Solubility improvement of progesterone from solid dispersions prepared by solvent evaporation and co-milling

The aim of this contribution was to evaluate the impact of processing methods and polymeric carriers on the physicochemical properties of solid dispersions of the poorly soluble drug progesterone (PG). Five polymers: hydroxypropyl methylcellulose (HPMC), hydroxypropyl methylcellulose acetate succinate (HPMCAS), microcrystalline cellulose (MCC), polyvinylpyrrolidone (PVP) and silica (SiO2), and two processing methods: solvent evaporation (SE) and mechano-chemical activation by co-milling (BM) were applied. H-bonding was demonstrated by FTIR spectra as clear shifting of drug peaks at 1707 cm−1 (C20 carbonyl) and 1668 cm−1 (C3 carbonyl). Additionally, spectroscopic and thermal analysis revealed the presence of unstable PG II polymorphic form and a second heating DSC cycle, the presence of another polymorph possibly assigned to form III, but their influence on drug solubility was not apparent. Except for PG–MCC, solid dispersions improved drug solubility compared to physical mixtures. For SE dispersions, an inverse relationship was found between drug water solubility and drug–polymer Hansen solubility parameter difference (∆δt), whereas for BM dispersions, the solubility was influenced by both the intermolecular interactions and the polymer Tg. Solubility improvement with SE was demonstrated for all except PG–MCC dispersions, whereas improvement with BM was demonstrated by the PG–HPMC, PG–PVP and PG–HPMCAS dispersions, the last showing impressive increase from 34.21 to 82.13 μg/mL. The extensive H-bonding between PG and HPMCAS was proved by FTIR analysis of the dispersion in the liquid state. In conclusion, although SE improved drug solubility, BM gave more than twice greater improvement. This indicates that directly operating intermolecular forces are more efficient than the solvent mediated

The Student – Educator Relationship as a Prevention and Management Tool for School Violence and Bullying

Abstract School violence and bullying are forms of aggressive behavior which as a rule are deliberate and harmful. In some cases, they are persistent and may continue for long periods of time such as months or even years. Most of the times the individuals who are subjected to school bullying are quite difficult to defend themselves. Aggressive behaviors and cases of violence and bullying constitute elements of a daily school reality. The intensity of such incidents and the scientific interest led to it becoming a research target for many fields such as psychology, sociology, pedagogy and political science, bringing to the surface at the same time the complexity and composite nature of the issue. The target of this research study is the qualitative examination of the educators’ and the students’ aspects concerning the role – tool of good interpersonal relationships and the prevention and management of incidents of school violence and bullying

Taxation of Intangibles

This paper examines the tax treatment of intangibles in Canada and recent developments internationally. It suggests that the special features of intangibles and the rapid rise of intangibles as value-drivers in the global economy may render existing tax rules inadequate in defining Canada’s tax base and/or competing for investment in research and development in Canada. Recent developments at the international level (such as the BEPS Project) and national level (such as US 2018 tax reform and changes in Japan, UK and China to implement BEPS recommendations) may point to some directions for Canada to consider

COMPARISON OF UPPER LIMB REACTION SPEED BETWEEN YOUNG TABLE TENNIS AND BADMINTON ATHLETES USING THE LYMMIC ELECTRONIC SYSTEM

The aim of the present study was to compare the upper limb reaction time between young athletes (boys) of table tennis and badminton. Two groups of 14 table tennis and badminton athletes (a total of 28 athletes) with a mean age of 14±1.65 and mean involvement in these sports of 5±1.32 were the sample of the study. The visual stimulus tests used to record reaction times were as follows: a) left hand simple reaction time test, b) right hand simple reaction time test, c) left hand choice reaction time test, d) right hand choice reaction time test. The tools used for the measurements were a special light sensor and other technological means. ANOVA and Duncan’s multiple range test (p<0.05) were applied for statistical data processing. The analysis of the results showed no statistically significant differences in any of the 4 tests of the athletes. The findings and the way of measuring reaction speed could be used by the athletes’ coaches to enrich and improve the training process.  Article visualizations

Federated Learning Under Restricted User Availability

Federated Learning (FL) is a decentralized machine learning framework that enables collaborative model training while respecting data privacy. In various applications, non-uniform availability or participation of users is unavoidable due to an adverse or stochastic environment, the latter often being uncontrollable during learning. Here, we posit a generic user selection mechanism implementing a possibly randomized, stationary selection policy, suggestively termed as a Random Access Model (RAM). We propose a new formulation of the FL problem which effectively captures and mitigates limited participation of data originating from infrequent, or restricted users, at the presence of a RAM. By employing the Conditional Value-at-Risk (CVaR) over the (unknown) RAM distribution, we extend the expected loss FL objective to a risk-aware objective, enabling the design of an efficient training algorithm that is completely oblivious to the RAM, and with essentially identical complexity as FedAvg. Our experiments on synthetic and benchmark datasets show that the proposed approach achieves significantly improved performance as compared with standard FL, under a variety of setups.Comment: 5 pages, 4 figure