The influence of isosorbide on thermal properties of poly(L‐lactide) synthesized by different methods

In this article, we analyzed the influence of isosorbide content on glass transition temperature and crystallinity of poly(L ‐lactide). Different synthesis methods were applied to determine optimal procedure for polymerization of L ‐lactide in the presence of isosorbide. Two procedures were performed with tin(II) 2‐ethylhexanoate as the catalyst: first, using the vacuum sealed vessel, and second, using microwave reactor bulk polymerizations. The solution polymerization (with trifluoromethanesulfonic acid as catalyst) was possible at the temperature of 40°C. Obtained polyesters had number average molecular weights ranging from 20,000 to 65,000 g mol^–1, according to the gel permeation chromatography measurements. The polymer structure was characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. Thermal properties of the obtained polymers were analyzed using thermogravimetry (TG) and differential scanning calorimetry (DSC). According to DSC measurements, the addition of isosorbide in the polyesters influenced the increase in both glass transition temperature and degree of crystallization for all samples. The results obtained by thermogravimetric analysis confirmed the strong influence of polymerization mechanism on synthesized poly(L ‐lactides) thermal properties. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Application of fuzzy measures and interval computation to financial portfolio selection

As many data‐driven fields, finance is rich in problems requiring high computational power and intelligent systems techniques. In particular, the problem of selecting an optimal financial portfolio can be conveniently represented as a constrained optimization problem or a decision‐making problem. The aim of this paper is to show how to express the optimal portfolio selection problem from a decision‐theoretic perspective and show how to address this problem using fuzzy measures and fuzzy integrals. © 2010 Wiley Periodicals, Inc.     

The validity and reliability of the Dutch Effort–Reward Imbalance Questionnaire.

The reliability and validity of the Effort–Reward Imbalance Questionnaire were tested in 775 blue- and white-collar workers in the Netherlands. Cronbach's alpha revealed sufficient internal consistency of all subscales except Need for Control. With exploratory probabilistic scaling (Mokken) analysis, the psychometric qualities of the Need for Control scale were improved. With confirmatory factor analysis, the factorial validity of the Extrinsic Effort and Reward subscales was confirmed. A model with 3 separate dimensions for reward (status control, esteem reward, and monetary gratification) proved adequate, emphasizing the importance of distinguishing subscales. The congruent validity of the subscales and a hypothesized relationship with an external construct, health functioning, were confirmed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Wish to Leave Ethnically Concentrated Neighbourhoods: The Role of Perceived Social Cohesion and Interethnic Attitudes

This paper aims to investigate the motives behind people's wishes to move out of ethnically concentrated neighbourhoods. We focus on the impact of perceived social cohesion and negative interethnic attitudes and hypothesise on moving wishes of ethnic majority and minority residents in the Netherlands (i.e. Turks and Moroccans). Data were derived from the first wave of the 2009 Netherlands Longitudinal Lifecourse Study, collected in 35 municipalities covering 800 neighbourhoods. Taking into account household, housing and other neighbourhood attributes, multilevel logistic regression models show that ethnic majority residents are more likely to have a wish to move when they live in neighbourhoods with a large percentage of ethnic minorities. This can be explained by a lack of perceived social cohesion, but not by their negative attitudes towards ethnic minorities. Controlling for housing and neighbourhood conditions, the percentage of ethnic minorities neither increases nor decreases minority residents' moving wishes.     

Durability of different carbon nanomaterial supports with PtRu catalyst in a direct methanol fuel cell

