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Synthesis of Core-Shell Nanoparticles of Cu-Ag for Application in Electrohydrodynamic Printing Technique 预览
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作者 Chinh Dung Trinh Dung My Thi Dang Chien Mau Dang 《材料科学与工程:中英文A版》 2019年第2期75-82,共8页
Core-shell nanoparticles of Cu-Ag (Cu core and Ag shell) were synthesized using chemical method. Polyvinyl pyrrolidone (PVP) was used as a surfactant, and ascorbic acid (C6H8O6) and sodium borohydride (NaBH4) were use... Core-shell nanoparticles of Cu-Ag (Cu core and Ag shell) were synthesized using chemical method. Polyvinyl pyrrolidone (PVP) was used as a surfactant, and ascorbic acid (C6H8O6) and sodium borohydride (NaBH4) were used as reducing agents to reduce the metal complexes [Cu(NH3)4]^2+ and [Ag(NH3)2]^+. The results of transmission electron microscope (TEM) analysis, ultraviolet-visible spectroscopic (UV-Vis) analysis, X-ray diffraction (XRD) analysis showed that the core-shell nanoparticles of Cu-Ag were successfully synthersized. The average particle size was 32 nm. The dispersion of the nanoparticles was still good after 80 days without the formation of the oxides of Cu and Ag. The properties of the nanoparticles suggested that they were suitable to be used as an electrically conductive material for conductive ink-jet printing inks. 展开更多
关键词 NANOPARTICLES NANO BIMETAL Ag NANOPARTICLES
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Removal of lead and cadmium ions by single and binary systems using phytogenic magnetic nanoparticles functionalized by 3-marcaptopropanic acid
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作者 Imran Ali Changsheng Peng Iffat Naz 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2019年第4期949-964,共16页
The present research study is focused on green fabrication of superparamagnetic Phytogenic Magnetic Nanoparticles(PMNPs), and then its surface functionalization with 3-Mercaptopropionic acid(3-MPA). The resulting mate... The present research study is focused on green fabrication of superparamagnetic Phytogenic Magnetic Nanoparticles(PMNPs), and then its surface functionalization with 3-Mercaptopropionic acid(3-MPA). The resulting material(i.e. 3-MPA@PMNPs) characterized by FTIR, powder XRD, SEM, TEM, EDX, VSM, BET and TGA techniques and then further employed for the investigation of the adsorptive removal of lead(Pb^2+) and cadmium(Cd^2+) ions from aqueous solutions in single and binary systems. The material showed fastest adsorptive rate(98.23%) for Pb^2+ and(96.5%) Cd2+within the contact time of 60 min at pH 6.5 in the single system. The experimental data were fitted well to Langmuir isotherm, indicated monolayer adsorption of both metal ions onto 3-MPA@PMNPs and an estimated comparable adsorptive capacity of 68.41 mg·g^-1(Pb2+) and 79.8 mg·g^-1(Cd2+) at p H 6.5. However, kinetic data agreed well with pseudo-second-order model, and indicated that the removal mainly supported chemisorption and/or ion-exchange mechanism. Thermodynamic parameters such asΔGo,ΔHo, and ΔSo, were-3259.20, 119.35 and 20.73 for Pb^2+, and-1491.10, 45.441 and 7.87 for Cd^2+ at temperature 298.15 K, confirmed that adsorption was endothermic, spontaneous and favorable. The material demonstrated higher selectivity of Pb2+ and its removal efficiency was(98.20 ± 0.3)% in binary system experiments. The material persisted performance up-to seven(07) consecutive treatment cycles without losing their stability and offered comparable fastest magnetic separation(35 s) from aqueous solutions. Therefore, it is recommended that the prepared material can be employed to remove toxic heavy metal ions from water/wastewaters and this "green" method can easily be implemented at large scale in low economy countries. 展开更多
