MATLAB-based software for Size-Specific Dose Estimation (SSDE) in Computed Tomography Examinations

Primary and widely in use Computed Tomography (CT) dose descriptor is a volumetric CT Dose Index (CTDIv) that is usually measured by a pencil ionization chamber with active length of 100mm and polymethyl methacrylate (PMMA) phantom. CTDIv depends on scan parameters such as mAs, kV, collimation, tube rotation time but is independent of patient’s size and shape. For the purpose of a good estimation of dose received by the patients, American Association of Physicists in Medicine (AAPM) published the conversion factors for both 16 and 32cm (head and body phantoms respectively); through this, users can extract conversion factors according to lateral (LAT) and/or anterior-posterior (AP) sizes and calculate real CTDIv. Since this procedure is time consuming, we designed MATLAB-based software to reduce such calculations. To design the software, GUI toolbar of MATLAB software was used. To test the software, scan parameters of two patients for head and pelvis scan were read from PACS and lateral (LAT) and anterior-posterior (AP) sizes were measured. Finally, SSDEs were calculated for two patients by the software. The software can be measured based on AP and/or LAT measures and/or in special cases (under the age of 18) through patients' age

Calculation of exposure rate constant for 60Co, 22Na and 111In Sources with FLUKA Monte Carlo Code

Exposure rate constant (G) relates activity of a point source to exposure rate at certain distance. It’s an important parameter in radiation protection, medical uses and radiological assessments. In this study, exposure rate constant for three radionuclides include 60Co, 22Na and 111In were calculated with FLUKA Monte Carlo method. Each source was simulated and exposure rate at different distances of 20, 30, 40, 60, 80, 100, 120, 150, 200 and 300cm from the sources were measured. For dose measurements,   a farmer ionization chamber was simulated with active volume of 0.6cm3, inner electrode of aluminium with diameter of1mm and wall of pure graphite with thickness of 0.75mm. Calculated exposure rate constants for 60Co, 22Na and 111In at 20 to 300cm from the source ranged from 33.45 to 0.16 mR/(mCi.h), 29.12 to 0.10 mR/(mCi.h) and 8.73 to 0.03 mR/(mCi.h) respectively which show a decreasing trend. Comparison of our results with other studies show that there are good agreement for 60Co and 22Na; the present values for exposure rate constant for 111In was higher than previous reports

Assessment and comparison of radiation dose and image quality in multi-detector CT scanners in non-contrast head and neck examinations

Purpose: To assess and compare radiation dose and image quality from non-contrast head and neck computed tomography (CT) examinations from four different multi-detector CT (MDCT) scanners. Material and methods: Four CT scanners with different numbers of detector rows including one 4-MDCT, a 6-MDCT, a 16-MDCT, and a 64-MDCT were investigated. Common CT dose descriptors including volumetric CT dose index (CTDIv), dose length product (DLP), and the effective dose (ED), and image quality parameters include image noise, uniformity, and spatial resolution (SR) were estimated for each CT scanner with standard tools and methods. To have a precise comparison between CT scanners and related doses and image quality parameters, the ImPACT Q-factor was used. Results: Minimum and maximum CTDIv, DLP, and ED in the head scan were 18 ± 3 and 49 ± 4 mGy, 242 ± 28 and 692 ± 173 mGy × cm, 0.46 ± 0.4 and 1.31 ± 0.33 mSv for 16-MDCT and 64-MDCT, respectively. And 16 ± 2 to 27 ± 3, 286 ± 127 to 645 ± 79 and 1.46 ± 0.65 to 3.29 ± 0.40 for neck scan, respectively. The Q-factor in head scan was 2.4, 3.3, 4.4 and 5.6 for 4-MDCT, 6-MDCT, 16-MDCT and 64-MDCT, respectively. The Q-factor in neck scan was 3.4, 4.6, 4.7 and 6.0 for 4-MDCT, 6-MDCT, 16-MDCT and 64-MDCT, respectively. Conclusions: The results clearly indicate an increasing trend in the Q-factor from 4-MDCT to 64-MDCT units in both head and neck examinations. This increasing trend is due to a better SR and less noise of images taken and/or fewer doses in 64-MDCT

