无机纳米粒子进入后肝癌细胞超微结构的变化

将生物性状较为稳定的二氧化钛（TiO2）和生物相容性较好的羟基磷灰石（HAP）纳米粒子,与肝癌细胞共同孵育1 h和8 h后,收集细胞并制样,用透射电镜观察肝癌细胞超微结构的变化.结果发现肝癌细胞质内有纳米粒子的团块,周围的细胞质有自行溶解现象,内质网过度肿胀,线粒体肿胀崩解、嵴结构紊乱,核膜周间隙扩大、核固缩等死亡现象.     

羟基磷灰石纳米粒子对肝癌细胞PCNA表达的影响

为了研究羟基磷灰石(HAP)纳米粒子对肝癌细胞增殖细胞核抗原表达的影响,采用均匀沉淀法制备了均匀分散的纳米尺度的HAP纳米粒子。以0.56 mmol/L的HAP纳米粒子与Bel-7402肝癌细胞作用后,采用流式细胞技术检测细胞周期时相的变化,行免疫细胞化学法PCNA染色,形态学观察和定量分析细胞的PCNA表达。结果显示HAP纳米粒子能使Bel-7402细胞的细胞增殖周期阻滞于G1期,PCNA表达降低,与对照组比较有显著性差异(P<0.01)。HAP纳米粒子可能通过抑制PCNA的表达,起到抑制肝癌细胞增殖的作用。     

基于金纳米粒子修饰的喜树碱纳米药物的构建及其抗癌活性

金纳米粒子具有抗癌及高光热转换效率的潜能,以透明质酸为稳定剂、金纳米粒子为还原及固定层,将化疗与光热疗法两种模式进行组合,合成了金纳米粒子修饰的纳米药物晶体(CPT-HA-AuNPs)。利用DLS、SEM等技术对CPT-HA-AuNPs的理化性质及药物控释行为进行表征,利用MTT、细胞摄取实验及AnnexinV-FITC/PI双染法对其生物活性进行了研究。结果表明,CPT-HA-AuNPs呈杆状纳米晶体结构,粒径(238.60±4.51) nm, Zeta电位(-47.29±0.84) mV,显示出较好的稳定性;具有较高的光热转换效率,并展现出光热及pH双响应性释放行为。与对照组相比,CPT-HA-AuNPs在NIR光激发条件下表现出显著提高的MDA-MB-231细胞摄取率、体外抗癌活性及促凋亡作用。     

金属纳米粒子的制备与应用

金属纳米粒子独特的结构决定了其独特的性能。评定了金属纳米粒子的制备、改性及应用的研究进展。     

金属纳米粒子的制备与应用

金属纳米粒子独特的结构决定了其独特的性能。评述了金属纳米粒子的制备、改性及应用的研究进展。     

SiO2／HAP晶须复合粒子的原位有机杂化（Ⅰ）——在PP中的应用

采用溶胶沉积法将HAP晶须加人到硅酸钠中．制成水性悬浮液，在酸性介质中，硅酸盐发生水解一缩合反应，使生成的溶胶沉积在HAP晶须粒子表面上，从而制备出具有壳一核结构的SiO2／HAP晶须复合粒子；在体系中引人亲油性诱导剂和有机改性剂，对该复合粒子进行原位有机杂化．将经上述表面改性的复合粒子作为填料填充到PP中，对其进行改性．实验表明：填充量为30％时，壳-核比为20％的SiO2／HAP晶须复合粒子为最佳填料；壳-核比为20％的SiO2／HAP晶须复合粒子为填料时，最佳填充量为20％～30％．     

纳米羟基磷灰石对肝癌细胞端粒酶基因表达的影响

研究羟基磷灰石（HAP）纳米粒子对Bel-7402人肝癌细胞端粒酶基因表达的影响。采用均相沉淀法制备出稳定单分散的HAP纳米粒子,应用透射电镜、电位粒度仪对其进行表征。HAP纳米粒子作用Bel-7402肝癌细胞4 h后,采用原位杂交技术检测Bel-7402肝癌细胞的端粒酶基因表达。结果表明HAP纳米粒子作用组的Bel-7402肝癌细胞的端粒酶阳性细胞比例为61.38%,而对照组的端粒酶阳性细胞比例为87.89%,2组有显著性差异（P〈0.01）。HAP纳米粒子可使Bel-7402肝癌细胞的端粒酶基因表达下调。     

铁酸锌纳米粒子的制备与表征

研究了草酸盐热分解法制备ＺｎＦｅ２Ｏ４纳米粒子,并用ＸＲＤ和ＴＥＭ技术进行了初步表征,在３００℃焙烧１ｈ后,所制备的球形粒子粒径约１０ｎｍ,大小均匀。     

Pt纳米粒子的制备

以聚乙烯吡咯烷酮(PVP)为保护剂,以醇为还原剂,制备了PVP-Pt纳米粒子,用透射电镜进行了表征。结果表明,所制得的铂纳米粒子的平均粒径大小在2.6~4.4nm之间,其粒径的标准偏差为0.35~0.93 nm。对同一种醇,铂纳米粒子粒径和标准偏差随着所用醇含量的升高而减小;另一方面,在醇水比一定时,铂纳米粒子粒径和标准偏差随着所用醇沸点的升高而减小。     

对苯二酚在金、银纳米粒子修饰的玻碳电极上电化学响应的比较

制备了柠檬酸钠保护的金和银纳米粒子,并用自组装法制备了金和银纳米粒子修饰的玻碳电极,在近中性的磷酸缓冲溶液中,比较研究对苯二酚在金和银纳米粒子修饰玻碳电极上的电化学响应情况。结果表明金和银纳米粒子均对对苯二酚的电氧化过程具有优越的电催化效果;与银纳米粒子修饰电极相比,金纳米粒子修饰电极表现出了良好的稳定性;对苯二酚在金纳米粒子修饰玻碳电极上的电化学反应是受扩散控制的。     

