New strategies for the decellularization of biological tissues

O início do século 21 tem sido marcado pelo aumento das doenças crónicas. Este desenvolvimento resultou num crescimento do interesse na criação de novas terapias, com foco na recuperação de tecidos através da transplantação do tecido danificado por matrizes “inteligentes” desenvolvidas recorrendo ao uso da Engenharia Biomédica. A descelularização, um processo que visa a remoção de material celular imunogénico de um tecido ou órgão, tem-se tornado num meio atraente para o desenvolvimento de novas matrizes funcionais e bioativas. A presente tese teve como objetivo explorar novas metodologias para a descelularização de tecidos biológicos. Para este propósito, é apresentada uma revisão da literatura relevante e um estudo que investiga o potencial de três diferentes protocolos para a descelularização de osso trabecular porcino usando o fosfato de tri-n-butilo (TnBP), dióxido de carbono supercrítico (scCO2), e uma combinação de ambos. O uso do TnBP como um agente de descelularização, ao invés do uso de produtos químicos mais prejudiciais como os detergentes, pode levar a uma maior preservação da matriz extracelular (ECM), tal como a propriedades bioquímicas e mecânicas mais desejáveis para a matriz resultante. O uso do scCO2 pode, também, resultar num processo de descelularização mais rápido, levando não só a uma redução do tempo de exposição dos tecidos a produtos químicos potencialmente prejudiciais, mas também a uma redução do preço financeiro deste processo. No total foram implementados e examinados cinco protocolos diferentes: 1% (v/v) TnBP durante 48 horas, scCO2 durante 1 hora e 3 horas, e scCO2 com 0.1% (p/v) TnBP com durante 1 hora e 3 horas. Devido à natureza inovadora deste projeto, usaram-se variáveis temporais para estudar qualquer efeito prejudicial devido ao efeito da exposição prolongada ao scCO2. Os resultados obtidos revelaram que tanto o TnBP como o scCO2 conseguiram diminuir a quantidade de DNA presente nas amostras, mas esta diminuição foi maior nos protocolos que onde o TnBP foi usado. A análise às propriedades mecânicas dos tecidos sujeitos a TnBP revelaram um aumento da força máxima e da tensão de limite elástico, o que poderá significar que ocorreu crosslinking das fibras de colagénio. Já o uso do scCO2 resultou na desidratação das amostras, aumentado os valores para o módulo de Young e força máxima. O protocolo de combinação scCO2-TnBP causou uma diminuição para metade da quantidade de DNA presente nas amostras tratadas em comparação a não-tratadas, demonstrado o potencial desta metodologia inovadora e abrindo novas possibilidade para otimizações futuras.The beginning of the 21st century has been marked by the rise of chronic diseases. This development has led to increased interest in the development of new therapies that focus on restoring normal tissue function through transplantation of injured tissue with biomedically engineered smart matrices. Decellularization, a process that focuses on the removal of immunogenic cellular material from a tissue or organ, has become an appealing methodology for the creation of functional and bioactive scaffolds. The present thesis focused on the creation of new methodologies for the decellularization of biological tissues. For this purpose, the author reviewed current decellularization literature and put forward a study that investigated the potential of three different decellularization protocols for porcine trabecular bone tissue using Tri(n-butyl) phosphate (TnBP), supercritical carbon dioxide (scCO2), and a combination of both. The use of TnBP as a decellularization agent, instead of harsh chemicals such as detergents, could lead to better preservation of the extracellular matrix (ECM), and better biochemical and mechanical properties to the resulting scaffold. As well, the use of supercritical fluids could lead to faster decellularization times, not only reducing the time tissues are exposed to potentially harmful agents, but also reducing the financial cost of the process. In total, five different protocols were implemented and examined: 1% (v/v) TnBP treatment for 48 hours, scCO2 treatment for 1 hour and 3 hours, and scCO2 treatment with 0.1% (w/v) TnBP for 1 hour and 3 hours. Due to the innovative nature of this work, time variants to protocols were implemented to investigate any possible harmful effects caused by prolonged exposure to scCO2 treatment. Results revealed that both TnBP and scCO2 led to the removal of DNA content, but this effect was more pronounced in treatments that used TnBP. Mechanical analysis of TnBP-treated samples revealed a higher ultimate strength and yield strain, suggesting some degree of crosslinking of collagen fibers occurred. Meanwhile, the use of scCO2 led to dehydration of samples, increasing values for Young’s Modulus and ultimate strength. The combined protocol of scCO2-TnBP led to a decrease in DNA content to about half of that measured for untreated samples, demonstrating the potential of this methodology and opening new possibilities for future optimizations that could achieve required decellularization levels

práticas artísticas no ensino básico e secundário

Para este número 18 da Revista Matéria-Prima reuniram-se 16 artigos que permitem colocar em perspetiva diversas dimensões da Educação Artística. Entre a consciência patrimonial e a emancipação, entre o domínio da técnica e do género, entre a integração e a maturação criadora, há um espaço a ser pesquisado, feito de história, de identidade, de ensaio e de inclusividadeinfo:eu-repo/semantics/publishedVersio

