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G4PAMAM/VEGFASODN抗乳腺癌血管生成的体外实验研究 被引量:2
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作者 赵新汉 李丽 +2 位作者 王志宇 张灵小 安改丽 《浙江大学学报(医学版)》 CAS CSCD 2008年第6期612-621,共10页
目的:探讨G4PAMAM/VEGFASODN复合物体外对乳腺癌细胞MDA-MB-231VEGF、VEGF mRNA表达的影响及血管内皮细胞生长的抑制作用。方法:用透射电镜观测G4PAMAM/VEGFASODN的粒径,在不同的酸碱度下观察G4PAMAM/VEGFASODN的稳定性;将G4PAMAM/VEGFA... 目的:探讨G4PAMAM/VEGFASODN复合物体外对乳腺癌细胞MDA-MB-231VEGF、VEGF mRNA表达的影响及血管内皮细胞生长的抑制作用。方法:用透射电镜观测G4PAMAM/VEGFASODN的粒径,在不同的酸碱度下观察G4PAMAM/VEGFASODN的稳定性;将G4PAMAM/VEGFASODN进行体外转染,流式细胞仪测定其转染率,激光共聚焦检测转染阳性细胞,MTT法检测转染后细胞的存活率;免疫组化检测VEGF蛋白的表达,RT-PCR检测VEGFmRNA的表达,MTT法测定此复合物对血管内皮细胞生长的抑制作用。结果:G4PAMAM/VEGFASODN的直径约10nm,呈较均匀的网状排列;酸碱度在5到10的范围内具有较高的稳定性,不同电荷比的G4PAMAM/VEGFASODN均没有出现被解离的现象;48h时G4PAMAM/VEGFASODN组在1∶40的条件下转染率明显高于脂质体组;各组转染物均对细胞无明显毒性;VEGF蛋白在G4PAMAM/VEGFASODN转染后的MDA-MB-231细胞胞浆中的染色强度明显减弱,阳性表达率显著降低,VEGF mRNA的表达也受到有效的抑制。结论:G4PAMAM/VEGFASODN复合物稳定性好、转染率高,是一种有良好应用前景的新型纳米载体基因转移系统;G4PAMAM/VEGFASODN复合物能够高效特异地抑制目的基因VEGF的表达,为进一步进行体内动物实验提供了依据。 展开更多
关键词 乳腺肿瘤/药物疗法 基因疗法 g4pamam g4pamam/VEGFASODN 乳腺癌 VEGF VEGF mRNA 血管内皮细胞
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基质金属蛋白酶响应性G4 PAMAM-IBU/GelMA水凝胶的构建及其特征研究 被引量:2
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作者 蔡传栋 王非 +2 位作者 崔文国 范存义 刘珅 《上海交通大学学报(医学版)》 CAS CSCD 北大核心 2021年第2期140-146,共7页
目的·构建负载第4代树枝状大分子聚酰胺-胺(generation 4 polyamindoamine,G4 PAMAM)/布洛芬(ibuprofen,IBU)复合物(G4 PAMAM-IBU)的基质金属蛋白酶(matrix metalloproteinase,MMP)响应性明胶(gelatin,Gel)水凝胶,并探究其体外特... 目的·构建负载第4代树枝状大分子聚酰胺-胺(generation 4 polyamindoamine,G4 PAMAM)/布洛芬(ibuprofen,IBU)复合物(G4 PAMAM-IBU)的基质金属蛋白酶(matrix metalloproteinase,MMP)响应性明胶(gelatin,Gel)水凝胶,并探究其体外特征。方法·将IBU粉末加入G4 PAMAM溶液中,经超声振荡得到G4 PAMAM-IBU复合物,利用紫外分光光度计检测饱和G4 PAMAM-IBU溶液中IBU的浓度,研究G4 PAMAM对IBU的增溶能力和G4 PAMAM-IBU复合物中IBU的释放。采用CCK-8试剂盒评估IBU与G4 PAMAM-IBU对大鼠成纤维细胞增殖的抑制能力。同时,为实现G4 PAMAM-IBU的按需释放,利用Gel与甲基丙烯酸酐的加成反应合成甲基丙烯酸酯明胶(methacrylate gelatin,GelMA),并在365 nm光交联下形成MMP响应性水凝胶,并将G4 PAMAM-IBU复合物包载于该水凝胶之中。扫描电子显微镜观察水凝胶的微观形态,紫外分光光度计测定水凝胶中药物的释放量。之后,将载药GelMA水凝胶与成纤维细胞共培养,采用CCK-8试剂盒与活/死细胞染色法评估水凝胶对成纤维细胞增殖的影响。采用单因素方差分析进行组间定量资料的比较。结果·IBU与G4 PAMAM成功组成复合物,并使IBU在水中的溶解度显著提高,且IBU在12 h内与G4 PAMAM逐渐解离并释放。与空白对照组相比,单纯的IBU浓度需达到300μg/mL才具有抑制成纤维细胞增殖的能力(P=0.023),而G4 PAMAM-IBU中IBU的浓度为100μg/mL时即可显著抑制成纤维细胞增殖(P=0.000)。所制备的G4 PAMAM-IBU/GelMA水凝胶经MMP处理后,内部孔隙增大,药物释放加快。同时,体外实验发现,与载IBU的GelMA水凝胶相比,G4 PAMAMIBU/GelMA水凝胶处理后的成纤维细胞活细胞减少,死细胞增多,对细胞增殖的抑制作用显著增强(均P=0.000);且加入MMP后,抑制作用进一步增强。结论·G4 PAMAM对IBU具有显著的增溶作用并可增强其药物效应;G4 PAMAM-IBU/GelMA水凝胶具有MMP响应性的药物缓释行为,并能够持续抑制成纤维细胞增殖。 展开更多
关键词 水凝胶 4代聚酰胺-胺 布洛芬 肌腱粘连
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4.5G PAMAM为保护剂CdS纳米粒子的合成
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作者 乔燕 《包头职业技术学院学报》 2014年第2期23-25,共3页
硫化镉CdS纳米材料的制备常见的方法有:气相法、液相法、和固相法。我们采用液相法以4.5G PAMAM树状大分子为保护剂制备了CdS纳米粒子,考察了保护剂4.5G PAMAM与CdS不同物质的量比时,纳米粒子大小和尺寸的变化情况。
关键词 液相法 制备 4 5G pamam CDS纳米粒子
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基于4G的机器人与云平台无线数据传输系统设计 被引量:1
