RT-PCR法检测大鼠组织中GLUT8基因表达特异性

采用半定量RT_PCR技术检测青春前期和成年大鼠的主要组织中GLUT8基因mRNA表达水平.实验结果显示,葡萄糖转运蛋白GLUT8基因在成年和青春前期大鼠的睾丸组织中都有高度表达,在心脏和肾脏组织中有少量表达,在肝、脾等组织中的表达是微量的;在成年大鼠睾丸组织中,Leydig细胞、睾丸生精细胞以及附睾的精子细胞中GLUT8基因都有大量的表达,其中以在Leydig细胞中的表达最丰富,而且GLUT8基因在睾丸生精细胞中的表达水平高于附睾的精子细胞.结果说明GLUT8蛋白主要分布在大鼠睾丸组织中,并且主要在Leydig细胞和精子细胞中参与葡萄糖转运和能量代谢与供应.     

Caco-2细胞单层模型构建及3种药物吸收机制评价

目的:研究3种不同特性药物体外Caco-2细胞转运及其机制.方法:构建Caco-2细胞单层模型,选择酚酸类药物丹参总酚酸,生物碱类药物盐酸小檗碱和皂苷类药物三七皂苷R1为模型药物,研究3种不同特性药物经Caco-2细胞单层膜转运特点,分析其转运机制.结果:丹参总酚酸在酸性条件下经Caco-2细胞单层膜转运较高,无外排机制.盐酸小檗碱外排机制较强,不受pH的影响.三七皂苷R1经Caco-2细胞转运较差,但无外排机制,不受pH的影响.结论:3种药物口服吸收均较差,但机制不同.提高3种药物口服吸收的措施:提高丹参总酚酸在胃中滞留时间;消除盐酸小檗碱的外排影响;改善三七皂苷R1的膜透性.     

槐属二氢黄酮G促进L6细胞内GLUT4的表达和转运

利用细胞葡萄糖摄取检测试剂盒检测苦参中槐属二氢黄酮G(Sophoraflavanone G,SFG) 对L6细胞葡萄糖摄取的影响,发现SFG能够增加大鼠成肌细胞 (L6) 的葡萄糖摄取;之后,使用Western blot检测发现SFG对L6细胞内GLUT4的表达有显著的促进作用;同时,在可稳定表达IRAP-mOrange荧光蛋白的L6细胞内,使用激光共聚焦显微镜监测SFG作用下葡萄糖转位蛋白4 (glucose transporter 4,GLUT4) 的转位,发现SFG对GLUT4的转位有显著的促进作用,而且SFG对GLUT4转位的促进呈浓度依赖性;另外,免疫荧光实验结果也显示SFG增强L6细胞中GLUT4与细胞膜的融合.这些结果显示利用SFG处理L6细胞后,L6细胞内GLUT4的表达、转运及与细胞膜的融合继而促进葡萄糖的摄取显著增强,说明SFG可能具备开发成一种新的降血糖药物的潜力.     

果糖代谢相关蛋白GLUT5和KHK在肺腺癌中的表达及其生物学功能

目的:检测果糖代谢相关蛋白葡萄糖转运蛋白5(GLUT5)和己酮糖激酶(KHK)在肺腺癌中的表达及生物学功能.方法:利用http://kmplot.com/analysis/上的数据分析GLUT5和KHK的mRNA表达水平对肺腺癌患者生存预后的影响;免疫组织化学方法检测GLUT5和KHK蛋白在肺腺癌及相应癌旁组织中的表达水平;SPSS统计分析GLUT5和KHK表达水平与肺腺癌患者年龄、性别、肿瘤大小、淋巴结转移、远处转移、临床分期、病理分级等临床病理指标之间的关系,以及对患者生存预后的影响;MTT和克隆形成实验检测无葡萄糖条件下果糖对肺腺癌细胞增殖和克隆形成的影响,以及沉默GLUT5和KHK对细胞生物学行为的影响.结果:GLUT5和KHK mRNA表达水平较高的肺腺癌患者,其总生存和无进展生存均较差;GLUT5和KHK在肺腺癌组织中的蛋白表达水平均高于癌旁组织(P0.01);GLUT5高表达与肿瘤大小、淋巴结转移和病理分化较差有关(P0.05);KHK高表达与肿瘤大小、临床分期和病理分化较差有关(P0.05);而且GLUT5和KHK高表达的患者预后较差(P0.05).果糖可促进肺腺癌细胞的增殖和克隆形成,沉默GLUT5和KHK后,细胞利用果糖的能力显著下降.结论:果糖可以促进肺腺癌细胞的增殖和克隆形成,果糖代谢相关蛋白GLUT5和KHK在肺腺癌组织中高表达,且与肺腺癌的恶性进展密切相关,GLUT5和KHK可作为治疗肺腺癌潜在临床靶点.     

恶性疟红细胞期葡萄糖转运关键蛋白的识别

恶性疟原虫(Plasmodium falciparum)感染人体后经历肝细胞期和红细胞期2个阶段.红细胞期是恶性疟原虫在人体内发育增殖和产生临床症状的主要阶段,其能量代谢完全依赖于吸收血液中的葡萄糖.葡萄糖首先通过宿主红细胞膜(erythrocyte plasma membrane,EPM)上的葡萄糖转运蛋白1(Glucose transporter 1,GLUT1)进入红细胞胞浆,再由疟原虫质膜(parasite plasma membrane,PPM)上的己糖转运蛋白(P.falciparum hexose transporter,Pf HT)完成疟原虫对葡萄糖的吸收.针对恶性疟原虫红细胞期葡萄糖转运途径中的关键蛋白进行序列分析,合成相应多肽,并获得了特异性识别GLUT1和Pf HT蛋白的抗体,为葡萄糖转运蛋白在恶性疟原虫感染中的机制研究,及抗疟药物治疗靶点的探索提供了必要条件.     

