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Biocompatible nanoparticles have been increasingly used in a variety of medical applications, including photodynamic therapy. Although the impact of synthesis parameters and purification methods is reported in previous studies, it is still challenging to produce a reliable protocol for the fabrication, purification, and characterization of nanoparticles in the 200-300 nm range that are highly monodisperse for biomedical applications.We investigated the synthesis of chitosan nanoparticles in the 200-300 nm range by evaluating the chitosan to sodium tripolyphosphate (TPP) mass ratio and acetic acid concentration of the chitosan solution. Chitosan nanoparticles were also crosslinked to rose bengal and incubated with human breast cancer cells (MCF-7) to test photodynamic activity using a green laser (λ = 532 nm, power = 90 mW).We established a simple protocol to fabricate and purify biocompatible nanoparticles with the most frequent size occurring between 200 and 300 nm. This was achieved using a chitosan to TPP mass ratio of 5:1 in 1% v/v acetic acid at a pH of 5.5. The protocol involved the formation of nanoparticle coffee rings that showed the particle shape to be spherical in the first approximation. Photodynamic treatment with rose bengal-nanoparticles killed ~98% of cancer cells.A simple protocol was established to prepare and purify spherical and biocompatible chitosan nanoparticles with a peak size of ~200 nm. These have remarkable antitumor activity when coupled with photodynamic treatment. more...

The synthesis of morphology‐controlled carbon‐coated nanostructured LiFePO4 (LFP/Carbon) cathode materials by surfactant‐assisted hydrothermal method using block copolymers is reported. The resulting nanocrystalline high surface area materials were coated with carbon and designated as LFP/C123 and LFP/C311. All the materials were systematically characterized by various analytical, spectroscopic and imaging techniques. The reverse structure of the surfactant Pluronic® 31R1 (PPO‐PEO‐PPO) in comparison to Pluronic® P123 (PEO‐PPO‐PEO) played a vital role in controlling the particle size and morphology which in turn ameliorate the electrochemical performance in terms of reversible specific capacity (163 mAh g−1 and 140 mAh g−1 at 0.1 C for LFP/C311 and LFP/C123, respectively). In addition, LFP/C311 demonstrated excellent electrochemical performance including lower charge transfer resistance (146.3 Ω) and excellent cycling stability (95 % capacity retention at 1 C after 100 cycles) and high rate capability (163.2 mAh g−1 at 0.1 C; 147.1 mAh g−1 at 1 C). The better performance of the former is attributed to LFP nanoparticles (, The Li‐Ion King! Morphology‐controlled carbon‐coated nanostructured LiFePO4/Carbon composites prepared by surfactant‐assisted hydrothermal method show promise in terms of electrochemical performance with a reversible specific capacity of 163 mAh g−1 and 140 mAh g−1 (at 0.1 C rate) for LFP/C311 and LFP/C123 composite, respectively. more...

L-3,4-dihydroxyphenylalanine (L-DOPA) is a naturally occurring catechol that is known to increase the adhesive strength of various materials used for tissue repair. With the aim of fortifying a porous and erodible chitosan-based adhesive film, L-DOPA was incorporated in its fabrication for stronger photochemical tissue bonding (PTB), a repair technique that uses light and a photosensitiser to promote tissue adhesion. The results showed that L-DOPA did indeed increase the tissue bonding strength of the films when photoactivated by a green LED, with a maximum strength recorded of approximately 30 kPa, 1.4 times higher than in its absence. The addition of L-DOPA also did not appreciably change the swelling, mechanical and erodible properties of the film. This study showed that strong, porous and erodible adhesive films for PTB made from biocompatible materials can be obtained through a simple inclusion of a natural additive such as L-DOPA, which was simply mixed with chitosan without any chemical modifications. In vitro studies using human fibroblasts showed no negative effect on cell proliferation indicating that these films are biocompatible. The films are convenient for various surgical applications as they can provide strong tissue support and a microporous environment for cellular infusion without the use of sutures. Statement of significance Tissue adhesives are not as strong as sutures on wounds under stress. Our group has previously demonstrated that strong sutureless tissue repair can be realised with chitosan-based adhesive films that photochemically bond to tissue when irradiated with green light. The advantage of this technique is that films are easier to handle than glues and sutures, and their crosslinking reactions can be controlled with light. However, these films are not optimal for high-tension tissue regenerative applications because of their non-porous structure, which cannot facilitate cell and nutrient exchange at the wound site. The present study resolves this issue, as we obtained a strong and porous photoactivated chitosan-based adhesive film, by simply using freeze drying and adding L-DOPA. more...

