氯化锂对MGC803细胞增殖及细胞周期的影响

研究氯化锂(LiCl)在体外对MGC803胃癌细胞增殖及周期的影响,以不同浓度的LiCl作用MGC803细胞24 h后,采用四甲基偶氮唑盐(MTT)比色法检测各组细胞的增殖活性,利用流式细胞术进行细胞周期分析.结果:①不同浓度的LiCl(10、20、40 mmol/L)均对MGC803细胞具有抑制增殖的作用,这种增殖抑制作用呈剂量依赖关系.②随着LiCl浓度的升高,发生G2/M期阻滞,与正常对照组相比,差异具统计学意义.说明LiCl能抑制MGC803胃癌细胞增殖和导致G2/M期阻滞.     

生物细胞在极低频电磁场中的效应

探讨极低频电磁场对洋葱根尖细胞及人肺成纤维细胞生物学特性的影响.对生长发育过程中洋葱根和体外培养的人肺成纤维细胞进行50 Hz,3 mT极低频电磁场(ELFMFS)处理,对洋葱根的外部形态及细胞有丝分裂指数、染色体形态等进行观察分析,对人肺成纤维细胞进行增殖量比较及凋亡分析.结果表明:50 Hz,3 mT ELFMFS在20 ℃时对洋葱根的生长量无明显影响,但在30 ℃下对洋葱根的生长起抑制作用且可导致根生长异常;正常培养条件下,ELFMFS照射组人肺成纤维细胞生长受到抑制,有细胞凋亡发生.ELFMFS与温度的叠加效应(50 Hz,3 mT,30 ℃)可对洋葱根的生长及根尖细胞的增殖产生重要作用,ELFMFS对人肺成纤维细胞的生长起抑制作用并可引起细胞凋亡.     

Communication between osteoblasts stimulated by electromagnetic fields

Pulsed electromagnetic field can affect the proliferation of osteoblasts, but the mechanism is obscure yet. The communication between osteoblasts, isolated from calvaria bone of newborn SD rats and stimulated with the rectangular electromagnetic field of 15 Hz and 4 mT, was studied. Our results showed that the osteoblasts radiated a kind of light after they were stimulated with the electromagnetic field and it is the light that promotes the proliferation of un-stimulated osteoblasts.     

Effects of extremely low frequency magnetic fields on gap junctional intercellular communication and its mechanism

The study on biological effect of electromagnetic fields has been paid close attention in recent years. Gap junctional intercellular communication (GJIC) plays an important role in the maintenance of cell proliferation and differentiation, and in the multistage process of carcinogenesis. A series of researches showed that xtremely low frequency (ELF) magnetic fields not only enhance the inhibition of GJIC induced by 12-O-tetradecanoylphorbol-13-acetate, but also inhibit GJIC directly when the intensity is equal to or more than 0.4 　mT, and that the mechanisms of GJIC inhibition by ELF magnetic fields are due to hyperphosphorylation of connexin 43, which is mediated by protein kinase C-activated signal transduction, and the internalization of connexin 43 from plasma membrane to cytoplasm.     

右旋一叶萩碱对小鼠黑色素瘤B16增殖及细胞周期的影响

目的:探讨右旋一叶萩碱对小鼠黑色素瘤B16细胞增殖和细胞周期的影响及其作用机制。方法:右旋一叶萩碱作用于小鼠黑色素瘤细胞B16,MTT法检测细胞增殖;流式细胞术检测细胞周期。结果:右旋一叶萩碱以时间和浓度依赖的方式抑制B16细胞生长;药物作用72 h IC50为63.34μmol/L;右旋一叶萩碱诱导B16细胞凋亡并显著减少S期、G2/M期细胞。结论:右旋一叶萩碱可以抑制黑色素瘤细胞的恶性增殖,其作用机制与诱导细胞凋亡、减少S期和G2/M期细胞有关。     

肝再生细胞周期中增殖启动及其调控研究

肝再生细胞周期中增殖启动及其调控是一个研究热点,到底是何种因素及其涉及到的信号传导途径诱导了Go期肝细胞的启动仍然是一个谜.本文主要以JNK、TNF-α、IL-6、一氧化氮等因子及其可能参与的调控途径综述了肝再生启动的一些最新研究进展.     

