WordNet

travel or traverse (a distance); "This car does 150 miles per hour"; "We did 6 miles on our hike every day"
the syllable naming the first (tonic) note of any major scale in solmization (同)doh, ut
proceed or get along; "How is she doing in her new job?"; "How are you making out in graduate school?"; "Hes come a long way" (同)fare, make_out, come, get along
create or design, often in a certain way; "Do my room in blue"; "I did this piece in wood to express my love for the forest" (同)make
carry on or function; "We could do with a little more help around here" (同)manage
get (something) done; "I did my job" (同)perform
the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay (同)radioactivity
energy that is radiated or transmitted in the form of rays or waves or particles
the act of spreading outward from a central source
a radial arrangement of nerve fibers connecting different parts of the brain
the spread of a group of organisms into new habitats
treat with an agent; add (an agent) to; "The ray dosed the paint"
the quantity of an active agent (substance or radiation) taken in or absorbed at any one time (同)dosage
a measured portion of medicine taken at any one time (同)dosage
treated with some kind of application; "a mustache dosed with bear grease"

PrepTutorEJDIC

《疑問文・否定文を作る》 / 《否定命令文を作る》 / 《助動詞とbe動詞のどちらも含まない文に用いて付加疑問を作る》 / 《強意語として》 / 《文》《助動詞とbe動詞のどちらも含まない文に用いて倒置文を作る》 / 《あいづちを打つ場合に》 / 《先行する動詞またはそれを含む述部の代用》 / 《so,nor,neitherで始まる簡略文で》 / …‘を'『する』,行う,果たす / 《通例have done,時にbe doneの形で》…‘を'『終える』,済ませる / …‘を'作る,作り出す / …‘を'『処理する』,整える,片付ける / 〈学課〉‘を'『勉強する』,専攻する / 〈利益・害など〉‘を'与える,もたらす / 〈人〉‘に'『役立つ』,用が足りる(serve) / …の速度で進む,距離を行く / …‘を'見物する / 〈劇〉‘を'上演する;…‘の'役を演じる / …の役目(仕事)をする / 《おもに英》…‘を'だます,かつぐ / 《話》…をへとへとにさせる / 『する』;活動する / 《通例have done,時にbe doneの形で》(…を)『終える』,済ます《+『with』+『名』》 / 〈事が〉『運ぶ』;〈人が〉暮らしていく,健康である / 〈物が〉(…に)『間に合う』,十分である;〈人が〉(…に)役に立つ,向く《+『for』+『名』》 / 《複数形で》すべきこと / 〈C〉《おもに英》大宴会,大パーティー / 〈C〉《英話》詐欺,ぺてん
ド(全音階の第1音)
〈U〉(光・熱・放射能などの)発散,放射 / 〈C〉放射物;放射線;輻射(ふくしゃ)熱 / 〈C〉(喜び・幸福感などの)発散《+『of』+『名』》 / =radioactivity
(おもに飲み薬1回分の)『服用量』 / (痛いこと・いやなことの)1回分,一定量 / (人などが受ける放射線の)線量 / 性病 / (…を)…‘に'投薬する,服用させる《+『名』+『with』+『名』》

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/06/23 13:51:02」(JST)

wiki en

Absorbed dose is a physical dose quantity D representing the mean energy imparted to matter per unit mass by ionizing radiation. In the SI system of units, the unit of measure is joules per kilogram, and its special name is gray (Gy).^[1] The non-SI CGS unit rad is sometimes also used, predominantly in the USA.

Uses

External dose quantities used in radiation protection and dosimetry

Absorbed dose is used in the calculation of dose uptake in living tissue in both radiation protection and radiology. It is also used to directly compare the effect of radiation on inanimate matter.

Radiological protection

The quantity absorbed dose is of fundamental importance in radiological protection for calculating radiation dose. However, absorbed dose is a physical quantity and used unmodified is not an adequate indicator of the likely health effects in humans.

It has been found that for stochastic radiation risk (defined as probability of cancer induction and genetic effects) consideration must be given to the type of radiation and the sensitivity of the irradiated tissues, which requires the use of modifying factors. Conventionally therefore, unmodified absorbed dose is not used for comparing stochastic risks but only used to compare against deterministic effects (severity of acute tissue effects that are certain to happen) such as in acute radiation syndrome.

To represent stochastic risk the equivalent dose H _T and effective dose E are used, and appropriate dose factors and coefficients are used to calculate these from the absorbed dose.^[2] Equivalent and effective dose quantities are expressed in units of the sievert or rem which implies that biological effects have been taken into account. These are usually in accordance with the recommendations of the International Committee on Radiation Protection (ICRP) and International Commission on Radiation Units and Measurements (ICRU). The coherent system of radiological protection quantities developed by them is shown in the accompanying diagram.

