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Monitoring a biological tissue as a three dimensional (3D) model is of high importance. Both the measurement technique and the measuring electrode play substantial roles in providing accurate 3D measurements. Bioimpedance spectroscopy has proven to be a noninvasive method providing the possibility of monitoring a 3D construct in a real time manner. On the other hand, advances in electrode fabrication has made it possible to use flexible electrodes with different configurations, which makes 3D measurements possible. However, designing an experimental measurement set-up for monitoring a 3D construct can be costly and time consuming and would require many tissue models. Finite element modeling methods provide a simple alternative for studying the performance of the electrode and the measurement set-up before starting with the experimental measurements. Therefore, in this study we employed the COMSOL Multiphysics finite element modeling method for simulating the effects of changing the electrode configuration on the impedance spectroscopy measurements of a venous segment. For this purpose, the simulations were performed for models with different electrode configurations. The simulation results provided us with the possibility of finding the optimal electrode configuration including the geometry, number and dimensions of the electrodes, which can be later employed in the experimental measurement set-up.

Rapid development in the field of tissue engineering necessitates implementation of monitoring methods for evaluation of the viability and characteristics of the cell cultures in a real-time, non-invasive and non-destructive manner. Current monitoring techniques are mainly histological and require labeling and involve destructive tests to characterize cell cultures. Bioimpedance measurement technique which benefits from measurement of electrical properties of the biological tissues, offers a non-invasive, label-free and real-time solution for monitoring tissue engineered constructs. This review outlines the fundamentals of bioimpedance, as well as electrical properties of the biological tissues, different types of cell culture constructs and possible electrode configuration set ups for performing bioimpedance measurements on these cell cultures. In addition, various bioimpedance measurement techniques and their applications in the field of tissue engineering are discussed.

Objective (s): To assess TCAM in medical theses during the recent 15 years in medical schools of Tehran, Iran. Methods: All medical theses in 4 main medical schools (Iran, Shahid Beheshti, Shahed and Tehran medical schools) registered during 1991-2006 were assessed to find subjects related to TCAM. Theses were evaluated regarding the type of study, grade/ specialty of author and type of TCAM. Results: In all, 28344 medical theses have been registered during the study period. Of these, 110 theses (3.88 per 1000) were related to TCAM. There was a statistically significant increasing trend in the proportion of TCAM subjects (P

Objective (s): To examine nutrition education as perceived by school children and their mothers. Methods: This was a qualitative study using focus group discussion (FGD). The research team consisted of a coordinator, one or two observers and two note takers Each FGD was held with 6 to 8 person and each session tasted about 60 minutes. The fieldwork ecuvtues of the study included 20 FGD sessions, 16 for children grades I" to 4•h and 4 for mothers. The study was held in 2 districts of Tehran. At the end of each group discussion all notes were completed, coded, analyzed and classified by team members. Results: The findings showed that children were eager to learn on effects of healthy foods. Children indicated that TV was the most important and effective teaching medium, In addition to TV, food advertisements, school staff especially teachers were among the most common named on childrenchr('39')s nutritional behaviors. Most of children preferred to learn nutritional subjects from father, mother and other family members. The mothers preferred teachers, health instructorschr('39') parents and classmates as the source of knowledge and schools as the most effective place for teaching/or educating nutritional subjects. Conclusion: The study results suggest that children need to learn more about nutrition and foods. Designing longitudinal nutrition education projects aiming at children through TV or other effective media arc essential

Effect of cement, Ground Granulated Blast Furnace Slag (GGBS), GGBS:magnesia (MgO) and GGBS:MgO:cement were studied as agents on stabilisation of a clay soil contaminated with glycerol solution. The contaminated soil was mixed with 5, 10 and 15% of the above agents. Atterberg limits and compaction tests were conducted on these mixtures. Additionally, strength and durability tests were performed on prepared samples at different curing times. The strength of soil contaminated with 4, 8, and 12% glycerol was reduced by 23.5, 30.1, and 36.5%, respectively, compared to the natural soil. By adding 5% cement to the soil contaminated with 4% glycerol, its strength after 7, 14, and 28 days of curing time was increased to 1581, 1984.5, and 2343.4 kPa, respectively. All the selected agents increased the strength of the contaminated soil and its increase was dependent on the percentage of the agent and curing time. It was revealed that GGBS:MgO:cement was more effective in increasing the strength than the other used agents. Durability tests also showed that the weight loss of the samples at different conditions was less than 10%. SEM results showed that the increase in strength of the soil results from the interaction between soil and agent. [ABSTRACT FROM AUTHOR]

A study was conducted on the effects of temperature and salt concentration of pore fluid on the properties of an expansive soil during drying and wetting cycles. The experimental tests were performed on modified and conventional odometers at constant and variable temperatures under 10 kPa surcharge pressure. Distilled water and solutions of sodium chloride and calcium chloride with concentration of 250 g/litre were used for making samples and distilled water was used for inundating samples during the wetting stage. The results showed that the swelling potential is decreased with increasing the number of cycles for both constant and variable temperature conditions. It was revealed that the potential of swelling is a function of salt concentration of pore fluid of the sample and the effect of temperature on the potential of shrinkage and swelling is negligible. The variation of void ratio with water content is dependent on the salt concentration of pore fluid and the position of void ratio-water content curve is a function of temperature. The results of scanning electron microscopy (SEM) tests showed that the structure of soil is changed during drying and wetting cycles which results in the reduction of potential of shrinkage and swelling. [ABSTRACT FROM AUTHOR]

In this article, the generalized total time on test transform and some related transforms for weighted variables are stated. Their characteristics and relationship with each other have been considered and also these transforms have been investigated in the weighted mode from the point of view of stochastic orders. Also, by presenting graphs of generalized total time on test transform for some common weight functions, its behavior with respect to the weighted function is studied. Then the relationship of this transform with its initial state is expressed. In the following, the topic under discussion is explained with some practical examples. Then providing a comprehensive exploration of the applications of the studied transforms within the domains of insurance and reliability. By delving into these practical contexts, we gain valuable insights into how these mathematical tools can be effectively utilized to address complex challenges in risk assessment, decision-making, and resource allocation. Additionally, the examination of the NBU class of distributions offers a deeper understanding of their behavior, shedding light on their relevance and applicability in various statistical analyses. Finally, the article concludes with a detailed discussion of a specific real dataset, offering a concrete demonstration of how the topic under study can be applied in practice. [ABSTRACT FROM AUTHOR]

In recent decades, various pollutants have been released into the environment in substantial amounts due to human activities. Oil pollution is one of these pollutants and can be harmful to both humans and the environment, making its detection and cleanup highly important. Considering the applicability of the electronic nose methods in various domains, including the food industry, environment, etc, this research aims to measure the feasibility of using electronic nose technology to detect soil contaminated with crude oil. An electronic nose system with eight metal oxide semiconductor sensors was used in this research. The soil used in this research was from one of the farms surrounding Karaj province, which, in the laboratory of the University of Tehran, was contaminated with crude oil at four concentrations: 200 ppm, 500 ppm, 1000 ppm, and 5000 ppm, and then the samples evaluated. This system was examined along with pattern recognition methods such as principal component analysis (PCA), linear discriminant analysis (LDA), and support vector machine (SVM). The results from the pattern recognition methods showed an accuracy of 92% for principal component analysis, 100% for linear discriminant analysis, and 100% for the support vector machine method. Moreover, by employing statistical data analysis using a factorial experiment method within a randomized block design and using decision tree regression, support vector regression, gradient boosted regression, and random forest regression, which has the pollutant detection rate with an average accuracy of 95.5% for the MQ3 sensor, showed the best performance, and detect the difference between the contaminated concentrations. In conclusion, by comparing the results of selected electronic nose sensors with the results obtained by the gas chromatography system on the soil contaminated with crude oil, they have had an acceptable sensitivity. [ABSTRACT FROM AUTHOR]

In recent years, magnesium oxide (MgO) has been considered by researchers as a new agent for the remediation of contaminated soils. In this paper, the effect of MgO and hydrated lime on the remediation of a clay soil contaminated with MTBE (Methyl Butyl Ether) was studied. The contaminated soil was made artificially by adding 2.25 g MTBE per kg of soil. MgO with different percentages (0.125, 0.25, 0.5, 5, 10, and 20%) and lime with 2.5, 5, and 10% percentages were added to the natural and contaminated soil. The results showed that by increasing the percentage of MgO or lime and curing time, the strength of natural and contaminated soil was improved. The results of the leaching tests showed that by adding 5, 10, or 20% MgO, all the existing MTBE in the soil samples were removed while for the smaller percentages of MgO (0.125, 0.25, and 0.5%) there was a decrease in the concentration of MTBE with time. The results of the leaching tests also revealed that the hydrated lime was effective in reducing the concentration of MTBE. The amount of reduction in the concentration of MTBE was dependent on the percentage of MgO or hydrated lime. The comparison of the results of the two binders showed that MgO was more effective than the hydrated lime in removing the MTBE from the soil. [ABSTRACT FROM AUTHOR]