Avaliação da influência do pH salivar na adesão de attachments com diferentes protocolos adesivos - Estudo in vitro

Introdução: Com o aumento das exigências estéticas, o recurso aos alinhadores invisíveis para a correção de más-oclusões tem sido cada vez mais frequente. Estes permitem a realização de movimentos dos mais simples aos mais complexos, no entanto necessitam de alguns auxiliares para esses movimentos serem mais eficientes, os attachments. Objetivo: Este estudo tem como objetivo avaliar a influência do pH na capacidade de adesão de um adesivo multimode primer (ScotchBondTM Universal, 3MTM) e de um etch-and-rinse primer (Prime&Bond® NT, Densply Sirona) na adesão de attachments e comparar a capacidade de adesão dos diferentes protocolos aplicáveis (self-etch e etch-and-rinse). Materiais e métodos: Foram utilizados 90 dentes bovinos: 30 como grupo de controlo (10 dentes com cada protocolo de adesão em meio seco), enquanto os restantes 60 dentes foram divididos e colocados em saliva artificial com pH 4 e pH 7, durante 7 dias a 37◦C, numa tentativa de simular o ambiente da cavidade oral. Foram aderidos 20 attachments com o protocolo etch-and-rinse com o adesivo Universal, 20 attachments com o protocolo etchand-rinse com o adesivo Prime&Bond NT e 20 attachments com o protocolo self-etch com o mesmo adesivo Universal previamente utilizado. Todos os attachments foram sujeitos à aplicação de uma força a velocidade constante, numa máquina de teste universal, até à perda de adesão. Resultados: Os attachments aderidos com os protocolos etch-and-rinse apresentaram maior adesão que os attachments aderidos com o protocolo selfetch (M=100.42, DP=47.49). Para além disso, o meio seco proporciona maior capacidade de adesão (M=209.27, DP=107.57) comparativamente aos meios com pH 4 e 7. Conclusão: Os resultados sugerem que os adesivos utilizados com protocolo etch-and-rinse apresentam maior capacidade de adesão dos attachments, podendo haver alguma influência do pH do meio, no entanto a adesão não está dependente da interação entre eles (protocolo adesivo e pH)Introduction: With the increase in aesthetic demands, the use of clear aligners to correct malocclusions has become more and more common. These allow the execution of movements from the simplest to the most complex. However, they need some auxiliaries for these movements to be more efficient- the attachments. Objective: This study aims to evaluate the influence of pH on the bonding strength of a multimode adhesive primer (ScotchBondTM Universal, 3MTM) and an etch-and-rinse primer (Prime&Bond® NT, Densply Sirona) in the bonding of attachments and to compare the bonding strength of the different applicable protocols (self-etch and etch-and-rinse). Materials and Methods: 90 bovine teeth were used: 30 as control group (10 teeth with each adhesion protocol), while the remaining 60 teeth were placed in artificial saliva with pH 4 and pH 7, for 7 days at 37◦C, in an attempt to simulate the environment of the oral cavity. Ten attachments were bonded with the etch-and-rinse protocol with Universal adhesive, 10 attachments with the etch-and-rinse protocol with Prime&Bond NT adhesive and 10 attachments with the self-etch protocol with the same previously used Universal adhesive. All attachments were subjected to the application of a force at constant speed, in a universal testing machine, until adhesion was lost. Results: The attachments bonded with the etch-and-rinse protocols showed greater adhesion than the attachments bonded with the self-etch protocol (M=100.42, SD=47.49). Beyond that, the dry environment provides greater adhesion capacity (M=209.27, SD= 107.57) compared to the environment with pH 4 and 7. Conclusion: The results suggest that the adhesives used with the etch-and-rinse protocol have a greater bonding strenght of the attachments, and there may be some influence of the pH of the environment, however the bonding is not dependent on the interaction between them (bonding protocol and pH)

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

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

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

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

© 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licenseBackground: Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide. Methods: A multimethods analysis was performed as part of the GlobalSurg 3 study—a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital. Findings: Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3·85 [95% CI 2·58–5·75]; p<0·0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63·0% vs 82·7%; OR 0·35 [0·23–0·53]; p<0·0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer. Interpretation: Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised. Funding: National Institute for Health and Care Research