Nanoparticles Containing Oxidized Cholesterol Deliver mRNA to the Liver Microenvironment at Clinically Relevant Doses

Using mRNA to produce therapeutic proteins is a promising approach to treat genetic diseases. However, systemically delivering mRNA to cell types besides hepatocytes remains challenging. Fast identification of nanoparticle delivery (FIND) is a DNA barcode‐based system designed to measure how over 100 lipid nanoparticles (LNPs) deliver mRNA that functions in the cytoplasm of target cells in a single mouse. By using FIND to quantify how 75 chemically distinct LNPs delivered mRNA to 28 cell types in vivo, it is found that an LNP formulated with oxidized cholesterol and no targeting ligand delivers Cre mRNA, which edits DNA in hepatic endothelial cells and Kupffer cells at 0.05 mg kg^?1. Notably, the LNP targets liver microenvironmental cells fivefold more potently than hepatocytes. The structure of the oxidized cholesterols added to the LNP is systematically varied to show that the position of the oxidative modification may be important; cholesterols modified on the hydrocarbon tail associated with sterol ring D tend to outperform cholesterols modified on sterol ring B. These data suggest that LNPs formulated with modified cholesterols can deliver gene‐editing mRNA to the liver microenvironment at clinically relevant doses.     

Some Properties of Oxidized Gelatin

Alkali processed inert type gelatin has been oxidized in a controlled stepivise fashion using H₂,0₂. The difference between oxidation degree of gelatin was detected by a simple physical ripening test and potentiometric titration with AgNO₃. The physical ripening was very influenced by pH and the variety of halide. The titration curve has an inflection point and the plot of pAg vs. logarithm of Ag ion concentration gives a straight line.     

快干型氧化淀粉粘合剂的研制

以玉米淀粉为原料,采用氧化法,在对淀粉粘合剂粘度影响因素考察的基础上,运用正交设计,用L9(3)4正交表安排实验,得到各因素对粘度影响的主次顺序,以及最佳工艺条件,并在此基础上,分别加入不同快干剂,研制出性能稳定、干燥速度快的淀粉粘合剂,以满足高速瓦楞纸板生产线的要求.     

热氧化对钛合金表面氧化层的影响

对钛合金Ti6Al7Nb(以下简称TAN)和Ti6Al4V(以下简称TAV)通过热氧化处理获得表面氧化层,用金相显微镜、维氏硬度计、XRD和XPS等手段对氧化层的性能进行表征。结果表明:相同氧化温度和氧化时间,TAN合金较TAV合金表面形成的氧化层更薄、致密度更好;合金表面硬度随热氧化温度的升高和氧化时间的延长而增加,但温度过高(TAN:1000℃;TAV:900℃)会使氧化层疏松多孔,硬度反而会下降;通过XPS对不同温度短时间氧化样品进行表面分析发现,氧化温度对合金中Nb添加元素的氧化行为影响较小,对V添加元素的氧化行为影响剧烈。两种合金元素对氧化过程有着显著的影响。     

过氧化氢氧化淀粉胶黏剂的研制

介绍了过氧化氢氧化淀粉胶黏剂的制备工艺,并着重分析了氢氧化钠、硫酸亚铁、过氧化氢、蒙脱石的添加质量对H2O2氧化淀粉胶黏剂性能的影响。实验结果表明,当过氧化氢氧化淀粉胶黏剂中各组分添加质量的配比为m（淀粉）：m（氢氧化钠）：m（水）：m（过氧化氢）：m（硫酸亚铁）：m（蒙脱石）=100：12：600：4．4：2．4：12时,所制得的氧化淀粉胶黏剂各项性能指标较好,是一种较理想的淀粉胶黏剂。     

氧化淀粉的制备工艺研究

对氧化淀粉的干法、半干法、湿法3种制备工艺进行了探讨。论述了各工艺的优缺点:干法工艺流程较短、单位产品能耗较低、生产设备较简便,但产品质量不太稳定;半干法工艺虽然增加了一定的生产用水量,但未大量增加工艺流程,且产品质量较高;湿法工艺反应均匀、产品质量较稳定、生产过程较易控制,但存在产品较难回收、生产用水量大,且生产过程中会产生大量污水,给生态环境带来较大压力等缺点。因此,应根据各工艺的缺陷优化氧化淀粉生产工艺,以获得最佳的生产工艺条件。     

氧化石墨烯及其与聚合物的复合

石墨烯是单原子厚度的二维碳原子晶体,也是性能优异的新型纳米复合填料.近三年来,石墨烯从概念上的二维材料变成现实材料,在化学和物理学界均引起轰动.通过述评氧化石墨及氧化石墨烯的制备、结构、改性及其与聚合物的复合,展望了石墨烯及其复合材料的研究前景,认为通过机械剥离氧化石墨可规模化制备氧化石墨烯,进一步将其化学改性并制备复合材料已取得较大进展,这一途径被认为足石墨烯规模化应用的战略起点.     

