Raman imaging of changes in the polysaccharides distribution in the cell wall during apple fruit development and senescence

Main conclusion Du ring on-tree ripening, the pectin distribution changed from polydispersed in cell wall to cumulated in cell wall corners. During apple storage, the pectin distribution returned to evenly dispersed along the cell wall. The plant cell wall influences the texture properties of fruit tissue for example apples become softer during ripening and postharvest storage. This softening process is believed to be mainly connected with changes in the cell wall composition due to polysaccharides undergoing an enzymatic degradation. These changes in polysaccharides are currently mainly investigated via chemical analysis or monoclonal labeling. Here, we propose the application of Raman microscopy for evaluating the changes in the polysaccharide distribution in the cell wall of apples during both ripening and postharvest storage. The apples were harvested 1 month and 2 weeks before optimal harvest date as well as at the optimal harvest date. The apples harvested at optimal harvest date were stored for 3 months. The Raman maps, as well as the chemical analysis were obtained for each harvest date and after 1, 2 and 3 months of storage, respectively. The analysis of the Raman maps showed that the pectins in the middle lamella and primary cell wall undergo a degradation. The changes in cellulose and hemicellulose were less pronounced. These findings were confirmed by the chemical analysis results. During development changes of pectins from a polydispersed form in the cell walls to a cumulated form in cell wall corners could be observed. In contrast after 3 months of apple storage we could observe an substantial pectin decrease. The obtained results demonstrate that Raman chemical imaging might be a very useful tool for a first identification of compositional changes in plant tissue during their development. The great advantage Raman microspectroscopy offers is the simultaneous localization and identification of polysaccharides within the cell wall and plant tissue

Heidegger on creativity: From boredom to re-engagement with the world

Experimental psychologists have discussed whether boredom can help us become more creative. At first blush, this would seem to be rather unlikely. When we are bored, we are disengaged; we cannot be bothered and nothing seems worthwhile; we have no interest in the world around us. Such a condition, surely, is not conducive to creativity (Haager et al. 2018). Yet some psychologists disagree (Gasper and Middlewood 2014). Boredom, they explain, breaks down entrenched routines and thought-patterns and provides us with an opportunity to think again and anew. Respondents in “approach-oriented states” such as boredom engage in more “associative thought” than those in “avoidance-oriented affective states.” This is how boredom comes to encourage “the quest for meaning and exploration” (Gasper and Middlewood 2014, pp. 53–55...2-s2.0-8508440789

Polymer materials for selective laser sintering : current state of the art

W artykule pokazano fundamentalne informacje na temat jednej z głównych technik wytwarzania przyrostowego, czyli metody selektywnego spiekania laserowego (SLS). Opisano rodzaje czynników i ich wpływ na jakość uzyskiwanych tą metodą modeli. Przedstawiono wymagania stawiane materiałom polimerowym wykorzystywanym w technice SLS oraz dokonano przeglądu literatury z ostatnich lat, dotyczącej nowych materiałów dedykowanych metodzie SLS.In the article, the fundamental information about one of the main techniques for incremental methods of production, that is, selective laser sintering (SLS) was described. Pointed out the types of factors and their influence on the quality of obtained by this method models. The requirements for polymer materials used in SLS technology were introduced and discussed. A review of the literature in recent years, concerning new, dedicated SLS method materials was presented