Potentiation of Anticancer Drugs: Effects of Pentoxifylline on Neoplastic Cells

The drug efflux activity of P-glycoprotein (P-gp, a product of the mdr1 gene, ABCB1 member of ABC transporter family) represents a mechanism by which tumor cells escape death induced by chemotherapeutics. In this study, we investigated the mechanisms involved in the effects of pentoxifylline (PTX) on P-gp-mediated multidrug resistance (MDR) in mouse leukemia L1210/VCR cells. Parental sensitive mouse leukemia cells L1210, and multidrug-resistant cells, L1210/VCR, which are characterized by the overexpression of P-gp, were used as experimental models. The cells were exposed to 100 μmol/L PTX in the presence or absence of 1.2 μmol/L vincristine (VCR). Western blot analysis indicated a downregulation of P-gp protein expression when multidrug-resistant L1210/VCR cells were exposed to PTX. The effects of PTX on the sensitization of L1210/VCR cells to VCR correlate with the stimulation of apoptosis detected by Annexin V/propidium iodide apoptosis necrosis kit and proteolytic activation of both caspase-3 and caspase-9 monitored by Western blot analysis. Higher release of matrix metalloproteinases (MMPs), especially MMP-2, which could be attenuated by PTX, was found in L1210/VCR than in L1210 cells by gelatin zymography in electrophoretic gel. Exposure of resistant cells to PTX increased the content of phosphorylated Akt kinase. In contrast, the presence of VCR eliminated the effects of PTX on Akt kinase phosphorylation. Taken together, we conclude that PTX induces the sensitization of multidrug-resistant cells to VCR via downregulation of P-gp, stimulation of apoptosis and reduction of MMPs released from drug-resistant L1210/VCR cells. These facts bring new insights into the mechanisms of PTX action on cancer cells

Інтеграція хмарних і проектних технологій у підготовці майбутніх психологів

The article is devoted to the integration of cloud and project technologies while teaching mathematics and IT courses for studentswhuch study psychology. The necessity for cloud technologies implementation into the educational process of modern Ukrainian universities has been proved. The urgency of project technologies application to prepare psychologists, aimed primarily at personal development, the formation of cooperation capacity as well as responsibility, initiative, creativity and mobility has been revealed. The experience of cloud services and project activity combination in teaching «Mathematical Statistics» and «Modern Information Technologies» for the students of psychological and pedagogical faculty of V.G. Korolenko PNPU obtaining «Psychology» training has been described.It has been determined that the best way to train students to work with the latest information and communication technologies is to introduce these technologies into the educational process. The analysis of best practices and our own experience in the use of cloud services in university has showed that information and communication technologies give the wealth of possibilities for students to organize their project activity and significantly increase the learning potential of the project method.It has been established that the use of cloud technologies in students’ project activity has been correlated with the type of training project (research, information, creative, telecommunication) as well as with its form of organization (personal, paired, group, collective). The type and form of the project choice depends on the content, purpose and objectives of discipline. Thus in training «Mathematical Statistics» for students of «Psychology» specialty for psychological and pedagogical faculty of Poltava National Pedagogical University named after V.G. Korolenko, the students’ independent work has been strengthened with the group research project activities to form the basic concepts of descriptive statistics and practical skills to carry out experimental data collection and initial processing of psychological researches results. The stages of the group research project have been characterized, they are identifying the problem and formulating research theme; finding out the status of definite problem, statistical analysis of experimental data; generalization of research results; presentation the group project result and its evaluation. The effectiveness of the research project in the context of the practical skills development to collect and process data of experimental psychological research with Google Apps has been clarified. The possibilities of information and telecommunication project while studying IT disciplines as the effective means of information and communication competence formation for future professionals have been considered.The course «Modern Information Technologies» for psychologists has described the tutor’s coordination concerning information and telecommunication projects implementation; indicative tasks for information and telecommunication projects using cloud services havebeen given.It has been found out that the combination of cloud and project technologies while studying mathematics and IT sciences for students of liberal arts simplifies understanding and assimilation of subjects content, forms subject and IT competence, capability of innovative activity, develops creative and research skills as well as critical thinking and flexibility, promotes communicative activity.Стаття присвячена інтеграції хмарних і проектних технологій при викладанні математичних та інформатичних дисциплін для студентів спеціальності «Психологія». Обгунтовано необхідність упровадження хмарних технологій у навчальний процес сучасних українських вишів. Описано досвід поєднання хмарних та проектних технологій навчання при викладанні «Математичної статистики» та «Сучасних інформаційних технологій» майбутнім психологам. З’ясовано ефекивність дослідницького проекту в контексті формування практичних умінь збирати та обробляти дані експериментального дослідження засобами Google Apps. Розглянено можливості інформаційно-телекомунікаційного проекту в процесі вивчення інформатичних дисциплін, описана координація інформаційно-телекомунікаційним проектом викладачем, наведено орієнтовні завдання інформаційно-телекомунікаційних проектів з використанням хмарних технологій