Radiology

The measurement of absorbed dose in tissue is of fundamental importance in radiobiology and radiation therapy as it is the measure of the amount of energy the incident radiation is imparting to the target tissue.

Component survivability

Absorbed dose is used to rate the survivability of devices such as electronic components in ionizing radiation environments.

Food irradiation

The international Radura logo, used to show a food has been treated with ionizing radiation.

Absorbed dose is the physical dose quantity used to ensure irradiated food has received the correct dose to ensure effectiveness. Variable doses are used depending on the application and can be as high as 70 kGy.

Computation

The absorbed dose is equal to the radiation exposure (ions or C/kg) of the radiation beam multiplied by the ionization energy of the medium to be ionized.

For example, the ionization energy of dry air at 20 °C and 101.325 kPa of pressure is 7001339700000000000♠33.97±0.06 J/c.^[3]^:305 (33.97 eV per ion pair) Therefore an exposure of 6996258000000000000♠2.58×10⁻⁴ C/kg (1 roentgen) would deposit an absorbed dose of 6997876000000000000♠8.76×10⁻³ J/kg (0.00876 Gy or 0.876 rad) in dry air at those conditions.

When the absorbed dose is not uniform, or when it is only applied to a portion of a body or object, an absorbed dose representative of the entire item can be calculated by taking a mass-weighted average of the absorbed doses at each point.

More precisely,^[4]

${\bar {D_{T}}}={\frac {\int _{T}D(x,y,z)\rho (x,y,z)dV}{\int _{T}\rho (x,y,z)dV}}$

Where

is the mass-averaged absorbed dose of the entire item T

is the item of interest

is the absorbed dose as a function of location

is the density as a function of location

is volume

Medical considerations

Non-uniform absorbed dose is common for soft radiations such as low energy x-rays or beta radiation. Self-shielding means that the absorbed dose will be higher in the tissues facing the source than deeper in the body.

The mass average can be important in evaluating the risks of radiotherapy treatments, since they are designed to target very specific volumes in the body, typically a tumour. For example, if 10% of a patient's bone marrow mass is irradiated with 10 Gy of radiation locally, then the absorbed dose in bone marrow overall would be 1 Gy. Bone marrow makes up 4% of the body mass, so the whole-body absorbed dose would be 0.04 Gy. The first figure (10 Gy) is indicative of the local effects on the tumour, while the second and third figure (1 Gy and 0.04 Gy) are better indicators of the overall health effects on the whole organism. Additional dosimetry calculations would have to be performed on these figures to arrive at a meaningful effective dose, which is needed to estimate the risk of cancer or other stochastic effects.

When ionizing radiation is used to treat cancer, the doctor will usually prescribe the radiotherapy treatment in units of gray. Medical imaging doses may be described in units of coulomb per kilogram, but when radiopharmaceuticals are used, they will usually be administered in units of becquerel.

Radiation-related quantities

Various doses of radiation in sieverts, ranging from trivial to lethal.

The following table shows radiation quantities in SI and non-SI units.

Quantity	Name	Symbol	Unit	Year	System
Exposure (X)	röntgen	R	esu / 0.001293 g of air	1928	non-SI
Absorbed dose (D)			erg•g⁻¹	1950	non-SI
	rad	rad	100 erg•g⁻¹	1953	non-SI
	gray	Gy	J•kg⁻¹	1974	SI
Activity (A)	curie	Ci	3.7 × 10¹⁰ s⁻¹	1953	non-SI
Activity (A)	becquerel	Bq	s⁻¹	1974	SI
Dose equivalent (H)	röntgen equivalent man	rem	100 erg•g⁻¹	1971	non-SI
Dose equivalent (H)	sievert	Sv	J•kg⁻¹	1977	SI
Fluence (Φ)	(reciprocal area)		cm⁻² or m⁻²	1962	SI (m⁻²)

Although the United States Nuclear Regulatory Commission permits the use of the units curie, rad, and rem alongside SI units,^[5] the European Union European units of measurement directives required that their use for "public health ... purposes" be phased out by 31 December 1985.^[6]

References

^ ICRP 2007, glossary.
^ ICRP 2007, paragraphs 104 and 105.
^ Podgorsak, E. B., ed. (2005). Radiation Oncology Physics: A Handbook for Teachers and Students (PDF). Vienna: International Atomic Energy Agency. ISBN 92-0-107304-6. Retrieved 25 November 2012.
^ ICRP 2007, p. 1.
^ 10 CFR 20.1004. US Nuclear Regulatory Commission. 2009.
^ The Council of the European Communities (1979-12-21). "Council Directive 80/181/EEC of 20 December 1979 on the approximation of the laws of the Member States relating to Unit of measurement and on the repeal of Directive 71/354/EEC". Retrieved 19 May 2012.

