119 research outputs found

    The influence of game addiction on human’s behavior

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    This paper studies game addiction. The positive and negative influence of videogames on human behavior and game addiction are considered. The consequences of this influence are presented

    Comparison of the diagnostic efficiency of various noninvasive methods for diagnosing liver fibrosis in patients with chronic viral hepatitis C

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    Summary: the article presents the results of the examination of patients with chronic viral hepatitis C namely the study of the informativeness of instrumental (fibroelastography) and serological (the content of hyaluronic acid in serum) of markers of fibrosis by assessing their predictive value by ROC- analysis. The purpose of the study: to find out the possibility of non-invasive methods for diagnosing liver fibrosis in patients with chronic viral hepatitis C (CHC). Materials and methods 66 patients with CHC with the 1-st genotype of the virus were examined, which were at the dispensary observation and ambulatory treatment at DCC CCH №1 in Vinnitsa and in the clinical department of viral hepatitis at the Institute of Epidemiology and Infectious Diseases named after L.V. Gromashevsky NAMS of Ukraine. All patients received fibroelastography (FEG) with a METAVIR score. All patients with CHC and group of control determined the content of hyaluronic acid (GA) in blood serum (ELISA using the Hyaluronic Acid (Corgenix, Inc., USA)). Research results Sensitivity of determination of GA in blood serum of patients with CHC with degree of fibrosis of liver F0-F2 was 91.23%, and specificity - 90.46%. For the FEG method, respectively: 74.33% and 77.25%. In the group of patients with degree of fibrosis F3 sensitivity of the definition of GA in blood serum was 72.21%, and specificity - 74.71%. The corresponding qualitative characteristics for FEG were: 98.32% and 91.45% respectively. The sensitivity of the determination of the content of GA in serum of patients with CHC with the degree of liver fibrosis F4 was 88.23%, and the specificity was 92.12%. For these patients the sensitivity and specificity of determining the degree of fibrosis by the FEG method were 87.78% and 91.45% respectively. Conclusions High diagnostic efficiency of determination of the content of GA in serum was established for assessing the degree of liver fibrosis in patients with CSF (AUC = 0,720-0,917, p˂0,01). Relatively higher sensitivity and specificity of the diagnosis of liver fibrosis was observed in determining the content of GA in serum compared with the FEG method (AUC = 0.914 vs. AUC = 0.817 (p˂0.05)) in the group with a lack or initial signs of liver fibrosis (F0-F2)

    The effect of phytohormones and light on the germination of apple pollen with reduced viability

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    Background. Studying the effect of phytohormones and light on the germination of apple pollen with reduced viability on an artificial nutrient medium is of importance, because it may facilitate an increase in the germination percentage among plant samples promising for breeding after their long-term preservation under low temperatures.Materials and methods. Pollen viability of the apple-tree cultivar ‘Krasnolistnaya’ was measured by germinating it on an artificial nutrient medium containing 10% sucrose solution and 0.8% agar. Drops of a distilled water suspension of pollen with added phytohormones were applied to the surface of the nutrient medium. Pollen was germinated in the dark (24 hours in a thermostat at 21°C) and under light (in an artificial light chamber at 21°C with a photoperiod of 16 hours of light / 8 hours of darkness). Results. Pollen of cv. ‘Krasnolistnaya’ with reduced viability most effectively germinated with the use of gibberellin at a concentration of 1 mg/l and 10 mg/l: the germination percentage was 22.3±0.8% and 21.8±1.3% respectively (сf. 10.9±1.5% in the reference). The most effective combination of phytohormones was gibberellin 10 mg/l + kinetin 10 mg/l – the percentage of germination was 22.8±6.3%; kinetin 1 mg/l + indolylbutyric acid 1 mg/l – the percentage of germination was 17.5±5.9% vs. 10.9±1.5% in the reference.Conclusion. Phytohormones were observed to have a significant effect on the germination of apple pollen with reduced viability. Effective concentrations and combinations of phytohormones that promote the germination of pollen with reduced viability have been identified. Light does not affect the germination of pollen with reduced viability

    Ємнісний негасенсор з частотним виходом

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    Досліджено схему ємнісного негасенсора з частотним виходом на RC-автогенераторі. Показано, що наявність від’ємної ємності С-негатрона приводить до підвищення чутливості сенсора в 2...5 разів, а наявність від’ємного активного опору С-негатрона забезпечує автогенераторний режим, що спрощує схемотехнічну реалізацію. Розроблено матрицю ємнісних негасенсорів, що має розширенні функціональні можливості.Исследовано схему емкостного негасенсора с частотным выходом на RC-автогенераторе. Показано, что наличие отрицательной емкости С-негатрона приводит к повышению чувствительности сенсора в 2 ... 5 раз, а наличие отрицательного активного сопротивления С-негатрона обеспечивает автогенераторный режим, упрощает схемотехническую реализацию. Разработана матрица емкостных негасенсоров, которая имеет расширенные функциональные возможности.Circuit of capacitance negasensor with frequency output on the RC-oscillator was researched. It is shown that the existence of negative capacitance of C-negatron causes increasing of the sensitivity of the sensor in 2 ... 5 times, and the presence of negative resistance of C-negatron provides autogenerating mode and simplifies circuit design implementation. Matrix of capacitive negasensors with enhanced functionality was developed

    A Study of Ta2O5 Nanopillars with Ni Tips Prepared by Porous Anodic Alumina Through-Mask Anodization

