Efficient chemotherapy of rat glioblastoma using Doxorubicin-loaded PLGA nanoparticles with different stabilizers

Background: Chemotherapy of glioblastoma is largely ineffective as the blood-brain barrier (BBB) prevents entry of most anticancer agents into the brain. For an efficient treatment of glioblastomas it is necessary to deliver anti-cancer drugs across the intact BBB. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles coated with poloxamer 188 hold great promise as drug carriers for brain delivery after their intravenous injection. In the present study the anti-tumour efficacy of the surfactant-coated doxorubicin-loaded PLGA nanoparticles against rat glioblastoma 101/8 was investigated using histological and immunohistochemical methods. Methodology: The particles were prepared by a high-pressure solvent evaporation technique using 1% polyvinylalcohol (PLGA/PVA) or human serum albumin (PLGA/HSA) as stabilizers. Additionally, lecithin-containing PLGA/HSA particles (Dox-Lecithin-PLGA/HSA) were prepared. For evaluation of the antitumour efficacy the glioblastoma-bearing rats were treated intravenously with the doxorubicin-loaded nanoparticles coated with poloxamer 188 using the following treatment regimen: 3×2.5 mg/kg on day 2, 5 and 8 after tumour implantation; doxorubicin and poloxamer 188 solutions were used as controls. On day 18, the rats were sacrificed and the antitumour effect was determined by measurement of tumour size, necrotic areas, proliferation index, and expression of GFAP and VEGF as well as Isolectin B4, a marker for the vessel density. Conclusion: The results reveal a considerable anti-tumour effect of the doxorubicin-loaded nanoparticles. The overall best results were observed for Dox-Lecithin-PLGA/HSA. These data demonstrate that the poloxamer 188-coated PLGA nanoparticles enable delivery of doxorubicin across the blood-brain barrier in the therapeutically effective concentrations

SIMULACRUM IN STATIC-DYNAMIC SCOPE OF THE SCREEN (a case study of polycode-multimodal texts of the Internet)

With onset of the computer and electronic revolution, with the expansion of the Internet the modern world culture is based not on the bookish, but on the screen form of the text existence. Heterogeneous texts have replace homogeneous texts. The most formed representatives of which are the movies and the television, that initiated the appearance of text with the unique structure, contaminating oral and written linguistic sense medium with the non-linguistic and which, having been digitized, are predominating in the Internet today. The spectator expects from these texts such stylistic features as authenticity and factual accuracy. These particular expectations are employed by the authors of such videos in order to manipulate the viewer and to create the impression, that the objects and phenomena on the screen possess the denotation in the real world, thus making the recipient believe into the modelled pattern of a real life and generating simulacra. This article is devoted to the analysis of peculiarities of the simulacra design in polycode-multimodal texts representing complex semiotic unity of verbal, iconic and acoustic components. Also it is examined how a real-life simulation is created in the case of three polycode-multimodal texts that describe the military actions in Syria. The analysis is carried out in the static and dynamic scope of the screen% at the visual (screenshots), verbal and acoustic levels. During the research lingual-semiotic peculiarities of the simulacra generation in the static scope of the screen are singled out and the instruments used to construct simulacra in the dynamic scope of the screen

The Problem of Semantic Shift in Modern Russian: Corpus Research on the Example of a News Media Discourse

