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21.
A hydrophilic and temperature-induced degradation drug, vinorelbine bitartrate (VB)-loaded phosphatidylethanolamin liposomes (PSLs), was prepared by the thin-film hydration method. Liposomes were made of phosphatidylethanolamine: cholesteryl: oleic acid (PE: CHOL: OA, 3:3:1 mass/mass). The mean particle size of the PSLs ranged from 293.06 nm. The transmission electron microscope (TEM) images displayed that the shape of the PSLs was multilamellar vesicles with smooth surface. The highest entrapment efficiency (EE) and drug loading capacity (DL) could reach up to 68.5% and 6.23%, respectively. The PSLs was evaluated by comparing the rate of release of encapsulated VB in different phosphate buffer solution (PBS), and the result showed that the rate of drug release in acid medium was faster than in pH 7.4. Pharmacokinetic characteristics in vivo and the tissue distribution in mice were investigated, which provided experimental and theoretical basis for utilizing liposomes in malignant tumor chemotherapy.  相似文献   
22.
The influence of environmentally friendly aqueous binders and carbon coating on the electrochemical performance of SiO powder anodes for lithium ion batteries has been investigated in detail. The SiO anode with sodium alginate (Alg), styrene butadiene rubber/sodium carboxymethyl cellulose (SCMC) or polyacrylic acid binder exhibits fairly good cycling stability. However, use of polyvinyl alcohol as binder results in rapid capacity loss during cycling. The positive effect of the former binders could be attributed to the amorphous structures and ester-like bond, which were detected by X-ray diffraction and Fourier transform infrared. The cycling performance is further enhanced by carbon coating on the surface of the SiO. The reversible capacity of SiO/C electrode with either Alg or SCMC can retain ca. 940 mAh g?1 after 100 cycles. In particular, a long-term cycling stability can be achieved for SiO/C electrode using SCMC binder. Additionally, the high irreversibility of SiO/C electrode at the first cycle can be completely compensated by a simple pretreatment.  相似文献   
23.
Corn fiber and sweet sorghum bagasse (SSB) are both pre-processed lignocellulosic materials that can be used to produce liquid biofuels. Pretreatment using dilute sulfuric acid at a severity factor of 1.06 and 1.02 released 83.2 and 86.5 % of theoretically available sugars out of corn fiber and SSB, respectively. The resulting hydrolysates derived from pretreatment of SSB at SF of 1.02 supported growth of Cryptococcus curvatus well. In 6 days, the dry cell density reached 10.8 g/l with a lipid content of 40 % (w/w). Hydrolysates from corn fiber, however, did not lead to any significant cell growth even with addition of nutrients. In addition to consuming glucose, xylose, and arabinose, C. curvatus also utilized formic acid, acetic acid, 4-hydroxymethylfurfural, and levulinic acid for growth. Thus, C. curvatus appeared to be an excellent yeast strain for producing lipids from hydrolysates developed from lignocellulosic feedstocks.  相似文献   
24.
Of the various beyond‐lithium‐ion batteries, lithium–sulfur (Li‐S) batteries were recently reported as possibly being the closest to market. However, its theoretically high energy density makes it potentially hazardous under conditions of abuse. Therefore, addressing the safety issues of Li‐S cells is necessary before they can be used in practical applications. Here, we report a concept to build a safe and highly efficient Li‐S battery with a flame‐inhibiting electrolyte and a sulfur‐based composite cathode. The flame retardant not only makes the carbonates nonflammable but also dramatically enhances the electrochemical performance of the sulfur‐based composite cathode, without an apparent capacity decline over 750 cycles, and with a capacity greater than 800 mA h?1 g?1(sulfur) at a rate of 10 C.  相似文献   
25.
