A Novel Method for the Improved Skin Whitening Effect Based on Nanostructured Lipid Carrier

The effect of humidity on the holographic grating diffraction efficiency and transmittance kinetics in the E204Q BR gelatin film is investigated. We found a correlation between the accumulation of the red-light absorbing O intermediate in the later part of the E204Q BR photocycle and sharpness (decay to the steady-state) of the holographic recording kinetics. As shown, at humidity exceeding 95% the ratio between the peak and steady-state of the diffraction efficiency for the weak probe beam (670 nm) can reach 8.7 in the E204Q BR film, which is sufficient for realization of an efficient novelty filter.     

Mn-Fe_2O_3载氧体作用下CO化学链燃烧特性及动力学研究

采用共沉淀法制备不同物质的量比Mn掺杂的铁基载氧体(Mn-Fe2O3),并进行XRD、BET和TEM表征。开展不同温度下Mn-Fe2O3与CO的化学链燃烧实验,研究载氧体的反应特性,确定较优的掺杂量和反应温度。结果表明,适量的Mn掺杂有助于改善铁基载氧体的反应活性,Fe∶Mn物质的量为50∶1时燃烧反应转化率最高。多循环化学链燃烧实验证实了载氧体稳定性较好。不同升温速率(30、40、50℃/min)下反应动力学分析表明,Mn-Fe2O3与CO的化学链燃烧还原反应均属于随机成核和随后生长的Avrami-Erofeev方程模型,并依据模型分别计算出了该模型的活化能和频率因子。     

Fabrication of Gene Carrier via Self-assembly of Poly[(dimethylamino)ethyl Methacrylate] and Poly(aspartic acid)-grafted-Poly(ethylene glycol)

A biocompatible complex has been prepared as gene carrier via electrostatic interaction, which is composed of a polycation, that is, poly[(dimethylamino)ethyl methacrylate] end-capped with cholesterol moiety (Chol-PDMAEMA₃₀), along with a polyanion named poly(aspartic acid)-grafted-poly(ethylene glycol) (PASP-g-PEG). The complexes have less cytotoxicity compared to the case of alone Chol-PDMAEMA₃₀ or branched polyethylenimine (PEI) system.

In the present study, biocompatible complexes have been prepared as gene carrier via electrostatic interaction, which is composed of a polycation, that is, poly[(dimethylamino)ethyl methacrylate] end-capped with cholesterol moiety (Chol-PDMAEMA₃₀), along with a polyanion named poly(aspartic acid)-grafted-poly(ethylene glycol) (PASP-g-PEG). We first synthesized polysuccinimide (PSI) via condensation polymerization of aspartic acid, and then used PEG-NH₂ to react with the partial pentacyclic rings of PSI to yield a kind of graft copolymer polysuccinimide-grafted-poly(ethylene glycol) (PSI-g-PEG). After hydrolysis of the residual succinimide units, a new biodegradable and biocompatible graft copolymer PASP-g-PEG was prepared successfully. Chol-PDMAEMA₃₀ was synthesized via oxyanion-initiated polymerization, as reported in our previous literature. We investigated the interactions between every pair among calf thymus DNA, Chol-PDMAEMA₃₀, and PASP-g-PEG by agarose gel retardation assay. The results indicate that the prepared complexes could completely bind DNA and may become more stable during systemic circulation. The complexes have less cytotoxicity compared to the case of alone Chol-PDMAEMA₃₀ or branched polyethylenimine (PEI) system. Furthermore, the physicochemical properties of the complexes were also investigated by zeta potential, transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements. These biodegradable and biocompatible polymeric carriers have potential applications in gene delivery.     

Study of Microwave Irradiation Polymerization in the Presence of Different Carriers

ABSTRACT

The influence of the presence of an inorganic carrier in the polymerization systems was investigated in this paper. Ten polymerization systems that contained different inorganic carriers such as Al₂O₃, SiO₂ were studied. The ten polymerization systems are dibutyltin Maleate (DBTM) and allyl thiourea (AT), DBTM and stearic acid vinyl ester (SAVE), SAVE and maleic anhydride (MH), SAVE and acrylamide (AM), itaconic acid (IA) and AM, SAVE and IA, AM and MH, IA, sodium acrylate (AANa), AM. It was found that the activity of monomer can be changed in the presence of a carrier and furthermore, the different species of carrier influence the activity of same monomer differently in the polymerization.     