氧化细菌纤维素的制备及其表征

目的 通过高碘酸钠氧化制备含醛基的氧化细菌纤维素,并改善细菌纤维素的抗菌性能,为细菌纤维素的综合利用提供新思路.方法 以氧化细菌纤维素中醛基的含量和保留率作为评价指标,通过单因素和正交试验对其进行优化,利用红外光谱仪、扫描电镜对氧化前后的细菌纤维素结构进行表征,以大肠杆菌、金黄色葡萄球菌为实验菌种,探究氧化细菌纤维素的抑菌性能.结果 当高碘酸钠浓度为0.3 mol/L,悬浮液pH为4.0,体系温度为50℃,反应时间为4.0 h时,制备的氧化细菌纤维素的最佳醛基含量为98％(质量分数)、保留率为78％.经氧化后,氧化细菌纤维素存在醛基官能团,其对大肠杆菌、金黄色葡萄球菌产生的抑菌圈直径分别为21.5,23.3 mm.结论 制得了含醛基的氧化细菌纤维素,且其具有较好的抗菌性.     

Oxidized iron nanoparticles obtained by high-power plasma cutting

A high-power industrial plasma cutting equipment was applied to carve a SAE 1010 carbon steel. The usually discarded cut material was observed by scanning electron microscopy (SEM) showing that hollow and entire microspheroidal particles were produced. The analysis with X-ray diffraction (XRD) evidenced that the composition of microparticles was FeO, Fe₂O₃ and Fe₃O₄. By transmission electron microscopy (TEM) it was found that spherical nanoparticles in the range of 2 to 150 nm in diameter were formed.     

淀粉氧化改性粘合剂发展现状及展望

对于淀粉氧化工艺以及氧化淀粉改性工艺进行了详细的探讨，对淀粉改性产物应用于包装行业中的应用情况进行了介绍，并提出了一些建议。     

Strong Electrochemiluminescence Emission from Oxidized Multiwalled Carbon Nanotubes

Carbon nanotubes (CNTs) as well‐known nanomaterials are extensively studied and widely applied in various fields. Nitric acid (HNO₃) is often used to treat CNTs for purification purposes and preparing oxidized CNTs for various applications. However, too little attention is paid to investigating the effect of HNO₃ treatment on the optical properties of CNTs. In this work, it is observed for the first time that HNO₃‐oxidized multiwalled carbon nanotubes (ox‐MWCNTs) have strong electrochemiluminescence (ECL) activity, which enables ox‐MWCNTs to become new and good ECL carbon nanomaterials after carbon quantum dots (CQDs) and graphene quantum dots (GQDs). Various characterization technologies, such as transmission electron microscope (TEM), X‐ray photoelectron spectroscopy (XPS), and Raman spectroscopy, are used to reveal the relationship between ECL activity and surface states. The ECL behaviors of ox‐MWCNTs are investigated in detail and a possible ECL mechanism is proposed. Finally, the new ECL nanomaterials of ox‐MWCNTs are envisioned to have promising applications in sensitive ECL sensing and in the study of CNT‐based catalysts.     

微弧氧化陶瓷膜层的性能及其应用

采用脉冲电源,对发动机活塞用铝合金（ＺＬ１０８）基体进行了微弧氧化处理,测定了陶瓷氧化物膜的表面粗糙度和膜层硬度,研究了电流密度和强化时间对陶瓷膜的硬度和耐磨性的影响,分析了影响表面粗糙度的因素,实验结果表明,随着电流密度和强化时间增加,膜层的表面度增大,而膜层硬度则在电流密度超过８Ａ／dm^2后趋于稳定,基机 归固于陶瓷氧化膜在强电流密度下烧结,实验条件下对磨损结果表明,铝合金活塞的耐磨性,经微弧氧化后提高３－４倍。     

Synthesis and Characterization of Thermally Oxidized ZnO Films

Metallic zinc thin films were deposited onto glass substrates using vacuum thermal evaporation method. By thermal oxidation of as-deposited Zn films, in ambient conditions, at different temperatures (570, 670 and 770 K, respectively, for 1 h) zinc oxide thin films were obtained. The structural characteristics of the obtained films were investigated by X-ray diffraction technique and atomic force microscopy. Characteristic XRD patterns of oxidized films show small and narrow peaks superimposed on the large broad background of the amorphous component of the substrate. Optical transmittance spectra were recorded and it was observed that the transmittances of the studied films increased with increasing oxidation temperature. The values of the optical bandgap, E _g, evaluated from Tauc plots, were found to be ranged between 3·22 and 3·27 eV. Electrical conductivity measurements were performed and it was observed that, after performing a heat treatment, the electrical conductivity of analysed samples decreased with one or two orders of magnitude. The gas sensitivity was investigated for some reducing gases such as acetone, methane and liquefied petroleum gas and it was observed that the films studied were selective to acetone.     

