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991.
Liposome Microencapsulation for the Surface Modification and Improved Entrapment of Cytochrome c for Targeted Delivery 下载免费PDF全文
Kazuaki Kajimoto Tatsuhito Katsumi Takashi Nakamura Masatoshi Kataoka Hideyoshi Harashima 《Journal of the American Oil Chemists' Society》2018,95(1):101-109
In this study, we established a procedure based on the microencapsulation vesicle (MCV) method for preparing surface‐modified liposomes, using polyethylene glycol (PEG) and a site‐directed ligand, with high entrapment efficiency of cytochrome c (Cyt c). For preparing a water‐in‐oil (W/O) emulsion, egg phosphatidylcholine and cholesterol were dissolved in organic solvents (O phase) and emulsified by sonication with aqueous solution of Cyt c (W1). Although the dispersion stability of the W1/O emulsion was low when n‐hexane was used to dissolve the lipids in the O phase, it was substantially improved by using mixed solvents consisting of n‐hexane and other organic solvents, such as ethanol and dichloromethane (DCM). The W1/O emulsion was then added to another water phase (W2) to prepare the W1/O/W2 emulsion. PEG‐ and/or ligand‐modified lipids were introduced into the W2 phase as external emulsifiers not only for stabilizing the W1/O/W2 emulsion but also for modifying the surface of liposomes obtained later. After solvent evaporation and extrusion for downsizing the liposomes, approximately 50% of Cyt c was encapsulated in the liposomes when the mixed solvent consisting of n‐hexane and DCM at a volume ratio of 75/25 was used in the O phase. Finally, the fluorescence‐labeled liposomes, with a peptide ligand having affinity to the vasculature in adipose tissue, were prepared by the MCV method and intravenously injected into mice. Confocal microscopy showed the substantial accumulation of these liposomes in the adipose tissue vessels. Taken together, the MCV technique, along with solvent optimization, could be useful for generating surface‐modified liposomes with high drug entrapment efficiency for targeted delivery. 相似文献
992.
《大分子材料与工程》2017,302(11)
The influence of annealing on mechanical αc‐relaxation of isotactic polypropylene (i PP) is investigated. In the sample without annealing, polymer chains in the intermediate phase are constrained by crystallites with a broad size distribution, leading to one αc‐relaxation peak with activation energy (E a) of 53.39 kJ mol−1. With an annealing temperature between 60 and 105 °C imperfect lamellae melting releases a part of the constraining force. Consequently, two αc‐relaxation peaks can be observed (αc1‐ and αc2‐relaxation in the order of increasing temperature). Both relaxation peaks shift to higher temperatures as annealing temperature increases. E a of αc1‐relaxation decreases from 38.43 to 35.55 kJ mol−1 as the intermediate phase thickness increases from 2.0 to 2.2 nm. With an annealing temperature higher than 105 °C, a new crystalline phase is formed, which enhances the constraining force on the polymer chains. So the αc1‐relaxation peak is broadened and its position shifts to a higher temperature. Moreover, the polymer chains between the initial and the newly formed crystalline phase are strongly confined. Therefore, the αc2‐relaxation is undetectable. E a of αc1‐relaxation decreases from 23.58 to 13.68 kJ mol−1 as the intermediate phase thickness increases from 2.3 to 3.0 nm. 相似文献
993.
Discovery of Methyl 4′‐Methyl‐5‐(7‐nitrobenzo[c][1,2,5]oxadiazol‐4‐yl)‐[1,1′‐biphenyl]‐3‐carboxylate,an Improved Small‐Molecule Inhibitor of c‐Myc–Max Dimerization 下载免费PDF全文
994.
Eco-friendly synthesis in “one-pot” of 2-methyl-3-phenyl-propanal from benzaldehyde and propanal was studied using a multifunctional catalyst as an alternative to the three-step conventional process involving basic, acidic and hydrogenating catalysts. Mg(Al)O mixed oxides obtained from hydrotalcite precursor achieved the two first steps of condensation and dehydration. Addition of water to the solvent improves the activities and selectivities of Mg(Al)O, thanks to the reconstruction of the lamellar structure with OH− as compensating anions, acting as Brønsted basic sites. Mg(Al)O was then used as support for a multifunctional catalyst impregnated with Pd. Pd/Mg(Al)O led to 45% dihydrocinnamaldehyde selectivity at 43% conversion in benzaldehyde in the “one-pot” process. 相似文献
995.
Xiaolin Pan Yong Luo Yechun Ding Xiaona Fan Jie Wu 《Advanced Synthesis \u0026amp; Catalysis》2014,356(5):1072-1078
1‐Bromo‐2‐(cyclopropylidenemethyl)benzenes react with 2‐alkynylphenols under palladium catalysis, leading to indeno[1,2‐c]chromenes in moderate to good yields. The molecular complexity and diversity can be introduced efficiently from easily available starting materials.
996.
