Riesgos y peligros laborales en termoeléctricas: una revisión de la literatura de 2007 a 2017 / Occupational hazards and risks in thermoelectric plants: a review of the literature from 2007 to 2017

Resumen Introducción: la demanda de energía eléctrica va de la mano del aumento de la población, por lo que para satisfacerla se debe asegurar la capacidad de generación eléctrica, esto incentivaría la construcción de plantas térmicas; aumentando los trabajadores expuestos a los peligros de termoeléctricas. Esta revisión tiene como fin identificar cuáles riesgos y peligros en termoeléctricas han sido estudiadas en el mundo durante el periodo 20072017. Objetivo: identificar, a través de una revisión bibliográfica, los principales peligros a que están expuestos los trabajadores de termoeléctricas. Materiales y métodos: se realizó una revisión sistemática teniendo en cuenta las recomendaciones de la guía PRISMA, se tuvieron en cuenta estudios acerca de los factores de riesgos a los que se exponen el personal de operaciones de centrales térmicas; para la búsqueda se establecieron dos algoritmos con descriptores DeCS y MeSH en las bases de datos Scopus, Pubmed, Scient Direct y Google académico, encontrándose 21 publicaciones que cumplían con los criterios de inclusión. Resultados: los peligros más relevantes para los trabajadores en termoeléctricas son físicos, ergonómicos, químicos, biológicos y psicosociales. Conclusión: los trabajadores de termoeléctricas están expuestos a varios peligros que pueden aumentar el riesgo de ocasionarles enfermedades respiratorias, musculoesqueleticas, pérdida de capacidad auditiva, cáncer, leucemia y su variedad, pericarditis, Alzheimer, Parkinson, daño genético y celular; también se pudo evidenciar que el efecto en la salud por exposición en campos magnéticos requiere de estudios de más profundidad.

Abstract Introduction: the demand for electric power, goes hand in hand with the population increasing, to satisfy it, the power generation capacity must be ensured, this would encourage the construction of thermal plants; increasing the exposition of workers to the thermoelectric plant dangers. This review aims to identify which risks and dangers in thermoelectric plants have been studied in the world for the period 2007-2017. Objective: identify the main hazards to which thermoelectric workers are exposed through a literature review. Materials and methods: a systematic review was carried out taking into account the recommendations of the PRISMA guide, studies were taken into account about the risk factors to which thermal power plant operations personnel are exposed; Two algorithms with DeCS and MeSH descriptors were established in the Scopus, PubMed, Scient Direct and Google academic databases, with 21 publications meeting the inclusion criteria. Results: the most relevant hazards for thermoelectric workers are physical, ergonomic, chemical, biological and psychosocial. Conclusion: thermoelectric workers are exposed to various hazards that may increase the risk of respiratory, musculoskeletal, hearing loss, cancer, leukemia and its variety, pericarditis, Alzheimer's, Parkinson's, genetic and cellular damage; It could also be evidenced that the effect on health by exposure in magnetic fields requires more in-depth studies.

Campo magnético ambiental en una Unidad de Terapia Intensiva Neonatal. Importancia de su verificación / Environmental magnetic field in a Neonatal Intensive Care Unit. A relevant verification

Los neonatos pretérminos nacen con inmadurez en los órganos, lo que lleva al compromiso del sistema inmunológico. Los campos electromagnéticos afectan la producción de melatonina a niveles bajos de exposición. Estos niños necesitan equipamiento médico las 24 horas del día para su recuperación, por lo que están expuestos a los campos magnéticos durante todo el tiempo que se encuentren en la Unidad de Terapia Intensiva. El objetivo fue medir los niveles de campo magnético que se generan alrededor de cada una de las incubadoras utilizando un gaussímetro y comparar los resultados con las recomendaciones de la Comisión Internacional para la Protección contra las Radiaciones No Ionizantes de 2010 y la norma de la International Electrotechnical Commission (IEC) IEC 60601-1-2:2004. En 11 neonatos internados, los valores de radiación se encontraban dentro de los recomendados, pero existía interferencia electromagnética por problemas de disposición de los equipos en el área.

Preterm infants are born with immature organs, thus affecting the immune system. Electromagnetic fields influence melatonin production with low exposure levels. These infants require medical equipment 24/7 to recover, so they are constantly exposed to magnetic fields during their stay in the Intensive Care Unit. Our objective was to measure magnetic field levels generated around each incubator using a gauss meter and compare our results to the 2010 recommendations by the International Commission on Non-Ionizing Radiation Protection and the IEC 60601-1-2:2004 standard by the International Electrotechnical Commission (IEC). Among 11 hospitalized newborn infants, radiation was found within the recommended limits, but there was electromagnetic interference resulting from medical equipment layout problems in the unit.

