Comparison of canal displacement rate of mesiobuccal root of the maxillary first molar after the preparation by two manual and rotating methods using stainless steel hand files

زمینه و هدف: ابزارهای گوناگونی برای کاهش زمان آماده سازی کانال معرفی شده است. یکی از این ابزار هندپیس نوین (TEP-E10R) است که به نام اندوگریپر معروف است. این مطالعه با هدف مقایسه میزان تغییر مرکزیت کانال ریشه مزیوباکال مولر اول فک بالا به دنبال آماده سازی به دو روش دستی و چرخشی با استفاده از فایل های دستی استنلس استیل انجام شده است. روش بررسی: در این مطالعه تجربی آزمایشگاهی 50 دندان کشیده شده مولر اول ماگزیلای انسانی انتخاب و به دو گروه تقسیم شدند. بعد از تهیه حفره دسترسی و قرار دادن فایل اولیه داخل کانال مزیو باکال، رادیو گرافی های دیجیتالی به صورتی که رابطه فیلم و زاویه تابش با نمونه ها ثابت باشند تهیه گردید، سپس آماده سازی کانال ها در گروه اول با فایل های استنس استیل به روش دستی و در گروه دو با فایل های استنس استیل با اندوگریپر انجام شد. تکنیک آماده سازی کانال هادر هر دو گروه passive step back بود. پس از آماده سازی، رادیوگرافی با فایل مستر اپیکال با همان شرایط رادیوگرافی اول انجام گرفت. میزان تغییر مرکزیت کانال رادیو گرافی اولیه و رادیوگرافی با فایل اصلی بر اساس تصاویر انطباقی بر حسب میلی متر توسط نرم افزار فتوشاپ و به کمک رادیولوژیست محاسبه شد. یافته ها: میانگین انحراف از مسیر اصلی کانال در گروه اول (36/1±45/3 میلیمتر) بیشتر از گروه دوم (69/1±75/1 میلیمتر) بود (045/0=P). همچنین میانگین زمان آماده سازی کانال ها در گروه اول (53/1±36/19 دقیقه) بیشتر از گروه دوم (55/1±03/12 دقیقه) بود (0001/0=P). نتیجه گیری: استفاده از فایل های استنلس استیل با هندپیس (رفت و برگشتی) reciprocal نسبت به استفاده از فایل های استنلس استیل به تنهایی مسیر اصلی کانال را بهتر حفظ می کند

Lung Ultrasound Findings Compared to Chest CT Scan in Patients with COVID-19 Associated Pneumonia: A Pilot Study

Introduction: Lung US has been reported to be as useful as a chest CT scan and much better than a chest x-ray for the evaluation of pneumonia. Objective: This study aimed to compare the findings of lung ultrasound (US) and chest CT scan of patients with COVID-19-associated pneumonia in the Emergency Department (ED). Methods: This retrospective observational pilot study was carried out on confirmed COVID-19 patients in the isolation corona ward of the Imam Hussein Hospital ED from March 15 to March 22, 2020. After obtaining demographic data, the patients underwent a pulmonary bedside US examination, with the patients in the sitting position, turning their back to the examiner. A 10-point lung US was performed. Each lung was divided into two areas: posterior (three zones) and lateral (two zones). The patients’ lung ultrasound and chest CT scan as the standard imaging were blindly reviewed and recorded. The clinical value of ultrasound was evaluated with different severity of lung involvement according to CT severity score. Results: Nineteen patients (38 zones), including 13 males, were evaluated with a mean age of 62.5±16.8 years. B2 lines and consolidation observed in the US examinations were significantly correlated with ground-glass opacity and consolidation observed in CT scan examinations, respectively (p <0.0001). US sensitivity and specificity of finding B2 lines were 90% and 100%, respectively. Also, the sensitivity and specificity of US in identifying consolidation were 82% and 100%, respectively. In the lungs with moderate and severe lobar involvement, US findings were significantly correlated (p <0.05) with CT scan findings. Conclusions: Ultrasound evaluation is a safe, fast, and rapid technique for the evaluation of patients with moderate to severe COVID-19-associated pneumonia. It is a reproducible procedure and can be implemented by the operator after a short course of training

Comparing Export and Import Sport Goods in Iran in 2014 to Implement Resistive Economics

