2,719 research outputs found

    An assessment of chemical contaminants in the marine sediments of southwest Puerto Rico

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    This report summarizes the results of a characterization of chemical contaminants in the sediments in southwest Puerto Rico. The report is part of a project to integrate various analytical specialties to assess linkages between chemical contaminants and the condition of coral reefs. In this phase of the project, over 120 chemical contaminants were analyzed in sediments collected, including a number of organic (e.g., hydrocarbons), inorganic (e.g., metals), and biological (bacterial) compounds/analytes. The report also provides a preliminary analysis of the association between sediment contaminants and coral species richness. Overall, the levels of chemical contaminants in the study area between Guanica Bay and the town of La Parguera were fairly low. At most of the sites sampled, particularly adjacent to the town of La Parguera, concentrations of organic and inorganic contaminants were below the median values from NOAA’s National Status and Trends Program, which monitors the Nation’s coastal and estuarine waters for chemical contaminants. Elevated levels of a number of contaminant classes were seen at the two sites sampled within Guanica Bay. An initial analysis of modeled PAH (hydrocarbon) data and coral species richness (reef building species) indicated a strong negative correlation between the presence of PAHs in the sediments and coral species richness. Additional work is needed to assess possible reasons for this observed pattern. (PDF contains 126 pages)

    Recent and Rapid Radiation of the Highly Endangered Harlequin Frogs (Atelopus) into Central America Inferred from Mitochondrial DNA Sequences

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    Populations of amphibians are experiencing severe declines worldwide. One group with the most catastrophic declines is the Neotropical genus Atelopus (Anura: Bufonidae). Many species of Atelopus have not been seen for decades and all eight Central American species are considered “Critically Endangered”, three of them very likely extinct. Nonetheless, the taxonomy, phylogeny, and biogeographic history of Central American Atelopus are still poorly known. In this study, the phylogenetic relationships among seven of the eight described species in Central America were inferred based on mitochondrial DNA sequences from 103 individuals, including decades-old museum samples and two likely extinct species, plus ten South American species. Among Central American samples, we discovered two candidate species that should be incorporated into conservation programs. Phylogenetic inference revealed a ladderized topology, placing species geographically furthest from South America more nested in the tree. Model-based ancestral area estimation supported either one or two colonization events from South America. Relaxed-clock analysis of divergence times indicated that Atelopus colonized Central America prior to 4 million years ago (Ma), supporting a slightly older than traditional date for the closure of the Isthmus. This study highlights the invaluable role of museum collections in documenting past biodiversity, and these results could guide future conservation efforts

    Magnetic and magnetorheological properties of nanofiber suspensions

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    International audienceIn this work the preparation and characterization of magnetorheological (MR) fluids constituted by CoNi nanofibers (56 nm length, 6.6 nm width) are reported. The properties of these new fluids were characterized by usual techniques (including magnetometry and magnetorheology). The results were compared with those obtained for conventional suspensions constituted by CoNi nanosperes

    Impacto del equipo multidisciplinario “ECMO Team” en el pronóstico de pacientes sometidos a membrana de oxigenación extracorpórea venoarterial por choque cardiogénico o paro cardiorrespiratorio refractario

