Cosmic Radiation Exposure of Future Hypersonic Flight Missions.

PubMed

Koops, L

2017-06-15

Cosmic radiation exposure in air traffic grows with flight altitude, geographical latitude and flight time. For future high-speed intercontinental point-to-point travel, the trade-off between reduced flight time and enhanced dose rate at higher flight altitudes is investigated. Various representative (partly) hypersonic cruise missions are considered and in dependence on solar activity the integral route dose is calculated for envisaged flight profiles and trajectories. Our results are compared to those for corresponding air connections served by present day subsonic airliners. During solar maximum, we find a significant reduction in route dose for all considered high-speed missions compared to the subsonic reference. However, during solar minimum, comparable or somewhat larger doses result on transpolar trajectories with (partly) hypersonic cruise at Mach 5. Both solar activity and routing are hence found to determine, whether passengers can profit from shorter flight times in terms of radiation exposure, despite of altitude-induced higher dose rates. Yet, aircrews with fixed number of block hours are always subject to larger annual doses, which in the considered cases take values up to five times the reference. We comment on the implications of our results for route planning and aviation decision-making in the absence of radiation shielding solutions. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Residues and dissipation kinetics of carbendazim and diethofencarb in tomato (Lycopersicon esculentum Mill.) and intake risk assessment.

PubMed

Li, Huidong; du, Hongxia; Fang, Liping; Dong, Zhan; Guan, Shuai; Fan, Wenjing; Chen, Zilei

2016-06-01

Dissipation behaviors and residues of carbendazim and diethofencarb in combination in tomato were investigated. The half-lives were 2.1-3.4 days for carbendazim, and 1.8-3.2 days for diethofencarb at a dose of 1.5 times of the recommended dosage. The residues of carbendazim and diethofencarb were below the maximum residue limits (MRLs) in China one day after application of the combination. The ultimate residues were significantly lower than the maximum permissible intake (MPI) in China at the recommended high dose for both child and adult. The values of the maximum dietary exposure for carbendazim and diethofencarb were 0.26 and 0.27 mg per person per day, respectively. The theoretical maximum daily intake (TMDI) values for carbendazim and diethofencarb were 1.5 and 0.5 mg/day, respectively. The dietary exposure was lower than the MPI, which indicates the harvested tomato samples under the experimental conditions (open field) are safe for human consumption at the recommended high dosage of the wettable powder. Copyright © 2016 Elsevier Inc. All rights reserved.

47 CFR 73.525 - TV Channel 6 protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... (4) The maximum permissible effective radiated power (ERP) and antenna height may be adjusted for..., the maximum permissible vertically polarized ERP will be the maximum horizontally polarized ERP... it does not. (ii) If the applicant chooses to use mixed polarity, the permissible ERP is as follows...

Comparison of dose volume parameters evaluated using three forward planning – optimization techniques in cervical cancer brachytherapy involving two applicators

PubMed Central

Basu-Roy, Somapriya; Kar, Sanjay Kumar; Das, Sounik; Lahiri, Annesha

2017-01-01

Purpose This study is intended to compare dose-volume parameters evaluated using different forward planning- optimization techniques, involving two applicator systems in intracavitary brachytherapy for cervical cancer. It looks for the best applicator-optimization combination to fulfill recommended dose-volume objectives in different high-dose-rate (HDR) fractionation schedules. Material and methods We used tandem-ring and Fletcher-style tandem-ovoid applicator in same patients in two fractions of brachytherapy. Six plans were generated for each patient utilizing 3 forward optimization techniques for each applicator used: equal dwell weight/times (‘no optimization’), ‘manual dwell weight/times’, and ‘graphical’. Plans were normalized to left point A and dose of 8 Gy was prescribed. Dose volume and dose point parameters were compared. Results Without graphical optimization, maximum width and thickness of volume enclosed by 100% isodose line, dose to 90%, and 100% of clinical target volume (CTV); minimum, maximum, median, and average dose to both rectum and bladder are significantly higher with Fletcher applicator. Even if it is done, dose to both points B, minimum dose to CTV, and treatment time; dose to 2 cc (D2cc) rectum and rectal point etc.; D2cc, minimum, maximum, median, and average dose to sigmoid colon; D2cc of bladder remain significantly higher with this applicator. Dose to bladder point is similar (p > 0.05) between two applicators, after all optimization techniques. Conclusions Fletcher applicator generates higher dose to both CTV and organs at risk (2 cc volumes) after all optimization techniques. Dose restriction to rectum is possible using graphical optimization only during selected HDR fractionation schedules. Bladder always receives dose higher than recommended, and 2 cc sigmoid colon always gets permissible dose. Contrarily, graphical optimization with ring applicators fulfills all dose volume objectives in all HDR fractionations practiced. PMID:29204164

7 CFR 51.1178 - Maximum anhydrous citric acid permissible for corresponding total soluble solids.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Maximum anhydrous citric acid permissible for... Common Sweet Oranges (citrus Sinensis (l) Osbeck) § 51.1178 Maximum anhydrous citric acid permissible for... following Table II together with the minimum ratio of total soluble solids to anhydrous citric acid: Table...

7 CFR 51.1178 - Maximum anhydrous citric acid permissible for corresponding total soluble solids.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Maximum anhydrous citric acid permissible for... Common Sweet Oranges (citrus Sinensis (l) Osbeck) § 51.1178 Maximum anhydrous citric acid permissible for... following Table II together with the minimum ratio of total soluble solids to anhydrous citric acid: Table...

Maximum permissible voltage of YBCO coated conductors

NASA Astrophysics Data System (ADS)

Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z.; Hong, Z.; Wang, D.; Zhou, H.; Shen, X.; Shen, C.

2014-06-01

Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (Ic) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the Ic degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

Calculation of Nuclear Particles Production at High-Energy Photon Beams from a Linac Operating at 6, 10 and 15 MV.

PubMed

Marchesini, Renato; Bettega, Daniela; Calzolari, Paola; Pignoli, Emanuele

2017-05-01

Production of photonuclear particles in a tissue-equivalent medium has been calculated for linacs at 6, 10 and 15 MV from Varian TrueBeam. Based on the knowledge of bremsstrahlung fluence spectra and linac photon beam parameters, numerical integration was performed on the cross sections for photoparticle production of the constituent elements of tissue (2H,12C,13C,16O,17O,18O,14N,15N). At 15 MV, at the depth of photon maximum dose, the total absorbed dose due to neutrons, protons, alphas and residual nuclei from photon reactions in tissue (5.5E-05 Gy per Gy of photons) is comparable to that due to neutrons from accelerator head. Results reasonably agree with data reported in the literature using Monte Carlo models simulating linac head components. This work suggests a simple method to estimate the dose contributed by the photon-induced nuclear particles for high-energy photon beams produced by linacs in use, as it might be relevant for late stochastic effects. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Methodology for an assessment of derived radiation levels for agrocenoses].

PubMed

Udalova, A A; Ul'ianenko, L N; Aleksakhin, R M; Geras'kin, S A; Filipas, A S

2010-01-01

Radiation protection of agrarian ecosystems should be considered as an integral part of a system for radiation protection of environment, with a special concern to agroecosystems' features. A methodology is proposed for an assessment of maximum permissible doses of radiation impact for agrocenoses based on an unified analysis of available data about effects of radiation in cultivated plants. It is considered as a component of radiation protection system for agricultural ecosystems. Critical doses and dose rates are estimated for crops under different exposure situations. It is shown that doses that could result in decreasing indexes of productivity and survival for main crops below 50% are unlikely up to 170-200 Gy and 15-17 Gy at an acute exposure of dormant seeds and vegetative plants, correspondingly. At chronic exposure, above 10% loss of productivity in crops is not expected at dose rates below 3-10 mGy/h.

STUDY OF THE SUITABILITY OF ISRAELI HOUSEHOLD SALT FOR RETROSPECTIVE DOSIMETRY.

PubMed

Datz, Hanan; Druzhyna, Sofia; Oster, Leonid; Orion, Itzhak; Horowitz, Yigal

2016-09-01

The first results of an in-depth evaluation of the practical potential of common household Israeli salt as a retrospective dosemeter in the event of a nuclear accident or terror attack are presented. Ten brands of salt were investigated with emphasis on four of the bestselling brands that constitute 76 % of the total consumer market. Eight of the ten brands show similar glow curves with two main glow peaks at maximum temperatures of ∼176°C and ∼225°C measured at a heating rate of 1°C s(-1) Chemical analysis of three major brands indicates substantial impurity levels of 200-500 ppm of Ca, K, Mg and S and significant differences of additional ppm trace impurities, which lead to an ∼50 % difference in the TL response of the three major brands. Fading in the dark is in significant but under room light is of the order of 35 % per day. The dose response is linear/supralinear with the threshold of supralinearity at ∼0.01 Gy reaching maximum value of ∼4 at 0.5-1 Gy for two of the major brands. The precision of repeated measurements is ∼10 % (1 SD), but the accuracy of dose assessment under field conditions requires further study. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

INTERCOMPARISON ON THE MEASUREMENT OF THE QUANTITY PERSONAL DOSE EQUIVALENT HP(10) IN PHOTON FIELDS. LINEARITY DEPENDENCE, LOWER LIMIT OF DETECTION AND UNCERTAINTY IN MEASUREMENT OF DOSIMETRY SYSTEMS OF INDIVIDUAL MONITORING SERVICES IN GABON AND GHANA.

PubMed

Ondo Meye, P; Schandorf, C; Amoako, J K; Manteaw, P O; Amoatey, E A; Adjei, D N

2017-12-01

An inter-comparison study was conducted to assess the capability of dosimetry systems of individual monitoring services (IMSs) in Gabon and Ghana to measure personal dose equivalent Hp(10) in photon fields. The performance indicators assessed were the lower limit of detection, linearity and uncertainty in measurement. Monthly and quarterly recording levels were proposed with corresponding values of 0.08 and 0.025 mSv, and 0.05 and 0.15 mSv for the TLD and OSL systems, respectively. The linearity dependence of the dosimetry systems was performed following the requirement given in the Standard IEC 62387 of the International Electrotechnical Commission (IEC). The results obtained for the two systems were satisfactory. The procedure followed for the uncertainty assessment is the one given in the IEC technical report TR62461. The maximum relative overall uncertainties, in absolute value, expressed in terms of Hp(10), for the TL dosimetry system Harshaw 6600, are 44. 35% for true doses below 0.40 mSv and 36.33% for true doses ≥0.40 mSv. For the OSL dosimetry system microStar, the maximum relative overall uncertainties, in absolute value, are 52.17% for true doses below 0.40 mSv and 37.43% for true doses ≥0.40 mSv. These results are in good agreement with the requirements for accuracy of the International Commission on Radiological protection. When expressing the uncertainties in terms of response, comparison with the IAEA requirements for overall accuracy showed that the uncertainty results were also acceptable. The values of Hp(10) directly measured by the two dosimetry systems showed a significant underestimation for the Harshaw 6600 system, and a slight overestimation for the microStar system. After correction for linearity of the measured doses, the two dosimetry systems gave better and comparable results. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Air radon concentration decrease in a waste water treatment plant.

PubMed

Juste, B; Ortiz, J; Verdú, G; Martorell, S

2015-06-01

(222)Rn is a naturally occurring gas created from the decay of (226)Ra. The long-term health risk of breathing radon is lung cancer. One particular place where indoor radon concentrations can exceed national guidelines is in wastewater treatment plants (WWTPs) where treatment processes may contribute to ambient airborne concentrations. The aim of this paper was to study the radon concentration decrease after the application of corrective measures in a Spanish WWTP. According to first measures, air radon concentration exceeded International Commission Radiologica1 Protection (ICRP) normative (recommends intervention between 400 and 1000 Bq m(-3)). Therefore, the WWTP improved mechanical forced ventilation to lower occupational exposure. This measure allowed to increase the administrative controls, since the limitation of workers access to the plant changed from 2 h d(-1) (considering a maximum permissible dose of 20 mSv y(-1) averaged over 5 y) to 7 h d(-1). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Single-Dose and Multiple-Dose Pharmacokinetics of Nicotine 6 mg Gum.

PubMed

Hansson, Anna; Rasmussen, Thomas; Kraiczi, Holger

2017-04-01

Under-dosing is a recognized problem with current nicotine replacement therapy (NRT). Therefore, a new 6mg nicotine gum has been developed. To compare the nicotine uptake from the 6mg gum versus currently available NRT products, two pharmacokinetic studies were performed. In one randomized crossover study, 44 healthy adult smokers received single doses of 6, 4, and 2mg nicotine gum, and 4mg nicotine lozenge on separate occasions. In a separate randomized crossover multiple-dose study over 11 hours, 50 healthy adult smokers received one 6mg gum every hour and 90 minutes, respectively, one 4mg gum every hour, and one 4mg lozenge every hour. In both studies, blood samples were collected over 12 hours to determine single-dose and multiple-dose pharmacokinetic variables. In the single-dose study, the amount of nicotine released from the 2, 4, and 6mg gums (1.44, 3.36, and 4.94mg) as well as the resulting maximum concentration and area under the curve (5.9, 10.1, and 13.8ng/mL, and 17.1, 30.7, 46.2ng/mL × h, respectively) increased with dose. The maximum concentration and area under the curve of the 6mg gum were 44% and 30% greater, respectively, than those for 4mg lozenge. Upon hourly administration, the steady-state average plasma nicotine concentration with 6mg gum (37.4ng/mL) was significantly higher than those for 4mg lozenge (28.3ng/mL) and 4mg gum (27.1ng/mL). Nicotine delivery via the 6mg gum results in higher plasma nicotine concentrations after a single dose and at steady state than with currently available oral NRT. Under-dosing is a recognized problem with current NRT. Therefore, a new 6mg nicotine gum has been developed. Our studies show that upon single-dose and multiple-dose administration, the 6mg gum releases and delivers more nicotine to the systemic circulation than 2mg gum, 4mg gum, and 4mg lozenge. Thus, each 6mg nicotine gum provides a higher degree of nicotine substitution and/or lasts for a longer period of time than currently available nicotine gums and lozenges. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

[Effect of anthropotechnogenic chemical factors on formation of somatotypes in children and adolescents of school age].

PubMed

Iudin, G V; Osipova, M I; Eremin, G A; Stroĭkova, S B

2003-01-01

This research was done to study the dynamics of a process of constitutional types formation in 163 schoolboys and 181 schoolgirls, who live and study in various regions of the city of Ivanovo which are characterized by a different degree of environmental pollution with heavy metal salts and lead in particular. To define the constitutional types, the method of V.G. Shtefko and A.D. Ostrovsky (1929) was used. It was demonstrated that environmental pollution with heavy metal salts, the absorbed dose of which 3 times exceeded the maximum permissible dose, lead to the delay of somatotype differentiation in children and adolescents, which was more pronounced in schoolboys than in schoolgirls.

Natural radioactivity and radon exhalation rates in man-made tiles used as building materials in Japan.

PubMed

Iwaoka, K; Hosoda, M; Suwankot, N; Omori, Y; Ishikawa, T; Yonehara, H; Tokonami, S

2015-11-01

Man-made tiles frequently used in Japan were collected, and activity concentrations and radon ((222)Rn) exhalation rates in these tiles were measured. Dose estimations for inhabitants living in houses built using these tiles were also carried out. The activity concentrations of (226)Ra, (228)Ra and (40)K in the man-made tiles were 31-170, 35-110 and 260-980 Bq kg(-1), respectively. The (222)Rn exhalation rates in the tiles were 8.8-21 μBq m(-2) s(-1). The ranges of experimental activity concentrations and (222)Rn exhalation rates were almost identical to those of natural rocks used as typical building materials in Japan. The maximum value of effective dose to inhabitants living in houses built with the man-made tiles was 0.14 mSv y(-1), which is lower than the reference level range (1-20 mSv y(-1)) for abnormally high levels of natural background radiation published in the ICRP Publication 103. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

5 CFR 890.1015 - Minimum and maximum length of permissive debarments.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES HEALTH BENEFITS PROGRAM Administrative Sanctions Imposed Against Health Care Providers Permissive Debarments § 890.1015 Minimum and maximum length of...

Dissipation kinetics and safety evaluation of tebuconazole and trifloxystrobin in tea under tropical field conditions.

PubMed

Paramasivam, Mariappan; Deepa, Manthirachalam; Selvi, Chellamuthu; Chandrasekaran, Subramanian

2017-12-01

Dissipation kinetics of tebuconazole, trifloxystrobin and its acid metabolite residues were studied in tea under tropical field conditions using GC-MS (SIM). The average recoveries ranged from 80.7% to 105.8%, with a RSD of <9.3%. Dissipation rate for both doses applied followed first-order kinetics, with half-lives in green leaves in the range of 2.8-3.3 and 2.9-3.3 days; ranges in processed tea were 2.7-3.6 days for trifloxystrobin and 3.0-3.1 days for tebuconazole. The trifloxystrobin residues were not transferred into the tea infusion during the infusion process; tebuconazole did transfer, in the range of 14.3-18.9%. As the theoretical maximum residue contributions on tea from initial deposits were found to be less than the maximum permissible intake values, at the recommended application dose a withdrawal period of 23 days before consumption should be applied to reduce risk.

Density Dependence and Growth Rate: Evolutionary Effects on Resistance Development to Bt (Bacillus thuringiensis).

PubMed

Martinez, Jeannette C; Caprio, Michael A; Friedenberg, Nicholas A

2018-02-09

It has long been recognized that pest population dynamics can affect the durability of a pesticide, but dose remains the primary component of insect resistance management (IRM). For transgenic pesticidal traits such as Bt (Bacillus thuringiensis Berliner (Bacillales: Bacillaceae)), dose (measured as the mortality of susceptibles caused by a toxin) is a relatively fixed characteristic and often falls below the standard definition of high dose. Hence, it is important to understand how pest population dynamics modify durability and what targets they present for IRM. We used a deterministic model of a generic arthropod pest to examine how timing and strength of density dependence interacted with population growth rate and Bt mortality to affect time to resistance. As in previous studies, durability typically reached a minimum at intermediate doses. However, high population growth rates could eliminate benefits of high dose. The timing of density dependence had a more subtle effect. If density dependence operated simultaneously with Bt mortality, durability was insensitive to its strengths. However, if density dependence was driven by postselection densities, decreasing its strength could increase durability. The strength of density dependence could affect durability of both single traits and pyramids, but its influence depended on the timing of density dependence and size of the refuge. Our findings suggest the utility of a broader definition of high dose, one that incorporates population-dynamic context. That maximum growth rates and timing and strength of interactions causing density dependent mortality can all affect durability, also highlights the need for ecologically integrated approaches to IRM research. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Analysis of the criteria used by the International Commission on Radiological Protection to justify the setting of numerical protection level values.

PubMed

2006-01-01

This report compiles the various numerical protection level values published by the International Commission on Radiological Protection (ICRP) since its 1990 Recommendations (Publication 60). Several terms are used to denominate the protection levels: individual dose limit, 'maximum' individual dose, dose constraint, exemption level, exclusion level, action level, or intervention level. The reasons provided by the Commission for selecting the associated numerical values is quoted as far as available. In some cases the rationale is not totally explicit in the original ICRP report concerned; in such cases the Task Group that prepared the present report have proposed their own interpretation. Originally, this report was prepared by a Task Group at CEPN, a French research and development center, in behalf of IRSN, a French public expert body engaged in radiological protection and nuclear safety. It is published here with kind permission by CEPN and IRSN.

75 FR 55389 - Self-Regulatory Organizations; National Stock Exchange, Inc.; Notice of Filing and Immediate...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-10

... Change To Amend Rule 11.13 Regarding Maximum Permissible Response Time for Users of Order Delivery... maximum permissible response time to an inbound order. The current rule filing does not propose to change...

[Comparative toxicity of photosensitizers in varying destruction].

PubMed

Sinitsina, O O; Zholdakova, Z I; Poliakova, E E; Golovach, E N; Sycheva, L P; Beliaeva, N N; Kuznetsova, N A

2007-01-01

The toxicity of the photosensitizers proflavine acetate (PA) versus methylene blue (MB) was evaluated during their varying destruction. Under the influence of visible light, a partial (25%) transformation of the photosensitizers was shown to be attended by their enhanced toxicity and 100% destruction of the parent substances caused a reduction in their hazard. PA and its phototransformation products mainly affect the antiperoxide protection system and the structural and functional states of the liver, kidney, and duodenum. The maximum noneffective dose is 0.002 mg/kg. The possibility of using PA for water disinfection depends on the ratio of safe and effective concentrations. A partial (25%) MB destruction products cause mutagenic effects; the permissible dose of the mutagen is 0.00025 mg/kg. MB is not recommended for disinfection of all types of waters.

5 CFR 890.1015 - Minimum and maximum length of permissive debarments.

Code of Federal Regulations, 2014 CFR

2014-01-01

... debarments. 890.1015 Section 890.1015 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES HEALTH BENEFITS PROGRAM Administrative Sanctions Imposed Against Health Care Providers Permissive Debarments § 890.1015 Minimum and maximum length of...

5 CFR 890.1015 - Minimum and maximum length of permissive debarments.

Code of Federal Regulations, 2010 CFR

2010-01-01

... debarments. 890.1015 Section 890.1015 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES HEALTH BENEFITS PROGRAM Administrative Sanctions Imposed Against Health Care Providers Permissive Debarments § 890.1015 Minimum and maximum length of...

5 CFR 890.1015 - Minimum and maximum length of permissive debarments.

Code of Federal Regulations, 2013 CFR

2013-01-01

... debarments. 890.1015 Section 890.1015 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES HEALTH BENEFITS PROGRAM Administrative Sanctions Imposed Against Health Care Providers Permissive Debarments § 890.1015 Minimum and maximum length of...

The Effect of Valve Cooling upon Maximum Permissible Engine Output as Limited by Knock

NASA Technical Reports Server (NTRS)

Munger, Maurice; Wilsted, H D; Mulcahy, B A

1942-01-01

A Wright GR-1820-G200 cylinder was tested over a wide range of fuel-air ratios at maximum permissible power output as limited by knock with three different degrees of valve cooling. The valves used were stock valves (solid inlet valve and hollow sodium-cooled exhaust valve), hollow valves with no coolant, and hollow valves with flowing water as a coolant. Curves showing the variation in maximum permissible values of inlet-air pressure, indicated mean effective pressure, cylinder charge, and indicated specific fuel consumption with change in fuel-air ratio and valve cooling are shown. The use of valves cooled by a stream of water passing through their hollow interiors permitted indicated mean effective pressures 10 percent higher than the mean effective pressures permissible with stock valves when the engine was operated with fuel-air ratios from 0.055 to 0.065. Operation of the engine with lean mixtures with uncooled hollow valves resulted in power output below the output obtained with the stock valves. The data show an increase in maximum permissible indicated mean effective pressure due to cooling the valves, which averages only 2.1 percent with fuel-air ratios from 0.075 to 0.105.

A phase I dose-escalation study of apatorsen (OGX-427), an antisense inhibitor targeting heat shock protein 27 (Hsp27), in patients with castration-resistant prostate cancer and other advanced cancers.

PubMed

Chi, K N; Yu, E Y; Jacobs, C; Bazov, J; Kollmannsberger, C; Higano, C S; Mukherjee, S D; Gleave, M E; Stewart, P S; Hotte, S J

2016-06-01

Heat shock protein 27 (Hsp27) is a chaperone protein that regulates cell survival via androgen receptor and other signaling pathways, thereby mediating cancer progression. Apatorsen (OGX-427) is a 2'-methoxyethyl-modified antisense oligonucleotide that inhibits Hsp27 expression. This study evaluated the safety profile and recommended phase II dosing of apatorsen in patients with advanced cancer. Patients with castration-resistant prostate (CRPC), breast, ovary, lung, or bladder cancer were enrolled to this phase I dose-escalation study. Apatorsen was administered i.v. weekly in 21-day cycles following 3 loading doses and over 5 dose levels (200-1000 mg). Apatorsen plasma concentrations, circulating tumor cells (CTCs) and CTC Hsp27 expression, and serum Hsp27 levels were evaluated. Forty-two patients were accrued, of which 52% had CRPC. Patients were heavily pretreated, with 57% having had ≥3 prior chemotherapy regimens. During the loading dose/cycle 1 and overall study period, 93% and 100% of patients (N = 42) experienced treatment-related adverse events, respectively; most were grade 1-2 and included chills, pruritus, flushing, prolonged aPTT, lymphopenia, and anemia. One patient experienced a dose-limiting toxicity at the 600 mg dose level (intracranial hemorrhage in a previously undiagnosed brain metastasis). A maximum tolerated dose was not defined. Apatorsen Cmax increased proportionally with dose. Decreases in tumor markers and declines in CTCs were observed, with a prostate-specific antigen decline >%50% occurring in 10% of patients with CRPC; 29/39 assessable patients (74%) had reductions from ≥5 CTC/7.5 ml at baseline to <5 CTC/7.5 ml post-treatment. Twelve patients had stable measurable disease as best response. Apatorsen was tolerated at the highest dose evaluated (1000 mg). Single-agent activity was suggested by changes in tumor markers, CTC, and stable measurable disease. Phase II studies evaluating apatorsen are underway. NCT00487786. © The Author 2016. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

30 CFR 57.5039 - Maximum permissible concentration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Maximum permissible concentration. 57.5039 Section 57.5039 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Air Quality, Radiation, Physical Agents, and Diesel...

30 CFR 57.5039 - Maximum permissible concentration.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Maximum permissible concentration. 57.5039 Section 57.5039 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Air Quality, Radiation, Physical Agents, and Diesel...

30 CFR 57.5039 - Maximum permissible concentration.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Maximum permissible concentration. 57.5039 Section 57.5039 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Air Quality, Radiation, Physical Agents, and Diesel...

30 CFR 57.5039 - Maximum permissible concentration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Maximum permissible concentration. 57.5039 Section 57.5039 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Air Quality, Radiation, Physical Agents, and Diesel...

30 CFR 57.5039 - Maximum permissible concentration.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Maximum permissible concentration. 57.5039 Section 57.5039 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Air Quality, Radiation, Physical Agents, and Diesel...

COMPREHENSIVE DATA CONCERNING COSMIC RADIATION DOSES AT GROUND LEVEL AND IN-FLIGHTS FOR TURKEY.

PubMed

Parmaksız, A

2016-12-01

Cosmic radiation doses of individuals living in 81 cities in Turkey were estimated by using CARI-6 software. Annual cosmic radiation doses of individuals were found to be between 308 and 736 µSv y -1 at ground level. The population-weighted annual effective dose from cosmic radiation was determined to be 387 µSv y -1 for Turkey. Cosmic radiation doses on-board for 137 (60 domestic and 77 international) flights varied from 1.2 to 83 µSv. It was estimated that six or over long-route round-trip air travels may cause cosmic radiation dose above the permissible limit for member of the public, i.e. 1 mSv y -1 According to the assumption of flights throughout 800 h on each route, cosmic radiation doses were found to be between 1.0 and 4.8 mSv for aircrew. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brent, R.L.

Many professionals are unfamiliar with radiation biology or the quantitative nature of the risks. Frequently, microwave, ultrasound, and ionizing radiation risks are confused. Although it is impossible to prove no risk for any environmental hazard, it appears that exposure to microwave radiation below the maximal permissible levels present no measurable risk to the embryo. Ultrasound exposure from diagnostic ultrasonographic imaging equipment also is quite innocuous. It is true that continued surveillance and research into potential risks of these low-level exposures should continue, but at present ultrasound not only improves obstetric care but also reduces the necessity of diagnostic x-ray procedures.more » In the field of ionizing radiation, we have as good a comprehension of the biologic effects and the quantitative maximum risks as of any other environmental hazard. Although the animal and human data support the conclusion that no increases in the incidence of gross congenital malformations, intrauterine growth retardation, or abortion will occur with exposures less than 5 rad, that does not mean that there are definitely no risks to the embryo exposed to lower doses of radiation. Whether there exists a linear or exponential dose-response relationship or a threshold exposure for genetic, carcinogenic, cell-depleting, and life-shortening effects has not been determined. In establishing maximum permissible levels for the embryo at low exposures, refer to Tables 4, 5, 6, 8, and 9. It is obvious that the risks of 1-rad or 5-rad acute exposure are far below the spontaneous risks of the developing embryo because 15 per cent of human embryos abort, 2.7 to 3.0 per cent of human embryos have major malformations, 4 per cent have intrauterine growth retardation, and 8 to 10 per cent have early- or late-onset genetic disease. 98 references.« less

Coffee-Antihypertensive Drug Interaction: A Hemodynamic and Pharmacokinetic Study With Felodipine.

PubMed

Bailey, David G; Dresser, George K; Urquhart, Brad L; Freeman, David J; Arnold, John Malcolm

2016-12-01

A period of abstinence from coffee to permit caffeine elimination appears to enable increased blood pressure on subsequent exposure. We hypothesized that this would offset the antihypertensive effect of the dihydropyridine calcium channel blocker felodipine. A randomized, single-dose, crossover study assessed hemodynamic and pharmacokinetic effects following 2 days without coffee and caffeine-containing foods. Consistently brewed black coffee (2×300ml), felodipine maximum recommended dose (10mg), and coffee plus felodipine were tested in middle-aged normotensive subjects. Pretreatment plasma caffeine concentrations were unquantifiable. After coffee, blood pressure changes (mm Hg) averaged over study hours 1-4 were increased for brachial systolic (7.6, P < 0.001) and diastolic (4.9, P < 0.001) and aortic systolic (7.4, P < 0.001), pulse (3.0, P < 0.05) and augmentation (1.4, P < 0.05) relative to baseline. After coffee plus felodipine, they were higher for brachial systolic (4.0, P < 0.05) and diastolic (3.9, P < 0.001) and aortic systolic (4.6, P < 0.05) compared to felodipine alone. The pressor effects of coffee and its modulation by felodipine were variable among individuals. Coffee containing caffeine (127mg) caused maximum pressor effect. Caffeine and felodipine pharmacokinetics were similar for coffee and felodipine given alone or in combination indicating an interaction having a pharmacodynamic basis. Plasma felodipine concentration-diastolic blood pressure reduction relationship shifted with coffee such that doubling the felodipine concentration would eliminate the pressor effect. However, this may increase the risk of adverse drug events particularly during the timeframe without coffee. Intermittent coffee ingestion might complicate hypertension diagnosis and management for many individuals. © American Journal of Hypertension, Ltd 2016. All rights reserved. For Permissions, please email: journals.permissions@oup.com

[Exposure to fluorides from drinking water in the city of Aguascalientes, Mexico].

PubMed

Trejo-Vázquez, R; Bonilla-Petriciolet, A

2001-08-01

Determine the fluoride content in all the wells that supply drinking water to the city of Aguascalientes, Mexico, in order to establish the population's degree of exposure. The fluoride content of the 126 wells that supply drinking water to the city of Aguascalientes was determined, using the SPADNS method, in accordance with two Mexican regulations, NMX-AA-77-1982 and NMX-014-SSAI-1993. Using that data, we created fluoride isopleth maps showing the distribution of fluoride concentrations in the water supplies for the city of Aguascalientes. We also estimated exposure doses for the city's inhabitants. The mean analysis uncertainty was 3.9%. Seventy-three wells had a fluoride concentration of" 1.5 mg/L, which was the maximum permissible value set by the Mexican standards then in effect. All the maximum exposure doses surpassed the minimum risk level set by Agency for Toxic Substances and Disease Registry (ATSDR) of the Department of Health and Human Services of the United States of America. In the children under 1 year of age, even the minimum does was slightly higher than the ATSDR risk level. From estimating the fluoride exposure doses caused by water consumption in the city of Aguascalientes and comparing those doses with ones from other states in Mexico, we concluded that the fluoride intake in Aguascalientes represents a potential risk for inhabitants' health. The fluoride content of the city's drinking water should be reduced to 0.69 mg/L.

The use of a numerical method to justify the criteria for the maximum settlement of the tank foundation

NASA Astrophysics Data System (ADS)

Tarasenko, Alexander; Chepur, Petr; Gruchenkova, Alesya

2017-11-01

The article examines the problem of assessing the permissible values of uneven settlement for a vertical steel tank base and foundation. A numerical experiment was performed using a finite element model of the tank. The model took into account the geometric shape of the structure and its additional stiffening elements that affect the stress-strain state of the tank. An equation was obtained that allowed determining the maximum possible deformation of the bottom outer contour during uneven settlement. Depending on the length of the uneven settlement zone, the values of the permissible settlement of the tank base were determined. The article proposes new values of the maximum permissible tank settlement with additional stiffening elements.

Phase I study of olaparib plus gemcitabine in patients with advanced solid tumours and comparison with gemcitabine alone in patients with locally advanced/metastatic pancreatic cancer.

PubMed

Bendell, J; O'Reilly, E M; Middleton, M R; Chau, I; Hochster, H; Fielding, A; Burke, W; Burris, H

2015-04-01

Olaparib (Lynparza) is an oral poly(adenosine diphosphate [ADP]-ribose) polymerase inhibitor that induces synthetic lethality in cancers with homologous recombination defects. In this phase I, dose-escalation trial, patients with advanced solid tumours received olaparib (50-200 mg capsules b.i.d.) continuously or intermittently (days 1-14, per 28-day cycle) plus gemcitabine [i.v. 600-800 mg/m(2); days 1, 8, 15, and 22 (cycle 1), days 1, 8, and 15 (subsequent cycles)] to establish the maximum tolerated dose. A separate dose-escalation phase evaluated olaparib in tablet formulation (100 mg o.d./b.i.d.; days 1-14) plus gemcitabine (600 mg/m(2)). In an expansion phase, patients with genetically unselected locally advanced or metastatic pancreatic cancer were randomised 2 : 1 to the tolerated olaparib capsule combination dose or gemcitabine alone (1000 mg/m(2)). Sixty-six patients were treated [dose-escalation phase, n = 44 (tablet cohort, n = 12); dose-expansion phase, n = 22 (olaparib plus gemcitabine, n = 15; gemcitabine alone, n = 7)]. In the dose-escalation phase, four patients (6%) experienced dose-limiting toxicities (raised alanine aminotransferase, n = 2; neutropenia, n = 1; febrile neutropenia, n = 1). Grade ≥3 adverse events were reported in 38/47 patients (81%) treated with olaparib capsules plus gemcitabine; most common were haematological toxicities (55%). Tolerated combinations were olaparib 100 mg b.i.d. capsule (intermittently, days 1-14) plus gemcitabine 600 mg/m(2) and olaparib 100 mg o.d. tablet (intermittently, days 1-14) plus gemcitabine 600 mg/m(2). There were no differences in efficacy observed during the dose-expansion phase. Olaparib 100 mg b.i.d. (intermittent dosing; capsules) plus gemcitabine 600 mg/m(2) is tolerated in advanced solid tumour patients, with no unmanageable/unexpected toxicities. Continuous dosing of olaparib or combination with gemcitabine at doses >600 mg/m(2) was not considered to have an acceptable tolerability profile for further study. NCT00515866. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

STUDIES OF RADIO CONTAMINATION OF FOOD STUFFS EFFECTED BY ATOMIC OR HYDROGEN BOMB EXPLOSION. IX. RADIO CHEMICAL ANALYSIS OF RADIO CONTAMINATED FISH LIVERS IN 1958 (in Japanese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagasawa, K.; Kasida, Y.; Kametani, K.

The contamination in 224 livers of tunny and sword fish caught in the Pacific 0cean was examined. As a result of radiochemical analysis in the four samples Fe/sup 59/ Zn/sup 65/, Sr/sup 90/, Y/sup 90/, and Cd/sup 115m/ were identified. The maximum concentrations of the elements determined were Fe/sup 59/ , 1.58 x l0/sup -4/ mu c; Zn/sup 65/, 4.58 x 10/sup -3/ mu c; Sr/sup 90/ and Y/ sup 90/, 8. 33 x 10/sup -7/ mu c; and Cd/sup 115m/, 3.66 x l0/sup -4/ mu c. When 10 g of wet sample was assumed to be the daily personalmore » intake dose, these were less than the maximum permissible concentrations. (auth)« less

What and how can affect the exploration of Mars

NASA Astrophysics Data System (ADS)

Vidmachenko, A. P.; Morozhenko, A. V.

2017-05-01

Going to Mars, astronauts are deprived of the protection of the magnetic field. And for 15 months of flight to Mars and back astronaut will receive maximum permissible for his entire career, a dose of radiation of 1 sievert. And when powerful flash can occur on the sun, the dose of radiation will grow by an order of magnitude and can even kill the crew. The radiation background in the orbit of Mars is more than 2.2 times higher than the radiation background at the Earth's orbital station. The smallest toxic dust on Mars is also can interfere with the colonization of Mars. This dust contains a large number of toxic compounds such as perchlorates, minerals of gypsum, compounds of chromium, fine-grained salts of silicic acid, etc. The listed above factors make forced to think seriously about the possibility of organizing a Mars mission, even in the distant future.

EVALUATION OF EYE LENS DOSES OF INTERVENTIONAL CARDIOLOGISTS.

PubMed

Yokoyama, Sumi; Suzuki, Shoichi; Toyama, Hiroshi; Arakawa, Shinji; Inoue, Satoshi; Kinomura, Yutaka; Kobayashi, Ikuo

2017-04-01

The effective dose of medical staff members, especially interventional radiologists and cardiologists, is classified as a relatively high level. We measured the dose for interventional cardiologists by using optically stimulated luminescence dosimeters (OSLDs). However, this quantity is not the same as Hp (3). In experiments, the dose at the eye-lens position of a phantom were measured using OSLDs and thermoluminescence dosimeters (TLDs). A conversion factor from dose measured by using TLDs to OSLDs was estimated from these results. In addition, the eye doses of interventional cardiologists in clinical situations were measured, and the effect of eyewear on the eye-lens dose was discussed. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of 2-Dose and 3-Dose 9-Valent Human Papillomavirus Vaccine Schedules in the United States: A Cost-effectiveness Analysis.

PubMed

Laprise, Jean-François; Markowitz, Lauri E; Chesson, Harrell W; Drolet, Mélanie; Brisson, Marc

2016-09-01

A recent clinical trial using the 9-valent human papillomavirus virus (HPV) vaccine has shown that antibody responses after 2 doses are noninferior to those after 3 doses, suggesting that 2 and 3 doses may have comparable vaccine efficacy. We used an individual-based transmission-dynamic model to compare the population-level effectiveness and cost-effectiveness of 2- and 3-dose schedules of 9-valent HPV vaccine in the United States. Our model predicts that if 2 doses of 9-valent vaccine protect for ≥20 years, the additional benefits of a 3-dose schedule are small as compared to those of 2-dose schedules, and 2-dose schedules are likely much more cost-efficient than 3-dose schedules. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Dosimetric comparison between proton beam therapy and photon radiation therapy for locally advanced non-small cell lung cancer.

PubMed

Wu, Chen-Ta; Motegi, Atsushi; Motegi, Kana; Hotta, Kenji; Kohno, Ryosuke; Tachibana, Hidenobu; Kumagai, Motoki; Nakamura, Naoki; Hojo, Hidehiro; Niho, Seiji; Goto, Koichi; Akimoto, Tetsuo

2016-08-10

To assess the feasibility of proton beam therapy for the patients with locally advanced non-small lung cancer. The dosimetry was analyzed retrospectively to calculate the doses to organs at risk, such as the lung, heart, esophagus and spinal cord. A dosimetric comparison between proton beam therapy and dummy photon radiotherapy (three-dimensional conformal radiotherapy) plans was performed. Dummy intensity-modulated radiotherapy plans were also generated for the patients for whom curative three-dimensional conformal radiotherapy plans could not be generated. Overall, 33 patients with stage III non-small cell lung cancer were treated with proton beam therapy between December 2011 and August 2014. The median age of the eligible patients was 67 years (range: 44-87 years). All the patients were treated with chemotherapy consisting of cisplatin/vinorelbine or carboplatin. The median prescribed dose was 60 GyE (range: 60-66 GyE). The mean normal lung V20 GyE was 23.6% (range: 14.9-32%), and the mean normal lung dose was 11.9 GyE (range: 6.0-19 GyE). The mean esophageal V50 GyE was 25.5% (range: 0.01-63.6%), the mean heart V40 GyE was 13.4% (range: 1.4-29.3%) and the mean maximum spinal cord dose was 40.7 GyE (range: 22.9-48 GyE). Based on dummy three-dimensional conformal radiotherapy planning, 12 patients were regarded as not being suitable for radical thoracic three-dimensional conformal radiotherapy. All the dose parameters of proton beam therapy, except for the esophageal dose, were lower than those for the dummy three-dimensional conformal radiotherapy plans. In comparison to the intensity-modulated radiotherapy plan, proton beam therapy also achieved dose reduction in the normal lung. None of the patients experienced grade 4 or worse non-hematological toxicities. Proton beam therapy for patients with stage III non-small cell lung cancer was feasible and was superior to three-dimensional conformal radiotherapy for several dosimetric parameters. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

DOSE COEFFICIENTS FOR LIVER CHEMOEMBOLISATION PROCEDURES USING MONTE CARLO CODE.

PubMed

Karavasilis, E; Dimitriadis, A; Gonis, H; Pappas, P; Georgiou, E; Yakoumakis, E

2016-12-01

The aim of the present study is the estimation of radiation burden during liver chemoembolisation procedures. Organ dose and effective dose conversion factors, normalised to dose-area product (DAP), were estimated for chemoembolisation procedures using a Monte Carlo transport code in conjunction with an adult mathematical phantom. Exposure data from 32 patients were used to determine the exposure projections for the simulations. Equivalent organ (H T ) and effective (E) doses were estimated using individual DAP values. The organs receiving the highest amount of doses during these exams were lumbar spine, liver and kidneys. The mean effective dose conversion factor was 1.4 Sv Gy -1 m -2 Dose conversion factors can be useful for patient-specific radiation burden during chemoembolisation procedures. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Conditioning of the 4 Curies Radium-226 Sealed Radiation Source in Thailand

DOE Office of Scientific and Technical Information (OSTI.GOV)

Punnachaiya, M.; Sawangsri, T.; Wanabongse, P.

This paper describes the conditioning of the 4 curies Radium-226 (Ra-226) sealed radiation source using as a teletherapy unit for cancer treatment in Thailand. The conditioning was under the International Atomic Energy Agency (IAEA) supervision and budgetary supports, comprised of 6 operational steps: the surface dose rate and actual dimension of radium unit measurements, the appropriate lead shielding design with IAEA approval, confirmation of radioactive contamination before conditioning (smear test and radon gas leakage test), transfer of radium source unit into the designed shielding, confirmation of radioactive contamination and dose rate measurement after conditioning, and transportation of Ra-226 conditioning wastemore » package to OAP interim waste storage. The Ra-226 unit was taken out of OAP temporary waste storage for the surface dose rate and the actual dimension measurements behind the 12 inches thick heavy concrete shielding. The maximum measured surface dose rate was 70 R/hr. The special lead container was designed according to its surface dose rate along the source unit which the maximum permissible dose limit for surface dose rate of waste package after conditioning at 2 mSv/hr was applied. The IAEA approved container had total weight of 2.4 ton. After the confirmation of radioactive contamination, Ra-226 source unit was transferred and loaded in the designed lead shielding within 2 minutes. The results of smear test before and after conditioning including radon gas leakage test revealed that there was no radioactive contamination. After conditioning, the surface dose rate measured on the top, bottom were 15,10 mR/hr and varied from 6 - 50 mR/hr around lead container. The Ra-226 conditioning waste package was safely transported to store in OAP interim waste storage. Total working time including the time consumed for radon gas leakage test was 3.5 hours. The total radiation dose received by 16 operators, were ranged from 1 - 69.84 {mu}Sv and the operational team completed the conditioning safely within the effective dose limit for occupational exposure of 50 mSv/year (200 {mu}Sv/day). (authors)« less

In vivo TLD dose measurements in catheter-based high-dose-rate brachytherapy.

PubMed

Adlienė, Diana; Jakštas, Karolis; Urbonavičius, Benas Gabrielis

2015-07-01

Routine in vivo dosimetry is well established in external beam radiotherapy; however, it is restricted mainly to detection of gross errors in high-dose-rate (HDR) brachytherapy due to complicated measurements in the field of steep dose gradients in the vicinity of radioactive source and high uncertainties. The results of in vivo dose measurements using TLD 100 mini rods and TLD 'pin worms' in catheter-based HDR brachytherapy are provided in this paper alongside with their comparison with corresponding dose values obtained using calculation algorithm of the treatment planning system. Possibility to perform independent verification of treatment delivery in HDR brachytherapy using TLDs is discussed. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Phase I trial of p28 (NSC745104), a non-HDM2-mediated peptide inhibitor of p53 ubiquitination in pediatric patients with recurrent or progressive central nervous system tumors: A Pediatric Brain Tumor Consortium Study.

PubMed

Lulla, Rishi R; Goldman, Stewart; Yamada, Tohru; Beattie, Craig W; Bressler, Linda; Pacini, Michael; Pollack, Ian F; Fisher, Paul Graham; Packer, Roger J; Dunkel, Ira J; Dhall, Girish; Wu, Shengjie; Onar, Arzu; Boyett, James M; Fouladi, Maryam

2016-09-01

p53 is a promising target in human cancer. p28 is a cell-penetrating peptide that preferentially enters cancer cells and binds to both wild-type and mutant p53 protein, inhibiting COP1-mediated ubiquitination and proteasomal degradation. This results in increased levels of p53, which induces cell cycle arrest at G2/M. We conducted a phase I study to determine the maximum-tolerated dose (MTD) and describe the dose-limiting toxicities (DLTs) and pharmacokinetics (PKs) of p28 in children. Children aged 3-21 years with recurrent or progressive central nervous system tumors were eligible. Intravenous p28 was administered 3 times weekly for 4 consecutive weeks of a 6-week cycle at 4.16 mg/kg/dose (the adult recommended phase II dose) using a rolling-6 study design. Expression status of p53 was characterized by immunohistochemistry, and serum PK parameters were established on the second dose. Of the 18 eligible patients enrolled in the study, 12 completed the DLT monitoring period and were evaluable for toxicity. p28 was well-tolerated; 7 participants received ≥2 courses, and the most common adverse event attributed to the drug was transient grade 1 infusion-related reaction. PK analysis revealed a profile similar to adults; however, an increased area under the curve was observed in pediatric patients. High p53 expression in tumor cell nuclei was observed in 6 of 12 available tissue samples. There were no objective responses; 2 participants remained stable on the study for >4 cycles. This phase I study demonstrated that p28 is well-tolerated in children with recurrent CNS malignancies at the adult recommended phase II dose. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

GAL-021, a new intravenous BKCa-channel blocker, is well tolerated and stimulates ventilation in healthy volunteers.

PubMed

McLeod, J F; Leempoels, J M; Peng, S X; Dax, S L; Myers, L J; Golder, F J

2014-11-01

Potassium-channels in the carotid body and the brainstem are important regulators of ventilation. The BKCa-channel contains response elements for CO, O2, and CO2. Its block increases carotid body signalling, phrenic nerve activity, and respiratory drive. GAL-021, a new BKCa-channel blocker, increases minute ventilation in rats and non-human primates. This study assessed the single-dose safety, tolerability, pharmacokinetics (PKs), and pharmacodynamics (PDs) of GAL-021 in healthy volunteers. Thirty subjects participated in a nine-period, randomized, double-blinded, placebo-controlled, crossover, ascending dose, first-in-human study with i.v. infusions of 0.1-0.96 mg kg(-1) h(-1) for 1 h and intermediate doses up to 4 h. Adverse event rates were generally similar among dose levels and between placebo- and GAL-021-treated subjects. At higher GAL-021 doses, a mild/moderate burning sensation at the infusion site occurred during the infusion. No clinically significant changes in vital signs or clinical chemistries were noted. Minute ventilation increased (AUE0-1 h ≈ 16%, P<0.05) and end-tidal carbon dioxide ([Formula: see text]) decreased (AUE0-1 h ≈ 6%, P<0.05) during the first hour at 0.96 mg kg(-1) h(-1) with 1/2-maximal [Formula: see text] and [Formula: see text]-change occurring by 7.5 min. Drug concentration rose rapidly during the infusion and decreased rapidly initially (distribution t1/2 of 30 min) and then more slowly (terminal t1/2 of 5.6 h). GAL-021 was safe and generally well tolerated with adverse events comparable with placebo except for an infusion site burning sensation. GAL-021 stimulated ventilation at the highest doses suggesting that greater infusion rates may be required for maximum PD effects. GAL-021 had PK characteristics consistent with an acute care medication. © The Author 2014. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radiation dose to workers due to the inhalation of dust during granite fabrication.

PubMed

Zwack, L M; McCarthy, W B; Stewart, J H; McCarthy, J F; Allen, J G

2014-03-01

There has been very little research conducted to determine internal radiation doses resulting from worker exposure to ionising radiation in granite fabrication shops. To address this issue, we estimated the effective radiation dose of granite workers in US fabrication shops who were exposed to the maximum respirable dust and silica concentrations allowed under current US regulations, and also to concentrations reported in the literature. Radiation doses were calculated using standard methods developed by the International Commission on Radiological Protection. The calculated internal doses were very low, and below both US occupational standards (50 mSv yr(-1)) and limits applicable to the general public (1 mSv yr(-1)). Workers exposed to respirable granite dust concentrations at the US Occupational Safety and Health Administration (OSHA) respirable dust permissible exposure limit (PEL) of 5 mg m(-3) over a full year had an estimated radiation dose of 0.062 mSv yr(-1). Workers exposed to respirable granite dust concentrations at the OSHA silica PEL and at the American Conference of Governmental Industrial Hygienists Threshold Limit Value for a full year had expected radiation doses of 0.007 mSv yr(-1) and 0.002 mSv yr(-1), respectively. Using data from studies of respirable granite dust and silica concentrations measured in granite fabrication shops, we calculated median expected radiation doses that ranged from <0.001 to 0.101 mSv yr(-1).

Output levels of commercially available portable compact disc players and the potential risk to hearing.

PubMed

Fligor, Brian J; Cox, L Clarke

2004-12-01

To measure the sound levels generated by the headphones of commercially available portable compact disc players and provide hearing healthcare providers with safety guidelines based on a theoretical noise dose model. Using a Knowles Electronics Manikin for Acoustical Research and a personal computer, output levels across volume control settings were recorded from headphones driven by a standard signal (white noise) and compared with output levels from music samples of eight different genres. Many commercially available models from different manufacturers were investigated. Several different styles of headphones (insert, supra-aural, vertical, and circumaural) were used to determine if style of headphone influenced output level. Free-field equivalent sound pressure levels measured at maximum volume control setting ranged from 91 dBA to 121 dBA. Output levels varied across manufacturers and style of headphone, although generally the smaller the headphone, the higher the sound level for a given volume control setting. Specifically, in one manufacturer, insert earphones increased output level 7-9 dB, relative to the output from stock headphones included in the purchase of the CD player. In a few headphone-CD player combinations, peak sound pressure levels exceeded 130 dB SPL. Based on measured sound pressure levels across systems and the noise dose model recommended by National Institute for Occupational Safety and Health for protecting the occupational worker, a maximum permissible noise dose would typically be reached within 1 hr of listening with the volume control set to 70% of maximum gain using supra-aural headphones. Using headphones that resulted in boosting the output level (e.g., insert earphones used in this study) would significantly decrease the maximum safe volume control setting; this effect was unpredictable from one manufacturer to another. In the interest of providing a straightforward recommendation that should protect the hearing of the majority of consumers, reasonable guidelines would include a recommendation to limit headphone use to 1 hr or less per day if using supra-aural style headphones at a gain control setting of 60% of maximum.

Haloperidol versus placebo for delirium prevention in acutely hospitalised older at risk patients: a multi-centre double-blind randomised controlled clinical trial.

PubMed

Schrijver, Edmée J M; de Vries, Oscar J; van de Ven, Peter M; Bet, Pierre M; Kamper, Ad M; Diepeveen, Sabine H A; van Marum, Rob J; van Strien, Astrid M; Anten, Sander; Lagaay, Anne M; Boelaarts, Leo; Bloemers, Frank W; Kramer, Mark H H; Nanayakkara, Prabath W B

2018-01-01

because the few randomised placebo-controlled trials investigating the potential role for prophylactic haloperidol in delirium prevention have focused on specific surgical populations, we investigated its efficacy and safety in acutely hospitalised older patients. this multi-centre, double-blind, stratified, block randomised, placebo-controlled trial was conducted at six Dutch hospitals. Patients age ≥70 years, acutely admitted through the emergency department for general medicine or surgical specialties and at risk for delirium were randomised (n = 245) to haloperidol or placebo 1 mg orally twice-daily (maximum of 14 doses) on top of standard nonpharmacological prevention strategies. The primary outcome was delirium incidence. Other endpoints included delirium severity and duration, drug safety and clinical outcomes. intention-to-treat analysis included 242 participants (calculated sample size n = 390, statistical power of current sample 59%) allocated to haloperidol (n = 118) or placebo (n = 124). In the haloperidol and placebo group, delirium incidence was 19.5 versus 14.5% (OR 1.43, 95% CI 0.72 to 2.78); median (IQR) delirium duration 4 (2, 5) versus 3 (1, 6) days (P = 0.366); maximum DRS-R-98 score 16 (9.8, 19.5) versus 10 (5.5, 22.5) (P = 0.549; 53.7% missing data); hospital LOS 7 (4, 10.3) versus 7 (5, 11.8) days (P = 0.343); 3-month mortality 9.9 versus 12.5% (OR 0.77, 95% CI 0.34 to 1.75), respectively. No treatment-limiting side effects were noted. prophylactic low-dose oral haloperidol did not reduce delirium incidence in acutely hospitalised older patients. Therefore, prophylactic use of haloperidol in this population is not recommended. © The Author 2017. Published by Oxford University Press on behalf of the British Geriatrics Society.All rights reserved. For permissions, please email: journals.permissions@oup.com

Doxorubicin plus the IGF-1R antibody cixutumumab in soft tissue sarcoma: a phase I study using the TITE-CRM model.

PubMed

Chugh, R; Griffith, K A; Davis, E J; Thomas, D G; Zavala, J D; Metko, G; Brockstein, B; Undevia, S D; Stadler, W M; Schuetze, S M

2015-07-01

Insulin-like growth factor receptor (IGF-1R) has been studied as an oncologic target in soft tissue sarcoma (STS), but its role in sarcoma biology is unclear. Anti-IGF-1R antibody cixutumumab demonstrated acceptable toxicity but limited activity as a single agent in STS. We carried out a dose-escalation study of cixutumumab with doxorubicin to evaluate safety and dosing of the combination. Eligible patients with advanced STS were treated with cixutumumab intravenously on days 1/8/15 at one of three dose levels (A: 1 mg/kg, B: 3 mg/kg, C: 6 mg/kg) with doxorubicin at 75 mg/m(2) as a 48 h infusion on day 1 of a 21 day cycle. After six cycles of the combination, patients could receive cixutumumab alone. The Time-to-Event Continual Reassessment Method was used to estimate the probability of dose-limiting toxicity (DLT) and to assign patients to the dose with an estimated probability of DLT≤20%. Between September 2008 and January 2012, 30 patients with advanced STS received a median of six cycles of therapy (range <1-22). Two DLTs were observed, grade 3 mucositis (dose level B) and grade 4 hyperglycemia (dose level C). Grade 2 and 3 reduced left ventricular ejection fraction was seen in three and two patients, respectively. Five partial responses were observed, and estimated progression-free survival was 5.3 months (95% confidence interval 3.0-6.3) in 26 response-assessable patients. Immunohistochemical staining of 11 available tumor samples for IGF-1R and phospho-IGF-1R was not significantly different among responders and non-responders, and serum analysis of select single-nucleotide polymorphisms did not predict for cardiotoxicity. The maximum tolerated dose was doxorubicin 75 mg/m(2) on day 1 and cixitumumab 6 mg/kg on days 1/8/15 of a 21 day cycle. Cardiac toxicity was observed and should be monitored in subsequent studies, which should be considered in STS only if a predictive biomarker of benefit to anti-IGF-1R therapy is identified. ClinicalTrials.gov:NCT00789633. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Automatic patient dose registry and clinical audit on line for mammography.

PubMed

Ten, J I; Vano, E; Sánchez, R; Fernandez-Soto, J M

2015-07-01

The use of automatic registry systems for patient dose in digital mammography allows clinical audit and patient dose analysis of the whole sample of individual mammography exposures while fulfilling the requirements of the European Directives and other international recommendations. Further parameters associated with radiation exposure (tube voltage, X-ray tube output and HVL values for different kVp and target/filter combinations, breast compression, etc.) should be periodically verified and used to evaluate patient doses. This study presents an experience in routine clinical practice for mammography using automatic systems. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Molecular identification of isolated fungi, microbial and heavy metal contamination of canned meat products sold in Riyadh, Saudi Arabia

PubMed Central

Nasser, Laila A.

2014-01-01

Several studies have shown that canned meat products may be contaminated with fungal elements, bacteria and even heavy metals which may occur during the transportation, storage and handling processes. We conducted this study to determine the fungal, microbial and heavy metal contents of canned meats in Saudi Arabia. Of the 13 canned meat samples studied, Aspergillus and Penicillium were found in more than 70% of the total samples. Sequences of Penicillium species isolated from meat samples generated a phylogenetic tree which shows that the studied isolates were clustered in four groups. No bacterial contamination was noted in all of the samples. Nine of the 13 samples had iron concentrations above the permissible limit. All samples had zinc and copper levels below the maximum permissible limit. Four samples had cadmium levels above the maximum permissible level. All samples had levels of lead above the maximum permissible levels. These results indicate that fungal elements and higher levels of heavy metals such as lead and cadmium can be found in canned meat products. This may pose as a real danger to consumers, since canned meat products are readily accessible and convenient in Saudi Arabia. PMID:26288552

Phase I/randomized phase II study of afatinib, an irreversible ErbB family blocker, with or without protracted temozolomide in adults with recurrent glioblastoma.

PubMed

Reardon, David A; Nabors, Louis B; Mason, Warren P; Perry, James R; Shapiro, William; Kavan, Petr; Mathieu, David; Phuphanich, Surasak; Cseh, Agnieszka; Fu, Yali; Cong, Julie; Wind, Sven; Eisenstat, David D

2015-03-01

This phase I/II trial evaluated the maximum tolerated dose (MTD) and pharmacokinetics of afatinib plus temozolomide as well as the efficacy and safety of afatinib as monotherapy (A) or with temozolomide (AT) vs temozolomide monotherapy (T) in patients with recurrent glioblastoma (GBM). Phase I followed a traditional 3 + 3 dose-escalation design to determine MTD. Treatment cohorts were: afatinib 20, 40, and 50 mg/day (plus temozolomide 75 mg/m(2)/day for 21 days per 28-day cycle). In phase II, participants were randomized (stratified by age and KPS) to receive A, T or AT; A was dosed at 40 mg/day and T at 75 mg/m(2) for 21 of 28 days. Primary endpoint was progression-free survival rate at 6 months (PFS-6). Participants were treated until intolerable adverse events (AEs) or disease progression. Recommended phase II dose was 40 mg/day (A) + T based on safety data from phase I (n = 32). Most frequent AEs in phase II (n = 119) were diarrhea (71% [A], 82% [AT]) and rash (71% [A] and 69% [AT]). Afatinib and temozolomide pharmacokinetics were unaffected by coadministration. Independently assessed PFS-6 rate was 3% (A), 10% (AT), and 23% (T). Median PFS was longer in afatinib-treated participants with epidermal growth factor receptor (EFGR) vIII-positive tumors versus EGFRvIII-negative tumors. Best overall response included partial response in 1 (A), 2 (AT), and 4 (T) participants and stable disease in 14 (A), 14 (AT), and 21 (T) participants. Afatinib has a manageable safety profile but limited single-agent activity in unselected recurrent GBM patients. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

EYE LENS EXPOSURE TO MEDICAL STAFF PERFORMING ELECTROPHYSIOLOGY PROCEDURES: DOSE ASSESSMENT AND CORRELATION TO PATIENT DOSE.

PubMed

Ciraj-Bjelac, Olivera; Antic, Vojislav; Selakovic, Jovana; Bozovic, Predrag; Arandjic, Danijela; Pavlovic, Sinisa

2016-12-01

The purpose of this study was to assess the patient exposure and staff eye dose levels during implantation procedures for all types of pacemaker therapy devices performed under fluoroscopic guidance and to investigate potential correlation between patients and staff dose levels. The mean eye dose during pacemaker/defibrillator implementation was 12 µSv for the first operator, 8.7 µSv for the second operator/nurse and 0.50 µSv for radiographer. Corresponding values for cardiac resynchronisation therapy procedures were 30, 26 and 2.0 µSv, respectively. Significant (p < 0.01) correlation between the eye dose and the kerma-area product was found for the first operator and radiographers, but not for other staff categories. The study revealed eye dose per procedure and eye dose normalised to patient dose indices for different staff categories and provided an input for radiation protection in electrophysiology procedures. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

RADIATION PROTECTION CABIN FOR CATHETER-DIRECTED LIVER INTERVENTIONS: OPERATOR DOSE ASSESSMENT.

PubMed

Maleux, Geert; Bergans, Niki; Bosmans, Hilde; Bogaerts, Ria

2016-09-01

The number and complexity of interventional radiological procedures and in particular catheter-directed liver interventions have increased substantially. The current study investigates the reduction of personal doses when using a dedicated radiation protection cabin (RPC) for these procedures. Operator and assistant doses were assessed for 3 series of 20 chemoinfusion/chemoembolisation interventions, including an equal number of procedures with and without RPC. Whole body doses, finger doses and doses at the level of knees and eyes were evaluated with different types of TLD-100 Harshaw dosemeters. Dosemeters were also attached on the three walls of the RPC. The operator doses were significantly reduced by the RPC, but also without RPC, the doses appear to be limited as a result of thorough optimisation with existing radiation protection tools. The added value of the RPC should thus be determined by the outcome of balancing dose reduction and other aspects such as ergonomic benefits. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Long-term mortality and cancer risk in irradiated rhesus monkeys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, D.H.

1989-01-01

Lifetime observations on a group of 358 rhesus monkeys indicate that life expectancy loss from exposure to protons in the energy range encountered in the Van Allen belts and solar proton events is influenced primarily by the dose rather than by the energy of radiation. After 24 years, life expectancy losses from similar surface doses of low-LET (138-2300 MeV) and high-LET (32-55 MeV) protons are not significantly different, but the high-LET protons are associated with more deaths in the early years, while the low-LET protons contribute more to mortality in later years. In males, the most significant cause of lifemore » shortening is nonleukemia cancers. In females, radiation increased the risk of endometriosis (an abnormal proliferation of the lining of the uterus) which resulted in significant mortality in the years before early detection and treatment methods were employed. The findings support the 1989 guidelines of the NCRP for maximum permissible radiation exposures in astronauts.« less

Defining an additivity framework for mixture research in inducible whole-cell biosensors

NASA Astrophysics Data System (ADS)

Martin-Betancor, K.; Ritz, C.; Fernández-Piñas, F.; Leganés, F.; Rodea-Palomares, I.

2015-11-01

A novel additivity framework for mixture effect modelling in the context of whole cell inducible biosensors has been mathematically developed and implemented in R. The proposed method is a multivariate extension of the effective dose (EDp) concept. Specifically, the extension accounts for differential maximal effects among analytes and response inhibition beyond the maximum permissive concentrations. This allows a multivariate extension of Loewe additivity, enabling direct application in a biphasic dose-response framework. The proposed additivity definition was validated, and its applicability illustrated by studying the response of the cyanobacterial biosensor Synechococcus elongatus PCC 7942 pBG2120 to binary mixtures of Zn, Cu, Cd, Ag, Co and Hg. The novel method allowed by the first time to model complete dose-response profiles of an inducible whole cell biosensor to mixtures. In addition, the approach also allowed identification and quantification of departures from additivity (interactions) among analytes. The biosensor was found to respond in a near additive way to heavy metal mixtures except when Hg, Co and Ag were present, in which case strong interactions occurred. The method is a useful contribution for the whole cell biosensors discipline and related areas allowing to perform appropriate assessment of mixture effects in non-monotonic dose-response frameworks

Definition of Local Diagnostic Reference Levels in a Radiology Department Using a Dose Tracking Software.

PubMed

Ghetti, C; Ortenzia, O; Palleri, F; Sireus, M

2017-06-01

Dose optimization in radiological examinations is a mandatory issue: in this study local Diagnostic Reference Levels (lDRLs) for Clinical Mammography (MG), Computed Tomography (CT) and Interventional Cardiac Procedures (ICP) performed in our Radiology Department were established. Using a dose tracking software, we have collected Average Glandular Dose (AGD) for two clinical mammographic units; CTDIvol, Size-Specific Dose Estimate (SSDE), Dose Length Product (DLP) and total DLP (DLPtot) for five CT scanners; Fluoro Time, Fluoro Dose Area Product (DAP) and total DAP (DAPtot) for two angiographic systems. Data have been compared with Italian Regulation and with the recent literature. The 75th percentiles of the different dosimetric indices have been calculated. Automated methods of radiation dose data collection allow a fast and detailed analysis of a great amount of data and an easy determination of lDRLs for different radiological procedures. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of Immunogenicity Between Inactivated and Live Attenuated Hepatitis A Vaccines Among Young Adults: A 3-Year Follow-up Study.

PubMed

Liu, Xue-en; Chen, Hai-ying; Liao, Zheng; Zhou, Yisheng; Wen, Hairong; Peng, Shihui; Liu, Yan; Li, Rui; Li, Jie; Zhuang, Hui

2015-10-15

A randomized clinical trial of hepatitis A vaccines (1 or 2 doses of inactivated vaccine [Healive] or 1 dose of live attenuated vaccine [Biovac]) was conducted among adults to evaluate seroprotection rates and geometric mean concentrations of antibody against hepatitis A virus for 36 months. High rates of seroprotection persisted for at least 36 months among adults who received 1 or 2 doses of inactivated hepatitis A vaccine but not among adults who received 1 dose of live attenuated hepatitis A vaccine. The long-term serial monitoring of immunogenicity induced by 1 dose of inactivated hepatitis A vaccine is needed to determine an effective alternative to a 2-dose schedule. NCT01865968. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Bioefficacy, residue dynamics and safety assessment of the combination fungicide trifloxystrobin 25% + tebuconazole 50%-75 WG in managing early blight of tomato (Lycopersicon esculentum Mill.).

PubMed

Saha, Sujoy; Purath, Ahammed Shabeer Thekkum; Jadhav, Manjusha R; Loganathan, M; Banerjee, Kaushik; Rai, A B

2014-01-01

This paper reports the in vitro and in vivo bioefficacy of a combination fungicide trifloxystrobin (25%) + tebuconazole (50%) against early blight disease of tomato (Lycopersicon esculentum Mill.) caused by Alternaria solani and their corresponding pre-harvest intervals (PHI) with reference to the maximum residue limits (European Union). Bioefficacy of the test fungicide combination revealed that in vitro conditions manifested the best control (75.1%) at 350 mg kg(-1) against 76.2% control under field conditions. A sample preparation method based on ethyl acetate extraction and estimation by LC-MS multiple reaction monitoring (MRM) was validated in tomato fruits at 0.01 mg/kg and dissipation studies were conducted in field at single and double doses. The residues of both the compounds on all the sampling days were below the European Union maximum residue limits (EU-MRLs) and the maximum permissible intakes (MPIs) were calculated on the basis of prescribed acceptable daily intake (ADI). The combined bioefficacy and residue dynamics information will support label-claim of this fungicide combination for the management of early blight in tomato.

EYE LENS DOSIMETRY FOR FLUOROSCOPICALLY GUIDED CLINICAL PROCEDURES: PRACTICAL APPROACHES TO PROTECTION AND DOSE MONITORING.

PubMed

Martin, Colin J

2016-06-01

Doses to the eye lenses of clinicians undertaking fluoroscopically guided procedures can exceed the dose annual limit of 20 mSv, so optimisation of radiation protection is essential. Ceiling-suspended shields and disposable radiation absorbing pads can reduce eye dose by factors of 2-7. Lead glasses that shield against exposures from the side can lower doses by 2.5-4.5 times. Training in effective use of protective devices is an essential element in achieving good protection and acceptable eye doses. Effective methods for dose monitoring are required to identify protection issues. Dosemeters worn adjacent to the eye provide the better option for interventional clinicians, but an unprotected dosemeter worn at the neck will give an indication of eye dose that is adequate for most interventional staff. Potential requirements for protective devices and dose monitoring can be determined from risk assessments using generic values for dose linked to examination workload. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Application of the ELDO approach to assess cumulative eye lens doses for interventional cardiologists.

PubMed

Farah, J; Struelens, L; Auvinen, A; Jacob, S; Koukorava, C; Schnelzer, M; Vanhavere, F; Clairand, I

2015-04-01

In preparation of a large European epidemiological study on the relation between eye lens dose and the occurrence of lens opacities, the European ELDO project focused on the development of practical methods to estimate retrospectively cumulative eye lens dose for interventional medical professionals exposed to radiation. The present paper applies one of the ELDO approaches, correlating eye lens dose to whole-body doses, to assess cumulative eye lens dose for 14 different Finnish interventional cardiologists for whom annual whole-body dose records were available for their entire working period. The estimated cumulative left and right eye lens dose ranged from 8 to 264 mSv and 6 to 225 mSv, respectively. In addition, calculations showed annual eye lens doses sometimes exceeding the new ICRP annual limit of 20 mSv. The work also highlights the large uncertainties associated with the application of such an approach proving the need for dedicated dosimetry systems in the routine monitoring of the eye lens dose. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

COMPARISON OF THE PERIPHERAL DOSES FROM DIFFERENT IMRT TECHNIQUES FOR PEDIATRIC HEAD AND NECK RADIATION THERAPY.

PubMed

Toyota, Masahiko; Saigo, Yasumasa; Higuchi, Kenta; Fujimura, Takuya; Koriyama, Chihaya; Yoshiura, Takashi; Akiba, Suminori

2017-11-01

Intensity-modulated radiation therapy (IMRT) can deliver high and homogeneous doses to the target area while limiting doses to organs at risk. We used a pediatric phantom to simulate the treatment of a head and neck tumor in a child. The peripheral doses were examined for three different IMRT techniques [dynamic multileaf collimator (DMLC), segmental multileaf collimator (SMLC) and volumetric modulated arc therapy (VMAT)]. Peripheral doses were evaluated taking thyroid, breast, ovary and testis as the points of interest. Doses were determined using a radio-photoluminescence glass dosemeter, and the COMPASS system was used for three-dimensional dose evaluation. VMAT achieved the lowest peripheral doses because it had the highest monitor unit efficiency. However, doses in the vicinity of the irradiated field, i.e. the thyroid, could be relatively high, depending on the VMAT collimator angle. DMLC and SMLC had a large area of relatively high peripheral doses in the breast region. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

33 CFR 401.29 - Maximum draft.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Maximum draft. 401.29 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.29 Maximum draft. (a) The draft...) The draft of a vessel shall not, in any case, exceed 79.2 dm or the maximum permissible draft...

33 CFR 401.29 - Maximum draft.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Maximum draft. 401.29 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.29 Maximum draft. (a) The draft...) The draft of a vessel shall not, in any case, exceed 79.2 dm or the maximum permissible draft...

33 CFR 401.29 - Maximum draft.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Maximum draft. 401.29 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.29 Maximum draft. (a) The draft...) The draft of a vessel shall not, in any case, exceed 79.2 dm or the maximum permissible draft...

Determination of As, Cd, Hg and Pb in continuous use drugs and excipients by plasma-based techniques in compliance with the United States Pharmacopeia requirements

NASA Astrophysics Data System (ADS)

da Silva, Caroline Santos; Pinheiro, Fernanda Costa; do Amaral, Clarice Dias Britto; Nóbrega, Joaquim Araújo

2017-12-01

Some inorganic impurities are toxic to human health even when present at low concentrations and therefore must be carefully monitored in products as continuous use drugs. This work aimed the development of a simple microwave-assisted digestion procedure for different types of drugs and excipients and the analytical determination of elemental impurities according to the new regulations of the United States Pharmacopeia (USP) 232 and 233 using inductively coupled plasma optical emission spectrometry (ICP-OES) or inductively coupled plasma mass spectrometry (ICP-MS). Eight drugs samples and two excipients of different brands were microwave-assisted digested with inverse aqua regia. Addition and recovery experiments were performed according to J values, once permissible daily exposure value is specific for each element and estimated according to the maximum daily dose of drug indicated by the label. Samples were spiked with values of 1.5J in order to check accuracies for As, Cd, Hg, and Pb. Recoveries obtained by ICP-OES ranged from 75 to 148% and for ICP-MS ranged from 74 to 120%. The limits of detection for ICP-OES ranged from 0.4 to 17 mg kg- 1 and for ICP-MS from 7.4 to 41.6 μg kg- 1. Both analytical methods were adequate in terms of accuracies and sensitivities. Considering the maximum daily dose, all drugs samples and excipients contained As, Cd, Hg and Pb below the maximum limits stipulated by USP since all of them presented contents below respective limits of detection.

Wavelength dependence of ocular damage thresholds in the near-ir to far-ir transition region: proposed revisions to MPES.

PubMed

Zuclich, Joseph A; Lund, David J; Stuck, Bruce E

2007-01-01

This report summarizes the results of a series of infrared (IR) laser-induced ocular damage studies conducted over the past decade. The studies examined retinal, lens, and corneal effects of laser exposures in the near-IR to far-IR transition region (wavelengths from 1.3-1.4 mum with exposure durations ranging from Q-switched to continuous wave). The corneal and retinal damage thresholds are tabulated for all pulsewidth regimes, and the wavelength dependence of the IR thresholds is discussed and contrasted to laser safety standard maximum permissible exposure limits. The analysis suggests that the current maximum permissible exposure limits could be beneficially revised to (1) relax the IR limits over wavelength ranges where unusually high safety margins may unintentionally hinder applications of recently developed military and telecommunications laser systems; (2) replace step-function discontinuities in the IR limits by continuously varying analytical functions of wavelength and pulsewidth which more closely follow the trends of the experimental retinal (for point-source laser exposures) and corneal ED50 threshold data; and (3) result in an overall simplification of the permissible exposure limits over the wavelength range from 1.2-2.6 mum. A specific proposal for amending the IR maximum permissible exposure limits over this wavelength range is presented.

Toxic metals in imported fruits and vegetables marketed in Kuwait

DOE Office of Scientific and Technical Information (OSTI.GOV)

Husain, A.; Baroon, Z.; Al-Khalafawi, M.

1995-12-31

The concentration of lead, cadmium, and mercury in 134 samples of imported fruits and vegetables marketed in Kuwait were determined using an atomic absorption spectrophotometer with a graphite furnace and the cold vapor technique. Results obtained showed that the concentration of these metal ions in most cases did not exceed the maximum permissible concentration of metals in fresh fruits and vegetables as restricted by some countries. Only a few samples of fruits and vegetables contained levels of mercury, cadmium, and lead which exceeded these maximum permissible levels.

Concentration of 129I in aquatic biota collected from a lake adjacent to the spent nuclear fuel reprocessing plant in Rokkasho, Japan.

PubMed

Ueda, Shinji; Kakiuchi, Hideki; Hasegawa, Hidenao; Kawamura, Hidehisa; Hisamatsu, Shun'ichi

2015-11-01

The spent nuclear fuel reprocessing plant in Rokkasho, Japan, has been undergoing final testing since March 2006. During April 2006-October 2008, that spent fuel was cut and chemically processed, the plant discharged (129)I into the atmosphere and coastal waters. To study (129)I behaviour in brackish Lake Obuchi, which is adjacent to the plant, (129)I concentrations in aquatic biota were measured by accelerator mass spectrometry. Owing to (129)I discharge from the plant, the (129)I concentration in the biota started to rise from the background concentration in 2006 and was high during 2007-08. The (129)I concentration has been rapidly decreasing after the fuel cutting and chemically processing were finished. The (129)I concentration factors in the biota were higher than those reported by IAEA for marine organisms and similar to those reported for freshwater biota. The estimated annual committed effective dose due to ingestion of foods with the maximum (129)I concentration in the biota samples was 2.8 nSv y(-1). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Degradation of chlorpyrifos residues in apple under temperate conditions of Kashmir Valley.

PubMed

Mukhtar, Malik; Sherwani, Asma; Wani, Ashraf Alam; Ahmed, Sheikh Bilal; Sofi, Javid Ahmad; Bano, Parveena

2015-08-01

The present studies were carried out to observe the dissipation pattern of chlorpyrifos on apple in Kashmir Valley. Persistence of chlorpyrifos in apple was studied following two applications rates of chlorpyrifos (Dursban 20 EC) at 200 g a.i. ha(-1) (single dose T 1) and 400 g a.i. ha(-1) (double dose T 2). The average initial deposit of chlorpyrifos was found to be 1.61 and 1.98 μg g(-1) for T 1 and T 2 application rates respectively on apple. The residues dissipated to 0.09 and 0.06 μg g(-1) after 15- and 30-day post treatment with half-life periods of 3.34 and 5.47 days in T 1 and T 2 application rates, respectively. The residues of chlorpyrifos dissipated to below limit of quantification (LOQ) of 0.04 μg g(-1) after 30 day at T 1 application rate. A waiting period of 6 days must be observed for chlorpyrifos on apple at recommended application rate for the safety of consumers. Theoretical maximum residue contribution (TMRC) values were found to be far less than maximum permissible intake (MPI) at 0 day in both the dosages suggesting chlorpyrifos on apple in Kashmir is unlikely to cause health risks.

Natural radionuclides in cigarette tobacco from Serbian market and effective dose estimate from smoke inhalation.

PubMed

Janković Mandić, Ljiljana; Đolić, Maja; Marković, Dragana; Todorović, Dragana; Onjia, Antonije; Dragović, Snežana

2016-01-01

The activity concentrations of natural radionuclides ((40)K, (210)Pb, (210)Po, (226)Ra and (228)Ra) in 17 most frequently used cigarette brands in Serbia and corresponding effective doses due to smoke inhalation are presented. The mean annual effective doses for (210)Pb and (210)Po were estimated to be 47.3 and 724 µSv y(-1) for (210)Pb and (210)Po, respectively. Serbia currently has the highest smoking rate in the world. The results of this study indicate the high contribution of the annual effective dose due to smoke inhalation to the total inhalation dose from natural radionuclides. The more effective implementation of actions for reducing smoking prevalence in Serbia is highly needed. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of gamma-irradiation sterilization and temperature on the fracture toughness of ultra-high-molecular-weight polyethylene.

PubMed

Pascaud, R S; Evans, W T; McCullagh, P J; FitzPatrick, D P

1997-05-01

Surface damage of the tibial plateau components of knee prostheses made from medical grade ultra-high-molecular-weight polyethylene (UHMW-PE) has been attributed to delamination wear caused by a fatigue fracture mechanism. It has been proposed that factors such as component design and method of sterilization contribute to such failure mechanisms. Understanding the fracture behaviour of UHMW-PE is therefore critical in optimizing the in vivo life-span of total joint components. The elastic-plastic fracture toughness parameter J was consequently determined for a commercial UHMW-PE at ambient and body temperatures, before and after gamma-irradiation sterilization in air at a minimum dose of 29 kGy. Both ductile stability theory and experimental data suggest that cracks propagate in a stable manner, although stability is affected by the sterilization process. Sterilization with gamma-irradiation results in a loss in fracture toughness JIc of 50% and a decrease in tearing modulus (Tm) of 30%. This dramatic reduction could result in a 50% decrease in the residual strength of the components, maximum permissible crack size under service loading and service life (assuming flaws such as fusion defects exist). The time required for a crack to grow from its original size to the maximum permissible size could be decreased by 30%, resulting in earlier failure. In terms of the design of joint replacement components the critical factor to envisage is the design stress level, which should be halved to account for the irradiation process. A scanning electron microscope study reveals that the material fails in layers parallel to the fracture surface.

Dose Estimating Application Software Modification: Additional Function of a Size-Specific Effective Dose Calculator and Auto Exposure Control.

PubMed

Kobayashi, Masanao; Asada, Yasuki; Matsubara, Kosuke; Suzuki, Shouichi; Matsunaga, Yuta; Haba, Tomonobu; Kawaguchi, Ai; Daioku, Tomihiko; Toyama, Hiroshi; Kato, Ryoichi

2017-05-01

Adequate dose management during computed tomography is important. In the present study, the dosimetric application software ImPACT was added to a functional calculator of the size-specific dose estimate and was part of the scan settings for the auto exposure control (AEC) technique. This study aimed to assess the practicality and accuracy of the modified ImPACT software for dose estimation. We compared the conversion factors identified by the software with the values reported by the American Association of Physicists in Medicine Task Group 204, and we noted similar results. Moreover, doses were calculated with the AEC technique and a fixed-tube current of 200 mA for the chest-pelvis region. The modified ImPACT software could estimate each organ dose, which was based on the modulated tube current. The ability to perform beneficial modifications indicates the flexibility of the ImPACT software. The ImPACT software can be further modified for estimation of other doses. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

PAEDIATRIC CT EXPOSURE PRACTICE IN THE COUNTY OF RIO DE JANEIRO: THE NEED TO ESTABLISH DIAGNOSTIC REFERENCE LEVELS.

PubMed

de Jesus, Fillipe M; Magalhães, Luis A G; Kodlulovich, Simone

2016-11-01

A pilot study of dose indicators in paediatric computed tomography (CT) was conducted to prove the need to establish diagnostic reference levels (DRLs) for the county of Rio de Janeiro. The dose descriptors were estimated from the beam dosimetry by applying the protocols used in each examination. The total patient sample included 279 children. Regarding the comparison of the dose-length product values among the hospitals, the high-resolution chest CT scans were distinguished among the three types of examinations, due to the discrepancies of 1148 % (1-5 y age group) and 2248 % (5-10 y age group) presented in Hospital A's dose-length product values relative to Hospital D's dose-length product values. The results showed that without DRL, the dose variation can be significant between hospitals in the same county for the same age group in the same examination. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Free Radical Oxidation in Rat Myocardium after Maximum Permissible Hepatic Resection.

PubMed

Ermolaev, P A; Khramykh, T P; Barskaya, L O

2016-03-01

Free radical oxidation in rat myocardial homogenate was studied by chemiluminescent assay during the early terms after maximum permissible liver resection. During this period, activation of free radical oxidation was biphasic. The critical terms characterized by dramatic intensification of free radical oxidation in the myocardium are the first hour and the first day after surgery. The period from 3 to 12 h after surgery, in which the indices of chemiluminescence decrease, can be tentatively termed as the period of "putative wellbeing". Normalization of the free radical oxidation processes in the myocardium occurred by day 7 after surgery.

Efficacy of losartan vs. atenolol for the prevention of aortic dilation in Marfan syndrome: a randomized clinical trial.

PubMed

Forteza, Alberto; Evangelista, Arturo; Sánchez, Violeta; Teixidó-Turà, Gisela; Sanz, Paz; Gutiérrez, Laura; Gracia, Teresa; Centeno, Jorge; Rodríguez-Palomares, José; Rufilanchas, Juan Jose; Cortina, José; Ferreira-González, Ignacio; García-Dorado, David

2016-03-21

To determine the efficacy of losartan vs. atenolol in aortic dilation progression in Marfan syndrome (MFS) patients. A phase IIIb, randomized, parallel, double-blind study was conducted in 140 MFS patients, age range: 5-60 years, with maximum aortic diameter <45 mm who received losartan (n = 70) or atenolol (n = 70). Doses were raised to a maximum of 1.4 mg/kg/day or 100 mg/day. The primary end-point was the change in aortic root and ascending aorta maximum diameter indexed by body surface area on magnetic resonance imaging after 36 months of treatment. No serious drug-related adverse effects were observed. Five patients presented aortic events during a follow-up (one in the losartan and four in the atenolol groups, P = 0.366). After 3 years of follow-up, aortic root diameter increased significantly in both groups: 1.1 mm (95% CI 0.6-1.6) in the losartan and 1.4 mm (95% CI 0.9-1.9) in the atenolol group, with aortic dilatation progression being similar in both groups: absolute difference between losartan and atenolol -0.3 mm (95% CI -1.1 to 0.4, P = 0.382) and indexed by BSA -0.5 mm/m2 (95% CI -1.2 to 0.1, P = 0.092). Similarly, no significant differences were found in indexed ascending aorta diameter changes between the losartan and atenolol groups: -0.3 mm/m2 (95% CI -0.8 to 0.3, P = 0.326). Among patients with MFS, the use of losartan compared with atenolol did not result in significant differences in the progression of aortic root and ascending aorta diameters over 3 years of follow-up. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Control of natural microorganisms in chamomile (Chamomilla recutita L.) by gamma ray and electron beam irradiation.

PubMed

Al-Bachir, Mahfouz

2017-01-01

Microbial contamination levels and corresponding sensitivities to gamma rays (GR) and elec- tron beam (EB) irradiation were tested in chamomile (Chamomile recutta L.). Chamomile powders were treated with 10 and 20 kGy by GR and EB, respectively. Microbiological and chemical analyses were performed on controls and treated samples immediately after irradiation, and after 12 months of storage. The control samples of chamomile exhibited rather high microbiological contamination, exceeding the levels of 4 log10 CFU g-1   (CFU - colony forming units) reported by national and international authorities as the maximum permissible total count level. Irradiation with GR and EB was found to cause a reduction in microbial contamination proportionate to the dose delivered. The sterilizing effect of EB on microorganisms was higher than the GR one. A dose of 10 kGy of GR and EB significantly (p < 0.05) reduced the total bacte- rial, total coliform and total fungal contamination. A dose of 20 kGy of GR significantly (p < 0.05) reduced the total bacterial and total fungal contamination, while a 20 kGy dose of EB reduced the initial bacterial, total coliform and total fungal contamination to below detection level when the analysis was carried out im- mediately after irradiation treatment or after 12 months of storage. The comparative study demonstrated that electron beam was more effective for decontamination of chamomile powder than gamma irradiation.

Measurements of eye lens doses in interventional cardiology using OSL and electronic dosemeters†.

PubMed

Sanchez, R M; Vano, E; Fernandez, J M; Ginjaume, M; Duch, M A

2014-12-01

The purpose of this paper is to test the appropriateness of OSL and electronic dosemeters to estimate eye lens doses at interventional cardiology environment. Using TLD as reference detectors, personal dose equivalent was measured in phantoms and during clinical procedures. For phantom measurements, OSL dose values resulted in an average difference of -15 % vs. TLD. Tests carried out with other electronic dosemeters revealed differences up to ±20 % versus TLD. With dosemeters positioned outside the goggles and when TLD doses were >20 μSv, the average difference OSL vs. TLD was -9 %. Eye lens doses of almost 700 μSv per procedure were measured in two cases out of a sample of 33 measurements in individual clinical procedures, thus showing the risk of high exposure to the lenses of the eye when protection rules are not followed. The differences found between OSL and TLD are acceptable for the purpose and range of doses measured in the survey. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

ESTIMATION OF EARLY INTERNAL DOSES TO FUKUSHIMA RESIDENTS AFTER THE NUCLEAR DISASTER BASED ON THE ATMOSPHERIC DISPERSION SIMULATION.

PubMed

Kim, Eunjoo; Tani, Kotaro; Kunishima, Naoaki; Kurihara, Osamu; Sakai, Kazuo; Akashi, Makoto

2016-11-01

Estimating the early internal doses to residents in the Fukushima Daiichi Nuclear Power Station accident is a difficult task because limited human/environmental measurement data are available. Hence, the feasibility of using atmospheric dispersion simulations created by the Worldwide version of System for Prediction of Environmental Emergency Dose Information 2nd Version (WSPEEDI-II) in the estimation was examined in the present study. This examination was done by comparing the internal doses evaluated based on the human measurements with those calculated using time series air concentration maps ( 131 I and 137 Cs) generated by WSPEEDI-II. The results showed that the latter doses were several times higher than the former doses. However, this discrepancy could be minimised by taking into account personal behaviour data that will be available soon. This article also presents the development of a prototype system for estimating the internal dose based on the simulations. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Changes in ambient dose equivalent rates around roads at Kawamata town after the Fukushima accident.

PubMed

Kinase, Sakae; Sato, Satoshi; Sakamoto, Ryuichi; Yamamoto, Hideaki; Saito, Kimiaki

2015-11-01

Changes in ambient dose equivalent rates noted through vehicle-borne surveys have elucidated ecological half-lives of radioactive caesium in the environment. To confirm that the ecological half-lives are appropriate for predicting ambient dose equivalent rates within living areas, it is important to ascertain ambient dose equivalent rates on/around roads. In this study, radiation monitoring on/around roads at Kawamata town, located about 37 km northwest of the Fukushima Daiichi Nuclear Power Plant, was performed using monitoring vehicles and survey meters. It was found that the ambient dose equivalent rates around roads were higher than those on roads as of October 2012. And withal the ecological half-lives on roads were essentially consistent with those around roads. With dose predictions using ecological half-lives on roads, it is necessary to make corrections to ambient dose equivalent rates through the vehicle-borne surveys against those within living areas. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Validation of a MOSFET dosemeter system for determining the absorbed and effective radiation doses in diagnostic radiology.

PubMed

Manninen, A-L; Kotiaho, A; Nikkinen, J; Nieminen, M T

2015-04-01

This study aimed to validate a MOSFET dosemeter system for determining absorbed and effective doses (EDs) in the dose and energy range used in diagnostic radiology. Energy dependence, dose linearity and repeatability of the dosemeter were examined. The absorbed doses (ADs) were compared at anterior-posterior projection and the EDs were determined at posterior-anterior, anterior-posterior and lateral projections of thoracic imaging using an anthropomorphic phantom. The radiation exposures were made using digital radiography systems. This study revealed that the MOSFET system with high sensitivity bias supply set-up is sufficiently accurate for AD and ED determination. The dosemeter is recommended to be calibrated for energies <60 and >80 kVp. The entrance skin dose level should be at least 5 mGy to minimise the deviation of the individual dosemeter dose. For ED determination, dosemeters should be implanted perpendicular to the surface of the phantom to prevent the angular dependence error. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

In vivo imaging of human retinal microvasculature using adaptive optics scanning light ophthalmoscope fluorescein angiography

PubMed Central

Pinhas, Alexander; Dubow, Michael; Shah, Nishit; Chui, Toco Y.; Scoles, Drew; Sulai, Yusufu N.; Weitz, Rishard; Walsh, Joseph B.; Carroll, Joseph; Dubra, Alfredo; Rosen, Richard B.

2013-01-01

The adaptive optics scanning light ophthalmoscope (AOSLO) allows visualization of microscopic structures of the human retina in vivo. In this work, we demonstrate its application in combination with oral and intravenous (IV) fluorescein angiography (FA) to the in vivo visualization of the human retinal microvasculature. Ten healthy subjects ages 20 to 38 years were imaged using oral (7 and/or 20 mg/kg) and/or IV (500 mg) fluorescein. In agreement with current literature, there were no adverse effects among the patients receiving oral fluorescein while one patient receiving IV fluorescein experienced some nausea and heaving. We determined that all retinal capillary beds can be imaged using clinically accepted fluorescein dosages and safe light levels according to the ANSI Z136.1-2000 maximum permissible exposure. As expected, the 20 mg/kg oral dose showed higher image intensity for a longer period of time than did the 7 mg/kg oral and the 500 mg IV doses. The increased resolution of AOSLO FA, compared to conventional FA, offers great opportunity for studying physiological and pathological vascular processes. PMID:24009994

A phase 1b clinical trial of the CD40-activating antibody CP-870,893 in combination with cisplatin and pemetrexed in malignant pleural mesothelioma.

PubMed

Nowak, A K; Cook, A M; McDonnell, A M; Millward, M J; Creaney, J; Francis, R J; Hasani, A; Segal, A; Musk, A W; Turlach, B A; McCoy, M J; Robinson, B W S; Lake, R A

2015-12-01

Data from murine models suggest that CD40 activation may synergize with cytotoxic chemotherapy. We aimed to determine the maximum tolerated dose (MTD) and toxicity profile and to explore immunological biomarkers of the CD40-activating antibody CP-870,893 with cisplatin and pemetrexed in patients with malignant pleural mesothelioma (MPM). Eligible patients had confirmed MPM, ECOG performance status 0-1, and measurable disease. Patients received cisplatin 75 mg/m(2) and pemetrexed 500 mg/m(2) on day 1 and CP-870,893 on day 8 of a 21-day cycle for maximum 6 cycles with up to 6 subsequent cycles single-agent CP-870,893. Immune cell subset changes were examined weekly by flow cytometry. Fifteen patients were treated at three dose levels. The MTD of CP-870,893 was 0.15 mg/kg, and was exceeded at 0.2 mg/kg with one grade 4 splenic infarction and one grade 3 confusion and hyponatraemia. Cytokine release syndrome (CRS) occurred in most patients (80%) following CP-870,893. Haematological toxicities were consistent with cisplatin and pemetrexed chemotherapy. Six partial responses (40%) and 9 stable disease (53%) as best response were observed. The median overall survival was 16.5 months; the median progression-free survival was 6.3 months. Three patients survived beyond 30 months. CD19+ B cells decreased over 6 cycles of chemoimmunotherapy (P < 0.001) with a concomitant increase in the proportion of CD27+ memory B cells (P < 0.001) and activated CD86+CD27+ memory B cells (P < 0.001), as an immunopharmacodynamic marker of CD40 activation. CP-870,893 with cisplatin and pemetrexed is safe and tolerable at 0.15 mg/kg, although most patients experience CRS. While objective response rates are similar to chemotherapy alone, three patients achieved long-term survival. ACTRN12609000294257. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Population Pharmacokinetics and Pharmacodynamics of Dexmedetomidine in Children Undergoing Ambulatory Surgery.

PubMed

Pérez-Guillé, María-Gabriela; Toledo-López, Alejandra; Rivera-Espinosa, Liliana; Alemon-Medina, Radames; Murata, Chiharu; Lares-Asseff, Ismael; Chávez-Pacheco, Juan Luis; Gómez-Garduño, Josefina; Zamora Gutiérrez, Ana-Lilia; Orozco-Galicia, Claudia; Ramírez-Morales, Karina; Lugo-Goytia, Gustavo

2018-05-17

Dexmedetomidine (DEX) is an α-2 adrenergic agonist with sedative and analgesic properties. Although not approved for pediatric use by the Food and Drug Administration, DEX is increasingly used in pediatric anesthesia and critical care. However, very limited information is available regarding the pharmacokinetics of DEX in children. The aim of this study was to investigate DEX pharmacokinetics and pharmacodynamics (PK-PD) in Mexican children 2-18 years of age who were undergoing outpatient surgical procedures. Thirty children 2-18 years of age with American Society of Anesthesiologists physical status score of I/II were enrolled in this study. DEX (0.7 µg/kg) was administered as a single-dose intravenous infusion. Venous blood samples were collected, and plasma DEX concentrations were analyzed with a combination of high-performance liquid chromatography and electrospray ionization-tandem mass spectrometry. Population PK-PD models were constructed using the Monolix program. A 2-compartment model adequately described the concentration-time relationship. The parameters were standardized for a body weight of 70 kg by using an allometric model. Population parameters estimates were as follows: mean (between-subject variability): clearance (Cl) (L/h × 70 kg) = 20.8 (27%); central volume of distribution (V1) (L × 70 kg) = 21.9 (20%); peripheral volume of distribution (V2) (L × 70 kg) = 81.2 (21%); and intercompartmental clearance (Q) (L/h × 70 kg) = 75.8 (25%). The PK-PD model predicted a maximum mean arterial blood pressure reduction of 45% with an IC50 of 0.501 ng/ml, and a maximum heart rate reduction of 28.9% with an IC50 of 0.552 ng/ml. Our results suggest that in Mexican children 2-18 years of age with American Society of Anesthesiologists score of I/II, the DEX dose should be adjusted in accordance with lower DEX clearance.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

CALCULATION OF GAMMA SPECTRA IN A PLASTIC SCINTILLATOR FOR ENERGY CALIBRATIONAND DOSE COMPUTATION.

PubMed

Kim, Chankyu; Yoo, Hyunjun; Kim, Yewon; Moon, Myungkook; Kim, Jong Yul; Kang, Dong Uk; Lee, Daehee; Kim, Myung Soo; Cho, Minsik; Lee, Eunjoong; Cho, Gyuseong

2016-09-01

Plastic scintillation detectors have practical advantages in the field of dosimetry. Energy calibration of measured gamma spectra is important for dose computation, but it is not simple in the plastic scintillators because of their different characteristics and a finite resolution. In this study, the gamma spectra in a polystyrene scintillator were calculated for the energy calibration and dose computation. Based on the relationship between the energy resolution and estimated energy broadening effect in the calculated spectra, the gamma spectra were simply calculated without many iterations. The calculated spectra were in agreement with the calculation by an existing method and measurements. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Early phase evaluation of SQ109 alone and in combination with rifampicin in pulmonary TB patients.

PubMed

Heinrich, Norbert; Dawson, Rodney; du Bois, Jeannine; Narunsky, Kim; Horwith, Gary; Phipps, Andrew J; Nacy, Carol A; Aarnoutse, Rob E; Boeree, Martin J; Gillespie, Stephen H; Venter, Amour; Henne, Sonja; Rachow, Andrea; Phillips, Patrick P J; Hoelscher, Michael; Diacon, Andreas H

2015-05-01

SQ109, an asymmetrical diamine, is a novel anti-TB drug candidate. This first study in patients was done to determine safety, tolerability, pharmacokinetics and bacteriological effect of different doses of SQ109 alone and in combination with rifampicin when administered over 14 days. Smear-positive pulmonary TB patients were randomized into six groups of 15 to receive once-daily oral treatment with 75, 150 or 300 mg of SQ109, rifampicin (10 mg/kg body weight), rifampicin plus 150 mg of SQ109, or rifampicin plus 300 mg of SQ109 for 14 days. Patients were hospitalized for supervised treatment, regular clinical, biochemical and electrocardiographic safety assessments, pharmacokinetic profiling and daily overnight sputum collection. SQ109 was safe and generally well tolerated. Mild to moderate dose-dependent gastrointestinal complaints were the most frequent adverse events. No relevant QT prolongation was noted. Maximum SQ109 plasma concentrations were lower than MICs. Exposure to SQ109 (AUC0-24) increased by drug accumulation upon repeated administration in the SQ109 monotherapy groups. Co-administration of SQ109 150 mg with rifampicin resulted in decreasing SQ109 exposures from day 1 to day 14. A higher (300 mg) dose of SQ109 largely outweighed the evolving inductive effect of rifampicin. The daily fall in log cfu/mL of sputum (95% CI) was 0.093 (0.126-0.059) with rifampicin, 0.133 (0.166-0.100) with rifampicin plus 150 mg of SQ109 and 0.089 (0.121-0.057) with rifampicin plus 300 mg of SQ109. Treatments with SQ109 alone showed no significant activity. SQ109 alone or with rifampicin was safe over 14 days. Upon co-administration with rifampicin, 300 mg of SQ109 yielded a higher exposure than the 150 mg dose. SQ109 did not appear to be active alone or to enhance the activity of rifampicin during the 14 days of treatment. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Critical Dose of Internal Organs Internal Exposure - 13471

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grigoryan, G.; Amirjanyan, A.; Grigoryan, N.

2013-07-01

The health threat posed by radionuclides has stimulated increased efforts to developed characterization on the biological behavior of radionuclides in humans in all ages. In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is assembling a set of age specific biokinetic models for environmentally important radioelements. Radioactive substances in the air, mainly through the respiratory system and digestive tract, is inside the body. Radioactive substances are unevenly distributed in various organs and tissues. Therefore, the degree of damage will depend not only on the dose of radiation have but also on themore » critical organ, which is the most accumulation of radioactive substances, which leads to the defeat of the entire human body. The main objective of radiation protection, to avoid exceeding the maximum permissible doses of external and internal exposure of a person to prevent the physical and genetic damage people. The maximum tolerated dose (MTD) of radiation is called a dose of radiation a person in uniform getting her for 50 years does not cause changes in the health of the exposed individual and his progeny. The following classification of critical organs, depending on the category of exposure on their degree of sensitivity to radiation: First group: the whole body, gonads and red bone marrow; Second group: muscle, fat, liver, kidney, spleen, gastrointestinal tract, lungs and lens of the eye; The third group: bone, thyroid and skin; Fourth group: the hands, forearms, feet. MTD exposure whole body, gonads and bone marrow represent the maximum exposures (5 rem per year) experienced by people in their normal activities. The purpose of this article is intended dose received from various internal organs of the radionuclides that may enter the body by inhalation, and gastrointestinal tract. The biokinetic model describes the time dependent distribution and excretion of different radionuclides that have intake into the organism or absorbed into blood. Transport of different radionuclides between compartments is assumed to follow first order kinetics provided the concentration in red blood cells (RBCs) stays below a nonlinear threshold concentration. When the concentration in RBCs exceeds that threshold, the transfer rate from diffusible plasma to RBCs is assumed to decrease as the concentration in RBCs increases. For the calculations used capabilities AMBER by using the traces of radionuclides in the body. Model for the transfer of radionuclides in the body has been built on the basis of existing models at AMBER for lead. (authors)« less

Public Risk Criteria and Rationale for Commercial Launch and Reentry

NASA Astrophysics Data System (ADS)

Wilde, P. D.

2012-01-01

This paper summarizes the rationale for risk criteria intended to protect the public during commercial spaceflight, including launch, reentry, and suborbital missions. The recommended approach includes: (1) safety goals to guide periodic updates of the quantitative collective risk limits if warranted based on the quantity of launch and reentry missions; the demonstrated safety record and benefits provided; technological capabilities and maturity of the industry; and contemporary attitudes about the risks from commercial space transportation; (2) separate limits on the risks from each type of mission with explicit definitions of the extent of launch and reentry missions; and (3) quantitative risk limits consistent with the safety goals. For current conditions, the author's recommends (a) maximum of 1E-6 probability of casualty per-mission (b) a maximum of 100E-6 expected casualties per-mission, and (c) equal per-mission risk limits for orbital and suborbital launches, as well as controlled and uncontrolled reentries.

[Acoustic conditions in open plan offices - Pilot test results].

PubMed

Mikulski, Witold

The main source of noise in open plan office are conversations. Office work standards in such premises are attained by applying specific acoustic adaptation. This article presents the results of pilot tests and acoustic evaluation of open space rooms. Acoustic properties of 6 open plan office rooms were the subject of the tests. Evaluation parameters, measurement methods and criterial values were adopted according to the following standards: PN-EN ISO 3382- 3:2012, PN-EN ISO 3382-2:2010, PN-B-02151-4:2015-06 and PN-B-02151-3:2015-10. The reverberation time was 0.33- 0.55 s (maximum permissible value in offices - 0.6 s; the criterion was met), sound absorption coefficient in relation to 1 m2 of the room's plan was 0.77-1.58 m2 (minimum permissible value - 1.1 m2; 2 out of 6 rooms met the criterion), distraction distance was 8.5-14 m (maximum permissible value - 5 m; none of the rooms met the criterion), A-weighted sound pressure level of speech at a distance of 4 m was 43.8-54.7 dB (maximum permissible value - 48 dB; 2 out of 6 rooms met the criterion), spatial decay rate of the speech was 1.8-6.3 dB (minimum permissible value - 7 dB; none of the rooms met the criterion). Standard acoustic treatment, containing sound absorbing suspended ceiling, sound absorbing materials on the walls, carpet flooring and sound absorbing workplace barriers, is not sufficient. These rooms require specific advanced acoustic solutions. Med Pr 2016;67(5):653-662. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

IDACstar: A MCNP Application to Perform Realistic Dose Estimations from Internal or External Contamination of Radiopharmaceuticals.

PubMed

Ören, Ünal; Hiller, Mauritius; Andersson, M

2017-04-28

A Monte Carlo-based stand-alone program, IDACstar (Internal Dose Assessment by Computer), was developed, dedicated to perform radiation dose calculations using complex voxel simulations. To test the program, two irradiation situations were simulated, one hypothetical contamination case with 600 MBq of 99mTc and one extravasation case involving 370 MBq of 18F-FDG. The effective dose was estimated to be 0.042 mSv for the contamination case and 4.5 mSv for the extravasation case. IDACstar has demonstrated that dosimetry results from contamination or extravasation cases can be acquired with great ease. An effective tool for radiation protection applications is provided with IDACstar allowing physicists at nuclear medicine departments to easily quantify the radiation risk of stochastic effects when a radiation accident has occurred. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

INTEGRATED CIRCUITS FROM MOBILE PHONES AS POSSIBLE EMERGENCY OSL/TL DOSIMETERS.

PubMed

Sholom, S; McKeever, S W S

2016-09-01

In this article, optically stimulated luminescence (OSL) data are presented from integrated circuits (ICs) extracted from mobile phones. The purpose is to evaluate the potential of using OSL from components in personal electronic devices such as smart phones as a means of emergency dosimetry in the event of a large-scale radiological incident. ICs were extracted from five different makes and models of mobile phone. Sample preparation procedures are described, and OSL from the IC samples following irradiation using a (90)Sr/(90)Y source is presented. Repeatability, sensitivity, dose responses, minimum measureable doses, stability and fading data were examined and are described. A protocol for measuring absorbed dose is presented, and it was concluded that OSL from these components is a viable method for assessing dose in the days following a radiological incident. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radiation dosimetry properties of smartphone CMOS sensors.

PubMed

Van Hoey, Olivier; Salavrakos, Alexia; Marques, Antonio; Nagao, Alexandre; Willems, Ruben; Vanhavere, Filip; Cauwels, Vanessa; Nascimento, Luana F

2016-03-01

During the past years, several smartphone applications have been developed for radiation detection. These applications measure radiation using the smartphone camera complementary metal-oxide-semiconductor sensor. They are potentially useful for data collection and personal dose assessment in case of a radiological incident. However, it is important to assess these applications. Six applications were tested by means of irradiations with calibrated X-ray and gamma sources. It was shown that the measurement stabilises only after at least 10-25 min. All applications exhibited a flat dose rate response in the studied ambient dose equivalent range from 2 to 1000 μSv h(-1). Most applications significantly over- or underestimate the dose rate or are not calibrated in terms of dose rate. A considerable energy dependence was observed below 100 keV but not for the higher energy range more relevant for incident scenarios. Photon impact angle variation gave a measured signal variation of only about 10 %. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Stochastic dosimetry model for radon progeny in the rat lung.

PubMed

Winkler-HeiI, R; Hofmann, W; Hussain, M

2014-07-01

The stochastic dosimetry model presented here considers the distinctly asymmetric, stochastic branching pattern reported in morphometric measurements. This monopodial structure suggests that an airway diameter is a more appropriate morphometric parameter to classify bronchial dose distributions for inhaled radon progeny than the commonly assigned airway generation numbers. Bronchial doses were calculated for the typical exposure conditions reported for the Pacific Northwest National Laboratory rat inhalation studies, yielding an average bronchial dose of 7.75 mGy WLM(-1). If plotted as functions of airway generations, the resulting dose distributions are highest in the central bronchial airways, while significantly decreasing towards peripheral generations. However, if plotted as functions of airway diameters, doses are much more uniformly distributed among bronchial airways. The comparison between rat and human lungs indicates that dose conversion coefficients for the rat lung are higher than the corresponding values for the human lung by a factor of 1.34 for the experimental PNNL exposure conditions, and of 1.25 for typical human indoor conditions. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

COMPARISON OF ORGAN DOSES IN HUMAN PHANTOMS: VARIATIONS DUE TO BODY SIZE AND POSTURE.

PubMed

Feng, Xu; Xiang-Hong, Jia; Qian, Liu; Xue-Jun, Yu; Zhan-Chun, Pan; Chun-Xin, Yang

2017-04-20

Organ dose calculations performed using human phantoms can provide estimates of astronauts' health risks due to cosmic radiation. However, the characteristics of such phantoms strongly affect the estimation precision. To investigate organ dose variations with body size and posture in human phantoms, a non-uniform rational B-spline boundary surfaces model was constructed based on cryosection images. This model was used to establish four phantoms with different body size and posture parameters, whose organs parameters were changed simultaneously and which were voxelised with 4 × 4 × 4 mm3 resolution. Then, using Monte Carlo transport code, the organ doses caused by ≤500 MeV isotropic incident protons were calculated. The dose variations due to body size differences within a certain range were negligible, and the doses received in crouching and standing-up postures were similar. Therefore, a standard Chinese phantom could be established, and posture changes cannot effectively protect astronauts during solar particle events. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SU-G-206-08: How Should Focal Spot Be Chosen for Optimized CT Imaging with Dose Modulation?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bache, S; Liu, X; Rong, J

Purpose: To choose the preferred focal spot for achieving optimized CT image quality with balanced tube heating considerations. Methods: An anthropomorphic pelvic phantom was scanned using a GE Discovery CT750 HD at 120 and 140kVp, 0.8s rotation time, and pitch of 0.984. “Smart mA” was enabled to simulate a routine abdomen–pelvis CT scan. Permissible mA values at 120 and 140 kVp were obtained from the Serial Load Rating table (for mimicking a busy CT clinical operation) in the scanner Technical Reference Manual. At each kVp station and two Noise Index levels, the mA Upper Limit was set above/below the permissiblemore » mA values. Scanned mA values and focal spot (FS) used were obtained from the DICOM header of each image, and the FS-mA relationship was analyzed. For visual confirmation beyond recorded FS information, a CatPhan with a fat-ring attached for mimicking patient size/shape was scanned at 120kVp. A group of radiologists/physicists compared a pair of CatPhan images qualitatively. Lastly, a number of patient cases were evaluated to confirm the FS-mA relationship. Results: When preset Upper Limit values were above the permissible mA values, the Large FS (labeled 1.2) was used in scans, even if the maximum scanned mA values were much lower than the permissible values at both 120 and 140 kVp. Otherwise the Small FS (labeled 0.7) was used. Visual evaluation of the high contrast module of CatPhan and additional analysis of patient cases further confirmed that the preset Upper Limit determines which focal spot is to be used, not the actual maximum mA value to be scanned. Conclusion: Specific FS can be selected by setting up appropriate mA Upper Limit in a protocol. CT protocols could be optimized by selecting appropriate FS for improving patient image quality, especially benefiting the small size and pediatric patients.« less

PROPOSALS FOR THE ESTABLISHMENT OF NATIONAL DIAGNOSTIC REFERENCE LEVELS FOR RADIOGRAPHY FOR ADULT PATIENTS BASED ON REGIONAL DOSE SURVEYS IN RUSSIAN FEDERATION.

