2024-03-29T12:10:19+03:30
http://ijrr.com/browse.php?mag_id=33&slc_lang=en&sid=1
33-726
2024-03-29
10.1002
International Journal of Radiation Research
Int J Radiat Res
2322-3243
2345-4229
10.61186/ijrr
2011
9
1
The effect of microwave radiation on osteogenesis and osteolysis of rats in the hypergravity condition and the role of Rana sylvatica Le conte oil as a radioprotector
S.
Pan
Y.D.
Yang
Y.P.
Li
J.C.
Wang
J.W.
Zhao
Y.
Wang
S.J.
Lv
W.G.
Pan
Z.L.
Gao
gaozhongli@yahoo.com.cn
Background: Microwave Thermotherapy has
been gradually used in radiotherapy and it is reported
that microwave radiation increases bone demineralization
rate independently of temperature. Furthermore,
it becomes more and more widespread that
the damage caused by the synergistic effect of microwave
radiation and hypergravity. The experiment was
designed to investigate the effect of microwave
radiation on osteogenesis and osteolysis of rats in
the hypergravity condition and to observe the role of
Rana sylvatica Le conte oil as a radioprotector.
Materials and Methods: Wistar rats were exposed to
microwave radiation of 200mW/cm2 power density
and +6G hypergravity, and the concentrations of
osteocalcin, calcitionin, calcium, phosphorus, and
hydroxyproline and the activity of alkaline
phosphatase were detected in serum. Results: The
serum concentrations of osteocalcin and calcitionin
and the activity of alkaline phosphatase decreased,
while the calcium, phosphorus and hydroxyproline
concentrations increased after the synergistic effect
of microwave radiation and hypergravity. Rana
sylvatica Le conte oil intervention inhibited
significantly the decrease of osteocalcin concentration
and restrained significantly the increases of
hydroxyproline and calcium concentrations in serum.
Conclusion: These results imply that the synergistic
effect of microwave radiation and hypergravity
inhibits osteogenesis and enhances osteolysis in rats
causing bone metabolic disturbance, while the injury
resulted from microwave radiation and hypergravity
could be protected by intervention with Rana
sylvatica Le conte oil and it provides an original
direction in the investigation of radioprotectors. Iran.
J. Radiat. Res., 2011 9(1): 1-8
Microwave radiation
hypergravity
osteogenesis
osteolysis
rana sylvatica Le conte oil.
2011
6
01
1
8
http://ijrr.com/article-1-726-en.pdf
33-727
2024-03-29
10.1002
International Journal of Radiation Research
Int J Radiat Res
2322-3243
2345-4229
10.61186/ijrr
2011
9
1
A comparative study on the increased radioresistance to lethal doses of gamma rays after exposure to microwave radiation and oral intake of flaxseed oil
S.M.J.
Mortazavi
mmortazavi@sums.ac.ir
M.A.
Mosleh-Shirazi
A.R.
Tavassoli
M.
Taheri
Z.
Bagheri
R.
Ghalandari
S.
Bonyadi
M.
Shafie
M.
Haghani
Background: Mobile phones, use electromagnetic
radiation in the microwave range. On the other
hand, there is only one report on radioprotective
effects of flaxseed oil. The aim of this study was to
investigate the effect of irradiation of rats with microwaves
and/or treatment with flaxseed oil on the
induction of adaptive response to a subsequent lethal
dose (LD) of gamma rays. Materials and Methods:
Eighty male rats were randomly divided into 6 groups
of 13-15 animals. The animals in the 1st to 5th groups
received microwave exposure, microwave+flaxseed
oil (dissolved in olive oil), flaxseed (continued after
LD), flaxseed, and olive oil. At day 5, all animals were
whole-body irradiated with a previously reported LD
50/30 of 8 Gy gamma radiation. The 6th group
(controls) received the same LD 50/30, but there was
not any other treatment before or after the LD.
Results: No death event was observed during days 1-9 after LD irradiation in either group. At day 10,
death events started in the 4th group. Thirty days after
irradiation of the animals, the survival fractions for
the control group, as expected, was 53.3% while
there was no death event in the 1st group (survival
rate of 100% in microwave-pretreated animals). The
survival fractions for the 2nd to 5th groups were
69.2%, 92.3%, 46.1%, and 61.5%, respectively.
Conclusion: While these findings open new horizons
in radiation protection, the radioresistance induced
by microwave radiations emitted by a mobile phone
may interfere with the outcome of any subsequent
therapeutic application of photons or radioisotopes.
Iran. J. Radiat. Res., 2011 9(1): 9-14
Microwave
adaptive response
nonionizing radiation
survival
rat.
2011
6
01
9
14
http://ijrr.com/article-1-727-en.pdf
33-728
2024-03-29
10.1002
International Journal of Radiation Research
Int J Radiat Res
2322-3243
2345-4229
10.61186/ijrr
2011
9
1
Monte Carlo estimation of electron contamination in a 18 MV clinical photon beam
M.
Allahverdi
M.
Zabihzadeh
M.R.
Ay
mohammadreza_ay@tums.ac.ir
S.R.
Mahdavi
M.
