基于PPCT混合编码的防篡改水印方案

简单介绍了动态图水印的特征,概括了典型的PPCT的编码特征和纠错属性,分析了分别将PPCT与排列图和k-基数相结合的编码方案,提出一种改进的PPCT防篡改水印方案。该方案在不改变PPCT结构的前提下,引入基数编码提高了水印的数据率;利用防篡改技术弥补了PPCT纠错属性的局限性,实现了水印的双重防篡改功能;采用水印的冗余嵌入实现了水印的容错提取,增强了水印的鲁棒性。     

基于UPLC-Q-TOF MS分析加工炮制对玄参化学成分的影响

为了全面阐明玄参加工工艺对其化学成分的影响,采用UPLC-Q-TOF MS技术对烘干玄参和传统加工玄参的化学成分进行分析比较,并运用主成分分析法(PCA)和正交偏最小二乘辨别分析法(OPLS-DA)进行数据统计,寻找差异性成分,同时依据一级质谱精确质荷比和二级质谱碎片信息进行成分解析。结果表明:与烘干玄参相比,传统加工玄参中共有26种成分的含量变化显著,实验鉴定出了其中的15种成分,包括9种环烯醚萜类化合物和6种苯丙素类化合物;含量降低的成分有桃叶珊瑚苷、6-O-甲基梓醇、哈巴俄苷、8-O-香豆酰基哈巴俄苷、8-O-阿魏酰基哈巴俄苷、阿格托苷、异阿格托苷、安格洛苷C和scrophuloside B1,其中scrophuloside B1为玄参中首次发现的成分;含量增加的成分有哈巴苷、哈巴俄苷同分异构体、6″-O-α-D-半乳糖哈巴俄苷、6-O-α-D-半乳糖哈巴俄苷、斩龙剑苷A和肉桂酸。本工作对研究玄参加工炮制机制有重要意义,同时可为阐明玄参药效的物质基础提供依据。     

甘草酸的提取和精制法研究现状

对几种从甘草中提取、精制甘草酸的主要方法进行了综述和讨论。     

丹参有效成分综合提取技术

采用薄层层析定性、高效液相色谱定量分析,以丹酚酸B、丹参素、丹参酮ⅡA、隐丹参酮为指标,系统考察了不同提取溶剂、溶剂提取顺序对丹酚酸B、丹参素、丹参酮ⅡA及隐丹参酮提取率的影响,确定了丹参活性成分的最佳提取顺序和提取溶剂。结果表明,先提取脂溶性成分再提取水溶性成分有利于丹参有效成分的综合提取,并且二氯甲烷对脂溶性成分提取率较高。在丹参活性成分的提取中,可先用二氯甲烷提取脂溶性成分后再用甲醇提取水溶性成分,实现丹参活性成分的综合提取。     

葛根提取方法的比较研究及其工艺条件优化

采用水提法、回流法、渗漉法、索氏提取法、微波辅助萃取法、超声提取法等不同的方法提取葛根药材,以干浸膏得率、总黄酮得率及葛根素粗品得率为考察指标,对6种提取方法进行比较,并对其中一种最优方法进行工艺优化。结果表明,传统水提法提取葛根药材的效果最好。通过正交试验获得最佳提取工艺条件为8倍量溶剂,提取3次,每次1.5 h,其中溶剂倍量和提取次数为显著影响因素。水提法提取葛根药材,方法简便,有效成分的提取率高。     

三维同步荧光结合二阶校正算法研究三七的荧光特征

三七在现代中成药市场作为原料有着巨大的消耗 量,根源是其具有重要的药物价值,因此对三七的 研究具有着现实意义。但是三七含有几十余种化学成分,是典型的多组分物质,普通二维荧 光光谱对其难 以进行定量分析。本文应用FLS920荧光光谱仪测量了22个不同浓度的三七粉水溶液样本的三维同步荧光 光谱,结合二阶校正算法以及分半信度法(Split half Method)、核一致诊断算法(Core Consistency Diagnostic) 等分析确定三七粉水溶液的平行因子模型组分数为3。第一组分荧光特征峰区间λEx=380 nm, λEm=465 nm;第二组分荧光特征峰区间λEx=465 nm,λEm=515 nm;第三组分荧光特征峰区间 λEx=330 nm,λEm =415 nm。其第三组分荧光可能是人参 皂苷R_g1的荧光表现。实验发现,对于多组 分物质应用三维同步荧光光谱法结合二阶校正算法进行分析,可以去除冗余干扰信息,简化 光谱分析难度,从全局视角表达三七的整体荧光特性,为天然药物的分析提供建议与帮助。     

