High-throughput screening of synthesis parameters in the formation of the metal-organic frameworks MOF-5 and HKUST-1

High-throughput methods were employed to study the influence of reaction parameters on the synthesis of the metal-organic frameworks MOF-5 (Zn₄O[(OOC)₂ · C₆H₄]₃) and HKUST-1 (Cu₃[(OOC)₃C₆H₃]₂(H₂O)₃ · xH₂O). Thus, compositional parameters (metal salt, reagent concentrations, and pH) as well as process parameters (temperature, time) were investigated in order to establish reaction trends and fields of formation. A multiclave reaction block was used to perform the investigation of 24 different solvothermal reactions at a time. Attention was focused on the phase purity and the crystal morphology of the resulting compounds. The characterization of the samples was performed by X-ray powder diffraction and high resolution scanning electron microscopy. The experimental results show that the formation, phase purity, and morphology of MOF-5 and HKUST-1 are extremely sensitive to the synthesis parameters explored in this study.     

Glass–ceramic scaffolds containing silica mesophases for bone grafting and drug delivery

Glass–ceramic macroporous scaffolds were prepared using glass powders and polyethylene (PE) particles of two different sizes. The starting glass, named as Fa-GC, belongs to the system SiO₂–P₂O₅–CaO–MgO–Na₂O–K₂O–CaF₂ and was synthesized by a traditional melting-quenching route. The glass was ground and sieved to obtain powders of specific size which were mixed with PE particles and then uniaxially pressed in order to obtain crack-free green samples. The compact of powders underwent a thermal treatment to remove the organic phase and to sinter the Fa-GC powders. Fa-GC scaffolds were characterized by means of X-Ray Diffraction, morphological observations, density measurements, image analysis, mechanical tests and in vitro tests. Composite systems were then prepared combining the drug uptake-delivery properties of MCM-41 silica micro/nanospheres with the Fa-GC scaffold. The system was prepared by soaking the scaffold into the MCM-41 synthesis batch. The composite scaffolds were characterized by means of X-Ray Diffraction, morphological observations, mechanical tests and in vitro tests. Ibuprofen was used as model drug for the uptake and delivery analysis of the composite system. In comparison with the MCM-41-free scaffold, both the adsorption capacity and the drug delivery behaviour were deeply affected by the presence of MCM-41 spheres inside the scaffold.     

Histamine food poisonings: A systematic review and meta-analysis

Objective: The aim of this study was to assess the mean of histamine concentration in food poisoning.

Design: Systematic review and meta-analysis of reports published between 1959 and 2013.

Study selection: Main criteria for inclusion of studies were: all report types that present outbreaks of “histamine poisoning' or “scombroid syndrome” from food, including histamine content and type of food. Health status of people involved must be nonpathological.

Results: Fifty-five (55) reports were included, these studies reported 103 incidents. All pooled analyses were based on random effect model; histamine mean concentration in poisoning samples was 1107.21 mg/kg with confidence interval for the meta-mean of 422.62–2900.78 mg/kg; heterogeneity index (I2) was 100% (P < 0.0001); prediction interval was 24.12–50822.78 mg/kg. Fish involved in histamine poisoning was mainly tuna or Istiophoridae species. No clues of association between concomitant conditions (female sex, alcohol consumption, previous medication, and consumption of histamine releasing food) and histamine poisoning, were highlighted.

Conclusions: This is the first systematic review and meta-analysis that analyzes all the available data on histamine poisoning outbreaks evaluating the histamine concentration in food involved. Histamine mean concentration in poisoning samples was fairly high. Our study suffers from some limitations, which are intrinsic of the studies included, for instance the lack of a complete anamnesis of each poisoning episode.

Protocol registration: Methods were specified in advance and have been published as a protocol in PROSPERO database (18/07/2012 -CRD42012002566).     

Titanium–Silica Catalysts for the Production of Fully Epoxidised Fatty Acid Methyl Esters

Grafted titanium-containing mesoporous silica catalysts were used in the selective epoxidation of C-18 unsaturated fatty acid methyl esters (FAMEs). High yields in mono- and diepoxide derivatives were obtained under acid-free reaction conditions with TBHP as oxidant. Ti-MCM-41 showed the best performance in terms of activity over the three FAMEs. Easy separation of the desired products and recycling of the catalyst were demonstrated.     

