35 research outputs found
Psychometric Evaluation of the Adequacy of the Teaching Performance Evaluation Questionnaire in Urmia University of Medical Sciences, Urmia, Iran, 2015
Background: Assisting teachers to modify and improve their method of teaching is among the main goals of teachers’ evaluations.
The current study aimed to psychometrically evaluate the teaching performance evaluation questionnaire in Urmia University of
Medical Sciences, Urmia, Iran.
Methods: The original 28-item scale was scored based on a Likert scale obtained from former studies and was translated into Persian
after obtaining permission from the designer. Then, the impact item score, content validity index (CVI), and content validity ratio
(CVR) of the questionnaire were assessed by 11 experts, and its structural validity was also evaluated using exploratory factor analysis.
The reliability of the scale was also assessed by its internal consistency and test-retest reliability.
Results: The reference version included 28 items, 23 of which were translated into Persian based on the impact factor 1.5, CVI > 0.59,
and CVR > 0.70. Based on the exploratory factor analysis, the final version of the questionnaire included 23 items, and 3 factors were
extracted. The scale could predict 51% of the total changes.
Conclusions: Results of the current study indicated refined structure factor and good reliability for the psychometric adequacy of
the teaching performance evaluation questionnaire. The results of the current study can be used by universities as well as other
educational institutes to evaluate teachers’ adequacy.
Keywords: Validity, Reliability, Psychometrics, Teachers’ Evaluation, Teacher
Differentially methylated topologically associating domains in brain tumors
In recent years, cancer has become one of the main causes of human death all over the world. Cancer is a generation of unhealthy cells that neither grow nor operate normally. Central nervous system (CNS) tumor is a creation of abnormal cells either in the spinal cord or in the brain. Tumor is result of chromosome changes that includes change in chromatin structure and change in genome. In epigenomic modification, change in gene expression happens without changing DNA sequences; it is result of other events such as modification of histone or DNA methylation. There are special regions in the structure of chromosomes called Topologically Associating Domain(s) (TADs). One main role of them is regulating gene expression. Modifying chromatin structure in a TAD regions affects gene expression. It is likely that aberrant gene expression converts a cell into an unhealthy cell.
One of the main factors that create epigenomic modification in a chromosome is the methylation of cytosine nucleotides in DNA. Microarray is a technique for measuring DNA methylation using probes. It is possible that aberrant methylation of cytosine changes gene expression.
The objective of this project has been to determin differentially methylated TADs. Collecting information of differentially methylated TADs is important because the information helps finding differences between different tumor types and normal samples.
In this project, epigenomic modification of CNS tumor has been investigated. Data of beta values (proportion of methylated DNA for each probe) has been imported into R programming language; then, by implementing different packages of R, computational and statistical analyses have been performed.There are three TAD boundaries samples, Neural Progenitor Cells (NPC), Embryonic Stem Cell (ESC) and Cortex. In addition, tumors/controls samples from 91 different methylation classes and a data set of normalized beta values had been provided. At the first step, filtering of TADs based on number and distance of overlapped probes was performed. Then, for visualizing beta value distribution in TAD or tumors/controls level, violin plots and box plots were drawn. Since there are too many TADs or tumors to be shown in a figure, TADs or tumors were randomly selected; therefore, resulted violin plots or box plots are only estimation of beta value distribution. In the next step, three sets heat maps of all chromosomes over all tumors/controls were drawn with three arithmetic calculations: mean, median and proportion of probes with beta value more than 0.6) to decide which of these method is suitable for following analysis. Next, density and heat maps of TADs with larger beta value variation were drawn to detect difference in density of beta values in different chromosome and visualize properties of special group of TADs with larger beta value variations respectively.
In the statistical analysis section, Medulloblastoma (MB), Atypical Teratoid/Rhabdoid Tumor (ATRT) and Choroid Plexus tumor( PLEX) tumor samples were compared in pairs. There have been more differentially methylated TADs when MB tumor was compared with ATRT and PLEX than when ATRT with PLEX was compared. Then, by drawing karyotypes, differentially methylated TADs were observed across autosomal chromosomes.