钢连铸电磁搅拌工艺中流场的数值模拟

利用旋转磁场特征变换模型方程并结合边界更新法,与k-ε湍流模型耦合计算了交变电磁场作用下连铸方坯内的流场.结果表明:电磁力使得钢液在水平方向形成旋转流动,能够降低向下过高的流速并增强回流;从搅拌区域垂直中心向下,水平旋转流动的速度逐渐变小.钢液旋转流速随电源电流和频率的增大而提高,并且在水平面上呈单峰值分布,在近壁面处最大.     

Effects of lanthanum and gadolinium on proliferation and differentiation of primary osteoblasts

The effects of La³⁺ and Gd³⁺ on the proliferation, differentiation and adipogenic transdifferentiation of rat calvarial osteoblast-like cells (ROB cells) were evaluated by MTT method， measuring the activity of alkaline phosphatase (ALP) and Oil red O measurement. Both of La³⁺ and Gd³⁺ inhibited the proliferation of ROB cells at all concentrations (1×10^-5, 1×10^-6, 1×10^-7, 1×10^-8, 1×10^-9 mol?L^-1). La³⁺ at concentration of 1×10^-5 mol?L^-1 significantly increased the alkaline phosphatase activity of ROB cells up to 3 folds (P<0.01). However, the effects reversed to inhibit at other concentrations. Gd³⁺ played a negative role in the alkaline phosphatase activity. La³⁺ inhibited the adipogenic transdifferentiation of ROB cells at all concentrations in a dose-dependent way. However, Gd³⁺ promoted the adipogenic transdifferentiation of ROB cells at 1×10^-8 and 1×10^-9 mol?L^-1. These findings suggested that the effects of rare earth elements on the proliferation, differentiation and adipogenic transdifferentiation of ROB cells were dependent on their concentrations and species     

细胞外信号调节激酶1/2信号通路在小鼠T细胞增殖、周期和活化中的作用

目的:探讨细胞外信号调节激酶1/2(ERK1/2)信号通路在小鼠T淋巴细胞增殖、周期和活化中的作用.方法:分离小鼠淋巴结细胞,藉多克隆刺激剂刀豆蛋白(ConA)或佛波醇酯(PDB)加离子霉素(Ion)刺激,流式细胞术分析ERK1/2信号通路的特异性阻断剂PD98059对小鼠T淋巴细胞增殖、周期和活化的影响.结果:活体染料羧基荧光素乙酰乙酸染色分析显示,不同浓度(5、10、20、30、40 μmol/L)的PD98059对ConA诱导的T淋巴细胞增殖具有明显的抑制作用,呈现剂量依赖关系(r=0.985,P＜0.01).碘化丙锭染色分析表明,PD98059可阻止ConA刺激的T淋巴细胞进入S期和G2/M期,PD98059对PDB Ion刺激的T淋巴细胞细胞周期的影响与ConA刺激相似,不同的是S期和G2/M期的变化较ConA作用更显著.荧光标记单克隆抗体染色显示,不同浓度的PD98059仅能轻微影响T淋巴细胞表面活化标志CD69和CD25的表达.结论:PD98059对小鼠T淋巴细胞的增殖有明显抑制作用,并阻止其进入S期和G2/M期,但不能明显抑制小鼠T淋巴细胞的早期和中期活化.     

桑色素对小鼠T细胞增殖、周期和巨噬细胞分泌NO的影响

目的:研究桑色素(morin)对小鼠T细胞增殖、细胞周期和腹腔巨噬细胞分泌一氧化氮(nitrogen monoxidum,NO)的影响.方法:以佛波醇酯(phorbol 12,13-dibutyrate,PDB)和离子霉素(ionomycin,Ion)联合刺激淋巴结来源的小鼠T淋巴细胞,再以不同终浓度的morin与上述细胞共培养,利用流式细胞术(FCM),以羧基荧光素双醋酸盐琥珀酰脂(carboxyfluorescein diacetate succinimide ester,CFDA-SE)染色检测T细胞的增殖;以碘化丙锭(propidiumiodide,PI)染色分析T细胞的细胞周期;脂多糖(Lipopolysaccharide,LPS)刺激小鼠腹腔巨噬细胞,与不同浓度morin共培养,以Griess反应检测上清液中的NO含量.结果:CFDA-SE染色分析显示,PDB Ion组的增殖指数(proliferation index,PI)为1.70±0.05,各浓度的morin对PDB Ion刺激的T细胞增殖,具有明显地抑制作用,以100 μmol/L的morin抑制作用最明显,PI为1.03±0.01(P＜0.01).细胞周期的分析结果表明,morin组中处于S期的细胞比率较高,与PDB Ion组相比有明显差异.Griess反应检测NO含量的结果显示,各浓度组的morin均抑制LPS刺激巨噬细胞产生NO,100 μmol/L的morin可将LPS刺激巨噬细胞产生NO为(12.89±0.11)μmol/L降低为(7.25±0.05)μmol/L,抑制作用最强.结论:Morin可显著抑制PDB Ion刺激的T细胞增殖;其对增殖的抑制作用主要表现为S期的细胞的阻滞;对LPS刺激巨噬细胞产生的NO也有显著的抑制作用.     

