采用表面修饰法制备了聚合物包覆的纳米 SiC 颗粒,采用 M-200 环块试验机进行摩擦磨损试验,研究了表面修饰的纳米 SiC 颗粒添加剂对发动机润滑油(15W/40)减摩性能的影响,并利用扫描电子显微镜对磨块的磨损表面形貌进行观察,分析了润滑...采用表面修饰法制备了聚合物包覆的纳米 SiC 颗粒,采用 M-200 环块试验机进行摩擦磨损试验,研究了表面修饰的纳米 SiC 颗粒添加剂对发动机润滑油(15W/40)减摩性能的影响,并利用扫描电子显微镜对磨块的磨损表面形貌进行观察,分析了润滑剂的减摩机理.结果表明:当滑动线速度为 0.42m/s、载荷低于 1000N 时,纳米 SiC 颗粒的加入导致磨损失重的提高;当载荷提高到 1300N 时,纳米 SiC 颗粒的加入使磨损失重低于相同条件下以基础油作润滑剂的磨损失重;当滑动线速度为 0.84 m/s、载荷为 1 000 N 时,纳米 SiC 颗粒的加入使磨损失重为相同条件下以基础油作为润滑剂磨损失重的 40%.展开更多
Nanoparticles of BaLiF3：Er^3＋ were prepared from the quaternary microemulsions of Cetyltrim-Enthyl Ammonium Bromide （CTAB）, n-butanol, n-octane, and water, using the hydrothermal-microemulsion technique. The compl...Nanoparticles of BaLiF3：Er^3＋ were prepared from the quaternary microemulsions of Cetyltrim-Enthyl Ammonium Bromide （CTAB）, n-butanol, n-octane, and water, using the hydrothermal-microemulsion technique. The complex fluorides were characterized by means of X-ray power diffraction, Environmental Scanning Electron Microscopy （ESEM）, and fluorescence spectra. The positions and intensifies of the peaks in the XRD pattern of the final products indicate the formation of BaLiF3·Er^3＋. No other peaks or impurities were detected. The average size of the nanoparticles, calculated with the Debye-Scherrer equation was 98.45 nm, which was in agreement with the result of ESEM. The infrared fluorescence spectra consisted of four peaks with a predominant peak located at 1540 nm.展开更多
Hepatocellular carcinoma(HCC) is the 5th most common malignancy which is responsible for more than half million annual mortalities; also, it is the third leading cause of cancer related death. Unfavorablesystemic side...Hepatocellular carcinoma(HCC) is the 5th most common malignancy which is responsible for more than half million annual mortalities; also, it is the third leading cause of cancer related death. Unfavorablesystemic side-effects of chemotherapeutic agents and susceptibility to the degradation of small interfering RNAs(si RNAs), which can knock down a specific gene involved in the disease, have hampered their clinical application. So, it could be beneficial to develop an efficient carrier for the stabilization and specific delivery of drugs and si RNA to cells. Targeted nanoparticles have gained considerable attention as an efficient drug and gene delivery system, which is due to their capability in achieving the highest accumulation of cytotoxic agents in tumor tissue, modifiable drug pharmacokinetic- and bio-distribution, improved effectiveness of treatment, and limited sideeffects. Recent studies have shed more light on the advantages of novel drug loaded carrier systems vs free drugs. Most of the animal studies have reported improvement in treatment efficacy and survival rate using novel carrier systems. Targeted delivery may be achieved passively or actively. In passive targeting, no ligand as homing device is used, while targeting is achieved by incorporating the therapeutic agent into a macromolecule or nanoparticle that passively reaches the target organ. However, in active targeting, the therapeutic agent or carrier system is conjugated to a tissue or cell-specific receptor which is overexpressed in a special malignancy using a ligand called a homing device. This review covers a broad spectrum of targeted nanoparticles as therapeutic and nonviral si RNA delivery systems, which are developed for enhanced cellular uptake and targeted gene silencing in vitro and in vivo and their characteristics and opportunities for the clinical applications of drugs and therapeutic si RNA are discussed in this article. Asialoglycoprotein receptors, low-density lipoprotein, ganglioside GM1 cell surface ligand, epidermal growth factor receptor receptors, monoclonal antibodies, retinoic acid receptors, integrin receptors targeted by Arg-Gly-Asp peptide, folate, and transferrin receptors are the most widely studied cell surface receptors which are used for the site specific delivery of drugs and si RNA-based therapeutics in HCC and discussed in detail in this article.展开更多
