Fabrication and Testing of Multi-Hierarchical Porous Scaffolds Designed for Bone Regeneration via Additive Manufacturing Processes

Bone implants or replacements are very scarce due to the low donor availability and the high rate of body rejection. For this reason, tissue engineering strategies have been developed as alternative solutions to this problem. This research sought to create a cellular scaffold with an intricate and complex network of interconnected pores and microchannels using salt leaching and additive manufacturing (3D printing) methods that mimic the hierarchical internal structure of the bone. A biocompatible hydrogel film (based on poly-ethylene glycol) was used to cover the surface of different polymeric scaffolds. This thin film was then exposed to various stimuli to spontaneously form wrinkled micropatterns, with the aim of increasing the contact area and the material’s biocompatibility. The main innovation of this study was to include these wrinkled micropatterns on the surface of the scaffold by taking advantage of thin polymer film surface instabilities. On the other hand, salt and nano-hydroxyapatite (nHA) particles were included in the polymeric matrix to create a modified filament for 3D printing. The printed part was leached to eliminate porogen particles, leaving homogenously distributed pores on the structure. The pores have a mean size of 26.4 ± 9.9 μm, resulting in a global scaffold porosity of ~42% (including pores and microchannels). The presence of nHA particles, which display a homogeneous distribution according to the FE-SEM and EDX results, have a slight influence on the mechanical resistance of the material, but incredibly, despite being a bioactive compound for bone cells, did not show a significant increase in cell viability on the scaffold surface. However, the synergistic effect between the presence of the hydrogel and the pores on the material does produce an increase in cell viability compared to the control sample and the bare PCL material

Prevalence of pulmonary embolism in patients with syncope

Background: The prevalence of pulmonary embolism (PE) in patients presenting with syncope to the emergency department (ED) is largely unknown. This information, however, is necessary to balance the potential medical benefit or harm of systematic PE screening in patients presenting with syncope to the ED. Objectives: This study sought to determine the prevalence of PE in patients with syncope. Methods: Unselected patients presenting with syncope to the ED were prospectively enrolled in a diagnostic multicenter study. Pre-test clinical probability for PE was assessed using the 2-level Wells score and the results of D-dimer testing using age-adapted cutoffs. Presence of PE was evaluated by imaging modalities, when ordered as part of the clinical assessment by the treating ED physician or by long-term follow-up data. Results: Long-term follow-up was complete in 1,380 patients (99%) at 360 days and 1,156 patients (83%) at 720 days. Among 1,397 patients presenting with syncope to the ED, PE was detected at presentation in 19 patients (1.4%; 95% confidence interval [CI]: 0.87% to 2.11%). The incidence of new PEs or cardiovascular death during 2-year follow-up was 0.9% (95% CI: 0.5% to 1.5%). In the subgroup of patients hospitalized (47%), PE was detected at presentation in 15 patients (2.3%; 95% CI: 1.4% to 3.7%). The incidence of new PEs or cardiovascular death during 2-year follow-up was 0.9% (95% CI: 0.4% to 2.0%). Conclusions: PE seems to be a rather uncommon cause of syncope among patients presenting to the ED. Therefore, systematic PE-screening in all patients with syncope does not seem warranted. (BAsel Syncope EvaLuation Study [BASEL IX]; NCT01548352)</p

Genetic and Genomic Approaches for Adaptation of Grapevine to Climate Change

The necessity to adapt to climate change is even stronger for grapevine than for other crops, because grape berry composition—a key determinant of fruit and wine quality, typicity and market value— highly depends on “terroir” (complete natural environment), on vintage (annual climate variability), and on their interactions. In the same time, there is a strong demand to reduce the use of pesticides. Thus, the equation that breeders and grape growers must solve has three entries that cannot be dissociated: adaptation to climate change, reduction of pesticides, and maintenance of wine typicity. Although vineyard management may cope to some extent to the short–medium-term effects of climate change, genetic improvement is necessary to provide long-term sustainable solutions to these problems. Most vineyards over the world are planted using vines that harbor two grafted plants’ genomes. Although this makes the range of interactions (scion-atmosphere, rootstock-soil, scion-rootstock) more complex, it also opens up wider possibilities for the genetic improvement of either or both the grafted genotypes. Positive aspects related to grapevine breeding are as follows: (a) a wide genetic diversity of rootstocks and scions that has not been thoroughly explored yet; (b) progress in sequencing technologies that allows high-throughput sequencing of entire genomes, faster mapping of targeted traits and easier determination of genetic relationships; (c) progress in new breeding technologies that potentially permit precise modifications on resident genes; (d) automation of phenotyping that allows faster and more complete monitoring of many traits on relatively large plant populations; (e) functional characterization of an increasing number of genes involved in the control of development, berry metabolism, disease resistance, and adaptation to environment. Difficulties involve: (a) the perennial nature and the large size of the plant that makes field testing long and demanding in manpower; (b) the low efficiency of transformation, regeneration and small size of breeding populations; (c) the complexity of the adaptive traits and the need to define more clearly future ideotypes; (d) the lack of shared and integrative platforms allowing a complete appraisal of the genotype-phenotype-environmental links; (e) legal, market and consumer acceptance of new genotypes. The present chapter provides an overview of suitable strategies and challenges linked to the adaptation of viticulture to a changing environment