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This study aims to investigate the psychometric properties of the social communication questionnaire (SCQ) in Iran by identifying children with autism spectrum disorder (ASD) who had Persian-speaking parents.

A case–control study was performed from June to August 2021 in Hamadan, Iran. The case group consisted of children who were examined by clinicians who used a coding scheme based on the DSM-V criteria for ASD by a psychiatrist. The control group consisted of non-ASD children who were asked to participate in the study. This study conducted the reliability, content and face validity to evaluate the psychometric properties of the tool. In the first step, Kaiser–Meyer–Olkin and Bartlett’s test were used to determine sampling adequacy and appropriateness of correlation matrix. In the second step, the exploratory factor analysis approach was used. The method of extracting the factors is done by using the varimax rotation method and selecting the number of factors using an eigenvalue and scree plot. Statistical analysis was performed using Software Package for Social Sciences 21 with the statistical significance set at level less than 0.05.

The quantitative content validity analysis revealed that the mean of content validity ratio and content validity index were 0.92 and 0.91, respectively. Mean score ± standard deviation in the two groups of ASD and control were 14.23 ± 3.84 and 7.83 ± 4.80, respectively. With cut-off point >12.5, sensitivity, specificity and misclassification error values were 73.33%, 80.0% and 23%, respectively.

The results showed that the internal consistency of the SCQ is desirable. Also, the internal consistency of its five subscales was obtained between 0.700 and 0.87. The findings showed that SCQ questionnaire is highly reliable in reciprocal social interaction (Factor 1) and the total score, while other factors were relatively reliable.

To the best of the authors’ knowledge, this is the first paper on psychometric properties of SCQ in ASD children in Iran.

This paper aims to provide a full introduction, new classification, comparison and investigation of the challenges as well as applications of layerless 3D printing, which is one of the industry 4.0 pioneers.

Given the significance and novelty of uniform 3D printing, more than 250 publications were collected and reviewed in an unbiased and clear manner.

As a result, the majority of uniform parts printed in polymer form are known up to this point. In a novel division for better researchers’ comprehension, uniform printing systems were classified into three categories: oxygen inhibition (OI), liquid lubrication (LL) and photon penetration (PP), and each was thoroughly investigated. Furthermore, these three approaches were evaluated in terms of printing speed, precision and accuracy, manufacturing scale and cost.

The parameters of each approach were compared independently, and then a practical comparison was conducted among these three approaches. Finally, a variety of technologies, opportunities, challenges and advantages of each significant method, as well as a future outlook for layerless rapid prototyping, are presented.

Knowledge management (KM) is regarded as an essential factor in project-based organizations (PBOs), leading to organizational learning across projects. Over recent years, most PBOs have inserted project management offices (PMOs) into their hierarchical charts to manage their projects much more coherently. These offices can correspondingly provide KM facilities in PBOs. Thus, this study aimed to analyze the relationship between PMO functions and KM infrastructure, as KM enablers in organizations, in Iranian oil and gas upstream PBOs.

A two-phase quantitative survey strategy was exercised in this research. The first phase was to investigate the relationship between PMOs and KM infrastructure and to prioritize PMO functions and KM infrastructure based on their existing implementation/establishment status in Iranian oil and gas upstream PBOs. The research participants, identified through the website of the National Iran Oil Company (NIOC), were comprised of 46 oil and gas upstream PBOs which applied for exploration and production (E&P) certificate in Iran in 2016 and 2017. Accordingly, a total number of 46 questionnaires were submitted to the aforementioned companies with a return rate of 41 cases. The second phase was fulfilled questioning 19 Iranian oil and gas industry experts to determine the one-to-one effect of PMO functions on KM infrastructure and to verify the first-phase results.

The results indicated a strong relationship between PMO functions and KM infrastructure. This relationship was significant with regard to “practice management” and “technical support”, having the most considerable connections with KM infrastructure. According to the first-phase results, the main functions of PMOs in Iranian oil and gas industry were “practice management” and “technical support”. Considering KM infrastructure, “structure” showed the lowest mean value while “culture”, “human resources” and “processes and procedures” obtained the highest scores. The results also demonstrated that PMO functions could lead to more improvements in “processes and procedures”, as a sub-component of KM infrastructure, compared with other sub-components. Furthermore, the oil and gas industry experts believed that “organizational culture” in KM could be shaped by most of PMO functions.

This study fulfilled the need for exploring the relationship between PMO functions and KM since academic literature lacked a thorough investigation, to the best of authors' knowledge, pertaining to the effects of PMO functions on KM development in oil and gas PBOs.

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease which has become a public health concern, whose growing prevalence has been reported as around 33.9% in Iran. As oxidative stress plays a crucial role in the pathogenesis of NAFLD, antioxidant compounds such as quercetin could ameliorate the side effect of oxidative stress. The aim of the current study was to assess the effect of quercetin on lipid profile, liver enzymes and inflammatory indices in NAFLD patients.

