Introducing a biosensor based technology for real-time biospecific interaction analysis

The peptido-leukotriene receptor(s) (PL) on the ferret isolated spleen strip have been characterised by functional studies using the naturally occurring leukotrienes (LTs), a range of structurally distinct PL antagonists, and by ligand binding studies. LTB4 (0.01-10 microM) was inactive on ferret spleen whereas LTC4, LTD4 and LTE4 produced concentration-related contractions with maximal responses, relative to noradrenaline, of 57% (EC50 0.28 microM), 60% (EC50 0.5 microM) and 7% respectively. The leukotriene responses were unaltered by L-serine borate, L-cysteine, indomethacin, phentolamine, propranolol, mepyramine, methysergide or atropine, suggesting that the peptido-leukotrienes were acting through distinct PL receptors. The PL1 antagonists, FPL 55712 (0.01-10 microM), ICI 198615 (10 microM), SK&F 104353 (10 microM) and MK541 (10 microM) were all inactive against LTC4- or LTD4-induced contractile responses. LTE4 was a partial agonist with respect to LTC4 and LTD4 with pKB values of 5.8 and 5.5 respectively. Nifedipine (0.1 microM) produced a rightward shift of the concentration-response curves to both LTC4 and LTD4 and depressed their maximal responses. An unacceptably high level of non-specific binding of [3H]LTD4 to membrane preparations of ferret spleen prevented characterisation of this receptor by ligand binding. These results suggest that the ferret spleen has a homogeneous population of a PL receptor type which is insensitive to existing PL1 receptor antagonists. The functional characteristics of this PL receptor type are similar to those of the PL2 receptor on other tissues. The absence of PL1 receptors on this tissue makes it particularly useful in identifying new and selective drug tools for the PL2 receptor.     

On Closure under Formation of Parallel Systems

A parallel system of s-independent, identical components has the same aging property (eg, IFR or IFRA) as the components.     

Photocross-linking of low-density polyethylene. I. Kinetics and reaction parameters

The kinetic characteristics and the reaction conditions of photocross-linking of low-density polyethylene (LDPE) in the melt have been studied using benzophenone (BP) and its derivatives such as 4-chlorobenzophenone (4-CBP) as photoinitiator and triallyl cyanurate (TAC) as cross-linker. The efficiency of the photoinitiated cross-linking system LDPEBP-TAC and various factors affecting the cross-linking process, such as photoinitiator and cross-linker and their concentrations, irradiation time, temperature, and atmosphere, and UV light intensity were examined extensively by determining gel content, IR, and UV spectra. It has been found (i) that LDPE samples of 2–3 mm thickness are easily cross-linked to a gel content of about 70% with a UV-irradiation time of about 15 s under optimum conditions; (ii) that the photoinitiating system of a suitable initiator combined with a multifunctional cross-linker such as 4-CBP–TAC can enhance the efficiency of photocross-linking reactions, especially by increasing the initial rate of cross-linking; (iii) that photocross-linking of LDPE should be carried out in the melt, which increases the penetration of UV light by decreasing the scattering by crystallites, and (iv) that the rate of cross-linking is proportional to the square of the light intensity. An increase in light intensity can decrease the concentration of photoinitiator required to reach a certain rate of cross-linking. The photocross-linking of polyethylene is promising for industrial applications. © 1993 John Wiley & Sons, Inc.     

Low-power state encoding for partitioned FSMs with mixed synchronous/asynchronous state memory

Partitioned finite state machine (FSM) architectures in general enable low-power implementations and it has been shown that for these architectures, state memory based on both synchronous and asynchronous storage elements gives lower power consumption compared to their fully synchronous counterparts. In this paper we present state encoding techniques for a partitioned FSM architecture based on mixed synchronous/asynchronous state memory. The state memory, in this case, is composed of a synchronous local state memory and an asynchronous global state memory. The local state memory uses synchronous storage elements and is shared by all sub-FSMs. The global state memory operates asynchronously and is responsible for handling the interaction between sub-FSMs. Even though the partitioned FSM contains the asynchronous mechanism, its input/output behaviour is still cycle by cycle equivalent to the original monolithic synchronous FSM. In this paper, we discuss the low-power state encoding method for the implementation of partitioned FSM with mixed synchronous/asynchronous state memory. For the local state assignment a, what we call, state-bundling procedure is presented to enable states residing in different sub-FSMs to share the same state codes. Based on state-bundles, two state encoding techniques, in which one is the employment of binary encoding and the other is the further optimization for low power, are compared.     