Photochemical tissue bonding with chitosan-based adhesive films is an experimental surgical technique that avoids the risk of thermal tissue injuries and the use of sutures to maintain strong tissue connection. This technique is advantageous over other tissue repair methods as it is minimally invasive and does not require mixing of multiple components before or during application. To expand the capability of the film to beyond just a tissue bonding device and promote tissue regeneration, in this study, we designed bioadhesive films that could also support stem cells. The films were modified with oligomeric chitosan to tune their erodibility and made porous through freeze-drying for better tissue integration. Of note, porous adhesive films (pore diameter ∼110 μm), with 10% of the chitosan being oligomeric, could retain similar tissue bonding strengths (13-15 kPa) to that of the nonporous chitosan-based adhesives used in previous studies when photoactivated. When tested in vitro, these films exhibited a mass loss of ∼20% after 7 days, swelling ratios of ∼270-300%, a percentage elongation of ∼90%, and both a tensile strength and Young's modulus of ∼1 MPa. The physical properties of the films were suitable for maintaining the viability and multipotency of bone-marrow-derived human mesenchymal stem cells over the duration of culture. Thus, these biocompatible, photoactivated porous, and erodible adhesive films show promise for applications in controlled cell delivery and regenerative medicine. more...

LiFePO 4 /Carbon nanocomposite was synthesised by two-step procedure hydrothermal synthesis in the presence of ascorbic acid followed by mixing of the product with citric acid and heating at 600 °C under a reducing atmosphere. During the first-step, slab or cuboid-shaped LiFePO 4 particles were formed with sizes of ∼100–150 nm in width and ∼300–600 nm in length. The second-step produced deformed slab or cuboid-like LiFePO 4 /Carbon nanocomposite with shapes somewhat resembling that of the precursor. The electrochemical properties were examined by electrochemical impedance spectroscopy (EIS) and potentiostatic intermittent titration technique (PITT) at a series of equilibrium potentials within the voltage range 2.7–4.2 V. From the PITT measurements of cathodes with two thicknesses, the LiFePO 4 /Carbon nanocomposite exhibits a specific discharge capacity of 150.3 mAh/g and 164.3 mAh/g, for 9.4 μm and 6.9 μm thickness, respectively. The current relaxation measurements also showed that the kinetics of Li-ion transfer depends strongly on the phase composition; in the solid-solution regions the Li-ion kinetics is dominated by diffusion whereas in the two-phase region it is by phase transformation. more...

In this work, nanocrystalline Ti/Cu multilayer thin films were fabricated using direct current magnetron sputtering with different layer thicknesses, namely 250, 100, 50, 25 and 5 nm. Additionally, a group of the film specimens were prepared with various modulation ratios where each bilayer was set to 100 nm. The size-dependent deformation behavior of the films was studied using the nano-indentation and nano-scratching techniques. The results showed that the flow strength of the films tended to increase as the layer thickness decreased. Moreover, the strength and scratch resistance of the films can be further enhanced by tailoring the thicknesses of two adjacent layers, while keeping the thickness of each bilayer unchanged. Finally, the size-dependent strengthening mechanism was discussed by recourse to microscopic examination. more...

Gypsum board with the advantages of low cost and ease of placement is widely used in buildings as ceiling and interior wall coverings. The interest in phase change material integrated gypsum board has been growing significantly over the last few years. In the present work, a composite form-stable phase change material (FSPCM) for use in gypsum board was developed based on methyl stearate and diatomite by a direct impregnation method. The material properties and thermal behaviour of the methyl stearate/diatomite composite were examined through different characterisation techniques to check its suitability for use in building materials, and particularly in gypsum board. Thermal cycling tests and thermogravimetric results confirmed that the FSPCM exhibited excellent thermal reliability and stability for long-term thermal management applications. The FSPCM was then integrated into gypsum board for potential use as building false ceiling for energy conservation. A small-scale test chamber with FSPCM-integrated gypsum board ceiling was prepared and modelled. The thermal/energy performance is evaluated and an economic analysis is performed against the conventional gypsum board without FSPCM in real environmental conditions. The results show that the use of FSPCM in gypsum board ceiling is economically feasible with cooling load savings of 16.2%. more...

