Search

Abstract Water is one of the vital needs of life. However, due to rapid industrialization, urbanization and lack of awareness, the world population now facing the threat of water shortage. To ensure that future living conditions are preserved, it is crucial to reduce water pollution and protect the ecosystem. Zinc oxide- reduced graphene oxide (ZnO-RGO) nanocomposite is used in this study as an adsorbent for the adsorption of methylene blue (MB) dye from an aqueous solution. An easy strategy was used for the synthesis of reduced graphene oxide nanoparticles (RGO), Zinc oxide nanoparticles (ZnO) and ZnO-RGO nanocomposite. The synthesis of reduced graphene oxide (RGO) was accomplished through the exothermic reaction of a modified Hummer's method. In a novel approach, zinc oxide nanoparticles (ZnO NPs) were synthesized using the green Leidenfrost technique. This study presents a comparative investigation of ZnO-RGO nanocomposite synthesis employing both green and chemical methods. Three distinct approaches were utilized to prepare the ZnO-RGO nanocomposite: (1) the innovative Leidenfrost green method for composite A1, (2) a chemical precipitation method for composite A2, and (3) a physical mixing sonication method for composite A3. This research marks the first application of the Leidenfrost technique in the synthesis of ZnO-RGO nanocomposites, contributing to the growing body of knowledge in this field. X-ray diffraction (XRD), Burnauer-Emmett-Teller (BET), Fourier transform infrared (FTIR), Zeta potential, transmittance electron microscope (TEM) and scanning electron microscope (SEM) analyses are conducted for synthesized sample characterization. Comparing the XRD patterns of the three synthesis methods, it is notable that the intensity peaks of composite A3 were the highest when ZnO was synthesized using a green method, indicating a higher degree of crystallinity. FTIR analysis approves that combining ZnO with RGO affects the functional groups of the three nanocomposite surfaces. The SEM analysis shows ZnO NPs and RGO sheets are incorporated together. In the case of A1 composite sharp angles make a flower shape was observed due to the unique synthesizing method. The surface area for A2 composite is the highest (7.29 m2/g) compared with A1 (2.91 m2/g) and A3(1.90 m2/g). A comparison study is made among the three nanocomposites for MB dye removal. The effect of adsorbent dose, pH, contact time and initial dye concentration on dye adsorption has been studied. The results show that A1 and A2 nanocomposites removed 85.5 and 87.5% of MB at the optimum adsorbent dose of 0.15 g/100 ml at pH8 and A3 removed 95% of MB at the optimum dose of 0.1 g/100 ml at pH 2. All three composites exhibited adherence to the Langmuir isotherm model, with correlation coefficients (R2) of 0.9858, 0.9904, and 0.9959 for A1, A2, and A3, respectively. Kinetic study results demonstrated that the pseudo-second-order model best described the adsorption process for all three composites, yielding R2 values of 0.9998, 0.9988, and 1.0000 for A1, A2, and A3, respectively. The A3 nanocomposite shows the highest adsorption capacity (104.5 mg/g) compared to the other composites (87.7 and 97.5 mg/g for A1 and A2, respectively). Desorption experiments revealed that the dye removal percentages varied with the ratio of the ethanol–water mixture used. Absolute ethanol achieved a 90% removal compared with 1:1 and 1:2 aqueous ethanol solutions (87.5% and 80%, respectively).

