{"title":"Induction of different classes of genetic effects in yeast using heavy ions.","authors":"S Nakai, R Mortimer","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"7 ","pages":"172-81"},"PeriodicalIF":0.0,"publicationDate":"1967-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17125190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L D Skarsgard, B A Kihlman, L Parker, C M Pujara, S Richardson
{"title":"Survival, chromosome abnormalities, and recovery in heavy-ion and x-irradiated mammalian cells.","authors":"L D Skarsgard, B A Kihlman, L Parker, C M Pujara, S Richardson","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"7 ","pages":"208-21"},"PeriodicalIF":0.0,"publicationDate":"1967-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17125194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Injury accumulation and recovery in sheep during protracted gamma irradiation.","authors":"G F Leong, N P Page, E J Ainsworth, G E Hanks","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"7 ","pages":"288-93"},"PeriodicalIF":0.0,"publicationDate":"1967-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17125202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Free radicals induced in enzymes by electrons and heavy ions.","authors":"T Henriksen","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"7 ","pages":"87-101"},"PeriodicalIF":0.0,"publicationDate":"1967-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"15400945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
in the tumor region might overcome some of the radioresistance of an anoxic tumor. The most useful beam available at the cyclotron for our purpose is a 90-MeV tr- beam. At this energy the intensity of the pion beam is a maximum and the background is not excessive. The range of these pions is around 25 cm of tissue, which is excessive for the therapeutic applications. In studying the effects of the stopping pions, therefore, an appreciable amount of Lucite absorber must be used, which not only attenuates the beam but also produces loss by divergence of the beam. These factors must be considered in irradiating biological materials. The dosimetry of this radiation presents a number of new problems that have not been entirely solved. Among these, at present, is the fact that the background radiation, consisting of electrons and muons in the beam, amounts to about 40% of the total number of particles in the beam. In spite of the questions that remain to be answered, it is nevertheless useful to
{"title":"Studies on Vicia faba root meristems irradiated with a pion beam.","authors":"S. Richman, C. Richman, M. R. Raju, B. Schwartz","doi":"10.2307/3583711","DOIUrl":"https://doi.org/10.2307/3583711","url":null,"abstract":"in the tumor region might overcome some of the radioresistance of an anoxic tumor. The most useful beam available at the cyclotron for our purpose is a 90-MeV tr- beam. At this energy the intensity of the pion beam is a maximum and the background is not excessive. The range of these pions is around 25 cm of tissue, which is excessive for the therapeutic applications. In studying the effects of the stopping pions, therefore, an appreciable amount of Lucite absorber must be used, which not only attenuates the beam but also produces loss by divergence of the beam. These factors must be considered in irradiating biological materials. The dosimetry of this radiation presents a number of new problems that have not been entirely solved. Among these, at present, is the fact that the background radiation, consisting of electrons and muons in the beam, amounts to about 40% of the total number of particles in the beam. In spite of the questions that remain to be answered, it is nevertheless useful to","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"1 1","pages":"182-9"},"PeriodicalIF":0.0,"publicationDate":"1967-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83418697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Space-flight-related stresses on the central nervous system.","authors":"R L Schoenbrun, W R Adey","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"7 ","pages":"423-38"},"PeriodicalIF":0.0,"publicationDate":"1967-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"16056977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Relative biological effectiveness of different types of ionizing radiations: cytogenetic effects in maize.","authors":"H H Smith","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"7 ","pages":"190-5"},"PeriodicalIF":0.0,"publicationDate":"1967-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17125192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A mortality determinant in nonuniform exposures of the mammal.","authors":"V P Bond, C V Robinson","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"7 ","pages":"265-75"},"PeriodicalIF":0.0,"publicationDate":"1967-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"17125201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pions, and in particular negative pions, are of interest to radiology for at least three outstanding reasons: First, a beam of negative pions can produce in tissue depth and isodose distributions which, for treatment of deep-seated tumors, give a considerably better tumor-to-total-dose ratio than any other commonly used therapeutic radiation source (1). This improved ratio with pion irradiation is largely due to the short-ranged, heavily ionizing products resulting from nuclear pion interactions at the end of the pion track. Thus, second, an additional effectiveness of the dose delivered to the tumor relative to that delivered to healthy tissue is likely because of the oxygen effect observed with heavily ionizing radiation (2). Third, a pion beam seems at present to be the best choice in order to create a well-defined region in which nuclear reactions or nuclear stars give a substantial contribution to the radiation dose. Such conditions are essential for dosimetry and radio-biological research of strong nuclear interactions and thus for approaching a deeper understanding of the particular problems of high-energy dosimetry and radiobiology (3). In the following discussion, some experimental studies of the pion beam from the CERN 600-MeV Synchro-Cyclotron are reported. The results are limited to dosimetry and radiation quality measurements in a water phantom exposed to a 70-MeV pion beam; an attempt was also made to evaluate the average local energy deposition per stopped pion. The results are of a preliminary nature, and more extensive experimental investigations along the same lines are continuing.
