Affinity ultrafiltration of DNA topoisomerases-targeted compounds determined with HPLC／ESI-MS for drug candidate screening

A method of screening assay is demonstrated. The approach is based on the affinity of antitumor candidates for topoisomerases. In this method, antitumor candidates are fished out using topoisomerases as targets. Traditional analysis of complex compounds typically encounters signal suppression due to the relatively low concentrations, but enzyme-affinity screening for the active compounds can effectively concentrate the desired analysts into a small volume of high concen-tration. Active compounds are separated from non-affinity compounds by ultrafiltration. The molecules-enzymes complexes that are retained on the filter are subsequently separated by acidification to obtain the topoisomerases-affinity compounds for analysis on High Performance Liquid Chromatography coupled with electrospray ionization mass spectrometric detec-tion (ESI-MS). This enzyme-affinity based screening assay provides a highly specific and efficient method that can directly screen, identify, and acquire drug candidates thus improving the accuracy and speed of high-throughput screening activities.     

Diversity-Oriented Organic Synthesis

A goal of chemical genetics is to find small molecules that modulate the individual functions of gene products with high potency and high specificity. Natural products and natural product-derived compounds provide many of the most striking examples, particularly in terms of their specificity. It seems unlikely that natural products alone will provide the hypothetical “complete” set of small molecules that would allow the functions of all proteins, as well as their individual domains, to be determined. For chemistry to have its maximal effect on biology, efficient methods based on diversity-oriented organic synthesis for discovering this set of small molecules are in great demand（See Fig. 1）.     

Design of a novel optically stimulated luminescent dosimeter using alkaline earth sulfides doped with SrS:Eu,Sm materials

Optically stimulated luminescence （OSL） is the luminescence emitted from an irradiated insulator or semiconductor during exposure to light. The OSL intensity is a function of the dose of radiation absorbed by the sample and thus can be used as the basis of a radiation dosimetry method. Alkaline earth sulfides doped with rare-earth elements such as Ce, Sm and Eu are OSL dosimeters having very high sensitivity, and the OSL with a short time constant is separated from the stimulated light. In this paper, a novel OSL dosimeter designed with SrS：Eu,Sm materials is described. The dosimeter takes advantage of the characteristics of charge trapping materials SrS：Eu,Sm that exhibit OSL. The measuring range of the dosimeter is from 0.01 to 100Gy. The equipment, which is relatively simple and small in size, is promising for applications in space exploration and high dose radiation dosimetry.     

Edge detection of range images using genetic neural networks

Due to the complexity and asymmetrical illumination, the images of object are difficult to be effectively segmented by some routine method. In this paper, a kind of edge detection method based on image features and genetic algorithms neural network for range images was proposed. Fully considering the essential difference between an edge point and a noise point, some characteristic parameters were extracted from range maps as the input nodes of the network in the algorithm. Firstly, a genetic neural network was designed and implemented. The neural network is trained by genetic algorithm, and then genetic neural network algorithm is combined with the virtue of global optimization of genetic algorithm and the virtue of parallel computation of neural network, so that this algorithm is of good global property. The experimental results show that this method can get much faster and more accurate detection results than the classical differential algorithm, and has better antinoise performance.     

Synthesis and antifungi activities of six coumarin compounds carrying halogen and trifluoromethyl

Aim To synthesize six kinds of compounds carrying halogen and trifluoromethyl and confirm their structures,and test their antifungi activities simultaneously.Method With 2-halogen resorcinol and beta ketone ester as raw materials,conducting in strong acid medium by Pechmann condensation reaction,then their products were mixed with different RCl by Williamson reaction to get target molecules.Their structures were confirmed by 1H NMR and MS spectrums,and the antibacterial activities were tested by the growth rate method.Results Six kinds of compounds carrying halogen and trifluoromethyl were synthesized and characterized,and their antifungi activities were tested,as well as the relationship between structures and antibacterial effects were speculated.Conclusion Six coumarin compounds have been prepared,and their structures were confirmed.The antibacterial test shows that compounds 2a～2d have strong activities against Fusarium graminearum Schw.The existence of 7-OH enabled the antibacterial activity enhancing,and 7-OH is the active group.     

