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1.
Radiat Prot Dosimetry ; 187(3): 279-285, 2019 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31251356

RESUMO

This study investigated the effect of short-term exposure to Wi-Fi signals on the cognitive functions of the mind. After obtaining permission from the local Ethics Committee of Shiraz University of Medical Sciences and approval by the Iranian Registry of Clinical Trials (IRCT2017041233398N1), 45 male and female students from Shiraz University of Medical Sciences volunteered to participate in this study. They were exposed to Wi-Fi signals in two sham and exposure sessions, each for 2 hours. After completion, they took part in reaction time, short-term memory, and reasoning ability tests. After scoring, the data were analysed by SPSS software. In addition, the electric field strength and power density were calculated. The results showed no statistically significant differences between the mean scores of reaction time, short-term memory, and reasoning ability in sham and exposure. Also, the obtained values from the electric field strength and power density (E = 4.1 Vm-1, P = 0.446 Wm-2) were lower than that of threshold values by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Our results can greatly reduce concerns regarding the effects of short-term exposure to Wi-Fi waves on cognitive functions.


Assuntos
Cognição/efeitos da radiação , Campos Eletromagnéticos/efeitos adversos , Memória de Curto Prazo/efeitos da radiação , Ondas de Rádio/efeitos adversos , Tempo de Reação/efeitos da radiação , Estudantes/psicologia , Tecnologia sem Fio/estatística & dados numéricos , Adulto , Feminino , Humanos , Masculino , Percepção Visual , Adulto Jovem
2.
J Biomed Phys Eng ; 8(3): 333-336, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30320037

RESUMO

MRI workers are occupationally exposed to static and time-varying gradient magnetic fields. While the 24-hour time-averaged exposure to static magnetic fields is about a few mT, the maximum static field strength can be as high as 500 mT during patient setup. Over the past several years, our laboratory has performed extensive experiments on the health effects of exposure of animal models and humans to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons and MRI. This study is to investigate the adverse health effects in MRI workers and also to assess the effect of exposure of MRI workers to static magnetic fields on their cognitive functions. In the first phase of this study a questionnaire was designed to collect information from 120 MRI personnel. The collection of data about the adverse health effects was based on self-reporting by the participants. In the second phase, 47 volunteer university students were asked to continuously move around a 1.5 T MRI scanner. Visual reaction time and working memory tests were performed on all participants before and after the experiment. Forward digit span and backward digit span were used for assessing the working memory. Furthermore, participants were asked to report the symptoms they had experienced during the movement. The first phase of our study showed increased frequencies of adverse health effects in MRI workers. In this study the rates of self-reported symptoms such as a headache, sleep problems, myalgia, palpitation, fatigue, concentration problems, attention problems, nervousness and backpain were possibly affected by static magnetic field. Furthermore we found that reaction time and working memory could be influenced by the movements of the body around a MRI scanner. It can be concluded that movement through a high magnetic field can also lead to some adverse cognitive effects in MRI staff.

3.
J Biomed Phys Eng ; 6(3): 139-146, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27853721

RESUMO

BACKGROUND: Hormesis is defined as the bio-positive response of something which is bio-negative in high doses. In the present study, the effect of radiation hormesis was evaluated on the survival rate of immunosuppressed BALB/c mice by Cyclosporine A. MATERIAL AND METHODS: We used 75 consanguine, male, BALB/c mice in this experiment. The first group received Technetium-99m and the second group was placed on a sample radioactive soil of Ramsar region (800Bq) for 20 days. The third group was exposed to X-rays and the fourth group was placed on the radioactive soil and then injected Technetium-99m. The last group was the sham irradiated control group. Finally, 30mg Cyclosporine A as the immunosuppressive agent was orally administered to all mice 48 hours after receiving X-rays and Technetium-99m. The mean survival rate of mice in each group was estimated during time. RESULTS: A log rank test was run to determine if there were differences in the survival distribution for different groups and related treatments. According to the results, the survival rate of all pre-irradiated groups was more than the sham irradiated control group (p < .05). The highest survival time was related to the mice which were placed on the radioactive soil of Ramsar region for 20 days and then injected Technetium-99m. CONCLUSION: This study confirmed the presence of hormetic models and the enhancement of survival rate in immunosuppressed BALB/c mice as a consequence of low-dose irradiation. It is also revealed the positive synergetic radioadaptive response on survival rate of immunosuppressed animals.

