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1.
BMC Public Health ; 14: 438, 2014 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-24886241

RESUMO

BACKGROUND: With the rapid increasing use of third generation (3 G) mobile phones, social concerns have arisen concerning the possible health effects of radio frequency-electromagnetic fields (RF-EMFs) emitted by wideband code division multiple access (WCDMA) mobile phones in humans. The number of people, who complain of various symptoms such as headache, dizziness, and fatigue, has also increased. Recently, the importance of researches on teenagers has been on the rise. However, very few provocation studies have examined the health effects of WCDMA mobile phone radiation on teenagers. METHODS: In this double-blind study, two volunteer groups of 26 adults and 26 teenagers were simultaneously investigated by measuring physiological changes in heart rate, respiration rate, and heart rate variability for autonomic nervous system (ANS), eight subjective symptoms, and perception of RF-EMFs during sham and real exposure sessions to verify its effects on adults and teenagers. Experiments were conducted using a dummy phone containing a WCDMA module (average power, 250 mW at 1950 MHz; specific absorption rate, 1.57 W/kg) within a headset placed on the head for 32 min. RESULTS: Short-term WCDMA RF-EMFs generated no significant changes in ANS, subjective symptoms or the percentages of those who believed they were being exposed in either group. CONCLUSIONS: Considering the analyzed physiological data, the subjective symptoms surveyed, and the percentages of those who believed they were being exposed, 32 min of RF radiation emitted by WCDMA mobile phones demonstrated no effects in either adult or teenager subjects.


Assuntos
Telefone Celular , Frequência Cardíaca/efeitos da radiação , Ondas de Rádio/efeitos adversos , Respiração/efeitos da radiação , Adolescente , Adulto , Fatores Etários , Método Duplo-Cego , Feminino , Humanos , Masculino , Percepção
2.
Med Biol Eng Comput ; 51(9): 1059-67, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23793529

RESUMO

This study sought to determine a mortality prediction model that could be used for triage in the setting of acute hemorrhage from trauma. To achieve this aim, various machine learning techniques were applied using the rat model in acute hemorrhage. Thirty-six anesthetized rats were randomized into three groups according to the volume of controlled blood loss. Measurements included heart rate (HR), systolic and diastolic blood pressures (SBP and DBP), mean arterial pressure, pulse pressure, respiratory rate, temperature, blood lactate concentration (LC), peripheral perfusion (PP), shock index (SI, SI = HR/SBP), and a new hemorrhage-induced severity index (NI, NI = LC/PP). NI was suggested as one of the good candidates for mortality prediction variable in our previous study. We constructed mortality prediction models with logistic regression (LR), artificial neural networks (ANN), random forest (RF), and support vector machines (SVM) with variable selection. The SVM model showed better sensitivity (1.000) and area under curve (0.972) than the LR, ANN, and RF models for mortality prediction. The important variables selected by the SVM were NI and LC. The SVM model may be very helpful to first responders who need to make accurate triage decisions and rapidly treat hemorrhagic patients in cases of trauma.


Assuntos
Inteligência Artificial , Modelos Estatísticos , Choque Hemorrágico/fisiopatologia , Animais , Temperatura Corporal , Hemodinâmica/fisiologia , Ácido Láctico/sangue , Modelos Logísticos , Masculino , Curva ROC , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Taxa Respiratória/fisiologia , Estatísticas não Paramétricas , Máquina de Vetores de Suporte
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