Assessment of the Antioxidative Potential of Rosmarinus officinalis L. (Lamiaceae) Irrigated with Static Magnetic Field-Treated Water

Abstract Phenolic compounds are one of the main groups of secondary metabolites in plants and are known for their antioxidant activity. Rosmarinus officinalis L. (rosemary) contains different phenolic compounds including carnosol, carnosic acid and rosmarinic acid. In Cuba, rosemary cultivation is limited because it is difficult to propagate and has a low yield. As a result, it was removed from the Herbal Medicine National Formulary. However, the National Public Health System has a strong interest in rosemary because of its value as a natural antioxidant medicine. Irrigation with water treated with a static magnetic field (SMF) is a possible strategy to increase rosemary yield. This technology has been applied to accelerate plant growth and increase crop quality. The aim of this study was to evaluate the content of phenolic compounds and antioxidant activity in aqueous leaf extracts from plants irrigated with SMF-treated water in comparison to control plants. Significant differences in phenolic content and antioxidant activity were observed between aqueous extracts of control plants and plants irrigated with SMF-treated water. Therefore, irrigation with SMF-treated water is a promising technology to improve the cultivation of rosemary as a raw material to obtain pharmaceutical products with high antioxidant activities.

Magnetic hyperthermia therapy in glioblastoma tumor on-a-Chip model / Terapia de magneto-hipertermia no modelo de tumor de glioblastoma on-a-Chip

ABSTRACT Objective: To evaluate the magnetic hyperthermia therapy in glioblastoma tumor-on-a-Chip model using a microfluidics device. Methods: The magnetic nanoparticles coated with aminosilane were used for the therapy of magnetic hyperthermia, being evaluated the specific absorption rate of the magnetic nanoparticles at 300 Gauss and 305kHz. A preculture of C6 cells was performed before the 3D cells culture on the chip. The process of magnetic hyperthermia on the Chip was performed after administration of 20μL of magnetic nanoparticles (10mgFe/mL) using the parameters that generated the specific absorption rate value. The efficacy of magnetic hyperthermia therapy was evaluated by using the cell viability test through the following fluorescence staining: calcein acetoxymethyl ester (492/513nm), for live cells, and ethidium homodimer-1 (526/619nm) for dead cells dyes. Results: Magnetic nanoparticles when submitted to the alternating magnetic field (300 Gauss and 305kHz) produced a mean value of the specific absorption rate of 115.4±6.0W/g. The 3D culture of C6 cells evaluated by light field microscopy imaging showed the proliferation and morphology of the cells prior to the application of magnetic hyperthermia therapy. Fluorescence images showed decreased viability of cultured cells in organ-on-a-Chip by 20% and 100% after 10 and 30 minutes of the magnetic hyperthermia therapy application respectively. Conclusion: The study showed that the therapeutic process of magnetic hyperthermia in the glioblastoma on-a-chip model was effective to produce the total cell lise after 30 minutes of therapy.

RESUMO Objetivo: Avaliar a terapia de magneto-hipertermia em modelo de tumor de glioblastoma on-a-Chip. Métodos: As nanopartículas magnéticas recobertas com aminosilana foram utilizadas para a terapia da magneto-hipertermia, sendo avaliada a taxa de absorção específica das nanopartículas magnéticas em 300 Gauss e 305kHz. Uma pré-cultura de células C6 foi realizada e, seguidamente, foi feito o cultivo das células 3D no chip. O processo de magneto-hipertermia no chip foi realizado após administração de 20μL de nanopartículas magnéticas (10mgFe/mL), utilizando os parâmetros que geraram o valor da taxa de absorção específica. A eficácia da terapia de magneto-hipertermia foi avaliada pela viabilidade celular por meio dos corantes fluorescentes acetoximetiléster de calceína (492/513nm), para células vivas, e etídio homodímero-1 (526/619nm), para células mortas. Resultados: As nanopartículas magnéticas, quando submetidas ao campo magnético alternado (300 Gauss e 305kHz), produziram um valor médio da taxa de absorção específica de 115,4±6,0W/g. A cultura 3D das células C6 avaliada por imagem de microscopia de campo claro mostrou a proliferação e a morfologia das células antes da aplicação da terapia de magneto-hipertermia. As imagens de fluorescência mostraram diminuição da viabilidade das células cultivadas no organ-on-a-Chip em 20% e 100% após 10 e 30 minutos, respectivamente, da aplicação da terapia de magneto-hipertermia. Conclusão: O processo terapêutico da magneto-hipertermia no modelo de tumor glioblastoma on-a-chip foi eficaz para produzir lise total das células após 30 minutos de terapia.

