体外培养癌细胞的吸收光谱

使用日本岛津3101分光光度计采集了宫颈癌细胞(Hela)和鼻咽癌细胞(Cne)在生长过程的紫外吸收光谱.得到了Hela细胞和Cne细胞在生长过程中,细胞体内氨基酸的含量随细胞生长周期的变化曲线.说明采集细胞生长周期的光谱,可分析细胞在生长过程蛋白质含量及结构的变化信息,能为细胞学、药物学研究提供有关细胞体内蛋白质的信息.     

细胞周期中内质网膜系统的组建

细胞周期与细胞癌变 ,胚胎发育 ,组织再生均有密切关系 ,对细胞周期的研究有助于探讨细胞癌变的机理。内质网膜系统不仅是细胞的其他膜性细胞器来源 ,在蛋白质和脂类合成中也起重要作用。因而观察与分析细胞周期中内质网系统的组建特点 ,对了解正常与癌变细胞的生物学特性均具有重要意义。材料与方法　将 CV- 1细胞 (非洲绿猴肾上皮细胞 )单层培养于培养皿中的盖玻片上。取经上述培养的处于对数生长期的细胞 ,用过量的胸腺嘧啶核苷双阻断法使细胞同步化 ,在不同时间分别收集不同时相的 G1,S,G2 和 M期的细胞。对不同时相的细胞应用流式细…     

Ras信号通路阻断剂FTI-277抑制HeLa细胞增殖及对cyclin E表达的影响

目的：观察Ras信号通路阻断剂（FTI-277）在人类宫颈癌细胞株HeLa细胞中对细胞周期素E（cyclin E）表达及对HeLa增殖、凋亡的影响情况。方法：采用MTT法观察不同浓度的FTI-277对HeLa细胞的生长抑制作用;流式细胞术（FCM）观察Hela细胞的细胞周期变化;RT-PCR、Western blot法检测FTI-277阻断Ras信号通路前后HeLa细胞cyclin E mRNA及蛋白表达。结果：各浓度范围FTI-277均能抑制HeLa细胞的增殖,且具有剂量依赖性和时间依赖性。流式细胞术分析显示,FTI-277作用后的HeLa细胞明显滞留于G1/S期,且具有时间依赖性。RT-PCR及Western blot结果显示,FTI-277作用前后HeLa细胞cyclin E mRNA表达无明显变化,而蛋白表达水平明显降低。结论：FTI-277可以抑制细胞增殖,Ras信号转导通路可能是通过影响HeLa细胞cyclin E转录后的翻译环节减少其表达。     

洋葱细胞周期中线粒体DNA合成的电镜放射自显影研究

许多工作表明,线粒体DNA的合成是在整个细胞周期中不断进行的,但在不同生物细胞周期的不同时相中线粒体DNA合成速度高低不同。过去这方面的研究通常都是用动物和低等植物进行的。本文以洋葱根端细胞为材料,用电镜放射自显影法研究了细胞周期各时相的线粒体DNA合成。幻根在~3H-胸腺嘧啶核苷溶液中培养10分钟,水洗5分钟,按常规制备了电镜自显影标本。有丝分裂间期各对相是按核内染色质集缩的形态特点、细胞板形成的进程和核内银粒的多少确定的。按Baserga(1985)报告,Gl期     

uPAR抗体对口腔癌HB细胞增殖的影响

目的:检测uPAR抗体对口腔癌HB细胞增殖的影响,并探讨其作用机制.方法:MTT法检测不同浓度的uPAR抗体(20、50、100μg/ml)作用于口腔癌HB细胞,并检测不同作用时间(24、48和72 h)的细胞增殖抑制率;流式细胞仪检测细胞周期的变化;Annexin V-FITC/PI染色法检测对细胞凋亡的影响;酶联免疫吸附法检测uPAR抗体对HB细胞分泌VEGF-D的影响.结果:uPAR抗体能抑制HB细胞的增殖,并呈现浓度和时间依赖关系.uPAR抗体可使HB细胞周期停滞于G0/G1期,随着uPAR抗体作用浓度的增加,G0/G1期细胞比例逐渐增高.uPAR抗体可促进HB细胞凋亡并呈现一定的浓度依赖关系.uPAR抗体对HB细胞分泌VEGF-D有抑制作用,随着uPAR抗体浓度的增高,其VEGF-D分泌量也逐渐降低.结论:uPAR抗体可抑制HB细胞增殖,其可能机制是使细胞周期停滞于G0/G1期,促进细胞凋亡及减少VEGF-D的分泌.     

