Three-arm polylactides (PLA) containing 0.2, 7.6, and 13% of d-lactic acid monomeric units were obtained and refunctionalized into ATRP macroinitiators via esterification of hydroxyl groups with 2-bromoisobutyryl bromide. These polymeric matrices underwent enzymatic degradation with various rates and revealed negative results on cytotoxicity and genotoxicity tests. Camptothecin (CPT), which is an anticancer active substance, was transformed into acrylic monomers; however, simple CPT acrylate was not able to polymerization whereas methacrylate with a linker was ready for FRP and ATRP. The latter monomer was used for ATRP initiated with various PLA macroinitiators in order to form block copolymer conjugates of CPT with high load of drug. Based on kinetic studies at various temperatures, it was found out that the polymerization stopped at certain monomer conversion because of the ceiling temperature. The content of CPT in these conjugates was estimated by means of 1H NMR, quadruple detection array GPC, and elemental analysis and was in the range 8.0–16.9 wt %. The products were morphologically heterogeneous, and the shapes and size of the nano-/microstructures were influenced by crystallinity of the PLA segment which was shown in AFM images. Terpolymer block conjugates consisting of addition PEGMA monomeric units were synthesized as well in order to increase hydrophilicity of the polymers and to protect a lactone ring in CPT structure. The studies on CPT release were carried out in vitro and revealed that the rate of CPT discharge was influenced by the structure of PLA and conjugate composition; however, it was near to zero-order kinetics. The analysis using the Korsmeyer–Peppas model suggests that drug release was governed rather according supercase II transport (n > 1) which shows that it is a highly controlled process.

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The main purpose of marriage ought to be active love, in other words, procreation-oriented fertile love. One notices, however, that the moral and social norms regarding this issue have presently undergone a far-reaching process of individualisation, as a result of which sexual functions have been separated from parental-reproductive ones. The following article sets out to present certain changes in the mentality of young people who are soon to be married with regard to conception control and abortion. The position of the Catholic Church on these matters is not acknowledged and frequently questioned by engaged couples. The sociological analysis shows that the moral consciousness of the Polish youth is undergoing a slow process of secularisation.

One of the essential elements of work technology assessment is task performance time. In the working day structure, production times are crucial; however, under certain conditions, complementary work times can have a share of up to 30%. Accurate determination of the time structure of a work shift is very time consuming and requires time measurements using the methods of cumulative timing or snapshot observations. For this reason, the overall share of complementary work times in a work shift is usually estimated roughly, equally for all timber harvesting conditions. The aim of this study was to determine the impact of selected working environment factors on the share of complementary work times in a work shift, in technologies on the manual-machine and the machine levels. The analyses were carried out in 33 forest districts of the Regional Directorate of State Forests in Wrocław. Among forest contractors, surveys were carried out to analyse the time structure of a working day. For each forest district, analyses of environmental factors potentially relevant to the share of complementary work times in a work shift were carried out; these included field features, dispersion of stands, features of timber, area accessibility. The total share of complementary work times in the machine-level technology variant amounted to approx. 40% and was higher than the manual-machine technological variant, where this share amounted to approx. 35%. The models developed for standardization of the share of variability of complementary work times, in the case of the manual-machine technology level, took into account the share of timber assortments with the length of over 2.5 m as well as the share of upland and mountain sites. In the case of timber harvesting at the machine technology level, the standardization model included as significant the factors such as the share of coniferous forest sites, the number of forest complexes with an area of over 100 hectares, and the total length of roads. Therefore, the above features could be selected as decisive for the share of the complementary work time category out of the full set of environmental variables taken into consideration in the estimation of the time-consumption of timber harvesting processes.

This paper presents chosen results of extensive research conducted on strain and compressive strength of concrete with admixtures causing expansion. The efficiency was tested with use of two commercially available products: MC-Einpresshilfe and Expancrete, as well as self developed, according to own recipe. Own apparatus was designed and presented, which was used for the strain study of concrete. From the tested admixtures, only Expancrete MAPEI allowed to obtain expansive concrete. Other used admixtures - MC-Einpresshilfe and composition of gypsum, lime and kaolin cannot be used to obtain expansive concrete. However, they can reduce concretes shrinkage.

W artykule przedstawiono wyniki badań wczesnego skurczu autogenicznego i skurczu przy wysychaniu betonu o niskim cieple hydratacji, stosowanego do wykonywania masywnych konstrukcji. Porównano wpływ różnych warunków pielęgnacji wodnej na wartości skurczu autogenicznego i od wysychania. Dane uzyskane z badań mogą stanowić istotny element analizy rysoodporności masywnych płyt fundamentowych oraz zaleceń dotyczących sposobów ich pielęgnacji w celu ochrony przed wczesnym zarysowaniem skurczowym.

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This article presents results of research aimed at identifying the phenomenon of stress relaxation in compressed concrete elements. The study used a special test stand, designed and constructed by Dr.Eng. Krzysztof Kaminski which allows permanent strain of cylindrical concrete sample by adjusting force. Cylindrical samples with a diameter of 15 cm and 10.5 cm and a height of 30 cm for the study were used. The samples were made of different classes of concrete. There was also defined the influence of applied tensile stress and the age of the sample on the relaxation phenomenon. The expected result of the research was to obtain relaxation curves of concrete samples with different compressive strength and age. Relaxation of concrete is important for the analysis of bending elements sections, which behavior during the operational phase of the concrete can significantly deviate from the assumed one, causing other than triangular or parabolic distribution of compressive stresses.