THE ROLE OF HISTONE DEMETHYLASE JMJD3 IN THE INFLAMMATORY RESPONSE: GENERATION AND ANALYSIS OF IN VIVO MODELS

Jmjd3, a JmjC family histone demethylase, is quickly induced by the transcription factor NF- kB in response to microbial stimuli. Jmjd3 erases trimethylated lysine 27 in histone H3 (H3K27me3), a histone mark associated with transcriptional repression and involved in lineage determination, differentiation and tissue homeostasis. However, the specific contribution of Jmjd3 induction and H3K27me3 demethylation to innate immunity and inflammation remains unknown. To define this role, we generated gene-targeted mice lacking histone demethylase using standard protocol to see the effect of this specific Histone demethylase depletion on all tissues and in particular in immune system to understand the biological functions of jmjd3 in inflammatory responses.. Strikingly, transcription of most Jmjd3 target genes was unaffected by its deletion, a few hundred genes including IL12b and Ccl5 showed mild to moderate mRNA changes associated with impaired transcription; however, no gene was completely dependent on Jmjd3 for induction. Importantly, most Jmjd3 target genes were not associated with detectable levels of H3K27me3, and the transcriptional effects of Jmjd3 absence in the window of time analyzed were uncoupled from measurable effects on this histone mark. Overall, these data demonstrate that Jmjd3 participates in fine- tuning the transcriptional output of LPS-activated macrophages in a manner that is largely independent of H3K27me3 demetylation

Prevalence of ruminants fascioliasis and their economic effects in Kashan, center of Iran

ABSTRACTObjectiveTo determine the prevalence and economic losses of Fasciola spp. isolates and costs incurred due to liver condemnation from ruminants in Kashan region, center of Iran from 2012 to 2013.MethodsIn this cross-sectional study, a total number of 251 325 slaughtered sheep, goats and cattle (88 939 sheep, 151 924 goats and 10 462 cattle) were examined via necropsy for fasciolasis in industrial Kashan abattoirs located in center of Iran. The average weight was calculated as 1 000 g for sheep, 900 g for goat and 5 000 g for cattle in this study region. Based on market value, the average price of a kilo gram of normal liver at Kashan city during the study period was 8 USD. The amount of main nutrients and vitamins elimination in liver contaminated to fascioliasis was determined.ResultsOverall 3.28% of the livers were found to be infected. For total number of sheep, goats and cattle slaughtered annually in region study, it was estimated that 7 505  livers were infected and total annual economic losses of fascioliasis of studied animals was 41 784 USD (based on market prices in study period). Of this, 23 360 USD, 30 240 USD and 15 400 USD were associated with the fascioliasis of sheep, goats and cattle, respectively.ConclusionsThis study indicated that the Fasciola sp. clearly remains prevalent and causes considerable economic losses in study region in sheep, goats and cattle and presumably, other areas and hosts of Iran, providing baseline data for the future monitoring of this potentially important parasitic infection in the country

Prevalence of high-level gentamicin-resistant Enterococcus faecalis and Enterococcus faecium in an Iranian hospital

This study was designed to determine the molecular characteristics and antimicrobial resistance of enterococcal strains isolated from patients admitted to an Iranian Hospital. Enterococcal strains were isolated from the burn patients. All strains were screened for genes encoding resistance to aminoglycoside aac(6')-Ie-aph(2'')-Ia, aph (3'), ant (4'), resistance to vancomycin (vanA, vanB), resistance to tetracycline (tetK, tetL, tetM, tetO), and resistance to erythromycin (ermA, ermB, ermC) by PCR and multiplex PCR-based methods. Genetic diversity was evaluated via Random Amplified Polymorphic DNA (RAPD)-PCR. All enterococcal isolates showed complete sensitivity to vancomycin with MIC � 0.5μg/ml. Resistance to gentamicin, tetracycline, erythromycin, ciprofloxacin or quinopristin-dalfopristin was detected, whilst more than 96.2% of isolates were high-level gentamicinresistant (HLGR) and multiple drug resistant. The most prevalent aminoglycoside resistance gene was aac(6')-Ie-aph(2'')-Ia, that was found in 96.2% (26/27) of the isolates. The most prevalent tetracycline resistance genes were tetM, found in 85.1% (23/27) followed by tetL and tetO found in 7.4% (2/27) of the isolates. The ermA and ermB genes were detected in 33.3% (9/27) and 44.4% (12/27) of the isolates respectively. RAPD-PCR analysis yielded 17 distinct profiles among 27 investigated isolates. One cluster of isolates shared the same RAPD pattern, while 16 isolates had unique RAPD pattern. Our study showed that during the examination time period one RAPD genotype was the common type and was disseminated among patients in the burn unit. Interestingly, most of these strains had an identical or very similar antibiotic and gene resistance pattern

Challenges, Opportunities and Future Directions of Dental Education in COVID-19 Pandemic: A Qualitative Study

Background: With the onset of the COVID-19 pandemic and the impossibility of face-to-face learning, universities sought alternative methods to continue education and adapt to the upcoming conditions. Although technology development and virtual education methods created many opportunities in dental education, these modern solutions were not free of problems.Objectives: The current study explored the challenges, opportunities, and future directions of dental education from the experience of dental students, faculty members, and the dean of Alborz Dental School during the COVID-19 pandemic.Methods: The current qualitative study was conducted in 2021 using the content analysis method and in-depth semi-structured interviews with faculty members and students of Alborz Dental School. Purposive sampling was implemented to collect data with maximum variability in the faculty and student groups. In addition, 19 semi-structured interviews were transcribed verbatim immediately after each interview. The results were analyzed using MAXQDA version 10 software through the content analysis method.Results: The results of data analysis in the evaluation of challenges and opportunities of dental education from the experience of dental students, faculty members, and the dean of Alborz Dental School during the COVID-19 pandemic detected three emerging categories: opportunities, challenges, and future direction with subcategories of e-learning, clinical training, infrastructures, and personal life.Conclusion: Despite creating new learning opportunities during the COVID-19 pandemic, faculty members and dental students faced many challenges. Therefore, identifying these challenges, taking advantage of opportunities, and using faculty members' and students' experiences and suggestions can improve the learning experience and quality of education during the post-pandemic era

SPONTANEOUS IMBIBITION OIL RECOVERY BY NATURAL SURFACTANT/NANOFLUID: AN EXPERIMENTAL AND THEORETICAL STUDY

Organic surfactants have been utilized with different nanoparticles in enhanced oil recovery (EOR) operations due to the synergic mechanisms of nanofluid stabilization, wettability alteration, and oil-water interfacial tension reduction. However, investment and environmental issues are the main concerns to make the operation more practical. The present study introduces a natural and cost-effective surfactant named Azarboo for modifying the surface traits of silica nanoparticles for more efficient EOR. Surface-modified nanoparticles were synthesized by conjugating negatively charged Azarboo surfactant on positively charged amino-treated silica nanoparticles. The effect of the hybrid application of the natural surfactant and amine-modified silica nanoparticles was investigated by analysis of wettability alteration. Amine-surfactant-functionalized silica nanoparticles were found to be more effective than typical nanoparticles. Amott cell experiments showed maximum imbibition oil recovery after nine days of treatment with amine-surfactant-modified nanoparticles and fifteen days of treatment with amine-modified nanoparticles. This finding confirmed the superior potential of amine-surfactant-modified silica nanoparticles compared to amine-modified silica nanoparticles. Modeling showed that amine surfactant-treated SiO2 could change wettability from strongly oil-wet to almost strongly water-wet. In the case of amine-treated silica nanoparticles, a strongly water-wet condition was not achieved. Oil displacement experiments confirmed the better performance of aminesurfactant- treated SiO2 nanoparticles compared to amine-treated SiO2 by improving oil recovery by 15%. Overall, a synergistic effect between Azarboo surfactant and amine-modified silica nanoparticles led to wettability alteration and higher oil recovery

The effect of antimicrobial activity of Teucrium Polium on Oral Streptococcus Mutans: A randomized cross-over clinical trial study

Background: The purpose of this study is to determine the effect of a mouthwash containing Teucriumpolium herb on Streptococcus mutans in mouth. Methods: This study was a randomized, crossover, double-blind clinical trial, where we selected 22 volunteers (dental students) randomly and we divided them into two groups. The study had two phases. In each phase, one group acted as the intervention group, while the other one was the control group. Both the intervention and control groups were given the mouthwash with and without Teucriumpolium, respectively. S. mutans of saliva were measured before and after each phase to compare the effects of the mouthwashes. A three-week washout period was considered between the two phases. An independent two-sample t-test was utilized to compare the mean of S. mutans colonies. Additionally, we used a standard AB/BA crossover model to find the results of the treatment and the impact of carryover on the residual’s biological effects. The significance level was considered 0.05 in this experiment. Results: There is no significant difference observed between the two groups in the number of S. mutans before using the mouthwashes. When the mouthwash containing Teucriumpolium was used, there was a significant decrease in the number of S. mutans colonies in both phases’ extract (P = 0.002). Conclusion: The results of this study indicate the mouthwash containing aqueous extract of Teucrium polium can majorly reduce the colonization of S. mutans in human saliva