The Cover Feature shows morphology‐controlled in‐situ carbon‐coated nanostructured LiFePO4 (LFP/Carbon) cathode materials prepared by surfactant‐assisted hydrothermal method using block copolymers such as Pluronic® P31R1 and Pluronic® P123. The resulting nanocrystalline high surface area materials show superior properties and were designated as LFP/C123 and LFP/C311, respectively. Further, the latter demonstrated outstanding electrochemical performance in terms of lower charge transfer resistance (146.3 Ω) with excellent cycling stability in terms of capacity retention (95% at 1 C after 100 cycles) and high rate capability (163.2 mAhg‐1 at 0.1 C). More information can be found in the Full Paper by Dr. G. S. Kamali Kannangara et al. on page 24 in Issue 1, 2020 (DOI: https://doi.org/10.1002/open.201900175).[Image: see text] more...

The sensitivity of glaciers to climatic change is key information in assessing the response and sea-level implications of projected future warming. New Zealand glaciers are important globally as an example of how maritime glaciers will contribute to sea-level rise. A spatially distributed energy-balance model is applied to Brewster Glacier, New Zealand, in order to calculate glacier mass balance, run-off and sensitivity to climate change. The model successfully simulates four annual mass-balance cycles. Close to half (52%) of the energy available for melt on the glacier is supplied by turbulent heat fluxes, with radiation less important, except during the winter. Model sensitivity to temperature change is one of the largest reported on Earth, at −2.0 m w.e. a−1 °C−1. In contrast, a 50% change in precipitation is required to offset the mass-balance change resulting from a 1 °C temperature change. Meltwater runoff sensitivity is also very high, increasing 60% with a 1°C warming. The extreme sensitivity of mass balance to temperature change suggests that significant ice loss will occur with even moderate climate warming. more...

La ville de New York est le centre reconnu de la choregraphie experimentale aux Etats-Unis aujourd’hui. Ce type de danse se pratique dans de petits lieux de spectacle situes dans le bas de Manhattan, ce qui explique qu’on s’y refere sous le nom de « downtown dance ». Les dix annees passees ont vu se produire dans ce milieu des changements institutionnels, economiques et stylistiques significatifs. D’importantes coupures budgetaires des subventions publiques destinees aux artistes ont affecte de maniere disproportionnee les choregraphes travaillant en dehors des grandes structures institutionnelles formelles. L’influence d’organismes producteurs et presentateurs de spectacles s’en est donc trouvee accrue. Parallelement – peut-etre aussi du fait de ces changements –, l’esthetique et les themes de la danse contemporaine a New York ont evolue vers un eclectisme stylistique et technique plus grand, ainsi que vers l’ouverture a la collectivite et un developpement de modes nouveaux, plus complexes, d’exploration du theme de l’identite dans les œuvres d’art. more...

This study explored reductions in tissue nitrogen concentration ([N]) at elevated CO2 concentrations ([CO2]), and changes in plant water and N uptake. Eucalyptus saligna Sm. seedlings were grown under three [CO2] levels (preindustrial (280 μL L–1), current (400 μL L–1) or projected (640 μL L–1)) and two air temperatures (current, (current + 4°C)). Gravimetric water use, leaf gas exchange and tissue dry mass and %N were determined. Solid-state 15N-NMR spectroscopy was used for determining the partitioning of N chemical groups in the dry matter fractions. Water use efficiency (WUE) improved with increasing [CO2] at ambient temperature, but strong leaf area and weak reductions in transpiration rates led to greater water use at elevated [CO2]. High temperature increased plant water use, such that WUE was not significantly stimulated by increasing [CO2] at high temperature. Total N uptake increased with increasing [CO2] but not temperature, less than the increase recorded for plant biomass. Tissue [N] decreased with rising [CO2] and at high temperature, but N use efficiency increased with rising [CO2]. Total N uptake was positively correlated with total water use and root biomass under all treatments. Growth [CO2] and temperature did not affect the partitioning of 15N among the N chemical groups. The reductions of tissue [N] with [CO2] and temperature were generic, not specific to particular N compounds. The results suggest that reductions in tissue [N] are caused by changes in root N uptake by mass flow due to altered transpiration rates at elevated [CO2] and temperature. more...