Gene expression and apoptosis response in hepatocellular carcinoma cells induced by biocompatible polymer/magnetic nanoparticles containing 5-fluorouracil

BackgroundSuper-paramagnetic iron oxide nanoparticles (SPION) contain a chemotherapeutic drug and are regarded as a promising technique for improving targeted delivery into cancer cells.ResultsIn this study, the fabrication of 5-fluorouracil (5-FU) was investigated with loaded Dextran (DEX-SPION) using the co-precipitation technique and conjugated by folate (FA). These nanoparticles (NPs) were employed as carriers and anticancer compounds against liver cancer cells in vitro. Structural, magnetic, morphological characterization, size, and drug loading activities of the obtained FA-DEX-5-FU-SPION NPs were checked using FTIR, VSM, FESEM, TEM, DLS, and zeta potential techniques. The cellular toxicity effect of FA-DEX-5-FU-SPION NPs was evaluated using the MTT test on liver cancer (SNU-423) and healthy cells (LO2). Furthermore, the apoptosis measurement and the expression levels of NF-1, Her-2/neu, c-Raf-1, and Wnt-1 genes were evaluated post-treatment using flow cytometry and RT-PCR, respectively. The obtained NPs were spherical with a suitable dispersity without noticeable aggregation. The size of the NPs, polydispersity, and zeta were 74 ± 13 nm, 0.080 and −45 mV, respectively. The results of the encapsulation efficiency of the nano-compound showed highly colloidal stability and proper drug maintenance. The results indicated that FA-DEX-5-FU-SPION demonstrated a sustained release profile of 5-FU in both phosphate and citrate buffer solutions separately, with higher cytotoxicity against SNU-423 cells than against other cells types. These findings suggest that FA-DEX-SPION NPs exert synergistic effects for targeting intracellular delivery of 5-FU, apoptosis induction, and gene expression stimulation.ConclusionsThe findings proved that FA-DEX-5-FU-SPION presented remarkable antitumor properties; no adverse subsequences were revealed against normal cells.How to cite: Mahdia SA, Kadhimb AA, Albukhaty S, et al. Gene expression and apoptosis response in hepatocellular carcinoma cells induced by biocompatible polymer/magnetic nanoparticles containing 5-fluorouracil. Electron J Biotechnol 2021;52. https://doi.org/10.1016/j.ejbt.2021.04.001     

排球视频中的运动目标跟踪及检测算法研究

为了提升排球视频中的对于目标的追踪能力的准确性,本文利用Mean shift算法,提出了一种高效率并且又稳定的运动目标跟踪检测算法。算法根据排球在x、y轴上的坐标位置和排球在在x、y上的速度,进行观测向量的设置,并求解观测值。实验过程中采用五台摄像机对排球运动场进行全方位的目标跟踪,最终求解得到排球在三维空间的运动轨迹。实践证明,本文算法图像处理信噪比高,时间复杂度低。     

Measuring success： Evaluating educational programs

This paper reveals a new evaluation model, which enables educational program and project managers to evaluate their programs with a simple and easy to understand approach. The ＂index of success model＂ is comprised of five parameters that enable to focus on and evaluate both the implementation and results of an educational program. The integration of these parameters forms a complete and comprehensive picture, which in turn provides the most information on the success or failure of the program. The parameters are： （1） the relevance index, referring to an evaluation of predefined objectives; （2） the efficiency index, referring to the fiscal efficiency of the program; （3） the effectiveness index evaluating the attainment of the program＇s objectives; （4） the impact index gauging the effect on the consumers, for whom the program is undertaken; and （5） the final parameter is the program＇s sustainability index. Since Israel＇s education strategy currently leans towards site-based monitoring and evaluation, such a model can potentially be of great help to school management and staff.     

机载单天线SAR动目标检测与参数估计

对机载单天线SAR/GMTI模式下动目标参数估计精度较低的问题进行研究.首先,用多普勒频移量和距离走动量来估计动目标径向速度,根据估计的结果校正距离走动.然后,用改进的反射特性位移法来估计动目标的多普勒调频率,在不存在加速度时估计出动目标方位向速度.这样就可以在进行动目标参数估计的同时实现聚焦成像.仿真结果验证了该方法的有效性.     