PubMed

Vodovatov, A V; Balonov, M I; Golikov, V Yu; Shatsky, I G; Chipiga, L A; Bernhardsson, C

2017-04-01

In 2009-2014, dose surveys aimed to collect adult patient data and parameters of most common radiographic examinations were performed in six Russian regions. Typical patient doses were estimated for the selected examinations both in entrance surface dose and in effective dose. 75%-percentiles of typical patient effective dose distributions were proposed as preliminary regional diagnostic reference levels (DRLs) for radiography. Differences between the 75%-percentiles of regional typical patient dose distributions did not exceed 30-50% for the examinations with standardized clinical protocols (skull, chest and thoracic spine) and a factor of 1.5 for other examinations. Two different approaches for establishing national DRLs were evaluated: as a 75%-percentile of a pooled regional sample of patient typical doses (pooled method) and as a median of 75%-percentiles of regional typical patient dose distributions (median method). Differences between pooled and median methods for effective dose did not exceed 20%. It was proposed to establish Russian national DRLs in effective dose using a pooled method. In addition, the local authorities were granted an opportunity to establish regional DRLs if the local radiological practice and typical patient dose distributions are significantly different. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radon decay products in realistic living rooms and their activity distributions in human respiratory system.

PubMed

Mohery, M; Abdallah, A M; Baz, S S; Al-Amoudi, Z M

2014-12-01

In this study, the individual activity concentrations of attached short-lived radon decay products ((218)Po, (214)Pb and (214)Po) in aerosol particles were measured in ten poorly ventilated realistic living rooms. Using standard methodologies, the samples were collected using a filter holder technique connected with alpha-spectrometric. The mean value of air activity concentration of these radionuclides was found to be 5.3±0.8, 4.5±0.5 and 3.9±0.4 Bq m(-3), respectively. Based on the physical properties of the attached decay products and physiological parameters of light work activity for an adult human male recommended by ICRP 66 and considering the parameters of activity size distribution (AMD = 0.25 μm and σ(g) = 2.5) given by NRC, the total and regional deposition fractions in each airway generation could be evaluated. Moreover, the total and regional equivalent doses in the human respiratory tract could be estimated. In addition, the surface activity distribution per generation is calculated for the bronchial region (BB) and the bronchiolar region (bb) of the respiratory system. The maximum values of these activities were found in the upper bronchial airway generations. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Utilization of Photochemically Induced Fluorescence Detection for HPLC Determination of Genotoxic Impurities in the Vortioxetine Manufacturing Process.

PubMed

Douša, Michal; Doubský, Jan; Srbek, Jan

2016-07-01

An analytical reversed-phase high-performance liquid chromatography (HPLC) method for the detection and quantitative determination of two genotoxic impurities at ppm level present in the vortioxetine manufacturing process is described. Applying the concept of threshold of toxicological concern, a limit of 75 ppm each for both genotoxic impurities was calculated based on the maximum daily dose of active pharmaceutical ingredients. The novel reversed-phase HPLC method with photochemically induced fluorescence detection was developed on XSELECT Charged Surface Hybrid Phenyl-Hexyl column using the mobile phase consisted a mixture of 10 mM ammonium formate pH 3.0 and acetonitrile. The elution was performed using an isocratic composition of 48:52 (v/v) at a flow rate of 1.0 mL/min. The photochemically induced fluorescence detection is based on the use of UV irradiation at 254 nm through measuring the fluorescence intensity at 300 nm and an excitation wavelength of 272 nm to produce fluorescent derivatives of both genotoxic impurities. The online photochemical conversion and detection is easily accomplished for two expected genotoxic impurities and provides a sufficiently low limit detection and quantification for the target analysis. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Unexpected paracetamol (acetaminophen) hepatotoxicity at standard dosage in two older patients: time to rethink 1 g four times daily?

PubMed

Ging, Patricia; Mikulich, Olga; O'Reilly, Katherine M A

2016-07-01

We present two cases of acute hepatotoxicity associated with elevated paracetamol (acetaminophen) levels in older patients. Both patients were receiving a standard European dose of oral paracetamol (2 × 500 mg QDS) with no risk factors for slowed metabolism (weight <50 kg, interacting medications, hepatic enzyme inducers, history of liver disease). Significantly, both patients had recently had a dose escalation from 'as needed' dosing to 4 g daily, and the medication was being administered by nursing staff. Our experience shows that even when prescribed appropriately at the usual therapeutic dosage, paracetamol can be hepatotoxic. © The Author 2016. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

OVERVIEW, PRACTICAL TIPS AND POTENTIAL PITFALLS OF USING AUTOMATIC EXPOSURE CONTROL IN CT: SIEMENS CARE DOSE 4D.

PubMed

Söderberg, Marcus

2016-06-01

Today, computed tomography (CT) systems routinely use automatic exposure control (AEC), which modulates the tube current. However, for optimal use, there are several aspects of an AEC system that need to be considered. The purpose of this study was to provide an overview of the Siemens CARE Dose 4D AEC system, discuss practical tips and demonstrate potential pitfalls. Two adult anthropomorphic phantoms were examined using two different Siemens CT systems. When optimising the CT radiation dose and image quality, the projection angle of the localiser, patient centring, protocol selection, scanning direction and the use of protective devices requires special attention. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Non-vascular interventional procedures: effective dose to patient and equivalent dose to abdominal organs by means of DICOM images and Monte Carlo simulation.

PubMed

Longo, Mariaconcetta; Marchioni, Chiara; Insero, Teresa; Donnarumma, Raffaella; D'Adamo, Alessandro; Lucatelli, Pierleone; Fanelli, Fabrizio; Salvatori, Filippo Maria; Cannavale, Alessandro; Di Castro, Elisabetta

2016-03-01

This study evaluates X-ray exposure in patient undergoing abdominal extra-vascular interventional procedures by means of Digital Imaging and COmmunications in Medicine (DICOM) image headers and Monte Carlo simulation. The main aim was to assess the effective and equivalent doses, under the hypothesis of their correlation with the dose area product (DAP) measured during each examination. This allows to collect dosimetric information about each patient and to evaluate associated risks without resorting to in vivo dosimetry. The dose calculation was performed in 79 procedures through the Monte Carlo simulator PCXMC (A PC-based Monte Carlo program for calculating patient doses in medical X-ray examinations), by using the real geometrical and dosimetric irradiation conditions, automatically extracted from DICOM headers. The DAP measurements were also validated by using thermoluminescent dosemeters on an anthropomorphic phantom. The expected linear correlation between effective doses and DAP was confirmed with an R(2) of 0.974. Moreover, in order to easily calculate patient doses, conversion coefficients that relate equivalent doses to measurable quantities, such as DAP, were obtained. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Dose limits to the lens of the eye: International Basic Safety Standards and related guidance.

PubMed

Boal, T J; Pinak, M

2015-06-01

The International Atomic Energy Agency (IAEA) safety requirements: 'General Safety Requirements Part 3--Radiation protection and safety of radiation sources: International Basic Safety Standards' (BSS) was approved by the IAEA Board of Governors at its meeting in September 2011, and was issued as General Safety Requirements Part 3 in July 2014. The equivalent dose limit for the lens of the eye for occupational exposure in planned exposure situations was reduced from 150 mSv year(-1) to 20 mSv year(-1), averaged over defined periods of 5 years, with no annual dose in a single year exceeding 50 mSv. This reduction in the dose limit for the lens of the eye followed the recommendation of the International Commission on Radiological Protection in its statement on tissue reactions of 21 April 2011. IAEA has developed guidance on the implications of the new dose limit for the lens of the eye. This paper summarises the process that led to the inclusion of the new dose limit for the lens of the eye in the BSS, and the implications of the new dose limit. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

AREA MONITORING OF AMBIENT DOSE RATES IN PARTS OF SOUTH-WESTERN NIGERIA USING A GPS-INTEGRATED RADIATION SURVEY METER.

PubMed

Okeyode, I C; Rabiu, J A; Alatise, O O; Makinde, V; Akinboro, F G; Al-Azmi, D; Mustapha, A O

2017-04-01

A radiation monitoring system comprising a Geiger-Muller counter connected to a smart phone via Bluetooth was used for a dose rate survey in some parts of south-western Nigeria. The smart phone has the Geographical Positioning System, which provides the navigation information and saves it along with the dose rate data. A large number of data points was obtained that shows the dose rate distribution within the region. The results show that the ambient dose rates in the region range from 60 to 520 nSv -1 and showed a bias that is attributable to the influence of geology on the ambient radiation dose in the region. The geology influence was demonstrated by superimposing the dose rate plot and the geological map of the area. The potential applications of the device in determining baseline information and in area monitoring, e.g. for lost or abandoned sources, radioactive materials stockpiles, etc., were discussed in the article, particularly against the background of Nigeria's plan to develop its nuclear power program. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Software Development for Estimating the Conversion Factor (K-Factor) at Suitable Scan Areas, Relating the Dose Length Product to the Effective Dose.

PubMed

Kobayashi, Masanao; Asada, Yasuki; Matsubara, Kosuke; Suzuki, Syouichi; Koshida, Kichiro; Matsunaga, Yuta; Kawaguchi, Ai; Haba, Tomonobu; Toyama, Hiroshi; Kato, Ryouichi

2017-05-01

We developed a k-factor-creator software (kFC) that provides the k-factor for CT examination in an arbitrary scan area. It provides the k-factor from the effective dose and dose-length product by Imaging Performance Assessment of CT scanners and CT-EXPO. To assess the reliability, we compared the kFC-evaluated k-factors with those of the International Commission on Radiological Protection (ICRP) publication 102. To confirm the utility, the effective dose determined by coronary computed tomographic angiography (CCTA) was evaluated by a phantom study and k-factor studies. In the CCTA, the effective doses were 5.28 mSv in the phantom study, 2.57 mSv (51%) in the k-factor of ICRP, and 5.26 mSv (1%) in the k-factor of the kFC. Effective doses can be determined from the kFC-evaluated k-factors in suitable scan areas. Therefore, we speculate that the flexible k-factor is useful in clinical practice, because CT examinations are performed in various scan regions. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

12 CFR 713.6 - What is the permissible deductible?

Code of Federal Regulations, 2011 CFR

2011-01-01

... based on it having assets in excess of $1 million as reflected in its most recent year-end 5300 call... assets up to a maximum of $200,000; for credit unions over $1 million in assets that qualify for NCUA's... 12 Banks and Banking 6 2011-01-01 2011-01-01 false What is the permissible deductible? 713.6...

12 CFR 713.6 - What is the permissible deductible?

Code of Federal Regulations, 2012 CFR

2012-01-01

... based on it having assets in excess of $1 million as reflected in its most recent year-end 5300 call... assets up to a maximum of $200,000; for credit unions over $1 million in assets that qualify for NCUA's... 12 Banks and Banking 7 2012-01-01 2012-01-01 false What is the permissible deductible? 713.6...

Lessons Learned from the Accident at the Fukushima Dai-ichi Nuclear Power Plant-More than Basic Knowledge: Education and its Effects Improve the Preparedness and Response to Radiation Emergency.

PubMed

Hachiya, Misao; Akashi, Makoto

2016-09-01

A huge earthquake struck the northeast coast of the main island of Japan on 11 March 2011 triggering an extremely large tsunami to hit the area. The earthquake and tsunami caused serious damage to the Fukushima nuclear power plants (NPPs) of Tokyo Electric Power Company (TEPCO), resulting in large amounts of radioactive materials being released into the environment. The major nuclides released were (131)I, (134)Cs and (137)Cs. The deposition of these radioactive materials on land resulted in a high ambient dose of radiation around the NPPs, especially within a 20-km radius. Dose assessments based on behavior survey and ambient dose rates revealed that external doses to most residents were lower than 5 mSv, with the maximum dose being 25 mSv. It was fortunate that no workers from the NPPs required treatment from the viewpoint of deterministic effects of radiation. However, a lack of exact knowledge of radiation and its effects prevented the system for medical care and transportation of contaminated personnel from functioning. After the accident, demands or requests for training courses have been increasing. We have learned from the response to this disaster that basic knowledge of radiation and its effects is extremely important for not only professionals such as health care providers but also for other professionals including teachers. © World Health Organisation 2016. All rights reserved. The World Health Organization has granted Oxford University Press permission for the reproduction of this article.

Nevirapine-Resistant HIV-1 DNA in Breast Milk After Single-Dose Nevirapine With or Without Zidovudine for Prevention of Mother-to-Child Transmission.

PubMed

Gantt, Soren; Payant, Rachel; Carlsson, Jacquelyn; Micek, Mark A; Blanco, Ana Judith; Beck, Ingrid A; Matunha, Laurinda; Montoya, Pablo; Matediana, Eduardo; Gloyd, Stephen; Frenkel, Lisa M

2012-09-01

Among 30 human immunodeficiency virus type 1 (HIV-1)-infected women who received single-dose nevirapine (NVP), 17 (57%) had NVP-resistant HIV-1 detected in breast milk. NVP resistance in breast milk persisted for at least 8 months postpartum and was apparently transmitted to at least 1 infant. NVP resistance was detected less often in women who also received zidovudine. © The Author 2012. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

RADIATION DOSE DUE TO RADON AND HEAVY METAL ANALYSIS IN DRINKING WATER SAMPLES OF JAMMU DISTRICT, JAMMU & KASHMIR, INDIA.

PubMed

Kumar, A; Kaur, M; Sharma, S; Mehra, R; Sharma, D K; Mishra, R

2016-10-01

In the present investigation, radon concentration and heavy metal analysis were carried out in drinking water samples in Jammu district, Jammu & Kashmir, India. The radon concentration was measured by using RAD-7, portable alpha particle detector. The values of radon concentration in drinking water samples were also compared within the safe limit recommended by different health agencies. The total annual effective dose ranged from 53.04 to 197.29 µSv y -1 The annual effective dose from few locations from the studied area was found to be greater than the safe limit (100 µSv y -1 ) suggested by World Health Organisation (WHO) and EU Council. Heavy metal concentration was determined by atomic absorption spectrophotometer. A total of eight elements were analysed, viz. arsenic, mercury, zinc, iron, copper, chromium, manganese and cadmium. Heavy metals are considered to be the major pollutants of water sources. The results were compared with the limits of WHO, EU and Indian organisations. The trace metal analysis is not on the exceeding side of the permissible limit in all the samples. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Fetus dose estimation in thyroid cancer post-surgical radioiodine therapy.

PubMed

Mianji, Fereidoun A; Diba, Jila Karimi; Babakhani, Asad

2015-01-01

Unrecognised pregnancy during radioisotope therapy of thyroid cancer results in hardly definable embryo/fetus exposures, particularly when the thyroid gland is already removed. Sources of such difficulty include uncertainty in data like pregnancy commencing time, amount and distribution of metastasized thyroid cells in body, effect of the thyroidectomy on the fetus dose coefficient etc. Despite all these uncertainties, estimation of the order of the fetus dose in most cases is enough for medical and legal decision-making purposes. A model for adapting the dose coefficients recommended by the well-known methods to the problem of fetus dose assessment in athyrotic patients is proposed. The model defines a correction factor for the problem and ensures that the fetus dose in athyrotic pregnant patients is less than the normal patients. A case of pregnant patient undergone post-surgical therapy by I-131 is then studied for quantitative comparison of the methods. The results draw a range for the fetus dose in athyrotic patients using the derived factor. This reduces the concerns on under- or over-estimation of the embryo/fetus dose and is helpful for personal and/or legal decision-making on abortion. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

75 FR 28091 - Self-Regulatory Organizations; NYSE Amex LLC; Notice of Filing and Immediate Effectiveness of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-19

..., as Modified by Amendment No. 1, To Adopt Rules Extending the Maximum Term of FLEX Index and FLEX...-2010-40 in order to revise the Statutory Basis section and to adopt rules extending the maximum term of... maximum term of FLEX Index and FLEX Equity options to the same term permissible on NYSE Arca Inc. (``Arca...

Incentives for nondiscriminatory wellness programs in group health plans. Final rule.

PubMed

2013-06-03

This document contains final regulations, consistent with the Affordable Care Act, regarding nondiscriminatory wellness programs in group health coverage. Specifically, these final regulations increase the maximum permissible reward under a health-contingent wellness program offered in connection with a group health plan (and any related health insurance coverage) from 20 percent to 30 percent of the cost of coverage. The final regulations further increase the maximum permissible reward to 50 percent for wellness programs designed to prevent or reduce tobacco use. These regulations also include other clarifications regarding the reasonable design of health-contingent wellness programs and the reasonable alternatives they must offer in order to avoid prohibited discrimination.

The safe disposal of radioactive wastes

PubMed Central

Kenny, A. W.

1956-01-01

A comprehensive review is given of the principles and problems involved in the safe disposal of radioactive wastes. The first part is devoted to a study of the basic facts of radioactivity and of nuclear fission, the characteristics of radioisotopes, the effects of ionizing radiations, and the maximum permissible levels of radioactivity for workers and for the general public. In the second part, the author describes the different types of radioactive waste—reactor wastes and wastes arising from the use of radioisotopes in hospitals and in industry—and discusses the application of the maximum permissible levels of radioactivity to their disposal and treatment, illustrating his discussion with an account of the methods practised at the principal atomic energy establishments. PMID:13374534

Methods of Statistical Control for Groundwater Quality Indicators

NASA Astrophysics Data System (ADS)

Yankovich, E.; Nevidimova, O.; Yankovich, K.

2016-06-01

The article describes the results of conducted groundwater quality control. Controlled quality indicators included the following microelements - barium, manganese, iron, mercury, iodine, chromium, strontium, etc. Quality control charts - X-bar chart and R chart - were built. For the upper and the lower threshold limits, maximum permissible concentration of components in water and the lower limit of their biologically significant concentration, respectively, were selected. The charts analysis has shown that the levels of microelements content in water at the area of study are stable. Most elements in the underground water are contained in concentrations, significant for human organisms consuming the water. For example, such elements as Ba, Mn, Fe have concentrations that exceed maximum permissible levels for drinking water.

Residue decline and risk assessment of fluopyram + tebuconazole (400SC) in/on onion (Allium cepa).

PubMed

Patel, Badal V; Chawla, Suchi; Gor, Hetal; Upadhyay, Payal; Parmar, Kaushik D; Patel, Anil R; Shah, Paresh G

2016-10-01

A method was validated for estimating fluopyram and tebuconazole in onion on LC-MS/MS using dispersive QuEChERS. Three sprays of a combination fungicide fluopyram + tebuconazole (Luna experience, 400 SC) were applied @ 75 + 75 and 150 + 150 g a.i. ha -1 at an interval of 10 days on onion using Knapsack sprayer. First spray was made at bulb setting stage. Spring onion samples were drawn at 0 (1 h), 1, 3, 5, 7, 10, 15, and 20 days and matured onion bulb at harvest (52 days) after the last spray. Soil samples were also drawn at harvest. Foliar application of the combination product resulted in 1.14 and 2.86 mg kg -1 fluopyram residues on spring onion at standard and double dose, respectively, one hour after the last application. The levels of fluopyram residues gradually declined and recorded 0.25 and 0.58 mg kg -1 on 20th day of application with half-lives of 8.8 and 9.1 days at standard and double dose, respectively. For tebuconazole, the corresponding residues observed after 1 h (0 day) of application were 0.92 and 2.29 mg kg -1 . The levels declined gradually to 0.12 and 0.33 mg kg -1 on 20th days with half-life of 6.7 to 7.7 days at standard and double dose, respectively. Here, we are proposing a pre-harvest interval of 7 day for fluopyram and tebuconazole in spring onion when applied at 75 + 75 g a.i. ha -1 (400 SC). Risk assessment was done by calculating hazard quotient and by comparing theoretical maximum residue intake (TMRI) with maximum permissible intake (MPI). In all the cases, results of the study showed that HQ (Hazard Quotient) ≤1 and TMDI < MPI. Hence, the use of this combination product can be recommended with pre harvest interval of 7 days. The data can be used in establishing MRLs (maximum residue limits) for spring onion after considering multilocation trials.

ESR dating of barite in sulphide deposits formed by the sea-floor hydrothermal activities.

PubMed

Toyoda, Shin; Fujiwara, Taisei; Uchida, Ai; Ishibashi, Jun-ichiro; Nakai, Shun'ichi; Takamasa, Asako

2014-06-01

Barite is a mineral newly found to be practically useful for electron spin resonance (ESR) dating of sulphide deposits formed by the sea-floor hydrothermal activities. The recent studies for the properties of the ESR dating signal in barite are summarised in the present paper as well as the formulas for corrections for accurate dose-rate estimation are developed including the dose-rate conversion factors, shape correction for gamma-ray dose and decay of (226)Ra. Although development of the techniques for ESR dating of barite has been completed, further comparative studies with other dating techniques such as U-Th and (226)Ra-(210)Pb dating are necessary for the technique to be widely used. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

49 CFR 178.812 - Top lift test.

Code of Federal Regulations, 2013 CFR

2013-10-01

... renders the IBC, including the base pallets when applicable, unsafe for transportation, and no loss of... twice the maximum permissible gross mass with the load being evenly distributed. (2) Flexible IBC design types must be filled to six times the maximum net mass, the load being evenly distributed. (c) Test...

49 CFR 178.812 - Top lift test.

Code of Federal Regulations, 2014 CFR

2014-10-01

... renders the IBC, including the base pallets when applicable, unsafe for transportation, and no loss of... twice the maximum permissible gross mass with the load being evenly distributed. (2) Flexible IBC design types must be filled to six times the maximum net mass, the load being evenly distributed. (c) Test...

49 CFR 178.812 - Top lift test.

Code of Federal Regulations, 2012 CFR

2012-10-01

... renders the IBC, including the base pallets when applicable, unsafe for transportation, and no loss of... twice the maximum permissible gross mass with the load being evenly distributed. (2) Flexible IBC design types must be filled to six times the maximum net mass, the load being evenly distributed. (c) Test...

49 CFR 178.812 - Top lift test.

Code of Federal Regulations, 2011 CFR

2011-10-01

... renders the IBC, including the base pallets when applicable, unsafe for transportation, and no loss of... twice the maximum permissible gross mass with the load being evenly distributed. (2) Flexible IBC design types must be filled to six times the maximum net mass, the load being evenly distributed. (c) Test...

COMPARISON OF COSMIC-RAY ENVIRONMENTS ON EARTH, MOON, MARS AND IN SPACECARFT USING PHITS.

PubMed

Sato, Tatsuhiko; Nagamatsu, Aiko; Ueno, Haruka; Kataoka, Ryuho; Miyake, Shoko; Takeda, Kazuo; Niita, Koji

2017-09-29

Estimation of cosmic-ray doses is of great importance not only in aircrew and astronaut dosimetry but also in evaluation of background radiation exposure to public. We therefore calculated the cosmic-ray doses on Earth, Moon and Mars as well as inside spacecraft, using Particle and Heavy Ion Transport code System PHITS. The same cosmic-ray models and dose conversion coefficients were employed in the calculation to properly compare between the simulation results for different environments. It is quantitatively confirmed that the thickness of physical shielding including the atmosphere and soil of the planets is the most important parameter to determine the cosmic-ray doses and their dominant contributors. The comparison also suggests that higher solar activity significantly reduces the astronaut doses particularly for the interplanetary missions. The information obtained from this study is useful in the designs of the future space missions as well as accelerator-based experiments dedicated to cosmic-ray research. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The impact of low-dose carcinogens and environmental disruptors on tissue invasion and metastasis.

PubMed

Ochieng, Josiah; Nangami, Gladys N; Ogunkua, Olugbemiga; Miousse, Isabelle R; Koturbash, Igor; Odero-Marah, Valerie; McCawley, Lisa J; Nangia-Makker, Pratima; Ahmed, Nuzhat; Luqmani, Yunus; Chen, Zhenbang; Papagerakis, Silvana; Wolf, Gregory T; Dong, Chenfang; Zhou, Binhua P; Brown, Dustin G; Colacci, Anna Maria; Hamid, Roslida A; Mondello, Chiara; Raju, Jayadev; Ryan, Elizabeth P; Woodrick, Jordan; Scovassi, A Ivana; Singh, Neetu; Vaccari, Monica; Roy, Rabindra; Forte, Stefano; Memeo, Lorenzo; Salem, Hosni K; Amedei, Amedeo; Al-Temaimi, Rabeah; Al-Mulla, Fahd; Bisson, William H; Eltom, Sakina E

2015-06-01

The purpose of this review is to stimulate new ideas regarding low-dose environmental mixtures and carcinogens and their potential to promote invasion and metastasis. Whereas a number of chapters in this review are devoted to the role of low-dose environmental mixtures and carcinogens in the promotion of invasion and metastasis in specific tumors such as breast and prostate, the overarching theme is the role of low-dose carcinogens in the progression of cancer stem cells. It is becoming clearer that cancer stem cells in a tumor are the ones that assume invasive properties and colonize distant organs. Therefore, low-dose contaminants that trigger epithelial-mesenchymal transition, for example, in these cells are of particular interest in this review. This we hope will lead to the collaboration between scientists who have dedicated their professional life to the study of carcinogens and those whose interests are exclusively in the arena of tissue invasion and metastasis. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of cosmic rays radiation detectors on-board commercial jet aircraft.

PubMed

Kubančák, Ján; Ambrožová, Iva; Brabcová, Kateřina Pachnerová; Jakůbek, Jan; Kyselová, Dagmar; Ploc, Ondřej; Bemš, Július; Štěpán, Václav; Uchihori, Yukio

2015-06-01

Aircrew members and passengers are exposed to increased rates of cosmic radiation on-board commercial jet aircraft. The annual effective doses of crew members often exceed limits for public, thus it is recommended to monitor them. In general, the doses are estimated via various computer codes and in some countries also verified by measurements. This paper describes a comparison of three cosmic rays detectors, namely of the (a) HAWK Tissue Equivalent Proportional Counter; (b) Liulin semiconductor energy deposit spectrometer and (c) TIMEPIX silicon semiconductor pixel detector, exposed to radiation fields on-board commercial Czech Airlines company jet aircraft. Measurements were performed during passenger flights from Prague to Madrid, Oslo, Tbilisi, Yekaterinburg and Almaty, and back in July and August 2011. For all flights, energy deposit spectra and absorbed doses are presented. Measured absorbed dose and dose equivalent are compared with the EPCARD code calculations. Finally, the advantages and disadvantages of all detectors are discussed. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Characteristic Dose Model for Historical Internal Dose Reconstruction in the Framework of the IAEC Compensation Programme.

PubMed

Kravchik, T; Abraham, A; Israeli, M; Yahel, E

2017-04-25

A model was developed at the Nuclear Research Centre Negev (NRCN) to assess historical doses from internal exposures by a relatively fast and simple procedure. These assessments are needed in the framework of a compensation programme for the Israeli Atomic Energy Commission (IAEC) workers, which were diagnosed for cancer diseases. This compensation programme was recently recommended by a public committee to avoid lengthy court procedures. The developed model is based on the recorded doses from external exposures of all the workers at the NRCN, who were divided into groups representing their different working environments. Each group of workers was characterised by three parameters: working period, working areas and occupation. The model uses several conservative assumptions in order to calculate the doses to various body organs in certain years, which are relevant to the calculation of the probability of causation (POC). The POC value serves as a main parameter in the compensation programme. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Fundamental study on the characteristics of a radiophotoluminescence glass dosemeter with no energy compensation filter for measuring patient entrance doses in cardiac interventional procedures.

PubMed

Kato, Mamoru; Chida, Koichi; Moritake, Takashi; Koguchi, Yasuhiro; Sato, Tadaya; Oosaka, Hajime; Tosa, Tetsuo; Kadowaki, Ken

2014-12-01

Cardiac interventional procedures have been increasing year by year. However, radiation skin injuries have been still reported. There is a necessity to measure the patient entrance skin dose (ESD), but an accurate dose measurement method has not been established. To measure the ESD, a lot of radiophotoluminescence dosemeters (RPLDs) provide an accurate measurement of the direct actual ESD at the points they are arrayed. The purpose of this study was to examine the characteristics of RPLD to measure the ESD. As a result, X-ray permeable RPLD (with no tin filter) did not interfere with the percutaneous coronary intervention procedure. The RPLD also had good fundamental performance characteristics. Although the RPLD had a little energy dependence, it showed excellent dose and dose-rate linearity, and good angular dependence. In conclusion, by calibrating the energy dependence, RPLDs are useful dosemeter to measure the ESD in cardiac intervention. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

²¹⁰Po in the diet at Seville (Spain) and its contribution to the dose by ingestion.

PubMed

Díaz-Francés, I; Mantero, J; Díaz-Ruiz, J; Manjón, G; García-Tenorio, R

2016-02-01

The activity concentrations of (210)Po have been determined in a total of 24 representative diet samples from Seville (south of Spain), inferring from the obtained values the annual intakes of (210)Po by ingestion of the affected population and the corresponding committed effective doses. The annual intakes of (210)Po and, consequently, the corresponding doses of this radionuclide show a high variability in correspondence with the variability in the composition of the analysed samples over time, and their magnitude is comparable with the estimated ones in other regions/countries of the world with similar diet habits (countries where the marine products have a considerable weight in the diets). Committed effective doses by ingestion higher than 0.1 mSv y(-1) have been estimated exclusively for (210)Po, reflecting the importance of this radionuclide and this route of incorporation in the magnitude of the total doses received by the affected population from natural sources. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

AN EVALUATION OF THE BASIC CHARACTERISTICS OF A PLASTIC SCINTILLATING FIBRE DETECTOR IN CT RADIATION FIELDS.

PubMed

Terasaki, Kento; Fujibuchi, Toshioh; Toyoda, Takatoshi; Yoshida, Yutaka; Akasaka, Tsutomu; Nohtomi, Akihiro; Morishita, Junji

2016-12-01

The ionisation chamber for computed tomography (CT) is an instrument that is most commonly used to measure the computed tomography dose index. However, it has been reported that the 10 cm effective detection length of the ionisation chamber is insufficient due to the extent of the dose distribution outside the chamber. The purpose of this study was to estimate the basic characteristics of a plastic scintillating fibre (PSF) detector with a long detection length of 50 cm in CT radiation fields. The authors investigated position dependence using diagnostic X-ray equipment and dependencies for energy, dose rate and slice thickness using an X-ray CT system. The PSF detector outputs piled up at a count rate of 10 000 counts ms -1 in dose rate dependence study. With calibration, this detector may be useful as a CT dosemeter with a long detection length except for the measurement at high dose rate. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Noise characterization of oil and gas operations.

PubMed

Radtke, Cameron; Autenrieth, Daniel A; Lipsey, Tiffany; Brazile, William J

2017-08-01

In cooperation with The Colorado Oil and Gas Conservation Commission, researchers at Colorado State University performed area noise monitoring at 23 oil and gas sites throughout Northern Colorado. The goals of this study were to: (1) measure and compare the noise levels for the different phases of oil and gas development sites; (2) evaluate the effectiveness of noise barriers; and (3) determine if noise levels exceeded the Colorado Oil and Gas Conservation Commission noise limits. The four phases of oil and gas development include drilling, hydraulic fracturing, completion and production. Noise measurements were collected using the A- and C-weighted sound scales. Octave band analysis was also performed to characterize the frequency spectra of the noise measurements.  Noise measurements were collected using noise dosimeters and a hand-held sound-level meter at specified distances from the development sites in each cardinal direction. At 350 ft (107 m), drilling, hydraulic fracturing, and completion sites without noise barriers exceeded the maximum permissible noise levels for residential and commercial zones (55 dBA and 60 dBA, respectively). In addition, drilling and hydraulic fracturing sites with noise barriers exceeded the maximum permissible noise level for residential zones (55 dBA). However, during drilling, hydraulic fracturing, and completion operations, oil producers are allowed an exception to the noise permissible limits in that they only must comply with the industrial noise limit (80 dBA). It is stated in Rule 604.c.(2)A. that: "Operations involving pipeline or gas facility installation or maintenance, the use of a drilling rig, completion rig, workover rig, or stimulation is subject to the maximum permissible noise levels for industrial zones (80dBA)." [8] Production sites were within the Colorado Oil and Gas Conservation Commission permissible noise level criteria for all zones. At 350 ft (107 m) from the noise source, all drilling, hydraulic fracturing, and completion sites exceeded 65 dBC.  Current noise wall mitigation strategies reduced noise levels in both the A- and C-weighted scale measurements. However, this reduction in noise was not sufficient to reduce the noise below the residential permissible noise level (55 dBA).

A METHOD TO IMPROVE DOSE ASSESSMENT BY RECONSTRUCTION OF THE COMPLETE ISOTOPES INVENTORY.

PubMed

Bonin, Alice; Tsilanizara, Aimé

2017-06-01

Radiation shielding assessments may underestimate the expected dose if some isotopes at trace level are not considered in the isotopes inventory of the shielded radioactive materials. Indeed, information about traces is not often available. Nevertheless, the activation of some minor isotopic traces may significantly contribute to the dose build-up. This paper presents a new method (Isotopes Inventory Reconstruction-IIR) estimating the concentration of the minor isotopes in the irradiated material at the beginning of the cooling period. The method requires the solution of the inverse problem describing the irradiated material's decay. In a mixture of an irradiated uranium-plutonium oxide shielded by a set-up made of stainless-steel, porous polyethylene plaster and lead methyl methacrylate, the comparison between different methods proves that the IIR-method allows better assessment of the dose than other approximate methods. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

THE CHALLENGE OF CIEMAT INTERNAL DOSIMETRY SERVICE FOR ACCREDITATION ACCORDING TO ISO/IEC 17025 STANDARD, FOR IN VIVO AND IN VITRO MONITORING AND DOSE ASSESSMENT OF INTERNAL EXPOSURES.

PubMed

Lopez, M A; Martin, R; Hernandez, C; Navarro, J F; Navarro, T; Perez, B; Sierra, I

2016-09-01

The accreditation of an Internal Dosimetry Service (IDS) according to ISO/IEC 17025 Standard is a challenge. The aim of this process is to guarantee the technical competence for the monitoring of radionuclides incorporated in the body and for the evaluation of the associated committed effective dose E(50). This publication describes the main accreditation issues addressed by CIEMAT IDS regarding all the procedures involving good practice in internal dosimetry, focussing in the difficulties to ensure the traceability in the whole process, the appropriate calculation of detection limit of measurement techniques, the validation of methods (monitoring and dose assessments), the description of all the uncertainty sources and the interpretation of monitoring data to evaluate the intake and the committed effective dose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

DOSE: an R/Bioconductor package for disease ontology semantic and enrichment analysis.

PubMed

Yu, Guangchuang; Wang, Li-Gen; Yan, Guang-Rong; He, Qing-Yu

2015-02-15

Disease ontology (DO) annotates human genes in the context of disease. DO is important annotation in translating molecular findings from high-throughput data to clinical relevance. DOSE is an R package providing semantic similarity computations among DO terms and genes which allows biologists to explore the similarities of diseases and of gene functions in disease perspective. Enrichment analyses including hypergeometric model and gene set enrichment analysis are also implemented to support discovering disease associations of high-throughput biological data. This allows biologists to verify disease relevance in a biological experiment and identify unexpected disease associations. Comparison among gene clusters is also supported. DOSE is released under Artistic-2.0 License. The source code and documents are freely available through Bioconductor (http://www.bioconductor.org/packages/release/bioc/html/DOSE.html). Supplementary data are available at Bioinformatics online. gcyu@connect.hku.hk or tqyhe@jnu.edu.cn. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

INADEQUACY OF THORON DOSE CALCULATIONS FROM THORON PROGENY MEASUREMENT ALONE.

PubMed

Lane-Smith, D; Wong, F K

2016-10-01

To determine the dose received by thoron ( 220 Rn) domestically, conventional methods measure the activity concentration of thoron progeny only (namely the 212 Pb atoms) and calculate the dose by using a set of conversion factors. This may be due to the measurement of progeny being simpler since it is longer lived and will be evenly spread throughout the room, whereas the thoron gas, with its short half-life, will exist only near the source and hence will not be of major concern for the majority of the room. However, concrete walls are a source of thoron, and spending prolonged amounts of time near them may lead to greatly increased radiation exposure, the degree of which is not revealed through progeny activity alone. The present paper compares the energy received from the ionising radiation of both thoron gas and thoron progeny near its source. Converting the energy dose to radiation dose is not within the scope of this paper. The results suggest a difference of an order of magnitude higher when taking into account the dose received by thoron gas. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Assessment of physician and patient (child and adult) equivalent doses during renal angiography by Monte Carlo method.

PubMed

Karimian, A; Nikparvar, B; Jabbari, I

2014-11-01

Renal angiography is one of the medical imaging methods in which patient and physician receive high equivalent doses due to long duration of fluoroscopy. In this research, equivalent doses of some radiosensitive tissues of patient (adult and child) and physician during renal angiography have been calculated by using adult and child Oak Ridge National Laboratory phantoms and Monte Carlo method (MCNPX). The results showed, in angiography of right kidney in a child and adult patient, that gall bladder with the amounts of 2.32 and 0.35 mSv, respectively, has received the most equivalent dose. About the physician, left hand, left eye and thymus absorbed the most amounts of doses, means 0.020 mSv. In addition, equivalent doses of the physician's lens eye, thyroid and knees were 0.023, 0.007 and 7.9E-4 mSv, respectively. Although these values are less than the reported thresholds by ICRP 103, it should be noted that these amounts are related to one examination. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Assessment of natural sepiolite on cadmium stabilization, microbial communities, and enzyme activities in acidic soil.

PubMed

Sun, Yuebing; Sun, Guohong; Xu, Yingming; Wang, Lin; Liang, Xuefeng; Lin, Dasong; Hu, Fazhi

2013-05-01

A pot trial was conducted to assess the efficiency of sepiolite-induced cadmium (Cd) immobilization in ultisoils. Under Cd concentrations of 1.25, 2.5, and 5 mg kg(-1), the available Cd in the soil after the application of 1-10 % sepiolite decreased by a maximum of 44.4, 23.0, and 17.0 %, respectively, compared with no sepiolite treatments. The increase in the values of soil enzyme activities and microbial number proved that a certain metabolic recovery occurred after sepiolite treatment. The dry biomass of spinach (Spinacia oleracea) increased with increasing sepiolite concentration in the soil. However, the concentration (dry weight) of Cd in the spinach shoots decreased with the increase in sepiolite dose, with maximum reduction of 92.2, 90.0, and 84.9 %, respectively, compared with that of unamended soils. Under a Cd level of 1.25 mg kg(-1), the Cd concentration in the edible parts of spinach at 1 % sepiolite amendment was lower than 0.2 mg kg(-1) fresh weight, the maximum permissible concentration (MPC) of Cd in vegetable. Even at higher Cd concentrations (2.5 and 5 mg kg(-1)), safe spinach was produced when the sepiolite treatment was up to 5 %. The results showed that sepiolite-assisted remediation could potentially succeed on a field scale by decreasing Cd entry into the food chain.

Estimation of staff lens doses during interventional procedures. Comparing cardiology, neuroradiology and interventional radiology.

PubMed

Vano, E; Sanchez, R M; Fernandez, J M

2015-07-01

The purpose of this article is to estimate lens doses using over apron active personal dosemeters in interventional catheterisation laboratories (cardiology IC, neuroradiology IN and radiology IR) and to investigate correlations between occupational lens doses and patient doses. Active electronic personal dosemeters placed over the lead apron were used on a sample of 204 IC procedures, 274 IN and 220 IR (all performed at the same university hospital). Patient dose values (kerma area product) were also recorded to evaluate correlations with occupational doses. Operators used the ceiling-suspended screen in most cases. The median and third quartile values of equivalent dose Hp(10) per procedure measured over the apron for IC, IN and IR resulted, respectively, in 21/67, 19/44 and 24/54 µSv. Patient dose values (median/third quartile) were 75/128, 83/176 and 61/159 Gy cm(2), respectively. The median ratios for dosemeters worn over the apron by operators (protected by the ceiling-suspended screen) and patient doses were 0.36; 0.21 and 0.46 µSv Gy(-1) cm(-2), respectively. With the conservative approach used (lens doses estimated from the over apron chest dosemeter) we came to the conclusion that more than 800 procedures y(-1) and per operator were necessary to reach the new lens dose limit for the three interventional specialties. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of 2D and 3D Imaging and Treatment Planning for Postoperative Vaginal Apex High-Dose Rate Brachytherapy for Endometrial Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russo, James K.; Armeson, Kent E.; Richardson, Susan, E-mail: srichardson@radonc.wustl.edu

2012-05-01

Purpose: To evaluate bladder and rectal doses using two-dimensional (2D) and 3D treatment planning for vaginal cuff high-dose rate (HDR) in endometrial cancer. Methods and Materials: Ninety-one consecutive patients treated between 2000 and 2007 were evaluated. Seventy-one and 20 patients underwent 2D and 3D planning, respectively. Each patient received six fractions prescribed at 0.5 cm to the superior 3 cm of the vagina. International Commission on Radiation Units and Measurements (ICRU) doses were calculated for 2D patients. Maximum and 2-cc doses were calculated for 3D patients. Organ doses were normalized to prescription dose. Results: Bladder maximum doses were 178% ofmore » ICRU doses (p < 0.0001). Two-cubic centimeter doses were no different than ICRU doses (p = 0.22). Two-cubic centimeter doses were 59% of maximum doses (p < 0.0001). Rectal maximum doses were 137% of ICRU doses (p < 0.0001). Two-cubic centimeter doses were 87% of ICRU doses (p < 0.0001). Two-cubic centimeter doses were 64% of maximum doses (p < 0.0001). Using the first 1, 2, 3, 4 or 5 fractions, we predicted the final bladder dose to within 10% for 44%, 59%, 83%, 82%, and 89% of patients by using the ICRU dose, and for 45%, 55%, 80%, 85%, and 85% of patients by using the maximum dose, and for 37%, 68%, 79%, 79%, and 84% of patients by using the 2-cc dose. Using the first 1, 2, 3, 4 or 5 fractions, we predicted the final rectal dose to within 10% for 100%, 100%, 100%, 100%, and 100% of patients by using the ICRU dose, and for 60%, 65%, 70%, 75%, and 75% of patients by using the maximum dose, and for 68%, 95%, 84%, 84%, and 84% of patients by using the 2-cc dose. Conclusions: Doses to organs at risk vary depending on the calculation method. In some cases, final dose accuracy appears to plateau after the third fraction, indicating that simulation and planning may not be necessary in all fractions. A clinically relevant level of accuracy should be determined and further research conducted to address this issue.« less

Radon Concentration And Dose Assessment In Well Water Samples From Karbala Governorate Of Iraq

NASA Astrophysics Data System (ADS)

Al-Alawy, I. T.; Hasan, A. A.

2018-05-01

There are numerous studies around the world about radon concentrations and their risks to the health of human beings. One of the most important social characteristics is the use of water wells for irrigation, which is a major source of water pollution with radon gas. In the present study, six well water samples have been collected from different locations in Karbala governorate to investigate radon concentration level using CR-39 technique. The maximum value 4.112±2.0Bq/L was in Al-Hurr (Al-Qarih Al-Easariah) region, and the lowest concentration of radon was in Hay Ramadan region which is 2.156±1.4Bq/L, with an average value 2.84±1.65Bq/L. The highest result of annual effective dose (AED) was in Al-Hurr (Al-Qarih Al-Easariah) region which is equal to 15.00±3.9μSv/y, while the minimum was recorded in Hay Ramadan 7.86±2.8μSv/y, with an average value 10.35±3.1μSv/y. The current results have shown that the radon concentrations in well water samples are lower than the recommended limit 11.1Bq/L and the annual effective dose in these samples are lower than the permissible international limit 1mSv/y.

Long-term mortality and cancer risk in irradiated rhesus monkeys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, D.H.

1991-05-01

Continuous, 24-year observations on a group of 358 rhesus monkeys reveal that life shortening from exposure to protons in the energy range encountered in the Van Allen belts and solar proton events is influenced primarily by the dose rather than by the energy of radiation. Life shortening in groups exposed to similar surface doses of 138- to 2300-MeV and 32- to 55-MeV protons are not significantly different, but the low-energy protons are associated with more deaths in the early years, while the high-energy protons contribute more to mortality in later years. In males, the most significant cause of life shorteningmore » is nonleukemia cancers. In females, radiation increased the risk of endometriosis (an abnormal proliferation of the lining of the uterus) which resulted in significant mortality in the years before early detection and treatment methods were employed. Animals exposed to 55-MeV protons had a high incidence of malignant brain tumors with latent periods ranging from 13 months to 20 years. The first fatal cancer among nonirradiated controls occurred 18 years after the study began. Analysis of the dose-response data supports the 1989 guidelines of the NCRP for maximum permissible radiation exposures in astronauts (NCRP, Guidance on Radiation Received in Space Activities, Report No. 98, National Council on Radiation Protection and Measurements, Bethesda, MD, 1989).« less

Emergency EPR and OSL dosimetry with table vitamins and minerals.

PubMed

Sholom, S; McKeever, S W S

2016-12-01

Several table vitamins, minerals and L-lysine amino acid have been preliminarily tested as potential emergency dosemeters using electron paramagnetic resonance (EPR) and optically stimulated luminescence (OSL) techniques. Radiation-induced EPR signals were detected in samples of vitamin B2 and L-lysine while samples of multivitamins of different brands as well as mineral Mg demonstrated prominent OSL signals after exposure to ionizing radiation doses. Basic dosimetric properties of the radiation-sensitive substances were studied, namely dose response, fading of the EPR or OSL signals and values of minimum measurable doses (MMDs). For EPR-sensitive samples, the EPR signal is converted into units of dose using a linear dose response and correcting for fading using the measured fading dependence. For OSL-sensitive materials, a multi-aliquot, enhanced-temperature protocol was developed to avoid the problem of sample sensitization and to minimize the influence of signal fading. The sample dose in this case is also evaluated using the dose response and fading curves. MMDs of the EPR-sensitive samples were below 2 Gy while those of the OSL-sensitive materials were below 500 mGy as long as the samples are analyzed within 1 week after exposure. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Technological advances in hybrid imaging and impact on dose.

PubMed

Mattsson, Sören; Andersson, Martin; Söderberg, Marcus

2015-07-01

New imaging technologies utilising X-rays and radiopharmaceuticals have developed rapidly. Clinical application of computed tomography (CT) has revolutionised medical imaging and plays an enormous role in medical care. Due to technical improvements, spatial, contrast and temporal resolutions have continuously improved. In spite of significant reduction of CT doses during recent years, CT is still a dominating source of radiation exposure to the population. Combinations with single photon emission computed tomography (SPECT) and positron emission tomography (PET) and especially the use of SPECT/CT and PET/CT, provide important additional information about physiology as well as cellular and molecular events. However, significant dose contributions from SPECT and PET occur, making PET/CT and SPECT/CT truly high dose procedures. More research should be done to find optimal activities of radiopharmaceuticals for various patient groups and investigations. The implementation of simple protocol adjustments, including individually based administration, encouraged hydration, forced diuresis and use of optimised voiding intervals, laxatives, etc., can reduce the radiation exposure to the patients. New data about staff doses to fingers, hands and eye lenses indicate that finger doses could be a problem, but not doses to the eye lenses and to the whole body. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

On-line data collection platform for national dose surveys in diagnostic and interventional radiology.

PubMed

Vassileva, J; Simeonov, F; Avramova-Cholakova, S

2015-07-01

According to the Bulgarian regulation for radiation protection at medical exposure, the National Centre of Radiobiology and Radiation Protection (NCRRP) is responsible for performing national dose surveys in diagnostic and interventional radiology and nuclear medicine and for establishing of national diagnostic reference levels (DRLs). The next national dose survey is under preparation to be performed in the period of 2015-16, with the aim to cover conventional radiography, mammography, conventional fluoroscopy, interventional and fluoroscopy guided procedures and CT. It will be performed electronically using centralised on-line data collection platform established by the NCRRP. The aim is to increase the response rate and to improve the accuracy by reducing human errors. The concept of the on-line dose data collection platform is presented. Radiological facilities are provided with a tool to determine local typical patient doses, and the NCRRP to establish national DRLs. Future work will include automatic retrieval of dose data from hospital picture archival and communicating system. The on-line data collection platform is expected to facilitate the process of dose audit and optimisation of radiological procedures in Bulgarian hospitals. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A comparison of hydraulic architecture in three similarly sized woody species differing in their maximum potential height.

PubMed

McCulloh, Katherine A; Johnson, Daniel M; Petitmermet, Joshua; McNellis, Brandon; Meinzer, Frederick C; Lachenbruch, Barbara

2015-07-01

The physiological mechanisms underlying the short maximum height of shrubs are not understood. One possible explanation is that differences in the hydraulic architecture of shrubs compared with co-occurring taller trees prevent the shrubs from growing taller. To explore this hypothesis, we examined various hydraulic parameters, including vessel lumen diameter, hydraulic conductivity and vulnerability to drought-induced embolism, of three co-occurring species that differed in their maximum potential height. We examined one species of shrub, one short-statured tree and one taller tree. We worked with individuals that were approximately the same age and height, which was near the maximum for the shrub species. A number of variables correlated with the maximum potential height of the species. For example, vessel diameter and vulnerability to embolism both increased while wood density declined with maximum potential height. The difference between the pressure causing 50% reduction in hydraulic conductance in the leaves and the midday leaf water potential (the leaf's hydraulic safety margin) was much larger in the shrub than the other two species. In general, trends were consistent with understory shrubs having a more conservative life history strategy than co-occurring taller species. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Peripheral photon and neutron doses from prostate cancer external beam irradiation.

PubMed

Bezak, Eva; Takam, Rundgham; Marcu, Loredana G

2015-12-01

Peripheral photon and neutron doses from external beam radiotherapy (EBRT) are associated with increased risk of carcinogenesis in the out-of-field organs; thus, dose estimations of secondary radiation are imperative. Peripheral photon and neutron doses from EBRT of prostate carcinoma were measured in Rando phantom. (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P glass-rod thermoluminescence dosemeters (TLDs) were inserted in slices of a Rando phantom followed by exposure to 80 Gy with 18-MV photon four-field 3D-CRT technique. The TLDs were calibrated using 6- and 18-MV X-ray beam. Neutron dose equivalents measured with CR-39 etch-track detectors were used to derive readout-to-neutron dose conversion factor for (6)LiF:Mg,Cu,P TLDs. Average neutron dose equivalents per 1 Gy of isocentre dose were 3.8±0.9 mSv Gy(-1) for thyroid and 7.0±5.4 mSv Gy(-1) for colon. For photons, the average dose equivalents per 1 Gy of isocentre dose were 0.2±0.1 mSv Gy(-1) for thyroid and 8.1±9.7 mSv Gy(-1) for colon. Paired (6)LiF:Mg,Cu,P and (7)LiF:Mg,Cu,P TLDs can be used to measure photon and neutron doses simultaneously. Organs in close proximity to target received larger doses from photons than those from neutrons whereas distally located organs received higher neutron versus photon dose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

USSR and Eastern Europe Scientific Abstracts, Biomedical and Behavioral Sciences, Number 86

DTIC Science & Technology

1978-02-03

Biochemistry 6 Epidemiology 15 Hydrobiology • • IT Immunology .. • 1° Industrial Microbiology 21 Industrial Toxicology 22 Marine Mammals 28...included measures to decrease the con- tamination of feeds and animal husbandry products with pesticides; improve- ment of methods and the organization...permissible levels of pesticide residues in agricultural products and the maximum permissible concentrations of pesticides for work- ers working with them

Meta-analysis for deriving age- and gender-specific dose-response relationships between urinary cadmium concentration and {beta} {sub 2}-microglobulinuria under environmental exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gamo, Masashi; Ono, Kyoko; Nakanishi, Junko

2006-05-15

A meta-analysis was conducted to derive age- and gender-specific dose-response relationships between urinary cadmium (Cd) concentration and {beta} {sub 2}-microglobulinuria ({beta}2MG-uria) under environmental exposure. {beta}2MG-uria was defined by a cutoff point of 1000 {mu}g {beta} {sub 2}-microglobulin/g creatinine. We proposed a model for describing the relationships among the interindividual variabilities in urinary Cd concentration, the ratio of Cd concentrations in the target organ and in urine, and the threshold Cd concentration in the target organ. The parameters in the model were determined so that good agreement might be achieved between the prevalence rates of {beta}2MG-uria reported in the literature andmore » those estimated by the model. In this analysis, only the data from the literature on populations environmentally exposed to Cd were used. Using the model and estimated parameters, the prevalence rate of {beta}2MG-uria can be estimated for an age- and gender-specific subpopulation for which the distribution of urinary Cd concentrations is known. The maximum permissible level of urinary Cd concentration was defined as the maximum geometric mean of the urinary Cd concentration in an age- and gender-specific subpopulation that would not result in a statistically significant increase in the prevalence rate of {beta}2MG-uria. This was estimated to be approximately 3 {mu}g/g creatinine for a population in a small geographical area and approximately 2 {mu}g/g creatinine for a nationwide population.« less

Monte Carlo calculations of lung dose in ORNL phantom for boron neutron capture therapy.

PubMed

Krstic, D; Markovic, V M; Jovanovic, Z; Milenkovic, B; Nikezic, D; Atanackovic, J

2014-10-01

Monte Carlo simulations were performed to evaluate dose for possible treatment of cancers by boron neutron capture therapy (BNCT). The computational model of male Oak Ridge National Laboratory (ORNL) phantom was used to simulate tumours in the lung. Calculations have been performed by means of the MCNP5/X code. In this simulation, two opposite neutron beams were considered, in order to obtain uniform neutron flux distribution inside the lung. The obtained results indicate that the lung cancer could be treated by BNCT under the assumptions of calculations. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Measuring radon concentrations and estimating dose in tourist caves.

PubMed

Martín Sánchez, A; de la Torre Pérez, J; Ruano Sánchez, A B; Naranjo Correa, F L

2015-11-01

Caves and mines are considered to be places of especial risk of exposure to (222)Rn. This is particularly important for guides and workers, but also for visitors. In the Extremadura region (Spain), there are two cave systems in which there are workers carrying out their normal everyday tasks. In one, visits have been reduced to maintain the conditions of temperature and humidity. The other comprises several caves frequently visited by school groups. The caves were radiologically characterised in order to estimate the dose received by workers or possible hazards for visitors. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

RADIOLOGICAL IMPACTS ASSESSMENT FOR WORKERS IN CERAMIC INDUSTRY IN SERBIA.

PubMed

Todorovic, Nataša; Mrda, Dušan; Hansman, Jan; Todorovic, Slavko; Nikolov, Jovana; Krmar, Miodrag

2017-11-01

Studies have been carried out to determine the natural radioactivity in some materials used in ceramic industry (zircon, zirkosil, Zircobit MO/S, zircon silicate, zirklonil frit, hematite, bentonite, wollastonite, raw kaolin, kaolinized granite, sileks ball, feldspar, pigment, white base serigraphic, engobe) and their associated radiation hazard. The external hazard index, Hex, values, radium equivalent activity, Raeq, total absorbed dose rates, D and annual effective dose, De were derived for all measured materials and compared with the recommended values to assess the external radiation hazards to workers who worked in ceramic industries in Serbia. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Dosimetry of secondary cosmic radiation up to an altitude of 30 km.

