基于球形标记的多模态医学体配准

本文提出在医学多模态数据集 (尤其是 MRI和 CT)中基于球形人造标记的体配准过程。此过程或是半自动或是全自动完成的。半自动方法要求数据集中标出球形标记的近似点位置 ,再自动进行配准。全自动方法不需要用户的任何交互操作 ,即所有配准子任务 (球体的分割、寻找两组球体的对应关系、最后把第一套球体映射成第二套球体的几何变换的计算 )能由计算机自动执行。在全自动配准中 ,积聚器算法和迭代最近点算法的结合证明是一种有效的和鲁棒性好的点匹配方法     

食管肿瘤干细胞抗辐射特性的实验研究

目的 :探讨食管肿瘤干细胞的抗辐射特性。方法 :采用无血清培养基培养人食管癌细胞ECA109,分离食管肿瘤干细胞,MTT法检测不同浓度环氧化酶-2选择性抑制剂NS398(2.5、5.0、10.0、20.0、40.0、80.0μmol/L)对细胞增殖的抑制作用,克隆形成实验检测亲本细胞和细胞球的增敏效应,成球实验分析NS398联合X线照射对细胞成球能力的影响,Western blot检测细胞β-catenin蛋白的表达水平。结果:NS398对亲本细胞和细胞球的增殖抑制作用均具有时间、浓度依赖性。20μmol/L NS398作用后,亲本细胞Do、Dq和SF2值均减小(P<0.05),放射增敏比(sensitization enhancement ratio,SER)为1.17;20μmol/L NS398作用后,细胞球Do、SF2减小(P<0.05),SER为1.12。照射使ECA109细胞成球率增加(P<0.05)。NS398联合X线照射组与单纯照射组相比,细胞成球率显著降低(t=7.01,P<0.01),亲本细胞和细胞球β-catenin的表达水平均降低(t=10.15,P<0.01;t=3.225,P<0.05)。结论 :细胞球的增敏效应小于亲本细胞,具有抗辐射特性,其机制可能与抑制细胞β-catenin蛋白表达有关。     

离子液体辅助合成磁性介孔炭微球及其对萘普生释放的影响

目的 考察磁性介孔炭对萘普生的吸附与释放行为.方法 通过简单的原位一锅法,以绿色溶剂离子液体辅助合成磁性介孔炭微球,通过N2吸附SEM、大角XRD和拉曼光谱对磁性介孔炭微球进行表征;并考察不同pH条件下,磁性介孔炭微球对萘普生释放的影响.结果 随着Fe(NO3)3·9H2O用量的增大,磁性介孔炭微球的比表面积、孔径及孔容逐渐减小.磁性介孔炭微球大大提高了萘普生的释放速率,且累积释放率随着Fe-C的比表面积和孔容的增大而增大.在所研究的pH范围内(5.0,6.8,8.0),当pH=8,0时,萘普生在Fe-C-1上的载药量最高、释放最快,且累积释放速率最大.结论 萘普生在磁性介孔炭微球上的释放分为3个阶段:第1阶段为中孔扩散,表面扩散过程占主导地位;第2阶段为孔L隙扩散速率限制阶段,是萘普生被吸附进炭微球的内部毛孔后再逐渐释放的过程;第3阶段为释放平衡状态.     

Study of the influence of coating methods on lipid spheres manufactured on rotor fluidized bed process

Abstract

Different previous works have shown that various kinds of spheres can be manufactured by rotor granulation in a ‘single-pot process’ using a lipid base: hydrogenated castor oil. This single-pot technology is based on wet granulation where all components are placed in the powder form in the rotor bowl; then, they are continuously suspended in a fluidized air, with a tangentially sprayed liquid solution. This process allows the granulation and manufacturing of sphere during the same time. Previous experiments have studied the influence of the formulation and the manufacturing process parameters on spheres in terms of feasibility and dissolution properties. Both the spraying time and the weight of liquid sprayed were found to be the most relevant parameters that govern the final quality of the sphere. Now, in a second part of the work, a first comparison is made with two different fluid bed methods: the tangential rotor spray and the Wurster bottom spray for coating the lipid spheres previously manufactured with the rotor tangential spray. The external aspect of the coated spheres manufactured has been evaluated with an electronic microscopy analysis and a study of dissolution properties of the active ingredient has been done by USP in vitro dissolution tests.     

放疗耐受的宫颈癌Hela细胞的生物学特性

 【目的】研究耐放疗的宫颈癌Hela细胞生物学特性的改变,并探讨其与宫颈癌肿瘤干细胞间的关系。【方法】采用多次分割剂量照射技术建立宫颈癌Hela细胞的耐放疗模型（Hela-R）,实验分4组：Hela-R1组,Hela-R2组,Hela-R3组和对照组。四甲基偶氮唑蓝法检测细胞生长情况,克隆形成实验测定放射敏感性和克隆能力,流式细胞术检测细胞周期分布和增殖能力,球囊培养法检测细胞自我更新能力。【结果】Hela、Hela-R细胞接受照射后均呈现先加速增殖后出现生长抑制的现象。Hela-R1、Hela-R2、Hela-R3的细胞倍增时间分别为（43.4±1.0）h、（49.2±2.0）h和（48.7±3.3）h,克隆形成率分别为（20.3±4.0）%、（49.3±11.6）%和（6.3±5.9）%,S期细胞比例分别为（9.9±0.4）%、（13.0±0.9）%和（9.6±0.7）%,增殖指数（PI）分别为（27.3±2.6）%、（31.8±4.9）%和（37.4±8.0）%。与对照组比较,Hela-R3组的放射抗拒性增强。非粘附性球囊培养法培养Hela及Hela-R细胞可得到肿瘤细胞球,四组的球囊形成率分别为（9.9±0.4）%、（13.0±0.9）%、（9.6±0.7）%和（5.0±0.3）%。【结论】多次分割剂量照射可在体外建立宫颈癌Hela细胞的耐放疗模型,并可富集肿瘤干细胞;多次分割照射后,Hela细胞生长速度减慢,增殖能力有升高趋势,自我更新能力、克隆能力增强,细胞周期无明显变化。     

