Association between vitamin d deficiencies in sarcoidosis with disease activity, course of disease and stages of lung involvements

Background: Despite negative association between 25-hydroxy vitamin D and incidence of many chronic respiratory diseases, this feature was not well studied in sarcoidosis. Current study investigated the association between 25-hydroxy vitamin D deficiency with sarcoidosis chronicity, disease activity, extra-pulmonary skin manifestations, urine calcium level and pulmonary function status in Iranian sarcoidosis patients. Results of this study along with future studies, will supply more effective programs for sarcoidosis treatment. Methods: Eighty sarcoidosis patients in two groups of insufficient serum level and sufficient serum level of 25-hydroxy vitamin D were studied. Course of sarcoidosis was defined as acute and chronic sarcoidosis. Pulmonary function test (PFT) was assessed by spirometry. Skin involvements were defined as biopsy proven skin sarcoidosis. 24-hour urine calcium level was used to specify the disease activity. Stages of lung involvements were obtained by CT-scan and chest X-ray. The statistical analyses were evaluated using Statistical Package for the Social Sciences. Results: A significant negative correlation was obtained between vitamin D deficiency in sarcoidosis patients and disease chronic course and stages two to four of lung involvements. Considering other parameters of the disease and vitamin D deficiency, no significant correlation was detected. Conclusions: In conclusion, results of the current study implies in the role of vitamin 25(OH)D deficiencies in predicting the course of chronic sarcoidosis. Furthermore, it was concluded that vitamin 25(OH)D deficiency can direct pulmonary sarcoidosis toward stage 2–4 of lung involvements

Thermal Stress Analysis of Absorber Tube for a Parabolic Collector under Quasi-Steady State Condition

AbstractThe design of parabolic trough collectors is based on the concentration of solar heat flux on its absorber tube. This may be subjected to high thermal stresses which could cause deflection of the absorber tube and failure of its cover glass tube. Investigation of earlier studies on thermal gradient and thermal stresses demonstrates that so far, the issue is considered for steady state condition based on the assumption of constant solar heat flux distribution during the day hours. However, in practice, solar heat flux distribution on the receiver tube has continues changes with respect to time and deformation is basically transient. Due the low speed of sun during a day and for specific time intervals, the average solar radiation could be considered constant for thermal stress and deflection analysis. Hence, in this study, thermal gradients as well as thermal stresses in the absorber tube are numerically investigated in quasi steady condition. Due to the wide changes of solar radiation during a year, computations are performed for four specific days of Spring Equinox, Summer Solstice, Autumnal Equinox and Winter Solstice. To compute solar heat flux distribution, SolTrace software is used and three dimensional heat flux distribution is applied as an external boundary condition to calculate temperature distribution in the absorber tube. By using Von-Misses theory, maximum equivalent of total stress is computed. Maximum deflection is evaluated for various different inlet temperatures and hot oil mass flow rates in the common range of solar thermal power plants for atypical parabolic trough collector which is under construction in Shiraz, Iran

Pregnancy Outcomes Among Hospitalized Patients Infected With 2009 H1N1 Influenza Virus in Qom, Iran, in Oct-Nov. 2009

Background: Pandemic H1N1 influenza A 2009 (H1N1/09) virus has been identified as a leading cause of febrile respiratory diseases worldwide, and pregnant women constitute a high risk group. Objectives: To determine the clinical characteristics and outcomes of pregnant women with H1N1 influenza A hospitalized in university hospitals of Qom city in Iran. Patients and Methods: This descriptive retrospective study was conducted using existed data related to October and November 2009. All pregnant women with influenza manifestations were admitted to the hospitals to undergo nasopharyngeal culture. H1N1 virus was confirmed in 11 cases. Data including demographic characteristics, clinical manifestations, laboratory test results, and pregnancy complications was extracted from medical records, and analyzed by descriptive statistics. Results: The mean age of the women was 28.1 ± 4.7 years with a mean gestational age of 28.7 ± 10.9 weeks. The most common clinical manifestations included coughing (100%), fever (87.5%), and dyspnea (75%). The most common abnormal test was anemia (88%). Pregnancy complications included preterm delivery (36.3%), low birth weight (18%), oligohydramnios (9%), gestational diabetes (9%), and fetal distress (9%). Also one (12.5%) wound dehiscence happened. Conclusions: vaccination seems to be necessary to prevent this potentially fatal infectious disease. Furthermore, timely prescription of antiviral medications is recommended to decrease the risk of severe complications

Modeling, Simulation and Control of a Tubular Fixed-bed Dimethyl Ether Reactor

This paper considers the modeling and control of a tubular fixed bed reactor with recycle stream for dimethyl ether (DME) production. For simulation purposes, a pseudo homogeneous model has been developed. By reactor simulation under steady state condition, effects of parameters such as feed rate, pressure and shell temperature are investigated. Using the steady state model, an optimizer that maximizes the reactor yield has been developed. For cooling the reactor, a steam drum that uses heat of reactions to produce steam was coupled with the reactor. Through dynamic simulation, system open loop response was obtained and two control loops were considered for controlling the reactor temperature and steam drum level. An optimizer that takes into account the feed variations was incorporated into the control system to maximize the DME production rate

The effect of brain-based electronic courseware on problem solving performance and motivation of students in computer programming course