PubMed

Wissmann, F; Burda, O; Khurana, S; Klages, T; Langner, F

2014-10-01

Dosimetric measurements in the field of secondary cosmic radiation were extensively made during the last years. Since the majority of these measurements were performed on-board passenger aircraft at altitudes between 10 and 12 km, measurements at higher altitudes are desirable for the verification of the legal dose assessment procedures for aircrew. A simple solution is to use a high-altitude balloon that reaches altitudes as high as 30 km. In this work, it is shown that the dose rate profile up to 30 km can be measured with acceptable uncertainties using a Si-detector. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

DEVELOPMENT OF A MULTIMODAL MONTE CARLO BASED TREATMENT PLANNING SYSTEM.

PubMed

Kumada, Hiroaki; Takada, Kenta; Sakurai, Yoshinori; Suzuki, Minoru; Takata, Takushi; Sakurai, Hideyuki; Matsumura, Akira; Sakae, Takeji

2017-10-26

To establish boron neutron capture therapy (BNCT), the University of Tsukuba is developing a treatment device and peripheral devices required in BNCT, such as a treatment planning system. We are developing a new multimodal Monte Carlo based treatment planning system (developing code: Tsukuba Plan). Tsukuba Plan allows for dose estimation in proton therapy, X-ray therapy and heavy ion therapy in addition to BNCT because the system employs PHITS as the Monte Carlo dose calculation engine. Regarding BNCT, several verifications of the system are being carried out for its practical usage. The verification results demonstrate that Tsukuba Plan allows for accurate estimation of thermal neutron flux and gamma-ray dose as fundamental radiations of dosimetry in BNCT. In addition to the practical use of Tsukuba Plan in BNCT, we are investigating its application to other radiation therapies. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

STABILITY OF THE NEUTRON DOSE DETERMINATION ALGORITHM FOR PERSONAL NEUTRON DOSEMETERS AT DIFFERENT RADON GAS EXPOSURES.

PubMed

Mayer, Sabine; Boschung, Markus; Butterweck, Gernot; Assenmacher, Frank; Hohmann, Eike

2016-09-01

Since 2008 the Paul Scherrer Institute (PSI) has been using a microscope-based automatic scanning system for assessing personal neutron doses with a dosemeter based on PADC. This scanning system, known as TASLImage, includes a comprehensive characterisation of tracks. The distributions of several specific track characteristics such as size, shape and optical density are compared with a reference set to discriminate tracks of alpha particles and non-track background. Due to the dosemeter design at PSI, it is anticipated that radon should not significantly contribute to the creation of additional tracks in the PADC detector. The present study tests the stability of the neutron dose determination algorithm of the personal neutron dosemeter system in operation at PSI at different radon gas exposures. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evaluation of human body irradiation caused by radionuclides deposited in the filtration unit of gas mask.

PubMed

Cerny, R; Johnova, K; Otahal, P; Thinova, L; Kluson, J

2017-12-01

Radioactive aerosol particles represent a serious risk for people facing the consequences of nuclear accident of any kind. The first responders to emergency situation need to be protected by personal protective equipment which includes radiation protection suit supplemented with gas mask. The purpose of this work is to estimate the dose to the organs of responder's body as a result of radionuclide deposition in the filtration unit of the gas mask. The problem was analyzed using Monte Carlo simulations. The dose absorbed by different organs for five representative radionuclides and the dose distribution over the responder's body are presented in this paper. Based on presented MC simulations, we suggest a method of evaluating the irradiation of the responder by the radionuclides deposited in the filtration unit of the gas mask. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of clouds on the cosmic radiation dose rate on aircraft.

PubMed

Pazianotto, Maurício T; Federico, Claudio A; Cortés-Giraldo, Miguel A; Pinto, Marcos Luiz de A; Gonçalez, Odair L; Quesada, José Manuel M; Carlson, Brett V; Palomo, Francisco R

2014-10-01

Flight missions were made in Brazilian territory in 2009 and 2011 with the aim of measuring the cosmic radiation dose rate incident on aircraft in the South Atlantic Magnetic Anomaly and to compare it with Monte Carlo simulations. During one of these flights, small fluctuations were observed in the vicinity of the aircraft with formation of Cumulonimbus clouds. Motivated by these observations, in this work, the authors investigated the relationship between the presence of clouds and the neutron flux and dose rate incident on aircraft using computational simulation. The Monte Carlo simulations were made using the MCNPX and Geant4 codes, considering the incident proton flux at the top of the atmosphere and its propagation and neutron production through several vertically arranged slabs, which were modelled according to the ISO specifications. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of standing positions and beam projections on effective dose and eye lens dose of anaesthetists in interventional procedures.

PubMed

Kong, Y; Struelens, L; Vanhavere, F; Vargas, C S; Schoonjans, W; Zhuo, W H

2015-02-01

More and more anaesthetists are getting involved in interventional radiology procedures and so it is important to know the radiation dose and to optimise protection for anaesthetists. In this study, based on Monte Carlo simulations and field measurements, both the whole-body doses and eye lens dose of anaesthetists were studied. The results showed that the radiation exposure to anaesthetists not only depends on their workload, but also largely varies with their standing positions and beam projections during interventional procedures. The simulation results showed that the effective dose to anaesthetists may vary with their standing positions and beam projections to more than a factor of 10, and the eye lens dose may vary with the standing positions and beam projections to more than a factor of 200. In general, a close position to the bed and the left lateral (LLAT) beam projection will bring a high exposure to anaesthetists. Good correlations between the eye lens dose and the doses at the neck, chest and waist over the apron were observed from the field measurements. The results indicate that adequate arrangements of anaesthesia device or other monitoring equipment in the fluoroscopy rooms are useful measures to reduce the radiation exposure to anaesthetists, and anaesthetists should be aware that they will receive the highest doses under left lateral beam projection. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A CONCEPTUAL FRAMEWORK FOR MANAGING RADIATION DOSE TO PATIENTS IN DIAGNOSTIC RADIOLOGY USING REFERENCE DOSE LEVELS.

PubMed

Almén, Anja; Båth, Magnus

2016-06-01

The overall aim of the present work was to develop a conceptual framework for managing radiation dose in diagnostic radiology with the intention to support optimisation. An optimisation process was first derived. The framework for managing radiation dose, based on the derived optimisation process, was then outlined. The outset of the optimisation process is four stages: providing equipment, establishing methodology, performing examinations and ensuring quality. The optimisation process comprises a series of activities and actions at these stages. The current system of diagnostic reference levels is an activity in the last stage, ensuring quality. The system becomes a reactive activity only to a certain extent engaging the core activity in the radiology department, performing examinations. Three reference dose levels-possible, expected and established-were assigned to the three stages in the optimisation process, excluding ensuring quality. A reasonably achievable dose range is also derived, indicating an acceptable deviation from the established dose level. A reasonable radiation dose for a single patient is within this range. The suggested framework for managing radiation dose should be regarded as one part of the optimisation process. The optimisation process constitutes a variety of complementary activities, where managing radiation dose is only one part. This emphasises the need to take a holistic approach integrating the optimisation process in different clinical activities. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SPECTRAL CORRECTION FACTORS FOR CONVENTIONAL NEUTRON DOSE METERS USED IN HIGH-ENERGY NEUTRON ENVIRONMENTS-IMPROVED AND EXTENDED RESULTS BASED ON A COMPLETE SURVEY OF ALL NEUTRON SPECTRA IN IAEA-TRS-403.

PubMed

Oparaji, U; Tsai, Y H; Liu, Y C; Lee, K W; Patelli, E; Sheu, R J

2017-06-01

This paper presents improved and extended results of our previous study on corrections for conventional neutron dose meters used in environments with high-energy neutrons (En > 10 MeV). Conventional moderated-type neutron dose meters tend to underestimate the dose contribution of high-energy neutrons because of the opposite trends of dose conversion coefficients and detection efficiencies as the neutron energy increases. A practical correction scheme was proposed based on analysis of hundreds of neutron spectra in the IAEA-TRS-403 report. By comparing 252Cf-calibrated dose responses with reference values derived from fluence-to-dose conversion coefficients, this study provides recommendations for neutron field characterization and the corresponding dose correction factors. Further sensitivity studies confirm the appropriateness of the proposed scheme and indicate that (1) the spectral correction factors are nearly independent of the selection of three commonly used calibration sources: 252Cf, 241Am-Be and 239Pu-Be; (2) the derived correction factors for Bonner spheres of various sizes (6"-9") are similar in trend and (3) practical high-energy neutron indexes based on measurements can be established to facilitate the application of these correction factors in workplaces. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SU-F-T-113: Inherent Functional Dependence of Spinal Cord Doses of Variable Irradiated Volumes in Spine SBRT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, L; Braunstein, S; Chiu, J

2016-06-15

Purpose: Spinal cord tolerance for SBRT has been recommended for the maximum point dose level or at irradiated volumes such as 0.35 mL or 10% of contoured volumes. In this study, we investigated an inherent functional relationship that associates these dose surrogates for irradiated spinal cord volumes of up to 3.0 mL. Methods: A hidden variable termed as Effective Dose Radius (EDR) was formulated based on a dose fall-off model to correlate dose at irradiated spinal cord volumes ranging from 0 mL (point maximum) to 3.0 mL. A cohort of 15 spine SBRT cases was randomly selected to derive anmore » EDR-parameterized formula. The mean prescription dose for the studied cases was 21.0±8.0 Gy (range, 10–40Gy) delivered in 3±1 fractions with target volumes of 39.1 ± 70.6 mL. Linear regression and variance analysis were performed for the fitting parameters of variable EDR values. Results: No direct correlation was found between the dose at maximum point and doses at variable spinal cord volumes. For example, Pearson R{sup 2} = 0.643 and R{sup 2}= 0.491 were obtained when correlating the point maximum dose with the spinal cord dose at 1 mL and 3 mL, respectively. However, near perfect correlation (R{sup 2} ≥0.99) was obtained when corresponding parameterized EDRs. Specifically, Pearson R{sup 2}= 0.996 and R{sup 2} = 0.990 were obtained when correlating EDR (maximum point dose) with EDR (dose at 1 mL) and EDR(dose at 3 mL), respectively. As a result, high confidence level look-up tables were established to correlate spinal cord doses at the maximum point to any finite irradiated volumes. Conclusion: An inherent functional relationship was demonstrated for spine SBRT. Such a relationship unifies dose surrogates at variable cord volumes and proves that a single dose surrogate (e.g. point maximum dose) is mathematically sufficient in constraining the overall spinal cord dose tolerance for SBRT.« less

Weak silica nanomaterial-induced genotoxicity can be explained by indirect DNA damage as shown by the OGG1-modified comet assay and genomic analysis.

PubMed

Pfuhler, Stefan; Downs, Thomas R; Allemang, Ashley J; Shan, Yuching; Crosby, Meredith E

2017-01-01

In a previous study, 15-nm silica nanoparticles (NPs) caused small increases in DNA damage in liver as measured in the in vivo comet and micronucleus assays after intravenous administration to rats at their maximum tolerated dose, a worst-case exposure scenario. Histopathological examination supported a particle-induced, tissue damage-mediated inflammatory response. This study used a targeted approach to provide insight into the mode of action (MoA) by examining transcriptional regulation of genes in liver in a time and dose-dependent manner at 1, 2, 4, 8 and 24 h after intravenous administration of 15-nm silica NPs. DNA damage was assessed using the standard comet assay and hOGG1 glycosylase-modified comet assay that also measures oxidative DNA damage. Potassium bromate, an IARC Class 2B carcinogen that specifically operates via an oxidative stress MoA, was used as a positive control for the hOGG1 comet assay and gave a strong signal in its main target organ, the kidney, while showing less activity in liver. Treatment of rats with silica NPs at 50 mg/kg body weight (bw) caused small, statistically insignificant increases in DNA damage in liver measured by the standard comet assay, while a statistically significant increase was observed at 4 h with the hOGG1 comet assay, consistent with a MoA involving reactive oxygen species. Histopathology showed liver damage and neutrophil involvement while genomic analysis and response pattern of key genes involved in inflammation and oxidative stress supported a tissue damage-mediated inflammatory response involving the complement system for removing/phagocytising damaged cells. No changes were observed for histopathology or gene array for the low-dose (5 mg/kg bw) silica NPs. The results of this study confirm our hypothesis that the weak DNA damage observed by silica NPs occurs secondary to inflammation/immune response, indicating that a threshold can be applied in the risk assessment of these materials. © The Author 2016. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

STUDY OF RADIATION EXPOSURE DUE TO RADON, THORON AND PROGENY IN THE INDOOR ENVIRONMENT OF YAMUNA AND TONS VALLEYS OF GARHWAL HIMALAYA.

PubMed

Prasad, Mukesh; Rawat, Mukesh; Dangwal, Anoop; Prasad, Ganesh; Mishra, Rosaline; Ramola, R C

2016-10-01

Long-term measurements of indoor radon, thoron and their progeny concentrations have been carried out in dwellings of Yamuna and Tons Valleys of Uttarkashi, Garhwal Himalaya to investigate the health risk associated with inhalation of radon, thoron and progeny. The experimentally determined values of radon, thoron and progeny concentrations were used to estimate the annual inhalation doses and annual effective doses. The annual inhalation dose has been found to vary from 0.8 to 3.9 mSv y -1 with an average of 1.8 mSv y -1 The annual effective dose from the exposure to radon and its progeny in the study area has been found to vary from 0.1 to 2.4 mSv with an average of 1.2±0.6 mSv. Similarly, the annual effective dose due to thoron and its progeny has been found to vary from 0.2 to 1.5 mSv with an average of 0.6±0.4. The measurement techniques and results obtained are discussed in detail. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

PLASTIC SCINTILLATOR FOR RADIATION DOSIMETRY.

PubMed

Kim, Yewon; Yoo, Hyunjun; Kim, Chankyu; Lim, Kyung Taek; Moon, Myungkook; Kim, Jongyul; Cho, Gyuseong

2016-09-01

Inorganic scintillators, composed of high-atomic-number materials such as the CsI(Tl) scintillator, are commonly used in commercially available a silicon diode and a scintillator embedded indirect-type electronic personal dosimeters because the light yield of the inorganic scintillator is higher than that of an organic scintillator. However, when it comes to tissue-equivalent dose measurements, a plastic scintillator such as polyvinyl toluene (PVT) is a more appropriate material than an inorganic scintillator because of the mass energy absorption coefficient. To verify the difference in the absorbed doses for each scintillator, absorbed doses from the energy spectrum and the calculated absorbed dose were compared. From the results, the absorbed dose of the plastic scintillator was almost the same as that of the tissue for the overall photon energy. However, in the case of CsI, it was similar to that of the tissue only for a photon energy from 500 to 4000 keV. Thus, the values and tendency of the mass energy absorption coefficient of the PVT are much more similar to those of human tissue than those of the CsI. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

RADIATION EXPOSURE OF THE POPULATION FROM 222Rn AND OTHER NATURAL RADIONUCLIDES AROUND MOCHOVCE NUCLEAR POWER PLANT, SLOVAKIA.

PubMed

Bulko, Martin; Holý, Karol; Pohronská, Žofia; Mullerová, Monika; Böhm, Radoslav; Holá, Ol'ga

2017-11-01

In this article, the effective dose to the population from natural sources of ionizing radiation in the vicinity of Mochovce nuclear power plant in Slovakia is presented. All major contributions to the effective dose were taken into account, including the contributions from gamma radiation of soil and rocks, cosmic radiation, and indoor and outdoor radon and thoron. On the basis of recent indoor radon measurements in Slovak cities and publicly available data about radon concentration in the soil air, a roughly linear relationship was found between these variables. Consequently, the annual effective dose from indoor radon and thoron was conservatively estimated. For the area of interest, a map of conservatively estimated potential effective doses was created. For the villages in the vicinity of Mochovce, the conservatively estimated effective dose to the population from natural sources ranged from 5.4 to 14.6 mSv, which is four orders of magnitude higher than the contribution of radioactive discharges from Mochovce nuclear power plant. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A MULTI-ELEMENT THICK GAS ELECTRON MULTIPLIER-BASED MICRODOSEMETER FOR MEASUREMENT OF NEUTRONS DOSE-EQUIVALENT: A MONTE CARLO STUDY.

PubMed

Moslehi, A; Raisali, G

2017-11-01

To determine the dose-equivalent of neutrons in an extended energy range, in the present work a multi-element thick gas electron multiplier-based microdosemeter made of PMMA (Perspex) walls of 10 mm in thickness is designed. Each cavity is filled with the propane-based tissue-equivalent (TE) gas simulating 1 µm of tissue. Also, a few weight fractions of 3He are assumed to be added to the TE gas. The dose-equivalents are determined for 11 neutron energies between thermal and 14 MeV using the lineal energy distributions calculated by Geant4 simulation toolkit and also the lineal energy-based quality factors. The results show that by adding 0.04% of 3He to the TE gas in each cavity, an energy-independent dose-equivalent response within 30% uncertainty around a median value of 0.91 in the above energy range is achieved. It is concluded that after its construction, the studied microdosemeter can be used to measure the dose-equivalent of neutrons, favorably. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Early effects comparison of X-rays delivered at high-dose-rate pulses by a plasma focus device and at low dose rate on human tumour cells.

PubMed

Virelli, A; Zironi, I; Pasi, F; Ceccolini, E; Nano, R; Facoetti, A; Gavoçi, E; Fiore, M R; Rocchi, F; Mostacci, D; Cucchi, G; Castellani, G; Sumini, M; Orecchia, R

2015-09-01

A comparative study has been performed on the effects of high-dose-rate (DR) X-ray beams produced by a plasma focus device (PFMA-3), to exploit its potential medical applications (e.g. radiotherapy), and low-DR X-ray beams produced by a conventional source (XRT). Experiments have been performed at 0.5 and 2 Gy doses on a human glioblastoma cell line (T98G). Cell proliferation rate and potassium outward currents (IK) have been investigated by time lapse imaging and patch clamp recordings. The results showed that PFMA-3 irradiation has a greater capability to reduce the proliferation rate activity with respect to XRT, while it does not affect IK of T98G cells at any of the dose levels tested. XRT irradiation significantly reduces the mean IK amplitude of T98G cells only at 0.5 Gy. This work confirms that the DR, and therefore the source of radiation, is crucial for the planning and optimisation of radiotherapy applications. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Spectral correction factors for conventional neutron dosemeters used in high-energy neutron environments.

PubMed

Lee, K W; Sheu, R J

2015-04-01

High-energy neutrons (>10 MeV) contribute substantially to the dose fraction but result in only a small or negligible response in most conventional moderated-type neutron detectors. Neutron dosemeters used for radiation protection purpose are commonly calibrated with (252)Cf neutron sources and are used in various workplace. A workplace-specific correction factor is suggested. In this study, the effect of the neutron spectrum on the accuracy of dose measurements was investigated. A set of neutron spectra representing various neutron environments was selected to study the dose responses of a series of Bonner spheres, including standard and extended-range spheres. By comparing (252)Cf-calibrated dose responses with reference values based on fluence-to-dose conversion coefficients, this paper presents recommendations for neutron field characterisation and appropriate correction factors for responses of conventional neutron dosemeters used in environments with high-energy neutrons. The correction depends on the estimated percentage of high-energy neutrons in the spectrum or the ratio between the measured responses of two Bonner spheres (the 4P6_8 extended-range sphere versus the 6″ standard sphere). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Looking into future: challenges in radiation protection in medicine.

PubMed

Rehani, M M

2015-07-01

Radiation protection in medicine is becoming more and more important with increasing wider use of X-rays, documentation of effects besides the potential for long-term carcinogenic effects. With computed tomography (CT) likely to become sub-mSv in coming years, positron emission tomography (PET), single photon emission computed tomography (SPECT) and some of the nuclear medical examination will become focus of attraction as high-dose examinations, even though they are less-frequent ones. Clarity will be needed on radiation effects at levels of radiation doses encountered in a couple of CT scans and if effects are really cumulative. There is challenge to develop radiation metrics that can be used as easily as units of temperature and length and avoidance of multiple meaning of a single dose metric. Other challenges include development of biological indicators of radiation dose, transition from dose to a representative phantom to dose to individual patient, system for tracking of radiation exposure history of patient, avoidance of radiation-induced skin injury in patients and radiation cataract in staff, cutting down inappropriate referrals for radiological examinations, confidence building in patient and patient safety in radiotherapy. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

49 CFR 178.812 - Top lift test.

Code of Federal Regulations, 2010 CFR

2010-10-01

... no loss of contents. [Amdt. 178-103, 59 FR 38074, July 26, 1994, as amended at 66 FR 33452, June 21... types must be loaded to twice the maximum permissible gross mass with the load being evenly distributed. (2) Flexible IBC design types must be filled to six times the maximum net mass, the load being evenly...

Maximum dose rate is a determinant of hypothyroidism after 131I therapy of Graves' disease but the total thyroid absorbed dose is not.

PubMed

Krohn, Thomas; Hänscheid, Heribert; Müller, Berthold; Behrendt, Florian F; Heinzel, Alexander; Mottaghy, Felix M; Verburg, Frederik A

2014-11-01

The determinants of successful (131)I therapy of Graves' disease (GD) are unclear. To relate dosimetry parameters to outcome of therapy to identify significant determinants eu- and/or hypothyroidism after (131)I therapy in patients with GD. A retrospective study in which 206 Patients with GD treated in University Hospital between November 1999 and January 2011. All received (131)I therapy aiming at a total absorbed dose to the thyroid of 250 Gy based on pre-therapeutic dosimetry. Post-therapy dosimetric thyroid measurements were performed twice daily until discharge. From these measurements, thyroid (131)I half-life, the total thyroid absorbed dose, and the maximum dose rate after (131)I administration were calculated. In all, 48.5% of patients were hypothyroid and 28.6% of patients were euthyroid after (131)I therapy. In univariate analysis, nonhyperthyroid and hyperthyroid patients only differed by sex. A lower thyroid mass, a higher activity per gram thyroid tissue, a shorter effective thyroidal (131)I half-life, and a higher maximum dose rate, but not the total thyroid absorbed dose, were significantly associated with hypothyroidism. In multivariate analysis, the maximum dose rate remained the only significant determinant of hypothyroidism (P < .001). Maximum dose rates of 2.2 Gy/h and higher were associated with a 100% hypothyroidism rate. Not the total thyroid absorbed dose, but the maximum dose rate is a determinant of successfully achieving hypothyroidism in Graves' disease. Dosimetric concepts aiming at a specific total thyroid absorbed dose will therefore require reconsideration if our data are confirmed prospectively.

Computer-determined dosage of insulin in the management of neonatal hyperglycaemia (HINT2): protocol of a randomised controlled trial.

PubMed

Alsweiler, Jane; Williamson, Kathryn; Bloomfield, Frank; Chase, Geoffrey; Harding, Jane

2017-03-06

Neonatal hyperglycaemia is frequently treated with insulin, which may increase the risk of hypoglycaemia. Computer-determined dosage of insulin (CDD) with the STAR-GRYPHON program uses a computer model to predict an effective dose of insulin to treat hyperglycaemia while minimising the risk of hypoglycaemia. However, CDD models can require more frequent blood glucose testing than common clinical protocols. The aim of this trial is to determine if CDD using STAR-GRYPHON reduces hypoglycaemia in hyperglycaemic preterm babies treated with insulin independent of the frequency of blood glucose testing. Design: Multicentre, non-blinded, randomised controlled trial. Neonatal intensive care units in New Zealand and Australia. 138 preterm babies ≤30 weeks' gestation or ≤1500 g at birth who develop hyperglycaemia (two consecutive blood glucose concentrations ≥10 mmol/L, at least 4 hours apart) will be randomised to one of three groups: (1) CDD using the STAR-GRYPHON model-based decision support system: insulin dose and frequency of blood glucose testing advised by STAR-GRYPHON, with a maximum testing interval of 4 hours; (2) bedside titration: insulin dose determined by medical staff, maximum blood glucose testing interval of 4 hours; (3) standard care: insulin dose and frequency of blood glucose testing determined by medical staff. The target range for blood glucose concentrations is 5-8 mmol/L in all groups. A subset of babies will have masked continuous glucose monitoring. is the number of babies with one or more episodes of hypoglycaemia (blood glucose concentration <2.6 mmol/L), during treatment with insulin. This protocol has been approved by New Zealand's Health and Disability Ethics Committee: 14/STH/26. A data safety monitoring committee has been appointed to oversee the trial. Findings will be disseminated to participants and carers, peer-reviewed journals, guideline developers and the public. 12614000492651. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Destruction of humic substances by pulsed electrical discharge

NASA Astrophysics Data System (ADS)

Lobanova, G. L.; Yurmazova, T. A.; Shiyan, L. N.; Machekhina, K. I.; Davidenko, M. A.

2017-01-01

Currently, the water recourses in the territory of Tomsk region are groundwater which is limited to the high concentration of iron and manganese ions and organic substances. These impurities present in water in different forms such as soluble salts ant the colloid forms. Therefore, the present work is a part of a continuations researcher of the processes in natural waters containing humic substances at the influence of pulsed electrical discharges in a layer of iron pellets. It is shown that the main stage of water purification process of humic substances during treatment by pulsed electric discharge in the layer of iron granules is a difficult process including several stages such as formation of iron oxyhydroxide colloid particles, sorption and coagulation with humic macromolecules substances, growth of particle dispersed phase and precipitation. The reason for the formation and coagulation of the dispersed phase is a different state of charge of the colloid particles (zeta potentials of (Fe (OH)3) is +8 mV, zeta potentials of (Humic substances) is -70 mV. The most intense permanganate oxidation reduction to the maximum permissible concentration occurs at the processing time equal to 10 seconds. The contact time of active erosion products with sodium humate is established and it equals to 1 hour. The value of permanganate oxidation achieves maximum permissible concentration during this time and iron concentration in solution achieves maximum permissible concentration after filtration.

SUDOQU: a new dose model to derive criteria for surface contamination of non-food (consumer) goods, containers and conveyances.

PubMed

van Dillen, Teun

2015-04-01

The Fukushima nuclear accident (Japan, 11 March 2011) revealed the need for well-founded criteria for surface contamination and associated screening levels related to the import of non-food (consumer) goods, containers and conveyances. The only available European-harmonised criteria are those laid down in the IAEA transport regulations, but these criteria date back from the early 1960s and only apply to the safe transport of radioactive materials. The main problem is that a generic dose-assessment model for consumer products is missing. Therefore, RIVM (National Institute for Public Health and the Environment) developed a new methodology entitled SUDOQU (SUrface DOse QUantification) to calculate the annual effective dose for both consumers and non-radiological workers, addressing issues of removability of surface contamination. The methodology can be used to derive criteria and screening levels for surface contamination and could serve as a useful tool for policy-makers and radiation-protection specialists. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SIMULATING LOCAL DENSE AREAS USING PMMA TO ASSESS AUTOMATIC EXPOSURE CONTROL IN DIGITAL MAMMOGRAPHY.

PubMed

Bouwman, R W; Binst, J; Dance, D R; Young, K C; Broeders, M J M; den Heeten, G J; Veldkamp, W J H; Bosmans, H; van Engen, R E

2016-06-01

Current digital mammography (DM) X-ray systems are equipped with advanced automatic exposure control (AEC) systems, which determine the exposure factors depending on breast composition. In the supplement of the European guidelines for quality assurance in breast cancer screening and diagnosis, a phantom-based test is included to evaluate the AEC response to local dense areas in terms of signal-to-noise ratio (SNR). This study evaluates the proposed test in terms of SNR and dose for four DM systems. The glandular fraction represented by the local dense area was assessed by analytic calculations. It was found that the proposed test simulates adipose to fully glandular breast compositions in attenuation. The doses associated with the phantoms were found to match well with the patient dose distribution. In conclusion, after some small adaptations, the test is valuable for the assessment of the AEC performance in terms of both SNR and dose. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Calibration of modified Liulin detector for cosmic radiation measurements on-board aircraft.

PubMed

Kyselová, D; Ambrožová, I; Krist, P; Kubančák, J; Uchihori, Y; Kitamura, H; Ploc, O

2015-06-01

The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them. Aircrew dosimetry is usually performed using special computer programs mostly based on results of Monte Carlo simulations. Contemporary, detectors are used mostly for validation of these computer codes, verification of effective dose calculations and for research purposes. One of such detectors is active silicon semiconductor deposited energy spectrometer Liulin. Output quantities of measurement with the Liulin detector are the absorbed dose in silicon D and the ambient dose equivalent H*(10); to determine it, two calibrations are necessary. The purpose of this work was to develop a calibration methodology that can be used to convert signal from the detector to D independently on calibration performed at Heavy Ion Medical Accelerator facility in Chiba, Japan. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Dose Equivalents for Antipsychotic Drugs: The DDD Method.

PubMed

Leucht, Stefan; Samara, Myrto; Heres, Stephan; Davis, John M

2016-07-01

Dose equivalents of antipsychotics are an important but difficult to define concept, because all methods have weaknesses and strongholds. We calculated dose equivalents based on defined daily doses (DDDs) presented by the World Health Organisation's Collaborative Center for Drug Statistics Methodology. Doses equivalent to 1mg olanzapine, 1mg risperidone, 1mg haloperidol, and 100mg chlorpromazine were presented and compared with the results of 3 other methods to define dose equivalence (the "minimum effective dose method," the "classical mean dose method," and an international consensus statement). We presented dose equivalents for 57 first-generation and second-generation antipsychotic drugs, available as oral, parenteral, or depot formulations. Overall, the identified equivalent doses were comparable with those of the other methods, but there were also outliers. The major strength of this method to define dose response is that DDDs are available for most drugs, including old antipsychotics, that they are based on a variety of sources, and that DDDs are an internationally accepted measure. The major limitations are that the information used to estimate DDDS is likely to differ between the drugs. Moreover, this information is not publicly available, so that it cannot be reviewed. The WHO stresses that DDDs are mainly a standardized measure of drug consumption, and their use as a measure of dose equivalence can therefore be misleading. We, therefore, recommend that if alternative, more "scientific" dose equivalence methods are available for a drug they should be preferred to DDDs. Moreover, our summary can be a useful resource for pharmacovigilance studies. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

CALCULATIONS OF SHUTDOWN DOSE RATE FOR THE TPR SPECTROMETER OF THE HIGH-RESOLUTION NEUTRON SPECTROMETER FOR ITER.

PubMed

Wójcik-Gargula, A; Tracz, G; Scholz, M

2017-12-13

This work presents results of the calculations performed in order to predict the neutron-induced activity in structural materials that are considered to be using at the TPR spectrometer-one of the detection system of the High-Resolution Neutron Spectrometer for ITER. An attempt has been made to estimate the shutdown dose rates in a Cuboid #1 and to check if they satisfy ICRP regulatory requirements for occupational exposure to radiation and ITER nuclear safety regulations for areas with personal access. The results were obtained by the MCNP and FISPACT-II calculations. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Altitude-Test-Chamber Investigation of a Solar Afterburner on the 24C Engine I - Operational Characteristics and Altitude Limits

NASA Technical Reports Server (NTRS)

1948-01-01

An altitude-test-chamber investigation was conducted to determine the operational characteristics and altitude blow-out limits of a Solar afterburner in a 24C engine. At rated engine speed and maximum permissible turbine-discharge temperature, the altitude limit as determined by combustion blow-out occurred as a band of unstable operation of about 8000 feet altitude in width with maximum altitude limits from 32,000 feet at a Mach number of 0.3 to about 42,000 feet at a Mach number of 1.0. The maximum fuel-air ratio of the afterburner, as limited by maximum permissible turbine-discharge gas temperatures at rated engine speed, varied between 0.0295 and 0.0380 over a range of flight Mach numbers from 0.25 to 1.0 and at altitudes of 20,000 and 30,000 feet. Over this range of operating conditions, the fuel-air ratio at which lean blow-out occurred was from 10 to 19 percent below these maximum fuel-air ratios. Combustion was very smooth and uniform during operation; however, ignition of the burner was very difficult throughout the investigation. A failure of the flame holder after 12 hours and 15 minutes of afterburner operation resulted in termination of the investigation.

Single Dose Versus 3 Doses of Intramuscular Benzathine Penicillin for Early Syphilis in HIV: A Randomized Clinical Trial.

PubMed

Andrade, Roberto; Rodriguez-Barradas, Maria C; Yasukawa, Kosuke; Villarreal, Erick; Ross, Michael; Serpa, Jose A

2017-03-15

Patients coinfected with syphilis and human immunodeficiency virus (HIV) may have a slower decrease in rapid plasma reagin (RPR) titers. Currently a single dose of 2.4 million units of intramuscular benzathine penicillin G (BPG) is recommended for the treatment of early syphilis. Some observational studies have suggested that this regimen may lead to high failure rates in coinfected patients. We conducted an open-label randomized clinical trial to compare the efficacy of single-dose and 3-dose regimens of BPG for the treatment of early syphilis in HIV-infected individuals. RPR titers were monitored every 3 months. Treatment success was defined as a decrease in RPR titers of ≥2 dilutions (4-fold) during a 12-month follow-up period. Sixty-four patients were included. In the intention-to-treat analysis, treatment success rates were 80% (28 of 35 subjects) and 93% (27 of 29 subjects) in the single-dose and 3-dose regimens, respectively (absolute difference, 13% [95% confidence interval {CI}, -5% to 30%; P = .17). In the per-protocol analysis, success rates were 93% (27 of 29) and 100% in the single-dose and 3-dose regimens, respectively (absolute difference, 7% [95% CI, -7% to 22%]; P = .49). CD4 T-cell count, RPR titer and syphilis stage did not affect treatment results. When compared with a single dose of BPG, a 3-dose regimen did not improve syphilis serological outcomes. Our results support the Centers for Disease Control and Prevention recommendation of a single dose of BPG in HIV-infected patients with early syphilis. NCT02611765. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

High-dose versus standard-dose radiotherapy with concurrent chemotherapy in stages II-III esophageal cancer.

PubMed

Suh, Yang-Gun; Lee, Ik Jae; Koom, Wong Sub; Cha, Jihye; Lee, Jong Young; Kim, Soo Kon; Lee, Chang Geol

2014-06-01

In this study, we investigated the effects of radiotherapy ≥60 Gy in the setting of concurrent chemo-radiotherapy for treating patients with Stages II-III esophageal cancer. A total of 126 patients treated with 5-fluorouracilbased concurrent chemo-radiotherapy between January 1998 and February 2008 were retrospectively reviewed. Among these patients, 49 received a total radiation dose of <60 Gy (standard-dose group), while 77 received a total radiation dose of ≥60 Gy (high-dose group). The median doses in the standard- and high-dose groups were 54 Gy (range, 45-59.4 Gy) and 63 Gy (range, 60-81 Gy), respectively. The high-dose group showed significantly improved locoregional control (2-year locoregional control rate, 69 versus 32%, P < 0.01) and progression-free survival (2-year progression-free survival, 47 versus 20%, P = 0.01) than the standard-dose group. Median overall survival in the high- and the standard-dose groups was 28 and 18 months, respectively (P = 0.26). In multivariate analysis, 60 Gy or higher radiotherapy was a significant prognostic factor for improved locoregional control, progression-free survival and overall survival. No significant differences were found in frequencies of late radiation pneumonitis, post-treatment esophageal stricture or treatment-related mortality between the two groups. High-dose radiotherapy of 60 Gy or higher with concurrent chemotherapy improved locoregional control and progression-free survival without a significant increase of in treatment-related toxicity in patients with Stages II-III esophageal cancer. Our study could provide the basis for future randomized clinical trials. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Estimation of Maximum Entrance Skin Dose during Cerebral Angiography].

PubMed

Kawauchi, Satoru; Moritake, Takashi; Hayakawa, Mikito; Hamada, Yusuke; Sakuma, Hideyuki; Yoda, Shogo; Satoh, Masayuki; Sun, Lue; Koguchi, Yasuhiro; Akahane, Keiichi; Chida, Koichi; Matsumaru, Yuji

2015-09-01

Using radio-photoluminescence glass dosimeter, we measured the entrance skin dose (ESD) in 46 cases and analyzed the correlations between maximum ESD and angiographic parameters [total fluoroscopic time (TFT); number of digital subtraction angiography (DSA) frames, air kerma at the interventional reference point (AK), and dose-area product (DAP)] to estimate the maximum ESD in real time. Mean (± standard deviation) maximum ESD, dose of the right lens, and dose of the left lens were 431.2 ± 135.8 mGy, 33.6 ± 15.5 mGy, and 58.5 ± 35.0 mGy, respectively. Correlation coefficients (r) between maximum ESD and TFT, number of DSA frames, AK, and DAP were r=0.379 (P<0.01), r=0.702 (P<0.001), r=0.825 (P<0.001), and r=0.709 (P<0.001), respectively. AK was identified as the most useful parameter for real-time prediction of maximum ESD. This study should contribute to the development of new diagnostic reference levels in our country.

7 CFR 51.1178 - Maximum anhydrous citric acid permissible for corresponding total soluble solids.

Code of Federal Regulations, 2010 CFR

2010-01-01

... of Florida Oranges and Tangelos Standards for Internal Quality of Common Sweet Oranges (citrus... Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF...

Interpretation of Biochemical Tests Using the Reference Change Value in Monitoring Adverse Effects of Oral Isotretinoin in 102 Ethnic Turkish Patients.

PubMed

Bugdayci, Guler; Polat, Mualla; Oguzman, Hamdi; Cinpolat, Havva Yasemin

2016-08-01

The aim of this study was to model the use of reference change values (RCVs) for the follow-up of 4 parameters of patients using oral isotretinoin which is gaining widespread popularity for monitoring the side effects of the treatment. 102 patients received 30 mg/day oral isotretinoin for 24 weeks for the diagnosis of acne vulgaris. Repetitive measurements of the patients were interpreted with RCVs, after comparing the first and second doses based on RCVs: TC, TG, AST and ALT results increased in 12%, 20%, 14% and 12% of the patients respectively. When the first dose was compared with the last dose, the increases were 20%, 29%, 22% and 18% respectively interpreted as significant changes based on laboratory medicine. A more sensitive follow-up is possible in the monitorization of adverse effects by using RCVs method. © American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Naturally induced secondary radiation in interplanetary space: Preliminary analyses for gamma radiation and radioisotope production from thermal neutron activation

NASA Technical Reports Server (NTRS)

Plaza-Rosado, Heriberto

1991-01-01

Thermal neutron activation analyses were carried out for various space systems components to determine gamma radiation dose rates and food radiation contamination levels. The space systems components selected were those for which previous radiation studies existed. These include manned space vehicle radiation shielding, liquid hydrogen propellant tanks for a Mars mission, and a food supply used as space vehicle radiation shielding. The computational method used is based on the fast neutron distribution generated by the BRYNTRN and HZETRN transport codes for Galactic Cosmic Rays (GCR) at solar minimum conditions and intense solar flares in space systems components. The gamma dose rates for soft tissue are calculated for water and aluminum space vehicle slab shields considering volumetric source self-attenuation and exponential buildup factors. In the case of the lunar habitat with regolith shielding, a completely exposed spherical habitat was assumed for mathematical convenience and conservative calculations. Activation analysis of the food supply used as radiation shielding is presented for four selected nutrients: potassium, calcium, sodium, and phosphorus. Radioactive isotopes that could represent a health hazard if ingested are identified and their concentrations are identified. For nutrients soluble in water, it was found that all induced radioactivity was below the accepted maximum permissible concentrations.

Naturally induced secondary radiation in interplanetary space: Preliminary analyses for gamma radiation and radioisotope production from thermal neutron activation

NASA Astrophysics Data System (ADS)

Plaza-Rosado, Heriberto

1991-09-01

Thermal neutron activation analyses were carried out for various space systems components to determine gamma radiation dose rates and food radiation contamination levels. The space systems components selected were those for which previous radiation studies existed. These include manned space vehicle radiation shielding, liquid hydrogen propellant tanks for a Mars mission, and a food supply used as space vehicle radiation shielding. The computational method used is based on the fast neutron distribution generated by the BRYNTRN and HZETRN transport codes for Galactic Cosmic Rays (GCR) at solar minimum conditions and intense solar flares in space systems components. The gamma dose rates for soft tissue are calculated for water and aluminum space vehicle slab shields considering volumetric source self-attenuation and exponential buildup factors. In the case of the lunar habitat with regolith shielding, a completely exposed spherical habitat was assumed for mathematical convenience and conservative calculations. Activation analysis of the food supply used as radiation shielding is presented for four selected nutrients: potassium, calcium, sodium, and phosphorus. Radioactive isotopes that could represent a health hazard if ingested are identified and their concentrations are identified. For nutrients soluble in water, it was found that all induced radioactivity was below the accepted maximum permissible concentrations.

Application of whole-body personal TL dosemeters in mixed field beta-gamma radiation.

PubMed

Ciupek, K; Aksamit, D; Wołoszczuk, K

2014-11-01

Application of whole-body personal TL dosemeters based on a high-sensitivity LiF:Mg,Cu,P (MCP-N) in mixed field beta-gamma radiation has been characterised. The measurements were carried out with (90)Sr/(90)Y, (85)Kr and (137)Cs point sources to calculate the energy response and linearity of the TLD response in a dose range of 0.1-30 mSv. From the result, calibration curves were obtained, enabling the readout of individual dose equivalent Hp(10) from gamma radiation and Hp(0.07) from beta radiation in mixed field beta-gamma. Limitation of the methodology and its application are presented and discussed. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SIMPLIFIED PRACTICAL TEST METHOD FOR PORTABLE DOSE METERS USING SEVERAL SEALED RADIOACTIVE SOURCES.

PubMed

Mikamoto, Takahiro; Yamada, Takahiro; Kurosawa, Tadahiro

2016-09-01

Sealed radioactive sources which have small activity were employed for the determination of response and tests for non-linearity and energy dependence of detector responses. Close source-to-detector geometry (at 0.3 m or less) was employed to practical tests for portable dose meters to accumulate statistically sufficient ionizing currents. Difference between response in the present experimentally studied field and in the reference field complied with ISO 4037 due to non-uniformity of radiation fluence at close geometry was corrected by use of Monte Carlo simulation. As a consequence, corrected results were consistent with the results obtained in the ISO 4037 reference field within their uncertainties. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Low dose in nuclear cardiology: state of the art in the era of new cadmium-zinc-telluride cameras.

PubMed

Acampa, Wanda; Buechel, Ronny R; Gimelli, Alessia

2016-06-01

The use of myocardial perfusion imaging has seen a tremendous growth during the last decade and has become the most commonly used non-invasive imaging tool for risk stratification in patients with suspected and known coronary artery disease. Adherence to radiation safety best practices varied significantly between laboratories but the possibility to use the new cameras in nuclear cardiology can reduce dramatically the radiation dose without losing accuracy. Moreover, the physical characteristics of ultrafast technology could be able to open new doors for the evaluation of old parameters, changing the impact of nuclear cardiology in the diagnostic strategies. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Dosimetric models of the eye and lens of the eye and their use in assessing dose coefficients for ocular exposures.

PubMed

Bolch, W E; Dietze, G; Petoussi-Henss, N; Zankl, M

2015-06-01

Based upon recent epidemiological studies of ocular exposure, the Main Commission of the International Commission on Radiological Protection (ICRP) in ICRP Publication 118 states that the threshold dose for radiation-induced cataracts is now considered to be approximately 0.5 Gy for both acute and fractionated exposures. Consequently, a reduction was also recommended for the occupational annual equivalent dose to the lens of the eye from 150 mSv to 20 mSv, averaged over defined periods of 5 years. To support ocular dose assessment and optimisation, Committee 2 included Annex F within ICRP Publication 116 . Annex F provides dose coefficients - absorbed dose per particle fluence - for photon, electron, and neutron irradiation of the eye and lens of the eye using two dosimetric models. The first approach uses the reference adult male and female voxel phantoms of ICRP Publication 110. The second approach uses the stylised eye model of Behrens et al., which itself is based on ocular dimensional data given in Charles and Brown. This article will review the data and models of Annex F with particular emphasis on how these models treat tissue regions thought to be associated with stem cells at risk. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Complex interactions between potentially pathogenic, opportunistic, and resident bacteria emerge during infection on a reef-building coral.

PubMed

Gignoux-Wolfsohn, Sarah A; Aronson, Felicia M; Vollmer, Steven V

2017-07-01

Increased bacterial diversity on diseased corals can obscure disease etiology and complicate our understanding of pathogenesis. To untangle microbes that may cause white band disease signs from microbes responding to disease, we inoculated healthy Acropora cervicornis corals with an infectious dose from visibly diseased corals. We sampled these dosed corals and healthy controls over time for sequencing of the bacterial 16S region. Endozoicomonas were associated with healthy fragments from 4/10 colonies, dominating microbiomes before dosing and decreasing over time only in corals that displayed disease signs, suggesting a role in disease resistance. We grouped disease-associated bacteria by when they increased in abundance (primary vs secondary) and whether they originated in the dose (colonizers) or the previously healthy corals (responders). We found that all primary responders increased in all dosed corals regardless of final disease state and are therefore unlikely to cause disease signs. In contrast, primary colonizers in the families Pasteurellaceae and Francisellaceae increased solely in dosed corals that ultimately displayed disease signs, and may be infectious foreign bacteria involved in the development of disease signs. Moving away from a static comparison of diseased and healthy bacterial communities, we provide a framework to identify key players in other coral diseases. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Outdoor solar UVA dose assessment with EBT2 radiochromic film using spectrophotometer and densitometer measurements.

PubMed

Abukassem, I; Bero, M A

2015-04-01

Direct measurements of solar ultraviolet radiations (UVRs) have an important role in the protection of humans against UVR hazard. This work presents simple technique based on the application of EBT2 GAFCHROMIC(®) film for direct solar UVA dose assessment. It demonstrates the effects of different parts of the solar spectrum (UVB, visible and infrared) on performed UVA field measurements and presents the measurement uncertainty budget. The gradient of sunlight exposure level permitted the authors to establish the mathematical relationships between the measured solar UVA dose and two measured quantities: the first was the changes in spectral absorbance at the wavelength 633 nm (A633) and the second was the optical density (OD). The established standard relations were also applied to calculate the solar UVA dose variations during the whole day; 15 min of exposure each hour between 8:00 and 17:00 was recorded. Results show that both applied experimental methods, spectrophotometer absorbance and densitometer OD, deliver comparable figures for EBT2 solar UVA dose assessment with relative uncertainty of 11% for spectral absorbance measurements and 15% for OD measurements. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Temporal Lobe Toxicity Analysis After Proton Radiation Therapy for Skull Base Tumors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pehlivan, Berrin; Ares, Carmen, E-mail: carmen.ares@psi.ch; Lomax, Antony J.

2012-08-01

Purpose: Temporal lobe (TL) parenchyma toxicity constitutes one of the most frequent late adverse event in high-dose proton therapy (PT) for tumors of the skull base. We analyzed clinical events with dosimetric parameters in our patients treated for skull base tumors with spot-scanning PT. Methods and Materials: Between 1998 and 2005, a total of 62 patients received PT to a median dose of 71.7 Gy (relative biologic effectiveness [RBE]) (range, 63-74 Gy). The dose-volume histogram of each TL and the entire brain parenchyma (BP) were analyzed according to maximum, mean, and minimum dose as well as doses to 0.5, 1,more » 2, and 3 cc of brain volume (D{sub 0.5}, D{sub 1}, D{sub 2}, D{sub 3}) and correlated with clinical events. Generalized equivalent uniform dose (gEUD) values were calculated. Results: At a mean follow-up of 38 months (range, 14-92 months), 2 patients had developed symptomatic Grade 3 and 5 patients asymptomatic Grade 1 TL toxicity. Mean doses to a 2-cc volume of BP increased from 71 {+-} 5 Gy (RBE) for no toxicity to 74 {+-} 5 Gy (RBE) for Grade 1 and to 76 {+-} 2 Gy (RBE) for Grade 3 toxicity. TL events occurred in 6 of 7 patients (86%) at or above dose levels of {>=}64 Gy (RBE) D{sub 3}, {>=}68 Gy (RBE) D{sub 2}, {>=}72 Gy (RBE) D{sub 1}, and {>=}73 Gy (RBE) D{sub 0.5}, respectively (p = NS). No statistically significant dose/volume threshold was detected between patients experiencing no toxicity vs. Grade 1 or Grade 3. A strong trend for Grade 1 and 3 events was observed, when the gEUD was 60 Gy. Conclusions: A statistically significant normal tissue threshold dose for BP has not been successfully defined. However, our data suggest that tolerance of TL and BP to fractionated radiotherapy appears to be correlated with tissue volume included in high-dose regions. Additional follow-up time and patient accrual is likely needed to achieve clinical significance for these dose-volume parameters investigated. Our findings support the importance of establishing an organ-at-risk maximally permissible dose for BP.« less

49 CFR 178.1060 - Topple test.

Code of Federal Regulations, 2013 CFR

2013-10-01

... there may be no loss of the filling substance. However a slight discharge (e.g., from closures or stitch... Container design types must be filled to their maximum permissible gross mass, the load being evenly...

49 CFR 178.1060 - Topple test.

Code of Federal Regulations, 2014 CFR

2014-10-01

... there may be no loss of the filling substance. However a slight discharge (e.g., from closures or stitch... Container design types must be filled to their maximum permissible gross mass, the load being evenly...

Maximum permissible exposure of the retina in the human eye in optical coherence tomography systems using a confocal scanning laser ophthalmoscopy platform

NASA Astrophysics Data System (ADS)

Rees, Sian; Dobre, George

2014-01-01

When using scanning laser ophthalmoscopy to produce images of the eye fundus, maximum permissible exposure (MPE) limits must be considered. These limits are set out in international standards such as the National Standards Institute ANSI Z136.1 Safe Use of Lasers (USA) and BS EN 60825-1: 1994 (UK) and corresponding Euro norms but these documents do not explicitly consider the case of scanned beams. Our study aims to show how MPE values can be calculated for the specific case of retinal scanning by taking into account an array of parameters, such as wavelength, exposure duration, type of scanning, line rate and field size, and how each set of initial parameters results in MPE values that correspond to thermal or photochemical damage to the retina.

Efficacy of Lens Protection Systems: Dependency on Different Cranial CT Scans in The Acute Stroke Setting.

PubMed

Guberina, Nika; Forsting, Michael; Ringelstein, Adrian

2017-06-15

To evaluate the dose-reduction potential with different lens protectors for patients undergoing cranial computed tomography (CT) scans. Eye lens dose was assessed in vitro (α-Al2O3:C thermoluminescence dosemeters) using an Alderson-Rando phantom® in cranial CT protocols at different CT scanners (SOMATOM-Definition-AS+®(CT1) and SOMATOM-Definition-Flash® (CT2)) using two different lens-protection systems (Somatex® (SOM) and Medical Imaging Systems® (MIS)). Summarised percentage of the transmitted photons: (1) CT1 (a) unenhanced CT (nCT) with gantry angulation: SOM = 103%, MIS = 111%; (2) CT2 (a) nCT without gantry angulation: SOM = 81%, MIS = 91%; (b) CT angiography (CTA) with automatic dose-modulation technique: SOM = 39%, MIS = 74%; (c) CTA without dose-modulation technique: SOM = 22%, MIS = 48%; (d) CT perfusion: SOM = 44%, MIS = 69%. SOM showed a higher dose-reduction potential than MIS maintaining equal image quality. Lens-protection systems are most effective in CTA protocols without dose-reduction techniques. Lens-protection systems lower the average eye lens dose during CT scans up to 1/3 (MIS) and 2/3 (SOM), respectively, if the eye lens is exposed to the direct beam of radiation. Considering both the CT protocol and the material of lens protectors, they seem to be mandatory for reducing the radiation exposure of the eye lens. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Factors associated with higher oxytocin requirements in labor.

PubMed

Frey, Heather A; Tuuli, Methodius G; England, Sarah K; Roehl, Kimberly A; Odibo, Anthony O; Macones, George A; Cahill, Alison G

2015-09-01

To identify clinical characteristics associated with high maximum oxytocin doses in women who achieve complete cervical dilation. A retrospective nested case-control study was performed within a cohort of all term women at a single center between 2004 and 2008 who reached the second stage of labor. Cases were defined as women who had a maximum oxytocin dose during labor >20 mu/min, while women in the control group had a maximum oxytocin dose during labor of ≤20 mu/min. Exclusion criteria included no oxytocin administration during labor, multiple gestations, major fetal anomalies, nonvertex presentation, and prior cesarean delivery. Multiple maternal, fetal, and labor factors were evaluated with univariable analysis and multivariable logistic regression. Maximum oxytocin doses >20 mu/min were administered to 108 women (3.6%), while 2864 women received doses ≤20 mu/min. Factors associated with higher maximum oxytocin dose after adjusting for relevant confounders included maternal diabetes, birthweight >4000 g, intrapartum fever, administration of magnesium, and induction of labor. Few women who achieve complete cervical dilation require high doses of oxytocin. We identified maternal, fetal and labor factors that characterize this group of parturients.

Eye lens dose in interventional cardiology.

PubMed

Principi, S; Delgado Soler, C; Ginjaume, M; Beltran Vilagrasa, M; Rovira Escutia, J J; Duch, M A

2015-07-01

The ICRP has recently recommended reducing the occupational exposure dose limit for the lens of the eye to 20 mSv y(-1), averaged over a period of 5 y, with no year exceeding 50 mSv, instead of the current 150 mSv y(-1). This reduction will have important implications for interventional cardiology and radiology (IC/IR) personnel. In this work, lens dose received by a staff working in IC is studied in order to determine whether eye lens dose monitoring or/and additional radiological protection measures are required. Eye lens dose exposure was monitored in 10 physicians and 6 nurses. The major IC procedures performed were coronary angiography and percutaneous transluminal coronary angioplasty. The personnel were provided with two thermoluminescent dosemeters (TLDs): one calibrated in terms of Hp(3) located close to the left ear of the operator and a whole-body dosemeter calibrated in terms of Hp(10) and Hp(0.07) positioned on the lead apron. The estimated annual eye lens dose for physicians ranged between 8 and 60 mSv, for a workload of 200 procedures y(-1). Lower doses were collected for nurses, with estimated annual Hp(3) between 2 and 4 mSv y(-1). It was observed that for nurses the Hp(0.07) measurement on the lead apron is a good estimate of eye lens dose. This is not the case for physicians, where the influence of both the position and use of protective devices such as the ceiling shield is very important and produces large differences among doses both at the eyes and on the thorax. For physicians, a good correlation between Hp(3) and dose area product is shown. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of the Immunogenicity of Various Booster Doses of Inactivated Polio Vaccine Delivered Intradermally Versus Intramuscularly to HIV-Infected Adults.