飞碟双向“快打”技术探讨

射击飞碟双向项目曾是我国拿过奥运会金牌的拳头项目，但随着国际射联不断修改规则增加难，加上我国的飞碟双向缺少一整套先进技术理论的支持，与世界先进水平距离逐渐拉大。要改变现状，迎状赶上，必须实践快打技术，培养“快打型”选手，形成快速、简捷、流畅的技术风格，实践证明：“快打型”技术能更有效地发挥弹丸的效能；有利于克服变化靶、不规则靶的不利因素；有利于射手整体动作程序的完成，防止击发瞬间注意力分散，在实际训练中则要强调人枪结合的质量，将发展速度与提高命中率有效地结合起来，注意发射速度规律性的培养，大胆实践飞碟射击概略瞄准的概念。     

老年患者下呼吸道感染革兰阴性菌分布及耐药性分析

目的:探讨某院呼吸内科老年患者下呼吸道感染革兰阴性菌的分布及其耐药性,指导临床治疗。方法:回顾性分析2013年1月-2014年12月老年患者下呼吸道感染染革兰阴性菌的分布及其耐药性;采用法国生物梅里埃公司全自动细菌鉴定仪VITEK2 compact进行菌株鉴定,采用K-B法进行药敏试验,按美国临床实验室标准化委员会(CLSI)2014年标准判读结果。结果:分离出的217株病原菌中,革兰阴性菌有156株(71.9%),前4位为肺炎克雷伯菌、大肠埃希菌、铜绿假单胞菌、鲍曼不动杆菌。肺炎克雷伯菌对氨苄西林、庆大霉素及氨曲南的耐药率较高,分别为96.6%、88.1%、81.4%,对亚胺培南的耐药率为0。结论:老年患者下呼吸道感染以革兰阴性菌为主,临床上应根据药敏结果合理选用抗菌药物。     

是教“书”,还是教“学生”？——中国现当代文学史教材编写的一些思考

中国现当代文学史的教材编写已经进入＂地方割据＂的＂战国时代＂。随着高校教材自编的频率和速率的加剧,本来在＂针对性＂方面颇有优势的自编教材,却没有太多的作为。论文基于参与教材编写的一些体会和思考,从三个层面揭示了现当代文学史教材在教＂书＂与教＂学生＂方面所存在的不足。     

Biochemical characterization of the recombinant schistosome tegumental protein SmALDH_312 produced in E. coli and baculovirus expression vector system

BackgroundThe heterologous expression of parasitic proteins is challenging because the sequence composition often differs significantly from host preferences. However, the production of such proteins is important because they are potential drug targets and can be screened for interactions with new lead compounds. Here we compared two expression systems for the production of an active recombinant aldehyde dehydrogenase (SmALDH_312) from Schistosoma mansoni, which causes the neglected tropical disease schistosomiasis.ResultsWe produced SmALDH_312 successfully in the bacterium Escherichia coli and in the baculovirus expression vector system (BEVS). Both versions of the recombinant protein were found to be active in vitro, but the BEVS-derived enzyme showed 3.7-fold higher specific activity and was selected for further characterization. We investigated the influence of Mg²⁺, Ca²⁺ and Mn²⁺, and found out that the specific activity of the enzyme increased 1.5-fold in the presence of 0.5 mM Mg²⁺. Finally, we characterized the kinetic properties of the enzyme using a design-of-experiment approach, revealing optimal activity at pH 7.6 and 41°C.ConclusionsAlthough, E. coli has many advantages, such as rapid expression, high yields and low costs, this system was outperformed by BEVS for the production of a schistosome ALDH. BEVS therefore provides an opportunity for the expression and subsequent evaluation of schistosome enzymes as drug targets.How to cite: Harnischfeger J, Beutler M, Salzig D, et al. Biochemical characterization of the recombinant schistosome tegumental protein SmALDH_312 produced in E. coli and baculovirus expression vector system. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.08.002     

Archaeosome: As New Drug Carrier for Delivery of Paclitaxel to Breast Cancer

In the present study, paclitaxel was archaeosomed to reduce side effects and improve its therapeutic index. Carriers have made a big evolution in treatment of many diseases in recent years. Lipid carriers are of special importance among carriers. Archaeosome is one of the lipid carriers. Paclitaxel is one of the drugs used to treat breast cancer which has some unwanted side effects despite its therapeutic effects. Archaeosomes were extracted from methanogenic archi bacteria and synthesized with a certain ratio of paclitaxel in PBS. The mean diameter of archaeosomal paclitaxel was measured by Zeta sizer instrument, Drug releasing of archaeosomal paclitaxel was examined within 26 h which results showed that the most drug releasing occurs during first 3 h. The cytotoxicity effect of archaeosomal paclitaxel on breast cancer’s cell line was evaluated by MTT assay which results showed that the cytotoxicity effect of archaeosomal paclitaxel on breast cancer’s cell line is more than that of the standard paclitaxel formulation. The results indicated that new drug delivery of paclitaxel using archaeosome, increases the therapeutic index of the drug.     

罕用药政策对生物医药产业的影响——基于美国生物科技公司的案例研究

美国罕用药物法案本意是用来鼓励制药产业研发和生产不具有商业价值的罕见药物,但是这项政策却对美国生物制药产业起到了关键性的推动作用。本文首先介绍了美国罕用药物法案颁布的背景及其所提供的优惠政策并回顾了颁布以来所取得的成就,然后以美国最成功的四家生物科技公司的发展为案例分析了罕用药物法案对美国生物医药产业的影响,结果表明通过科技推动和经济拉动罕用药物政策不但鼓励了罕用药的研发和生产还成功地推动了美国生物医药产业发展。