High refractive index hyperbranched polymers with different naphthalene contents prepared through thiol-yne click reaction using di-substituted asymmetric bulky alkynes

In the present study, different aromatic moieties, naphthalene and benzene, were introduced into alkynes to constitute 1,3,5-tris(naphthylethynyl)benzene as B₃ monomer. This monomer could be reacted with different ratios of hexane-1,6-dithiol (A₂ monomer) via mono-selective Thiol-Yne reaction (TYR) to form hyperbranched polymers PI. TYR yielded in both, model reactions and polymerizations, mono-adducts with high regioselectivity and proved the absence of any bis-adducts. Polymers of very high molecular weights of up to 625,000 g/mol could be achieved without any sign of gel formation. All the polymers exhibit high transparency in the visible wavelength range and also show high refractive indices of up to 1.745 at 589.7 nm due to the high incorporation of naphthalene and phenyl groups. Besides, all polymers prove excellent solubility and processability together with excellent thermal properties.     

Carbon nanofibers produced from modified electrospun PAN/hydroxyapatite precursors as scaffolds for bone tissue engineering

In the current study we have proposed a method to obtain a carbon/HAp bioactive nanofibrous scaffold. The modified carbon nanofibrous nonwoven' fabrics were obtained by the use of electrospinning and subsequent stabilization and carbonization processes. The modified with HAp powder nanofibrous PAN nonwovens were thermally stabilized using a multi-stage process in the temperature ranging from 100 °C to 300 °C in an oxidative environment and then carbonized at 1000 °C in argon atmosphere. The changes of properties of composite precursor membranes taking place during stabilization and carbonization processes were investigated using the methods of: DSC, TGA, FTIR, SEM, EDX, WAXD and mechanical tests. Bioactivity was determined by assessing the formation of crystalline apatite on the surface of membranes upon immersion in Simulated Body Fluid (SBF). The FTIR, SEM and WAXD investigation clearly prove that hydroxyapatite added to the electrospinning solution was present also in composites nanofibrous nonwovens after stabilization and carbonization process. It was found that due to HAp addition: the significant decrease of fibers average diameter occurs and that the average pore size for modified membranes is smaller than for the unmodified one. On the other hand it was shown that the ceramic additive protects fibers from mass reduction during the stabilization treatment. Finally a drastic increase of mineralization activity of nCF/HAp scaffolds as compared to their nCF counterparts has been proved.     

Biological activities of malvidin, a red wine anthocyanidin

Malvidin (mv) has been identified as a potential inhibitor of 3',5'-cyclic adenosine monophosphate (cAMP) phosphodiesterases (PDE). This study was to investigate if, as a possible consequence of intracellular PDE inhibition, the activity of the mitogen-activated protein kinase (MAPK) cascade is affected by mv treatment. At a concentration of 5 microM of mv a significant decrease of phosphorylated ERK1 and ERK2 (ERK, extracellular regulated kinase) in HT29 cells was observed. However, an increase in substance concentration led to a substantial recurrence of the phosphorylated enzymes. Cell cycle analysis underlined that indeed G(1)-relevant targets are only marginally affected by mv. The recurrence of phosphorylated ERK1/2 and the lack of effectiveness on the G(1)-passage up to 100 microM indicated that the inhibition of cAMP-specific PDEs is of minor relevance for the growth-inhibitory properties of mv in HT29 cells. In contrast, the release of cells, synchronised in the G(2)/M-phase of the cell cycle by nocodazole treatment, was effectively blocked in the presence of 1 microM mv. These results suggest that mv interferes with cellular targets relevant for G(2)/M-progression which have not been identified so far.     

Effect of cultivar and fruit storage on basic composition of clear and cloudy pear juices

BackgroundPears due to low acidity are a suitable raw material for the production of multifruit nectars thus it is justified to determine the chemical composition and investigate the effect of cultivar and fruit maturity on juices quality.MethodsJuices from ‘Alexander Lucas’ and ‘Conference’ cultivars were produced after harvest and after 3 months of pears storage.ResultsAverage yield of clear juices was 76.4% for ‘Conference’ cultivar and 74.3% for ‘Alexander Lucas’. In the case of cloudy juices, the yield was lower by about 3%. Processing of ‘Conference’ cv. from stored fruit resulted in yield decrease compared to fruits after harvest; this was not in case of ‘Alexander Lucas’ in 2008, where juices produced from stored fruits were characterized by a higher yield compared to fresh fruit.Total solids content in clear juices was 125–135 g/L and 135–141 g/L for cloudy juices. ABTS^●+ and total phenolics analysis showed that cloudy juices were characterized by a higher antioxidant activity and phenolics content than the clear ones.ConclusionPear storage, on the contrary to apples, does not decrease their suitability for cloudy juice production. Cloudy juices as a rule have higher antioxidant activity than the clear ones.     

Physical properties of muffins sweetened with steviol glycosides as the sucrose replacement

Overconsumption of sweets contributes to increasing obesity among children and adults. Functional food brings an opportunity to improve nutritional value of commonly eaten products, e.g., pastry products. New trends in the food industry tend to produce low-calorie products by replacing sugar or fat with additives having pro-health benefits. The aim of this study was to determine the effect of replacing sucrose with steviol glycosides (natural non-caloric sweetener) on the quality properties of bakery products. The analysis of muffin’s texture, color, cooking yield, browning index, and sensory analysis were performed. The study showed that a 25% addition of steviol sweetener (as a sucrose replacement) was the most appropriate modification of the basic formula. The resulting muffins gained sensory attractiveness and health-promoting qualities. Moreover, the study showed that a reduction of sucrose in excess of 50% had a negative impact on the quality of muffins and their sensory profiles.     

The NavChair Assistive Wheelchair Navigation System.

The NavChair Assistive Wheelchair Navigation System [19] is being developed to reduce the cognitive and physical requirements of operating a power wheelchair for people with wide ranging impairments that limit their access to powered mobility. The NavChair is based on a commercial wheelchair system with the addition of a DOS-based computer system, ultrasonic sensors, and an interface module interposed between the joystick and power module of the wheelchair. The obstacle avoidance routines used by the NavChair in conjunction with the ultrasonic sensors are modifications of methods originally used in mobile robotics research. The NavChair currently employs three operating modes: general obstacle avoidance, door passage, and automatic wall following. Results from performance testing of these three operating modes demonstrate their functionality. In additional to advancing the technology of smart wheelchairs, the NavChair has application to the development and testing of "shared control" systems where a human and machine share control of a system and the machine can automatically adapt to human behaviors.     

Lifestyle Meets Market: Bohemian Entrepreneurs in Creative Industries

By linking lifestyle studies with creative industries research, this article opens a new perspective on creativity and innovation management. We argue that artists in the creative industries have to bridge the gap between artistic work and the economic need for self‐management, and that a bohemian lifestyle essentially supports them in doing so. The bohemian lifestyle, which is characterized by a devotion to art for art’s sake, is an essential source for work motivation of artists and an increasing number of other creative workers. The article draws upon an empirical study into artistic work and employment in German theatres. Enacting a bohemian lifestyle enables actors as ‘bohemian entrepreneurs’ to integrate intensive self‐management and self‐marketing as well as subordination of private life to work into their artistic work life. Analysing the link between lifestyle and creative work is crucial for understanding the way in which creative workers become artists and, at the same time, entrepreneurs of their creative talent.