关键词 Green RECIPE Phytogenic magnetic NANOPARTICLES Physical characterization of NANOPARTICLES Lead and CADMIUM IONS REMOVAL
氧化铁纳米粒子在骨组织修复再生中的研究与应用 预览
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作者 沈梦杰 杨琨 刘琪 《中国组织工程研究》 CAS 北大核心 2019年第14期2248-2253,共6页
背景:氧化铁纳米粒子是一种磁性纳米材料,具有优良的特性,使其在医学上的应用越来越广泛,尤其在骨组织再生修复方面起到了积极作用。目的:综述氧化铁纳米粒子在骨组织修复再生中的研究进展及应用。方法:应用计算机检索中国生物医学文献... 背景:氧化铁纳米粒子是一种磁性纳米材料,具有优良的特性,使其在医学上的应用越来越广泛,尤其在骨组织再生修复方面起到了积极作用。目的:综述氧化铁纳米粒子在骨组织修复再生中的研究进展及应用。方法:应用计算机检索中国生物医学文献数据库、CNKI数据库、PubMed数据库及Elsevier数据库中发表的相关文献,检索词为“骨修复,骨再生,氧化铁纳米粒子,磁性纳米粒子;IONPs,bone repair,bone regenerate,iron oxide nanoparticles,osteogenesis,stem cell”,查阅2004年5月至2018年1月期间收录的氧化铁纳米粒子在骨组织再生医学方面的相关文章。结果与结论:近年来,磁性纳米粒子在医学研究中得到了广泛应用,例如靶向给药、磁共振成像(MRI)、局部组织热疗和肿瘤治疗、生物分离和生物传感等,目前较为常用的磁性纳米粒子是氧化铁纳米粒子。研究已证明氧化铁纳米粒子与干细胞归巢有密切关系,并且能够携带药物进入特定的靶向部位及促进骨组织再生修复。虽然氧化铁纳米粒子促进骨组织修复研究取得了初步成效,但对于其促进骨愈合机制尚未完全阐明,大部分研究仅局限于基础研究,未来还需加强关于氧化铁纳米粒子促进骨组织愈合通路机制的研究及临床研究。 展开更多
关键词 氧化铁纳米粒子 磁性纳米粒子 骨修复 干细胞 成骨 磁性给药 骨再生 纳米粒 四氧化三铁 磁铁矿纳米颗粒 组织工程
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A homogeneous DNA assay by recovering inhibited emission of rare earth ions-doped upconversion nanoparticles
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作者 Yingzhu Zhou Yinghui Chen +4 位作者 Hao He Jiayan Liao Hien T.T.Duong Maryam Parviz Dayong Jin 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第1期11-18,M0002共9页
Robust and easy-to-use kits specific for a particular DNA sequence are desirable for early detection of diseases. However, the major challenge with these tests is often the background fluorescence artifacts arising fr... Robust and easy-to-use kits specific for a particular DNA sequence are desirable for early detection of diseases. However, the major challenge with these tests is often the background fluorescence artifacts arising from biological species due to employing UV and visible range of light. Here, we have reported a near-infrared (NIR) fluorescence "turn-on" kit based on rare earth ions doped nanoparticles, upconversion nanoparticles (UCNPs), and gold nanoparticles (AuNPs), which forms a fluorescence-quencher pair,brought together by a hairpin structure through the formation of double-stranded DNA (dsDNA), with quenched upconversion luminescence. In the presence of analytes, the molecular beacon opens to push AuNPs away from UCNPs, with a distance longer than the efficient quenching distance, so that the inhibited upconversion emission will be restored. We demonstrated that this assay provides a homogeneous, facile, simple and highly selective HIV-1 based DNA detection system with restore efficiency up to 85%, and the detection limit of 5 nm. 展开更多
关键词 UPCONVERSION NANOPARTICLES Gold NANOPARTICLES LRET HOMOGENOUS ASSAY DNA ASSAY Fluorescence recovery
Red blood cell membrane-camouflaged nanoparticles: a novel drug delivery system for antitumor application
