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The reconstruction or regeneration of damaged bone tissue is one of the challenges of orthopedic surgery and tissue engineering. Among all strategies investigated, additive manufacturing by fused deposition modeling (3D-FDM printing) opens the possibility to obtain patient-specific scaffolds with controlled architectures. The present work evaluates in depth 3D direct printing, avoiding the need for a pre-fabricated filament, to obtain bone-related scaffolds from direct mixtures of polylactic acid (PLA) and hydroxyapatite (HA). For it, a systematic physicochemical characterization (SEM-EDS, FT-Raman, XRD, micro-CT and nanoindentation) was performed, using different PLA/HA ratios and percentages of infill. Results prove the versatility of this methodology with an efficient HA incorporation in the 3D-printed scaffolds up to 13 wt.% of the total mass and a uniform distribution of the HA particles in the scaffold at the macro level, both longitudinal and cross sections. Moreover, an exponential distribution of the HA particles from the surface toward the interior of the biocomposite cord (micro level), within the first 80 µm (10% of the entire cord diameter), is also confirmed, providing the scaffold with surface roughness and higher bioavailability. In relation to the pores, they can range in size from 250 to 850 µm and can represent a percentage, in relation to the total volume of the scaffold, from 24% up to 76%. The mechanical properties indicate an increase in Young’s modulus with the HA content of up to ~50%, compared to the scaffolds without HA. Finally, the in vitro evaluation confirms MG63 cell proliferation on the 3D-printed PLA/HA scaffolds after up to 21 days of incubation.

The characteristics of the soil pore network condition the flow of nutrients, liquids, gases, and temperature through this medium. We hypothesized that soil structure properties will also control soil microbial processes. To test this, we selected soil samples where land use generated differences in soil structure. Unaltered soil samples from three adjacent plots were analysed: a potato field soil, ploughed after harvesting, two weeks before sampling (Control); another ploughed potato plot, in which bioaugmentators (plant growth promoting bacteria) had been applied to increase soil biodiversity (Bio); and a third soil, dedicated to melon cultivation, without bioaugmentation, followed by six months of fallow (Melon). In each soil, three different depths were analysed (between 0/-3.33 cm; -3.33/-6.67 cm; and -6.67/-10 cm), and, at each depth, we separated aggregates into three size categories: >0.8 cm, 0.8-0.2 cm, and 0.86) and optical density (r > 0.69), while respiration increased with the number of pores (r > 0.75) and pore length (r > 0.71). The respiration rate within small aggregates (0.2 to 0.8 cm) increased with the length and number of pores (r > 0.84).In conclusion, aggregation seems to have a greater effect on the physical and biological properties of the soil than differences between land uses studied and the depths considered. On the other hand, characteristics such as connectivity, tortuosity, and the length and number of pores seem to regulate both bacterial growth and respiration, while fungal growth appears independent.

InBestSoil (IBS) project has been funded under the call "Incentives and business models for soil health" from the EU Missions program (Horizon Europe) — Grant Agreement n° 1010910990. The University of Vigo leads the project within a consortium of 19 partners from 10 countries with a 48-month duration.The IBS aims to quantify the economic benefits of the different ecosystem services that healthy soils can provide and analyze the costs and benefits of the interventions to improve soil health. This economic valuation will facilitate investments in soil health and the generation of new businesses, incentives, and policies that help us to reclaim degraded soils or improve the quality of existing ones.In IBS, we analyzed nine case studies across Europe with different land uses (agricultural, forestry, urban, and mining) across four different biogeographic regions (Boreal, Continental, Atlantic and Mediterranean). These long-term experiments have been running for years into an established network of stakeholders and businesses created to exploit improved soil quality benefits. In each case study, we will assess the outcome of soil reclamation actions by examining the actual soil quality indicators and comparing them with the antecedent indicators before the restoration process. Then, we will conduct an economic valuation of the soil quality differences by considering the potential income from the enhanced ecosystem services that have proved effective in improving soil quality indicators.To develop a multi-actor approach, we will gather data and opinions from stakeholders about every relevant item in this transformation, i.e., from selecting soil indicators to creating new incentives and policies. These consultations will be done at each step of the project through a collaborative platform developed specifically for the IBS. The IBS partners come from a wide range of sectors (from universities to distribution companies of organic products), allowing us to create an extensive network of stakeholders to share information, feedback experiences, and diffusion of results.With this information, we will first try to scale up by exporting to other areas the business models that were created around our case studies. Second, we will use the information obtained through the economic valuation to develop new business models. Finally, we will try to integrate the information obtained to develop a set of incentive support systems and new policies. Acknowledgments: This study has been funded by the Horizon Europe Project InBestSoil (GA 101091099).

Tunable Resistive Pulse Sensing, TRPS, is an emerging technique used in quantification and measuring the size (particle-by-particle) of viruses, exosomes and engineered colloidal spheres in biological fluids. We study the features of TRPS to enhance size characterization and quantification of submicron-sized microplastics, also called plastic microparticles, MP, in freshwater environments. We report alterations on the detection of the resistive pulses in the TRPS caused by humic acids, HA, during the size measurement of polystyrene microspheres used as MP surrogate. We discuss the alteration of the electric field in the measuring channel of the TRPS apparatus induced by the passage of HA. TRPS is a fast and precise technique for counting and size determination of MP but needs the evaluation of the influence of the organic matter on the current blockades. We show that statistical clustering models of the magnitude distribution of the resistive pulses can help to detect and quantify changes in the pulse size distributions induced by flocculation of humic acids. Conclusions of this study indicate that TRPS can be a valuable tool to improve the knowledge of the MP fate in surface waters, in the vadose zone and groundwater.

Discontinuous air–water displacement at the pore scale (from 10 −5to 10 −3m) affects fluid invasion in porous media at the core scale (10 −3to 1 m). Understanding of this effect is essential to upscale flow processes. In this study we used the analysis of pressure jumps to propose an upscaling mechanism. Large pressure jumps occur during drainage in macroporous structured soils; we suggest a hypothesis for their occurrence. Drainage experiments in packed sand and structured soils enclosing large pores showed large jumps (?5-hPa peak pressure). Large jumps resulted from a pressure relaxation process that first initiates from pore-scale air–water displacements and then expands to larger scales. We found that the power-law exponents for the distribution of the size of large jumps found in structured soil are greater than the typical values reported for Haines jumps in packed granular porous media. The difference in the exponent suggests that the magnitude of displacements occurring in structured soil has different scaling factors than in simple media. A mechanism for this change of scale is proposed on the basis of the large contrast between pore throat and matrix in macroporous soil. The mechanism consists of a fast pressure relaxation in the macropores triggered by a break in the capillary shield at the pore throat. These findings contribute to an explanation of the scaling relations of air–water displacements in complex porous media and unveil links between the soil structure and flow of fluids.