香附药材HPLC指纹图谱研究及相似度评价

目的：研究香附药材的HPLC色谱,并对其进行相似度评价。方法：采用梯度洗脱法测定12批香附药材的HPLC色谱,流动相为甲醇一水线性梯度洗脱,检测波长为254nm;记录时间为70min。采用“中药色谱指纹图谱相似度评价系统2004A版”进行评价。结果：12批香附高效液相色谱与对照HPLC指纹图谱比较,中位数相关系数在0．901～0．993之间,均值相关系数在0．913～0．996之间。结论：香附药材指纹图谱相似度较高。表明该方法准确、重复性好。     

盐酸双苯氟嗪单层芯渗透泵控释片的研制

目的:研制盐酸双苯氟嗪(DH)单层芯渗透泵控释片,并考察各因素对其体外释放度的影响。方法:以醋酸纤维素等为包衣材料制备DH单层芯渗透泵控释片,采用相似因子(f2)法考察片芯中助溶剂的种类、致孔剂聚乙二醇6000用量及包衣增重各因素对药物释放度的影响,确定最佳处方并进行验证。结果:各考察因素均为影响药物释放的主要因素(f2值均小于60),确定酒石酸3%和;丁所二制酸3(批6制5∶剂13在0)1为2助h内溶释剂药,采速用率醋基酸本纤恒维定素,呈与现聚良乙好二的醇零60级00(释1放0∶特1)征混(合r=作0为.99包6衣3)膜。组结成论,:致DH孔单剂层用芯量渗为透1泵0%控,释包片衣工增艺重稳为定,符合控释片要求。     

补肾健骨胶囊高效液相色谱指纹图谱及主成分分析

目的：建立补肾健骨胶囊的高效液相色谱法(HPLC)指纹图谱,并进行主成分分析。方法：采用HPLC,色谱柱为Thermo-Hypersil GOLD^TM-C18(250 mm×4.6 mm×5μm),流动相为乙腈-0.2%磷酸水溶液(梯度洗脱),流速为1.0 mL/min,检测波长为235 nm,柱温为30℃,进样量为10μL。根据15批样品的HPLC检测图谱,采用国家药典委员会《中药色谱指纹图谱相似度评价系统》(2012年版)进行相似度评价和共有峰的确定,并采用Minitab17.0软件进行主成分分析。结果：补肾健骨胶囊指纹图谱共标出13个共有峰,并指认了其中3个共有峰,分别为莫诺苷、马钱苷、淫羊藿苷;15批样品的相似度均大于0.9,各批次样品之间有良好的相似性。经主成分分析,共提取出2个主成分,方差累计贡献率为92.3%,样品中1、2、4、6、8、13号共有峰(特别是13号共有峰)对应成分的含量变化是导致样品质量差异的重要原因。结论：所建HPLC指纹图谱及主成分分析结果可为补肾健骨胶囊的质量评价提供参考。     

中药材白英XRD指纹图谱及相似度分析

目的:建立白英药材XRD的鉴定分析新方法。方法:对白英药材不同药用部位进行X射线衍射分析,并按2θ进行相似度计算与分析。结果:获得了白英药材不同药用部位的X射线衍射Fourier指纹图谱。结论:粉末X射线衍射Fourier指纹图谱鉴定法可用于白英药材不同药用部位的鉴定和识别,相似度的计算结果进一步证明了方法的可行性。     

采用视频跟踪技术考察酒石酸美托洛尔片的溶出行为

目的 采用视频跟踪技术考察酒石酸美托洛尔片的溶出行为,为仿制药的质量评价提供新的技术参考。方法 以酒石酸美托洛尔片为模型药物,pH1.2的氯化钠盐酸溶液为溶出介质,采用摄像头视频跟踪直观考察溶出行为;同时测定酒石酸美托洛尔片的溶出曲线并计算相似因子(f₂),并对处方组成、比例及其制剂工艺进行剖析。结果 各时间点的视频图显示各企业样品均为溶蚀性崩解,与原研一致;企业A的样品与原研溶出行为最为接近,B、G和J的25 mg规格样品以及企业E、I和J的50 mg规格样品与原研溶出行为存在较大的差异,与溶出曲线获得的结果一致。溶出视频记录的溶散速率和崩解的颗粒大小、形态更直观反映出处方工艺的差异。结论 视频跟踪技术清晰客观地反映了酒石酸美托洛尔片的溶出行为,为溶出质量评价提供新思路新方法。     

