Focus ion beam/scanning electron microscopy characterization of osteoclastic resorption of calcium phosphate substrates

This article presents the application of dual focused ion beam/scanning electron microscopy (FIB-SEM) imaging for preclinical testing of calcium phosphates with osteoclast precursor cells and how this high-resolution imaging technique is able to reveal microstructural changes at a level of detail previously not possible. Calcium phosphate substrates, having similar compositions but different microstructures, were produced using low- and high-temperature processes (biomimetic calcium-deficient hydroxyapatite [CDHA] and stoichiometric sintered hydroxyapatite, respectively). Human osteoclast precursor cells were cultured for 21 days before evaluating their resorptive potential on varying microstructural features. Alternative to classical morphological evaluation of osteoclasts (OC), FIB-SEM was used to observe the subjacent microstructure by transversally sectioning cells and observing both the cells and the substrates. Resorption pits, indicating OC activity, were visible on the smoother surface of high-temperature sintered hydroxyapatite. FIB-SEM analysis revealed signs of acidic degradation on the grain surface under the cells, as well as intergranular dissolution. No resorption pits were evident on the surface of the rough CDHA substrates. However, whereas no degradation was detected by FIB sections in the material underlying some of the cells, early stages of OC-mediated acidic degradation were observed under cells with more spread morphology. Collectively, these results highlight the potential of FIB to evaluate the resorptive activity of OC, even in rough, irregular, or coarse surfaces where degradation pits are otherwise difficult to visualize.Peer ReviewedPostprint (author's final draft

Total Synthesis and Structural Revision of the Alkaloid Incargranine B

Seeing double: Consideration of the biosynthetic origins of incargranineB, which was originally assigned an unprecedented indolo[1.7]naphthyridine structure, led to the proposal of a dipyrroloquinoline framework as a more biosynthetically feasible struct

Tuning ubiquinone position in biomimetic monolayer membranes

Artificial lipid bilayers have been extensively studied as models that mimic natural membranes (biomimetic membranes). Several attempts of biomimetic membranes inserting ubiquinone (UQ) have been performed to enlighten which the position of UQ in the lipid layer is, although obtaining contradictory results. In this work, pure components (DPPC and UQ) and DPPC:UQ mixtures have been studied using surface pressure-area isotherms and Langmuir-Blodgett (LB) films of the same compounds have been transferred onto solid substrates being topographically characterized on mica using atomic force microscopy and electrochemically on indium tin oxide slides. DPPC:UQ mixtures present less solid-like physical state than pure DPPC indicating a higher-order degree for the latter. UQ influences considerably DPPC during the fluid state, but it is mainly expelled after the phase transition at ˜˜ 26 mN·m^-1 for the 5:1 ratio and at ˜˜ 21 mN·m^-1 for lower UQ content. The thermodynamic studies confirm the stability of the DPPC:UQ mixtures before that event, although presenting a non-ideal behaviour. The results indicate that UQ position can be tuned by means of the surface pressure applied to obtain LB films and the UQ initial content. The UQ positions in the biomimetic membrane are distinguished by their formal potential: UQ located in “diving” position with the UQ placed in the DPPC matrix in direct contact with the electrode surface ( -0.04±0.02 V), inserted between lipid chains without contact to the substrate ( 0.00±0.01 V) and parallel to the substrate, above the lipid chains ( 0.09±0.02 V).Peer ReviewedPostprint (author's final draft

Sustainable Approaches in Built Environment in Preparing for Global Environmental Change

No Abstrac

D-STEM: a Design led approach to STEM innovation

Advances in the Science, Technology, Engineering and Maths (STEM) disciplines offer opportunities for designers to propose and make products with advanced, enhanced and engineered properties and functionalities. In turn, these advanced characteristics are becoming increasingly necessary as resources become ever more strained through 21st century demands, such as ageing populations, connected communities, depleting raw materials, waste management and energy supply. We need to make things that are smarter, make our lives easier, better and simpler. The products of tomorrow need to do more with less. The issue is how to maximize the potential for exploiting opportunities offered by STEM developments and how best to enable designers to strengthen their position within the innovation ecosystem. As a society, we need designers able to navigate emerging developments from the STEM community to a level that enables understanding and knowledge of the new material properties, the skill set to facilitate absorption into the design ‘toolbox’ and the agility to identify, manage and contextualise innovation opportunities emerging from STEM developments. This paper proposes the blueprint for a new design led approach to STEM innovation that begins to redefine studio culture for the 21st Century

