呼气相胸片的识别研究

根据呼气相胸片中肺部区域灰度较高的特点，通过边缘提取和边缘跟踪确定胸部区域，运用最大类间方差方法确定图像分割的阈值．再提取出肺部区域，然后求出肺部的灰度均值。但这样的结果并不理想。于是在此基础上提出修正方案，即以肺部灰度均值和骨骼灰度均值的比值作为特征值．即比例法。此方法可以较客观的识别呼气相胸片。最后用类间距离对这两种方法进行了量化比较。     

Elastofibroma dorsi has distinct cytomorphologic features, making diagnostic surgical biopsy unnecessary: cytomorphologic study with clinical, radiologic, and electron microscopic correlations

Elastofibroma dorsi (EFD) is a relatively rare soft tissue mass, probably of reactive nature. The lesion is typically located near the inferior margin of the scapula or between the inferior part of scapula and the chest wall in elderly women. Although location of the tumor together with the age/sex of the patients and radiologic findings is often suggestive of the diagnosis, tissue examination has been considered necessary to confirm the diagnosis. Although the histologic features of EFD are well known, there are only four single case reports of the cytologic findings in the English language literature. We describe the cytologic features of EFD in five patients with correlations to clinical, radiologic, histologic, and electron microscopic findings. The current study suggests that the fine-needle aspiration (FNA) features are highly diagnostic, permitting a firm diagnosis of EFD in a typical clinical setting and eliminating the need for preoperative histologic examination.     

基于模糊连接度的多发性硬化症MR图像自动分割算法

多发性硬化症(MS)是一种严重威胁中枢神经功能的疾病,利用磁共振成像技术能够无损伤地检出其病灶。为了自动地对多发性硬化症病灶进行分割,提出了基于模糊连接度的分割算法,实现了种子点的自动选取。作为多发性硬化症分割的预处理,针对脑部MR FLAIR图像的特征,基于区域增长方法,还提出了脑部组织提取算法。通过对临床患者MR图像的分割实验,表明该分割算法能够比较准确地分割多发性硬化症病灶,其分割效果明显好于模糊C-均值聚类算法和基于马尔可夫场模型的分割算法。该算法还具有无监督、运算速度快、稳健性好等优点,能够应用于多发性硬化症的临床辅助诊断。     

改进的小波域医学图像序列的运动估计

医学图像序列压缩是远程医疗系统中的重要技术，而运动估计在视频序列压缩中起着关键作用。我们提出了一种改进的正方形-菱形搜索算法来实现医学图像序列的运动估计。这种改进的正方形-菱形算法减少了搜索点数。我们将其应用于小波域的医学图像序列的运动估计，并对数字减影血管造影图像序列（DSA）进行实验。结果表明，改进后的小波域正方形-菱形算法较其他算法精度高。     

运动应激对大鼠胃肠道5-HT免疫反应细胞的影响

目的　探讨力竭游泳对大鼠胃肠道 5 HT免疫反应细胞 (5 HTIR细胞 )的影响。方法　本研究以力竭游泳大鼠为运动模型 ,游泳后即刻取大鼠胃窦、十二指肠、空肠和回肠用免疫组织化学SP法检测 5 HT ,用图像分析系统测定胃肠 5 HTIR细胞数和平均灰度。结果　 (1)游泳后胃窦 5 HTIR细胞数虽与对照组无明显差异 ,但阳性细胞的平均灰度却明显下降 (P <0 .0 5)。 (2 )十二指肠、空肠、回肠 5 HTIR细胞数都明显下降 ,与对照组相比有显著性差异 (P <0 .0 5) ,但只有空肠 5 HTIR细胞平均灰度明显增加 ,与对照组间有明显差异 (P <0 .0 5)。结果　胃肠道不同区域 5 HTIR细胞以不同的反应方式应答运动应激。     

Early recognition of newborn goat kids by their mother: II. Auditory recognition and evidence of an individual acoustic signature in the neonate

The vocal recognition of newborn kids by their mother at 2 days postpartum and the possible existence of interindividual differences in the voice structure of newborn kids were investigated in two separate studies. The ability of goats to discriminate between the bleats of their own versus an alien kid was tested at 2 days postpartum in mothers being prevented access to visual and olfactory cues from the young. Goats spent significantly more time on the side of the enclosure from which their own kid was bleating, looked in its direction for longer, and responded more frequently to the bleats of their own than to those of the alien kid (p < 0.05). In the second study, the sonograms of 13 kids, studied from Days 1 to 5, showed significant interindividual differences for the five variables taken into account and on each of the 5 days (duration of bleat, fundamental frequency, peak frequency, and numbers of segments and of harmonics). The potential for individual coding ranged between 1.1 and 4.1, indicating that for some variables variations between individuals were greater than intraindividual variations. Furthermore, when considering the five parameters together, the discriminating scores showed an average of 95% in the 78 combinations of any 2 kids for any given day. Finally, some significant intraindividual differences also were found between days, suggesting ontogenic changes in the characteristics of the kid's voice in early life. Therefore, mother goats are likely to recognize the vocalizations of their 48-hr-old kids, as they show sufficient interindividual variability to allow the existence of individual vocal signatures, even though some of the characteristics of the bleats change rapidly over time.     

Computer image sperm selection as a novel approach to subzonal insemination in the human

Utilizing real-time computer image analysis, individual spermatozoawere selected using microaspiration. Selection criteria werebased on potential hyperactivation motility characteristics;the amplitude of lateral head displacement >7.5 µm,curvilinear velocity >70 µm/s and linearity of <30%.For this pilot study, 16 patients (eight in each group) wererecruited. Using subzonal insemination (SUZI), up to five (mean= 4.4 ± 0.3) spermatozoa selected using computer-imagesperm selection (CISS) were microinjected, or up to 15 (mean= 12.8 ± 1.3 SD) unselected spermatozoa. In the groupwhich utilized CISS, 28 out of 49 (57%) oocytes were fertilizedcompared with 13 out of 52 (25%) utilizing conventional SUZI(P < 0.04); polyspermy was 20% (n = 10) and 2% (n = 1) respectively.CISS with SUZI showed increased efficiency in achieving fertilizationand is a novel approach to studying individual sperm functionin a sperm egg bioassay where gamete ratios are close to unity.     

The molecular basis of Natural Killer (NK) cell recognition and function

Natural Killer cells are likely to play an important role in the host defenses because they kill virally infected or tumor cells but spare normal self-cells. The molecular mechanism that explains why NK cells do not kill indiscriminately has recently been elucidated. It is due to several specialized receptors that recognize major histocompatibility complex (MHC) class I molecules expressed on normal cells. The lack of expression of one or more HLA class I alleles leads to NK-mediated target cell lysis. Different types of receptors specific for groups of HLA-C, HLA-B, and, very recently, HLA-A alleles have been identified. While in most instances, they function as inhibitory receptors, an activatory form of the HLA-C-specific receptors has been identified in some donors. Molecular cloning of HLA-C-, HLA-B- or HLA-A-specific receptors has revealed new members of the immunoglobulin superfamily with two or three Ig-like domains, respectively, in their extracellular portion. While the inhibitory form is characterized by a long cytoplasmic tail associated with a non-polar transmembrane portion, the activatory one has a short tail asociated with a Lys-containing transmembrane portion. Thus, these human NK receptors are different from the murine Ly49, that is a type II transmembrane protein characterized by a C-type lectin domain. A subset of activated T lymphocytes expresses NK-type class I-specific receptors. These receptors exert an inhibiting activity on T cell receptor-mediated functions and may provide an important mechanism of downregulation of T cell responses.     

致癌物分子结构识别中的一种特征提取方法

本文论述基于拓扑参数的致癌物分子结构识别中的一种特征参数－－特征片段的提取方法；对一组活性已知的分子训练集，将其分子结构用ＫＬＮ编码法进行编码并输入计算机，在三个约束条件下用深度第一法对各分子进行结构分解，生成片段文件，并汇总成片段总库，然后用统计检验和聚类分析提取和优化特征片段，从而为识别模型提供合理有效的特征参数。