Near-infrared absorption imaging and processing technologies based on gold nanorods

Noble metal nanoparticles with localized surface plasmon resonance (LSPR) properties are widely used as optical sensors in biochemical detection and medical diagnosis. In this paper, we propose an effective determination method to measure the LSPR absorption intensity of gold nanorods (GNRs). A near-infrared (NIR) imaging system is established, and an NIR absorption image of the multiple samples of the colloidal GNRs is captured. Then, the LSPR absorption intensities of these samples are obtained by calculating the average grayscale of the target areas based on the NIR image processing technology. By using this method, the LSPR absorption intensities of the multiple samples are determined all at once, and their accuracy is as high as that obtained by using spectrophotometry. These results suggest that this method is an efficient multi-channel determination technique with high-throughput sensing applications.     

Real time observation of the photocleavage of single DNA molecules

A method for real time observation of photo-cleavage of stratched λDNA at single molecular level by a fluorescent microscope coupled with CCD is developed.DNA molecules stained with YOYO-1 are stretched by the mo-lecular combing technique and fixed on a modified slide.Then the Process of Photocleavage and relaxation of DNA under radiation of blue light is observed.We speculate that the conformation change of stretched DNA and the effect of water are likely to facilitate the effect of YOYO photocleav-age DNA molecules.The photocleavage effect of YOYO for stretched DNA may be useful to study DNA elasticity,cancer research as well as the interaction between DNA and dyes.     

Wave impedance of W-Mo system composite

W-Mo composites with different mass fractions of W and Mo were prepared at 1473 K by Spark Plasma Sintering technique. The transverse and longitudinal wave velocities of the samples were accurately measured using the ultrasonic pulse echo overlap method, and the wave impedance values of the samples were then calculated. The results show that W-Mo system composites are of nearly full dense and can be regarded as a mechanical mixture system. The ideal mixture model was adopted to estimate the wave impedance of W-Mo composites. Comparisons with the experimental data demonstrate that the suggested model is sufficiently accurate to predict the wave impedance of W-Mo composites.     

Construction of heteroduplex DNA and<Emphasis Type="Italic">in vitro</Emphasis> model for functional analysis of mismatch repair

Functional deficiency of mismatch repair (MMR) system is one of the mechanisms of tumorigenesis. With the development of the investigation and the requirement from the clinical diagnosis and treatment it is necessary to build up a method to evaluate the functional status of the whole MMR system in the concerned tumors. The original ssDNA and dsDNA from wild type (wt) bacteriophage M13mp2 and its three derivates with mutation points in the lacZα gene have been used to construct two kinds of hetero-duplex DNA molecules. One named del(2) has two bases deleted in the negative strand, the other has a G·G mismatch base pair in the negative strand too. Introducing this heteroduplex DNA into E. coli NR9162 (mutS-) without the MMR ability on the indicator plate with x-gal and IPTG, there are three kinds of plaques, mixture plaque as the characteristic phenotype of heteroduplex DNA, blue and clear plaques. If the cell extract is mismatch repair competent the percentage of the mixture plaque will decrease after incubation with these heteroduplex DNA, the repair efficiency is expressed in percentage as 100× (1 minus the ratio of percentages of mixture plaque obtained from the extract-treated sample and untreated samples), which can imply the functional status of MMR system of certain samples. After large T-antigen-dependent SV-40 DNA replication assay cell extract from TK6, a human lymphoblastoid B-cell lymphoma cell line with MMR ability, and Lovo, a human colonic carcinoma cell line with MMR deficiency have incubated with these heteroduplex DNA. The repair efficiency of TK6 to del(2) is more than 60%, to G-G is more than 50%. The Lovo efficiency to del(2) is less than 10%, to G-G is less than 20%. Therefore, in this in vitro model used for functional analysis of mismatch repair of heteroduplex DNA as the repair target, TK6 can serve as the control for MMR proficiency and Lovo as the control for MMR deficiency. Using this model the tumor tissue from a case of hereditary nonpolyposis colorectal cancer (microsatellite instability high, MSI-H) was measured and lack of MMR ability was shown. And a case of sporadic rectal cancer (SRC) (microsatellite stability, MSS) maintains MMR proficiency. The results indicate that the model is sensitive and dependable. It could be used to measure the func- tion status of MMR system in tumor cell and/or tissues. This is a reliable method to investigate the mechanic of tumori-genesis. It is meaningful in the observation of the role of MMR in the initiation and progression of concerned tumors.     

