31 research outputs found

    The association of heart rate recovery immediately after exercise with coronary artery calcium: the coronary artery risk development in young adults study

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    We tested whether slower heart rate recovery (HRR) following graded exercise treadmill testing (GXT) was associated with the presence of coronary artery calcium (CAC). Participants (n = 2,648) ages 18–30 years at baseline examination underwent GXT, followed by CAC screening 15 years later. Slow HRR was not associated with higher odds of testing positive (yes/no) for CAC at year 15 (OR = 0.99, p = 0.91 per standard deviation change in HRR). Slow HRR in young adulthood is not associated with the presence of CAC at middle age

    Study of cold atmospheric plasma jet at the end of flexible plastic tube for microbial decontamination

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICORecently, cold atmospheric plasmas have demonstrated very promising antimicrobial activity in vitro and in vivo including selective destruction of tumor cells. However, the size and the rigidity of most plasma systems limit the clinical application for treatments in internal organs or regions with difficult access (e.g., mouth). Here, we report a device that allows ignition of cold He plasma jet at the tip of 1m long, 3.5 mm diameter, flexible plastic tube. It is connected to a dielectric enclosure where dielectric barrier discharge (DBD) is generated by a low-frequency AC power supply. A thin wire at floating potential put inside the plastic tube assists the formation of plasma jet at the downstream tube end. The flexible tube can be kept and manipulated by hand without electric shock and thus the plasma jet can be easily directed to a target. Variation of duty cycle of the applied voltage signal allows precise adjustment of the discharge power. The anti-microbial efficiency of plasma jet system with flexible tube was tested against fungus Candida albicans seeded on agar.Recently, cold atmospheric plasmas have demonstrated very promising antimicrobial activity in vitro and in vivo including selective destruction of tumor cells. However, the size and the rigidity of most plasma systems limit the clinical application for treatments in internal organs or regions with difficult access (e.g., mouth). Here, we report a device that allows ignition of cold He plasma jet at the tip of 1m long, 3.5 mm diameter, flexible plastic tube. It is connected to a dielectric enclosure where dielectric barrier discharge (DBD) is generated by a low-frequency AC power supply. A thin wire at floating potential put inside the plastic tube assists the formation of plasma jet at the downstream tube end. The flexible tube can be kept and manipulated by hand without electric shock and thus the plasma jet can be easily directed to a target. Variation of duty cycle of the applied voltage signal allows precise adjustment of the discharge power. The anti-microbial efficiency of plasma jet system with flexible tube was tested against fungus Candida albicans seeded on agar.1212SI13831391FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCNPq [470995/2013-0]2013/06732-3, 2014/00719-8470995/2013-02. International Workshop on Plasma for Cancer Treatment16 a 17 de Março de 2015Nagoya, JapãoNagoya Universit

    Non-thermal atmospheric pressure plasma jet applied to inactivation of different microorganisms

