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Fulltext Enhancement of Dose Response and Nuclear Magnetic Resonance Image of PAGAT Polymer Gel Dosimeter by Adding Silver Nanoparticles

Sabbaghizadeh R, Shamsudin R, Deyhimihaghighi N, Sedghi A

PLoS One, 2017;12(1):e0168737.
PMID: 28060829 DOI: 10.1371/journal.pone.0168737

In the present study, the normoxic polyacrylamide gelatin and tetrakis hydroxy methyl phosphoniun chloride (PAGAT) polymer gel dosimeters were synthesized with and without the presence of silver (Ag) nanoparticles. The amount of Ag nanoparticles varied from 1 to 3 ml with concentration 3.14 g/l, thus forming two types of PAGAT polymer gel dosimeters before irradiating them with 6 to 25 Gy produced by 1.25-MeV 60Co gamma rays. In this range, the predominant gamma ray interaction with matter is by Compton scattering effect, as the photoelectric absorption effect diminishes. MRI was employed when evaluating the polymerization of the dosimeters and the gray scale of the MRI film was determined via an optical densitometer. Subsequent analyses of optical densities revealed that the extent of polymerization increased with the increase in the absorbed dose, while the increase of penetration depth within the dosimeters has a reverse effect. Moreover, a significant increase in the optical density-dose response (11.82%) was noted for dosimeters containing 2 ml Ag nanoparticles.

Matched MeSH terms: Dose-Response Relationship, Radiation*
Effects of different doses of gamma irradiation on oxygen and water vapour transmission rate of preserved human amniotic membrane

Zahari NK, Sheikh Ab Hamid S, Yusof N

Cell Tissue Bank, 2015 Mar;16(1):55-63.
PMID: 24647964 DOI: 10.1007/s10561-014-9438-9

Preserved human amniotic membrane either air dried or glycerol preserved has been used effectively to treat superficial and partial thickness wounds without leaving any obvious hypertrophic scar. The preserved amnion, sterilised by ionising radiation, is known as an effective barrier for heat, fluid and protein loss while adheres nicely on wound. Air drying slightly reduced the oxygen transmission rate (OTR) of the amnion and the value significantly dropped after 15 kGy (p < 0.05). Glycerol preservation significantly reduced (p < 0.05) the OTR indicating less oxygen transmitted through the well structured cells of the amnion. Increase in the OTR with the increasing radiation doses up to 35 kGy possibly due to direct effects of radiation that resulted in large intercellular gaps. Both preservation methods significantly increased (p < 0.05) the water vapour transmission rate (WVTR). However, the low WVTR in the air dried amnion at 15 and 25 kGy was postulated due to cross-linking of collagen. Changes in the biophysical properties can be linked to direct and indirect effects of radiation on collagen bundles. The radiation dose of 25 kGy caused no adverse effect on biophysical properties hence it is still acceptable to sterilize both the air dried and the glycerol preserved amnions.

Matched MeSH terms: Dose-Response Relationship, Radiation
Fulltext Dose enhancement effects by different size of gold nanoparticles under irradiation of megavoltage photon beam

Wan Nordiana W Abd Rahman, Raizulnasuha Ab Rashid, Mahfuzah Muhammad, Khairunisak Abdul Razak, Norhayati Dollah, Moshi Geso