The purpose of the research was to compare export and import sport goods in Iran in 2014 to implement the Resistive Economics. There was used laboratory and past vision method in the research. The registered comprehensive statics in official website of Chamber of Commerce, industries, mines and agriculture of Tehran were used to collect data. Its population included all registered export and import goods in Iran; among them, export and import sport equipments in Iran in 2014 were considered as the research sample. Goods exporter and importer countries to Iran were classified in 14 and 7 categories respectively. Then sport goods were 10 categories homogenously. Ranking export and import of sport goods was measured according to commercial partners and their dollar worth. The goods were compared by considering their Rial worth. The descriptive test and independent t-test were used to analyze data. Meanwhile, α= 0.05 was considered as significant level. The research findings showed 64% of importers of sport goods to Iran were China (36%), UAE (21%) and Turkey (7%). The imported sport goods were prioritized according to their Rial worth as follows: toys (56%), treadmill (24%), various rockets (5%), various balls (3%) and game facilities in open air (3%). In contrast, in terms of Rial worth, Iran exported sport goods to Iraq (70%), Turkmenistan (8%) and Afghanistan (7%). However, 100% exported sport goods included toys, treadmill and game facilities in open air. Finally, the research final findings showed no significant relationship between export and import sport equipments in Iran in 2014, in terms of their Rial worth. Now, it is suggested to explain necessary facilities to establish workshops and manufacturer factories based on ranking the imported goods within Iran. However, the imports should be controlled to support new established firms. It results in job creation and reduces foreign currency exit. Consequently, we should export sport goods and find consumer countries. Finally, free business policy should be considered to improve quality of the goods. As a result, we can satisfy consumer and control prices. In this way, we can improve Iran’s commercial balance and implement the Resistive Economics

5G NR-V2X: Towards Connected and Cooperative Autonomous Driving

This paper is concerned with the key features and fundamental technology components for 5G New Radio (NR) for genuine realization of connected and cooperative autonomous driving. We discuss the major functionalities of physical layer, Sidelink features and its resource allocation, architecture flexibility, security and privacy mechanisms, and precise positioning techniques with an evolution path from existing cellular vehicle-to-everything (V2X) technology towards NR-V2X. Moreover, we envisage and highlight the potential of machine learning for further enhancement of various NR-V2X services. Lastly, we show how 5G NR can be configured to support advanced V2X use cases in autonomous driving

Prevalence of Bacterial Meningitis in Children with Apparent Febrile Convulsion

Background: As a pediatric emergency, febrile convulsion is the most common form of seizure in children in the age range of four months to five years. Therefore, this study aimed to investigate the prevalence of bacterial meningitis among children with simple febrile convulsion. Methods: In this retrospective study, all children aged 6 to 18 months presenting with the first episodes of simple febrile convulsions admitted to Dr. Sheikh and Imam Reza Pediatric Hospitals in Mashhad between 2011 and 2015 were tested for cerebrospinal fluid. Analysis of Age, Gender, cerebrospinal fluid, and cerebrospinal fluid culture was recorded. Results: From among 1,164 patients, 305 children were enrolled in this study. Out of them, 16 patients (5.2%) reported positive Lumbar Puncture outcomes, one (6.3%) of whom was less than one year old, and 15 (93.7 percent) were more than one year old. Six of these patients had received the MMR vaccine one to three weeks before admission. One of the patients who tested positive for Lumbar Puncture and had a negative cerebrospinal fluid culture was admitted to the hospital with personal consent. Aseptic meningitis was diagnosed with non-positive culture in the other nine patients. No bacterial meningitis was confirmed between the evaluated patients. Conclusion: It is confirmed that the incidence of bacterial meningitis in simple febrile convulsion is very low. Therefore, the results may recommend avoiding routine Lumbar Punctures in patients with simple febrile convulsion

Applications of SSAFT EOS for determination of the solubilities of solid compounds in supercritical CO2.

Using statistical thermodynamics such as Simplified SAFT equation of state (SSAFTEoS) for estimating phase equilibrium and fluid properties of different materials have been used widely. SSAFT EoS has been developed for associative and non-associative compounds. At high pressure inter molecular forces are very important, on the other hand, in spite of the fact that SSAFT EoS has strength theoretical foundation, it can predict the behavior of high pressure systems. In this research, four solid solubility of benzoic acid, naphthalene, pyrene and Phenanthrene in supercritical carbon dioxide have been studied, SSAFT EoS has been used for modeling. At the end the results have been compared with experimental data. The highest and the absolute average deviation error (AAPD), for carbon dioxide - Phenanthrene and benzoic acid - carbon dioxide systems have been reported 2.22 and 4.43 respectively.Keywords: SSAFT EoS; Supercritical carbon dioxide; Solid compounds; Solubility

Nanotechnology and supercritical fluids

Supercritical fluid (SCF) technology has become an important tool of materials processing in the last two decades. Supercritical CO2 and H2O are extensively being used in the preparation of a great variety of nanomaterials. The interest in the preparation and application of nanometer size materials is increasing since they can exhibit properties of great industrial interest. Several techniques have been proposed to produce nanomaterials using supercritical fluids. These processes, taking advantage of the specific properties of supercritical fluids, are generally flexible, more simplified and with a reduced enviromental impact. The result is that nanomaterials with potentially better performances have been obtained. We propose a critical review of the supercritical based techniques applied to the production of nanoparticles materials.Keywords: Supercritical fluids; Nanoparticles; SCF technology; RESS; SAS