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Background: Radiation therapy (RT) plays a crucial role in breast cancer management. However, RT may inadvertently expose neighboring organs to potential adverse effects. This study aimed to quantitatively analyze the radiation dose delivered to the cervical and thoracic esophagus during RT, focusing on patients undergoing postmastectomy adjuvant RT. Materials and Methods: This cross-sectional study included 100 breast cancer patients who underwent post-mastectomy adjuvant RT to the chest wall and supraclavicular field (SCF) using 3-Dimensional Conformal Radiation Therapy (3DCRT). The dosimetric parameters, including mean dose (Dmean), V5, V10 and V30, were estimated from dose-volume histogram (DVH) data for the cervical and thoracic esophagus. Results: The mean age of the patients was 54.01 (± 11.62) years. The Dmean (± SD) for the thoracic and cervical esophagus were 1.15 (± 0.52) and 3.06 (± 2.09), respectively, with statistically significant different doses between the thoracic and cervical esophagus (P-value < 0.001). The V5, V10, and V30 for the thoracic esophagus were zero; however, the V5, V10 and V30 for the cervical esophagus were 7.07 (± 15.83), 2.29 (± 8.04) and 0.29 (± 1.99), respectively. The V5 values were significantly higher than V10 (P-value < 0.001) and V30 (P-value < 0.001), while V10 and V30 did not differ significantly (P-value = 0.155). Conclusions: This study reveals distinct dosimetric patterns for the cervical and thoracic esophagus during RT. The thoracic esophagus received low radiation doses, whereas the cervical esophagus demonstrated higher doses and more significant variability. Findings emphasize the importance of meticulous treatment planning to minimize potential late radiationinduced complications, especially in the cervical region. [ABSTRACT FROM AUTHOR]

Ali Asghar Ghorbani, 1 Zohreh Sohrabi, 2 Shahram Yazdani, 3 Salimeh Khalili Azandehi 4 1Department of Medical Education, Faculty of Medicine, CERMS (Center of Educational Research in Medical Sciences), Iran University of Medical Sciences, Tehran, Iran; 2School of Medicine, Department of Medical Education, CERMS (Center of Educational Research in Medical Sciences), Iran University of Medical Sciences, Tehran, Iran; 3School of Medical Education, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 4Social Security Organization, Valiasr Regional Hospital, Education & Research Unit, Ghaemshahr, IranCorrespondence: Zohreh SohrabiSchool of Medicine, Department of Medical Education, Iran University of Medical Sciences, Iran, Tehran Tel +98-21-88622607Email zo_sohrabi@yahoo.comIntroduction: Given the social, economic, environmental and internal developments of universities, the necessity for medical universities to move to being third-generation universities has been demonstrated. These universities, along with the requirements of entrepreneurship and commercialization of research, are in need of structural requirements. This study was conducted with the aim to identify and introduce the structural requirements of medical sciences universities in Iran in the transition to the third-generation universities.Materials and Methods: This study was a qualitative approach using a conventional content analysis method. The contributors comprised 16 faculty members working in medical universities in Iran who were purposefully recruited and interviewed face to face in semi-structured interviews between October 2018 and March 2019.Results: Two wide classifications containing macro-structural requirements (institutional requirements) and micro-structural requirements (organizational requirements) were developed. Institutional requirements included four subcategories including redefining the university as a holding of knowledge business units, redefining academic units as a strategic business unit (SBU) which refer to the mission of the universities and eliminate bureaucracy, independence, and ‘Competition in recruitment and contracts’ which refer to the administrative requirements of the universities. The organizational requirements included units and offices, centers, and parks that are grouped because of similarities in internal processes.Conclusion: Medical universities need structural requirements to move to third-generation universities and improve infrastructure. These requirements, which develop in a spiral over time, must be appropriate and tailored to the capacity of each university.Keywords: third generation university, medical sciences universities, structural requirements, Iran