Remineralization strategies in oral hygiene: a position paper of Italian Society of Oral Hygiene Sciences-S.I.S.I.O. working group

Background/Objective: The clinical conditions that lead to an alteration of the enamel structure are numerous. The diet high in sugars and acidifying substances, psychological stress that triggers parafunctional behaviors, the reduced intake of fiber-rich foods or alkalizing substances, together with other factors, contribute to demineralization of the tooth enamel. Dental mineralizing products on the current market are distinguished according to the dosage form, the active ingredient, the release technology, clinical indications and patient choice. Currently, it is necessary to propose to oral health professionals a guide to orient themselves in this chaotic choice, in order to prefer the most effective product for their own clinical target. Methods: Italian Society of Oral Hygiene Sciences-S.I.S.I.O. is one of the leading scientific Italian societies representing those dental hygienists working with high-quality standards and in agreement with scientific evidence: in the last year, the SISIO working group has carried out a study focused on remineralizing agents in dentistry, in order to give an authoritative point of view to indicate a guideline in the decision process of the choice of a remineralizing agent. We will report the results pointed out from the last consensus meeting in 2017. Results: We have reported the good the bad and the ugly have been discussed in a critical discussion of such topic. Conclusion: The SISIO experience has been reported in this position paper with the aim to serve as a useful aid in the daily choice of the clinical steps to perform, when dental professionals need to treat demineralized teeth. Keywords: Dental Hygiene, Oral health, Dental Remineralizing, Enamel, Toothpaste, Mouthwash

Mitigation of GHGs Emission From Soils by a Catalyzed In-Situ Photo-Oxidative Polymerization of Soil Organic Matter

Agricultural lands under food and bio-energy crops, managed grass and permanent crops including agro-forestry, occupy about 40-50% of the Earth's land surface^1^. In 2005, agriculture accounted for an estimated emission of 5.1 to 6.1 GtCO2-eq/yr (10-12% of total global anthropogenic emissions of greenhouse gases (GHGs))^1^. However, measures to mitigate GHGs emission from agricultural soils are limited to improved cropland practices such as crop rotation, nutrient management, tillage/residue management, agroforestry, and return to natural vegetation^2^. These practices are not only far from substantially reducing GHGs emissions from soils or permanentlystabilizing soil organic matter^1-4^, but are also predicted to hardly match more than amaximum of 25% of the GHGs reductions required by the Kyoto Protocol within 2050^5^.Despite the knowledge that GHGs release from soil largely derives from biochemicaltransformations of plant litter and soil organic matter (SOM)^6-8^, no new and much wished biotechnological measures are adopted so far to augment mitigation^1^. Here we propose an innovative approach to mitigate GHGs emissions from soils based on the insitu photo-polymerization of SOM under biomimetic catalysis. Three Mediterranean soils of different physical and chemical properties were added with a synthetic watersolubleiron-porphyrin, irradiated by solar light, and subjected to 15, and 30 wetting and drying cycles. We found that the in situ catalysed photo-polymerization of SOM increased soil physical aggregation, shifted OC into larger soil aggregates, and reduced CO~2~ released by microbial respiration. Our findings suggest that "green" catalytic technologies can become viable soil management practices to enhance mitigation of GHGs emission from arable soils and contribute to match the expectations of the post-Kyoto Protocol in the agricultural sector

Biomimetic spatial and temporal (4D) design and fabrication

We imagine the built environment of the future as a ‘bio-hybrid machine for living in’ that will sense and react to activities within the space in order to provide experiences and services that will elevate quality of life while coexisting seamlessly with humans and the natural environment. The study of Hierarchical design in biological materials has the potential to alter the way designers/ engineers/ crafts-men of the future engage with materials in order to realise such visions. We are ex-ploring this design approach using digital manufacturing technologies such as jac-quard weaving and 3D printing