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作者 Qing Xia Yongtai Zhang +2 位作者 Zhe Li Xuefeng Hou Nianping Feng 《药学学报:英文版》 CSCD 2019年第4期675-689,共15页
Erythrocytes(red blood cells, RBCs) are the most abundant circulating cells in the blood and have been widely used in drug delivery systems(DDS) because of their features of biocompatibility,biodegradability, and long... Erythrocytes(red blood cells, RBCs) are the most abundant circulating cells in the blood and have been widely used in drug delivery systems(DDS) because of their features of biocompatibility,biodegradability, and long circulating half-life. Accordingly, a 'camouflage' comprised of erythrocyte membranes renders nanoparticles as a platform that combines the advantages of native erythrocyte membranes with those of nanomaterials. Following injection into the blood of animal models, the coated nanoparticles imitate RBCs and interact with the surroundings to achieve long-term circulation. In this review, the biomimetic platform of erythrocyte membrane-coated nano-cores is described with regard to various aspects, with particular focus placed on the coating mechanism, preparation methods, verification methods, and the latest anti-tumor applications. Finally, further functional modifications of the erythrocyte membranes and attempts to fuse the surface properties of multiple cell membranes are discussed,providing a foundation to stimulate extensive research into multifunctional nano-biomimetic systems. 展开更多
关键词 Red BLOOD cells MEMBRANE NANOPARTICLES DRUG delivery ANTITUMOR BIOMIMETIC NANOPARTICLES
PLGA微米与纳米载药颗粒用于药物携带与递送的比较研究 预览
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作者 林彦霞 白睿 +1 位作者 刘志强 刘惠亮 《武警医学》 CAS 2019年第2期120-123,127共5页
目的通过评价聚乳酸-羟基乙酸共聚物(polylactic acid-glycolic acid copolymer,PLGA)微米颗粒(micron parti-cle,MP)与纳米颗粒(nanoparticle,NP)的表面特征、载药能力、药物缓释能力及细胞吞噬能力等方面来比较阐述PLGA纳米与微米颗... 目的通过评价聚乳酸-羟基乙酸共聚物(polylactic acid-glycolic acid copolymer,PLGA)微米颗粒(micron parti-cle,MP)与纳米颗粒(nanoparticle,NP)的表面特征、载药能力、药物缓释能力及细胞吞噬能力等方面来比较阐述PLGA纳米与微米颗粒在细胞预处理与修饰中的合理应用。方法分别制备PLGA纳米颗粒与微米颗粒,并进行表征;随后,比较其载药能力,并对药物的释放特征进行测定;最后,在不同时间点通过荧光强度评价两种颗粒与细胞结合或进入细胞的能力。结果所制备的纳米粒与微米颗粒粒径分别分布在200~300 nm和2~4μm;两种颗粒载药量相当,分别为14. 3%和14. 1%;在药物缓释方面,纳米颗粒存在显著的早期突释现象;微米颗粒释放缓慢,持续缓释可达一周左右;粒径相对小的纳米粒更容易进入或与细胞结合,共孵育12 h即达到最大值,微米颗粒相对较慢,最大值出现在共孵育24 h后。结论 PLGA纳米颗粒作为药物载体更适合于急性组织或细胞保护,微米颗粒更适合于慢性持续性保护。 展开更多
关键词 纳米颗粒 微米颗粒 药物携带
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纳米颗粒增强无铅钎料的研究进展 预览
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作者 王剑豪 薛松柏 +2 位作者 吕兆萍 王刘珏 刘晗 《材料导报》 EI CAS CSCD 北大核心 2019年第13期2133-2145,共13页
电子产业的发展离不开封装材料的进步。随着科学技术的进步,电子器件集成度逐渐提高,引脚尺寸和间距不断减小,而电子产品的服役条件也日趋复杂,因此对钎料的性能要求越来越严苛。与无铅钎料相比,传统的SnPb钎料因为成本低廉、性能优异,... 电子产业的发展离不开封装材料的进步。随着科学技术的进步,电子器件集成度逐渐提高,引脚尺寸和间距不断减小,而电子产品的服役条件也日趋复杂,因此对钎料的性能要求越来越严苛。与无铅钎料相比,传统的SnPb钎料因为成本低廉、性能优异,得到了电子工业的青睐。随着人们环保意识的提高,有毒元素铅在电子产业中的使用受到了限制,推动了电子封装材料朝着无铅化发展。但是目前,无铅钎料合金体系均存在成本高、润湿性差、可靠性不足、熔化特性与生产体系不匹配等问题,难以满足电子工业发展的需要。因此,探索改善无铅钎料性能的方法,研发性能优异的无铅钎料以替代SnPb钎料成为电子封装领域研究的一个热点。目前无铅钎料改性的研究主要集中在微合金化和纳米颗粒增强两个方面。微合金化就是向钎料中添加微量的合金元素,通过改变钎料合金成分来改善钎料的组织性能。无铅钎料微合金化的研究起步较早,目前已经取得了大量的研究成果,添加如Ag、In等元素均可以显著改善钎料的力学性能和可靠性,其中稀土元素由于活性较高,被视为无铅钎料合金化的理想合金元素。但是微合金化只能部分地提高钎料的性能,还不能满足生产的需要。纳米材料以其特殊的尺寸效应和优异的理化特性而受到广泛关注,同时纳米颗粒作为增强材料,在改善金属材料组织性能方面也具有非常明显的作用。将细小的纳米颗粒弥散地分布于钎料基体中,能够显著影响无铅钎料的性能,这也是一个较为新颖的研究方向。常见的纳米增强颗粒主要有金属纳米颗粒、氧化物纳米颗粒、陶瓷纳米颗粒和碳基材料纳米颗粒等。本文综合评述了纳米颗粒增强无铅钎料的研究进展。首先对目前纳米颗粒复合无铅钎料的三种制备方法的工艺特点进行了介绍;然后讨论了不同类型 展开更多
