A study has been conducted in order to determine presence of free volume gaps in the structure of structure of polymer hydrogel contact lenses made in phosphoryl choline technology and of the degree of defect of its structure. The study was made by means of positron annihilation lifetime spectroscopy. As a result of the conducted measurements, curves were obtained, which described numbers of counts of the acts of annihilation in the time function. The conducted studies revealed existence of three components τ1, τ2 and τ3. The τ3 component is attributed to the pick-off annihilation of o-Ps orthopositronium trapping by free volume gaps and provides information about geometrical parameters of the volumes. At the same time, the UV–vis–NIR spectrometry examination was conducted on the same samples in the spectral range 200–1,000 nm.

Positron lifetime spectroscopy has been applied to study free volume related properties of bifocal contact lenses. The measurements were made on new lenses and then after one, two, and three weeks wearing. The longest lifetime, obtained via three-component analyses of the spectra, was associated with the pick-off annihilation of ortho-positronium trapped in the free volume. After wearing of the lenses, changes in the ortho-positronium lifetimes and the relative intensity of the longest component were observed. The results are discussed on the basis of a free volume model.

Introduction. Stroke units are wards created to provide specialized care after stroke. Comprehensiveness of actions taken according to the latest recommendation is a priority. A nurse plays an important role at every stage of therapeutic activities. The actions taken by her should be based on the EBNP (Evidence Based Nursing Practice) and cover all aspects of care of the patient after stroke. By using up-to-date results of scientific studies in practice, the patient has been guaranteed the highest quality of care and safety. Aim. In this study there has been discussed the issue of knowledge of the nursing staff from the Stroke Unit in the context of theoretical and practical information related to stroke. Material and Methods. The research was conducted among 26 nurses from the Neurology and Stroke Unit. The diagnostic survey method was used. The research tool was an authorial questionnaire. Results. Non-modifiable risk factors of stroke were indicated by 77% of people. The set of tests used to diagnose stroke was indicated by 15.4% of the respondents. A physical examination was often omitted. The recombinant plasminogen activator (rt-PA), as a medicine was marked by 52% participants, whereas as a medicine used for treatment was indicated by 32% of them. The meaning of the term thrombolysis is known by 100% of individuals, however, the possibility of performing intra-arterial thrombolysis was indicated by 30% of respondents. The recombinant plasminogen activator (rt-PA), as a medicine used in the thrombolysis was chosen by 43.5% respondents, and streptokinase by 39% of them. The sources of knowledge include professional work (54%), education (27%), trainings (19%). Conducting education among the patients is declared by 96% of the respondents. Conclusions. 1) Knowledge of the nurses from the Stroke Unit on the basic matters regarding stroke is at a good level. 2) Knowledge of the nurses is mainly based on their personal experience. 3) Theoretical basics regarding new treatment techniques should be strengthened. 4) There is a need to organize courses to update the gained knowledge on new guidelines and information regarding the new scientific research. (JNNN 2017;6(4):150-156)