nadia naghavi

The research was conducted with the aim of explaining the model of self-directed learning based on cognitive creativity with regard to the mediating role of successful intelligence in the students of the second year of elementary school in Kerman province. The current research was descriptive and of correlation and structural equations type. The statistical population included all the students of the second period of elementary school in Kerman province in the academic year of 2022-2023 in the number of 170066 people. 310 people were selected from 4 cities (Ravar, Baft, Bam, Rafsanjan) based on multi-stage random cluster sampling method. In order to collect data, Abedi's cognitive creativity standard (1993), Sternberg and Grigorenko's successful intelligence (2002) and Naghavi Self directed learning (2022) questionnaires were used. Then scoring was done with SPSS version 23 statistical software and data analysis was done using structural equation modeling method in AMOS-23 software. The results showed that there is a significant relationship between successful intelligence and self-directed learning (P<0.01). Also, the results showed that the indirect paths of self-directed learning based on cognitive creativity with the mediating role of students' successful intelligence were significant. According to the findings, the final model had a good fit (P<0.01). The findings of this research can have an impact on the design of curricula and lead students in the path of effective cognitive creativity and the use of successful intelligence to solve problems by teachers and designers.

The mediating role of critical thinking in interacting with help-seeking can deepen our understanding of how to increase students' independence and adequacy in the learning process. However, few investigations have been conducted into these complex dimensions and interactions, a research gap that reinforces the necessity and value of future studies to improve current educational systems.

The current research was conducted with the objective of explaining the self-directed learning model based on help-seeking, considering the mediating role of critical thinking among students of the second elementary stage in Kerman province.

The current research is descriptive, correlational, and employs structural equation modeling. The statistical population included all students of the second elementary stage in Kerman province during the academic year 2022-2023, totaling 170,066 students. Out of this population, 310 individuals were selected as samples through a multi-stage random cluster sampling method, from 4 counties (Ravar, Baft, Bam, and Rafsanjan).

The results indicated that there is a significant relationship between critical thinking and self-directed learning (P< 0.01). Additionally, the results showed that the direct paths in this research were significant, and the indirect pathways of self-directed learning based on help-seeking through the mediating role of students’ critical thinking were also significant. Based on the findings, the final model had a satisfactory fit (P< 0.01).

The findings of this research can concretely impact the design and implementation of curricular programs and educational interventions, particularly in promoting intellectual independence and effective learning in students. With a better understanding of the role of critical thinking as a mediating factor in the self-directed learning process, teachers and curriculum designers can employ related approaches and techniques in the classroom to guide students towards effective help-seeking and the use of critical thinking for evaluating and solving problems.

Ionic Polymer Metal Composites (IPMC) are smart materials that consist of two parts, metal, and elastomer. Functionally, IPMCs are a group of electroactive polymers that, due to their special structure, are a suitable option for use as sensors and soft actuators with low excitation voltage. When used as an actuator, in addition to the excitation voltage, IPMC bending is affected by intrinsic and environmental factors. One of the serious challenges in the practical application of IPMC is the prediction of the "Back-Relaxation effect". The term back-relaxation effect is a term used for the gradual reduction of IPMC bending and return to the cathode side under constant voltage excitation. In this research, the effect of back-relaxation on the bending behavior of IPMC has been modeled in three dimensions with Comsol software, for the first time. The comparison of the results with the practical test data indicates high accuracy of 93% of the modeling in predicting displacement, which also confirms other important performance information such as concentration changes and stress distribution in the material. Using this model to predict IPMC behavior will be very cost-effective in terms of time and cost compared to practical tests.

Periodic and brief electrical stimulations (ES) are used as therapeutic protocols to improve nerve regeneration and functional recovery in various nervous system disorders. Periodic ES is applied transcutaneously for several sessions post-surgery, but brief ES is applied directly to the nerve during the surgery. Brief ES has no negative effects on functional recovery but applying periodic ES may delay the recovery. In most research studies, brief ES has been applied for 1-hour, although in some studies shorter durations were used. In this research, to reduce the risk of infection and cost, brief ESs with different durations (1-hour and shorter durations) were studied in a comparative study.

The right sciatic nerve of 24 adult male Wistar rats was transected and sutured to a silicone tube. Experimental groups were stimulated by 10, 30, and 60 minutes ES (20Hz, 3V, 100µs). The hot plate test was done biweekly. At the end of the experimental period (12 weeks), the histomorphometric assessments were performed on the intra silicon tube segment of the regenerated nerve and its tibial branch.

Hot plate test results showed an increase in the regeneration speed in experimental groups; furthermore, the 60-min ES group had better outcomes in histomorphometric assessment than other groups that may be due to the ES effect on the neuronal cell bodies.

As the results indicate, the 60-min ES had a better outcome compared to other groups. Other specifics of a brief ES such as frequency, pulse width, and waveform (monophasic or biphasic) may be studied in future research.

As a tumor grows, the demand for oxygen and nutrients increases and it grows further if acquires the ability to induce angiogenesis. In this study, we aimed to present a two-dimensional continuous mathematical model for avascular tumor growth, coupled with a discrete model of angiogenesis. In the avascular growth model, tumor is considered as a single mass, which uptakes oxygen through diffusion and invades the extracellular matrix (ECM). After the tumor reaches its maximum size in the avascular growth phase, tumor cells may be in three different states (proliferative, quiescent and apoptotic), depending on oxygen availability. Quiescent cells are assumed to secrete tumor angiogenic factors, which diffuse into the surrounding tissue until reaching endothelial cells. The mathematical model for tumor angiogenesis is consisted of a five-point finite difference scheme to simulate the progression of endothelial cells in ECM and their penetration into the tumor. The morphology of produced networks was investigated, based on various ECM degradation patterns. The generated capillary networks involved the rules of microvascular branching and anastomosis. Model predictions were in qualitative agreement with experimental observations and might have implications as a supplementary model to facilitate mathematical analyses for anti-cancer therapies. Our numerical simulations could facilitate the qualitative comparison between three layers of tumor cells, their TAF-producing abilities and subsequent penetration of micro-vessels in order to determine the dynamics of microvascular branching and anastomosis in ECM and three different parts of the tumor.

Insulin therapy for type 1 diabetes patients often causes high fluctuations in their blood glucose and hypoglycemic/hyperglycemic events. Closed loop control of blood glucose using artificial pancreas can improve life quality of patients. In this paper, physiological behaviour of the system has been modeled inversely using daily patient data acquired GIM simulator. Then, considering the delaed nature of the system, a novel adaptive control structure has been proposed for time-delayed systems, which is a combination of the model reference adaptive control with modified Smith Predictor. Due to extensive variability among patients in metabolism, an in silico trial consisting of 30 patients with random changes and sinusoidal oscillation in parameters of Dalla Man glucose-insulin model has been used to simulate the personal variability in the glucose control system. Performance of the proposed algorithm has been compared to the PID controller with Smith Predictor, based on the quantitative and qualitative indicatirs. Simulation results showthat the proposed controlscheme is effective in fasting conditions, meal disturbance rejection, and robustness against inter-patients variability.

The ultimate goal of endodontic treatment is to eliminate the bacterial infection in the root canal system. While mechanical debridement combined with chemical irrigation removes the bulk of microorganisms, residual bacteria are readily detectable in approximately one-half of teeth just prior to obturation. Laser light can be used to destroy bacteria. This in vitro study was performed to evaluate the effect of diode laser and calcium hydroxide on mono-infected dental canals. Fifty five single-rooted human premolars were prepared and contaminated with Enterococcus faecalis. After three weeks of incubation, the samples were divided into three experimental groups (n = 15) and two control groups (n = 5). In the first and second groups, the teeth were rinsed for 5 min with either sterile saline or 5.25% NaOCl and irradiated with a 810-nm diode laser at 1.5 W output for 5 × 4s. In the third group, the teeth were rinsed with 5.25% NaOCl and then Ca(OH)2 paste was inserted in the canals for 1 week. Intracanal bacterial sampling was done and the samples were plated to determine the CFU count. 5.25% NaOCl plus laser was as effective as calcium hydroxide and significantly more effective than sterile saline (P>0.05) in elimination of E. faecalis. Complete elimination of E. faecalis was seen only for the one week calcium hydroxide treatment. Combination therapy with NaOCl irrigation and diode laser irradiation can be recommended as an effective treatment option for elimination of E. faecalis from the root canal system.

During the process photodynamic therapy (PDT), bleaching of photosensitizer induced by irradiation and generation of reactive oxygen species (ROS) can provide some information concerning the efficiency of treatment. Since gold nanoparticles (GNPs) have been highlighted as efficient drug delivery systems, in this study, by utilizing GNPs conjugated with 5 aminolevulinic acid (5-ALA-GNPs), the photobleaching of ALA-induced protoporphyrin IX (PpIX) was estimated on a colon carcinoma tumor model. CT26 tumor models were prepared by subcutaneous injection of 5×105 cells into the right flank of Balb/c inbred mice. To estimate the time required to reach maximum concentration of PpIX in the tumors, the fluorescence signal of PpIX was monitored and PDT was performed by intratumoral injection of 5-ALA-GNPs, GNPs, and 5-ALA in separated groups for 15 min with a cycle of 5 min irradiation and 1 min darkness. The photobleaching rate was calculated from recorded fluorescence signals at the darkness intervals. The maximum fluorescence of PpIX was recorded 3 and 5 hr after injection of 5-ALA and 5-ALA-GNPs, respectively. Despite the low PpIX accumulation in tumors receiving conjugate, the photobleaching rate of PpIX was determined to be higher than 5-ALA. The reduction of the fluorescence signal due to 5-ALA-GNPs clearance was higher than that of 5-ALA. Administration of 5-ALA-GNPs, intensification of ROS generating and the subsequent elevation of photobleaching results in higher treatment efficiency. Also, more rapid clearance of PpIX has an important implication in clinical application of 5-ALA-GNPs that decreases the undesirable effects on healthy tissues.

Today, the idea of photodynamic therapy (PDT) is considered as one of the fundamental basis of the new cancer treatment methods. One of the important issues in the application of this therapy is choosing the optimal dosimetry method. At best, PDT dosimetry should be done based on estimation of the accumulated singlet oxygen dose within the target tissue and comparison with the threshold value to ensure the efficacy of the treatment. In order to estimate the accumulated singlet oxygen level within the tissue, the most appropriate method is modeling the process of treatment. In this context, it is necessary to obtain enough information about the drug concentration within the target tissue, the amount of light absorbed by the drug, the amount of oxygen into the tissue, and the interactions between them that produce singlet oxygen. In this study modeling and simulation of the photobleaching has been investigated, considering the importance of the level of drug concentration in the target tissue which would be decreased by photobleaching. Simulation was done with Matlab software. A Comparison of simulation results with those of experimental methods showed that in the state of non-uniform drug distribution, simulation follows experimental results at the initial phase of rapid decline of drug concentration.