Literature

ICRP (2007). "The 2007 Recommendations of the International Commission on Radiological Protection". Annals of the ICRP. ICRP publication 103 37 (2-4). ISBN 978-0-7020-3048-2. Retrieved 17 May 2012.

External links

Specific Gamma-Ray Dose Constants for Nuclides Important to Dosimetry and Radiological Assessment, Laurie M. Unger and D. K . Trubey, Oak Ridge National Laboratory, May 1982 - contains gamma-ray dose constants (in tissue) for approximately 500 radionuclides.

UpToDate Contents

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English Journal

IMRT Treatment Planning on 4D Geometries for the Era of Dynamic MLC Tracking.

Suh Y1, Murray W, Keall PJ.
Technology in cancer research & treatment.Technol Cancer Res Treat.2014 Dec;13(6):505-15. doi: 10.7785/tcrtexpress.2013.600276. Epub 2013 Dec 17.
The problem addressed here was to obtain optimal and deliverable dynamic multileaf collimator (MLC) leaf sequences from four-dimensional (4D) geometries for dynamic MLC tracking delivery. The envisaged scenario was where respiratory phase and position information of the target was available during t
PMID 24354751

A novel technique for image-guided local heart irradiation in the rat.

Sharma S1, Moros EG, Boerma M, Sridharan V, Han EY, Clarkson R, Hauer-Jensen M, Corry PM.
Technology in cancer research & treatment.Technol Cancer Res Treat.2014 Dec;13(6):593-603. doi: 10.7785/tcrtexpress.2013.600256. Epub 2013 Aug 31.
In radiotherapy treatment of thoracic, breast and chest wall tumors, the heart may be included (partially or fully) in the radiation field. As a result, patients may develop radiation-induced heart disease (RIHD) several years after exposure to radiation. There are few methods available to prevent o
PMID 24000983

Radiation-treated ready-to-eat (RTE) chicken breast Adobo for immuno-compromised patients.

Feliciano CP1, De Guzman ZM2, Tolentino LM2, Cobar ML2, Abrera GB2.
Food chemistry.Food Chem.2014 Nov 15;163:142-6. doi: 10.1016/j.foodchem.2014.04.087. Epub 2014 May 9.
Usually in hospitals low-bacterial diets are served to immuno-compromised patients (ICPs). However, low-bacterial diets still pose a high risk of microbial infections and limit the food selection of the patients. Thus, pathogen-free dishes must be made available. This study presents the development
PMID 24912709

Japanese Journal

精巣鞘膜に発生した悪性中皮腫の1例

鄭裕元,倉橋俊史,丸山聡,田中宏和,田代敬
泌尿器科紀要 59(9), 603-606, 2013-09-00
… He received external beam radiation therapy at a total dose of 44 Gy. …
NAID 120005333762

Effects of UV wavelength on cell damages caused by UV irradiation in PC12 cells

Masuma Runa,Kashima Sakura,Kurasaki Masaaki,Okuno Tsutomu
Journal of Photochemistry and Photobiology B: Biology 125, 202-208, 2013-08-05
… This study was conducted to determine the toxicological effects of different wavelengths (250, 270, 290, and 310 nm) and doses of UV radiation on cell viability, DNA structure, and DNA damage repair mechanisms in a PC12 cell system. … Cell survival rate was markedly decreased 24 h after UV irradiation in a dose-dependent manner at all wavelengths (except at 310 nm). …
NAID 120005311826

Acid Diffusion Length in Line-and-Space Resist Patterns Fabricated by Extreme Ultraviolet Lithography

Kozawa Takahiro,Santillan Julius Joseph,Itani Toshiro
Jpn J Appl Phys 52(7), 076501-076501-5, 2013-07-25
… Acids generated upon exposure to radiation induce the polarity change of the polymer through catalytic chain reactions in chemically amplified resists. … The acid diffusion length depended on the nominal line width and exposure dose. … Upon exposure to EUV radiation with an exposure dose of 16 mJ cm<sup>-2</sup>, the acid diffusion length (three-dimensional) in a line-and-space pattern with 21 nm nominal line width was 9.5 nm. …
NAID 150000107355