Targeting of temozolomide using magnetic nanobeads: an in vitro study

Temozolomide, a chemotherapeutic drug that is often administered for the treatment of brain cancer has severe side effects and a poor aqueous solubility. In order to decrease the detrimental effect of the drug over healthy cells, a novel drug delivery vehicle was developed where the therapeutic drug was encapsulated within the hydrophobic cavities of b-CD modified magnetite nanoparticles, which are embedded in chitosan nanobeads prepared by salt addition. In-vitro studies have shown that the magnetic properties of the novel delivery vehicle are adequate for targeted drug delivery applications under an external magnetic field. Additionally, an increase in the amount of chitosan was shown to exhibit a strong shielding effect over the magnetic properties of the delivery vehicle, which lead to deterioration of the amount of captured drug at the targeted area, suggesting a delicate balance between the amounts of constituents composing the drug delivery vehicle.

Effect of simulated geomagnetic activity on myocardial ischemia/reperfusion injury in rats

Abstract Objective: To study the response of myocardial ischemia/reperfusion injury (MI/RI) in rats to simulated geomagnetic activity. Methods: In a simulated strong geomagnetic outbreak, the MI/RI rat models were radiated, and their area of myocardial infarction, hemodynamic parameters, creatine kinase (CK), lactate dehydrogenase (LDH), melatonin, and troponin I values were measured after a 24-hour intervention. Results: Our analysis indicates that the concentrations of troponin I in the geomagnetic shielding+operation group were lower than in the radiation+operation group (P<0.05), the concentrations of melatonin in the shielding+operation group and normal+operation group were higher than in the radiation + operation group (P<0.01), and the concentrations of CK in the shielding + operation group were lower than in the radiation + operation group and normal + operation group (P<0.05). Left ventricular developed pressure (LVDP) and ± dP/dtmax in the radiation+operation group were lower than in the shielding + operation group and normal+operation group (P<0.01). Left ventricular end-diastolic pressure (LEVDP) in the shielding + operation group was higher than in the normal + operation group (P<0.05). There was no significant difference in area of myocardial infarction and LDH between the shielding + operation group and the radiation + operation group. Conclusion: Our data suggest that geomagnetic activity is important in regulating myocardial reperfusion injury. The geomagnetic shielding has a protective effect on myocardial injury, and the geomagnetic radiation is a risk factor for aggravating the cardiovascular and cerebrovascular diseases.

Efeito de campos magnéticos estáticos e compensados na proliferação celular in vitro / Proteomics of the effect of compensated and static magnetic fields on cell proliferation in vitro

Inserido no paradigma da transdisciplinaridade, o presente trabalho foi desenvolvido em etapas, com os seguintes objetivos: a) Construir um dispositivo com base de metal não magnético para ímãs permanentes, visando à geração de um Campo Magnético Estático (CME) ou de um Campo Magnético Compensado (CMC); b) Expor culturas de células mesenquimais a um CME e a um CMC, ou a nenhum campo (controle); c) Analisar a influência destes campos na viabilidade e proliferação celular e nos casos em que houve alteração em pelo menos um destes parâmetros, utilizar a análise proteômica como ferramenta para a compreensão dos mecanismos envolvidos. O dispositivo foi construído utilizando aço inoxidável, capaz de gerar dois tipos de Campos Magnéticos: Compensado (CMC) com intensidade de aproximadamente 0 mT e Estático (CME) com intensidade média de 165 mT. Estes campos foram aplicados a culturas de células mesenquimais de medula óssea de camundongos AJ (MSC/AJ), nos períodos de 0, 24, 48, 72 e 96 h (CMC) e 24 h (CME). Os efeitos sobre a proliferação e a viabilidade foram avaliados por método de contagem manual de células com marcação por azul de tripan. A análise proteômica foi realizada para os experimentos com CMC, com o objetivo de descrever as proteínas envolvidas nas alterações encontradas. A exposição ao CMC tendeu a reduzir a proliferação das células de medula óssea MSC/AJ em relação ao controle em 96 h, porém sem diferença significativa, o que poderia estar relacionado a proteínas que inibem a transcrição, como a Forkhead box protein P2 Foxp2. Este mesmo campo aumentou a viabilidade celular em relação ao baseline para todos os tempos experimentais, o que poderia estar relacionado a proteínas relacionadas à ligação ao Ca+2. Esses mecanismos, entretanto, precisam ser estudados mais profundamente para que possam ser comprovados ou não. Já a exposição ao CME levou a uma tendência à diminuição da proliferação e viabilidade celular em relação ao grupo controle, embora sem diferenças significativas, provavelmente por conta do tamanho amostral e tempo de avaliação (24 h).(AU)

