新型植物来源生物碱——唐松草阿原碱对人体肿瘤细胞株的细胞毒性研究

研究从毛莨科唐松草属植物尖叶唐松草根部提取的新型醚键双生物碱－唐松草阿原碱对几种人体肿瘤细胞株的毒性作用。唐松草阿原碱以质量浓度从2．5μg/mL到100μg/mL作用于6种体外培养的肿瘤细胞株及2种正常细胞株,对其中4个肿瘤细胞株种表现了强烈的杀伤作用。IC50分别为：宫颈癌Hela37 μg/mL,肝癌LCC60μg/ml,胃癌MGC65μg/mL,非小细胞肺癌PLA－80182μg/mL,对2个正常细胞株的毒性分别为：肝细胞L－0265μg/mL,小鼠成纤维细胞NIH3T378μg/mL,而对另一株肝癌HepG2及乳腺癌细胞MCF－7无明显作用（IC50＞100μg/mL）。     

硫酸甘油糖脂体外抑制肿瘤细胞增殖活性的研究

目的:检测海藻硫酸甘油糖脂化合物(SQDG)的体外抗肿瘤活性,为寻找有效的抗癌新药提供理论依据.方法:采用MTT法检测SQDG对正常细胞的细胞毒性.在倒置显微镜下观察7种人类肿瘤细胞经SQDG处理72 h后的形态学变化,并用MTT法定量测定其生长抑制情况,同时应用流式细胞术检测细胞周期的改变.结果:SQDG对正常细胞Vero和MC的毒性都很小,其CC50值均大于500 μg/mL.它对人乳腺癌细胞MCF-7的生长抑制效果最明显,IC50值为69.1μg/mL,在质量浓度为125μg/mL时完全抑制MCF-7细胞生长.SQDG对H460、A549、HEp2和HeLa细胞也有一定的抑制效果,但对HepG2和A375细胞几乎没有影响.流式细胞术检测发现,SQDG能扰乱MCF-7的细胞周期,促使细胞凋亡或坏死,从而产生有效的生长抑制效果.但SQDC对H460和HepG2细胞周期的改变无统计学意义.结论:硫酸甘油糖脂SQDG对正常细胞无毒害,能选择性地有效抑制体外培养的乳腺癌细胞的生长,是一种有发展潜力的抗肿瘤药物.     

苍耳子提取物对斑马鱼的发育及运动行为的毒性研究

为研究苍耳子提取物对斑马鱼胚胎发育及运动行为的影响,取受精后12/24 h斑马鱼胚胎,将胚胎分别置于不同浓度苍耳子提取物溶液中,在作用不同时间后,显微镜下统计孵化率、死亡率和心率;取受精后120 h斑马鱼胚胎,用不同浓度苍耳子提取物处理60 min后,利用行为学分析系统统计各组斑马鱼在0~10、10~20、20~30 min内行为轨迹,基于游行距离与游行时间得到游行速度,并统计转圈值。结果表明,苍耳子提取物对受精后12 h斑马鱼胚胎的发育有毒性,使斑马鱼胚胎的孵化率降低,在提取物浓度大于15μg/mL时,孵化率低于40%;0.93μg/mL苍耳子提取物可提高24 h斑马鱼胚胎的心率(P≤0.01),当提取物浓度大于7.5μg/mL时,心率显著性降低(P≤0.01);在行为学分析中发现,当苍耳子提取物浓度大于3μg/mL时,游行速度与转圈均值明显增加。研究认为,苍耳子提取物对斑马鱼胚胎发育有毒性作用,能够兴奋斑马鱼胚胎心率并增加其游行速度。     

CHD5在胚胎干细胞向神经前体细胞分化过程中的功能研究

CHD5蛋白是一种ATP依赖性染色质重塑解旋酶,属于CHD家族.CHD家族成员在胚胎发育及肿瘤发生发展过程中具有重要的作用.前期研究发现CHD5在多种不同类型的肿瘤中发挥抑癌功能,但不清楚CHD5是否影响早期胚胎干细胞分化.本研究发现随着胚胎干细胞向神经前体细胞的分化,CHD5的表达显著上调.干扰CHD5的表达之后对细胞进行向神经前体细胞分化的诱导,发现POU5F1和NANOG等胚胎干细胞标志基因表达上调,Wnt信号通路激活,而PAX6和SOX1等神经前体细胞的标志基因表达得以抑制,表明CHD5在胚胎干细胞向神经前体细胞分化过程中具有重要功能.     

人类胚胎干细胞来源的心肌细胞模型的建立及系统鉴定方案

心肌细胞是研究心血管疾病的重要工具之一,但是人类心肌细胞较难获得和培养.为人类胚胎干细胞诱导分化成心肌细胞提供一个有用的实验方法和鉴定方案.人胚胎干细胞以其多向分化的特性为体外研究提供了细胞资源.在人胚胎干细胞诱导分化为心肌细胞的过程中,通过荧光定量聚合酶链式反应(polymerase chain reaction,PCR)检测发现,在分化过程中干细胞标记物Cripto,Dnmt3b,Wnt3,KIF4,Oct4,SOX2和Nanog表达下降,心肌特异性结构蛋白cTnT和α-actinin以及心脏前体细胞分化标记物Nkx2.5表达上升.分化完成后用免疫荧光检测心肌特异性结构蛋白Tnn T2和α-actinin,通过分析Tnn T2阳性细胞的比例,α-actinin阳性细胞的比例,以及Tnn T2和α-actinin双阳性细胞的比例发现,在所提出的胚胎干细胞诱导分化体系中,三者比例分别为90.80%,91.00%,90.91%,表明在此诱导分化条件下人胚胎干细胞可成功分化成为心肌细胞.成功建立了人胚胎干细胞来源的心肌细胞模型以及基于标记物荧光定量PCR及免疫荧光系统检测的鉴定方案,为未来心血管疾病的基础研究及心脏毒性药物检测奠定了一定的基础.     