In summary, it has been concluded that there are meaningful differences in methylation level of different TADs and these differences also appear as differences between tumor types
Polyvinyl Alcohol/Sodium Alginate Hydrogels Incorporated with Silver Nanoclusters via Green Tea Extract for Antibacterial Applications
Chronic lymphocytic leukemia, biology, new diagnosis and treatment: review article
Chronic lymphocytic leukemia (CLL) is a malignancy of B CD5+cells and is the most common type of leukemia in adults. The disease is more common in men over 50 years in western countries. CLL is associated with defective apoptosis in B cells. CLL was traditionally regarded as a disease that occurs before naïve B cells meet the antigen in the lymph nodes. Laboratory diagnosis requires white blood cell count, blood smear and immunophenotyping of lymphoid cells by flow cytometry. The disease most often associated with the accumulation of CD5+ CD19+ and CD23+ B cell with reduced number of surface membrane immunoglobulin in peripheral blood, bone marrow, and lymph nodes. Clinical progression of CLL is heterogeneous, some patients need treatment immediately after diagnosis, and others do not require treatment for many years after diagnosis. Over the past decades, considerable effort has been made to understanding the molecular mechanisms underlying the heterogeneous clinical course of the disease and finding prognostic markers for clinical classification. Patients with advanced Binet or Rai stages of disease require treatment. In addition to the interactions that exist between CLL cells, number of non-tumor cell types such as bone marrow stromal cells (BMSCs), nurse like cells (NLCs), follicular dendritic cells (FDCs), T cells, and some cytokines like IL-4 in tumor microenvironment play an important role in the CLL pathogenesis. Various factors including: IGVH mutation status, genetic variation, patient age and presence of other disorders are important for disease management and the type of treatment. CLL patients carrying p53 pathway dysfunction have poor prognosis and poor responses to therapy and very short survival. Available treatments include chemotherapy, chemoimmunotherapy, or drugs targeting B cell receptor signaling, Bruton's tyrosine kinase (BTK) or inhibitors of apoptosis, such as BCL2 and new class of small molecules. Understanding the CLL biology is important in identifying high-risk patients as well as the drug and relevant therapeutic methods for better management of patients. In this review paper, the microenvironment and genetic abnormalities in the CLL as well as new diagnostic and therapeutic approaches based on the new understanding of molecular biology of CLL are discussed
Modeling of the Phase Equilibrium for Aqueous Solutions of Brij 58 Surfactant and Three Salts
The Role of Social Media on Entrepreneurship Intention
The present study seeks to evaluate the effect of social media on people's entrepreneurial intention. In this study, the components of entrepreneurial intention are derived from the Linan’s Entrepreneurial Intention Model. These components include attitudes towards entrepreneurial behaviors, social norms, and self-belief. The present study is quantitative and the research method is descriptive. In this research, questionnaire was used for data collection. Students of Allameh Tabatabaei University in Tehran are samples of the study. Gathered data was analyzed by using t-test, factor analysis, and structural equation model with SPSS and LISREL software. Results showed that there was a significant relationship between social media and entrepreneurial intention and its components. Furthermore, social media strongly influences entrepreneurial intention and its components. Moreover, the most significant impacts were related to entrepreneurial self-belief, social norms, and attitudes towards entrepreneurial behavior, respectively. Finally, all hypotheses were confirmed by structural analysis and structural equation modeling.