采用电感耦合等离子体质谱法(ICP–MS),在不同的模拟迁移条件(模拟物、盛放温度、接触时间、乙酸浓度、使用次数等)下,研究聚酯类食品包装材料中二氧化钛在6种食品模拟物(水、4%乙酸、10%乙醇、65%乙醇、正己烷和异辛烷)中的迁移规律。结果显示:食品模拟物的属性对迁移行为有显著影响,迁移量随温度的升高及时间的延长而增加,食品的酸性越强,二氧化钛的迁移量越大。因此需适量控制聚酯类食品包装材料的反复使用次数、盛放食品时的温度和时间以降低二氧化钛迁出风险。  相似文献   
26.
张杰  崔艳娜  刘绣华 《化学研究》2014,25(6):551-562
安石榴苷是石榴皮多酚的主要成分,具有抗氧化、抗癌、抗菌、抗病毒、抗炎等多种药理学功效.本文作者主要对国内外关于安石榴苷的研究进行了综述,详细阐述了安石榴苷的结构、提取分离方法、含量测定、活性及代谢方式等研究进展,以期为安石榴苷的开发应用提供参考依据.  相似文献   
27.
The qualitative and quantitative capability of the ion trap mass analyzer could be greatly affected by the accumulation time. However, the importance of the accumulation time has not so far been thoroughly explored. Here, the influence of ion accumulation time on qualitative and quantitative analysis of complicated components was systematically investigated based on the case study of 40 ophiopogonins in Ophiopogon extract by hybrid ion trap time-of-flight mass spectrometry (LCMS-IT-TOF). In this process, the accumulation time was set at 10, 25, 50, 100, and 200 ms, respectively. The effect of accumulation time on qualitative analysis of ophiopogonins was studied by comparing the total ion current (TIC) of MS1, TIC of MS2, and the number and signal of fragmental ions. The results demonstrated that the signal could be greatly influenced by varying the accumulation time. The number and signal of the fragmental ions were increased significantly with a longer accumulation time in the range of 10–100 ms. Also, the effect of accumulation time on quantitative analysis of ophiopogonins was investigated by comparing the linearity, accuracy, and precision measured on LCMS-IT-TOF. Importantly, quantitative parameters could all be significantly improved by choosing an appropriate accumulation time.  相似文献   
28.
在球形SiO_2颗粒表面包覆适量的CuO,经还原得到铜包覆的多孔硅复合材料[p-Si@Cu(x)].利用X射线衍射、扫描电子显微镜、透射电子显微镜和比表面积分析等手段对样品的组成、物相结构、微观形貌和孔结构进行分析,并初步研究了材料的循环性能和倍率性能.结果表明,铜包覆量x=0.05时,在100 mA/g电流密度下,样品的首次放电容量为3596.9 mA·h/g,首次充电容量为2590.7 mA·h/g,首次库仑效率为72.03%;在1C倍率下可逆容量为1004.9 mA·h/g,0.1C倍率下循环100周后的可逆容量仍为1706.5mA·h/g,容量保持率为76.1%.  相似文献   
29.
We first design and synthesize a MWNT/C/Mg1.03Mn0.97SiO4 hierarchical nanostructure composed of MWNTs pinning the surface of the Mg1.03Mn0.97SiO4 nanoparticles, with simultaneous tethering to Mg1.03Mn0.97SiO4 particles via an interfacial amorphous carbon phase bonding, through a facile CVD method. It is further demonstrated that the nanocomposite exhibits a reversible capacity as high as 300 mAh g−1 at 0.2 C and a stable cycling performance at 0.5 C when utilized as a cathode material for rechargeable magnesium batteries.  相似文献   
30.

Abstract  

The synthesis and single-crystal structure of a Na-salt compound Na10[Co4(OH2)2(AsW9O34)2]·32H2O (1) was reported. Compound 1 crystallizes in triclinic system, space group P−1, with the lattice parameters: a = 11.6040(10) ?, b = 12.9361(13) ?, c = 17.396(2) ?, α = 97.4120(10)°, β = 106.8590(10)°, γ = 111.867(2)° and Z = 1. Compound 1 consists of a pure inorganic network based on tetra-sodium capped sandwich-type anionic clusters [Co4(OH2)2(AsW9O34)2]10− bridged through Na–OH2 subunits. The thermogravimetric and electrochemistry measurements had also been studied.  相似文献   
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