科创中国

CdSe/CdS semiconductor quantum dots co-sensitized TiO2 nanorod array was fabricated on the transparent conductive fluorine-doped tin oxide (FTO) substrate using the hydrothermal and successive ionic layer adsorption and reaction (SILAR) process. The structural and morphological properties of the samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The results indicate that CdSe/CdS QDs are uniformly coated on the surface of the TiO2 nanorods. The shift of light absorption edge was monitored by taking UV-visible absorption spectra. Compared with the absorption spectra of the TiO2 nanorod array, deposition of CdSe/CdS QDs shifts the absorption edge to the higher wavelength. The enhanced light absorption in the visible-light region of CdSe/CdS/TiO2 nanorod array indicates that CdSe/CdS layers can act as co-sensitizers in quantum dots sensitized solar cells (QDSSCs). By optimizing the CdSe layer deposition cycles, a photocurrent of 5.78 mA/cm2, an open circuit photovoltage of 0.469 V and a conversion efficiency of 1.34 % were obtained under an illumination of 100 mw/cm2.

A root hinge drive assembly is preferred in place of the classical viscous damper in a large solar array system.It has advantages including better deployment control and higher reliability.But the traditional single degree of freedom model should be improved.A multiple degrees of freedom dynamics model is presented for the solar arrays deployment to guide the drive assembly design.The established model includes the functions of the torsion springs,the synchronization mechanism and the lock-up impact.A numerical computation method is proposed to solve the dynamics coupling problem.Then considering the drive torque requirement calculated by the proposed model,a root hinge drive assembly is developed based on the reliability engineering design methods,and dual actuators are used as a redundancy design.Pseudo-efficiency is introduced and the major factors influencing the(pseudo-)efficiency of the gear mechanism designed with high reduction ratio are studied for further test data analysis.A ground prototype deployment test is conducted to verify the capacity of the drive assembly.The test device consists of a large-area solar array system and a root hinge drive assembly.The RHDA development time is about 43 s.The theoretical drive torque is compared with the test values which are obtained according to the current data and the reduction efficiency analysis,and the results show that the presented model and the calibration methods are proper enough.

目的:探讨皖南蝮蛇毒抑瘤组分I(AHVAC-I)对人胃癌细胞株SGC-901生长增殖的影响及作用机制.方法:AHVAC-I处理SGC-7901细胞.CCK-8法检测其生长抑制作用,光镜观察细胞形态变化,TUNEL法检测细胞凋亡情况.结果:AHVAC-I抑制SGC-901细胞的生长增殖,并呈浓度依赖性,半数抑制浓度(IC50)为58.197μg/ml;镜下可见SGC-901细胞悬浮、胞核固缩等典型凋亡形态学变化;TUNEL法显示凋亡指数随浓度增加而增加.结论:AHVAC-I对人胃癌细胞株SGC-7901具有生长抑制作用,诱导凋亡可能是其主要的作用机制之一.

Objective To detect the cell viability and the expressions of stem cell surface markers after chemotherapeutic drug treatment.Methods We observed the cytotoxic effects of three chemotherapeutic agents[epirubicin(Epi),fluorouracil(5-FU)and cyclophosphamide(Cyc)]in three cell lines,and the cell viabilities after removed these chemotherapeutic agents.Expressions of stem cell surface markers CD44,CD24,CD90,CD14 and aldehyde dehydrogenase1(ALDH1)in breast cancer cells were analyzed by real-time PCR.The post hoc analysis(Tukey's tests)in conjunction with one-way ANOVA was used for statistical analysis.Results The initial cytotoxic efficacy was most notable.After the treatment of the same therapeutic agents,cell viability was decreased by 64.8%35.14%,32.25%in BT-483 cells,66.4%,22.94%and 45.88%in MDA-MB-231 cells,97.1%,99.5%and 76.4%in MCF cells.The difference was significant compared with that before treatment(P=0.000).However,the inhibitory effects were diminished after chemotherapeutic agent withdrawal.Cell viabilities were increased to 167.9%,212.04%and 188.66%in MDA-MB-231 cells at48 h after withdrawal.At 72 h after withdrawal,cell viability was increased with a significant difference in three cell lines(all P values=0.000).Expressions of CD44 and ALDH1 were most prevalent for MDA-MB-231,BT-483 and MCF-7 cells.ALDH1 mRNA level was significant higher in BT-483(HER-2 overexpression cell line)than MDA-MB-231(triple negative cell line)(P=0.012).CD14 mRNA level in MCF-7 cells were significantly lower than that in MDA-MB-231 and BT-483(P=0.003,0.001).BT-483 showed significantly higher level of CD44 than MDA-MB-231 and MCF-7 cell line(P=0.013,0.020),and no significant difference was detected between MDA-MB-231 and MCF-7 breast cancer cells(P=0.955).CD90 mRNA expressions were detected in MDA-MB-231 cells and MCF-7 cells,but not in BT-483 cells.Conclusion Some malignant cells could survive in vitro and begin to proliferate again between cycles of chemotherapy.

