大型医疗建筑设计

本文从医疗设施新的发展趋势入手,从工作团队架构、建筑形态演变、系统化建立、人性化空间考量以及面对突发事件之空间策略等几方面阐述了大型医疗建筑设计的原则及方法。     

Fabricating niobium test loops for the SP-100 space reactor

This article describes the successful fabrication, operation, and evaluation of a series of niobium-alloy (Nb-1Zr and PWC-11) thermal convection loops designed to contain and circulate molten lithium at 1,350 K. These loops were used to establish the fabrication variables of significance for a nuclear power supply for space. Approximately 200 weldments were evaluated for their tendency to be attacked by lithium as a function of varying atmospheric contamination. No attack occurred for any weldment free of contamination, with or without heat treatment, and no welds accidentally deviated from purity. The threshold oxygen content for weldment attack was determined to be 170–200 ppm. Attack varied directly with weldment oxygen and nitrogen contents.     

Lysophosphatidylcholine accumulation in the ischemic canine heart

The production of cardiac arrhythmias and the elevation of lysophosphatidylcholine level in the ischemic myocardium have been well-documented in a number of studies. However, the relationship between the production arrhythmias and the elevation of tissue lysophosphatidylcholine level was not reported. In this study, the lysophosphatidylcholine level and the occurrence of cardiac arrhythmias in the ischemic canine heart were monitored. A temporal relationship between the accumulation of lysophosphatidylcholine and the occurrence of arrhythmias was established after five hr of ischemia. A significant elevation of lysophosphatidylcholine was detected at three hr of ischemia without the occurrence of arrhythmias. The results indicate that cardiac arrhythmias did not cause the elevation of lysophosphatidylcholine and if lysophospholipids are causally related to the arrhythmias that a critical level of the lysophospholipid must accumulate in order to elicit electrophysiological alterations.     

Pedestrian navigation using the sense of touch

Haptics is a feedback technology that takes advantage of the human sense of touch by applying forces, vibrations, and/or motions to a haptic-enabled user device such as a mobile phone. Historically, human–computer interaction has been visual, data, or images on a screen. Haptic feedback can be an important modality in Mobile Location-Based Services like – knowledge discovery, pedestrian navigation and notification systems. In this paper we describe a methodology for the implementation of haptics in four distinct prototypes for pedestrian navigation. Prototypes are classified based on the user’s navigation guidance requirements, the user type (based on spatial skills), and overall system complexity. Here haptics is used to convey location, orientation, and distance information to users using pedestrian navigation applications. Initial user trials have elicited positive responses from the users who see benefit in being provided with a “heads up” approach to mobile navigation. We also tested the spatial ability of the user to navigate using haptics and landmark images based navigation. This was followed by a test of memory recall about the area. Users were able to successfully navigate from a given origin to a Destination Point without the use of a visual interface like a map. Results show the users of haptic feedback for navigation prepared better maps (better memory recall) of the region as compared to the users of landmark images based navigation.     

Evaluating the protective role of carrier microparticles in preserving protein secondary structure within electrospun meshes

Direct incorporation of proteins into electrospun meshes using approaches such as blend electrospinning can promote adverse interactions with hydrophobic polymers, organic solvents and high voltage, potentially leading to loss of protein activity. However, pre-encapsulation within a protective carrier phase can preserve protein conformation by avoiding exposure to harsh processing conditions. In this study, bovine serum albumin (BSA) was loaded within cellulose microparticles (MPs) and the BSA-loaded MPs were dispersed in a solution of poly(ethylene oxide) (PEO). Particle-mesh composites were created using a sacrificial fiber/co-electrospinning approach in which the BSA/MP/PEO solution was simultaneously electrospun against a poly(caprolactone) (PCL) solution. Post-fabrication, sacrificial PEO fibers were selectively dissolved by treatment with ethanol. Microscopy, weight loss analysis and FTIR spectroscopy together confirmed selective dissolution of PEO fibers and the retention of BSA-loaded MPs within the PCL network without significant loss of either the MPs or the protein. Circular dichroism spectroscopy and intrinsic fluorescence measurements on BSA extracted from the co-electrospun meshes indicated minimal disruption to secondary structure, although partial sheet induction was observed. In contrast, direct exposure of BSA to four commonly used electrospinning solvents resulted in a large decrease in helical content and significant induction of sheets, revealing significant changes to the secondary structure. In summary, our results demonstrate the protective role of MPs in minimizing adverse effects of electrospinning on the secondary structure of incorporated protein.     

Internal friction peak P1 in copper

The present theoretical knowledge concerning deformation-induced relaxation peaks in metals is still in the early stage of development, despite the many models proposed. All of these models contain fundamental flaws and cannot, when compared with experimental evidence, account for the characteristics of the peaks. Experimental results are given to illustrate the weakness of the present theories regarding the Hasiguti peak P₁; and a model, based upon the occasional breakaway of dislocation loops from vacancy pinning points, is postulated on the basis of modulus defect results associated with the peak. This is shown to account for the major aspects of the peak.