The morphological cell transforming activities of three dihydrodiols of benzo[c]chrysene (B[c]C), trans?B[c]C-7,8-diol, trans?B[c]C-9,10-diol, and trans?B[c]C-1,2-diol were compared to those of B[c]C in order to study the possible routes of metabolic activation in transformable C3H10T1/2 mouse embryo fibroblasts. B[c]C-treated C3H10T1/2 cells exhibited a concentration-related increase in morphologically transformed foci over a concentration range of 0–3 μg/ml. At 3 μg/ml, B[c]C induced 1.23 Type II & III foci/dish, with 73% of the dishes exhibiting Type II or Type III foci, and a survival of 87%. trans?B[c]C-7,8-diol produced concentration-related responses over a range of 0–5 μg/ml. At 3 μg/ml, trans?B[c]C-7,8-diol produced 1.13 Type II & III foci/dish with 72% of the dishes exhibiting foci, and a survival of 76%. trans?B[c]C-9,10-diol was inactive as a morphological cell transforming agent over a concentration range of 0–3 μg/ml. trans?B[c]C-1,2-diol was also inactive as a morphological cell transforming agent over a concentration range of 0–3 μg/ml. These results suggest that a K-region dihydrodiol of B[c]C, trans?B[cC-7,8-diol, may play a role in the ability of B[c]C to morphologically transform C3H10T1/2 cells. 相似文献
997.
Thomas Bodner Lisa Ellmaier Verena Schenk Jörg Albering Frank Wiesbrock 《Polymer International》2011,60(8):1173-1179
The inventory of the single‐crystal X‐ray structures of aliphatic and aromatic 2‐oxazolines, namely 2‐nonyl‐2‐oxazoline, 2,2′‐tetramethylenebis(2‐oxazoline) and 2‐phenyl‐2‐oxazoline, reveals significant delocalization of π‐electrons along the N? C? O segment. The delocalization of π‐electrons is stabilized by inductive and resonance contributions of the side‐chains; in 2‐phenyl‐2‐oxazoline, also π‐arene interactions between the benzene ring and the C? N and the C? O bond stabilize the crystalline phase. This delocalization gives a partial negative charge to the nitrogen atom and a partial positive charge to the oxygen atom. The partial negative charge of the nitrogen atom makes this atom the exclusive reaction partner also for highly reactive non‐selective cations, which explains the regioselectivity of electrophilic attacks in cationic ring‐opening polymerizations. Copyright © 2011 Society of Chemical Industry 相似文献
998.
Adsorption mechanism and property of novel composite material PMAA/SiO2 towards phenol 总被引:1,自引:0,他引:1
Fuqiang An Baojiao Gao Xiaoqin Feng 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2009,153(1-3):108-113
In this paper, functional macromolecule poly(methacrylic acid) (PMAA) was grafted on the surface of silica gel particles using 3-methacryloxypropyl trimethoxysilane (MPS) as intermedia, and the grafted particle PMAA/SiO2 with strong adsorption ability for phenol was prepared. The adsorption mechanism and properties of PMAA/SiO2 for phenol were researched by static and dynamic methods. The experimental results showed that PMAA/SiO2 possesses strong adsorption ability for phenol with interaction of three kinds of hydrogen bonds including peculiar O–Hπ hydrogen bond (aromatic hydrogen bond) and O–HOC π hydrogen bond. The saturated adsorption amount could reach up to 162.88 mg g−1. The empirical Freundlich isotherm was found to describe well the equilibrium adsorption data. pH and temperature were found to have great influence on the adsorption amount. Finally, PMAA/SiO2 was observed to possess excellent reusability properties as well. 相似文献
999.
Tetsuji Ishitani Yasuhiro Niikura Makoto Ikenaga Manabu Kobayashi Momoko Kato Yuko Oe Masaru Nakano Hideaki Shishido Yoshiharu Hirakata Shunpei Yamazaki Daisuke Kurosaki 《Journal of the Society for Information Display》2013,21(1):9-15
We have developed a polymer‐stabilized blue‐phase LCD in which the diffraction wavelength of blue‐phase liquid crystal is in the ultraviolet region and which is driven at a low voltage of V100 = 27 V. Prototypes of 3.4‐in polymer‐stabilized blue‐phase LCDs were made, which include a highly reliable crystalline oxide semiconductor. We succeeded in fabricating not a test cell but a display having a contrast ratio higher than 1000 : 1 for the first time in the world. 相似文献
1000.
The bisimulation “up-to-…” technique provides an effective way to relieve the amount of work in proving bisimilarity of two processes. This paper develops a fresh and direct approach to generalize this set-theoretic “up-to-...” principle to the setting of coalgebra theory. The notion of consistent function is introduced, as a generalization of Sangiorgi's sound function. Then, in order to prove that there are only bisimilar pairs in a relation, it is sufficient to find a morphism from it to the “lifting” of its image under some consistent function. One example is given showing that every self-bisimulation in normed BPA is just such a relation. What's more, we investigate the connection between span-bisimulation and ref-bisimulation. As a result, λ-bisimulation turns out to be covered by our new principle. 相似文献