耳蜗微血管内皮细胞通透性体外模型的研究

目的 建立豚鼠耳蜗微血管内皮细胞通透性体外模型。方法 采用活体组织细胞分离及培养技术 ,获取培养的豚鼠耳蜗微血管单层融合内皮细胞 ,免疫组化法检测内皮细胞标志物Ⅷ因子鉴定培养细胞的性质及其纯度 ,小池技术构建通透模型 ,以脑微血管内皮细胞通透模型为阳性对照、肺微血管内皮细胞通透模型为阴性对照和无内皮细胞的小池为空白对照 ,12 5I标记牛血清白蛋白检测本模型的通透性特点。结果 ①耳蜗血管纹组织块培养后 2d ,边缘即有细胞生长 ,之后细胞数量逐渐增多 ,10d左右细胞增殖成数个细胞集落 ;纯化后 ,单个培养细胞一般呈梭形 ,传代细胞培养 8d后 ,细胞增殖形成片状单层 ,紧密排列 ,显微镜下呈现培养内皮细胞典型的“铺路石”样外观。免疫组化检查 ,95 %以上的培养细胞胞浆有桔黄色着色 ,呈阳性反应 ,而对照组无此着色。②实验组对牛血清白蛋白的通透性大于阳性对照组 (P <0 0 5 ) ,小于阴性对照组和空白对照组 (P <0 0 1)。结论 建立的豚鼠耳蜗微血管内皮细胞通透性体外模型适合于耳蜗微血管内皮细胞通透性的研究 ,为今后研究血迷路屏障通透性及其调控机理奠定了良好的基础。

马铃薯糖苷生物碱的抑菌活性及其对菌体细胞膜透性的影响

【目的】通过探究马铃薯糖苷生物碱对几种经济林病原真菌的抑菌活性及其可能的作用机理,为其在植物病害的无公害防治应用中提供理论依据.【方法】采用生长速率法,测定其对3种常见经济林植物病原真菌:腐皮镰刀菌(Fusarium solani),核桃盘二孢(Marssonina juglands),煤炱菌(Capnodiume leaophilum)的抑菌活性,并以腐皮镰刀菌为试材,应用电导仪测定其对菌体细胞膜通透性的影响.【结果】当马铃薯糖苷生物碱质量浓度为2g/mL时的抑菌效果最好;其中对腐皮镰刀菌的抑菌活性最强,其EC50为0.268 0g/mL,煤炱菌次之,对核桃盘二孢(Marssonina juglands)抑菌活性最弱,EC50为1.490 7g/mL;通过菌体细胞液电导率的测定,发现马铃薯糖苷生物碱作用下,腐皮镰刀菌菌体的相对渗透率增加了25.2%.【结论】马铃薯糖苷生物碱提取液对3种供试真菌均具有一定的抑菌活性,以对腐皮镰刀菌的抑制效果最佳,并引起其菌体细胞膜透性的增强.

豚鼠耳蜗微血管内皮细胞体外通透性的研究

目的 研究豚鼠耳蜗微血管内皮细胞的体外通透性特征。方法 在成功建立豚鼠耳蜗微血管内皮细胞体外通透性模型的基础上 ,研究该体外模型跨细胞电阻及对12 5I 牛血清白蛋白的通透性。结果 ①耳蜗微血管内皮细胞在培养增殖过程中其跨细胞电阻呈动态变化过程 ,以 5× 10 4/cm2 的细胞密度接种时 ,7d左右电阻到达峰值 ,其跨细胞电阻峰值大小为 (118 9± 18 5 )Ω/cm2 ;②体外模型中加入12 5I 牛血清白蛋白后 ,其通透性呈上升期抛物线型曲线 ,90min内几乎呈直线。结论 跨细胞电阻及对12 5I

豚鼠耳蜗微血管内皮细胞的体外通透性

目的 研究豚鼠耳蜗微血管内皮细胞的体外通透性特征。方法 (1)用小池技术建立起内皮细胞通透性的体外模型 ;(2 )研究该体外模型耳蜗微血管内皮细胞的跨细胞电阻及对12 5I 牛血清白蛋白的通透曲线 ,并与脑及肺的内皮细胞通透性进行对照。结果 (1) 3种内皮细胞的体外模型中加入12 5I 牛血清白蛋白后 ,贝克 时间变化图均呈抛物线型上升曲线 ,其通透性从小到大依次为脑、耳蜗、肺内皮细胞 ,各组间相差显著 (P <0 .0 1) ;(2 )耳蜗、脑及肺 3种内皮细胞在培养增殖过程中其跨细胞电阻呈动态增加过程 ,以 5× 10 4/cm2 的细胞密度接种时 ,7d左右电阻均到达峰值 ,其跨细胞电阻峰值大小分别为脑 (2 4 4 .7± 4 6 .9Ω/cm2 ) >耳蜗 (118.9± 18.5Ω/cm2 ) >肺 (4 6 .6± 5 .9Ω/cm2 ) ,且各组间相差显著 (P <0 .0 1)。结论 该模型下耳蜗微血管内皮细胞的通透性与其活体时的通透性特征基本一致。

