紫外线照射所致的DNA损伤对连接转化的影响

目的探讨DNA经不同波长紫外线照射与经紫外线照射不同时间所致损伤对基因库构建中DNA连接转化效率的影响。方法经改造的质粒DNA使用SfiI酶切过夜,1%琼脂糖凝胶电泳分离,在不同波长不同时间紫外线照射的条件下回收目的片断,并进行目的片断的连接转化,计数菌落数,计算转化效率。结果经302nm波长紫外线照射后,其连接转化的菌落数极少(60个/ngDNA),365nm波长紫外线照射条件下回收的DNA仍可被有效连接转化。在365nm波长紫外线照射下,与未经照射进行比较,当照射时间在30min,其连接转化成功率低于50%,而照射5min、15min的连接转化成功率仍高于70%,可满足大部分分子生物学实验的需要。回收的DNA连接转化的最大效率可超过20000个菌落/1ngDNA。结论在构建大容量基因库回收目的片断时,应避免紫外线的照射;在需要时,应选择在365nm波长紫外线照射条件下进行,且照射时间应尽量缩短,以不超过15min为宜。     

Comparison of Recurrence Rates with Contour-Loop Excision of the Transformation Zone (C-LETZ) and Large Loop Excision of the Transformation Zone (LLETZ) for CIN

Aim: To compare recurrence rates of large loop excision of the transformation zone (LLETZ) with those of contour-loop excision of the transformation zone (C-LETZ) in the management of cervical intraepithelial neoplasia (CIN). Materials and Methods: The medical records of 177 patients treated consecutively by LLETZ and C-LETZ for CIN at Rajavithi Hospital between 2006 and 2009 were retrospectively reviewed. Results: Of the 87 women in the C-LETZ group, 2 cases (2.30%) had recurrence compared with 13 cases (14.4%) of the 90 women in the LLETZ group, the higher recurrence rate in the latter being statistically significant (p<0.05). Median times of follow up in the C-LETZ and LLETZ groups were 12 months and 14 months respectively (p>0.05). The C-LETZ group showed less intraoperative bleeding compared to the LLETZ group, but the rate of achievement of single specimens and positive margins were similar in the two groups. Conclusions: The present study demonstrated the superiority of C-LETZ over LLETZ in terms of efficacy; C-LLETZ is associated with a lower recurrence rate and also carries a smaller risk of intraoperative bleeding than LLETZ. The rotatingtechnique still has a potential role in treating precancerous lesions of the cervix.     

卵巢子宫内膜异位症恶变与卵巢癌的相关性研究及预后分析

目的:探讨不同原因所致卵巢癌,尤其是是否由卵巢子宫内膜异位症(EMT)恶变而来的卵巢癌的临床病理及预后特征。方法:纳入2006年1月至2011年8月在四川大学华西第二医院病理检查确诊的有随访资料(术后随访时间2~89月)的EMT恶变者所致原发性卵巢癌患者49例为EMT恶变组,其病理类型为透明细胞癌、子宫内膜样腺癌及混合性腺癌;另选择非EMT恶变所致卵巢癌并与EMT恶变者具有相同组织学类型的卵巢癌患者188例为非EMT恶变组,比较两组卵巢癌的临床病理特征及预后特征。结果:1与非EMT恶变组比较,EMT恶变组在40岁人群中所占比例较大、CA125更多表现为正常而非升高、FIGO分期早期病例比例更多、透明细胞癌及子宫内膜样腺癌这两种病理类型的比例较高,两组差异有统计学意义(P0.05)。2单因素预后分析:EMT恶变所致透明细胞癌的生存率明显高于非EMT恶变所致透明细胞癌(P=0.010),是否由EMT恶变对子宫内膜样腺癌及混合性腺癌的预后影响不确切(P0.05)。3多因素COX回归分析:EMT恶变、手术满意度及FIGO分期是影响预后的独立危险因素。结论:EMT恶变所致卵巢癌病理类型主要包括透明细胞癌和子宫内膜样腺癌,EMT恶变是卵巢癌预后的独立影响因素,EMT恶变患者年龄相对较年轻、FIGO分期相对较早,尤其对透明细胞癌而言,EMT恶变的患者可能拥有更好的预后。     

基于小波和卡尔曼平滑的事件相关电位单次提取

本研究提出一种事件相关电位单次提取方法,可有效减少实验次数,并可探索实验之间ERP的变异性。此方法基于小波和卡尔曼平滑,首先利用小波变换考察ERP平均信号的时频特性,根据ERP不同分量出现的时间位置,在不同尺度上选取特定的单次实验ERP小波系数构成观测向量,其为真实ERP小波系数状态向量与噪声之和,然后对观测向量进行卡尔曼平滑,最后对卡尔曼平滑后的小波系数进行小波重构,得到单次提取的ERP信号。仿真实验表明,基于小波和卡尔曼平滑的方法不仅信噪比提高约16~18 dB,优于30次叠加平均、简单小波方法和基于高斯基函数的卡尔曼滤波方法,还可以跟踪ERP的幅度趋势变异性。与基于高斯基函数的卡尔曼滤波方法相比,所提方法降低了计算量。真实脑电ERP提取实验表明本方法较好地从单次记录中提取出了事件相关电位,并可解释ERP因适应和应激引起的趋势变异性。     

皮肤药物不良反应的研究进展

药物不良反应十分常见,而皮肤是其重要的靶器官之一.皮肤药物不良反应(cutaneous adverse drug reaction,CADR)的发病机制复杂,临床表现多样,病因诊断较为困难.现概述CADR的特殊临床表现、发生机制和诊断方法.一、药物皮肤不良反应的临床表现1.痤疮样疹或脓疱型药疹:痤疮样疹可由碘剂、溴剂、促肾上腺皮质激素、糖皮质激素、异烟肼、雄激素、锂剂、放线菌素D和苯妥英引起[1].     

