Mechanical properties and chemical stability of pivalolactone-based poly(ether ester)s

The processing, mechanical and chemical properties of poly(ether ester)s, prepared from pivalolactone (PVL), 1,4-butanediol (4G) and dimethyl terephthalate (DMT), were studied. The poly(ether ester)s could easily be processed by injection moulding, owing to their favourable rheological and thermal properties. The tensile response of a poly(ether ester) with a butylene terephthalate (4GT) content of 72 mol%, which exhibited the phenomena of necking and strain-hardening, was related to the morphology of these copolymers. The influence of the short 4G-PVL segments was reflected in a high Young's modulus and yield stress, and resulted in a tough behaviour for the poly(ether ester), with an ultimate elongation of 500%. The poly(ether ester)s were stable towards treatment at room temperature with water or weakly acidic or alkaline solutions. Conditioning at 90°C in water for 264 h resulted in a water uptake of 1 wt%, whereas the rate of hydrolysis was 0.0003 (expressed in An rel h-1) for the poly(ether ester) with a 4GT content of 72 mol%. Although a decay in the mechanical properties for the PVL-based poly(ether ester) after exposure to water at 90°C was observed, these materials were assumed to have a higher hydrolytical stability than other poly(ether ester)

FIVA:Functional Information Viewer and Analyzer extracting biological knowledge from transcriptome data of prokaryotes

FIVA (Function Information Viewer and Analyzer) aids researchers in the prokaryotic community to quickly identify relevant biological processes following transcriptome analysis. Our software assists in functional profiling of large sets of genes and generates a comprehensive overview of affected biological processes.

Annexin A2 depletion delays EGFR endocytic trafficking via cofilin activation and enhances EGFR signaling and metastasis formation

Computer Systems, Imagery and Medi

Multivalent Tryptophan‐ and Tyrosine‐Containing [60]Fullerene Hexa‐Adducts as Dual HIV and Enterovirus A71 Entry Inhibitors

Unprecedented 3D hexa-adducts of [60]fullerene peripherally decorated with twelve tryptophan (Trp) or tyrosine (Tyr) residues have been synthesized. Studies on the antiviral activity of these novel compounds against HIV and EV71 reveal that they are much more potent against HIV and equally active against EV71 than the previously described dendrimer prototypes AL-385 and AL-463, which possess the same number of Trp/Tyr residues on the periphery but attached to a smaller and more flexible pentaerythritol core. These results demonstrate the relevance of the globular 3D presentation of the peripheral groups (Trp/Tyr) as well as the length of the spacer connecting them to the central core to interact with the viral envelopes, particularly in the case of HIV, and support the hypothesis that [60]fullerene can be an alternative and attractive biocompatible carbon-based scaffold for this type of highly symmetrical dendrimers. In addition, the functionalized fullerenes here described, which display twelve peripheral negatively charged indole moieties on their globular surface, define a new and versatile class of compounds with a promising potential in biomedical applications

Design and evaluation of a visualization application for the analysis of transcriptome data

Data from DNA micro-arrays provide biologists with huge amounts of information on gene activity. Following statistical analysis of the raw gene expression values, genes can be grouped in clusters exhibiting the same expression patterns. Relating the cluster information to known biological processes by hand is tedious and error-prone. To assist biologists in analyzing these data, the computer application FIVA (Functional Information Viewer and Analyzer) was developed. The application combines cluster information with information on known biological processes and generates colormaps showing the obtained functional profile. FIVA was developed from a biological point of view and was in need of a redesign. To guide us in creating a new design and implementation of FIVA, we used known concepts from the field of information visualization like the visualization mantra about interaction, eight guidelines on multiple views and color gradient interpretation information. The visualization in the new version of FIVA uses two different view types. One view displays an overview of all information, the other view shows the details a user has selected. To test whether the new implementation of FIVA satisfies real-life users, it was subjected to a usability study with ten specialized biologists as participants. We used a think-aloud protocol with coaching to study the interaction of the participants with FIVA when solving a set of real-world biological problems. After completing the tasks, participants were subjected to an interview. All participants stated that. they. 'iere satisfied and were planning to use the application in the future. The main, usability problems include the lack of an adequate filtering option, inconsistent buttonlocations, ihecolors that are used in the visualization and navigating through the overview diagram. The analysis of these usability problems showed that some problems could be traced back to violation of two multiple view guidelines and providing too little support for a part of the visualization mantra. The solutions to usability problems that could quickly be solved were implemented after the usability study.

Reactive blending of polypivalolactone with polycarbonate

Blends of polypivalolactone (PPVL) with bisphenol‐A polycarbonate (PC) were studied. Physical PPVL/PC blends showed one Tg close to the Tg of 145 °C for PC, indicating immiscibility. Reactive blending of PPVL and PC with 0.5 wt.‐% tetrabutylorthotitanate was performed in diphenyl ether (260 °C) and in a twin screw extruder (TSE) at 280 °C. Based on the results from NMR, FT‐IR and thermal analysis, it was concluded that interchange reactions had occurred. The thermal properties indicated that, due to these interchange reactions, PPVL/PC blends had become more miscible. Although blending in a TSE was more efficient with respect to interchange reactions compared with blending in diphenyl ether, complete randomization was not observed