3,814 research outputs found
Rhetorical Moves in Applied Linguistics Articles and their Corresponding Iranian Writer Identity
AbstractEmerging from Kaplan's (1966) pioneering work on contrastive rhetoric, rhetorical organization is today practiced with current critical views in language teaching and is regarded as a major pedagogical tool in writing various articles. The present study aimed to investigate the possible relationship between generic organizations of research articles in applied linguistics Iranian journals and negotiation of researchers’ identities. Overall, 30 published research-based articles were selected randomly from four journals. After applying Pho's (2008b) model of move analysis, the obtained results were associated with the instances of writer identity using Hyland's framework (2002). The findings demonstrated different percentages of writer identity categories across different moves of articles. Results suggested that rhetorical moves performing various functions in articles need to be carried out by specific categories of authorial identity to better satisfy the expectations of their respective applied linguistics communities
Evaluation of the Quality of Four Root Canal Obturation Techniques Using Micro-Computed Tomography
Introduction: One of the key factors in successful endodontic therapy is to adequately fill the root canals. The aim of this in vitro study was to compare the quality of four different root canal obturation techniques: cold lateral condensation (CLC), warm vertical condensation (WVC), Obtura II (OII) and Gutta Flow (GF) by using micro-computed tomography (micro CT). Materials and Methods: A total of 20 extracted maxillary first molars prepared with ProTaper files, were randomly divided into four groups. Micro CT was used to measure the internal volume of root canals. Following application of AH26 sealer to canal obturation, new micro-CT images were taken and the volume percentage (VP) of voids, gutta-percha and sealer at different levels were calculated with CT software. Data was statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests. Results: The highest percentage of filling material was observed in GF group followed by OII with no statistically significant difference (P>0.05). These two groups had a significantly more acceptable filling than WVC and CLC groups (P<0.05). Voids were detected in all samples. There was a significant difference between the highest and the lowest percentage of voids in CLC (19.6%) and GF groups (6.7%), respectively. In the apical third, CLC and OII showed the highest and the lowest percentage of voids (5.5% and 2.6%) and the lowest and highest percentage of gutta-percha (76.52% and 94.26%), respectively. These differences were statistically significant (P<0.05). Conclusion: None of the root canal filled teeth were gap-free. GF and CLC techniques showed the highest and lowest VP of obturation materials, respectively
The Relationship between agency theory and the theory of signaling on Voluntary Disclosure: Case study in Iran
This study investigates The Relationship between agency theory and the theory of signaling on Voluntary Disclosure . empirically the research data is collected from 70 firms in the Tehran Security Exchange (TSE) during 2009-2014.multiple regressions technique is used for examining the stated hypotheses. It is used for, two models. The first model is based on agency theory and the second model is based on signaling theory.The relationship between ratio of fixed assets, Leverage, ROE, Liquidity on the level of voluntary disclosure.. In order to examine the hypotheses, data is collected from the annual reports of the companies using official bulletins of the Tehran stock exchange, mainly, through Novin software, Tadbir Pardaz software, and stock sites such as www.rdis.ir & www.irbourse.com.The results indicate that based on the models, ratio of fixed assets, and, Liquidity are associated significantly and positively with the level of voluntary disclosure. Keywords: agency theory, signaling theory, voluntary disclosur
Evaluation of Root Canal Morphology and Root Apex Anatomy of Mandibular Premolars in an Iranian Population: an ex-vivo study
Objectives Adequate knowledge about canal anatomy is necessary for clinicians to prevent any damage to the periodontium. The aim of this study was to evaluate the canal and apical complexities of the mandibular first and second premolars in an Iranian population.Methods One-hundred mandibular first (n=50) and second (n=50) premolars were collected. After access cavity preparation, 2% methylene blue was injected into the canals, and they were sealed with Coltosol and nail varnish. Next, demineralization and clearing with 5% nitric acid and methyl salicylate were performed. Apical morphology including the presence of accessory canals, apical delta, anastomoses and canal configurations was evaluated under a stereomicroscope at x16 magnification. Descriptive statistics (including tables, central tendency and dispersion tests) were used for data analysis.Results The most prevalent form of canal type was Vertucci’s type I in first and second premolars. The mean distance between the apical foramen and anatomic apex, apical foramen and apical constriction, and apical constriction and anatomic apex was 0.3, 0.6 and 0.9 mm, respectively for the first premolars. These values were 0.3, 0.5 and 0.8 mm, respectively for the second premolars.Conclusion Although most mandibular premolars have one canal, using appropriate cleaning methods is imperative because of high prevalence of accessory canals, anastomoses and apical deltas. First premolars pose more challenges in this respec
The Relationship between Organizational Justice Perception and Self- efficacy in Staff of a Selected Educational Hospital: a case study
Background & Objectives: Hospitals are one of the important components in a health care system and have significant role in health of humans. Organizational justice shows the perception of fairness and equality in the workplace by staff and affects their behavior. This study examines the relationship between organizational justice perception and self-efficacy in employees of a selected hospital of Tabriz/ Iran.
Methods: This was a cross-sectional descriptive- analytic study performed on 156 employees of one of the selected hospitals of Tabriz University of Medical Sciences. Chen, Gully & Eden Self-efficacy questionnaire and Rego and Cunha organizational justice questionnaire were used as data collection tools. Data analysis was done through SPSS23 and using analytic statistical tests such as Spearman correlation, Chi-Square and regression.
Results: There was a significant positive relationship between dimensions of organizational justice and self- efficacy (P<0.01). Also, based on the results of regression analysis, information justice was a stronger predictor of self- efficacy. Eventually, the elements of procedural, interactions and information justice could predict 14% of variations of self- efficacy.
Conclusion: Since dimensions of organizational justice affect employees' self- efficacy, hospital managers should find appropriate strategies for improving organizational justice in order to increase self- efficacy and ultimately the performance of their employees.
Key¬words: Distributive justice, Procedural Justice, Interactional Justice, Informational Justice, Self efficacy, Staff, Educational Hospital
Citation: Janati A, Chegini Z, Gholizadeh M, Naseri N, Ahmadi Z. The Relationship between Organizational Justice Perception and Self- efficacy in Staff of a Selected Educational Hospital: a case study. Journal of Health Based Research 2017; 3(2): 127-13
Extended Bandwidth Doherty Power Amplifier for Carrier Aggregated Signals
In the conventional classes of power amplifiers the efficiency drops at power back-off, whereas in order to maximize the spectral efficiency and data rate, wireless communication standards employ signals with high peak to average power ratio. This results in low average efficiency for power amplifiers, which in turn results in heavy cooling requirements and damage to the environment. To improve the low back-off efficiency Doherty technique has been widely investigated. But, the conventional Doherty power amplifiers are fairly narrowband, while modern transmitters are needed to support multiple standards and operate at multiple frequency bands.
This thesis proposes two novel output combiners for Doherty power amplifiers with extended bandwidth. It will be shown analytically how the problem of wideband Doherty can be converted into an impedance synthesization problem. Then two networks to synthesize the desired impedance are proposed. To achieve the proper load modulation over a wide bandwidth, the first proposed combiner employs a quarter-wave short-circuited stub at the output of the peaking transistor and the second proposed combiner uses a parallel LC tank at the same node.
In addition to inherent wideband characteristics, the proposed Doherty output combiners have three other important benefits. First, they present small low-frequency impedance for both the main and peaking transistors, which results in improved linearity and linearizability when the amplifier is concurrently driven with multi-band modulated signals. Second, the new combiners result in smaller group delay variation across the band compared to the conventional Doherty amplifier, which results in improved linearizability when the amplifier is driven with extra wideband modulated signals. Finally, the output capacitance of the peaking transistor can be easily absorbed into the combiners without compromising the performance of the amplifier.
The thesis starts with an overview of the Doherty power amplifier principles and provides a bandwidth analysis for the conventional Doherty power amplifier. Then it continues with the new approach to extend the bandwidth of Doherty amplifiers with respect to requirements of multi-band transmission. Based on the proposed combiners, two Gallium Nitride 20 W Doherty power amplifiers have been designed and fabricated. The measurement results have been provided to validate the developed theory. The first amplifier covers 1.72 to 2.27 GHz and the second one covers 700 to 950 MHz and both maintain higher than 48 % of drain efficiency at 6 dB back-off across the band. The two amplifiers are successfully linearized when driven with carrier aggregated modulated signals
In Vitro Comparison of Antibacterial Efficacy of a New Irrigation Solution Containing Nanosilver with Sodium Hypochlorite and Chlorhexidine
Objective: Antibacterial properties of silver nanoparticles have recently come into the spotlight in endodontic therapy. This study was conducted aiming at comparing the antimicrobial activity of a new irrigation solution containing nanosilver particles with that of sodium hypochlorite and chlorhexidine against Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa and Candida albicans with direct culture technique.Methods: In this in vitro experimental study, Mueller Hinton agarmedium was prepared for cultivation of E. coli, C. albicans and P. aeruginosa species and Bile-Esculin agar culture medium was used for E. faecalis. Understudy irrigation solutions were chlorhexidine 2%, chlorhexidine 0.2%, sodium hypochlorite 5.25%, sodium hypochlorite 2.5%, sodium hypochlorite 1.125% andnanosilver solutions of 25, 50, 100, 150, 200, 400 and 4000 ppm. After preparation, the bacteria were exposed to these solutions and the culture media were stored in an incubator at 37°C for 24 hours.The diameter of growth inhibition zone was determined for different microbial species and data were analyzed using Kruskal-Wallis and Dunnett’s tests.Results: Significant differences were found between various irrigation solutions based on the diameter of growth inhibition zones for E. faecalis, E. coli, C. albicans and P. aeruginosa (P<0.0001). The greatest antimicrobial activity against microbial species belonged to sodium hypochlorite 5.25% and 2.5%. Silver nanoparticle solution had an acceptable antimicrobial activity in comparison to other solutions and its antimicrobial property constantly improved by increased concentration of Ag ions. The nanosilver containing irrigation solution at different concentrations up to 100 ppm did not show a significant difference with sodium hypochlorite 1.25% in terms of antimicrobial efficacy. Furthermore, the greatest antibacterial activity against P.aeruginosa was observed at different concentrations of nanosilver up to 100 ppm; whereas, chlorhexidine showed no antimicrobial activity against this microorganism.Conclusion: Based on the obtained results, nanosilver canal irrigation solution had a lower but acceptable antimicrobial activity against various bacterial species compared to conventional irrigation solutions. Therefore, once other characteristics of nanosilver are approved, further studies can be performed to improve its properties and use it as an alternative to conventional root canal irrigation solutions
Colonic basidiobolomycosis in a child: report of a culture-proven case
SummaryBasidiobolomycosis is a rare fungal disease caused by Basidiobolus ranarum, which is endemic in tropical and subtropical regions of Africa, Asia, and Latin America. Gastrointestinal basidiobolomycosis poses diagnostic difficulties due to the non-specific clinical presentation and absence of predisposing factors. Eight pediatric cases of the disease have been reported recently from Iran, but none of these, or most of the other cases reported in the literature, has been proven by culture, which is the gold standard method for diagnosis. We present a case of culture-proven colonic basidiobolomycosis that occurred in a 3-year-old boy. The outcome was successful following surgical excision and antifungal therapy with posaconazole
Mixture of Arnebia euchroma and Matricaria chamomilla (Marhame-Mafasel) for pain relief of osteoarthritis of the knee – a two-treatment, two-period crossover trial
Predictive Significance of Interleukins 17A and 33 in Risk of Relapsing–Remitting Multiple Sclerosis
تعتبر الحركيات الخلوية جزيئات مرسلة للإشارات بين الخلايا المناعية وتلعب دوراً اساسياً في الامراضية ومنها الانترلوكينات 17A و 33 . لقد هدفت دراسة المرضى-السيطرة الحالية التحري عن دور هذين الحركيين الخلويين في خطورة تطور مرض التصلب العصبي. لقد تمت مشاركة ثمان وستون مريضاً مصاباً بالتصلب العصبي المتعدد من نوع الانتكاسي-المتحسن وعشرون شخصا من الاصحاء (مجموعة سيطرة) واستخدمت طريقة الادمصاص المناعي المرتبط بالأنزيم (الاليزا) لقياس المستوى المصلي. لقد اظهرت النتائج بوجود زيادة معنوية في المستويات المصلية لكل من A17 IL- و 33 IL-مقارنة مع مجموعة السيطرة (14.1 ± 4.5 مقابل 7.5 ±3.8 ،P > 10.00 و65.3 ± 16.3 مقابل 49.3 ± 20.0 ، P > 10,00 ) بيكوغرام/ مل على التوالي. لقد اظهر تحليل منحنى خصائص تشغيل المستقبِل ROC بان الحركي الخلوي IL17A يمثل عامل تنبؤ جيد لمرض التصلب العصبي (المنطقة اسفل المنحنى AUC =0,869، 95% CI =0.779 -0.965 ،> p 0,001 ، القيمة النهائية = 10.2 بيكوغرام/ مل ، الحساسية= 80.8%، النوعية= 75%. كما وان هناك تنبؤاً مشابهاً للانترلوكين 33 ولكن هناك انخفاضاً في قيمة المنطقة أسفل المنحنى (AUC =0,762 , 95% CI =0,63 - 0,89 ،> P 0,001 ، القيمة النهائية = 56,4 بيكوغرام/ مل ، الحساسية= 70.6%، النوعية= 70%. لقد تم اثبات اهمية الانترلوكينات 17 و33 في خطورة مرض التصلب العصبي من خلال تحليل الانحدار المنطقي المتعدد، وبوجود ثلاث نماذج تحليلية، لقد قُدرت قيمة الارجحية اعلى من 1 لكل من الانترلوكين 17 (1.5، 1.49 ،1.5) والانترلوكين 33 (1.05، 1.05، 1.06). لم تظهر فروقاً معنوية للمرضى المصنفين حسب الجنس (الذكر والانثى)، مقياس حالة العجز الحركي الموسّعة ( EDSS > 3 و EDSS ≤ 3) أو العلاج (ما قبل العلاج وما بعده) وفقاً للمستوى المصلي لكلا الانترلوكينين. ووفقاً للاستجابة للعلاج، فقد تبين بأن المستوى المصلي للانترلوكين 33 كان اعلى للمرضى المستجيبين للعلاج من هؤلاء الذين لم يستجيبوا له (70,9 ± 12,2 مقابل 57,2 ± 18.2 بيكوغرام/ مل، p = 0.018 ، وهذا الفرق لم نلاحظه للانترلوكينA 17 . وقد اظهر تحليل بيرسون للعلاقة بان كلا الانترلوكينين غير مرتبطين معنوياً مع بعضهما. وكاستنتاج نهائي، لقد بينت الدراسة بان الانترلوكينين A17 و33 يزداد انتاجهما في مرضى التصلب العصبي غير ان هذا الانتاج غير متأثر بالعمر والجنس وقيمة EDSS او العلاج ولكن ازدياد المستوى المصلي للانترلوكين 33 كان واضحاً بالنسبة للمرضى المستجيبين للعلاج.Cytokines are signaling molecules between inflammatory cells that play a significant role in the pathogenesis of a disease. Among these cytokines are interleukins (ILs) 17A and 33, and accordingly, the current case-control study sought to investigate the role of each of the two cytokines in the risk of developing multiple sclerosis (MS). Sixty-eight relapsing-remitting MS (RRMS) Iraqi patients and twenty healthy individuals (control group) were enrolled. Enzyme linked immunosorbent assay (ELISA) kits were used to determine serum levels of IL-17A and IL-33. Results revealed that IL-17A and IL-33 levels were significantly higher in MS patients than in controls (14.1 ± 4.5 vs. 7.5 ± 3.8 pg/mL; p < 0.001 and 65.3 ± 16.3 vs. 49.3 ± 20.0 pg/mL; p < 0.001, respectively). Receiver operating characteristic (ROC) curve analysis demonstrated that IL-17A was a very good predictor of MS (area under curve [AUC] = 0.869; 95% CI = 0.779 - 0.960; p < 0.001; cut-off value = 10.2 pg/mL; sensitivity = 80.8%; specificity = 75.0%). A similar prediction was presented by IL-33, but the AUC value was lower (AUC = 0.762; 95% CI = 0.63 - 0.89; p < 0.001; cut-off value = 56.4 pg/mL; sensitivity = 70.6%; specificity = 70.0%). Multinomial logistic regression analysis confirmed the significance of IL-17A and IL-33 in MS risk, and under three models of analysis, the estimated odds ratios for IL-17A (1.50, 1.49 and 1.50, respectively) and IL-33 (1.05, 1.05 and 1.06) were above 1.0. Patients stratified by gender (male and female), expanded disability status scale (EDSS: < 3 and ≥ 3) or medication (pre- and post-medication) showed no significant differences in serum levels of IL-17A and IL-33 for each stratum. However, with regard to response to medication, it was found that responding patients showed significantly higher levels of IL-33 than non-responders (70.9 ± 12.2 vs. 57.2 ± 18.2 pg/mL; p = 0.018). This difference was not observed when considering IL-17A. Pearson correlation analysis between IL-17A and IL-33 revealed that both cytokines were not significantly correlated. In conclusion, the study indicated that IL-17A and IL-33 were up-regulated in serum of MS patients, and this up-regulation was not influenced by age, gender, EDSS or medication status, but the elevated level of IL-33 was more pronounced in patients who responded to medication
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