43 research outputs found

    Pigmentos, fenóis solúveis totais e lignina em plântulas de cafeeiro inoculadas com Colletotrichum gloeosporioides

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    The objective of this work was to study the effects of different isolates of Colletotrichum gloeosporioides, as topigment level (chlorophyll a, b and total), total soluble phenols and soluble lignin in coffee seedlings obtained by artificially inoculatedtissue culture. The experiment was carried out in randomized block design in a 2 x 3 factorial scheme (2 genetic materials), 3 isolates(an isolate from mango fruits and another one from coffee plants), with 5 replicates and control (plants without inoculation). Theplants were inoculated with a suspension of 2 x 106 conidia.ml-1. The conidial suspension was sprayed on previously injured leaves.Leaves of inoculated plants were collected at 3 and 7 days after inoculation, except for leaves on the lower part of the plants.Afterwards, samples were prepared for the evaluation of chlorophyll, total soluble phenols and soluble lignin. The results showedthat the presence of the pathogen in healthy and diseased plants significantly reduced the amount of chlorophyll. At 7 days afterinoculation of healthy and diseased coffee plants higher total soluble phenol and soluble lignin levels were observed in response to theattack by Colletotrichum gloeosporioides.Objetivou-se, neste trabalho, estudar os efeitos de diferentes isolados de Colletotrichum gloeosporioides sobre osteores de pigmentos (clorofila a, b e total), fenóis solúveis totais e lignina solúvel, em dois diferentes tempos, sobre mudas de caféobtidas por cultura de tecidos e inoculadas artificialmente. O experimento foi conduzido em blocos casualizados em esquemafatorial 2 x 3 (2 materiais génticos), 3 isolados (um obtido de mangueira e 2 isolados obtidos de plantas de café) + 2 (testemunhassem inoculação), com 5 repetições. As plantas foram inoculadas com uma suspensão de 2 x 106 conídios.ml-1. A suspensão deconídios foi pulverizada sobre folhas de cafeeiro, previamente feridas. Foram realizadas duas coletas, aos 3 e 7 dias apósinoculação, de todas as folhas da muda, exceto as folhas baixeiras. Em seguida, foi feito o preparo das amostras para avaliaçãode clorofila, fenóis solúveis totais e lignina solúvel. A partir dos resultados, pode-se concluir que a presença do patógeno, tantoem plantas sadias, como em plantas doentes diminuíram significativamente a quantidade de clorofila. Aos 7 dias após inoculaçãodas plantas de café sadias e doentes, observou-se um maior teor de fenóis solúveis totais e lignina solúvel em resposta ao ataquede Colletotrichum gloeosporioides

    Efeito de temperatura e molhamento foliar em Phoma tarda e mancha de phoma em mudas de cafeeiro

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    Phoma leaf spot is a major disease of coffee plants in regions with specific conditions of temperature and humidity. Despite the importance of environmental variables for disease progression, so far they have been poorly understood. Thus, we assessed the effect of different temperatures (15, 20, 25 and 30 oC) on mycelial growth, production and germination of conidia of Phoma tarda; and the same effect of temperature (15, 20, 25 and 30 oC) and leaf wetness duration (6, 12, 24, 36 and 48 hours) on fungal infection and severity of disease over time in coffee plants. Disease assessment was integrated in the area using the disease progress curve (AUDPC) and the infection processes were observed by scanning electron microscopy (SEM). The optimal temperatures for fungus growth, conidial production and germination in vitro were 22.9, 29.8, and 25.1 °C, respectively. Temperatures ranging from 15-20 °C significantly increased germ tube length and provided favorable conditions for pathogen infection through observation of early events such as cuticle separation from leaf tissue. The same temperature range combined with increasing leaf wetness periods, reached the highest value of the AUDPC of phoma leaf spot. Thus, it was found that both temperature and leaf wetness duration in the variables assessed and the difference in relation to temperature for in vitro growth and sporulation for in vivo tests were important.Mancha de Phoma é uma das principais doenças do cafeeiro em zonas com condições específicas de temperatura e umidade. Apesar da importância das variáveis ambientais para o progresso da doença, até agora essas têm sido mal compreendidas. Avaliou-neste estudo, o efeito de diferentes temperaturas (15, 20, 25 e 30 ºC) sobre o crescimento micelial, produção e germinação de conídios de Phoma tarda, e o efeito da temperatura (15, 20, 25 e 30 ºC) e da duração do período de molhamento (6, 12, 24, 36 e 48 horas) sobre a infecção fúngica e severidade da doença, ao longo do tempo em plantas de café. A avaliação da doença realizada através da área abaixo da curva de progresso da doença (AACPD) e os processos de infecção foram observados por microscopia eletrônica de varredura (MEV). As temperaturas ótimas para o crescimento de fungos, produção de conídios e germinação foram de 22,9, 29,8, 25,1 °C, respectivamente. Temperaturas variando entre 15-20 °C aumentaram, significativamente, o comprimento do tubo germinativo e proporcionaram condições favoráveis para a infecção pelo patógeno através da observação dos primeiros eventos, tais como a separação da cutícula do tecido foliar. A mesma faixa de temperatura combinada com períodos crescentes de molhamento foliar, no máximo, 48 horas, atingiu os maiores valores da AACPD da Mancha Phoma. Assim, verificou-se que, tanto a temperatura quanto a duração do molhamento para testes in vivo e a influência da temperatura para o crescimento e esporulação in vitro foram importantes

    Clinical Findings Arising from the Use of Silver Diamine Fluoride to Prevent or Treat Caries Lesions and Dentinal Hypersensitivity: A Data Mining Analysis

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    Objective: To summarize data of clinical trials that used silver diamine fluoride (SDF) to prevent and treat caries lesions and dentinal hypersensitivity. Material and Methods: Six electronic databases were searched in May 2022. The concentration of SDF, type of usage (alone/combined), dentition, anterior/posterior teeth, tooth region, dental tissue, number of the treated surfaces, the intervention environment, participants' age, frequency and duration of SDF application, purpose, and outcome were the extracted variables. The type of study, year of publication, authors, journals, and country were also investigated. Results: From 8860 articles, 53 were selected. Most were randomized (n=38), that applied 38% SDF (n=43), alone (n=44), on multiple surfaces (n=44), only in dentin (n=36), of the crown (n=46) of anterior and posterior (n=36) primary teeth (n=39). The studies were preferably carried out outside the clinic (n=31), only in children (n=33), with reapplication of SDF (n=30), but did not inform the duration of application (n=19). SDF was most used to treat (n=46) only caries lesions (n=50). They were published between 2001 and 2022, mainly in the Journal of Dentistry (n=10). China (n=19) and Lo E.C.M (n=19) were the countries and authors that published the most, respectively. Conclusion: The silver diamine fluoride 38% alone was most used to treat caries lesions in the dentin of the crown of all primary teeth, preferably applied on multiple surfaces, requiring reapplication, and outside the clinic

    Síndrome de Chiari e Hidrossiringomielia com comprometimento neurológico: um relato de caso

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    A Malformação de Chiari (MC) pertence a um amplo grupo de raras deformidades estruturais da junção craniocerebelomedular. O tipo I da doença caracteriza-se pela herniação tonsilar ou amigdaliana cerebelar devido à anomalia da base do crânio e da parte superior da coluna cervical, além de a porção medial do lobo inferior do cerebelo pelo canal cervical também se protuberar através do forame magno, impedindo que o líquor flua normalmente através do canal. A real prevalência da doença é desconhecida, pois muitos pacientes com herniação cerebelar são assintomáticos e o problema agrava-se na fase adulta, com queixas de cefaleia intensa e, por vezes, parestesia. O objetivo deste estudo é relatar um caso de síndrome de Chiari (SC) em uma paciente de 53 anos, ao abordar sua apresentação clínica, diagnóstico e tratamento. Paciente do sexo feminino, 53 anos, foi admitida em um hospital da rede pública de referência se queixando de cefaleia occipital intensa e cervicalgia com irradiação da dor para os membros superiores, acompanhada de parestesia nos quatro segmentos. Relatou já sentir dor há 2 anos, mas apresentou piora do quadro clínico há 8 meses. Foi, também, observada incontinência urinária devido à dissinergia detrusora-esfincteriana por provável bexiga neurogênica. Foi, então, realizado exame de imagem de ressonância magnética (RNM) do crânio e da coluna cervical, com obtenção de sequências ponderadas em T1, T2 e STIR, nos planos sagital e transverso com contraste, o qual evidenciou leve alargamento medular, além de sinais de hidrossiringomielia difusa, com hipossinal na sequência T2 intramedular na altura de D1-D2 (coluna dorsal). Foi notada discreta herniação das tonsilas cerebelares junta ao forame magno, típica da SC, sendo, por fim, confirmado o diagnóstico. A paciente, no entanto, não apresentava hidrocefalia, mesmo com a interrupção do fluxo do líquido cefalorraquidiano (LCR) para o canal vertebral. Ela encaixou- se nos parâmetros de indicação cirúrgica, sendo realizada craniotomia occipital, com acesso ao plexo coroide do quarto ventrículo do tronco encefálico com o intuito de elevar as tonsilas cerebelares baixas, herniadas no canal espinhal cervical e bloqueando o fluxo do LCR. Após a descompressão craniocervical, o curso do líquor foi restaurado e a paciente foi, por fim, encaminhada à sala de recuperação pós-operatória. A SC é uma rara doença que apresenta quadro clínico e alterações radiológicas complexas e extensas e, por vezes, o diagnóstico é retardado devido à inespecificidade dos sintomas confundidos com cervicalgias e cefaleias comuns. A hipótese diagnóstica deve ser embasada nas queixas do paciente, na anamnese minuciosa, exame clínico e nos exames de imagens, sendo a prevalência desta patologia de difícil definição e com faixas etárias distintas

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension

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    OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo

    Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab

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    The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension

    Pervasive gaps in Amazonian ecological research

    Get PDF

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
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