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排序方式: 共有139条查询结果,搜索用时 15 毫秒
1.
甲壳素、壳聚糖及其衍生物在医药领域的应用 总被引:1,自引:0,他引:1
对近年来甲壳素、壳聚糖及其衍生物在医药领域的应用研究进行了综述. 相似文献
2.
Surface N-maleylation and N-naphthaloylation of chitin nanofiber (NF) were achieved by reaction with maleic and naphthalic anhydrides in water, respectively. Maleyl and naphthaloyl groups were sufficiently introduced to an amino group on a surface-deacetylated chitin NF. The characteristic nanofiber morphology was maintained after maleylation and naphthaloylation. These NFs were homogeneously dispersed in several organic solvents. Especially, naphthaloyl chitin NF was dispersed even in aromatic solvents, owing to the high level of solvation interactions with the naphthaloyl group. The NF dispersions in those aromatic solvents exhibited a dispersive-to-precipitate transition response at approximately 29 °C. Moreover, the naphthaloyl chitin NF dispersion cut harmful ultraviolet light. The maleyl chitin NF formed a self-standing gel after cross-linking polymerization. 相似文献
3.
ZnO nanowires were synthesized on UV-cured chitin film by using a hydrothermal method. Structural and optical characterization showed that one dimensional nanowires can be produced on the UV-cured chitin film. The morphological analysis indicated that nanowires structures can be obtained at about 30 nm radius and 10 µm length. Surface morphology of the ZnO coated UV-cured chitin film was also investigated and a three-dimensional surface profile and high surface roughness were obtained. X-ray diffraction analysis of the film showed large and pure crystals of ZnO nanowires with wurtzite structure and UV–visible absorbance spectrum indicated that ZnO nanowires have 3.39 eV band-gap energy and nanostructures have very good transparency of about 80% in blue region. Also ZnO coated film was tested for its biocidal action against Gram positive Staphylococcus aureus using an agar plate method. This newly developed nano-biomaterial exhibited a strong antibacterial effect. 相似文献
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Chitin extraction by biological way, using the lactobacilli Lactobacillus helveticus, is a non-polluting method and offers the opportunity to preserve the exceptional qualities of chitin and its derivatives. However, the major disadvantage of the fermentative way is the low efficiency of demineralization and deproteinization. The aim of our study is to improve the yield of extraction. 相似文献
6.
The use of 0.02 or 0.05% chitosan is proposed to reduce from 450 to 150mgkg(-1) the SO(2) required to preserve pork burgers aerobically packed and stored at 2°C for up to 21days under retail display conditions. The effects of chitosan and/or sulfite addition and the storage time were determined in fresh (color deterioration, lipid oxidation, pH, total viable counts, Escherichia coli and coliforms, Salmonella, appearance and odor) and cooked (appearance, odor, flavor and texture) burgers. The addition of either 0.02 or 0.05% chitosan was not detected by sensory analysis, and extended the shelf life of low-SO(2) burgers from 7 to 14days. Chitosan enhanced the preservative effects of sulfite at a low dose, acting on the main causes of meat deterioration (bacterial spoilage, color stability and lipid oxidation), and provided good sensory properties to fresh and cooked pork burgers. 相似文献
7.
壳聚糖的降解改性及其应用 总被引:1,自引:0,他引:1
本文简要总结了国内外有关壳聚糖的降解改性方法以及它在生物医学上的研究成果。这些结果表明,壳聚糖是一类性能优异的生物材料,具有广阔的应用前景。 相似文献
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《国际聚合物材料杂志》2012,61(1-2):25-32
Abstract Circular dichroism has become a popular method for following conformational transitions induced in optically active polymers. Recent refinement of experimental spectra obtained from model polypeptides by computer fitting to spectra obtained from solutions of proteins of known conformation has verified the applicability of the models chosen for the α helical and β conformations. However, the spectrum required for disordered regions was in conflict with much of the literature and agrees with our assignment based on studies of collagen and collagen models at elevated temperature. This spectrum consists of two troughs, one at ~225 nm and the other at ~200 nm. The latter had previously been associated with random polypeptides and we have shown the former to be sensitive to disorder in polymers approaching the 31 helical conformation. This paper presents the results from a study of three polypeptides which undergo a 31 helix → disorder transition. 相似文献
10.
《Drug development and industrial pharmacy》2013,39(8):979-984
Dibutyrylchitin (DBC), a lipophilic chitin diester, has been synthesized from chitin and butyric anhydride with methanesulfonic acid as catalyst. Exhaustive esterification of free alcoholic groups of chitin was assessed by FT-IR and 1H-NMR spectroscopy. High degree of alkyl substitution allowed DBC to acquire an almost completely lipophilic character. Tablets of paracetamol and metformin employing DBC as major excipient, in comparison with starch, microcrystalline cellulose, lactose and polyvinylpyrrolidone, were prepared and rates of drug release were checked by dissolution test assays. DBC released drug at a lower rate than that of the other tested materials. A comparison study of rate release of metformin from DBC tablets and from metformin-hydroxypropyl methylcellulose prolonged release oral formulation available on the market has been also curried out. Under the same conditions and in the presence of the same amount of loaded drug, DBC released 64% of metformin whereas hypromellose-based tablets released 87%. 相似文献