Inotropic effects of the K+ channel blocker 3,4-diaminopyridine: differential responses of rat soleus and extensor digitorum longus.

The K+ channel blocker 3,4-diaminopyrindine (DAP) increases diaphragm force, use of which could potentially improve muscle performance during functional neuromuscular stimulation. To determine the extent of hindlimb muscle force augmentation, and delineate whether DAP effects vary in muscles comprised of mainly slow versus fast fibers, rat soleus, extensor digitorum longus (EDL) and diaphragm muscle samples were studied in vitro. DAP increased force of all three muscles, but at high concentrations the force increases were transient and were followed by declines in force below baseline. The maximum DAP-induced twitch force increase was smaller for soleus (38 +/-7%) than both EDL (94+/-12%) (P < 0.05) and diaphragm (93+/-13%) (P < 0.01). During fatigue-inducing 20 Hz stimulation (tested at an intermediate DAP concentration), force of soleus muscle remained significantly elevated by DAP for the entire testing period, force of DAP-treated EDL muscle rapidly declined to values in untreated muscle, and force of DAP-treated diaphragm had an intermediate force-time profile. Muscles varied in extent to which isometric contractile kinetics were altered by DAP. Thus, the K+ channel blocker DAP improves contractile performance of limb muscles, but the profile of improvement is distinct between the soleus and EDL muscles.     

Low‐temperature amorphous‐silicon backplane technology development for flexible displays in a manufacturing pilot‐line environment

Abstract— A low‐temperature amorphous‐silicon (a‐Si:H) thin‐film‐transistor (TFT) backplane technology for high‐information‐content flexible displays has been developed. Backplanes were integrated with frontplane technologies to produce high‐performance active‐matrix reflective electrophoretic ink, reflective cholesteric liquid crystal and emissive OLED flexible‐display technology demonstrators (TDs). Backplanes up to 4 in. on the diagonal have been fabricated on a 6‐in. wafer‐scale pilot line. The critical steps in the evolution of backplane technology, from qualification of baseline low‐temperature (180°C) a‐Si:H process on the 6‐in. line with rigid substrates, to transferring the process to flexible plastic and flexible stainless‐steel substrates, to form factor scale‐up of the TFT arrays, and finally manufacturing scale‐up to a Gen 2 (370 × 470 mm) display‐scale pilot line, will be reviewed.     

On quadratic isoparametric transition elements for a crack normal to a bimaterial interface

The quadratic isoparametric crack‐tip elements proposed by R. E. Abdi and G. Valentin (Computers and Structures 33, 241–248) are reconsidered and a simpler method for calculating the optimal position of the side nodes proposed. Quadratic isoparametric transition elements for an r^λ−1 (0<λ<1) strain singularity are formulated. The effects of these transition elements on the accuracy of the calculated stress intensity factors are shown numerically for a crack normal to and terminating at a bimaterial interface. Finally, layered transition elements are formulated for this case and their effects studied numerically. Copyright © 1999 John Wiley & Sons, Ltd.     

SPECTRAL STUDIES AND EQUILIBRIUM ANALYSIS OF THE DIDODECYLNAPHTHALENE SULFONIC ACID,DICYCL0HEXAN0-18-CR0WN-6, Sr2+EXTRACTION SYSTEM

The species and equilibria present in the synergistic extraction system for strontium, composed of didodecylnaphthalene sulfonic acid (HDDNS) and dicyclohexano-18-crown-6 (DC18C6) in CCI⁴, have been studied by IR and proton NMR spectroscopies, vapor pressure osmometry (VPO), and Karl Fischer (KF) titrations. With the aid of least-squares computer methods to fit the IR and VPO results, a series of proposed equilibria and associated equilibrium constants have been shown to adequately account for all of the observed behavior. The sulfonic acid and the salt of the acid alone in CCI⁴solution form the micellar species (HDDNS·xH₂O) ₁₁(× is in the range 7-8) and (Sr(DDNS)₂· 11 H₂O) ₆respectively. The sulfonic acid alone, under conditions of intermediate loadings with Sr²⁺, yields the predominant species (Sr(DDNS) ₂)₃(HDDNS) ₅·×H₂O. When alone in solution, DC18C6 is a monomer, but it forms adducts with the free sulfonic acid and its strontium salt, yielding the respective product species (HDDNS) ₇·DC18C6· ×H₂O and Sr(DC18C6)(DDNS)₂· 2H₂O. An excess of HDDNS or Sr(DDNS)₂in the presence of Sr(DC18C6)(DDNS) ₂2H₂O yields predominantly Sr(DC18C6)(DDNS)₂(HDDNS)₂· ×H₂O and (Sr(DC18C6)(DDNS)₂) ₂(Sr(DDNS)₂) ₃3' · ×H₂O respectively.     

A First Order Solution for the Stress Concentration Present at the End of Roller Contact

An approximate solution of the “critical” maximum compressive stress present in rolling contact fatigue is given. Geometries normally used in rolling contact rig tests having contact areas varying from rectangular to full elliptical contact are considered. For cylinders in contact it is shown that the first order solution for end of contact stress is considerably above the nominal line contact Hertz stress usually calculated. Confirmation of the approximate stresses calculated is provided by deformation studies just into the plastic regime, and rolling contact fatigue tests on both cylindrical and 100-inch radius toroidal specimen rollers.     

Reinforcement or Reactance? Examining the Effect of an Explicit Persuasive Appeal Following an Entertainment‐Education Narrative

Entertainment‐education interventions frequently include an explicit persuasive appeal, such as an epilogue, at their conclusion. This may help to overcome potential limitations of narrative persuasion by highlighting and clarifying the underlying message. Despite this potential, an explicit persuasive appeal may also undermine the subtle approach that distinguishes narrative persuasion and thereby induce reactance and/or counterarguing. The purpose of this study was to experimentally test these two possible outcomes. In particular, the effect of an explicit persuasive appeal in the context of a dramatic television program about the dangers of drinking and driving was examined. Overall, results revealed that the narrative and explicit persuasive appeal interact to influence drinking‐and‐driving attitudes. Theoretical and practical implications are discussed.     

Enhanced firewall infrastructure testing methodology

The demand for effective firewall penetration testing procedures is increasing, not decreasing, as more and more organizations connect their networks to the Internet. Organizations are also increasing their reliance on the Internet for real, bottom-line profit. Upper management, now more than ever, is asked to make risk decisions based on incomplete information. More and more frequently, upper management calls for penetration tests as a mechanism for evaluating their overall risk. Most penetration tests run today are too weak for that purpose. I would like to present a methodology for conducting thorough penetration tests against firewall infrastructure systems.