Stresses Variation due to the Anomalies in Circle of Willis

The aneurysm is a complex phenomenon which is affected by different factors, such as the biological diseases and the blood flow parameters. The wall shear stress and pressure are the main factors in the establishment and growth of cerebral aneurysm. The circle of Willis is a prevalent location for aneurysm. On the other hand, the anomalies of circle of Willis cause variations in flow field pattern and also the wall shear stress and pressure. In the present study, the effects of some anomalies in the flow pattern are investigated using three dimensional simulation of the Circle of Willis. The simulations are conducted using commercial ANSYS FLUENT. The obtained results show the major anomalies cause increase wall shear stress and pressure on the wall of circle of Willis. This factor can lead to increase the risk of aneurysm

Trajectory Range Visibility

We study the problem of Trajectory Range Visibility, determining the sub-trajectories on which two moving entities become mutually visible. Specifically, we consider two moving entities with not necessarily equal velocities and moving on a given piece-wise linear trajectory inside a simple polygon. Deciding whether the entities can see one another with given constant velocities, and assuming the trajectories only as line segments, was solved by P. Eades et al. in 2020. However, we obtain stronger results and support queries on constant velocities for non-constant complexity trajectories. Namely, given a constant query velocity for a moving entity, we specify all visible parts of the other entity's trajectory and all possible constant velocities of the other entity to become visible. Regarding line-segment trajectories, we obtain $\mathcal{O}(n \log n)$ time to specify all pairs of mutually visible sub-trajectories s.t. $n$ is the number of vertices of the polygon. Moreover, our results for a restricted case on non-constant complexity trajectories yield $\mathcal{O}(n + m(\log m + \log n))$ time, in which $m$ is the overall number of vertices of both trajectories. Regarding the unrestricted case, we provide $\mathcal{O}(n \log n + m(\log m + \log n))$ running time. We offer $\mathcal{O}(\log n)$ query time for line segment trajectories and $\mathcal{O}(\log m + k)$ for the non-constant complexity ones s.t. $k$ is the number of velocity ranges reported in the answer. Interestingly, our results require only $\mathcal{O}(n + m)$ space for non-constant complexity trajectories

Where Quantum Complexity Helps Classical Complexity

Scientists have demonstrated that quantum computing has presented novel approaches to address computational challenges, each varying in complexity. Adapting problem-solving strategies is crucial to harness the full potential of quantum computing. Nonetheless, there are defined boundaries to the capabilities of quantum computing. This paper concentrates on aggregating prior research efforts dedicated to solving intricate classical computational problems through quantum computing. The objective is to systematically compile an exhaustive inventory of these solutions and categorize a collection of demanding problems that await further exploration

A Novel Parallel Algorithm Based on the Gram-Schmidt Method for Tridiagonal Linear Systems of Equations

This paper introduces a new parallel algorithm based on the Gram-Schmidt orthogonalization method. This parallel algorithm can find almost exact solutions of tridiagonal linear systems of equations in an efficient way. The system of equations is partitioned proportional to number of processors, and each partition is solved by a processor with a minimum request from the other partitions' data. The considerable reduction in data communication between processors causes interesting speedup. The relationships between partitions approximately disappear if some columns are switched. Hence, the speed of computation increases, and the computational cost decreases. Consequently, obtained results show that the suggested algorithm is considerably scalable. In addition, this method of partitioning can significantly decrease the computational cost on a single processor and make it possible to solve greater systems of equations. To evaluate the performance of the parallel algorithm, speedup and efficiency are presented. The results reveal that the proposed algorithm is practical and efficient

Social impact of the Iraq-Iran war as experienced by Iranian surgeons

Surgeons played a vital role in the Iraq-Iran War by healing injured soldiers and reducing the rate of death. The purpose of this study was to describe their lived experiences and social impact during the war. This qualitative study was conducted from May 2018-June 2019 and surgeons who participated in the Iraq-Iran War were invited. Semi-structured in-depth interviews were used to collect the data from 28 participants. Four main themes emerged from the data:  1- Military role was important in providing essential facilities and safe zones for personnel and soldiers at the warfront. 2- It was critical to reinforce the infrastructure for immediate medical assistance. 3- Disaster training for medical personnel was vital for triage, treatment, education and research planning. 4- Spiritual and religious beliefs. Disaster planning and training for physicians by drills is essential to meet the challenges of unexpected events and operative readiness requires drill training on a quarterly or semi-annual basis