线粒体通透性转变孔道与神经系统疾病

线粒体通透性转变孔道被认为可能主要由位于线粒体外膜的电压依赖性阴离子通道(voltage—dependent anion channel,VDAC)、位于内膜的腺苷酸转移酶(adenine nucleotide translocase,ANT)和位于线粒体基质的亲环素D(cyclophilin-D,CyP—D)组成。多种因素可以调节该孔道的形成和开放,包括小分子物质、信号传导通路以及蛋白与蛋白的相互作用。线粒体通透性转变孔道开放将增加线粒体内膜的通透性,导致线粒体功能紊乱,这一变化可能参与了神经系统疾病的病理发展过程。

钝顶螺旋藻部分原生质体及单细胞的制备与培养

于1992年1月-1994年4月，进行超声波处理方法制备钝顶螺旋藻部分原生质体以作为基因工程受体，以及制备单细胞用于固体平板克隆化培养的研究。研究结果表明：超声波以20kHz频率、15W功率作用30s，可使藻丝体断裂成15．0±1．6个细胞长度；延长作用时间，至2－6个细胞长度时，细胞壁结构遭到破坏，形成部分原生质体；继续作用，可形成少量原生质体和大量单细胞。断裂藻丝体、部分原生质体、单细胞以及原生质体均可涂布于固体培养基上再生或生长。以一定密度涂布单细胞与原生质体，能够形成彼此分开的单个克隆，可用于筛选及遗传分析。本文提供了一种节省溶菌酶的制备螺旋藻透性体的方法，超声波作用利于外源基因的导入，而涂布培养利于进一步的筛选和形成克隆。

The Study of Dipivefrin Hydrochloride Ophthalmic Gel

Dipivefrin hydrochloride ophthalmic gel was prepared and the release test and the isolated cornea permeation test of the formulation in vitro were investigated. The release test of the formulation was studied by using permeable membrane. The content and the release amount of Dipivefrin hydrochloride from the gel base were measured by high performance liquid chromatography. The cornea permeation test of the formulation was studied by using isolated rabbit corneas. The formulation release behavior in vitro followed the first-order kinetic equation. The release amount of Dipivefrin hydrochloride raised significantly with less polymer in the formulation. The cornea permeation behavior of the drug in vitro followed the first-order kinetic equation. The eye irritancy of Dipivefrin hydrochloride gel is lower than that of eyedrops.

Characterization of Energy_Transduction in Thermal Pretreated Chloroplast from Spinach

Characterization of energy-transduction on die chloroplast thylakoid membranes from spinach (Spinacia oleracca L.) after thermal pretreatment was investigated. The related reactions of energy-transduction in chloroplasts were seriously affected by thermal pretreatment. The results were obtained as following: (1) The rate of cyclic photophosphorylation declined when the pretreatment temperature increased in the range of 25 to 45 degreesC. (2) The thermal pretreatment led to a decrease of the activity of thylakoid membrane-bounded ATPase. (3) Proton uptake of chloroplasts acid the fluorescence quenching of 9-aminoacridine (9-AA) in thylakoid membrane decreased after the thermal pretreatment, but addition of dicyclohexylcarbodiimide (DCCD) could partially restore the fluorescence quenching of 9-AA. (4) Both the rates of fast phase in electrochroism absorption change at 515 nm and the millisecond delayed light emission (ms-DLE) of chloroplast showed a progressive decrease upon raising the temperature of pretreatment. (5) Immunbloting analysis showed that the thermal pretreatment caused the changes of protein content and the electrophoresis mobility of thylakoid membrane-bound ATPase and its alpha -subunit. (6) If the temperature of pretreatment were higher than 33 degreesC, oxygen uptake of PS I -mediated in the samples was rapidly inhibited, but addition of sinapine into the reaction medium could partially restore the ability of oxygen uptake in the samples. These results are briefly discussed in relation to the change of permeability of thylakoid membranes, the dissociation of coupling factor complex as well as accumulation of the radicals in the thylakoid membranes after thermal pretreatment.

The Effect of pH on the Permeation of Lidocaine Hydrochloride Across Excised Rat Skin

The effect of pH on the permeation of Lidocaine hydrochloride (LH) across excised rat skin was studied, the steady state flux (JSS) at different pH being determined using improved Valia-Chien diffusion cells. JSS increased substantially when pH was close to the pKa of LH. The profile of JSS versus pH showed an 慡?shaped curve. JSS of Lidocaine free base (LFB) was fourteen times that of LH. The pH of vehicle influences the permeation of LH significantly and should be considered as an important factor when a formulation is developed.

