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This study demonstrates the potential of using hydrogel material for encapsulation of plant poplyphenols to improve their functionality and stability in food products.

In this work, we describe an optimized procedure based on gradual hemolysis for the isolation of hemoglobin derived from bovine slaughterhouse erythrocytes in a membrane bioreactor. The membrane bioreactor system that provided high yields of hemoglobin (mainly oxyhemoglobin derivate) and its separation from the empty erythrocyte membranes (ghosts) was designed at a pilot scale. Ten different concentrations of hypotonic media were assessed from the aspect of the extent of hemolysis, hematocrit values of the erythrocyte suspensions, cell swelling, and membrane deformations induced by decreased salt concentration. Effective gradual osmotic hemolysis with an extent of hemolysis of 88% was performed using 35 mM Na-phosphate/NaCl buffer of pH 7.2-7.4. Under these conditions most of the cell membranes presented the appearance of the normal ghosts under phase contrast microscope. The hemoglobin purity of >80% was confirmed by SDS-PAGE. Kinetic studies showed that maximal concentration of hemoglobin was reached after 40 min, but the process cycle at which recovery of 83% was achieved lasted for 90 min. The dynamics of both steps, (1) transport through the membrane of erythrocytes during process of hemolysis and (2) transport through the reactor filters, were evaluated.

Lipid particles, as drug carriers, are of increasing research interest, because a sustained drug release and avoidance of side effects could be achieved by using them. Lidocaine hydrochloride is a very efficient local anesthetic, but it has a short effect. The objective was to prolong the effect of the drug by encapsulating lidocaine hydrochloride in phospholipids microparticles. Two different procedures were used for the preparation of phospholipids microparticles. In both cases, phosphatidylcholine and lysophosphatidylcholine were used for the preparation of microparticles in which 5 % w/w lidocaine hydrochloride solution was encapsulated. The standard Franz diffusion cell was used for the experimental diffusion rate determination. The obtained results show that diffusion rate from microparticles is significantly lower than from the lidocaine hydrochloride solution, which means that this kind of microparticles could be used for the prolonged drug release. There was no much difference in diffusion rates from microparticles obtained by different procedures. That indicates that only the composition of the particles membrane has an influence on the lidocaine hydrochloride release rate.

Introduction. Assisting students face high academic demands which, together with interpersonal, intrapersonal and professional requirements, can be a significant source of stress. The aim of the research was to examine the intensity and frequency of the source of stress, coping strategies and identify gender differences among students, future assisting professionals. Methods. An observational, cross-sectional study was conducted amongst the students of the University of the Belgrade Faculty of Security (Serbia) who, after graduation, will acquire the title of a security manager responsible for human resources in the civil sector. The data were collected in the period October/November 2018. The authorized questionnaire SSM-30 by Jović (Stress scale for the young -30) was used, which enables students to assess the tress situations intensity on a scale from 1 (minimum) to 10 (maximum intensity). The SSM-30 questionnaire is a combination of the standard Life Events Scale -Holmes Rashe Life Events Scale, also known as the Social readjustment Rating Scale and life events characteristic for the student population. The questionnaire also included the sample demographic characteristics -gender, and a year of study. The SSM-30 scale includes a list of stressful events and stress coping mechanisms shown in the results. Results. The most common sources of stress in both genders were social and academic ones: death in the family, critical illness in the family, an accident of a person I love, unwanted pregnancy, lie by lose people, disagreement with parents, loss of a study year, crisis, uncertainty after graduation and partner'sinfidelity. The most frequently used mechanisms for controlling and overcoming stress were mostly social: talking with friends, listening to music, family support, frequent walks, socializing and going out, using the Internet, frequent sleep, intense physical activity, crying and relaxation. Statistically significant differences between the gender -female students demonstrated self-worth of higher intensity during the majority of stressful situations, as they use different stress coping mechanisms from their male students. 4Conclusion. The results obtained with regard to the assessment of stressors and the use of specific mechanisms for coping indicate the necessary additional education of students in this field in order to be more focused and open forfree professional help, when necessary.