498 research outputs found
Fault Diagnosis Method for Mobile Ad-hoc Network by Using Smart Neural Networks
AbstractMANETs are dynamic collection of autonomous nodes that communicate with each other via wireless connections. One of the events that the network should have expected it to be a fault, and the behavior is more important, in this network. So that fault diagnosis can effect on final performance of the network in such a way that it does not fall under the negative impact of the fault. A non-linear neural network is a statistical method for modeling data or the tools to make decisions. Artificial neural network is a method for pattern recognition and classification. Error detection is a problem of categorization or classification. The use of neural networks can be useful in fault diagnosis in MANETs because of fault diagnosis is a classification problem. But one problem with this method is placed in a local optimum. Here a method based on the combination of the back-propagation algorithm, a local search algorithm and learning automata as efficient global search, is proposed. In the proposed method, the algorithm of learning automata adjusting learning rate on neural network according to given formula. For training and testing the neural network of the mobile network parameters that were measured, were used as input and output. The results show that the proposed method in terms of repeatability, reliability and lack of placement in a local optimum is better
Dynamic model with factors of polycystic ovarian syndrome in infertile women
Background: Previous studies present various methods for prediction disease based on statistics or neural networks.These models use statistics and results from past procedures to provide prediction through probability analysis.
Objective: In this article, the authors present a dynamic model aiming at predicting the treatment result of infertile women with the factor of polycystic ovary syndrome. Materials and Methods: For this purpose, the authors have divided the study population into five groups: women prone to infertility, PCOS women, infertile women undergoing the treatment with Clomiphene Citrate and Gonadotropin, infertile women under IVF treatment, and improved infertile women. Therefore, the authors modeled the disease in infertile women mathematically and indicated that the free equilibrium point was asymptotically stable. Also the possibility of other equilibrium point of the system has been studied.
Results: The authors showed that this equilibrium point was marginally stable. Using Stoke’s Theorem, the authors proved that the recurrence of the disease cycle with the factor of polycystic ovary syndrome was not intermittent in infertile women. They solved this model numerically using Rung-Kutta method and sketched the figures of the resulted solutions.
Conclusion: It shows that with increasing age, the ovarian reserve is decreased and the treatment Clomiphene Citrate and Gonadotropin are not responsive, so IVF treatment is recommended in this group of patients considering the graphs of the model
The Effectiveness of Sonic-Activated Irrigation in Reducing Intratubular Enterococcus faecalis
Introduction: The purpose of this in vitro study was to compare the effectiveness of sonic activation and syringe irrigation of 5.25% sodium hypochlorite in removing the Enterococcus faecalis (E. faecalis) biofilm. Methods and Materials: Root canals of 54 extracted human single-rooted central incisors were prepared with ProTaper S1-S2-F1-F2 and Gates Gliden burs size 1, and 2 at the working length. After sterilization, the root canals were contaminated with E. faecalis suspension and randomly assigned to three groups: G1, conventional syringe irrigation; G2, sonic agitation of NaOCl with Endo Activator system; and G3, no subjected to the mentioned irrigation techniques (negative control). Canals were sampled after the disinfection procedure. The colony forming units (CFU) count was evaluated. Samples were also visualized under fluorescent microscope to count viable bacteria. Data were statistically analyzed using the Kruskal-Wallis and one-way ANOVA followed by Tukey’s test (P<0.05). Results: There was a significant reduction in the CFU count after both irrigation techniques. There was no significant difference between two techniques (P=0.874). Using bacterial viability kit, Endo Activator displayed the least viable bacteria than the other groups (P<0.001) and control group showed the greatest one (P<0.001). Conclusion: In this in vitro study, the Endo Activator system was more successful in reducing intratubular viable bacteria compared with NaOCl syringe irrigation alone.Keywords: Enterococcus faecalis; Irrigation; Root Canal Disinfection; Sodium Hypochlorite; Sonic Irrigatio
Clinicopathological Study of 307 Patients with Lichen Planus Actinicus and Pigmentosus Referred to Razi Skin Hospital from 2016 to 2021
Introduction: The two less-known subtypes of lichen planus (LP) are lichen planus actinicus (LPA) and lichen planus pigmentosus (LPP), with the highest prevalence in the Middle East. Objectives: We aimed to evaluate the clinicopathological profile of these patients. Methods: 307 cases including 184 LPA and 123 LPP patients were recruited from the registered pathology reports of Razi Skin Hospital of Tehran from April 2016 to March 2021. The clinical features and pathological reports were extracted and analyzed. Results: Among 307 patients, 117 (63.9%) in the LPA group and 88 (71.5%) in the LPP group were women. Duration of disease ranged from 1 month to 20 years and 1 month to 12 years in the LPA and LPP groups, respectively. Face (159 patients), limbs (68), and neck (23) were the most frequent sites of involvement in LPA patients, whereas face (60 patients), limbs (47), and trunk (42) were more commonly involved in the LPP patients. Pruritus and oral mucosal lesions were found with similar frequency in both groups. Pathological evaluation showed vacuolar degeneration of basal layer (100%), lymphocytes infiltration (97.3%), and melanin incontinence (58.2%) as the most frequent findings in LPA and vacuolar degeneration of basal layer (100%), lymphocytes infiltration (100%), and melanin incontinence (52/8%) as the most frequent findings in LPP cases.Conclusion: LPA and LPP were both more prevalent among women. Face was the most common site of involvement in both LPA and LPP. Vacuolar degeneration, lymphocyte infiltration, melanin incontinence, and hyperkeratosis were more common histological findings in this study
Prevalence of Multiple Sclerosis in Vitiligo Patients and Their First-Degree Relatives: Two Diseases with Similarities in Pathogenesis and Treatment
Introduction: Vitiligo is a common pigmentation disorder manifested by white macules and patches. It is accompanied by some autoimmune and neurological diseases. Recently, it has been suggested that multiple sclerosis (MS) is more common in vitiligo patients and that they have a higher risk of developing MS during their lifetime.
Objectives: In this study, we aimed to determine the prevalence of MS in patients with vitiligo and their first-degree relatives and compare it with the prevalence in the population.
Methods: In this cross-sectional study, data were consecutively collected from patients referred to Razi Hospital from March 2020 to December 2021.
Results: 709 patients with vitiligo participated in this study, and 15 reported a history of MS (2.12%, 95% CI: 1.06-3.17%). This rate was significantly higher than the prevalence of MS in the average population of Tehran (p < 0.001). Of the 2886 first-degree relatives of the patients, 10 had MS (0.35%, 95% CI: 0.13-0.56%), which was higher than the prevalence of MS, yet not statistically significant.
Conclusions: A significant association between vitiligo and MS was observed, which should be of clinical and therapeutic importance. However, the prevalence of MS in first-degree relatives of vitiligo patients was higher than the average rate, yet not statistically significant
Vacuolating encephalopathy and retinopathy associated with a nodavirus-like agent: a probable cause of mass mortality of wild Golden grey mullet (Liza aurata) and Sharpnose grey mullet (Liza saliens) in Iranian waters of the Caspian Sea
Mullets are dominant fishes in the catch composition in the southern coasts of the Caspian Sea and after (Rutilus frisii kutum Kamensky, 1901) have a worthy role in production of marine proteins and incomings of north provinces of Iran. Mullets stocks decreased dramatically in recent decades in the Caspian Sea and catch amount reached from 6446 MT on 2002 to 2151 MT in 2012. Mysterious mortalities occurred in wild mullet (Liza auratu) and (Liza saliens) in Iranian waters of Caspian Sea in recent years. Regarding to investigation of causative agent of mentioned outbreak about 322 suspected samples were collected from coastal capture sites of Iranian north provinces in 2008 till 2011. Moribund fish revealed skin darkening, erratic swimming, belly-up at rest and high distension of swim bladder. Target tissues such as brain and eye were removed and then fixed for histopathology and TEM assay. Widespread and massive vacuolation were observed in brain, spinal cord, retina and optical nerve and intracytoplasmic vacuoles and virus particles in retina. So concerning to clinical signs, histopathological and TEM findings, it could be concluded that nodavirus-like agent could be probable cause of mass mortality of wild mullet in Iranian waters of the Caspian Sea
Is preoperative serum creatinine a reliable indicator of outcome in patients undergoing coronary artery bypass surgery?
ObjectiveEvaluating renal function by calculating creatinine clearance as an alternative measure to serum creatinine may give a better estimation of postoperative renal function in patients undergoing coronary artery bypass grafting.MethodsUsing our database, we conducted a retrospective review of the records of all 11,884 patients aged 21 years or older undergoing pure bypass grafting who required cardiopulmonary bypass. Preoperative renal function was categorized as normal renal function (serum creatinine ≤1.1 mg/dL and creatinine clearance > 60 mL/min), occult renal insufficiency (serum creatinine ≤ 1.1 mg/dL and creatinine clearance ≤ 60 mL/min), mild renal insufficiency (1.1 mg/dL < serum creatinine ≤ 1.5 mg/dL and creatinine clearance ≤ 60 mL/min) or moderate renal insufficiency (serum creatinine > 1.5 mg/dL and creatinine clearance ≤ 60 mL/min).ResultsOut of 11,884 patients in the sample, 7856 (66.1%) had normal renal function, and 706 (5.9%) had occult renal insufficiency. The rate of postoperative mortality, renal failure, atrial fibrillation, prolonged ventilation, intra-aortic balloon pump usage, and prolonged hospital stay (>7 days) was higher in patients with occult renal insufficiency than in the normal group in univariable analysis. Multivariable logistic regression analysis demonstrated that patients with occult renal insufficiency compared with the group with normal renal function were at higher risk for mortality (odds ratio = 2.59, 95% confidence interval 1.15–5.86; P = .022) and prolonged hospital stay (>7 d) (odds ratio = 1.30, 95% confidence interval 1.08–1.57; P = .005).ConclusionsTo identify higher-risk patients requiring special intensive care, and in whom new interventions can be performed to improve outcome, we recommend the preoperative calculation of creatinine clearance, especially in older women with a lower body mass index
Effect of 670 Nm Laser Beam on the Action Potentials of Sural Nerve in Healthy Individuals
Introduction: Low Level Laser (LLL) is being used in physiotherapy for pain relief in various pathologies and particularly on peripheral nerve entrapments. In the present study, the effect of LLL on the electrophysiological parameters of sural in humans was investigated. The results might be used as a basis for further clinical research in abnormal conditions. Methods and Materials: Thirty-eight normal men voluntarily participated in the current study and 670 nm LLL beam was applied to the left sural nerve at 5 points for 10 sessions. The electrophysiological parameters such as onset latency, peak latency, negative peak amplitude, peak to peak amplitude, and duration were measured before and after the application of LLL (0.5, 1.5 & 2.5 J/cm² energy density). Results: Overall, 670 nm laser beam increased the latency and reduced the nerve conduction velocity (NCV). In addition, LLL beam decreased the amplitude of action potentials. Among the various values of energy densities, application of 2.5 J/cm² had the most effective results (P < 0.001). Conclusion: These results might suggest that 670 nm laser beam could affect the latency and reduce the NCV in sural nerve of human. Probably, LLL affects the bioelectric and bioenergetic properties of the neural biomembrane. These findings might have clinical signlificance in non-surgical treatment of entrapment syndromes, such as carpal, tarsal syndromes and trigeminal entrapment in human. Further investigations are needed to elucidate the effects of LLL beam on the human peripheral nerves in pathological conditions.Keywords: Low-level laser, Sural nerve, Electrophysiology, Pai
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