Synthesis of the Sulphonate and Phosphonate Derivatives of Mercaptoacetyltriglycine. X-Ray Crystal Structure of Na(2)[ReO(Mercaptoacetylglycylglycylaminomethanesulphonate)].3H(2)O

Mercaptoacetyltriglycine forms complexes with (186/188)Re and (99m)Tc radionuclides that are useful in nuclear medicine because they are substrates of the renal anion transport system. However, the renal clearance of [MO(MAG(3))](2-)(MAG(3) = penta-anionic form of mercaptoacetyltriglycine, M = Re, Tc) complexes are less than ideal. Organic sulphonates are also transported by the renal anion transport system and phosphonates are similar to sulphonates in size and shape. In an effort to develop new ligands that form Re and Tc complexes and have improved renal clearances compared to [MO(MAG(3))](2-) complexes, the sulphonate and phosphonate derivatives of mercaptoacetyltriglycine were synthesized. The dianion [ReO(MAG(2)-AMS)](2-) (MAG(2)-AMS = penta-anionic form of mercaptoacetylglycylglycylaminomethanesulphonic acid) was prepared for characterization by exchange reaction of ReOCl(3)(Me(2)S)(OPPh(3)) and isolated as the disodium salt. The structure of Na(2)[ReO(MAG(2)-AMS)].3H(2)O (6) was determined by X-ray diffraction. The coordination geometry is pseudo square pyramidal, with the nitrogen and sulfur donor atoms forming a square base and the oxo ligand at the apex. The deprotonated sulphonate group has a syn conformation with respect to the oxo ligand. The renal clearances of [(99m)TcO(MAG(2)-AMS)](2-) and [(99m)TcO(MAG(2)-AMP)](3-) were similar in rats and suggest that the difference in total charge between the SO(3) (-) and PO(3) (2-) groups is not important to renal clearance. However, their renal clearances were 40-50% less than that of [(99m)TcO(MAG(3))](2-) suggesting that the size and shape of the large tetrahedral SO(3) (-) and PO(3) (2-) groups of [(99m)TcO(MAG(2)-AMS)](2-) and [(99m)TcO(MAG(2)-AMP)](3-) inhibit recognition by the renal transport system compared to the small planar CO(2) (-) group of [(99m)TcO(MAG(3))](2-).     

吡唑-4-基烷基酮衍生物的合成、结构和除草活性

原卟啉原氧化酶(protox)最近被证实是已知光动力作用除草剂化合物的靶标。如许多其他除草剂的结合位置一样,原卟啉原氧化酶是几种化学结构上三级交叉类型的除草剂(图1)的酶靶标,包括二苯基醚类[如乙氧氟草醚(Oxyfluorfen),Ⅰa;三氟羧草醚(acifluorfen),Ⅰb]、噁二唑类[如噁草酮(Oxadiazon)、吡啶衍生物类(如LS82-556,(S)-2,6-二甲基-N-(α-甲基苄基)-5-丙酰基烟酰胺];吡唑-4-腈类[如M&B39279,5-氨基-1-(2,6-二氯-4-三氟甲基)苯基吡唑-4-腈,Ⅱa]和推测可能是吡唑-4-腈的类似物(如Ⅲa,表1)。可以认     

Photoresponsive dendritic azobenzene peptides

Two dendritic peptides containing a branched lysine core and up to eight azobenzene moieties in the periphery were synthesized on solid support employing the omega-amino acid 4-(aminomethyl)phenylazobenzoic acid. With an additional peptidic tail consisting of an oligolysine portion, water solubility was achieved for the dendrimers, which allowed for the characterization of the cis/trans photoisomerization of the dendritic azobenzene species in both organic and aqueous media. Despite the interactions between the chromophores, which occur particularly in aqueous media, at higher dilution the photoisomerization process was found to proceed to extents that should permit photomodulation of molecular recognition processes between ligands grafted to the photosensitive azobenzene units and receptor molecules.     