Detection of low enersy solar neutrinos by a two-phase cryosenic e-bubble detector

A new two-phase cryogenic neutrino detector using electron bubble （e-bubble） specifically in liquid helium is proposed and being developed for real time, high rate measurements of low-energy p-p reac- tion neutrinos from the sun. The e-bubble detector is a time projection chamber-like （TPC） tracking detector. The task of such a neutrino detector is to detect the ionization of the elastically scattered target electrons by incident neutrinos, and then to characterize their energy and direction and to dis- tinguish them from radioactive backgrounds. The ionization signals are expected to be small and hence undergo avalanche amplification in the saturated vapor above the liquid phase by gas electron multi- pliers （GEMs） at high gain. Higher granularity and intrinsically suppressed ion feedback give a good spatial resolution and are the major advantages of this technology. It should be possible to construct such a detector to track charged particles down to 100--200 keV in a massive liquid helium target with fractional millimeter spatial resolution in three-dimensional space, using the GEM-based TPC with a high-resolution CCD camera, for both the electronic and light readout.     

叠氮法合成谷氨酰胺类化合物及其抗肿瘤活性

研究发现抗癌酮（Antineoplaston A10）降解物中谷氨酰胺与异谷氨酰胺类衍生物显示出抗肿瘤少性。为此，设计并合成了一系列苯乙酰谷氨酰胺类化合物供抗肿瘤活性筛选，采用合成酰基叠氮化合物，再与胺类于低湿下反应生成酰胺类目标化合物，该方法反应条件温和，收率好，而且手性中心不发生消旋化，所合成化合物结构经IR、^1HNMR、MS及元素分析方法鉴定。对所合成目标化合物做抗肿瘤活性评价，采用MTT法对L1210细胞进行了测试，初步结果显示有一定的抑制肿瘤细胞存活的作用。     

枣庄柴里煤氧化产物的热重和红外分析

先用溶剂对柴里煤进行彻底萃取,再用双氧水将萃余煤进行氧化,对原煤、萃余煤和氧化残煤用热重和红外进行分析.结果表明：萃余煤和氧化残煤的内部结构发生变化,原煤的结构最复杂,萃余煤中的小分子相对减少了很多,但氧化残煤内部又有小分子出现,说明氧化能断开煤分子内部的某些键.由红外光谱分析得出煤是一种含有多官能团的复杂的混合物,萃取和氧化使煤中的有机物发生了改变,两者产生的变化是有一定的差别的,但是由各谱图吸收峰可以看出,萃取或氧化前后煤中的官能团种类变化并不大,其中某些物质的含量却发生了较大的变化.     

结合灰度熵变换的PCNN小目标图像检测新方法

为了自动地进行小目标图像分割检测,从含单一弱小目标图像的特征出发,提出了一种结合灰度熵变换的脉冲耦合神经网络(PCNN)小目标图像分割检测新方法. 该方法在对有随机噪声和复杂背景图像进行非线性灰度熵变换滤波的基础上,考虑灰度熵值灰度图在满足先验概率目标背景比条件下,选择包含单一小目标局部窗口作为处理图像区域,并在局部最小交叉熵判据下,进行改进型PCNN迭代分割检测处理. 实验结果表明,该方法不仅能可靠地检测出复杂背景及随机噪声干扰下弱小目标,并且在PCNN运行处理过程中,可自动地完成最佳分割检测.     

基于非线性局部滤波的红外小目标检测方法

为提高复杂环境下红外小目标的检测效率,将图像分为平坦区域、边缘区域和小目标区域三种区域,并针对三种成分的特点,提出基于拉普拉斯金字塔的非线性局部滤波检测方法。首先将图像进行高斯金字塔分解,将高斯低通金字塔与原图像尺寸匹配后,相减并进行阈值操作,抑制平坦区域;其次将标记像素灰度值与其周围环域均值的最小差作为指标,滤除边界区域;最后将非线性局部滤波结果生成相应的拉普拉斯金字塔各层系数,重构得到高对比度的检测图像,利用邻域特点剔除孤立噪声点并通过简单阈值标记红外小目标。实验结果表明：与现有其他算法相比,该检测算法能够对复杂背景有效抑制,检测速度快。     

Component fractionation of wood-tar by column chromatography with the packing material of silica gel

Bio-oil can be an important fuel resource for automobiles in the future,while its complex composition restricts the direct application of the bio-oil extremely.So it is necessary to separate the complex mixture to relatively simplified fractions for goal directed specific treatments to reach the fuel quality for automobiles,and meanwhile different functional chemical materials and fine chemicals can be obtained.So it is significant to investigate the bio-oil component separating methods.Herein the method of column chromatography by the packing material of silica gel with two series of eluants of cyclohexane-benzene-methanol and cyclohexane-dichloromethane-methanol were investigated for component fractionation of the raw wood tar (oil fraction of the liquid product by slow pyrolysis of wood).The analytical results show that the components in cyclohexane are rich in alkoxyl-monophenols;the components of alkyl-monophenols and five ring oxygen-containing compounds are abundant in benzene and in dichloromethane similarly;in the methanol fraction,the components are diverse and diphenols are relatively in higher content,comparatively small polar molecules and five ring oxygen-containing compounds are more abundant in the methanol fraction after being eluted by dichloromethane,and the content of 1-(4-hydroxy-3-methoxyphenyl)-2-propanone is higher after being eluted by benzene.     

