金属纳米颗粒-刺激响应型水凝胶：活性成分递送体系研究进展

刺激响应型水凝胶活性成分递送体系因其对不同环境具有独特的溶胀和降解特性,在食品、医药等领域已有广泛研究。然而,部分水凝胶作为活性成分递送载体时存在荷载效率和靶向释放效率低等问题。基于金属纳米颗粒具有高比表面积和多孔结构的特点,可增强刺激响应型水凝胶的活性成分荷载能力。将金属纳米颗粒和刺激响应型水凝胶杂化制备得到的复合材料,在环境响应型的活性成分递送和控制释放领域已得到大量研究。论文综述了金属纳米颗粒-刺激响应型水凝胶复合材料的特点、种类和制备方法,总结了其在活性成分递送领域的应用,并对其作为递送体系的未来发展进行了展望。     

壳聚糖-海藻酸钠缓释制备红景天苷微囊

用壳聚糖 海藻酸钠微囊技术制备了一系列红景天苷微囊。试验结果表明 :海藻酸钠的浓度、壳聚糖的浓度及壳聚糖溶液的pH值对海藻酸钠 壳聚糖微囊的包埋率、载药量及缓释性能有影响 ,海藻酸钠和壳聚糖微囊能作为红景天苷活性成分的载体。     

Pd/C催化剂的制备、表征及活性研究

以活性炭为载体负载贵金属钯制备Pd/C催化剂.先将氯化钯吸附在活性炭上，再通过氢氧化钠溶液使其以氧化钯或氢氧化钯的形式吸附在活性炭上，干燥还原后作为硬脂腈加氢制备长链烷基二甲基叔胺的催化剂，研究炭钯催化剂对长链烷基二甲基叔胺的活性.通过N2-吸附测试了活性炭的比表面、孔径分布和孔型结构以及在负载活性组分钯后的活性炭表面状况，透射电子显微镜表征了钯在载体活性炭上的分散状况，X-射线衍射分析了活性炭上负载新鲜钯的晶体结构，并用气相色谱对产品进行了定性定量分析，最后以电位滴定测定催化反应时二甲基叔胺得率对其进行活性评价.应用研究表明，活性炭作为载体负载贵金属钯，作为硬脂腈催化加氢制备长链烷基二甲基叔胺的催化剂，其结果较好.     

壳聚糖及其衍生物用于降血糖的最新研究进展

壳聚糖是甲壳质的脱乙酰基产物,分子中含有多个氨基和羟基等活性基团,经化学修饰得到的衍生物具有诸多新的性能。壳聚糖及其衍生物不但本身具有降血糖的生物活性,而且可以作为胰岛素基因载体制成治疗胰岛素依赖型糖尿病的生物药物,也可用于制备胰岛素口服制剂,如壳聚糖胰岛素脂质体、壳聚糖胰岛素纳米粒、壳聚糖胰岛素微球、微囊等,从而延长胰岛素药物的作用时间,达到缓释控释的目的。壳聚糖还可用于胰岛素直肠粘膜、鼻腔粘膜、舌下粘膜吸收的促进剂,改变胰岛素的吸收途径,有效防止了胰岛素在胃肠道的降解。     

乳铁蛋白基姜黄素纳米载体颗粒的制备及其对大鼠抗疲劳能力的影响

本实验制备了乳铁蛋白基姜黄素纳米载体颗粒并对其结构进行了分析,通过体内吸收实验比对了姜黄素纳米载体颗粒与姜黄素单体在体内吸收的特性,在运动性疲劳大鼠模型下通过测定力竭游泳时长、血乳酸动态变化、肌糖原、肝糖原、血尿素氮含量以及抗氧化物酶活性和脂质过氧化产物在机体内的水平,综合评判姜黄素纳米载体颗粒的抗疲劳活性。结果显示,姜黄素纳米载体颗粒粒径约593.8 nm,在溶液中分布均一、形态稳定,具有较好的负载率（152.03±2.43） mg/g与包封率63.57%±0.74%。在体内吸收实验中,姜黄素纳米载体颗粒有效降低首过效应,能够在血浆中以较高浓度维持更长时间,表明乳铁蛋白载体起到了一定的缓释作用;在运动性疲劳模型中,大鼠在饲喂姜黄素纳米载体颗粒后,促进了肌糖原与肝糖原的合成,并能够显著提高力竭游泳的时长（P<0.05）,大幅加速运动后90 min内血乳酸的代谢速率,并通过血尿素氮含量的降低、抗氧化物酶活性的提升以及脂质过氧化产物的下降。综合验证了姜黄素纳米载体颗粒具有抗疲劳活性,其抗疲劳活性与摄入剂量相关。     

