吡咯烷基二氨基嘧啶氧化物/ 腺苷/ 活性肽复合纳米脂质体体外防脱发研究

采用高压均质技术将不同机制的防脱发活性成分吡咯烷基二氨基嘧啶氧化物、腺苷和活性肽制备成复合纳米脂质体,检测理化性质。采用流式细胞仪定量分析毛乳头细胞对荧光染料异硫氰酸酯(FITC)标记的纳米脂质体的摄取量。采用细胞增殖-毒性检测试剂盒(CCK-8)、活性氧检测试剂盒及线粒体膜电位检测试剂盒检测复合防脱纳米脂质体在毛乳头细胞中的作用效果。结果表明,与FITC相比,FITC标记的纳米脂质体更易被毛乳头细胞摄取,且细胞安全性好。与游离活性物比较,复合纳米脂质体能够显著减轻过氧化氢对毛乳头细胞的氧化损伤(P 0.01),显著减少活性氧的产生(P 0.05),逆转线粒体膜电位降低,抑制细胞凋亡。研究结果提示复合纳米脂质体在防脱发产品中具有良好的应用前景。     

防脱生发活性物共输送纳米脂质体的制备及功效评价

采用高压均质技术制备了载有二氨基嘧啶氧化物(Kopexil)和吡咯烷基二氨基嘧啶氧化物(Kopyrrol)这两种防脱生发活性物的共输送纳米脂质体(Kopexil/Kopyrrol-LPs),其平均粒径为(81.2±1.3)?nm,多分散系数PDI为0.104±0.006,Zeta电位为(-15.6±0.6)?mV。纳米脂质体中Kopexil的载药量和包封率分别为22.1%和93.8%,Kopyrrol的载药量和包封率分别为11.0%和94.6%。采用Franz扩散池法研究Kopexil/Kopyrrol-LPs的体外释放和透皮特性,结果表明,纳米脂质体中Kopexil和Kopyrrol呈明显的缓释行为,其Kopexil的皮肤累积渗透量和滞留量分别为95.66和7.23?μg/cm~2,Kopyrrol的皮肤累积渗透量和滞留量分别为40.48和6.07?μg/cm~2。Kopexil/Kopyrrol-LPs中Kopexil和Kopyrrol的24?h皮肤滞留量分别较游离活性物提升约1.8和2.2倍。比较连续给药21天后雄激素脱发模型小鼠背部毛发生长情况以及皮肤组织切片,结果显示Kopexil/Kopyrrol-LPs组小鼠生发速度以及毛囊数量均显著高于游离活性物组。     

类水滑石复合氧化物在烟道气脱SO2和NOx中的应用

简述了类水滑石复合氧化物的制备方法，并对类水滑石化合物为前驱体的复合氧化物作为环境友好催化材料在烟道气脱SO₂、NOx方面的研究进行了综述，指出应把研究重点放在类水滑石复合氧化物同时氧化吸附脱SO₂和NOx上     

Al2O3-ZrO2负载Ni2P催化剂加氢脱硫脱氮活性

采用浸渍-沉淀法制备Al2O3-ZrO2复合氧化物,通过程序升温还原法制备Ni2P/Al2O3-ZrO2催化剂。运用X射线衍射、N2吸附-脱附、X射线光电子能谱技术对载体和催化剂进行表征,并以噻吩加氢脱硫、吡啶加氢脱氮反应为探针考察复合氧化物对Ni2P催化剂加氢活性的影响。结果表明,在Al2O3表面引入少量ZrO2,既保持了γ-Al2O3大比表面积的结构优势,又减少了P或Ni与Al2O3表面的接触,促进Ni2P的形成。载体中ZrO2质量分数20%的Ni2P/Al2O3-ZrO2催化剂活性最高,载体焙烧温度过高会导致催化剂活性下降。     

水介质中2-巯基嘧啶脱巯基的绿色合成工艺

采用中性水介质代替传统的有机溶剂,以活性Raney Ni考察了2-巯基嘧啶脱巯基的绿色合成工艺,对含有氨基和羟基的2-巯基嘧啶的脱巯基反应条件进行优化,研究了取代基效应、反应溶剂、反应温度对Raney Ni直接脱硫收率的影响,同时对Raney Ni及水的回收利用进行了考察,并以此制备了4-羟基嘧啶、4-氨基嘧啶、4-氨基-6-羟基嘧啶和4,5-二氨基-6-羟基嘧啶,其脱硫收率分别为98%、74%、87%及89%。该工艺条件为加热回流搅拌,反应时间1⁴ h,可避免有机溶剂的使用,具有生产安全等优点。     

疏水支链水性聚氨酯/蒙脱土复合乳液的制备及性能研究

以2-氨基-2-甲基-1,3-丙二醇与十八烷基异氰酸酯反应制备带支链的二元醇,再以支链二元醇、聚(己二酸-新戊二醇酯)二醇、蒙脱土(MMT)、二羟甲基丙酸与异佛尔酮二异氰酸酯反应,原位反应制备了具有疏水功能的支链水性聚氨酯与蒙脱土的纳米复合乳液。主要研究了不同种类和用量的MMT对纳米复合乳液相关性能的影响。研究结果表明:以有机改性蒙脱土(O-MMT)制备的纳米复合乳液具有良好的综合力学性能、粘结性能及耐水性。     

