8 research outputs found

    Hydrothermal synthesis of pyrrhotite (Fex-1S) nanoplates and their antibacterial, cytotoxic activity study

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    The aim of this study was to synthesize and characterize Fex-1S 2D-nanostructures with pyrrhotite phase, as well as to explore their biological (antibacterial and cytotoxic) properties, namely the expression of reactive oxygen species (ROS) in the exposure of cells and bacteria. Based on hydrothermal synthesis, the characterization of as-prepared 2D-nanostructures was performed by XRD, SEM, EDS, and TEM, in which the single-crystalline pyrrhotite phased Fex-1S nanoplate morphology was observed. The antibacterial activities of Fex-1S nanoplates against human pathogenic strains such as Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis were tested. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined following the broth microdilution method. Cytotoxicity and expression of intracellular ROS of pyrrhotite nanoplates on Human Gingival Fibroblast (HGF), Human Pulp Cells (HPC) and Human Osteoblast (HBC) were calculated. Cell viability was determined by the MTT method. All experiments were performed of three independent experiments and data were analyzed by Kruskal-Wallis and Mann-Whitney tests, also Pearson´s Correlation was performed. The nanoplates exhibited good bactericidal effect. All types of cells tested showed slight cytotoxicity. It was found that intracellular ROS is produced when cells and bacteria tested are exposed to pyrrhotite nanoplates in presence of both air and peroxide hydrogen. ROS production levels were higher in the bacteria than the cells exposed to these nanoplates. Keywords: Hydrothermal synthesis, Iron sulfide nanoplates, Minimal inhibitory concentration, Antibacterial effect, Cytotoxicity assa

    A non-invasive faecal survey for the study of spatial ecology and kinship of solitary felids in the Viruá National Park, Amazon Basin

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    Jaguars and pumas are the largest felids in the Americas. Information about these two species is scarce, especially where both species are sympatric. We studied the use and selection of macrohabitats, spatial segregation and kinship in jaguars and pumas in the Viruá National Park (Amazonian lowlands) by non-invasive genetic analyses of faecal samples. Seven different jaguars (six males and one female) and nine different pumas (five males and four females) were identified. We found space use segregation between the two species, with pumas using mostly forested habitats and jaguars using open habitats slightly more than the forested ones. This result is unexpected, since previous studies have found that pumas favour more open habitats than jaguars. The results suggest that jaguars use the areas in a more random manner, corresponding to the habits of a dominant generalist species, whereas pumas use the area to reduce encounter rates with jaguars. Nevertheless, both species mainly used areas near upland forest-flooding habitats. Some kinship categories were supported with a p < 0.05 in 57 and 83% of the pair comparisons between the identified jaguars and the identified pumas, respectively. Non-invasive genetic analysis of faeces was useful to study the spatial ecology of solitary, rare and cryptic species in the Amazon.Peer reviewe

    NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

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    Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data

    Delayed colorectal cancer care during covid-19 pandemic (decor-19). Global perspective from an international survey

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    Background The widespread nature of coronavirus disease 2019 (COVID-19) has been unprecedented. We sought to analyze its global impact with a survey on colorectal cancer (CRC) care during the pandemic. Methods The impact of COVID-19 on preoperative assessment, elective surgery, and postoperative management of CRC patients was explored by a 35-item survey, which was distributed worldwide to members of surgical societies with an interest in CRC care. Respondents were divided into two comparator groups: 1) ‘delay’ group: CRC care affected by the pandemic; 2) ‘no delay’ group: unaltered CRC practice. Results A total of 1,051 respondents from 84 countries completed the survey. No substantial differences in demographics were found between the ‘delay’ (745, 70.9%) and ‘no delay’ (306, 29.1%) groups. Suspension of multidisciplinary team meetings, staff members quarantined or relocated to COVID-19 units, units fully dedicated to COVID-19 care, personal protective equipment not readily available were factors significantly associated to delays in endoscopy, radiology, surgery, histopathology and prolonged chemoradiation therapy-to-surgery intervals. In the ‘delay’ group, 48.9% of respondents reported a change in the initial surgical plan and 26.3% reported a shift from elective to urgent operations. Recovery of CRC care was associated with the status of the outbreak. Practicing in COVID-free units, no change in operative slots and staff members not relocated to COVID-19 units were statistically associated with unaltered CRC care in the ‘no delay’ group, while the geographical distribution was not. Conclusions Global changes in diagnostic and therapeutic CRC practices were evident. Changes were associated with differences in health-care delivery systems, hospital’s preparedness, resources availability, and local COVID-19 prevalence rather than geographical factors. Strategic planning is required to optimize CRC care
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