Estudio del efecto de la variación de la viscosidad sobre el poder adhesivo del cianoacrilato de n-butilo

Los cianoacrilatos se adhieren fuertemente a los tejidos vivos cuando son aplicados en forma de una delgada capa, esto ha promovido el estudio y uso de estos materiales como adhesivos tisulares. Ellos poseen también la propiedad de favorecer la coagulación de la sangre por lo que se han estudiado y aplicado como agentes hemostáticos. La viscosidad de estos compuestos se encuentra en el rango de 2 a 2,5 cP medidos a 26 0C. Sin embargo en estudios de estabilidad realizados en el laboratorio a temperatura de conservación por debajo de 8 0C se ha detectado que en el período de un año se incrementa gradualmente este valor, aunque se mantiene dentro de los límites aceptables para su aplicación en la medicina. En este trabajo se comprobó, mediante mediciones de fuerzas de cizalla a probetas de TR1 utilizando cianoacrilato de n-butilo como adhesivo, que la variación de la viscosidad dentro del rango de aplicación en medicina no afecta significativamente la fuerza de adhesión del adhesivo. Se demostró también un comportamiento lineal en un rango de valores de hasta 20 cP entre la fuerza de cizalla y la viscosidad y que el mecanismo de ruptura de las probetas de fallo cohesivo, es decir, que en estos casos la fuerza de adhesión es óptima.Peer Reviewe

The effect of age on the acquisition and selection of cancer driver mutations in sun-exposed normal skin

BACKGROUND: The accumulation of somatic mutations contributes to ageing and cancer. Sunlight is the principal aetiological factor associated with skin cancer development. However, genetic and phenotypic factors also contribute to skin cancer risk. This study aimed at exploring the role of photoaging, as well as other well-known epidemiological risk factors, in the accumulation of somatic mutations in cancer-free human epidermis. MATERIAL AND METHODS: We deeply sequenced 46 genes in normal skin biopsies from 127 healthy donors, from which phenotypic data (including age, pigmentation-related genotype and phenotype) and sun exposure habits were collected. We determined the somatic mutational burden, mutational signatures, clonal selection and frequency of driver mutations in all samples. RESULTS: Our results reveal an exponential accumulation of UV-related somatic mutations with age, matching skin cancer incidence. The increase of mutational burden is in turn modified by an individual's skin phototype. Somatic mutations preferentially accumulated in cutaneous squamous cell carcinoma (cSCC) cancer genes and clonally expanded with age, with distinct mutational processes underpinning different age groups. Our results suggest loss of fidelity in transcription-coupled repair later in life. CONCLUSION: Our findings reveal that aging is not only associated with an exponential increase in the number of somatic mutations accumulated in normal epidermis, but also with selection and expansion of cancer-associated mutations. Aged, sun-exposed normal skin is thus an extended mosaic of multiple clones with driver mutations, poised for the acquisition of transforming events

Analysis of mangrove forest succession, using sediment cores: A case study in the cananéia -iguape coastal system, São Paulo-Brazil

Sediment cores are an essential tool for the analysis of the dynamics of mangrove succession. Coring was used to correlate changes in depositional environments and lateral sedimentary facies with discrete stages of forest succession at the Cananeia-Iguape Coastal System in southeastern Brazil. A local level successional pattern was examined based on four core series T1) a sediment bank; T2) a smooth cordgrass Spartina alterniflora bank; T3) an active mangrove progradation fringe dominated by Laguncularia racemosa, and; T4) a mature mangrove forest dominated by Avicennia schaueriana. Cores were macroscopically described in terms of color, texture, sedimentary structure and organic components. The base of all cores exhibited a similar pattern suggesting common vertical progressive changes in depositional conditions and subsequent successional colonization pattern throughout the forest. The progradation zone is an exposed bank, colonized by S. alterniflora. L. racemosa, replaces S. alterniflora as progradation takes place. As the substrate consolidates A. schaueriana replaces L. racemosa and attains the greatest structural development in the mature forest. Cores collected within the A. schaueriana dominated stand contained S. alterniflora fragments near the base, confirming that a smooth cordgrass habitat characterized the establishment and early seral stages. Cores provide a reliable approach to describe local-level successional sequences in dynamic settings subject to drivers operating on multiple temporal and spatial scales where spatial heterogeneity can lead to multiple equilibria and where similar successional end-points may be reached through convergent paths

