1,342 research outputs found

    Determination of pKa and Hydration Constants for a Series of α-Keto-Carboxylic Acids Using Nuclear Magnetic Resonance Spectrometry

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    The determination of the acid-base dissociation constants, and thus the pKa values, of α-keto acids such as pyruvic acid is complex because of the existence of these acids in their hydrated and nonhydrated or oxo state. Equilibria involved in the hydration and dehydration of the α-keto group of pyruvic acid and three other α-keto acids, 3-methyl-2-oxobutanoic acid, 4-methyl-2-oxopentanoic acid, and 2-oxo-2-phenylacetic acid, were investigated by proton and carbon nuclear magnetic resonance spectrometry, at constant ionic strength, 0.15, and 25°C. Dissociation constants for the oxo (pKaoxo) and hydrated (pKahyd) acids of each compound were estimated from the change in the degree of hydration with changes in pH and directly from the changes in chemical shifts of various hydrogen and carbons nuclei with pH. α-Keto acids showed greater hydration in their acidic forms than their carboxylate forms. The degree of hydration was sensitive to steric and electronic/resonance factors. As expected, the oxo forms of the acids were stronger acids compared with their hydrated analogs, and their dissociation constants were also sensitive to steric and electronic factors

    Emotional management and biological markers of dietetic regimen in chronic kidney disease patients

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    The aim of the study was to investigate the association between psychological characteristics and biological markers of adherence in chronic kidney disease patients receiving conservative therapy, hemodialysis, peritoneal dialysis (PD), or kidney transplantation. Seventy-nine adult patients were asked to complete the following questionnaires: Toronto Alexithymia scale, Snaith–Hamilton Pleasure Scale, and Short Form Health Survey. Biological markers of adherence to treatment were measured. Peritoneal dialysis patients showed a lower capacity to feel pleasure from sensorial experience (p = .011) and a higher values of phosphorus compared to the other patients’ groups (p = .0001). The inability to communicate emotions was negatively correlated with hemoglobin levels (r = −(0).69; p = .001) and positively correlated with phosphorus values in the PD patients (r = .45; p = .050). Findings showed higher psychological impairments and a lower adherence to the treatment in PD patients and suggest the implication of emotional competence in adherence to treatment.The aim of the study was to investigate the association between psychological characteristics and biological markers of adherence in chronic kidney disease patients receiving conservative therapy, hemodialysis, peritoneal dialysis (PD), or kidney transplantation. Seventy-nine adult patients were asked to complete the following questionnaires: Toronto Alexithymia scale, Snaith-Hamilton Pleasure Scale, and Short Form Health Survey. Biological markers of adherence to treatment were measured. Peritoneal dialysis patients showed a lower capacity to feel pleasure from sensorial experience (p = .011) and a higher values of phosphorus compared to the other patients' groups (p = .0001). The inability to communicate emotions was negatively correlated with hemoglobin levels (r = -(0).69; p = .001) and positively correlated with phosphorus values in the PD patients (r = .45; p = .050). Findings showed higher psychological impairments and a lower adherence to the treatment in PD patients and suggest the implication of emotional competence in adherence to treatment

    Growth patterns of tomato plants subjected to two non-conventional abiotic stresses: UV-C irradiations and electric fields

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    Ultraviolet-C radiation (UV-C = 100-280 nm) is strongly affected by ozone levels, so that the amount of this radiation reaching the Earth's surface is extremely low. In the future, UV-C radiation is expected to increase as the result of stratospheric ozone depletion due to atmospheric pollution, with strong negative effects on economically important crops. High UV-C doses determine irreversible damages both at plant physiological and morphological levels, leading plants to death. Also electric fields (EFs) can determine changes at morphological and physiological levels in plants. Electro-culture can accelerate growth rates, increase yields, improve crop quality and plant protection against from diseases, insects and frost. This chapter is focused on the effects of the exposition of tomato (Lycopersicon esculentum Mill.), one of the most economically important crop, to UV-C radiation and DC-electric field, able to determine important and significant alterations in plant growth. The protection of tomato plants against UV-C, combined with the growth-promoting effects of electro-culture, could allow farmers to grow bigger and better crops in less time, with less effort, and at a lower cost