PubMed

Troy, Stephanie B; Kouiavskaia, Diana; Siik, Julia; Kochba, Efrat; Beydoun, Hind; Mirochnitchenko, Olga; Levin, Yotam; Khardori, Nancy; Chumakov, Konstantin; Maldonado, Yvonne

2015-06-15

Inactivated polio vaccine (IPV) is necessary for global polio eradication because oral polio vaccine can rarely cause poliomyelitis as it mutates and may fail to provide adequate immunity in immunocompromised populations. However, IPV is unaffordable for many developing countries. Intradermal IPV shows promise as a means to decrease the effective dose and cost of IPV, but prior studies, all using 20% of the standard dose used in intramuscular IPV, resulted in inferior antibody titers. We randomly assigned 231 adults with well-controlled human immunodeficiency virus infection at a ratio of 2:2:2:1 to receive 40% of the standard dose of IPV intradermally, 20% of the standard dose intradermally, the full standard dose intramuscularly, or 40% of the standard dose intramuscularly. Intradermal vaccination was done using the NanoPass MicronJet600 microneedle device. Baseline immunity was 87%, 90%, and 66% against poliovirus serotypes 1, 2, and 3, respectively. After vaccination, antibody titers increased a median of 64-fold. Vaccine response to 40% of the standard dose administered intradermally was comparable to that of the standard dose of IPV administered intramuscularly and resulted in higher (although not significantly) antibody titers. Intradermal administration had higher a incidence of local side effects (redness and itching) but a similar incidence of systemic side effects and was preferred by study participants over intramuscular administration. A 60% reduction in the standard IPV dose without reduction in antibody titers is possible through intradermal administration. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Geological sources of fluoride and acceptable intake of fluoride in an endemic fluorosis area, southern Iran.

PubMed

Battaleb-Looie, Sedigheh; Moore, Farid; Jacks, Gunnar; Ketabdari, Mohammad Reza

2012-10-01

The present study is the first attempt to put forward possible source(s) of fluoride in the Dashtestan area, Bushehr Province, southern Iran. In response to reports on the high incidence of dental fluorosis, 35 surface and groundwater samples were collected and analysed for fluoride. The results indicate that dissolved fluoride in the study area is above the maximum permissible limit recommended by the World Health Organization (WHO). An additional 35 soil and rock samples were also collected and analysed for fluoride, and rock samples were subjected to petrographic investigations and X-ray diffraction. The results of these analyses show that the most likely source for fluoride in the groundwater is from clay minerals (chlorite) and micas (muscovite, sericite, and biotite) in the soils and rocks in the area. We also note that due to the high average temperatures all year round and excessive water consumption in the area, the optimum fluoride dose level should be lower than that recommended by the WHO.

[Experimental assessment of combined effect of nitrates and acute gamma-irradiation on green algae Scenedesmus quadricauda growth].

PubMed

Triapitsyna, G A; Tarasova, S P; Atamaniuk, N I; Osipov, D I; Priakhin, E A

2012-01-01

The combined effect of acute gamma-irradiation at doses of 0, 50, 100, 150 and 200 Gy and nitrates in concentrations of 0.04 g/dm3 (that corresponds to maximum permissible concentrations for fishery waters), 0.1, 0.25, 0.5, 1.0, 2.5 g/dm3 (that is close to NO3(-) level in water of a reservoir R-17 used as radioactive waste storage of the "Mayak" Production Association) and 5.0 g/dm3 (that is close to NO3(-) level in the water of radioactive waste storage reservoir R-9) on the unicellular green algae Scenedesmus quadricauda growth has been studied in laboratory conditions. It was shown that the joint effects of nitrates and y-radiation had an antagonistic character. Thus, it may be concluded that chemical pollution is the factor limiting the development of green algae in reservoir R-17; probably, both factors, chemical and radiating, are essential to the algocenosis degradation in reservoir R-9.

ASSESSMENT OF EYE LENS DOSES IN INTERVENTIONAL RADIOLOGY: A SIMULATION IN LABORATORY CONDITIONS.

PubMed

Čemusová, Z; Ekendahl, D; Judas, L

2016-09-01

As workers in interventional radiology belong to one of the most occupationally exposed groups, methods for sufficiently accurate quantification of their external exposure are sought. The objective of the authors' experiment was to investigate the relations between eye lens dose and Hp(10), Hp(3) or Hp(0.07) values measured with a conventional whole-body personal thermoluminescence dosemeter (TLD). Conditions of occupational exposure during common interventional procedures were simulated in laboratory. An anthropomorphic phantom represented a physician. The TLDs were fixed to the phantom in different locations that are common for purposes of personal dosimetry. In order to monitor the dose at the eye lens level during the exposures, a special thermoluminescence eye dosemeter was fixed to the phantom's temple. Correlations between doses measured with the whole-body and the eye dosemeters were found. There are indications that personnel in interventional radiology do not need to be unconditionally equipped with additional eye dosemeters, especially if an appropriate whole-body dosimetry system has been already put into practice. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cardiac surgery antibiotic prophylaxis and calculated empiric antibiotic therapy.

PubMed

Gorski, Armin; Hamouda, Khaled; Özkur, Mehmet; Leistner, Markus; Sommer, Sebastian-Patrick; Leyh, Rainer; Schimmer, Christoph

2015-03-01

Ongoing debate exists concerning the optimal choice and duration of antibiotic prophylaxis as well as the reasonable calculated empiric antibiotic therapy for hospital-acquired infections in critically ill cardiac surgery patients. A nationwide questionnaire was distributed to all German heart surgery centers concerning antibiotic prophylaxis and the calculated empiric antibiotic therapy. The response to the questionnaire was 87.3%. All clinics that responded use antibiotic prophylaxis, 79% perform it not longer than 24 h (single-shot: 23%; 2 doses: 29%; 3 doses: 27%; 4 doses: 13%; and >5 doses: 8%). Cephalosporin was used in 89% of clinics (46% second-generation, 43% first-generation cephalosporin). If sepsis is suspected, the following diagnostics are performed routinely: wound inspection 100%; white blood cell count 100%; radiography 99%; C-reactive protein 97%; microbiological testing of urine 91%, blood 81%, and bronchial secretion 81%; procalcitonin 74%; and echocardiography 75%. The calculated empiric antibiotic therapy (depending on the suspected focus) consists of a multidrug combination with broad-spectrum agents. This survey shows that existing national guidelines and recommendations concerning perioperative antibiotic prophylaxis and calculated empiric antibiotic therapy are well applied in almost all German heart centers. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

The Mayak Worker Dosimetry System (MWDS-2013): Implementation of the Dose Calculations.

PubMed

Zhdanov, А; Vostrotin, V; Efimov, А; Birchall, A; Puncher, M

2016-07-15

The calculation of internal doses for the Mayak Worker Dosimetry System (MWDS-2013) involved extensive computational resources due to the complexity and sheer number of calculations required. The required output consisted of a set of 1000 hyper-realizations: each hyper-realization consists of a set (1 for each worker) of probability distributions of organ doses. This report describes the hardware components and computational approaches required to make the calculation tractable. Together with the software, this system is referred to here as the 'PANDORA system'. It is based on a commercial SQL server database in a series of six work stations. A complete run of the entire Mayak worker cohort entailed a huge amount of calculations in PANDORA and due to the relatively slow speed of writing the data into the SQL server, each run took about 47 days. Quality control was monitored by comparing doses calculated in PANDORA with those in a specially modified version of the commercial software 'IMBA Professional Plus'. Suggestions are also made for increasing calculation and storage efficiency for future dosimetry calculations using PANDORA. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radon dose assessment in underground mines in Brazil.

PubMed

Santos, T O; Rocha, Z; Cruz, P; Gouvea, V A; Siqueira, J B; Oliveira, A H

2014-07-01

Underground miners are internally exposed to radon, thoron and their short-lived decay products during the mineral processing. There is also an external exposure due to the gamma emitters present in the rock and dust of the mine. However, the short-lived radon decay products are recognised as the main radiation health risk. When inhaled, they are deposited in the respiratory system and may cause lung cancer. To address this concern, concentration measurements of radon and its progeny were performed, the equilibrium factor was determined and the effective dose received was estimated in six Brazilian underground mines. The radon concentration was measured by using E-PERM, AlphaGUARD and CR-39 detectors. The radon progeny was determined by using DOSEman. The annual effective dose for the miners was estimated according to United Nations Scientific Committee on the Effects of Atomic Radiation methodologies. The mean value of the equilibrium factor was 0.4. The workers' estimated effective dose ranged from 1 to 21 mSv a(-1) (mean 9 mSv a(-1)). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

DOSE AND GAMMA-RAY SPECTRA FROM NEUTRON-INDUCED RADIOACTIVITY IN MEDICAL LINEAR ACCELERATORS FOLLOWING HIGH-ENERGY TOTAL BODY IRRADIATION.

PubMed

Keehan, S; Taylor, M L; Smith, R L; Dunn, L; Kron, T; Franich, R D

2016-12-01

Production of radioisotopes in medical linear accelerators (linacs) is of concern when the beam energy exceeds the threshold for the photonuclear interaction. Staff and patients may receive a radiation dose as a result of the induced radioactivity in the linac. Gamma-ray spectroscopy was used to identify the isotopes produced following the delivery of 18 MV photon beams from a Varian 21EX and an Elekta Synergy. The prominent radioisotopes produced include 187 W, 63 Zn, 56 Mn, 24 Na and 28 Al in both linac models. The dose rate was measured at the beam exit window (12.6 µSv in the first 10 min) following 18 MV total body irradiation (TBI) beams. For a throughput of 24 TBI patients per year, staff members are estimated to receive an annual dose of up to 750 μSv at the patient location. This can be further reduced to 65 μSv by closing the jaws before re-entering the treatment bunker. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Dose validation of PhIP hair level as a biomarker of heterocyclic aromatic amines exposure: a feeding study.

PubMed

Le Marchand, Loïc; Yonemori, Kim; White, Kami K; Franke, Adrian A; Wilkens, Lynne R; Turesky, Robert J

2016-07-01

Hair measurement of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a promising biomarker of exposure to this carcinogen formed in cooked meats. However, the dose relationship between normal range intake and hair levels and the modulating effects of CYP1A2 metabolism and hair melanin need to be evaluated. We conducted a randomized, cross-over feeding study among 41 non-smokers using ground beef cooked to two different levels of doneness, 5 days a week for 1 month. PhIP was measured by liquid chromatography/mass spectrometry in food (mean low dose = 0.72 µg/serving; mean high dose = 2.99 µg/serving), and change in PhIP hair level was evaluated. CYP1A2 activity was assessed in urine with the caffeine challenge test and head hair melanin was estimated by UV spectrophotometry. We observed a strong dose-dependent increase in hair PhIP levels. This increase was highly correlated with dose received (ρ = 0.68, P < 0.0001). CYP1A2 activity and normalizing for hair melanin did not modify the response to the intervention. Consumption of PhIP at doses similar to those in the American diet results in a marked dose-dependent accumulation of PhIP in hair. Hair PhIP levels may be used as a biomarker of dietary exposure in studies investigating disease risk. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Nitric oxide is not permissive for cutaneous active vasodilatation in humans.

PubMed

Wilkins, Brad W; Holowatz, Lacy A; Wong, Brett J; Minson, Christopher T

2003-05-01

The precise role of nitric oxide (NO) in cutaneous active vasodilatation in humans is unknown. We tested the hypothesis that NO is necessary to permit the action of an unknown vasodilator. Specifically, we investigated whether a low-dose infusion of exogenous NO, in the form of sodium nitroprusside (SNP), would fully restore vasodilatation in an area of skin in which endogenous NO was inhibited during hyperthermia. This finding would suggest a 'permissive' role for NO in active vasodilatation. Eight subjects were instrumented with three microdialysis fibres in forearm skin. Sites were randomly assigned to (1) Site A: control site; (2) Site B: NO synthase (NOS) inhibition during established hyperthermia; or (3) Site C: NOS inhibition throughout the protocol. Red blood cell flux was measured using laser-Doppler flowmetry (LDF) and cutaneous vascular conductance (CVC; LDF/mean arterial pressure) was normalized to maximal vasodilatation at each site. In Site B, NG-nitro-L-arginine methyl ester (L-NAME) infusion during hyperthermia reduced CVC by approximately 32 % (65 +/- 4 % CVCmax vs. 45 +/- 4 % CVCmax; P < 0.05). Vasodilatation was not restored to pre-NOS inhibition values in this site following low-dose SNP infusion (55 +/- 4 % CVCmax vs. 65 +/- 4 % CVCmax; P < 0.05). CVC remained significantly lower than the control site with low-dose SNP infusion in Site C (P < 0.05). The rise in CVC with low-dose SNP (deltaCVC) was significantly greater in Site B and Site C during hyperthermia compared to normothermia (P < 0.05). No difference in deltaCVC was observed between hyperthermia and normothermia in the control site (Site A). Thus, NO does not act permissively in cutaneous active vasodilatation in humans but may directly mediate vasodilatation and enhance the effect of an unknown active vasodilator.

Deaths, late deaths, and role of infecting dose in Ebola virus disease in Sierra Leone: retrospective cohort study.

PubMed

Bower, Hilary; Smout, Elizabeth; Bangura, Mohamed S; Kamara, Osman; Turay, Cecilia; Johnson, Sembia; Oza, Shefali; Checchi, Francesco; Glynn, Judith R

2016-05-17

 To assess the frequency of fatal recrudescence from Ebola virus disease after discharge from treatment centres, and explore the influence of infecting dose on case fatality rates.  Retrospective cohort study.  Western Area, Sierra Leone.  151 survivors treated for Ebola virus disease at the Kerry Town treatment centre and discharged. Survivors were followed up for a vital status check at four to nine months after discharge, and again at six to 13 months after discharge. Verbal autopsies were conducted for four survivors who had died since discharge (that is, late deaths). Survivors still living in Western Area were interviewed together with their household members. Exposure level to Ebola virus disease was ascertained as a proxy of infecting dose, including for those who died.  Risks and causes of late death; case fatality rates; odds ratios of death from Ebola virus disease by age, sex, exposure level, date, occupation, and household risk factors.  Follow-up information was obtained on all 151 survivors of Ebola virus disease, a mean of 10 months after discharge. Four deaths occurred after discharge, all within six weeks: two probably due to late complications, one to prior tuberculosis, and only one after apparent full recovery, giving a maximum estimate of recrudescence leading to death of 0.7%. In these households, 395 people were reported to have had Ebola virus disease, of whom 227 died. A further 53 people fulfilled the case definition for probable disease, of whom 11 died. Therefore, the case fatality rate was 57.5% (227/395) for reported Ebola virus disease, or 53.1% (238/448) including probable disease. Case fatality rates were higher in children aged under 2 years and adults older than 30 years, in larger households, and in infections occurring earlier in the epidemic in Sierra Leone. There was no consistent trend of case fatality rate with exposure level, although increasing exposure increased the risk of Ebola virus disease.  In this study of survivors in Western Area, Sierra Leone, late recrudescence of severe Ebola virus disease appears to be rare. There was no evidence for an effect of infecting dose (as measured by exposure level) on the severity of disease. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Maximum tolerated dose of nalmefene in patients receiving epidural fentanyl and dilute bupivacaine for postoperative analgesia.

PubMed

Dougherty, T B; Porche, V H; Thall, P F

2000-04-01

This study investigated the ability of the modified continual reassessment method (MCRM) to determine the maximum tolerated dose of the opioid antagonist nalmefene, which does not reverse analgesia in an acceptable number of postoperative patients receiving epidural fentanyl in 0.075% bupivacaine. In the postanesthetic care unit, patients received a single intravenous dose of 0.25, 0.50, 0.75, or 1.00 microg/kg nalmefene. Reversal of analgesia was defined as an increase in pain score of two or more integers above baseline on a visual analog scale from 0 through 10 after nalmefene administration. Patients were treated in cohorts of one, starting with the lowest dose. The maximum tolerated dose of nalmefene was defined as that dose, among the four studied, with a final mean probability of reversal of anesthesia (PROA) closest to 0.20 (ie., a 20% chance of causing reversal). The modified continual reassessment method is an iterative Bayesian statistical procedure that, in this study, selected the dose for each successive cohort as that having a mean PROA closest to the preselected target PROA of 0.20. The modified continual reassessment method repeatedly updated the PROA of each dose level as successive patients were observed for presence or absence of ROA. After 25 patients, the maximum tolerated dose of nalmefene was selected as 0.50 microg/kg (final mean PROA = 0.18). The 1.00-microg/kg dose was never tried because its projected PROA was far above 0.20. The modified continual reassessment method facilitated determination of the maximum tolerated dose ofnalmefene . Operating characteristics of the modified continual reassessment method suggest it may be an effective statistical tool for dose-finding in trials of selected analgesic or anesthetic agents.

Ovarian Cancer

MedlinePlus

... term use and in large doses. Age when menstruation started and ended. Beginning menstruation at an early age or starting menopause at ... Advertising and sponsorship opportunities Reprint Permissions A single copy of these materials may be reprinted for noncommercial ...

Dosimetric response for crystalline and nanostructured aluminium oxide to a high-current pulse electron beam.

PubMed

Nikiforov, S V; Kortov, V S

2014-11-01

The main thermoluminescent (TL) and dosimetric properties of the detectors based on anion-defective crystalline and nanostructured aluminium oxide after exposure to a high-current pulse electron beam are studied. TL peaks associated with deep-trapping centres are registered. It is shown that the use of deep-trap TL at 200-600°С allows registering absorbed doses up to 750 kGy for single-crystalline detectors and those up to 6 kGy for nanostructured ones. A wide range of the doses registered, high reproducibility of the TL signal and low fading contribute to a possibility of using single-crystalline and nanostructured aluminium oxide for the dosimetry of high-current pulse electron beams. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Georgia fishery study: implications for dose calculations. Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turcotte, M.D.S.

Fish consumption will contribute a major portion of the estimated individual and population doses from L-Reactor liquid releases and Cs-137 remobilization in Steel Creek. It is therefore important that the values for fish consumption used in dose calculations be as realistic as possible. Since publication of the L-Reactor Environmental Information Document (EID), data have become available on sport fishing in the Savannah River. These data provide SRP with a site-specific sport fish harvest and consumption values for use in dose calculations. The Georgia fishery data support the total population fish consumption and calculated dose reported in the EID. The datamore » indicate, however, that both the EID average and maximum individual fish consumption have been underestimated, although each to a different degree. The average fish consumption value used in the EID is approximately 3% below the lower limit of the fish consumption range calculated using the Georgia data. Maximum fish consumption in the EID has been underestimated by approximately 60%, and doses to the maximum individual should also be recalculated. Future dose calculations should utilize an average adult fish consumption value of 11.3 kg/yr, and a maximum adult fish consumption value of 34 kg/yr. Consumption values for the teen and child age groups should be increased proportionally: (1) teen average = 8.5; maximum = 25.9 kg/yr; and (2) child average = 3.6; maximum = 11.2 kg/yr. 8 refs.« less

Cellular and Humoral Responses to a Second Dose of Herpes Zoster Vaccine Administered 10 Years After the First Dose Among Older Adults.

PubMed

Levin, Myron J; Schmader, Kenneth E; Pang, Lei; Williams-Diaz, Angela; Zerbe, Gary; Canniff, Jennifer; Johnson, Michael J; Caldas, Yupanqui; Cho, Alice; Lang, Nancy; Su, Shu-Chih; Parrino, Janie; Popmihajlov, Zoran; Weinberg, Adriana

2016-01-01

Herpes zoster vaccine (ZV) was administered as a second dose to 200 participants ≥ 70 years old who had received a dose of ZV ≥ 10 years previously (NCT01245751). Varicella zoster virus (VZV) antibody titers (measured by a VZV glycoprotein-based enzyme-linked immunosorbent assay [gpELISA]) and levels of interferon γ (IFN-γ) and interleukin 2 (IL-2; markers of VZV-specific cell-mediated immunity [CMI], measured by means of ELISPOT analysis) in individuals aged ≥ 70 years who received a booster dose of ZV were compared to responses of 100 participants aged 50-59 years, 100 aged 60-69 years, and 200 aged ≥ 70 years who received their first dose of ZV. The study was powered to demonstrate noninferiority of the VZV antibody response at 6 weeks in the booster-dose group, compared with the age-matched first-dose group. Antibody responses were similar at baseline and after vaccination across all age and treatment groups. Both baseline and postvaccination VZV-specific CMI were lower in the older age groups. Peak gpELISA titers and their fold rise from baseline generally correlated with higher baseline and postvaccination VZV-specific CMI. IFN-γ and IL-2 results for subjects ≥ 70 years old were significantly higher at baseline and after vaccination in the booster-dose group, compared with the first-dose group, indicating that a residual effect of ZV on VZV-specific CMI persisted for ≥ 10 years and was enhanced by the booster dose. These findings support further investigation of ZV administration in early versus later age and of booster doses for elderly individuals at an appropriate interval after initial immunization against HZ. NCT01245751. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

AN ESTIMATION OF THE EXPOSURE OF THE POPULATION OF ISRAEL TO NATURAL SOURCES OF IONIZING RADIATION.

PubMed

Epstein, L; Koch, J; Riemer, T; Haquin, G; Orion, I

2017-11-01

The radiation dose to the population of Israel due to exposure to natural sources of ionizing radiation was assessed. The main contributor to the dose is radon that accounts for 60% of the exposure to natural sources. The dose due to radon inhalation was assessed by combining the results of a radon survey in single-family houses with the results of a survey in apartments in multi-storey buildings. The average annual dose due to radon inhalation was found to be 1.2 mSv. The dose rate due to exposure to cosmic radiation was assessed using a code that calculates the dose rate at different heights above sea level, taking into account the solar cycle. The annual dose was calculated based on the fraction of time spent indoors and the attenuation provided by buildings and was found to be 0.2 mSv. The annual dose due to external exposure to the terrestrial radionuclides was similarly assessed. The indoor dose rate was calculated using a model that takes into account the concentrations of the natural radionuclides in building materials, the density and the thickness of the walls. The dose rate outdoors was calculated based on the concentrations of the natural radionuclides in different geological units in Israel as measured in an aerial survey and measurements above ground. The annual dose was found to be 0.2 mSv. Doses due to internal exposure other than exposure to radon were also calculated and were found to be 0.4 mSv. The overall annual exposure of the population of Israel to natural sources of ionizing radiation is therefore 2 mSv and ranges between 1.7 and 2.7 mSv. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Development and application of a complex numerical model and software for the computation of dose conversion factors for radon progenies.

PubMed

Farkas, Árpád; Balásházy, Imre

2015-04-01

A more exact determination of dose conversion factors associated with radon progeny inhalation was possible due to the advancements in epidemiological health risk estimates in the last years. The enhancement of computational power and the development of numerical techniques allow computing dose conversion factors with increasing reliability. The objective of this study was to develop an integrated model and software based on a self-developed airway deposition code, an own bronchial dosimetry model and the computational methods accepted by International Commission on Radiological Protection (ICRP) to calculate dose conversion coefficients for different exposure conditions. The model was tested by its application for exposure and breathing conditions characteristic of mines and homes. The dose conversion factors were 8 and 16 mSv WLM(-1) for homes and mines when applying a stochastic deposition model combined with the ICRP dosimetry model (named PM-A model), and 9 and 17 mSv WLM(-1) when applying the same deposition model combined with authors' bronchial dosimetry model and the ICRP bronchiolar and alveolar-interstitial dosimetry model (called PM-B model). User friendly software for the computation of dose conversion factors has also been developed. The software allows one to compute conversion factors for a large range of exposure and breathing parameters and to perform sensitivity analyses. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Internal thyroid doses to Fukushima residents-estimation and issues remaining.

PubMed

Kim, Eunjoo; Kurihara, Osamu; Kunishima, Naoaki; Momose, Takumaro; Ishikawa, Tetsuo; Akashi, Makoto

2016-08-01

Enormous quantities of radionuclides were released into the environment following the disastrous accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011. It is of great importance to determine the exposure doses received by the populations living in the radiologically affected areas; however, there has been significant difficulty in estimating the internal thyroid dose received through the intake of short-lived radionuclides (mainly, (131)I), because of the lack of early measurements on people. An estimation by the National Institute of Radiological Sciences for 1 April 2012 to 31 March 2013 was thus performed using a combination of the following three sources: thyroid measurement data ((131)I) for 1080 children examined in the screening campaign, whole-body counter measurement data ((134)Cs, (137)Cs) for 3000 adults, and atmospheric transport dispersion model simulations. In this study, the residents of Futaba town, Iitate village and Iwaki city were shown to have the highest thyroid equivalent dose, and their doses were estimated to be mostly below 30 mSv. However, this result involved a lot of uncertainties and provided only representative values for the residents. The present paper outlines a more recent dose estimation and preliminary analyses of personal behavior data used in the new method. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A booster dose of an inactivated enterovirus 71 vaccine in chinese young children: a randomized, double-blind, placebo-controlled clinical trial.

PubMed

Shenyu, Wang; Jingxin, Li; Zhenglun, Liang; Xiuling, Li; Qunying, Mao; Fanyue, Meng; Hua, Wang; Yuntao, Zhang; Fan, Gao; Qinghua, Chen; Yuemei, Hu; Xin, Yao; Huijie, Guo; Fengcai, Zhu

2014-10-01

A significant waning of enterovirus 71 (EV71) antibody titer after priming immunization with an inactivated EV71 vaccine implied the potential need for a booster dose. In this randomized, double-blind, placebo-controlled clinical trial, we recruited participants who had received at least 1 dose of priming EV71 vaccine in an early phase 2 clinical trial that was conducted in healthy infants and children aged 6-35 months. All participants were grouped according to the priming EV71 vaccine formulations (160 U, 320 U, and 640 U with adjuvant and 640 U without adjuvant) and then randomly assigned (ratio, 2:1) to receive a booster dose of vaccine or placebo within each formulation group. The primary end point was the geometric mean titer 28 days after the booster dose. A total of 773 participants were enrolled. Significantly greater immunological responses were induced by the booster shot of all 4 formulations of EV71 vaccine, compared with that induced by placebo (P < .0001). The frequencies of adverse reactions were similar between vaccine and placebo groups within each formulation group. A booster dose of EV71 vaccine 1 year after the priming EV71 immunization shows excellent immunogenicity and good safety profile. Clinical Trials Registration: NCT01734408. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Patient grouping for dose surveys and establishment of diagnostic reference levels in paediatric computed tomography.

PubMed

Vassileva, J; Rehani, M

2015-07-01

There has been confusion in literature on whether paediatric patients should be grouped according to age, weight or other parameters when dealing with dose surveys. The present work aims to suggest a pragmatic approach to achieve reasonable accuracy for performing patient dose surveys in countries with limited resources. The analysis is based on a subset of data collected within the IAEA survey of paediatric computed tomography (CT) doses, involving 82 CT facilities from 32 countries in Asia, Europe, Africa and Latin America. Data for 6115 patients were collected, in 34.5 % of which data for weight were available. The present study suggests that using four age groups, <1, >1-5, >5-10 and >10-15 y, is realistic and pragmatic for dose surveys in less resourced countries and for the establishment of DRLs. To ensure relevant accuracy of results, data for >30 patients in a particular age group should be collected if patient weight is not known. If a smaller sample is used, patient weight should be recorded and the median weight in the sample should be within 5-10 % from the median weight of the sample for which the DRLs were established. Comparison of results from different surveys should always be performed with caution, taking into consideration the way of grouping of paediatric patients. Dose results can be corrected for differences in patient weight/age group. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of dosemeter position for the assessment of eye lens dose during interventional cardiology.

PubMed

Principi, Sara; Ginjaume, Mercè; Duch, Maria Amor; Sánchez, Roberto M; Fernández, Jose M; Vano, Eliseo

2015-04-01

The equivalent dose limit for the eye lens for occupational exposure recommended by the ICRP has been reduced to 20 mSv y(-1) averaged over defined periods of 5 y, with no single year exceeding 50 mSv. The compliance with this new requirement could not be easy in some workplace such as interventional radiology and cardiology. The aim of this study is to evaluate different possible approaches in order to have a good estimate of the eye lens dose during interventional procedures. Measurements were performed with an X-ray system Philips Allura FD-10, using a PMMA phantom to simulate the patient scattered radiation and a Rando phantom to simulate the cardiologist. Thermoluminescence (TL) whole-body and TL eye lens dosemeters together with Philips DoseAware active dosemeters were located on different positions of the Rando phantom to estimate the eye lens dose in typical cardiology procedures. The results show that, for the studied conditions, any of the analysed dosemeter positions are suitable for eye lens dose assessment. However, the centre of the thyroid collar and the left ear position provide a better estimate. Furthermore, in practice, improper use of the ceiling-suspended screen can produce partial protection of some parts of the body, and thus large differences between the measured doses and the actual exposure of the eye could arise if the dosemeter is not situated close to the eye. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

PATIENT RADIATION DOSE FROM CHEST X-RAY EXAMINATIONS IN THE WEST BANK-PALESTINE.

PubMed

Lahham, Adnan; Issa, Ahlam; ALMasri, Hussein

2018-02-01

Radiation doses to patients resulting from chest X-ray examinations were evaluated in four medical centers in the West Bank and East Jerusalem-Palestine. Absorbed organ and effective doses were calculated for a total of 428 adult male and female patients by using commercially available Monte Carlo based softwares; CALDOSE-X5 and PCXMC-2.0, and hermaphrodite mathematical adult phantoms. Patients were selected randomly from medical records in the time period from November 2014 to February 2015. A database of surveyed patients and exposure factors has been established and includes: patient's height, weight, age, gender, X-ray tube voltage, electric current (mAs), examination projection (anterior posterior (AP), posterior anterior (PA), lateral), X-ray tube filtration thickness in each X-ray equipment, anode angle, focus to skin distance and X-ray beam size. The average absorbed doses in the whole body from different projections were: 0.06, 0.07 and 0.11 mGy from AP, PA and lateral projections, respectively. The average effective dose for all surveyed patients was 0.14 mSv for all chest X-ray examinations and projections in the four investigated medical centers. The effect of projection geometry was also investigated. The average effective doses for AP, PA and lateral projections were 0.14, 0.07 and 0.22 mSv, respectively. The collective effective dose estimated for the exposed population was ~60 man-mSv. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radiological protection in computed tomography and cone beam computed tomography.

PubMed

Rehani, M M

2015-06-01

The International Commission on Radiological Protection (ICRP) has sustained interest in radiological protection in computed tomography (CT), and ICRP Publications 87 and 102 focused on the management of patient doses in CT and multi-detector CT (MDCT) respectively. ICRP forecasted and 'sounded the alarm' on increasing patient doses in CT, and recommended actions for manufacturers and users. One of the approaches was that safety is best achieved when it is built into the machine, rather than left as a matter of choice for users. In view of upcoming challenges posed by newer systems that use cone beam geometry for CT (CBCT), and their widened usage, often by untrained users, a new ICRP task group has been working on radiological protection issues in CBCT. Some of the issues identified by the task group are: lack of standardisation of dosimetry in CBCT; the false belief within the medical and dental community that CBCT is a 'light', low-dose CT whereas mobile CBCT units and newer applications, particularly C-arm CT in interventional procedures, involve higher doses; lack of training in radiological protection among clinical users; and lack of dose information and tracking in many applications. This paper provides a summary of approaches used in CT and MDCT, and preliminary information regarding work just published for radiological protection in CBCT. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Eye Lens Radiation Exposure in Greek Interventional Cardiology Article.

PubMed

Thrapsanioti, Zoi; Askounis, Panagiotis; Datseris, Ioannis; Diamanti, Ramza Anastasia; Papathanasiou, Miltiadis; Carinou, Eleftheria

2017-07-01

The lens of the eye is one of the radiosensitive tissues of the human body; if exposed to ionizing radiation can develop radiation-induced cataract at early ages. This study was held in Greece and included 44 Interventional Cardiologists (ICs) and an unexposed to radiation control group of 22 persons. Of the note, 26 ICs and the unexposed individuals underwent special eye examinations. The detected lens opacities were classified according to LOCS III protocol. Additionally, the lens doses of the ICs were measured using eye lens dosemeters. The mean dose to the lenses of the ICs per month was 0.83 ± 0.59 mSv for the left and 0.35 ± 0.38 mSv for the right eye, while the annual doses ranged between 0.7 and 11 mSv. Regarding the lens opacities, the two groups did not differ significantly in the prevalence of either nuclear or cortical lens opacities, whereas four ICs were detected with early stage subcapsular sclerosis. Though no statistically difference was observed in the cohort, the measured doses indicate that the eye doses received from the ICs can be significant. To minimize the radiation-induced risk at the eye lenses, the use of protective equipment and appropriate training on this issue is highly recommended. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

AIR KERMA TO Hp(3) CONVERSION COEFFICIENTS FOR IEC 61267 RQR X-RAY RADIATION QUALITIES: APPLICATION TO DOSE MONITORING OF THE LENS OF THE EYE IN MEDICAL DIAGNOSTICS.

PubMed

Principi, S; Guardiola, C; Duch, M A; Ginjaume, M

2016-09-01

Recent studies highlight the fact that the new eye lens dose limit can be exceeded in interventional radiology procedures and that eye lens monitoring could be required for these workers. The recommended operational quantity for monitoring of eye lens exposure is the personal dose equivalent at 3 mm depth Hp(3) (ICRU 51). However, there are no available conversion coefficients in international standards, while in the literature coefficients have only been calculated for monoenergetic beams and for ISO 4037-1 X-ray qualities. The aim of this article is to provide air kerma to Hp(3) conversion coefficients for a cylindrical phantom made of ICRU-4 elements tissue-equivalent material for RQR radiation qualities (IEC-61267) from 40 to 120 kV and for angles of incidence from 0 to 180°, which are characteristic of medical workplace. Analytic calculations using interpolation techniques and Monte Carlo modelling have been compared. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Collaboration of local government and experts responding to increase in environmental radiation level due to the nuclear disaster: focusing on their activities and latest radiological discussion.

PubMed

Iimoto, T; Nunokawa, J; Fujii, H; Takashima, R; Hashimoto, M; Fukuhara, T; Yajima, T; Matsuzawa, H; Kurosawa, K; Yanagawa, Y; Someya, S

2015-11-01

Activities were introduced in Kashiwa city in the Tokyo metropolitan area to correspond to the elevated environmental radiation level after the disaster of the Fukushima Daiichi nuclear power plant. These were based on a strong cooperation between local governments and experts. Ambient dose rate and radioactivity of foodstuff produced inside of the city have been monitored. Representative ambient dose rates around living environments have almost already become their original levels of the pre-accident because of the decontamination activity, natural washout and effective half-lives of radioactivity. The internal annual dose due to radioactive cesium under the policy of 'Local Production for Local Consumption' is estimated as extremely low comparing the variation range due to natural radioactivity. Systematic survey around a retention basin has been started. All of these latest monitoring data would be one of the core information for the policy making as well as a cost-benefit discussion and risk communication. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Benefits of an automatic patient dose registry system for interventional radiology and cardiology at five hospitals of the Madrid area.

PubMed

Fernandez-Soto, J M; Ten, J I; Sanchez, R M; España, M; Pifarre, X; Vano, E

2015-07-01

The purpose of this article is to present the results of connecting the interventional radiology and cardiology laboratories of five university hospitals to a unique server using an automatic patient dose registry system (Dose On Line for Interventional Radiology, DOLIR) developed in-house, and to evaluate its feasibility more than a year after its introduction. The system receives and stores demographic and dosimetric parameters included in the MPPS DICOM objects sent by the modalities to a database. A web service provides a graphical interface to analyse the information received. During 2013, the system processed 10 788 procedures (6874 cardiac, 2906 vascular and 1008 neuro interventional). The percentages of patients requiring clinical follow-up due to potential tissue reactions before and after the use of DOLIR are presented. The system allowed users to verify in real-time, if diagnostic (or interventional) reference levels are fulfilled. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Stress analysis on passenger deck due to modification from passenger ship to vehicle-carrying ship

NASA Astrophysics Data System (ADS)

Zubaydi, A.; Sujiatanti, S. H.; Hariyanto, T. R.

2018-03-01

Stress is a basic concept in learning about material mechanism. The main focus that needs to be brought to attention in analyzing stress is strength, which is the structural capacity to carry or distribute loads. The structural capacity not only measured by comparing the maximum stress with the material’s yield strength but also with the permissible stress required by the Indonesian Classification Bureau (BKI), which certainly makes it much safer. This final project analyzes stress in passenger deck that experiences modification due to load changes, from passenger load to vehicle one, carrying: 6-wheels truck with maximum weight of 14 tons, a passenger car with maximum weight of 3.5 tons, and a motorcycle with maximum weight of 0.4 tons. The deck structure is modelled using finite element software. The boundary conditions given to the structural model are fix and simple constraint. The load that works on this deck is the deck load which comes from the vehicles on deck with three vehicles’ arrangement plans. After that, software modelling is conducted for analysis purpose. Analysis result shows a variation of maximum stress that occurs i.e. 135 N/mm2, 133 N/mm2, and 152 N/mm2. Those maximum stresses will not affect the structure of passenger deck’s because the maximum stress that occurs indicates smaller value compared to the Indonesian Classification Bureau’s permissible stress (175 N/mm2) as well as the material’s yield strength (235 N/mm2). Thus, the structural strength of passenger deck is shown to be capable of carrying the weight of vehicles in accordance with the three vehicles’ arrangement plans.

48 CFR 27.102 - General guidance.

Code of Federal Regulations, 2011 CFR

2011-10-01

... to its needs. (e) Generally, the Government requires that contractors obtain permission from... REQUIREMENTS PATENTS, DATA, AND COPYRIGHTS General 27.102 General guidance. (a) The Government encourages the maximum practical commercial use of inventions made under Government contracts. (b) Generally, the...

Influence of CT automatic tube current modulation on uncertainty in effective dose.

PubMed

Sookpeng, S; Martin, C J; Gentle, D J

2016-01-01

Computed tomography (CT) scanners are equipped with automatic tube current modulation (ATCM) systems that adjust the current to compensate for variations in patient attenuation. CT dosimetry variables are not defined for ATCM situations and, thus, only the averaged values are displayed and analysed. The patient effective dose (E), which is derived from a weighted sum of organ equivalent doses, will be modified by the ATCM. Values for E for chest-abdomen-pelvis CT scans have been calculated using the ImPACT spreadsheet for patients on five CT scanners. Values for E resulting from the z-axis modulation under ATCM have been compared with results assessed using the same effective mAs values with constant tube currents. Mean values for E under ATCM were within ±10 % of those for fixed tube currents for all scanners. Cumulative dose distributions under ATCM have been simulated for two patient scans using single-slice dose profiles measured in elliptical and cylindrical phantoms on one scanner. Contributions to the effective dose from organs in the upper thorax under ATCM are 30-35 % lower for superficial tissues (e.g. breast) and 15-20 % lower for deeper organs (e.g. lungs). The effect on doses to organs in the abdomen depends on body shape, and they can be 10-22 % higher for larger patients. Results indicate that scan dosimetry parameters, dose-length product and effective mAs averaged over the whole scan can provide an assessment in terms of E that is sufficiently accurate to quantify relative risk for routine patient exposures under ATCM. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Therapeutic Vaccine for Genital Herpes Simplex Virus-2 Infection: Findings From a Randomized Trial.

PubMed

Bernstein, David I; Wald, Anna; Warren, Terri; Fife, Kenneth; Tyring, Stephen; Lee, Patricia; Van Wagoner, Nick; Magaret, Amalia; Flechtner, Jessica B; Tasker, Sybil; Chan, Jason; Morris, Amy; Hetherington, Seth

2017-03-15

Genital herpes simplex virus type 2 (HSV-2) infection causes recurrent lesions and frequent viral shedding. GEN-003 is a candidate therapeutic vaccine containing HSV-2 gD2∆TMR and ICP4.2, and Matrix-M2 adjuvant. Persons with genital herpes were randomized into 3 dose cohorts to receive 3 intramuscular doses 21 days apart of 10 µg, 30 µg, or 100 µg of GEN-003, antigens without adjuvant, or placebo. Participants obtained genital swab specimens twice daily for HSV-2 detection and monitored genital lesions for 28-day periods at baseline and at intervals after the last dose. One hundred and thirty-four persons received all 3 doses. Reactogenicity was associated with adjuvant but not with antigen dose or dose number. No serious adverse events were attributed to GEN-003. Compared with baseline, genital HSV-2 shedding rates immediately after dosing were reduced with GEN-003 (from 13.4% to 6.4% for 30 μg [P < .001] and from 15.0% to 10.3% for 100 µg [P < .001]). Lesion rates were also significantly (P < .01) reduced immediately following immunization with 30 µg or 100 µg of GEN-003. GEN-003 elicited increases in antigen binding, virus neutralizing antibody, and T-cell responses. GEN-003 had an acceptable safety profile and stimulated humoral and cellular immune responses. GEN-003 at doses of 30 µg and 100 µg reduced genital HSV shedding and lesion rates. NCT01667341 (funded by Genocea). © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

FDA-sunlamp recommended Maximum Timer Interval And Exposure Schedule: consensus ISO/CIE dose equivalence.

PubMed

Dowdy, John C; Czako, Eugene A; Stepp, Michael E; Schlitt, Steven C; Bender, Gregory R; Khan, Lateef U; Shinneman, Kenneth D; Karos, Manuel G; Shepherd, James G; Sayre, Robert M

2011-09-01

The authors compared calculations of sunlamp maximum exposure times following current USFDA Guidance Policy on the Maximum Timer Interval and Exposure Schedule, with USFDA/CDRH proposals revising these to equivalent erythemal exposures of ISO/CIE Standard Erythema Dose (SED). In 2003, [USFDA/CDRH proposed replacing their unique CDRH/Lytle] erythema action spectrum with the ISO/CIE erythema action spectrum and revising the sunlamp maximum exposure timer to 600 J m(-2) ISO/CIE effective dose, presented as being biologically equivalent. Preliminary analysis failed to confirm said equivalence, indicating instead ∼38% increased exposure when applying these proposed revisions. To confirm and refine this finding, a collaboration of tanning bed and UV lamp manufacturers compiled 89 UV spectra representing a broad sampling of U.S. indoor tanning equipment. USFDA maximum recommended exposure time (Te) per current sunlamp guidance and CIE erythemal effectiveness per ISO/CIE standard were calculated. The CIE effective dose delivered per Te averaged 456 J(CIE) m(-2) (SD = 0.17) or ∼4.5 SED. The authors found that CDRH's proposed 600 J(CIE) m(-2) recommended maximum sunlamp exposure exceeds current Te erythemal dose by ∼33%. The current USFDA 0.75 MED initial exposure was ∼0.9 SED, consistent with 1.0 SED initial dose in existing international sunlamp standards. As no sunlamps analyzed exceeded 5 SED, a revised maximum exposure of 500 J(CIE) m(-2) (∼80% of CDRH's proposal) should be compatible with existing tanning equipment. A tanning acclimatization schedule is proposed beginning at 1 SED thrice-weekly, increasing uniformly stepwise over 4 wk to a 5 SED maximum exposure in conjunction with a tan maintenance schedule of twice-weekly 5 SED sessions, as biologically equivalent to current USFDA sunlamp policy.

A Retrospective Study Evaluating the Effect of Low Doses of Perineural Dexamethasone on Ropivacaine Brachial Plexus Peripheral Nerve Block Analgesic Duration.

PubMed

Schnepper, Gregory D; Kightlinger, Benjamin I; Jiang, Yunyun; Wolf, Bethany J; Bolin, Eric D; Wilson, Sylvia H

2017-09-23

Examination of the effectiveness of perineural dexamethasone administered in very low and low doses on ropivacaine brachial plexus block duration. Retrospective evaluation of brachial plexus block duration in a large cohort of patients receiving peripheral nerve blocks with and without perineural dexamethasone in a prospectively collected quality assurance database. A single academic medical center. A total of 1,942 brachial plexus blocks placed over a 16-month period were reviewed. Demographics, nerve block location, and perineural dexamethasone utilization and dose were examined in relation to block duration. Perineural dexamethasone was examined as none (0 mg), very low dose (2 mg or less), and low dose (greater than 2 mg to 4 mg). Continuous catheter techniques, local anesthetics other than ropivacaine, and block locations with fewer than 15 subjects were excluded. Associations between block duration and predictors of interest were examined using multivariable regression models. A subgroup analysis of the impact of receiving dexamethasone on block duration within each block type was also conducted using a univariate linear regression approach. A total of 1,027 subjects were evaluated. More than 90% of brachial plexus blocks contained perineural dexamethasone (≤4 mg), with a median dose of 2 mg. Increased block duration was associated with receiving any dose of perineural dexamethasone (P < 0.0001), female gender (P = 0.022), increased age (P = 0.048), and increased local anesthetic dose (P = 0.01). In a multivariable model, block duration did not differ with very low- or low-dose perineural dexamethasone after controlling for other factors (P = 0.420). Perineural dexamethasone prolonged block duration compared with ropivacaine alone; however, duration was not greater with low-dose compared with very low-dose perineural dexamethasone. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Qualitative and quantitative approaches in the dose-response assessment of genotoxic carcinogens.

PubMed

Fukushima, Shoji; Gi, Min; Kakehashi, Anna; Wanibuchi, Hideki; Matsumoto, Michiharu

2016-05-01

Qualitative and quantitative approaches are important issues in field of carcinogenic risk assessment of the genotoxic carcinogens. Herein, we provide quantitative data on low-dose hepatocarcinogenicity studies for three genotoxic hepatocarcinogens: 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and N-nitrosodiethylamine (DEN). Hepatocarcinogenicity was examined by quantitative analysis of glutathione S-transferase placental form (GST-P) positive foci, which are the preneoplastic lesions in rat hepatocarcinogenesis and the endpoint carcinogenic marker in the rat liver medium-term carcinogenicity bioassay. We also examined DNA damage and gene mutations which occurred through the initiation stage of carcinogenesis. For the establishment of points of departure (PoD) from which the cancer-related risk can be estimated, we analyzed the above events by quantitative no-observed-effect level and benchmark dose approaches. MeIQx at low doses induced formation of DNA-MeIQx adducts; somewhat higher doses caused elevation of 8-hydroxy-2'-deoxyquanosine levels; at still higher doses gene mutations occurred; and the highest dose induced formation of GST-P positive foci. These data indicate that early genotoxic events in the pathway to carcinogenesis showed the expected trend of lower PoDs for earlier events in the carcinogenic process. Similarly, only the highest dose of IQ caused an increase in the number of GST-P positive foci in the liver, while IQ-DNA adduct formation was observed with low doses. Moreover, treatment with DEN at low doses had no effect on development of GST-P positive foci in the liver. These data on PoDs for the markers contribute to understand whether genotoxic carcinogens have a threshold for their carcinogenicity. The most appropriate approach to use in low dose-response assessment must be approved on the basis of scientific judgment. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The maximum single dose of resistant maltodextrin that does not cause diarrhea in humans.

PubMed

Kishimoto, Yuka; Kanahori, Sumiko; Sakano, Katsuhisa; Ebihara, Shukuko

2013-01-01

The objective of the present study was to determine the maximum dose of resistant maltodextrin (Fibersol)-2, a non-viscous water-soluble dietary fiber), that does not induce transitory diarrhea. Ten healthy adult subjects (5 men and 5 women) ingested Fibersol-2 at increasing dose levels of 0.7, 0.8, 0.9, 1.0, and 1.1 g/kg body weight (bw). Each administration was separated from the previous dose by an interval of 1 wk. The highest dose level that did not cause diarrhea in any subject was regarded as the maximum non-effective level for a single dose. The results showed that no subject of either sex experienced diarrhea at dose levels of 0.7, 0.8, 0.9, or 1.0 g/kg bw. At the highest dose level of 1.1 g/kg bw, no female subject experienced diarrhea, whereas 1 male subject developed diarrhea with muddy stools 2 h after ingestion of the test substance. Consequently, the maximum non-effective level for a single dose of the resistant maltodextrin Fibersol-2 is 1.0 g/kg bw for men and >1.1 g/kg bw for women. Gastrointestinal symptoms were gurgling sounds in 4 subjects (7 events) and flatus in 5 subjects (9 events), although no association with dose level was observed. These symptoms were mild and transient and resolved without treatment.

Estimation of eye lens doses received by pediatric interventional cardiologists.

PubMed

Alejo, L; Koren, C; Ferrer, C; Corredoira, E; Serrada, A

2015-09-01

Maximum Hp(0.07) dose to the eye lens received in a year by the pediatric interventional cardiologists has been estimated. Optically stimulated luminescence dosimeters were placed on the eyes of an anthropomorphic phantom, whose position in the room simulates the most common irradiation conditions. Maximum workload was considered with data collected from procedures performed in the Hospital. None of the maximum values obtained exceed the dose limit of 20 mSv recommended by ICRP. Copyright © 2015 Elsevier Ltd. All rights reserved.

Knowledge of appropriate acetaminophen doses and potential toxicities in an adult clinic population.

PubMed

Stumpf, Janice L; Skyles, Amy J; Alaniz, Cesar; Erickson, Steven R

2007-01-01

To evaluate the knowledge of appropriate doses and potential toxicities of acetaminophen and assess the ability to recognize products containing acetaminophen in an adult outpatient setting. Cross-sectional, prospective study. University adult general internal medicine (AGIM) clinic. 104 adult patients presenting to the clinic over consecutive weekdays in December 2003. Three-page, written questionnaire. Ability of patients to identify maximum daily doses and potential toxicities of acetaminophen and recognize products that contain acetaminophen. A large percentage of participants (68.3%) reported pain on a daily or weekly basis, and 78.9% reported use of acetaminophen in the past 6 months. Only 2 patients correctly identified the maximum daily dose of regular acetaminophen, and just 3 correctly identified the maximum dose of extra-strength acetaminophen. Furthermore, 28 patients were unsure of the maximum dose of either product. Approximately 63% of participants either had not received or were unsure whether information on the possible danger of high doses of acetaminophen had been previously provided to them. When asked to identify potential problems associated with high doses of acetaminophen, 43.3% of patients noted the liver would be affected. The majority of the patients (71.2%) recognized Tylenol as containing acetaminophen, but fewer than 15% correctly identified Vicodin, Darvocet, Tylox, Percocet, and Lorcet as containing acetaminophen. Although nearly 80% of this AGIM population reported recent acetaminophen use, their knowledge of the maximum daily acetaminophen doses and potential toxicities associated with higher doses was poor and appeared to be independent of education level, age, and race. This indicates a need for educational efforts to all patients receiving acetaminophen-containing products, especially since the ability to recognize multi-ingredient products containing acetaminophen was likewise poor.

The lens of the eye: exposures in the UK medical sector and mechanistic studies of radiation effects.

PubMed

Bouffler, S D; Peters, S; Gilvin, P; Slack, K; Markiewicz, E; Quinlan, R A; Gillan, J; Coster, M; Barnard, S; Rothkamm, K; Ainsbury, E

2015-06-01

The recommendation from the International Commission on Radiological Protection that the occupational equivalent dose limit for the lens of the eye should be reduced to 20 mSv year(-1), averaged over 5 years with no year exceeding 50 mSv, has stimulated a discussion on the practicalities of implementation of this revised dose limit, and the most appropriate risk and protection framework to adopt. This brief paper provides an overview of some of the drivers behind the move to a lower recommended dose limit. The issue of implementation in the medical sector in the UK has been addressed through a small-scale survey of doses to the lens of the eye amongst interventional cardiologists and radiologists. In addition, a mechanistic study of early and late post-irradiation changes in the lens of the eye in in-vivo-exposed mice is outlined. Surveys and studies such as those described can contribute to a deeper understanding of fundamental and practical issues, and therefore contribute to a robust evidence base for ensuring adequate protection of the eye while avoiding undesirable restrictions to working practices. © The International Society for Prosthetics and Orthotics Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

DEEP, SHALLOW AND EYE LENS DOSES FROM 106Ru/106Rh-A COMPARSION.

PubMed

Kumar, Munish; Bakshi, A K; Rakesh, R B; Ratna, P; Kulkarni, M S; Datta, D

2017-11-01

106Ru/106Rh is unique amongst other commonly used beta sources such as 147Pm, 85Kr, 204Tl, 32P, natU and 90Sr/90Y in the sense that it is capable of simultaneously delivering shallow/skin, eye lens and deep/whole body doses (WBDs) and they differ from each other substantially. In view of this, the investigation of various quantities defined for individual monitoring is possible and this makes 106Ru/106Rh beta source, a classical example in radiation protection and dosimetry. This led us to estimate skin, eye lens and WBDs for 106Ru/106Rh beta source. Optically stimulated luminescence based ultra-thin α-Al2O3:C disc dosimeters were used in the present study. Typical values (relative) of the eye lens and whole body/deep doses with respective to the skin dose (100%) were experimentally measured as ~66 ± 4.6% and 17 ± 3.9%, respectively. The study shows that 106Ru/106Rh beta source is capable of delivering even WBD which is not the case with other beta sources. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Programmed Cell Death in the Honey Bee (Apis mellifera) (Hymenoptera: Apidae) Worker Brain Induced by Imidacloprid.

PubMed

Wu, Yan-Yan; Zhou, Ting; Wang, Qiang; Dai, Ping-Li; Xu, Shu-Fa; Jia, Hui-Ru; Wang, Xing

2015-08-01

Honey bees are at an unavoidable risk of exposure to neonicotinoid pesticides, which are used worldwide. Compared with the well-studied roles of these pesticides in nontarget site (including midgut, ovary, or salivary glands), little has been reported in the target sites, the brain. In the current study, laboratory-reared adult worker honey bees (Apis mellifera L.) were treated with sublethal doses of imidacloprid. Neuronal apoptosis was detected using the TUNEL technique for DNA labeling. We observed significantly increased apoptotic markers in dose- and time-dependent manners in brains of bees exposed to imidacloprid. Neuronal activated caspase-3 and mRNA levels of caspase-1, as detected by immunofluorescence and real-time quantitative PCR, respectively, were significantly increased, suggesting that sublethal doses of imidacloprid may induce the caspase-dependent apoptotic pathway. Additionally, the overlap of apoptosis and autophagy in neurons was confirmed by transmission electron microscopy. It further suggests that a relationship exists between neurotoxicity and behavioral changes induced by sublethal doses of imidacloprid, and that there is a need to determine reasonable limits for imidacloprid application in the field to protect pollinators. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

COMPARISON STUDY OF VARIOUS PLASTICS AS THE WALL MATERIAL OF THGEM-BASED MICRODOSEMETERS FOR FAST NEUTRON MEASUREMENTS.

PubMed

Moslehi, A; Raisali, G; Lamehi, M

2017-04-15

To find appropriate substitutions for the expensive plastics of A-150 and rexolite used in the construction of thick gas electron multiplier (THGEM)-based tissue-equivalent proportional counters, in the present work, the responses of a THGEM-based microdosimetric detector made of A-150 and rexolite and three others composed of plexiglas (PMMA), polyethylene and polystyrene plastics as the wall materials have been compared. Lineal energy distribution, frequency-averaged lineal energy, dose-averaged lineal energy, mean quality factor and dose-equivalent for 0.1, 1 and 10 MeV neutrons and also for 241Am-Be neutrons are calculated using Geant4 simulation toolkit. Frequency-averaged lineal energy, dose-averaged lineal energy, mean quality factor and dose-equivalent values for all plastics are found similar. In addition, the response of an indigenously constructed microdosemeter with PMMA walls is also measured for 241Am-Be neutrons. The experimental results are in good agreement with the simulation predictions. Conclusively, it was found that the three considered plastics can be used as good candidates instead of A-150 and rexolite plastics in fast neutron microdosimetry. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Dietary Regulation of PTEN Signaling and Mammary Tumor Initiating Cells: Implications for Breast Cancer Prevention

DTIC Science & Technology

2011-01-01

All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org 1491 at U niversity of A rkansas for M edical S ciences ...U niversity of A rkansas for M edical S ciences Library on A pril 7, 2011 carcin.oxfordjournals.org D ow nloaded from In addition, this dose is...nuclear PTEN–p53 cross talk by GEN 1493 at U niversity of A rkansas for M edical S ciences Library on A pril 7, 2011 carcin.oxfordjournals.org D ow

Innate Immune Factors in Mothers' Breast Milk and Their Lack of Association With Rotavirus Vaccine Immunogenicity in Nicaraguan Infants.

