Search

In the digital era, there has been a growing focus on seeking online academic help-seeking as an effective factor for success in the virtual learning environment. However, the Social Networking Self-efficacy (SNS) and social presence of students in online learning environments remain underexplored. This study employed a structural model to investigate the relationship between students' SNS, academic help-seeking, and social presence, as well as the mediating role of academic help-seeking between these two factors. The research design was quantitative, using a descriptive and correlational approach. Data were collected from 339 students at an Iranian university in Hamedan and analyzed using structural equation modeling. The findings indicated that SNS had both direct and indirect influences on social presence, through academic help-seeking. Additionally, academic help-seeking was found to impact social presence, thus mediating the relationship between SNS and social presence. Therefore, educators and policy-makers should consider the role of academic help-seeking and SNS to enhance social presence.

Preeclampsia (PE) remains a significant cause of maternal and neonatal morbidity and mortality, particularly in high-riskpregnancies. The present study aims to assess the efficacy of L-arginine supplementation in preventing PE and improvingmaternal and neonatal outcomes in high-risk pregnancies. We searched international databases (ISI, PubMed, Scopus,and Embase) and extracted studies that evaluated the efficacy of L-arginine for preventing PE and improving maternaland neonatal outcomes in high-risk pregnancies. The data collected were analysed utilising the random-effects modelin Stata (version 15). Out of the collected studies, 10 met the eligibility criteria, comprising a total sample size of 1165subjects (586 cases and 584 controls). The mean age of the cases was 28 ± 5.05 years, while that of the controls was 27.32± 4.58 years. The results revealed that L-arginine was more effective in reducing the incidence of PE than placebo [oddsratio (OR)=0.36, 95% confidence interval (CI): 0.17, 0.77]. Also, the results showed no statistically significant differencebetween the two groups in systolic blood pressure (SBP; standard mean difference (SMD): -0.35, 95% CI: -91, 21)and diastolic blood pressure (DBP; SMD: -0.50, 95% CI: -1.08, 0.07). There was a statistically significant difference inneonatal birth weight between the two groups (SMD: -0.16, 95% CI: -31, -0.01). No statistically significant differenceexisted between the two groups in terms of gestational age (SMD: 0.6, 95% CI: -0.06, 0.18). Furthermore, there was nosignificant difference between the two groups in the APGAR score at one minute (SMD: 0.40, 95% CI: -0.02, 0.82). Ourfindings revealed that L-arginine supplementation during pregnancy reduced the incidence of PE in high-risk pregnancies.However, it does not significantly improve maternal and neonatal outcomes.

Abstract Motivated by recent study on synthesized N, N-diphenylaniline (DPA)-based dyes [DOI: https://doi.org/10.1016/j.solener.2022.01.062 ] for use in dye-sensitized solar cells (DSSCs), we theoretically design several dyes and explore their potential for enhancing the efficiency of DSSCs. Our designed dyes are based on the molecular structure of synthesized DPA-azo-A and DPA-azo-N dyes with a donor-π-bridge-acceptor (D-π-A) framework. In this research, we aim to develop the power conversion efficiency (PCE) of DSSCs by fine-tuning the molecular structure of the synthesized dyes. To this end, we focus on designing dyes by replacing the units of DPA-azo-A and DPA-azo-N with a variety of donor, π-bridge, and acceptor. Hence the density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations are done to explore their structure, electronic, optical, charge transport, and photovoltaic properties. Among all newly designed and reference dyes, the D3-azo-N and DPA-π3-N dyes which are designed by substituting the donor (DPA) and π-bridge (azo) units of DPA-azo-N with D3 and π3, respectively exhibit the highest PCE of 45.46% (for D3-azo-N) and 43.20% (for DPA-π3-N) and can be favorable dyes for improving the efficiency of DSSCs. Therefore, the dyes that are designed by substituting the donor and π-bridge units of synthesized dyes have more impact on improving the efficiency of DSSCs than those that involve replacing the acceptor units. Consequently, our theoretical findings will provide valuable insights for the experimentalists to employ these novel effective dyes and boost the performance of DSSCs.