Water is one of the vital needs of life. However, due to rapid industrialization, urbanization and lack of awareness, the world population now facing the threat of water shortage. To ensure that future living conditions are preserved, it is crucial to reduce water pollution and protect the ecosystem. Zinc oxide- reduced graphene oxide (ZnO-RGO) nanocomposite is used in this study as an adsorbent for the adsorption of methylene blue (MB) dye from an aqueous solution. An easy strategy was used for the synthesis of reduced graphene oxide nanoparticles (RGO), Zinc oxide nanoparticles (ZnO) and ZnO-RGO nanocomposite. The synthesis of reduced graphene oxide (RGO) was accomplished through the exothermic reaction of a modified Hummer's method. In a novel approach, zinc oxide nanoparticles (ZnO NPs) were synthesized using the green Leidenfrost technique. This study presents a comparative investigation of ZnO-RGO nanocomposite synthesis employing both green and chemical methods. Three distinct approaches were utilized to prepare the ZnO-RGO nanocomposite: (1) the innovative Leidenfrost green method for composite A1, (2) a chemical precipitation method for composite A2, and (3) a physical mixing sonication method for composite A3. This research marks the first application of the Leidenfrost technique in the synthesis of ZnO-RGO nanocomposites, contributing to the growing body of knowledge in this field. X-ray diffraction (XRD), Burnauer-Emmett-Teller (BET), Fourier transform infrared (FTIR), Zeta potential, transmittance electron microscope (TEM) and scanning electron microscope (SEM) analyses are conducted for synthesized sample characterization. Comparing the XRD patterns of the three synthesis methods, it is notable that the intensity peaks of composite A3 were the highest when ZnO was synthesized using a green method, indicating a higher degree of crystallinity. FTIR analysis approves that combining ZnO with RGO affects the functional groups of the three nanocomposite surfaces. The SEM analysis shows ZnO NPs and RGO sheets are incorporated together. In the case of A1 composite sharp angles make a flower shape was observed due to the unique synthesizing method. The surface area for A2 composite is the highest (7.29 m2/g) compared with A1 (2.91 m2/g) and A3(1.90 m2/g). A comparison study is made among the three nanocomposites for MB dye removal. The effect of adsorbent dose, pH, contact time and initial dye concentration on dye adsorption has been studied. The results show that A1 and A2 nanocomposites removed 85.5 and 87.5% of MB at the optimum adsorbent dose of 0.15 g/100 ml at pH8 and A3 removed 95% of MB at the optimum dose of 0.1 g/100 ml at pH 2. All three composites exhibited adherence to the Langmuir isotherm model, with correlation coefficients (R2) of 0.9858, 0.9904, and 0.9959 for A1, A2, and A3, respectively. Kinetic study results demonstrated that the pseudo-second-order model best described the adsorption process for all three composites, yielding R2 values of 0.9998, 0.9988, and 1.0000 for A1, A2, and A3, respectively. The A3 nanocomposite shows the highest adsorption capacity (104.5 mg/g) compared to the other composites (87.7 and 97.5 mg/g for A1 and A2, respectively). Desorption experiments revealed that the dye removal percentages varied with the ratio of the ethanol–water mixture used. Absolute ethanol achieved a 90% removal compared with 1:1 and 1:2 aqueous ethanol solutions (87.5% and 80%, respectively). [ABSTRACT FROM AUTHOR]

This paper considers the dynamical properties of a space and time discrete fractional reaction–diffusion epidemic model, introducing a novel generalized incidence rate. The linear stability of the equilibrium solutions of the considered discrete fractional reaction–diffusion model has been carried out, and a global asymptotic stability analysis has been undertaken. We conducted a global stability analysis using a specialized Lyapunov function that captures the system’s historical data, distinguishing it from the integer-order version. This approach significantly advanced our comprehension of the complex stability properties within discrete fractional reaction–diffusion epidemic models. To substantiate the theoretical underpinnings, this paper is accompanied by numerical examples. These examples serve a dual purpose: not only do they validate the theoretical findings, but they also provide illustrations of the practical implications of the proposed discrete fractional system.

This research article exploresand studiesthe role of the English novel in English Language Teaching (ELT) from the students’ perspective. Novels are considered to motivate and enhance literary materials used in the classroom. The study used a qualitative approach. The research targeted senior students selected from an English Department. Use of the novel was observed to be a flexible learning tool. Novels have the ability to appeal and satisfy each learner’s unique style of learning. It can touch on the learners’ creativity andenhance their descriptive and dialogue abilities.

Masoumeh Gharib,1 Zahra Nikfarjam2 1Department of Pathology, Mashhad University of Medical Sciences, Mashhad, Iran; 2Student Research Committee, Mashhad University of Medical Sciences, Mashhad, IranCorrespondence: Zahra NikfarjamDepartment of Pathology, Ghaem Educational, Research, and Treatment Center, Ahmadabad Avenue, Mashhad, Khorasan Razavi 99199-91766, IranTel +98 51 38400000Fax +98 51 38453239Email NikfarjamZ961@mums.ac.irAbstract: Chondroma is a benign tumor of mature hyaline cartilage that is often found in the long bones and may be rarely diagnosed in other parts of the body. Here, we present a young patient with the definitive diagnosis of intra-axial intracranial chondroma and without dural connection. The presenting symptoms of the patient were headache and impaired vision. The brain magnetic resonance imaging (MRI) revealed a huge enhancing parasagittal brain mass. The diagnosis was confirmed by immunohistochemistry, which was positive for S100.Keywords: case report, intracranial chondroma, rare malignant tumors

Background. Displacement encoded Cardiovascular MR (CMR) can provide high spatial resolution measurements of three-dimensional (3D) Lagrangian displacement. Spatial gradients of the Lagrangian displacement field are used to measure regional myocardial strain. In general, adjacent parallel slices are needed in order to calculate the spatial gradient in the through-slice direction. This necessitates the acquisition of additional data and prolongs the scan time. The goal of this study is to define an analytic solution that supports the reconstruction of the out-of-plane components of the Lagrangian strain tensor in addition to the in-plane components from a single-slice displacement CMR dataset with high spatio-temporal resolution. The technique assumes incompressibility of the myocardium as a physical constraint. Results. The feasibility of the method is demonstrated in a healthy human subject and the results are compared to those of other studies. The proposed method was validated with simulated data and strain estimates from experimentally measured DENSE data, which were compared to the strain calculation from a conventional two-slice acquisition. Conclusion. This analytical method reduces the need to acquire data from adjacent slices when calculating regional Lagrangian strains and can effectively reduce the long scan time by a factor of two. © 2010 Moghaddam et al; licensee BioMed Central Ltd.

