142 research outputs found

    Testing a system specified using Statecharts and Z

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    A hybrid specification language SZ, in which the dynamic behaviour of a system is described using Statecharts and the data and the data transformations are described using Z, has been developed for the specification of embedded systems. This paper describes an approach to testing from a deterministic sequential specification written in SZ. By considering the Z specifications of the operations, the extended finite state machine (EFSM) defined by the Statechart can be rewritten to produce an EFSM that has a number of properties that simplify test generation. Test generation algorithms are introduced and applied to an example. While this paper considers SZ specifications, the approaches described might be applied whenever the specification is an EFSM whose states and transitions are specified using a language similar to Z

    Effect of chronic lithium administration on endothelium-dependent relaxation of rat corpus cavernosum: The role of nitric oxide and cyclooxygenase pathways

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    OBJECTIVE: To verify the effect of chronic lithium administration on the endothelium-dependent relaxation of rat corpus cavernosum, as lithium is a major drug for treating bipolar disorder and some studies showed that lithium might cause erectile dysfunction in such patients, by a mechanism as yet unknown. MATERIALS AND METHODS: LiCl (600 mg/L) was dissolved in drinking water and Sprague-Dawley rats received the solution for 30 days; control rats received tap water. After 30 days corporeal strips were prepared from both groups, mounted under tension in oxygenated organ baths, and pre-contracted with phenylephrine (7.5 μm). After equilibration, the strips were relaxed by acetylcholine (10 nm to 1 mm) in the presence or absence of indomethacin (a cyclooxygenase inhibitor; 20 μm). Furthermore, the relaxant responses to sodium nitroprusside (1 nm to 1 mm), a nitric oxide (NO) donor, were investigated in both groups. NADPH-diaphorase histochemistry was used to identify NO synthase within cavernosal tissue strips of both groups. RESULTS: The acetylcholine-dependent relaxation was significantly lower in lithium-treated rats than in controls. Although indomethacin decreased significantly the relaxant responses to acetylcholine in controls, it increased the relaxant responses in lithium-treated rats. NADPH-diaphorase staining was greater in the chronic lithium-treated than in control preparations. Sodium nitroprusside produced similar relaxation in both groups. CONCLUSION: Chronic lithium administration can impair the endothelium-dependent relaxation of rat corpus cavernosum; NO availability might decrease after lithium administration and the cyclooxygenase pathways might have a role in this effect. © 2006 The Authors

    IMECE2003-44300 Boundary Layer Solution for the Turbulent Swirling Decay Flow Through a Fixed Pipe: SBR at the Inlet

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    ABSTRACT In this study the developing turbulent swirling pipe flow is investigated both numerically and analytically. Governing equations are derived accompanying the boundary layer assumptions. Uniform and solid body rotation (SBR) distributions are taken into account for the axial and tangential velocities at the inlet of the pipe, respectively. Beyond the boundary layers, the flow pattern is considered to be the potential flow. Making use of the fourth-order Runge-Kutta scheme, the numerical solution of the differential equations is obtained. Further more, by simplifying the governing equations for large Rossby number, the analytical solution is performed. The results of numerical and analytical swirl intensity have been compared showing reasonable agreement. As an alternative solution, a CFD analysis has been done as well, having applied FLUENT software to support the ability of our methodology

    NADPH diaphorase staining of the corpus cavernosum in cholestatic rats: Role of nitrergic and opioid systems

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    Background: Relaxation of the corpus cavernosum plays an important role in penile erection. Previous studies have suggested that nitric oxide (NO) appears to be the most important relaxant involved in the erection process. The aim of the present study was to evaluate the effect of cholestasis in nNOS and eNOS activity of corpus cavernosum. Methods: forty-two adult male Sprague-Dawley rats were divided equally into seven groups: control, sham operated, 2-, 7-, and 14-day bile duct-ligated animals, 7-day bile duct-ligated chronically treated with L-NAME (3mg/kg/day, i.p.) and 7-day bile duct-ligated animals chronically treated with Naltrexone (20 mg/kg/day, i.p.). The animals in each group were killed and the cavernosal tissues analyzed histologically by light and transmission electron microscopy, with NOS activity detected on NANC nerves and endothelium using an NADPH-diaphorase staining technique. Results: our results showed that NADPH diaphorase staining in corporal NANC nerves and endothelium of sham-operated and control group had equal intensity. The staining was more intense in 2-day cholestatic rats than in control group, the staining intensity increased in 7-, and 14-day groups too. There were no significant differences between control group and 7-day cholestatic rats that had been treated chronically with L-NAME or Naltrexone. Conclusions: These results state that in corpus cavernosum of cholestatic rats there is a time-dependent increase in NOS activity of the corporal NANC nerves and endothelium. inhibition of nitric oxide and endogenous opioids by L-NAME or Naltrexone during cholestasis may play a key role in preventing the adverse effects of cholestasis. © 2008, Tehran University of Medical Sciences. All rights reserved

    Double Whammy: Concomitant acute type B aortic dissection and acute pulmonary embolism

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    The concomitant occurrence of acute type B aortic dissection (TBAD) and acute pulmonary embolism (PE) is a rare but challenging condition. Although anticoagulation therapy is essential in the treatment of PE, it may increase the risk of aortic rupture and bleeding complications. We herein describe a patient with acute TBAD complicated by PE, which was successfully treated with early thoracic endovascular aortic repair (TEVAR) followed by anticoagulation. The present case report demonstrates that early TEVAR not only treats the aortic pathology but also allows the safe initiation of anticoagulation therapy. Copyright © 2020, The Korean Society for Vascular Surgery

    HT2005-72679 THERMAL CHARACTERIZATION OF DIELECTRIC AND PHASE CHANGE MATERIALS FOR THE OPTICAL RECORDING APPLICATIONS

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    Abstract Advances in the phase change optical recording technology strongly depend on the optical and thermal optimizations of the metal/ZnS-SiO 2 /phase change multilayer structure, which requires accurate modeling and thermal characterization of PC media structure. In the present work, the thermal conductivities of the amorphous and crystalline Ge 4 Sb 1 Te 5 (GST) phase change; and ZnS-SiO 2 dielectric layers of thickness in the range of 50 nm to 300 nm have been measured using the transient thermoreflectance technique. The data are between a factor of 2-4 different from the previously measured values for thin film and bulk samples. The thermal boundary resistance at metal/ZnS-SiO 2 interface is found to be around 7×10 -8 m 2 W -l . This might have serious implications for the future phase change recording application which attempts to achieve the high writing speeds by decreasing the thickness of ZnS-SiO 2 dielectric layer

    Cardiovascular Complications of COVID-19: Pharmacotherapy Perspective

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    Coronavirus disease of 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is spreading rapidly the world over. The disease was declared �pandemic� by the World Health Organization. An approved therapy for patients with COVID-19 has yet to emerge; however, there are some medications used in the treatment of SARS-CoV-2 infection globally including hydroxychloroquine, remdesivir, dexamethasone, protease inhibitors, and anti-inflammatory agents. Patients with underlying cardiovascular disease are at increased risk of mortality and morbidity from COVID-19. Moreover, patients with chronic stable states and even otherwise healthy individuals might sustain acute cardiovascular problems due to COVID-19 infection. This article seeks to review the latest evidence with a view to explaining possible pharmacotherapies for the cardiovascular complications of COVID-19 including acute coronary syndrome, heart failure, myocarditis, arrhythmias, and venous thromboembolism, as well as possible interactions between these medications and those currently administered (or under evaluation) in the treatment of COVID-19. © 2020, Springer Science+Business Media, LLC, part of Springer Nature
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