122 research outputs found
The association of stone opacity in plain radiography with percutaneous nephrolithotomy outcomes and complications
Purpose: To investigate the influence of stone opacity in plain radiography on stone free rate and complications of percutaneous nephrolithotomy (PCNL). Materials and Methods: A number of 101 patients who underwent PCNL between July-September 2015 were prospectively included. Stone opacity was judged on preoperative plain Kidney-Ureter-Bladder X-ray. Stone free rate was evaluated two weeks after the operation by ultrasonography and KUB. Results: There were 61 patients with opaque stones and 40 patients with non-opaque stones. The age, body mass index, preoperative creatinine, history of stone surgery, and stone size was not statistically different between patients with opaque and non-opaque stones. Neither operation duration nor access numbers were statistically significant between opaque and non-opaque stones. The frequency of stone free patients in opaque stones and nonopaque stones were 55/61 (90) and 30/40 (75) respectively (P = .04) The magnitude of hemoglobin drop in opaque stones and non-opaque stones were 1.9 ± 1.2 mg/dL versus 2.9 ± 1.7 mg/dL (P = .005). Conclusion: The stone free rate is lower and the magnitude of bleeding is higher in PCNL of non-opaque stones when compared to opaque stones if rigid instruments are used for nephroscopy
Solar collectors and photovoltaics as combined heat and power systems: A critical review
A main method to increase the solar energy utilization efficiency is to combine heat and power generation together. In this paper, a critical review of the literature on solar combined heat and power systems (CHP) is conducted, which includes solar photovoltaic/thermal systems, concentrated photovoltaic/thermal systems, and various combination with different solar collectors and applications. It shows that there are serious gaps in this field, which calls for more research. The modeling and analysis of the electrical parts of the CHP systems are not adequate, and there are limited studies on the economic and exergy assessments of the solar concentrating CHP systems. The solar collectors for combined CHP were focused on optimizing the performance of the maximum average useful power generation and minimum total heat transfer area, little environment impact analysis was conducted. Careful exergy, economic and environmental analysis on both electronic and thermal performance is suggested, especially for large CHP system. Also, further studies are recommend for investigating the hybrids of concentrating collectors with CHP, with considering the economic issues
Investigation of the effect of educational program based on the health belief model on preventing behaviors exposure to polluted air among pregnant women
BACKGROUND AND OBJECTIVE: Air pollution creates a wide range of acute and chronic effects in pregnant mothers. This study was carried out to determine the effect of education using Health Belief Model on improving the prevention of exposure to polluted air in pregnant women.
METHODS:This quasi-experimental study was carried out in two cross-sectional and interventional sections. In the cross-sectional study, 208 pregnant women were randomly selected and data were collected based on Health Belief Model questionnaire (sensitivity, severity, benefits, barriers, practice guidance and perceived self-efficacy, while calculating the scores of each section based on 100). In the intervention study, a total of 114 pregnant women (6 to 24 weeks) were selected by multistage sampling and randomly divided into two groups of case and control. The intervention was performed according to the Health Belief Model and the subjects were followed for three months and then the data were collected and analyzed.
RESULTS: The variables of external action, sensitivity and barriers, predicted a total of 25% of behavioral changes. In the intervention study, the mean awareness score of mothers in the intervention group increased significantly from 43.18±15.50 before the intervention to 71.39±16.68 after the intervention and the mean performance score increased significantly form 73.14±11.29 to 84.75±8.54 (p<0.001).