二种光敏剂加激光照射对不同时相Hela细胞杀伤效应的比较

对人宫颈癌细胞Hela进行同步化处理,收集并接触到Rose小室中。同含有叶绿素衍生物或竹红菌甲素的培养基分别处理处于G_1,S和G_2时期的细胞,然后用632.8nm波长的激光进行微束照射。结果表明竹红菌甲素对细胞的杀伤力明显高于叶绿素衍生物。不同时相Hela细胞对竹红菌甲素加激光的可见损伤反应顺序为:S期>G_1期>G_2期,而对叶绿素衍生物的反应顺序为S期>G_2期>G_1期。     

不同浓度的碘化丙啶染色对细胞周期分布的影响

研究不同浓度的碘化丙啶(PI)染色对细胞周期分布的影响。293T细胞经0、2、4、6Gy的X射线照射后,用浓度分别为5、10、20、50μg/ml 的PI染色后,流式细胞仪检测细胞周期的分布情况。0、2、4、6 Gy时,不同浓度PI染色时G1/G0期的比例变化如下：(35.90±0.17)至(37.65±0.42),(18.05±0.40)至(19.08±2.01),(4.24±1.31)至(5.89±1.08),(2.88±0.16)至(4.04±1.06),G2/M 期的比例变化如下：(13.36±0.36)至(15.39±0.33),(54.56±0.34)至(58.98±1.46),(83.92±4.50)至(84.80±1.43),(92.29±1.56)至(92.89±1.49);S期的比例变化如下：(45.63±0.97)至(49.74±0.16),(22.45±0.35)至(27.04±0.36),(10.05±0.79)至(11.29±0.11),(3.71±1.06)至(4.99±1.01)。在同一照射剂量下,不管是G1/G0期、S期还是G2/M期,不同浓度PI染色对细胞周期分布没有明显差异( P>0.05);但不管5、10、20μg/ml还是50μg/ml 的PI染色,随着照射剂量的增加,G2/M期细胞比例明显增加(P<0.01)。随着照射剂量的增加,G2/M期细胞比例明显增加;但对于同一照射剂量,不同浓度PI染色对细胞周期分布没有明显差异,做周期分布实验时选择5μg/ml的PI染色即可。     

Rh-6G/DNA-CTMA薄膜的制备与光电特性表征

采用旋涂法和自组装成膜法制备了不同厚度的Rh-6G/DNA-CTMA复合薄膜.通过对Rh-6G/DNA-CTMA薄膜的表面形貌、Rh-6G/DNA-CTMA样品溶液及薄膜的紫外/可见吸收光谱和透过率的测量,以及对薄膜样品交流电阻的表征,研究了薄膜的光电特性与成膜质量.实验结果表明:制备的Rh-6G/DNA-CTMA溶液在533 nm处出现吸收峰,且随着掺杂Rh-6G浓度的增加吸收增强,在其他波段无明显吸收;制备的Rh-6G/DNA-CTMA掺杂薄膜在小于280 nm范围只有很小的透射,在540 nm处有明显吸收.此外,未掺杂薄膜的交流电阻随着频率的增加而减小,而掺杂薄膜的交流电阻的变化相反,并在频率为10 MHz和55 MHz处出现明显的突变.     

基于多波长透射光谱的水体细菌生长阶段特征参数反演研究

研究细菌的生长规律,快速获取细菌在生长过程中浓度、结构、化学组分等特征参数的变化,能够为环境评估、微生物研究等领域的细菌快速检测提供依据。采用紫外-可见光分光光度法测定水体常见大肠埃希氏菌(大肠杆菌)在生长过程中240~900nm波段的透射光谱,基于Mie散射理论对测量得到的可见光波段的透射光谱进行解析,得到细菌的浓度和大小等信息;以核酸、发色团氨基酸吸收特性为基础,根据细菌紫外吸收光谱计算了细菌的核酸含量。结果表明:通过透射光谱反演出的参数能够反映细菌在生长过程中浓度、大小和化学组分的变化,这些变化表明大肠杆菌在适宜的生长条件下经历了不同的生长时期,符合细菌生长规律。多波长透射光谱技术可以对细菌在生长过程中进行动态跟踪检测,获得细胞形态学和化学组分信息,为研究细菌多参数测量提供了一种新方法。     