Chemical inhibitors when timing is critical: a pharmacological concept for the maturation of T cell contacts

Cellular signal transduction proceeds through a complex network of molecular interactions and enzymatic activities. The timing of these molecular events is critical for the propagation of a signal and the generation of a specific cellular response. To define the timing of signalling events, we introduce the combination of high-resolution confocal microscopy with the application of small-molecule inhibitors at various stages of signal transduction in T cells. Inhibitors of Src-family tyrosine kinases and actin dynamics were employed to dissect the role of the lymphocyte-specific tyrosine kinase Lck in the formation and maintenance of T cell receptor/CD3-dependent contacts. Anti-CD3epsilon-coated coverslips served as a highly defined stimulus. The kinetics of the recruitment of the yellow fluorescent protein-tagged signalling protein ZAP-70 were detected by high-resolution confocal microscopy. The analysis revealed that at 5 min after receptor engagement, Lck activity was required for maintenance of contacts. In contrast, after 20 min of receptor engagement, the contacts were Lck-independent. The relevance of the timing of inhibitor application provides a pharmacological concept for the maturation of T cell-substrate contacts.     

杀螟硫磷原药和制剂气相色谱测定法的协作研究

世界卫生组织(WHO)于1973年首次把杀螟硫磷(fenitrothion)编入农药规格手册。有效成份的分析采用滴定法,该法基于杀螟硫磷在酸性溶液中被锌还原,然后用亚硝酸钠滴定还原产物胺。方法包括原药及其可湿性粉剂的测定。这一方法并不是专一的而且费时。在WHO杀虫剂化学与规格专家委员会1977年会议上,J.W.Miles和D.L.Mount     

荷意公司合作研发出MMT轮胎生产线

据国外媒体报道，荷兰VMI公司和意大利马朗责尼（Mararlgoni）公司合作，研发一种称之为MMT的轮胎生产线，MMT即集成轮胎制造（ModuIar Tyre Mallufacttlring）。据介绍，MMT由1台四鼓成型机配6分挤出机、6台双模液压硫化机、1台喷涂机、1套材料准备装置、1台总控制器、1套质量控制系统6大部分组成。根据协议，VMI提供轮胎成型机，包括成型鼓及辅助装置；马朗贡尼提供挤出机及缠绕装置，同时负责总装。     

火炬牌40．00—5768PR和29．5—2528PR工程机械轮胎下线

2007年4月21日，吴华南方（桂林）橡胶有限责任公司桂林轮胎厂第1条40．00～5768PR无内胎工程机械轮胎下线，这是其目前生产的最大规格轮胎。同期推出的新产品还有29．5—2528PR无内胎工程机械轮胎。     

Albumin stimulates lysophosphatidic acid acyltransferase activity in T-lymphocyte membranes

Phosphatidic acid (PtdOH) and lysophosphatidic acid (lysoPtdOH) have been shown to enhance T-lymphocyte function. However, the FA preference and influence of acyl-CoA binding proteins on lysoPtdOH and PtdOH biosynthesis are not known. Therefore, we determined glycerol-3-phosphate acyltransferase (GPAT) and lysophosphatidic acid acyltransferase (LAT) activity in rat T-lymphocyte and liver membrane preparations in the presence of palmitoyl-CoA and oleoyl-CoA with or without BSA. We found two different properties of GPAT and LAT in whole T-lymphocyte membrane preparations relative to liver. First, T-lymphocyte basal GPAT and LAT activities were similar, whereas in liver membranes LAT activity was 10-fold higher than GPAT. Second, T-lymphocyte LAT, but not GPAT, activity was inducible (fivefold) by the addition of albumin in the presence of palmitoyl-CoA but not oleoyl-CoA. In contrast, albumin stimulated GPAT, but not LAT, activity in liver membranes in the presence of palmitoyl-CoA. These results show, for the first time, that T-lymphocyte LAT activity can be increased by the presence of an acyl-CoA binding protein, which may indicate a new important control mechanism for regulating intracellular lysoPtdOH and PtdOH levels in T-lymphocytes.     

冠带层新平台技术

子午线轮胎出现不久，就采用钢丝带束层代替了纤维带束层，这对于实现子午线轮胎提高使用寿命和改善操纵性能的潜能是必要的。