The response of benthic foraminifera to pollution and environmental stress in Ria de Aveiro (N Portugal)

This work evaluates the quality of the sediment in Ria de Aveiro, a coastal lagoon located at N of Portugal that is under strong anthropic influence, and the effects of the contamination on benthic foraminifera. The initial approach for measuring pollution was done through the load pollution index (LPI), based on As, Cd, Cr, Cu, Ni, Pb and Zn concentrations, and determined by total digestion of the sediments (TDS). This information was complemented by conducting a metal fractionation technique (sequential chemical extraction - SCE) in some of the most contaminated samples in order to define the relevance of different metal bearing- phases (exchangeable cations adsorbed by clay and co-precipitated with carbonates, absorbed by organic matter and retained in the mineralogical phase) and to evaluate the toxic heavy metal availability. Multivariable statistical analyses were carried out taking into consideration the geochemical results, as well as the biotic (percentage of species/groups of species; foraminifer abundance and diversity) and abiotic variables, such as sediment content in mud, total organic carbon (TOC) and Eh. SCE results show that most of the element concentration in the sediments is retained in the resistant mineralogical phase. However, the higher bioavailability of some toxic elements, such as As, Cd, Cu, Hg, Ni, Pb and Zn, found in Laranjo Bay, Aveiro City, Aveiro Harbours and Espinheiro Channel, have a generic negative impact on benthic foraminifera of the Aveiro lagoon. Differential sensitivity of benthic foraminifera to high concentrations of heavy metals may exist. quinqueloculina seminulum, for instance, seems to be more tolerant to higher bioavailable concentrations of Pb and Cu than Ammonia tepida or Haynesina germanica. Both species were previously considered to be the most heavy metal-tolerant foraminifer species. This study confirmed the use of benthic foraminifera as an important tool for the evaluation of the environmental quality of an ecosystem and for monitoring and restoring it.FCT (Portugal) [POCTI/ECM/59958/2004]; Geobiotec Research Centre, of Aveiro Universit

Estudio de foraminífiros bentónicos en escala mensual en una bahía subtropical moderadamente afectada por efluentes urbanos

Benthic foraminifera were sampled monthly during a one-year period in order to examine their biological response to the environmental factors in the Ubatuba Bay (northern coast of São Paulo State, Brazil). The area is a popular tourist destination with a population that varies during the year, as does the untreated sewage carried into the bay by the rivers. Four sites were analysed. Each station is near one of the rivers that discharge into the bay. Biological data were analysed with multivariate and univariate techniques. The influence of the abiotic parameters on the foraminiferal fauna was inferred through statistical methods and time correlation functions. Geochemical and populational parameter differences allowed the sites to be separated into two groups according to their stress conditions. One group was dominated by Ammonia tepida—a herbivore species—and showed higher densities indicating a more productive and less contaminated location. The other one was dominated by Buliminella elegantissima—a detritivore species. Species diversity did not seem to be a good indicator of environmental health in this area due to the low densities and the high dominance of few species. Nevertheless, density and richness were used as evidence of local productivity and environmental conditions. Quasi-azoic moments related to the high degree of contamination were observed. Anthropogenic effects were stronger in the austral summer period, when sewage input through the rivers increases due to mass tourism.Fueron analizados foraminíferos bentónicos en cuatro estaciones muestreadas mensualmente con la intención de investigar la respuesta biológica a los factores ambientales en la Ensenada de Ubatuba (costa noreste de São Paulo, Brasil). El área es un importante local turístico cuya población fluctúa a través del año y recibe efluentes no tratados a través de los ríos que en ella desembocan. Fueron analizados cuatro locales. Cada estación se encuentra localizada próxima a uno de los cuatro ríos que desembocan en la bahía. Los datos biológicos fueron analizados con técnicas uni y multivariadas. La influencia de los parámetros abióticos sobre la fauna de foraminíferos fue inferida a través de métodos estadísticos y de funciones de correlación temporal. Parámetros geoquímicas y poblacionales permitieron distinguir dos grupos de estaciones que reflejan las condiciones de estrés local. Uno de los grupos estuvo dominado por Ammonia tepida –especie herbívora– y se mostró más productivo y menos contaminado. El otro local estuvo dominado por Buliminella elegantísima –especie detritívora. La diversidad especifica no se mostró un buen indicador de la salud ambiental en esta región debido a las bajas densidades y a la alta dominancia de unas pocas especies. Sin embargo, la densidad y riqueza pudieron ser utilizadas como evidencias de la productividad local y condiciones ambientales. Fueron observados momentos casi azoicos relacionados con el alto grado de contaminación. Los efectos antropogénicos fueron mayores durante el período de verano austral, cuando la entrada de deshechos domésticos a través de los ríos aumenta como consecuencia del incremento del turismo