大功率电磁发射机开关频率精确控制研究

发射频率范围宽,精度高的大功率电磁发射机可以实现对不同深度目标体的探测。提出了使用DSP+FPGA架构来实现发射机发射频点精确性的方案,介绍了大功率电磁发射机的拓扑结构及H型逆变桥的工作原理,并对如何采用DSP控制FPGA实现PWM波形频率、占空比及死区时间的精确控制进行了研究。在此基础上,研制了输出功率为25 kW样机。野外实验结果证明,所设计的大功率电磁发射机可发射频点的精确度高,范围宽,能应用于实际地质勘探中。     

Effects of hyaluronic acid－chitosan－gelatin complex on the apoptosis and cell cycle of L929 cells

With the development in the field of tissue engineering, the interaction between biomaterials and cells has been deeply studied. Viewing the cells seeded on the surface of materials as an organic whole, cell cycle and apoptosis are analyzed to deepen the study of cell compatibility on biomaterials, while cell proliferation and differentiation are studied at the same time. In this paper, hyaluronic acid is incorporated into the chitosan-gelatin system. Propidium iodide (PI) was used in cell cycle analysis and the double-staining of cells with annexin-V and PI was applied in cell apoptosis analysis. The results show that incorporated hyaluronic acid shortens the adaptation period of cells on the material surface, and then cells enter the normal cell cycle quickly. In addition, added hyaluronic acid inhibits cell apoptosis triggered by the membranes. Therefore, hyaluronic acid improves the cell compatibility of chitosan-gelatin system and benefits the design of biomimetic materials.     

极低频电磁场对小鼠脑组织脂质过氧化及白细胞的影响

在小鼠上观测了50Hz、4mT电磁场间断暴露后脑组织超氧化物歧化酶（SOD）活力和丙二醛（MDA）含量以及血液白细胞总数和分类的变化。结果表明：SOD活力在暴露10天和20天时下降显著;MDA含量在暴露1天和10天时明显下降,但在20天时显著升高。血液白细胞数在暴露1天和20天时均显著减少,但在10天时显著增多;嗜中性粒细胞百分率在暴露1天和20天时显著上升,与此同时淋巴百分率显著下降。提示在本实验条件下,50Hz电磁场可加剧脑组织的脂质过氧化,改变血液白细胞组分的计数;这些变化与磁场暴露的持续时间有关,类似于一种应激效应。     

Effects of lanthanum and gadolinium on proliferation and differentiation of primary osteoblasts

The effects of La3 and Gd3 on the proliferation, differentiation and adipogenic transdifferentiation of rat calvarial osteoblast-like cells (ROB cells) were evaluated by MTT method, measuring the activity of alkaline phosphatase (ALP) and Oil red O measurement. Both of La3 and Gd3 inhibited the proliferation of ROB cells at all concentrations (1×10-5, 1×10-6, 1×10-7, 1×10-8, 1×10-9 mol·L-1). La3 at concentration of 1×10-5mol·L-1 significantly increased the alkaline phosphatase activity of ROB cells up to 3 folds (P<0.01). However, the effects reversed to inhibit at other concentrations. Gd played a negative role in the alkaline phosphatase activity. La3 inhibited the adipogenic transdifferentiation of ROB cells at all concentrations in a dose-dependent way. However, Gd promoted the adipogenic transdifferentiation of ROB cells at 1×10 and 1×10 mol·L . These findings suggested that the effects of rare earth elements on the proliferation, differentiation and adipogenic transdifferentiation of ROB cells were dependent on their concentrations and species.     

