Less is more: possibility and necessity as centres of gravity in a usage-based classification of core modals in Polish

In this paper we present the results of an empirical study into the cognitive reality of existing classifications of modality using Polish data. We analyzed random samples of 250 independent observations for the 7 most frequent modal words (móc, można, musieć, należy, powinien, trzeba, wolno), extracted from the Polish national corpus. Observations were annotated for modal type according to a number of classifications, including van der Auwera and Plungian (1998), as well as for morphological, syntactic and semantic properties using the Behavioral Profiling approach (Divjak and Gries 2006). Multiple correspondence analysis and (polytomous) regression models were used to determine how well modal type and usage align. These corpus-based findings were validated experimentally. In a forced choice task, naive native speakers were exposed to definitions and prototypical examples of modal types or functions, then labeled a number of authentic corpus sentences accordingly. In the sorting task, naive native speakers sorted authentic corpus sentences into semantically coherent groups. We discuss the results of our empirical study as well as the issues involved in building usage-based accounts on traditional linguistic classifications

Polymeric in situ forming systems forbiomedical applications. Part I. Injectable implants

Artykuł stanowi przegląd literatury (111 poz. lit.) dotyczącej polimerowych implantów formowanych w miejscu wprowadzenia do organizmu. Materiały takie mogą pełnić zarówno funkcję konstrukcyjną, jak też służyć jako nośnik substancji bioaktywnych. Implanty formowane in situ (ISFI) można otrzymać w wyniku reakcji grup funkcyjnych składników układu lub w wyniku procesów fizycznych. Omówiono ISFI stosowane w charakterze rusztowań wstrzykiwalnych, przeznaczonych do wspomagania regeneracji tkanek, a także wykorzystywane jako układy kontrolowanego uwalniania leków, ze szczególnym uwzględnieniem preparatów używanych w praktyce klinicznej. Skoncentrowano się na układach formowanych w wyniku separacji fazy stałej, opartych na poliestrach alifatycznych zaakceptowanych do zastosowań biomedycznych. Omówiono skład takich układów oraz wpływ rodzaju rozpuszczalnika i masy molowej użytego polimeru na szybkość tworzenia implantu, a także kinetykę uwalniania zawartej w nim substancji bioaktywnej.The paper is a literature review with 111 references on the polymeric implants forming in the site of incorporation into organism. This kind of materials may have only a structural function, but they can also serve as carriers of bioactive compounds in the treated site. In situ forming implants (ISFI) can be obtained by reaction of functional groups contained in the system components or as a result of physical processes. ISFI serving as injectable scaffolds intended for tissue regeneration and the requirements that should be fulfilled by these materials are presented. Also, various ideas for using ISFI as controlled drug delivery systems, in particular clinically used materials, are described. The attentionis focused on the systems solidifying by solid phase separation, based on aliphatic polyesters accepted for biomedical applications. The composition of these systems and the influence of solvent and polymer molecular weight on the rate of implant formation as well as kinetics of bioactive substance release are discussed

Polymeric in situ forming systems for biomedical applications. Part II. Injectable hydrogel systems

Część druga pracy przeglądowej poświęconej układom polimerowym formowanym wmiejscu zastosowania (in situ), dotycząca wstrzykiwalnych układów hydrożelowych. Przedstawiono główne strategie otrzymywania hydrożeli formowanych w miejscu implantowania, z zasadniczym podziałem na sieciowanie chemiczne i fizyczne.The paper is the second part of a review concerning polymeric systems formed at the site of application (in situ). The following presentation relates to injectable hydrogel systems. Brief description of the polymers applied in such systems is given. The main strategies for preparing hydrogels at the target site are also described. In situ gelling systems have been essentially classified into chemically and physically crosslinked ones

DMA analysis of the structure of crosslinked poly(methyl methacrylate)s

Purpose: This paper presents the study aimed at the development of crosslinked poly(methyl methacrylate)s (X-PMMA) of varied crosslink density and the investigation of the relationships between the polymer network structure and dynamic mechanical properties. Methods: A series of model X-PMMA networks were crosslinked by the introduction of: 1, 2, 5, 10 and 20% of triethylene glycol dimethacrylate (TEGDMA). The copolymerizations led to various glass-rubber relaxation properties of the polymer networks, as revealed by dynamic-mechanical analysis (DMA). Glass temperature (Tg) and storage modulus above the Tg ( ) Erubbery were a sensitive function of network architecture. DMA data were used for calculating the network parameter (Mc), crosslink density (q) and its alternative measure – the degree of crosslinking (DX). Results: The viscoelastic properties as well as structural parameters calculated from those showed correlation with the amount of the crosslinker. The increase in TEGDMA content resulted in the Tg, q and DX increases, whereas Mc decrease. The possible incomplete conversion of double bonds was detected in the DMA analysis, which was confirmed by the degree of conversion (DC), measured by FTIR spectroscopy. Additionally, some amount of sol fraction was found by 1H NMR experiments. Conclusions: The structure-property relationships developed for the system presented in this work could be useful in tissue engineering, where X-PMMA is applied. The direct measure of storage modulus values before and above glass transition may serve as a simple and fast indicator of the X-PMMA crosslink density