基于薄板样条的医学图像弹性配准

非刚体配准是神经外科和放疗计划设汁中的一个关键问题。使用薄板样条方法，利用两个对应标志点集对眼底、脑等多种医学图像进行弹性配准。其中，弹性插值法是将两个点集绝对对齐，常会出现严重的局部畸变；而弹性近似法充分考虑了整体平滑性的要求，对定位有误差的标志点约束的图像配准更为优越。实验结果表明，使用上述两种方法获得了很好的配准效果?     

EEG电极与MRI头模型的配准方法

脑功能成像研究中 ,脑电信号与磁共振图像融合分析是一种重要的研究方法。在实现融合分析时首先要解决的问题是电极与头模型的配准 ,目前有三种基本的配准方法 :基准点法、电极可视化方法和表面配准法。本文对这三种方法作了介绍 ,并对这三种方法的特点作了评述。     

医学图像配准方法分类

医学图像配准是医学图像融合的前提，具有重要的临床诊断和治疗价值，它可以把来自不同模态、不同人或不同时间的多幅图像进行配准。本文依据九个标准对医学图像配准的方法进行了总结。     

医学图像弹性配准中弹性模型的建立

医学图像配准是医学图像处理中的一个重要研究课题，它是图像融合、图像与标准图谱的匹配、显微图像的重建等研究的基础。图像的配准方法有多种，它们可以分为刚性和弹性配准两大类。相对于刚性配准，弹性配准有着更高的精确性，而对于变形大的图像的配准，它是必须的。因此弹性配准的研究有着广泛的意义。本文根据图像的特征，结合弹性力学的理论和方法，建立了一种用于精确配准的弹性数学模型，并用这一模型进行图像的弹性配准，取得了较好的效果。     

一种基于感兴趣点旋转不变性特征的图像配准新方法

目的:图像配准是图像处理领域重要的研究方向,是图像融合、图像重建和图像分析等研究的基础。在图像配准的主要方法中,基于图像特征的配准方法和基于图像灰度的配准方法各有优缺点,通过结合这两种方法的优点,我们提出了一种基于感兴趣点的旋转不变性特征图像配准的新方法。方法:首先利用Harris角点检测技术,提取模板图像和目标图像的感兴趣点。然后把感兴趣点的旋转不变形特征和灰度值组成图像的特征描述向量,并提出新的代价函数。最后采用分级优化的策略优化代价函数,在配准初期,采用显著的特征点进行配准,以保证配准的速度与鲁棒性,随后通过逐步增加特征点的数量,则保证了配准的精度。结果:为显示本文方法的优越性,实验利用本文方法和基于互信息的B样条方法分别对标准测试图像进行配准,实验结果表明,本文方法较基于互信息的B样条方法在配准精度上有明显提高。结论:本文方法在保持配准鲁棒性的前提下,获得了较高的配准精度。     

自适应指数加权互信息配准医学图像的测度及相应算法

为配准医学图像,本文提出了一种新的自适应指数加权的互信息(Adaptive Exponential Weighted Mutual Informa-tion,AEWMI)测度,分析表明:通过对互信息(Mutual Information,MI)测度进行指数加权可以提高测度曲线的峰值尖锐性和平滑性;而指数的权值则可以通过评估待配准图像的质量和分辨率大小来自适应确定.仿真实验结果在验证分析结果的同时也表明,基于本文AEWMI测度的配准方案,对图像噪声、分辨率差异等有较高的鲁棒性,且可有效地提高配准的成功率.     