关键词 纳米颗粒 无铅钎料 直接混合法 电化学沉积法 原位生成法 微观组织 润湿性能
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The influence of particle size and concentration combined with pH on coagulation mechanisms
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作者 Hongyan Sun Ruyuan Jiao +2 位作者 Hui Xu Guangyu An Dongsheng Wang 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第8期39-46,共8页
In order to evaluate the influence of particle size and particle concentration on the coagulation process, two kinds of particle suspensions, nanoparticles and microparticles,were employed to investigate the effect of... In order to evaluate the influence of particle size and particle concentration on the coagulation process, two kinds of particle suspensions, nanoparticles and microparticles,were employed to investigate the effect of particle size on coagulation mechanisms with varying coagulation parameters. Results showed that it is easier for nanoparticles to cause self-aggregation because of Brownian motion, while interception and sedimentation are the mainly physical processes affecting particle transport for microparticles, so they are more stable and disperse more easily. The particle size distribution and particle concentration had distinct influence on the coagulation mechanisms. Under neutral conditions, as the amount of coagulant increased, the coagulation mechanism for nanoparticles changed from charge neutralization to sweep flocculation and the nanoparticles became destabilized, re-stabilized and again destabilized. For microparticles, although the coagulation mechanism was the same as that of nanoparticles, the increased rate of aluminum hydroxide precipitation exceeded the adsorption of incipiently formed soluble alum species, resulting in the disappearance of the re-stabilization zone. Under acidic conditions, Brownian motion dominates for nanoparticles at low particle concentrations, while sweep flocculation is predominant at high particle concentrations. As for microparticles, charge neutralization and sweep flocculation are the mechanisms for low and high particle concentrations respectively.Under alkaline condition, although the mechanisms for both nano-and microparticles are the same, the morphology of flocs and the kinetics of floc formation are different. At low particle concentrations, nanoparticles have larger growth rate and final size of flocs, while at high particle concentrations, nanoparticles have higher fractal dimension and recovery factors. 展开更多
关键词 Nanoparticles MICROPARTICLES PARTICLE size distribution COAGULATION MECHANISMS ALUM
咪唑啉表面活性剂的制备及吸附性能 预览
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作者 周亭 杨世超 张志庆 《实验室研究与探索》 CAS 北大核心 2019年第5期15-19,共5页
采用潜溶剂法合成了咪唑啉表面活性剂(命名为IM-14),核磁共振氢谱证实为目标产物;通过芘荧光探针法探究其胶束化性质,测得临界胶束浓度为9. 3μmol/L。选择氧化铝纳米颗粒(Al2O3NPs)作为固体模型,研究了咪唑啉表面活性剂在纳米颗粒上的... 采用潜溶剂法合成了咪唑啉表面活性剂(命名为IM-14),核磁共振氢谱证实为目标产物;通过芘荧光探针法探究其胶束化性质,测得临界胶束浓度为9. 3μmol/L。选择氧化铝纳米颗粒(Al2O3NPs)作为固体模型,研究了咪唑啉表面活性剂在纳米颗粒上的吸附动力学和吸附热力学,确定了吸附方式是多层吸附;通过改变环境温度和引入竞争吸附确立了吸附主要通过氢键作用、π-π堆积和疏水作用进行。 展开更多
关键词 咪唑啉表面活性剂 吸附 纳米颗粒
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A free-standing superhydrophobic film for highly efficient removal of water from turbine oil
