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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]

The speedy development of intelligent technologies and gadgets has led to a drastic increment of dimensions within the datasets in recent years. Dimension reduction algorithms, such as feature selection methods, are crucial to resolving this obstacle. Currently, metaheuristic algorithms have been extensively used in feature selection tasks due to their acceptable computational cost and performance. In this article, a binary-modified version of aphid-ant mutualism (AAM) called binary aphid-ant mutualism (BAAM) is introduced to solve the feature selection problems. Like AAM, in BAAM, the intensification and diversification mechanisms are modeled via the intercommunication of aphids with other colonies' members, including aphids and ants. However, unlike AAM, the number of colonies' members can change in each iteration based on the attraction power of their leaders. Moreover, the second- and third-best individuals can take the place of the ringleader and lead the pioneer colony. Also, to maintain the population diversity, prevent premature convergence, and facilitate information sharing between individuals of colonies including aphids and ants, a random cross-over operator is utilized in BAAM. The proposed BAAM is compared with five other feature selection algorithms using several evaluation metrics. Twelve medical and nine non-medical benchmark datasets with different numbers of features, instances, and classes from the University of California, Irvine and Arizona State University repositories are considered for all the experiments. Moreover, a coronavirus disease (COVID-19) dataset is used to validate the effectiveness of the BAAM in real-world applications. Based on the acquired outcomes, the proposed BAAM outperformed other comparative methods in terms of classification accuracy using various classifiers, including K nearest neighbor, kernel-based extreme learning machine, and multi-class support vector machine, choosing the most informative features, the best and mean fitness values and convergence speed in most cases. As an instance, in the COVID-19 dataset, BAAM achieved 96.53% average accuracy and selected the most informative feature subset. [ABSTRACT FROM AUTHOR]