BACKGROUND Although phosphodiesterase 4 inhibitors and the volatile anesthetic sevoflurane are known to have independent bronchodilator properties, the combined administration of these two agents may have the potential to exert an additive or synergistic bronchodilator effect. The authors tested this hypothesis and investigated the common site of this combined relaxation effect in a model of ai...

Improving the design and performance of medical stents for implantation in the human body is of current interest. This paper describes a study of fatigue-crack propagation behavior in the superelastic alloy Nitinol. Specifically, the objective of this work was to study the effect of environment on cyclic crack-growth resistance in an approximately 50Ni-50Ti (atom %) alloy and to provide the nec...

Ultra low cycle fatigue (ULCF) is a phenomenon that can be summarily defined as the deterioration of material properties under high amplitude cyclic loading, under which failure is reached typically within ten to twenty cycles. This phenomenon is observed in extreme loading scenarios such as earthquakes or exceptional winds where large cyclic strains are expected. Particularly sensitive are str...

The aim of this study was to evaluate the resistance to fracture of endodontically treated teeth with flared canals restored with different post and core restorations under static and cyclic fatigue loadings. Sixty human maxillary central incisors were used. Two main groups (non-ferrule and 1-mm ferrule) were divided into three types of restoration: custom cast post-and-core (MPC), resin compos...

Both the mammalian thick ascending limb of Henle's loop and the shark rectal gland actively transport Cl against an electrochemical gradient by mechanisms involving hormone-sensitive NaCl transport. In contrast to mammalian renal tubules, individual tubules of the shark rectal gland previously have not been perfused in vitro. Using a combination of renal slice and microdissection techniques we ...

Metallic glasses (MGs) exhibit greater elastic limit and stronger resistance to plastic deformation than their crystalline metal counterparts. Their capacity to withstand plastic straining is further enhanced at submicrometer length scales. For a range of microelectromechanical applications, the resistance of MGs to damage and cracking from thermal and mechanical stress or strain cycling under ...

This thesis investigates the reliability of printed conductors on flexible substrates under cyclic bending. The topic is approached by studying the effects of several key design parameters on the bending lifetime of printed conductors under dynamic loading. In this thesis, the test specimens with various cross-sectional geometries were printed on different plastic and paper substrates. The test...

We have examined endogenous cyclic AMP-stimulated phosphorylation of subcellular fractions of rat brain enriched in synaptic plasma membranes (SPM), purified synaptic junctions (SJ), and postsynaptic densities (PSD). The analyses of these fractions are essential to provide direct evidence for cyclic AMP-dependent endogenous phosphorylation at discrete synaptic junctional loci. Protein kinase ac...

The infusion of L-arginine induces the production of nitric oxide and stimulates the immediate secretion of insulin. To examine the relationship between insulin resistance and endothelium-dependent vascular relaxation in patients with essential hypertension, we evaluated the renal and insulin responses to L-arginine, 500 mg/kg infused intravenously over 30 minutes, in 23 patients with mild esse...