Properties controlling the difusion and release of water-soluble solutes from poly(ethylene oxide) hydrogels: 3. Device geometry

The diffusive release from hydrogels can be determined by both composition and geometry. This paper presents a theoretical and experimental comparison of the release characteristics of proxyphylline in water-swollen slabs, spheres, and cylinders of a urethane cross-linked poly(ethylene oxide). Contrary to general conventional wisdom it was found that practically cylinders and spheres, which have considerable potential advantages for oral delivery, can provide good 'anomalous' rates for which the 'exponent of release' into water from the dry xerogels is c. 0.8 compared with 1.0 for zero order. An exponent of 0.94 was found for release into water from 'larger' xerogel flat slabs thus confirming that these configurations can provide essentially constant delivery formulations from which the active agent cannot be 'dumped'. For up to 40% total drug release, the theoretical release profiles were essentially of identical form for all three geometries in the swollen state and, as expected in theory and practice, showed an exponent for release of close to 0.5. However, the experimental release of proxyphylline was found to be more sustained from swollen spheres of these polymers than theory would predict. The half life times for release were further extended by approximately two and a half times for the initially dry devices compared with the initially swollen ones.     

T(2)-shortening by strongly magnetized spheres: a chemical exchange model.

It is shown that a chemical exchange model can reproduce nuclear magnetic relaxation caused by diffusion of water molecules near strongly magnetized particles. The agreement is based on the similarity (but not equivalence) of the respective "visit-limiting" mechanisms in the echo-limited regime. The model leads to a single equation that predicts relaxation behavior in both the motional-averaging and visit-limited regimes. When combined with the static-dephasing regime equation, the result is a simple theory (for spheres) that covers the entire range of diffusion times.     

HT29和HCT116结肠癌细胞无血清培养形成肿瘤干细胞球特性的差异性研究

目的比较HT29和HCT116两种结肠癌细胞系中肿瘤干细胞的差异，初步探讨结肠癌干细胞研究模型。方法以无血清培养法培养HT29和HCT116细胞，观察其在不同时间形成肿瘤干细胞球的差异，用限制性稀释法计算两者的成球率；流式细胞术分析HT29和HCT116细胞系中CD44／CD24的表达情况；裸鼠体内成瘤实验鉴定HT29细胞球与HCT116细胞球成瘤能力。结果无血清培养法发现HCT116较HT29更易形成肿瘤干细胞球且所需时间更短，即HT29在无血清培养的第7天开始形成规则的球体，而HCT116则在第5天就已形成规则的球体，HCT116成球率（11．4±1．15）％高于HT29（3．31±0．27）％，且差异有统计学意义（P〈0．05）；HT29和HCT116中CD44±／CD24±各细胞含量有显著差异，结果显示具有干细胞特性的CD44＋／CD24＋结肠癌细胞在HCT116中所占比例（60．33±5．75）％明显高于HT29（9．23±2．15）％，差异有统计学意义（t=13．939，P〈0．05）；体内成瘤实验发现HCT116细胞球在裸鼠体内的成瘤能力明显强于HT29细胞球，HCT116细胞球的成瘤速度及瘤体生长速度都较HT29细胞球快。结论与HT29相比，HCT116结肠癌细胞系更适合作为肿瘤干细胞研究的模型。     

Photodeformable Microspheres from Methacrylate‐Based Azo Homopolymers

In this study, two methacrylate‐based azo homopolymers are synthesized and used to fabricate photodeformable microspheres through a self‐assembling approach. The methacrylate‐based azo homopolymer with the narrow molecular weight distribution is synthesized by reversible addition fragmentation chain transfer polymerization, while the other with the relatively broad molecular weight distribution is synthesized by conventional radical polymerization. The azo polymers are characterized by proton nuclear magnetic resonance (¹H‐NMR), Fourier transform infrared spectroscopy (FT‐IR), differential scanning calorimetry (DSC), thermal gravimetric analysis TGA, gel permeation chromatography GPC, and ultraviolet‐visible spectroscopy (UV–vis) m. The colloidal spheres are obtained by gradually adding deionized water into the solutions of the azo polymers in N ,N‐dimethylformamide. Laser light scattering analysis and transmission electron microscopy observations show that although both azo polymers can form uniform colloidal spheres in the dispersions, the molecular weight and its distribution show significant effects on the colloid formation process and the sizes of the colloidal spheres formed in the process. Upon irradiation with a linearly polarized Ar⁺ laser beam for a period of time, the azo polymer microspheres show the elongated deformation along the polarization direction of the actinic light.