Inserted in the transdisciplinarity paradigm, the present work was developed by steps with the following aims: a) To build a device of non-magnetic metal to hold permanent magnets for the generation of a Static Magnetic Field (SMF) or a Compensated Magnetic Field (CMF); b) To expose mesenchimal cells to the SMF and to CMF or to none of the fields (control); c) To analyze the influence of these fields on cell viability and cell proliferation and in the case where it occurred alteration in at least one of these parameters, to use proteomics as a tool for the comprehension of the involved mechanisms. The device was built in stainless steel, able to generate two kinds of Magnetic Fields: Compesated (CMF) with an intensity of nearly zero mT and Static (SMF) with a mean intensity of 165 mT. These fields were applied to bone marrow mesenchimal cell cultures from AJ mice (MSC/AJ), for 0, 24, 48, 72 and 96 h (CMF) and 24 h (SMF) periods. The effects on the proliferation and viability were assessed by tripan blue dying and manual counting of the cells. Proteomics was done for the experiments with CMF, aiming to describe the involved proteins on found alterations. The exposition to CMF tends to reduce the bone marrow cell proliferation of MSC/AJ in relation to control in 96 h, but with no significant difference, which may be related to proteins that inhibit the transcription, like Forkhead box protein P2 Foxp2. This very field raised the cell viability in relation to the baseline for all the experimental times that could be related to proteins connected to Ca2+ binding. However, these mechanisms need more experiments, so they can be confirmed or not. The exposition to the SMF tends to decrease both cell proliferation and viability in relation to the control group, although with no significant difference, probably because of the sample number and the exposition time (24h).(AU)

Effects of a buried magnetic field on cranial bone reconstruction in rats

ABSTRACT The understanding of bone repair phenomena is a fundamental part of dentistry and maxillofacial surgery. Objective The present study aimed to evaluate the influence of buried magnetic field stimulation on bone repair in rat calvaria after reconstruction with autogenous bone grafts, synthetic powdered hydroxyapatite, or allogeneic cartilage grafts, with or without exposure to magnetic stimulation. Material and Methods Ninety male Wistar rats were divided into 18 groups of five animals each. Critical bone defects were created in the rats’ calvaria and immediately reconstructed with autogenous bone, powdered synthetic hydroxyapatite or allogeneic cartilage. Magnetic implants were also placed in half the animals. Rats were euthanized for analysis at 15, 30, and 60 postoperative days. Histomorphometric analyses of the quantity of bone repair were performed at all times. Results These analyses showed significant group by postoperative time interactions (p=0.008). Among the rats subjected to autogenous bone reconstruction, those exposed to magnetic stimulation had higher bone fill percentages than those without magnetic implants. Results also showed that the quality of bone repair remained higher in the former group as compared to the latter at 60 postoperative days. Conclusions After 60 postoperative days, bone repair was greater in the group treated with autogenous bone grafts and exposed to a magnetic field, and bone repair was most pronounced in animals treated with autogenous bone grafts, followed by those treated with powdered synthetic hydroxyapatite and allogeneic cartilage grafts.

Influencia del campo magnético sobre el crecimiento de microorganismos patógenos ambientales aislados en el Archivo Nacional de la República de Cuba / Influence of magnetic field on the growth of pathogen microorganisms isolated from the indoor environment at the Archivo Nacional de la República de Cuba

