In this article we describe the preparation and characterization of a water-triggered shape memory polymer (SMP) family, PCL–PEG based thermoplastic polyurethanes (TPUs). Upon immersion in water, water molecules selectively swelled the hydrophilic PEG domains, resulting in durable hydrogels with strain-to-failure values greater than 700%. Dry samples fixed in a temporary shape underwent watertr...

BACKGROUND Assessment of myocardial viability based on wall-motion scoring (WMS) during dobutamine echocardiography (DbE) is difficult and subjective. Strain-rate imaging (SRI) is quantitative, but its incremental value over WMS for prediction of functional recovery after revascularization is unclear. METHODS AND RESULTS DbE and SRI were performed in 55 stable patients (mean age, 64+/-10 year...

BACKGROUND Cytoplasmic pH homeostasis in Escherichia coli includes numerous mechanisms involving pH-dependent catabolism and ion fluxes. An important contributor is transmembrane K+ flux, but the actual basis of K+ compensation for pH stress remains unclear. Osmoprotection could mediate the pH protection afforded by K+ and other osmolytes. METHODS AND PRINCIPAL FINDINGS The cytoplasmic pH of ...

This paper is concerned with the interpretation of isostatic recovery data in terms of the flow properties of the earth's mantle. A hydrodynamic analysis is first presented that allows straightforward calculation of the relaxation time for isostatic recovery within a mantle in which the viscosity varies continuously with depth. However, it transpires that no curve of this type (i.e., choice of ...

dynamic recrystallization, drx, behaviour of a precipitation hardened, ph, stainless steel was studied in connection with microstructural developments in a compression test. the experimental results showed that the dominant mechanism of softening is drx, but at high strain rates and low temperatures, ie, high zener-holman parameter, z, work hardening and dynamic recovery, drv, produced a pancke...

We examined left ventricular (LV) performance before, during, and following prolonged exercise (EX) in 12 healthy middle-aged men [means +/- SE: age = 43.5 +/- 1.9 yr; maximal O(2) uptake (Vo(2max)) = 51.7 +/- 1.5 ml.kg(-1).min(-1)]. Subjects cycled for 120 min at 65% Vo(2max) (75% of maximal heart rate). Two-dimensional echocardiography (ECHO) to determine tissue-Doppler longitudinal myocardia...

The compressive creep and the recovery of commercially available composites, 2 kinds for posterior and 2 kinds for anterior use, in water were examined. In posterior composites, creep strain after 500h at a stress level of 8.3 kgf/mm2 was significantly small (within 1%). The results of the compressive creep test showed that posterior composites would be resistant to occlusal stress. Creep strai...

Heating of green wood involves a complex set of deformation processes, including reversible thermal strain, reversible shrinkage due to decrease of moisture content, and irreversible viscoelatic recovery of growth stress activated by temperature called hygrothermal recovery (HTR). Experimental tests were performed on small Japanese Cypress specimens oriented in the three principal R, T, L direc...

A method that gives high recovery of deoxyribonucleic acid (DNA) from crude bacterial lysates using ethidium bromide-cesium chloride density gradient centrifugation is presented. After Pronase digestion and shearing of the lysate, essentially 100% recovery of chromosomal DNA and a reproducible recovery of covalently closed circular (CCC) plasmid DNA is obtained for a specific plasmid in a given...

The recovery stress of martensitic shape-memory alloy [SMA] wires can be used to confine concrete, and the confining effectiveness of the SMA wires was previously proved through experimental tests. However, the behavior of SMA wires under recovery stress has not been seriously investigated. Thus, this study conducted a series of tests of NiTiNb martensitic SMA wires under recovery stress with v...