131 resultados para heavy metal detection


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Introduction: Previous studies have shown that relaxation music increases the heart's parasympathetic modulation as well as reducing its sympathetic activity. However, what is lacking in the literature is information on the acute effects of different intensities of music on cardiac autonomic regulation. We aimed to evaluate the acute effects of baroque and heavy-metal music on cardiac autonomic regulation at different intensities. Method The study was performed in 16 healthy men aged between 18 and 25 years. The main outcomes were the geometric indices of heart-rate variability (HRV) [i.e. triangular index (RRtri); triangular interpolation of RR intervals (TINN) and Poincaré plot: SD1, SD2 and SD1/SD2 ratio]. First, HRV was recorded at rest for 10 min. The volunteers were then exposed to baroque or heavy-metal music for 5 min through an earphone; subjects were exposed to each song at three different sound levels (60–70, 70–80 and 80–90 decibels). After the first song, subjects remained at rest for 5 min before being exposed to the next song. The sequence of songs and sound intensity were randomised for each individual. Results Musical auditory stimulation with baroque music did not influence the geometric indices of HRV. The same was observed with heavy-metal musical auditory stimulation at the three sound-level ranges. Conclusion Musical auditory stimulation at different sound intensities did not influence the geometric indices of HRV in men.

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Background: Chronic classical music was reported to increase parasympathetic activitywhen evaluating heart rate variability (HRV). It is poor in the literature investigation of the acute effects of baroque and heavy metal styles of musical auditory stimulation on HRV. In this study we evaluated the acute effects of relaxant baroque and excitatory heavy metal music on the geometric indices of HRV in healthy men. Method: The study was performed in 12 healthy men between 18 and 30 years old. We excluded persons with previous experience with music instrument and those who had affinity with the song styles. We analyzed the following indices: RRtri, TINN and Poincaré plot (SD1, SD2 and SD1/SD2 ratio). HRV was recorded at rest for ten minutes. Subsequently they were exposed to relaxant baroque or excitatory heavy metal music for five minutes through an earphone. After the first music exposure they remained at rest for more five minutes and them they were exposed again to Baroque or Heavy Metal music (65–80 dB). The sequence of songs was randomized for each individual. Results: The RRTri and SD2 indices were reduced during the heavy metal musical auditory stimulation (p < 0.05). No changes were observed regarding TINN, SD1 and SD1/SD2 ratio (p > 0.05).The qualitative Poincaré plot analysis indicated that during relaxant classical baroque music there was observed a higher beat-to-beat dispersion of RR intervals compared with no music exposure and during excitatory heavy metal musical auditory stimulation, showing higher HRV. Conclusion: We suggest that excitatory heavy metal music acutely decreases global HRV.

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The aim of this study was to investigate acute cardiac response and heart rate variability (HRV) when listening to differing forms of music. Eleven healthy men aged between 18 and 25 years old were included in the study. HRV was recorded at rest for ten minutes with no music, then were asked to listen to classical baroque or heavy metal music for a period of 20 min. It was noted that heart rate variability did not affect HRV indices for time and frequency. In conclusion, music with different tempos does not influence cardiac autonomic regulation in men. However more studies are suggested to explore this topic in greater detail.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Water is an essential factor in maintaining the vital functions of living beings. We have observed a growing commitment of quality, are due to pollution from many sources and even entire watersheds, whether for industrial waste, sewage, or for substances used in farming such as pesticides, herbicides and fertilizers. Nickel is the 24th most abundant element on earth, is a heavy metal that, in the form of chloride, is a proven genotoxic and mutagenic. Due to its industrial use, there was considerable increase of its concentration in surface sediments. Fish combine characteristics that make them excellent experimental models for aquatic toxicology studies, which are particularly usable as warn about the potential danger of chemicals or the possibility of environmental pollution. Due to impaired water quality and the few published studies relating the nickel with the tissue change, this study aimed at assessing the consequences of the presence of nickel in the aquatic environment. For this analysis, we used individuals of Oreochromis niloticus, exposed for 96 hours at three different concentrations of nickel dissolved in water compared to a control group. After exposure, the gills were removed and these were analyzed by ultramorphological, histological and histochemical analysis. The results indicate that all concentrations used in the experiment altered the histophysiology of exposed individuals. We observed the following changes: rupture of paviment cells, thus resulting in bleeding, loss of microridges surface of these cells and epithelial loss in the gills of all animals in all treatments with nickel chloride, the histochemical analysis showed non-proliferation of chloride cells. However, there was a dose-dependent increase of mucus cells in all animals. Therefore, nickel has toxic potential to fish, from the smallest concentration used up to twice as permitted by law, indicating... (Complete abstract click electronic access below)

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Pós-graduação em Fisioterapia - FCT

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The acute effects after exposure to different styles of music on cardiac autonomic modulation assessed through heart rate variability (HRV) analysis have not yet been well elucidated. We aimed to investigate the recovery response of cardiac autonomic modulation in women after exposure to musical auditory stimulation of different styles. The study was conducted on 30 healthy women aged between 18 years and 30 years. We did not include subjects having previous experience with musical instruments and those who had an affinity for music styles. The volunteers remained at rest for 10 min and were exposed to classical baroque (64-84 dB) and heavy metal (75-84 dB) music for 10 min, and their HRV was evaluated for 30 min after music cessation. We analyzed the following HRV indices: Standard deviation of normal-to-normal (SDNN) intervals, root mean square of successive differences (RMSSD), percentage of normal-to-normal 50 (pNN50), low frequency (LF), high frequency (HF), and LF/HF ratio. SDNN, LF in absolute units (ms (2) ) and normalized (nu), and LF/HF ratio increased while HF index (nu) decreased after exposure to classical baroque music. Regarding the heavy metal music style, it was observed that there were increases in SDNN, RMSSD, pNN50, and LF (ms (2) ) after the musical stimulation. In conclusion, the recovery response of cardiac autonomic modulation after exposure to auditory stimulation with music featured an increased global activity of both systems for the two musical styles, with a cardiac sympathetic modulation for classical baroque music and a cardiac vagal tone for the heavy metal style.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Heavy metals are found naturally in soils at low concentrations, but their content may be increased by human activity, making them one of the barriers in management of tropical soils. These chemical elements can be found in the composition of organic and inorganic fertilizers, insecticides, fungicides, mine tailings, and urban waste, and may cause serious damage to the environment and human health. Thus, adsorption studies are essential in assessing the behavior of heavy metals in the soil. The objective of this study was to evaluate the influence of soil chemical, particle size, and mineralogical properties on adsorption of cadmium (Cd), evaluated by Langmuir and Freundlich models, in Latossolos (Oxisols) with or without human activity. Soil samples were collected from the surface layer, 0.00-0.20 m, and chemical, particle size, and mineralogical analyzes were performed. In the adsorption study, concentrations of 0, 5, 25, 50, 100, 200, 300, and 400 mu g L-1 of Cd were used in the form of Cd(NO3)(2). The empirical mathematical models of Langmuir and Freundlich were used for construction of adsorption isotherms. Data were analyzed by means of multivariate statistical techniques, Cluster Analysis and Principal Component Analysis. The data from the adsorption experiment showed a good fit to the Langmuir and Freundlich models. Soils with a lower goethite/hematite ratio and greater cation exchange capacity and pH, showed higher maximum adsorption capacity of Cd.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)