Introducción. En el Archivo Nacional de la República de Cuba, existe contaminación electromagnética y la influencia del campo magnético oscilante de frecuencia extremadamente baja podría cuantificarse con microorganismos patógenos aislados de su ambiente interior. Objetivo. Cuantificar la influencia de este tipo de campo magnético sobre el crecimiento de microorganismos patógenos aislados del ambiente en el Archivo Nacional de la República de Cuba. Materiales y métodos. Se emplearon cinco microorganismos: Streptococcus sp. (1), Listeria sp. (2) y Candida guillermondii (3), aislados en el Archivo, así como Escherichia coli ATCC 25922 (4) y Saccharomyces cerevisiae (5), como referencia. Se les aplicó un campo magnético oscilante de frecuencia extremadamente baja de 60 Hz/220 V de 3 mT durante dos horas, en tres tubos de cultivo con agua destilada y con caldo nutriente. Después se inocularon 0,1 ml en placas de Petri con los medios de cultivo agar CromoCen SC (1 y 2), agar de dextrosa y papa (3), agar CromoCen CC 4227 (4) y agar con extracto de malta (5). Las colonias se contaron (log UFC/ml) mediante el procesamiento digital de las imágenes de las placas de Petri empleando el programa MatLab ® . Resultados. Se observó una estimulación significativa (p=0,05) de la cantidad de colonias tratadas con respecto a los controles, siendo mayor en el caldo nutriente que en el agua destilada y más en las bacterias (caldo nutriente-colonias tratadas: 9,43 a 10,62 UFC/ml) que en las levaduras (caldo nutriente-colonias tratadas: 8,31 a 8,79 UFC/ml). La estimulación se produjo en orden decreciente así: Listeria sp., E. coli ATCC 25922, Streptococcus sp., C. guillermondii y S. cerevisiae . Conclusión. Se concluyó que el campo magnético aplicado tuvo un efecto estimulante sobre los microorganismos estudiados, lo cual potencia el riesgo para la salud del personal y los visitantes del Archivo Nacional de la República de Cuba.

Introduction: Electromagnetic pollution has been detected at the Archivo Nacional de la República de Cuba and the influence of extremely low frequency magnetic fields could be quantified with pathogenic microorganisms isolated from the indoor environment. Objective: To quantify the influence of an extremely low frequency magnetic field on the growth of pathogenic microorganisms isolated from the environment at the Archivo Nacional. Materials and methods: We used five microorganisms isolated at the Archivo Nacional: Streptococcus sp. (1), Listeria sp. (2) and Candida guillermondii (3), and Escherichia coli ATCC 25922 (4) and Saccharomyces cerevisiae (5) as references. We applied this magnetic field of extremely low frequency, 60 Hz/220 V (3 mT), for two hours to these microorganisms on three culture tubes with distilled water and nutrient broth. Then we inoculated 0.1 mL in the following solid culture mediums on Petri dishes: CromoCen SC Agar (1 and 2), Potato Dextrose Agar (3), CromoCen DC 4227 (4) and Malt Extract Agar (5). The colonies were counted (log CFU/mL) by digital processing of the images of Petri dishes using the MatLab ® tool. Results: We observed a statistically significant stimulation (p=0.05) in the quantity of treated colonies as compared to controls, which was higher in nutrient broth than in distilled water, and in bacteria (nutrient broth and treated colonies: 9.43 to 10.62 CFU/mL) as compared with yeasts (nutrient broth-treated colonies: 8.31 to 8.79 CFU/mL). In decreasing order, stimulation was as follows: Listeria sp., E. coli ATCC 25922, Streptococcus sp., C. guillermondii and S. cerevisiae . Conclusion: We concluded that the magnetic field applied had a stimulating effect on the microorganisms under study, which increases the risk to the health of staff and visitors at the Archivo Nacional .

Los campos electromagnéticos de frecuencia extremadamente baja y su impacto sobre la salud de los seres humanos / Extremely low frequency electromagnetic fields and their impact on human health

Introducción: la intensidad registrada del campo electromagnético de frecuencia extremadamente baja proveniente del uso de la energía eléctrica en los ambientes laborales y comunales, supera varias veces los valores del fondo natural y se espera que se incrementen en los próximos años. El acercamiento a los CEM y el conocimiento de lo controvertido del tema, motivó la realización de este trabajo. Objetivo: mostrar la influencia de los mismos en el cuerpo humano y sus posibles implicaciones a la salud. Métodos: se realizó una revisión temática sobre este tema en revistas especializadas en salud ambiental, publicadas de 1988-1997, entre las que se encuentran: Occupational and Medicine, Scandinavian Journal of Work, Environmental and Health. Se exploraron bases de datos internacionales, otras fuentes y recursos de información. Resultados: del total de publicaciones referenciadas, solo en 4 no se relaciona la exposición a campo electromagnético con la aparición de afecciones a la salud humana; pero la gran mayoría (55 documentos) si las consideran de una u otra forma; 6 hacen referencias a que los campo electromagnético producen de alguna manera cambios a nivel biológico y fisiológico en humanos, y 49, los asocian a la ocurrencia de enfermedades. Conclusiones: es indudable que el desarrollo tecno productivo no ha sido inocente con la salud de los seres humanos. Es una necesidad actual el determinar, cuantificar y evaluar el riesgo en aras de precisar su relación con la salud humana, lo que permitirá tomar medidas en función de la protección y seguridad en el futuro(AU)