Expression and Identification of Mycoplasma penetrans P35 Lipoprotein

Objective: To study the biological activity of Myco-plasma penetrans 35kDa lipoprotein(P35) in vitro, prokaryotic expression vector pQE31//p35 was constructed and recombinant fusion protein P35 (rP35) was expressed in E.coli. Methods: The p35 gene was amplified by polymerase chain reaction(PCR), cloned to pQE31, and a positive clone was screened. PCR-mediated mutagenesis was used to change the two "TGA" triplets to "TGG" triplets within the p35 gene. Production of the recombinant protein was induced by the addition of IPTG to the E.coli culture. rP35 was purified with a Ni-NTA Spin Kit and rP35 purification was analyzed by Western blot. Results: About 1Kb PCR amplification was cloned into pQE31. The two "TGA" triplets within the p35 gene were successfully changed to "TGG" triplets. The pQE31/p35 vector expressed a protein with a calculated molecular mass of 37.4kDa in E.coli. Western blot indicated the 37.4kDa protein was rP35 . Conclusion: PQE31/p35, a prokaryotic expression vector containing p35 gene, was successfully constructed and expressed in E.coli.

Numerical modelling rock deformation subject to nitrogen cooling to study permeability evolution

How to model the permeability evolution of rock subjected to liquid nitrogen cooling is a key issue. This paper proposes a simple but practical method to study the permeability evolution of rocks subject to liquid nitrogen cooling. FLAC with FISH function was employed to numerically model the rock behavior under cooling. The enhanced perme- ability of the volumetric strain was defined, and the permeability was directly evaluated based on element＇s volumetric strain. Detailed procedures for implementing the evolution model of permeability in this paper were presented. A case study was carried out to simulate a coal bed where liquid nitrogen was injected in the bore hole. And a semi-submerged test of liquid nitrogen was performed. The method to model the permeability evolution of rocks subject to liquid nitrogen shock in this paper was proved to be right by the test results. This simulation results are discussed with the hope to provide some insight into understanding the nitrogen cooling practice.

Numerical Investigation of Penetration Performance of Non-Ideal Segmented-Rod Projectiles

The design of a segmented-rod projectile is often simplified into an ideal one in theoreti-cal analysis for the convenience of modeling of its performance.But the actual performance of non-ideal segmented-rod projectiles over the impact velocity range in practical applications was rarely explored.AUTODYN numerical code is used to investigate the influence of the component design upon the penetration performance of non-ideal segmented-rod projectiles over a wide range of impact velocities,which can be used to guide the optimal design of weaponry segmented-rod projectiles.

Permeability and Selectivity of Sulfur Dioxide and Carbon Dioxide in Supported Ionic Liquid Membranes

Permeabilities and selectivities of gases such as carbon dioxide （CO2）, sulfur dioxide （SO2）, nitrogen （N2） and methane （CH4） in six imidazolium-based ionic liquids （[emim][BF4], [bmim][BF4], [bmim][PF6], [banim][BF4], [bmim][Tf2N] and [emim][CF3SO3]） supported on polyethersulfone microfiltration membranes are investigated in a single gas feed system using nitrogen as the environment and reference component at temperature from 25 to 45℃ and pressure of N2 from 100 to 400 kPa. It is found that SO2 has the highest permeability in the tested supported ionic liquid membranes, being an order of magnitude higher than that of CO2, and about 2 to 3 orders of magnitude larger than those of N2 and CH4. The observed selectivity of SO2 over the two ordinary gas components is also striking. It is shown experimentally that the dissolution and transport of gas components in the supported ionic liquid membranes, as well as the nature of ionic liquids play important roles in the gas permeation. A nonlinear increase of permeation rate with temperature and operation pressure is also observed for all sample gases. By considering the factors that influence the permeabilities and selectivities of CO2 and SO2, it is expected to develop an optimal supported ionic liquid membrane technology for the isolation of acidic gases in the near future.

A method of determining the permeability coefficient of coal seam based on the permeability of loaded coal

This study developed the equipment for thermo-fluid–solid coupling of methane-containing coal, and investigated the seepage character of loaded coal under different working conditions. Regarding the effective pressure as a variable, the variation characteristics of the gas permeability of loaded methane-containing coal has been studied under the conditions of different confining pressures and pore pressures. The qualitative and quantitative relationship between effective stress and permeability of loaded methane-containing coal has been established, considering the adsorption of deformation, amount of pore gas compression and temperature variation. The results show that the permeability of coal samples decreases along with the increasing effective stress. Based on the Darcy law, the correlation equation between the effective stress and permeability coefficient of coal seam has been established by combining the permeability coefficient of loaded coal and effective stress. On the basis of experimental data, this equation is used for calculation, and the results are in accordance with the measured gas permeability coefficient of coal seam. In conclusion, this method can be accurate and convenient to determine the gas permeability coefficient of coal seam, and provide evidence for forecasting that of the deep coal seam.