In a randomized, double-blind, placebo-controlled trial conducted as a pilot study, 90 patients with NAFLD were supplemented with either a quercetin or a placebo capsule twice daily (500 mg) for 12 weeks. Both groups were advised to follow an energy-balanced diet with physical activity recommendations. Blood sample was obtained for laboratory parameters at baseline and the end of week 12.

At the end of the follow-up, quercetin group had significantly greater reduction in anthropometric parameters, cholesterol (−15 ± (−41, 0.00) in Q group versus −1± (−8, 2) in control group, p = 0.004), TG (−56.7 ± 22.7) in Q group versus −13.4 ± 27.7 in control group, p = 0.04), and tumor necrosis factor-α (TNF-α) (−49.5 ± (−99, 21) in Q group versus −5 ± (−21, 0.30) in the control group, p < 0.0001) compared to the control group. However, changes in fatty liver grade, liver enzymes, as well as high density lipoprotein-cholesterol and high-sensitivity C-reactive protein were not significantly different between the two groups.

To the best of the authors’ knowledge, this was the first study which assessed the effect of quercetin supplementation on liver enzymes, lipid profile and inflammatory indices of NAFLD patients as a double-blind placebo-controlled pilot study.

Because of the increasing global oil demand, efforts have been made to further extract oil using chemical enhanced oil recovery (CEOR) methods. However, unlike water flooding, understanding the physicochemical properties of crude oil and its sandstone reservoir makeup is the first step before embarking to CEOR projects. These properties play major roles in the area of EOR technologies and are important for the development of reliable chemical flooding agents; also, they are key parameters used to evaluate the economic and technical feasibilities of production and refining processes in the oil industries. Consequently, this paper aims to investigate various important physicochemical properties of crude oil (specific gravity; American Petroleum Institute [API]; viscosity; pour point; basic sediment and water; wax; and saturate, aromatic, resins and asphaltenes components) and sandstone reservoir makeup (porosity, permeability, bulk volume and density, grain volume and density, morphology and mineral composition and distributions) obtained from Malaysian oil field (MOF) for oil recovery prediction and design of promising chemical flooding agents.

Three reservoir sandstones from different depths (CORE 1; 5601, CORE 2; 6173 and CORE 3; 6182 ft) as well as its crude oil were obtained from the MOF, and various characterization instruments, such as high temperature gas chromatography and column chromatography for crude’s fractions identification; GC-simulated distillation for boiling point distribution; POROPERM for porosity and permeability; CT-Scan and scanning electron microscopy-energy dispersive X-ray for morphology and mineral distribution; wax instrument (wax content); pour point analyser (pour point); and visco-rheometre (viscosity), were used for the characterizations.

Experimental data gathered from this study show that the field contains low viscous (0.0018-0.014 Pa.s) sweet and light-typed crude because of low sulfur content (0.03 per cent), API gravity (43.1o), high proportion of volatile components (51.78 per cent) and insignificant traces of heavy components (0.02 per cent). Similarly, the rock permeability trend with depth was found in the order of CORE 1 < CORE 2 < CORE 3, and other parameters such as pore volume (Vp), bulk volume (Vb) and grain volume (Vg) also decrease in general. For grain density, the variation is small and insignificant, but for bulk density, CORE 2 records lower than CORE 3 by more than 1 per cent. In the mineral composition analysis, the CORE 2 contains the highest identified mineral content, with the exception of quarts where it was higher in the CORE 3. Thus, a good flow crude characteristic, permeability trend and the net mineral concentrations identified in this reservoir would not affect the economic viability of the CEOR method and predicts the validation of the MOF as a potential field that could respond to CEOR method successfully.

This paper is the first of its kind to combine the two important oil field properties to scientifically predict the evaluation of an oil field (MOF) as a step forward toward development of novel chemical flooding agents for application in EOR. Hence, information obtained from this paper would help in the development of reliable chemical flooding agents and designing of EOR methods.

The purpose of this paper is to evaluate the qualitative effect of corporate governance components, in the form of managerial entrenchment index, on earnings management and innovation.

In this study, the variable of managerial entrenchment, which includes the variables of management independence, dual role of management, management tenure, the board compensation and the board ownership percentage, was initially estimated through the exploratory factor analysis and its effect was evaluated on the dependent variables of the study using the test of multivariable regressions. Hence, a total of 103 listed companies on the Tehran Stock Exchange were selected and analyzed during 2011–2016. In this paper, the Jones model is used as the variable of accrued earnings management and for calculating the real earnings management, the models of abnormal operational cash flows, abnormal production costs and abnormal optional costs are employed. Moreover, the research and development cost to total costs ratio is used for calculating the innovation.