Indirect hydrogen analysis by gas chromatography coupled to mass spectrometry (GC–MS)

Gas chromatography (GC) is an analytical tool very useful to investigate the composition of gaseous mixtures. The different gases are separated by specific columns but, if hydrogen (H₂) is present in the sample, its detection can be performed by a thermal conductivity detector or a helium ionization detector. Indeed, coupled to GC, no other detector can perform this detection except the expensive atomic emission detector. Based on the detection and analysis of H₂ isotopes by low‐pressure chemical ionization mass spectrometry (MS), a new method for H₂ detection by GC coupled to MS with an electron ionization ion source and a quadrupole analyser is presented. The presence of H₂ in a gaseous mixture could easily be put in evidence by the monitoring of the molecular ion of the protonated carrier gas. Copyright © 2013 John Wiley & Sons, Ltd.     

空气稳定的氮杂蔻电子传输材料分子设计及三氮杂蔻衍生物迁移率计算

采用密度泛函理论研究氮功能化对蒄类化合物几何构型、电子结构及载流子传输性质的影响. 结果表明, 引入杂N原子可以线性降低前线轨道能级, 增强电子注入能力与空气稳定性, 且邻位掺杂较迫位和均匀掺杂调节效果更为显著. 其中, 十二氮杂蒄（12ac）具有新颖的“碗状”构型和高的电子亲和势（3.45 eV）, 是潜在的空气稳定电子传输材料构筑单元. 理论预测室温下2,6,10-三对甲氧基苯基-3,4,7,8,11,12-六甲氧基三氮杂蒄（3b）晶体的电子迁移率为0.242 cm2/V s, 预计是良好的电子传输材料, 值得进一步器件化研究.     

碳酸钾催化的铁基氧载体煤催化化学链燃烧

研究了K₂CO₃催化剂及惰性担体对铁基氧载体煤化学链燃烧的影响.实验结果表明,K₂CO₃的添加可明显促进铁基氧载体与煤之间的反应速率,其原因可归结为从氧载体上迁移到煤颗粒上的K₂CO₃对煤-CO₂气化步骤的催化作用(该步骤为整个还原过程的速率控制步骤);由于K₂CO₃本身的促熔效果及加入K₂CO₃后导致的剧烈氧化还原反应,可以发现,K₂CO₃会增大铁基氧载体的烧结;不同惰性担体对铁基氧载体与煤的反应性影响不大,这是由于惰性担体对还原速控步没有影响;K₂CO₃在多循环化学链燃烧过程中依然可以保持一定的催化活性,另外由于催化剂的流失与失活,使得氧载体的反应活性有所下降.     

铜基载氧体与可燃固体废弃物化学链燃烧特性研究

采用机械混合法制备了铜基载氧体,利用两段式管式炉反应平台和磁悬浮热重分析仪分别研究了铜基载氧体与石墨、可燃固体废弃物典型组分及可燃固体废弃物热解气模型物CH₄的化学链燃烧特性。结果表明,机械混合法制备的Cu80Si950载氧体强度高,具有良好的转化率和循环稳定性,是实现可燃固体废弃物化学链燃烧的一种比较理想的载氧体。利用扫描电镜(SEM)、X射线衍射仪(XRD)和颗粒强度测定仪对各个反应阶段载氧体进行分析。结果表明,Cu80Si950载氧体参与反应后表面结构发生巨大改变,机械强度骤降。多次循环之后载氧体结构趋于规则均匀化,形成类似球棒形状的大孔隙率结构,强度保持不变,使得载氧体在长时间使用过程中反应性能得以维持。     

Fe2O3/Al2O3氧载体用于甲烷化学链燃烧：负载量与制备方法的影响

以不同方法制备了系列Fe₂O₃/Al₂O₃氧载体,采用XRD、H₂-TPR、CH₄-TPR、O₂-TPD和BET等分析技术对氧载体进行了表征。研究了不同Fe₂O₃负载量氧载体的甲烷化学链燃烧性能,考察了不同制备方法对Fe₂O₃/Al₂O₃氧载体结构、反应性和产物选择性的影响。结果表明,Fe₂O₃负载量对氧载体活性及产物中CO₂选择性的影响较大,负载量较低时氧载体活性较低且引起甲烷部分氧化产物CO含量增加。制备方法亦对氧载体与甲烷的反应活性有所影响,整体上共沉淀法制备的质量分数60％Fe₂O₃/Al₂O₃氧载体具有较高的氧化活性和化学链循环稳定性。其在反应温度850℃、反应时间15 min、30次循环后甲烷转化率及产物中CO₂选择性均未见明显降低。