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3D bioprinting is a powerful fabrication technique in biomedical engineering, which is currently limited by the number of available materials that meet all physicochemical and cytocompatibility requirements for biomaterial inks. Inspired by the key role of coacervations in the extrusion and spinning of many natural materials, hyaluronic acid-chitosan complex coacervates are proposed here as tunable biomaterial inks. Complex coacervates are obtained through an associative liquid-liquid phase separation driven by electrostatic attraction between oppositely charged macromolecules. They offer bioactive properties as well as facile modulation of their mechanical properties through mild physicochemical changes in the environment, rendering them attractive for 3D bioprinting. Fine-tuning the salt concentration, pH, and molecular weight of the constituent polymers results in biomaterial inks that are printable in air and water. The biomaterial ink, initially a viscoelastic fluid, transitions into a viscoelastic solid upon printing due to dehydration (for printing in air) or due to a change in pH and ionic composition (for printing in water). Consequently, scaffolds printed using the complex coacervate inks are stable without the need for post-printing processing. Cell culture scaffolds fabricated in this way are cytocompatible and show long-term topological stability. These results pave the way to a new class of easy-to-handle tunable biomaterials for biofabrication.

OBJECTIVE: To examine sustainability of symptom outcomes of a 1-year phase-based trauma-focused, multimodal, and multicomponent group therapy in a day treatment program for posttraumatic stress disorder (PTSD) over an average period of 7 years. METHOD: Iranian and Afghan patients (N = 69) were assessed with self-rated symptom checklists for PTSD, anxiety, and depression symptoms before (T1), after (T2), and up to 11 years upon completion of the treatment (T3). A series of mixed model regression analyses was applied to determine the course of the measured symptoms over time. RESULTS: At T2, all symptoms were reduced, but PTSD symptoms showed the strongest reduction. The trend of symptom reduction continued up to 5 years posttreatment and was similar for all the examined symptoms. After 5 years, all symptoms started to worsen, but remained under baseline levels at T3. CONCLUSIONS: The applied treatment appears to improve mental health of the studied sample on both the short and longer term. Language: en

Mesoporous and highly crystalline TiO2 (anatase)/carbon composites with large (>5?nm) and uniform pores were synthesized using PI-b-PEO block copolymers as structure directing agents. Pore sizes could be tuned by utilizing block copolymers with different molecular weights. The resulting mesoporous TiO2/carbon was successfully used as an anode material for Li ion batteries. Without addition of conducting aid (Super P), the electrode showed high capacity during the first insertion/desertion cycle due to carbon wiring inside the walls of mesoporous TiO2/carbon. The electrode further showed stable cycle performance up to 50 cycles and the specific charge capacity at 30?C was 38?mA h (g of TiO2)-1, which indicates CCM-TiO2/carbon can be used as a material for high rate use.

Nature has developed elegant and economical strategies to produce materials that are well-adapted to their purposes. As biology evolved to remarkable and complex designs, synthetic mimics are evolving toward new levels of complexity achieving larger combinations of properties within one material. The field of bioinspiration encompasses a wide range of advanced materials ranging from biooptics to energy materials, to biomaterials. In this paper an overview is given of selected recent developments in the field of bioinspired material design focusing on gecko-inspired adhesives, mussel-inspired coatings, and spider silk-inspired biomaterials.

Mould powders play an important role in the stability of the continuous casting process of steel at all casting speeds. The main functions of mould slag (i.e. molten powder) are to provide sufficient lubrication and to control the heat transfer in horizontal direction between the developing steel shell and the copper mould. Several authors have reviewed the composition, properties and operational experience of mould powders for conventional slab casting [1-2]. However, only a few publications have been issued on the design and use of mould powders for thin slab casting [3-4]. Compared with conventional slab casting, process control in thin slab casting is more critical and it can be assumed that mould powder demands for thin slab casting become more critical as well [5-6]. Thus a more extensive understanding of mould powder properties and functions is needed to meet the increasing demands of high-speed thin slab casting. Nevertheless, a lot of improvements (mould powder developments) are based on trial and error and are focussing on casting speeds up to 2 m/min (conventional slab casting). A general approach is to relate the chemical composition of a mould powder to the operational behaviour (in-mould behaviour) during casting. In doing this, some physical properties of the mould slag like the viscosity and the melting point are addressed as well. However, this approach will not automatically result in a suitable mould powder or an in-depth knowledge on powder design and required slag properties. At Corus IJmuiden, a project started in the framework of the Netherlands Institute for Metals Research with the aim to develop mould powders suitable for high-speed thin slab casting with a maximum casting speed up to 8 m/min. For this work, a fundamental understanding and quantification of the melting and solidification behaviour of mould slag as well as the functions of mould powder is needed.