Discrimination of pistachio cultivars based on multi-elemental fingerprinting by pattern recognition methods
The potential of multi-elemental fingerprinting based on inductively coupled plasma optical emission measurements (ICP OES) was examined to classify pistachio cultivars. Five pistachio cultivar samples were collected during the harvesting period 2017–2018 from Kerman in Iran. The ability of multivariate data analysis approaches, such as principal component analysis (PCA) and principal component analysis-linear discriminant analysis (PCA-LDA) have been investigated in order to achieve discrimination of different cultivars. Eighteen variables i.e. the contents of Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr and Zn at mg g−1 level, determined by ICP OES were used. The results showed that the five pistachio cultivars can be identified based on the multi-elemental fingerprints. The loading plot of PCA illustrated that Pb, Cr, Co, Cd, and Ba have the lowest contributions in discrimination of the different pistachio cultivars. Almost all samples were correctly classified by the PCA-LDA model using cross validation (99.0%). The mean sensitivity and specificity were 98.0% and 99.6%, respectively, indicating the satisfactory performance of the model. The results demonstrate multi-elemental fingerprinting combined with multivariate data analysis methods can be employed as an effective and feasible method for classification of Iranian pistachio based on their cultivars.Financiado para publicación en acceso aberto: Universidade de Vigo/CISU
Synthesis, Characterization, Cytotoxicity and DNA/BSA Interaction of Pd(II) Complexes with Alkyl-Amine and 1,10-Phenanthroline
A novel series of Pd(II) complexes, [Pd(alkyl-amine)2(phen)](NO3)2, I-V, (where alkylamine is ethyl-, propyl-, butyl-, hexyl- and octyl-amine and phen is 1,10-phenanthroline) were synthesized and characterized based on FT-IR, 1H NMR, COSY-NMR, UV-Vis, molar conductivity, elemental analysis and density functional theory (DFT) approaches. The group, I-V, was screened for their primary in-vitro cytotoxic action against human cancer cell line MOLT-4, showing promising anti-tumor activities. Their interaction activity was tested using various spectroscopic techniques to explain the mode of binding between these compounds with CT-DNA and BSA. Results of UV-Vis studies showed that, at low concentrations, they all interacted effectively with CT-DNA and BSA. Studies of fluorescence emission spectra displayed that the complexes quenched CT-DNA pretreated with methylene blue (MB) and the intrinsic fluorescence of BSA via static quenching. Using thermodynamic parameters (ΔG°, ΔH°, and ΔS°) obtained from fluorescence studies, it was proposed that the hydrogen bonding and van der Waals forces play the main role between metal complexes with CT-DNA and BSA. The binding was spontaneous in all cases due to ΔG° <0. Also, Molecular docking simulation of all five Pd(II) complexes with DNA was performed to determine the compound with the highest binding affinity and investigate its binding mode. Next, molecular docking was utilized for this compound to study its BSA binding mode and affinity. The results obtained from this work may lay the foundation for structural changes exerted on DNA and BSA by Pd(II) antitumor compounds bearing various hydrocarbon chain length as well as structural relationship which are vital for pharmacokinetic and pharmacodynamics.</p
Apoptotic effect of berberine via Bcl-2, ROR1, and mir-21 in patients with B-chronic lymphocytic leukemia
Berberine is a natural isoquinoline alkaloid that has been shown to inhibit the proliferation and induce apoptosis in a wide variety of tumor cells. However, the action mechanism of berberine in CLL cells is unknown. The previous study has shown that berberine leads to reduced viability and elevated levels of apoptosis in PBMCs of CLL patients. CLL cells are characterized by remarkable expression of Bcl-2 and ROR1 which leads to activation and survival and increases disease progression in patients. High-level expression of miR-21 in patients with CLL is associated with a higher risk of death. Here we investigated the anticancer effects of berberine upon peripheral blood mononuclear cells (PBMCs) of CLL patients. To evaluate the expression of anti-apoptotic proteins and ROR1 using flow cytometry and western blot, PBMCs were treated with 25 μM of berberine for 24 hr. The expression levels of mir-21 were evaluated by real-time PCR. Examination of treated cells demonstrated that berberine decreased Bcl-2 and ROR1 levels. Although western blot results did not show any change in Bax as a pro-apoptotic protein, an increased Bax/Bcl-2 ratio indicated that mitochondrial pathway is involved in berberine-induced apoptosis of CLL cells. Interestingly, berberine could reduce the expression of miR-21 in comparison to the untreated group. Our findings describe some of the molecular mechanisms of berberine by decreasing Bcl-2, ROR1, and mir-21 which may be considered as a novel apoptosis inducer in CLL cells. © 2020 John Wiley & Sons, Ltd