PubMed

Becker-Dreps, Sylvia; Choi, Wan Suk; Stamper, Lisa; Vilchez, Samuel; Velasquez, Daniel E; Moon, Sung-Sil; Hudgens, Michael G; Jiang, Baoming; Permar, Sallie R

2017-03-01

To better understand underlying causes of lower rotavirus vaccine effectiveness in low-middle income countries (LMICs), we measured innate antiviral factors in Nicaraguan mothers' milk and immune response to the first dose of the pentavalent rotavirus vaccine in corresponding infants. No relationship was found between concentrations of innate factors and rotavirus vaccine response. © The Author 2015. Published by Oxford University Press on behalf of the Pediatric Infectious Diseases Society. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

CHARACTERIZATION OF CLYC SCINTILLATOR COUPLED WITH PHOTOMULTIPLIERS AND A LARGE SIPM ARRAY.

PubMed

Dinar, N; Celeste, D; Puzo, P; Silari, M

2017-09-29

CERN Radiation Protection group has recently developed a novel radiation survey meter called B-RAD able to operate in the presence of a strong magnetic field. The B-RAD will be equipped with a series of probes for gamma dose rate, gamma spectrometry and surface contamination measurements. The feasibility of developing a probe for neutron dose rate and possibly spectral measurements is being investigated. The determination of the breakdown voltage of the SiPM as well as its uniformity between the pixels was performed. The energy resolution of the Cs2LiYCl6:Ce (CLYC) scintillator was measured with the SiPM and compared with two different PMT models: Bialkali and Superbialkali. The temperature sensitivity of the system CLYC + SiPM was measured from -10 to + 40°C. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Development of Northeast Asia Nuclear Power Plant Accident Simulator.

PubMed

Kim, Juyub; Kim, Juyoul; Po, Li-Chi Cliff

2017-06-15

A conclusion from the lessons learned after the March 2011 Fukushima Daiichi accident was that Korea needs a tool to estimate consequences from a major accident that could occur at a nuclear power plant located in a neighboring country. This paper describes a suite of computer-based codes to be used by Korea's nuclear emergency response staff for training and potentially operational support in Korea's national emergency preparedness and response program. The systems of codes, Northeast Asia Nuclear Accident Simulator (NANAS), consist of three modules: source-term estimation, atmospheric dispersion prediction and dose assessment. To quickly assess potential doses to the public in Korea, NANAS includes specific reactor data from the nuclear power plants in China, Japan and Taiwan. The completed simulator is demonstrated using data for a hypothetical release. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Low-level gamma and neutron monitoring based on use of proportional counter filled with 3He in polythene moderator: study of the responses to gamma and neutrons.

PubMed

Pszona, S; Bantsar, A; Tulik, P; Wincel, K; Zaręba, B

2014-10-01

It has been shown that a proportional counter filled with (3)He placed centrally inside a polythene sphere opens a new possibility for measuring gamma photons and neutrons in the separate pulse-height windows. The responses to gamma and neutrons (in terms of ambient dose equivalent) of the detector assembly consisting of 203-mm polythene sphere with centrally positioned 40-mm diameter (3)He proportional counter have been studied. The response to secondary gammas from capture process in hydrogen has also been studied. The rather preliminary studies indicate that the proposed measuring system has very promising features as an ambient dose equivalent device for mixed gamma-neutron fields. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Surface dose measurements for highly oblique electron beams.

PubMed

Ostwald, P M; Kron, T

1996-08-01

Clinical applications of electrons may involve oblique incidence of beams, and although dose variations for angles up to 60 degrees from normal incidence are well documented, no results are available for highly oblique beams. Surface dose measurements in highly oblique beams were made using parallel-plate ion chambers and both standard LiF:Mg, Ti and carbon-loaded LiF Thermoluminescent Dosimeters (TLD). Obliquity factors (OBF) or surface dose at an oblique angle divided by the surface dose at perpendicular incidence, were obtained for electron energies between 4 and 20 MeV. Measurements were performed on a flat solid water phantom without a collimator at 100 cm SSD. Comparisons were also made to collimated beams. The OBFs of surface doses plotted against the angle of incidence increased to a maximum dose followed by a rapid dropoff in dose. The increase in OBF was more rapid for higher energies. The maximum OBF occurred at larger angles for higher-energy beams and ranged from 73 degrees for 4 MeV to 84 degrees for 20 MeV. At the dose maximum, OBFs were between 130% and 160% of direct beam doses, yielding surface doses of up to 150% of Dmax for the 20 MeV beam. At 2 mm depth the dose ratio was found to increase initially with angle and then decrease as Dmax moved closer to the surface. A higher maximum dose was measured at 2 mm depth than at the surface. A comparison of ion chamber types showed that a chamber with a small electrode spacing and large guard ring is required for oblique dose measurement. A semiempirical equation was used to model the dose increase at the surface with different energy electron beams.

76 FR 36349 - Diethylene Glycol MonoEthyl Ether (DEGEE); Exemption From the Requirement of a Tolerance

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-22

... use on growing crops and raw agricultural commodities, without limitation. Huntsman, Dow AgroSciences... a maximum permissible level for residues of DEGEE on growing crops and raw agricultural commodities... antifreeze [[Page 36350

7 CFR 51.1176 - U.S. Grade AA Juice (Double A).

Code of Federal Regulations, 2013 CFR

2013-01-01

... less than 5 gallons (18.9 liters) of juice per standard packed box of 13/5 bushels. (b) The average... less than one-half of 1 percent anhydrous citric acid, or more than the permissible maximum acid...

33 CFR 401.68 - Explosives Permission Letter.

Code of Federal Regulations, 2013 CFR

2013-07-01

... following cases: (1) For all vessels carrying any quantity of explosives with a mass explosive risk, up to a... and up to a maximum of 50 tonnes of explosives that do not explode en masse (IMO Class 1, Division 1.2...

Bioremediation of arsenic from water with citric acid cross-linked water hyacinth (E. crassipes) root powder.

PubMed

Gogoi, Pankaj; Adhikari, Pooja; Maji, Tarun K

2017-08-01

A green and novel approach was demonstrated for successful remediation of arsenic from contaminated water by citric acid (CA) cross-linked water hyacinth root powder (RP). Different analytical techniques were used to investigate the binding and structural properties of prepared materials. Titanium dioxide played a significant role in the cross-linking process. Incorporation of CA into RP enhanced its integrity, and thus removal efficiency remained unaffected after several cyclic runs. Also the turbidity which formed due to treatment with uncross-linked RP was reduced to below the permissible limit. Effect of the amount of CA, material dose, treatment time, initial ion concentration, and pH were investigated. Use of 10% (w/w) CA was found to be sufficient to bring down the turbidity of the treated water below 2.5 nephelometric turbidity unit (NTU) without hampering the removal capacity/rate. A material dose of 5 g/L removed successfully total inorganic arsenic concentration to below 10 μg/L. The sorption process could be reasonably explained by Langmuir isotherm, and the maximum adsorption capacity was found to be 28 μg of arsenic/g. The material was found to be more efficient at acidic pH (pH ZPC  = 6.72). The sorption process was governed by a pseudo-second-order kinetic model.

Coagulation-flocculation mechanisms in wastewater treatment plants through zeta potential measurements.

PubMed

López-Maldonado, E A; Oropeza-Guzman, M T; Jurado-Baizaval, J L; Ochoa-Terán, A

2014-08-30

Based on the polyelectrolyte-contaminant physical and chemical interactions at the molecular level, this article analyzed and discussed the coagulation-flocculation and chemical precipitation processes in order to improve their efficiency. Bench experiments indicate that water pH, polyelectrolyte (PE) dosing strategy and cationic polyelectrolyte addition are key parameters for the stability of metal-PE complexes. The coagulation-flocculation mechanism is proposed based on zeta potential (ζ) measurement as the criteria to define the electrostatic interaction between pollutants and coagulant-flocculant agents. Polyelectrolyte and wastewater dispersions are exposed to an electrophoretic effect to determine ζ. Finally, zeta potential values are compared at pH 9, suggesting the optimum coagulant dose at 162mg/L polydadmac and 67mg/L of flocculant, since a complete removal of TSS and turbidity is achieved. Based on the concentration of heavy metals (0.931mg/L Sn, 0.7mg/L Fe and 0.63mg/L Pb), treated water met the Mexican maximum permissible limits. In addition, the treated water has 45mg O2/L chemical oxygen demand (COD) and 45mg C/L total organic carbon (TOC). The coagulation-flocculation mechanism is proposed taking into account both: zeta potential (ζ)-pH measurement and chemical affinity, as the criteria to define the electrostatic and chemical interaction between pollutants and polyelectrolytes. Copyright © 2014 Elsevier B.V. All rights reserved.

Individual Genetic Susceptibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eric J. Hall

2008-12-08

Risk estimates derived from epidemiological studies of exposed populations, as well as the maximum permissible doses allowed for occupational exposure and exposure of the public to ionizing radiation are all based on the assumption that the human population is uniform in its radiosensitivity, except for a small number of individuals, such as ATM homozygotes who are easily identified by their clinical symptoms. The hypothesis upon which this proposal is based is that the human population is not homogeneous in radiosensitiviry, but that radiosensitive sub-groups exist which are not easy to identify. These individuals would suffer an increased incidence of detrimentalmore » radiation effects, and distort the shape of the dose response relationship. The radiosensitivity of these groups depend on the expression levels of specific proteins. The plan was to investigate the effect of 3 relatively rare, high penetrate genes available in mice, namely Atm, mRad9 & Brca1. The purpose of radiation protection is to prevent! deterministic effects of clinical significance and limit stochastic effects to acceptable levels. We plan, therefore to compare with wild type animals the radiosensitivity of mice heterozygous for each of the genes mentioned above, as well as double heterozygotes for pairs of genes, using two biological endpoints: a) Ocular cataracts as an important and relevant deterministic effect, and b) Oncogenic transformation in cultured embryo fibroblasts, as a surrogate for carcinogenesis, the most relevant stochastic effect.« less

Uncertainties in estimating heart doses from 2D-tangential breast cancer radiotherapy.

PubMed

Lorenzen, Ebbe L; Brink, Carsten; Taylor, Carolyn W; Darby, Sarah C; Ewertz, Marianne

2016-04-01

We evaluated the accuracy of three methods of estimating radiation dose to the heart from two-dimensional tangential radiotherapy for breast cancer, as used in Denmark during 1982-2002. Three tangential radiotherapy regimens were reconstructed using CT-based planning scans for 40 patients with left-sided and 10 with right-sided breast cancer. Setup errors and organ motion were simulated using estimated uncertainties. For left-sided patients, mean heart dose was related to maximum heart distance in the medial field. For left-sided breast cancer, mean heart dose estimated from individual CT-scans varied from <1Gy to >8Gy, and maximum dose from 5 to 50Gy for all three regimens, so that estimates based only on regimen had substantial uncertainty. When maximum heart distance was taken into account, the uncertainty was reduced and was comparable to the uncertainty of estimates based on individual CT-scans. For right-sided breast cancer patients, mean heart dose based on individual CT-scans was always <1Gy and maximum dose always <5Gy for all three regimens. The use of stored individual simulator films provides a method for estimating heart doses in left-tangential radiotherapy for breast cancer that is almost as accurate as estimates based on individual CT-scans. Copyright © 2016. Published by Elsevier Ireland Ltd.

Evaluation of a new very low dose imaging protocol: feasibility and impact on X-ray dose levels in electrophysiology procedures.

PubMed

Bourier, Felix; Reents, Tilko; Ammar-Busch, Sonia; Buiatti, Alessandra; Kottmaier, Marc; Semmler, Verena; Telishevska, Marta; Brkic, Amir; Grebmer, Christian; Lennerz, Carsten; Kolb, Christof; Hessling, Gabriele; Deisenhofer, Isabel

2016-09-01

This study presents and evaluates the impact of a new lowest-dose fluoroscopy protocol (Siemens AG), especially designed for electrophysiology (EP) procedures, on X-ray dose levels. From October 2014 to March 2015, 140 patients underwent an EP study on an Artis zee angiography system. The standard low-dose protocol was operated at 23 nGy (fluoroscopy) and at 120 nGy (cine-loop), the new lowest-dose protocol was operated at 8 nGy (fluoroscopy) and at 36 nGy (cine-loop). Procedural data, X-ray times, and doses were analysed in 100 complex left atrial and in 40 standard EP procedures. The resulting dose-area products were 877.9 ± 624.7 µGym² (n = 50 complex procedures, standard low dose), 199 ± 159.6 µGym² (n = 50 complex procedures, lowest dose), 387.7 ± 36.0 µGym² (n = 20 standard procedures, standard low dose), and 90.7 ± 62.3 µGym² (n = 20 standard procedures, lowest dose), P < 0.01. In the low-dose and lowest-dose groups, procedure times were 132.6 ± 35.7 vs. 126.7 ± 34.7 min (P = 0.40, complex procedures) and 72.3 ± 20.9 vs. 85.2 ± 44.1 min (P = 0.24, standard procedures), radiofrequency (RF) times were 53.8 ± 26.1 vs. 50.4 ± 29.4 min (P = 0.54, complex procedures) and 10.1 ± 9.9 vs. 12.2 ± 14.7 min (P = 0.60, standard procedures). One complication occurred in the standard low-dose and lowest-dose groups (P = 1.0). The new lowest-dose imaging protocol reduces X-ray dose levels by 77% compared with the currently available standard low-dose protocol. From an operator standpoint, lowest X-ray dose levels create a different, reduced image quality. The new image quality did not significantly affect procedure or RF times and did not result in higher complication rates. Regarding radiological protection, operating at lowest-dose settings should become standard in EP procedures. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

HADOC: a computer code for calculation of external and inhalation doses from acute radionuclide releases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strenge, D.L.; Peloquin, R.A.

The computer code HADOC (Hanford Acute Dose Calculations) is described and instructions for its use are presented. The code calculates external dose from air submersion and inhalation doses following acute radionuclide releases. Atmospheric dispersion is calculated using the Hanford model with options to determine maximum conditions. Building wake effects and terrain variation may also be considered. Doses are calculated using dose conversion factor supplied in a data library. Doses are reported for one and fifty year dose commitment periods for the maximum individual and the regional population (within 50 miles). The fractional contribution to dose by radionuclide and exposure modemore » are also printed if requested.« less

Single visit rabies pre-exposure priming induces a robust anamnestic antibody response after simulated post-exposure vaccination: results of a dose-finding study.

PubMed

Jonker, Emile F F; Visser, Leonardus G

2017-09-01

The current standard 3-dose intramuscular rabies PrEP schedule suffers from a number of disadvantages that severely limit accessibility and availability. The cost of is often prohibitive, it requires 3 visits to the clinic, and there are regular vaccine shortages. Volunteers ( N  = 30) were randomly assigned to 4 study arms: 1 standard dose intramuscular (IM) dose of PVRV (purified Vero cell rabies vaccine, Verorab), and 1/5th, 2/5th or 3/5th- fractional intradermal (ID) dose of PVRV in a single visit. All subjects received a simulated rabies post-exposure prophylaxis (D0, D3) 1 year later. Rabies virus neutralizing antibodies (RVNA) were determined by virus neutralization microtest (FAVN) on D0, D7, D28, Y1 and Y1 + D7. 28 out of 30 subjects (93%) seroconverted 1 month after primary vaccination; 1 subject in the 1-dose IM arm and 1 in the 1/5th-fractional dose ID arm did not. After 1 year, 22 out of 30 subjects (73%) no longer had RVNA above 0.5 IU/ml, with no discernible difference between study groups. After 1 year, all 30 subjects mounted a booster response within 7 days after simulated PEP, with the highest titers found in the single dose IM group ( P  < 0.03). This dose finding study demonstrates that priming with a single dose of rabies vaccine was sufficient to induce an adequate anamnestic antibody response to rabies PEP in all subjects 1 year later, even in those in whom the RVNA threshold of 0.5 IU/ml was not reached after priming. © International Society of Travel Medicine, 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

OUT-OF-FIELD DOSES IN CHILDREN TREATED FOR LARGE ARTERIOVENOUS MALFORMATIONS USING HYPOFRACTIONATED GAMMA KNIFE RADIOSURGERY AND INTENSITY-MODULATED RADIATION THERAPY.

PubMed

De Saint-Hubert, Marijke; Majer, Marija; Hršak, Hrvoje; Heinrich, Zdravko; Kneževic, Željka; Miljanic, Saveta; Porwol, Paulina; Stolarczyk, Liliana; Vanhavere, Filip; Harrison, Roger M

2018-01-17

The purpose of this study was to measure out-of-field organ doses in two anthropomorphic child phantoms for the treatment of large brain arteriovenous malformations (AVMs) using hypofractionated gamma knife (GK) radiosurgery and to compare these with an alternative treatment using intensity-modulated radiation therapy (IMRT). Target volume was identical in size and shape in all cases. Radiophotoluminescent (RPL), thermoluminescent (TL) and optically stimulated luminescent (OSL) dosimeters were used for out-of-field dosimetry during GK treatment and a good agreement within 1-2% between results was shown. In addition, the use of multiple dosimetry systems strengthens the reliability of the findings. The number of GK isocentres was confirmed to be important for the magnitude of out-of-field doses. Measured GK doses for the same distance from the target, when expressed per target dose and isocentre, were comparable in both phantoms. GK out-of-field doses averaged for both phantoms were evaluated to be 120 mGy/Gy for eyes then sharply reduced to 20 mGy/Gy for mandible and slowly reduced up to 0.8 mGy/Gy for testes. Taking into account the fractionation regimen used to treat AVM patients, the total treatment organ doses to the out-of-field organs were calculated and compared with IMRT. The eyes were better spared with GK whilst for more distant organs doses were up to a factor of 2.8 and 4 times larger for GK compared to IMRT in 5-year and 10-year old phantoms, respectively. Presented out-of-field dose values are specific for the investigated AVM case, phantoms and treatment plans used for GK and IMRT, but provide useful information about out-of-field dose levels and emphasise their importance. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Developing an Optimum Protocol for Thermoluminescence Dosimetry with GR-200 Chips using Taguchi Method.

PubMed

Sadeghi, Maryam; Faghihi, Reza; Sina, Sedigheh

2017-06-15

Thermoluminescence dosimetry (TLD) is a powerful technique with wide applications in personal, environmental and clinical dosimetry. The optimum annealing, storage and reading protocols are very effective in accuracy of TLD response. The purpose of this study is to obtain an optimum protocol for GR-200; LiF: Mg, Cu, P, by optimizing the effective parameters, to increase the reliability of the TLD response using Taguchi method. Taguchi method has been used in this study for optimization of annealing, storage and reading protocols of the TLDs. A number of 108 GR-200 chips were divided into 27 groups, each containing four chips. The TLDs were exposed to three different doses, and stored, annealed and read out by different procedures as suggested by Taguchi Method. By comparing the signal-to-noise ratios the optimum dosimetry procedure was obtained. According to the results, the optimum values for annealing temperature (°C), Annealing Time (s), Annealing to Exposure time (d), Exposure to Readout time (d), Pre-heat Temperature (°C), Pre-heat Time (s), Heating Rate (°C/s), Maximum Temperature of Readout (°C), readout time (s) and Storage Temperature (°C) are 240, 90, 1, 2, 50, 0, 15, 240, 13 and -20, respectively. Using the optimum protocol, an efficient glow curve with low residual signals can be achieved. Using optimum protocol obtained by Taguchi method, the dosimetry can be effectively performed with great accuracy. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of intravenous opioid dose on postoperative ileus.

PubMed

Barletta, Jeffrey F; Asgeirsson, Theodor; Senagore, Anthony J

2011-07-01

Intravenous opioids represent a major component in the pathophysiology of postoperative ileus (POI). However, the most appropriate measure and threshold to quantify the association between opioid dose (eg, average daily, cumulative, maximum daily) and POI remains unknown. To evaluate the relationship between opioid dose, POI, and length of stay (LOS) and identify the opioid measure that was most strongly associated with POI. Consecutive patients admitted to a community teaching hospital who underwent elective colorectal surgery by any technique with an enhanced-recovery protocol postoperatively were retrospectively identified. Patients were excluded if they received epidural analgesia, developed a major intraabdominal complication or medical complication, or had a prolonged workup prior to surgery. Intravenous opioid doses were quantified and converted to hydromorphone equivalents. Classification and regression tree (CART) analysis was used to determine the dosing threshold for the opioid measure most associated with POI and define high versus low use of opioids. Risk factors for POI and prolonged LOS were determined through multivariate analysis. The incidence of POI in 279 patients was 8.6%. CART analysis identified a maximum daily intravenous hydromorphone dose of 2 mg or more as the opioid measure most associated with POI. Multivariate analysis revealed maximum daily hydromorphone dose of 2 mg or more (p = 0.034), open surgical technique (p = 0.045), and days of intravenous narcotic therapy (p = 0.003) as significant risk factors for POI. Variables associated with increased LOS were POI (p < 0.001), maximum daily hydromorphone dose of 2 mg or more (p < 0.001), and age (p = 0.005); laparoscopy (p < 0.001) was associated with a decreased LOS. Intravenous opioid therapy is significantly associated with POI and prolonged LOS, particularly when the maximum hydromorphone dose per day exceeds 2 mg. Clinicians should consider alternative, nonopioid-based pain management options when this occurs.

Safety and pharmacokinetics of ramucirumab in combination with docetaxel in Japanese patients with locally advanced or metastatic breast cancer: a Phase Ib study.

PubMed

Masuda, Norikazu; Iwata, Hiroji; Aogi, Kenjiro; Xu, Yihuan; Ibrahim, Ayman; Gao, Ling; Dalal, Rita; Yoshikawa, Reigetsu; Sasaki, Yasutsuna

2016-12-01

The primary objective of this study was to investigate the safety and tolerability and to confirm the recommended dose of the anti-vascular endothelial growth factor receptor 2 monoclonal antibody ramucirumab in combination with docetaxel in Japanese patients with metastatic/locally advanced breast cancer. In this multicenter, single-arm, Phase Ib trial, eligibility criteria included: 20 years or older, Eastern Cooperative Oncology Group performance status of 0/1 and confirmed diagnosis of human epidermal growth factor receptor 2-negative metastatic/locally recurrent inoperable breast adenocarcinoma. Patients received docetaxel (75 mg/m 2 ) followed by ramucirumab (10 mg/kg) on Day 1 of 21-day cycles. Recommended dose was defined as <33% dose-limiting toxicities in dose-limiting toxicity-evaluable patients in Cycle 1. The safety, pharmacokinetics, immunogenicity and antitumor activity were examined. Seven patients were treated. Most adverse events were mild to moderate. Two patients during Cycle 1 experienced a dose-limiting toxicity; one patient each experienced Grade 3 febrile neutropenia and Grade 3 gingivitis. Both dose-limiting toxicities subsequently resolved. No patients discontinued study therapies during Cycle 1. Four serious adverse events were possibly related to ramucirumab in combination with docetaxel. Anti-ramucirumab antibodies were not detected. Pharmacokinetic analysis revealed low total body clearance and long apparent terminal elimination half-life (~7-12 days). Partial response was reported in four patients. The combination of ramucirumab and docetaxel was tolerable in female Japanese patients with breast cancer. Ramucirumab 10 mg/kg in combination with docetaxel (75 mg/m 2 ) was confirmed as the recommended dose among Japanese patients, supporting its use in future studies. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Gamma Irradiation as a Phytosanitary Treatment of Bactrocera tau (Diptera: Tephritidae) in Pumpkin Fruits.

PubMed

Guoping, Zhan; Lili, Ren; Ying, Shao; Qiaoling, Wang; Daojian, Yu; Yuejin, Wang; Tianxiu, Li

2015-02-01

The fruit fly Bactrocera tau (Walker) is an important quarantine pest that damages fruits and vegetables throughout Asian regions. Host commodities shipped from infested areas should undergo phytosanitary measures to reduce the risk of shipping viable flies. The dose-response tests with 1-d-old eggs and 3-, 5-, 7-, 8-d-old larvae were initiated to determine the most resistant stages in fruits, and the minimum dose for 99.9968% prevention of adult eclosion at 95% confidence level was validated in the confirmatory tests. The results showed that 1) the pupariation rate was not affected by gamma radiation except for eggs and first instars, while the percent of eclosion was reduced significantly in all instars at all radiation dose; 2) the tolerance to radiation increased with increasing age and developmental stage; 3) the estimated dose to 99.9968% preventing adult eclosion from late third instars was 70.9 Gy (95% CL: 65.6-78.2, probit model) and 71.8 Gy (95% CL: 63.0-87.3, logit model); and iv) in total, 107,135 late third instars cage infested in pumpkin fruits were irradiated at the target dose of 70 Gy (62.5-85.0, Gy measured), which resulted in no adult emergence in the two confirmatory tests. Therefore, a minimum dose of 85 and 72 Gy, which could prevent adult emergence at the efficacy of 99.9972 and 99.9938% at the 95% confidence level, respectively, can be recommended as a minimum dose for phytosanitary treatment of B. tau in any host fruits and vegetables under ambient atmospheres. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effect of Repeated Vaccination With the Same Vaccine Component Against 2009 Pandemic Influenza A(H1N1) Virus.

PubMed

Martínez-Baz, Iván; Casado, Itziar; Navascués, Ana; Díaz-González, Jorge; Aguinaga, Aitziber; Barrado, Laura; Delfrade, Josu; Ezpeleta, Carmen; Castilla, Jesús

2017-03-15

The 2009 pandemic influenza A(H1N1) (A[H1N1]pdm09) vaccine component has remained unchanged from 2009. We estimate the effectiveness of current and prior inactivated influenza A(H1N1)pdm09 vaccination from influenza seasons 2010-2011 to 2015-2016. Patients attended with influenza-like illness were tested for influenza. Four periods with continued A(H1N1)pdm09 circulation were included in a test-negative design. We enrolled 1278 cases and 2343 controls. As compared to individuals never vaccinated against influenza A(H1N1)pdm09, the highest effectiveness (66%; 95% confidence interval, 49%-78%) was observed in those vaccinated in the current season who had received 1-2 prior doses. The effectiveness was not statistically lower in individuals vaccinated in the current season only (52%) or in those without current vaccination and >2 prior doses (47%). However, the protection was lower in individuals vaccinated in the current season after >2 prior doses (38%; P = .009) or those currently unvaccinated with 1-2 prior doses (10%; P < .001). Current-season vaccination improved the effect in individuals with 1-2 prior doses and did not modify significantly the risk of influenza in individuals with >2 prior doses. Current vaccination or several prior doses were needed for high protection. Despite the decreasing effect of repeated vaccination, current-season vaccination was not inferior to no current-season vaccination. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

MEASUREMENT OF RADIATION DOSES TO THE EYE LENS DURING ORTHOPEDIC SURGERY USING AN C-ARM X-RAY SYSTEM.

PubMed

Suzuki, Akira; Matsubara, Kosuke; Sasa, Yuko

2018-04-01

The present study aimed to determine doses delivered to the eye lenses of surgeons while using the inverted-C-arm technique and the protective effect of leaded spectacles during orthopedic surgery. The kerma in air was measured at five positions on leaded glasses positioned near the eye lens and on the neck using small optically stimulated luminescence (OSL) dosemeters. The lens equivalent dose was also measured at the neck using an OSL dosemeter. The maximum equivalent dose to the eye lens and the maximum kerma were 0.8 mSv/month and 0.66 mGy/month, respectively. The leaded glasses reduced the exposure by ~60%. Even if the surgeons are exposed to the maximum dose of X-ray radiation for 5 years, the equivalent doses to the eye lens will not exceed the present limit recommended by the ICRP.

CERTAIN PHYSICO-CHEMICAL AND CHEMICAL INDICES OF THE BLOOD IN CHRONIC ACTION OF LOW DOSES OF IONIZING RADIATION (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorn, L.E.

1960-06-01

Results are reported from a study on 45 persons subjected during work to the protracted action of rontgen and gamma rays in doses exceeding the maximal permissible ones. It was found that the creatine, aromatic amino acids, and non- hemoglobin iron, as well as the redox potential of the serum, do not differ from the respective values in healthy subjects. (auth)

Direct measurement of a patient's entrance skin dose during pediatric cardiac catheterization

PubMed Central

Sun, Lue; Mizuno, Yusuke; Iwamoto, Mari; Goto, Takahisa; Koguchi, Yasuhiro; Miyamoto, Yuka; Tsuboi, Koji; Chida, Koichi; Moritake, Takashi

2014-01-01

Children with complex congenital heart diseases often require repeated cardiac catheterization; however, children are more radiosensitive than adults. Therefore, radiation-induced carcinogenesis is an important consideration for children who undergo those procedures. We measured entrance skin doses (ESDs) using radio-photoluminescence dosimeter (RPLD) chips during cardiac catheterization for 15 pediatric patients (median age, 1.92 years; males, n = 9; females, n = 6) with cardiac diseases. Four RPLD chips were placed on the patient's posterior and right side of the chest. Correlations between maximum ESD and dose–area products (DAP), total number of frames, total fluoroscopic time, number of cine runs, cumulative dose at the interventional reference point (IRP), body weight, chest thickness, and height were analyzed. The maximum ESD was 80 ± 59 (mean ± standard deviation) mGy. Maximum ESD closely correlated with both DAP (r = 0.78) and cumulative dose at the IRP (r = 0.82). Maximum ESD for coiling and ballooning tended to be higher than that for ablation, balloon atrial septostomy, and diagnostic procedures. In conclusion, we directly measured ESD using RPLD chips and found that maximum ESD could be estimated in real-time using angiographic parameters, such as DAP and cumulative dose at the IRP. Children requiring repeated catheterizations would be exposed to high radiation levels throughout their lives, although treatment influences radiation dose. Therefore, the radiation dose associated with individual cardiac catheterizations should be analyzed, and the effects of radiation throughout the lives of such patients should be followed. PMID:24968708

Bone fractures following external beam radiotherapy and limb-preservation surgery for lower extremity soft tissue sarcoma: relationship to irradiated bone length, volume, tumor location and dose.

PubMed

Dickie, Colleen I; Parent, Amy L; Griffin, Anthony M; Fung, Sharon; Chung, Peter W M; Catton, Charles N; Ferguson, Peter C; Wunder, Jay S; Bell, Robert S; Sharpe, Michael B; O'Sullivan, Brian

2009-11-15

To examine the relationship between tumor location, bone dose, and irradiated bone length on the development of radiation-induced fractures for lower extremity soft tissue sarcoma (LE-STS) patients treated with limb-sparing surgery and radiotherapy (RT). Of 691 LE-STS patients treated from 1989 to 2005, 31 patients developed radiation-induced fractures. Analysis was limited to 21 fracture patients (24 fractures) who were matched based on tumor size and location, age, beam arrangement, and mean total cumulative RT dose to a random sample of 53 nonfracture patients and compared for fracture risk factors. Mean dose to bone, RT field size (FS), maximum dose to a 2-cc volume of bone, and volume of bone irradiated to >or=40 Gy (V40) were compared. Fracture site dose was determined by comparing radiographic images and surgical reports to fracture location on the dose distribution. For fracture patients, mean dose to bone was 45 +/- 8 Gy (mean dose at fracture site 59 +/- 7 Gy), mean FS was 37 +/- 8 cm, maximum dose was 64 +/- 7 Gy, and V40 was 76 +/- 17%, compared with 37 +/- 11 Gy, 32 +/- 9 cm, 59 +/- 8 Gy, and 64 +/- 22% for nonfracture patients. Differences in mean, maximum dose, and V40 were statistically significant (p = 0.01, p = 0.02, p = 0.01). Leg fractures were more common above the knee joint. The risk of radiation-induced fracture appears to be reduced if V40 <64%. Fracture incidence was lower when the mean dose to bone was <37 Gy or maximum dose anywhere along the length of bone was <59 Gy. There was a trend toward lower mean FS for nonfracture patients.

Randomized Trial of 2 Versus 1 Dose of Measles Vaccine: Effect on Hospital Admission of Children After 9 Months of Age.

PubMed

Brønd, Marie; Martins, Cesario L; Byberg, Stine; Benn, Christine S; Whittle, Hilton; Garly, May-Lill; Aaby, Peter; Fisker, Ane B

2017-06-15

Two doses of measles vaccine (MV) might reduce the nonmeasles mortality rate more than 1 dose of MV does. The effect of 2 versus 1 dose on morbidity has not been examined. Within a randomized trial of the effect of 2 doses versus 1 dose of MV on mortality in Guinea-Bissau, we investigated the effect on hospital admissions. Children were randomly assigned 1:2 to receive MV at 4.5 and 9 months of age or the currently recommended dose at 9 months. We compared hospital admission rates among children between 9 and 18 months of age in a Cox regression model with age as the underlying time scale. Half of the children had received neonatal vitamin A supplementation (NVAS) in another trial. The beneficial effect of MV at 4.5 and 9 months on mortality was limited to children who had not received NVAS; therefore, we investigated the interaction of MV with NVAS on admission rates. Among 5626 children (2 doses of MV, 1960 children; 1 dose of MV, 3666), we identified 311 hospital admissions of children between 9 and 18 months of age. Overall, compared to 1 dose of MV, 2 doses reduced the risk of hospital admission for children who had not received NVAS (hazard ratio [HR], 0.66 [95% confidence interval (CI), 0.47-0.93]), but we found no effect among NVAS recipients (HR, 1.16 [95% CI, 0.82-1.63]) (P = .02 for interaction). The benefit of 2 doses of MV was limited to children who had not received NVAS. NVAS is not generally recommended; hence, an early 2-dose measles vaccination policy might reduce hospital admissions more than the current policy of providing the first MV at 9 months of age. ClinicalTrials.gov identifier NCT00168558. © The Author 2017. Published by Oxford University Press on behalf of The Journal of the Pediatric Infectious Diseases Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dose-Response for Multiple Biomarkers of Exposure and Genotoxic Effect Following Repeated Treatment of Rats with the Alkylating Agents, MMS and MNU.

PubMed

Ji, Zhiying; LeBaron, Matthew J; Schisler, Melissa R; Zhang, Fagen; Bartels, Michael J; Gollapudi, B Bhaskar; Pottenger, Lynn H

2016-05-01

The nature of the dose-response relationship for various in vivo endpoints of exposure and effect were investigated using the alkylating agents, methyl methanesulfonate (MMS) and methylnitrosourea (MNU). Six male F344 rats/group were dosed orally with 0, 0.5, 1, 5, 25 or 50mg/kg bw/day (mkd) of MMS, or 0, 0.01, 0.1, 1, 5, 10, 25 or 50 mkd of MNU, for 4 consecutive days and sacrificed 24h after the last dose. The dose-responses for multiple biomarkers of exposure and genotoxic effect were investigated. In MMS-treated rats, the hemoglobin adduct level, a systemic exposure biomarker, increased linearly with dose (r (2) = 0.9990, P < 0.05), indicating the systemic availability of MMS; however, the N7MeG DNA adduct, a target exposure biomarker, exhibited a non-linear dose-response in blood and liver tissues. Blood reticulocyte micronuclei (MN), a genotoxic effect biomarker, exhibited a clear no-observed-genotoxic-effect-level (NOGEL) of 5 mkd as a point of departure (PoD) for MMS. Two separate dose-response models, the Lutz and Lutz model and the stepwise approach using PROC REG both supported a bilinear/threshold dose-response for MN induction. Liver gene expression, a mechanistic endpoint, also exhibited a bilinear dose-response. Similarly, in MNU-treated rats, hepatic DNA adducts, gene expression changes and MN all exhibited clear PoDs, with a NOGEL of 1 mkd for MN induction, although dose-response modeling of the MNU-induced MN data showed a better statistical fit for a linear dose-response. In summary, these results provide in vivo data that support the existence of clear non-linear dose-responses for a number of biologically significant events along the pathway for genotoxicity induced by DNA-reactive agents. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

ASSESSMENT OF INHALATION DOSE FROM THE INDOOR 222Rn AND 220Rn USING RAD7 AND PINHOLE CUP DOSEMETERS.

PubMed

Mehra, R; Jakhu, R; Bangotra, P; Kaur, K; Mittal, H M

2016-10-01

Radon is the most important source of natural radiation and is responsible for approximately half of the received dose from all sources. Most of this dose is from inhalation of the radon progeny, especially in closed atmospheres. Concentration of radon ( 222 Rn) and thoron ( 220 Rn) in the different villages of Jalandhar and Kapurthala district of Punjab has been calculated by pinhole cup dosemeters and RAD7. On an average, it has been observed from the study that the values of all the parameters calculated are higher in case of active monitoring than the passive monitoring. The calculated equilibrium equivalent 222 Rn concentration (EEC Rn ) and equilibrium equivalent 220 Rn concentration (EEC Th ) fluctuate in the range from 5.58 to 34.29 and from 0.35 to 2.7 Bq m -3 as estimated by active technique, respectively. Similarly, the observed mean value of the potential alpha energy concentration of 222 Rn (PAEC Rn ) and 220 Rn (PAEC Th ) is 4.55 and 4.34 mWL, respectively. The dose rate to the soft tissues and lung from indoor 222 Rn varies from 0.06 to 0.38 and from 0.50 to 3.05 nGy h -1 , respectively. The total annual effective dose for the residents of the study area is less than 10 mSv. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Risk of eye lens radiation exposure for members of the public.

PubMed

Chevallier, M-A; Rannou, A; Villagrasa, C; Clairand, I

2016-01-01

In 2011, the International Commission on Radiological Protection (ICRP) reviewed its recommendation concerning the equivalent dose limit for the eye lens, lowering it to 20 mSv in a year, for occupational exposure in planned exposure situations. The ICRP's statement does not contain any explicit recommendations regarding the organ dose limit for the eye lens for public exposure. For the moment, no change is proposed. But, to be coherent in the overall approach, the current equivalent limit for the public might be lowered. A similar yardstick than in the former recommendation may be used, that is to say a reduction of 10 times lower than that for occupational exposure. In this context, additional data on potential scenarios for public exposure of the eye lens are necessary. This paper, mainly based on a literature study, aims to provide, as far as possible, an exhaustive list of the situations in which members of the public can be exposed at the level of the eye lens. Once these situations have been defined, some calculations, made to assess the associated doses to the eye lens, are presented. This literature study did not reveal any current situations where members of the public would receive significant radiation doses to the eye lens. Indeed, the situations in which the dose to the eye lens might reach around 1 mSv per year for the public are extremely rare. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The financial and service implications of splitting fixed-dose antiretroviral drugs - a case study.

PubMed

Taylor, R; Carlin, E; Sadique, Z; Ahmed, I; Adams, E J

2015-02-01

In 2010/2011, regional commissioners withdrew payment for the fixed-dose combination Combivir, forcing a switch to component drugs. This was deemed clinically acceptable and annual savings of £44 k expected. We estimated the true costs of switching and examined patient outcomes. Information for 46 patients using Combivir was extracted from case notes for each clinical contact in the 12 months pre- and post-switch (clinician seen, tests, antiretrovirals). Post-switch care costs £93/patient more annually versus pre-switch (95% CI £424 to £609), yielding £4278/year more post-switch for all patients. Drug and pathology costs were more expensive post-switch and extra clinical visits required. None of these results were statistically significant. Forty-two per cent of patients switched directly or in the subsequent year to an alternative fixed-dose combination rather than generics. Costs in this group were significantly higher post-switch driven by drug cost. Six patients (13%) reported problems with the switch including confusion around dosing and new side effects. As less-expensive generic antiretroviral drugs become available, it may appear cheaper to switch from fixed-dose combinations to component drugs. However, the additional clinical costs involved may outweigh the initial cost savings of the drugs and switching may cause confusion for some patients, risking loss of adherence. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

RESPONSE OF THE GREEK EARLY WARNING SYSTEM REUTER-STOKES IONIZATION CHAMBERS TO TERRESTRIAL AND COSMIC RADIATION EVALUATED IN COMPARISON WITH SPECTROSCOPIC DATA AND TIME SERIES ANALYSIS.

PubMed

Leontaris, F; Clouvas, A; Xanthos, S; Maltezos, A; Potiriadis, C; Kiriakopoulos, E; Guilhot, J

2018-02-01

The Telemetric Early Warning System Network of the Greek Atomic Energy Commission consists mainly of a network of 24 Reuter-Stokes high-pressure ionization chambers (HPIC) for gamma dose rate measurements and covers all Greece. In the present work, the response of the Reuter-Stokes HPIC to terrestrial and cosmic radiation was evaluated in comparison with spectroscopic data obtained by in situ gamma spectrometry measurements with portable hyper pure Germanium detectors (HPGe), near the Reuter-Stokes detectors and time series analysis. For the HPIC detectors, a conversion factor for the measured absorbed dose rate in air (in nGy h-1) to the total ambient dose equivalent rate Ḣ*(10), due to terrestrial and cosmic component, was deduced by the field measurements. Time series analysis of the mean monthly dose rate (measured by the Reuter-Stokes detector in Thessaloniki, northern Greece, from 2001 to 2016) was performed with advanced statistical methods (Fast Fourier Analysis and Zhao Atlas Marks Transform). Fourier analysis reveals several periodicities (periodogram). The periodogram of the absorbed dose rate in air values was compared with the periodogram of the values measured for the same period (2001-16) and in the same location with a NaI (Tl) detector which in principle is not sensitive to cosmic radiation. The obtained results are presented and discussed. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Monitoring of arsenic levels in some ready-to-use anti-malaria herbal products from drug sales outlets in the Madina area of Accra, Ghana.

PubMed

Affum, A O; Shiloh, D O; Adomako, D

2013-06-01

In Ghana anti-malaria herbal medicines or products are used to compliment commercial drugs in treatment and prevention of Plasmodium falciparum infections. In this study, four common aqueous based anti-malaria herbal products (coded HEB, KFE, MDM and NIB) which are used by Ghanaian population from pharmacy/herbal stores in the Madina area, Accra were blindly and randomly sampled for cadmium (Cd), arsenic (As) and Lead (Pb) analysis using Atomic Absorption Spectrophotometry technique. Arsenic concentrations were 1.087 μg/mL (108.7%), 1.027 μg/mL (102.7%), 0.330 μg/mL (33.0%) and 0.274 μg/mL (27.4%) in MDM, KFE, NIB and HEB respectively. Arsenic concentration determined in MDM and KFE were above the maximum permissible limit of 1.0 ppm determined by WHO/FAO. Cadmium concentration in each of the four products as well as lead concentration in KFE, NIB and HEB were below the detection limit of <0.002 mg/mL (Cd) and <0.005 mg/mL (Pb) respectively. The maximum permissible limits for Pb and Cd determined by WHO/FAO are 10.0 ppm and 0.3 ppm respectively. Thus, random assessment on the safety of some ready-to-use aqueous based anti-malaria herbal products on the market is necessary to prevent public health hazards associated with consuming these plant extracts. Although lead and cadmium concentration in the anti-malaria herbal products were below the maximum permissible limits, their cumulative effect on the health of an individual which consume recommended volume of not less than 1000 mL for effective malaria parasite clearance cannot be ignored. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modeling adverse event counts in phase I clinical trials of a cytotoxic agent.

PubMed

Muenz, Daniel G; Braun, Thomas M; Taylor, Jeremy Mg

2018-05-01

Background/Aims The goal of phase I clinical trials for cytotoxic agents is to find the maximum dose with an acceptable risk of severe toxicity. The most common designs for these dose-finding trials use a binary outcome indicating whether a patient had a dose-limiting toxicity. However, a patient may experience multiple toxicities, with each toxicity assigned an ordinal severity score. The binary response is then obtained by dichotomizing a patient's richer set of data. We contribute to the growing literature on new models to exploit this richer toxicity data, with the goal of improving the efficiency in estimating the maximum tolerated dose. Methods We develop three new, related models that make use of the total number of dose-limiting and low-level toxicities a patient experiences. We use these models to estimate the probability of having at least one dose-limiting toxicity as a function of dose. In a simulation study, we evaluate how often our models select the true maximum tolerated dose, and we compare our models with the continual reassessment method, which uses binary data. Results Across a variety of simulation settings, we find that our models compare well against the continual reassessment method in terms of selecting the true optimal dose. In particular, one of our models which uses dose-limiting and low-level toxicity counts beats or ties the other models, including the continual reassessment method, in all scenarios except the one in which the true optimal dose is the highest dose available. We also find that our models, when not selecting the true optimal dose, tend to err by picking lower, safer doses, while the continual reassessment method errs more toward toxic doses. Conclusion Using dose-limiting and low-level toxicity counts, which are easily obtained from data already routinely collected, is a promising way to improve the efficiency in finding the true maximum tolerated dose in phase I trials.

[Radiation exposure of radiologists during angiography: dose measurements outside the lead apron].

PubMed

Fischer, H; Przetak, C; Teubert, G; Ewen, K; Mödder, U

1995-02-01

The aim of this study was to provide practical information to angiographers concerning radiation exposure to body parts not covered by lead aprons. Individual doses to the neck and hands of radiologists measured in micro-Sieverts were obtained during the course of 80 angiographies of various types. The number of diagnostic and interventional procedures, which might lead to exceeding permissible doses, have been calculated. Possibilities of estimating doses during angiography by means of parameters such as screening times were examined statistically. Especially with regard to the hands, estimations of the doses are insufficient (correlation r = 0.21). Radiologists who undertake much angiographic and particularly interventional work may reach exposure levels requiring protective measures in addition to lead aprons.

High doses of granulocyte-macrophage colony stimulating factor inhibit antibody responses in rectal secretions and diminish MVA/SIV vaccine protection in TRIM5α restrictive macaques

PubMed Central

Kannanganat, Sunil; Wyatt, Linda S; Gangadhara, Sailaja; Chamcha, Venkateswarlu; Chea, Lynette S.; Kozlowski, Pamela A; LaBranche, Celia C; Chennareddi, Lakshmi; Lawson, Benton; Reddy, Pradeep B. J.; Styles, Tiffany M.; Vanderford, Thomas H; Montefiori, David C; Moss, Bernard; Robinson, Harriet L; Amara, Rama Rao

2016-01-01

Here, we test in rhesus macaques the effects of a 500-fold range of an admixed recombinant modified vaccinia Ankara (MVA) expressing rhesus GM-CSF (MVA/GM-CSF) on the immunogenicity and protection elicited by an MVA/simian immunodeficiency macaque 239 (SIVmac239) vaccine. High doses of the MVA/GM-CSF did not affect the levels of systemic Env-specific Ab but did decrease the expression of the gut homing receptor α4β7 on plasmacytoid dendritic cells (p<0.01) and the magnitudes of Env-specific IgA (p=0.01) and IgG (p<0.05) in rectal secretions. The protective effect of the vaccine was evaluated using 12 weekly rectal challenges in rhesus subgrouped by tripartite motif-containing protein 5α (TRIM5α) genotypes that are restrictive or permissive for infection by the challenge virus, SIVsmE660. Eight of 9 TRIM5α-restrictive animals receiving no, or the lowest dose [1×105 plaque forming units (pfu)] of MVA/GM-CSF resisted all 12 challenges. In the comparable TRIM5α-permissive group only 1 of 12 animals resisted all 12 challenges. In the TRIM5α restrictive, but not permissive animals, the number of challenges to infection directly correlated with the magnitudes of Env-specific rectal IgG (r=0.6) and IgA (r=0.6), the avidity of Env-specific serum IgG (r=0.5), and antibody dependent cell-mediated virus inhibition (r=0.6). Titers of neutralizing Ab did not correlate with protection. We conclude that (i) protection elicited by MVA/SIVmac239 is strongly dependent on the presence of the TRIM5α restriction, (ii) in TRIM5α restrictive animals, non-neutralizing Ab responses contribute to protection against SIVsmE660, and (iii) high doses of co-expressed MVA/GM-CSF inhibit mucosal Ab responses and MVA/SIV239-elicited protection. PMID:27683750

Dexmedetomidine inhibits activation of the MAPK pathway and protects PC12 and NG108-15 cells from lidocaine-induced cytotoxicity at its maximum safe dose.

PubMed

Wang, Qiong; Tan, Yonghong; Zhang, Na; Xu, Yingyi; Wei, Wei; She, Yingjun; Bi, Xiaobao; Zhao, Baisong; Ruan, Xiangcai

2017-07-01

The developing brains of pediatric patients are highly vulnerable to anesthetic regimen (e.g., lidocaine), potentially causing neurological impairment. Recently, dexmedetomidine (DEX) has been used as an adjunct for sedation, and was shown to exert dose-dependent neuroprotective effects during brain injury. However, the maximum safe dose of DEX is unclear, and its protective effects against lidocaine-related neurotoxicity need to be confirmed. In this study, PC12 and NG108-15 cells were used to estimate safe, non-cytotoxic doses of DEX. We found that 100 and 60μM are the maximum safe dose of DEX for PC12 and NG108-15 cells, respectively, with no significant cytotoxicity. Lidocaine was found to remarkably inhibit cell vitality, but could be reversed by different doses of DEX, especially its maximum safe dose. Furthermore, the apoptosis induced by lidocaine was also assessed, and 100 and 60μM DEX showed optimal protective effects in PC12 and NG108-15 cells, respectively. Mechanistically, DEX activated the mitogen-activated protein kinase (MAPK) pathway, impaired caspase-3 expression, and enhanced anti-apoptotic factor Bcl-2 to resist lidocaine-induced apoptosis, indicating that the optimal dose of DEX alleviates lidocaine-induced cytotoxicity and should be considered in clinical application. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

The biological effects of space radiation during long stays in space.

PubMed

Ohnishi, Ken; Ohnishi, Takeo

2004-12-01

Many space experiments are scheduled for the International Space Station (ISS). Completion of the ISS will soon become a reality. Astronauts will be exposed to low-level background components from space radiation including heavy ions and other high-linear energy transfer (LET) radiation. For long-term stay in space, we have to protect human health from space radiation. At the same time, we should recognize the maximum permissible doses of space radiation. In recent years, physical monitoring of space radiation has detected about 1 mSv per day. This value is almost 150 times higher than that on the surface of the Earth. However, the direct effects of space radiation on human health are currently unknown. Therefore, it is important to measure biological dosimetry to calculate relative biological effectiveness (RBE) for human health during long-term flight. The RBE is possibly modified by microgravity. In order to understand the exact RBE and any interaction with microgravity, the ISS centrifugation system will be a critical tool, and it is hoped that this system will be in operation as soon as possible.

78 FR 57285 - 2,5-Furandione, Polymer With Ethenylbenzene, Hydrolyzed, 3-(Dimethylamino)propyl Imide, Imide...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-18

..., Polymer With Ethenylbenzene, Hydrolyzed, 3- (Dimethylamino)propyl Imide, Imide With Polyethylene..., polymer with ethenylbenzene, hydrolyzed, 3-(dimethylamino)propyl imide, imide with polyethylene... to establish a maximum permissible level for residues of 2,5-furandione, polymer with ethenylbenzene...

24 CFR 2700.210 - Finance charges.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Finance charges. 2700.210 Section 2700.210 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... HOMEOWNERS' LOAN PROGRAM Emergency Assistance § 2700.210 Finance charges. The maximum permissible finance...

24 CFR 2700.210 - Finance charges.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Finance charges. 2700.210 Section 2700.210 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... HOMEOWNERS' LOAN PROGRAM Emergency Assistance § 2700.210 Finance charges. The maximum permissible finance...

24 CFR 2700.210 - Finance charges.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Finance charges. 2700.210 Section 2700.210 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... HOMEOWNERS' LOAN PROGRAM Emergency Assistance § 2700.210 Finance charges. The maximum permissible finance...

24 CFR 2700.210 - Finance charges.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Finance charges. 2700.210 Section 2700.210 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... HOMEOWNERS' LOAN PROGRAM Emergency Assistance § 2700.210 Finance charges. The maximum permissible finance...

49 CFR 178.975 - Top lift test.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Packagings design types designed to be lifted from the top, there may be no permanent deformation which renders the Large Packagings unsafe for transport and no loss of contents. ... design types must be filled to six times the maximum permissible gross mass, the load being evenly...

49 CFR 178.975 - Top lift test.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Packagings design types designed to be lifted from the top, there may be no permanent deformation which renders the Large Packagings unsafe for transport and no loss of contents. ... design types must be filled to six times the maximum permissible gross mass, the load being evenly...

49 CFR 178.975 - Top lift test.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Packagings design types designed to be lifted from the top, there may be no permanent deformation which renders the Large Packagings unsafe for transport and no loss of contents. ... design types must be filled to six times the maximum permissible gross mass, the load being evenly...

49 CFR 178.975 - Top lift test.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Packagings design types designed to be lifted from the top, there may be no permanent deformation which renders the Large Packagings unsafe for transport and no loss of contents. ... design types must be filled to six times the maximum permissible gross mass, the load being evenly...

22 CFR 62.17 - Fees and charges.

Code of Federal Regulations, 2010 CFR

2010-04-01

...—September 30, 2009): (1) For filing an application for program designation and/or redesignation (Form DS-3036)—$1,748. (2) For filing an application for extension beyond the maximum duration, change of category, reinstatement, reinstatement-update SEVIS status, ECFMG-sponsorship authorization, and permission...

Field and modeling framework and case study of truck weigh station operations

DOT National Transportation Integrated Search

2002-01-01

Weigh-in-Motion (WIM) systems improve the capacity of weigh station operations significantly by screening trucks while traveling at high speeds and only requiring trucks within a threshold of a maximum permissible gross of axle weight to be weighed o...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loupot, S; Han, T; Salehpour, M

Purpose: To quantify the difference in dose to PTV-EVAL and OARs (skin and rib) as calculated by (TG43) and heterogeneous calculations (CCC). Methods: 25 patient plans (5 Contura and 20 SAVI) were selected for analysis. Clinical dose distributions were computed with a commercially available treatment planning algorithm (TG43-D-(w,w)) and then recomputed with a pre-clinical collapsed cone convolution algorithm (CCCD-( m,m)). PTV-EVAL coverage (V90%, V95%), and rib and skin maximum dose were compared via percent difference. Differences in dose to normal tissue (V150cc, V200cc of PTV-EVAL) were also compared. Changes in coverage and maximum dose to organs at risk are reportedmore » in percent change, (100*(TG43 − CCC) / TG43)), and changes in maximum dose to normal tissue are absolute change in cc (TG43 − CCC). Results: Mean differences in V90, V95, V150, and V200 for the SAVI cases were −0.2%, −0.4%, −0.03cc, and −0.14cc, respectively, with maximum differences of −0.78%, −1.7%, 1.28cc, and 1.01cc, respectively. Mean differences in the 0.1cc dose to the rib and skin were −1.4% and −0.22%, respectively, with maximum differences of −4.5% and 16%, respectively. Mean differences in V90, V95, V150, and V200 for the Contura cases were −1.2%, −2.1%, −1.8cc, and −0.59cc, respectively, with maximum differences of −2.0%, −3.16%, −2.9cc, and −0.76cc, respectively. Mean differences in the 0.1cc dose to the rib and skin were −2.6% and −3.9%, respectively, with maximum differences of −3.2% and −5.7%, respectively. Conclusion: The effects of translating clinical knowledge based on D-(w,w) to plans reported in D-(m,m) are minimal (2% or less) on average, but vary based on the type and placement of the device, source, and heterogeneity information.« less

COMMENTS ON THE DEFINITION OF THE CURIE, WITH SPECIAL REFERENCE TO NATURAL RADIOACTIVE MATERIALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaeger, R.G.; Houtermans, H.

