An Ising model on a 3D honeycomb zigzag-ladder lattice : a solution to the ground-state problem

A complex, seven-parameter ground-state problem for an Ising model on a 3D honeycomb zigzag-ladder lattice, containing two types of magnetic sites, is considered in the presence of an external field using the method of basic rays and basic sets of cluster configurations. It is shown that the geometrical frustration due to the presence of triangle elements leads to the emergence of a large variety of magnetic phases, the majority of which are highly degenerate. The obtained theoretical results are used to elucidate the sequence of phase transitions in the family of rare-earth oxides with a honeycomb zigzag-ladder lattice. New phases predicted by our model and observed experimentally do not appear in previously considered simpler models for noninteracting zigzag-ladders

Tuberculosis-HIV Co-infection in Kiev City, Ukraine

In 2004, we tested all patients with newly diagnosed tuberculosis (TB) for HIV in Kiev City. The results were compared to information from medical records of 2002, when co-infection prevalence was 6.3%. Of 968 TB patients, 98 (10.1%) were HIV infected. TB-HIV co-infection is increasing, especially in injecting drug users

Chronicles of nature calendar, a long-term and large-scale multitaxon database on phenology

We present an extensive, large-scale, long-term and multitaxon database on phenological and climatic variation, involving 506,186 observation dates acquired in 471 localities in Russian Federation, Ukraine, Uzbekistan, Belarus and Kyrgyzstan. The data cover the period 1890-2018, with 96% of the data being from 1960 onwards. The database is rich in plants, birds and climatic events, but also includes insects, amphibians, reptiles and fungi. The database includes multiple events per species, such as the onset days of leaf unfolding and leaf fall for plants, and the days for first spring and last autumn occurrences for birds. The data were acquired using standardized methods by permanent staff of national parks and nature reserves (87% of the data) and members of a phenological observation network (13% of the data). The database is valuable for exploring how species respond in their phenology to climate change. Large-scale analyses of spatial variation in phenological response can help to better predict the consequences of species and community responses to climate change.Peer reviewe

Analysis of the Weak Soil Behavior, Modified Through Cementation

The purpose of the study is to conduct thorough theoretical research and literature overview regarding possible ways of soil stabilization on the basis of this practice increasing demand. In particular an emphasis is made on the chemical technique for weak soils strengthening, due to its prevalence and various practical and economic advantages. Great amount of promiscuous data was analyzed and organized; in addition on its basis an attempt is made to provide convincing calculation technique for further usage in engineering soils` stabilization practice. Besides, various factors which could influence on the results` accuracy are identified with corresponding recommendations for further possible research on this issue

Influence of information communicative technologies on students’ sport-oriented physical education interest

Purpose: determination the influence of information communicative technologies on students’ interest in regular exercise of sport-oriented physical education. Material and Methods: in the researches were involved 1–5 year basic department students of V. N Karazin Kharkov National University (n=36402). Methods: analysis of literature sources, formatted pedagogical experiment, sociological research, maths statistics. Results: through experimental research we found out that that usage of information communicative technologies in authors’ model of sport-oriented physical education in high schools had provided increase in amount of students, who engaged in chosen sports (moving activity), by 14,4% (1463 persons). Conclusion: the usage of information communicative technologies in educational process promoted increasing of student quantity in the sport-oriented group

Вдосконалення тренувального процесу юних тенісистів та баскетболістів 10-14 років з урахуванням часу простої та складної реакції

Purpose: perfection of process of preparation of young tennis players and basketball-players 10-14 years taking into account time of simple and difficult reaction. Material and methods : theoretical analysis and generalization of literary sources; pedagogical supervision; pedagogical experiment; психофизиологическое testing; methods of mathematical statistics. Young tennis players (n=30) and basketball-players (n=27) took part in research. Results: Conducted factor analysis of structure of development of сенсомоторних functions of young sportsmen which engage in the playing types of sport and the models of development of сенсомоторних reactions and quickness are built. Conclusions: the factor of sporting specialization of basketball-players and tennis players has an influence on development of difficult сенсомоторної reaction with a choice or without a choice; conducted analysis of indexes of time the outage of сенсомоторної reaction and теппинг-теста testifies to their dependence on age of sportsman. Finding can be used for a selection on corresponding sporting specializations.Цель: совершенствование процесса подготовки юных теннисистов и баскетболистов 10-14 лет с учетом времени простой и сложной реакции. Материал и методы: теоретический анализ и обобщение литературных источников; педагогическое наблюдение; педагогический эксперимент; психофизиологическое тестирование; методы математической статистики. В исследовании принимали участие юные теннисисты (n=30) и баскетболисты (n=27). Результаты: Проведены факторный анализ структуры развития сенсомоторних функций юных спортсменов, которые занимаются игровыми видами спорта и построены модели развития сенсомоторних реакций и быстроты. Выводы: фактор спортивной специализации баскетболистов и теннисистов имеет влияние на развитие сложной сенсомоторной реакции с выбором или без выбора; проведенный анализ показателей времени простой сенсомоторной реакции и теппинг-теста свидетельствует об их зависимости от возраста спортсмена. Полученные данные могут быть использованы при отборе на соответствующие спортивные специализации.Мета: вдосконалення процесу підготовки юних тенісистів та баскетболістів 10–14 років з урахуванням часу простої та складної реакції. Матеріал і методи: теоретичний аналіз та узагальнення літературних джерел; педагогічне спостереження; педагогічний експеримент; психофізіологічне тестування; методи математичної статистики. У дослідженні приймали участь юні тенісисти (n=30) та баскетболісти (n=27). Результати: Проведено факторний аналіз структури розвитку сенсомоторних функцій юних спортсменів, що займаються ігровими видами спорту та побудовано моделі розвитку сенсомоторних реакцій та бистроти. Висновки: фактор спортивної спеціалізації баскетболістів та тенісистів має вплив на розвиток складної сенсомоторної реакції з вибором або без вибору; проведений аналіз показників часу простої сенсомоторної реакції та теппінг-тесту свідчить про їх залежність від віку спортсмена. Отримані дані можуть бути використані при відборі на відповідні спортивні спеціалізації

