Healing patterns of transplanted roots coated with an allogeneic fibrin-fibronectin concentrate

This experiment was designed to evaluate whether an allogeneic fibrin-fibronectin protein concentrate (AFFP) can not only prevent ankylosis and root resorption of autotransplanted roots during healing but contribute to regenerate a periodontal attachment as well. In two adult male baboons (Papio ursinus), four horizontal alveoli, 2 to 3 mm deep, were prepared bilaterally in the buccal alveolar and basal bone adjacent to the first and second mandibular molars to receive the roots of the adjacent two molars. Following hemisection, the first and second mandibular molars were extracted, the coronal two-thirds of the roots were planed to remove the remnants of the periodontal ligament and cementum and a notch was placed at the junction between the planed and non-planed surfaces. The planed surfaces were demineralised with citric acid at pH 1 for 3 min. Before transplantation, the crowns were resected and the experimental roots and alveoli were coated with the AFFP prepared from pooled fresh-frozen baboon plasma. The animals were killed 55 days after the transplantations. Histometrical evaluation was performed on serial sections cut in a bucco-lingual direction parallel to the long axis of the transplanted roots. An analysis of variance, in relation to the extent of ankylosis and root resorption, revealed minimal differences between the treatments of experimental and control roots both in the planed and non-planed sections. In this primate autotransplantation model, the treatment with AFFP did not prevent ankylosis and root resorption and did not result in the establishment of a new periodontal attachment. Key words: non-human primates, autotransplanted roots, fibrin-fibronectin concentrate

The carbon footprint of future engineered wood construction in Montreal

Engineered wood (EW) has the potential to reduce global carbon emissions from the building sector by substituting carbon-intensive concrete and steel for carbon-sequestering wood. However, studies accounting for material use and embodied carbon in buildings rarely analyse the city-scale or capture connections between the city and supplying hinterlands. This limits our knowledge of the effectiveness of decarbonising cities using EW and its potential adverse effects, such as deforestation. We address this gap by combining bottom-up material accounting of construction materials with life cycle assessment to analyse the carbon emissions and land occupation from future residential construction in Montreal, Canada. We compare material demand and environmental impacts of recent construction using concrete and steel to future construction using EW at the neighbourhood, urban scales under high- and low-density growth scenarios. We estimate that baseline embodied carbon per capita across the Agglomeration of Montreal is 3.2 tonnes per carbon dioxide equivalents (CO _2 eq.), but this ranges from 8.2 tonnes CO _2 eq. per capita in areas with large single-family housing to 2.0 tonnes CO _2 eq. per capita where smaller homes predominate. A Montreal-wide transition to EW may increase carbon footprint by up to 25% under certain scenarios, but this varies widely across the city and is tempered through urban densification. Likewise, a transition to EW results in less than 0.1% land transformation across Quebec’s timbershed. Moreover, sustainable logging practices that sequester carbon can actually produce a carbon-negative building stock in the future if carbon in the wood is not re-emitted when buildings are demolished or repurposed. To decarbonise future residential construction, Montreal should enact policies to simultaneously promote EW and denser settlement patterns in future construction and work with construction firms to ensure they source timber sustainably

Global impact of the first coronavirus disease 2019 (COVID-19) pandemic wave on vascular services

This online structured survey has demonstrated the global impact of the COVID-19 pandemic on vascular services. The majority of centres have documented marked reductions in operating and services provided to vascular patients. In the months during recovery from the resource restrictions imposed during the pandemic peaks, there will be a significant vascular disease burden awaiting surgeons. One of the most affected specialtie

Documenting the Recovery of Vascular Services in European Centres Following the Initial COVID-19 Pandemic Peak: Results from a Multicentre Collaborative Study

Objective: To document the recovery of vascular services in Europe following the first COVID-19 pandemic peak. Methods: An online structured vascular service survey with repeated data entry between 23 March and 9 August 2020 was carried out. Unit level data were collected using repeated questionnaires addressing modifications to vascular services during the first peak (March - May 2020, "period 1"), and then again between May and June ("period 2") and June and July 2020 ("period 3"). The duration of each period was similar. From 2 June, as reductions in cases began to be reported, centres were first asked if they were in a region still affected by rising cases, or if they had passed the peak of the first wave. These centres were asked additional questions about adaptations made to their standard pathways to permit elective surgery to resume. Results: The impact of the pandemic continued to be felt well after countries' first peak was thought to have passed in 2020. Aneurysm screening had not returned to normal in 21.7% of centres. Carotid surgery was still offered on a case by case basis in 33.8% of centres, and only 52.9% of centres had returned to their normal aneurysm threshold for surgery. Half of centres (49.4%) believed their management of lower limb ischaemia continued to be negatively affected by the pandemic. Reduced operating theatre capacity continued in 45.5% of centres. Twenty per cent of responding centres documented a backlog of at least 20 aortic repairs. At least one negative swab and 14 days of isolation were the most common strategies used for permitting safe elective surgery to recommence. Conclusion: Centres reported a broad return of services approaching pre-pandemic "normal" by July 2020. Many introduced protocols to manage peri-operative COVID-19 risk. Backlogs in cases were reported for all major vascular surgeries