Viagem espacial: Um desafio sob o ponto de vista da oftalmologia / Space travel: A challenge from the point of view of ophthalmology

RESUMO No final do século vinte, com o surgimento de novas tecnologias e de novos programas espaciais, a medicina aeroespacial ganhou destaque no meio científico uma vez que os estudos relacionados às alterações da fisiologia humana no espaço tornaram-se cada vez mais necessário para a manutenção da saúde de cosmonautas. Os olhos são considerados uma das estruturas mais sensíveis do corpo às alterações vasculares, estruturais e bioquímicas provocadas pela microgravidade e radiação cósmica. Nesse sentido, essa revisão narrativa busca identificar e explicar as principais alterações morfológicas e funcionais que ocorrem no sistema visual em decorrência de missões espaciais.

ABSTRACT At the end of the twentieth century, with the emergence of new technologies and new space programs, aerospace medicine gained prominence in the scientific community since studies related to changes in human physiology in space have become increasingly necessary for the maintenance of cosmonaut health. The eyes are considered one of the most sensitive structures in the body to vascular, structural and biochemical changes caused by microgravity and cosmic radiation. In this sense, this narrative review seeks to identify and explain the main morphological and functional changes that occur in the visual system as a result of space missions.

Efeitos biológicos das radiações ionizantes: acidente radiológico de Goiânia / Biological effects of ionizing radiation: radiological accident in Goiânia

Neste artigo apresentamos as bases da Física das radiações, as fontes naturais e artificiais, os efeitos biológicos, a proteção radiológica. Examinamos também a sequência de eventos que resultou no acidente de Goiânia com uma fonte de césio-137 de um equipamento de radioterapia abandonado e suas terríveis consequências.

Cyclic patterns of incidence rate for skin malignant melanoma: association with heliogeophysical activity / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

<p><b>BACKGROUND</b>Our previous studies revealed cyclicity in the incidence rate of skin malignant melanoma (SMM; ICD9, Dx:172) in the Czech Republic (period T=7.50-7.63 years), UK (T=11.00 years) and Bulgaria (T=12.20 years). Incidences compared with the sunspot index Rz (lag-period dT=+2, +4, +6, +10 or +12 years) have indicated that maximal rates are most likely to appear on descending slopes of the 11-year solar cycle, i.e., out of phase. We summarized and explored more deeply these cyclic variations and discussed their possible associations with heliogeophysical activity (HGA) components exhibiting similar cyclicity.</p><p><b>METHODS</b>Annual incidences of SMM from 5 countries (Czech Republic, UK, Bulgaria, USA and Canada) over various time spans during the years 1964-1992 were analyzed and their correlations with cyclic Rz (sunspot number) and aa (planetary geomagnetic activity) indices were summarized. Periodogram regression analysis with trigonometric approximation and phase-correlation analysis were applied.</p><p><b>RESULTS</b>Previous findings on SMM for the Czech Republic, UK and Bulgaria have been validated, and cyclic patterns have been revealed for USA (T=8.63 years, P<0.05) and Canada (Ontario, T=9.91 years, P<0.10). Also, various 'hypercycles' were established (T=45.5, 42.0, 48.25, 34.5 and 26.5 years, respectively) describing long-term cyclic incidence patterns. The association of SMM for USA and Canada with Rz (dT=+6 and +7 years, respectively) and aa (dT=-10 and +9 years, respectively) was described. Possible interactions of cyclic non-photic influences (UV irradiation, Schumann resonance signal, low-frequency geomagnetic fluctuations) with brain waves absorbance, neuronal calcium dynamics, neuro-endocrine axis modulation, melatonin/serotonin disbalance and skin neuro-immunity impairment as likely causal pathways in melanoma appearance, were also discussed.</p><p><b>CONCLUSION</b>The above findings on cyclicity and temporal association of SMM with cyclic environmental factors could not only allow for better forecasting models but also lead to a better understanding of melanoma aetiology.</p>

Gamma background radiation in Yazd province, a preliminary report

There are relatively rich uranium mines in regions of Saghand and Bafgh in Yazd province. This survey was carried out to provide a map of ambient gamma radiation of Yazd province and the probable effects of the existence of these mines on background radiation dose rates. The measurements of the outdoor and indoor-environmental exposures [including cosmic and terrestrial components] were accomplished by a portable Geiger Muller detector in the five areas in each of eight big cities of Yazd province. The average exposure rates of indoor and outdoor ambient of Yazd province were 13.9 +/- 0.7 microRh[-1] and 11.6 +/- 0.8 microRh-1 respectively. The average dose rates in air, resulting from gamma background radiation of indoor and outdoor were 122 +/- 6.8 nSvh[-1] and 101.4 +/- 7.4 nSvh[-1] respectively. The annual average of equivalent dose in air was found to be 1.03 +/- 0.05 mSv, and the annual average of effective dose was 0.72 mSv. The results of this study in comparison with the same measurements in some other cities in Iran such as Isfahan and Tabriz, proves that the existence of uranium mines doesn't affect gamma background radiation of Yazd province

Concentration of natural radionuclides in soil and assessment of external exposure to the public in Tehran

Natural radionuclides in soil constitute a significant component of the background exposure sources of the population. A meaningful contribution to the total dose from natural sources comes from terrestrial radionuclides such as 238U, 232Th and 40K. The concentrations of natural radionuclides of 238U, 232Th and 40K in surface soil [5 cm depth] of Tehran have been measured by gamma spectrometry. The samples were dried and homogenized and measured for 60k seconds after radionuclides secular equilibrium, using a high purity germanium [HPGe] gamma-ray spectrometer. The high energy resolution of this type of detector is particularly useful for activity measurements of uranium and thorium chain members due to their complex spectras. The absorbed dose rates in air were also measured by using ionization-chamber at the point where soil samples were collected which includes terrestrial and cosmic rays. The natural gamma emitting terrestrial radionuclides in soils are directly relevant to outdoor exposure. The average activity concentrations of 238U, 232Th and 40K in different districts of Tehran were found to be 24, 28 and 635 Bq kg-1, respectively. The average outdoor gamma absorbed dose rate in air at 1 meter above ground was calculated as 102 nGy h-1. By using the data obtained in this study the average annual effective dose equivalent for a person living in Tehran Sv. According to data of 66 soil samples was found to be about 125 measurement covering 22 districts in Tehran, the average outdoor gamma dose rate in air due to terrestrial and cosmic radiation was found to be about 102 nGy h-1 and the average annual effective dose equivalent for a person living in Tehran Svmicrois about 125

Suporte médico em viagens aéreas / Advanced life support during air travel

Säo abordados aspectos médicos da aviaçäo e ocorrências das emergências näo-cardiológicas durante um vôo; alteraçäo da pressäo barométrica, diminuiçäo da tensäo de oxigênio, turbulência, alteraçäo circadiana, ortostase, exposiçäo à radiaçäo cósmica, estresse psicológico, envenenamentos, a gestante e viagens aéreas. Analisa-se o tratamento das seguintes situaçöes cardiológicas: doença coronariama, arritmias, ressuscitaçäo cardiopulmonar, utilizaçäo de marcapasso, e outras rotinas cardiológicas.

Cosmic radiation in concorde operations and the impact of new ICRP recommendations on commercial aviation

No abstract available.