313 research outputs found

    Sublethal effects of chlorantraniliprole and thiamethoxam seed treatments when Lysiphlebus testaceipes feed on sunflower extrafloral nectar

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    Citation: Moscardini, V. F., Gontijo, P. C., Michaud, J. P., & Carvalho, G. A. (2014). Sublethal effects of chlorantraniliprole and thiamethoxam seed treatments when Lysiphlebus testaceipes feed on sunflower extrafloral nectar. Retrieved from http://krex.ksu.eduThe extrafloral nectar (EFN) of sunflower, Helianthus annuus L., is an important summer resource for many insects and represents a potential route of exposure to systemic insecticides applied as seed treatments to cultivated varieties. Among the many parasitoids that utilize sunflower EFN, Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae) is an important generalist parasitoid of cereal aphids in North America. This study evaluated the performance of adult wasps fed EFN of sunflower plants grown from seed treated with chlorantraniliprole and thiamethoxam. Consumption of EFN from treated sunflower seedings caused no lethal effects, but reduced the numbers of greenbug nymphs, Schizaphis graminum Rondani, attacked and parasitized when wasps foraged in Petri dish arenas. Whereas control females self-superparasitized every fourth host, those exposed to chlorantraniliprole did not. Offspring developmental time and adult emergence were unaffected by either treatment, but thiamethoxam greatly reduced the proportion of female offspring

    Non-target effects of chlorantraniliprole and thiamethoxam on Chrysoperla carnea when employed as sunflower seed treatments

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    Citation: Gontijo, P. C., Moscardini, V. F., Michaud, J. P., & Carvalho, G. A. (2014). Non-target effects of chlorantraniliprole and thiamethoxam on Chrysoperla carnea when employed as sunflower seed treatments. Retrieved from http://krex.ksu.eduThe use of systemic insecticides as seed treatments has raised concern about the possible impacts of these products on natural enemies. This study assessed the effects of sunflower seed treatments with chlorantraniliprole and thiamethoxam on Chrysoperla carnea by exposing larvae and adults to sunflower stem segments grown from treated seeds and the nectar secreted by their extrafloral nectaries. Confinement of larvae with stem segments for their entire developmental period had no effect on their survival or any life history parameter, except that the sex ratio of resulting adults was lower in the thiamethoxam treatment than in chlorantraniliprole. However, when adult pairs of C. carnea were exposed to treated stem segments during their maturation period, their subsequent survival and fecundity was significantly reduced by both materials, with thiamethoxam reducing median survival (LT[subscript 50]) and fecundity to a greater degree than chlorantraniliprole. Insufficient offspring were obtained from adults exposed to thiamethoxam to permit assessment of their fitness, but the offspring in the chlorantraniliprole-exposed adults had reduced larval survival relative to controls. The greater impact of seed treatments on adult lacewings may be partly attributable to their greater consumption of extra-floral nectar. Our results indicate that seed treatment with systemic insecticides can cause negative effects on beneficial insects, potentially disrupting their population dynamics, and should not be assumed compatible with biological control and IPM simply because this mode of application limits direct exposure

    Toxic effects of Ricinus communis non-protein trypsin inhibitor on Spodoptera frugiperda (J. E. Smith) (Lepidoptera:Noctuidae)

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    In the study reported herein, we aimed to isolate a trypsin inhibitor from Ricinus communis leaves through chromatographic and spectrometric techniques and evaluate its toxic effects on the development of Spodoptera frugiperda larvae. Plant extracts were submitted to fractionation in adsorption column. The fraction 10, which showed the highest inhibitory activity, were incorporated into an artificial diet at the concentrations of 0, 0.06, 0.12, 0.25 and 0.5%, and offered to S. frugiperda larvae. Fresh weight of larvae, food consumed and weight of eliminated faeces were registered. Based on these parameters the following nutritional index were calculated: Relative Consumption Rate (RCR), Relative Metabolic Rate (RMR), Relative Growth Rate (RGR), Approximated Digestibility (AD), Efficiency of Ingested Food Conversion (EIC), Efficiency of Digested Food Conversion (EDC) and the Metabolic Cost (100 - EDC). The inhibitor at 0.5% concentration was deleterious to S. frugiperda, extending the larval stage in 11 days, with higher RCR and ECD, and lower RGR, ECI and ECD. Therefore, the trypsin inhibitor from leaves of R. communis affected the S. frugiperda larval development, being promising in studies of alternative and sustainable control methods for lepidopteran pest species.Keywords: Castor beans, enzymatic inhibition, integrated pest management, plant defense against herbivor