Background and Objectives: The rapid growth of science and technology and the subsequent emergence of e-learning have revolutionized education. Also in this period, becoming aware of how the brain functions during the learning process has had important effects on training and learning. Educators are looking for ways to the most usage of technology-based facilities and new findings in educational neuroscience to obtain the optimal learning, especially in difficult subject matters such as computer programming course, which are associated with the problem-solving process. The aim of this study was to investigate the effect of electronic courseware designed based on the brain based learning principles on problem-solving performance and motivation of the students in computer programming course. Methods: This research is a quasi-experimental study, and was conducted with a pretest posttest control group design. In this study, sampling was done by cluster sampling method and thus 60 female students of the eleventh grade of computer fields of vocational schools in Isfahan were selected to participate in the study. Participants were randomly divided into 3 groups of 20 (experimental, control 1 and control 2). A literature review was conducted to identify the brain based learning strategies. Based on the lesson objectives and the strategies derived from the principles of brain based learning, an electronic courseware was designed and developed by the researcher and the expert team. The validity of this courseware was confirmed by experts. The intrinsic and extrinsic motivation subscales of Pintrich et al.'s questionnaire as well as a teacher-made computer programming problem-solving test were used as data collection tools, which were used as a pre-test and post-test, before and after the training, in all 3 groups.  The same content from the computer programming course was taught in all three groups. In the experimental group, in addition to the conventional method, an electronic courseware based on brain based learning strategies was used. In the first control group, in addition to conventional method, a non-brain based electronic courseware was used. The second control group was trained only in the conventional method. Findings: The research data were analyzed using univariate covariance analysis on problem-solving performance test scores and multivariate covariance analysis on intrinsic and extrinsic motivation scores. The results of the study showed that the problem solving performance of experimental group was significantly better than the control 1 and control 2 groups (P <0.05) in computer programming course. Also, the extrinsic motivation of the experimental group was significantly higher (P <0.05) than the first control group. Based on these findings, the use of non-brain based courseware significantly (P <0.05) reduced the extrinsic motivation of control group 2 students compared to control group 1. Conclusion: The use of electronic courseware designed and developed based on brain based learning principles has a significant impact on increasing student computer problem solving performance. Also, the application of brain based learning principles in designing and developing the electronic courseware makes more external motivation in the users of this courseware than the users of typical courseware while learning.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Simulation of transport in laterally gated junctionless transistors fabricated by local anodization with an atomic force microscope

In this paper, we have investigated the characteristics and transport features of junctionless lateral gate transistors via measurement and simulations. The transistor is fabricated using an atomic force microscopy (AFM) nanolithography technique on silicon-on-insulator (SOI) wafer. This work develops our previous examination of the device operation by using 3D numerical simulations to offer a better understanding of the origin of the transistor operation. We compare the experimental measurements and simulation results in the transfer characteristic and drain conductance. We also explore the behavior of the device in on and off states based on the variation of majority and minority carriers' density, electric-field components, and recombination/generation rate of carriers in the active region of the device. We show that the device is a normally on device that can force the current through a depleted region (off state) and uses bulk conduction instead of surface conduction. We also found that due to the lateral gate design, low-doped channel, and lack of the gate oxide the electrostatic squeezing of the channel effectively forces the device into the off state, but the current improvement by accumulation of carriers is not significant

The Effect of the Immunization Schedule and Antibody Levels (Anti-S) on the Risk of SARS-CoV-2 Infection in a Large Cohort of Healthcare Workers in Northern Italy

Given their occupational risk profile, HCWs were the first to receive anti-SARS-CoV-2 vaccination. However, breakthrough infections remained common, mainly sustained by new SARS-CoV-2 variants of concern (VOCs) that rapidly spread one after another in Italy. Evidence suggests that the measured level of anti-SARS-CoV-2 antibodies does not clearly predict the level of protection conferred by either natural infection or vaccine-induced immunization, highlighting the need for further study on the diversity in susceptibility to SARS-CoV-2 infection. The present study aimed to characterize different risk profiles for SARS-CoV-2 infection in HCWs who had recently received the booster dose, and who were classified according to their immunization profile. The very small number of workers infected during the 8 months following the primary-cycle administration represents proof of the vaccine's effectiveness against non-omicron strains. The comparison among different immunization profiles showed that hybrid immunization (vaccine plus natural infection) elicits higher antibody levels. However, hybrid immunization does not always provide better protection against reinfection, thus suggesting that the immunization profile plays a major role as a virus-host interaction modifier. Despite the high resistance to the reinfection, the peri-booster infection had a not-neglectable infection rate (5.6%), this further reinforcing the importance of preventive measures

Ultra-Broadband, Lithography-Free, and Large-Scale Compatible Perfect Absorbers: The Optimum Choice of Metal layers in Metal-Insulator Multilayer Stacks

We report ultra-broadband perfect absorbers for visible and near-infrared applications that are based on multilayers of metal-insulator (MI) stacks fabricated employing straightforward layer deposition techniques and are, therefore, lithography-free and large-scale compatible. We scrutinize the impact of different physical parameters of an MIMI absorber structure with analysis of each contributing metal layer. After obtaining the optimal design parameters (i.e. material selection and their thicknesses) with both simulation and numerical analysis (Transfer Matrix Method) methods, an experimental sample is fabricated and characterized. Our fabricated MIMI absorber consists of an optically thick tungsten (W) back reflector layer followed by 80 nm aluminum oxide (Al2O3), 10 nm titanium (Ti), and finally another 80 nm Al2O3. The experimental results demonstrate over 90 percent absorption between 400 nm and 1640 nm wavelengths that is optimized for ultra-broadband absorption in MIMI structures. Moreover, the impedance matching method with free-space is used to shed light on the metallic layer selection process. © 2017 The Author(s)