Jurnal Sains Nuklear Malaysia, 2018;30(2):23-29.
MyJurnal

Gold nanoparticles (AuNPs) have been extensively investigated as dose enhancement agent to increase the lethal dose to the tumours while minimizing dose to the normal tissue. Their intriguing properties and characteristics such as small size and shape provide favorable option in increasing radiotherapy therapeutic efficiency. In this study, the effects of AuNPs size on the dose enhancement effects irradiated under megavoltage photon beams were investigated. The study was conducted in-vitro on HeLa cells using AuNPs of 5 nm and 15 nm sizes. The cells samples were incubated with AuNPs and irradiated with photon beam of energy 6 MV and 10 MV at 100 cm SSD and 10 cm x 10 cm field size. Clonogenic assay were performed to observe the dose enhancement effects on cell survival. Dose enhancement factor (DEF) were extrapolated and evaluated from the cell survival curves. The results show that both sizes of AuNPs produce dose enhancement with the larger size AuNPs of 15 nm produce more dose enhancement compare to 5 nm AuNPs for 6 MV photon beam. Dose enhancements were observed for 10 MV photon beams but DEF for both sizes AuNPs shows no differences. In conclusion, larger size AuNPs produce higher dose enhancement compare to small size of AuNPs which conclude that nanoparticles size is important factor that need to be taken into account for AuNPs to be applied in radiotherapy.

Matched MeSH terms: Dose-Response Relationship, Radiation
Fulltext Multicentre dose audit for clinical trials of radiation therapy in Asia

Mizuno H, Fukuda S, Fukumura A, Nakamura YK, Jianping C, Cho CK, et al.

J Radiat Res, 2017 May 01;58(3):372-377.
PMID: 27864507 DOI: 10.1093/jrr/rrw108

A dose audit of 16 facilities in 11 countries has been performed within the framework of the Forum for Nuclear Cooperation in Asia (FNCA) quality assurance program. The quality of radiation dosimetry varies because of the large variation in radiation therapy among the participating countries. One of the most important aspects of international multicentre clinical trials is uniformity of absolute dose between centres. The National Institute of Radiological Sciences (NIRS) in Japan has conducted a dose audit of participating countries since 2006 by using radiophotoluminescent glass dosimeters (RGDs). RGDs have been successfully applied to a domestic postal dose audit in Japan. The authors used the same audit system to perform a dose audit of the FNCA countries. The average and standard deviation of the relative deviation between the measured and intended dose among 46 beams was 0.4% and 1.5% (k = 1), respectively. This is an excellent level of uniformity for the multicountry data. However, of the 46 beams measured, a single beam exceeded the permitted tolerance level of ±5%. We investigated the cause for this and solved the problem. This event highlights the importance of external audits in radiation therapy.

Matched MeSH terms: Dose-Response Relationship, Radiation*
Fulltext Germination response of MR 219 rice variety to different exposure times and periods of 2450 MHz microwave frequency

Talei D, Valdiani A, Maziah M, Mohsenkhah M

ScientificWorldJournal, 2013;2013:408026.
PMID: 24307869 DOI: 10.1155/2013/408026

Germination is a key process in plants' phenological cycles. Accelerating this process could lead to improvment of the seedling growth as well as the cultivation efficiency. To achieve this, the effect of microwave frequency on the germination of rice seeds was examined. The physiological feedbacks of the MR 219 rice variety in terms of seed germination rate (GR), germination percentage (GP), and mean germination time (MGT) were analyzed by exposing its seeds to 2450 MHz of microwave frequency for one, four, seven, and ten hours. It was revealed that exposing the seeds to the microwave frequency for 10 hours resulted in the highest GP. This treatment led to 100% of germination after three days with a mean germination time of 2.1 days. Although the other exposure times of microwave frequency caused the moderate effects on germination with a GP(a3) ranged from 93% to 98%, they failed to reduce the MGT(a3). The results showed that ten-hour exposure times of microwave frequency for six days significantly facilitated and improved the germination indices (primary shoot and root length). Therefore, the technique is expected to benefit the improvement of rice seed germination considering its simplicity and efficacy in increasing the germination percentage and rate as well as the primary shoot and root length without causing any environmental toxicity.

Matched MeSH terms: Dose-Response Relationship, Radiation
Investigation of the dependence of inactivation coefficient on pertinent physical quality parameters to low doses ionizing radiation

Yousif AA, Bin Bahari I, Yasir MS

Curr Radiopharm, 2012 Jan;5(1):34-7.
PMID: 21864247

Inactivation constant for V79 cells has been extracted from radiobiology experiments that utilize charged particles to irradiate mammal cells in vitro. Physical parameters such as effective charge, radiation mean free path and linear ionization which characterized protons and heluim-4 particles are determined using of standard values. The relationship between inactivation constant α and physical quality parameters have been determined, in this research, for protons and heluim-4 particles. This approach allows getting the characteristic biological response of inactivation of V79 cells in terms of each selected physical quality parameter. The best regression models are formulated for each obtained relationship.