Shahram Yazdani, Maryam Hoseini AbardehDepartment of Medical Education, School of Medical Education, Shahid Beheshti University of Medical Sciences, Tehran, IranCorrespondence: Maryam Hoseini AbardehSchool of Medical Education, Shahid Beheshti University of Medical Sciences, Shahid Chamran Highway, Tehran Velenjak Street, Tehran, IranTel +98 212 243 9982Fax +98 212 243 9784Email hoseini.abardeh@sbmu.ac.irAbstract: Clinical reasoning is a complex cognitive process that is essential to evaluate and manage a patient’s medical problem. The aim of this paper was to provide a critical review of the research literature on clinical reasoning theories and models. To conduct our study, we applied the process of conducting a literature review in four stages in accordance with the approach of Carnwell and Daly. First, we defined the scope of the review as being limited to clinical reasoning theories and models in medical education. In the second stage, we conducted a search based on related words in PubMed, Google Scholar, PsycINFO, ERIC, ScienceDirect and Web of Science databases. In the third stage, we classified the results of the review into three categories, and in the fourth stage, we concluded and informed further studies. Based on the inclusion and exclusion criteria, 31 articles were eligible to be reviewed. Three theories and two models were recognized and classified into three categories. Several theories and models have been proposed in relation to clinical reasoning, but it seems that these theories and models could only explain part of this complex process and not the whole process. Therefore, to fulfill this gap, it may be helpful to build a Meta-model or Meta-theory, which unified all the models, and theories of clinical reasoning.Keywords: clinical reasoning, medical education, review

The control of laser emission angles in laser devices is essential for many optoelectronic and photonic applications such as optical sensing and displays. In this context, we studied the light diffraction pattern of laser beams in a one-dimensional sampled distributed feedback resonator having organic gain media. The gratings consist of the repetition of supercells having a mixed-order sampled grating in which 1st-order gratings surround a 2nd-order grating. The experimental results showed that the diffraction angles of the laser beams are quite diverse depending on the supercell structures. We demonstrate that the interval of the diffraction angle (θ) of the laser beams is inversely proportional to the length of the supercell experimentally and theoretically. By tuning the length of supercells as well as the length of 1st-order and 2nd-order regions, the interval θ was tuned from 0.1° to 43° with the different arc emission patterns. With the reduction of θ, i.e., the longer 1st-order region, a significant decrease in the laser threshold was obtained, resulting in the lowest lasing threshold of 2.5 ± 0.1 μJ/cm2 with ∼3.5 ns of a long pulse width excitation source. [ABSTRACT FROM AUTHOR]

Background and Objective: Cardioembolic stroke account for one-fifth of ischemic stroke and atrial fibrillation is the most common underlying cause. Taking an oral anticoagulation (Warfarin) is an effective way of preventing ischemic stroke but bleeding complication is common. This study was carried out to evaluate the validation of HASBLED score in prediction of hemorrhagic complications in patients with brain ischemia and atrial fibrillation under warfarin therapy. Methods: In this cohort study 112 patients with non-valvular atrial fibrillation in term of major and minor bleeding complications were followed to the predictive value of HASBLED criteria for one year. Major bleeding complications defined as intracranial bleeding, bleeding leading to hospitalization, drop of hemoglubin of more than 2gr/dl or requiring transfusion. HASBLED criteria were defined as hypertension, abnormality in liver and renal function tests, history of stroke, history of bleeding, large fluctuations in coagulation tests results, age more than 65 years and an Anti-platelet and non steroidal anti-inflammatory drugs and alcohol use one point is awarded to each of the aboves. Results: During one year follow up, 10 (9.1%) of patients had major bleeding and 28 (25%) patients had minor bleeding. The risk of major bleeding was significantly related with a history of minor bleeding and HASBLED scores (P3 was associated with the likelihood of major bleeding in future. Conclusion: Patients with HASBLED score>3 should be causious in initial stage of taking oral anticoagulant.

Background and Objective: The staging of gastrointestinal cancer has an important role in the treatment of tumor. This study was done to determine the efficacy of endosonography method for determining the stage and deepth of esophagus and stomach cancers. Materials and Methods: In this descriptive study, endosonographic staging was performed in 23 patients (15 male and 8 female) with esophagus and stomach cancers, confirmed with pathologic findings in Taleghani hospital, Tehran, Iran during 2002-04. The results of surgical staging compared to preoperative endosonographic method. Results: Mean age of 23 patients was 57.2 years (43-72 years). 30% and 70% of the patients had esophageal and gastric cancers, respectively. The accuracy of endosonographic staging of esophagus and stomach cancers was 82%. The accuracy of diagnosis, positive and negative predictive value of cancers in assessment of the depth of the tumor by endosonography procedure were 79.4%, 69.6% and 84.9%, respectively. Conclusion: Endosonography is a precise method for evaluating depth and staging of tumor and lymph node involvement.