Characterization of the bioactive form and molecular determinants of recognition of cyclic enkephalin peptides at the delta-opioid receptor

An extensive and systematic search strategy to determine the conformational profile of 12 cyclic disulfide-bridged opioid peptides with varying affinities at the delta receptor has been carried out to identify the structure that is recognized by the delta receptor for each analogue. The methods and procedures used here for the conformational search have already been validated for [D-Pen2,D-Pen5] enkephalin (DPDPE), one member of this family. Use of these methods led to a low-energy solution conformation of DPDPE in excellent agreement with all the geometric properties deduced from its solution nmr spectra. Each of the analogue was subjected to the same procedure, involving a combination of molecular dynamics simulations at high and low temperature. The study was repeated in two environmental conditions, an apolar environment, simulated by using a distance-dependent dielectric constant, and a polar environment by embedding the peptides in a high constant dielectric (epsilon = 80). An automated comparison of the different conformers based on their backbone rms and average distance between the key aromatic moieties was followed by graphic analysis using maximum structural overlap. The cross-comparison of the conformations for each analogue revealed a unique conformer that may be recognized by the delta receptor for each high-affinity analogue that permitted maintaining the critical elements required for recognition in a simple spatial orientation, while maximizing similarity in other regions.     

添加剂强化重油催化裂化的过程分析与应用

运用工程化学原理分析讨论了添加剂强化重油催化裂化的过程，包括分散稳定气泡、改善雾化、保护酸中心、抑制焦炭生成以及提高重油气化率的胶体结构改性、降低表面张力和改善微孔润湿，并用以指导强化重油催化裂化添加剂的筛选。建立小型固定流化床催化裂化实验装置评价了添加剂的强化效果。结果表明，添加剂强化重油催化裂化可降低催化剂生焦1．0％左右，提高总液体收率1．0％～2．8％。     

一种新型艺术釉——绒光釉

通过分析易结晶原料的性能特点，确立了合理的绒光釉配方及相应的工艺参数，探讨了釉料形成机理，研制出一种适合精陶及其它陶瓷产品的艺术釉－绒光釉。     

温度场下超长楼板中抗裂筋的定量分析

本文对超长结构楼板在温度场下的行为进行理论研究和计算分析，并推导简便可行的计算公式。为超长楼板抗裂筋设计提供定量的方法，可供相关专业技术人员参考。     

风雨操场综合楼改造工程设计与施工

某风雨操场综合楼改造工程拆除了辅助用房及支撑网架屋面的西根框架柱改造成为球场看台。设计采用钢结构桁架托换技术，将屋面荷载转移至两侧的保留柱上，跨度拓展到30m。钢桁架与框架柱上安装的牛腿铰接连接，通过牛腿背面框架柱间的混凝土墙平衡牛腿传来的弯矩。在施工安装过程中合理地利用待拆除框架柱，保持屋面的完整性提升屋面，达到了对屋面扰动影响最小的目的。     

相干光被粗糙表面散射后衍射谱的分布探讨

利用傅立叶光学的基本原理，对相干光波被粗糙表面散射后衍射谱的分布进行探讨。     

Pharmacokinetics of phenprobamate after oral administration to healthy subjects

Phenprobamate (CAS 673-31-4) is a centrally acting skeletal-muscle relaxant agent. There are only two studies in the literature about the pharmacokinetics of phenoprobamate in man. The inconsistency between the results of these studies can be attributed partly to the different analytical methodologies used. A sensitive, specific and reproducible HPLC-assay, which may increase the reliability of the pharmacokinetic studies of phenprobamate in plasma, has been developed recently. The objective of this investigation was to assess the single-dose kinetics of phenprobamate in human and to determine the pharmacokinetic parameters of clinical and regulatory concern. The plasma pharmacokinetics of phenprobamate have been investigated following single oral administration at a dose of 800 mg in eleven healthy volunteers.