The possibility of releasing unburned hydrocarbons and other compounds resulting from incomplete combustion from the exhaust is considered a common industrial issue. Pathing the exhaust gas through catalysts is a common way to lower the emissions. Alternatively, catalytic flameless combustion, used in a wide range of dilute air-fuel mixtures due to its optimal performance, is of interest for local radiative heating applications because of its low emission and high combustion efficiency (over 90%). However, using platinum catalysts in these systems increases production costs, and its surface temperature, ranging from 400-600 °C, faces a temperature limit in some applications. In this study, the feasibility of using a Pd-Au catalyst, with lower temperature and production costs, in a flameless catalytic counter-diffusive system was experimentally evaluated for the first time to reduce pollutants. A methane conversion rate of 98.3% in the 200-250 °C temperature range and a long life without CO and NOx pollutants were observed. This not only leads to reducing environmental pollutants, but by producing low-temperature radiant heat, it also provides the possibility of producing heat from exhaust gases, making it a dual-function solution in the field.

Abstract The synthesis and characterization of metal complexes have garnered significant attention due to their versatile applications in scientific and biomedical fields. In this research, two novel copper (Cu) complexes, [Cu(L)(L′)(H2O)2] (1) and [Cu(L)(Im)H2O] (2), where L = pyridine-2,6-dicarboxylic acid, L′ = 2,4-diamino-6-hydroxypyrimidine, and Im = imidazole, were investigated concerning their sonochemical synthesis, spectroscopic analysis, and biological activity. The complexes’ structural characterization was achieved using analytical techniques, including single-crystal X-ray structure determination, FTIR, PXRD, TGA and DTA, SEM, TEM, and EDS. Complex (1) displayed a six-coordinated Cu2+ ion, while complex (2) exhibited a five-coordinated Cu2+ ion. The crystal structures revealed monoclinic (C2/c) and triclinic (P-1) space groups, respectively. Both complexes showcased zero-dimensional (0D) supramolecular networks, primarily driven by hydrogen bonding and π–π stacking interactions, which played pivotal roles in stabilizing the structures and shaping the unique supramolecular architecture. Both complexes demonstrated significant antioxidant activity, suggesting their capability to neutralize free radicals and mitigate oxidative stress-related diseases. Hemolysis percentages were less than 2%, per the ASTM F756-00 standard, indicating non-hemolytic behavior. Low cytotoxicity was observed against fibroblast and MCF-7 cell lines. They do not exhibit antibacterial activity against Escherichia coli and Staphylococcus aureus. These findings suggest that the synthesized Cu2+‒complexes hold considerable promise for applications in drug delivery and cancer treatment. This research contributes to the advancement of supramolecular chemistry and the development of multifunctional materials for diverse scientific and medical applications.

The prevalent "core phonological deficit" model of dyslexia proposes that the reading and spelling difficulties characterizing affected children stem from prior developmental difficulties in processing speech sound structure, for example, perceiving and identifying syllable stress patterns, syllables, rhymes and phonemes. Yet spoken word production appears normal. This suggests an unexpected disconnect between speech input and speech output processes. Here we investigated the output side of this disconnect from a speech rhythm perspective by measuring the speech amplitude envelope (AE) of multisyllabic spoken phrases. The speech AE contains crucial information regarding stress patterns, speech rate, tonal contrasts and intonational information. We created a novel computerized speech copying task in which participants copied aloud familiar spoken targets like "Aladdin." Seventy-five children with and without dyslexia were tested, some of whom were also receiving an oral intervention designed to enhance multi-syllabic processing. Similarity of the child's productions to the target AE was computed using correlation and mutual information metrics. Similarity of pitch contour, another acoustic cue to speech rhythm, was used for control analyses. Children with dyslexia were significantly worse at producing the multi-syllabic targets as indexed by both similarity metrics for computing the AE. However, children with dyslexia were not different from control children in producing pitch contours. Accordingly, the spoken production of multisyllabic phrases by children with dyslexia is atypical regarding the AE. Children with dyslexia may not appear to listeners to exhibit speech production difficulties because their pitch contours are intact.