微通道内液-液两相流流型及传质的研究进展

微通道内液-液两相流流动在微化工系统中占有重要的地位,了解微通道内液-液两相流体流动和传质规律对推动其工业化应用有重要作用。本文以微通道内液-液两相流系统为研究对象,简述了不同工况下微通道内液-液两相流流型和混合传质效率,分析了微通道特征、流体性质和流体流动速度等对流型形成和传质效率的影响。指出目前对于微通道内液-液两相流的研究多处于定性研究,定量研究仅针对某一体系展开,所得结果具有一定的局限性。关于微通道内液-液两相流传质研究实验较多而数值模拟方法相对较少,接下来的研究工作中应该考虑建立微通道内液-液两相流基础研究的数据库,通过分析大量的数据获得有效的流型划分准则和相关经验式以此推动微通道内液-液两相流的工业化应用。同时在传质研究过程中应研究开发相应的数值模拟模型,保证实验和数值模拟相结合,提出有效的传质效率评价机制。     

Turbulent heat transfer characteristics of supercritical n‐decane in a vertical tube under various operating pressures

To explore the effect of the operating pressure on the flow and thermal characteristics in a vertical tube with supercritical n‐decane, the inner wall temperature along the streamwise direction, the applicability of empirical correlations and buoyancy criteria are studied firstly. The mechanisms in views of density distribution, velocity field, turbulence intensity, the thickness of the thermal boundary layer, and secondary flow are then analyzed. It is observed that the buoyancy is helpful for the phenomenon of heat transfer deterioration at lower operating pressures but higher operating pressures can diminish this tendency. According to this reason, the empirical correlation proposed by Bae and Kim is suitable for the higher operating pressures but cannot well predict the occurrence of heat transfer deterioration. However, it can be evaluated by the buoyancy criterion Gr/Re² = 0.01 qualitatively. The decrease of turbulence intensity, the thickened thermal boundary layer, and secondary flow generation make contributions to the heat transfer deterioration in particular. Similarly, this situation can be diminished and even removed by the higher operating pressures.     

A combined reflectometry and quartz crystal microbalance with dissipation setup for surface interaction studies

We have developed an instrument for surface interaction studies, which combines a newly invented four detector optical reflectometry setup with quartz crystal microbalance with dissipation (QCM-D) monitoring. The design is such that data from both techniques can be obtained simultaneously on the same sensor surface, with the same signal-to-noise ratio and time resolution, as for the individual techniques. In addition, synchronized information about structural transformations, molecular mass, and the hydration of thin films on solid surfaces can be obtained on the same specimen, as validated by monitoring the formation of supported lipid bilayers on a silica-coated QCM sensor surface. We emphasize that the optical (molecular) mass can be separated from the acoustic mass including hydrodynamically coupled solvent, which means, in turn, that the amount of solvent sensed by the QCM-D technique can be dynamically resolved during adsorption processes. In addition, the advantage/necessity to use four, compared to two, detector reflectometry is emphasized.     

用石灰及水泥土柱稳定边坡和深开挖

本文介绍用生石灰粉或水泥与软粘土就地搅拌在地基内形成土柱以稳定沟槽,深开挖以及边坡的设计与施工方法。石灰土柱具有石灰用量低,施工振动小,挤土扰动少,透水性好的优点。文中讨论了石灰土的强度机理,石灰土柱的受力及破坏形式,给出了计算图式及应取的安全系数值。全文结合瑞典工程实例阐述。