Post-discharge follow-up of patients with spine trauma in the National Spinal Cord Injury Registry of Iran during the COVID-19 pandemic:Challenges and lessons learned

Purpose: The purpose of the National Spinal Cord Injury Registry of Iran (NSCIR-IR) is to create an infrastructure to assess the quality of care for spine trauma and in this study, we aim to investigate whether the NSCIR-IR successfully provides necessary post-discharge follow-up data for these patients. Methods: An observational prospective study was conducted from April 11, 2021 to April 22, 2022 in 8 centers enrolled in NSCIR-IR, respectively Arak, Rasht, Urmia, Shahroud, Yazd, Kashan, Tabriz, and Tehran. Patients were classified into 3 groups based on their need for care resources, respectively: (1) non-spinal cord injury (SCI) patients without surgery (group 1), (2) non-SCI patients with surgery (group 2), and (3) SCI patients (group 3). The assessment tool was a self-designed questionnaire to evaluate the care quality in 3 phases: pre-hospital, in-hospital, and post-hospital. The data from the first 2 phases were collected through the registry. The post-hospital data were collected by conducting follow-up assessments. Telephone follow-ups were conducted for groups 1 and 2 (non-SCI patients), while group 3 (SCI patients) had a face-to-face visit. This study took place during the COVID-19 pandemic. Data on age and time interval from injury to follow-up were expressed as mean ± standard deviation (SD) and response rate and follow-up loss as a percentage. Results: Altogether 1538 telephone follow-up records related to 1292 patients were registered in the NSCIR-IR. Of the total calls, 918 (71.05%) were related to successful follow-ups, but 38 cases died and thus were excluded from data analysis. In the end, post-hospital data from 880 patients alive were gathered. The success rate of follow-ups by telephone for groups 1 and 2 was 73.38% and 67.05% respectively, compared to 66.67% by face-to-face visits for group 3, which was very hard during the COVID-19 pandemic. The data completion rate after discharge ranged from 48% – 100%, 22% – 100% and 29% – 100% for groups 1 – 3. Conclusions: To improve patient accessibility, NSCIR-IR should take measures during data gathering to increase the accuracy of registered contact information. Regarding the loss to follow-ups of SCI patients, NSCIR-IR should find strategies for remote assessment or motivate them to participate in follow-ups through, for example, providing transportation facilities or financial support.</p

Post-discharge follow-up of patients with spine trauma in the National Spinal Cord Injury Registry of Iran during the COVID-19 pandemic:Challenges and lessons learned

PURPOSE: The purpose of the National Spinal Cord Injury Registry of Iran (NSCIR-IR) is to create an infrastructure to assess the quality of care for spine trauma and in this study, we aim to investigate whether the NSCIR-IR successfully provides necessary post-discharge follow-up data for these patients.METHODS: An observational prospective study was conducted from April 11, 2021 to April 22, 2022 in 8 centers enrolled in NSCIR-IR, respectively Arak, Rasht, Urmia, Shahroud, Yazd, Kashan, Tabriz, and Tehran. Patients were classified into three groups based on their need for care resources, respectively: (1) non-spinal cord injury (SCI) patients without surgery (group 1), (2) non-SCI patients with surgery (group 2), and (3) SCI patients (group 3). The assessment tool was a self-designed questionnaire to evaluate the care quality in 3 phases: pre-hospital, in-hospital, and post-hospital. The data from the first 2 phases were collected through the registry. The post-hospital data were collected by conducting follow-up assessments. Telephone follow-ups were conducted for groups 1 and 2 (non-SCI patients), while group 3 (SCI patients) had a face-to-face visit. This study took place during the COVID-19 pandemic. Data on age and time interval from injury to follow-up were expressed as mean ± standard deviation (SD) and response rate and follow-up loss as a percentage.RESULTS: Altogether 1538 telephone follow-up records related to 1292 patients were registered in the NSCIR-IR. Of the total calls, 918 (71.05%) were related to successful follow-ups, but 38 cases died and thus were excluded from data analysis. In the end, post-hospital data from 880 patients alive were gathered. The success rate of follow-ups by telephone for groups 1 and 2 was 73.38% and 67.05% respectively, compared to 66.67% by face-to-face visits for group 3, which was very hard during the COVID-19 pandemic. The data completion rate after discharge ranged from 48% to 100%, 22%-100% and 29%-100% for groups 1 - 3.CONCLUSIONS: To improve patient accessibility, NSCIR-IR should take measures during data gathering to increase the accuracy of registered contact information. Regarding the loss to follow-ups of SCI patients, NSCIR-IR should find strategies for remote assessment or motivate them to participate in follow-ups through, for example, providing transportation facilities or financial support.</p