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    Objectives. Veno-arterial Extracorporeal membrane oxygenation (VA ECMO) is a salvage intervention in patients with cardiogenic shock (CS), and cardiac arrest  (CA) refractory to standard therapies. The design of ECMO Teams has achieved the standardization of processes, although its impact on survival and prognosis is unknown. Objective: We aimed to analyze whether the creation of an ECMO Team has modified the prognosis of patients undergoing VA ECMO for refractory CS or CA. Materials and methods. We conducted a single-center retrospective cohort study. Patients with refractory CS or CA who underwent VA ECMO were divided in two consecutive periods: from 2014 to April 2019 (pre-ECMO T) and from May 2019 to December 2022 (Post ECMO T). The main outcomes were survival on ECMO, in-hospital survival, complications, and annual ECMO volume. Results. Eighty-three patients were included (36 pre-ECMO T and 47 post-ECMO T). The mean age was 53 +/-13 years. The most common reason for  device indication was different:  postcardiotomy shock (47.2%) pre-ECMO T and refractory cardiogenic shock (29.7%) post-ECMO T. The rate of extracorporeal  cardiopulmonary resuscitation was 14.5%.  The median duration of VA ECMO was longer after ECMO team implementation: 8 days (IQR 5-12.5) vs. five days (IQR 2-9, p=0.04). Global in-hospital survival was 45.8% (38.9% pre-ECMO T vs. 51.1% post-ECMO T; p=0.37),  and the survival rate from VA ECMO was 60.2% (55.6% pre-ECMO T vs 63.8% post-ECMO T; p= 0.50). The volume of VA ECMO implantation was significantly higher in the post-ECMO team period (13.2  +/3.5 per year vs. 6.5 +/-3.5 per year, p: 0.02). The rate of complications was similar in both groups. Conclusions. After the implementation of an ECMO team, there was no statistical difference in the survival rate of patients treated with VA ECMO. However, a significant increase in the number of patients supported per year was observed after the implementation of this multidisciplinary team. Post-ECMO T, the most common reason for device indication was cardiogenic shock, with longer run times and a higher rate of extracorporeal cardiopulmonary resuscitation.Introducción. La oxigenación por membrana extracorpórea venoarterial (ECMO VA) es una intervención de rescate utilizada en choque cardiogénico (CC) o paro cardiorrespiratorio (PCR) refractario. La creación de equipos multidisciplinarios ECMO Teams (ECMO T), ha permitido la estandarización de procesos, aunque se desconoce su impacto en  sobrevida y pronóstico. Objetivo: El propósito es analizar si la creación del ECMO Team ha modificado el pronóstico de los pacientes sometidos a ECMO VA por CC o PCR refractario. Materiales y métodos. Estudio observacional, unicéntrico, retrospectivo, que comparó los resultados del implante de ECMO VA por CC o PCR refractario en dos períodos consecutivos: entre 2014 y abril de 2019 (pre-ECMO T), y entre mayo de 2019 y diciembre de 2022 (pos-ECMO T). Como puntos finales, se evaluó la sobrevida intrahospitalaria y en ECMO, complicaciones, y volumen de ECMO anual. Resultados. Se analizaron 83 pacientes (36 pre-ECMO T, y 47 pos-ECMO T), con edad de 53 +/-13 años. La causa más frecuente de asistencia fue: poscardiotomía pre-ECMO T (47,2%) y CC refractario pos-ECMO T (29,7%). En el 14,5% se realizó ECMO en PCR. La mediana de asistencia fue mayor pos-ECMO T (8 días, RIC 5-12,5 vs. 5 días, RIC 2-9 pre-ECMO T; p:0,04). La supervivencia al alta fue del 45,8% (38,9% pre-ECMO T vs. 51,1% pos-ECMO T;p:0,37) y en ECMO VA del 60,2% (55,6% pre-ECMO T y 63,8% pos-ECMO T; p:0,50). El volumen de ECMO VA fue significativamente mayor pos-ECMO T (13,2+/3,5 por año vs. 6,5+/-3,5 por año, p: 0,02). La tasa de complicaciones fue similar en ambos períodos. Conclusiones.Luego de la implementación del ECMO Team no se observó una diferencia significativa en la sobrevida en pacientes asistidoscon ECMO VA. Sin embargo, luego de su creación se evidenció un aumento significativo del volumen de pacientes asistidos por año. Pos-ECMO T se asistió mayor número de pacientes por choque cardiogénico, en PCR y con más días de asistencia

    Exploring host genetic polymorphisms involved in SARS-CoV infection autcomes: implications for personalized medicine in COVID-19

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    Objective. To systematically explore genetic polymorphisms associated with the clinical outcomes in SARS-CoV infection in humans. Methods. This comprehensive literature search comprised available English papers published in PubMed/Medline and SCOPUS databases following the PRISMA-P guidelines and PICO/AXIS criteria. Results. Twenty-nine polymorphisms located in 21 genes were identified as associated with SARS-CoV susceptibility/resistance, disease severity, and clinical outcomes predominantly in Asian populations. Thus, genes implicated in key pathophysiological processes such as the mechanisms related to the entry of the virus into the cell and the antiviral immune/inflammatory responses were identified. Conclusions. Although caution must be taken, the results of this systematic review suggest that multiple genetic polymorphisms are associated with SARS-CoV infection features by affecting virus pathogenesis and host immune response, which could have important applications for the study and understanding of genetics in SARS-CoV-2/COVID-19 and for personalized translational clinical practice depending on the population studied and associated environments
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