3种重金属对斑马鱼的联合毒性及迷迭香酸的保护作用研究

对氯化镉、硝酸铅、硫酸铜3种重金属单一以及联合情况下对早期斑马鱼胚胎发育毒性的影响进行考察,并采用不同浓度的迷迭香酸进行干预,同时观察96 hpf胚胎的死亡率和孵化率.Cd-Pb、Cd-Cu、Pb-Cu、Cd-Pb-Cu对斑马鱼胚胎的毒性作用类型分别为协同作用、协同作用、拮抗作用、协同作用.60μmol/L RA对斑马鱼胚胎死亡、幼鱼畸形及胚胎孵化率无明显影响.Cd~(2+)-Pb~(2+)-Cu~(2+)联合处理,胚胎死亡率明显上升,60μmol/L RA与Cd~(2+)-Pb~(2+)-Cu~(2+)联合处理,胚胎死亡率降低约20%(P<0.01);胚胎凋亡细胞数目明显减少,Bcl-2/Bax的基因表达水平明显上调(P<0.01),Caspase 3基因表达下调(P<0.05).表明RA对Cd~(2+)-Pb~(2+)-Cu~(2+)的联合毒性具有保护作用,其机制可能与上调Bcl-2/Bax,降低Caspase 3基因表达,减少胚胎细胞凋亡有关.     

大蒜素对人肺腺癌细胞SLC-89增殖的影响

目的:观察大蒜素对人肺腺癌细胞SLC-89增殖的影响。方法:不同浓度的大蒜素与SLC-89细胞共培养72 h,运用MTT法测定大蒜素的IC50。将IC50、IC50/2、IC50/4剂量的大蒜素与SLC-89细胞共培养72 h后,运用端粒重复序列扩增-酶联免疫吸附法分别测定细胞端粒酶活性,运用流式细胞技术测定细胞PCNA的表达率。加入等量生理盐水共培养作为对照组。结果:大蒜素能抑制SLC-89细胞的增殖,其IC50为79.8μg/mL,IC50和IC50/2剂量的大蒜素能显著抑制SLC-89细胞端粒酶的活性,IC50、IC50/2、IC50/4剂量的大蒜素都能显著抑制SLC-89细胞PCNA的表达。结论:大蒜素能抑制SLC-89细胞的增殖,其PCNA的表达比端粒酶活性更容易受到下调。     

肉苁蓉水提液对猪早期体外发育胚胎中NO浓度含量的影响

目的探讨肉苁蓉水提液对猪早期体外发育胚胎中一氧化氮浓度的影响,以研究肉苁蓉促进猪胚胎发育的药理作用。方法将采集的猪卵母细胞随机分为试验组和对照组,试验组在胚胎培养时在基础液中加入50μg/mL肉苁蓉水提液。将培养至囊胚阶段的胚胎取出,用Griess试剂法测定囊胚细胞中NO含量。结果细胞中NO含量显著低于对照组(P<0.05)。结论肉苁蓉水提液减少了胚胎细胞中NO含量,这可能是其促进细胞体外发育的作用机理之一。     

小鼠胚胎干细胞R1表面特异结合多肽的筛选

胚胎干细胞是从哺乳动物胚胎发育早期的囊胚的内细胞团内分离出来的一类细胞,具有自我更新和全能性的基本特征.作者利用M13噬菌体展示技术筛选与未分化的小鼠胚胎干细胞R1表面特异结合的多肽.实验利用未分化的小鼠胚胎干细胞为筛选靶细胞,分化的小鼠胚胎干细胞为吸附细胞,进行3轮的消减筛选,经细胞ELISA鉴定,噬菌体DNA测序和多肽序列分析,得到13条能与小鼠胚胎干细胞特异结合的多肽.通过BLASTP比对发现有11个体内的同源蛋白,为进一步研究小鼠胚胎干细胞表面分子提供研究基础.     

牡丹籽粕多酚和黄酮提取工艺优化及其抗氧化和降糖活性研究

采用响应面法优化同时提取牡丹籽粕多酚和黄酮并检测其抗氧化和降糖活性，最优工艺为乙醇质量分数90%，提取温度85℃，提取时间50 min，料液比1∶40，在此条件下得到的多酚和黄酮提取量分别为（17.59±0.82）mg/g、（0.74±0.09）mg/g，并采用D101大孔树脂对牡丹籽粕提取液进行纯化得到牡丹籽粕多酚和黄酮成分，该成分对DPPH自由基、ABTS自由基的清除能力的IC50值分别为（313.67±42.67）μg/mL、（243.67±22.12）μg/mL，对铁离子还原能力为（438.78±3.36）μmol TE/g，对α-葡萄糖苷酶的半数抑制浓度IC50值为（31.11±2.44）μg/mL，稍优于阿卡波糖IC50值（34.42±1.58）μg/mL.牡丹籽粕多酚和黄酮富集成分具有较好的抗氧化和降血糖活性.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that