170 research outputs found
The effect of surface charge on nonspecific uptake and cytotoxicity of CdSe/ZnS core/shell quantum dots
No full textIn this work, cytotoxicity and cellular impedance response was compared for CdSe/ZnS core/shell quantum dots (QDs) with positively charged cysteamine–QDs, negatively charged dihydrolipoic acid–QDs and zwitterionic D-penicillamine–QDs exposed to canine kidney MDCKII cells. Pretreatment of cells with pharmacological inhibitors suggested that the uptake of nanoparticles was largely due to receptor-independent pathways or spontaneous entry for carboxylated and zwitterionic QDs, while for amine-functionalized particles involvement of cholesterol-enriched membrane domains is conceivable. Cysteamine–QDs were found to be the least cytotoxic, while D-penicillamine–QDs reduced the mitochondrial activity of MDCKII by 20–25%. Although the cell vitality appeared unaffected (assessed from the changes in mitochondrial activity using a classical MTS assay after 24 h of exposure), the binding of QDs to the cellular interior and their movement across cytoskeletal filaments (captured and characterized by single-particle tracking), was shown to compromise the integrity of the cytoskeletal and plasma membrane dynamics, as evidenced by electric cell–substrate impedance sensing
Emotional Intelligence as a Personal Resource of Professional Becoming of Specialists of Socionomic Professions
No full textThe article presents the theoretical analysis of the problem of emotional intelligence as a personal resource of professional becoming of specialists of socionomic professions. The author\u27s structural-functional model of emotional intelligence is presented. It shows the levels of functioning, functional characteristics, emotional competencies and substantial characteristics of emotional intelligence. The influence of emotional competences on professional activities of specialists of socionomic professions is analyzed. Such emotional competences are described: the ability to understand own emotions and emotions of others, the ability to demonstrate emotional attitude to situations and other people adequately; the productive interaction and psychological flexibility in relations with others
Peculiarities of the solar wind interaction with the upper atmospheres of Venus and Mars
No full textMediciones de plasma y de campos magnéticos en Venus y Marte así como observaciones de radio ocultamiento de satélites por sus atmósferas y ionosferas superiores revelan algunas diferencias y semejanzas en la configuración del flujo del viento solar alrededor de estos planetas. Ambos planetas tienen campos magnéticos muy débiles comparados con el de la Tierra y sus ionosferas están caracterizadas por un máximo de densidad electrónica similar. Sin embargo, la ionosfera Marciana está más protegida de la acción directa del viento solar que la de Venus y algunas propiedades de la ionosfera superior Marciana se asemejan a las de la ionosfera superior de la Tierra. Se concluye que la ionosfera de Venus y el campo magnético inducido (el campo magnético del viento solar acumulado alrededor de la ionosfera del planeta) son elementos decisivos para la formación del obstáculo efectivo en Venus. En Marte, el campo magnético intrínseco domina y juega un papel importante en la formación del obstáculo y en la desaceleración del viento solar.
doi: https://doi.org/10.22201/igeof.00167169p.1980.19.1.82
Assessment of the Effect of Biological Growth-Regulating Preparations on the Yield of Agricultural Crops under the Conditions of Steppe Zone
No full textIncreasing the production of high-quality agricultural products with minimal negative impact on environmental components is one of the priority tasks of modern agriculture. Due to the global world trends aimed at ensuring a sustainable and safe economy and reducing the use of chemical protection agents, it is predicted that the share of alternative biological methods in the European agricultural sector will increase to 10%, the area of agricultural land for organic farming will increase by 50%. Under the conditions of intensification of agricultural production, a comprehensive approach to the use of microelements and microbial biological preparations, which enhance growth processes, anti-stress, protective effect and increase the yield of agricultural crops, becomes expedient. The article deals with the effects of biological growth-regulating preparations on winter wheat, sunflower hybrids, and vegetable peas. It was established that when processing winter wheat with the “Grainactive-C” preparation, the greatest increase in grain yield was observed under the conditions of 3-fold treatment of crops in the phase of tillering, flag leaf, and grain filling (3.2 t/ha, or 18%). At the same time, the greatest effect was recorded when treating crops in the tillering phase, where the yield increase was 2.9 c/ha, or +16% compared to the control. It has been studied that the effectiveness of the preparation “Nano-Agro” when applied to sunflower hybrids also depends on the time of its application. The same increase – 0.9 t/ha of seeds (+12% compared to the control) was observed during pre-sowing treatment of seeds and during the vegetation phase (before flowering), but the yield increase when treating sunflower after flowering phase was only 0.32 t/ha (4%). In order to restore disturbed soils and increase the efficiency of agricultural production, the introduction of leguminous crops into the crop rotation becomes important, after harvesting them up to 80 kg/ha of biological nitrogen remains and humus accumulates in the arable layer of the soil up to 10.8 t/ha. Treatment of vegetable peas seeds with Rhizohumin contributed to the accumulation of humus by 3.96 t/ha. Through field studies, the article proves the positive effect of growth-regulating preparations on agricultural crops under the conditions of the Steppe zone of Ukraine
Description of organic compound vapor-phase sorption by geosorbents: Adequacy of the isotherm approximation
No full textThe approximation of isotherms of vapor-phase sorption of organic compounds (OC) is a long-standing problem. It is especially difficult to solve in case of natural heterogeneous sorbents (soils, sediments, aquifers, etc.) since these sorbents contain sites with different sorption activity. The aim of this work was the statistical evaluation of the adequacy of the approximation of isotherms of vapor-phase sorption of OC by geosorbents in water-unsaturated conditions by employing various fitting equations. Vapor sorption isotherms were measured by the static headspace gas-chromatographic analysis method for 27 various organic sorbates (13 hydrocarbons and 5 chlorinated hydrocarbons, 7 oxygenated and 2 nitrogenated OC) on geosorbents (6 soils typical for Middle Russia regions, separate soil layers of 2 dark-gray forest soils, natural zeolite-containing material and bentonite clay, and two clay-humic complexes). The computer-assisted special sorption database with the corresponding software was created, and on the whole, 103 experimental sorption isotherms (86 isotherms measured and 17 taken from the literature) were used for the approximation. The adequacy of isotherm approximation by different sorption models was compared: Brunauer-Emmett-Teller (BET), modified BET (MBET), Pickett-Dellyes (PD), Guggenheim-Anderson-De Boer (GAB), Aranovich-Donohue (AD), Hinz (HZ) and polynomial (PN) equation. For the comparison of the adequacy of isotherm approximation by different equations, the following three criteria were used: (a) s 5% - the average probability of the location of experimental sorption values within the range of 5% of the theoretical curve; (b) two interconnected parameters: R 2 - the square of correlation coefficient and k - the slope tangent for the linear regression (V E; V T) at various sorbate activities; (c) D̄ - relative sample variance as a characteristics of the optimal ratio between numbers of parameters of the fitting equation and its approximation quality. For the description of the vapor sorption of OC by geosorbents, the new MGAB equation (the modified GAB equation) was suggested. It is characterized by the optimal ratio between the 'complexity' of an equation (MGAB is a four-parametrical equation) and its approximation quality (MGAB shows one of the best isotherm approximations). The following rank of the decrease of the adequacy (upon D̄ criterion) of examined fitting equations in relation to the OC sorption isotherm approximation in the whole isotherm range was formed: MGAB > HZ > PD > GAB > AD > PN. © 2005 Elsevier B.V. All rights reserved
Sources of heavy ions in the Venusian magnetosheath and their role in solar wind loading processes.
No full text- …