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作者 Fan Shu Meng Wang +1 位作者 Jinbo Pang Ping Yu 《化学科学与工程前沿:英文版》 EI CAS CSCD 2019年第2期393-399,共7页
A free-standing superhydrophobic film is prepared by sequentially dip-coating a commercially available filter paper with nano SiO2 suspension, epoxy emulsion, and octyltrimethoxysilane solution. A surface with micro- ... A free-standing superhydrophobic film is prepared by sequentially dip-coating a commercially available filter paper with nano SiO2 suspension, epoxy emulsion, and octyltrimethoxysilane solution. A surface with micro- or nano-roughness is formed because SiO2 nanoparticles are uniformly and firmly adhered on the backbone of the filter paper by the cured epoxy resin. Furthermore, the surface energy is significantly reduced because of introducing octytrimethoxysilane. Such a surface structure makes the prepared film a superhydrophobic material. Due to its free-standing nature, this superhydrophobic film can be used to remove water from turbine oil by filtration. The efficiency of water removal is high (up to 94.1%), and the filtration process is driven solely by gravity without extra energy consumption. Because of the facile fabrication process and the high efficiency of water removal, this free-standing superhydrophobic film may find application in power industry. 展开更多
关键词 SUPERHYDROPHOBICITY nanoparticles DIP coating epoxy EMULSION turbine oil
In acidic porous medium under the action of humic acid, riceTio2. Migration and retention mechanisms 预览
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作者 Wang Bingkun Yu Yaotian 《探索-环境科学与技术》 2019年第1期14-17,共4页
Mechanisms. mobility, retention. titanium dioxide nanoparticles (ntio2). Well-defined Porous Media Composite of clean quartz sand in the presence of full acid (FA) and humic acid (HA) were studied under acidic conditi... Mechanisms. mobility, retention. titanium dioxide nanoparticles (ntio2). Well-defined Porous Media Composite of clean quartz sand in the presence of full acid (FA) and humic acid (HA) were studied under acidic conditions. ntio2.Were immobile in the Poland media in the absence of FA and HA at pH 4.0. FA and ha could be absorbed into the surface of ntio2., Change the electrochemical properties of ntio2.The transport of ntio2.. The elution of ntio2.Increased from 0.01 and 0.94 to 0.91 and 0.88 with the increase of FA and ha from 1 mg/L to 10 mg/L specially. Compared to FA, more ha was absorbed onto ntio2., And us the affected Effect of ha on transport of ntio2.Was stronger. ions inhibited the mobility of ntio2., And the effect of CaCl2.Was greater than that of NaCl in same concentration. The mobility of ntio2.Was better in the presence of HA than FA. In addition, 7%~ 56% ntio2.Was preserved in the secondary energy minimum well in the presence of HA, higher than 4%~ 17% in the presence of FA, which could be easily released when the environmental conditions have changed. High Energy barriers between ntio2.And quartz promoted the mobility of ntio2., While a combination of the secondary minimum energy, strain, diffusion and gratational position were involved in the retention of ntio2.. 展开更多
关键词 Titanium Oxide Nanoparticles Fulvic ACID HUMIC ACID Stability Transport
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海扇壳源性碳酸钙纳米微粒对大鼠的急性毒性作用 预览