This study discusses the issue of semantic shifts observed in high-frequency words, such as discourse, paradigm, narrative , in the news media discourse in the Russian language. It is shown that one of the effective methods of research is corpus analysis, for which an author’s corpus was created based on a random sample of texts of news articles published on the portal of the state news agency RIA Novosti over 2020-2023. Dynamic processes in the semantics of the analyzed highfrequency words were studied on the material of the National Corpus of the Russian language for the period 2000-2019. When considering the results obtained by the corpus analysis method, it was found out that, being initially the linguistic term, “narrative” turned into a functional proforma as a result of a semantic shift that occurred due to the diversity of newly acquired meanings, i.e. there was a modification of the original meaning of the word ‘ story, narration’ , which made the world into the universal one. The classical meaning of the word ‘ paradigm’ , characteristic of linguistics, is not represented in journalism, in the news media discourse it has been given other connotations such as scheme, model, idea, situation , which have moved into the core, nuclear area from the position of the near periphery. Some values are unique, so they have a small frequency (ipm). The interdisciplinary term “discourse” has turned into a term with vague semantics, but, unlike “narrative”, it is not a universal professional form, although it denotes processes occurring in various social spheres. It is shown that the semantic shift is not identical to the increase in the meaning of the word and is not determined strictly contextually. It is necessary to distinguish between the concept of semantic shift and the appearance of new meanings of the word, since the former is fixed in non-standard contexts and the demonstrated meaning cannot be clearly defined. In the course of the study, it was possible to establish that not all semantic shifts should be classified as erroneous, since it depends on the sphere in which the shift was detected. The use of the considered words in a different meaning is not profane, since the mobility of the lexical level of the language leads to transformations in speech and media discourse, allowing the appearance of texts stylistically close to the spoken style. Thus, we have identified and confirmed quantitatively the process of transformation of the words selected for analysis into pro-forms used as substitutes for a wide range of concepts

ANALYSIS OF COMPETITIVE ACTIVITY HIGH RANKED FIGHTERS OF MIXED MARTIAL ARTS

Mixed martial arts - a sport, which is a combination of many techniques, schools and direction of combat sports. Nowadays, mixed martial arts are the most popular and spectacular sport of all combat sports. Analysis of competitions performances is an important aspect of training athletes. The quantitative characteristics of competitive activity make it possible to model the training process at different stages of fighters. Aim of the research – to analyze the quantitative characteristics of competitive activity of high ranked fighters. All matches of Mixed martial arts Russian Cup in 2018 were analyzed: 84 preliminary and 8 final fights (for 1 place) in all weight categories.  The following quantitative characteristics of the competitive activities of high ranked fighters were analyzed in the study: average fight time; average fight time in the standing and ground positions; distribution of fights by types of victory; activity, defense and reliability performing takedowns for each weight category. Also, a comparative analysis was carried out with the competitive activity characteristics of the top athletes from the Ultimate Fighting Championship rating for each weight group. These data can be used as model when planning the training process of both young and qualified athletes

Methods of improving the system of motivation of the university teaching staff

The purpose of the article is a systematic scientific study of the most optimal methods for motivating personnel of higher educational institutions and their improvement, taking into account the economic state of the country and the specifics of the processes of social transformation, which formed the basis for the development of methodological and practical recommendations. The main research methods were information retrieval methods, universal scientific methods, including methods of comparative and factor analysis, detailing, synthesis, generalization. This publication examines the methods of motivation and incentives for the teaching staff of universities, which are in demand for use in the transition to the forms of blended and e-learning, along with the use of traditional approaches; a method for calculating the fund of surcharges, allowances and other incentive payments to the teaching staff is proposed, reflecting the relationship and mutual influence of workload, remuneration and surcharges, an objective assessment of work with the volume of work actually performed, overtime work, scientific work, the introduction of modern methods and technologies of teaching allows you to optimally distribute funds to motivate the teaching staff. The materials of the article will be of interest to scientific and practical workers, graduate students and students

Penetration of PLGA nanoparticles into the intracranial rat C6 Glioma: Influence of surfactant coating