Introduction: recorded intensity of the extremely low frequency electromagnetic field (EMF) from the use of electricity at work and in community settings, exceeds several times the natural background values and is expected to increase in the coming years. The approach to the EMF and knowledge of the controversial issue prompted us to prepare this paper. Objective: to show the influence of the electromagnetic fields on the human body and its possible implications for health. Methods: occupational and Medicine, Scandinavian Journal of Work, Environmental and Health were among the specialized journals on environmental health published from 1988-1997 and used to make a literature review on this topic. International databases, sources and other information resources were explored. Results: of the total number of publications, only 4 did not relate exposure to electromagnetic field with onset of human health problems; but the vast majority (55 documents) did so in one way or another. Six made reference to the electromagnetic field causing somehow biological and physiological changes in humans whereas 49 associated it with the occurrence of diseases. Conclusions: there is no doubt that the productive and technical development has not been unrelated to human health. Therefore, it is required to determine, quantify and assess the risk in order to clarify its relation to human health, which will allow taking actions towards protection and safety in the future(AU)

A major problem in strabismus and its possible solution / Um grande problema no estrabismo e suas possíveis soluções

Purpose: One of the challenges in strabismus is to guarantee stability of the surgical corrections. Re-surgeries are often required even after careful diagnosis, planning, and execution. Several factors contribute to this undesired outcome and the existing management strategies are ineffective. The present alternative is to compensate for their consequences. Ocular rotations are evoked by muscular contractions and relaxations (active forces). During eye movement, periocular tissues are stretched, storing part of the kinetic energy, which may be posteriorly recovered (passive forces), whereas the remaining part of the energy is lost via friction and inelastic deformations (dissipative forces). A method for measuring the forces that cause post-surgery eye drift has not been reported. However, this may be indirectly determined as a function of the respective mechanical variables. The estimated ratio between the kinetic energies of a post-surgery eye drift and a normal pursuit eye movement is ~10-15. Theoretically, it can be expected that the addition of continuously acting forces of such magnitudes to the oculomotor system might prevent the undesired post-surgery eye movement. Methods: Several methods for increasing the restraining, dissipative forces to ocular rotations may be conceived. One method is to increase the friction to ocular movements, as for instance, by periocular injection of viscous substances. Another possibility is to use the forces of a magnetic field, which may stabilize the eye in a desired position without avoiding the rotations caused by greater muscular forces acting on it. It has been demonstrated that these forces neutralize the nystagmic movements, whose intensities of mechanical variables are much higher than those of a post-surgery eye drift. Some models of application of this technique are then discussed. Small magnets fixed to the orbit and metallic ferromagnetic elements fixed to the sclera to cover a suitable ...

Objetivo: Um grande problema nos estrabismos é garantir um resultado bom e estável de suas correções cirúrgicas. A necessidade de reoperações é relativamente alta, apesar de cuidadosos procedimentos diagnósticos, planejamento cirúrgico e execução tenham sido tomados. O resultado indesejado é devido a muitos fatores que ainda não são apropriadamente controlados. A alternativa atual é, então, compensar as consequências correspondentes. Rotações oculares são evocadas por contrações e relaxamentos musculares (forças ativas). Nesses movimentos oculares, tecidos perioculares são distendidos, mantendo parte da energia cinética, que pode ser posteriormente recuperada (forças passivas), enquanto outra parte é definitivamente perdida em fricção e deformações inelásticas (forças dissipativas). Não é conhecida a medida das forças que causam um desvio ocular pós-operatório, mas ela pode ser indiretamente determinada como função das respectivas variáveis mecânicas. A relação entre as energias cinéticas de um desvio ocular pós-operatório e de um movimento ocular persecutório normal pode ser então estimada como de cerca 10-15. Teoricamente, pode-se esperar que a adição de forças dessas magnitudes ao sistema oculomotor, continuadamente atuantes, possam prevenir os movimentos pós-operatórios indesejados. Métodos: Podem ser concebidas várias possibilidades de aumento das forças dissipativas, restritivas de rotações oculares. Uma é a de aumentar a fricção aos movimentos oculares como, por exemplo, por injeções perioculares de substâncias viscoelásticas. Outra possibilidade é oferecida por forças de campos magnéticos ...

