Design,synthesis and evaluation of PPAR gamma binding activity of 2-thioxo-4-thiazolidinone derivatives

We designed and synthesized a series of 2-thioxo-4-thiazolidinone derivatives and evaluated them on peroxisome proliferator activated receptor γ(PPARγ) binding activities.Through the biological assays,compounds 18 and 38 were highlighted with K_i values of 12.15 nmol/Land 14.46 nmol/L,respectively.Then structure-activity relationship(SAR) was analyzed to screen privileged structural modifications.Moreover,molecular fitting of these compounds onto the approved drug Rosightazone in the PPARγligand binding domain was performed to elucidate the SAR and explore potential receptor-ligand interactions.These results demonstrate that the 2-thioxo-4-thiazolidinones can be considered as new promising molecular probes with excellent binding activities to PPARγ.     

Cationic derivatives of the plant resistance inducer benzo[1,2,3]thiadiazole-7-carbothioic acid S-methyl ester (BTH) as bifunctional ionic liquids

We have synthesized, new salt derivatives of benzo[1,2,3]thiadiazole-7-carbothioic acid S-methyl ester (BTH) containing BTH as the cation in combination with anions, which modify the physical and antibacterial properties of the resulting product while preserving the systemic acquired resistance (SAR) induction properties. The obtained compounds were tested toward induction of resistance in tobacco (Nicotiana tabacum var. Xanthi), which was later infected with OLV-1 and TMV viruses. Moreover in vitro tests on bacteria confirmed the preservation of antibacterial properties brought about by a docusate anion.     

一种多方向的合成孔径雷达图像边缘检测方法

经典的边缘检测方法(Canny, Roberts, Prewitt等)受合成孔径雷达(SAR)图像斑点噪声的影响致使其检测效果不佳;基于SAR图像的假设检验方法(Ratio算法等)其检测性能不随图像强度的变化而变化,边缘检测错误率低,但检测到的边缘片段较粗;针对上述问题,结合小波的多分辨分析特性以及Contourlet变换的充分捕获高维奇异信号的能力,提出一种改进的Contourlet变换与改进小波变换的模极大值方法对SAR图像进行边缘检测,在16个方向上对SAR图像进行边缘提取,进而保证了边缘信息的丰富性;试验结果表明,该方法提取的SAR图像边缘位置精确,运算速度较快,利于后续的图像匹配。     

Cross-calibration between beta and gamma sources using quartz OSL: Consequences of the use of the SAR protocol in optical dating

The radiation dose delivered by the ⁹⁰Sr beta source of a TL-OSL reader and the one delivered by a ¹³⁷Cs gamma source were compared using OSL dating techniques and tools. Three sets of quartz of different origins (rock, sediment and loess) were studied and measured by the SAR protocol (Single aliquot regenerative dose protocol) after irradiations carried out either by the ⁹⁰Sr source or by a ¹³⁷Cs source. Measurements show that the values obtained by the SAR protocol must be corrected in order to provide an acceptable cross-calibration of the beta and gamma source. Once applied, measurement sets become self-consistent and compatible with expected values. The consequences of the above mentioned observations on the methodology of OSL dating are discussed and suggest that a mixed protocol be used including both the SAR protocol and an added dose techniques close to the SARA protocol (Single aliquot regenerative and added dose protocol).     

结合边缘信息和图像特征信息的曲波域遥感图像融合

曲波变换是一种更适合于图像处理的多尺度几何分析方法,具有比小波变换更强的方向选择和辨识能力,而且对图像边缘的表达更优于小波.结合色度-饱合度-亮度变换将其应用于合成孔径雷达图像和多光谱图像融合可以更好地表示图像中的有用特征.首先对多光谱图像进行色度-饱合度-亮度变换,得到亮度分量I,对雷达图像和I分量进行曲波变换得到粗尺度系数和细节尺度系数;将雷达图像的粗尺度系数和细节尺度系数进行叠加,计算归一化的曲波系数直方图,定义边缘有效因子,利用合成孔径雷达图像的特征信息将曲波变换系数分为均匀区、非均匀区和亮点目标区.然后采用相应的融合规则对融合图像的粗尺度系数进行处理,对细节尺度系数采用简单的直接取大方法,逆变换后得到新的亮度分量.用新的亮度分量替代原亮度分量进行逆色度-饱合度-亮度变换得到最终融合结果,利用统计类指标对融合结果进行评价.实验结果表明,该方法在保持光谱信息和提高空间分辨率上都有较好的效果.     