4.
J Biomed Phys Eng ; 6(4): 220-234, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28144591

RESUMO

BACKGROUND: Much research has widely been conducted into thyroid hormones levels following radiotherapy for breast cancer. Consequently, in this study, we evaluated to relate the rate of thyroid hormones levels with the dose distribution among breast cancer patients. MATERIAL AND METHODS: Thirty patients were treated with 4-field breast cancer radiotherapy. The dose volume histograms, the volume percentage of the thyroid absorbing respectively 20, 30, 40 and 50 Gy were then estimated (V20, V30, V40 and V50) together with the individual average thyroid dose over the whole gland derived from their computed tomography-based treatment plans. Then, in serum samples triiodothyronine [T3], thyroxine [T4], thyroid-stimulating hormone [TSH] of the patients were measured before and after radiotherapy. RESULTS: There were no significant differences in thyroid hormones levels before and after radiotherapy for patients with breast cancer (P value >.05). CONCLUSION: On the balance, we understood that thyroid stimulating hormones levels did not change before and after cancer breast radiotherapy.

5.
J Biomed Phys Eng ; 6(4): 229-234, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28144592

RESUMO

BACKGROUND: Much research has widely been conducted into thyroid hormones levels following radiotherapy for breast cancer. Consequently, in this study, we evaluated to relate the rate of thyroid hormones levels with the dose distribution among breast cancer patients. MATERIAL AND METHODS: Thirty patients were treated with 4-field breast cancer radiotherapy. The dose volume histograms, the volume percentage of the thyroid absorbing respectively 20, 30, 40 and 50 Gy were then estimated (V20, V30, V40 and V50) together with the individual average thyroid dose over the whole gland derived from their computed tomography-based treatment plans. Then, in serum samples triiodothyronine [T3], thyroxine [T4], thyroid-stimulating hormone [TSH] of the patients were measured before and after radiotherapy. RESULTS: There were no significant differences in thyroid hormones levels before and after radiotherapy for patients with breast cancer (P value >.05). CONCLUSION: On the balance, we understood that thyroid stimulating hormones levels did not change before and after cancer breast radiotherapy.

6.
J Biomed Phys Eng ; 6(4): 235-242, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28144593

RESUMO

BACKGROUND: The rapidly increasing use of mobile phones has led to public concerns about possible health effects of these popular communication devices. This study is an attempt to investigate the effects of radiofrequency (RF) radiation produced by GSM mobile phones on the insulin release in rats. METHODS: Forty two female adult Sprague Dawley rats were randomly divided into 4 groups. Group1 were exposed to RF radiation 6 hours per day for 7 days. Group 2 received sham exposure (6 hours per day for 7 days). Groups 3 and 4 received RF radiation 3 hours per day for 7 days and sham exposure (3 hours per day), respectively. The specific absorption rate (SAR) of RF was 2.0 W/kg. RESULTS: Our results showed that RF radiations emitted from mobile phone could not alter insulin release in rats. However, mild to severe inflammatory changes in the portal spaces of the liver of rats as well as damage in the cells of islet of Langerhans were observed. These changes were linked with the duration of the exposures. CONCLUSION: RF exposure can induce inflammatory changes in the liver as well causing damage in the cells of islet of Langerhans.

7.
J Biomed Phys Eng ; 6(4): 279-284, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28144597

RESUMO

As a tendency to use new technologies, gadgets such as laptop computers are becoming more popular among students, teachers, businessmen and office workers. Today laptops are a great tool for education and learning, work and personal multimedia. Millions of men, especially those in the reproductive age, are frequently using their laptop computers on the lap (thigh). Over the past several years, our lab has focused on the health effects of exposure to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons and Magnetic Resonance Imaging (MRI). Our own studies as well as the studies performed by other researchers indicate that using laptop computers on the lap adversely affects the male reproductive health. When it is placed on the lap, not only the heat from a laptop computer can warm men's scrotums, the electromagnetic fields generated by laptop's internal electronic circuits as well as the Wi-Fi Radiofrequency radiation hazards (in a Wi-Fi connected laptop) may decrease sperm quality. Furthermore, due to poor working posture, laptops should not be used on the lap for long hours.