分子对接技术筛选沉香中抗新型冠状病毒活性成分

从沉香中筛选潜在的抗新型冠状病毒活性成分,指导以沉香小分子作为SARS-CoV-2潜在阻断剂和抑制剂药物的研发.根据沉香已知的化学成分,采用分子对接的方法,以血管紧张素转化酶-2(ACE2)、SARS-CoV-2的3CL水解酶(3CLpro)为靶标,通过结合打分值以及与靶蛋白受体的相互作用模式,获得沉香中具有潜在抗SA...     

核磁共振技术追踪白花蛇舌草分离纯化过程中化学成分的变化

利用核磁共振技术追踪检测白花蛇舌草活性部位分离纯化过程中化学成分的变化,通过HPLC-MS法分析化学成分含量呈动态分布的系列混合物.以核磁共振和高效液相色谱-质谱动态谱学方法追踪检测四种单体,准确的指导了有效部位的分离纯化过程.结果表明,将核磁共振技术作为选择性提取分离的监测手段,依据目标化合物的NMR谱学特征,以1H-NMR监控和指导从白花蛇舌草有效部位中寻找和得到四种化合物收到了较好的效果,传统检测手段HPLC-MS在结果上达到了高度的一致.并运用多种核磁共振技术对分离得到的化合物进行了结构解析,提高了复杂很合物的分析效率.     

基于视觉的水面垃圾清理机器人目标检测算法

针对中小型水域漂浮垃圾清理困难问题,通过分析水面图像的特点,提出基于视觉的水面机器人垃圾检测方法。首先使用Mean-shift滤波平滑算法,在保持目标边缘的基础上尽可能平滑波纹的干扰;然后使用基于色差灰度模型与改进的OTSU阈值法分割出水面目标,能有效地抑制水面光照不均和水面倒影的问题;接下来采用先闭运算后开运算的形态学处理,填充小孔、消除孤立噪声点;最后计算各目标对象的质心坐标,最小外界矩,对目标进行标记,进为机器人的进一步动作提供依据。实验结果表明该方法能够较好地克服水面复杂环境影响,快速、准确地提取出水面的漂浮垃圾。     

基于联合对抗训练的鲁棒度量迁移

迁移度量学习旨在从强大且可靠的距离度量中迁移知识来改善目标度量的效果,这些度量往往来自于学习目标相关的任务.现有的迁移度量学习算法仅关注于如何迁移知识,而这些知识容易过拟合到源域中.首先研究如何在源域中训练一个适合于迁移的源域度量,然后设计了一种通用的深度异质迁移算法来进行高效的迁移学习.值得注意的是,将源域度量以联合对抗学习的方式进行训练,再以深度神经网络的方式将其参数化表示并对其进行迁移.迁移中通过表征模仿的方式来学习源域度量中的知识,这种方式允许源域和目标域中的知识来自于异质域.此外,严格限制目标度量网络的大小,使得目标网络更够进行高效的推理计算.在人脸识别数据集上的实验展现了本方法的有效性.     

复杂背景下目标树叶自动分割的Grabcut算法

针对传统GrabCut算法需要人机交互且难以在复杂背景或光照不均匀时准确分割目标树叶的缺点,提出一种基于GrabCut算法的复杂背景下或光照不均匀时目标树叶的自动分割算法。本算法利用模糊高斯混合模型(FGMM)和图像的颜色信息对原始图像进行标记实现自动分割。首先选取合适的模糊因子利用模糊高斯混合模型对图像像素进行一次标记;在一次标记的基础上再结合超绿算法(EXG)选取合适的阈值对图像像素进行二次标记;最后将二次标记图像初始化GrabCut算法实现目标树叶的自动分割。利用几种不同的样本对提出算法的有效性和错分率进行探讨。结果表明,所提出的算法可以实现复杂背景下或光照不均匀时目标树叶的自动分割,且平均错分率达到1.625。