The co-assembly between a polyisoprene-block-poly(dimethylaminoethyl methacrylate) block copolymer and poly(ureamethylvinyl)silazane is investigated. The hybrid morphology can be controlled by systematically increasing the inorganic-to-organic ratio or by changing the molecular weight of the block copolymer. Temperature treatment up to 1500 °C of the hybrids resulted in mesoporous, ordered non-oxide-type ceramics. The results suggest that careful control of co-assembly processes enables access to nanostructured high-temperature ceramics that may have novel mechanical, thermal, and chemical properties.

In this work the primary mechanical property profiles of a specific class of nano-structured polymer/inorganic hybrid materials are characterized. By utilizing sol-gel aluminosilicate synthesis with amphiphilic polyisoprene-block-poly(ethylene oxide) block copolymers as structure-directing agents, block copolymer/aluminosilicate hybrid materials are prepared with nanometer scale hexagonally packed cylinders and lamellae of the inorganic hybrid components, as evidenced by small-angle X-ray scattering. Systematic thermal and dynamic mechanical analyses are performed on these hybrids as well as on the constituting components. Results reveal two transitions from the low temperature, glassy state of the hybrids into high temperature elastic plateau regions, with moduli that vary over orders of magnitude as a function of composition and morphology. The first transition can be assigned to the glass transition of the PI domains while the second is ascribed to a temperature induced softening of the organic components within the PEO/hybrid domains. The results suggest that in the present nanostructured block copolymer/aluminosilicate hybrid materials composition and morphology provide a powerful tool to tailor mechanical property profiles.

Catechols play an important role in many natural systems. They are known to readily interact with both organic (e.g., amino acids) and inorganic (e.g., metal ions, metal oxides) compounds, thereby providing a powerful system for protein curing. Catechol crosslinked protein networks, such as sclerotized cuticle and byssal threads of the mussel, have been shown to exhibit excellent mechanical properties. A lot of effort has been devoted to mimicking the natural proteins using synthetic catechol-functionalized polymers. Despite the success in developing catechol-functionalized materials, the crosslinking chemistry of catechols is still a subject of debate. To develop materials with controlled and superior properties, a clear understanding of the crosslinking mechanism of catechols is of vital importance. This review describes the crosslinking pathways of catechol and derivatives in both natural and synthetic systems. We discuss existing pathways of catechol crosslinking and parameters that affect the catechol chemistry in detail. This overview will point towards a rational direction for further investigation of the complicated catechol chemistry.

13C-labelled cinnamonitrile, a compound that possesses both the aromatic functionality of styrene and the nitrile functionality of acrylonitrile has been synthesized in one step using β-bromostyrene and potassium [13C]cyanide. The preparation of a target material using 13C -labelled cinnamonitrile may provide a cost-effective method for producing nitrogen-13 via proton irradiation for Positron Emission Tomography. Copyright © 2002 John Wiley & Sons, Ltd.

This paper explores the variation in generation time of bacterial systems growing at suboptimal temperatures. Generation time generally has a distribution with a long right-hand tail, suggesting a model with variance proportional to the second or third power of its mean. Suitable non-normal probability distributions include the 'gamma' and 'inverse Gaussian', with the modelling being carried out by 'generalized linear regression'. The procedure is illustrated with replicated data on Pseudomonas fluorescens obtained using a gradient temperature incubator with nutrient broth as the growth medium. The results show that the 'gamma' distribution is a suitable stochastic assumption when modelling generation time. This enables one to predict, for example, a mean generation time of 615 min at 2.4°C, and that 0.1% of the observed values will fall below 471 min and one in a million below 405 min. Use of an unreplicated set of data gave less conclusive results but favoured the 'inverse Gaussian' distribution as the stochastic model.