Efficient parallel algorithms for graph problems

We present an efficient technique for parallel manipulation of data structures that avoids memory access conflicts. That is, this technique works on the Exclusive Read/Exclusive Write (EREW) model of computation, which is the weakest shared memory, MIMD machine model. It is used in a new parallel radix sort algorithm that is optimal for keys whose values are over a small range. Using the radix sort and known results for parallel prefix on linked lists, we develop parallel algorithms that efficiently solve various computations on trees and unicycular graphs. Finally, we develop parallel algorithms for connected components, spanning trees, minimum spanning trees, and other graph problems. All of the graph algorithms achieve linear speedup for all but the sparsest graphs.Part of this work was done while the first author was at the University of Illinois, Urbana-Champaign, the second author was at Carnegie-Mellon University, and the third author was at the Hebrew University and the Courant Institute of Mathematical Sciences, New York University. A preliminary version of this work was presented at the 1986 International Conference on Parallel Processing.     

Preparation of nasal temperature-sensitive in situ gel of Radix Bupleuri and evaluation of the febrile response mechanism

Objective: This study developed a nasal temperature-sensitive in situ gel system for Radix Bupleuri. Method: Using 20% Poloxamer 407 as the gel base and 6% PEG 4000 adjusting the gelation temperature. Results: The system is liquid at 4°C. It can change its phase to gel above 30°C, which is close to the temperature in nasal cavity. The antipyretic effect produced by Radix Bupleuri in situ gel formulation was investigated in fevered rabbits. The results show that it can prolong the effective time to 24 hours compared with 4–6 hours in Radix Bupleuri intranasal solution. The antipyretic response mechanism was researched by evaluating the relationship between body temperature and concentrations of cyclic adenosine monophosphate in cerebrospinal fluid. The results showed that the two parameters were positively correlated (r = 0.9435, P < 0.05). Six hours later after given in situ gel, the concentrations of cAMP were significantly lower than those in the solution group. It confirmed that temperature-sensitive Radix Bupleuri in situ gel applied in the nasal sprays had a longer residence and release time. Conclusion: Radix Bupleuri nasal temperature-sensitive in situ gel has a higher medical effect and a longer effective time. Compared to the traditional nasal spray, it is more applicable for the treatment of fever.     

Radix Paeoniae Rubra and Radix Paeoniae Alba Attenuate CCl4-Induced Acute Liver Injury: An Ultra-Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS) Based Metabolomic Approach for the Pharmacodynamic Study of Traditional Chinese Medicines (TCMs)

Metabolomics has been frequently used in pharmacodynamic studies, especially those on traditional Chinese medicine (TCM). Radix Paeoniae Alba and Radix Paeoniae Rubra are popularly used in TCM, and both have hepatoprotective effects. In this study, a CCl₄-induced acute liver injury rat model was established and confirmed by the observed serum aminotransferase activities. The metabolomics approach was applied to study the influence of Radix Paeoniae Alba and Radix Paeoniae Rubra on the metabolic changes in rats with acute liver injury. The partial least-squares-discriminant analysis (PLS-DA) of rat serum and their ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) fingerprints allowed discrimination of controlled, acute liver injury-model rats after administration of the two types of TCMs. The time-dependent PLS-DA plots showed that the changes in the metabolic patterns of the rats, which were administered with the TCMs, had stabilized within 2 h after they received the intraperitoneal CCl₄ injection. The results indicated the protective effect of TCMs against liver injury. Several potential biomarkers were detected and identified, which included creatine, deoxycholic acid, choline, 5-methylenetetrahydrofolate, folic acid, and glycocholic acid. The physiological significance of these metabolic changes was discussed.