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    The paper discusses the formation of Ta2O5 pillars with Ni tips during thin porous anodic alumina through-mask anodization on Si/SiO2 substrates. The tantalum nanopillars were formed through porous masks in electrolytes of phosphoric and oxalic acid. The Ni tips on the Ta2O5 pillars were formed via vacuum evaporation through the porous mask. The morphology, structure, and magnetic properties at 4.2 and 300 K of the Ta2O5 nanopillars with Ni tips have been studied using scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry. The main mechanism of the formation of the Ta2O5 pillars during through-mask anodization was revealed. The superparamagnetic behavior of the magnetic hysteresis loop of the Ta2O5 nanopillars with Ni tips was observed. Such nanostructures can be used to develop novel functional nanomaterials for magnetic, electronic, biomedical, and optical nano-scale devices

    Isostatic Hot Pressed W–Cu Composites with Nanosized Grain Boundaries: Microstructure, Structure and Radiation Shielding Efficiency against Gamma Rays

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    Abstract: The W–Cu composites with nanosized grain boundaries and high effective density were fabricated using a new fast isostatic hot pressing method. A significantly faster method was proposed for the formation of W–Cu composites in comparison to the traditional ones. The influence of both the high temperature and pressure conditions on the microstructure, structure, chemical composition, and density values were observed. It has been shown that W–Cu samples have a polycrystalline well-packed microstructure. The copper performs the function of a matrix that surrounds the tungsten grains. The W–Cu composites have mixed bcc-W (sp. gr. Im 3 m) and fcc-Cu (sp. gr. Fm 3 m) phases. The W crystallite sizes vary from 107 to 175 nm depending on the sintering conditions. The optimal sintering regimes of the W–Cu composites with the highest density value of 16.37 g/cm3 were determined. Tungsten–copper composites with thicknesses of 0.06–0.27 cm have been fabricated for the radiation protection efficiency investigation against gamma rays. It has been shown that W–Cu samples have a high shielding efficiency from gamma radiation in the 0.276–1.25 MeV range of energies, which makes them excellent candidates as materials for radiation protection. © 2022 by the authorsLicensee MDPI, Basel, Switzerland.Ministry of Education and Science of the Russian Federation, Minobrnauka: 075-15-2020-926Funding: M.V.S. acknowledges financial support from the Ministry of Science and Higher Education of the Russian Federation within the framework of state support for the creation and development of World-Class Research Centers “Digital Biodesign and Personalized Healthcare” No. 075-15-2020-926

    Композиционные материалы системы эпоксидная смола–W для радиационной защиты от гамма-излучения

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    Сomposite materials based on the epoxy resin–W system with varying W content (0–80 %) were obtained using the method of chemical curing. Microstructural investigations of the samples showed that with increasing W content there is a more uniform distribution of grains in the epoxy resin matrix could be observed. Agglomeration of W grains is noted for samples with filler content up to 40 %. Statistical analysis of the grain size of the initial W powder revealed that the probable diameter of W grains is 475 nm. The values of effective and relative densities of the experimental samples were obtained using the Archimedes method. The effective density varied from 1.16 to 4.36 g/cm3 with W powder content rising. The relative density values received ranged from 91 to 94 %, indica ting that there were no significant defects in the samples. X-ray diffraction analysis showed the presence of vcc-W and WO2 phases, indicating the oxidation of W in the thin surface layer of the powder. Calculation in Phy-X/PSD software allowed to evaluate the gamma radiation shielding efficiency for the epoxy resin–W system composite materials in 0.8–2.5 MeV energy range. It was observed that samples with filler content of 60 and 80 % were the most suitable for radiation shielding. It was found that the addition of W powder to the epoxy matrix contributed to the reduction of half attenuation layer values by 3.5 times from 9.448 to 2.672 cm for samples with 0 and 80 % W content, respectively, for 1.25 MeV radiation energy. The obtained results demonstrate the high efficiency of the proposed composite materials for shielding gamma radiation, which makes them a perspective candidate for manufacturing radiation shields.С использованием метода химического отверждения получены композиционные материалы на основе системы эпоксидная смола–W с варьированием содержания W от 0 до 80 %. Проведенное исследование микроструктуры образцов показало, что при увеличении содержания W наблюдается более равномерное распределение зерен в матрице эпоксидной смолы. Для образцов с содержанием наполнителя до 40 % отмечена агломерация зерен W. Статистический анализ размеров зерен исходного порошка W выявил, что вероятный их диаметр составляет 475 нм. Получены значения эффективной и относительной плотностей экспериментальных образцов с помощью метода Архимеда. Эффективная плотность изменялась в пределах от 1,16 до 4,36 г/см3 с увеличением содержания порошка W. Значения относительной плотности варьировались от 91 до 94 %, что свидетельствовало об отсутствии существенных дефектов при проведении испытания. Рентгеноструктурный анализ показал наличие фаз ОЦК-W и WO2, что указывает на окисление W в тонком поверхностном слое материала. Моделирование в программном обеспечении Phy-X/PSD позволило оценить эффективность экранирования от гамма-излучения композиционных материалов при энергии излучения в диапазоне 0,8–2,5 МэВ. Образцы с содержанием наполнителя 60 и 80 % оказались наиболее подходящими для создания экранов радиационной защиты. Обнаружено, что добавление порошка W в эпоксидную матрицу способствовало уменьшению значений слоя половинного ослабления в 3,5 раза с 9,448 до 2,672 см для образцов с содержанием W 0 и 80 % соответственно при энергии излучения гамма-квантов 1,25 МэВ. Полученные результаты демонстрируют высокую эффективность предложенных композиционных материалов в экранировании гамма-излучения, что делает их достойным вариантом для создания экранов радиационной защиты

    An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

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    For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
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