Stem cell therapy: A novel & futuristic treatment modality for disaster injuries.

Stem cell therapy hold the potential to meet the demand for transplant cells/tissues needed for treating damages resulting from both natural and man-made disasters. Pluripotency makes embryonic stem cells and induced pluripotent stem cells ideal for use, but their teratogenic character is a major hindrance. Therapeutic benefits of bone marrow transplantation are well known but characterizing the potentialities of haematopoietic and mesenchymal cells is essential. Haematopoietic stem cells (HSCs) have been used for treating both haematopoietic and non-haematopoietic disorders. Ease of isolation, in vitro expansion, and hypoimmunogenecity have brought mesenchymal stem cells (MSCs) into limelight. Though differentiation of MSCs into tissue-specific cells has been reported, differentiation-independent mechanisms seem to play a more significant role in tissue repair which need to be addressed further. The safety and feasibility of MSCs have been demonstrated in clinical trials, and their use in combination with HSC for radiation injury treatment seems to have extended benefit. Therefore, using stem cells for treatment of disaster injuries along with the conventional medical practice would likely accelerate the repair process and improve the quality of life of the victim.

Mortality of a cohort of employees in a certain factory / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To follow up the cohort of a certain factory and analyze the death cause of the employees.</p><p><b>METHODS</b>A dynamic cohort was adopted and the study population consisted of all workers stayed at the factory for more than 1 year. The cohort data was mainly from the personnel ministry in the factory,the death data provided by the personnel ministry,the labour union and the hospital. All cause of death of the all employee and the death condition of radiation group and no-radiation group were analyzed and compared.</p><p><b>RESULTS</b>The mortality of the workers in the factory was significantly lower than national population, the SMR of all cause of death in all employee, radiation group and no-radiation group were 0.41 (95% CI: 0.37-0.45), 0.24, 0.75 respectively; all cancer death in the three group was 0.59, 0.40 and 0.92. But the death order was different in radiation group and no-radiation group,the order of liver cancer was list first in radiation group, which was unlike that of the nation order and the no-radiation order.</p><p><b>CONCLUSION</b>There have no excess death in the factory, but the order of liver cancer is precedence.</p>

Production of a datolite-based heavy concrete for shielding nuclear reactors and megavoltage radiotherapy rooms

Biological shielding of nuclear reactors has always been a great concern and decreasing the complexity and expense of these installations is of great interest. In this study, we used datolite and galena [DaGa] minerals for production of a high performance heavy concrete. Datolite and galena minerals which can be found in many parts of Iran were used in the concrete mix design. To measure the gamma radiation attenuation of the DaGa concrete samples, they were exposed to both narrow and wide beams of gamma rays emitted from a cobalt-60 radiotherapy unit. An Am-Be neutron source was used for assessing the shielding properties of the samples against neutrons. To test the compression strengths, both types of concrete mixes [DaGa and ordinary concrete] were investigated. The concrete samples had a density of 4420-4650 kg/m[3] compared to that of ordinary concrete [2300-2500 kg/m[3]] or barite high density concrete [up to 3500 kg/m[3]]. The measured half value layer thickness of the DaGa concrete samples for cobalt-60 gamma rays was much less than that of ordinary concrete [2.56 cm compared to 6.0 cm]. Furthermore, the galena concrete samples had a significantly higher compressive strength as well as 20% more neutron absorption. The DaGa concrete samples showed good shielding/ engineering properties in comparison with other reported samples made, using high-density materials other than depleted uranium. It is also more economic than the high-density concretes. DaGa concrete may be a suitable option for shielding nuclear reactors and megavoltage radiotherapy rooms

Production of an economic high-density concrete for shielding megavoltage radiotherapy rooms and muclear reactors

In megavoltage radiotherapy rooms, ordinary concrete is usually used due to its low construction costs, although higher density concrete are sometimes used, as well. The use of high-density concrete decreases the required thickness of the concrete barrier; hence, its disadvantage is its high cost. In a nuclear reactor, neutron radiation is the most difficult to shield. A method for production of economic high-density concrete with appropriate engineering properties would be very useful. Galena [PbS] mineral was used to produce of a high-density concrete. Galena can be found in many parts of Iran. Two types of concrete mixes were produced. The water-to-concrete [w/c] ratios of the reference and galena concrete mixes were 0.53 and 0.25, respectively. To measure the gamma radiation attenuation of Galena concrete samples, they were exposed to a narrow beam of gamma rays emitted from a cobalt-60 therapy unit. The Galena mineral used in this study had a density of 7400 kg/m[3]. The concrete samples had a density of 4800 kg/m[3]. The measured half value layer thickness of the Galena concrete samples for cobalt- 60 gamma rays was much less than that of ordinary concrete [2.6 cm compared to 6.0 cm]. Furthermore, the galena concrete samples had significantly higher compressive strength [500 kg/cm[2] compared to 300 kg/cm[2]]. The Galena concrete samples made in our laboratories had showed good shielding/engineering properties in comparison with all samples made by using high-density materials other than depleted uranium. Based on the preliminary results, Galena concrete is maybe a suitable option where high-density concrete is required in megavoltage radiotherapy rooms as well as nuclear reactors

