Quantitative structure-activity relationship analysis of a novel series of chemicals antagonizing WT and MT AR

In the clinical treatment of prostate cancer, mutation in the androgen receptor (AR) that occurred in patients, often results in drug resistance because the agonist activity of the drug increases while the antagonist activity decreases. Recently a novel series of diazacycloundecane AR antagonists were reported, and their abilities to antagonize the wild type (WT) AR as well as antagonize the mutated type (MT) AR (T877A) were determined experimentally. In this paper, to understand more about the drug resistance and to help to design more active antagonists, the quantitative structure-activity relationship (QSAR) of these compounds were analyzed, and the different interactions of these antagonists with two types of AR were compared. As a result two robust and predictive QSAR models were proposed, and the different structure features related with the antagonist activities on WT and MT AR were analyzed separately.     

基于MT8880-DTMF的逆变电源的设计与开发

双音多频(DTMF)编解码通信具有抗干扰强、低成本、远距离的特点.本文提出基于DTMF远程通信的逆变电源系统.介绍DTMF收发控制器MT8880和三相PWM发生器SA8282的结构特性,由MT8880与单片机80C51和SA8282及IPM组成的基于DTMF技术的逆变电源,具有低成本高可靠远程数据通信的功能,形成远程遥...     

Synthesis and SAR Studies of Isoquinoline and Tetrahydroisoquinoline Derivatives as Melatonin Receptor Ligands

In our constant search for new successors of agomelatine, we report herein a new series of compounds resulting from bioisosteric modulation of the naphthalene ring. The isoquinoline and tetrahydroisoquinoline derivatives were synthesized and pharmacologically evaluated. This isosteric replacement of the naphthalene group of agomelatine has led to potent agonist and partial agonist compounds with nanomolar melatonergic binding affinities. Overall, the presence of a nitrogen atom was accompanied with a decrease in the binding affinity toward both MT₁ and MT₂ and the loss of 5HT_2C response, especially for tetrahydroisoquinoline in comparison with the parent compound. Interestingly, due to the presence of this nitrogen atom, a notable improvement in the pharmacokinetic properties was observed for all compounds.     

地球物理测量在广西罗维多金属矿勘查的应用效果

广西罗维多金属矿区出露地层为寒武系小内冲组和黄洞口组,分布多处土壤Ag、Pb、Zn、W、Bi异常,异常具Pb-Ag-Zn、Bi-W、Zn-Bi-W-Pb等组合特征。区内砂泥岩和铅锌矿石样品的磁性无明显差别。经高精度磁测圈出异常3个,反演估算异常磁源体顶面埋深23～43 m或更深；利用EH4大地电磁测深对高磁异常进行查证,以反演电阻率断面图确定低阻和中低阻区的空间分布。经综合“地、化、物”资料后进行钻探工程验证,发现多个银铅锌钨铋多金属矿体,找矿效果甚佳。     

Material Testing 2.0: A brief review

With the advent of camera-based full-field measurement techniques such as digital image correlation (DIC), researchers have been trying to exploit such rich data sets through the use of more complex test configurations than the standard ones (uniaxial tension/compression, bending etc.). This new paradigm in mechanical testing of materials has recently been christened ‘Material Testing 2.0’. This paper provides a brief overview of this field, which is currently seeing a large increase in research effort.     

Mapping the Melatonin Receptor. 8. Selective MT2 Agonists Derived from 5,6-Dihydroindolo[2,1-a]isoquinolines and Related Systems

A series of substituted indolo[2,1-a]isoquinolines and indolo[1,2-a]benzoxazines have been prepared, as melatonin analogues, to investigate the nature of the binding site of the melatonin receptor. Agonist and antagonist potency of all the analogues was measured using the [35S]GTPγS binding assay protocol. The binding affinity of the analogues were measured by competition binding studies against the human MT1 (hMT1) and MT2 (hMT2) receptors stably transfected in Chinese Hamster Ovarian (CHO) cells, using 2-[¹²⁵I]-iodomelatonin, as a ligand. N-Acetyl 2-(10-methoxy-5,6-dihydroindolo[2,1-a]isoquinolin-12-yl)propyl-1-amine (12 a) binds strongly to both the hMT1 and hMT2 receptors, and shows a preference for the hMT2, as does its propanamido counterpart 12 b . The introduction of two methyl groups into their side chain, analogues 15 a and 1 5 b , leads to antagonism, in the case of the former, and drastically diminishes its hMT1 binding; an analogous profile is seen for 15 b , which, however, is a partial agonist. Introduction of chlorine or methoxy groups into ring 4 gives compounds, that are weakly binding, with a preference for MT2. Substitution of oxygen for carbon at position 5 gives the indolo[1,2-c]benzoxazines 33 , 36 a and b , that bind strongly to the human receptors, 33 , 36 b being potent agonists at the melatonin receptors, but do not discriminate between hMT1 and hMT2.