MAMMALS IN PORTUGAL : A data set of terrestrial, volant, and marine mammal occurrences in P ortugal

Mammals are threatened worldwide, with 26% of all species being includedin the IUCN threatened categories. This overall pattern is primarily associatedwith habitat loss or degradation, and human persecution for terrestrial mam-mals, and pollution, open net fishing, climate change, and prey depletion formarine mammals. Mammals play a key role in maintaining ecosystems func-tionality and resilience, and therefore information on their distribution is cru-cial to delineate and support conservation actions. MAMMALS INPORTUGAL is a publicly available data set compiling unpublishedgeoreferenced occurrence records of 92 terrestrial, volant, and marine mam-mals in mainland Portugal and archipelagos of the Azores and Madeira thatincludes 105,026 data entries between 1873 and 2021 (72% of the data occur-ring in 2000 and 2021). The methods used to collect the data were: live obser-vations/captures (43%), sign surveys (35%), camera trapping (16%),bioacoustics surveys (4%) and radiotracking, and inquiries that represent lessthan 1% of the records. The data set includes 13 types of records: (1) burrowsjsoil moundsjtunnel, (2) capture, (3) colony, (4) dead animaljhairjskullsjjaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8),observation in shelters, (9) photo trappingjvideo, (10) predators dietjpelletsjpine cones/nuts, (11) scatjtrackjditch, (12) telemetry and (13) vocalizationjecholocation. The spatial uncertainty of most records ranges between 0 and100 m (76%). Rodentia (n=31,573) has the highest number of records followedby Chiroptera (n=18,857), Carnivora (n=18,594), Lagomorpha (n=17,496),Cetartiodactyla (n=11,568) and Eulipotyphla (n=7008). The data setincludes records of species classified by the IUCN as threatened(e.g.,Oryctolagus cuniculus[n=12,159],Monachus monachus[n=1,512],andLynx pardinus[n=197]). We believe that this data set may stimulate thepublication of other European countries data sets that would certainly contrib-ute to ecology and conservation-related research, and therefore assisting onthe development of more accurate and tailored conservation managementstrategies for each species. There are no copyright restrictions; please cite thisdata paper when the data are used in publications.info:eu-repo/semantics/publishedVersio

Mammals in Portugal: a data set of terrestrial, volant, and marine mammal occurrences in Portugal

Mammals are threatened worldwide, with ~26% of all species being included in the IUCN threatened categories. This overall pattern is primarily associated with habitat loss or degradation, and human persecution for terrestrial mammals, and pollution, open net fishing, climate change, and prey depletion for marine mammals. Mammals play a key role in maintaining ecosystems functionality and resilience, and therefore information on their distribution is crucial to delineate and support conservation actions. MAMMALS IN PORTUGAL is a publicly available data set compiling unpublished georeferenced occurrence records of 92 terrestrial, volant, and marine mammals in mainland Portugal and archipelagos of the Azores and Madeira that includes 105,026 data entries between 1873 and 2021 (72% of the data occurring in 2000 and 2021). The methods used to collect the data were: live observations/captures (43%), sign surveys (35%), camera trapping (16%), bioacoustics surveys (4%) and radiotracking, and inquiries that represent less than 1% of the records. The data set includes 13 types of records: (1) burrows | soil mounds | tunnel, (2) capture, (3) colony, (4) dead animal | hair | skulls | jaws, (5) genetic confirmation, (6) inquiries, (7) observation of live animal (8), observation in shelters, (9) photo trapping | video, (10) predators diet | pellets | pine cones/nuts, (11) scat | track | ditch, (12) telemetry and (13) vocalization | echolocation. The spatial uncertainty of most records ranges between 0 and 100 m (76%). Rodentia (n =31,573) has the highest number of records followed by Chiroptera (n = 18,857), Carnivora (n = 18,594), Lagomorpha (n = 17,496), Cetartiodactyla (n = 11,568) and Eulipotyphla (n = 7008). The data set includes records of species classified by the IUCN as threatened (e.g., Oryctolagus cuniculus [n = 12,159], Monachus monachus [n = 1,512], and Lynx pardinus [n = 197]). We believe that this data set may stimulate the publication of other European countries data sets that would certainly contribute to ecology and conservation-related research, and therefore assisting on the development of more accurate and tailored conservation management strategies for each species. There are no copyright restrictions; please cite this data paper when the data are used in publications

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit