40 research outputs found

    Spatial and temporal changes in interstitial meiofauna on a sandy ocean beach of South America

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    Os padrões de distribuição espacial e temporal da meiofauna em uma praia arenosa do Brasil foram analisados usando um modelo estatístico que considerou os dados biológicos como variáveis e as características granulométricas, % de matéria orgânica, temperatura como covariáveis. Quatro zonas litorais foram amostradas durante o período de um ano e três cores de sedimento foram coletados em cada zona. A meiofauna foi composta de 12 taxa principais e os Tardigrada e Nematoda representaram 92% da fauna total. A densidade média da meiofauna variou de 1.556,25 a 13.125,25 ind.10cm-2, com as mais altas densidades em dezembro. Os resultados da regressão múltipla mostraram que os efeitos médios das zonas, estratos e meses nos organismos foram significativamente correlacionados com os principais grupos da meiofauna. A zona de retenção e o estrato de 0-10 cm apresentaram os mais altos valores de densidade. A distribuição temporal mostrou diferentes padrões, onde alguns taxa foram mais abundantes na estação seca e outros na estação úmida. As variáveis sedimentológicas tiveram um forte efeito significante sobre os grupos meiofaunísticos. As ótimas condições de vida da zona de retenção para o meiobentos fazem desta região uma área favorável para estudos de ecologia básica e aplicada.Spatial and temporal patterns of meiofauna community from a Brazilian sandy beach were investigated. The objective of this work was to analyze the meiofauna distribution using a statistical model that considers the biological data as variables, and granulometric characteristics, organic matter, and temperature as covariables.Four zones were sampled throughout one year in a Brazilian sandy beach and three sediment cores were taken monthly from each zone. The meiofauna was composed by 12 taxa, with tardigrades and nematodes comprising 92% of the total fauna. The meiofauna mean density varied from 1556.25 to 13125.25 ind.10 cm-2, with the highest densities in December. The results of multiple regression showed that the mean effects of zones, vertical layers, and months on the organisms were significantly correlated with the principal taxa of meiofauna. The retention zone and the 0-10 cm layer presented the highest densities. The temporal distribution showed different patterns and some taxa were more abundant in the dry season, and others in the rainy season. Sedimentological variables had strong and significant effects on the meiofauna taxa. According to the results, physical variables at the retention zone create optimal living conditions for the meiobentos, making this zone an area that favors the basic and applied ecological studies

    Gender Differences in COVID-19 Among Liver Transplant Recipients: Results from a Multicenter Brazilian Cohort

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    Introduction: Existing literature presents varying perspectives on the impact of COVID-19 on liver transplant recipients.However, no research has specifically investigated the role of gender differences in the manifestation of COVID-19 among liver transplant recipients. This study aims to examine the effects of COVID-19 on liver transplant recipients, with a focus on gender differences in disease presentation and progression. Methods: Conducted as a multicenter historical cohort study, this research collected patient records through an online questionnaire. Assessing COVID-related mortality was the main objective. Additionally, demographic, clinical, and laboratory data pertaining to disease presentation and progression werecollected. Results: The study included a total of 283 patients, of whom 76 were female and 206 were male. The median follow-up period for males was 99 days (IQR 38-283), while for females, it was 126 days (IQR 44-291). A higher prevalence of cardiovascular disease was observed in males (p=0.002). Females frequently experienced a loss of smell (p=0.021), whereas males commonly exhibited fever (p=0.031). Levels of ALT and gamma-glutamyl transferase were significantly elevated in males (p=0.008 and 0.004, respectively). Although there was a trend towards increased mortality in males, it did not reach statistical significance. Conclusion: This study is the first attempt to investigate gender differences in COVID-19 among liver transplant recipients. Our findings highlight the need for a comprehensive and personalised approach to treating this patient population and underscore the importance of further elucidating the disease presentation in these individuals

    Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

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    Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

    3th International Congress of Speleology 4th Speleological Congress of Latin América and Caribbean 26th Brazilian Congress of Speleology Brasília DF, 15-22 de julho de 2001 Palaeobiogeography of the Freshwater Isopods Microcerberidae (Crustacea) from Cari

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    Abstract Freshwater species of the interstitial Microcerberidae (Crustacea Isopoda) occur in restricted, local areas of the world, compared to the world-wide distribution of the coastal marine representatives. In U.S.A., two inland species of Microcerberus form the sister group of the species from Rumania and Bulgaria. On Cuba, Yvesia lives in brackish water of wells. The two genera exhibit plesiomorphic characters. Both plate tectonics and Tethys regressions provide an understanding of their evolutionary history. The marine ancestors lived in the littoral of the Tethys since the opening of the Central Atlantic and could have settled in freshwater of Southeastern USA at the end of the Cenomanian regression. The Caribbean plate derived from the Pacific toward the East, between the North and South American plates and small islands emerged since the Aptian. On Cuba, the ancestor of Yvesia striata might have been left by one of the regressions from Aptian up to the Eocene

    Pseudo-Peptides Derived from Isomannide as Potential Inhibitors of Serine Proteases

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    Hepatitis C, dengue and West Nile virus are among of the most important flaviviruses that share one important serine protease enzyme. Serine proteases belong to the most studied class of proteolytic enzymes, and are a primary target in the drug development field. In this paper, we describe the synthesis and preliminary molecular modeling studies of a novel class of N-t-Boc amino acid amides derived of isomannide as potential serine proteases inhibitors

    N-t-Boc-amino Acid Esters of Isomannide: Potential Inhibitors of Serine Proteases

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    Hepatitis C, Dengue and West Nile virus are some of the most important flaviviruses, that share one important serine protease enzyme. Serine proteases are the most studied class of proteolytic enzyme and, in these cases, a primary target for drug discovery. In this paper, we describe the synthesis and preliminary molecular modeling studies of a novel class of N-t-Boc amino acid esters derived of isomannide as potential serine proteases inhibitors

    Gamma 60Co DL50/30 of Biomphalaria glabrata (Say, 1818) DL50/30 raios gama de 60Co em Biomphalaria glabrata (Say, 1818)

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    The variation of resistance to 60Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose) to increasing doses of gamma radiation. Doses of 10, 20, 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell 60Co irradiator, were applied to the test groups and two groups control (non-irradiated) of snails - isolated and colony - were kept apart. After have been exposed, the snails were drew back to the aquaria where they were maintained before. The survival was estimated on a daily score of the alive animals in each group-dose, starting after the irradiation exposure day. As a result, the survival self-fertilization forms (DL50/30 = 218.2 Gy) was found greater than in cross-fecundation forms. These data point to a low radio-resistance on the cross-fertilization forms - the sexual reproductive form - which is most found in nature. The lower radio-resistance of the cross-fertilization forms suggests the presence of some sex-linked hormonal factor related to this phenomenon.<br>A variação da resistência entre indivíduos em autofecundação e fecundação cruzada de Biomphalaria glabrata foram estudadas. Uma população de 480 moluscos foi observada durante 29 dias, distribuída em 8 grupos de caramujos isolados e 8 grupos em colônias após a exposição (30 caramujos por grupo-dose) a doses crescentes de radiação gama. Foram usadas doses de 10, 20, 40, 60, 80, 160, 320 e 640 Gy de um irradiador Gamma-Cell 60Co. Dois grupos não irradiados - isolado e colônia - foram separados como controle e após a irradiação todos os caramujos voltaram para aquários onde viviam antes. A sobrevida foi estimada pela contagem diária dos animais vivos em cada grupo-dose, a partir do dia da irradiação. O resultado mostrou maior sobrevivência nos grupos isolados (DL50/30 = 218.2 Gy) que nos grupos colonizados (DL50/30 = 59 Gy). Estes dados apontam para uma baixa radio-resistência nos grupos colonizados - com forma de reprodução sexuada - que são mais comuns na natureza. A baixa resistência observada sugere a presença de fatores humorais e hormônios sexuais ligados ao fenômen

    Short report: Introduction of chikungunya virus ECSA genotype into the Brazilian Midwest and its dispersion through the Americas.

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    Since introduction into Brazil in 2014, chikungunya virus (CHIKV) has presented sustained transmission, although much is unknown about its circulation in the midwestern states. Here, we analyze 24 novel partial and near complete CHIKV genomes from Cuiaba, an urban metropolis located in the Brazilian midwestern state of Mato Grosso (MT). Nanopore technology was used for sequencing CHIKV complete genomes. Phylogenetic and epidemiological approaches were used to explore the recent spatio-temporal evolution and spread of the CHIKV-ECSA genotype in Midwest Brazil as well as in the Americas. Epidemiological data revealed a reduction in the number of reported cases over 2018-2020, likely as a consequence of a gradual accumulation of herd-immunity. Phylogeographic reconstructions revealed that at least two independent introductions of the ECSA lineage occurred in MT from a dispersion event originating in the northeastern region and suggest that the midwestern Brazilian region appears to have acted as a source of virus transmission towards Paraguay, a bordering South American country. Our results show a complex dynamic of transmission between epidemic seasons and suggest a possible role of Brazil as a source for international dispersion of the CHIKV-ECSA genotype to other countries in the Americas
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