3,532 research outputs found
Nanohyperthermia of malignant tumors.i. lanthanum-strontium manganite magnetic fluid as potential inducer of tumor hyperthermia
Objectives: To synthesize magnetic particles of lanthanum-strontium manganite, prepare the magnetic fluid (MF), evaluate the generation of heat by particles and determine their common toxiсity. Methods: Nanoparticles based on the solid solutions of lanthanum-strontium manganite (La1-xSrxMnO3) have been synthesized by a sol-gel method. Conventional methods of experimental oncology were used. Results: Nanoparticles of ferromagnetic materials on the basis of solid solutions of lanthanum strontium manganite by sol-gel method were synthesized. It was shown the possibility to regulate the aggregate form of particles that are formed during the synthesis. Magnetic fluid based on the synthesized nanoparticles and water solutions of agarose have been produced. It was shown the possibility to heat this magnetic fluid up to 42–45 °С in externally applied alternating magnetic field (AMF) operated at 100–400 kHz. It was determined that under long-term influence of AMF nanofluid is heated up to temperature which is not over that of magnetic phase transition. It was detected that magnetic powder as well as fluid have not displayed acute toxicity or side effects (intraperitoneal or intratumoral administration) in animals either intact or with transplanted tumors. Conclusions: Possibility of synthesized magnetic fluid to generate heat in externally applied AMF as well as lack of side effects allow to consider its as a potential mean for tumor hyperthermia (HT)
Political Activity of Russians: Current Trends and Resources of Media Influence
Authors assume that in the post-Soviet time, political consciousness among the
Russians has significantly changed. Causes of this not only include general depoliticization in the society, but also a modified nature of the media influence.
The research purpose is to search for reasons that cause booms and falls in the
interest of the Russians in politics. The methodological framework of the research
included the Verba-Pye model of engagement in politics, Lipset's conclusions
about citizens' engagement in political affairs; assumptions from the LipsetRokkan model of political preferences of citizens; Scott's concept of imitation of
political activism, and Bryant's conclusions about specifics of media influence on
public opinion. The empirical basis of the research includes data from sociological
and marketing research made by Russian centers for the study of public opinion.
As a result of the research, its authors have established that country residents do
not mostly show high political engagement and civil activis
Coalition or Opposition? The Behaviour of Regionalist Parties in Multi-level Competition: The Cases of the Basque Country and Scotland
This article compares the positioning behaviour of parties and reveals why one party joins a coalition, while others do not. The cases of two regionalist parties of the UK and Spain are depicted: the Scottish National Party (SNP) and Basque National Party (BNP). The study is a contribution to the problems of positioning behaviour of parties in decentralised systems with strong regionalist elements and incentives of regionalist parties (RPs) to enter a coalition with state-wide parties (SWPs). Based on process tracing and comparative analysis of the main regionalist parties, electoral data, public statements, and media statements we conclude that the ideological proxi mity on the economic dimension of the parties, and the territorial dimension are of key importance in evaluating the coalition potential between SWPs and the RPs. Moreover, competition at the regional level creates incentives for RPs to enter a coalition with SWPs and there is no evident support for the minority government to be disposed to enter a coalition rather than a majority government
Nanohyperthermia of malignant tumors. II. In vivo tumor heating with manganese perovskite nanoparticles
Objectives: To evaluate the ability of manganese perovskite nanoparticles (lanthanum-strontium manganite) to heat the tumor tissue in vivo under action of external alternating magnetic field. Materials and Methods: The magnetic fluid on the basis of nanoparticles of perovskite manganite was tested in the heating experiments using of alternating magnetic field of frequency 300 kHz and amplitude 7.7 kA/m. Guerin carcinoma was transplanted into the muscle of rat. Magnetic fluid was injected intramuscularly or intratumorally. Temperature was measured by copper-constantan thermocouple. Results: Temperature of magnetic fluid was increased by 56 °C for 10 min of alternating magnetic field action. Administration of magnetic fluid into the muscle followed by alternating magnetic field resulted in the elevation of muscle temperature by 8 °C after 30 min post injection. Temperature of the tumor injected with magnetic fluid and treated by alternating magnetic field was increased by 13.6 °C on the 30 min of combined influence. Conclusion: In vivo study with rat tissue has demonstrated that magnetic fluid of manganite perovskite injected in the tumor increases the tumor temperature under an alternating magnetic field. Obtained results emphasize that magnetic fluid of manganite perovskite can be considered as effective inducer of tumor hyperthermia
Rapid Depletion of Target Proteins Allows Identification of Coincident Physiological Responses
Targeted protein degradation is a powerful tool that can be used to create unique physiologies depleted of important factors. Current strategies involve modifying a gene of interest such that a degradation peptide is added to an expressed target protein and then conditionally activating proteolysis, either by expressing adapters, unmasking cryptic recognition determinants, or regulating protease affinities using small molecules. For each target, substantial optimization may be required to achieve a practical depletion, in that the target remains present at a normal level prior to induction and is then rapidly depleted to levels low enough to manifest a physiological response. Here, we describe a simplified targeted degradation system that rapidly depletes targets and that can be applied to a wide variety of proteins without optimizing target protease affinities. The depletion of the target is rapid enough that a primary physiological response manifests that is related to the function of the target. Using ribosomal protein Si as an example, we show that the rapid depletion of this essential translation factor invokes concomitant changes to the levels of several mRNAs, even before appreciable cell division has occurred
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