三维井间电磁场的联合反演方法

考虑到井间电磁测量信息量的局限性,基于积分方程在发射接收剖面对三维电导率异常体进行近似成像。成像过程中将沿垂直于发射接收剖面方向的成像区域限制在一定范围并假设电导率在该方向不变。成像实例显示,这种剖面成像的精度取决于垂直于发射接收剖面方向的成像范围与异常体在该方向实际范围的接近程度。考虑到实际情况下背景层电导率值往往是未知的或虽已知但并不准确,还提出了联合反演方法,以一维反演结果作为初始值,既反演一维背景地层的电导率,也反演三维异常体在发射接收剖面的电导率,两个过程交替进行。反演实例显示,经过几轮迭代后,背景层电导率分布及异常体在发射接收剖面的电导率分布均大大改善,说明了联合反演的有效性和必要性。     

Dual regulatory effects of resveratrol on activation of NF-κB and cell proliferation in human embryonal kidney 293 cells

Resveratrol (3,4‘,5-trihydroxystilbene, Res), a naturally occurring polyphenol, exhibits antioxidant, antiinflammatory, potential chemopreventive and chemotherapeutic properties in preclinical studies. To further understand its potential clinical efficacy and safety, effect of Res at 10^-9-10^-4 mol/L on human embryonal kidney (HEK293) cell proliferation and its potential mechanism were investigated in present study. Cell viability was detected by using trypan blue dye exclusion method. Cell cycle and apoptosis were analyzed by flow cytometry with propidium iodide stain.Activation of nuclear factor-κB (NF-κB) was determined by luciferase reporter gene assay using stably transfected HEK293/κB-luc cells. Secretion of human interleukin-8(hlL-8) was measured by ELISA. Our results show that HEK293 cell proliferation was significantly stimulated by 10^-7 mol/L Res after treatment for 48 hours, or by 10^-8-10^-7mol/L Res combinated with 10 ng/mL TNFα for 24 h, but was suppressed by 10^-4 mol/L Res with or without TNFα. Both endogenous and TNFα-induced NF-κB activation were downregulated by Res at 10^-7 mol/L, but were upregulated at 10^-4 mol/L. With 10^-4 mol/L Res, the content of secreted IL-8 was increased, and apoptosis rate was increased from lessthan 5 % to 10%, together with significant cell-cycle arrest in S phase. TNFα has coordinative effects with Res on HEK293 cell apoptosis, cell-cycle arrest and IL-8 secretion. These results indicate that Res promotes cell proliferation at low concentration through down-regulation of NF-κB activation in HEK293, but suppresses its growth at high concentration through up-regulation of NF-κB activation, increasing IL-8 and cell-cycle arrest. As resveratrol has dual regulatory effect on cell proliferation in vitro, comprehensive evaluation of its potential clinical utility is needed.     

二维井间电磁场的正反演计算

提出了一种改进的逐次逼近解法 ,并用该方法对轴对称二维井间电磁场进行了正反演计算。与逐次逼近解法相比 ,该方法收敛性强 ,应用范围广 ,可适用于高电导率对比地层。与直接求解积分方程相比 ,由于不必进行直接的大型复矩阵求逆运算 ,该方法计算速度快 ,所需内存少。反演中采用了Born迭代算法 ,将成像区域集中于一定范围内。考虑到信息量和计算机内存的限制 ,采用双重面元分割法 ,将反演区域分割为一定数目的大面元 ,每个大面元被分割为几个小面元。属于同一大面元的不同小面元具有不同的磁矢势 ,但具有相同的电导率 ,从而减少了反演过程中未知量的数目。根据第一次成像结果确定出更准确的成像范围 ,并进行第二次成像。数值计算结果表明 ,改进的逐次逼近解法是计算二维井间电磁场的一种有效方法 ,将该方法用于反演过程能够得到较高分辨率的二维井间电导率图像。     

基于频度的概念漂移中低频概念的消减

由于数据流中概念漂移现象的影响,使得传统的分类方法不再适用,因此研究快速、精确及稳定的数据流挖掘方法和系统具有较高的理论和应用价值;文章研究了基于频度的概念漂移中低频概念对分类时空性能的影响,提出了对其中的低频概念进行消减的算法,实验表明LFCR算法比RePro算法有更好的分类性能。     

测试系统的低频特性补偿研究

针对现有测试系统的低频特性不满足测试需求的情况下,在不改变原有测试系统硬件的基础上,通过软件补偿即对此测试系统的传递函数采用零极点相消的方法,使原有测试系统的低频特性从8Hz拓展到了2.5Hz左右,并利用MATLAB编程仿真,验证了此方法的可行性。