Foraminíferos Recentes do Canal de São Sebastião SP, e suas Relações com os Padrões de Sedimentação

O presente estudo é parte integrante da primeira fase do projeto de monitoramento do sistema de tratamento de efluentes do Canal de São Sebastião. Este estudo objetivou caracterizar as comunidades de foraminíferos e os sedimentos de fundo do canal, procurando estabelecer a distribuição das associações microfaunísticas e suas relações com o meio, antes da construção desses efluentes no canal. As associações microfaunísticas e os dados sedimentológicos revelaram uma diferenciação entre o ambiente deposicional oeste e leste do canal. O lado oeste caracterizou-se pela presença marcante de minerais micáceos, sedimentos pelíticos com altos teores de carbono e nitrogênio, diversidade baixa de foraminíferos, aparecimento de espécies de tamanho reduzido e dominância de espécies típicas de ambiente rico em matéria orgânica (Buliminella elegantíssima e Fursenkoina pontoni). Tais resultados permitiram inferir domínio de baixa energia nesta região. Já no lado leste do canal, observou-se uma diminuição dos minerais micáceos, abundância de areia e biodetritos marinhos, diversidade relativamente alta e aparecimento da epifauna. Tais dados demonstram que o hidrodinamismo aumentou sensivelmente, sugerindo ambiente de maior energia e oxidação. Além disso, através das associações foi possível detectar uma influência oceânica maior no lado meridional do canal. Quanto ao lado setentrional e central, estes caracterizaram-se por possuir associações típicas de água costeira. Foi observada também a presença de Cassidulina crassa, associada possivelmente à ACAS (Água Central do Atlântico Sul)

Intravenous single dose of tranexamic acid safely reduces blood loss and the need for transfusion in elderly patients with hip fracture. A randomized double-blinded controlled trial at 1-year follow-up

Background: A hip fracture usually presents significant blood loss in the perioperative period, with a transfusion rate of 20-60%. In order to reduce the complications associated with this procedure, the administration of Tranexamic Acid (TXA) has been implemented in the treatment of perioperative anemia. The objectives were to evaluate the effectiveness and safety of a single dose of intravenous Tranexamic Acid (TXA) in reducing perioperative blood loss and the requirement for transfusion in elderly patients undergoing hip fracture surgery within one postoperative year. Methods: A double-blind randomized controlled trial was conducted on 129 patients with hip fractures. After randomization, at the start of the surgery, 65 patients received a single dose of 1 gram of intravenous TXA (TXA group), and 64 received a placebo (placebo group). The primary effectiveness outcomes were the total blood loss and transfusion rate. The primary safety outcome was the rate of thromboembolic events. Data on surgical or medical infection, readmission and death were also collected. Results: The TXA group had a significant decrease in blood loss (p = 0.006) and requirement for transfusion (p < 0.001) compared with the placebo group. Likewise, there were no thromboembolic events in the TXA group and seven in the placebo group (p = 0.006). Mortality within 1-year postoperatively was not significantly different (p = 0.115). Conclusion: Using a single dose of intravenous TXA at the start of the surgery significantly reduces blood loss and the requirement for transfusion without increasing the risk of thromboembolic events or mortality within 1-year postoperatively in patients with hip fracture undergoing surgery. Registration number: NCT03211286. https://clinicaltrials.gov/ct2/show/NCT03211286. Level of evidence: I