Introduction: For those with ST-segment myocardial infarction (STEMI), therapeutic delays are the leading cause of mortality. Contacting a health-care provider takes longer than the emergent prehospital system, the patient referral process, the emergency room, and within the hospital. In our nation’s various cities, we aimed to compare these variables. Methods: In the Iranian cities of Sanandaj and Tehran, the Rajaie Cardiovascular Medical and Research Center (RHC) and Tohid Hospital, respectively, undertook this multicenter, multiprefectural, cross-sectional study between 2016 and 2020. Baseline characteristics were gathered from medical records, including age, sex, and employment. In two centers, the first medical contact-to-door (FTD) and door-to-balloon (DTB) times as well as electrocardiographic abnormalities, adjunctive therapy, causal lesions, and FTD and DTB times were evaluated. Results: The study population consisted of 600 STEMI patients, 300 from each institutions. Most of the participants were male, approximately a third of the patients arrived at the hospital using emergency medical service, the most frequent culprit artery in both hospitals was the left anterior descending artery, the average FTD was 333 min in Tehran and 151 min in Sanandaj, with the statistical significance difference (P < 0.001), DTB was significantly lower at RHC than at Tohid Hospital (54.8 min vs. 88.3 min; P < 0.001), the maximum FTD was observed among patients older than 70-year-old (284.72 min). Conclusion: Preparing sufficient facilities for primary percutaneous coronary intervention units, increasing the number of specialists and ensuring their permanent presence in hospitals, and providing health-care personnel with improved training may play significant roles in minimizing DTB.

Abstract Background & aim: The knowledge of the biochemical composition of salivary stones (sialoliths) is necessary for their aetiology and formation mechanism. A small number of studies have investigated sialoliths' elemental composition and clinical symptoms, probably due to the unknowingness and uncertainties of their formation. The purpose of this study was to determine the occurrence, physicochemical characteristics and clinical symptoms of salivary stones (sialoliths). Methods: This is a semi-experimental study that was conducted in Shiraz medical centers in 2023. Sialoliths' physical properties (colour, size, weight and hardness) and elemental composition (using an SEM-EDS) after non-randomly collecting from available samples in Shiraz health centres in 2022 for 9 months were determined. The target population included male and female patients of different age ranges. Statistical tests of Shapiro-Wilk and Mann-Whitney were applied to identify the data normality and find significant differences between the distribution of elements and individual factors, respectively. Results: Salivary stones comprised white to light brown colours and a 1 to 40 mm size range, with a mean weight of 0.65 g and hardness of 2 to 4. Salivary stones dominantly constitute oxygen (O), carbon (C), calcium (Ca), phosphorus (P), sodium (Na) and chlorine (Cl), respectively (98%). No significant difference was found between the distribution of elements and the individual factors (gender and age). A strong positive correlation between Ca and P (r = 0.86) and a good positive correlation between Ca and P with sialoliths' physical parameters (35 < r < 0.60) reflected that Ca and P comprise biomineral phases similar to carbonated calcium phosphates. Conclusion: The results of the present study provided a good insight into sialoliths' elemental composition, physicochemical properties and clinical symptoms. The high weight percentage of O, C, Ca and P suggested phosphorated carbonate compounds. Ca and P were two important explanatory factors for the weight and size of salivary stones. Also, age and gender were not considered the main factors controlling elements in sialoliths.

Abstract Background Radioactive iodine (RAI) therapy is the standard treatment approach after total thyroidectomy in patients with papillary thyroid carcinoma (PTC). We aimed to identify predictive factors of response to the treatment in intermediate and high-risk patients with PTC. In addition, the impact of multiple RAI treatments was explored. Methods In a 3-year retrospective study, data from intermediate and high-risk patients with PTC who received RAI therapy following total thyroidectomy, were analyzed by the end of year-one and year-three. Demographic data, tumor size, capsular/vascular invasion, extrathyroidal extension, local or distant metastasis, initial dose and cumulative dose of RAI, serum thyroglobulin(Tg), antithyroglobulin antibody(TgAb), and imaging findings were investigated. Patients with an excellent response to a single dose of RAI treatment, after three years of follow-up were classified as the “Responder group”. Excellent response was defined as stimulated serum Tg less than 1 ng/ml, or unstimulated serum Tg less than 0.2 ng/ml in TgAb-negative patients with negative imaging scans. Results 333 patient records with a complete data set were analyzed in this study. After three years of initial treatment, 271 patients were non-responders (NR) and 62 were responders (R). At baseline, the median pre-ablation serum Tg level was 5.7 ng/ml in the NR group, and 1.25 ng/ml in the R group (P