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作者 邵春燕 付文亮 Md Zuki Bin Abu Bakar ZAKARIA 《吉林大学学报:医学版》 CAS CSCD 北大核心 2019年第3期524-530,I0003共8页
目的:观察海扇壳源性碳酸钙纳米微粒(CCNPs)对SD大鼠的毒性作用,初步探讨CCNPs的安全剂量和生物学效应。方法:将40只健康雄性SD大鼠随机分为对照组,低、中和高剂量CCNPs组(分别给予剂量0、30、60和120mg·kg^-1 CCNPs),每组10只大... 目的:观察海扇壳源性碳酸钙纳米微粒(CCNPs)对SD大鼠的毒性作用,初步探讨CCNPs的安全剂量和生物学效应。方法:将40只健康雄性SD大鼠随机分为对照组,低、中和高剂量CCNPs组(分别给予剂量0、30、60和120mg·kg^-1 CCNPs),每组10只大鼠。尾静脉注射给药每天1次,连续14d。检测各组大鼠体质量和日平均进摄食量、血液学指标、血清生化指标、器官相对质量及主要器官的组织病理形态表现。结果:在14d重复剂量的毒性试验中,高剂量组中有2只大鼠死亡,而在低和中剂量组中均未发现有大鼠死亡。各剂量CCNPs组大鼠体质量增加幅度和日平均进食量低于对照组,但差异无统计学意义(P>0.05)。各剂量CCNPs组大鼠血清学指标与对照组比较差异无统计学意义(P>0.05)。各剂量CCNPs组大鼠肺脏相对质量高于对照组(P<0.05);低和中剂量CCNPs组大鼠脾脏相对质量高于对照组(P<0.05);高剂量CCNPs组大鼠脾脏相对质量与对照组比较差异无统计学意义(P<0.05)。低剂量CCNPS组大鼠部分脏器呈轻度的炎性浸润,未发现明显的病理学改变;中和高剂量CCNPs组大鼠主要脏器呈明显的组织病理学改变,包括炎性细胞浸润,肝细胞排列轻度紊乱,肝细胞空泡增多,肺泡间质增厚及大量肉芽肿形成,心肌纤维肿胀、断裂甚至坏死,肾小球出现萎缩和裂隙等。结论:小剂量CCNPs静脉给药不会引起大鼠严重的急性毒性反应。 展开更多
关键词 碳酸钙 纳米微粒 载药体系 毒性 海扇壳
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核壳磁性纳米粒子在环境治理中的应用进展 预览
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作者 肖治国 成岳 +1 位作者 唐伟博 余宏伟 《材料导报》 EI CAS CSCD 北大核心 2019年第13期2174-2183,共10页
景德镇陶瓷大学材料科学与工程学院,景德镇 333403核壳磁性纳米粒子是一类具有核壳结构的磁性纳米粒子。它的核壳型结构使其易于被功能化而满足不同场合下的要求;它的纳米级尺寸使其拥有高比表面积;它的磁性使其易于被永磁体回收再利用... 景德镇陶瓷大学材料科学与工程学院,景德镇 333403核壳磁性纳米粒子是一类具有核壳结构的磁性纳米粒子。它的核壳型结构使其易于被功能化而满足不同场合下的要求;它的纳米级尺寸使其拥有高比表面积;它的磁性使其易于被永磁体回收再利用。目前核壳磁性纳米粒子被广泛应用于生物研究、医疗卫生及催化等方面。在环境修复的研究中,这种材料达到了吸附剂的要求,将是未来废水处理的理想材料之一。核壳磁性纳米粒子的制备方法多种多样,合适的制备方法更有利于达到高效去除污染物的目的。核与壳的制备顺序对实验条件的要求各不相同;核与壳的制备方法各有差别;不同制备方法的组合对核与壳尺寸的影响也有差异。核壳磁性纳米粒子对污染物的吸附能力、自身在环境中存在的潜在风险和附加设施对环境的影响引人注目。目前核壳磁性纳米粒子的制备方法中,以从核到壳的顺序为主。磁核的制备以化学共沉淀法、溶剂热法居多,壳层的制备以St ber法、溶胶-凝胶法居多,化学共沉淀法与St ber法的组合逐渐成为制备Fe 3O 4@SiO 2的经典方法之一。核壳磁性纳米粒子可高效去除多种污染物,包括有机污染物和重金属离子等,吸附过程大多符合Langmuir吸附等温模型和伪二级动力学模型。少量的核壳磁性纳米粒子对生态环境的危害较小,过量的核壳磁性纳米粒子则会对生物细胞产生不良影响。静态磁场不但可以回收核壳磁性纳米粒子,而且可以降低污泥体积指数等。本文对核壳磁性纳米粒子的制备方法进行了总结,对各类方法进行了简要的说明和对比。本文不仅归纳了这类吸附剂对污染物的去除效果及吸附过程,还对这类吸附剂本身所带来的环境风险进行了简要阐述。另外,对静态磁场这种附加设施对活性污泥的影响进行了说明,最后对核壳磁性纳米粒� 展开更多
关键词 核壳 磁性 纳米粒子 吸附
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Dual-enzyme-propelled unbounded DNA walking nanomachine for intracellular imaging of lowly expressed microRNA
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作者 Tianshu Chen Yaoyao Chen +4 位作者 Huinan Chen Fan Zhang Qianqian Zhang Guifang Chen Xiaoli Zhu 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第5期1055-1060,共6页
Despite the progress on the analysis of miRNA either in vitro or in vivo,intracellular imaging of lowly expressed microRNA remains a challenge.Here we develop a novel dual-enzyme-propelled DNA walking nanomachine,whic... Despite the progress on the analysis of miRNA either in vitro or in vivo,intracellular imaging of lowly expressed microRNA remains a challenge.Here we develop a novel dual-enzyme-propelled DNA walking nanomachine,which is tailored to accomplish this mission.The nanomachine is constructed with nanoparticles-loaded DNA tracks,on which the targeted miRNA working as a single-foot DNA walker can move autonomously under the catalysis of two cooperative enzymes.Cleavage of the DNA tracks like a "burnt-bridge" mechanism is thereafter triggered,resulting in an amplified fluorescent signal.After the comprehensive study and optimization of the DNA nanomachine,miR-892b,a significantly down-regulated miRNA in breast cancer cells,is selected as a model target.Sensitivity detection in vitro is achieved