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    CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPNon-thermal atmospheric pressure,plasma jets (APPJs) are capable of generating cold plasma plumes that are not confined by electrodes, which makes them very attractive for bio-medical applications. In the present work, the inactivation efficiency of cold APPJ was evaluated against three pathogenic microorganisms with different cell wall characteristics. The Gram-positive bacterium Enterococcus faecalis (ATCC 29212), the Gram-negative bacterium Pseudomonas aeruginosa (ATCC 15442) and the fungus Candida albicans (SC 5314) were plated on standard Petri dishes filled with specific culture media. The plasma jet with mean power of 1.8 W was directed perpendicularly on agar plates and the system was flushed with pure helium at two different flows, 2.0 and 4.0 SLM. During the treatments, time and distance between nozzle and agar were varied. The presence of excited reactive species was confirmed by optical emission spectroscopy. Scanning electron microscopy (SEM) was applied for investigation of cell morphology. The microbicidal efficiency was evaluated by measuring the area of inhibition zone (where there was no cell growth). For different flows of helium, no significant difference of inhibition zone size was noted for the same microbial species. However, high flows led to formation of non-homogenous inhibition zones, presenting microcolonies distributed through the inactivated region. The Gram-positive bacterium was more susceptible to the plasma antimicrobial effects than the other microorganisms. (C) 2016 Elsevier B.V. All rights reserved.Non-thermal atmospheric pressure,plasma jets (APPJs) are capable of generating cold plasma plumes that are not confined by electrodes, which makes them very attractive for bio-medical applications. In the present work, the inactivation efficiency of cold APPJ was evaluated against three pathogenic microorganisms with different cell wall characteristics. The Gram-positive bacterium Enterococcus faecalis (ATCC 29212), the Gram-negative bacterium Pseudomonas aeruginosa (ATCC 15442) and the fungus Candida albicans (SC 5314) were plated on standard Petri dishes filled with specific culture media. The plasma jet with mean power of 1.8 W was directed perpendicularly on agar plates and the system was flushed with pure helium at two different flows, 2.0 and 4.0 SLM. During the treatments, time and distance between nozzle and agar were varied. The presence of excited reactive species was confirmed by optical emission spectroscopy. Scanning electron microscopy (SEM) was applied for investigation of cell morphology. The microbicidal efficiency was evaluated by measuring the area of inhibition zone (where there was no cell growth). For different flows of helium, no significant difference of inhibition zone size was noted for the same microbial species. However, high flows led to formation of non-homogenous inhibition zones, presenting microcolonies distributed through the inactivated region. The Gram-positive bacterium was more susceptible to the plasma antimicrobial effects than the other microorganisms.3121924CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP470995/2013-02014/02354-713. International Conference on Plasma-Based Ion Implantation and Deposition5 a 9 de Outubro de 2015Buenos Aires, ArgentinaUniversity of Buenos AiresArgentine National Research Counci

    Enhanced energy transfer efficiency in a four-electrodes configuration DBD plasma jet

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    In this work a dielectric barrier discharge (DBD) plasma jet that uses a multiple electrodes configuration is investigated. The results show that both plasma power and its rotational and vibrational temperatures tend to increase with the number of powered electrodes in the DBD device. The emission intensities of the excited species in the plasma, and consequently their number density, also grow as a function of the number of powered electrodes. Based on these facts and since the electric power provided by the power supply was kept constant, there is an indication that the use of multiple electrodes improves the energy efficiency of the device

    Enhanced energy transfer efficiency in a four-electrodes configuration DBD plasma jet

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    CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPIn this work a dielectric barrier discharge (DBD) plasma jet that uses a multiple electrodes configuration is investigated. The results show that both plasma power and its rotational and vibrational temperatures tend to increase with the number of powered electrodes in the DBD device. The emission intensities of the excited species in the plasma, and consequently their number density, also grow as a function of the number of powered electrodes. Based on these facts and since the electric power provided by the power supply was kept constant, there is an indication that the use of multiple electrodes improves the energy efficiency of the device.711116CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP150570/2016-32015/21989-

    Heart rate recovery after exercise: relations to heart rate variability and complexity

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    Physical exercise is associated with parasympathetic withdrawal and increased sympathetic activity resulting in heart rate increase. The rate of post-exercise cardiodeceleration is used as an index of cardiac vagal reactivation. Analysis of heart rate variability (HRV) and complexity can provide useful information about autonomic control of the cardiovascular system. The aim of the present study was to ascertain the association between heart rate decrease after exercise and HRV parameters. Heart rate was monitored in 17 healthy male subjects (mean age: 20 years) during the pre-exercise phase (25 min supine, 5 min standing), during exercise (8 min of the step test with an ascending frequency corresponding to 70% of individual maximal power output) and during the recovery phase (30 min supine). HRV analysis in the time and frequency domains and evaluation of a newly developed complexity measure - sample entropy - were performed on selected segments of heart rate time series. During recovery, heart rate decreased gradually but did not attain pre-exercise values within 30 min after exercise. On the other hand, HRV gradually increased, but did not regain rest values during the study period. Heart rate complexity was slightly reduced after exercise and attained rest values after 30-min recovery. The rate of cardiodeceleration did not correlate with pre-exercise HRV parameters, but positively correlated with HRV measures and sample entropy obtained from the early phases of recovery. In conclusion, the cardiodeceleration rate is independent of HRV measures during the rest period but it is related to early post-exercise recovery HRV measures, confirming a parasympathetic contribution to this phase
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