1962-06-01

An analysis of maximum permissible levels of radionuclides showed that the definition of the curie, when applied to natural radioactive materials, is ambiguous. The history of the definition of the curie is reviewed. In the past, no clear distinction was raade between the curie as a unit of the quantity of a radioactive substance, and the curie as a unit of radioactivity. This has caused different interpretation of the curic as applied to natural radioactive materials, e.g., natural uranium and natural thorium. A redefinition of the curie as a pure unit of radioactivity is suggested, and maximum permissible levels ormore » concentrations of natural radioactive materials, such as uranium or thorium, should be stated in mass per unit mass or volume of air, water, food, etc. It is recommended that, in legislation listing the amounts of naturally occurring radioactive substances, these amounts be stated in milligrams or Kilograms. (auth)« less

Aquifer-yield continuum as a guide and typology for science-based groundwater management

NASA Astrophysics Data System (ADS)

Pierce, Suzanne A.; Sharp, John M.; Guillaume, Joseph H. A.; Mace, Robert E.; Eaton, David J.

2013-03-01

Groundwater availability is at the core of hydrogeology as a discipline and, simultaneously, the concept is the source of ambiguity for management and policy. Aquifer yield has undergone multiple definitions resulting in a range of scientific methods to calculate and model availability reflecting the complexity of combined scientific, management, policy, and stakeholder processes. The concept of an aquifer-yield continuum provides an approach to classify groundwater yields along a spectrum, from non-use through permissive sustained, sustainable, maximum sustained, safe, permissive mining to maximum mining yields, that builds on existing literature. Additionally, the aquifer-yield continuum provides a systems view of groundwater availability to integrate physical and social aspects in assessing management options across aquifer settings. Operational yield describes the candidate solutions for operational or technical implementation of policy, often relating to a consensus yield that incorporates human dimensions through participatory or adaptive governance processes. The concepts of operational and consensus yield address both the social and the technical nature of science-based groundwater management and governance.

THE CHALLENGES IN THE ESTIMATION OF THE EFFECTIVE DOSE WHEN WEARING RADIOPROTECTIVE GARMENTS.

PubMed

Saldarriaga Vargas, C; Struelens, L; Vanhavere, F

2018-01-01

The performance of a single or double dosimetry (SD or DD) algorithm on estimating effective dose wearing radioprotective garments (ERPG) depends on the specific irradiation conditions. This study investigates the photon energies and angles of incidence for which the estimation of ERPG with the personal dose equivalents measured over and under the RPG (Ho and Hu) becomes more challenging. The energy and angular dependences of ERPG, Ho and Hu were Monte Carlo calculated for photon exposures. The personal dosimeter of SCK · CEN was modeled and used to determine Ho and Hu. Different SD and DD algorithms were tested and critical exposure conditions were identified. Moreover, the influence of calibration methods was investigated for the SCK · CEN dosimeter when worn over RPG. We found that the accuracy with which ERPG is calculated using SD and DD is strongly dependent on the energy and angle of incidence of photons. Also, the energy of the photon beam used to calibrate the Ho dosimeter can bias the estimation of ERPG. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

EXPERIMENTAL EVALUATION OF DOSIMETRIC CHARACTERIZATION OF GAFCHROMIC EBT3 AND EBT-XD FILMS FOR CLINICAL CARBON ION BEAMS.

PubMed

Yonai, Shunsuke; Arai, Chinatsu; Shimoyama, Kaoru; Fournier-Bidoz, Nathalie

2018-02-03

Radiochromic film is a very useful tool for 2D dosimetric measurements in radiotherapy because it is self-developing and has very high-spatial resolution. However, considerable care has to be taken in ion beam radiotherapy owing to the quenching effect of high-linear energy transfer (LET) radiation. In this study, the dose responses of GAFchromic EBT3 and EBT-XD films were experimentally investigated using the clinical carbon ion beam at the Heavy Ion Medical Accelerator in Chiba. Results showed that the relations between absorbed dose and net optical density could be expressed well using an equation proposed by Reinhardt (2015). The quenching effect was evaluated by determining their relative efficiencies for photon irradiation as a function of LET. A correction equation derived in this study allowed the absorbed dose to be determined in the small irradiation field used for carbon ion radiotherapy eye treatments. This study contributes to establishing an absolute dosimetry procedure for heavy ion beams using radiochromic film. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Bubble-detector measurements in the Russian segment of the International Space Station during 2009-12.

PubMed

Smith, M B; Khulapko, S; Andrews, H R; Arkhangelsky, V; Ing, H; Lewis, B J; Machrafi, R; Nikolaev, I; Shurshakov, V

2015-01-01

Measurements using bubble detectors have been performed in order to characterise the neutron dose and energy spectrum in the Russian segment of the International Space Station (ISS). Experiments using bubble dosemeters and a bubble-detector spectrometer, a set of six detectors with different energy thresholds that is used to determine the neutron spectrum, were performed during the ISS-22 (2009) to ISS-33 (2012) missions. The spectrometric measurements are in good agreement with earlier data, exhibiting expected features of the neutron energy spectrum in space. Experiments using a hydrogenous radiation shield show that the neutron dose can be reduced by shielding, with a reduction similar to that determined in earlier measurements using bubble detectors. The bubble-detector data are compared with measurements performed on the ISS using other instruments and are correlated with potential influencing factors such as the ISS altitude and the solar activity. Surprisingly, these influences do not seem to have a strong effect on the neutron dose or energy spectrum inside the ISS. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kitabatake, T.; Kaneko, M.; Takagi, Y.

Dosimetry was used to estimate the radiation dose received by dertal patients and dentists in dental clinics in Japan, and the results were compared with those obtained by an enlargement technique. The phantom of paraffin used for measuring exposure doses was based on a whole-body plaster of panis cast of a Japanese of medium size. The lungs in the phantom were made of cork with a specific gravity of 0.2, and three holes were constructed in the oral cavity, lower abdomen (ovary region), and testicular region for insertion of a dosimeter. Since in most dental clinics in Japan the x-raymore » apparatus is installed in the corner of the treatment room without any Pb protection, dose distribution of scattered x rays was also surveyed. Four types of x-ray units were used, and measurement was performed at distances 50 to 200 cm at levels of 50 and 100 cm from the floor. The gonads received a dose of about 0.5 to 3 mr per exposure in males, and 0.03 to 1 mr in females. Patients received radiation doses of 10 to l000 mr per exposure at the eye lens, 1500 mr on the nasal apex, and 500 mr on the thyroid region. Not less than 100 mr of radiation was distributed in the regions of the pharynx and cervical spine. For dentists holding the film in the patient's mouth, about 1 to 3 r were received per exposure. They also received whole-body irradiation of scattered rays of about 500 to 2000 mr/hr. Since in Japan, even at present, the dentist usually holds the fllm in the patient's mouth during radiography, and if he conducts dental radiography 10 times a day, he should receive 10 to 30 r on his hands a day, or 3000 to 9000 r a year. Furthermore, the dentist standing near the patient is exposed to scattered rays of about 1.4 mr per exposure. Therefore 11 exposures per day give the upper limit of irradiation dose according to maximum permissible dose. The long-cone method, it is suggested, is of value not only for making enlargement radiograms but also for diminishing the exposure dose of dentists since it prevents the production of scattered rays. (BBB)« less

HOW DO HOSPITAL STERILISATION PROCEDURES AFFECT THE RESPONSE OF PERSONAL EXTREMITY RINGS AND OF EYE LENS TL DOSEMETERS?

PubMed

Kopeć, Renata; Bubak, Anna; Budzanowski, Maciej; Sas-Bieniarz, Anna; Szumska, Agnieszka

2016-09-01

Stringent standards of hygiene must be applied in medical institutions, especially at operating blocks or during interventional radiology procedures. Medical equipment, including personal dosemeters that have to be worn by medical staff during such procedures, needs therefore to be sterilised. In this study, the effect of various sterilisation procedures has been tested on the dose response of extremity rings and of eye lens dosemeters in which thermoluminescent (TL) detectors (of types MTS-N and MCP-N, respectively) are used. The effects of medical sterilisation procedures were studied: by chemicals, by steam or by ultraviolet (UV), on the dose assessment by extremity rings and by eye lens dosemeters. Since it often happens that a dosemeter is accidentally machine-washed together with protective clothing, the effect of laundering on dose assessment by these dosemeters was also tested. The sterilisation by chemicals is mostly safe for TL detectors assuming that the dosemeters are waterproofed. Following sterilisation by water vapour, the response of these dosemeters diminished by some 30 %, irrespectively of the period of sterilisation; therefore, this method is not recommended. UV sterilisation can be applied to EYE-D™ eye lens dosemeters if their encapsulation is in black. The accidental dosemeter laundry in a washing machine has no impact on measured dose. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Measurement of dose equivalent distribution on-board commercial jet aircraft.

PubMed

Kubančák, J; Ambrožová, I; Ploc, O; Pachnerová Brabcová, K; Štěpán, V; Uchihori, Y

2014-12-01

The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them [International Commission on Radiation Protection. 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Ann. ICRP 21: (1-3), (1991)]. According to the Monte Carlo simulations [Battistoni, G., Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the doses to aircrew members taking into consideration the aircraft structures. Adv. Space Res. 36: , 1645-1652 (2005) and Ferrari, A., Pelliccioni, M. and Villari, R. Evaluation of the influence of aircraft shielding on the aircrew exposure through an aircraft mathematical model. Radiat. Prot. Dosim. 108: (2), 91-105 (2004)], the ambient dose equivalent rate Ḣ*(10) depends on the location in the aircraft. The aim of this article is to experimentally evaluate Ḣ*(10) on-board selected types of aircraft. The authors found that Ḣ*(10) values are higher in the front and the back of the cabin and lesser in the middle of the cabin. Moreover, total dosimetry characteristics obtained in this way are in a reasonable agreement with other data, in particular with the above-mentioned simulations. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Bubble-detector measurements of neutron radiation in the international space station: ISS-34 to ISS-37.

PubMed

Smith, M B; Khulapko, S; Andrews, H R; Arkhangelsky, V; Ing, H; Koslowksy, M R; Lewis, B J; Machrafi, R; Nikolaev, I; Shurshakov, V

2016-02-01

Bubble detectors have been used to characterise the neutron dose and energy spectrum in several modules of the International Space Station (ISS) as part of an ongoing radiation survey. A series of experiments was performed during the ISS-34, ISS-35, ISS-36 and ISS-37 missions between December 2012 and October 2013. The Radi-N2 experiment, a repeat of the 2009 Radi-N investigation, included measurements in four modules of the US orbital segment: Columbus, the Japanese experiment module, the US laboratory and Node 2. The Radi-N2 dose and spectral measurements are not significantly different from the Radi-N results collected in the same ISS locations, despite the large difference in solar activity between 2009 and 2013. Parallel experiments using a second set of detectors in the Russian segment of the ISS included the first characterisation of the neutron spectrum inside the tissue-equivalent Matroshka-R phantom. These data suggest that the dose inside the phantom is ∼70% of the dose at its surface, while the spectrum inside the phantom contains a larger fraction of high-energy neutrons than the spectrum outside the phantom. The phantom results are supported by Monte Carlo simulations that provide good agreement with the empirical data. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SU-E-T-270: Optimized Shielding Calculations for Medical Linear Accelerators (LINACs).

PubMed

Muhammad, W; Lee, S; Hussain, A

2012-06-01

The purpose of radiation shielding is to reduce the effective equivalent dose from a medical linear accelerator (LINAC) to a point outside the room to a level determined by individual state/international regulations. The study was performed to design LINAC's room for newly planned radiotherapy centers. Optimized shielding calculations were performed for LINACs having maximum photon energy of 20 MV based on NCRP 151. The maximum permissible dose limits were kept 0.04 mSv/week and 0.002 mSv/week for controlled and uncontrolled areas respectively by following ALARA principle. The planned LINAC's room was compared to the already constructed (non-optimized) LINAC's room to evaluate the shielding costs and the other facilities those are directly related to the room design. In the evaluation process it was noted that the non-optimized room size (i.e., 610 × 610 cm 2 or 20 feet × 20 feet) is not suitable for total body irradiation (TBI) although the machine installed inside was having not only the facility of TBI but the license was acquired. By keeping this point in view, the optimized INAC's room size was kept 762 × 762 cm 2. Although, the area of the optimized rooms was greater than the non-planned room (i.e., 762 × 762 cm 2 instead of 610 × 610 cm 2), the shielding cost for the optimized LINAC's rooms was reduced by 15%. When optimized shielding calculations were re-performed for non-optimized shielding room (i.e., keeping room size, occupancy factors, workload etc. same), it was found that the shielding cost may be lower to 41 %. In conclusion, non- optimized LINAC's room can not only put extra financial burden on the hospital but also can cause of some serious issues related to providing health care facilities for patients. © 2012 American Association of Physicists in Medicine.

A retrospective analysis of rectal and bladder dose for gynecological brachytherapy treatments with GZP6 HDR afterloading system.

PubMed

Bahreyni Toossi, Mohammad Taghi; Ghorbani, Mahdi; Makhdoumi, Yasha; Taheri, Mojtaba; Homaee Shandiz, Fatemeh; Zahed Anaraki, Siavash; Soleimani Meigooni, Ali

2012-01-01

The aim of this work is to evaluate rectal and bladder dose for the patients treated for gynecological cancers. The GZP6 high dose rate brachytherapy system has been recently introduced to a number of radiation therapy departments in Iran, for treatment of various tumor sites such as cervix and vagina. Our analysis was based on dose measurements for 40 insertions in 28 patients, treated by a GZP6 unit between June 2009 and November 2010. Treatments consisted of combined teletherapy and intracavitary brachytherapy. In vivo dosimetry was performed with TLD-400 chips and TLD-100 microcubes in the rectum and bladder. The average of maximum rectal and bladder dose values were found to be 7.62 Gy (range 1.72-18.55 Gy) and 5.17 Gy (range 0.72-15.85 Gy), respectively. It has been recommended by the ICRU that the maximum dose to the rectum and bladder in intracavitary treatment of vaginal or cervical cancer should be lower than 80% of the prescribed dose to point A in the Manchester system. In this study, of the total number of 40 insertions, maximum rectal dose in 29 insertions (72.5% of treatment sessions) and maximum bladder dose in 18 insertions (45% of treatments sessions) were higher than 80% of the prescribed dose to the point of dose prescription. In vivo dosimetry for patients undergoing treatment by GZP6 brachytherapy system can be used for evaluation of the quality of brachytherapy treatments by this system. This information could be used as a base for developing the strategy for treatment of patients treated with GZP6 system.

A retrospective analysis of rectal and bladder dose for gynecological brachytherapy treatments with GZP6 HDR afterloading system

PubMed Central

Bahreyni Toossi, Mohammad Taghi; Ghorbani, Mahdi; Makhdoumi, Yasha; Taheri, Mojtaba; Homaee Shandiz, Fatemeh; Zahed Anaraki, Siavash; Soleimani Meigooni, Ali

2012-01-01

Aim The aim of this work is to evaluate rectal and bladder dose for the patients treated for gynecological cancers. Background The GZP6 high dose rate brachytherapy system has been recently introduced to a number of radiation therapy departments in Iran, for treatment of various tumor sites such as cervix and vagina. Materials and methods Our analysis was based on dose measurements for 40 insertions in 28 patients, treated by a GZP6 unit between June 2009 and November 2010. Treatments consisted of combined teletherapy and intracavitary brachytherapy. In vivo dosimetry was performed with TLD-400 chips and TLD-100 microcubes in the rectum and bladder. Results The average of maximum rectal and bladder dose values were found to be 7.62 Gy (range 1.72–18.55 Gy) and 5.17 Gy (range 0.72–15.85 Gy), respectively. It has been recommended by the ICRU that the maximum dose to the rectum and bladder in intracavitary treatment of vaginal or cervical cancer should be lower than 80% of the prescribed dose to point A in the Manchester system. In this study, of the total number of 40 insertions, maximum rectal dose in 29 insertions (72.5% of treatment sessions) and maximum bladder dose in 18 insertions (45% of treatments sessions) were higher than 80% of the prescribed dose to the point of dose prescription. Conclusion In vivo dosimetry for patients undergoing treatment by GZP6 brachytherapy system can be used for evaluation of the quality of brachytherapy treatments by this system. This information could be used as a base for developing the strategy for treatment of patients treated with GZP6 system. PMID:24377037

Cosmic radiation exposure of biological test systems during the EXPOSE-E mission.

PubMed

Berger, Thomas; Hajek, Michael; Bilski, Pawel; Körner, Christine; Vanhavere, Filip; Reitz, Günther

2012-05-01

In the frame of the EXPOSE-E mission on the Columbus external payload facility EuTEF on board the International Space Station, passive thermoluminescence dosimeters were applied to measure the radiation exposure of biological samples. The detectors were located either as stacks next to biological specimens to determine the depth dose distribution or beneath the sample carriers to determine the dose levels for maximum shielding. The maximum mission dose measured in the upper layer of the depth dose part of the experiment amounted to 238±10 mGy, which relates to an average dose rate of 408±16 μGy/d. In these stacks of about 8 mm height, the dose decreased by 5-12% with depth. The maximum dose measured beneath the sample carriers was 215±16 mGy, which amounts to an average dose rate of 368±27 μGy/d. These values are close to those assessed for the interior of the Columbus module and demonstrate the high shielding of the biological experiments within the EXPOSE-E facility. Besides the shielding by the EXPOSE-E hardware itself, additional shielding was experienced by the external structures adjacent to EXPOSE-E, such as EuTEF and Columbus. This led to a dose gradient over the entire exposure area, from 215±16 mGy for the lowest to 121±6 mGy for maximum shielding. Hence, the doses perceived by the biological samples inside EXPOSE-E varied by 70% (from lowest to highest dose). As a consequence of the high shielding, the biological samples were predominantly exposed to galactic cosmic heavy ions, while electrons and a significant fraction of protons of the radiation belts and solar wind did not reach the samples.

Radiation Standards: The Last Word or at Least a Definitive One

ERIC Educational Resources Information Center

Gillette, Robert

1972-01-01

Discusses the report of the National Academy of Science Committee on the Biological Effects of Ionizing Radiation, with particular reference to the possibilities for lowering maximum permissible standards for exposure to man-made radiation. The excessive use of diagnostic X-rays is considered. (AL)

77 FR 48899 - Flutriafol; Pesticide Tolerances for Emergency Exemptions

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-15

... cotton, undelinted seed; cotton, meal; cotton, refined oil; and cotton gin byproducts. This action is in..., and Rodenticide Act (FIFRA) authorizing use of the pesticide on cotton. This regulation establishes a maximum permissible level for residues of flutriafol in or on cotton commodities. The time-limited...

Management of Lignite Fly Ash for Improving Soil Fertility and Crop Productivity

NASA Astrophysics Data System (ADS)

Ram, Lal C.; Srivastava, Nishant K.; Jha, Sangeet K.; Sinha, Awadhesh K.; Masto, Reginald E.; Selvi, Vetrivel A.

2007-09-01

Lignite fly ash (LFA), being alkaline and endowed with excellent pozzolanic properties, a silt loam texture, and plant nutrients, has the potential to improve soil quality and productivity. Long-term field trials with groundnut, maize, and sun hemp were carried out to study the effect of LFA on growth and yield. Before crop I was sown, LFA was applied at various doses with and without press mud (an organic waste from the sugar industry, used as an amendment and source of nutrients). LFA with and without press mud was also applied before crops III and V were cultivated. Chemical fertilizer, along with gypsum, humic acid, and biofertilizer, was applied in all treatments, including the control. With one-time and repeat applications of LFA (with and without press mud), yield increased significantly (7.0-89.0%) in relation to the control crop. The press mud enhanced the yield (3.0-15.0%) with different LFA applications. The highest yield LFA dose was 200 t/ha for one-time and repeat applications, the maximum yield being with crop III (combination treatment). One-time and repeat application of LFA (alone and in combination with press mud) improved soil quality and the nutrient content of the produce. The highest dose of LFA (200 t/ha) with and without press mud showed the best residual effects (eco-friendly increases in the yield of succeeding crops). Some increase in trace- and heavy-metal contents and in the level of γ-emitters in soil and crop produce, but well within permissible limits, was observed. Thus, LFA can be used on a large scale to boost soil fertility and productivity with no adverse effects on the soil or crops, which may solve the problem of bulk disposal of fly ash in an eco-friendly manner.

Analysis of DNA Double-Strand Breaks and Cytotoxicity after 7 Tesla Magnetic Resonance Imaging of Isolated Human Lymphocytes

PubMed Central

Guttek, Karina; Hartig, Roland; Godenschweger, Frank; Roggenbuck, Dirk; Ricke, Jens; Reinhold, Dirk; Speck, Oliver

2015-01-01

The global use of magnetic resonance imaging (MRI) is constantly growing and the field strengths increasing. Yet, only little data about harmful biological effects caused by MRI exposure are available and published research analyzing the impact of MRI on DNA integrity reported controversial results. This in vitro study aimed to investigate the genotoxic and cytotoxic potential of 7 T ultra-high-field MRI on isolated human peripheral blood mononuclear cells. Hence, unstimulated mononuclear blood cells were exposed to 7 T static magnetic field alone or in combination with maximum permissible imaging gradients and radiofrequency pulses as well as to ionizing radiation during computed tomography and γ-ray exposure. DNA double-strand breaks were quantified by flow cytometry and automated microscopy analysis of immunofluorescence stained γH2AX. Cytotoxicity was studied by CellTiter-Blue viability assay and [3H]-thymidine proliferation assay. Exposure of unstimulated mononuclear blood cells to 7 T static magnetic field alone or combined with varying gradient magnetic fields and pulsed radiofrequency fields did not induce DNA double-strand breaks, whereas irradiation with X- and γ-rays led to a dose-dependent induction of γH2AX foci. The viability assay revealed a time- and dose-dependent decrease in metabolic activity only among samples exposed to γ-radiation. Further, there was no evidence for altered proliferation response after cells were exposed to 7 T MRI or low doses of ionizing radiation (≤ 0.2 Gy). These findings confirm the acceptance of MRI as a safe non-invasive diagnostic imaging tool, but whether MRI can induce other types of DNA lesions or DNA double-strand breaks during altered conditions still needs to be investigated. PMID:26176601

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, C; Lin, M; Chen, L

Purpose: Recent in vitro and in vivo experimental findings provided strong evidence that pulsed low-dose-rate radiotherapy (PLDR) produced equivalent tumor control as conventional radiotherapy with significantly reduced normal tissue toxicities. This work aimed to implement a PLDR clinical protocol for the management of recurrent cancers utilizing IMRT and VMAT. Methods: Our PLDR protocol requires that the daily 2Gy dose be delivered in 0.2Gy×10 pulses with a 3min interval between the pulses. To take advantage of low-dose hyper-radiosensitivity the mean dose to the target is set at 0.2Gy and the maximum dose is limited to 0.4Gy per pulse. Practical planning strategiesmore » were developed for IMRT and VMAT: (1) set 10 ports for IMRT and 10 arcs for VMAT with each angle/arc as a pulse; (2) set the mean dose (0.2Gy) and maximum dose (0.4Gy) to the target per pulse as hard constraints (no constraints to OARs); (3) select optimal port/arc angles to avoid OARs; and (4) use reference structures in or around target/OARs to reduce maximum dose to the target/OARs. IMRT, VMAT and 3DCRT plans were generated for 60 H and N, breast, lung, pancreas and prostate patients and compared. Results: All PLDR treatment plans using IMRT and VMAT met the dosimetry requirements of the PLDR protocol (mean target dose: 0.20Gy±0.01Gy; maximum target dose < 0.4Gy). In comparison with 3DCRT, IMRT and VMAT exhibited improved target dose conformity and OAR dose sparing. A single arc can minimize the difference in the target dose due to multi-angle incidence although the delivery time is longer than 3DCRT and IMRT. Conclusion: IMRT and VMAT are better modalities for PLDR treatment of recurrent cancers with superior target dose conformity and critical structure sparing. The planning strategies/guidelines developed in this work are practical for IMRT/VMAT treatment planning to meet the dosimetry requirements of the PLDR protocol.« less

Point Organ Radiation Dose in Abdominal CT: Effect of Patient Off-Centering in an Experimental Human Cadaver Study.

PubMed

Ali Khawaja, Ranish Deedar; Singh, Sarabjeet; Padole, Atul; Otrakji, Alexi; Lira, Diego; Zhang, Da; Liu, Bob; Primak, Andrew; Xu, George; Kalra, Mannudeep K

2017-08-01

To determine the effect of patient off-centering on point organ radiation dose measurements in a human cadaver scanned with routine abdominal CT protocol. A human cadaver (88 years, body-mass-index 20 kg/m2) was scanned with routine abdominal CT protocol on 128-slice dual source MDCT (Definition Flash, Siemens). A total of 18 scans were performed using two scan protocols (a) 120 kV-200 mAs fixed-mA (CTDIvol 14 mGy) (b) 120 kV-125 ref mAs (7 mGy) with automatic exposure control (AEC, CareDose 4D) at three different positions (a) gantry isocenter, (b) upward off-centering and (c) downward off-centering. Scanning was repeated three times at each position. Six thimble (in liver, stomach, kidney, pancreas, colon and urinary bladder) and four MOSFET dosimeters (on cornea, thyroid, testicle and breast) were placed for calculation of measured point organ doses. Organ dose estimations were retrieved from dose-tracking software (eXposure, Radimetrics). Statistical analysis was performed using analysis of variance. There was a significant difference between the trends of point organ doses with AEC and fixed-mA at all three positions (p < 0.01). Variation in point doses between fixed-mA and AEC protocols were statistically significant across all organs at all Table positions (p < 0.001). There was up to 5-6% decrease in point doses with upward off-centering and in downward off-centering. There were statistical significant differences in point doses from dosimeters and dose-tracking software (mean difference for internal organs, 5-36% for fixed-mA & 7-48% for AEC protocols; p < 0.001; mean difference for surface organs, >92% for both protocols; p < 0.0001). For both protocols, the highest mean difference in point doses was found for stomach and lowest for colon. Measured absorbed point doses in abdominal CT vary with patient-centering in the gantry isocenter. Due to lack of consideration of patient positioning in the dose estimation on automatic software-over estimation of the doses up to 92% was reported. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Survey of Occupational Noise Exposure in CF Personnel in Selected High-Risk Trades

DTIC Science & Technology

2003-11-01

peak, maximum level , minimum level , average sound level , time weighted average, dose, projected 8-hour dose, and upper limit time were measured for...10 4.4.2 Maximum Sound Level ...11 4.4.3 Minimum Sound Level

EFFECTIVE DOSE IN TWO DIFFERENT DENTAL CBCT SYSTEMS: NEWTOM VGi AND PLANMECA 3D MID.

PubMed

Ghaedizirgar, Mohammad; Faghihi, Reza; Paydar, Reza; Sina, Sedigheh

2017-11-01

Cone beam computed tomography, CBCT, is a kind of CT scanner producing conical diverging X-rays, in which a large area of a two-dimensional detector is irradiated in each rotation. Different investigations have been performed on dosimetry of dental CBCT. As there is no special protocol for dental CBCT, CT scan protocols are used for dosimetry. The purpose of this study is measurement of dose to head and neck organs in two CBCT systems, i.e. Planmeca 3D Mid (PM) and NewTom VGi (NT), using thermoluminescence dosimetry and Rando phantom. The thermoluminescent dosimetry (TLD)-100 chips were put at the position of different organs of the head and neck. Two TLD-100 chips were inserted at each position, the dose values were measured for several different field sizes, i.e. 8 × 8, 12 × 8 and 15 × 15 cm2 for NewTom, and 10 × 10 and 20 × 17 cm2 for Planmeca systems. According to the results, the average effective dose in PM is much more than the NT system in the same field size, because of the greater mAs values. For routine imaging protocols used for NT, the effective dose values are 70, 73 and 121 µSv for 8 × 8, 12 × 8 and 15 × 15 cm2 field sizes, respectively. In PM, the effective dose in 10 × 10 cm2 and 17 × 20 cm2 is 259 and 341 µSv, respectively. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Statistical controversies in clinical research: building the bridge to phase II-efficacy estimation in dose-expansion cohorts.

PubMed

Boonstra, P S; Braun, T M; Taylor, J M G; Kidwell, K M; Bellile, E L; Daignault, S; Zhao, L; Griffith, K A; Lawrence, T S; Kalemkerian, G P; Schipper, M J

2017-07-01

Regulatory agencies and others have expressed concern about the uncritical use of dose expansion cohorts (DECs) in phase I oncology trials. Nonetheless, by several metrics-prevalence, size, and number-their popularity is increasing. Although early efficacy estimation in defined populations is a common primary endpoint of DECs, the types of designs best equipped to identify efficacy signals have not been established. We conducted a simulation study of six phase I design templates with multiple DECs: three dose-assignment/adjustment mechanisms multiplied by two analytic approaches for estimating efficacy after the trial is complete. We also investigated the effect of sample size and interim futility analysis on trial performance. Identifying populations in which the treatment is efficacious (true positives) and weeding out inefficacious treatment/populations (true negatives) are competing goals in these trials. Thus, we estimated true and false positive rates for each design. Adaptively updating the MTD during the DEC improved true positive rates by 8-43% compared with fixing the dose during the DEC phase while maintaining false positive rates. Inclusion of an interim futility analysis decreased the number of patients treated under inefficacious DECs without hurting performance. A substantial gain in efficiency is obtainable using a design template that statistically models toxicity and efficacy against dose level during expansion. Design choices for dose expansion should be motivated by and based upon expected performance. Similar to the common practice in single-arm phase II trials, cohort sample sizes should be justified with respect to their primary aim and include interim analyses to allow for early stopping. © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Electron fluence correction factors for various materials in clinical electron beams.

PubMed

Olivares, M; DeBlois, F; Podgorsak, E B; Seuntjens, J P

2001-08-01

Relative to solid water, electron fluence correction factors at the depth of dose maximum in bone, lung, aluminum, and copper for nominal electron beam energies of 9 MeV and 15 MeV of the Clinac 18 accelerator have been determined experimentally and by Monte Carlo calculation. Thermoluminescent dosimeters were used to measure depth doses in these materials. The measured relative dose at dmax in the various materials versus that of solid water, when irradiated with the same number of monitor units, has been used to calculate the ratio of electron fluence for the various materials to that of solid water. The beams of the Clinac 18 were fully characterized using the EGS4/BEAM system. EGSnrc with the relativistic spin option turned on was used to optimize the primary electron energy at the exit window, and to calculate depth doses in the five phantom materials using the optimized phase-space data. Normalizing all depth doses to the dose maximum in solid water stopping power ratio corrected, measured depth doses and calculated depth doses differ by less than +/- 1% at the depth of dose maximum and by less than 4% elsewhere. Monte Carlo calculated ratios of doses in each material to dose in LiF were used to convert the TLD measurements at the dose maximum into dose at the center of the TLD in the phantom material. Fluence perturbation correction factors for a LiF TLD at the depth of dose maximum deduced from these calculations amount to less than 1% for 0.15 mm thick TLDs in low Z materials and are between 1% and 3% for TLDs in Al and Cu phantoms. Electron fluence ratios of the studied materials relative to solid water vary between 0.83+/-0.01 and 1.55+/-0.02 for materials varying in density from 0.27 g/cm3 (lung) to 8.96 g/cm3 (Cu). The difference in electron fluence ratios derived from measurements and calculations ranges from -1.6% to +0.2% at 9 MeV and from -1.9% to +0.2% at 15 MeV and is not significant at the 1sigma level. Excluding the data for Cu, electron fluence correction factors for open electron beams are approximately proportional to the electron density of the phantom material and only weakly dependent on electron beam energy.

A Phase I study of bizelesin (NSC 615291) in patients with advanced solid tumors.

PubMed

Pitot, Henry C; Reid, Joel M; Sloan, Jeff A; Ames, Matthew M; Adjei, Alex A; Rubin, Joseph; Bagniewski, Pamela G; Atherton, Pamela; Rayson, Daniel; Goldberg, Richard M; Erlichman, Charles

2002-03-01

To evaluate the toxicities, characterize the pharmacokinetics, and determine the maximum-tolerated dose of bizelesin administered once every 4 weeks. Patients with advanced solid tumors received escalating doses of bizelesin as an i.v. push every 4 weeks. Pharmacokinetic studies were performed with the first treatment cycle. Nineteen eligible patients received a total of 54 courses of bizelesin at doses ranging from 0.1 to 1 microg/m(2). Dose-limiting toxicity of neutropenia was seen in 2 of 4 patients treated at the 1 microg/m(2) dose level. Nonhematological toxicity was generally mild with maximum toxicity being

Sugammadex and neostigmine dose-finding study for reversal of residual neuromuscular block at a train-of-four ratio of 0.2 (SUNDRO20)†,.

PubMed

Kaufhold, N; Schaller, S J; Stäuble, C G; Baumüller, E; Ulm, K; Blobner, M; Fink, H

2016-02-01

The aim of this dose-finding study was to evaluate the dose-response relationship of sugammadex and neostigmine to reverse a commonly observed level of incomplete recovery from rocuronium-induced neuromuscular block, that is, a train-of-four ratio (TOFR) ≥0.2. Ninety-nine anaesthetized patients received rocuronium 0.6 mg kg(-1) i.v. for tracheal intubation and, if necessary, incremental doses of 0.1-0.2 mg kg(-1). Neuromuscular monitoring was performed by calibrated electromyography. Once the TOFR recovered to 0.2, patients were randomized to receive sugammadex (0.25, 0.5, 0.75, 1.0, or 1.25 mg kg(-1) i.v.), neostigmine (10, 25, 40, 55, or 70 µg kg(-1) i.v.), or saline (n=9 per group). Primary and secondary end points were the doses necessary to restore neuromuscular function to a TOFR≥0.9 with an upper limit of 5 and 10 min for 95% of patients, respectively. Neostigmine was not able to fulfil the end points. Based on the best-fitting model, the sugammadex dose estimation for recovery to a TOFR≥0.9 for 95% of patients within 5 and 10 min was 0.49 and 0.26 mg kg(-1), respectively. A residual neuromuscular block of a TOFR of 0.2 cannot be reversed reliably with neostigmine within 10 min. In the conditions studied, substantially lower doses of sugammadex than the approved dose of 2.0 mg kg(-1) may be sufficient to reverse residual rocuronium-induced neuromuscular block at a recovery of TOFR≥0.2. NCT01006720. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Population pharmacokinetics of ϵ-aminocaproic acid in adolescents undergoing posterior spinal fusion surgery.

PubMed

Stricker, P A; Gastonguay, M R; Singh, D; Fiadjoe, J E; Sussman, E M; Pruitt, E Y; Goebel, T K; Zuppa, A F

2015-04-01

Despite demonstrated efficacy of ϵ-aminocaproic acid (EACA) in reducing blood loss in adolescents undergoing spinal fusion, there are no population-specific pharmacokinetic data to guide dosing. The aim of this study was to determine the pharmacokinetics of EACA in adolescents undergoing spinal fusion surgery and make dosing recommendations. Twenty children ages 12-17 years were enrolled, with 10 children in each of two groups based on diagnosis (idiopathic scoliosis or non-idiopathic scoliosis). Previously reported data from infants undergoing craniofacial surgery were included in the model to enable dosing recommendations over a wide range of weights, ages, and diagnoses. A population non-linear mixed effects modelling approach was used to characterize EACA pharmacokinetics. Population pharmacokinetic parameters were estimated using a two-compartment disposition model with allometrically scaled weight and an age effect on clearance. Pharmacokinetic parameters for the typical patient were a plasma clearance of 153 ml min(-1) 70 kg(-1) (6.32 ml min(-1) kg(-0.75)), intercompartmental clearance of 200 ml min(-1) 70 kg(-1) (8.26 ml min(-1) kg(-0.75)), central volume of distribution of 8.78 litre 70 kg(-1) (0.13 litre kg(-1)), and peripheral volume of distribution of 15.8 litre 70 kg(-1) (0.23 litre kg(-1)). Scoliosis aetiology did not have a clinically significant effect on drug pharmacokinetics. The following dosing schemes are recommended according to patient weight: weight <25 kg, 100 mg kg(-1) loading dose and 40 mg kg(-1) h(-1) infusion; weight ≤25 kg-<50 kg, 100 mg kg(-1) loading dose and 35 mg kg(-1) h(-1) infusion; and weight ≥50 kg, 100 mg kg(-1) loading dose and 30 mg kg(-1) h(-1) infusion. An efficacy trial employing this dosing strategy is warranted. NCT01408823. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Single-dose Live Oral Cholera Vaccine CVD 103-HgR Protects Against Human Experimental Infection With Vibrio cholerae O1 El Tor.

PubMed

Chen, Wilbur H; Cohen, Mitchell B; Kirkpatrick, Beth D; Brady, Rebecca C; Galloway, David; Gurwith, Marc; Hall, Robert H; Kessler, Robert A; Lock, Michael; Haney, Douglas; Lyon, Caroline E; Pasetti, Marcela F; Simon, Jakub K; Szabo, Flora; Tennant, Sharon; Levine, Myron M

2016-06-01

No licensed cholera vaccine is presently available in the United States. Cholera vaccines available in other countries require 2 spaced doses. A single-dose cholera vaccine that can rapidly protect short-notice travelers to high-risk areas and help control explosive outbreaks where logistics render 2-dose immunization regimens impractical would be a major advance.PXVX0200, based on live attenuated Vibrio cholerae O1 classical Inaba vaccine strain CVD 103-HgR, elicits seroconversion of vibriocidal antibodies (a correlate of protection) within 10 days of a single oral dose. We investigated the protection conferred by this vaccine in a human cholera challenge model. Consenting healthy adult volunteers, 18-45 years old, were randomly allocated 1:1 to receive 1 oral dose of vaccine (approximately 5 × 10(8) colony-forming units [CFU]) or placebo in double-blind fashion. Volunteers ingested approximately 1 × 10(5) CFU of wild-type V. cholerae O1 El Tor Inaba strain N16961 10 days or 3 months after vaccination and were observed on an inpatient research ward for stool output measurement and management of hydration. The vaccine was well tolerated, with no difference in adverse event frequency among 95 vaccinees vs 102 placebo recipients. The primary endpoint, moderate (≥3.0 L) to severe (≥5.0 L) diarrheal purge, occurred in 39 of 66 (59.1%) placebo controls but only 2 of 35 (5.7%) vaccinees at 10 days (vaccine efficacy, 90.3%; P < .0001) and 4 of 33 (12.1%) vaccinees at 3 months (vaccine efficacy, 79.5%; P < .0001). The significant vaccine efficacy documented 10 days and 3 months after 1 oral dose of PXVX0200 supports further development as a single-dose cholera vaccine. NCT01895855. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

The Effects of Engine Speed and Mixture Temperature on the Knocking Characteristics of Several Fuels

NASA Technical Reports Server (NTRS)

Lee, Dana W

1940-01-01

Six 100-octane and two 87-octane aviation engine fuels were tested in a modified C.F.R. variable-compression engine at 1,500, 2,000 and 2,500 rpm. The mixture temperature was raised from 50 to 300 F in approximately 50 degree steps and, at each temperature, the compression ratio was adjusted to give incipient knock as shown by a cathode ray indicator. The results are presented in tabular form. The results are analyzed on the assumption that the conditions which determine whether a given fuel will knock are the maximum values of density and temperature reached by the burning gases. A maximum permissible density factor, proportional to the maximum density of the burning gases just prior to incipient knock, and the temperature of the burning gases at that time were computed for each of the test conditions. Values of the density factors were plotted against the corresponding end-gas temperatures for the three engine speeds and also against engine speed for several and end-gas temperatures. The maximum permissible density factor varied only slightly with engine speed but decreased rapidly with an increase in the end-gas temperature. The effect of changing the mixture temperature was different for fuels of different types. The results emphasize the desirability of determining the anti knock values of fuels over a wide range of engine and intake-air conditions rather that at a single set of conditions.

Estimation of attached and unattached progeny of 222Rn and 220Rn concentration using deposition based progeny sensors.

PubMed

Mehra, Rohit; Bangotra, Pargin; Kaur, Kirandeep; Kanse, Sandeep; Mishra, Rosaline

2015-11-01

The attached and unattached radon and thoron progeny concentrations have been calculated using deposition-based progeny sensors in Mansa, Muktsar, Bathinda and Faridkot districts of Punjab, India. The total (attached + unattached) equilibrium-equivalent (222)Rn concentration (EECRA + U) and total (attached + unattached) equilibrium-equivalent (220)Rn concentration (EECTA + U) were found to vary from 9 to 46 Bqm(-3) and 0.5 to 3.1 Bq m(-3), respectively. The concentrations of attached progeny nuclides for both (222)Rn and (220)Rn have been found to be greater than the unattached progeny nuclides in the dwellings of studied area. An attempt has also been made to assess the effective dose for (222)Rn and (220)Rn in the studied area. The radiation dose originated from (222)Rn and (220)Rn progeny is low and health risk is negligible. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Implications in dosimetry of the implementation of the revised dose limit to the lens of the eye.

PubMed

Broughton, J; Cantone, M C; Ginjaume, M; Shah, B; Czarwinski, R

2015-04-01

In 2012, International Radiation Protection Association (IRPA) established a Task Group to provide an assessment of the impact of the implementation of the ICRP-revised dose limit for the lens of the eye for occupational exposure. Associated Societies (ASs) of IRPA were asked to provide views and comments on the basis of a questionnaire addressing three principal topics: (i) implications for dosimetry, (ii) implications for methods of protection and (iii) wider implications of implementing the revised limits. A summary of the collated responses regarding dosimetry is presented and discussed. There is large agreement on the most critical aspects and difficulties in setting up an appropriate monitoring programme for the lens of the eyes. The recent international standards and technical documents provide guidance for some of the concerns but other challenges remain in terms of awareness, acceptance and practicalities. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Paediatric CT protocol optimisation: a design of experiments to support the modelling and optimisation process.

PubMed

Rani, K; Jahnen, A; Noel, A; Wolf, D

2015-07-01

In the last decade, several studies have emphasised the need to understand and optimise the computed tomography (CT) procedures in order to reduce the radiation dose applied to paediatric patients. To evaluate the influence of the technical parameters on the radiation dose and the image quality, a statistical model has been developed using the design of experiments (DOE) method that has been successfully used in various fields (industry, biology and finance) applied to CT procedures for the abdomen of paediatric patients. A Box-Behnken DOE was used in this study. Three mathematical models (contrast-to-noise ratio, noise and CTDI vol) depending on three factors (tube current, tube voltage and level of iterative reconstruction) were developed and validated. They will serve as a basis for the development of a CT protocol optimisation model. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Jasmine flower extract lowers prolactin.

PubMed

Finny, Philip; Stephen, Charles; Jacob, Rajesh; Tharyan, Prathap; Seshadri, Mandalam S

2015-04-01

Antipsychotic drugs frequently cause amenorrhoea and galactorrhoea. Jasmine flowers used topically were as effective as oral Bromocriptine in suppressing puerperal lactation. This study aims to evaluate the efficacy and safety of intranasal jasmine flower extract (JFE) to reduce prolactin levels of patients on stable doses of antipsychotic drugs. This is a randomized, double blind, crossover clinical trial. An aqueous-ethanol extract of jasmine flowers was prepared and used as nasal drops. A decrease in serum prolactin of ≥25 ng/mL was considered a significant response. Ten out of 35 women had a significant drop in the serum prolactin while on the JFE. The non-responders to JFE were on higher doses of antipsychotic drugs. The main side effect was a transient and mild burning sensation in the nose. A cost analysis favoured JFE over dopamine agonists. JFE contains a prolactin-lowering substance which needs further characterisation. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

EURADOS strategic research agenda: vision for dosimetry of ionising radiation.

PubMed

Rühm, W; Fantuzzi, E; Harrison, R; Schuhmacher, H; Vanhavere, F; Alves, J; Bottollier Depois, J F; Fattibene, P; Knežević, Ž; Lopez, M A; Mayer, S; Miljanić, S; Neumaier, S; Olko, P; Stadtmann, H; Tanner, R; Woda, C

2016-02-01

Since autumn 2012, the European Radiation Dosimetry Group (EURADOS) has been developing its Strategic Research Agenda (SRA), which is intended to contribute to the identification of future research needs in radiation dosimetry in Europe. The present article summarises-based on input from EURADOS Working Groups (WGs) and Voting Members-five visions in dosimetry and defines key issues in dosimetry research that are considered important for the next decades. The five visions include scientific developments required towards (a) updated fundamental dose concepts and quantities, (b) improved radiation risk estimates deduced from epidemiological cohorts, (c) efficient dose assessment for radiological emergencies, (d) integrated personalised dosimetry in medical applications and (e) improved radiation protection of workers and the public. The SRA of EURADOS will be used as a guideline for future activities of the EURADOS WGs. A detailed version of the SRA can be downloaded as a EURADOS report from the EURADOS website (www.eurados.org). © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

IMAGE-GUIDED TREATMENT USING AN X-RAY THERAPY UNIT AND GOLD NANOPARTICLES: TEST OF CONCEPT.

PubMed

Le Loirec, Cindy; Chambellan, Dominique; Tisseur, David

2016-06-01

Gold nanoparticles (GNPs) have the potential to enhance the radiation dose locally in conjunction with kV X-rays used for radiation therapy. As for other radiotherapy modalities, the absorbed dose needs to be controlled. To do that, it is an advantage to know the distribution of GNPs. However, no effective imaging tool exists to determine the GNP distribution in vivo. Various approaches have been proposed to determine the concentration of GNPs and its distribution in a tumour and in other organs and tissues. X-ray fluorescence computed tomography (XFCT) is a promising imaging technique to do that. A new experimental device based on the XFCT technique allowing the in vivo control of GNP radiotherapy treatments is proposed. As a test of concept, experimental acquisitions and Monte Carlo simulations were performed to determine the performance that a XFCT detector has to fulfil. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A REVIEW OF THE FUNDAMENTAL PRINCIPLES OF RADIATION PROTECTION WHEN APPLIED TO THE PATIENT IN DIAGNOSTIC RADIOLOGY.

PubMed

Moores, B Michael

2017-06-01

A review of the role and relevance of the principles of radiation protection of the patient in diagnostic radiology as specified by ICRP has been undertaken when diagnostic risks arising from an examination are taken into account. The increase in population doses arising from diagnostic radiology over the past 20 years has been due to the widespread application of higher dose CT examinations that provide significantly more clinical information. Consequently, diagnostic risks as well as radiation risks need to be considered within the patient radiation protection framework. Justification and optimisation are discussed and the limitations imposed on patient protection by employing only a radiation risk framework is highlighted. The example of radiation protection of the patient in breast screening programmes employing mammography is used to highlight the importance of defined diagnostic outcomes in any effective radiation protection strategy. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Bayesian Approach for Measurements of Stray Neutrons at Proton Therapy Facilities: Quantifying Neutron Dose Uncertainty.

PubMed

Dommert, M; Reginatto, M; Zboril, M; Fiedler, F; Helmbrecht, S; Enghardt, W; Lutz, B

2017-11-28

Bonner sphere measurements are typically analyzed using unfolding codes. It is well known that it is difficult to get reliable estimates of uncertainties for standard unfolding procedures. An alternative approach is to analyze the data using Bayesian parameter estimation. This method provides reliable estimates of the uncertainties of neutron spectra leading to rigorous estimates of uncertainties of the dose. We extend previous Bayesian approaches and apply the method to stray neutrons in proton therapy environments by introducing a new parameterized model which describes the main features of the expected neutron spectra. The parameterization is based on information that is available from measurements and detailed Monte Carlo simulations. The validity of this approach has been validated with results of an experiment using Bonner spheres carried out at the experimental hall of the OncoRay proton therapy facility in Dresden. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Role of step size and max dwell time in anatomy based inverse optimization for prostate implants

PubMed Central

Manikandan, Arjunan; Sarkar, Biplab; Rajendran, Vivek Thirupathur; King, Paul R.; Sresty, N.V. Madhusudhana; Holla, Ragavendra; Kotur, Sachin; Nadendla, Sujatha

2013-01-01

In high dose rate (HDR) brachytherapy, the source dwell times and dwell positions are vital parameters in achieving a desirable implant dose distribution. Inverse treatment planning requires an optimal choice of these parameters to achieve the desired target coverage with the lowest achievable dose to the organs at risk (OAR). This study was designed to evaluate the optimum source step size and maximum source dwell time for prostate brachytherapy implants using an Ir-192 source. In total, one hundred inverse treatment plans were generated for the four patients included in this study. Twenty-five treatment plans were created for each patient by varying the step size and maximum source dwell time during anatomy-based, inverse-planned optimization. Other relevant treatment planning parameters were kept constant, including the dose constraints and source dwell positions. Each plan was evaluated for target coverage, urethral and rectal dose sparing, treatment time, relative target dose homogeneity, and nonuniformity ratio. The plans with 0.5 cm step size were seen to have clinically acceptable tumor coverage, minimal normal structure doses, and minimum treatment time as compared with the other step sizes. The target coverage for this step size is 87% of the prescription dose, while the urethral and maximum rectal doses were 107.3 and 68.7%, respectively. No appreciable difference in plan quality was observed with variation in maximum source dwell time. The step size plays a significant role in plan optimization for prostate implants. Our study supports use of a 0.5 cm step size for prostate implants. PMID:24049323

Protocol for the isotoxic intensity modulated radiotherapy (IMRT) in stage III non-small cell lung cancer (NSCLC): a feasibility study.

PubMed

Haslett, Kate; Franks, Kevin; Hanna, Gerard G; Harden, Susan; Hatton, Matthew; Harrow, Stephen; McDonald, Fiona; Ashcroft, Linda; Falk, Sally; Groom, Nicki; Harris, Catherine; McCloskey, Paula; Whitehurst, Philip; Bayman, Neil; Faivre-Finn, Corinne

2016-04-15

The majority of stage III patients with non-small cell lung cancer (NSCLC) are unsuitable for concurrent chemoradiotherapy, the non-surgical gold standard of care. As the alternative treatment options of sequential chemoradiotherapy and radiotherapy alone are associated with high local failure rates, various intensification strategies have been employed. There is evidence to suggest that altered fractionation using hyperfractionation, acceleration, dose escalation, and individualisation may be of benefit. The MAASTRO group have pioneered the concept of 'isotoxic' radiotherapy allowing for individualised dose escalation using hyperfractionated accelerated radiotherapy based on predefined normal tissue constraints. This study aims to evaluate whether delivering isotoxic radiotherapy using intensity modulated radiotherapy (IMRT) is achievable. Isotoxic IMRT is a multicentre feasibility study. From June 2014, a total of 35 patients from 7 UK centres, with a proven histological or cytological diagnosis of inoperable NSCLC, unsuitable for concurrent chemoradiotherapy will be recruited. A minimum of 2 cycles of induction chemotherapy is mandated before starting isotoxic radiotherapy. The dose of radiation will be increased until one or more of the organs at risk tolerance or the maximum dose of 79.2 Gy is reached. The primary end point is feasibility, with accrual rates, local control and overall survival our secondary end points. Patients will be followed up for 5 years. The study has received ethical approval (REC reference: 13/NW/0480) from the National Research Ethics Service (NRES) Committee North West-Greater Manchester South. The trial is conducted in accordance with the Declaration of Helsinki and Good Clinical Practice (GCP). The trial results will be published in a peer-reviewed journal and presented internationally. NCT01836692; Pre-results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Effects and dose-response relationships of resistance training on physical performance in youth athletes: a systematic review and meta-analysis.

PubMed

Lesinski, Melanie; Prieske, Olaf; Granacher, Urs

2016-07-01

To quantify age, sex, sport and training type-specific effects of resistance training on physical performance, and to characterise dose-response relationships of resistance training parameters that could maximise gains in physical performance in youth athletes. Systematic review and meta-analysis of intervention studies. Studies were identified by systematic literature search in the databases PubMed and Web of Science (1985-2015). Weighted mean standardised mean differences (SMDwm) were calculated using random-effects models. Only studies with an active control group were included if these investigated the effects of resistance training in youth athletes (6-18 years) and tested at least one physical performance measure. 43 studies met the inclusion criteria. Our analyses revealed moderate effects of resistance training on muscle strength and vertical jump performance (SMDwm 0.8-1.09), and small effects on linear sprint, agility and sport-specific performance (SMDwm 0.58-0.75). Effects were moderated by sex and resistance training type. Independently computed dose-response relationships for resistance training parameters revealed that a training period of >23 weeks, 5 sets/exercise, 6-8 repetitions/set, a training intensity of 80-89% of 1 repetition maximum (RM), and 3-4 min rest between sets were most effective to improve muscle strength (SMDwm 2.09-3.40). Resistance training is an effective method to enhance muscle strength and jump performance in youth athletes, moderated by sex and resistance training type. Dose-response relationships for key training parameters indicate that youth coaches should primarily implement resistance training programmes with fewer repetitions and higher intensities to improve physical performance measures of youth athletes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Effect of the Maximum Dose on White Matter Fiber Bundles Using Longitudinal Diffusion Tensor Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Tong; Chapman, Christopher H.; Tsien, Christina

2016-11-01

Purpose: Previous efforts to decrease neurocognitive effects of radiation focused on sparing isolated cortical structures. We hypothesize that understanding temporal, spatial, and dosimetric patterns of radiation damage to whole-brain white matter (WM) after partial-brain irradiation might also be important. Therefore, we carried out a study to develop the methodology to assess radiation therapy (RT)–induced damage to whole-brain WM bundles. Methods and Materials: An atlas-based, automated WM tractography analysis was implemented to quantify longitudinal changes in indices of diffusion tensor imaging (DTI) of 22 major WM fibers in 33 patients with predominantly low-grade or benign brain tumors treated by RT. Sixmore » DTI scans per patient were performed from before RT to 18 months after RT. The DTI indices and planned doses (maximum and mean doses) were mapped onto profiles of each of 22 WM bundles. A multivariate linear regression was performed to determine the main dose effect as well as the influence of other clinical factors on longitudinal percentage changes in axial diffusivity (AD) and radial diffusivity (RD) from before RT. Results: Among 22 fiber bundles, AD or RD changes in 12 bundles were affected significantly by doses (P<.05), as the effect was progressive over time. In 9 elongated tracts, decreased AD or RD was significantly related to maximum doses received, consistent with a serial structure. In individual bundles, AD changes were up to 11.5% at the maximum dose locations 18 months after RT. The dose effect on WM was greater in older female patients than younger male patients. Conclusions: Our study demonstrates for the first time that the maximum dose to the elongated WM bundles causes post-RT damage in WM. Validation and correlative studies are necessary to determine the ability and impact of sparing these bundles on preserving neurocognitive function after RT.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Small, Katherine; Kelly, Chris; Beldham-Collins, Rachael

A comparative study was conducted comparing the difference between (1) conformal radiotherapy (CRT) to the whole breast with sequential boost excision cavity plans and (2) intensity-modulated radiation therapy (IMRT) to the whole breast with simultaneously integrated boost to the excision cavity. The computed tomography (CT) data sets of 25 breast cancer patients were used and the results analysed to determine if either planning method produced superior plans. CT data sets from 25 past breast cancer patients were planned using (1) CRT prescribed to 50 Gy in 25 fractions (Fx) to the whole-breast planning target volume (PTV) and 10 Gy inmore » 5Fx to the excision cavity and (2) IMRT prescribed to 60 Gy in 25Fx, with 60 Gy delivered to the excision cavity PTV and 50 Gy delivered to the whole-breast PTV, treated simultaneously. In total, 50 plans were created, with each plan evaluated by PTV coverage using conformity indices, plan maximum dose, lung dose, and heart maximum dose for patients with left-side lesions. CRT plans delivered the lowest plan maximum doses in 56% of cases (average CRT = 6314.34 cGy, IMRT = 6371.52 cGy). They also delivered the lowest mean lung dose in 68% of cases (average CRT = 1206.64 cGy, IMRT = 1288.37 cGy) and V20 in 88% of cases (average CRT = 20.03%, IMRT = 21.73%) and V30 doses in 92% of cases (average CRT = 16.82%, IMRT = 17.97%). IMRT created more conformal plans, using both conformity index and conformation number, in every instance, and lower heart maximum doses in 78.6% of cases (average CRT = 5295.26 cGy, IMRT = 5209.87 cGy). IMRT plans produced superior dose conformity and shorter treatment duration, but a slightly higher planning maximum and increased lung doses. IMRT plans are also faster to treat on a daily basis, with shorter fractionation.« less

77 FR 7005 - Airworthiness Directives; Eurocopter Deutschland GMBH Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-10

... delivered fuel flow than the engine fuel flow demand needed to achieve the OEI rating at high altitude. They...-engine-inoperative (OEI) rating at altitudes above 10,000 feet. This condition could result in high... AD would require installing a placard that corresponds to the maximum permissible flight altitude...

