Polyacrylic acid was firstly grafted by N-amino-4-N-methylpiperazine-1,8-naphthlimide (AMN) to prepare a amphiphilic polymer, which was self-assembled in water producing nanoparticles called as PAAMN.Then the morphology, structure and fluorescence properties of PAAMN were investigated by various methods including transmission electron microscopy, dynamic light scattering, ultraviolet-visible spectroscopy (UV-Vis), nuclear magnetic resonance spectroscopy (HNMR) and fluorescence spectroscopy.MTT assay was carried out to assess the cell compatibility of PAAMN.Finally, the fluorescence from PAAMN self and HeLa cells incubated with PAAMN was observed by fluorescence microscope.The results revealed that PAAMN had spherical structure, in which naphthlimide fluorphores were immobilized in the polyacrylic acid matrix with the degree of substitution of 4.1%.Under the physiological pH condition, PAAMN excited at 390 nm could emit strong and stable fluorescence at 534 nm.In the range of pH 4.0-10.0, its excitation and emission wavelengths had no obvious change.The fluorescence intensity of PAAMN increased with the decrease of pH values, but the pH sensitivity of PAAMN was much lower than that of AMN.PAAMN had good cell compatibility.From the pictures of fluorescence imaging, it was found that both PAAMN self and cells-engulfed PAAMN could emit green fluorescence upon excited at 390 nm, indicating the potential of the developed nanoparticle for cell imaging.

[Objective To explore the effect of problem-based learning(PBL) in biochemistry teaching in medical college. Methods Totally 128 students(2011 grade) of medical laboratory major were derived into experiment group(n=64)and control group(n=64). Lecture-based learning(LBL) was used in control group and PBL was used in experiment group.In control group,teachers did teaching design according to the needs of curriculum standards,employed multimedia courseware,explained the basic content of each chapter,class exercises and homework after class. In experimental group,PBL was conducted through establishing biochemistry teaching website based on school's teaching platform. Teach-ing process in experiment group included:grouping-selecting appropriate cases-consulting data-group discussing-summarizing by teachers. Theory test was carried out after the course and questionnaire was conducted for students in experiment group . Data were analyzed using the independent sample t test . Results Average test scores were higher in PBL group than in traditional group,with statistically signif-icant differences[(83.15±11.87)vs. (76.15±12.48)]. Questionnaire survey showed that more than 90.0%students in experiment group were interested in the PBL teaching method and thought that the PBL teach-ing method can enhance the enthu-siasm of learning, independent learning ability and comprehensive analysis ability. Conclusions PBL teaching method can improve the quality and the effect of biochemi-stry teaching and culture students' comprehensive ability. It is worthy of further study and popularization.

[摘 要] 目的：检测lncRNA LOC440173在NSCLC组织和细胞中的表达及探讨其对癌细胞恶性生物学行为的影响。方法：选取河北医科大学第四医院生物标本库中2014至2017年手术切除的72例NSCLC患者的癌及癌旁组织标本，应用qPCR法检测NSCLC组织和癌旁组织中，以及6种NSCLC细胞株（H520、H358、A549、HCC827、H1703和H1299）中LOC440173的表达水平；构建LOC440173的敲低及过表达载体，分别转染H520和H1703细胞，应用MTS、克隆形成及Transwell小室迁移和侵袭实验分别检测敲低及过表达LOC440173对NSCLC细胞增殖、迁移及侵袭能力的影响，qPCR法检测LOC440173对于EMT过程相关标志物（E-cadherin、N-cadherin及vimentin）mRNA表达水平的影响，WB法检测其对E-cadherin、N-cadherin蛋白表达的影响。结果：LOC440173在NSCLC组织中的表达明显高于癌旁组织（P<0.01），并与淋巴结转移、组织学分化程度、TNM分期和肿瘤大小有关联（P<0.05或P<0.01）。敲低LOC440173可以抑制H520细胞的体外增殖、迁移和侵袭（P<0.05或P<0.01），过表达LOC440173可显著促进H1703细胞的增殖、迁移和侵袭（P<0.05或P<0.01）。在转录水平上，敲低LOC440173后，E-cadherin的表达水平升高，间充质相关标志物N-cadherin、vimentin的表达水平降低（P<0.05或P<0.01）；而过表达LOC440173后，E-cadherin的表达水平降低，间充质相关标志物N-cadherin、vimentin的表达水平升高（P<0.05或P<0.01）。在转录后水平上，LOC440173负向调节E-cadherin蛋白的表达、正向调节N-cadherin的蛋白表达（均P<0.05）。结论：LOC440173在NSCLC组织中的异常高表达可能与NSCLC的发生发展有关，LOC440173可显著提高NCSCL细胞的体外增殖、迁移、侵袭能力，且其作用机制可能与调控EMT相关基因表达有关。