Shahriari
A.
Mesbahi
H.
Alijanzadeh
Background: The electron contamination may
reduce or even diminish the skin sparing property of
the megavoltage beam. The detailed characteristics
of contaminant electrons are presented for different
field sizes and cases. Materials and Methods: The
Monte Carlo code, MCNPX, has been used to
simulate 18 MV photon beam from a Varian
Linac-2300 accelerator. All dose measurements
were carried out using a PTW-MP2 scanner with an
ionization chamber (0.6 CC) at the water phantom.
Results: The maximum electron contaminant dose at
the surface ranged from 6.1 % for 5 × 5 cm2 to 38.8
% for 40 × 40 cm2 and at the depth of maximum
dose was 0.9 % up to 5.77 % for the 5 × 5 cm2 to the
40 × 40 cm2 field sizes, respectively. The additional
contaminant electron dose at the surface for the field
with tray increased 2.3 % for 10 × 10 cm2, 7.3 % for
20 × 20 cm2, and 21.4 % for 40 × 40 cm2 field size
comparing to the standard field without any
accessories. This increase for field with tray and
shaping block was 5.3 % and 13.3 % for 10 × 10 and
20 × 20 cm2, respectively, while, the electron
contamination decreased for the fields with wedge,
i.e. 2.2 % for the 10 × 10 cm2 field. Conclusion: The
results have provided more comprehensive knowledge
of the high-energy clinical beams and may be
useful to develop the accurate treatment planning
systems capable of taking the electron contamination
in to account. Iran. J. Radiat. Res., 2011 9(1): 15-28
Monte Carlo simulation
MV photon beam
electron contamination
relative absorbed dose.
2011
6
01
15
28
http://ijrr.com/article-1-728-en.pdf
33-729
2024-03-29
10.1002
International Journal of Radiation Research
Int J Radiat Res
2322-3243
2345-4229
10.61186/ijrr
2011
9
1
Evaluation of the electron energy fluence and angular distributions from a clinical accelerator. A BEAMnrc Monte Carlo study
N.
Jabbari
njabbarimp@gmail.com
H.
Nedaie
A.
Zeinali
Background: Understanding of the incident electron
energy and angular distributions from clinical
electron accelerators (linacs) is important for
dosimetry and treatment planning. The most
important goals of this study were to evaluate the
energy fluence and angular distributions of electron
beams from a Neptun 10PC linac using the Monte
Carlo (MC) code. Materials and Methods: The linac
electron beams (6, 8, and 10 MeV) were modeled,
using the BEAMnrc MC system based on the Electron-
Gamma-Shower (EGSnrc) code. Central axis depthdose
curves and dose profiles of the electron beams
were measured experimentally, and calculated with
the MC for three field sizes. In order to benchmarking
the simulated models, the calculated and measured
dose distributions were compared with Kolmogorov–
Smirnov (KS) statistical test. Results: The KS test
indicated that the calculated percent depth dose
(PDD) and dose profile values for the three electron
beam energies well agree with measured data (within
2% everywhere). The results also showed good
agreement (discrepancies smaller than 1%) between
the simulated electron energy parameters and those
calculated from energy-range relationships using
equations for the reference field size. Conclusion: The
results showed that there was no significant
difference between energy fluence curves of each
electron beam energy at different field sizes. In
addition, the results of the calculated angular
distributions showed that the direction of the electron
emerged from the treatment head and trimmer
applicators were in forward direction. Iran. J. Radiat.
Res., 2011 9(1): 29-36
Linac
electron beam
energy fluence
angular distribution
Monte Carlo.
2011
6
01
29
36
http://ijrr.com/article-1-729-en.pdf
33-730
2024-03-29
10.1002
International Journal of Radiation Research
Int J Radiat Res
2322-3243
2345-4229
10.61186/ijrr
2011
9
1
Radiation attenuation of boron doped clay for 662, 1173 and 1332 keV gamma rays
I.
Akkurt
iskender@fef.sdu.edu.tr
H.
Canakci
Background: Radiation shielding properties is an
important for a material wish can be used the photon
attenuation coefficients of clay produced using
different rate of boron have been measured for the
purpose of radioactive waste disposal. Materials and
Methods: The measurement has been performed
using gamma spectrometer contains NaI (Tl) detector
at the photon energies of 662, 1173 and 1332 keV.
The mean free path and transmission rate of the
samples were also obtained. Results: From the
measurement of linear attenuation coefficients it was
found that using boron in the clay increased the
linear attenuation coefficients. Conclusion: It can be
concluded from this work that the boron is effective
to shield radiation and it can be used for storing of
nuclear waste. Iran. J. Radiat. Res., 2011 9(1): 37-40
Photon attenuation coefficient
radioactive waste
boron
clay
NaI (Tl).
2011
6
01
37
40
http://ijrr.com/article-1-730-en.pdf
33-731
2024-03-29
10.1002
International Journal of Radiation Research
Int J Radiat Res
2322-3243
2345-4229
10.61186/ijrr
2011
9
1
Polonium-210 activity in human hair samples and factors affecting its accumulation
C.R.
Rathi
E.M.