The efficacy of surgical decompression before 24 hours versus 24 to 72 hours in patients with spinal cord injury from T1 to L1 – with specific consideration on ethics: a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>There is no clear evidence that early decompression following spinal cord injury (SCI) improves neurologic outcome. Such information must be obtained from randomized controlled trials (RCTs). To date no large scale RCT has been performed evaluating the timing of surgical decompression in the setting of thoracolumbar spinal cord injury. A concern for many is the ethical dilemma that a delay in surgery may adversely effect neurologic recovery although this has never been conclusively proven. The purpose of this study is to compare the efficacy of early (before 24 hours) verse late (24–72 hours) surgical decompression in terms of neurological improvement in the setting of traumatic thoracolumbar spinal cord injury in a randomized format by independent, trained and blinded examiners.</p> <p>Methods</p> <p>In this prospective, randomized clinical trial, 328 selected spinal cord injury patients with traumatic thoracolumbar spinal cord injury are to be randomly assigned to: 1) early surgery (before 24 hours); or 2) late surgery (24–72 hours). A rapid response team and set up is prepared to assist the early treatment for the early decompressive group. Supportive care, i.e. pressure support, immobilization, will be provided on admission to the late decompression group. Patients will be followed for at least 12 months posttrauma.</p> <p>Discussion</p> <p>This study will hopefully assist in contributing to the question of the efficacy of the timing of surgery in traumatic thoracolumbar SCI.</p> <p>Trial Registration</p> <p><b>RCT registration number: ISRCTN61263382</b></p

Health-related quality of life among individuals with long-standing spinal cord injury: a comparative study of veterans and non-veterans

<p>Abstract</p> <p>Background</p> <p>Spinal cord-injured (SCI) patients experience poor health-related quality of life (HRQOL) and they usually report lower HRQOL than the general population or population subgroups in Iran and elsewhere. The aim of this study was to compare HRQOL between veterans and non-veterans with SCI in Iran.</p> <p>Methods</p> <p>This was a cross-sectional study. HRQOL was measured using the 36-item Short Form Health Survey (SF-36). Thirty-nine male veterans and 63 non-veteran males with SCI were included in the study. Regression analyses were applied to determine the variables affecting physical and mental health-related quality of life among the patients.</p> <p>Results</p> <p>The male veterans had a lower HRQOL than the non-veterans with SCI. The differences were significant for all measures except for physical and social functioning. The greatest difference was observed for bodily pain (P = 0.001). The regression analysis results indicated that a longer time since injury was associated (P = 0.01) with better physical health-related quality of life (PCS), while being a veteran (P < 0.001) and having a spinal lesion in the cervical region (P = 0.001) were associated with poorer PCS. Older age (P < 0.001) and higher education (P = 0.01) were associated with better mental health-related quality of life (MCS), while being a veteran and having a spinal lesion in the cervical region (P = 0.02) were associated with poorer MCS.</p> <p>Conclusion</p> <p>The study findings showed that veterans with SCI experienced lower HRQOL than their non-veteran counterparts. A qualitative study is recommended to evaluate why HRQOL was lower in veterans than in non-veterans with SCI although veterans had higher incomes as a result of their pensions and increased access to equipment, and medications. To improve quality of life in both veterans and non-veterans with spinal cord injuries, policy changes or implementation of new interventions may be essential so that veterans could receive additional support (e.g. counseling, recreation therapy, vocational therapy, etc.) and non-veterans could meet their basic needs.</p

Benefits of collaborative learning

AbstractCollaborative learning is an educational approach to teaching and learning that involves groups of learners working together to solve a problem, complete a task, or create a product. This review article outlines benefits of learning in collaboration style, begins with the concept of the term and continues with the advantages created by collaborative methods. This paper sets out major benefits of collaborative learning into four categories of; social, psychological, academic, and assessment benefits. Each of them is further subdivided to more specific themes