Crescimento vascular em membrana do saco vitelínico e desenvolvimento embrionário de codornas japonesas (Coturnix japonica) expostas a campo magnético de baixa frequência / Vascular growth in yolk sac membrane and embryonic development of Japanese quail (Coturnix japonica) exposed to low frequency magnetic field

O objetivo deste trabalho foi observar a influência do campo magnético (CM) de baixa frequência na membrana do saco vitelínico (MSV) e no desenvolvimento do embrião de codornas japonesas (Coturnix japonica) em 72 horas de incubação. Ovos fertilizados foram expostos a nove horas consecutivas de CM, sendo um grupo a partir das 48 horas e o outro a partir das 63 horas de incubação. A quantificação da vascularização da MSV foi determinada pela obtenção da dimensão fractal por meio dos métodos de box-counting e de dimensão de informação, enquanto o peso corporal e o percentual de comprimento cefálico dos embriões foram utilizados como parâmetros de desenvolvimento embrionário. O CM não causou diferenças significativas na densidade vascular da MSV nem no desenvolvimento embrionário, quando comparados ao grupo controle...

The aim of this study was to observe the influence of the low frequency magnetic field (MF) on the yolk sac membrane (YSM) and embryonic development of Japanese quail (Coturnix japonica) in 72 hours of incubation. Fertilized eggs were exposed to 9 consecutive hours of MF, with a group from 48 hours and the second group from 63 hours of incubation. The evaluation of YSM vascularization was determined by the fractal dimensions obtained through box-counting method and information dimension, while body weight of the embryo and percentage of cephalic length were used as parameters for embryo development. The MF caused no significant differences in vessel density in the YSM, nor in the embryonic development considering the body weight and percentage cephalic length, when were compared to the control group...

Fundamentos y aplicaciones clínicas de la estimulación magnética transcraneal en neuropsiquiatría / Fundamentals and Clinical Applications of Transcranial Magnetic Stimulation in Neuropsychiatry

La estimulación magnética transcraneal (EMT) es una herramienta no invasiva de estimulación cerebral que se basa en la capacidad de un campo magnético generado para penetrar el cráneo y las meninges y originar una corriente eléctrica secundaria en el tejido cerebral que produce despolarización neuronal. Esta técnica se puede aplicar en un solo estímulo, en pares de estímulos separados por intervalos o en trenes de estímulos repetidos a varias frecuencias. Si bien el mecanismo de acción exacto se desconoce, la EMT repetitiva puede modular la excitabilidad de la corteza cerebral, por lo cual se ha vislumbrado como una posible herramienta diagnóstica y terapéutica en el área de neuropsiquiatría. El objetivo de este artículo es revisar el conocimiento actual de la EMT en cuanto a principios básicos, mecanismos fisiopatológicos y utilidad en la práctica clínica de la neuropsiquiatría.

Transcranial Magnetic Stimulation (TMS) is a non-invasive method for stimulation of brain that is based on the ability of a generated magnetic field to penetrate skull and brain meninges, inducing an electric current in the brain tissues that produces neuronal depolarization. TMS can be applied as single pulse of stimulation, pairs of stimuli separated by variable intervals to the same or different brain areas, or as trains of repetitive stimuli at various frequencies. Its mechanism of action is currently unknown. Repetitive TMS can modify the excitability of the cerebral cortex, and has been postulated as a diagnostic and therapeutic tool in the area of neuropsychiatry. The aim of this article is to review the knowledge of the TMS as regards its basic principles, pathophysiological mechanism, and its usefulness in clinical practice.

Perception of risk from electric and magnetic fields: Stress effects and psychological aspects / Percepção de risco de campos elétricos e magnéticos: efeitos do estresse e outros aspectos psicológicos

The present study aimed to investigate the perception of risk in the Brazilian population related to electric and magnetic fields. Six hundred adults were recruited from the surrounding communities. Three hundred of them lived in large cities and an equal number lived in small towns. A short questionnaire was constructed to assess risk perception, trust in government to control risk exposure, level of comfort with exposure to extra-low-frequency electromagnetic fields, measures perceived as necessary to reduce emotional discomfort, and trust in the regulatory agencies. The Lipp Inventory of Stress Symptoms for Adults was applied to assess stress levels. Findings indicate that the majority of the participants in this study did not trust the Government to provide protective measures from exposure to electric and magnetic fields, did not trust the regulatory agencies, felt that there is no adequate risk control and thought about it frequently, and some felt that line installations were being performed in excess and that this should be stopped. Results endorse the need for risk education and indicate that risk perception and feelings should be considered before starting new line installations. Risk communication should incorporate knowledge regarding social cognition since a large proportion of the people were concerned about electric and magnetic fields. Lack of communication can lead to a rejection of necessary transmission line installation, and to unnecessary or exaggerated fear...