    TRATAMENTO NÃO OPERATÓRIO DO TRAUMA DE VÍSCERAS ABDOMINAIS PARENQUIMATOSAS

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    Nonoperative management of the solid organ injuries (liver, spleen and kidneys) in hemodynamically patients has become the standard of care in the last decade. Computed tomography scan is invaluable in determining appropriate patient selection and to exclude other injuries that may necessitate laparotomy. Nonoperative management strategies primarily consist of careful observation with or without the use of adjunctive angiography. The widespread use of angiographic embolization has increased the number and type of patients that can be safety managed without operative intervention. The increasing use of nonoperative management is based on the low failure rates reported in most studies. Success rates of nonoperative treatment have increase to > 90% for these injuries. Practitioners must remain vigilant, however, because failures of nonoperative management may need immediate intervention. This review will discuss current concepts in nonoperative management, including diagnosis, patient selection, nonoperative treatment strategies, benefits, risks, and complications.O tratamento não operatório das lesões de órgãos parenquimatosos abdominais (fígado, baço e rins) em pacientes com estabilidade hemodinâmica tem se tornado o método de escolha na última década. A TC é indispensável para a adequada seleção do paciente e para excluir outras lesões que podem necessitar de laparotomia. As estratégias de tratamento não operatório consistem da observação clínica e monitorização cuidadosa com ou sem o uso adjunto da angiografia. A utilização disseminada de embolização angiográfica tem aumentado o número e o tipo de pacientes que podem ser tratados sem cirurgia. O aumento desta modalidade de tratamento não operatório é baseado nas baixas taxas de falha terapêutica relatado na maioria dos estudos. As taxas de sucesso do tratamento não operatório é maior de 90% para estas lesões. Este artigo de revisão discutirá os conceitos atuais no manuseio não operatório, incluindo o diagnóstico, a seleção dos pacientes, as estratégias utilizadas no tratamento não operatório, os benefícios, os riscos e as complicações

    Triterpenos e flavonóides isolados de flores de laseguea erecta (apocynaceae)

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    Das flores de Laseguea erecta isolaram-se o lupeol, ácido ursólico e os flavonóides quercetina (3,5,7,3’,4’-pentaidroxiflavona) e 3-O-a-L-arabinopiranosil quercetina. Esta é o primeiro estudo sobre metabólitos especiais em flores desse género. As estruturas foram determinadas através da análise dos dados espectrais de IV, RMN de 1H e 13C (1D e 2D) e comparação com valores registrados na literatura.Das flores de Laseguea erecta isolaram-se o lupeol, ácido ursólico e os flavonóides quercetina (3,5,7,3’,4’-pentaidroxiflavona) e 3-O-a-L-arabinopiranosil quercetina. Esta é o primeiro estudo sobre metabólitos especiais em flores desse género. As estruturas foram determinadas através da análise dos dados espectrais de IV, RMN de 1H e 13C (1D e 2D) e comparação com valores registrados na literatura.From the flowers of Laseguea erecta were isolated the lupeol, ursolic acid, quercetin (3,5,7,3’,4’-pentahydroxyflavone) and 3-O-a-L-arabinopyranosylquercetin. This is the first phytochemical study of this genera flowers’. The structures were established by the IR, 1H and 13C NMR (1D, 2D) spectral data analysis and by comparison with literature data

    Cofilin-1 is a mechanosensitive regulator of transcription

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    The mechanical properties of the extracellular environment are interrogated by cells and integrated through mechanotransduction. Many cellular processes depend on actomyosin-dependent contractility, which is influenced by the microenvironment's stiffness. Here, we explored the influence of substrate stiffness on the proteome of proliferating undifferentiated human umbilical cord-matrix mesenchymal stem/stromal cells. The relative abundance of several proteins changed significantly by expanding cells on soft (∼3 kPa) or stiff substrates (GPa). Many such proteins are associated with the regulation of the actin cytoskeleton, a major player of mechanotransduction and cell physiology in response to mechanical cues. Specifically, Cofilin-1 levels were elevated in cells cultured on soft comparing with stiff substrates. Furthermore, Cofilin-1 was de-phosphorylated (active) and present in the nuclei of cells kept on soft substrates, in contrast with phosphorylated (inactive) and widespread distribution in cells on stiff. Soft substrates promoted Cofilin-1-dependent increased RNA transcription and faster RNA polymerase II-mediated transcription elongation. Cofilin-1 is part of a novel mechanism linking mechanotransduction and transcription.publishe