Matched MeSH terms: Dose-Response Relationship, Radiation
Characterisation of a Ferrous Agarose Xylenol (FAX) gel for radiotherapy dose measurement

Leong LH, Kandaiya S, Seng NB

Australas Phys Eng Sci Med, 2007 Jun;30(2):135-40.
PMID: 17682403

The oxidation of ferrous to ferric ions due to ionizing radiation has been used for chemical dosimetry since 1927. The introduction of metal indicator dye xylenol orange (XO) sensitises the measurement of ferric ion yield. A ferrous sulphate- agarose- xylenol orange (FAX) gel was prepared and the gel then exposed to dose ranging from 0.2 to 10 Gy using various high energy photon and electron beams from a linear accelerator. Some general characteristics of FAX such as energy dependence, optical density (OD)-dose relationship, reproducibility and auto-oxidation of ferrous ions were analysed. The radiation yield G of the gel was calculated for gels prepared in oxygen and in air and the values were 46.3 +/- 2.1 and 40.9 +/- 1.4 Fe3+ per 100 eV for photons respectively. However for stock gel which was kept for 5 days pre-irradiation the G value decreased to 36.6 +/- 1.1. The gel shows linearity in OD-dose relationship, energy independence and reproducibility over the dose range investigated. Auto-oxidation of ferrous ions resulted in optical density changes of less than 1.5% per day.

Matched MeSH terms: Dose-Response Relationship, Radiation
Fulltext The Thermoluminescence Response of Ge-Doped Flat Fibers to Gamma Radiation

Nawi SN, Wahib NF, Zulkepely NN, Amin YB, Min UN, Bradley DA, et al.

Sensors (Basel), 2015;15(8):20557-69.
PMID: 26307987 DOI: 10.3390/s150820557

Study has been undertaken of the thermoluminescence (TL) yield of various tailor-made flat cross-section 6 mol% Ge-doped silica fibers, differing only in respect of external dimensions. Key TL dosimetric characteristics have been investigated, including glow curves, dose response, sensitivity, fading and reproducibility. Using a (60)Co source, the samples were irradiated to doses within the range 1 to 10 Gy. Prior to irradiation, the flat fibers were sectioned into 6 mm lengths, weighed, and annealed at 400 °C for 1 h. TL readout was by means of a Harshaw Model 3500 TLD reader, with TLD-100 chips (LiF:Mg, Ti) used as a reference dosimeter to allow the relative response of the fibers to be evaluated. The fibers have been found to provide highly linear dose response and excellent reproducibility over the range of doses investigated, demonstrating high potential as TL-mode detectors in radiation medicine applications. Mass for mass, the results show the greatest TL yield to be provided by fibers of the smallest cross-section, analysis indicating this to be due to minimal light loss in transport of the TL through the bulk of the silica medium.

Matched MeSH terms: Dose-Response Relationship, Radiation
Fulltext In Vitro Mean Red Blood Cell Volume Change Induced by Diode Pump Solid State Low-Level Laser of 405 nm

Musawi MS, Jafar MS, Al-Gailani BT, Ahmed NM, Suhaimi FM, Suardi N

Photomed Laser Surg, 2016 May;34(5):211-4.
PMID: 26966989 DOI: 10.1089/pho.2015.4043

