3D-printed PMMA preform for hollow-core POF drawing

In this paper we report the first, to our knowledge, 3D-printed hollow-core poly(methyl methacrylate) (PMMA) preform for polymer optical fibre drawing. It was printed of commercial PMMA by means of fused deposition modelling technique. The preform was drawn to cane, proving good enough quality of drawing process and the PMMA molecular weight to be appropriate for drawing. This ascertains that the manufacturing process provides preforms suitable for hollow-core fibre drawing. The paper focuses on maximisation of transparency of PMMA 3D printouts by optimising printing process parameters: nozzle temperature, printing speed and infill

Embedding low loss polymer optical fibre Bragg gratings:two different approaches

In this paper, we present two different ways to embed polymer fibre Bragg gratings (FBGs) into polymer matrices. In the first experiment, we embedded the FBG into a 3D printed polymer structure, whereas in the second experiment, the coating was polymerized around the fibre. In both cases, the response of the grating was unchanged, without any loss or distortion of the FBG signal compared with the bare fibre response. The design of the polymer coating was optimised for the measurement of a single measurand. We highlighted two possible applications: surface bend deformation monitoring and improved-sensitivity temperature sensing

PARP1 catalytic variants reveal branching and chain length-specific functions of poly(ADP-ribose) in cellular physiology and stress response

Poly(ADP-ribosyl)ation regulates numerous cellular processes like genome maintenance and cell death, thus providing protective functions but also contributing to several pathological conditions. Poly(ADP-ribose) (PAR) molecules exhibit a remarkable heterogeneity in chain lengths and branching frequencies, but the biological significance of this is basically unknown. To unravel structure-specific functions of PAR, we used PARP1 mutants producing PAR of different qualities, i.e. short and hypobranched (PARP1\G972R), short and moderately hyperbranched (PARP1\Y986S), or strongly hyperbranched PAR (PARP1\Y986H). By reconstituting HeLa PARP1 knockout cells, we demonstrate that PARP1\G972R negatively affects cellular endpoints, such as viability, cell cycle progression and genotoxic stress resistance. In contrast, PARP1\Y986S elicits only mild effects, suggesting that PAR branching compensates for short polymer length. Interestingly, PARP1\Y986H exhibits moderate beneficial effects on cell physiology. Furthermore, different PARP1 mutants have distinct effects on molecular processes, such as gene expression and protein localization dynamics of PARP1 itself, and of its downstream factor XRCC1. Finally, the biological relevance of PAR branching is emphasized by the fact that branching frequencies vary considerably during different phases of the DNA damage-induced PARylation reaction and between different mouse tissues. Taken together, this study reveals that PAR branching and chain length essentially affect cellular functions, which further supports the notion of a ‘PAR code’

Analysis of Interaction of Surfactant Molecules with Si(hkl) Planes on the Basis of Anisotropic Etching in Alkaline Solutions

In the paper, measurements of surface tension of solutions used for silicon etching and results of etching in the solutions are presented. Based on the obtained results, the analysis of interactions of surfactants with differently oriented silicon planes has been carried out

Mszaki jako element krajobrazu kulturowego: biologia, miejsce, rola

Bryophytes are small spore plants which occurs in all climates zones and plant formations. They form zonal (tundra) and azonal (bogs) environments or are integral part of other communities. They are very well adapted to the colonization of extreme and initial habitats. Civilization development has created for them adequate ecological niches like walls, roofs, sidewalks, lawns, parks or cemeteries. The bryophytes spontaneously colonize them, becoming an integral part of the small-town and metropolitan landscape. This paper presents the biology of bryophytes, pays attention to the key features enabling them to inhabit architectural elements. The role and place of these plants in the urbanized space were characterized, the urbanophile bryophyte species were pointed, and places in the cultural landscape where they abundantly grow were indicated. Also the potential exploiting of bryophytes in the urban conditions in utilitarian, functional and decorative form were highlighted.Mszaki to niewielkie rośliny zarodnikowe obecne we wszystkich strefach klimatycznych i ekosystemach. Tworzą zonalne (tundra) i ekstrazonale (torfowiska) formacje roślinne lub są integralnym elementem innych zbiorowisk. Są bardzo dobrze przystosowane do kolonizacji ekstremalnych i inicjalnych siedlisk, a rozwój cywilizacyjny wykreował dla nich także nisze ekologiczne w postaci murów, dachów, chodników, trawników, parków czy cmentarzy. Mszaki spontanicznie je zasiedliły, stając się integralną częścią krajobrazów małomiasteczkowych i wielkomiejskich. W niniejszym opracowaniu przybliżono biologię mszaków, zwracając uwagę na cechy kluczowe przy zasiedlaniu elementów architektonicznych. Określono rolę i miejsce tych roślin w przestrzeni zurbanizowanej, wskazano gatunki urbanofilne oraz miejsca w krajobrazie kulturowym, gdzie obficie występują. Zwrócono także uwagę na potencjał wykorzystania mszaków w warunkach miejskich w utylitarnej, funkcjonalnej i dekora- cyjnej formie

The natural values of selected dry grasslands under sheep grazing in the Kozki Nature Reserve

The studies of vegetation were carried out in the years 2010–2013. One of the study objectives was to update the assessment of the natural value of psammophilous grasslands 20 years after the establishment of Kózki nature reserve (mazowieckie voivodship). The phytosociological survey results were compared with the archive survey results available in the nature reserve’s documentation. There were noted some significant changes in the species composition of plant communities. The assessment of natural values of psammophilous grasslands confirmed the occurrence a simplified form of the Corynephoro-Silenetum tataricae association – priority habitats for protection, the presence of 6 dry grassland indicator species, one endangered species (Carex praecox) and one plant species (Helichrysum arenarium) under legal protection was determined

A contribution to the moss and liverwort flora of the Reberce Nature Reserve at the Przemyśl Foothills (Western Carpathians, Poland)

The paper presents the results of studies on bryophyte flora of the Reberce forest reserve located in the Przemyśl foothills. Thirty-three species of liverworts, 70 species and two varieties of mosses were found. Terrestrial (66 species) and epixylic (58) bryophytes formed the largest ecological groups in the reserve. Twenty-four protected species were also recorded, eight endangered bryophytes and six taxa considered as primeval forest species. The most interesting finds are: Bazzania trilobata, Buxbaumia viridis, Calypogeia suecica, Cephalozia catenulata, Frullania dilatata, Metzgeria conjugata, Nowellia curvifolia, Orthotrichum lyellii, O. stramineum, Trichocolea tomentella and Ulota crispa

A contribution to the moss and liverwort flora of the Reberce Nature Reserve at the Przemysl Foothills (Western Carpathians, Poland)

The paper presents the results of studies on bryophyte flora of the Reberce forest reserve located in the Przemyśl foothills. Thirty-three species of liverworts, 70 species and two varieties of mosses were found. Terrestrial (66 species) and epixylic (58) bryophytes formed the largest ecological groups in the reserve. Twenty-four protected species were also recorded, eight endangered bryophytes and six taxa considered as primeval forest species. The most interesting finds are: Bazzania trilobata, Buxbaumia viridis, Calypogeia suecica, Cephalozia catenulata, Frullania dilatata, Metzgeria conjugata, Nowellia curvifolia, Orthotrichum lyellii, O. stramineum, Trichocolea tomentella and Ulota crispa