MoP/TiO2-ZrO2催化剂制备及加氢脱氮性能考察

采用溶胶-凝胶法制备了TiO₂-ZrO₂复合载体,并用共浸渍法制备负载型MoP/TiO₂-ZrO₂催化剂,通过原位还原技术对催化剂进行还原处理后,在连续固定床反应器上进行活性评价。结果表明, TiO₂和ZrO₂物质的量比以及Mo负载量对催化剂活性有较大影响,当n(Ti)∶n(Zr)=4∶1和Mo负载质量分数为20%时,MoP/TiO₂-ZrO₂催化剂的加氢脱氮效果最好,并且TiO₂-ZrO₂复合载体比TiO₂-Al₂O₃复合载体的活性提高12.4个百分点。     

油酸锌/脲嘧啶复合热稳定剂对PVC性能的影响

为了改善软质聚氯乙烯(PVC)的初始白度和长期热稳定性,制备由具有不饱和链的油酸锌和含氨基的脲嘧啶(6-氨基-1,3-二甲基脲嘧啶,DAU)组成的复合热稳定剂,添加合适的辅助稳定剂和增塑剂,进行聚氯乙烯热加工。采用刚果红试验法和干燥箱热老化试验法分析复合稳定剂对PVC静态热稳定性的影响;采用转矩流变测试评价其对PVC动态热稳定性的影响;利用红外光谱法研究复合稳定剂的热稳定机理。结果表明,油酸锌与脲嘧啶复合后,稳定剂与PVC的相容性提高,初始白度得到改善;复合稳定剂中DAU与油酸锌(DAU/Zn)的最佳比例为4∶1,长期热稳定性可达100 min;另外,加入辅助稳定剂和增塑剂使PVC的热稳定效果得到进一步改善。     

Ni-Cu/蒙脱土乙醇水蒸气重整制氢催化剂性能研究

生物乙醇重整制氢是一种具有良好应用前景的制氢技术,是当前低碳能源领域的研究热点.本文采用离子交换法制备了Ni-Cu/蒙脱土双金属催化剂,并将其应用于乙醇水蒸气重整制氢.采用X射线衍射(XRD)、比表面积测定(BET)、H2-程序升温还原(H2-TPR)和透射电子显微镜(TEM)等表征手段对催化剂的物相结构、织构性质、还原性能、微观形貌等进行了研究.结果表明:Ni、Cu均为乙醇水蒸气重整制氢的活性组分,铜的加入可以减少镍颗粒的尺寸、优化镍组分的分布状态.此外,Ni-Cu双金属催化剂的双功能特性使其优于单一金属催化剂.Ni-Cu/蒙脱土在焙烧温度500℃、水醇比为8∶1、空速为80000 mL/gcat·h,反应进行10 h后,仍保持72.09％的氢气的选择性,说明Ni-Cu/蒙脱土双金属催化剂在乙醇水蒸气重整制氢中具有良好的催化活性和稳定性.     

插层聚合法制备MMT/聚乙烯纳米塑料

本研究以2,6-二乙酰基吡啶、2,4,6-三甲基苯胺和FeCl2.4H2O为原料,制备了后过渡金属铁的二亚胺配合物。将其负载在改性蒙脱土上,以己烷为溶剂、AlEt3为助催化剂进行聚合反应。通过红外光谱、X射线分析、热分析等,系统地研究了蒙脱土的改性条件对蒙脱土结构、蒙脱土载体铁系催化剂的聚合行为及聚合物结构与热性能的影响。研究表明最佳插层条件是：1831为插层剂、80℃、反应2 h、蒙脱土/1831（质量比）为3/1,此时层间距为2.72 nm,催化剂活性达1.073×106（g PE/mol Fe.h）,聚乙烯堆密度为0.351g/cm3,形成MMT/PE纳米塑料。     

Wet Milling of Fe/Al/Al2O3 and Fe2O3/Al/Al2O3 Powder Mixtures

Wet milling of Al₂O₃-aluminide alloy (3A) precursor powders in acetone has been investigated by milling Fe/Al/Al₂O₃ and Fe₂O₃/Al/Al₂O₃ powder mixtures. The influence of the milling process on the physical and chemical properties of the milled powders has been studied. Particle refinement and homogenization were found not to play a dominant role, whereas plastic deformation of the metal particles leads to the formation of dislocations and a highly disarranged polycrystalline structure. Although no chemical reactions among the powder components in Fe₂O₃/Al/Al₂O₃ powder mixtures were observed, the formation of a nanocrystalline, ordered intermetallic FeAl phase in Fe/Al/Al₂O₃ powder mixtures caused by mechanical alloying was detected. Chemical reactions of Fe and Al particle surfaces with the atmosphere and the milling media lead to the formation of highly porous hydroxides on the particle surfaces. Hence the specific surface area of the powders increases, while the powder density decreases during milling. The fraction of Fe oxidized during milling was determined to be 0.13. The fraction of Al oxidized during milling strongly depends on the metal content of the powder mixture. It ranges between 0.4 and 0.8.     

