3,068 research outputs found

    Allelopathic effect of the Cladonia verticillaris lichen extracts and fumarprotocetraric acid on the early growth of germinated seedlings in Allium cepa L.

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    The allelopathic activity of the different type of Cladonia verticillaris lichen extracts and fumarprotocetraric acid on the early growth of A. cepa (IPA 6) germinated seedlings depends on their chemical composition and concentration, respectively. It was observed that the length of the radicle was significantly stimulated by fumarprotocetraric acid at high concentrations and by the total extract of C. verticillaris thalli, which contained high level of fumarprotocetraric, acid confirmed by HPLC – technique. In addition, it was found, that the phosphate buffer extract, which contained high level of methy betha-orcinol carboxilate measured by HPLC, significantly reduced the length of the hypocotyls. Under our experimental conditions there was no influence of different type of extract and fumarprotocetraric acid on the seed germination ratio of A. cepa, in relation to control. From the study of HPLC it was found that fumarprotocetraric acid and methy betha-orcinol carboxilate were present in all extracts at different concentrations, according to the method of extraction

    Noise Generation in Household Refrigerators: An Experimental Study on fluid Borne Noise

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    The oscillatory pressure disturbance created by the refrigerant flow through pipes and components is one of the main sources of noise in household refrigerators. This type of excitation is transmitted to the pipes and travels through the structure reaching the cabinet and other parts exposed to the air, where audible airborne sound waves are created. In order to get a better understanding of this type of noise a household refrigerator was especially instrumented with thermocouples, absolute and dynamic pressure transducers and accelerometers. Tests were carried out at different operating conditions, when it was found that the compressor was the main source of excitation, practically affecting the entire refrigeration loop. It was also found that the flow velocity at the outlet of the capillary tube was high enough to induce significant vibrations in the evaporator. Finally, it was found that the entrance of vapor bubbles in the capillary tube produces sporadic and strong excitations. However those excitations do not travel very far along the flow, being attenuated by the condenser and the evaporator, but can nevertheless be transmitted to the pipes. In view of the collected database, comments and suggestions concerning the design of household refrigerators are presented and discussed

    O efeito da infecção pelo Schistosoma mansoni sobre a morbidade de crianças do Estado da Bahia, Brasil: II Análise ao nível individual

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    The present investigation was carried out on a sample of 840 children (5 to 16 years old) from ten small towns of the State of Bahia in northeastern Brazil. The objetive was to study, by using a cross sectional methodology, the evolution of schistosomiasis morbidity (hepatic and splenic enlargement) in children, and the role of the intensity of S. mansoni infection in this process. The children were analised in three age groups (5 to 8, to 12 and 13 to 16 years old) and classified as uninfected, mildly infected, moderately infected and heavily infected according to the number of eggs in the stool. In children aged 5 to 8 years, increasing egg counts were not associated with increasing frequencies of hepatic or splenic enlargement. In the 9 to 12 years old group and association was observed with the prevalence of hepatic enlargement, but not with the prevalence of spleen enlargement. In the oldest group, 13 to 16 years old, an association was observed with the prevalence of enlargement of both organs. It was evident that in this population schistosomiasis morbidity develops in the early period of life as a gradual process starting with liver enlargement and followed by spleen enlargement some years later. It was found that the intensity of infection has a fundamental role in this process, although there is a latent period of some years before clinical splenomegaly appears in moderate-heavily infected children. The Authors suggest that the prevalence of splenomegaly in the 13 to 16 years old group is a good measure of the community level of schistosomiasis morbidity and could be used to measure the impact of control programs.Foi estudada uma amostra de 840 crianças de 5 a 16 anos em 10 pequenas cidades do Estado da Bahia. O objetivo foi, analisar, através de um estudo de prevalência, as características evolutivas da morbidade esquistossomótica em crianças, bem como o papel da intensidade da infecção pelo S. mansoni neste processo. As crianças foram agregadas em 3 grupos de idade (5-8, 9-12 e 13-16 anos) e foram classificadas com relação ao número de ovos excretados em: não infectados, infecção leve, infecção moderada e infecção grave. No grupo de 5 a 8 anos o aumento do número de ovos não se associou a uma maior prevalência de hepatomegalia ou esplenomegalia. No grupo de 9 a 12 anos observou-se uma associação com a prevalência de hepatomegalia mas não com a prevalência de esplenomegalia. No grupo de 13 a 16 anos a associação foi observada com as prevalências de hepatomegalia e esplenomegalia. Ficou evidente nesta população que, a morbidade esquistossomótica é um processo gradual, que se inicia em uma etapa precoce da vida e tem como primeiro sinal a hepatomegalia, seguida pela esplenomegalia, após alguns anos. A intensidade da infecção tem um papel fundamental neste processo, porém é necessário um período de latência de alguns anos para ocorrer o desenvolvimento de esplenomegalia clínica no grupo com infecção moderada ou grave. Os Autores propõem o uso da prevalência de esplenomegalia no grupo de 13 a 16 anos de idade como um bom indicador do nível de morbidade esquistossomótica na comunidade, útil para avaliar o impacto de programas de controle sobre a morbidade