BACKGROUND: Trauma is one of the causes of death and part of the cause of disability in the active population in developing countries. This study aimed to investigate trauma and consequences in emergency patients of Kowsar Hospital, Sanandaj, Iran, in 2018-2019. METHODS: In this cross-sectional study, the files of 245 patients who referred to the emergency department (ED) of Kowsar Hospital from April 2018 to March 2019 with the diagnosis of trauma equal to the prepared checklist were examined and the required information was extracted and analyzed using SPSS software. RESULTS: 74.3% were men and 25.7% were women. The average age was 26.49 ± 11.43 years. 58% of trauma mechanisms was related to accidents, 40% to falls, and 2% was due to conflicts. 51% of patients were hospitalized in the emergency room and 5.7% in the intensive care unit (ICU). 41.6% were discharged and 1.6% died as a result of trauma. There was a significant relationship between the scene of the accident, transfer to the hospital from the scene of the accident, and the location of the lesion with the outcome of trauma in the studied patients (P < 0.0001). CONCLUSION: The results of the present study showed that accidents and falls were the main reasons for patients to visit the emergency trauma department. There was a significant relationship between the anatomical location of the injury and the trauma's outcome. Most of the patients were admitted to the emergency room. The outcomes were trauma, hospitalization, discharge with personal consent, and death.

Background: Industrial radiography uses gamma or X-ray radionuclide sources to investigate the safety of industrial materials. Industrial radiation workers receive the highest occupational radiation doses. Objective: The present study investigates the relationship between Bax and Bcl-2 gene expression variables in industrial radiation workers. Material and Methods: In this case-control study, data was collected using blood sampling from 40 workers, including two groups of non-radiation and radiation workers employed at the location. Expression levels of Bax and Bcl-2 genes were assessed in the laboratory. The environmental and absorbed doses of workers were measured using environmental and pen dosimeters. Results: Statistical analysis showed that the radiation group’s Bcl-2 gene expression level was significantly higher. Findings also demonstrated a correlation between Bcl-2 gene expression and the number of workdays. Also, the Bax gene expression did not show a significant change, and the expression ratio of Bax/Bcl-2 was insignificant in the two groups. Conclusion: Exposure to low doses of radiation could promote an adaptive response in cells by increasing Bcl-2 gene expression.

Background: The ability of Pseudomonas aeruginosa to produce biofilm has established it as one of the most significant pathogens. The purpose of this study was to evaluate antimicrobial resistance and conduct a molecular investigation of the virulence genes PslB and PelD in Pseudomonas aeruginosa species isolated from patients. Methodology: One hundred clinical isolates were collected from patients of different age groups who were hospitalized in Kermanshah and Sonqor hospitals. The isolates were obtained through culture on specific media, biochemical confirmatory tests, and gram staining for confirmation. Biofilm production was assessed using an indirect quantification method with crystal violet. Additionally, antibiotic resistance was determined through the disc various method following Clinical and Laboratory Standards Institute guidelines. Finally, the presence of genes related to PlsB and PelD in resistant strains was examined using The polymerase chain reaction (PCR). Results: The results indicate that the highest resistance and lowest sensitivity were related to nitrofurantoin 100 μg, while the lowest resistance and highest sensitivity were related to cefepime 30 mg. Biofilm phenotypes were categorized as weak in 7% ( n = 7) of isolates, medium in 13% ( n = 13), and high in 80% ( n = 80). The PslB and PelD genes were identified in 86% ( n = 86) and 38% ( n = 38) of isolates, respectively, while 4% ( n = 4) did not possess either of these two genes. Additionally, a majority of the isolates exhibited multidrug-resistance (87%) due to their moderate-to-high biofilm formation. Conclusion: All isolates were capable of producing biofilm. A significant association were between strains with the high biofilm and multidrug-resistance species ( p

In the present work, Palladium nanoparticles were supported on Cinchonine functionalized ZrFe2O4 MNPs. The structure, morphology, and physicochemical properties of the particles were characterized through different analytical techniques, including fourier transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductively coupled plasma (ICP), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), energy dispersive X-ray spectroscopy (EDS) and vibrating sample magnetometer (VSM) techniques. Moreover, it was obtained as an efficient catalyst for Hiyama and Suzuki reactions under green conditions with good to excellent yields. This method has the advantages of simple methodology, high yields, easy work-up, greener conditions, and short reaction times. This catalyst was reused four times in C-C coupling reaction without loss of its catalytic activity. The reused catalyst was characterized by ICP and FT-IR techniques. Heterogeneity and stability of ZrFe2O4@SiO2-S-CCH-Pd were studied by hot filtration test and ICP analysis.

Abstract In order to identify the effect of genotype × trait, 20 maize (Zea mays L.) hybrids were cultivated and investigated in a randomized complete block design in three replications in the Karaj region. The results of the analysis of variance showed that the effect of genotype in terms of all traits except for the traits of days until the tassel dries, peduncle outside the flag leaf, tassel length, the number of fill seeds, and the depth of the seeds are significantly different. Based on the mean comparison done by Duncan's method, G3, G6, G7, and G4 genotypes were identified as favorable hybrids. Based on the graphic analysis, the genotypes G5, G4, G6, G3, G9, and G14 can be identified as desirable hybrids. The correlation diagram indicated that the grain yield trait has a positive correlation with tassel length, leaf length, leaf width, and leaf surface traits. Based on the principal component analysis, the first 10 components explained more than 74% of the data variance. The traits were classified into 10 components: components of ear characteristics, time characteristics in terms of maturity, leaf characteristics, characteristics of maize plant 1 (cob corn diameter, peduncle length, and grain yield traits), characteristics of maize plant 2 (number of tassel branches, leaf surface, and grain yield traits), physiological characteristics and germination, the crown part of the ear characteristics, grain characteristics, grain yield, and characteristics of the ear head. The experiment results indicated that G8, G15, G1, and G6 hybrids were more favorable in terms of grain yield trait.

Introduction: Adequate knowledge and positive attitude among nurses are essential for successful pain management as a fundamental aspect of patients' rights. This study aimed to assess the knowledge, attitude and perceived barriers of nurses regarding acute pain management in emergency department. Methods: In this cross-sectional study, participating nurses were selected using a consecutive sampling technique within a medical university. Data were collected using 4 questionnaires, which consisted of demographic information checklist, Pain Management Principles Assessment Tool (PMPAT), Nurses’ Attitude Survey (NAS), and Nurses’ practice checklist. The correlation between knowledge, attitude, and barriers with each other and with baseline characteristics of participates were studied. Results: 400 nurses with the mean age of 38.26±10.39 years were studied (63% male). The average knowledge score of studied nurses was 7.38 ± 2.16 (range: 1 -14). All 400 (100%) nurses exhibited a low level of knowledge. The mean attitude score of participants was 58.47± 22.08 (range:26-100). 214 (53.5%) cases had low attitude, 44 (11.0 %) average attitude, and 142 (35.5%) cases exhibited a high attitude score. The mean score of barriers about pain management was 36.48 ± 23.52 (range: 0 – 80). 23 (5.8%) participants answered the perceived barriers as never, 113 (28.3%) as seldom, 71 (17.8%) as sometimes, 133 (33.3%) as often, and 60 (15.0%) as routine. There was an reverse relationship between the knowledge score and perceived barriers of pain management (r=-0.164, p 0.065). Conclusions: The findings of this study highlight the need for ongoing training and the organization of workshops for nurses due to their low levels of knowledge and attitude. These training sessions should focus on the concept of pain, assessment methods, pain relief, as well as pharmacology and the physiology of pain.