缓释制剂的研究进展

介绍了国内外缓释制剂的载体材料、制备方法、外观形态与结构的检测、缓释性能的表征等。     

纤维素纳米纤丝复合材料在药物缓释中的应用

纳米纤维素具有可再生、环境友好、可生物降解、比表面积大、弹性模量高、生物相容性好等优异特性。利用纤维素纳米纤丝开发药物载体材料,有助于促进农林生物质资源的高值化应用。本文系统地综述纤维素纳米纤丝复合水凝胶材料、复合气凝胶材料、复合膜材料在药物缓释领域中的研究现状,阐述其药物缓释机理,并展望纳米纤维素在药物缓释领域的发展方向。     

缓释技术及其在食品工业中的应用

缓释制剂 (技术 )就是使目的物 (如药物、食品添加剂等 )从制剂中按一定规律缓慢地释放。缓释技术在医药上应用较多 ,能延长药物的作用时间 ,使机体内药物浓度保持相对恒定 ,从而发挥治疗作用 ,消去或减轻副作用 ,确保疗效和安全。医用缓释制剂的类型很多 ,有前体药物制剂[1]、微胶囊[1,2 ]、渗透泵制剂[3 ]、生物粘附剂[4,5 ]、脂质体制剂[6 ,7]、微球和磁性微球[1]等。缓释作为一门技术广泛应用于医药、农药[8]、化肥[9]、食品、仓储[10 ]等领域。在食品加工和贮藏中 ,香精香料的挥发损失、异味的出现、防腐剂的添加量与毒性、生理活性物…     

γ-聚谷氨酸钙的制备及其性质研究

用γ-聚谷氨酸(γ-PGA)作为载体,鏊合金属离子钙,得到一种新型的钙制剂,并对其制备工艺、结构表征及生物学活性进行了初步研究。结果表明,当-COOH与Ca2+摩尔比为1:2时,结合率可达54%。经检测γ-聚谷氨酸钙具有缓释能力,并且其缓释能力不依赖于胃酸,在酸性及中性条件下均能缓慢释放Ca2+。小鼠实验表明γ-聚谷氨酸钙能被小鼠吸收利用,骨钙及骨磷都有所增加。通过本研究得到一种不依赖胃酸,可持续释放Ca2+并能被生物体吸收从而增加其骨钙的新钙制剂。     

基于β-乳球蛋白配体结合特性的活性成分包埋和保护研究现状

虽然营养活性成分具有调节生理机能的功能,但环境敏感性和低溶解度限制了许多活性成分在功能食品、药品和化妆品开发中的应用。可食用载体体系的设计和研发提供了克服这些限制的可能性。阐明载体物质和活性成分间作用机制,是设计和制备非乳状液型载体体系的关键。食品蛋白由于具有高营养价值和多种功能特性,因此被广泛应用于制备载体体系。β-乳球蛋白是牛乳中主要乳清蛋白,具有多个配体结合位点,可结合脂肪酸、维生素、磷脂、多酚类化合物等多种物质。β-乳球蛋白也可同时结合叶酸、白藜芦醇和维生素E,生成蛋白质-多配体复合物。本文概述了β-乳球蛋白与不同营养活性成分间相互作用,以及生成复合物对活性成分的保护作用,讨论了天然β-乳球蛋白作为营养活性成分载体的优、缺点以及开发基于此蛋白的多活性成分载体的可能性。     

纳米硒多糖载体的构建及其抗肿瘤应用的研究进展

纳米硒具有独特的性质,在食品、医药和农业等领域具有潜在的应用前景。多糖是一种天然的生物聚合物,由于其优异的生物相容性和生物可降解性,被认为是合成纳米硒最有前景的载体。本文首先介绍了以多糖为模板合成纳米硒的机制以及不同种类多糖、不同合成条件等因素对合成硒纳米复合材料性能的影响。随后,本文总结了合成多糖-纳米硒材料在抗肿瘤方面的应用,为今后以多糖为载体构建纳米硒的合成方法及在医学和食品领域的潜力应用提供了新的思路。     

几种中草药提取物抑菌作用研究

采用黄芩、连翘、丁香等中常见草药作为研究对象,用几种不同溶剂进行提取,通过抑菌试验筛选出抑菌作用阳强的制剂。并将其中效果较好的两种 药提取物进行复配,测定其在不同溶剂中的抑菌效果,与１０％的苯甲酸钠和丙酸钙水溶液相比较 。结果不同中草药提取行抑菌效果不同,复配后的提取物具有比１０％的苯甲酸钠和丙酸钙更明显的抑菌防霉效果。     

Die natürliche Dauerhaftigkeit von vier chilenischen Holzarten

The natural durability of the wood of Coigüe, Tepa, Ulmo and Olivillo against Coriolus versicolor, Coniophora puteana and Gloeophyllum trabeum was studied on the basis of numerous representative samples, and the results were statistically analyzed. All the wood species examined posses only a low natural durability towards the fungi tested: thus deviations from these results found in the literature presumably have to be traced back to the insufficient number of samples previously used. Mycelium growth of Coniophora puteana, determined on culture media with extractives from the sapwood and heartwood zones of the above species, showed no general correlation between the absolute amount of extractives and natural durability, except for Coigüe heartwood near to the sapwood.     

预处理对菌株X4、青霉ZCF57麦草生物化学制浆的影响

研究了预处理对菌株X4、青霉ZCF57麦草生物化学制浆的影响。结果表明:预处理对生物化学制浆没有明显的改善,可能是因为热水预处理、蒸汽预处理、机械预处理均使麦草原料中的水抽出物含量降低,低分子量水溶性抽出物的减少使菌生长过程中易于利用的碳源、氮源受到一定的影响,因而影响了菌株的生长。     

基于ZnCo2O4的多孔碳纳米纤维制备及其储能性能

针对锂硫电池循环过程中容量衰减快的问题,采用水热法制备ZnCo₂O₄纳米颗粒,然后与聚丙烯腈(PAN)混合,通过静电纺丝法制备复合纳米纤维并进行炭化处理得到复合多孔碳纳米纤维。借助扫描电子显微镜、透射电子显微镜、X射线光电子能谱仪、拉曼光谱仪、比表面积测试仪表征复合多孔碳纳米纤维的微观结构和物化性能,优化得到最佳制备工艺;并将其作为正极硫载体测试电化学性能。结果表明:基于ZnCo₂O₄制备的复合多孔碳纳米纤维存在大量孔孔相连的通道,比表面积高达210.85 m²/g;组装成的锂硫电池具有典型的充放电平台以及明显的氧化还原峰,其初始放电比容量为759.2 mA·h/g,50圈充放电循环后,仍具有74.0%的可逆比容量,相比于不掺杂ZnCo₂O₄的静电纺丝碳纳米纤维具有更高的比容量,更好的倍率性能。     

低成本吸附剂处理印染废水的研究进展及发展趋势

吸附技术广泛应用于印染废水中染料的去除,目前普遍使用商业活性炭作为吸附材料,由于成本高、再生困难,限制了其应用和发展,因此研究价格低廉的新型吸附剂替代活性炭十分必要。简单介绍了工业废弃物、天然材料和生物吸附剂,并描述了它们的优点和局限性。     

Über die Extraktstoffe des Stammaterials der Kletterpalme Korthalsia rigida Blume

The extractives from the stems ofKorthalsia rigida Blume were isolated by successive extractions with solvents of increasing polarity. The lipophilic extractives mainly consist of free fatty acids, glycerides and sterol esters besides of free sterols. Principal components of the acids (free and esterified) are palmitic, linolenic, and linolic acid. Furthermore, very small amounts of dehydroabietic acid and three other diterpene acids have been identified as free acids. In the mixture of the free acids from the ether extract a fairly high amount of p-hydroxy benzoic acid is present. The bulk of the extraneous components is present in the polar extract fractions which contain besides of simple sugars mainly condensed tannins and related natural pholobaphenes.     