    Carbohydrates, proteins and free aminoacids content during the development of tuberous root on yam beam (Pachyrrhizus tuberosus (Lam.) Spreng.), cultivated at the floodplain area, Amazonas State, Brazil

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    Among the species of plants that produce tuberous starched roots in the tropical region, Pachyrrhizus tuberosus, leguminous plant, which is popularly named "feijão macuco", "jacatupé" or yam bean. This study proposed to identify some physiological aspects of the yam bean cultivated in foodplain areas (várzeas). Three different genetic materials (2.2, 1.2 and 1.1.6) studied by the breeding program of National Institute for Amazonian Research (INPA) (numbered 1, 2 and 3), were submitted to two different kinds of cultivation methods: with and without tutoring and with and without inflorescence pruning. Inflorescence pruning improved the xilose, glicose, reduced sugars, protein and aminoacid contents. The genetic materials did not present differences in terms of plant development, but some variations of xilose, reduced sugars and protein contents were observed among them. The starch content in the roots did not present variation during the plant growth under any of the treatments studied.Entre as espécies que produzem tubérculos amiláceos nas condições tropicais, encontra-se Pachyrrhizus tuberosus, leguminosa conhecida popularmente como feijão macuco ou jacatupé. Propôs-se estudar alguns aspectos fisiológicos do desenvolvimento dessa espécie em uma area de várzea. Foi estudado o comportamento de três introduções (2.2, 1.2 e 1.1.6) da coleção do programa de melhoramento de hortaliças do Instituto Nacional de Pesquisas da Amazônia - INPA (definidas como 1, 2 e 3), submetidas a duas formas de manejocom e sem tutoramento das plantas e com e sem poda das inflorescências. A poda das inflorescências resultou em um aumento nos teores de xilose, glicose, açúcares redutores, proteínas e aminoácidos ao longo do desenvolvimento. Foram observadas variações nos teores de xilose, açúcares redutores e proteínas entre as introduções estudadas. O teor de amido nas raízes tuberosas não mostrou variação ao longo do desenvolvimento, em nenhum dos tratamentos estudados

    Prior Exercise Reduces Fast-Start Duration and End-Spurt Magnitude during Cycling Time-Trial

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    We examined the pacing strategy and the magnitude of the end spurt during a 200-kJ cycling time trial performed 12–14 h after an exercise protocol designed to reduce muscle glycogen content. 9 physically-active men performed 5 familiarization sessions and 2 experimental 200-kJ time trials in either a control condition (CON) or after an exercise protocol performed the previous evening that was designed to induce muscle glycogen depletion (EP). Mean total time was faster and power output was higher in the CON than in the EP (P<0.01). A fast-start was maintained until the 50-kJ section in CON, but only the 25-kJ section for EP (P<0.05). The power outputs during the 50-, 150- and 200-kJ sections, and the magnitude of the end-spurt, were significantly higher for the CON than for the EP condition (P<0.05). There was no significant difference in the rating of perceived exertion (overall feeling and feeling in legs) between conditions. In conclusion, a protocol designed to decrease muscle glycogen stores reduced the duration of the fast-start and the magnitude of the end spurt during a 200-kJ cycling time trial, impairing the overall performance

    Influência da função pulmonar e da força muscular na capacidade funcional de portadores de doença pulmonar obstrutiva crónica = The influence of lung function and muscular strength on the functional capacity of chronic obstructive pulmonary disease patients

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    Objectivo : Determinar que variável entre o volume expirado forçado no primeiro segundo (VEF1), a pressão parcial do oxigénio no sangue arterial (PaO2), a hipoxemia nocturna e a força muscular do quadricípite femoral pode predizer a distância percorrida no teste de caminhada de seis minutos (TC6) em doentes com DPOC. Doentes e métodos : Um estudo observacional do tipo transversal, envolvendo trinta doentes encaminhados a um programa de reabilitação pulmonar de um hospital universitário. A função pulmonar foi avaliada por espirometria, gasometria arterial e oximetria nocturna. A função muscular pela força muscular do quadricípite femoral e a avaliação da capacidade funcional pelo TC6. Resultados : A análise de regressão bivariada mostrou que a força do quadricípite femoral foi a única variá- vel que se mostrou estatisticamente significativa (p = 0,002) em predizer a distância, sendo responsá- vel por 38% da variância do TC6. Para essas variáveis a relação estabelecida estatisticamente foi que para cada quilo de força do quadricípite femoral, os doentes caminharam 5,9 metros no TC6. Conclusão : Os resultados indicam a importância da força muscular do MI em testes de esforço submáximo. Entre as variáveis estudadas, apenas a força muscular do quadricípite femoral pôde predizer a distância percorrida no TC6 em portadores de doença pulmonar obstrutiva crónica. Aim : To determine which variable (forced expiratory volume in 1 second (FEV1), partial pressure of oxygen in arterial blood (PaO2), nocturnal hypoxaemia and muscular strength of femoral quadriceps) can predict the distance walked in the six-minute walk test (6MWT) by COPD patients. Methods : A cross-sectional and observational study of thirty patients referred to a pulmonary rehabilita tion programme at a university hospital. Lung function was evaluated by spirometry, arterial blood gas analysis and nocturnal oximetry. Muscle function was evaluated by quadriceps strength and functional capacity by the 6MWT. Results : Bivariate regression analysis showed that quadriceps strength, was the only variable to correlate significantly with the distance walked in the 6MWT (p=0.002), accounting for 38% of the 6MWT variance. The statistical relationship established for these variables was 1kg of quadriceps strength equalled 5.9 metres walked in the 6MWT. Conclusions : Our results showed the importance of lower limb muscle strength in submaximal exercise testing. We conclude that femoral quadriceps muscle strength is the only one of the variables studied which can predict the distance COPD patients walk in the 6MWT