Production of [18 F] fluoride with a high-current two layer spherical gold target

Fluoride-18 is the most widely used radioisotope for Positron Emission Tomography [PET]. [18F] 2-flouro- 2-deoxy D-glucose [FDG] has become a standard tool in the area of clinical research. The oxygen-18 enriched water is the most widely used target for the production of fluoride-18. The use of the nuclear reaction 18O [p,n]18F has been found as the most effective method for the production of [18F] fluoride. Materials and methods: Gold is a chemically resistant metal, which has been found wide application in the chemical industry where it is often used in corrosive environments at high temperature.It is also one of the highest thermal conductivity of metals. A two layer-spherical gold chamber design was chosen to obtain a maximum pressure stability under high beam currents. The target body is consisted of two chambers, internal chamber for internal cooling and external chamber for enriched water target. The target is irradiated with 28 MeV protons energy. The incident energy on the target chamber is 18 MeV. This target is operated without external over-pressure and has been tested for beam currents up to 60 micro A. The measured target yield is 2655 MBq/micro Ah. There is found that saturation yield is 8.3 GBq/micro A and shows 80% of theoretical yield. It was observed that gold is a good material for the construction of the target chamber, and also the spherical chambers are the best construction to bearing high pressure under high-current beam condition up to 60 micro A

Dosimetry of the Low Fluence Fast Neutron Beams for Boron Neutron Capture Therapy / 대한방사선종양학회지

PURPOSE: For the research of Boron Neutron Capture Therapy (BNCT), fast neutrons generated from the MC-50 cyclotron with maximum energy of 34.4 MeV in Korea Cancer Center Hospital were moderated by 70 cm paraffin and then the dose characteristics were investigated. Using these results, we hope to establish the protocol about dose measurement of epi-thermal neutron, to make a basis of dose characteristic of epi-thermal neutron emitted from nuclear reactor, and to find feasibility about accelerator-based BNCT. METHOD AND MATERIALS: For measuring the absorbed dose and dose distribution of fast neutron beams, we used Unidos 10005 (PTW, Germany) electrometer and IC-17 (Far West, USA), IC-18, EIC-1 ion chambers manufactured by A-150 plastic and used IC-17M ion chamber manufactured by magnesium for gamma dose. There chambers were flushed with tissue equivalent gas and argon gas and then the flow rate was 5 cc per minute. Using Monte Carlo N-Particle (MCNP) code, transport program in mixed field with neutron, photon, electron, two dimensional dose and energy fluence distribution was calculated and there results were compared with measured results. RESULTS: The absorbed dose of fast neutron beams was 6.47x10-3 cGy per 1 MU at the 4 cm depth of the water phantom, which is assumed to be effective depth for BNCT. The magnitude of gamma contamination intermingled with fast neutron beams was 65.2+/-0.9% at the same depth. In the dose distribution according to the depth of water, the neutron dose decreased linearly and the gamma dose decreased exponentially as the depth was deepened. The factor expressed energy level, D20/D10, of the total dose was 0.718. CONCLUSION: Through the direct measurement using the two ion chambers, which is made different wall materials, and computer calculation of isodose distribution using MCNP simulation method, we have found the dose characteristics of low fluence fast neutron beams. If the power supply and the target material, which generate high voltage and current, will be developed and gamma contamination was reduced by lead or bismuth, we think, it may be possible to accelerator-based BNCT.

Monitorizaçäo em tempo real dos níveis de radiaçäo gama nos arredores do reator nuclear da Pennsylvania State University / Monitoring in real time of gama radiation levels in nearly of Nuclear Reactor of Pennsylvania State University

Medidas de nível de radiação gama ambiental rotineiramente realizadas pelo Health Physics Office da Pennsylvania State University (PSU) com dosímetros termoluminescentes revelam que alguns locais próximos ao Breazeale Nuclear Reactor da Universidade apresentam níveis maiores que os esperados e que esses níveis não estão relacionadas com a operação do próprio reator. Nesse projeto foram realizadas medidas adicionais para tentar desvendar a origem dessas flutuações.

A cancer mortality study in Bombay-based atomic energy community: 1975-1987.

Cancer deaths recorded by the centralised health services of the Department of Atomic Energy (DAE) among its employees and their families stationed in Bombay during 1975-1987 have been analysed. Expected number of deaths due to cancer in the study group has been estimated by using the age-sex-specific cancer death rates reported for Bombay resident population for the year 1983. The size of the database for the entire DAE community is about 702,000 person years and the number of cancer deaths observed in 154. Analysis has been done separately for employees and their families, individually for important groups of cancer sites such as respiratory organs, digestive organs, breast, genito-urinary organs and lymphatic and haematopoietic systems. The standardised mortality ratios are generally lower than 100, which may partly be due to the 'healthy worker effect' in the DAE community and partly because of its differences in the social class distribution and the concomitant differences in lifestyle with respect to the comparison group of Bombay city.