    Enhancing the longevity and functionality of Ti-Ag dry electrodes for remote biomedical applications: a comprehensive study

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    This study aims to evaluate the lifespan of Ti-Ag dry electrodes prepared using flexible polytetrafluoroethylene (PTFE) substrates. Following previous studies, the electrodes were designed to be integrated into wearables for remote electromyography (EMG) monitoring and electrical stimulation (FES) therapy. Four types of Ti-Ag electrodes were prepared by DC magnetron sputtering, using a pure-Ti target doped with a growing number of Ag pellets. After extensive characterization of their chemical composition and (micro)structural evolution, the Ti-Ag electrodes were immersed in an artificial sweat solution (standard ISO-3160-2) at 37 °C with constant stirring. Results revealed that all the Ti-Ag electrodes maintained their integrity and functionality for 24 h. Although there was a notable increase in electrical resistivity beyond this timeframe, the acquisition and transmission of (bio)signals remained viable for electrodes with Ag/Ti ratios below 0.23. However, electrodes with higher Ag content (Ag/Ti = 0.31) became insulators after 7 days of immersion due to excessive Ag release into the sweat solution. This study concludes that higher Ag/Ti atomic ratios result in heightened corrosion processes on the electrode’s surface, consequently diminishing their lifespan despite the advantages of incorporating Ag into their composition. This research highlights the critical importance of evaluating electrode longevity, especially in remote biomedical applications like smart wearables, where electrode performance over time is crucial for reliable and sustained monitoring and stimulation.This research was funded by the European Regional Development Fund (ERDF) through the Operational Programme for Competitiveness and Internationalization (COMPETE 2020) under Portugal 2020, in the framework of the NanoStim (POCI-01-0247-FEDER-045908) and NanoID (NORTE-01-0247-FEDER-046985) Projects

    Cytotoxic, antitumor and toxicological profile of Passiflora alata leaf extract

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    Passiflora alata or passion fruit is a native flowering plant from Amazon, geographically spread from Peru to Brazil. The plant has long been used in folks medicine for its pharmacological properties and is included in the Brazilian Pharmacopoeia since 1929. The aim of this study was to evaluate the potential cytotoxic and antitumor activities of Passiflora alata leaf extract (PaLE) in S180-tumor bearing mice. The percentage of cell proliferation inhibition (% CPI) and IC50 in relation to 4 tumor cell lines were determined in PC3, K-562, HepG2 and S180 cell lines using the MTT assay. PaLE showed a CPI > 75% and greater potency (IC50 < 30 µg/mL) against PC3 and S180 cell lines. PaLE showed antitumor activity in treatments intraperitoneally (36.75% and 44.99% at doses of 100 and 150 mg/kg/day, respectively). Toxicological changes were shown in the reduced body mass associated with reduced food consumption, increased spleen mass associated with histopathological increase in the white pulp of the spleen and increased number of total leukocytes with changes in the percentage relationship between lymphocytes and neutrophils. Our outcomes corroborate the conclusion that PaLE has antitumor activity in vitro and in vivo with low toxicity.This research was funded by the Coordenação Aperfeiçoamento de Pessoal de Nivel Superior (CAPES), Fundação de Ámparo à Pesquisa do Estado de Sergipe (FAPITEC) (PROCESSO: 88887.159533/2017-00 extração, encapsulação e caracterização de bioativos para o interesse biotecnologico), Banco do Nordeste (grant FUNDECI/2016.0015), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 301964/2019-0 Chamada 06/2019, and Chamada CNPq nº 01/2019) and by the Portuguese Science and Technology Foundation (FCT) project UIDB/04469/2020 (strategic fund).info:eu-repo/semantics/publishedVersio
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