with a superior detection limit of 4 pM.While being delivered into cells,the DNA nanomachine is available for the imaging of the lowly expressed microRNA,which is totally missing using the conventional fluorescence in situ hybridization (FISH) method.Up-regulation or down-regulation of the miRNA by exogenous regulatory factors can be also well evaluated.This DNA nanomachine provides a competitive approach for the analysis of miRNA,and has the potential to be extended to some other biomolecules. 展开更多
关键词 DNA WALKER nanomachine MICRORNA nanoparticles imaging analysis
贵金属纳米颗粒的微生物合成
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作者 白睿 田晓春 +3 位作者 王淑华 严伟富 冮海银 肖勇 《化学进展》 SCIE CAS CSCD 北大核心 2019年第6期872-881,共10页
金属纳米颗粒在材料、催化、医学、环境等众多领域应用广泛,其中,金、银、铂、钯等贵金属的纳米颗粒作为良好的催化剂可提高反应的速率,因此,贵金属纳米颗粒的合成吸引了众多研究者的关注。传统的物理化学法虽能高效、可控地合成贵金属... 金属纳米颗粒在材料、催化、医学、环境等众多领域应用广泛,其中,金、银、铂、钯等贵金属的纳米颗粒作为良好的催化剂可提高反应的速率,因此,贵金属纳米颗粒的合成吸引了众多研究者的关注。传统的物理化学法虽能高效、可控地合成贵金属纳米颗粒,但是合成条件苛刻、成本昂贵、且会产生对环境有害的化学物质。因此,探索节能、环保、可持续的绿色合成方法成为纳米合成研究的热点之一。贵金属纳米颗粒的微生物合成法具备绿色合成技术的诸多要素,研究表明某些微生物能将金属盐转化成纳米材料,且微生物繁殖速度快、培养成本低、生长条件温和,从而得到了研究者们的广泛关注。本文归纳总结了目前微生物合成贵金属纳米颗粒的主要研究进展,包括贵金属纳米颗粒可能的合成机制以及尺寸与形貌控制方法,探讨了其在医学、催化、生物传感、环境方面的具体应用,并对贵金属纳米颗粒微生物合成的未来发展进行了展望。 展开更多
关键词 微生物 贵金属 纳米颗粒 生物合成 绿色化学
Hierarchical Ag-SiO2@Fe3O4magnetic composites for elemental mercury removal from non-ferrous metal smelting flue gas
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作者 Yongpeng Ma Bailong Mu +4 位作者 Xiaojing Zhang Hongzhong Zhang Haomiao Xu Zan Qu Li Gao 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第5期111-120,共10页
Hierarchical Ag-SiO2@Fe3O4 magnetic composites were selected for elemental mercury(Hg0) removal from non-ferrous metal smelting flue gas in this study. Results showed that the hierarchical Ag-SiO2@Fe3O4 magnetic compo... Hierarchical Ag-SiO2@Fe3O4 magnetic composites were selected for elemental mercury(Hg0) removal from non-ferrous metal smelting flue gas in this study. Results showed that the hierarchical Ag-SiO2@Fe3O4 magnetic composites had favorable Hg0 removal ability at low temperature. Moreover, the adsorption capacity of hierarchical magnetic composite is much larger than that of pure Fe3O4 and SiO2@Fe3O4. The Hg0 removal efficiency reached the highest value as approximately 92% under the reaction temperature of 150°C, while the removal efficiency sharply reduced in the absence of O2. The characterization results indicated that Ag nanoparticles grew on the surface of SiO2@Fe3O4 support. The large surface area of SiO2 supplied efficient reaction room for Hg and Ag atoms. Ag–Hg amalgam is generated on the surface of the composites. In addition, this magnetic material could be easily separated from fly ashes when adopted for treating real flue gas, and the spent materials could be regenerated using a simple thermal-desorption method. 展开更多
关键词 ELEMENTAL MERCURY SILVER nanoparticles Magnetic composites Non-ferrous metal FLUE gas
虾青素纳米载药颗粒靶向神经元细胞的可行性研究
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作者 尤宗琦 吴琪 +5 位作者 周晓明 张翔圣 袁斌 徐伟东 唐祥龙 张鑫 《中华实验外科杂志》 CAS CSCD 北大核心 2019年第8期1387-1390,共4页