The effect of photoaging on the accumulation of somatic mutations in cancer-free human skin

This is a pre-print of an article published in Annals of Oncology. The final authenticated version is available online at: https://doi.org/10.1016/j.annonc.2020.11.023Background: The accumulation of somatic mutations contributes to ageing and cancer. Sunlight is the principal aetiological factor associated with skin cancer development. However, genetic and phenotypic factors also contribute to skin cancer risk. This study aimed at exploring the role of photoaging, as well as other well-known epidemiological risk factors, in the accumulation of somatic mutations in cancer-free human epidermis. Material and methods: We deeply sequenced 46 genes in normal skin biopsies from 123 healthy donors, from which phenotypic data (including age, pigmentation-related genotype and phenotype) and sun exposure habits were collected. We determined the somatic mutational burden, mutational signatures, clonal selection and frequency of driver mutations in all samples. Results: Our results reveal an exponential accumulation of UV-related somatic mutations with age, matching skin cancer incidence. The increase of mutational burden is in turn modified by an individual's skin phototype. Somatic mutations preferentially accumulated in cutaneous squamous cell carcinoma cancer genes and clonally expanded with age, with distinct mutational processes underpinning different age groups. Our results suggest a loss of fidelity in transcription-coupled repair later in life. Conclusion: Our findings reveal that ageing is not only associated with an exponential increase in the number of somatic mutations accumulated in normal epidermis, but also with selection and expansion of cancer-associated mutations. Aged, sun-exposed normal skin is thus an extended mosaic of multiple clones with driver mutations, poised for the acquisition of transforming events

Change in 1-year mortality after hip fracture surgery over the last decade in a European population

Objective: There are scarce data on the mortality after hip fracture surgery for patients treated in the most recent years. The objective of this study was to analyze whether the overall initiatives introduced over the last decade for elderly patients with hip fractures had a positive impact on the 1-year mortality. Methods: Patients treated during 2010–2012 were compared with patients treated during 2018–2020 for all-cause 1-year mortality. Variables influencing mortality were collected based on the literature, including demographic, comorbidity, cognitive status, and preinjury physical function. Crude mortalities were compared between periods, as well as with the expected mortality in the general population adjusted for age, gender, and year of surgery using the standardized mortality ratio (SMR). A multivariate model was used to identify mortality risk factors. Results: 591 patients older than 65 years were treated during 2010–2012 and 642 patients during 2018–2020. The mean age increased significantly between periods (78.9 vs. 82.6 years, respectively, p = 0.001) in both genders, together with an increase in comorbidity (p = 0.014). The in-hospital mortality risk had no significant difference between periods (2.5 vs. 2.0%, p = 0.339), but the 30-day mortality risk (8.3 vs. 5.5%, p = 0.031) and 1-year mortality risk (16.1 vs. 11.9%, p = 0.023) declined significantly. However, 1-year mortality in 2020 had an excess of 1.33 in SMR. Age older than 80 years, male gender, and Charlson comorbidity index > 2 were significant predictors of 1-year mortality. Conclusion: The important evolution achieved in the last decade for the management of patients with hip fracture surgery has led to a significant decline in 1-year mortality, but the 1-year mortality remains significantly higher compared to the general population of similar age and gender.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature