Adaptive Mesh Refinement for Electromagnetic Simulation

We consider problems related to initial meshing and adaptive mesh refinement for the electromagnetic simulation of various structures. The quality of the initial mesh and the performance of the adaptive refinement are of great importance for the finite element solution of the Maxwell equations, since they directly affect the accuracy and the computational time. In this paper, we describe the complete meshing workflow, which allows the simulation of arbitrary structures. Test simulations confirm that the presented approach allows to reach the quality of the industrial simulation software

An evaluation for the standardization of the Allium cepa test as cytotoxicity and genotoxicity assay

A general report on the use of the Allium test as cytotoxicological and genotoxicological assay is proposed, with particular emphasis about the standardization of the test in several common applications. The intraspecific variation in Allium cepa has been overlooked, as in most investigations no mention is made about origin and denomination of the onion cultivar used. A standardization of the used material would allow a better generalization of the results, since we cannot be sure that all cultivars would give the same response. A more frequent use of transmission electron microscopy (TEM) investigation is proposed. Even if relatively time consuming and not available in all laboratories, it may help to better understand the mechanism of cytotoxicity, since many morphological characters may appear similar but be arisen from different processes observable only with TEM. About statistical testing, tests other than chi-squared may be used in case of a lower amount of data. The most commonly used statistical tests are the parametric tests ANOVA and Student’s t, and the nonparametric tests Kruskal–Wallis and Mann–Whitney U, for analysis of variance. Tests should be used also to assess the minimal sample dimension for obtaining significance, since data collection (microscope observation) appears to be one of the main bottle necks of the test. Also the use of the Allium test for testing liposomes and other nanovectors for drug delivery is proposed, in order to assess the cytotoxicity of these types of medium and the possible increase in cytotoxicity of the associated drug

Интраоперационный контроль криодеструкции глиальных опухолей головного мозга

Purpose: to determine the most useful quantitative parameter of diffusion-weighted images (DWI) in the differential diagnosis of focal liver lesions. Aim: To develop and assess the technique of intraoperative sonography during cryoablation of neuroepithelial brain tumors. Materials and methods. 27 patients with brain tumors of glial cells underwent cryosurgery under control of intraoperative sonography (IS). Cryotherapy was performed using a new cryosurgical apparatus. The tumors had both superficial and deep localization in functionally important areas of the brain, the size ranged from 4.4 to 240.5 cm3 (mean 40.1 cm3). Results. Cryotherapy and intraoperative sonography were performed through a single burr hole in 20 cases, through two burr holes - in 7. Through one burr hole accurate tumor volume measurement is possible only up to 23 cm3, with larger volumes measurement error significantly increases. Two burr hole technique helps to improve the accuracy up to 80 cm3. IS allows us to control the positioning and immersion depth of the cryoprobe. The analysis showed that the intraoperative values corresponded to the calculated values obtained from the preoperative planning. It should be noted that thanks to the possibility to intraoperatively monitor the formation and size of the iceball, for the group of total cryo-therapy, the area subjected to cryogenic treatment slightly exceeded the tumor volume (by an average of 2.7 cm3) in all cases after surgery. Conclusion. IS during brain tumor cryoablation increases the accuracy of cryogenic instrument positioning, allows us to visualize the iceball in real time, confidently perform several cycles of cryotherapy, reliably monitor all stages of cryosurgery.Цель исследования: разработать и оценить возможности методики интраоперационной сонографии при криодеструкции нейроэпителиальных опухолей головного мозга. Материал и методы. Произведены операции 27 пациентам с опухолями головного мозга глиального ряда: была выполнена криодеструкция под контролем интраоперационной сонографии (ИС). Криовоздействие проводили новым криохирургическим аппаратом АКХА-3. Опухоли имели поверхностную и глубинную локализацию в функционально значимых зонах мозга, размер составлял от 4,4 до 240,5 см3 (в среднем 40,1 см3). Результаты. Криодеструкцию и ИС проводили через одно фрезевое отверстие в 20 наблюдениях, через 2 фрезевых отверстия - в 7. Через одно фрезевое отверстие точно измерять объем опухоли возможно до 23 см3, при большем объеме значительно нарастает ошибка в измерениях. Методика двух фрезевых отверстий позволяет повысить точность до 80 см3. ИС помогает контролировать позиционирование и глубину погружения криозонда. Как показал анализ, интраоперационные значения соответствовали расчетным показателям, полученным на этапе предоперационного планирования. Следует отметить, что благодаря возможности интраоперационного контроля процесса формирования ледяного шара и его размера в группе с полной криодеструкцией зона, подвергнутая криовоздействию, после операции во всех наблюдениях незначительно превышала объем опухоли (в среднем на 2,7 см3). Выводы. ИС при криодеструкции опухолей головного мозга увеличивает точность позиционирования криоинструмента, позволяет визуализировать ледяной шар в режиме реального времени и уверенно проводить несколько циклов криовоздействия, надежно контролировать все этапы криодеструкции

Data on synthesis of 6 new derivatives of pyrido[1,2-a]benzimidazoles with potential anticancer activity and data on its genotoxic effects

We describing protocol for synthesis of 6 new derivatives of pyrido[1,2-a]benzimidazoles, which have a wide spectrum of biological activity and are of interest as candidates for new drugs. Assessment of potential genotoxic effects of this derivatives is of great importance for creation of new drugs.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Allium test genotoxicity data on water from river valley of Irtysh, West Siberia

Provided genotoxicity data for the Irtysh river valey (West Siberia). To assess genotoxic effects used Allium test. Ana-telophase chromosomal aberration assay and micronuclei test we performed to determine genotoxic effects. Obtained data for mitotic index and other phase indexes. The data allow other researchers to conduct a comprehensive analysis of the genotoxicity of natural waters on the landscape gradient of a river valley (terrace-floodplain-river) and an analysis of the possible causes of the observed effects.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Experimental study of mutagenous and mitosis modifying activity of silver nanoparticles

Mutagenous and mitosis modifying impact of silver nanoparticles has been studied on outbred mice. Nanoparticles were of round shape with dimensions of 5-50 nm, size of generated organic shell of 2-5 nm, the quantity in 1 mcm3 makes 120-270. Metaphasic analysis of mice bone marrow cells was used as a testing technique. The frequency of chromosome aberrations and mitotic index of preparations were accounted. During single intraperitoneal administration of the agent in the dose of 250 mcg/kg the silver nanoparticles demonstrated mitosis stimulating activity. No mutagenous effect of silver nanoparticles by daily administration for 4 days of 25 mcg/kg and single administration in the dose of 250 mcg/kg has been registered, but there is statistically insignificant tendency of aberrant metaphases increase. Consequently silver nanoparticles in the investigated doses demonstrated no mutagenous activity and can be considered safe for mammalian cells

Genotoxicity of Natural Water during the Mass Development of Cyanobacteria Evaluated by the Allium Test Method: A Model Experiment with Microcosms

Cyanobacteria, which develop abundantly in aquatic ecosystems, can be harmful to humans and animals not only by releasing toxins that cause poisoning but also by provoking cytogenetic effects. The influence of the mass development of cyanobacteria on the genotoxic properties of natural water has been studied in model ecosystems (microcosms) with different compositions of biotic components (zooplankton, amphipods and fish). The validated plant test system “Allium test” was used in this study. Genotoxic effects were detected at microcystin concentrations below those established by the World Health Organization (WHO) for drinking water. In all experimental treatments, cells with disorders such as polyploidy and mitotic abnormalities associated with damage to the mitotic spindle, including c-mitosis, as well as lagging chromosomes were found. Genotoxic effects were associated with the abundance of cyanobacteria, which, in turn, depended on the composition of aquatic organisms in the experimental ecosystem. Fish, to a greater extent than other aquatic animals, maintain an abundance of cyanobacteria. After one month, in microcosms with fish, mitotic abnormalities and polyploidy continued to be detected, whereas in other treatments, there were no statistically significant genotoxic effects. In microcosms with amphipods, the number and biomass of cyanobacteria decreased to the greatest extent, and only one parameter of genotoxic activity (frequency of polyploidy) significantly differed from the control