Clinically Relevant Solution for the Hypothermic Storage and Transportation of Human Multipotent Mesenchymal Stromal Cells

The wide use of human multipotent mesenchymal stromal cells (MSCs) in clinical trials requires a full-scale safety and identity evaluation of the cellular product and subsequent transportation between research/medical centres. This necessitates the prolonged hypothermic storage of cells prior to application. The development of new, nontoxic, and efficient media, providing high viability and well-preserved therapeutic properties of MSCs during hypothermic storage, is highly relevant for a successful clinical outcome. In this study, a simple and effective trehalose-based solution was developed for the hypothermic storage of human bone marrow MSC suspensions for further clinical applications. Human bone marrow MSCs were stored at 4°C for 24, 48, and 72 hrs in the developed buffered trehalose solution and compared to several research and clinical grade media: Plasma-Lyte® 148, HypoThermosol® FRS, and Ringer’s solution. After the storage, the preservation of viability, identity, and therapeutically associated properties of MSCs were assessed. The hypothermic storage of MSCs in the new buffered trehalose solution provided significantly higher MSC recovery rates and ability of cells for attachment and further proliferation, compared to Plasma-Lyte® 148 and Ringer’s solution, and was comparable to research-grade HypoThermosol® FRS. There were no differences in the immunophenotype, osteogenic, and adipogenic differentiation and the immunomodulatory properties of MSCs after 72 hrs of cold storage in these solutions. The obtained results together with the confirmed therapeutic properties of trehalose previously described provide sufficient evidence that the developed trehalose medium can be applied as a low-cost and efficient solution for the hypothermic storage of MSC suspensions, with a high potential for translation into clinical practice

Mechanical Regulation of Mitochondrial Dynamics and Function in a 3D-Engineered Liver Tumor Microenvironment

It has become evident that physical stimuli of the cellular microenvironment transmit mechanical cues regulating key cellular functions, such as proliferation, migration, and malignant transformation. Accumulating evidence suggests that tumor cells face variable mechanical stimuli that may induce metabolic rewiring of tumor cells. However, the knowledge of how tumor cells adapt metabolism to external mechanical cues is still limited. We therefore designed soft 3D collagen scaffolds mimicking a pathological mechanical environment to decipher how liver tumor cells would adapt their metabolic activity to physical stimuli of the cellular microenvironment. Here, we report that the soft 3D microenvironment upregulates the glycolysis of HepG2 and Alexander cells. Both cell lines adapt their mitochondrial activity and function under growth in the soft 3D microenvironment. Cells grown in the soft 3D microenvironment exhibit marked mitochondrial depolarization, downregulation of mitochondrially encoded cytochrome c oxidase I, and slow proliferation rate in comparison with stiff monolayer cultures. Our data reveal the coupling of liver tumor glycolysis to mechanical cues. It is proposed here that soft 3D collagen scaffolds can serve as a useful model for future studies of mechanically regulated cellular functions of various liver (potentially other tissues as well) tumor cells

Mechanical Regulation of Mitochondrial Dynamics and Function in a 3D-Engineered Liver Tumor Microenvironment

It has become evident that physical stimuli of the cellular microenvironment transmit mechanical cues regulating key cellular functions, such as proliferation, migration, and malignant transformation. Accumulating evidence suggests that tumor cells face variable mechanical stimuli that may induce metabolic rewiring of tumor cells. However, the knowledge of how tumor cells adapt metabolism to external mechanical cues is still limited. We therefore designed soft 3D collagen scaffolds mimicking a pathological mechanical environment to decipher how liver tumor cells would adapt their metabolic activity to physical stimuli of the cellular microenvironment. Here, we report that the soft 3D microenvironment upregulates the glycolysis of HepG2 and Alexander cells. Both cell lines adapt their mitochondrial activity and function under growth in the soft 3D microenvironment. Cells grown in the soft 3D microenvironment exhibit marked mitochondrial depolarization, downregulation of mitochondrially encoded cytochrome c oxidase I, and slow proliferation rate in comparison with stiff monolayer cultures. Our data reveal the coupling of liver tumor glycolysis to mechanical cues. It is proposed here that soft 3D collagen scaffolds can serve as a useful model for future studies of mechanically regulated cellular functions of various liver (potentially other tissues as well) tumor cells