CONCLUSION: The results of this study showed that the implementation of training program based on Health Belief Model with emphasis on predictive behaviors can be effective in reducing exposure to air pollution in pregnant women
Differentiation of wharton's jelly derived mesenchymal stem cells into insulin producing cells
Background: Diabetes caused by insulin production disturbance is considered as the most common metabolic disorder all over the world. Diabetes may outbreak because of low insulin secretion by Islets of Langerhans β-cells, insulin resistance or both of them. In this way, using stem cells, which have the capability to differentiate into Pancreatic β-cells, is one of novel methods in this field. MSCs are the most important candidates for cellular therapy. Materials and Methods: Insulin level was examined using ELIZA method. In order to examine the morphology of differentiated cells, they were stained by Dithizone. Insulin-producer cells are cells which turn into red as a result of staining. Specific gene involving insulin-producing cells was evaluated by Real Time-PCR method. Results: The ELISA results showed that the treated cells secreted more insulin than the control group. Moreover, we found differentiation of MSCs toward insulin-secreting cells. In order to evaluate insulin production in clusters on day 21 of differentiation, we used dithizone (DTZ) staining. PDX-1 gene was confirmed by RT-PCR analysis. Conclusion: In this study, we differentiated MSCs into insulin-producing cells in vitro. It is concluded that MSCs may be considered as an excellent candidate in β-cell therapy in diabetes patients. © 2018, Tehran University of Medical Sciences (TUMS). All rights reserved
Accuracy of endoscopic ultrasonography for determination of tumor invasion depth in gastric cancer
Background: Gastric cancer (GC) is one the common lethal cancers in Iran. Detection of GC in the early stages would assesses to improve the survival of patients. In this study, we attempt to evaluate the accuracy of EUS in detection depth of invasion of GC among Iranian Patients. Materials and Methods: This study is a retrospective study of patients with pathologically confirmed GC. They underwent EUS before initiating the treatment. The accuracy of EUS and agreement between the two methods was evaluated by comparing pre treatment EUS finding with post operative histopathological results. Results: The overall accuracy of EUS for T and N staging was 67.9 and 75.47, respectively. Underestimation and overestimation was seen in 22 (14.2) and 40 (25.6) respectively. The EUS was more accurate in large tumors and the tumors located in the middle and lower parts of the stomach. The EUS was more sensitive in T3 staging. The values of weighted Kappa from the T and N staging were 0.53 and 0.66, respectively. Conclusions: EUS is a useful modality for evaluating the depth of invasion of GC. The accuracy of EUS was higher if the tumor was located in the lower parts of the stomach and the size of the tumor was more than 3 cm. Therefore, judgments made upon other criteria evaluated in this study need to be reconsidered
A model for pushover analysis of confined masonry structures : implementation and validation
Confined masonry (CM) is a typical building technique in Latin American countries. This technique, due to its simplicity of construction and similarity with traditional practices of reinforced concrete building, presents a potential of use in European regions with moderate-to-high seismicity. However, most of the procedures for seismic design in codes for Latin America are force-based, which appears to be inadequate due to the high dissipative response observed for CM. This paper presents a simplified numerical-analytical approach to model CM structures using pushover analysis, aiming to apply performance-based design procedures. First, a data mining process is performed on a database of experimental results collected from lateral tests on CM walls to adjust prediction models for the wall shear strength and to determine the input relevance through a sensitivity analysis. Then, an analytical model of CM structures for pushover analysis is proposed with basis on a wide-column approach that employs an adaptive shear load-displacement constitutive relation. The proposed method is compared with a discrete element model that represents explicitly the confinements-masonry interaction, against the experimental results obtained in a quasi-static test of a full-scale tridimensional CM structure. The accuracy of the predictions from both methods is very satisfactory, allowing to capture the base shear-displacement envelope and also the damage patterns of the structure, thus, demonstrating the ability of the methods to be used in performance-based seismic assessment and design of CM buildings.The first author acknowledges the financial support from the Portuguese Foundation for Science and Technology (FCT) through the Ph.D. Grant SFRH/BD/41221/2007
Wharton's jelly derived-mesenchymal stem cells: Isolation and characterization
Wharton`s jelly-derived mesenchymal stem cells (WJ-MSCs), have a high proliferation valency and they do not produce teratogen or carcinogen after subsequent transplantation. They are known as regenerative medicine. Thus more research is needed on the isolation and characterization of mesenchymal stem cells. In this experimental study, we obtained Wharton's jelly tissues from mothers during normal vaginal delivery, after obtaining their informed consent. Mesenchymal stem cells were isolated from cultured Wharton`s jelly, cultured, and were then examined for their proliferation, immunophenotypes, and differentiation capacities. The immunophenotypes of WJ-MSCs were analyzed by flow cytometry. Differentiation was performed resulting in osteogenic, chondrogenic and adipogenic cells. WJ-MSCs formed a homogenous monolayer of adherent spindle-shaped cells. Our results showed the high capacity of the proliferation of WJ-MSCs. Immunophenotyping further confirmed the purity of the isolated cells; their surface antigen expression showed the phenotypical properties like those of WJ-MSCs. The expanded cells were positive for CD 90, CD105, and CD44; they were negative for CD34 and HLA-DR surface markers. The cells had the adipocytic, osteocytic and chondrogenic differentiation capacity. The isolation and characterization of WJ-MSCs with high purity had been conducted, and the results were obtained in a short span. The present study has revealed the feasibility of the culture medium with high glucose and 15 FBS in isolation and proliferation of WJ-MSCs. When Wharton`s jelly pieces were put in the dry bottom of the flask, very effective separation of the MSCs was achieved. © 2018 Tehran University of Medical Sciences. All rights reserved
Wharton's jelly derived-mesenchymal stem cells: Isolation and characterization
Wharton`s jelly-derived mesenchymal stem cells (WJ-MSCs), have a high proliferation valency and they do not produce teratogen or carcinogen after subsequent transplantation. They are known as regenerative medicine. Thus more research is needed on the isolation and characterization of mesenchymal stem cells. In this experimental study, we obtained Wharton's jelly tissues from mothers during normal vaginal delivery, after obtaining their informed consent. Mesenchymal stem cells were isolated from cultured Wharton`s jelly, cultured, and were then examined for their proliferation, immunophenotypes, and differentiation capacities. The immunophenotypes of WJ-MSCs were analyzed by flow cytometry. Differentiation was performed resulting in osteogenic, chondrogenic and adipogenic cells. WJ-MSCs formed a homogenous monolayer of adherent spindle-shaped cells. Our results showed the high capacity of the proliferation of WJ-MSCs. Immunophenotyping further confirmed the purity of the isolated cells; their surface antigen expression showed the phenotypical properties like those of WJ-MSCs. The expanded cells were positive for CD 90, CD105, and CD44; they were negative for CD34 and HLA-DR surface markers. The cells had the adipocytic, osteocytic and chondrogenic differentiation capacity. The isolation and characterization of WJ-MSCs with high purity had been conducted, and the results were obtained in a short span. The present study has revealed the feasibility of the culture medium with high glucose and 15 FBS in isolation and proliferation of WJ-MSCs. When Wharton`s jelly pieces were put in the dry bottom of the flask, very effective separation of the MSCs was achieved. © 2018 Tehran University of Medical Sciences. All rights reserved
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A population-based dataset concerning predictors of willingness to get a COVID-19 vaccine in Iran
The global issue of preventing the spread of COVID-19 is challenging. One of the most efficient ways to control the pandemic is to have a full coverage of COVID-19 vaccination. Therefore, this paper collected survey data to understand the intention and willingness of COVID-19 vaccination uptake in Qazvin, Iran. With the use of a paper-and-pencil method and multistage stratified cluster sampling, research personnel approached and interviewed a representative sample of adults in Qazvin (n = 10843) between February 19 and April 9, 2021. The survey asked questions regarding sociodemographic information, fear of COVID-19, perceived COVID-19 infectability, perceived behavioral control over COVID-19 vaccination, subjective norm of COVID-19 vaccination, attitude towards COVID-19 vaccination, and intention to get COVID-19 vaccinated. The data collected from this survey were analyzed using descriptive statistics, which were carried out using the IBM SPSS version 17.0
Lymphocyte Subpopulations in Lymph Nodes and Peripheral Blood: A Comparison between Patients with Stable Angina and Acute Coronary Syndrome
Objective: Atherosclerosis is characterized by a chronic inflammatory response involving activated T cells and impairment of natural killer (NK) cells. An increased T cell activity has been associated with plaque instability and risk of acute cardiac events. Lymphocyte analyses in blood are widely used to evaluate the immune status. However, peripheral blood contains only a minor proportion of lymphocytes. In this study, we hypothesized that thoracic lymph nodes from patients with stable angina (SA) and acute coronary syndrome (ACS) might add information to peripheral blood analyses. less thanbrgreater than less thanbrgreater thanMethods: Peripheral blood and lymph nodes were collected during coronary by-pass surgery in 13 patients with SA and 13 patients with ACS. Lymphocyte subpopulations were assessed by flow cytometry using antibodies against CD3, CD4, CD8, CD19, CD16/56, CD25, Foxp3, CD69, HLA-DR, IL-18 receptor (R) and CCR4. less thanbrgreater than less thanbrgreater thanResults: Lymph nodes revealed a lymphocyte subpopulation profile substantially differing from that in blood including a higher proportion of B cells, lower proportions of CD8(+) T cells and NK cells and a 2-fold higher CD4/CD8 ratio. CD4(+)CD69(+) cells as well as Foxp3(+) regulatory T cells were markedly enriched in lymph nodes (p andlt; 0.001) while T helper 1-like (CD4(+)IL-18R(+)) cells were more frequent in blood (p andlt; 0.001). The only significant differences between ACS and SA patients involved NK cells that were reduced in the ACS group. However, despite being reduced, the NK cell fraction in ACS patients contained a significantly higher proportion of IL-18R(+) cells compared with SA patients (p andlt; 0.05). less thanbrgreater than less thanbrgreater thanConclusion: There were several differences in lymphocyte subpopulations between blood and lymph nodes. However, the lymphocyte perturbations in peripheral blood of ACS patients compared with SA patients were not mirrored in lymph nodes. The findings indicate that lymph node analyses in multivessel coronary artery disease may not reveal any major changes in the immune response that are not detectable in blood.Funding Agencies|Swedish Heart-Lung Foundation|20090489|Swedish Research Council|2008-2282
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