Compatibilization of polypropylene/polyamide 6 blends using new synthetic nanosized talc fillers: Morphology,thermal, and mechanical properties

New synthetic nanotalc and a commercially available natural fine talc (Luzenac© A3) were chosen in order to establish a comparative study in terms of their contributions on the improvement of the morphology as well as the final properties of PP/PA6 blends prepared by melt processing. At first, the TEM and SEM micrographs showed that both talc particles have a preferential affinity for the more hydrophilic polyamide 6 phase compared with the continuous PP matrix. Moreover, in both cases, the addition of talc fillers induces a significant decrease of the size of the PA6 domains but the better compatibilization efficiency was obtained in the presence of synthetic nanotalc particles. In this work, the positive change induced by the talc nanofillers on the crystallization kinetics and final morphology was highlighted. In addition, compared with natural talc, a highly level of dispersion of talc layers has been obtained with the synthetic nanotalc which is more hydrophilic. Thus, this better dispersion greatly improves the thermal stability of PP/PA6 blends and leads to better mechanical properties (+ 40% in Young's modulus). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40453.     

Lactational changes in concentration and distribution of ganglioside molecular species in human breast milk from Chinese mothers

Gangliosides play a critical role in human brain development and function. Human breast milk (HBM) is an important dietary source of gangliosides for the growing infant. In this study, ganglioside concentrations were measured in the breast milk from a cross‐sectional sample of Chinese mothers over an 8‐month lactation period. The average total ganglioside concentration increased from 13.1 mg/l during the first month to 20.9 mg/l by 8 months of lactation. The average concentration during the typically solely breast‐feeding period of 1?6 months was 18.9 mg/l. This is the first study to report the relative distribution of the individual ganglioside molecular species through lactation for any population group. The ganglioside molecular species are made up of different fatty acid moieties that influence the physical properties of these gangliosides, and hence affect their function. The GM₃ molecular species containing long‐chain acyl fatty acids had the most prominent changes, increasing in both concentration and relative distribution. The equivalent long‐chain acyl fatty acid GD₃ molecular species typically decreased in concentration and relative distribution. The lactational trends for both concentration and relative distribution for the very long‐chain acyl fatty acid molecular species were more varied. The major GM₃ and GD₃ molecular species during lactation were d40:1 and d42:1, respectively. An understanding of ganglioside molecular species distribution in HBM is essential for accurate application of mass spectrometry methods for ganglioside quantification.     

Grundwassergleichenplan für Brandenburg – Interpolation mittels Kriging mit externer Drift

In Brandenburg, Germany, state-wide water table contours that are based on data at a common reference date were created for the first time. These contour maps are needed as a basis for hydrological and hydrogeological analyses. All hydraulic heads were measured in 2011 using data from the regional authority and from about 100 other official institutions. Regionalisation was achieved with geostatistical interpolation using “kriging with external drift”. Additional information exists in terms of a conceptual model, which characterises water table contours and was used as a secondary variable in the kriging process. This method provides a significantly better approximation of the groundwater system in comparison to ordinary kriging while decreasing the number of required supporting points and improving reproducibility. The water table contours of 2011 can be used as a basis for external drift in future mapping campaigns, which will help to reduce the need for field measurements and mapping.     

Visualising distant off-screen landmarks on mobile devices to support spatial orientation

Mobile devices have become increasingly popular in supporting persons to find their ways in our daily lives. Research has been initiated to address issues including the efficiency of wayfinding instructions and the effect of using mobile devices on spatial awareness including cognitive mapping and spatial orientation. In this paper, we present our initial work on the design of mobile map display that visualises distant landmarks at the edge of mobile screen to support spatial orientation. Empirical assessments show that the visualisation of distant landmarks, in comparison with the visualisation without distant landmarks, contributes positively to persons with low sense of direction to be spatially oriented. Furthermore, this design dramatically reduces the frequency of zooming activity on mobile devices. Results indicate the potentials and challenges of extending this design into routing services that could further support user's wayfinding efficiency and spatial awareness.     

Mucoadhesive nano-sized supramolecular assemblies for improved pre-corneal drug residence time

Abstract

Context: Mucoadhesive nanoparticles were compared with non-aggregated constituent polymers for effect on pre-corneal residence of dexamethasone phosphate (DP) or met-enkephalin (ME), administered by eye-drops to rabbits.

Objective: Deepening the knowledge of ophthalmic nanoparticulate systems in terms of ability to prolong pre-corneal residence.

Materials and methods: Medicated nanoparticles resulted from gelation of quaternary ammonium–chitosan conjugate or its thiolated derivative with hyaluronan in the presence of drug. Particles were analyzed by light scattering. Dialysis removed non-encapsulated drug, dynamic dialysis measured drug–polymer interactions, and lyophilization-stabilized product. Dispersions were regenerated from lyophilized products. Also solutions of non-thiolated or thiolated chitosan derivative were administered. Mean drug residence time (MRT) in tears was determined by collecting samples from lower marginal tear strip of albino rabbits using capillaries.