OBJECTIVE: This study was conducted to investigate the effects of low-level laser (LLL) doses on human red blood cell volume. The effects of exposure to a diode pump solid state (DPSS) (λ = 405 nm) laser were observed.
BACKGROUND DATA: The response of human blood to LLL irradiation gives important information about the mechanism of interaction of laser light with living organisms. Materials and methods Blood samples were collected into ethylenediaminetetraacetic acid (EDTA)-containing tubes, and each sample was divided into two equal aliquots, one to serve as control and the other for irradiation. The aliquot was subjected to laser irradiation for 20, 30, 40, or 50 min at a fixed power density of 0.03 W/cm(2). Mean cell volume (MCV) and red blood cell (RBC) counts were measured immediately after irradiation using a computerized hemtoanalyzer.
RESULTS: Significant decrease in RBC volume (p

Matched MeSH terms: Dose-Response Relationship, Radiation
Fulltext Electronic Characterization of Au/DNA/ITO Metal-Semiconductor-Metal Diode and Its Application as a Radiation Sensor

Al-Ta'ii HM, Periasamy V, Amin YM

PLoS One, 2016;11(1):e0145423.
PMID: 26799703 DOI: 10.1371/journal.pone.0145423

Deoxyribonucleic acid or DNA molecules expressed as double-stranded (DSS) negatively charged polymer plays a significant role in electronic states of metal/silicon semiconductor structures. Electrical parameters of an Au/DNA/ITO device prepared using self-assembly method was studied by using current-voltage (I-V) characteristic measurements under alpha bombardment at room temperature. The results were analyzed using conventional thermionic emission model, Cheung and Cheung's method and Norde's technique to estimate the barrier height, ideality factor, series resistance and Richardson constant of the Au/DNA/ITO structure. Besides demonstrating a strongly rectifying (diode) characteristic, it was also observed that orderly fluctuations occur in various electrical parameters of the Schottky structure. Increasing alpha radiation effectively influences the series resistance, while the barrier height, ideality factor and interface state density parameters respond linearly. Barrier height determined from I-V measurements were calculated at 0.7284 eV for non-radiated, increasing to about 0.7883 eV in 0.036 Gy showing an increase for all doses. We also demonstrate the hypersensitivity phenomena effect by studying the relationship between the series resistance for the three methods, the ideality factor and low-dose radiation. Based on the results, sensitive alpha particle detectors can be realized using Au/DNA/ITO Schottky junction sensor.

Matched MeSH terms: Dose-Response Relationship, Radiation
Fulltext On the Use of Optically Stimulated Luminescent Dosimeter for Surface Dose Measurement during Radiotherapy

Yusof FH, Ung NM, Wong JH, Jong WL, Ath V, Phua VC, et al.

PLoS One, 2015;10(6):e0128544.
PMID: 26052690 DOI: 10.1371/journal.pone.0128544

This study was carried out to investigate the suitability of using the optically stimulated luminescence dosimeter (OSLD) in measuring surface dose during radiotherapy. The water equivalent depth (WED) of the OSLD was first determined by comparing the surface dose measured using the OSLD with the percentage depth dose at the buildup region measured using a Markus ionization chamber. Surface doses were measured on a solid water phantom using the OSLD and compared against the Markus ionization chamber and Gafchromic EBT3 film measurements. The effect of incident beam angles on surface dose was also studied. The OSLD was subsequently used to measure surface dose during tangential breast radiotherapy treatments in a phantom study and in the clinical measurement of 10 patients. Surface dose to the treated breast or chest wall, and on the contralateral breast were measured. The WED of the OSLD was found to be at 0.4 mm. For surface dose measurement on a solid water phantom, the Markus ionization chamber measured 15.95% for 6 MV photon beam and 12.64% for 10 MV photon beam followed by EBT3 film (23.79% and 17.14%) and OSLD (37.77% and 25.38%). Surface dose increased with the increase of the incident beam angle. For phantom and patient breast surface dose measurement, the response of the OSLD was higher than EBT3 film. The in-vivo measurements were also compared with the treatment planning system predicted dose. The OSLD measured higher dose values compared to dose at the surface (Hp(0.0)) by a factor of 2.37 for 6 MV and 2.01 for 10 MV photon beams, respectively. The measurement of absorbed dose at the skin depth of 0.4 mm by the OSLD can still be a useful tool to assess radiation effects on the skin dermis layer. This knowledge can be used to prevent and manage potential acute skin reaction and late skin toxicity from radiotherapy treatments.