目的:研究从白屈菜乙醇提取物中分离出的白屈菜碱在诱导HeLa细胞凋亡中的作用及参与其作用的主要信号转导通路.方法:细胞先以不同浓度白屈菜碱处理48h,用噻唑蓝法分析确定半数致死量(medianlethaldose,LD50).用4',6-二脒基-2-苯基吲哚染色,追踪分析核浓染以及DNA损伤和碎片的形态学变化,并用流式细胞术分析检测活性氧(reactive oxygen species,ROS)的产生以及细胞周期阻滞和线粒体膜电位的变化.用圆二色光谱分析寻找白屈菜碱和小牛胸腺DNA可能的相互作用.用逆转录聚合酶链反应和蛋白免疫印迹法测定p38、p53、蛋白激酶B(proteinkinase B,AKT)、磷脂酰肌醇3激酶(phosphatidylinositol 3-kinases,PI3K)、Janus激酶3(Janus kinase 3,JAK3)、信号转导及转录激活因子3(signal transducer and activator of transcription 3,STAT3)等的mRNA和蛋白表达,以及E6、E7癌基因和促凋亡基因、抗凋亡基因的mRNA和蛋白表达.结果:根据白屈菜碱的LD50(30μg/mL),选定3种实验剂量,即22.5、30和37.5μg/mL.结果显示,白屈菜碱抑制了HeLa细胞增殖,诱发其细胞凋亡,表现为ROS的产生,细胞亚G1和G0/G1周期阻滞,线粒体膜电位变化和DNA碎片产生.圆二色光谱分析结果显示白屈菜碱和小牛胸腺DNA间存在有效的相互作用.信号通路的研究显示白屈菜碱通过上调p38、p53和其他促凋亡基因的表达,以及下调AKT、P13K、JAK3、STAT3、E6、E7和其他抗凋亡基因的表达,有效诱发细胞凋亡.结论:从白屈菜中分离出的自屈菜碱能通过改变p38-p53及AKT/P13激酶信号转导通路有效地诱发HeLa细胞凋亡.

目的:通过检测梅毒血清固定患者外周血CD4+CD25+调节性T细胞(regulatoryTcells,Treg)比例和功能的改变,探讨Treg在梅毒血清固定现象形成中的作用.方法:收集梅毒血清固定患者26例,正常对照23例,利用流式细胞术分别检测外周血Treg比例及Treg内Foxp3、细胞毒性T淋巴细胞抗原(cTLA)-4及白介素(IL)-10的定量表达情况.结果:梅毒血清固定组患者外周血Treg比例明显高于正常对照组(P〈0.01);且Treg内转录因子Foxp3及功能性分子cTLA-4和IL-10的表达量也明显高于正常对照组(P〈0.05或P〈0.01).结论:梅毒血清固定患者外周血Treg比例和功能的异常,可能是导致该现象形成的重要原因之一.

近期,英国太阳能展览会(Solar Energy UK 2014)在伯明翰NEC国际会展中心隆重举行,上海兆能在此次展会上首次发布其自主研发的新型TRB系列4k W-9k W三相光伏逆变器.这是上海兆能继混合储能机、35k W三相逆变器之后,今年推出的又一新品.其中TRB8000TL和TRB9000TL产品的紧凑设计在行业中非常具有竞争力,体积仅约0.05m3,重量仅24kg."我们新推出的这款TRB系列三相逆变器的设计旨在提供更高的转换效率,

目的:构建表达人LIM矿化蛋白-1(LIM mineralization protein-1,LMP-1)基因的腺病毒重组体,体外感染骨肉瘤(Osteosarcoma,OS)细胞系U2OS,并鉴定LMP-1基因在U2OS中的表达.方法:以K562细胞的cDNA为文库,采用PCR方法对LMP-1进行扩增,通过TA克隆与pGEM-T载体连接并DNA测序.双酶切后并将目的基因插入至腺病毒穿梭质粒pAdtrack-CMV,对腺病毒穿梭质粒pAdtrack-CMV-LMP-1行双酶切和DNA测序鉴定,并通过荧光显微镜、RT-qPCR和Western blot检测pAdtrack-CMV-LMP-1在HEK-293T细胞中的表达.线性化pAdtrack-CMV-LMP-1,在BJ5183菌内完成与骨架质粒pAdeasy-1的同源重组,构建重组腺病毒质粒Ad-LMP-1.通过脂质体介导,在HEK-293A细胞内包装出复制缺陷的重组腺病毒Ad-LMP-1,大量扩增、纯化并测定滴度.用Ad-LMP-1感染OS细胞系U2OS,通过荧光显微镜、RT-qPCR和Western blot检测LMP-1在U2OS细胞中的表达.结果:双酶切和DNA测序鉴定穿梭质粒pAdtrack-CMV-LMP-1构建成功,荧光显微镜证实转染了pAdtrack-CMV-LMP-1质粒的HEK-293T细胞内有绿色荧光蛋白表达,RT-qPCR和Western blot验证了LMP-1基因的表达量明显高于对照组.通过扩增、纯化,Ad-LMP-1滴度达到1.5*109pfu/ml.荧光显微镜下观察重组腺病毒感染的U2OS内有绿色荧光蛋白表达,RT-qPCR和Western blot检测发现重组腺病毒感染U2OS后,LMP-1的mRNA和蛋白表达量明显高于对照组.结论:成功构建了人LMP-1基因腺病毒重组体,为进一步的实验研究奠定了基础.

目的:构建含变形链球菌表面蛋白A区编码基因(pacA)、葡糖基转移酶催化区编码基因(gtfB-cat)及霍乱毒素B亚单位编码基因(ctxB)的嵌合表达质粒并表达目的蛋白.方法:将目的基因pacA、gtfB-cat、ctxB克隆至原核克隆载体pET32-a(+)构建嵌合质粒pET-pacA-cat-ctxB,将其转入表达宿主菌E.coliBL21(DE3),并测量其表达情况.结果:构建的重组质粒经酶切、PCR鉴定及测序,证实目的基因均正确插入到载体pET'32a(+)中,插入的相位正确,未改变目的基因的阅读框架,经诱导后表达目的蛋白,分子质量大小与预期-致.结论:成功构建了嵌合质粒pET-pa-cA-cat-ctxB,且它们均在原核细胞内获得正确表达.