Results and discussion: Nanoparticle size of regenerated dispersions was 400–430?nm (DP-systems), 360–370?nm (ME-systems); the drug content was 2.5?mg/mL (DP) or 0.3?mg/mL (ME). The MRT for DP nanoparticles from non-thiolated derivative was higher than that for non-aggregated polymer, due to stronger concurrent interactions of positively charged nanoparticles with ocular surface and drug. Thiolated polymer nanoparticles and non-aggregated parent polymer, both interacting weakly with DP, showed similar MRT values. The MRT of ME could only be enhanced by protecting drug from enzymatic hydrolysis. This was done by nanoparticle systems, whereas non-aggregated polymers were ineffective.

Conclusion: Developing a nanoparticle system rather than a solution of mucoadhesive polymer, for prolonging pre-corneal residence, is convenient, provided nanoparticles interact strongly with both ocular surface and drug, or protect drug from metabolic degradation.     

Linking human behaviour to environmental effects using a case study of urban rodent control

Pest control is common in many land use activities and can affect non‐target species. Our objectives were to evaluate, among chemical rodent control product (rodenticide) users, awareness of non‐target effects on wildlife and willingness to change rodent control behaviour given knowledge of possible local non‐target effects. Approximately half of respondents to a resident survey in California (USA) practised rodent control; of these, approximately 45% were chemical rodenticide users. Few (10%) were aware of possible non‐target effects. Then, we asked subjects about their potential to pursue each of four rodent control behaviours: continue current use, change product use, reduce use, or stop use. Most respondents indicated that they were most likely to change their rodent control behaviour given the knowledge that rodenticides were possibly affecting non‐target wildlife. Among the four behaviours, the greatest frequency of respondents indicated a potential change of product(s) used. Concern about rodenticides affecting wildlife was the most consistent predictor of potential to change or not change behaviour. Our results highlight importance of awareness about environmental effects of personal actions, and promotion of stewardship may be most effective if efforts focus on development of long‐term personal value in the environment.     

Social outcomes in the construction industry: the case of the Western Australian ‘Percent for Art’ policy

Social outcomes, in particular intangible social outcomes, are generally difficult to achieve in the construction industry due to the predominantly episodic, fragmented and heavily regulated nature of construction that presupposes a tendency towards mainstream construction processes and design. The Western Australian ‘Percent for Art’ policy is recognized for stimulating social outcomes, by creating richer and more aesthetically pleasing social environments through the incorporation of artwork into public buildings. A case study of four Percent for Art projects highlights the role of the Artwork Selection Committee in incorporating artwork into construction. A total of 20 semi-structured interviews were conducted with committee members and policy officers. Data analysis involved a combination of pattern coding and matrix categorization, and resulted in the identification of the committee’s three key elements of collaborative communication, democratic decision-making and project champions. The findings suggest these key elements foster the interaction, communication and relationships needed to facilitate feedback, enhance relationships, create cross-functional teams and lower project resistance, which are all necessary to overcome constraints to social outcomes in construction. The findings provide greater insight into the mechanisms for achieving social outcomes and a basis for future discussion about the processes for achieving social outcomes in the construction industry.     

H-bonding driven assembly of colloidal Au nanoparticles on nanostructured poly(styrene-b-ethylene oxide) block copolymer templates

A facile, cost-effective, and general solution-based “bottom-up” method for nanopatterning dense arrays of colloidal Au nanoparticles (NPs) has been developed. The organization of the NPs has been successfully achieved onto a microphase-separated poly(styrene-block-ethylene oxide) (PS-b-PEO) block copolymer (BCP) thin film which acts as structural template. The NP assembly process occurs by incubating the BCP films in dispersions of the ex situ synthesized Au NPs, not requiring any chemical pre-treatment or activation step of the copolymer surface, and has demonstrated to be distinctively controlled by multiple, cooperative, and selective hydrogen bonding interactions between hydroxyl functionalities of the capping molecules coating the Au NP surface and the hydrophilic PEO block. The effect of incubation time and concentration of NPs on the selectivity of the assembly has been investigated by atomic force and scanning electron microscopy. The results show that the BCP pattern is preserved after decoration with the Au NPs. The fabricated nanopatterns are good candidates for nanostructure integration in sensing and optoelectronic applications, as well as in memory devices and photonic systems. Moreover, the proposed immobilization protocol represents a model system that can be extended to other NPs having different compositions and surface chemistries.     

Integration of binding peptide selection and multifunctional particles as tool-box for capture of soluble proteins in serum

In this paper, we report on a general approach for the detection of a specific tumoural biomarker directly in serum. Such detection is made possible using a protein-binding peptide selected through an improved phage display technique and then conjugated to engineered microparticles (MPs). Protein biomarkers represent an unlimited source of information for non-invasive diagnostic and prognostic tests; MP-based assays are becoming largely used in manipulation of soluble biomarkers, but their direct use in serum is hampered by the complex biomolecular environment. Our technique overcomes the current limitations as it produces a selective MP—engineered with an antifouling layer—that ‘captures’ the relevant protein staying impervious to the background. Our system succeeds in fishing-out the human tumour necrosis factor alpha directly in serum with a high selectivity degree. Our method could have great impact in soluble protein manipulation and detection for a wide variety of diagnostic applications.