A hybrid zeolitic imidazolate framework Co-IM-mIM membrane for gas separation

A zeolitic imidazolate hybrid membrane(Co-IM-mIM) containing two imidazolate ligands deposited on a macroporous α-alumina support was prepared by pre-depositing and secondary growth technique. XRD, TGA and SEM characterizations demonstrate that a stable and thin, but dense and pure-phase Co-IM-mIM membrane can be obtained on the macroporous-alumina discs in Teflon-lined autoclave at 120 °C after pre-depositing by dip-coating at room temperature. No visible cracks, pinholes or other defects were observed on the membrane layer. The gas separation studies of Co-IM-mIM membrane were carried out at 25 °C and 1×10~5 Pa, showing ideal selectivity of 6.95, 5.25, 3.40 for H_2/CO_2, H_2/N_2 and H_2/CH_4, respectively, and a permeance of 17.37× 10^(-6) mol/(m^2·s·Pa) for H_2. The influence of temperature and trans-membrane pressure on hydrogen separation and permeation was also carried out. The gas permeation and selectivity demonstrate that this membrane may have potential applications for efficient H_2 separation.

XMT enabled prediction of structure and permeability of flocculated structures and sediments

3D visualisations of the microstructure of flocculated particulates and sediments using optical confocal laser mi- croscopy and high resolution X-ray microtomography (XMT) methods are described. Data obtained from in-situ measurements should enable direct computation of the properties of solids assembly (shape, size, contact area) and their permeability to fluids. A specific application relating to the formation of silica aggregates is described from which the behaviour of sediments containing these materials can be predicted on the basis of a bench-top test and the use of a Lattice Boltzman simulation. It is proposed that the method can potentially be used to predict trends such as the filtration behaviour of porous structures under different states of compression. This offers a significant benefit in assisting the formulation design of flocculated materials pertinent to a number of industrial sectors wishing to design optimal filtration or relevant operations.

Influence of green tea polyphenols on mitochondrial permeability transition pore and Ca^2＋ transport

The authors investigated the influence of green tea polyphenols (GTPs) on the liver mitochondria permeability transition pore (PTP) opening through mitochondria swelling and change of mitochondria membrane potential. The data showed that GTPs had obvious protective effect on the Ca 2+-induced PTP opening in a dose-dependent manner detected by mitochondria swelling. The results were obtained by measuring the change of mitochondria membrane potential through Rh 123. Further experiments were conducted to examine the detailed influence of GTPs on Ca 2+import and export of mitochondria. The results showed that GTPs had remarkably inhibitory effect on the Ca 2+-induced Ca 2+ import in mitochondria; and that they could accelerate Ca 2+-release from mitochondria. Our data provide an alternate interpretation of the potent protective function of GTPs on cell against apoptosis.

Ceramic Supported PDMS and PEGDA Composite Membranes for CO2 Separation

Composite membranes have attracted increasing attentions owing to their potential applications for CO2 separation. In this work, ceramic supported polydimethylsiloxane （PDMS） and poly （ethylene glycol） diacrylate （PEGDA） composite membranes were prepared. The microstructure and physicochemical properties of the compos- ite membranes were characterized. Preparation conditions were systematically optimized. The gas separation performance of the as-prepared membranes was studied by pure gas and binary gas permeation measurement of CO〉 N2 and H〉 Experiments showed that PDMS, as silicone rubber, exhibited larger permeance and lower separation factors. Conversely, PEGDA composite membrane presented smaller gas permeance but higher ideal selectivity for CO2/N2. Compared to the performance of those membranes using polymeric supports or freestanding membranes, the two kinds of ceramic supported composite membranes exhibited higher gas permeance and acceptable selectivity. Therefore, the ceramic supported composite membrane can be expected as a candidate for CO2 separation from light gases.

Experimental study on gas permeability by adsorption under 3D-stress

Using self-developed gas-seepage experimental installation,under the sameeffective stress conditions,coal permeability experiments on different adsorption characteristicsof gases,different temperatures and different gas adsorption contents were performed,and the influence law of adsorption on coal permeability was studied.At the sametime,experimental analogy showed clearly that gas drawing plucks the permeability variationlaw.The results show that adsorption has a major impact on coal permeability.Thegreater the adsorption,the more the gas adsorption capacity and the coal permeabilitybecomes smaller.Permeability becomes smaller along with confining of pressure andtemperature,and this is in accord with local practice results.