bovine,
caprine, and ovine DNA. The results of qualitative PCR over 27 ICPH samples showed that all samples were porcine in origin
and that 17 had ruminant contaminants. The results of quantitative PCR further showed that out of all 17 samples with ruminant
contaminants, seven samples had bovine, ovine, and caprine contaminants, two samples had bovine and ovine contaminants, and
eight samples had only ovine contaminants. In conclusion, the qualitative PCR system was found to be a relatively inexpensive,
rapid, and flexible method of identifying the porcine origin of and ruminant contaminants in ICPH, while the quantitative
PCR was found suitable to accurately analyze the components and contaminants in detail. Both methods are suitable for routine
control assays for the evaluation of ICPH purity and origins of contaminants. 相似文献
946.
SL Chan S Gao SS Chui L Shek JS Huang CM Che 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(36):11228-11237
Ru(3) (TSA)(6) (1; H(2) TSA=2-thiosalicylic acid), which bears six peripheral carboxylate groups and was isolated in the form [NEt(4) ](1.5) [Ru(3) (HTSA)(2) (TSA)(4) ](OAc)(0.5) ?3.5?H(2) O, serves as a building block for assembly of heterometallic coordination polymers. Treatment of 1 with [Fe(acac)(3) ] (acac=acetylacetonate) in EG/H(2) O (EG=ethylene glycol) afforded 1D Ru(3) -Fe coordination polymer 2 by means of the connection of the building block 1 through iron centers. Treatment of 1 with MnCl(2) in EG resulted in the formation of 1D Ru(3) -Mn(3) coordination polymer 3, which features self-assembled polynuclear linking units Mn(3) (OCH(2) CH(2) O)(3) , each of which contains a planar Mn(3) O(3) ring. By treating 1 with Gd(NO(3) )(3) and NaHCO(3) in EG, a 3D Ru(3) -Gd(6) coordination polymer 4 was obtained; this 3D coordination polymer features unprecedented Gd(6) (μ(3) -CO(3) )(4) units. The magnetic properties of 1-4, along with DFT calculations on the electronic structure of 1, are also described. 相似文献
947.
CC Yeh CN Tseng JI Yang HW Huang Y Fang JY Tang FR Chang HW Chang 《Molecules (Basel, Switzerland)》2012,17(9):10916-10927
The water extract of Gracilaria tenuistipitata have been found to be protective against oxidative stress-induced cellular DNA damage, but the biological function of the ethanolic extracts of G. tenuistipitata (EEGT) is still unknown. In this study, the effect of EEGT on oral squamous cell cancer (OSCC) Ca9-22 cell line was examined in terms of the cell proliferation and oxidative stress responses. The cell viability of EEGT-treated OSCC cells was significantly reduced in a dose-response manner (p < 0.0001). The annexin V intensity and pan-caspase activity of EEGT-treated OSCC cells were significantly increased in a dose-response manner (p < 0.05 to 0.0001). EEGT significantly increased the reactive oxygen species (ROS) level (p < 0.0001) and decreased the glutathione (GSH) level (p < 0.01) in a dose-response manner. The mitochondrial membrane potential (MMP) of EEGT-treated OSCC cells was significantly decreased in a dose-response manner (p < 0.005). In conclusion, we have demonstrated that EEGT induced the growth inhibition and apoptosis of OSCC cells, which was accompanied by ROS increase, GSH depletion, caspase activation, and mitochondrial depolarization. Therefore, EEGT may have potent antitumor effect against oral cancer cells. 相似文献
948.
Supramolecular polymers, polymeric systems beyond the molecule, have attracted more and more attention from scientists due to their applications in various fields, including stimuli-responsive materials, healable materials, and drug delivery. Due to their good selectivity and convenient enviro-responsiveness, crown ether-based molecular recognition motifs have been actively employed to fabricate supramolecular polymers with interesting properties and novel applications in recent years. In this tutorial review, we classify supramolecular polymers based on their differences in topology and cover recent advances in the marriage between crown ether-based molecular recognition and polymer science. 相似文献
949.
A novel lignan glysocide, namely sagitiside A (1), together with two known ones, (+)-lyoniresinol-2α-O-β-D-glucopyranoside (2) and (+)-5'-methoxyisolariciresinol 3α-O-β-D-glucopyranoside (3), was isolated from the 95% ethanol extract of dry roots of Tinospora sagittata var. yunnanensis. The structure of the new compound (1) was determined based on MS, 1D and 2D NMR spectral data. Compounds 1-3 showed antioxidant activity with EC(50) values 55, 75 and 80?μM by 1,1-diphenyl-2-picryhydrazyl (DPPH) radical-scavenging assay. 相似文献
950.
Shan Jin Liliana I. Duarte Guoxing Huang Christian Leinenbach 《Monatshefte für Chemie / Chemical Monthly》2012,33(2):1263-1274