氧化淀粉基复合材料的制备及力学性能

为提高淀粉基复合材料的力学性能,采用对原生淀粉进行氧化改性,通过模压发泡工艺制备了氧化淀粉基复合材料(OS复合材料)。力学测试结果表明,OS复合材料在力学性能方面有很大程度的提升,且最佳氧化比为m(淀粉)∶m(H_2O_2)=10∶1.5。此时拉伸强度为3.05 MPa,压缩强度6.724 MPa,与原生淀粉基复合材料相比分别提高21.03%、14.65%,缓冲性能最佳;其压缩强度明显优于聚苯乙烯发泡塑料(EPS),缓冲系数与EPS接近。为揭示性能变化的内在机理,通过红外光谱分析发现,氧化过程使得淀粉内部官能基团改变,形成更强的氢键,与剑麻纤维的结合更紧固;通过X射线衍射分析得到,淀粉氧化改性后,结晶度降低,内部形成更均匀的相,裸露的支链增多,其与剑麻纤维结合得更好。为探究复合材料的界面结合情况,采用扫描电镜观察,图像显示OS复合材料内部生成了较好的泡孔结构,并且其淀粉基质均匀地附着在纤维的表面,淀粉和纤维形成了很好的结合。     

Oxidized potato-starch films as primer coatings of aluminium

Potato-starch (PS) films for use as primer coatings of aluminium substrates were prepared in two steps, chemical-thermal-catalysed oxidation routes. The PS was modified with cerium (IV) ammonium nitrate (CAN) as a chemical oxidizer, followed by thermal oxidation at 150°C in the presence of atmospheric oxygen; this led to the formation of a functional carbonyl derivative caused by cleavage of the glycol C-C bonds in glycosidic rings, thereby resulting in the ring openings. Increasing oxidation by raising the temperature to 200 and 250°C promoted the conversion of carbonyl into carboxylate derivatives, while facilitating the breakage of C-O-C linkages in the open rings. The latter phenomenon reflected the formation of another carboxylate. The intermediate carboxylate derivatives favourably reacted with Ce4+ ions released from CAN to form cerium-bridged carboxylate complexes. Cerium-complexed carboxylate films used as primer coatings not only afforded some protection of aluminium substrates against corrosion, but also displayed excellent adhesion to both the polyurethane (PU) top-coating and aluminium sites. The latter demonstrated that the loss of adhesion at PU/primer/aluminium joints occurs in the PU layers, representing the mode of cohesive failure. This revised version was published online in November 2006 with corrections to the Cover Date.     

Ni／氧化金刚石催化裂解甲烷制氢技术研究

通过在TG上程序升温催化裂解甲烷实验，研究了不同Ni负载量的氧化金刚石催化剂对甲烷催化活性的影响。研究表明，Ni负载量越多，催化剂催化活性越高。氧化金刚石作载体的Ni基催化剂在550℃的温度条件下，甲烷催化裂解效率较高，80min内甲烷转化率维持在7N以上；空速对甲烷转化率影响较大，空速越快，转化率越低。指出氧化金刚石将是一种有效的催化剂载体材料。     

氧化醋酸酯淀粉粘合剂的制备与性能改善

以木薯淀粉为原料,FeSO4、H2O2和醋酸乙烯酯分别作为催化剂、氧化剂和酯化剂,合成了高性能氧化醋酸酯淀粉粘合剂.通过正交实验优化得到工艺参数分别为:氧化过程,催化剂用量(质量分数)0.1%,pH＝10,H2O2用量6%,反应温度为50℃;酯化过程,反应时间1.5h,酯化剂用量6%,反应温度为35℃,pH=9.探讨了改性木薯淀粉和不同取代度的氧化醋酸酯淀粉的糊凝沉性质:改性淀粉的糊凝沉性质呈下降趋势,从60%下降到42%;且随着取代度的提高,糊凝沉性质也呈下降趋势,从50%下降到40%.最后还探讨了助剂对粘合剂干燥速度的影响.