医学图像中粘连细胞分割方法研究

研究粘连细胞图像的分割问题。针对医学细胞图像中,细胞经常发生粘连,细胞粘连部分由于发生像素灰度混合,造成图像不清晰。传统的应用灰度的分割算法由于不能很好的区分粘连部分的灰度,不能完整的分割细胞的问题。为了解决上述问题,提出了自适应阀值调整的粘连细胞分割方法。通过求得粘连部位的细胞像素的具体特征,运用阀值的自适应变化区分粘连部位像素之间的不同,对像素进行划分,克服了传统方法像素划分不清的弊端。实验表明,方法能够有效的分割医学图像中的粘连细胞,取得了比较好的效果。     

Simulated Microgravity Inhibits the Proliferation of Chang Liver Cells by Attenuation of the Major Cell Cycle Regulators and Cytoskeletal Proteins

Simulated microgravity (SMG) induced the changes in cell proliferation and cytoskeleton organization, which plays an important factor in various cellular processes. The inhibition in cell cycle progression has been considered to be one of the main causes of proliferation inhibition in cells under SMG, but their mechanisms are still not fully understood. This study aimed to evaluate the effects of SMG on the proliferative ability and cytoskeleton changes of Chang Liver Cells (CCL-13). CCL-13 cells were induced SMG by 3D clinostat for 72 h, while the control group were treated in normal gravity at the same time. The results showed that SMG reduced CCL-13 cell proliferation by an increase in the number of CCL-13 cells in G0/G1 phase. This cell cycle phase arrest of CCL-13 cells was due to a downregulation of cell cycle-related proteins, such as cyclin A1 and A2, cyclin D1, and cyclin-dependent kinase 6 (Cdk6). SMG-exposed CCL-13 cells also exhibited a downregulation of α-tubulin 3 and β-actin which induced the cytoskeleton reorganization. These results suggested that the inhibited proliferation of SMG-exposed CCL-13 cells could be associate with the attenuation of major cell cycle regulators and main cytoskeletal proteins.     

Ozone Contactor Hydrodynamics

Tracer tests were conducted at the 6,000 pounds of ozone per day Tucson, CAP Water Treatment Plant in Tucson, Arizona. The tests were designed to determine T₁₀ values through the contactors at various operating conditions. The tests were modeled using three techniques. Peclet Number was calculated for each of the runs, which would indicate the hydrodynamic conditions inside the ozone contactor. The results indicated that the increase in water flow rate and the number of cells with gas flow increased Peclet Number. The flow rate of liquid seemed to impact the Peclet Number more than gas flow. The headloss in each cell appeared to be important in controlling the distribution of liquid and gas through the cell. A correlation was developed between the product of gas and liquid phase Reynolds Number and Peclet Number.     

Preparation and cell-materials interactions of plasma sprayed strontium-containing hydroxyapatite coating

The use of strontium-containing hydroxyapatite (Sr-HA) as a biomaterial has been reported recently. In vitro and in vivo studies have shown that Sr-HA promotes osteoblast response and stimulates new bone formation. In order to extend its usage to major load-bearing applications, such as artificial hip replacement, it has been proposed that the material could be used in the form of a coating on implant surfaces. This paper reports a preliminary study of biocompatibility of plasma sprayed Sr-HA coatings on a metallic substrate. Coatings of Sr-HA containing 10 mol% Sr²⁺ was produced on titanium alloy substrates. The coating exhibited good bonding with the substrate. The bioactivity of Sr-HA coating was evaluated in vitro by immersion in simulated body fluid (SBF). After immersion in SBF, Sr-HA coating exhibited great ability to induce apatite precipitation on its surface. The possible effects of cell-materials interactions of Sr-HA coating were examined by culturing osteoprecursor cells (OPC1) on coating surfaces. The effect of Sr-HA was also compared to a hydroxyapatite (HA) coating, which is widely used in orthopedics and dentistry. The results indicated that Sr-HA coating had good biocompatibility with human osteoblasts. OPC1 cells survived and proliferated well on the surface of coating. Sr-HA coating promoted OPC1 cells attachment, and more local contacts were produced on the surface. The presence of Sr stimulated OPC1 cell differentiation and ALP expression. No deleterious effect on ECM formation and mineralization was found with Sr-HA coating. The results indicated that Sr-HA coating had good mechanical properties and bioactivity in vitro.     

痰液显微图像细胞边缘提取的数学形态学新方法

根据痰液细胞图像的边缘灰度变化特点,在经典微分算子检测基础上,运用适当的改进的数学形态学方法对痰液细胞进行边缘提取。在实验中对同一幅痰液细胞图像分别用Sobel算子、Roberts算子、Laplacian算子和基于数学形态学的方法进行边缘检测。结果表明,基于数学形态学的边缘提取算法对于痰液细胞图像边缘提取有很好的效果。     

X射线照射对人树突状细胞免疫功能的影响

采用免疫荧光标记、流式细胞仪、3^H-TdR掺入和MTT技术，研究χ射线照射对人外周血来源的树突状细胞（DCs）和T细胞免疫功能的影响。结果显示，不同剂量（0．1～0．5Gy）χ射线照射后使DCs的HLA-DR、CD86和CD40分子表达上调，CD80分子表达下调；与其他剂量组相比，O．2Gy照射DCs可调节T细胞CD4／CD8比值，增强T细胞的增殖能力，同时还可提高特异性CTL细胞的杀伤能力。说明0．2Gyχ射线体外照射可一定程度提高受辐射损伤机体的免疫功能，是体外处理治疗性DCs较为合理的剂量。