    Candida spp. occurrence in oral cavities of breastfeeding infants and in their mothers' mouths and breasts

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    O objetivo do estudo foi verificar a presença de leveduras do gênero Candida na cavidade bucal de lactentes em aleitamento materno predominante e nas bocas e mamas de suas mães, assim como na cavidade bucal de lactentes em aleitamento artificial e em mulheres na ausência de lactação. Participaram do estudo 169 mulheres e 85 lactentes divididos em quatro grupos: 1) crianças em aleitamento natural predominante (n = 55) e suas mães (n = 55); 2) crianças em aleitamento artificial (n = 30); 3) mulheres que não estavam amamentando, em que se realizaram coletas bucais (n = 80) e, 4) mulheres em ausência de lactação em que se realizaram coletas mamárias (n = 34). "Swabs" bucais e mamários, foram semeados em ágar Sabouraud dextrose com cloranfenicol, e as cepas de levedura isoladas foram identificadas utilizando-se provas morfológicas e bioquímicas. Espécies de Candida foram detectadas a partir de um número significativamente menor de crianças em aleitamento natural predominante que de crianças em aleitamento artificial. Também foi significativa a maior freqüência dessas espécies nas mamas de nutrizes em relação ao controle.This study aimed to determine the occurrence of Candida spp. in the oral cavity of predominantly breastfed infants and in their mothers' mouths and breasts, as well as in the oral cavity of bottlefed infants and in non-lactating women. One hundred and sixty nine women and eighty-five milk-fed infants took part in this study and were divided into four groups: 1) infants predominantly on breastfeeding (n = 55) and their mothers (n = 55); 2) infants on bottlefeeding (n = 30); 3) non-lactating women on whom oral collections were performed (n = 80) and, 4) non-lactating women on whom breast collections were performed (n = 34). Oral and mammary swabs were cultured on Sabouraud agar dextrose with chloramphenicol. The Candida yeast strains found were isolated and identified through morphological and biochemical tests. Candida species were much less frequent in infants who were predominantly breastfed than in those who were bottlefed. Yeasts were much more frequent on the breasts of lactating women, with statistical difference in relation to the control group

    Effects of UV-C radiation on common dandelion and purple coneflower: First results

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    Ultraviolet-C (UV-C) light (100 ≤ λ ≤ 280 nm) is a ionizing radiation that can damage living organisms. An experiment was conducted on plants of common dandelion (Taraxacum officinale Weber, T. Densleonis Desf.) and purple coneflower [Echinacea purpurea, (L.) Moench] irradiated with UV-C at different exposition times, under controlled conditions and grown in self-produced characterized compost, to assess the effect of different doses UV-C radiation on some physiological parameters. Trials have been carried out using a black chamber equipped with an UV-C lamp in which plants were divided in four groups on the basis of UV-C irradiation period (10, 30, 60, and 120 min). Non-irradiated plants were kept as controls. Plant photosynthetic performance, chlorophyll content (SPAD) and some morphologic traits were recorded before, immediately after irradiations and 20 days weeks later. The effects on photosynthetic performances and chlorophyll contents (SPAD) were evaluated and compared with data obtained in similar experiments where tomato plants were irradiated at different times with UVC light. In both species, SPAD values decreased as the irradiation period became longer. The two species showed different gas exchange dynamics, depending on the UV-C exposure time. Two months after the UV-C irradiation, plant dry weight measured at 120-min UV-C exposure was significantly lower than the control