Preparation and properties of poly(Nε,Nε-dicarboxymethyl-l-lysine)

A new ampholytic homopolypeptide, $\text{poly}\text{(N}{}^{\mathrm{\epsilon }}\text{,N}{}^{\mathrm{\epsilon }}\text{-}\text{dicarboxy-methyl-}\text{l}\text{-lysine}\text{)}$, which has one tertiary amino and two carboxyl groups in the side chain has been derived from a hydrochloride salt of poly(L-lysine). The polymer in aqueous solution seems to be in the coil form with locally extended structure (LES) at neutral pH. In both the acidic and alkaline regions, the molar ellipticity of the polymer changes as a result of change in net charge on the side chain. The conformational changes may be from the coil with LES to other coiled forms. 5–7 M NaClO₄ and 80% aqueous methanol induce the α-helix in the polymer at neutral pH. Divalent cations, Cu²⁺ and Ca²⁺, do not induce any remarkably ordered structures such as α-helix or β-structure in the polymer in aqueous solution at any pH. Ultraviolet absorption studies show an absorption peak of the polymer-Cu²⁺ complex near 240 nm. Dependence of the peak intensity on pH at various q values ($\text{q =}\text{[}\text{Cu}{}^{\mathrm{2+}}\text{]}\text{[}\text{residue}\text{]}$) indicates the two steps of the complex formation. At q less than 0.64, the formation is described only with the first step. An average coordination number for Cu²⁺ at the first step was calculated to be about 2 by the method of Mandel and Leyte. The association constant of Cu²⁺ with the residue at the step was determined from the absorption data to be far smaller than that for the Cu²⁺-EDTA complex. The second step of the formation occurs in the case of large q but the absorption data for the second step cannot be obtained exactly due to precipitation.     

Participation of lewis base on vinyl chloride polymerization with Al(C2H5)3CCl4 catalyst system

The polymerization of vinyl chloride has been investigated using an $\text{Al}\text{(}\text{C}{}_2\text{H}{}_5\text{)}{}_3\text{CCl}{}_4$ catalyst system in the presence of various Lewis bases. Effective Lewis bases are γ-butyrolactone, diglyme and diethylenetriamine which are multidentate. The rate of polymerization is dependent not only on the basicity of the Lewis base used but also on a coordination number of one. The latter is the predominant factor. For the effect of polymeric amines, a tentative hypothesis is discussed.     

Ag2O-Doped Bi2Sr2Ca1Cu2Ox Superconductors Prepared via Melt-Quenching

Ag₂O-doped superconducting Bi₂Sr₂Ca₁Cu₂O _x ceramics were prepared by a melt-quenching–reheating method. It is found that the Ag₂O-doped, as-cast specimens exhibit superconductivity ( T _c= around 80 K) by heat treatment at temperatures around 800°C even in an evacuated and sealed silica glass tube, while the undoped specimens do not and vaporize by the corresponding heat treatment. Conversion of the Ag₂O-doped, as-cast specimens into superconducting ceramics when heated in an evacuated vessel is explained in terms of the oxygen donor of Ag₂O in the specimen. This finding enables us to fabricate a desired shape of superconducting Bi₂Sr₂Ca₁Cu₂O _x ceramics sealed in metals or glasses. The addition of Ag₂O to Bi₂Sr₂Ca₁Cu₂O _x melt, however, had deleterious influences on the superconducting properties ( T _c and J _c) of the resultant ceramics when obtained by heat treatment in air.     

Synthesis and Characterization of Ti0.33Ta0.33Nb0.33C and Ti0.33Ta0.33Nb0.33CxN1-x Whiskers

Ta_0.33Ti_0.33Nb_0.33C and Ta_0.33Ti_0.33Nb_0.33C _x N_{1− x} whiskers were synthesized via a carbothermal vapor-liquid-solid growth mechanism in the temperature range 900°-1450°C in Ar or N₂. The optimum temperature was 1250°C. Whiskers were obtained in a yield of 70-90 vol%. The whiskers were 0.5–1 µm in diameter and 10–30 µm in length. The starting materials that produced the highest whisker yield were: TiO₂, Ta₂O₅, Nb₂O₅, C, Ni, and NaCl. C was added to reduce the oxides, and Ni to catalyze whisker growth. NaCl was used as a source of Cl for vapor-phase transportation of Ta and Nb oxochlorides and Ti chlorides to the catalyst. The catalyst metal was recycled several times during the synthesis and was transported as NiCl₂( g ) according to thermodynamic calculations. The rate of formation and the chemical composition of the whiskers depended on the synthesis temperature, the choice of catalyst, and the atmosphere. At low temperatures, the whiskers were enriched in Nb and Ta, whereas the Ti content increased with increased synthesis temperature.