Ross
S.G.
Wesley
godwinwesley@yahoo.com
Background: Due to the presence of radioactive
minerals such as monazite, the beach sand of the
west coast of Kanyakumari exhibits high natural
background radiation. Hair is a good indicator of
radionuclides in the human body. An attempt is
taken to measure the 210Po activity in human hair
samples and the factors affecting it. Material and
Methods: 210Po activity was analysed in 47 individuals
including males and females living in Kanyakumari
district, Tamil Nadu, India. The activities were
measured using a Nucleonix® Radiation Counting
System (RC 605A). Results: The activity was in the
range of 9.89 ± 4.43 to 58.85 ± 6.27 milli Becquerel
per gram. 210Po activity was observed in the hair
samples when compared to the global values were
comparatively higher. Conclusion: Hair samples
obtained from the users of home-made and medicinal
oil had higher concentration of 210Po compared to
that of people using branded oils. These high values
may be attributed to the hair oil usage and this is a
topic of interest for future studies. Iran. J. Radiat. Res.,
2011 9(1): 41-47
210Po
human hair
indicator
cosmetics
accumulation.
2011
6
01
41
47
http://ijrr.com/article-1-731-en.pdf
33-732
2024-03-29
10.1002
International Journal of Radiation Research
Int J Radiat Res
2322-3243
2345-4229
10.61186/ijrr
2011
9
1
Evaluation of dosimetric characteristics of a grid block fabricated for Mega-voltage grid therapy purposes
K.
Ghazi-khanlou Sani
ghazi@umsha.ac.ir
M.
Mohammadi
A.
Eskandarlo
H.
Gholam-hosseinian
Background: In conventional radiation therapy,
regarding normal tissue tolerance, the treatment of
bulk tumors is one of the remaining challenges. Grid
Radiation Therapy (GRT) is a technique to deliver high
doses, approximately 15 – 20 Gy per fraction, to several
small volumes located in a large radiation field.
This can be performed using a grid block. The current
work has concentrated on the dosimetric characteristics
of a designed mega-voltage grid, used for a
unique treatment modality. Materials and Methods:
All measurements performed using a Neptune linear
accelerator (9 MV photon beam). A square 16 × 16
array grid block was designed and fabricated. Several
dosimetric characteristics including: depth dose,
Valley To Peak (VTP) ratio, and grid out-put factor
were evaluated using a calibrated diode dosimeter for
a range of radiation fields. Results: The percent depth
dose curves, measured in the presence of grid block,
lie within those measured for the corresponding open
field and a narrow beam. At the Dmax, the VTP ratio
was found to be within 17% - 28%, while these ranges
between 23% - 35% at a depth of 10 cm. The grid out
-put factor found to be 0.78 and it slightly decreases
with increasing of radiation field size. Conclusion:
The VTP ratio found to be dependent strongly on the
grid design and manufacturing properties. However,
other parameters such as radiation field size and the
depth of measurement should also be addressed as
important factors. The measured dosimetric characteristics
of grid block indicate that the mega-voltage
grid therapy can be applied as a possible clinical
modality for palliative cases. Iran. J. Radiat. Res., 2011
9(1): 49-56
Grid therapy
palliation
mega-voltage
radiation dosimetry.
2011
6
01
49
56
http://ijrr.com/article-1-732-en.pdf
33-733
2024-03-29
10.1002
International Journal of Radiation Research
Int J Radiat Res
2322-3243
2345-4229
10.61186/ijrr
2011
9
1
Radon exhalation rates from stone and soil samples of Aravali hills in India
R.P.
Chauhan
chauhanrpc@gmail.com
Background: The most popular building
materials are soil bricks and different types of stones.
Radon is released into ambient air from soil and
stones due to ubiquitous uranium and radium in
them, thus increasing the airborne radon concentration.
The radioactivity in soils is related to radioactivity
in the rocks from which the soil is formed. In the
present investigation, the radon emanated from soil
and stone samples collected from different locations
of Aravali range of hills in the Haryana state of
Northern India has been estimated. Materials and
Methods: For the measurement of radon concentration
emanated from these samples, alpha-sensitive
LR-115 type II plastic track detectors have been
used. The alpha particles emitted from the radon
form tracks in these detectors. After chemical etching
the track density of registered tracks is used to
calculate radon concentration and exhalation rates of
radon using required formulae. Results: The radon
concentration in stone samples collected from Aravali
range of hills varied from 729 Bq m-3 to 1958 Bq m-3
with an average of 1440 ± 134 Bq m-3 whereas it
varied from 806 Bq m-3 to 1325 Bq m-3 with an
average of 1040 ± 101 Bq m-3 in case of soil
samples. Based upon the data, the mass and the
surface exhalation rates of radon emanated from
them have also been calculated. Conclusion: The
measurements indicate normal to some higher levels
of radon concentration emanated from the samples
collected from Aravali range of hills of north India.
Iran. J. Radiat. Res., 2011 9(1): 57-61
Radioactivity
radon concentration
nuclear tracks
exhalation rates
stone
soil.
2011
6
01
57
61
http://ijrr.com/article-1-733-en.pdf