MEASUREMENT OF CONSUMER ETHNOCENTRISM OF SLOVAK CONSUMERS

The conceptualization of consumer ethnocentrism is inferred from the general concept of ethnocentrism which assumes that ethnocentrism starts with the culture into which an individual is born. Over time, the individual will accept the values and behaviour of this particular culture as a norm. However, when the individual becomes aware of other cultures with different values and behaviours, there develops the need of belonging and identification with own culture rather than that of others. When analysing the consumer ethnocentrism, it is also essential to examine whether consumer ethnocentrism operates uniformly across all consumers or there exist some specific factors moderating their ethnocentric tendencies. A lot of studies researching these issues can be found in various cultural contexts, however in Slovakia we found certain gap since there is just a few of them. The aim of the paper is to investigate the level of consumer ethnocentricity of Slovak consumers in general and with the respect to chosen variables – age and gender. The results can serve as an information base for decision-making process of marketing managers focusing especially on local production of domestic products

Phenolic Contents and Postharvest Quality Changes of Norwegian ‘Mallard’ plums (Prunus domestica L.) as a Consequence of Delayed Time to Low Temperature Storage

During the picking season in the Norwegian plum production areas, the harvested plums are brought to cold storage in packing houses once or twice a day. Plums picked late in the afternoon may even not be cooled properly until the next day. The average time from picking until the plums are placed in a cold storage is approximately 8 hours. Previous reports have shown that delayed cooling of sweet cherries and apples reduced the fruits’ susceptibility to physiological or fungal decay. An experiment was performed in order to evaluate the impact of different delay-to-cold storage times (0, 5, 10, 15 and 25 hours) on quality and phenolic contents changes of Norwegian ‘Mallard’ plums during cold storage, transport, and retail in normal atmosphere (NA). The fruits (10 fruits in PE tray, n=3) were stored for 14 days at 1°C, followed by 3 days at 7°C and then for 4 days at 20°C. Fruit quality parameters (firmness, colour in CIE L, a*, b* colour space, weight, rot occurrence (%)) and total phenol and anthocyanin content were determined. Samples were analyzed just before cold storage and then after 14 days at 1°C, 3 days at 7°C, or 4 days at 20°C. Evaluation of results has shown that delay of cooling has a retarding effect on rot development during 20°C storage (post cold transport), weight loss and stimulates anthocyanin accumulation and colour changes to some extent. At the end of storage no effect on fruit firmness could be observed

Basic Phosphonium Ionic Liquids as Wittig Reagents

The possibility of designing a solvent/reagent for Wittig reactions from basic phosphonium salts is explored theoretically. In the suggested R₄P⁺PhO^– and Ph₃PR⁺PhO^– ionic liquids (ILs), the phenolate anion is prone to remove the α-proton from the alkyl chains, forming a phosphorous ylide. Significant hydrogen bonding between the oxygen atoms of the anions and α-hydrogen atoms of the cations were found by molecular dynamics simulations of these substances; therefore, proton transfer between the two ions is inherently supported by the structure of the liquid as well. The subsequent steps of the Wittig reaction from the phosphorous ylide were also found to be energetically possible. The mesoscopic structure of these materials exhibits a significant segregation into polar and nonpolar domains, which may also allow an easy dissolution of the substrates. The formation of a pentacoordinated phosphorous derivative through P–O bond formation was found to be also possible in the gas phase for both kind of compounds. Accordingly, having such basic anions in phosphonium-based ILs may produce such a neutral and therefore volatile species, which may hold further significant applications for these solvents in ion-exchange and separation techniques and in synthesis

Supramolecular Viologen-Cyclodextrin Electrolytes for Aqueous Organic Redox Flow Batterie

Along with a primary modification of redox active materials, an additional introduction of secondary noncovalent interactions can synergistically enhance bulk properties of electrolytes for redox flow batteries. Herein, we highlight the host–guest complex formation between tailored viologens and highly water soluble (2-hydroxypropyl)-β-cyclodextrin as a key electrolyte interaction to modulate relevant electrochemical properties of aqueous redox flow batteries (AORFBs). The cyclodextrin-modified AORFB anolytes demonstrated a complex interrelation of molecular structure and inherent binding activity as well as bulk electrochemical stability of the anolyte. The screening of different combinations of viologen substituents in the presence of cyclodextrin enabled an electrochemically stable AORFB performance for more than 500 cycles with a temporary capacity fade rate of 0.26%/day at high energy (>70%) and Coulombic (>99.7%) efficiencies. A selective interplay of supporting electrolytes and engineered redox active materials is a promising strategy for enhanced energy characteristics of AORFB electrolytes

Host‐Guest Interactions Enhance the Performance of Viologen Electrolytes for Aqueous Organic Redox Flow Batteries

Host-guest interactions are an attractive approach to design redox electrolytes, enabling to precisely tune the key properties for redox flow batteries such as half-cell redox potential, solubility, and stability. Herein we report a host-guest complex of highly water soluble (2-hydroxypropyl)-β-cyclodextrin with 1-decyl-1′-ethyl-4,4′-bipyridinium dibromide as anolyte in a new aqueous organic redox flow battery (AORFB). The supramolecular anolyte ensured the total RFB voltage increase of ≈9 % up to 0.97 V and provided a stable capacity delivery for more than 500 cycles with a capacity fade rate of 0.037 %/cycle (2.84 %/day) at high Coulombic (>99.5 %) and energy (>62 %) efficiencies. The results highlight host-guest interactions as promising strategy towards more effective storage of renewable energy within AORFBs