Sterols and Triterpenyl alcohols in common pulpwoods and black liquor soaps

The amount and composition of lipophilic extractives, and especially of sterols and triterpenyl alcohols, were analysed for six important pulpwood species, i.e., Scots pine, Loblolly and Longleaf pine, Norway spruce, Siberian larch and Silver birch. Sulphate soaps (tall oil soaps) derived from these species were also analysed. Scots pine and Loblolly pine contained the highest amounts and Siberian larch the lowest amounts of lipophilic extractives. The highest amounts of sterols were found in birch. The sterols in wood occurred mainly as esters. Sitosterol was the main sterol in all species. Isolation and analysis of the steryl esters confirmed the natural occurrence of sitostanol esters in wood. Considering the use of sitosterol or sitostanol as cholesterol-lowering component in food products, a high ratio of sitosterol to campesterol is beneficial. This ratio was high in birch and pines but clearly lower in spruce and larch. The highest ratios of sitosterol to campesterol were found in soaps from pines and birch.     

Dehalogenation of polybrominated diphenyl ethers and polychlorinated biphenyl by bimetallic, impregnated, and nanoscale zerovalent iron

Nanoscale zerovalent iron particles (nZVI), bimetallic nanoparticles (nZVI/Pd), and nZVI/Pd impregnated activated carbon (nZVI/Pd-AC) composite particles were synthesized and investigated for their effectiveness to remove polybrominated diphenyl ethers (PBDEs) and/or polychlorinated biphenyls (PCBs). Palladization of nZVI promoted the dehalogenation kinetics for mono- to tri-BDEs and 2,3,4-trichlorobiphenyl (PCB 21). Compared to nZVI, the iron-normalized rate constants for nZVI/Pd were about 2-, 3-, and 4-orders of magnitude greater for tri-, di-, and mono-BDEs, respectively, with diphenyl ether as a main reaction product. The reaction kinetics and pathways suggest an H-atom transfer mechanism. The reaction pathways with nZVI/Pd favor preferential removal of para-halogens on PBDEs and PCBs. X-ray fluorescence mapping of nZVI/Pd-AC showed that Pd mainly deposits on the outer part of particles, while Fe was present throughout the activated carbon particles. While BDE 21 was sorbed onto activated carbon composites quickly, debromination was slower compared to reaction with freely dispersed nZVI/Pd. Our XPS and chemical data suggest about 7% of the total iron within the activated carbon was zerovalent, which shows the difficulty with in-situ synthesis of a significant fraction of zerovalent iron in the microporous material. Related factors that likely hinder the reaction with nZVI/Pd-AC are the heterogeneous distribution of nZVI and Pd on activated carbon and/or immobilization of hydrophobic organic contaminants at the adsorption sites thereby inhibiting contact with nZVI.     

Spectral evaluation of total phenolic components in Vitis vinifera: Grapes and wines

Whereas high levels of flavonoid extractives are responsible for the characteristic λ_Dmax at about 280 nm in the ultra-violet spectra of red wines, there is wide variability in the spectral features of natural white wines, in which the phenolic content is often minimal. For the latter, λ_Dmax may occur anywhere within the range 265–285nm, with relatively strong absorbance at 320 nm arising from the presence of hydroxycinnamate esters. Massive fining of many white wines and juices with polyvinylpyrrolidone (10% w/v) has shown residual non-phenolic u.v. absorbing constituents to be sufficiently uniform to enable direct spectral measurement of total hydroxycinnamates in white juices, white wines and rosés as (E₃₂₀-1.4) absorbance units. For white grape juices and white wines, total hydroxycinnamates are directly quantitated as mg litre^?1 ‘caffeic acid equivalents’ and total flavonoid extractives may also be estimated. Total phenolic components of red wines are accounted as (E₂₈₀-4) absorbance units. The spectral interpretations enable comparative estimation of flavonoid extractives in all natural wine types.