参麦注射液与人血清白蛋白相互作用的多光谱研究

参麦注射液是一种中药复合物，广泛应用于癌症患者的辅助治疗中。在生理（PH7.4）环境下，通过荧光光谱与紫外吸收光谱研究了参麦注射液与人血清白蛋白的相互作用。荧光光谱和紫外吸收光谱实验结果表明，参麦注射液能够有效地引起人血清白蛋白的内荧光源淬灭，其淬灭机理为动态淬灭。利用Stern-Volmer方程对荧光光谱数据进行分析，得到不同温度（296，303，310 K）下的结合常数（KA）。通过Van't Hoff方程计算出热力学参数（△G0，△H 0，△S 0），该结果表明疏水力是人血清白蛋白与参麦注射液结合时的主要相互作用力及结合过程是一个自发过程。此外，同步荧光光谱实验结果表明，当参麦注射液与人血清白蛋白结合时，主要结合点位于酪氨酸残基，且引起了人血清白蛋白的结构变化。     

Light optical and electron microscopic studies of the tumor cells in rats exposed to vinblastine against a background of increased activity of the anticoagulating system

It is shown that the damage of sarcoma 45 cells at different stages of cell life cycle occurs under the effect of vinblastine treatment against a background of higher activity of the blood anticoagulating system. A decrease in the mitotic activity, mitosis accumulation in prophase and especially in the metaphase as well as essential changes in the interphase cell ultrastructure are detected.     

开博通对激光血管成形术后平滑肌细胞增殖周期的影响

采用球囊拉伤动脉内膜加高脂饲养建立兔髂动脉粥样硬化模型．对模型兔进行Ｎｄ：ＹＡＧ激光血管成形术。应用流式细胞计数仪分析细胞中ＤＮＡ含量。结果表明，治疗组血管平滑肌细胞周期中增殖细胞数明显低于对照组，提示开博通能抑制激光血管成形术后血管平滑肌细胞的增殖。     

Multilayer Hybrid Films Consisting of Alternating Graphene and Titania Nanosheets with Ultrafast Electron Transfer and Photoconversion Properties

Alternating graphene (G) and titania (Ti_0.91O₂) multilayered nanosheets are fabricated using layer‐by‐layer electrostatic deposition followed by UV irradiation. Successful assemblies of graphene oxide (GO) and titania nanosheets in sequence with polyethylenimine as a linker is confirmed by UV–vis absorption and X‐ray diffraction. Photocatalytic reduction of GO into G can be achieved upon UV irradiation. Ultrafast photocatalytic electron transfer between the titania and graphene is demonstrated using femtosecond transient absorption spectroscopy. Efficient exciton dissociation at the interfaces coupled with cross‐surface charge percolation allows efficient photocurrent conversion in the multilayered Ti_0.91O₂/G films.     

Intrinsic scattering and absorption losses of Ge- and F-doped optical fibres prepared by PCVD

The scattering absorption and profile losses of PCVD fibres are analysed. The Rayleigh scattering increases proportionally to the sum of the F- and Ge-dopant concentrations, the UV absorption is proportional to the Ge concentration, and profiling losses are negligible.<>     

Changes occurring on the cell surface during KSHV reactivation

Following an infection, Kaposi's sarcoma-associated herpes virus (KSHV) exists predominantly in its latent state, with only 1-2% of infected cells undergoing lytic reactivation. We have previously demonstrated along with others a relationship between lytic reactivation and cell cycle progression (Bryan et al., 2006. J. Gen. Virol. 87: 519; McAllister et al., 2005. J. Virol. 79: 2626). Infected cells in the S phase are much more likely to undergo lytic reactivation when compared to those in G(0)/G(1) phase. Through the use of scanning electron microscopy (SEM), we analyzed changes occurring on the surface of cells undergoing KSHV reactivation. KSHV reactivation was observed predominantly in cells with smoother surface topology; a hallmark of cells derived from S phase. Interestingly, during the late stages of the reactivation process, we observed KSHV particles to egress cells through budding. Taken together, based on scanning electron microscopy and transmission electron microscopy evidences, we demonstrate for the first time the existence of a direct link between cell surface topology, cell cycle progression and KSHV reactivation.     

