A novel separation/preconcentration procedure using in situ sorbent formation microextraction for the determination of cobalt (II) in water and food samples by flame atomic absorption spectrometry

AbstractA new, simple, low cost, and rapid solid phase extraction method, that was named in situ sorbent formation microextraction (ISSFME), was developed for the selective separation and determination of cobalt (II) in various water and food samples. In the present work, cetyltrimethylammonium bromide was used as a cationic surfactant, perchlorate ion as an ion-pairing agent, and 2-nitroso-1-naphthol as a complexing agent. After extraction, the concentration of cobalt was determined by flame atomic absorption spectrometer. Several variables that affect the extraction efficiencies were investigated and optimized. Under the optimized conditions, the limit of detection was 0.8μgL−1 with a preconcentration factor of 50. The RSD for 10 replicate measurements of 50μgL−1 of cobalt was 2.3%. The accuracy and applicability of the method were tested by evaluating the amount of cobalt in water certified reference materials and various water and food samples

Effect of root canal rinsing protocol on dentin bond strength of two resin cements using three different method of test

Background: Different studies have used different tests to evaluate bond strength of resin cements to root dentin. In this in vitro study, three different tests were used to evaluate the bond strength of two resin cements to root dentin using two root dentin irrigation protocols. Material and Methods: Ninety-six intact single-rooted teeth were selected for this study. Forty-eight teeth, with a root length of 15mm, were randomly divided into two groups and irrigated with normal saline or 2.5% sodium hypochlorite solutions during root canal preparation, respectively. For each 12 specimens from each group, fiber post #1 was bonded using an etch-and-rinse (Duo-Link) and a self-adhesive (BisCem) resin cement, respectively. After incubation, two specimens were prepared for the push-out test from the middle thirds of the roots. In another 24 teeth, after two 1.5-mm sections were prepared from the middle thirds of the prepared roots, sections of the post were bonded in two subgroups with each of the cements mentioned above and the samples were prepared for the pull-out test. For shear test, the crowns of 48 teeth were cut away, the dentin surfaces were prepared, the two irrigation solutions were used, and the resin cements were bonded. Data collected from the three tests were evaluated by ANOVA, post-hoc Tukey and Weibull tests (α=0.05). Results: There were significant differences in the mean bond strength values between the three bond strength tests (P<0.001). Rinsing protocol and cement type resulted in similar variations in the mean bond strength in all tests (P>0.05). Conclusions: Under the limitations of the present study, the method of the test used had an effect on the recorded bond strength between the resin cement and root dentin. Cement type and irrigation protocol resulted in similar variations with all the tests. Push-out and shear tests exhibited more coherent results

Public intention to prepare for earthquakes:Psychometric properties of persian version

Background: People are still not prepared for earthquakes in vulnerable areas although preparedness consid-ered an effective way of reducing the disastrous consequences. A proper tool was needed to assess the predicting factors of mitigation behaviors in a large vulnerable community who speak Persian. This study aimed to in-troduce the valid and reliable Persian version of public intention to prepare against earthquakes. Methods: Translation, validation and reliability checking articulated according to the standard methodology for Forward-Backward translation and psychometric evaluation. Totally, 369 Tehran households were selected through stratified random sampling from Oct 2016 to Jun 2017. Exploratory Factor Analysis used to check the construct validity of all scales. Results: Face, content and construct validity of all scales confirmed (S-CVR:.65) and (S-CVI/Universal:.98). The finalized Persian version (69 items in 8 scales) showed good reliability over time in test-retest (ICC:.92) and high internal consistency both in the pilot (α:.94) and main studies (α:.94). No significant floor and ceiling effects were found in any of scales. Conclusion: Persian version of Earthquake Public Intention to Prepare is applicable as a valid and reliable instrument for research regarding disaster preparedness in Persian speaking communities.</p

Comparison between High Cell-Density Culture Systems for Chondrogenic Differentiation and Articular Cartilage Reconstruction of Human Mesenchymal Stem Cells: A Literature Review

High-cell density culture is based on the chondrogenic differentiation of human mesenchymal stem cells (hMSCs), and because the high density ofcell and reduced oxygen tension are effective in chondrogenic differentiation. In the present paper, there will be a review about the methods ofchondrogenic differentiation of hMSCs that utilized in in vitro and in vivo chondrogenic differentiation of stem cells for treatment of osteoarthritis.There are three High-cell density culture systems; micromass, pellet culture, and alginate culture have been used to induce chondrogenicdifferentiation of hMSCs. Transplanted naive MSCs can cause problems such as heterogeneous populations. To overcome this problem, newstrategies for inducing differentiation of MSCs are needed. One possibility is a cell culture system. Collagen II and aggrecan are critical protein inchondrogenic differentiation. In all different methods, real time RT-PCR analysis demonstrates that collagen II and aggrecan mRNA are upregulated while collagen X and collagen I mRNA are down regulated. So these three high-density cell culture systems have been approved forchondrogenic differentiation. On the other hand, In micromass method, the induced-cartilage tissues are larger, more homogenous and rich incartilage specific collagen II, but collagen I, collagen X and hypertrophic chondrocyte features are markedly decreased compared to other culturesystem. Thus, the micromass culture system is the best tool for in vitro chondrogenic differentiation studies

