Reconfigurable Antennas in mmWave MIMO Systems

The key obstacle to achieving the full potential of the millimeter wave (mmWave) band has been the poor propagation characteristics of wireless signals in this band. One approach to overcome this issue is to use antennas that can support higher gains while providing beam adaptability and diversity, i.e., reconfigurable antennas. In this article, we present a new architecture for mmWave multiple-input multiple-output (MIMO) communications that uses a new class of reconfigurable antennas. More specifically, the proposed lens-based antennas can support multiple radiation patterns while using a single radio frequency chain. Moreover, by using a beam selection network, each antenna beam can be steered in the desired direction. Further, using the proposed reconfigurable antenna in a MIMO architecture, we propose a new signal processing algorithm that uses the additional degrees of freedom provided by the antennas to overcome propagation issues at mmWave frequencies. Our simulation results show that the proposed reconfigurable antenna MIMO architecture significantly enhances the performance of mmWave communication systems

Variations in wood density, annual ring width and vessel properties of quercus brantii affected by crown dieback

Funding: This research received no external funding. Acknowledgments: We would like to thank A. Hawasi and S. Soltani for their kind help during this work.Peer reviewedPublisher PD

Trend of bladder cancer mortality in Iran (2006 to 2010)

Abstract Introduction: Bladder cancer is the most common tumor of the urinary tract and the ninth cancer in terms of incidence in both sexes in the world. Bladder cancer is the second most common cancer in men in Iran. This study aimed to investigate the trend of death from bladder cancer in Iran. Materials and Methods: This study was conducted by the use of data on mortality in Iran during 2006-10. Data on mortality from cancer within the study period were collected and entered on a pre-designed form. Mortality rates per 105 persons were calculated by age group and sex, and the trend of mortality from this cancer was determined. Results: The results from the calculation of mortality rates per 105 persons indicated that the death rate from bladder cancer is reduced from 1.12 to 1.09. The mortality rates during all the years under study showed that increasing age increases bladder cancer in men. Discussion: No particular change was observed in the analysis of the trend of tobacco use in Iran in the last two decades, which can be considered as one of the causes of constancy of mortality trend from bladder cancer. However, given the increase in the number of people over 65 and the observed growing trend in bladder cancer incidence in various regions of the country, it is recommended that health policies are adopted in order to prevent risk factors behind this type of cancer such as tobacco and harmful industrial materials

Spin-orbit torque switching of synthetic antiferromagnets

We report that synthetic antiferromagnets (SAFs) can be efficiently switched by spin-orbit torques (SOTs) and the switching scheme does not obey the usual SOT switching rule. We show that both the positive and negative spin Hall angle (SHA)-like switching can be observed in Pt/SAF structures with only positive SHA, depending on the strength of applied in-plane fields. A new switching mechanism directly arising from the asymmetric domain expansion is proposed to explain the anomalous switching behaviors. Contrary to the macrospin-based switching model that the SOT switching direction is determined by the sign of SHA, the new switching mechanism suggests that the SOT switching direction is dominated by the field-modulated domain wall motion and can be reversed even with the same sign of SHA. The new switching mechanism is further confirmed by the domain wall motion measurements. The anomalous switching behaviors provide important insights for understanding SOT switching mechanisms and also offer novel features for applications.Comment: 40 pages, 14 figure

Association Between Serum Homocysteine Concentration with Coronary Artery Disease in Iranian Patients

<p><strong>BACKGROUND</strong>: The role of novel biomarkers like homocystein as a risk factor of coronary artery disease (CAD) is being increasingly recognized. There is a marked geographical variation in plasma homocystein concentration. In spite of importance of hyperhomocysteinemia in CAD risk, there is a paucity of studies in Iran that evaluate it. Consequently, we evaluated the association between plasma total homocystein (tHcy) concentration and CAD risk in an Iranian population.</p><p><strong>METHODS:</strong> In a case-control study, we compared the level of tHcy of forty five patients with angiographically proved CAD with forty five age and gender matched subjects without CAD as control group. The patients with diabetes, hypertension, thyroid dysfunction, chronic renal failure, hyperlipidemia and obesity and other conventional CAD risk factors were excluded from the study. Plasma tHcy was measured using immunoturbidimetry.</p> <p><strong>RESULTS:</strong> Homocystein level was higher in men than women (16.7 &plusmn; 5.2 versus 14.3 &plusmn; 3.9 micromol/lit, P = 0.019). CAD patients had higher mean plasma tHcy than control group (17.1 &plusmn; 5.3 versus 14.2 &plusmn; 3.8 micromol/lit, P = 0.004).</p> <p><strong>CONCLUSION:</strong> This study denoted that high plasma homocystein concentration is associated with CAD risk in Iranian people.</p> Keywords: Coronary Artery Disease, Homocystein<strong>, Iran.<br /></strong