O estudo teve como objetivo investigar a percepção de risco relacionada a campos eletromagnéticos de baixa frequência na população brasileira. Participaram seiscentos adultos, sendo metade constituída por habitantes de cidades grandes e a outra metade por habitantes de cidades pequenas. Um breve questionário foi utilizado para avaliar: (1) percepção de risco associada aos campos eletromagnéticos; (2) confiança no governo para proteger o povo do risco de exposição; (3) nível de conforto emocional frente à exposição às linhas de transmissão elétrica; (4) medidas percebidas como capazes de reduzir desconforto emocional; e (5) confiança nas concessionárias. Adicionalmente, foi aplicado o Inventário de Sintomas de Stress de Lipp, com o intuito de identificar o nível de estresse dos respondentes. Os dados indicaram que a maioria dos participantes (51,59%) deste estudo não confia que o governo tome as medidas necessárias para controlar os riscos; 28,05% não confiam nas concessionárias quanto ao controle de exposição excessiva; 33,0% sentem que não há um controle adequado do risco; e 17,00% pensam que a instalação de linhas de transmissão é excessiva, devendo-se parar com sua colocação. Os dados mostram a necessidade de se implementar um programa de educação quanto aos riscos reais, que leve em consideração o modo de pensar e sentir do povo brasileiro, antes de se instalar novas linhas de transmissão. A falta de comunicação pode levar o povo a rejeitar a instalação de linhas de transmissão necessárias e criar um medo desproporcional quanto a este assunto...

Campos eletromagnéticos e leucemia linfocítica aguda em crianças residentes na região metropolitana de São Paulo / Electromagnetic fields and acute lymphocytic leukemia in children living in the Metropolitan Area of Sao Paulo

Introdução- As Leucemias Linfocíticas Agudas (LLA) constituem-se na mais comum das neoplasias em crianças. Alguns estudos epidemiológicos identificaram riscos aumentados de LLA em crianças expostas a campos magnéticos gerados por linhas de força de alta tensão, porém, essa associação não foi confirmada por outros estudos. Objetivo- Verificar a associação entre exposição a campos magnéticos e a incidência da LLA em crianças residentes na Região Metropolitana de São Paulo, considerando-se a distância das residências das crianças de linhas de transmissão de energia (88, 138, 230, 345 e 440 kV). Métodos- Estudo casocontrole de base populacional. Os casos foram selecionados em cinco hospitais na capital do município de São Paulo, que concentram o atendimento a crianças com LLA. Quatro controles populacionais foram selecionados para cada caso, emparelhados por sexo, idade e cidade de nascimento. Casos e controles foram entrevistados utilizando-se questionário similar para obtenção de informações sobre as variáveis de interesse e potenciais variáveis de confusão. Os domicílios foram avaliados em relação às distâncias de linhas de transmissão de energia mais próxima utilizando-se o Global Positioning System (GPS). Na análise da associação entre campos magnéticos e LLA foi utilizada regressão logística condicional, incluindo o controle de potenciais variáveis de confusão. Foram calculados os odds ratios (OR) e os respectivos intervalos com 95 por cento de confiança (IC95 por cento). Resultados- A associação entre a distância de linhas de transmissão e LLA foi ajustada pela variável escolaridade da pessoa entrevistada, resultando em OR de 2,91 (IC95 por cento 0,92-9,22). Conclusão- Concluiu-se que, crianças residentes a menos de 160 metros de linhas de transmissão de energia na RMSP apresentam risco maior, porém não estatisticamente significativo de desenvolver LLA quando comparadas com as que residem a mais que 160 metros.

Introduction-The Acute Lymphocytic Leukemia (ALL) is the most common cancers in children. Some epidemiological studies have identified increased risk of ALL in children exposed to magnetic fields generated by high voltage power lines, however, this association was not confirmed by other studies. Purpose- Check the association between exposure to magnetic fields and the incidence of ALL in children residing in the Metropolitan Region of São Paulo, considering the distance from childrens home and transmission lines (88, 138, 230, 345 and 440 kV). Methods- A population-based case-control study. The cases were selected in five hospitals in the city of Sao Paulo, which account for the care of children with ALL. Four population controls were selected for each case, matched by sex, age and city of birth. Cases and controls were interviewed using a similar questionnaire to obtain information on the interest variables and potential confounding variables. The homes were evaluated by distances of the nearest transmission lines using the Global Positioning System (GPS). To examine the association between magnetic fields and ALL was used conditional logistic regression, including the control of potential confounding variables. We calculated the odds ratios (OR) and their 95per cent confidence interval (95 per cent CI). Results-The association between the distance of transmission lines and ALL was adjusted by education of the person interviewed, and the OR was 2.91 (95 per cent CI 0.92-9.22). Conclusion- Children living at less than 160 m of power transmission lines in RMSP have higher risk, though not statistically significant, when compared with those living in more than 160 m.