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)

Becoming productive 21st century citizens: A systematic review uncovering design principles for integrating community service learning into higher education courses

Background: To prepare students to become productive 21st century citizens, universities have to be more engaged with society. Shifting towards community service learning (CSL) enables students to participate in, and reflect on, services that both benefit the public and also contribute to their own learning. There has been considerable research conducted on the improved student competencies, both academic and personal, resulting from CSL. There is, however, no consensus on how to integrate CSL into courses successfully, owing to the diverse contextual factors that influence implementation. Purpose: By means of conducting a review, this study aimed to establish general design principles to help guide course coordinators in implementing CSL in their academic courses. Design and methods: A systematic review was conducted of articles describing the implementation of CSL in academic courses within various disciplines. Implementation elements and principles were extracted from the articles and inductively grouped together, thereby identifying various design principles. Findings: Our analysis of the literature highlighted three steps that, according to the literature, are important in the implementation of CSL: (1) aligning course objectives and format; (2) establishing a relationship with the community partner; and (3) defining a reflection and evaluation strategy. We found that the nature of the design principles and specific approaches underlying these implementation steps should depend on the students’ capabilities, which include their pre-CSL experiences. Conclusion: The implementation steps and underlying design principles uncovered by this review may help guide and support course coordinators in their efforts to integrate CSL in their academic courses. The diverse range of design principles makes it possible to acknowledge students’ pre-CSL experiences and, thus, construct appropriate scaffolding, which i

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

Comparing exploration strategies for Q-learning in random stochastic mazes

Balancing the ratio between exploration and exploitation is an important problem in reinforcement learning. This paper evaluates four different exploration strategies combined with Q-learning using random stochastic mazes to investigate their performances. We will compare: UCB-1, softmax, greedy, and pursuit. For this purpose we adapted the UCB-1 and pursuit strategies to be used in the Q-learning algorithm. The mazes consist of a single optimal goal state and two suboptimal goal states that lie closer to the starting position of the agent, which makes efficient exploration an important part of the learning agent. Furthermore, we evaluate two different kinds of reward functions, a normalized one with rewards between 0 and 1, and an unnormalized reward function that penalizes the agent for each step with a negative reward. We have performed an extensive grid-search to find the best parameters for each method and used the best parameters on novel randomly generated maze problems of different sizes. The results show that softmax exploration outperforms the other strategies, although it is harder to tune its temperature parameter. The worst performing exploration strategy is greedy