Porous Silicon Films Micropatterned with Bioelements as Supports for Mammalian Cells

Porous silicon (pSi) surfaces have been chemically patterned via a UV initiated hydrosilylation reaction of an alkene through a photomask, introducing chemical functionality in the exposed surface areas. A secondary, UV initiated hydrosilylation reaction with a second alkene of different functionality is performed to backfill the silicon hydride terminated regions on the surface, thereby affording patterned porous films with dual, surface chemistry. UV initiated hydrosilylations were performed using the alkene undecylenic acid N‐hydroxysuccinimide (NHS) ester, and the pSi surfaces were stabilized by a second hydrosilylation reaction with a polyethylene glycol (PEG) appended alkene. NHS ester and PEG functionalized surfaces were used for the selective immobilization of the cell adhesion mediator protein fibronectin (FN), in the NHS‐functional regions. Matrix‐assisted laser desorption/ionization mass spectrometry imaging on the protein functionalized pSi surface confirmed the patterned conjugation of the FN to the NHS functionalized regions. Mammalian cells cultured on these surfaces showed attachment that was confined to the patterned areas of FN on the pSi surface.     

Optimal sizing and life cycle assessment of residential photovoltaic energy systems with battery storage

This paper presents the optimal sizing and life cycle assessment of residential photovoltaic (PV) energy systems. The system consists of PV modules as the main power producer, and lead–acid batteries as the medium of electricity storage, and other essential devices such as an inverter. Five‐parameter analytic PV cell model is used to calculate the energy production from the modules. Electrical needs for a family living under normal conditions of comfort are modelled and used within simulation of the system performance, with an average daily load of approximately 9·0 kWh. The system's performance simulations are carried out with typical yearly solar radiation and ambient temperature data from five different sites in Turkey. The typical years are selected from a total of 6 years data for each site. The life cycle cost of the PV system is analysed for various system configurations for a 20‐year system life. The role of the batteries in PV energy systems are analysed in terms of the cost and power loss. The system performance is analysed as a function of various parameters such as energy production and cost. It is shown that these change substantially for different system configurations and locations. The life cycle assessment of the energy system described was also carried out to determine the environmental impact. It was found that, with the conservative European average electricity mix, energy pay back time (EPBT) is 6·2 years and CO₂ pay back time is 4·6 years for the given system. Copyright © 2007 John Wiley & Sons, Ltd.     

乳腺疾病患者血清的紫外吸收谱分析

测量了不同乳腺疾病患者血清的紫外吸收谱。人血清的紫外吸收谱约在230nm附近有一极强的吸收峰,在279nm有一较强的吸收峰,该吸收峰为蛋白质芳香族氨基酸的特征,在253nm有吸收谷。分析表明,不同乳腺疾病患者血清的紫外吸收谱有差异。血清紫外吸收谱的279nm吸收峰位及1279／1253的差异,反映了样品中芳香族氨基酸的成分及含量的差异;有无414nm吸收峰的差异主要反映了样品是否有溶血发生。这些光谱差异对于乳腺疾病光谱诊断的研究具有参考价值,为应用光谱技术进行血清检测,诊断疾病寻求简便的方法和途径。     

Design of Ag nanograting for broadband absorption enhancement in amorphous silicon thin film solar cells

Light trapping is one of the key issues to improve the light absorption and increase the efficiency of thin film solar cells. The effects of the triangular Ag nanograting on the absorption of amorphous silicon solar cells were investigated by a numerical simulation based on the finite element method. The light absorption under different angle and area of the grating has been calculated. Furthermore, the light absorption with different incident angle has been calculated. The optimization results show that the absorption of the solar cell with triangular Ag nanograting structure and anti-reflection film is enhanced up to 96% under AM1.5 illumination in the 300–800 nm wavelength range compared with the reference cell. The physical mechanisms of absorption enhancement in different wavelength range have been discussed. Furthermore, the solar cell with the Ag nanograting is much less sensitive to the angle of incident light. These results are promising for the design of amorphous silicon thin film solar cells with enhanced performance.