Photodynamic Cancer Therapy Using Wavelet Based Monte Carlo Computation of Light Absorption with a Genetic Algorithm

Objective: The method to treating cancer that combines light and light-sensitive drugs to selectively destroy tumour cells without harming healthy tissue is called photodynamic therapy (PDT). It requires accurate data for light dose distribution, generated with scalable algorithms. One of the benchmark approaches involves Monte Carlo (MC) simulations. This gives an accurate assessment of light dose distribution, but is very demanding in computation time, which prevents routine application for treatment planning. Methods: In order to resolve this problem, a design for MC simulation based on the gold standard software in biophotonics was implemented with a large modern wavelet based genetic algorithm search (WGAS). Result: The accuracy of the proposed method was compared to that with the standard optimization method using a realistic skin model. The maximum stop band attenuation of the designed LP, HP, BP and BS filters was assessed using the proposed WGAS algorithm as well as with other methods. Conclusion: In this paper, the proposed methodology employs intermediate wavelets which improve the diversification rate of the charged genetic algorithm search and that leads to significant improvement in design effort efficiency.     

MRI Brain Tumour Segmentation Using Hybrid Clustering and Classification by Back Propagation Algorithm

Generally the segmentation refers, the partitioning of an image into smaller regions to identify or locate the region ofabnormality. Even though image segmentation is the challenging task in medical applications, due to contrary image,local observations of an image, noise image, non uniform texture of the images and so on. Many techniques are availablefor image segmentation, but still it requires to introduce an efficient, fast medical image segmentation methods. Thisresearch article introduces an efficient image segmentation method based on K means clustering integrated witha spatial Fuzzy C means clustering algorithms. The suggested technique combines the advantages of the two methods.K means segmentation requires minimum computation time, but spatial Fuzzy C means provides high accuracy forimage segmentation. The performance of the proposed method is evaluated in terms of accuracy, PSNR and processingtime. It also provides good implementation results for MRI brain image segmentation with high accuracy and minimalexecution time. After completing the segmentation the of abnormal part of the input MRI brain image, it is compulsoryto classify the image is normal or abnormal. There are many classifiers like a self organizing map, Back propagationalgorithm, support vector machine etc., The algorithm helps to classify the abnormalities like benign or malignant braintumour in case of MRI brain image. The abnormality is detected based on the extracted features from an input image.Discrete wavelet transform helps to find the hidden information from the MRI brain image. The extracted features aretrained by Back Propagation Algorithm to classify the abnormalities of MRI brain image.     

药用植物中转基因元件筛查策略研究

通过对已有药用植物转基因研究文献进行总结分析,为药用植物和中药材转基因监管提供有效策略。采用关键词检索法对中国知网和SCI两大数据库进行查询,建立48种常用药用植物转基因研究中常用表达元件的数据库,分析转基因元件使用情况,并总结外源转基因的筛查策略。获得1993年4月至2016年5月的转基因研究文献281篇,包括中文文献230篇,英文文献51篇。40.4%的中文文献和54.9%的英文文献研究目的为优化药用植物遗传转化体系。常用启动子包括P-35S、P-Ubi、P-GPD和P-act,其中P-35S的使用频率最高,为68.7%。常用标记基因包括NPTII、HPT、Gent、Bar和aad A,其中NPTII的使用频率最高,为37.4%。常用报告基因包括GUS和GFP,GUS使用频率达到35.2%。常用终止子包括T-NOS、T-35S和T-OCS,其中T-NOS的使用频率最高,为58%。对各元件进行配组分析,发现"P-35S+T-NOS+NPTII+GUS"组合筛选成功率为86.1%,在此基础上加入有一定使用频率的HPT、Bar和GFP,对药用植物转基因元件的筛查率达到91.5%。对于使用同源或内源启动子、标记基因和终止子的研究,可基于T-DNA边界序列进行转基因检测。     

Multiresolution wavelet framework models brightness induction effects

A new multiresolution wavelet model is presented here, which accounts for brightness assimilation and contrast effects in a unified framework, and includes known psychophysical and physiological attributes of the primate visual system (such as spatial frequency channels, oriented receptive fields, contrast sensitivity function, contrast non-linearities, and a unified set of parameters). Like other low-level models, such as the ODOG model [Blakeslee, B., & McCourt, M. E. (1999). A multiscale spatial filtering account of the white effect, simultaneous brightness contrast and grating induction. Vision Research, 39, 4361-4377], this formulation reproduces visual effects such as simultaneous contrast, the White effect, grating induction, the Todorovi? effect, Mach bands, the Chevreul effect and the Adelson-Logvinenko tile effects, but it also reproduces other previously unexplained effects such as the dungeon illusion, all using a single set of parameters.