基于小波变换极大模的多模医学图像融合

多模态医学图像融合由于其对医学临床诊断的意义已引起广泛的关注,基于图像边缘特性的融合方法逐渐成为研究的重点。本文提出了一种基于离散二进小波变换的多尺度边缘检测和图像融合的方法,实现了特征级图像融合。不同于以往的从极大模值点直接重建图像,本文的算法利用极大模值点建立有效的融合规则,然后从融合的小波系数重构信号。融合图像的交互信息和峰值信噪比等检测指标表明此方法优于传统融合算法。     

Studies on purity and stability of photopatch test substances

19 photo substances were studied by thin-layer chromatography (TLC) as fresh solutions, and during storage under various conditions. Chlorhexidine was excluded as it is sparingly soluble and only used in commercial products as a derivative. Trichlorocarbanilide was the only substance shown to be impure from the start. Only benzocaine, buclosamide, chlorhexidine acetate and chlorhexidine gluconate remained unchanged to the naked eye, and in TLC. The other substances were changed in colour and/or in their TLC-pattern. An extraction method is described which makes it possible to use TLC for the examination of substances in petrolatum preparations. UV-absorption spectra have also been examined for all the substances.     

用奇异性检测技术提取诱发电位

本文介绍了用 小波变换模极大 值检测信号奇 异性的方法， 讨论了 信号与 白噪声 的小 波变换 和奇 异性指数之间区 别，模极大值沿 尺度 传递 的不同 特点 ，并 利用它 们的 区别 消除 诱发 电位 信号 中的噪 声，重 构出消 噪后 的信号， 取得 了较好 的效果 ，利用 较少的 刺激 次数就 可获取 诱发电 位信 号，有 效地提高 了信 噪比，大 大减 少了迭 加次数 ，特征 波的潜 伏期 及幅值 容易辨 认，易 于测量 ，且无 信号 失真。奇异性检 测技术有望成为 临床实用的诱 发电位提取 技术，并 可应用 于其他 生物 医学信 号的 消噪。     

Coccidiosis: localization of lymphoblasts in the infected small intestine

Summary Peripheral blood lymphocytes of chickens and thoracic duct lymphocytes and mesenteric lymph node cells of rats, were labelled with ¹²⁵-deoxyuridine and injected intravenously into chickens or rats respectively. Sixteen to 18 h later the intestines of coccidia infected animals contained more radioactivity than those of uninfected controls. This result was obtained with cell suspensions from both infected and normal donors indicating that, as with nematode infected rodents, the increased homing of the cells to parasitised gut was not antigen specific. In chickens the stimulus which causes the increased homing of cells to the intestine was induced within hours of parasite inoculation. This reflects the rapid response of this host, previously described with other parameters, and which may be characteristic of birds.     

A comparison of the responses of the isolated vas deferens of the rat to field stimulation and to noradrenaline added cumulatively and non-cumulatively

The maxima, slopes and positions of cumulative and non-cumulative dose-response curves for noradrenaline were determined on the isolated vas deferens of the rat. Cumulative log dose-response curves were flatter and reached a lower maximum than the non-cumulative curves. However transformation of the responses to fractions of the maximal responses produced curves with identical slopes and only slight differences in positions. Field stimulation led to larger and more rapidly attained maximal responses than did the addition of exogenous noradrenaline. Responses to field stimulation applied at the plateau of the cumulative dose-response curves were similar to those occurring in the control situation. It is suggested that the effectiveness of noradrenaline in producing contraction of the vas deferens may be related to the rate at which its concentration rises at the effector cells.     

短指软珊瑚属次级代谢产物化学成分及其生物活性研究进展

短指软珊瑚属（Sinularia）分布十分广泛,富含结构新颖、生物活性显著的次级代谢产物,已成为国际上海洋天然产物的研究热点之一。该属软珊瑚中的次级代谢产物主要涉及倍半萜、二萜、倍半萜一二萜二聚体、二萜二聚体、降倍半萜、降二萜、降二萜二二聚体、杂萜、甾体及其糖苷、神经酰胺、长链烷基糖苷、亚精胺等结构类型,其中很多化合物具有抗肿瘤、抗菌、抗病毒和抗炎等生物活性。本文综述了1975年至2013年4月间报道的短指软珊瑚中的次级代谢产物及其生物活性的研究进展,以期为该领域海洋天然产物的后续研究与开发提供参考。     

西沙短指软珊瑚Sinularia notanda化学成分研究△

目的 研究西沙短指软珊瑚Sinularia notanda的化学成分。方法 利用薄层色谱,硅胶柱色谱、凝胶(Sephadex LH-20)柱色谱、MPLC、HPLC、GC-MS等分析分离方法对Sinularia notanda中的化学成分进行分离纯化,并进一步对NMR、MS等其数据进行分析,同时对照文献鉴定所得化合物的结构。结果 从短指软珊瑚的甲醇提取物中,分离鉴定了11个化合物：顺-5,8,11,14,17-二十碳五烯酸甲酯(1),顺-4,7,10,13,16,19-二十二碳六烯酸甲酯(2),顺-5,8,11,14-二十四碳烯酸甲酯(3),顺-9,12-十八碳二烯酸甲酯(4),laurenisol(5),2,4-二乙基-5-羟基-2-辛烯醛(6),麦角甾-5,24(28)-二烯-3β-醇(7),3β-羟基-麦角甾-5,24(28) –二烯-7-酮(8),(+)-3,4-二甲基-5-羟基-5-戊基呋喃-2(5H)-酮(9),尿嘧啶(10),胸腺嘧啶(11)。     

巨型艾美球虫第二代裂殖体的分离纯化

目的 寻找分离纯化巨型艾美球虫第二代裂殖体效率更高的方法 . 方法 用孢子化的巨型艾美球虫卵囊喂食21～28日龄SPF雏鸡,平均50万个/只,72 h后剖检出小肠中段,综合运用酶消化、离心洗涤、红细胞裂解和Percoll密度梯度离心等方法分离纯化巨型艾美球虫的第二代裂殖体.结果 从35羽鸡的小肠中段中纯化到裂殖体4.1×105个,平均每羽鸡获得裂殖体1.17×104个,回收率约为89.6%. 结论 此方法简单易行,纯化回收结果适用于艾美属球虫分子生物学方面的研究.     

ERP单次提取中的小波变换模极大值恢复算法

自发脑电的频谱不规则,与有效信号ＥＲＰ频谱相重叠,传统滤波方法难以奏效。但由于随机噪声奇异性指数与有效信号奇异性指数大小不一样,小波变换模极大值在不同尺度下传播行为也不一样,据此可将有效信号从随机噪声中提取出来。我们发现利用小波变换模极大值算法可以提取出单次ＥＲＰ,并将此方法用于１１名被试听觉的实时提取研究。     

Cytotoxic steroid derivatives from the Vietnamese soft coral Sinularia brassica

Using various chromatographic separations, six ergostane-type steroids, including one new compound sinubrassione (1), and two pregnene-type steroid glycosides, including one new compound sinubrassioside (7), were isolated from methanol extract of the Vietnamese soft coral Sinularia brassica. The structure elucidation was confirmed by spectroscopic methods including 1D, 2D NMR and HR-ESI-MS. The cytotoxic activities of all the isolated compounds against three human cancer cell lines were also evaluated using MTT-based colorimetric assays.