Heterogeneous Photooxidation of Phenol by Catalytic Membranes

In this work the heterogenization in polymeric membranes of decatungstate, a photocatalyst for oxidation reactions, was reported. Solid state characterization techniques confirmed that the catalyst structure was preserved within the polymeric membranes. The catalytic membranes were successfully applied in the aerobic photo-oxidation of phenol, one of the main organic pollutants in wastewater, providing stable and recyclable photocatalytic systems. The dependence of the phenol degradation rate by the catalyst loading and transmembrane pressure was shown. By comparison with homogeneous reaction, the catalyst heterogenised in membrane appears to be more efficient concerning the rate of phenol photodegradation and mineralization.     

Technical, economic and environmental assessment of sludge treatment wetlands

Sludge treatment wetlands (STW) emerge as a promising sustainable technology with low energy requirements and operational costs. In this study, technical, economic and environmental aspects of STW are investigated and compared with other alternatives for sludge management in small communities (<2000 population equivalent). The performance of full-scale STW was characterised during 2 years. Sludge dewatering increased total solids (TS) concentration by 25%, while sludge biodegradation lead to volatile solids around 45% TS and DRI_24h between 1.1 and 1.4 gO₂/kgTS h, suggesting a partial stabilisation of biosolids. In the economic and environmental assessment, four scenarios were considered for comparison: 1) STW with direct land application of biosolids, 2) STW with compost post-treatment, 3) centrifuge with compost post-treatment and 4) sludge transport to an intensive wastewater treatment plant. According to the results, STW with direct land application is the most cost-effective scenario, which is also characterised by the lowest environmental impact. The life cycle assessment highlights that global warming is a significant impact category in all scenarios, which is attributed to fossil fuel and electricity consumption; while greenhouse gas emissions from STW are insignificant. As a conclusion, STW are the most appropriate alternative for decentralised sludge management in small communities.     

Landscape and Infrastructures: Design Issues for the Integration of Parking Areas in Non-urban Contexts

This work represents a critical review of a selection of significant parking area projects chosen within the contemporary international context, aimed at discussing the role of parking architecture conceived as an opportunity to reinvent non-urban landscapes. Such an issue is part of the very topical broader theme of relationships between infrastructure and landscape, and of the various space and time scales on which landscape is perceived. Nowadays designers have to deal with several parking design opportunities related to the construction of intermodal stations, airports, shopping malls, industrial areas, as well as natural, cultural and leisure parks. Even if these places and design themes have now become usual, they still require an appropriate and original design research. Parking areas, besides their specific original function, can represent gardens and public spaces lying between the city and the countryside, capable of producing new hybrid landscapes blending art, nature and architecture.     

Tailored Hydrogel Membranes for Efficient Protein Crystallization

Crystallization still represents the bottleneck in the process of protein structure determination at high resolution, despite high‐throughput structural genomics programs requiring optimized crystallization strategies regarding crystal quality, time, success rate, reproducibility, and used protein amount. On the other hand, the development of suitable materials for controlled heterogeneous nucleation might facilitate biomacromolecular crystallization in a variety of experimental conditions which are not conventionally fruitful. Here, the possibility to fabricate hydrogel membranes displaying controlled chemical composition and nanostructure and to use them as heterogeneous supports for biomacromolecular crystallization is demonstrated. Diverse gel morphologies are obtained by controlling phase separation kinetics during gel layer formation on membrane support. These composite materials are found to increase the efficiency of the crystallization process so that crystals with enhanced diffraction properties are produced at lower protein concentration than conventional technique, thus affording the possibility to improve current approaches to protein crystallization and to be adapted to specific targets.     

Feasibility, tailoring and properties of polyurethane/bioactive glass composite scaffolds for tissue engineering

This research work aims to propose highly porous polymer/bioactive glass composites as potential scaffolds for hard-tissue and soft-tissue engineering. The scaffolds were prepared by impregnating an open-cells polyurethane sponge with melt-derived particles of a bioactive glass belonging to the SiO₂–P₂O₅–CaO–MgO–Na₂O–K₂O system (CEL2). Both the starting materials and the composite scaffolds were investigated from a morphological and structural viewpoint by X-ray diffraction analysis and scanning electron microscopy. Tensile mechanical tests, carried out according to international ISO and ASTM standards, were performed by using properly tailored specimens. In vitro tests by soaking the scaffolds in simulated body fluid (SBF) were also carried out to assess the bioactivity of the porous composites. It was found that the composite scaffolds were highly bioactive as after 7 days of soaking in SBF a HA layer grew on their surface. The obtained polyurethane/CEL2 composite scaffolds are promising candidates for tissue engineering applications.