Sar modeling of unbalanced data sets

Abstract

The increased acceptance of SAR approaches to hazard identification has led us to investigate methods to improve the predictive performance of SAR models. In the present study we demonstrate that although on theoretical grounds the ratio of active to inactive chemicals in the learning set should be unity, SAR models can ?tolerate‘ an unbalanced range in ratios from 3 : 1 (i.e., 75% actives) to 1 : 2 (i.e., 33% actives) and still perform adequately. On the other hand SAR models derived from learning sets with ratios in excess of 4 : 1 (80% actives), even when corrected for the initial ratio do not perform satisfactorily.     

ToxRead: A tool to assist in read across and its use to assess mutagenicity of chemicals

Life sciences, and toxicology in particular, are heavily impacted by the development of methods for data collection and data analysis; they are moving from an analytical approach to a modelling approach. The scarce availability of experimental data is a known bottleneck in assessing the properties of new chemicals. Even when a model is available, the resulting predictions have to be assessed by close scrutiny of the chemicals and the biological properties of the compounds concerned. To avoid unnecessary testing, a read across strategy is often suggested and used. In this paper we discuss how to improve and standardize read across activity using ad hoc visualization and data search methods which use similarity measures and fragment search to organize in a chart a picture of all the relevant information that the expert needs to make an assessment. We show in particular how to apply our system to the case of mutagenicity.     

SAR EVALUATION IN THE 0.25 MM HUMAN EYE MODEL EXPOSED TO 30 GHz MILLIMETER WAVE

We have evaluated the specific absorption rate (SAR) in the eye induced by the perpendicular incidence of 30 GHz uniform plane millimeter wave (MMW). An anatomically based 0.25 mm voxel model of the eye with 10 types of tissue is constructed. Debye’s dispersion equation is used to derive the dielectric properties of the eye tissues and biological materials in the neighboring region. The three-dimensional (3-D) finite-difference time-domain (FDTD) algorithm and the perfectly matched layer (PML) absorbing boundary conditions are used in the numerical simulation. The FDTD code is validated against the Mie theory. The SAR deposition in the eye is calculated and displayed, with the analysis on the SAR distribution characteristics. The average SAR values in the cornea, the lens cortex, the lens nucleus, the humor, and the whole eye are statistically derived and examined against present irradiation safety standard.     

Design,synthesis and immunomodulating activity of C-pseudonucleosides containing thiazolidin-4-one and phenyl connected by acetamide bond

Several novel C-pseudonucleosides containing thiazolidin-4-one and phenyl connected by acetamide bond were rationally designed and easily synthesized at room temperature by using the unprotected sugar aldehyde as the starting material. The effects of the compounds on Con A-induced T cell proliferation were evaluated at five concentrations of 5, 10, 25, 50, and 100 mmol/L Interestingly, compounds 7a and 8a (n = 2, R = H) exhibited immunostimulating activities, while compounds 5a, 6a (n = 1, R = H) and 7b, 8b (n = 2,R = CH₃) showed immunosuppressive activities. Another two compounds 5b and 6b (n = 1,R = CH3) had no immunomodulating activities. These initial biological results suggested that subtle structural changes to the phenyl and acetamide bond of C-pseudonucleosides could have a significant effect on T cell proliferation bias, although it was difficult to formulate a rigorous structureactivity relationship based on the observed activities.