As shown by our previous studies, the PLGA nanoparticles (NP) coated with poloxamer 188 (P188) enable brain delivery of doxorubicin and its high anti-tumour effect against the intracranial glioblastoma in rats [1]. The objective of the present study was to evaluate the uptake of the P188-coated PLGA NP in the intracranial C6 glioma in rats. For visualization using scanning laser confocal microscopy (SLCM) and an intravital fluorescence imaging system IvisÒSpectrum CT (Perkin-Elmer), the NP were labeled with DiI (DiI-PLGA NP). The DiI-PLGA NP were administered i.v. into rats with intracranial C6 glioma on day 15 after tumour implantation. The presence of mass lesion was verified by previous MRI. Two hours after administration of the NP, the rats were perfused transcardially with paraformaldehyde, organs were recovered, and the fluorescence intensity was assessed using an IvisÒSpectrum CT system. The fluorescence intensity of the hemisphere with the implanted glioma was \u3e 4-fold higher for the P188-coated NP (DiI-PLGA/P188 NP), as compared to the uncoated NP (45.1×106 vs 9.5×106 photons/sec/cm2, respectively (Figure). The quantitative fluorescence analysis on the tumor sections using SLCM also showed a significantly higher accumulation of the DiI-PLGA/P188 NP, as compared to the uncoated DiI-PLGA NP (Fig. 2). Mean fluorescence intensity values in the tumor were 1698.9±536.6 and 558.9±181.0 CU for the P188-coated and uncoated NP, respectively. The intensity values in the contralateral hemispheres for the same preparations were 293.4 ± 32.3 and 203.2 ± 22.9 CU, respectively. Thus, according to the SLCM data, the penetration of the DiI-PLGA/P188 NP into the tumor was 3 times more effective than that of the uncoated NP. Please click Additional Files below to see the full abstract

Selective interactions of boundaries with upstream region of Abd-B promoter in Drosophila bithorax complex and role of dCTCF in this process

Expression of the genes Ubx, abd-A, and Abd-B of the bithorax complex depends on its cis-regulatory region, which is divided into discrete functional domains (iab). Boundary/insulator elements, named Mcp, Fab-6, Fab-7 and Fab-8 (PTS/F8), have been identified at the borders of the iab domains. Recently, binding sites for a Drosophila homolog of the vertebrate insulator protein CTCF have been identified in Mcp, Fab-6 and Fab-8 and also in several regions that correspond to predicted boundaries, Fab-3 and Fab-4 in particular. Taking into account the inability of the yeast GAL4 activator to stimulate the white promoter when the activator and the promoter are separated by a 5-kb yellow gene, we have tested functional interactions between the boundaries. The results show that all dCTCF-containing boundaries interact with each other. However, inactivation of dCTCF binding sites in Mcp, Fab-6 and PTS/F8 only partially reduces their ability to interact, suggesting the presence of additional protein(s) supporting distant interactions between the boundaries. Interestingly, only Fab-6, Fab-7 (which contains no dCTCF binding sites) and PTS/F8 interact with the upstream region of the Abd-B promoter. Thus, the boundaries might be involved in supporting the specific interactions between iab enhancers and promoters of the bithorax complex

The cultural and creative function of moving image literacy in the subject of English in the Greek secondary school

Teaching media literacy as a separate school subject or as part of another school subject is lacking from the Greek educational reality, despite the international academic research and the development and application of media literacy teaching models. This thesis is an analysis of two case study research projects carried out in groups of students in two Greek secondary schools with the aim to study the students’ response to media projects, which are totally new for the Greek educational reality, realized in the English as a Foreign Language class. The data is analyzed according to Burn and Durran’s 3-Cs model of media literacy, and more precisely its Cultural and Creative functions are the aspects used that include the concepts of Cultural Taste, Identity, and Creativity. These concepts are interpreted within the framework of Cultural Studies and Psychology theories. Important theoreticians considered are Bourdieu, Bennett, Giddens, Vygotsky, Jenkins and Bakhtin. The examination of students’ participation in the media projects and their production work suggest that their cultural taste is a combination of global and local influences, a glocal result, in which the family, the peers, the media and the education play an important role. Their identity is multi-faceted, as a reflection of various aspects of their selves, and it is closely related to their cultural taste and their cultural capital. Students’ creativity is also expressed as a complex process, affected both by the guidance of the official educational context and the youth popular culture tendencies. The tensions that emerge in the expression of the students’ cultural taste, identity and creativity during moving image projects characterize the Greek adolescents’ response to the newly-learnt moving image literacy, and raise important questions for educators and researchers