4,908 research outputs found
Altered levels of nodal excitability by rate-dependent inhibitory effects of essential oil of Citrus aurantium on the electrophysiological properties of isolated perfused rabbit AV-Node. Protective role in the prevention of ouabain toxicity [Alteración de los niveles de excitabilidad nodal por efectos inhibitorios velocidad-dependiente del aceite esencial de Citrus aurantium sobre las propiedades electrofisiológicas del nodo AV aislado y perfundido de conejo. Papel protector en la prevención de toxicidad por ouabaína]
Treatment of supraventricular arrhythmia includes a wide range of medical interventions. Herbal remedies are suitable alternatives to synthetic drugs due to their availability, minimal side effects and lower price. Pharmacological studies and traditional medical literature point to the cardiovascular effects of Citrus aurantium L. (Rutaceae) in many instances. In the present study we used isolated perfused AV-node of rabbit as an experimental model to determine the effect of various concentrations of essential oil of C. aurantium (0.1-0.3 v/v) on the nodal conduction time and refractoriness of an isolated rabbit AV-nodal preparations. Selective stimulation protocols were used to independently quantify AV nodal recovery, facilitation and fatigue in 18 rabbits. Our results showed concentration-dependent and rate-independent suppressive effects of essence of C. aurantium on the Wenchebach cycle length (WBCL), AV Conduction Time (AVCT) and effective and functional refractory periods (ERP & FRP). Functional properties such as facilitation and fatigue were significantly increased by this plant. Citrus aurantium plays a protective role against the toxic effects of ouabaine by increasing AV nodal conduction time and refractoriness. The above results indicated differential effects of C. aurantium on slow and fast pathways, with a dominant role on fast pathways. This research has explained the protective role of C. aurantium on ouabaine toxicity. All results indicated the potential anti-arrhythmic effects of C. aurantium in treating supraventricular tachyarrhythmia
The Participants' viewpoint of continuing medical education courses
Background: Continuing education is one of the most effective methods to empower the
employees for challengesthey face on their jobs. Dramatic advances in medicine, rapid
cultural and social changes, increasing cost of healthcare, development of diagnostic
technology and a transition in the pattern of diseases, highlight the necessity ofcontinuing
education in all medical groups. Purpose: To evaluate the effectiveness of continuing
medical education (CME) programs in Shahr-Kord MedicalUniversityfrom 1996-2001
The Remarkable Beneficial Effect of Adding Oral Simvastatin to Topical Betamethasone for Treatment of Psoriasis: A Double-blind, Randomized, Placebo-controlled Study
Psoriasis is a common chronic inflammatory disease with unpredictableprognosis. Given the immunomodulatory effects of statins, the present study was conducted to determine whether the addition of orally administered simvastatin to the topical betamethasone, a standard antipsoriatic treatment, can produce a more powerful therapeutic response against this clinical conundrum.In a double-blind study, 30 patients with plaque type psoriasis were randomly divided into two equal treatment groups. Group 1 received oralsimvastatin (40 mg/d) plus topical steroid (50% betamethasone in petrolatum) for 8 weeks and group 2 received oral placebo plus the same topical steroid for the same time period. Psoriasis Area and Severity Index (PASI) score was checked before and at the end of the treatment period.PASI score decreased significantly in both groups, but the decline of PASI score was more significant in patients who received simvastatin(Mann-Whitney test; P-value=0.001). No side effect or any laboratory abnormality was detected in patients.Our work, which is the first doubleblind, randomized, placebo-controlled study on this subject, shows that oral simvastatin enhances the therapeutic effect of topical steroids against psoriasis. The increased risk of cardiovascular accidents in psoriatic patients and the protective effect of statins against cardiovascular disease further encourages their use in the treatment of this clinical conundrum.Keywords: Simvastatin – Psoriasis – Treatment – Topical Steroid
The effect of HESA-A (natural drug) on visual acuity in age related macular degeneration: a randomized double blind controlled clinical trial
We investigated the clinical efficacy and safety of HESA-A (a drug of herbal-marine origin) in the treatment of age related macular degeneration (AMD). In a randomized double blind clinical trial 280 eyes of 280 (157 F, 123 M) patients with wet and dry AMD were randomly assigned in treatment or placebo groups. Patients in treatment group received HESA-A tablet 25 mg/Kg twice a day orally and controls received placebo with the same method for 4 weeks. Visual acuity at baseline and after one month of treatment was measured and compared between two groups. All patients were followed up for 5 months after treatment. Mean patients’ age was 69.06±8.49 years. At the end of study visual acuity improved significantly from 1.69±0.65 LogMar to 1.03± 0.40 LogMar in treatment group but not in controls (P: 0.000 and P: 0.67 in treatment and control groups respectively). No drug reaction or recurrence was reported during the study and 5-month post treatment follow up period in HESA-A treated group. This study showed significant efficacy and safety of HESA-A in improvement of visual acuity in AMD patients in short term.Key words: age related macular degeneration, HESA-A
Comparison of 2D and 3D modeling for deriving effective hydraulic properties of stony soils
Stone, gravel or rock fragments that are embedded in a matrix of fine soil have a substantial effect on effective soil hydraulic and transport properties. Understanding the role of stones in soils is important not only for soil water transport processes such as infiltration, evaporation and redistribution, but also for related solute transport processes. A variety of models has been proposed in the past to predict the systematic effect of varying amounts of stones on effective saturated conductivity and water retention of a soil-stone mixture. Respective studies for unsaturated hydraulic conductivity are still missing. To test the accuracy and validity of such predictive models, and to expand them to unsaturated conductivity, the investigation of virtual porous media, which can be obtained by numerical forward modeling of water and solute transport in soil-stone mixtures is the method of choice. Furthermore, to test the postulate that effective homogeneous properties exist and can replace the heterogeneous system, the ability of a 1D model with assumed homogeneous soil properties to match “observed” state variables and fluxes of a higher-dimensional heterogeneous model under a variety of conditions is a necessary requirement. With few exceptions, such heterogeneous modeling studies have hitherto been performed only for simplified cases, i.e., either under fully saturated conditions, or with a reduced dimensionality, i.e., 2D simulations of soil/stone mixtures. In this work, we use the simulation tool HYDRUS-2D3D to investigate the systematic differences that occur when modeling partially unsaturated transient water in stony soils, based on the Richards equation. Specifically, we compare truly 3D with 2D simulations and discuss the implications for effective 1D hydraulic properties
Effect of oral evening primrose capsules on ripening of the cervix in nulliparous Iranian pregnant women (A randomized trial)
Introduction: Ripening of the cervix and uterine contractions are two basic factors of a successful delivery. Lack of ripening of the cervix is considered to be one of the problems of delivery. Thus, the present research was designed to determine the effect of oral evening primrose capsules on the ripening of cervix in nulliparous women. Materials and methods: This research has been conducted with the triple-blind randomized trial method on 80 nulliparous women in the 40th week of pregnancy (6th day + 40 weeks) visiting the prenatal clinic Prenatal clinic Shahid Akbarabadi educational and medical center of Iran University of Medical Sciences in 2015. Samples were divided into two equal groups of medicine and placebo with the randomized allocation method. Each of the participants took a bottle containing 14 1000mg oral evening primrose capsules (2 capsules per day, each 12 twelve hours for a week) or the placebo containing 14 1000mg oral capsules of paraffin in similar bottles. Data collecting tools include: demographic specifications questionnaire and the form of the records of the examinations. Data was analyzed through statistical tests and SPSS software version 16 using descriptive inferential statistic. Findings: Similarity of the two groups in terms of individual specifications and Bishop Score before the intervention were reviewed in the two groups and no significant statistical difference was seen between the two groups. The mean of the Bishop score for those who had taken 10 or more capsules after the intervention did not show a statistically significant difference (p=0.110). Conclusion: Consumption of evening primrose did not show a considerable improvement in the score. It is recommended to do more comparative studies in this field in later weeks of pregnancy due to the conflicts of the studies
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On viscoelastic cavitating flows: A numerical study
The effect of viscoelasticity on turbulent cavitating flow inside a nozzle is simulated for Phan-Thien-Tanner (PTT) fluids. Two different flow configurations are used to show the effect of viscoelasticity on different cavitation mechanisms, namely, cloud cavitation inside a step nozzle and string cavitation in an injector nozzle. In incipient cavitation condition in the step nozzle, small-scale flow features including cavitating microvortices in the shear layer are suppressed by viscoelasticity. Flow turbulence and mixing are weaker compared to the Newtonian fluid, resulting in suppression of microcavities shedding from the cavitation cloud. Moreover, mass flow rate fluctuations and cavity shedding frequency are reduced by the stabilizing effect of viscoelasticity. Time averaged values of the liquid volume fraction show that cavitation formation is strongly suppressed in the PTT viscoelastic fluid, and the cavity cloud is pushed away from the nozzle wall. In the injector nozzle, a developed cloud cavity covers the nozzle top surface, while a vortex-induced string cavity emerges from the turbulent flow inside the sac volume. Similar to the step nozzle case, viscoelasticity reduces the vapor volume fraction in the cloud region. However, formation of the streamwise string cavity is stimulated as turbulence is suppressed inside the sac volume and the nozzle orifice. Vortical perturbations in the vicinity of the vortex are damped, allowing more vapor to develop in the string cavity region. The results indicate that the effect of viscoelasticity on cavitation depends on the alignment of the cavitating vortices with respect to the main flow direction
A novel approach to study laser induced void array formation in fused silica
This study investigated multi-void formation in fused silica using high
resolution Finite-Difference-Time-Domain (FDTD) simulations. Despite extensive
research dedicated to understanding the mechanisms behind multi-void formation
in materials, the fundamental aspects and mechanisms governing self-void array
formation in dielectrics and polymers remain poorly understood. By modeling the
voids as concentric spheres with densified shells and simulating the laser
interaction with the voids, we showed that void array generation in fused
silica is a linear mechanism. This study provides valuable insight into the
mechanism behind the formation of void arrays in fused silica.Comment: arXiv admin note: substantial text overlap with arXiv:2305.0297
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