The results indicate a negative and significant relationship between managerial entrenchment and accrual-based earnings management; moreover, the entrenched managers are less likely to engage in manipulating the real activities accruals in Iran context. Furthermore, the findings show that there is a positive and significant relationship between managerial entrenchment and firm innovation.

What really sets this paper apart from other studies is that this research will make aware investors and stakeholders of this fact that managerial entrenchment will be a good way to diminish the manipulation of financial reporting and improve the corporate situation in emerging markets, particularly those bazaars facing with economic sanctions such as Iran. Undeniably, the study results will complete the knowledge gap between the developed economies and the emerging markets.

The present study aims to assess the effect of managerial entrenchment on firms’ corporate social responsibility (CSR) activities and financial performance in Iran.

In this paper, the variable of managerial entrenchment, which includes board independence, management duality, management tenure, the board compensation, independence and ownership percentage, is initially analyzed using the exploratory factor analysis method, and its effect on performance and CSR is evaluated using the multivariable regression test. Given that a total of 103 listed companies on the Tehran Stock Exchange are selected during 2012–2017. In this paper, return on assets (ROA) and Tobin’s Q are the two variables to measure financial performance.

The results of hypotheses testing indicate that there is a positive and significant relationship between managerial entrenchment and financial performance based on the ROA and Tobin’s Q indices, separately. Moreover, the results of this study indicate that there is also a positive and significant relationship between managerial entrenchment and CSR activities.

The current study almost is the first study, conducted in a developing country similar to Iran, and the provided results might be beneficial to other developing countries.

The authors performed a systematic review and meta-analysis of all published randomized controlled trials with the aim to determine and quantify the anti-hyperglycemic effects of glutamine (Gln) in acute and chronic clinical settings.

The authors conducted a comprehensive search of all randomized clinical trials performed up to December 2018, to identify those investigating the impact of Gln supplementation on fasting blood sugar (FBS), insulin levels and homeostatic model assessment-insulin resistance (HOMA-IR) via ISI Web of Science, Cochrane library PubMed and SCOPUS databases. A meta-analysis of eligible studies was conducted using random effects model to estimate the pooled effect size. Fractional polynomial modeling was used to explore the dose–response relationships between Gln supplementation and diabetic indices.

The results of the present meta-analysis suggest that of Gln supplementation had a significant effect on FBS (weighted mean difference (WMD): –2.868 mg/dl, 95 per cent CI: –5.467, –0.269, p = 0.031). However, the authors failed to observe that Gln supplementation affected insulin levels (WMD: 1.06 units, 95 per cent CI: –1.13, 3.26, p = 0.34) and HOMA-IR (WMD: 0.001 units, 95 per cent CI: –2.031, 2.029, p = 0.999). Subgroup analyses showed that the highest decrease in FBS levels was observed when the duration of intervention was less than two weeks (WMD: –4.064 mg/dl, 95 per cent CI: –7.428, –0.700, p = 0.01) and when Gln was applied via infusion (WMD: –5.334 mg/dl, 95 per cent CI: –10.48, 0.17, p = 0.04).

The results from this meta-analysis show that Gln supplementation did not have a significant effect on insulin levels and HOMA-IR. However, it did significantly reduce the levels of FBS, obtaining a higher effect when the duration of the intervention period was less than two weeks.

This study aims to investigate the relationship between information technology and internal controls of state agencies in Iran.

The research population includes all auditors and managers working in public sector. Data collection instrument is a questionnaire designed by the researcher and administrated during March 5, 2016. The collected data are analyzed through descriptive and inferential statistics (binomial test).

The findings of the research show that there is a significant relationship between information technology and internal controls (administrative, financial and accounting controls, risk assessment, information and communication, control activities and monitoring). Moreover, the alteration of data collection methods (from traditional to modern) and the written instructions (in information technology) have a positive effect on the internal control and its subscales.

With regard to the emphasis on the development of computer application and the use of new processing facilities and the exchange of information and its specific controlling consequences, this is an innovative research.

The current study aims to investigate the relationship between relative performance and change manager in Iran.

For this study, the reasons for CEO change and the contributing factors to performance were defined based on the industry type. A systematic elimination approach is applied to select the study sample among listed companies on the Tehran Stock Exchange during 2012–2016. Finally, a 390 firm-year population was tested using multiple regression.

The results of hypothesis testing indicate that the possibility of managerial change is less likely after a positive return of the market performance. Moreover, hypothesis testing results reveal that peer firms and specific-firm performance do not contribute to managerial change. The findings also demonstrate that systematic risk has a negative impact on managerial change, whereas unsystematic risks do not significantly play a part in managerial change.

As the present study is the pioneer study on the impact of managerial change factors on Iranian firms' relative performance, the findings of this study can contribute to the realm of this study and the related literature.