Coarse grained molecular dynamics and theoretical studies of carbon nanotubes entering cell membrane

Motivated by recent experimental observations that carbon nanotubes （CNT） can enter animal cells, here we conduct coarse grained molecular dynamics and theoretical studies of the intrinsic interaction mechanisms between CNT＇s and lipid bilayer. The results indicate that CNT-cell interaction is dominated by van der Waals and hydrophobic forces, and that CNT＇s with sufficiently small radii can directly pierce through cell membrane while larger tubes tend to enter cell via a wrapping mechanism. Theoretical models are proposed to explain the observed size effect in transition of entry mechanisms.

A Method of Inversing the Peak Density of Atomic Oxygen Vertical Distribution in the MLT Region From the OI (557.7 nm)Night Airglow Intensity

In this paper, using the MSISE-90 model as the reference atmosphere, we discuss the feasibility and method of deducing the peak densities of the undisturbed atomic oxygen profiles in the MLT region (the mesosphere and lower thermosphere region) from OI (557.7 nm) night airglow intersities. The peak densities for different seasons, latitudes and longitudes are deduced from OI (557.7nm) airglow intensities through this expression. We analyze the features of inversion relative errors and discuss the influence of the variations in temperature on inversion errors. The results indicate that all inversion errors are less than 5% except for those at high altitudes in the summer hemisphere. And the impact of the variations in temperature on errors is not significant.

The Nonlinear Model of the Response of Airglow to Gravity Waves

In this paper, we develope a timodependent, nonlinear, photochemical-dynamical 2-D model which is composed of 3 models: dynamical gravity wave model, middle atmospheric photochemical model, and airglow layer photochemical model. We use the model to study the effect of the gravity wave propagation on the airglow layer. The comparison between the effects of the different wavelength gravity wave on the airglow emission distributions is made. When the vertical wavelength of the gravity wave is close to or is shorter than the thickness of the airglow layer, the gravity wave can make complex structure of the airglow layer, such as the double and multi-peak structures of the airglow layer. However, the gravity wave that has long vertical wavelength can make large scale perturbation of the airglow emission distribution.

纳米链霉素在小鼠结核病模型中的治疗作用研究

目的对比研究链霉素纳米制剂与普通制剂一硫酸链霉素注射液在小鼠体内肠胃外给药时的抗结核活性。方法雌性BALB／c小鼠尾静脉感染结核分枝杆菌H37Rv1×10^7CFU。感染后第二天开始按照空白对照组、阳性对照组、比较对照组和纳米链霉素SM-NPBSA组、纳米链霉素SM．NPCRM组的剂量和频率分别腹腔注射给药，给药至感染后28天。在感染的14、28、56天分别处死每组4只小鼠进行脾、肺活菌计数。结果SM-NPCRM组在整个实验期间的存活率是100％，SM-NPBSA组第28天和第56天的存活率分别为83％和75％。治疗14天时，比较对照组小鼠脾、肺的菌量较阳性对照组大，而SM--BSA与SM—CRM组小鼠脾、肺的活菌数较阳性对照组降低；治疗4周时，各组的活菌数与2周时相比没有明显变化，但SM．NPBSA与SM-NPCRM组的脾、肺活菌数均比比较对照组低，且具有统计学差异。感染8周时，SM-NPBSA、SM-NPCRM组肺的活菌数量仍比阳性对照组小，且具有统计学意义。结论纳米链霉素制剂SM-NPBSA、SM-NPCRM与普通链霉素注射液相比，在给药剂量与给药频率降低时，在小鼠急性结核病感染模型中表现的抗菌活性仍与阳性对照相当，值得进一步研究。