PtRu catalysts with similar particle size and composition were deposited on three different carbon supports: Vulcan, graphitized carbon nanofibers (GNF) and few-walled carbon nanotubes (FWCNT) and their performance for methanol oxidation was studied in an electrochemical cell and in a single cell DMFC. The electrochemical results indicate that with PtRu/GNF and PtRu/FWCNT higher current densities are obtained and oxidation intermediates deactivate the surface less compared to the same catalyst on Vulcan support. Conversely, PtRu/Vulcan provided the highest open circuit voltage OCV and current densities in DMFC experiments due to a well-optimized electrode layer structure. Because stability is a key requirement for fuel cell commercialization, 6-day-long fuel cell stability tests were carried out, showing that PtRu/Vulcan degraded significantly. This was due to the collapse of the secondary structure of the electrode layer revealed by post characterization of the membrane electrode assembly (MEA) with SEM and TEM. PtRu/GNF exhibited slightly poorer initial performance but better stability because the structure of the anode layer was maintained. PtRu/FWCNT showed the worst initial performance and long-term stability. The good stability of non-optimized PtRu/GNF MEAs shows the potential of these novel nanocarbon supported catalysts as stable fuel cell components after proper MEA optimization.     

Deformation of the compound middle lamella in spruce latewood by micro-pillar compression of double cell walls

The mechanical integrity of the interface between two adjacent cells in spruce late wood was studied by uniaxial compression of focused ion beam machined micro-pillars of double cell walls (DCW) containing the compound middle lamella (CML). The DCW reveals a lower yield strength and stiffness than the secondary cell wall (S2). Failure occurs by tearing of the interface between the first (S1) and second layers (S2) of the secondary cell wall exposing the internal arrangement of the microfibrils, while the CML remains intact.     

Attachment of Cancer Urothelial Cells to the Bladder Epithelium Occurs on Uroplakin-Negative Cells and Is Mediated by Desmosomal and Not by Classical Cadherins

Urinary bladder cancer is often multifocal; however, the intraluminal dissemination of the urothelial cancer cells is poorly understood. The involvement of N-cadherin in the adhesion of the cancer urothelial cells to the urothelium had not previously been studied. Therefore, we herein explore the possibility of the intraluminal dissemination of the urothelial cancer cells by evaluating the role of classical cadherins in the adhesion of urothelial cancer cells to the urothelium. We used E-cadherin negative T24 cells and established a T24 Ncad^low cell line with an additionally decreased expression of N-cadherin in the plasma membrane and a decreased secretion of proform of metalloproteinase 2. The labelled T24 and T24 Ncad^low cells were seeded onto urothelial in vitro models. After 24 h in co-culture, unattached cancer cells were rinsed and urothelia with attached cancer urothelial cells were processed for fluorescence and electron microscopy. Both the T24 and T24 Ncad^low cells attached to the urothelium, yet only to the uroplakin-negative urothelial cells. The ultrastructural analysis showed that T24 and T24 Ncad^low cells adhere to poorly differentiated urothelial cells by desmosomes. To achieve this, they first disrupt tight junctions of superficial urothelial cells. This study indicates that the lack of E-cadherin expression and decreased expression of N-cadherin in the plasma membrane of T24 cells does not interfere with their adhesion to the urothelium; therefore, our results suggest that intraluminal dissemination of cancer urothelial cells along the urothelium occurs on uroplakin-negative cells and is desmosome-mediated.     

Das Verbot der pränatalen Diagnostik spätmanifestierender Erkrankungen im deutschen Gendiagnostikgesetz – eine Diskussion medizinischer und rechtlicher Aspekte und deren Implikation für die medizinethische Diskussion

Definition of the problem The German Genetic Diagnosis Act (Genetic Diagnosis Act, GenDG) became effective on February 1, 2010. Although this act was welcomed by many, the debate surrounding some regulatory areas, for example, screening newborns, continues. One aspect of this new legislation, however, has received little attention: the prohibition of prenatal diagnosis of so-called late-onset diseases—where first symptoms only develop after completion of the 18th year of life—constitutes an internationally unique prohibition. In this publication, we would like to contribute to a more differentiated discussion of § 15(2) GenDG that sanctions this diagnosis. Arguments and conclusion There are arguments supporting this prohibition (especially the right of the child not to know). However, based on medical concerns as well as an analysis of ethical and legal pros and cons, we conclude that maintaining this general prohibition of diagnosing late-onset diseases might be insufficient as well as inconsistent with other regulations; thus, possible alternatives are discussed.