灰度与形状同步匹配的非刚性配准研究

基于灰度的非刚性配准算法一般假设参考图像和浮动图像对应结构之间的灰度保持一致,然而在基于图谱的图像配准应用中,这种假设往往不符合实际。本文在给出一种可以同时校正灰度和形状差异的弹性配准算法的同时,针对该算法不能校正局部微小形变的弱点,提出采用自由项变换的方法进行校正以提高配准精度。配准实验基于20个IBSR真实脑部MRI图像,结果表明配准后图像与参考图像间的互相关系数得到明显提高。实验证明,本文提出的方法不仅能够同时校正形状差异和灰度变化,而且具有较高的配准质量。     

时间图像序列配准的研究

本文分析了时间图像序列配准的特殊性，提出了应从以下五个方面来设计时序图像的配准：预处理以补偿外部条件的变化、分析时序图像的不变量以确定代价函数的项、将目标物分解为几部分从而最终确定代价函数、选择较优的算法以提高配准速度。研究了甲襞毛细血管的时序图像配准，分析了甲襞毛细血管时序图像的不变量，提出了多模板－序列阈值配准算法，实验表明，此算法能成功地完成甲襞毛细血管的时序图像配准。     

一种基于距离图和分级配准策略的人脑图像非刚体配准方法

目的:基于特征的配准方法中,特征配准结果的好坏决定着最终配准结果的好坏.方法:本文提出了一种基于距离图和分级配准策略的人脑MR图像非刚体配准方法.首先使用C-V模型完成特征的提取工作,并设计了相应的预处理过程,来获得适合进行特征配准的边界点集.接着采用分级配准策略来完成特征配准工作,包括逐条仿射配准和非刚体配准两个子步骤.为了方便计算,距离图被引入到算法过程中,以方便点距的查询.最终的全局配准工作基于特征配准的结果进行,配准问题转化为相应的插值问题进行求解.结果:针对两组初始差异较大的脑部图像进行实验,均可以达到配准要求.结论:实验结果证明,新算法能够适合初始偏差较大配准场合的需求.     

EEG电极与MRI头模型的配准方法

脑功能成像研究中,脑电信号与磁共振图像融合分析是一种重要的研究方法。在实现 事分析时首先要解决的问题是电极与头模型的配准,目前有三种基本的配准方法,基准点法、电极方法和表面配准法。本对这三种方法作了介绍,并对这三种方法的特点作了评述。     

高血压患者人巨细胞病毒感染率及其血浆中和抗体水平分析

目的 对高血压患者人巨细胞病毒（HCMV）感染率及其血浆中和抗体水平展开研究分析,研究高血压与人巨细胞病毒感染的相关性.方法 随机选取2011年12月-2013年12月期间接收治疗的50例高血压患者血标本作为观察组,同时选取50例健康体检人员的血标本作为对照组.对两组标本人巨细胞病毒特异性中和抗体、人巨细胞病毒特异性IgG和IgM、人巨细胞病毒特异性UL93 DNA进行检测.结果 观察组HCMV UL93 DNA的阳性率为72.0％,HCMV IgG阳性率为70.0％,HCMV IgM阳性率为4.0％;对照组HCMV UL93 DNA阳性率为54.0％,HCMV IgG阳性率为52.0％,HCMV IgM阳性率为2.0％;观察组HCMV UL93 DNA阳性率、HCMV IgG阳性率显著高于对照组,数据差异具有统计学意义（P＜0.05）;两组HCMV IgM阳性率数据对比差异无统计学意义（P＞0.05）.结论 高血压患者人巨细胞病毒感染率显著高于健康对照组,但特异性中和抗体水平较健康对照组显著下降,即高血压患者的人巨细胞病毒感染体液免疫状态不足,高血压与人巨细胞病毒感染显著相关.     

Differential human handling and the development of agonistic behavior in basenji and shetland sheep dogs

This experiment tested the hypothesis that differential treatment will increase the amount of aggressive interactions between young puppies. Litters of Shetland sheepdogs and African basenjis were weaned at 4 weeks of age and reared in pairs. In one pair, one pup was favored through playful interaction by a human experimenter, while the other pup was ignored. In a second pair, both pups were ignored. Significantly greater amounts of aggressive behavior occurred in the differentially treated pairs, both during and immediately after the treatment periods. This behavior carried over into competitive situations involving a food or bone and was still present 9 weeks after treatment had been discontinued. Breed differences were observed in almost all measurements taken. In particular, shelties learned to inhibit their behavior much more rapidly than basenjis. Such differences are comparable to what might be expected from genetic differences between individuals in human subjects. The experiment is not comparable to sibling rivalry in human families, where differential treatment is imposed because of difference in ages, but the results support the hypothesis that lessening of differential treatment should reduce the occurrence of quarrels between siblings.     

互隔交链孢霉提取物对淋巴细胞核仁形成区及细胞增殖周期的影响

本实验应用人类核仁形成区(NORs)选择性银染方法和细胞光度术,观察了互隔交链孢霉两菌株提取物261-B_2-3和C_(12)b_3-2对人淋巴细胞NORs活性的影响以及后者对细胞增殖周期移行的影响。结果显示,应用不同浓度的261-B_2-3和C_(12)b_3-2提取物处理细胞后,细胞携带Ag-NORs的染色体数明显减少,与对照组比较差异极显著(P<0.01)。表明两株提取物能明显抑制淋巴细胞NORs的活性。细胞暴露于不同浓度的C_(12)b_3-2提取物后,G_1%明显增多,S%和G_2+M%显著减少,与对照相比差异极显著(P<0.01)。说明C_(12)b_3-2提取物可能作用于G_1后期或S早期,延缓和阻滞了细胞周期的移行。     

人与猪肝门静脉生物力学特性的比较研究

目的：比较研究人与猪肝门静脉生物力学特性的异同，为猪→人异种肝移植提供理论依据。方法：取人与不同月龄猪肝门静脉，利用软组织生物力学试验机测量压力一直径关系数据，推导出其弹性模量和顺应性。结果：猪肝门静脉的弹性模量随月龄的增大和血管内压力的升高而增大；顺应性则随月龄的增大而下降。与人肝门静脉相比，6月龄猪肝门静脉的弹性模量和顺应性与人相近。结论：6月龄猪肝门静脉的力学特性与成人相近，在行猪→人异种肝移植时，人与6月龄猪肝门静脉的吻合是可行的。     

中国大学生的人性观与美国常模比较研究

目的：探讨中国大学生的人性特点。方法：使用人性的哲学量表对192名中国大学生进行调查，并与美国常模进行比较。结果：（1）中美大学生在值得信任，意志力与理性，独立性方面没有显著差异，但中国男女大学生之间在值得信任方面存在显著差异，中国女大学生信任度较低。（2）中美大学生在利他主义方面存在显著差异，中国大学生有更强的利他意识。（3）中美大学生在人性复杂性，人性变异性得分均偏高，但两者仍存在显著差异，中国男女大学生在人性复杂性方面存在极显著差异，结论：不同文化背景的大学生在人性观点看法迥异。     

Frequent structural chromosome aberrations in immotile human sperm exposed to culture media

BACKGROUND: The influence of culture media or centrifugation on chromosomes of immotile human sperm was examined using ICSI into mouse oocytes. METHODS: In experiment 1, immotile and motile human sperm retrieved directly from ejaculates were injected into mouse oocytes. In experiment 2, immotile human sperm were exposed to seminal plasma or one of four kinds of culture media (HEPES-BWW, modified-BWW, modified-human tubal fluid (HTF) and Dulbecco's phosphate-buffered saline) for 1.5-2.5 h at 18 degrees C in air before microinjection. In experiment 3, immotile human sperm were centrifuged along with HEPES-BWW before microinjection. In experiment 4, frozen-thawed immotile human sperm washed with seminal plasma or HEPES-BWW were injected into mouse oocytes. The hybrid oocytes were prepared for chromosome slides at first cleavage metaphase and were then examined cytogenetically. RESULTS: In experiment 1, there was no significant difference in the incidences of structural chromosome aberrations between motile and immotile sperm (4.3% versus 5.8%). In experiment 2, culture media caused more frequent structural chromosome aberrations (14.3-32.6%) in immotile sperm than did seminal plasma (5.4%). In experiment 3, structural chromosome aberrations were found in 48.1% of the centrifuged immotile sperm, and a live/dead sperm viability test intimated that the aberrant sperm were probably dead. In experiment 4, the incidence of structural chromosome aberrations in frozen-thawed immotile sperm was significantly higher in HEPES-BWW (62.2%) than in seminal plasma (17.2%). CONCLUSIONS: The results indicate that immotile sperm do not have significantly more DNA lesions than motile sperm, although DNA of immotile sperm appears to be vulnerable to damage caused by different culture media.     

一种可能的泡球蚴免疫逃避行为——泡球蚴免疫组织化学研究

泡球蚴免疫组织化学研究中发现,正常人体和小鼠免疫球蛋白与泡球蚴有明显的免疫反应,提示泡球蚴具有与人体和小鼠免疫球蛋白某些分子相同或类似的成分。这一现象很可能是泡球蚴的一种免疫逃避行为。兔抗鼠免疫球蛋白Fc段单克隆抗体封闭实验证实,这种与正常小鼠免疫球蛋白发生结合的泡球蚴成分,并非小鼠免疫球蛋白的Fc受体。本实验的结果与已经报告的两种类似结果均有所不同,本文就此进行了讨论分析     

网络成瘾大学生社会自我概念中的认知偏差

目的探讨大学生网络成瘾者社会自我概念存在的认知偏差。方法随机选取某师范学院28名大学生作为被试,采用内隐联想测验范式进行了实验研究。结果①在自我评价实验中,网络成瘾大学生与非网络成瘾者在不同联合任务中反应时无显著差异(F=0.219,P>0.05);②在行动度测试中,网络成瘾大学生与非网络成瘾者在不同联合任务中反应时无显著差异(F=0.529,P>0.05)。结论网络成瘾大学生对社会自我概念的自我评价中存在认知偏差,对自我行动度的评价也存在认知偏差。     

Habituation of the electrodermal orienting reaction to potentially phobic and supposedly neutral stimuli in normal human subjects

Three experiments concerning habituation of the electrodermal orienting response to pictures of phobic and neutral objects in normal human subjects are reported. In the first one, two independent groups were given either 16 presentations of snake pictures, or 16 presentations of pictures of houses. The pictures differed between subjects but a certain subject saw the same pictures throughout the experiment. The results showed no significant difference between groups in response magnitude, but significantly fewer trials to habituation in the group given neutral pictures. The second experiment used a within-subject design, with mixed presentation of either a snake and a house picture, or a spider and house picture. The responses to phobic stimuli were larger than those to neutral ones, and the latter took significantly fewer trials to habituate. The third experiment used a between-subject design where some shocks were given before the experiment, and the subject was threatened that some shocks would also be given during the experiment. This procedure potentiated the difference between the stimuli, so that the responses to the phobic pictures were about four times as large as those to the neutral stimuli.     

Polarity effect of the thimble-type ionization chamber at a low dose rate

It is known that the current collected from an ionization chamber exposed to a constant radiation intensity changes in magnitude when the polarity of the collecting potential is reversed. It is called the polarity effect of the ionization chamber. There are many possible causes that induce the polarity effect and one of them can be a field distortion due to a potential difference between the guard electrode and the collector. We studied how much the polarity effect depends on the design of the electrodes in the thimble-type ionization chamber. Two thimble-type ionization chambers, which had different electrode structures, were designed and fabricated at KAERI. We calculated the field distortions due to the potential difference between the guard electrode and the collector for the two ionization chambers. MAXWELL and Garfield were employed to calculate the electron drift lines inside the chamber. The polarity effects of the two ionization chambers were measured, and they were consistent with the field calculation. We could conclude that the polarity effect is mostly induced from the field distortion due to the potential difference between the guard electrode and the collector in our experiment and it depends significantly on the design of the electrodes.