目的为改善虾青素(ATX)水溶性差等问题,使用Fe3O4纳米颗粒(NPs)包封ATX,通过体外培养皮层神经元细胞评价其靶向聚集性.方法首先利用改良的高温热解法制备Fe3 O4纳米颗粒,并利用疏水相互作用制备出内包封ATX而表面分子末端修饰聚乙二醇(P... 目的为改善虾青素(ATX)水溶性差等问题,使用Fe3O4纳米颗粒(NPs)包封ATX,通过体外培养皮层神经元细胞评价其靶向聚集性.方法首先利用改良的高温热解法制备Fe3 O4纳米颗粒,并利用疏水相互作用制备出内包封ATX而表面分子末端修饰聚乙二醇(PEG)的虾青素纳米载药颗粒(ATX-NPs),同时为了增强神经元细胞的靶向作用,利用碳化二亚胺法进一步耦联转铁蛋白.通过透射电镜(TEM)观察纳米颗粒形态,动态光散射(DLS)测定其粒径及电势大小.体外实验中,采用16 ~ 18 d孕龄C57BL/6小鼠胚胎的大脑皮层培育原代神经元细胞,用乳酸脱氢酶(LDH)法测定ATX-NPs对神经元细胞损伤的影响,其次分别采用TEM、共聚焦显微镜(LSCM)及流式细胞术分析ATX-NPs对神经元细胞的靶向聚集性,应用SPSS 25.0软件进行分析.结果 TEM观察可见,制备的ATX-NPs呈近似球形,DLS结果显示,粒径大小约为21 nm,zeta电位约为-28.8 mV.LSCM显示在24 h内ATX-NPs在神经元细胞胞质内有较多聚集.神经元培养基中加入ATX-NPs共同培养24h后,TEM观察到ATX-NPs通过转铁蛋白靶向神经元内吞形成的内涵体,同时流式细胞术也明确了ATX-NPs聚集于神经元细胞内,LDH法检测结果表明,不同浓度的ATX-NPs未使培养液中的LDH发生明显变化(F=0.610,P>0.05).结论耦联转铁蛋白的ATX-NPs有良好的稳定性及生物相容性,并能够靶向聚集于神经元细胞. 展开更多
关键词 虾青素 纳米颗粒 转铁蛋白 原代神经元细胞 靶向聚集
负载型纳米金属催化剂在乙炔选择加氢反应中的研究进展 预览
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作者 彭爽 孙逊 +3 位作者 孙立波 苏慧娟 刘琦 祁彩霞 《石油化工》 CAS CSCD 北大核心 2019年第3期303-306,共4页
综述了不同负载型纳米金属催化剂在乙炔选择加氢反应中的表现,重点探讨金属活性组分及其载体对催化性能的影响。Pd和Ni基催化剂普遍有着较高的乙炔转化率,Au基催化剂更容易获得高的乙烯选择性。而载体的酸碱性、缺陷位、结构性能等也对... 综述了不同负载型纳米金属催化剂在乙炔选择加氢反应中的表现,重点探讨金属活性组分及其载体对催化性能的影响。Pd和Ni基催化剂普遍有着较高的乙炔转化率,Au基催化剂更容易获得高的乙烯选择性。而载体的酸碱性、缺陷位、结构性能等也对催化性能发挥着至关重要的作用。最后,对双金属、活泼载体负载型催化剂在乙炔选择加氢反应中的发展前景进行了展望。 展开更多
关键词 乙炔 乙烯 纳米颗粒 金属催化剂 选择加氢
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百里香酚纳米级防腐微粒的制备及表征
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作者 初丽君 寇莉萍 《中国食品学报》 EI CAS CSCD 北大核心 2019年第1期75-82,共8页
为提高百里香酚在食品保鲜中的应用,以壳聚糖为载体,TPP为交联剂,百里香酚为包埋药物,吐温-80为乳化剂,采用离子交联和乳化相结合的方法制备百里香酚-壳聚糖纳米级防腐微粒。通过正交试验,以包封率及粒径为指标,所得纳米微粒的最佳制备... 为提高百里香酚在食品保鲜中的应用,以壳聚糖为载体,TPP为交联剂,百里香酚为包埋药物,吐温-80为乳化剂,采用离子交联和乳化相结合的方法制备百里香酚-壳聚糖纳米级防腐微粒。通过正交试验,以包封率及粒径为指标,所得纳米微粒的最佳制备工艺为:壳聚糖质量浓度5 mg/mL,百里香酚质量浓度为0.8 mg/mL,TPP质量浓度1 mg/mL,CS和TPP质量比5∶1,所得纳米微粒包封率为61%,粒径为338.92 nm。透射电镜下纳米微粒分布均匀,无团聚现象,缓释效率试验表明在48 h可释放74.15%,。通过FTIR、XRD分析证实形成壳聚糖与TPP交联体系。 展开更多
关键词 百里香酚 壳聚糖 离子交联 乳化 纳米微粒
La2Ce2O7 supported ruthenium as a robust catalyst for ammonia synthesis
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作者 Wenfeng Han Zhi Li Huazhang Liu 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第5期492-499,共8页
La2Ce2O7 nanoparticles were prepared by citric acid complexation method followed by calcination at varied temperatures. Then, supported with 4 wt% Ru, they were evaluated as the catalysts for ammonia synthesis under c... La2Ce2O7 nanoparticles were prepared by citric acid complexation method followed by calcination at varied temperatures. Then, supported with 4 wt% Ru, they were evaluated as the catalysts for ammonia synthesis under conditions similar with industry. With La2Ce2O7 being calcinated at 700 or 800℃, the experimental results indicate that the Ru/La2Ce2O7 catalyst exhibits much higher ammonia concentration or ammonia synthesis rate than that of Ru/CeO2 and Ru/La2O3. In addition, Ru/La2Ce2O7 possesses high stability under over-heating test. In the absence of any promotor, ammonia concentration of Ru/La2Ce2O7 catalyst approaches 14% at 450℃, GHSV of 10000 h-1 and pressure of 10 MPa. The rate-determining step of ammonia synthesis, dissociation of N2 is significantly facilitated by the strong metalesupport interaction(SMSI) between Ru and La2Ce2O7. Due to the interaction, La2Ce2O7 tends to donate electrons to Ru,resulting in the high electron density over the surface of Ru active sites which is favorable for the dissociation of N2. Consequently, high activity is achieved. 展开更多
关键词 AMMONIA synthesis RUTHENIUM La2Ce2O7 ACTIVATION energy Nanoparticles RARE earths
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