    Carbon Monoxide Modulation of Microglia-Neuron Communication: Anti-Neuroinflammatory and Neurotrophic Role

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    This work was financed by FEDER-Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020-Operational Programme for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT-Fundação para a Ciência e a Tecnologia/Ministério da Ciência (FCT), Tecnologia e Ensino Superior in the framework of FCT-ANR/NEU-NMC/0022/2012 grant, PTDC/MEC-NEU/28750/2017 grant, Applied Molecular Biosciences Unit-UCIBIO (UID/Multi/04378/2019) grant; LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy; and FCT provided individual financial support to NLS (PD/BD/127819/2016), BFM (PD/BD/128336/2017) and HLAV (IF/00185/2012).Microglia, the ‘resident immunocompetent cells’ of the central nervous system (CNS), are key players in innate immunity, synaptic refinement and homeostasis. Dysfunctional microglia contribute heavily to creating a toxic inflammatory milieu, a driving factor in the pathophysiology of several CNS disorders. Therefore, strategies to modulate the microglial function are required to tackle exacerbated tissue inflammation. Carbon monoxide (CO), an endogenous gaseous molecule produced by the degradation of haem, has anti-inflammatory, anti-apoptotic, and pro-homeostatic and cytoprotective roles, among others. ALF-826A, a novel molybdenum-based CO-releasing molecule, was used for the assessment of neuron-microglia remote communication. Primary cultures of rat microglia and neurons, or the BV-2 microglial and CAD neuronal murine cell lines, were used to study the microglia-neuron interaction. An approach based on microglial-derived conditioned media in neuronal culture was applied. Medium derived from CO-treated microglia provided indirect neuroprotection against inflammation by limiting the lipopolysaccharide (LPS)-induced expression of reactivity markers (CD11b), the production of reactive oxygen species (ROS) and the secretion of inflammatory factors (TNF-α, nitrites). This consequently prevented neuronal cell death and maintained neuronal morphology. In contrast, in the absence of inflammatory stimulus, conditioned media from CO-treated microglia improved neuronal morphological complexity, which is an indirect manner of assessing neuronal function. Likewise, the microglial medium also prevented neuronal cell death induced by pro-oxidant tert-Butyl hydroperoxide (t-BHP). ALF-826 treatment reinforced microglia secretion of Interleukin-10 (IL-10) and adenosine, mediators that may protect against t-BHP stress in this remote communication model. Chemical inhibition of the adenosine receptors A2A and A1 reverted the CO-derived neuroprotective effect, further highlighting a role for CO in regulating neuron-microglia communication via purinergic signalling. Our findings indicate that CO has a modulatory role on microglia-to-neuron communication, promoting neuroprotection in a non-cell autonomous manner. CO enhances the microglial release of neurotrophic factors and blocks exacerbated microglial inflammation. CO improvement of microglial neurotrophism under non-inflammatory conditions is here described for the first time.publishersversionepub_ahead_of_prin

    Genome-wide profiling of p53-regulated enhancer RNAs uncovers a subset of enhancers controlled by a lncRNA

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    p53 binds enhancers to regulate key target genes. Here, we globally mapped p53-regulated enhancers by looking at enhancer RNA (eRNA) production. Intriguingly, while many p53-induced enhancers contained p53-binding sites, most did not. As long non-coding RNAs(lncRNAs) are prominent regulators of chromatin dynamics, we hypothesized that p53-induced lncRNAs contribute to the activation of enhancers by p53. Among p53-induced lncRNAs, we identified LED and demonstrate that its suppression attenuates p53 function. Chromatin-binding and eRNA expression analyses show that LED associates with and activates strong enhancers. One prominent target of LED was located at an enhancer region within CDKN1A gene, a potent p53-responsive cell cycle inhibitor. LED knockdown reduces CDKN1A enhancer induction and activity, and cell cycle arrest following p53 activation. Finally, promoter-associated hypermethylation analysis shows silencing of LED in human tumours. Thus, our study identifies a new layer of complexity in the p53 pathway and suggests its dysregulation in cancer
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