Mitra Gharib,1 Mitra Zolfaghari,2 Rita Mojtahedzadeh,1 Aeen Mohammadi,1 Atoosa Gharib3 1E-learning in Medical Education Department, Virtual School, Tehran University of Medical Sciences, 2E-learning in Medical Education Department, Virtual School, Nursing and Midwifery Care Research Center, Tehran University of Medical Sciences, 3Pathology Department, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Background: With the increasing popularity of e-learning programs, educational stakeholders are attempting to promote critical thinking in the virtual education system. This study aimed to explore the experiences of both the instructors and the students about critical thinking promotion within the virtual education system.Methods: This qualitative study recruited the instructors and students from four academic disciplines provided by the Virtual School of Tehran University of Medical Sciences (Tehran, Iran). All programs were master’s degree programs and utilized a blended (combination of e-learning and face to face) training. Semistructured interviews with the participants were used to collect data.Results: The participants had a variety of experiences about how to promote critical thinking. These experiences were conceptualized in four main themes, namely, instructional design, educational leadership and management, local evidence, and belief systems.Conclusion: The present study clarified the factors affecting critical thinking promotion in e-learning. Not only the instructors but also the educational designers and leaders can benefit from our findings to improve the quality of virtual education programs and promote critical thinking. Keywords: thinking, distance education, graduate education, learning, framework

Background and Objective: Improving the ability to walk is often a key target for the treatment of abnormal gait in children with spastic diplegic cerebral palsy (CP). One of the goals of orthotic rehabilitation is to improve walking in this field. The aims of this study was to design and manufacture the dynamic neoprene orthoses and evaluate its impact on the gait parameters in children with cerebral palsy. Materials and Methods: This quasi-experimental study was done on 12 children with spastic CP at University of Social Welfare and Rehabilitation, in Tehran, Iran during 2010-11. Initially neoprene dynamic orthosis is designed specifithy for each subject, this neoprene dynamic orthosis was used for six weeks and 6-8 hrs daily. For evaluating the walking speed and the gait variation, 10 meter walking test and visual analogue scale have been used. Modified Ashworth’s Scale and electro-goniometre were used to assess muscle spasticity and the flexion degrees of knee joint. Data were analyzed using SPSS-16, Kolmogorov-Smirnov and Paired t-tests. Results: The alteration of knee flexion angle, walking speed and walking distance following dynamic orthosis were -18.31±4.61 (degree), -0.50±1.82 (meter) and 4.18±1.51, respectively. The improvement in knee joint angle and walking following dynamic orthosis was significant (P

Background and Objective: Constraint induced movement therapy is an approach that with limitation of the healthy upper limb movement of a person with hemiplegia obligate to use the affected limb. This study was done to determine the modified constraint induced movement therapy on quality of upper extremity skills in affected limb in children with hemiplegic cerebral palsy. Materials and Methods: This single blind randomized clinical trial was carried out on 21 children with hemiplegic cerebral palsy referred to rehabilitation centers in Tehran-Iran during 2008. Samples randomly were divided into experimental (n=11) and control (n=10). Common therapeutic physical practice was carried out for 6 weeks in both groups equally. In treatment group intervention was practiced by constrain induced movement therapy methods for 3 hours daily. Quality of upper extremity skills pre and post intervention based on the quality of upper extremity skills test (QUEST) was evaluated. Data were analyzed by SPSS-16 software, Kolmogrov-Smirnoff, chi-square, T student and repeated measurement tests. Results: Mean age of children in the experimental group (7 girls, 4 boys) and control group children (5 female, 5 male) were 46.55±17.5 and 48.10±19.2 months respectively. Internal analysis of all items in interventional group were significant after 6 weeks of treatment (P

Background & Objective: Administrators have to pay attention to nurses as an important group among hospitals employees in order to have better patient outcomes. Recently, nurses' quality of work life is a new concept that attention to it can improve organizational efficiency. This research is to investigate the quality of work life of nurses at Tehran University of Medical Sciences Hospitals in 2005-2006.Methods & Materials: This is a cross-sectional study. The research was conducted among 349 nursing employees. Data were gathered using a questionnaire consisted of 30 elements of QWL. The respondents were asked to determine their overall quality of work life. Validity of the questionnaire was evaluated using content validity and reliability was determined using test-retest method. Statistical analysis was carried out using SPSS statistical software package.Results: The results showed that the majority of nurses were dissatisfied with environmental health and safety at work, monetary compensation and job welfare. There was significant correlation between the executive position of nurses, years of experience and their salary (P