77 FR 32884 - Airworthiness Directives; Eurocopter Deutschland GMBH Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-04

... than the engine fuel flow demand needed to achieve the OEI rating at high altitude. They state that... above 10,000 feet. This condition could result in high altitude operations when full OEI engine power is... installing a placard that corresponds to the maximum permissible flight altitude, amending the Rotorcraft...

24 CFR 290.27 - Up-front grants and loans.

Code of Federal Regulations, 2011 CFR

2011-04-01

... may provide up-front grants and loans for rehabilitation, demolition, rebuilding and other related... determination that such a grant or loan, plus any additional project-based assistance made available, would be more cost-effective than the use of the maximum permissible project-based rental assistance alone. (b...

24 CFR 245.310 - Notice to tenants.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the maximum permissible rents for [name of apartment complex] to the United States Department of... Act. In addition, in projects with more than 1 type of apartment having the same number of bedroom but... apartment complex] and, if the tenants wish, by legal or other representatives acting for them individually...

77 FR 38397 - Agency Information Collection (Interest Rate Reduction Refinancing Loan Worksheet) Activities...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-27

... . Please refer to ``OMB Control No. 2900- 0386.'' SUPPLEMENTARY INFORMATION: Title: Interest Rate Reduction... guaranty on all interest rate reduction refinancing loan and provide a receipt as proof that the funding... ensure lenders computed the funding fee and the maximum permissible loan amount for interest rate...

14 CFR 33.88 - Engine overtemperature test.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.88 Engine overtemperature test. (a) Each engine must run for 5 minutes at maximum permissible rpm with the gas temperature at... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Engine overtemperature test. 33.88 Section...

14 CFR 33.88 - Engine overtemperature test.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine overtemperature test. 33.88 Section... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.88 Engine overtemperature test. (a) Each engine must run for 5 minutes at maximum permissible rpm with the gas temperature at...

Preschool Teachers' Exposure to Classroom Noise

ERIC Educational Resources Information Center

Grebennikov, Leonid

2006-01-01

This research examined exposure to classroom noise of 25 full-time teaching staff in 14 preschool settings located across Western Sydney. The results indicated that one teacher exceeded the maximum permissible level of daily noise exposure for employees under the health and safety legislation. Three staff approached this level and 92% of teachers…

“Hallucinations” Following Acute Cannabis Dosing: A Case Report and Comparison to Other Hallucinogenic Drugs

PubMed Central

Barrett, Frederick S.; Schlienz, Nicolas J.; Lembeck, Natalie; Waqas, Muhammad; Vandrey, Ryan

2018-01-01

Abstract Introduction: Cannabis has been historically classified as a hallucinogen. However, subjective cannabis effects do not typically include hallucinogen-like effects. Empirical reports of hallucinogen-like effects produced by cannabis in controlled settings, particularly among healthy research volunteers, are rare and have mostly occurred after administration of purified Δ-9 tetrahydrocannabinol (THC) rather than whole plant cannabis. Methods: The case of a healthy 30-year-old male who experienced auditory and visual hallucinations in a controlled laboratory study after inhaling vaporized cannabis that contained 25 mg THC (case dose) is presented. Ratings on the Hallucinogen Rating Scale (HRS) following the case dose are compared with HRS ratings obtained from the participant after other doses of cannabis and with archival HRS data from laboratory studies involving acute doses of cannabis, psilocybin, dextromethorphan (DXM), and salvinorin A. Results: Scores on the Volition subscale of the HRS were greater for the case dose than for the maximum dose administered in any other comparison study. Scores on the Intensity and Perception subscales were greater for the case dose than for the maximum dose of cannabis, psilocybin, or salvinorin A. Scores on the Somaesthesia subscale were greater for the case dose than for the maximum dose of DXM, salvinorin A, or cannabis. Scores on the Affect and Cognition subscales for the case dose were significantly lower than for the maximum doses of psilocybin and DXM. Conclusion: Acute cannabis exposure in a healthy adult male resulted in self-reported hallucinations that rated high in magnitude on several subscales of the HRS. However, the hallucinatory experience in this case was qualitatively different than that typically experienced by participants receiving classic and atypical hallucinogens, suggesting that the hallucinatory effects of cannabis may have a unique pharmacological mechanism of action. This type of adverse event needs to be considered in the clinical use of cannabis. PMID:29682608

The use of paracetamol (acetaminophen) among a community sample of people with chronic non-cancer pain prescribed opioids.

PubMed

Hoban, B; Larance, B; Gisev, N; Nielsen, S; Cohen, M; Bruno, R; Shand, F; Lintzeris, N; Hall, W; Farrell, M; Degenhardt, L

2015-11-01

The regular use of simple analgesics in addition to opioids such as paracetamol (or acetaminophen) is recommended for persistent pain to enhance analgesia. Few studies have examined the frequency and doses of paracetamol among people with chronic non-cancer pain including use above the recommended maximum daily dose. To assess (i) the prevalence of paracetamol use among people with chronic non-cancer pain prescribed opioids, (ii) assess the prevalence of paracetamol use above the recommended maximum daily dose and (iii) assess correlates of people who used paracetamol above the recommended maximum daily dose including: age, gender, income, education, pain severity and interference, use of paracetamol/opioid combination analgesics, total opioid dose, depression, anxiety, pain self-efficacy or comorbid substance use, among people prescribed opioids for chronic non-cancer pain. This study draws on baseline data collected for the Pain and Opioids IN Treatment (POINT) study and utilises data from 962 interviews and medication diaries. The POINT study is national prospective cohort of people with chronic non-cancer pain prescribed opioids. Participants were recruited from randomly selected pharmacies across Australia. Sixty-three per cent of the participants had used paracetamol in the past week (95% CI = 59.7-65.8). Among the paracetamol users 22% (95% CI = 19.3-24.6) had used paracetamol/opioid combination analgesics and 4.8% (95% CI = 3.6-6.3) had used paracetamol above the recommended maximum daily dose (i.e. > 4000 mg/day). Following binomial logistic regression (χ(2) = 25.98, df = 10, p = 0.004), people who had taken above the recommended maximum daily dose were less likely to have low income (AOR = 0.52, 95% CI = 0.27-0.99), more likely to use paracetamol/opioid combination analgesics (AOR = 2.01, 95% CI = 1.02-3.98) and more likely to take a higher opioid dose (AOR = 1.00, 95% CI = 1.00-1.01). The majority of people with chronic non-cancer pain prescribed opioids report using paracetamol appropriately. High income, use of paracetamol/opioid combination analgesics and higher opioid dose were independently associated with paracetamol use above the recommended maximum daily dose. © 2015 John Wiley & Sons Ltd.

Degradation kinetics and safety evaluation of buprofezin residues in grape (Vitis vinifera L.) and three different soils of India.

PubMed

Oulkar, Dasharath P; Banerjee, Kaushik; Patil, Sangram H; Upadhyay, Ajay K; Taware, Praveen B; Deshmukh, Madhukar B; Adsule, Pandurang G

2009-02-01

This work was undertaken to determine the preharvest interval (PHI) of buprofezin to minimize its residues in grapes and thereby ensure consumer safety and avoid possible non-compliance in terms of residue violations in export markets. Furthermore, the residue dynamics in three grapevine soils of India was explored to assess its environmental safety. Residues dissipated following non-linear two-compartment first + first-order kinetics. In grapes, the PHI was 31 days at both treatments (312.5 and 625 g a.i. ha(-1)), with the residues below the maximum permissible intake even 1 h after foliar spraying. Random sampling of 5 kg comprising small bunchlets (8-10 berries) collected from a 1 ha area gave satisfactory homogeneity and representation of the population. A survey on the samples harvested after the PHI from supervised vineyards that received treatment at the recommended dose showed residues below the maximum residue limit (MRL) of 0.02 mg kg(-1) applicable for the European Union. In soil, the degradation rate was fastest in clay soil, followed by sandy loam and silty clay, with a half-life within 16 days in all the soils. The recommendation of the PHI proved to be effective in minimizing buprofezin residues in grapes. Thus, this work is of high practical significance to the domestic and export grape industry of India to ensure safety compliance in respect of buprofezin residues, keeping in view the requirements of international trade.

RADIATION HAZARD IN THE TREATMENT OF SKIN DISEASES WITH THORIUM X

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiskemann, A.; Janssen, U.

Possible hazards, particularly to the dermatologist and his assistants, in the use of local applications of thorium X (Ra/sup 224/) in salves and ointments for the treatment of skin diseases, such as psoriasis, nevus flammeus, and lichen ruber verrucosus, were assessed. The decay scheme of thorium X through its daughter products (thoron and thorium A, B, C, C', C", and D), the half lives of the products, and their emission characteristics are discussed. Studies in rats showed that topically applied ointment containing thorium X leads to measurable blood levels of radioactivity and deposition of daughter products in various tissues, includingmore » gonads. Radioautographs of rat lung and ovary demonstrated alpha -particle tracks in various tissue constituents. In humans receiving skin treatments with 1000 units thorium X (70 mu C/cm/sup 3/) the blood dose reached 2 rem, from which it was estimated that the whole-body dose would be approximates 3 rem/yr. In the treatment of a number of patients with a total of 30000 units thorium X, it was calculated that the whole-body to the person giving the treatment would be approximates 15 mr, although at chest level as much as 473 mr would be received. However, this is only 1/4 to 1/7 the permissible weekly gamma dose. Use of film dosimeters by persons applying treatments showed that the permissible dose was not being exceeded. Measurements of the radiation dose received by the personnel showed that it is mostly from inhalation of air in the treatment room. (TCO)« less

High-Dose Vitamin C Injection to Cancer Patients May Promote Thrombosis Through Procoagulant Activation of Erythrocytes.

PubMed

Kim, Keunyoung; Bae, Ok-Nam; Koh, Sung-Hee; Kang, Seojin; Lim, Kyung-Min; Noh, Ji-Yoon; Shin, Sue; Kim, Inho; Chung, Jin-Ho

2015-10-01

Potential risk of high-dose vitamin C consumption is often ignored. Recently, gram-dose vitamin C is being intravenously injected for the treatment of cancer, which can expose circulating blood cells to extremely high concentrations of vitamin C. As well as platelets, red blood cells (RBCs) can actively participate in thrombosis through procoagulant activation. Here, we examined the procoagulant and prothrombotic risks associated with the intravenous injection of gram-dose vitamin C. Vitamin C (0.5-5 mM) increased procoagulant activity of freshly isolated human RBCs via the externalization of phosphatidylserine (PS) to outer cellular membrane and the formation of PS-bearing microvesicles. PS exposure was induced by the dysregulation of key enzymes for the maintenance of membrane phospholipid asymmetry, which was from vitamin C-induced oxidative stress, and resultant disruption of calcium and thiol homeostasis. Indeed, the intravenous injection of vitamin C (0.5-1.0 g/kg) in rats in vivo significantly increased thrombosis. Notably, the prothrombotic effects of vitamin C were more prominent in RBCs isolated from cancer patients, who are at increased risks of thrombotic events. Vitamin C-induced procoagulant and prothrombotic activation of RBCs, and increased thrombosis in vivo. RBCs from cancer patients exhibited increased sensitivity to the prothrombotic effects of vitamin C, reflecting that intravenous gram-dose vitamin C therapy needs to be carefully revisited. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Optimization of the strength of the efavirenz/lamivudine/abacavir fixed-dose combination for paediatric patients.

PubMed

Bouazza, Naïm; Cressey, Tim R; Foissac, Frantz; Bienczak, Andrzej; Denti, Paolo; McIlleron, Helen; Burger, David; Penazzato, Martina; Lallemant, Marc; Capparelli, Edmund V; Treluyer, Jean-Marc; Urien, Saïk

2017-02-01

Child-friendly, low-cost, solid, oral fixed-dose combinations (FDCs) of efavirenz with lamivudine and abacavir are urgently needed to improve clinical management and drug adherence for children. Data were pooled from several clinical trials and therapeutic drug monitoring datasets from different countries. The number of children/observations was 505/3667 for efavirenz. Population pharmacokinetic analyses were performed using a non-linear mixed-effects approach. For abacavir and lamivudine, data from 187 and 920 subjects were available (population pharmacokinetic models previously published). Efavirenz/lamivudine/abacavir FDC strength options assessed were (I) 150/75/150, (II) 120/60/120 and (III) 200/100/200 mg. Monte Carlo simulations of the different FDC strengths were performed to determine the optimal dose within each of the WHO weight bands based on drug efficacy/safety targets. The probability of being within the target efavirenz concentration range 12 h post-dose (1-4 mg/L) varied between 56% and 60%, regardless of FDC option. Option I provided a best possible balance between efavirenz treatment failure and toxicity risks. For abacavir and lamivudine, simulations showed that for option I >75% of subjects were above the efficacy target. According to simulations, a paediatric efavirenz/lamivudine/abacavir fixed-dose formulation of 150 mg efavirenz, 75 mg lamivudine and 150 mg abacavir provided the most effective and safe concentrations across WHO weight bands, with the flexibility of dosage required across the paediatric population. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Multiple Endocrine Disrupting Effects in Rats Perinatally Exposed to Butylparaben.

PubMed

Boberg, J; Axelstad, M; Svingen, T; Mandrup, K; Christiansen, S; Vinggaard, A M; Hass, U

2016-07-01

Parabens comprise a group of preservatives commonly added to cosmetics, lotions, and other consumer products. Butylparaben has estrogenic and antiandrogenic properties and is known to reduce sperm counts in rats following perinatal exposure. Whether butylparaben exposure can affect other endocrine sensitive endpoints, however, remains largely unknown. In this study, time-mated Wistar rats (n = 18) were orally exposed to 0, 10, 100, or 500 mg/kg bw/d of butylparaben from gestation day 7 to pup day 22. Several endocrine-sensitive endpoints were adversely affected. In the 2 highest dose groups, the anogenital distance of newborn male and female offspring was significantly reduced, and in prepubertal females, ovary weights were reduced and mammary gland outgrowth was increased. In male offspring, sperm count was significantly reduced at all doses from 10 mg/kg bw/d. Testicular CYP19a1 (aromatase) expression was reduced in prepubertal, but not adult animals exposed to butylparaben. In adult testes, Nr5a1 expression was reduced at all doses, indicating persistent disruption of steroidogenesis. Prostate histology was altered at prepuberty and adult prostate weights were reduced in the high dose group. Thus, butylparaben exerted endocrine disrupting effects on both male and female offspring. The observed adverse developmental effect on sperm count at the lowest dose is highly relevant to risk assessment, as this is the lowest observed adverse effect level in a study on perinatal exposure to butylparaben. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Contura Multi-Lumen Balloon breast brachytherapy catheter: comparative dosimetric findings of a phase 4 trial.

PubMed

Arthur, Douglas W; Vicini, Frank A; Todor, Dorin A; Julian, Thomas B; Cuttino, Laurie W; Mukhopadhyay, Nitai D

2013-06-01

Final dosimetric findings of a completed, multi-institutional phase 4 registry trial using the Contura Multi-Lumen Balloon (MLB) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI) in patients with early-stage breast cancer are presented. Three dosimetric plans with identical target coverage were generated for each patient for comparison: multilumen multidwell (MLMD); central-lumen multidwell (CLMD); and central-lumen single-dwell (CLSD) loading of the Contura catheter. For this study, a successful treatment plan achieved ideal dosimetric goals and included the following: ≥ 95% of the prescribed dose (PD) covering ≥ 95% of the target volume (TV); maximum skin dose ≤ 125% of the PD; maximum rib dose ≤ 145% of the PD; and V150 ≤50 cc and V200 ≤ 10 cc. Between January 2008 and February 2011, 23 institutions participated. A total of 318 patients were available for dosimetric review. Using the Contura MLB, all dosimetric criteria were met in 78.93% of cases planned with MLMD versus 55.38% with the CLMD versus 37.66% with the CLSD (P ≤.0001). Evaluating all patients with the full range of skin to balloon distance represented, median maximum skin dose was reduced by 12% and median maximum rib dose by 13.9% when using MLMD-based dosimetric plans compared to CLSD. The dosimetric benefit of MLMD was further demonstrated in the subgroup of patients where skin thickness was <5 mm, where MLMD use allowed a 38% reduction in median maximum skin dose over CLSD. For patients with rib distance <5 mm, the median maximum rib dose reduction was 27%. Use of the Contura MLB catheter produced statistically significant improvements in dosimetric capabilities between CLSD and CLMD treatments. This device approach demonstrates the ability not only to overcome the barriers of limited skin thickness and close rib proximity, but to consistently achieve a higher standard of dosimetric planning goals. Copyright © 2013 Elsevier Inc. All rights reserved.

Contura Multi-Lumen Balloon Breast Brachytherapy Catheter: Comparative Dosimetric Findings of a Phase 4 Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arthur, Douglas W., E-mail: darthur@mcvh-vcu.edu; Vicini, Frank A.; Todor, Dorin A.

2013-06-01

Purpose: Final dosimetric findings of a completed, multi-institutional phase 4 registry trial using the Contura Multi-Lumen Balloon (MLB) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI) in patients with early-stage breast cancer are presented. Methods and Materials: Three dosimetric plans with identical target coverage were generated for each patient for comparison: multilumen multidwell (MLMD); central-lumen multidwell (CLMD); and central-lumen single-dwell (CLSD) loading of the Contura catheter. For this study, a successful treatment plan achieved ideal dosimetric goals and included the following: ≥95% of the prescribed dose (PD) covering ≥95% of the target volume (TV); maximum skin dose ≤125%more » of the PD; maximum rib dose ≤145% of the PD; and V150 ≤50 cc and V200 ≤10 cc. Results: Between January 2008 and February 2011, 23 institutions participated. A total of 318 patients were available for dosimetric review. Using the Contura MLB, all dosimetric criteria were met in 78.93% of cases planned with MLMD versus 55.38% with the CLMD versus 37.66% with the CLSD (P≤.0001). Evaluating all patients with the full range of skin to balloon distance represented, median maximum skin dose was reduced by 12% and median maximum rib dose by 13.9% when using MLMD-based dosimetric plans compared to CLSD. The dosimetric benefit of MLMD was further demonstrated in the subgroup of patients where skin thickness was <5 mm, where MLMD use allowed a 38% reduction in median maximum skin dose over CLSD. For patients with rib distance <5 mm, the median maximum rib dose reduction was 27%. Conclusions: Use of the Contura MLB catheter produced statistically significant improvements in dosimetric capabilities between CLSD and CLMD treatments. This device approach demonstrates the ability not only to overcome the barriers of limited skin thickness and close rib proximity, but to consistently achieve a higher standard of dosimetric planning goals.« less

The effect of dose heterogeneity on radiation risk in medical imaging.

PubMed

Samei, Ehsan; Li, Xiang; Chen, Baiyu; Reiman, Robert

2013-06-01

The current estimations of risk associated with medical imaging procedures rely on assessing the organ dose via direct measurements or simulation. The dose to each organ is assumed to be homogeneous. To take into account the differences in radiation sensitivities, the mean organ doses are weighted by a corresponding tissue-weighting coefficients provided by ICRP to calculate the effective dose, which has been used as a surrogate of radiation risk. However, those coefficients were derived under the assumption of a homogeneous dose distribution within each organ. That assumption is significantly violated in most medical-imaging procedures. In helical chest CT, for example, superficial organs (e.g. breasts) demonstrate a heterogeneous dose distribution, whereas organs on the peripheries of the irradiation field (e.g. liver) might possess a discontinuous dose profile. Projection radiography and mammography involve an even higher level of organ dose heterogeneity spanning up to two orders of magnitude. As such, mean dose or point measured dose values do not reflect the maximum energy deposited per unit volume of the organ. In this paper, the magnitude of the dose heterogeneity in both CT and projection X-ray imaging was reported, using Monte Carlo methods. The lung dose demonstrated factors of 1.7 and 2.2 difference between the mean and maximum dose for chest CT and radiography, respectively. The corresponding values for the liver were 1.9 and 3.5. For mammography and breast tomosynthesis, the difference between mean glandular dose and maximum glandular dose was 3.1. Risk models based on the mean dose were found to provide a reasonable reflection of cancer risk. However, for leukaemia, they were found to significantly under-represent the risk when the organ dose distribution is heterogeneous. A systematic study is needed to develop a risk model for heterogeneous dose distributions.

Effects of malathion, diazinon, and parathion on mallard embryo development and cholinesterase activity

USGS Publications Warehouse

Hoffman, D.J.; Eastin, W.C.

1981-01-01

The effects of external exposure of mallard (Anas platyrhynchos) eggs to malathion, diazinon, and parathion were examined using formulations and concentrations similar to field applications. Treatment with aqueous emulsion simulated exposure at the rate of 100 gal per acre (153 liters/hectare) with three to six different doses per compound with treatment at 3 and 8 days of embryonic development. Treatment with a nontoxic oil vehicle simulated exposure at the rate of 11 gal per acre (16.8 liters/hectare) with three to six different doses per compound. The order of embryotoxicity on a pounds-per-acre basis was parathion > diazinon > malathion with either vehicle. However, the potential hazard under conditions of up to five times the maximum field level of application was greater for malathion because of the high permissible level of application for malathion on certain crops. Parathion, the most embryotoxic of the three, had the most pronounced effects when an oil vehicle was used, as reflected by an LC50 of about 2 lb of active ingredient per acre, stunted growth, and a high frequency of malformations involving distortion of the axial skeleton, particularly in the cervical region. All three compounds resulted in significant depression of plasma and brain cholinesterase activity, but parathion caused the most depression throughout development, which was still apparent in hatchlings. Treatment with either distilled water or oil vehicle alone did not result in any of these effects seen with organophosphorous insecticides.

Radiation dose to the Malaysian populace via the consumption of bottled mineral water

NASA Astrophysics Data System (ADS)

Khandaker, Mayeen Uddin; Nasir, Noor Liyana Mohd; Zakirin, Nur Syahira; Kassim, Hasan Abu; Asaduzzaman, Khandoker; Bradley, D. A.; Zulkifli, M. Y.; Hayyan, Adeeb

2017-11-01

Due to the geological makeup of the various water bodies, mineral- and groundwater can be expected to contain levels of naturally occurring radioactive material (NORM) exceeding that of tap and surface water. Acknowledging mineral water to form a vital component of the intake in maintaining the healthy life of an individual, it nevertheless remains important to study the associated radiological implications of NORM content, especially in regard to the consumption of bottled mineral water, the presence of which is prevalent in modern urban society. In present study, various brands of bottled mineral waters that are commonly available in Malaysia were obtained from local markets, the presence of NORM subsequently being assessed by HPGe γ-ray spectrometry. The activity concentrations of the radionuclides of particular interest, 226Ra, 232Th and 40K, were found to be within the respective ranges of 1.45±0.28‒3.30±0.43, 0.65±0.18‒3.39±0.38 and 21.12±1.74‒25.31±1.84 Bq/L. The concentrations of 226Ra, of central importance in radiological risk assessment, exceed the World Health Organisation (WHO, 2011) recommended maximum permissible limit of 1.0 Bq/L; for all three radionuclides taken together, the annual effective doses are greater than the WHO recommended limit of 0.1 mSv/y, a matter of especial concern for those in the developmental stages of life.

Impacts on Reticulitermes flavipes (Infraorder Isoptera: Rhinotermitidae) by Chlorantraniliprole Applied to Soil Surrounding Established Tunnels.

PubMed

Thorne, B L; Breisch, N L; Scherer, C W

2015-10-01

Soil-applied liquid termiticides are the most common control measure for subterranean termites. Characteristics unique to insecticidal chemistries such as repellency, toxicity, and time between contact and mortality, influence the interaction of termites with treated soil and overall treatment success. Two different treated-tunnel bioassays were used to evaluate the behavioral impacts and mortality of termites from treatment with chlorantraniliprole (the active ingredient in Altriset® termiticide) to existing, mature tunnels. Termites that were provided constant access to a 10-cm-long mature tunnel within soil treated with 5 or 50 ppm chlorantraniliprole were not repelled by the treatment and began exhibiting slower, uncoordinated movement, and cessation of tunneling and feeding in as little as 1 h after access. Termites provided access for 7, 14, or 21 d to previously constructed tunnels recently treated with 50 ppm chlorantraniliprole exhibited complete or near complete mortality by 28 d. The second bioassay design resembled a more typical field situation with a 40-cm-long mature tunnel and termites allowed access for a maximum of 5 min. Termites collected after just 5 min of access to the previously constructed tunnels recently treated with 50 ppm chlorantraniliprole exhibited similar symptomology within an hour followed by complete mortality at 18 d after exposure. These test designs simulate what occurs in the soil around an infested structure at the time of treatment. Results from these evaluations suggest that termites readily crawl through chlorantraniliprole-treated mature tunnels, rapidly lose ability to feed, and acquire a lethal dose from brief exposures. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Long-term effects of inhaled budesonide on screening-detected lung nodules.

PubMed

Veronesi, G; Lazzeroni, M; Szabo, E; Brown, P H; DeCensi, A; Guerrieri-Gonzaga, A; Bellomi, M; Radice, D; Grimaldi, M C; Spaggiari, L; Bonanni, B

2015-05-01

A previously carried out randomized phase IIb, placebo-controlled trial of 1 year of inhaled budesonide, which was nested in a lung cancer screening study, showed that non-solid and partially solid lung nodules detected by low-dose computed tomography (LDCT), and not immediately suspicious for lung cancer, tended to regress. Because some of these nodules may be slow-growing adenocarcinoma precursors, we evaluated long-term outcomes (after stopping the 1-year intervention) by annual LDCT. We analyzed the evolution of target and non-target trial nodules detected by LDCT in the budesonide and placebo arms up to 5 years after randomization. The numbers and characteristics of lung cancers diagnosed during follow-up were also analyzed. The mean maximum diameter of non-solid nodules reduced significantly (from 5.03 mm at baseline to 2.61 mm after 5 years) in the budesonide arm; there was no significant size change in the placebo arm. The mean diameter of partially solid lesions also decreased significantly, but only by 0.69 mm. The size of solid nodules did not change. Neither the number of new lesions nor the number of lung cancers differed in the two arms. Inhaled budesonide given for 1 year significantly decreased the size of non-solid nodules detected by screening LDCT after 5 years. This is of potential importance since some of these nodules may progress slowly to adenocarcinoma. However, further studies are required to assess clinical implications. NCT01540552. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Skin color and tissue thickness effects on transmittance, reflectance, and skin temperature when using 635 and 808 nm lasers in low intensity therapeutics.

PubMed

Souza-Barros, Leanna; Dhaidan, Ghaith; Maunula, Mikko; Solomon, Vaeda; Gabison, Sharon; Lilge, Lothar; Nussbaum, Ethne L

2018-04-01

To examine the role of skin color and tissue thickness on transmittance, reflectance, and skin heating using red and infrared laser light. Forty volunteers were measured for skin color and skin-fold thickness at a standardized site near the elbow. Transmittance, reflectance and skin temperature were recorded for energy doses of 2, 6, 9, and 12 Joules using 635 nm (36 mW) and 808 nm (40 mW) wavelength laser diodes with irradiances within American National Standards Institute safety guidelines (4.88 mm diameter, 0.192 W/cm 2 and 4.88 mm diameter, 0.214 W/cm 2 , respectively). The key factors affecting reflectance to an important degree were skin color and wavelength. However, the skin color effects were different for the two wavelengths: reflectance decreased for darker skin with a greater decrease for red light than near infrared light. Transmittance was greater using 808 nm compared with 635 nm. However, the effect was partly lost when the skin was dark rather than light, and was increasingly lost as tissue thickness increased. Dose had an increasing effect on temperature (0.7-1.6°C across the 6, 9, and 12 J doses); any effects of wavelength, skin color, and tissue thickness were insignificant compared to dose effects. Subjects themselves were not aware of the increased skin temperature. Transmittance and reflectance changes as a function of energy were very small and likely of no clinical significance. Absorption did not change with higher energy doses and increasing temperature. Skin color and skin thickness affect transmittance and reflectance of laser light and must be accounted for when selecting energy dose to ensure therapeutic effectiveness at the target tissue. Skin heating appears not to be a concern when using 635 and 808 nm lasers at energy doses of up to 12 J and irradiance within American National Standards Institute standards. Photobiomodulation therapy should never exceed the American National Standards Institute recommendation for the maximum permissible exposure to the skin. Lasers Surg. Med. 50:291-301, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Dose and Dose Risk Caused by Natural Phenomena - Proposed Powder Metallurgy Core Manufacturing Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holmes, W.G.

2001-08-16

The offsite radiological effects from high velocity straight winds, tornadoes, and earthquakes have been estimated for a proposed facility for manufacturing enriched uranium fuel cores by powder metallurgy. Projected doses range up to 30 mrem/event to the maximum offsite individual for high winds and up to 85 mrem/event for very severe earthquakes. Even under conservative assumptions on meteorological conditions, the maximum offsite dose would be about 20 per cent of the DOE limit for accidents involving enriched uranium storage facilities. The total dose risk is low and is dominated by the risk from earthquakes. This report discusses this test.

Fast neutron dosemeter using pixelated detector Timepix.

PubMed

Bulanek, Boris; Ekendahl, Daniela; Prouza, Zdenek

2014-10-01

A Timepix detector covered with polyethylene convertors of different thicknesses is presented as a fast neutron real-time dosemeter. The application of different weighting factors in connection with the position of a signal in a Timepix detector enables one to obtain an energy-dependent signal equal to neutron dose equivalents. A simulation of a Timepix detector covered with polyethylene convertors using monoenergetic neutrons is presented. The experimental set-up of a dosemeter was also produced. The first results of detector response using different fast neutron sources are presented. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Clinical assessment of the jaw-tracking function in IMRT for a brain tumor

NASA Astrophysics Data System (ADS)

Kim, Jin-Young; Kim, Shin-Wook; Choe, Bo-Young; Suh, Tae-Suk; Park, Sung-Kwang; Jo, Sun-Mi; Oh, Won-Yong; Shin, Jung-Wook; Cho, Gyu-Seok; Nam, Sang-Hee; Chung, Jin-Beom; Kim, Jung-Ki; Lee, Young-Kyu

2015-01-01

Intensity-modulated radiotherapy (IMRT) improves dose conformity and saves critical organs. IMRT is widely used in cases of head and neck, prostate, and brain cancer due to the close location of the targets to critical structures. However, because IMRT has a larger amount of radiation exposure than 3 dimensional-conformal radiation therapy (3D-CRT), it has disadvantages such as increases in the low dose irradiation to normal tissues and in the accumulated dose for the whole volume due to leakage and transmission of the multi-leaf collimator (MLC). The increased accumulated dose and the larger low dose may increase the occurrence of secondary malignant neoplasms. For these reasons, the jaw-tracking function of the TrueBeam (Varian Medical Systems, Palo Alto, CA) was developed to reduce the leakage and the transmission dose of the MLC with linear accelerators. However, the change in the superficial dose has not been verified with a quantitative analysis of the dose reduction in a brain tumor. Therefore, in the present study, we intended to verify the clinical possibility of utilizing the jaw-tracking function for a brain tumor by comparing treatment plans and superficial doses. To accomplish this, we made three types of original treatment plans using Eclipse11 (Varian Medical Systems, Palo Alto, CA): 1) farther than 2 cm from the organs at risk (OAR); 2) within 2 cm of the OAR; and 3) intersecting with the OAR. Jaw-tracking treatment plans were also made with copies of the original treatment plan using Smart LMC Version 11.0.31 (Varian Medical Systems, Palo Alto, CA). A comparison between the original treatment plans and jaw-tracking treatment plans was performed using the difference of the mean dose and maximum dose to the OARs in cumulative Dose Volume Histogram (DVH). In addition, the dependencies of the effects of transmission and the scattering doses according to jaw motion were assessed through the difference in the surface doses. In the DVH comparison, a maximum dose difference of 0.4% was observed between the planning methods in the case of over 2 cm distance, and the maximum dose of 0.6% was obtained for within the 2 cm distance. For the case intersecting with the OAR, the maximum dose difference of 2.3% was achieved. According to these results, the differences in the mean doses and the maximum doses to the OARs ware larger when the OARs and the planning target volume (PTV) were closer. In addition, small differences in the surface dose measurements were observed. In the case of the inside field, the differences were under 2% of the prescription dose while the difference was under 0.1% in the case of the outside field. Therefore, treatment plans with the jaw-tracking function consistently affected the dose reduction for a brain tumor, and the clinical possibility could be verified as the surface dose was not increased.

On stabilization of field emission and increase in the current density of planar nanostructures with DLC films

NASA Astrophysics Data System (ADS)

Yakunin, Alexander N.; Aban'shin, Nikolay P.; Avetisyan, Yuri A.; Akchurin, Georgy G.; Loginov, Alexander P.; Mosiyash, Denis S.; Akchurin, Garif G.

2018-04-01

The paper provides a justification and a comparative analysis of the scaling directions of the developed and investigated planar triode field emission cathode unit with the aim of increasing the maximum field current density up to 0.75 A-cm-2 without sacrificing durability. The design features of the vacuum device with a planar structure provided low-voltage control - at 150 V in the mode of long-term durability and not more than 250 V in the mode of the maximum permissible emission current.

Fluoride in the drinking water of Nagaur tehsil of Nagaur District, Rajasthan, India.

PubMed

Arif, M; Hussain, I; Hussain, J; Sharma, S; Kumar, S

2012-06-01

Fluoride concentration of groundwater samples from 100 villages of Nagaur tehsil was determined, 85 villages were found to have fluoride concentration more than 1.5 mg/L. The maximum fluoride concentration was recorded 6.6 mg/L in groundwater of Singhani village, while the minimum was recorded in Kurchhi village. As per the desirable and maximum permissible limit for fluoride in drinking water, determined by World Health Organization, the groundwater of about 85 villages of the studied sites is unfit for drinking purpose.

Developability assessment of clinical drug products with maximum absorbable doses.

PubMed

Ding, Xuan; Rose, John P; Van Gelder, Jan

2012-05-10

Maximum absorbable dose refers to the maximum amount of an orally administered drug that can be absorbed in the gastrointestinal tract. Maximum absorbable dose, or D(abs), has proved to be an important parameter for quantifying the absorption potential of drug candidates. The purpose of this work is to validate the use of D(abs) in a developability assessment context, and to establish appropriate protocol and interpretation criteria for this application. Three methods for calculating D(abs) were compared by assessing how well the methods predicted the absorption limit for a set of real clinical candidates. D(abs) was calculated for these clinical candidates by means of a simple equation and two computer simulation programs, GastroPlus and an program developed at Eli Lilly and Company. Results from single dose escalation studies in Phase I clinical trials were analyzed to identify the maximum absorbable doses for these compounds. Compared to the clinical results, the equation and both simulation programs provide conservative estimates of D(abs), but in general D(abs) from the computer simulations are more accurate, which may find obvious advantage for the simulations in developability assessment. Computer simulations also revealed the complex behavior associated with absorption saturation and suggested in most cases that the D(abs) limit is not likely to be achieved in a typical clinical dose range. On the basis of the validation findings, an approach is proposed for assessing absorption potential, and best practices are discussed for the use of D(abs) estimates to inform clinical formulation development strategies. Copyright © 2012 Elsevier B.V. All rights reserved.

Individual dose adjustment of riociguat in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension.

PubMed

Hill, Nicholas S; Rahaghi, Franck F; Sood, Namita; Frey, Reiner; Ghofrani, Hossein-Ardeschir

2017-08-01

Riociguat is a soluble guanylate cyclase stimulator that has been approved for the treatment of pulmonary arterial hypertension and inoperable chronic thromboembolic pulmonary hypertension or persistent/recurrent pulmonary hypertension following pulmonary endarterectomy. Riociguat is administered using an 8-week individual dose-adjustment scheme whereby a patient initially receives riociguat 1.0 mg three times daily (tid), and the dose is then increased every 2 weeks in the absence of hypotension, indicated by systolic blood pressure measurements and symptoms, up to a maximum dose of 2.5 mg tid. The established riociguat dose-adjustment scheme allows the dose of riociguat to be individually optimized in terms of tolerability and efficacy. The majority of patients in the phase III clinical trials and their long-term extension phases achieved the maximum riociguat dose, whereas some patients remained on lower doses. There is evidence that these patients may experience benefits at riociguat doses lower than 2.5 mg tid, with improvement in exercise capacity being observed after only 2-4 weeks of treatment in the phase III studies and in the exploratory 1.5 mg-maximum patient group of PATENT-1. This review aims to provide an overview of the rationale behind the riociguat dose-adjustment scheme and examine its application to both clinical trials and real-life clinical practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

FIRST EURADOS INTERCOMPARISON EXERCISE OF EYE LENS DOSEMETERS FOR MEDICAL APPLICATIONS.

PubMed

Clairand, I; Ginjaume, M; Vanhavere, F; Carinou, E; Daures, J; Denoziere, M; Silva, E H; Roig, M; Principi, S; Van Rycheghem, L

2016-09-01

In the context of the decrease in the eye lens dose limit for occupational exposure to 20 mSv per year stated by the recent revision of the European Basic Safety Standards Directive 2013/59/EURATOM, the European Radiation Dosimetry Group (EURADOS) has organised in 2014, for the first time, an intercomparison exercise for eye lens dosemeters. The main objective was to assess the capabilities of the passive eye lens dosemeters currently in use in Europe for occupational monitoring in medical fields. A total of 20 European individual monitoring services from 15 different countries have participated. The dosemeters provided by the participants were all composed of thermoluminescent detectors, of various types and designs. The irradiations were carried out with several photon fields chosen to cover the energy and angle ranges encountered in medical workplace. Participants were asked to report the doses in terms of Hp(3) using their routine protocol. The results provided by each participant were compared with the reference delivered doses. All the results were anonymously analysed. Results are globally satisfactory since, among the 20 participants, 17 were able to provide 90 % of their response in accordance with the ISO 14146 standard requirements. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

GHSI EMERGENCY RADIONUCLIDE BIOASSAY LABORATORY NETWORK: SUMMARY OF A RECENT EXERCISE.

PubMed

Li, Chunsheng; Ansari, Armin; Bartizel, Christine; Battisti, Paolo; Franck, Didier; Gerstmann, Udo; Giardina, Isabella; Guichet, Claude; Hammond, Derek; Hartmann, Martina; Jones, Robert L; Kim, Eunjoo; Ko, Raymond; Morhard, Ryan; Quayle, Deborah; Sadi, Baki; Saunders, David; Paquet, Francois

2016-11-01

The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop their collective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency. A recent exercise was conducted to test the participating laboratories for their capabilities in screening and in vitro assay of biological samples, performing internal dose assessment and providing advice on medical intervention, if necessary, using a urine sample spiked with a single radionuclide, 241 Am. The laboratories were required to submit their reports according to the exercise schedule and using pre-formatted templates. Generally, the participating laboratories were found to be capable with respect to rapidly screening samples for radionuclide contamination, measuring the radionuclide in the samples, assessing the intake and radiation dose, and providing advice on medical intervention. However, gaps in bioassay measurement and dose assessment have been identified. The network may take steps to ensure that procedures and practices within this network be harmonised and a follow-up exercise be organised on a larger scale, with potential participation of laboratories from the networks coordinated by the International Atomic Energy Agency and the World Health Organization. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

STUDY OF NATURAL RADIOACTIVITY (226Ra, 232Th AND 40K) IN SOIL SAMPLES FOR THE ASSESSMENT OF AVERAGE EFFECTIVE DOSE AND RADIATION HAZARDS.

PubMed

Bangotra, Pargin; Mehra, Rohit; Kaur, Kirandeep; Jakhu, Rajan

2016-10-01

The activity concentration of 226 Ra (radium), 232 Th (thorium) and 40 K (potassium) has been measured in the soil samples collected from Mansa and Muktsar districts of Punjab (India) using NaI (Tikl) gamma detector. The concentration of three radionuclides ( 226 Ra, 232 Th and 40 K) in the studied area has been varied from 18±4 to 46±5, 53±7 to 98±8 and 248±54 to 756±110 Bq kg -1 , respectively. Radium equivalent activities (Ra eq ) have been calculated in soil samples for the assessment of the radiation hazards arising due to the use of these soil samples. The absorbed dose rate of 226 Ra, 232 Th and 40 K in studied area has been varied from 8 to 21, 33 to 61 and 9 to 25 nGy h -1 , respectively. The corresponding indoor and outdoor annual effective dose in studied area was 0.38 and 0.09 mSv, respectively. The external and internal hazard has been also calculated for the assessment of radiation hazards in the studied area. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

THE EFFECT OF BACKGROUND SIGNAL AND ITS REPRESENTATION IN DECONVOLUTION OF EPR SPECTRA ON ACCURACY OF EPR DOSIMETRY IN BONE.

PubMed

Ciesielski, Bartlomiej; Marciniak, Agnieszka; Zientek, Agnieszka; Krefft, Karolina; Cieszyński, Mateusz; Boguś, Piotr; Prawdzik-Dampc, Anita

2016-12-01

This study is about the accuracy of EPR dosimetry in bones based on deconvolution of the experimental spectra into the background (BG) and the radiation-induced signal (RIS) components. The model RIS's were represented by EPR spectra from irradiated enamel or bone powder; the model BG signals by EPR spectra of unirradiated bone samples or by simulated spectra. Samples of compact and trabecular bones were irradiated in the 30-270 Gy range and the intensities of their RIS's were calculated using various combinations of those benchmark spectra. The relationships between the dose and the RIS were linear (R 2  > 0.995), with practically no difference between results obtained when using signals from irradiated enamel or bone as the model RIS. Use of different experimental spectra for the model BG resulted in variations in intercepts of the dose-RIS calibration lines, leading to systematic errors in reconstructed doses, in particular for high- BG samples of trabecular bone. These errors were reduced when simulated spectra instead of the experimental ones were used as the benchmark BG signal in the applied deconvolution procedures. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The QDREC web server: determining dose-response characteristics of complex macroparasites in phenotypic drug screens.

PubMed

Asarnow, Daniel; Rojo-Arreola, Liliana; Suzuki, Brian M; Caffrey, Conor R; Singh, Rahul

2015-05-01

Neglected tropical diseases (NTDs) caused by helminths constitute some of the most common infections of the world's poorest people. The etiological agents are complex and recalcitrant to standard techniques of molecular biology. Drug screening against helminths has often been phenotypic and typically involves manual description of drug effect and efficacy. A key challenge is to develop automated, quantitative approaches to drug screening against helminth diseases. The quantal dose-response calculator (QDREC) constitutes a significant step in this direction. It can be used to automatically determine quantitative dose-response characteristics and half-maximal effective concentration (EC50) values using image-based readouts from phenotypic screens, thereby allowing rigorous comparisons of the efficacies of drug compounds. QDREC has been developed and validated in the context of drug screening for schistosomiasis, one of the most important NTDs. However, it is equally applicable to general phenotypic screening involving helminths and other complex parasites. QDREC is publically available at: http://haddock4.sfsu.edu/qdrec2/. Source code and datasets are at: http://tintin.sfsu.edu/projects/phenotypicAssays.html. rahul@sfsu.edu. Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Multileaf collimator tongue-and-groove effect on depth and off-axis doses: A comparison of treatment planning data with measurements and Monte Carlo calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hee Jung; Department of Biomedical Engineering, Seoul National University, Seoul; Department of Radiation Oncology, Soonchunhyang University Hospital, Seoul

2015-01-01

To investigate how accurately treatment planning systems (TPSs) account for the tongue-and-groove (TG) effect, Monte Carlo (MC) simulations and radiochromic film (RCF) measurements were performed for comparison with TPS results. Two commercial TPSs computed the TG effect for Varian Millennium 120 multileaf collimator (MLC). The TG effect on off-axis dose profile at 3 depths of solid water was estimated as the maximum depth and the full width at half maximum (FWHM) of the dose dip at an interleaf position. When compared with the off-axis dose of open field, the maximum depth of the dose dip for MC and RCF rangedmore » from 10.1% to 20.6%; the maximum depth of the dose dip gradually decreased by up to 8.7% with increasing depths of 1.5 to 10 cm and also by up to 4.1% with increasing off-axis distances of 0 to 13 cm. However, TPS results showed at most a 2.7% decrease for the same depth range and a negligible variation for the same off-axis distances. The FWHM of the dose dip was approximately 0.19 cm for MC and 0.17 cm for RCF, but 0.30 cm for Eclipse TPS and 0.45 cm for Pinnacle TPS. Accordingly, the integrated value of TG dose dip for TPS was larger than that for MC and RCF and almost invariant along the depths and off-axis distances. We concluded that the TG dependence on depth and off-axis doses shown in the MC and RCF results could not be appropriately modeled by the TPS versions in this study.« less

Confusion: acetaminophen dosing changes based on NO evidence in adults.

PubMed

Krenzelok, Edward P; Royal, Mike A

2012-06-01

Acetaminophen (paracetamol) plays a vital role in American health care, with in excess of 25 billion doses being used annually as a nonprescription medication. Over 200 million acetaminophen-containing prescriptions, usually in combination with an opioid, are dispensed annually. While acetaminophen is recognized as a safe and effective analgesic and antipyretic, it is also associated with significant morbidity and mortality (hepatotoxicity) if doses in excess of the therapeutic amount are ingested inappropriately. The maximum daily therapeutic dose of 3900-4000 mg was established in separate actions in 1977 and 1988, respectively, via the Food and Drug Administration (FDA) monograph process for nonprescription medications. The FDA has conducted multiple advisory committee meetings to evaluate acetaminophen and its safety profile, and has suggested (but not mandated) a reduction in the maximum daily dosage from 3900-4000 mg to 3000-3250 mg. In 2011, McNeil, the producer of the Tylenol® brand of acetaminophen, voluntarily reduced the maximum daily dose of its 500 mg tablet product to 3000 mg/day, and it has pledged to change the labeling of its 325 mg/tablet product to reflect a maximum of 3250 mg/day. Generic manufacturers have not changed their dosing regimens and they have remained consistent with the established monograph dose. Therefore, confusion will be inevitable as both consumers and health care professionals try to determine the proper therapeutic dose of acetaminophen. Which is the correct dose of acetaminophen: 3000 mg if 500 mg tablets are used, 3250 mg with 325 mg tablets, or 3900 mg when 650 mg arthritis-strength products are used?

Influence of lead apron shielding on absorbed doses from cone-beam computed tomography.

PubMed

Rottke, Dennis; Andersson, Jonas; Ejima, Ken-Ichiro; Sawada, Kunihiko; Schulze, Dirk

2017-06-01

The aim of the present work was to investigate absorbed and to calculate effective doses (EDs) in cone-beam computed tomography (CBCT). The study was conducted using examination protocols with and without lead apron shielding. A full-body male RANDO® phantom was loaded with 110 GR200A thermoluminescence dosemeter chips at 55 different sites and set up in two different CBCT systems (CS 9500®, ProMax® 3D). Two different protocols were performed: the phantom was set up (1) with and (2) without a lead apron. No statistically significant differences in organ and absorbed doses from regions outside the primary beam could be found when comparing results from exposures with and without lead apron shielding. Consequently, calculating the ED showed no significant differences between the examination protocols with and without lead apron shielding. For the ProMax® 3D with shielding, the ED was 149 µSv, and for the examination protocol without shielding 148 µSv (SD = 0.31 µSv). For the CS 9500®, the ED was 88 and 86 µSv (SD = 0.95 µSv), respectively, with and without lead apron shielding. The results revealed no statistically significant differences in the absorbed doses between examination with and without lead apron shielding, especially in organs outside the primary beam. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The modified unified interaction model: incorporation of dose-dependent localised recombination.

PubMed

Lavon, A; Eliyahu, I; Oster, L; Horowitz, Y S

2015-02-01

The unified interaction model (UNIM) was developed to simulate thermoluminescence (TL) linear/supralinear dose-response and the dependence of the supralinearity on ionisation density, i.e. particle type and energy. Before the development of the UNIM, this behaviour had eluded all types of TL modelling including conduction band/valence band (CB/VB) kinetic models. The dependence of the supralinearity on photon energy was explained in the UNIM as due to the increasing role of geminate (localised recombination) with decreasing photon/electron energy. Recently, the Ben Gurion University group has incorporated the concept of trapping centre/luminescent centre (TC/LC) spatially correlated complexes and localised/delocalised recombination into the CB/VB kinetic modelling of the LiF:Mg,Ti system. Track structure considerations are used to describe the relative population of the TC/LC complexes by an electron-hole or by an electron-only as a function of both photon/electron energy and dose. The latter dependence was not included in the original UNIM formulation, a significant over-simplification that is herein corrected. The modified version, the M-UNIM, is then applied to the simulation of the linear/supralinear dose-response characteristics of composite peak 5 in the TL glow curve of LiF:Mg,Ti at two representative average photon/electron energies of 500 and 8 keV. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Safety and Immunogenicity of Cell Culture-Derived A/H3N2 Variant Influenza Vaccines: A Phase I Randomized, Observer-Blind, Dose-Ranging Study.

PubMed

Johnson, Casey; Hohenboken, Matthew; Poling, Terry; Jaehnig, Peter; Kanesa-Thasan, Niranjan

2015-07-01

A/H3N2 variant (H3N2v) influenza may sustain human-to-human transmission, and an available candidate vaccine would be important. In this phase I, randomized, observer-blind, dose-ranging study, 627 healthy subjects ≥ 3 years of age were randomized to receive 2 vaccinations with H3N2c cell-culture-derived vaccine doses containing 3.75 µg, 7.5 µg, or 15 µg hemagglutinin antigen of H3N2v with or without MF59 (registered trademark of Novartis AG) adjuvant (an oil-in-water emulsion). This paper reports Day 43 planned interim data. Single MF59-adjuvanted H3N2c doses elicited immune responses in almost all subjects regardless of antigen and adjuvant dose; the Center for Biologics Evaluation Research and Review (CBER) licensure criteria were met for all groups. Subjects with prevaccination hemagglutination inhibition titers <10 and children 3-<9 years achieve CBER criteria only after receiving 2 doses of nonadjuvanted H3N2c vaccine. Highest antibody titers were observed in the 7.5 µg + 0.25 mL MF59 groups in all age cohorts. MF59-adjuvanted H3N2c vaccines showed the highest rates of solicited local and systemic events, predominately mild or moderate. A single dose of H3N2c vaccine may be immunogenic and supports further development of MF59-adjuvanted H3N2c vaccines, especially for pediatric populations. ClinicalTrials.gov identifier NCT01855945 (http://clinicaltrials.gov/ct2/show/NCT01855945). © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

MutAIT: an online genetic toxicology data portal and analysis tools.

PubMed

Avancini, Daniele; Menzies, Georgina E; Morgan, Claire; Wills, John; Johnson, George E; White, Paul A; Lewis, Paul D

2016-05-01

Assessment of genetic toxicity and/or carcinogenic activity is an essential element of chemical screening programs employed to protect human health. Dose-response and gene mutation data are frequently analysed by industry, academia and governmental agencies for regulatory evaluations and decision making. Over the years, a number of efforts at different institutions have led to the creation and curation of databases to house genetic toxicology data, largely, with the aim of providing public access to facilitate research and regulatory assessments. This article provides a brief introduction to a new genetic toxicology portal called Mutation Analysis Informatics Tools (MutAIT) (www.mutait.org) that provides easy access to two of the largest genetic toxicology databases, the Mammalian Gene Mutation Database (MGMD) and TransgenicDB. TransgenicDB is a comprehensive collection of transgenic rodent mutation data initially compiled and collated by Health Canada. The updated MGMD contains approximately 50 000 individual mutation spectral records from the published literature. The portal not only gives access to an enormous quantity of genetic toxicology data, but also provides statistical tools for dose-response analysis and calculation of benchmark dose. Two important R packages for dose-response analysis are provided as web-distributed applications with user-friendly graphical interfaces. The 'drsmooth' package performs dose-response shape analysis and determines various points of departure (PoD) metrics and the 'PROAST' package provides algorithms for dose-response modelling. The MutAIT statistical tools, which are currently being enhanced, provide users with an efficient and comprehensive platform to conduct quantitative dose-response analyses and determine PoD values that can then be used to calculate human exposure limits or margins of exposure. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Double oral esomeprazole after a 3-day intravenous esomeprazole infusion reduces recurrent peptic ulcer bleeding in high-risk patients: a randomised controlled study.

PubMed

Cheng, Hsiu-Chi; Wu, Chung-Tai; Chang, Wei-Lun; Cheng, Wei-Chun; Chen, Wei-Ying; Sheu, Bor-Shyang

2014-12-01

Patients with high Rockall scores have increased risk of ulcer rebleeding after 3-day esomeprazole infusions. To investigate whether double oral esomeprazole given after a 3-day esomeprazole infusion decreases ulcer rebleeding for patients with high Rockall scores. We prospectively enrolled 293 patients with peptic ulcer bleeding who had achieved endoscopic haemostasis. After a 3-day esomeprazole infusion, patients with Rockall scores ≥6 were randomised into the oral double-dose group (n=93) or the oral standard-dose group (n=94) to receive 11 days of oral esomeprazole 40 mg twice daily or once daily, respectively. The patients with Rockall scores <6 served as controls (n=89); they received 11 days of oral esomeprazole 40 mg once daily. Thereafter, all patients received oral esomeprazole 40 mg once daily for two more weeks until the end of the 28-day study period. The primary end point was peptic ulcer rebleeding. