基于人工视网膜神经节细胞感受野的图像边缘检测

用光电池组装一个工感受野，在一维上模拟视网膜神经节细胞的零交叉滤波特性，进一步用该工工感受野构建一个图像边缘检测系统，并成功地用系统检测到图像边缘。一与般的基于视觉原理的图像系统相比，这种以人工感受野灵基础的系统，在图像输入的同时即可并行地提取图像边缘信息，而更接近于动物视觉系统原型，此结果将为人工视觉和图像技术的发展提供新的探索。     

In vitro effects of low-intensity ultrasound stimulation on the bone cells

Mechanical perturbations serve as extracellular signals to a variety of cells, including bone cells. Low-intensity pulsed ultrasound produces significant multifunctional effects that are directly relevant to bone formation and resorption. Ultrasound stimulation has been shown to accelerate bone-defect healing and trabecular bone regeneration. In this study, we use an in vitro bone cell culture model to investigate the effect of low-intensity pulsed ultrasound. The rat alveolar mononuclear cell-calvaria osteoblast coculture system was used in this study. Before treatment, the bone cells were cultured for 3 days to facilitate their attachment and differentiation. Then, ultrasound exposure (frequency = 1 MHz, intensity = 0.068 W/cm(2)) or sham exposure for 20 min per day was applied until the end of the experiment. Half of the culture media were obtained on the 4th, 5th, 6th, 7th, 8th, 9th, and 10th days for the analysis of cytokines and biochemical parameters. At the end of the experiment, cells were fixed and stained for identification and quantification of the osteoblast and osteoclast cells. After low-intensity pulse ultrasound stimulation, the osteoblast cell counts were significantly increased, whereas the osteoclast cell counts were significantly decreased. The total alkaline phosphatase amount in the culture medium was increased after 7 days of ultrasound stimulation, and tumor necrosis factor-alpha in ultrasound-stimulated bone cells was significantly increased after the 7th day of culture and reached 474.77% of the control medium on the 10th day of culture. The results of this study suggest that low-intensity ultrasound treatment may have a stimulatory effect on bone-healing processes.     

桥粒斑蛋白II在肿瘤组织中的表达

桥粒斑蛋白ＩＩ（ＤＰＩＩ）是一种新的上皮和上皮性肿瘤标记物。我们应用针对石蜡切片的抗ＤＰＩＩ单抗和抗细胞角蛋白（ＣＫ）单抗对２ｌ７例肿瘤作了免疫组织化学ＡＢＣ法染色的研究，结果：在１６３例上皮性肿瘤和双向分化的肿瘤中，１４７例表达ＤＰＩＩ，占９０．７％，９２例表达ＣＫ，占５６．４％。ＣＫ阳性染色全部位于细胞浆内，ＤＰＩＩ阳性染色则同时分布在细胞交界面上和细胞浆中。其他５４例不含桥粒的肿瘤均无ＤＰＩＩ和ＣＫ表达。结果表明，ＤＰＩＩ单抗是有用的含桥粒肿瘤的免疫组化探针。因ＤＰＩＩ不存在于一切含桥粒肿瘤，故在鉴别上皮性肿瘤时，ＤＰＩＩ单抗尚需与其他上皮标记物的抗体合并使用。     

The C. elegans microRNA let-7 binds to imperfect let-7 complementary sites from the lin-41 3'UTR

Caenorhabditis elegans let-7, a founding member of the microRNA family, is predicted to bind to six sites in the 3'UTR of the mRNA of its target gene, lin-41, to down-regulate LIN-41. Here, we demonstrate that wild-type let-7 microRNA binds in vitro to RNA from the lin-41 3'UTR. This interaction is dependent on two conserved let-7 complementary sites (LCSs). A 27-nucleotide sequence between the LCSs is also necessary for down-regulation in vivo. LCS mutations compensatory to the lesion in let-7(n2853) can partially restore lin-41 3'UTR function in a let-7(n2853) background, providing the first experimental evidence for an animal miRNA binding directly to its validated target in vivo.     

Pregnancy-associated plasma proteins in pregnant and pseudopregnant rats.

As in the human, the rat pregnancy-associated plasma proteins consisted of four distinct entities as revealed by immunological methods. All showed gradual increases during gestation and rapid disappearance postpartum. They could be physicochemically, although not immunologically, tentatively related to the human pregnancy proteins. None of them was detectable in the serum of rats at various stages of pseudopregnancy, nor in nonpregnant rats.     

非霍奇金淋巴瘤与p53蛋白表达的关系

目的 :探讨非霍奇金淋巴瘤 (NHL)与 p5 3蛋白表达的关系。 方法 :用免疫组化S P法检测 10 2例 (低度恶性 2 3例 ,中度恶性 36例 ,高度恶性 4 3例 )NHLp5 3蛋白表达 ,根据 p5 3蛋白阳性细胞百分率将其表达水平分为 4级 :0级 (阴性 ) ,1级 (1%～ 2 5 % ) ,2级 (2 6 %～ 5 0 % ) ,3级 (>5 0 % )。结果 :低度恶性组 2 0 / 2 3(87% )p5 3表达为 0级 ,中度恶性组 31/ 36 (86 1% )表达为 1级 ,高度恶性组 33/ 4 3(76 7% )表达为 2～ 3级。 2 5例随访 7～ 6 8个月 ,p5 30～ 1级NHL完全缓解率 (CRR ,11/ 14 )高于p5 32～ 3级NHLCRR (1/ 11,P <0 0 1) ,前者生存率 (13/ 14 )高于后者 (3/ 11,P <0 0 1)。NHLp5 3蛋白表达水平与其恶性度密切相关 (P <0 0 1)。结论 :p5 3蛋白表达阳性细胞百分率是判断NHL恶性度、疗效及预后较可靠的参数。肿瘤性p5 3蛋白表达检测对中高度恶性NHL的诊断有参考价值     

一种基于独立成分分析的功能磁共振数据处理方法

独立成分分析（ICA）是统计信号处理中的一项新技术，用来从混合信号的多维观测中提取具有统计独立性的成分。我们针对功能磁共振数据处理，采用先对相邻的两体元信号作ICA分离，然后与参考信号进行相关，把相关系数大于一定阈值的体元作为刺激引起兴奋的体元，从而实现刺激的功能定位。经实际脑功能磁共振数据试验，初步证明了方法的有效性。     

生物钟相关基因在原发性肝细胞癌中的表达及临床意义——基于TCGA数据集分析

目的：探究生物钟相关基因在原发性肝细胞癌（简称肝癌）中的表达及意义。方法：从美国癌症和肿瘤基因图谱数据库（The Cancer Genome Atlas,TCGA）中下载肝癌数据424例,包括374例肝癌患者样本及50例正常对照样本。运用DECenter软件对51个生物钟相关基因进行差异表达分析,比较生物钟基因在肝癌患者及正常样本之间的表达情况。运用DAVID在线工具分析差异基因的GO及KEGG功能富集通路,并通过STRING数据库构建差异基因之间蛋白质相互作用网络。了解生物钟基因肝癌发生发展过程中的主要作用。结果：在374例肝癌患者样本的51个生物钟相关基因中,有21个基因在肝癌样本中表达上调（P<0.05）,3个基因表达下调（P<0.05）。生物钟基因高表达样本主要富集于Wnt信号通路、Hedgehog信号通路及Hippo信号通路（P<0.001）。参与调节昼夜节律和细胞代谢的10个生物钟基因在蛋白质相互作用网络中相关性最为紧密（P<0.001）。GO分析差异基因集中作用于调节昼夜节律、细胞代谢过程、基因表达等通路（P<0.001）。结论：生物钟相关基...     

基于荧光素酶生物发光检测方法的研究及其应用进展

生物发光现象广泛存在于自然界中,不管是在陆地或是海洋都有发光生物的踪迹。其中基于荧光素酶的生物发光系统被广泛研究,启发着人类在基因、表观遗传等方面进行探索,并且开发出一系列相关的检测方法,用于体内体外各方面研究。本文从生物发光系统、荧光素酶的种类以及荧光素酶生物发光检测方法的开发与应用这几个方面进行总结,简要概括近年来基于荧光素酶生物发光检测的研究进展。