8.
J Biomed Phys Eng ; 5(3): 151-4, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26396971

RESUMO

BACKGROUND: Nowadays, mothers are continuously exposed to different sources of electromagnetic fields before and even during pregnancy.  It has recently been shown that exposure to mobile phone radiation during pregnancy may lead to adverse effects on the brain development in offspring and cause hyperactivity. Researchers have shown that behavioral problems in laboratory animals which have a similar appearance to ADHD are caused by intrauterine exposure to mobile phones. OBJECTIVE: The purpose of this study was to investigate whether the maternal exposure to different sources of electromagnetic fields affect on the rate and severity of speech problems in their offspring. METHODS: In this study, mothers of 35 healthy 3-5 year old children (control group) and 77 children and diagnosed with speech problems who had been referred to a speech treatment center in Shiraz, Iran were interviewed. These mothers were asked whether they had exposure to different sources of electromagnetic fields such as mobile phones, mobile base stations, Wi-Fi, cordless phones, laptops and power lines. RESULTS: We found a significant association between either the call time (P=0.002) or history of mobile phone use (months used) and speech problems in the offspring (P=0.003). However, other exposures had no effect on the occurrence of speech problems. To the best of our knowledge, this is the first study to investigate a possible association between maternal exposure to electromagnetic field and speech problems in the offspring. Although a major limitation in our study is the relatively small sample size, this study indicates that the maternal exposure to common sources of electromagnetic fields such as mobile phones can affect the occurrence of speech problems in the offspring.

9.
J Biomed Phys Eng ; 5(3): 143-50, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26396970

RESUMO

BACKGROUND: Airport workers are continuously exposed to different levels of radiofrequency microwave (RF/MW) radiation emitted by radar equipments. Radars are extensively used in military and aviation industries. Over the past several years, our lab has focused on the health effects of exposure to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons and MRI. The main goal of this study was to investigate if occupational exposure of Shahid Dastghieb international airport workers to radiofrequency radiation affects their short term memory and reaction time. METHODS: Thirty two airport workers involved in duties at control and approach tower (21 males and 11 females), with the age range of 27-67 years old (mean age of 37.38), participated voluntary in this study. On the other hand, 29 workers (13 males, and 16 females) whose offices were in the city with no exposure history to radar systems were also participated in this study as the control group. The employees' reaction time and short term memory were analyzed using a standard visual reaction time (VRT) test software and the modified Wechsler memory scale test, respectively. RESULTS: The mean± SD values for the reaction times of the airport employees (N=32) and the control group (N=29) were 0.45±0.12 sec and 0.46±0.17 sec, respectively.  Moreover, in the four subset tests; i.e. paired words, forward digit span, backward digit span and word recognition, the following points were obtained for the airport employees and the control group, respectively: (i) pair words test: 28.00±13.13 and 32.07±11.65, (ii) forward digit span: 8.38±1.40 and 9.03±1.32, (iii) backward digit span: 5.54±1.87 and 6.31±1.46, and (iv) word recognition: 5.73±2.36 and 6.50±1.93. These differences were not statistically significant. CONCLUSION: The occupational exposure of the employees to the RF radiation in Shahid Dastghieb international airport does not have any significant detrimental effect on their reaction time as well as short term memory.

