基于细胞状演化神经网络的黄河三角洲区域预测

将细胞状遗传算法( cGA)与反向传播( BP) 神经网络相结合, 构建了一个细胞状演化神经网络时间序列模型, 以 1984~ 2000年间的多时相遥感影像为主要数据源, 应用该模型对黄河口地区陆地面积进行预测, 并分析了其将来的演变 趋势. 结果表明, 在2001~ 2010年间研究区域陆地面积将呈现增长与蚀退交替演变、增长高峰逐渐下降的趋势.福建省青年科技人才基金项目( 2002 J005)资

An Dose Optimization Algorithm in Brachytherapy

高剂量率后装近距离治疗现在已成为放射治疗的常用方法之一,近距放射治疗计划系统的应用也越来越广泛,主要目的就是通过优化源的驻留位置和时间来改善剂量分布,提高治疗质量。提出了一种连续驻留位置和驻留时间的近距离放疗剂量优化算法。在插值路径为直线、照射源为点源的情况下,首先将驻留时间T看成是位置X的一个连续函数,计算每个参考剂量点的剂量,再用计算剂量和目标剂量值之差的加权平方和为目标函数,然后用复合型调优法求解最优的曲线参数。曲线可以根据具体情况进行分段,得到曲线后再用积分的数值逼近方法将其离散化,得到最终的驻留位置和驻留时间。实验结果表明,本算法不仅避免了负的驻留时间问题,还可使相邻驻留位置的驻留时间更加平滑;在最后的离散化过程中,可以得到不同的驻留位置和驻留时间结果,使计划具有更好的灵活性。Brachytherapy is an anti-tumor treatment by means of radioactive sources that are placed at short distances from the target tumor tissues and becoming more and more widely used.In this paper,we proposed an algorithm to optimize the dwell time of radioactive source for computer-based high-dose-rate afterloading implants planning system of brachytherapy.The dwell time was considered as a continuous function of the dwell position,calculated the dose values of referenced dose points.The minimal difference between these dose values and demanded dose values was used as the objective to get the optimized function parameters.The function curve could be separated to several sects.The optimized curve was dispersed using compound trapezoid formula to get the dwell positions and dwell times.This method could avoid the emergence of negative dwell time,and reduce the dwell time gradient as well.When dispersing the curves,different dwell times and dwell positions could be obtained,which made the brachytherapy treatment plan more flexible.国家自然科学基金资助项目(60371012、60701022

戊型肝炎病毒衣壳蛋白中和表位间的构象诱导

重组蛋白NE2包含了戊型肝炎病毒(HEV)衣壳蛋白(pORF2)的aa394～606片段。在NE2上已鉴定出了2个HEV中和表位,并获得了3个识别中和表位的单克隆抗体(MAb)8C11、13D8和8H3。这3个MAb间的交叉阻断ELISA实验发现,8C11和13D8可以彼此完全阻断,8H3对8C11和13D8均不能阻断,而8C11非但不能阻断8H3,反而显著增强了8H3与抗原的结合。用生物传感器进行的抗体与抗原结合的动力学分析也证实了这一现象。这些结果提示,在NE2上8H3表位区域受到抗原上某些结构的掩盖,而8C11与NE2的结合引起了抗原空间结构的改变,导致了掩盖8H3表位的结构的去除和8H3表位的充分暴露。免疫捕获RT PCR发现,8C11同样可以显著增强8H3对天然HEV病毒的捕获能力,提示这种结合诱导的衣壳蛋白空间构象改变在天然HEV病毒颗粒上同样存在

Computer Simulation of Nasopharyngeal Carcinoma Brachytherapy

近距离放疗是鼻咽癌治疗的主要手段之一。其计算机仿真可帮助医生制定详细的放疗方案,对鼻咽癌精确放疗具有显著意义。一个完整的鼻咽癌近距离放疗仿真的方案被提出。首先,对CT图像进行分割,重建三维组织模型。然后,设计了基于Ta-chih Lee细化算法的鼻咽腔放疗源虚拟输送路径。最后,对125I柱状放射源放射剂量分布进行了蒙特卡罗仿真。初步实现了鼻咽癌近距离放疗的计算机仿真。Brachytherapy is one of the major means of nasopharyngeal carcinoma treatments. Computer simulation of the process is of great value to radiotherapy planning. A complete solution for computer simulation of nasopharyngeal carcinoma brachytherapy was proposed. Firstly,the CT images of the nasopharyngeal tissues were segmented and the 3D models of nasopharyngeal tissues were reconstructed. Then the 3D delivery path of radioactive source based on Ta-chih Lee’s thinning algorithm was designed. Finally,the simulation of cylindrical 125I dose distribution was realized by Monte Carlo method. A primary computer simulation of nasopharyngeal carcinoma Brachytherapy was realized.国家自然科学基金项目(60601025);; 福建省科技重点项目(2005Y0018

Study for the Anterior Capsule of Human Crystalline Lens with Nonlinear Finite Element Analysis

在临床试验获得的形态数据和物理数据的基础上,建立了连续环形撕囊后前囊膜的物理模型,利用非线性有限元分析法对撕开口大小与囊膜最大拉伸长度之间的关系进行了仿真计算。结果表明,随撕开口的增大,囊膜所能承受的最大拉伸长度显著增加,最大拉伸状态下的撕开口周长Cr与撕开口初始周长Cc的比值(Cr/Cc)也增大。该结论与实验研究的结论一致,表明前囊膜的可拉伸性能随着撕开口的增大而增大。进一步分析指出,拉伸时,撕开口边缘处外力作用的范围会显著影响最大拉伸长度:外力作用范围越大,囊膜所能承受的最大拉伸长度也就越大;增大幅度随作用范围的增加而减小。研究结果表明,仿真分析取得的结果与实验研究结果相符。Based on experimental data,a nonlinear finite element model of the anterior capsule was constructed to study the relationship between the diameter of continuous circular capsulorhexis(ccc) and the maximum extend of the anterior capsule by finite element analysis.Calculating results showed that the capsule could be extended larger by an external force as the diameter of CCC aperture increasing.This result is accord with the results of experimental studies on lens capsules of human body.Furthermore,simulation indicates that the contact area of the external force has a great influence on the max extend length: giving the same diameter of CCC,the capsule's extend length increasing as the contact area of the external force become larger.This result remains undiscovered in experimental studies.The current work demonstrates that simulation analysis is believed to be a promising,powerful tool in the field of biology medical engineering.国家自然科学基金资助项目(60371012);; 福建省科技重点项目(2002Y021

传染性非典型肺炎病毒核蛋白的表达与活性检测

用PCR方法,人工合成传染性非典型肺炎病毒(SARS-CoV)核蛋白(N)全编码基因,并构建原核表达载体,在大肠杆菌中进行表达。结果重组N蛋白表达产量占菌体总蛋白的40％以上,主要以可溶形式存在。用SARS患者急性期血清进行蛋白印迹检测,表明可溶形式和包含体形式均有明显活性。包含体形式的重组蛋白经纯化后纯度可达90％以上,活性与纯化前相当,可作为SARS抗体诊断试剂盒的抗原原料

下调基因PTTG1对人胶质瘤细胞SHG44增殖、凋亡、迁移和侵袭能力的影响

背景与目的:研究表明垂体瘤转化基因1(pituitary tumor-transforming gene 1,PTTG1)在多种癌症中高表达。该研究旨在探讨其对胶质瘤细胞SHG44增殖、凋亡、迁移和侵袭能力的影响。方法:用PTTG1 siRNA干扰胶质瘤细胞SHG44的基因表达,通过实时荧光定量聚合酶链反应(real-time fluorescence quantitative polymerase chain reaction,RTFQ-PCR)和蛋白质印迹法(Western blot)分别在mRNA和蛋白质水平上评估PTTG1沉默效率,进一步检测其对SHG44细胞增殖、凋亡、迁移和侵袭能力的影响。结果:沉默PTTG1基因表达可以显著抑制SHG44细胞增殖(P<0.05)、迁移(P<0.01)和侵袭(P<0.001)能力,增加细胞凋亡(P<0.05)。结论:下调PTTG1的表达可以降低神经胶质瘤的恶化程度,有望成为临床胶质瘤治疗的新靶点。福建省自然科学基金(2016D019);;\n福建省卫计委医学创新项目(2016-CXB-12

Retinal Vessel Image Segmentation and Three-dimensional Reconstruction of Retinal Vessel

眼底视网膜图像的血管分布情况为高血压、糖尿病等疾病的早期诊断提供了重要依据.计算机处理眼底图像可以减少医生的重复劳动.本文提出了一种新的眼底视网膜血管图像分割算法.利用构建的局部归一化方法消除视网膜血管图像背景的差异性.利用期望最大化算法进行聚类,实现了眼底视网膜血管图像分割.最后,根据眼底图像成像原理,通过投影逆变换构建了眼底视网膜图像的三维模型.构建的模型可以进行多角度观察分析.Retinal vessel appearance is an important indicator for many early diagnoses,including diabetes,hypertension, and arteriosclerosis.Computer processing can help doctors' work and a retinal vessel image segmentation algorithm was proposed.A local normalization algorithm was used to eliminate background differences.Expectation-maximization algorithm was used to classify the pixels into several classes to obtain segmentation results.At last,based on the anatomical and physiological characteristics of the eye,a reconstruction method to reconstruct three-dimensional retinal vessel was realized by inverse projection theory.The model can be viewed from different directions.国家自然科学基金(60371012;60601025)资助---

Mechanistic Discrimination of the Reaction of 1-aminopyrene and N-methyl-p-anisidine on an Electron Transfer Stopped-Flow Method

在电子转移停流注射法中通过电子转移,1 芘胺,N 甲基对茴香胺与较稳定的阳离子自由基反应生成活泼的阳离子自由基并偶合.用密度泛函理论(DFT)B3LYP方法,在6 31G 基组下,计算研究了中间产物的几何构型和热力学性质,通过反应过程的能量变化及电荷布居分析推测出其偶合机理.并用电喷雾质谱法检测其偶合产物,实验结果与推测值吻合.Using an electron transfer stopped-flow method,the reactions of short-lived 1-aminopyrene and N-methyl-p-anisidine cation radicals,which were formed via the electron transfer reactions with stable cation radicals,were analysed.Dimerization mechanisms about those compounds are studied by density functional theory (DFT) at B3LYP/6-31G~* level,and any possible types of dimerization processes are established and are calculated.The results about equilibrium geometries,the population regularities of the atomic net charges and thermodynamics energies of these compounds show that mechanisms are in accordance with the experiment.The dimmer compounds were analysed by using ESI-MS to confirm the structures.国家自然科学基金(20375033);; 国家教育部高等学校骨干教师资助计划资

The Study of 3D Reconstruction of Nasopharyngeal Tissues Based on Visualization Toolkit

放射治疗是鼻咽癌治疗的主要手段.为了提高放射治疗的成功率,本文采用可视化工具包(VTK)分别实现了鼻咽部组织的表面重建和体重建.表面重建用移动立方体法和轮廓拼接法实现,体重建则用光线投射法实现.利用一种改进的高斯拉普拉斯核进行平滑和锐化处理,并通过调整光照参数和透明度值使重建效果达到最佳.在此基础上,比较了两种重建方法的优缺点.实验结果表明,利用VTK可实现复杂组织结构的多彩色三维重建和三维图像的优化处理.Radiation therapy is the primary means of nasopharyngeal carcinoma(NPC) treatment.In the present work,in order to improve the success rate of radiotherapy we used the visualization toolkit(VTK) to achieve the surface and volume reconstruction of the nasopharyngeal tissues.The surface reconstruction was realized by marching cubes algorithm and contour connecting algorithm,and the volume reconstruction was implemented by ray-casting method.An improved Laplace and Gaussian nuclear was used for sharpening and smoothing.By adjusting the parameters of light and transparency,we achieved the best reconstruction effect.On this basis,the comparison was given on the advantages and disadvantages of the two methods of reconstruction.The results of experiment show that the VTK can be used to achieve multi-color 3D reconstruction of complex organizational structure and optimization of 3D image.卫生部联合基金(WKJ2005-2-001);; 福建省科技攻关课题(2004Y008)资