两个Caco-2细胞系模型铁生物有效性评价效果研究

研究Caco-2细胞吸收转运模型(模型Ⅰ)和吸收转化模型(模型Ⅱ)对铁生物有效性的评价效果.用不同浓度,pH的硫酸亚铁溶液及稻米分别处理两种模型的Caco-2细胞单层22 h后,测定两种模型细胞铁吸收差异.结果表明Caco-2细胞铁蛋白形成量随铁浓度增加而增加,且模型I高于模型Ⅱ,当铁浓度≥25μmol.L-1时,差异达显著水平(p0.05);细胞铁蛋白形成量和转运铁量均与pH呈负相关,两模型间达到显著相关(p0.05).模型Ⅰ和模型Ⅱ均可用于膳食铁生物有效性评价,高铁浓度时,模型Ⅰ效果优于模型Ⅱ.     

不同接种密度对Caco-2细胞吸收模型分化及去极化评价指标的影响

为确定不同接种密度对Caco-2细胞吸收模型分化及去极化评价指标的影响,以及细胞模型适用于吸收和转运试验的时间,采用Caco-2细胞高密度(1×105cells·cm-2)、中密度(5×104cells·cm-2)和低密度(3×104cells·cm-2)等3个接种密度,分别接种于带聚碳酸酯微孔滤膜插槽的Transwell 6孔板上,培养29 d,通过测定跨膜电阻值(TEER)、碱性磷酸酶活性(ALP)和酚红透过率,评价细胞单层的完整性、极化和透过性。结果表明,高、中、低密度接种分别于第12天、第15天和第18天TEER值超过600Ω·cm2,第27天、第29天和第29天TEER值开始下降。高、中、低密度接种分别于第15天、第18天和第21天上下侧碱性磷酸酶活性的比值都能达到10倍以上,第29天开始降低。高、中、低密度接种分别于第9天、第12天和第15天酚红透过率小于0.5%。综合以上3项指标,高密度接种细胞在第15天、中密度接种细胞在第18天、低密度接种细胞在第21天开始,可以用于吸收和转运试验,27 d以后细胞活力就开始下降,不适合做细胞模型。     

Caco-2细胞模型建立及其在纳米脂质体包裹胰岛素体外吸收研究中的应用

为建立Caco-2细胞模型，并用于纳米脂质体包裹胰岛素的体外吸收特性研究．通过Caco-2细胞培养于Transwell上，培养20余天，使其生长分化成单层小肠上皮样细胞，然后以单层细胞电阻，电镜观察小肠上皮结构的形成，碱性磷酸酶反应测定单层细胞极性以及对葡聚糖的通透特性等指标对该模型进行评估，并运用Caco-2细胞模型，对胰岛素和纳米脂质体胰岛素进行通透特性研究．结果表明，Caco-2细胞形成刷状缘及紧密连接结构，碱性磷酸酶活性集中在刷状缘侧，单层细胞电阻达到300～500Ω／cm^2，类似小肠上皮．纳米脂质体包裹后，胰岛素的通透量显著增加．说明纳米脂质体包裹可提高胰岛素的通透性，可以作为胰岛素口服用药的有效方法．     

敲开葡萄糖转运之门

<正>前不久,清华大学医学院颜宁教授的研究组解析出了人源葡萄糖转运蛋白GLUT1的晶体结构,引起学术界的关注。什么是"人源葡萄糖转运蛋白",它的结构又是如何得到的?2014年5月18日,清华大学医学院颜宁教授的研究组在《自然》(Nature)在线发表了题为"人源葡萄糖转运蛋白GLUT1的晶体结构"的研究论文,首次报道了这种蛋白的晶体结构。这篇文章6月5日在《自然》杂志正式发表。这个成果一经发表,很快就引起国际学术界的注意,被认为是一个"里程碑"式的成就。"葡萄糖转运蛋白GLUT1",这个名字听起来很专业,似乎与我们的日常生活关系不大,但实际上,这种蛋白却与我们的生命和健康息息相关。弄明白这个GLUT1到底是什么,我们也就知道研究它的结构有什么意义了。     

纳米三羟异黄酮Caco-2细胞吸收实验

文章通过实验研究了牛血清白蛋白(bovine serum albumin,BSA)包裹大豆三羟异黄酮(genistein,Gen)纳米体在小肠吸收的可行性。构建Caco-2单细胞模拟小肠上皮细胞对Gen纳米体的吸收转移模型,利用苯酚红通透性试验以及碱性磷酸酶(alkaline phosphatase,AKP)活性检测验证模型,实验结果显示Gen纳米体在跨膜转运的过程中发生了代谢与转化,Gen纳米体在单层细胞模型的顶(apical,AP)侧与基底(basolateral,BL)侧的表观渗透系数Papp均高于Gen单体对照组,说明由BSA包裹的Gen纳米体比Gen单体较易被Caco-2细胞吸收。     

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