文摘采用表面修饰法制备了聚合物包覆的纳米 SiC 颗粒,采用 M-200 环块试验机进行摩擦磨损试验,研究了表面修饰的纳米 SiC 颗粒添加剂对发动机润滑油(15W/40)减摩性能的影响,并利用扫描电子显微镜对磨块的磨损表面形貌进行观察,分析了润滑剂的减摩机理.结果表明:当滑动线速度为 0.42m/s、载荷低于 1000N 时,纳米 SiC 颗粒的加入导致磨损失重的提高;当载荷提高到 1300N 时,纳米 SiC 颗粒的加入使磨损失重低于相同条件下以基础油作润滑剂的磨损失重;当滑动线速度为 0.84 m/s、载荷为 1 000 N 时,纳米 SiC 颗粒的加入使磨损失重为相同条件下以基础油作为润滑剂磨损失重的 40%.
基金Project supported by the Foundation of Science and Technology Department of Jilin Province (20050507)
文摘Nanoparticles of BaLiF3：Er^3＋ were prepared from the quaternary microemulsions of Cetyltrim-Enthyl Ammonium Bromide （CTAB）, n-butanol, n-octane, and water, using the hydrothermal-microemulsion technique. The complex fluorides were characterized by means of X-ray power diffraction, Environmental Scanning Electron Microscopy （ESEM）, and fluorescence spectra. The positions and intensifies of the peaks in the XRD pattern of the final products indicate the formation of BaLiF3·Er^3＋. No other peaks or impurities were detected. The average size of the nanoparticles, calculated with the Debye-Scherrer equation was 98.45 nm, which was in agreement with the result of ESEM. The infrared fluorescence spectra consisted of four peaks with a predominant peak located at 1540 nm.
文摘Hepatocellular carcinoma(HCC) is the 5th most common malignancy which is responsible for more than half million annual mortalities; also, it is the third leading cause of cancer related death. Unfavorablesystemic side-effects of chemotherapeutic agents and susceptibility to the degradation of small interfering RNAs(si RNAs), which can knock down a specific gene involved in the disease, have hampered their clinical application. So, it could be beneficial to develop an efficient carrier for the stabilization and specific delivery of drugs and si RNA to cells. Targeted nanoparticles have gained considerable attention as an efficient drug and gene delivery system, which is due to their capability in achieving the highest accumulation of cytotoxic agents in tumor tissue, modifiable drug pharmacokinetic- and bio-distribution, improved effectiveness of treatment, and limited sideeffects. Recent studies have shed more light on the advantages of novel drug loaded carrier systems vs free drugs. Most of the animal studies have reported improvement in treatment efficacy and survival rate using novel carrier systems. Targeted delivery may be achieved passively or actively. In passive targeting, no ligand as homing device is used, while targeting is achieved by incorporating the therapeutic agent into a macromolecule or nanoparticle that passively reaches the target organ. However, in active targeting, the therapeutic agent or carrier system is conjugated to a tissue or cell-specific receptor which is overexpressed in a special malignancy using a ligand called a homing device. This review covers a broad spectrum of targeted nanoparticles as therapeutic and nonviral si RNA delivery systems, which are developed for enhanced cellular uptake and targeted gene silencing in vitro and in vivo and their characteristics and opportunities for the clinical applications of drugs and therapeutic si RNA are discussed in this article. Asialoglycoprotein receptors, low-density lipoprotein, ganglioside GM1 cell surface ligand, epidermal growth factor receptor receptors, monoclonal antibodies, retinoic acid receptors, integrin receptors targeted by Arg-Gly-Asp peptide, folate, and transferrin receptors are the most widely studied cell surface receptors which are used for the site specific delivery of drugs and si RNA-based therapeutics in HCC and discussed in detail in this article.