Matched MeSH terms: Dose-Response Relationship, Radiation
Synchronous flowering of the rubber tree (Hevea brasiliensis) induced by high solar radiation intensity

Yeang HY

New Phytol, 2007;175(2):283-9.
PMID: 17587376

How tropical trees flower synchronously near the equator in the absence of significant day length variation or other meteorological cues has long been a puzzle. The rubber tree (Hevea brasiliensis) is used as a model to investigate this phenomenon. The annual cycle of solar radiation intensity is shown to correspond closely with the flowering of the rubber tree planted near the equator and in the subtropics. Unlike in temperate regions, where incoming solar radiation (insolation) is dependent on both day length and radiation intensity, insolation at the equator is due entirely to the latter. Insolation at the upper atmosphere peaks twice a year during the spring and autumn equinoxes, but the actual solar radiation that reaches the ground is attenuated to varying extents in different localities. The rubber tree shows one or two flowering seasons a year (with major and minor seasons in the latter) in accordance with the solar radiation intensity received. High solar radiation intensity, and in particular bright sunshine (as distinct from prolonged diffuse radiation), induces synchronous anthesis and blooming in Hevea around the time of the equinoxes. The same mechanism may be operational in other tropical tree species.

Matched MeSH terms: Dose-Response Relationship, Radiation
Characterization and biocompatibility evaluation of bacterial cellulose-based wound dressing hydrogel: effect of electron beam irradiation doses and concentration of acrylic acid

Mohamad N, Buang F, Mat Lazim A, Ahmad N, Martin C, Mohd Amin MCI

J Biomed Mater Res B Appl Biomater, 2017 Nov;105(8):2553-2564.
PMID: 27690276 DOI: 10.1002/jbm.b.33776

The use of bacterial cellulose (BC)-based hydrogel has been gaining attention owing to its biocompatibility and biodegradability. This study was designed to investigate the effect of radiation doses and acrylic acid (AA) composition on in vitro and in vivo biocompatibility of BC/AA as wound dressing materials. Physical properties of the hydrogel, that is, thickness, adhesiveness, rate of water vapor transmission, and swelling were measured. Moreover, the effect of these parameters on skin irritation and sensitization, blood compatibility, and cytotoxicity was studied. Increased AA content and irradiation doses increased the thickness, crosslinking density, and improved the mechanical properties of the hydrogel, but reduced its adhesiveness. The swelling capacity of the hydrogel increased significantly with a decrease in the AA composition in simulated wound fluid. The water vapor permeability of polymeric hydrogels was in the range of 2035-2666 [g/(m-2 day-1 )]. Dermal irritation and sensitization test demonstrated that the hydrogel was nonirritant and nonallergic. The BC/AA hydrogel was found to be nontoxic to primary human dermal fibroblast skin cells with viability >88% and was found to be biocompatible with blood with a low hemolytic index (0.80-1.30%). Collectively, these results indicate that these hydrogels have the potential to be used as wound dressings. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2553-2564, 2017.

Matched MeSH terms: Dose-Response Relationship, Radiation
Effects of low-level laser irradiation on human blood lymphocytes in vitro

Al Musawi MS, Jaafar MS, Al-Gailani B, Ahmed NM, Suhaimi FM, Suardi N

Lasers Med Sci, 2017 Feb;32(2):405-411.
PMID: 28044209 DOI: 10.1007/s10103-016-2134-1

Low-level laser irradiation (LLLI) has various effects on cultured human lymphocytes in vitro, but little is known about such effects in whole blood. This study investigated whether LLLI affected lymphocyte count in human whole blood in vitro. A total number of 130 blood samples were collected from apparently healthy adult patients through venipuncture into tubes containing EDTA. Each sample was divided into two equal aliquots to be used as a non-irradiated control sample and an irradiated sample. The irradiated aliquot was subjected to laser wavelengths of 405, 589, and 780 nm with different fluences of 36, 54, 72, and 90 J/cm(2), at a fixed irradiance of 30 mW/cm(2). A paired student t test was used to compare between non-irradiated and irradiated samples. The lymphocyte counts were measured using a computerized hematology analyzer and showed a significant (P

Matched MeSH terms: Dose-Response Relationship, Radiation
Dosimetric characterisation of the optically-stimulated luminescence dosimeter in cobalt-60 high dose rate brachytherapy system

Rejab M, Wong JHD, Jamalludin Z, Jong WL, Malik RA, Wan Ishak WZ, et al.

Australas Phys Eng Sci Med, 2018 Jun;41(2):475-485.
PMID: 29756166 DOI: 10.1007/s13246-018-0647-6

This study investigates the characteristics and application of the optically-stimulated luminescence dosimeter (OSLD) in cobalt-60 high dose rate (HDR) brachytherapy, and compares the results with the dosage produced by the treatment planning system (TPS). The OSLD characteristics comprised linearity, reproducibility, angular dependence, depth dependence, signal depletion, bleaching rate and cumulative dose measurement. A phantom verification exercise was also conducted using the Farmer ionisation chamber and in vivo diodes. The OSLD signal indicated a supralinear response (R2 = 0.9998). It exhibited a depth-independent trend after a steep dose gradient region. The signal depletion per readout was negligible (0.02%), with expected deviation for angular dependence due to off-axis sensitive volume, ranging from 1 to 16%. The residual signal of the OSLDs after 1 day bleached was within 1.5%. The accumulated and bleached OSLD signals had a standard deviation of ± 0.78 and ± 0.18 Gy, respectively. The TPS was found to underestimate the measured doses with deviations of 5% in OSLD, 17% in the Farmer ionisation chamber, and 7 and 8% for bladder and rectal diode probes. Discrepancies can be due to the positional uncertainty in the high-dose gradient. This demonstrates a slight displacement of the organ at risk near the steep dose gradient region will result in a large dose uncertainty. This justifies the importance of in vivo measurements in cobalt-60 HDR brachytherapy.

Matched MeSH terms: Dose-Response Relationship, Radiation
Inclusion of dosimetric data as covariates in toxicity-related radiogenomic studies : A systematic review

Yahya N, Chua XJ, Manan HA, Ismail F

Strahlenther Onkol, 2018 08;194(8):780-786.
PMID: 29774397 DOI: 10.1007/s00066-018-1303-5

PURPOSE: This systematic review evaluates the completeness of dosimetric features and their inclusion as covariates in genetic-toxicity association studies.
MATERIALS AND METHODS: Original research studies associating genetic features and normal tissue complications following radiotherapy were identified from PubMed. The use of dosimetric data was determined by mining the statement of prescription dose, dose fractionation, target volume selection or arrangement and dose distribution. The consideration of the dosimetric data as covariates was based on the statement mentioned in the statistical analysis section. The significance of these covariates was extracted from the results section. Descriptive analyses were performed to determine their completeness and inclusion as covariates.
RESULTS: A total of 174 studies were found to satisfy the inclusion criteria. Studies published ≥2010 showed increased use of dose distribution information (p = 0.07). 33% of studies did not include any dose features in the analysis of gene-toxicity associations. Only 29% included dose distribution features as covariates and reported the results. 59% of studies which included dose distribution features found significant associations to toxicity.
CONCLUSION: A large proportion of studies on the correlation of genetic markers with radiotherapy-related side effects considered no dosimetric parameters. Significance of dose distribution features was found in more than half of the studies including these features, emphasizing their importance. Completeness of radiation-specific clinical data may have increased in recent years which may improve gene-toxicity association studies.

Matched MeSH terms: Dose-Response Relationship, Radiation*
Fulltext An evaluation of dose equivalence between synchrotron microbeam radiation therapy and conventional broad beam radiation using clonogenic and cell impedance assays

Ibahim MJ, Crosbie JC, Yang Y, Zaitseva M, Stevenson AW, Rogers PA, et al.

PLoS One, 2014;9(6):e100547.
PMID: 24945301 DOI: 10.1371/journal.pone.0100547

High-dose synchrotron microbeam radiation therapy (MRT) has shown the potential to deliver improved outcomes over conventional broadbeam (BB) radiation therapy. To implement synchrotron MRT clinically for cancer treatment, it is necessary to undertake dose equivalence studies to identify MRT doses that give similar outcomes to BB treatments.

Matched MeSH terms: Dose-Response Relationship, Radiation
Fulltext Effect of acute gamma irradiation on Curcuma alismatifolia varieties and detection of DNA polymorphism through SSR marker

Taheri S, Abdullah TL, Ahmad Z, Abdullah NA

Biomed Res Int, 2014;2014:631813.
PMID: 24719878 DOI: 10.1155/2014/631813

The effects of eight different doses (0, 10, 20, 25, 35, 40, 60, and 100 Gy) of acute gamma irradiation on 44 (three varieties of Curcuma alismatifolia: Chiang Mai Red, Sweet Pink, Kimono Pink, and one Curcuma hybrid (Doi Tung 554) individual plants were investigated. Radiation sensitivity tests revealed that the LD50 values of the varieties were achieved at 21 Gy for Chiang Mai Red, 23 Gy for Sweet Pink, 25 Gy for Kimono Pink, and 28 Gy for Doi Tung 554. From the analysis of variance (ANOVA), significant variations were observed for vegetative traits, flowering development, and rhizome characteristics among the four varieties of Curcuma alismatifolia and dose levels as well as the dose × variety interaction. In irradiated plants, the leaf length, leaf width, inflorescence length, the number of true flowers, the number of pink bracts, number of shoots, plant height, rhizome size, number of storage roots, and number of new rhizomes decreased significantly (P < 0.05) as the radiation dose increased. The cophenetic correlation coefficient (CCC) between genetic dissimilarity matrix estimated from the morphological characters and the UPGMA clustering method was r = 0.93, showing a proof fit. In terms of genetic variation among the acutely irradiated samples, the number of presumed alleles revealed by simple sequence repeats ranged from two to seven alleles with a mean value of 3.1, 4.5, and 5.3 alleles per locus for radiation doses of 0, 10, and 20 Gy, respectively. The average values of the effective number of alleles, Nei's gene diversity, and Shannon's information index were 2.5-3.2, 0.51-0.66, and 0.9-1.3, respectively. The constructed dendrogram grouped the entities into seven clusters. Principal component analysis (PCA) supported the clustering results. Consequently, it was concluded that irradiation with optimum doses of gamma rays efficiently induces mutations in Curcuma alismatifolia varieties.

Matched MeSH terms: Dose-Response Relationship, Radiation
A 45-degree radiographic method for measuring the neck shaft angle and anteversion of the femur: a pilot study

Teo PC, Kassim AY, Thevarajan K

J Orthop Surg (Hong Kong), 2013 Dec;21(3):340-6.
PMID: 24366797

To propose a novel method to measure the neck shaft angle and anteversion of the femur using anteroposterior and 45-degree oblique radiographs.

Matched MeSH terms: Dose-Response Relationship, Radiation
Fulltext Morphological and biochemical responses of Oryza sativa L. (cultivar MR219) to ion beam irradiation

Ling AP, Ung YC, Hussein S, Harun AR, Tanaka A, Yoshihiro H

J Zhejiang Univ Sci B, 2013 Dec;14(12):1132-43.
PMID: 24302713 DOI: 10.1631/jzus.B1200126

Heavy ion beam, which has emerged as a new mutagen in the mutation breeding of crops and ornamental plants, is expected to result in the induction of novel mutations. This study investigates the morphological and biochemical responses of Oryza sativa toward different doses of carbon ion beam irradiation.

Matched MeSH terms: Dose-Response Relationship, Radiation

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