{"title":"Radiological physics of pions.","authors":"J. Baarli","doi":"10.2307/3583695","DOIUrl":"https://doi.org/10.2307/3583695","url":null,"abstract":"Pions, and in particular negative pions, are of interest to radiology for at least three outstanding reasons: First, a beam of negative pions can produce in tissue depth and isodose distributions which, for treatment of deep-seated tumors, give a considerably better tumor-to-total-dose ratio than any other commonly used therapeutic radiation source (1). This improved ratio with pion irradiation is largely due to the short-ranged, heavily ionizing products resulting from nuclear pion interactions at the end of the pion track. Thus, second, an additional effectiveness of the dose delivered to the tumor relative to that delivered to healthy tissue is likely because of the oxygen effect observed with heavily ionizing radiation (2). Third, a pion beam seems at present to be the best choice in order to create a well-defined region in which nuclear reactions or nuclear stars give a substantial contribution to the radiation dose. Such conditions are essential for dosimetry and radio-biological research of strong nuclear interactions and thus for approaching a deeper understanding of the particular problems of high-energy dosimetry and radiobiology (3). In the following discussion, some experimental studies of the pion beam from the CERN 600-MeV Synchro-Cyclotron are reported. The results are limited to dosimetry and radiation quality measurements in a water phantom exposed to a 70-MeV pion beam; an attempt was also made to evaluate the average local energy deposition per stopped pion. The results are of a preliminary nature, and more extensive experimental investigations along the same lines are continuing.","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"1 1","pages":"10-9"},"PeriodicalIF":0.0,"publicationDate":"1967-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77059482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
atomic nuclei of elements heavier than carbon and as heavy as iron. They are stripped of their electrons and thus are highly charged. As these particles are slowed down in tissue, they interact with the elements of the tissue and cause very energetic 6 rays to be emitted. The result is a track in tissue having very dense ionization near the end of its path, and this is known as a "thindown." This thindown region may be as much as 0.025 mm in diameter and 1.5 mm long. Schaefer (1) has computed that the radiation dose in this ionization core may be as much as 10,000 rads at its center, tapering off to low values toward the edges. Only the particles having energies less than about one billion electron volts per nucleon will cause this type of damage, since particles of higher energies will form stars and dissipate their energies widely. It would be virtually impossible to shield against these latter particles in a space craft because even a very heavy shield would only slow down the very energetic particles to the point where they would become highly ionizing and thus dangerous. In assessing the biological effect of such particles it would obviously not be correct to apply the usual rules for tolerance doses-that is, to compute the total dose from the energy deposited in the body of an average man. For heavy particles the energy is all deposited in very small volumes, or "hot spots," leaving the rest unaffected. This then constitutes a special radiobiological problem. These particles cannot presently be generated in the laboratory with sufficient energy to be used for mammalian experiments. Consequently an indirect experimental approach had to be developed (2). This consisted in confining the 22-MeV deuterons from the Brookhaven 60-inch cyclotron in a beam 0.025 mm in diameter. This microbeam was arranged in such a way that it could be directed at any pre1 Research carried out at Brookhaven National Laboratory under the auspices of the U. S.
{"title":"The use of deuteron microbeam for simulating the biological effects of heavy cosmic-ray particles.","authors":"H. Curtis","doi":"10.2307/3583718","DOIUrl":"https://doi.org/10.2307/3583718","url":null,"abstract":"atomic nuclei of elements heavier than carbon and as heavy as iron. They are stripped of their electrons and thus are highly charged. As these particles are slowed down in tissue, they interact with the elements of the tissue and cause very energetic 6 rays to be emitted. The result is a track in tissue having very dense ionization near the end of its path, and this is known as a \"thindown.\" This thindown region may be as much as 0.025 mm in diameter and 1.5 mm long. Schaefer (1) has computed that the radiation dose in this ionization core may be as much as 10,000 rads at its center, tapering off to low values toward the edges. Only the particles having energies less than about one billion electron volts per nucleon will cause this type of damage, since particles of higher energies will form stars and dissipate their energies widely. It would be virtually impossible to shield against these latter particles in a space craft because even a very heavy shield would only slow down the very energetic particles to the point where they would become highly ionizing and thus dangerous. In assessing the biological effect of such particles it would obviously not be correct to apply the usual rules for tolerance doses-that is, to compute the total dose from the energy deposited in the body of an average man. For heavy particles the energy is all deposited in very small volumes, or \"hot spots,\" leaving the rest unaffected. This then constitutes a special radiobiological problem. These particles cannot presently be generated in the laboratory with sufficient energy to be used for mammalian experiments. Consequently an indirect experimental approach had to be developed (2). This consisted in confining the 22-MeV deuterons from the Brookhaven 60-inch cyclotron in a beam 0.025 mm in diameter. This microbeam was arranged in such a way that it could be directed at any pre1 Research carried out at Brookhaven National Laboratory under the auspices of the U. S.","PeriodicalId":77888,"journal":{"name":"Radiation research. Supplement","volume":"38 1","pages":"250-7"},"PeriodicalIF":0.0,"publicationDate":"1967-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86781818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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