基于改进SLNC的2D-3D医学图像配准

介绍了一种基于改进SLNC(sum of local normalized correlation,SLNC)的2D-3D医学图像配准方法。首先对CT体积数据进行三线性插值,得到各向分辨率相同的体积数据,采用光线跟踪算法对其进行数字图像重建。针对不同位置和方向的重建图像,在灰度级压缩的基础上,用改进SLNC函数评价其与X线透视图像的相似性,利用与Brent相结合的Powell优化方法,搜索出相似性最大时的投影变换参数。将此方法用于移动数字X线投影设备——Biplanar 500采集的X线透视图像与相应CT体积数据的配准实验,得到较好的2D-3D图像配准效果。     

中医医案方剂多维相似度算法设计与探索＊

中医医案方剂具有多维度的特性，单独采用一种相似度算法难以展现方剂数据在各维度的相似情况，具有一定的局限性。本研究基于中医医案方剂的多维数据特点，结合中医临床遣方用药的思维过程，设计了中医医案方剂的多维相似度算法，并以七则国医大师医案为示例，详细展示了该算法的计算过程，同时将多维相似度算法计算结果与传统算法计算结果进行了对比分析。通过对比可以看出本算法能够相对全面地反映不同方剂间的相似度，且结果更为合理也更贴合中医临床实际。     

How do taxonomic versus thematic relations impact similarity and difference judgments? An ERP study

Taxonomically related concepts like “bee” and “butterfly” and thematically related concepts like “bee” and “honey” have different roles in similarity judgments. We examined the complex impact of taxonomic and thematic relations on similarity and difference judgments via ERPs in a S1–S2 paradigm. Subjects were required to remember a word denoting some object or animal (S1), and compare that to a second word (S2) that was either thematically related, taxonomically related or unrelated to S1, making a “high” or “low” similarity and difference judgments in separate blocks. We found two main differences that suggest thematic and taxonomic relations engage distinct neural processes. The first difference is an N400 effect peaking between 300 ms and 400 ms that is more negative for unrelated words than for thematically and taxonomically related words. The second difference is a frontally distributed P600 peaking between 500 ms and 600 ms that is larger for taxonomically related words than for both unrelated and thematically related words. These results suggest that the dual process model for perceiving similarity is superior to the comparison only model of similarity judgments, and furthermore, provide evidence that the thematic relations are dissociative from taxonomic relations in making similarity and difference judgments.     

A Novel Similarity Learning Method via Relative Comparison for Content-Based Medical Image Retrieval

Nowadays, the huge volume of medical images represents an enormous challenge towards health-care organizations, as it is often hard for clinicians and researchers to manage, access, and share the image database easily. Content-based medical image retrieval (CBMIR) techniques are employed to facilitate the above process. It is known that a few concrete factors, including visual attributes extracted from images, measures encoding the similarity between images, user interaction, etc. play important roles in determining the retrieval performance. This paper concentrates on the similarity learning problem of CBMIR. A novel similarity learning paradigm is proposed via relative comparison, and a large database composed of 5,000 images is utilized to evaluate the retrieval performance. Extensive experimental results and comprehensive statistical analysis demonstrate the superiority of adopting the newly introduced learning paradigm, compared with several conventional supervised and semi-supervised similarity learning methods, in the presented CBMIR application.     

In silico strategies on prion pathogenic conversion and inhibition from PrPC –PrPSc

Introduction: To date, various therapeutic strategies identified numerous anti-prion compounds and antibodies that stabilize PrP^C, block the conversion of PrP^C-PrP^Sc and increased effect on PrP^Sc clearance. However, no suitable drug has been identified clinically so far due to the poor oral absorption, low blood–brain-barrier [BBB] penetration, and high toxicity. Although some of the drugs were proven to be effective in prion-infected cell culture and whole animal models, none of them increased the rate of survival compared to placebo.

Areas covered: In this review, the authors highlight the importance of in silico approaches like molecular docking, virtual screening, pharmacophore analysis, molecular dynamics, QSAR, CoMFA and CoMSIA applied to detect molecular mechanisms of prion inhibition and conversion from PrP^C-PrP^Sc.

Expert opinion: Several in silico approaches combined with experimental studies have provided many structural and functional clues on the stability and physiological activity of prion mutants. Further, various studies of in silico and in vivo approaches were also shown to identify several new small organic anti-scrapie compounds to decrease the accumulation of PrP^res in cell culture, inhibit the aggregation of a PrP^C peptide, and possess pharmacokinetic characteristics that confirm the drug-likeness of these compounds.