Investigation of HAP Nanoparticles Absorbed by Hepatoma Cells in vitro

Many particles are found in the cytoplasm area after the mixture of hydroxyapatite(HAP) nanoparticles and cultured cancer cells.The purpose of this study was to confirm whether these particles in cytoplasm are HAP nanoparticles exactly.BEL7402 cells were incubated in HAP sol for 8 hours.Then,the cells were collected for specimen preparation.Transmission electron microscope(TEM),energy dispersing spectrum (EDS)and electronic diffraction(ED)attached to TEM were used to detect the properties of the particles.It is found that many particles similar to HAP in shape are in the cytoplasm under TEM.By EDS analysis,they are the particles containing calcium(Ca)and phosphorus(P).The classic rings of HAP crystal appear in the ED pictures of these particles.So the particles are confirmed as HAP nanoparticles.Thus,it is concluded that HAP nanoparticles as the crystal particles can be absorbed by hepatoma cells.     

Investigation of HAP Nanopartieles Absorbed by Hepatoma Cells in vitro

Many particles are found in the cytoplasm area after the mixture of hydroxyapatite （HAP） nanoparticles and cultured cancer cells. The purpose of this study was to confirm whether these particles in cytoplasm are HAP nanoparticles exactly. BEL7402 cells were incubated in HAP sol for 8 hours. Then, the cells were collected for specimen preparation. Transmission electron microscope （TEM）, energy dispersing spectrum （EDS） and electronic diffraction （ED） attached to TEM were used to detect the properties of the particles. It is found that many particles similar to HAP in shape are in the cytoplasm under TEM. By EDS analysis, they are the particles containing calcium （Ca） and phosphorus （P）. The classic rings of HAP crystal appear in the ED pictures of these particles. So the particles are confirmed as HAP nanoparticles. Thus, it is concluded that HAP nanoparticles as the crystal particles can be absorbed by hepatoma cells.     

煅烧温度对沉淀法制备羟基磷灰石纯度的影响

利用沉淀法制备羟基磷灰石（HAP）,对影响HAP的工艺因素——煅烧温度进行了分析研究．试验结果表明,随着煅烧温度的提高,有利于获得纯度较高的HAP;但煅烧温度达到1000℃时,红外图谱中3640cm-1左右的OH吸收峰变弱,HAP产物分解;当Ca／P比为1．67时,有利于获得高纯度的HAP．     

陈化时间对沉淀法制备羟基磷灰石纯度的影响研究

对沉淀法制备羟基磷灰石进行了研究.结果表明:随着陈化时间的延长,OH-的吸收强度越来越突出(说明沉淀反应越来越充分),制备的HAP也越纯、越多;为了得到数量多、纯度高的羟基磷灰石,陈化时间要超过22 h;煅烧有利于获得高纯度的羟基磷灰石;当pH值为10时,制备得到的羟基磷灰石纯度高.     

Size Depending Separation of HAP:Eu Nanoparticles in Dispersed Sol

1Introduction Hydroxyapatite(Ca10(PO4)6(OH)2)isanimportant biomaterialthatiswidelyusedassubstituteorfillingma terialforscleroustissuesduetoitsgoodbiocompatibility andosteoconductivity[1,2].Inordertoinvestigatethein teractionsbetweenHAPnanoparticleswithana…     

Change in Shape and Crystal Structure of HAP Nanoparticles during Absorption into Cell

The change of hydroxyapatite （HAP） nanoparticles in shape and crystal structure after endocytosis into cancer cells was studied. BEL7402 cells were incubated with HAP nanoparticles for 2 hour, 8 hours, 20 hours, respectively. Then, the cells were collected and viewed under a transmission electronic microscope （TEM）. Electronic diffraction （ED） attached to TEM was used to detect the properties of the particles. The results show that HAP particles in the cytoplasm can be degraded in cytoplasm. The degradation process is prolonged by more than 20 hours. Thus, it is concluded that HAP nanoparticles would be degraded after kill cells or delivery gene.     

多媒体教学方法与传统教学方法比较研究

多媒体教学在教学活动中应用广泛,已成为教育与信息工程创新和信息化教育发展的一个显著标志。通过对多媒体教学的介绍、多媒体教学和传统教学的对比研究,指出了两种教学方法优劣。同时结合自身教学经验和进一步思考研究,提出了优势互补、有机结合是当前主要的教学模式。     

Effect of hydroxyapatite nanoparticles on K562 cells in vitro

Stable and single-dispersed hydroxyapatite （HAP） nanoparticles were synthesized with ultrasonic-assisted method. HAP nanoparticles were characterized by dynamic light scattering, XRD （X-ray diffraction） and TEM （Transmission Electron Microscopy）. The effect of HAP nanoparticles on the K562 human myelogenous leukemia cell line was investigated by MTT assay and cell count test, and the mechanism was studied through the changes of cell cycle and ultrastructure. The results showed that HAP nanoparticles inhibited the proliferation of K562 cells dramatically in vitro. HAP nanoparticles entered the cytoplasm of K562 cells and the cells were arrested at G/M phase, thus, the cells died directly.     

英汉缩略语的比较研究

指出了缩略语是现代语言中一种常见的语言现象,它是语言的主要构词手段,也是语言交际中的常用手段,英汉两种语言在缩略语的构成方面有着明显的差异。阐述了英汉缩略语的含义,对比分析了它们的构成方式、修辞特点、互译方法,讨论了英汉缩略语的发展趋势。