How Tree Decline Varies the Anatomical Features in Quercus brantii

Funding: This research was funded by Ilam University, grant number 805‑1397‑12.Peer reviewedPublisher PD

A New Reconfigurable Antenna MIMO Architecture for mmWave Communication

The large spectrum available in the millimeter- Wave (mmWave) band has emerged as a promising solution for meeting the huge capacity requirements of the 5th generation (5G) wireless networks. However, to fully harness the potential of mmWave communications, obstacles such as severe path loss, channel sparsity and hardware complexity should be overcome. In this paper, we introduce a generalized reconfigurable antenna multiple-input multiple-output (MIMO) architecture that takes advantage of lens-based reconfigurable antennas. The considered antennas can support multiple radiation patterns simultaneously by using a single RF chain. The degrees of freedom provided by the reconfigurable antennas are used to, first, combat channel sparsity in MIMO mmWave systems. Further, to suppress high path loss and shadowing at mmWave frequencies, we use a rate-one space-time block code. Our analysis and simulations show that the proposed reconfigurable MIMO architecture achieves full-diversity gain by using linear receivers and without requiring channel state information at the transmitter. Moreover, simulations show that the proposed architecture outperforms traditional MIMO transmission schemes in mmWave channel settings

Is Montreal Cognitive Assessment a valuable test for the differentiation of Alzheimer's disease, frontotemporal dementia, dementia with Lewy body, and vascular dementia?

Peer reviewe

Emergency Department Quality Dashboard; a Systematic Review of Performance Indicators, Functionalities, and Challenges

Introduction: Effective information management in the emergency department (ED) can improve the control and management of ED processes. Dashboards, known as data management tools, efficiently provide information and contribute greatly to control and management of ED. This study aimed to identify performance indicators and quality dashboard functionalities, and analyze the challenges associated with dashboard implementation in the ED. Methods: This systematic review began with a search in four databases (Web of Science, PubMed, Embase, and Scopus) from 2000 to May 30, 2020, when the final search for papers was conducted. The data were collected using a data extraction form and the contents of the extracted papers were analyzed through ED performance indicators, dashboard functionalities, and implementation challenges. Results: Performance indicators reported in the reviewed papers were classified as the quality of care, patient flow, timeliness, costs, and resources. The main dashboard functionalities noted in the papers included reporting, customization, alert creation, resource management, and real-time information display. The dashboard implementation challenges included data sources, data quality, integration with other systems, adaptability of dashboard functionalities to user needs, and selection of appropriate performance indicators. Conclusions: Quality dashboards facilitate processes, communication, and situation awareness in the ED; hence, they can improve care provision in this department. To enhance the effectiveness and efficiency of ED dashboards, officials should set performance indicators and consider the conformity of dashboard functionalities with user needs. They should also integrate dashboards with other relevant systems at the departmental and hospital levels

Effectiveness of Cognitive Orientation to Daily Occupational Performance in Parkinson’s Disease: A Case Report

Introduction: Parkinson’s disease is a chronic progressive neurodegenerative disorder causing impaired motor function and various non-motor symptoms. One of the most common problems in Parkinson’s patients is occupational performance problems. The cognitive orientation to daily occupational performance (CO-OP) is one of the client-centered and problem-solving approaches in occupational therapy evaluations and interventions. This study aims to determine the effectiveness of the CO-OP approach on perceived satisfaction and occupational performance in a 62-year-old woman with Parkinson’s disease. Case Description: The client was a 62-year-old woman with moderate cognitive impairment, stage 3 on the Hoehn and Yahr scale, and signs of depression. In our case study, the outcome measures were the Canadian occupational performance measure (COPM), functional independence measure (FIM), Montreal cognitive assessment (MOCA), and Beck depression inventory-II (BDI-II). We administered the CO-OP intervention for six weeks. Sessions were performed twice a week for one hour per session. Results: The results indicate that the CO-OP intervention improves the client’s satisfaction, occupational performance, and functional independence. Although the results from this single case cannot be generalized, the findings suggest that CO-OP intervention may help improve satisfaction and occupational performance in adults with Parkinson’s disease. Further investigation is necessary. Conclusion: These results suggest that CO-OP can be a valuable occupational therapy interventions for individuals with Parkinson’s disease. We recommend that occupational therapists consider using this approach in their practice to improve the occupational performance of their patients with Parkinson’s disease