    A multi-artifact EEG denoising by frequency-based deep learning

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    Electroencephalographic (EEG) signals are fundamental to neuroscience research and clinical applications such as brain-computer interfaces and neurological disorder diagnosis. These signals are typically a combination of neurological activity and noise, originating from various sources, including physiological artifacts like ocular and muscular movements. Under this setting, we tackle the challenge of distinguishing neurological activity from noise-related sources. We develop a novel EEG denoising model that operates in the frequency domain, leveraging prior knowledge about noise spectral features to adaptively compute optimal convolutional filters for noise separation. The model is trained to learn an empirical relationship connecting the spectral characteristics of noise and noisy signal to a non-linear transformation which allows signal denoising. Performance evaluation on the EEGdenoiseNet dataset shows that the proposed model achieves optimal results according to both temporal and spectral metrics. The model is found to remove physiological artifacts from input EEG data, thus achieving effective EEG denoising. Indeed, the model performance either matches or outperforms that achieved by benchmark models, proving to effectively remove both muscle and ocular artifacts without the need to perform any training on the particular type of artifact.Comment: Accepted at the Italian Workshop on Artificial Intelligence for Human-Machine Interaction (AIxHMI 2023), November 06, 2023, Rome, Ital

    A pioneering experience in Brazil: the creation of a center for assistance and research for medical residents (NAPREME) at the Escola Paulista de Medicina, Federal University of São Paulo

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    The decision to develop a treatment service for medical residents at Escola Paulista de Medicina was influenced by three main factors: the suicide of four young doctors (2 residents) at this institution between 1995 and 1996, a research study that investigated stress among medical residents and the experience of other countries in response to similar problems. NAPREME has the following objectives: to help to reduce stress among residents, stimulate professional and personal development, prevent professional dysfunction and emotional disorders, offer psychological treatment, assess the tutors of residency programmes and develop research programmes to better identify risk factors for emotional problems during the residency period. We hope that by doing this the overall quality of the residency programme will improve, both for the professionals and the patients.A decisão de criar um centro de assistência e pesquisa em Residência Médica na Escola Paulista de Medicina/Universidade Federal de São Paulo (UNIFESP) foi influenciada por três principais fatores: o suicídio de quatro jovens médicos (2 residentes) nos anos de 1995 e 1996, uma pesquisa sobre fontes de estresse durante o treinamento na Residência Médica nessa instituição e a experiência de outros países com relação a questões semelhantes.O Núcleo de Assistência e Pesquisa em Residência Médica (NAPREME) tem como objetivos: contribuir para a redução do estresse do treinamento, promover o crescimento profissional e pessoal dos residentes, prevenir disfunções profissionais e distúrbios emocionais, oferecer atendimento psicológico, assessorar os preceptores dos Programas de Residência Médica e desenvolver projetos de pesquisa que identifiquem as dificuldades emocionais que ocorrem durante o treinamento. O objetivo final é aperfeiçoar o sistema de capacitação profissional na Residência Médica, aprimorando a assistência prestada aos pacientes e a qualidade de vida dos profissionais encarregados dessa assistência.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL

    UV-C irradiation effects on young tomato plants: Preliminary results

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    Ultraviolet-C radiation (UV-C = 100-280 nm) is strongly affected by ozone levels, so that the amount of this radiation reaching the Earth's surface is extremely low. In the future, UV-C radiation is expected to increase as the result of stratospheric ozone depletion due to atmospheric pollution, with strong negative effects on economically important crops. To assess the effect of UV-C irradiation on young tomato plants (Lycopersicon esculentum Mill.; cv Cuore di bue), an experiment was conducted in controlled conditions, using a black chamber equipped with an UV-C lamp. Tomato plants were divided in four groups on the basis of UV-C irradiation time (10, 30, 60, and 120 min), and non-irradiated plants were kept as controls. Plant gas exchange, leaf color and morphologic traits were recorded before and after UV-C treatments. The photosynthetic apparatus was influenced by UV-C treatment, as shown by the strong increase in intracellular CO2, particularly evident in the 120 min treatment (338 μL L–1). This was due both to the stomatal and non-stomatal inhibition of the assimilation activity due to UV-C exposure. In 10 and 30-min treated plants, leaf color, measured immediately after the irradiation, did not statistically change, whereas the 60 and 120-min treatments were characterized by a deep senescence with a general stem and leaf yellowing. The results demonstrate that high UV-C doses determined irreversible damages, both at physiological and morphological levels, that lead plants to death, whereas lower irradiations (up to 60 min) allowed plants to partially recovery their normal physiological status
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