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作者 聂冬 宋阳 +2 位作者 周海波 严佳欢 赵一娇 《天津理工大学学报》 2021年第6期11-15,共5页
将机器人采集到的温度、湿度和位置等数据信息传送至云平台服务器,便于云端数据分析、机器人数据共享以及人机信息交互等。本文应用第4代移动通信技术(the 4th generation mobile communication technology,4G)无线传输技术,设计的机器... 将机器人采集到的温度、湿度和位置等数据信息传送至云平台服务器,便于云端数据分析、机器人数据共享以及人机信息交互等。本文应用第4代移动通信技术(the 4th generation mobile communication technology,4G)无线传输技术,设计的机器人与云平台无线数据传输系统主要包括硬件和软件实现2个部分,硬件方面机器人通过32位微控制器(STMicroelectronics32,STM32)嵌入式系统与4G模块组合,将传感器采集到的数据信息,通过Internet网络传输到云平台服务器中,软件部分运用C语言编程通过网络透传模式(transmission control protocol/user datagram protocol, TCP/UDP)实现无线通信过程,最终实验验证了机器人与云平台服务器之间的双向无线数据传输功能。 展开更多
关键词 机器人 云平台 32位微控制器(STMicroelectronics32 STM32)嵌入式系统 第四代移动通信技术(the 4th generation mobile communication technology 4G) 开放式系统互联通信参考模型(open system interconnection reference model OSI) 网络透传模式
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Performance Evaluation of Scheduling Algorithms for 4G (LTE) 被引量:2
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作者 Bamidele Moses Kuboye 《Communications and Network》 2018年第4期152-163,共12页
Long Term Evolution (LTE) is designed to revolutionize mobile broadband technology with key considerations of higher data rate, improved power efficiency, low latency and better quality of service. This work analyzes ... Long Term Evolution (LTE) is designed to revolutionize mobile broadband technology with key considerations of higher data rate, improved power efficiency, low latency and better quality of service. This work analyzes the impact of resource scheduling algorithms on the performance of LTE (4G) and WCDMA (3G) networks. In this paper, a full illustration of LTE system is given together with different scheduling algorithms. Thereafter, 3G WCDMA and 4G LTE networks were simulated using Simulink simulator embedded in MATLAB and performance evaluations were carried out. The performance metrics used for the evaluations are average system throughput, packet delay, latency and allocation of fairness using Round Robin, Best CQI and Proportional fair Packet Scheduling Algorithms. The results of the evaluations on both networks were analysed. The results showed that 4G LTE network performs better than 3G WCDMA network in all the three scheduling algorithms used. 展开更多
关键词 LONG TERM Evolution THIRD generation (3G) FOURTH generation (4G) Network Algorithms Scheduling
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金纳米粒子的制备与表征
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作者 乔燕 《苏州科技学院学报(自然科学版)》 CAS 2014年第3期33-35,55,共4页
以4.5 G PAMAM(4.5代聚酰胺-胺型)树状大分子为保护剂,利用微波法还原HAuCl4溶液制备金纳米粒子。考察了在同一照射条件下,4.5 G PAMAM与HAuCl4不同物质的量比对金纳米粒子大小及形状的影响。利用紫外可见分光光度计、透射电子显微镜以... 以4.5 G PAMAM(4.5代聚酰胺-胺型)树状大分子为保护剂,利用微波法还原HAuCl4溶液制备金纳米粒子。考察了在同一照射条件下,4.5 G PAMAM与HAuCl4不同物质的量比对金纳米粒子大小及形状的影响。利用紫外可见分光光度计、透射电子显微镜以及X射线衍射分析对其进行了表征。结果表明,照射时间相同时,以30 s为例,当4.5 G PAMAM与HAuCl4物质的量比为5时,得到的金纳米粒子最小;随着4.5 G PAMAM与HAuCl4物质的量比值的减小,金纳米粒子变大,且发生了不同程度的聚集。 展开更多
关键词 微波法 金纳米粒子 4 5 G pamam
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Anti-angiogenesis effect of generation 4 polyamidoamine/vascular endothelial growth factor antisense oligodeoxynucleotide on breast cancer in vitro 被引量:4
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作者 Shan-zhi GU Xin-han ZHAO +4 位作者 Ling-xiao ZHANG Li LI Zhi-yu WANG Min MENG Gai-li AN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2009年第3期159-167,共9页
Objective:To study the effects of the generation 4 polyamidoamine/vascular endothelial growth factor antisense oligodeoxynucleotide(G4PAMAM/VEGFASODN) compound on the expressions of vascular endothelial growth factor(... Objective:To study the effects of the generation 4 polyamidoamine/vascular endothelial growth factor antisense oligodeoxynucleotide(G4PAMAM/VEGFASODN) compound on the expressions of vascular endothelial growth factor(VEGF) and its mRNA of breast cancer cells and on the inhibition of vascular endothelial cells. Methods:We examined the morphology of G4PAMAM/VEGFASODN compound and its pH stability,in vitro transfection efficiency and toxicity,and the expressions of VEGF and its mRNA. Methyl thiazolyl tetrazolium assay was used to detect the inhibitory function of the compound on vascular endothelial cells. Results:The compound was about 10 nm in diameter and was homogeneously netlike. From pH 5 to 10,it showed quite a buffered ability. The 48-h transfection rate in the charge ratio of 1:40 was 98.76%,significantly higher than that of the liposome group(P<0.05). None of the transfection products showed obvious toxicity on the cells. The expressions of both VEGF protein and its mRNA after G4PAMAM/VEGFASODN transfection decreased markedly. Conclusion:With a low toxicity,high safety,and high transfection rate,G4PAMAM/VEGFASODN could be a promising gene vector. Specifically,it inhibits VEGF gene expression efficiently,laying a basis for further in vivo animal studies. 展开更多
关键词 Breast cancer Vascular endothelial growth factor (VEGF) VEGF mRNA generation 4 polyamidoamine(g4pamam generation 4 polyamidoamine/vascular endothelial growth factor antisense oligodeoxynucleotide(g4pamam/VEGFASODN) Vascular endothelial cell
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UEs Power Reduction Evolution with Adaptive Mechanism over LTE Wireless Networks
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作者 Ruchi Sachan Chang Wook Ahn 《Journal of Electronic Science and Technology》 CAS CSCD 2018年第1期79-83,共5页
At present, the major drawback for mobile phones is the issue of power consumption. As one of the alternatives to decrease the power consumption of standard, power-hungry location-based services usually require the kn... At present, the major drawback for mobile phones is the issue of power consumption. As one of the alternatives to decrease the power consumption of standard, power-hungry location-based services usually require the knowledge of how individual phone features consume power. A typical phone feature is that the applications related to multimedia streaming utilize more power while receiving, processing, and displaying the multimedia contents, thus contributing to the increased power consumption. There is a growing concern that current battery modules have limited capability in fulfilling the long-term energy need for the progress on the mobile phone because of increasing power consumption during multimedia streaming processes. Considering this, in this paper, we provide an offline meaning sleep-mode method to compute the minimum power consumption comparing with the power-on solution to save power by implementing energy rate adaptation(RA) mechanism based on mobile excess energy level purpose to save battery power use. Our simulation results show that our RA method preserves efficient power while achieving better throughput compared with the mechanism without rate adaptation(WRA). 展开更多
关键词 Green communication 4 generation long term evolution(4G LTE) networks rate adaptation(RA) power consumption model
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A New OFDM System Based on Lifting Wavelet Transform for Wireless Channel 被引量:2
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作者 GAO Jian-bo ZHAO Er-yuan 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2005年第3期21-25,共5页
It is well known that the Orthogonal Frequency Division Multiplexing ( OFDM ) system has a high ability to overcome the effect of multipath and can obtain high spectral efficiency in the wireless communication chann... It is well known that the Orthogonal Frequency Division Multiplexing ( OFDM ) system has a high ability to overcome the effect of multipath and can obtain high spectral efficiency in the wireless communication channel. However, avoid Interchannel Interference (ICI) and Intersymbol Interference (ISI) in wireless channel, a guard interval longer than channel delay is used in conventional OFDM system, which cause the efficiency of bandwidth usage reduced. Due to the superior spectral containment of wavelets, this paper proposed a new OFDM system based on Lifting Wavelet Transform (LWT-OFDM), which adopts lifting wavelet transform to replace the conventional Fourier transform. This new OFDM system doesn't need the Cyclic Prefix (CP) so its structure is more simply than FFT-OFDM and its algorithm is as simply as FFT-OFDM. The new LWT-OFDM system can mitigates some disadvantages of FFT-OFDM system, such as a relatively large peak-to-average power ratio, more sensitive to carrier frequency offset and phase noise. Simulations show that the LWT-OFDM system is more effective and attractive than conversional FFT-OFDM in wireless channel. 展开更多
关键词 OFDM 4G wavelet transform lifting theory. the second generation wavelet signal processing
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