Donkey Bite Leading to a Catastrophic Outcome: Bilateral Visual Loss

In this report we present a case of severe facial injury due to a donkey bite. Immediate repair with surgical flaps was performed. No significant complication was observed at the time of surgery or during follow up and the result was acceptable. Animal bites are relatively frequent and most often are done by dogs. Besides dogs, other animals such as cats, horses and donkeys may be responsible for this type of injuries. Although donkey bites to the facial area are very rare, they can cause severe and life-threatening injuries. Early management of facial injuries caused by animal bites is acceptable nowadays and guarantees satisfactory outcome

A brief review on DNA vaccines in the era of COVID-19

This article provides a brief overview of DNA vaccines. First, the basic DNA vaccine design strategies are described, then specific issues related to the industrial production of DNA vaccines are discussed, including the production and purification of DNA products such as plasmid DNA, minicircle DNA, minimalistic, immunologically defined gene expression (MIDGE) and Doggybone (TM). The use of adjuvants to enhance the immunogenicity of DNA vaccines is then discussed. In addition, different delivery routes and several physical and chemical methods to increase the efficacy of DNA delivery into cells are explained. Recent preclinical and clinical trials of DNA vaccines for COVID-19 are then summarized. Lastly, the advantages and obstacles of DNA vaccines are discussed

A SURVEY OF RELATION BETWEEN LEARNING STYLES AND PREFERRED THACHING METHODS IN STUDENTS OF NURSING, ISFAHAN UNIVERSITY OF MEDICAL SCIENCES

Introduction: The relationship between students' learning styles and their preferred teaching methods has been considered in recent years. This relationship was explored in the present study. Methods: This is a descriptive-analytic study. A stratified sample of nursing students out of all grades participated in it. Students' learning styles were explored with the Kolb's questionnaire for learning style. Their preferred teaching methods were determined using another questionnaire. Results: A correlation between learning styles and some preferred teaching methods was observed for theoretical courses. There was not such correlation in for practical courses. Conclusions: Considering students' learning styles may help university teachers to choose more appropriate teaching methods

The Factor Structure of the Spiritual Well-Being Scale in Veterans Experienced Chemical Weapon Exposure

This study aimed to determine the factor structure of the spiritual well-being among a sample of the Iranian veterans. In this methodological research, 211 male veterans of Iran–Iraq warfare completed the Paloutzian and Ellison spiritual well-being scale. Maximum likelihood (ML) with oblique rotation was used to assess domain structure of the spiritual well-being. The construct validity of the scale was assessed using confirmatory factor analysis (CFA), convergent validity, and discriminant validity. Reliability was evaluated with Cronbach’s alpha, Theta (h), and McDonald Omega (X) coefficients, intraclass correlation coefficient (ICC), and construct reliability (CR). Results of ML and CFA suggested three factors which were labeled ‘‘relationship with God,’’ ‘‘belief in fate and destiny,’’ and ‘‘life optimism.’’ The ICC, coefficients of the internal consistency, and CR were[.7 for the factors of the scale. Convergent validity and discriminant validity did not fulfill the requirements. The Persian version of spiritual well-being scale demonstrated suitable validity and reliability among the veterans of Iran–Iraq warfare

Evaluating Intra- and inter-rater reliability for "Cleft palate speech assessment test based on universal parameters system- in Persian"

Introduction: Cleft palate is one of the most common congenital birth defects. Individuals with cleft palate have certain speech characteristics that can be identified perceptually by speech-language pathologists. Perceptual assessment has been regarded to as the gold standard for evaluating cleft palate speech. Considering the prevalence of cleft palate and its related speech characteristics, it is necessary for clinicians to use a reliable test for perceptual assessment of cleft palate speech errors. The aim of this study was to evaluate Intra- and inter-rater reliabilities for a recently developed assessment tool named "Cleft palate speech assessment test based on universal parameters system– Farsi version". Materials and Methods: In this descriptive-analytic cross-sectional study, speech samples obtained from 34 five-to-nine-year-old Farsi-speaking children with cleft palate who were referred to Isfahan cleft palate clinic were rated by two speech-language pathologists (one of them was considered as a naive and the other one as an expert rater). Two months later, 30% of the same speech samples were randomly selected and rerated by the same raters. Speech materials included 40 single words and 17 sentences along with a sample of connected speech. Intra- and inter-rater reliability measures were calculated via Intraclass Correlation Coefficient (ICC). Results: Mean Intra-rater reliability measured by ICC was found to be 0.967 and 0.971 for the naive and expert raters respectively. Mean Inter-rater reliability was 0.957 as measured by ICC. Conclusion: This test has an acceptable Intra and inter-rater reliability to be used in assessment of cleft palate speech and can be applied in those studies aimed at evaluating different aspects of speech in Farsi-speaking children with cleft palate aged from 5 to 9 years. Keywords: Cleft palate, Reliability, Perceptual speech assessment, Universal parameters syste

Relation between obesity and depression using structural equation modelling

no abstract availabl