10.
World J Emerg Med ; 4(2): 123-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-25215105

RESUMO

BACKGROUND: Uncontrolled bleeding is the first leading cause of preventable death in the battlefield and the 2nd cause of mortality in civil accidents. Incompressible hemorrhage control is among the interventions that drastically increase the survival rate in wound individuals. We have previously shown that a certain mixture of bentonite and zeolite minerals can significantly decrease the bleeding in rats. METHODS: In this study, nine healthy hybrid dogs were selected and after induction of anesthesia with ether, either arterial puncture by a needle or arteriotomy was performed on both groin regions of the dogs. For control arteries (either the right or left femoral artery), only pressure by sterilized gauze was performed, while for the femoral arteries of the opposite side, our invented hemostatic agent, namely CoolClot, was topically used before applying the pressure. In the second stage of the study, to assess the coagulation time, blood samples were collected from 10 volunteer students. RESULTS: CoolClot significantly decreased the bleeding time in animals whose femoral arteries were cut or punctured. In the human phase of the study, the mean coagulation time in control blood samples was 253.4±44.1 seconds, whereas it was 149.5±50.0, 162.3±74.6 and 143.4±114.6 seconds, respectively in blood samples treated with bentonite, zeolite and CoolClot (P<0.05). CONCLUSIONS: As controlling bleeding after a life-threatening arterial damage is critical for increasing the chance of survival, the results obtained in this study indicate the significant efficacy of CoolClot in shortening the bleeding time. Our experiments also indicate that CoolClot can significantly reduce the clotting time in human blood samples.

11.
Artigo em Inglês | WPRIM (Pacífico Ocidental) | ID: wpr-789608

RESUMO

@#BACKGROUND: Uncontrolled bleeding is the first leading cause of preventable death in the battlefield and the 2nd cause of mortality in civil accidents. Incompressible hemorrhage control is among the interventions that drastically increase the survival rate in wound individuals. We have previously shown that a certain mixture of bentonite and zeolite minerals can significantly decrease the bleeding in rats. METHODS: In this study, nine healthy hybrid dogs were selected and after induction of anesthesia with ether, either arterial puncture by a needle or arteriotomy was performed on both groin regions of the dogs. For control arteries (either the right or left femoral artery), only pressure by sterilized gauze was performed, while for the femoral arteries of the opposite side, our invented hemostatic agent, namely CoolClot, was topically used before applying the pressure. In the second stage of the study, to assess the coagulation time, blood samples were collected from 10 volunteer students. RESULTS: CoolClot significantly decreased the bleeding time in animals whose femoral arteries were cut or punctured. In the human phase of the study, the mean coagulation time in control blood samples was 253.4±44.1 seconds, whereas it was 149.5±50.0, 162.3±74.6 and 143.4±114.6 seconds, respectively in blood samples treated with bentonite, zeolite and CoolClot (P<0.05). CONCLUSIONS: As controlling bleeding after a life-threatening arterial damage is critical for increasing the chance of survival, the results obtained in this study indicate the significant efficacy of CoolClot in shortening the bleeding time. Our experiments also indicate that CoolClot can significantly reduce the clotting time in human blood samples.

12.
Acta Neurol Belg ; 112(2): 171-5, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22426673

RESUMO

The worldwide dramatic increase in mobile phone use has generated great concerns about the detrimental effects of microwave radiations emitted by these communication devices. Reaction time plays a critical role in performing tasks necessary to avoid hazards. As far as we know, this study is the first survey that reports decreased reaction time after exposure to electromagnetic fields generated by a high specific absorption rate mobile phone. It is also the first study in which previous history of mobile phone use is taken into account. The aim of this study was to assess both the acute and chronic effects of electromagnetic fields emitted by mobile phones on reaction time in university students. Visual reaction time (VRT) of young university students was recorded with a simple blind computer-assisted-VRT test, before and after a 10 min real/sham exposure to electromagnetic fields of mobile phones. Participants were 160 right-handed university students aged 18-31. To assess the effect of chronic exposures, the reaction time in sham-exposed phases were compared among low level, moderate and frequent users of mobile phones. The mean ± SD reaction time after real exposure and sham exposure were 286.78 ± 31.35 ms and 295.86 ± 32.17 ms (P < 0.001), respectively. The age of students did not significantly alter the reaction time either in talk or in standby mode. The reaction time either in talk or in standby mode was shorter in male students. The students' VRT was significantly affected by exposure to electromagnetic fields emitted by a mobile phone. It can be concluded that these exposures cause decreased reaction time, which may lead to a better response to different hazards. In this light, this phenomenon might decrease the chances of human errors and fatal accidents.


Assuntos
Telefone Celular , Campos Eletromagnéticos/efeitos adversos , Tempo de Reação/efeitos da radiação , Adulto , Fatores Etários , Desenho Assistido por Computador , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Estimulação Luminosa , Fatores Sexuais , Fatores de Tempo , Adulto Jovem
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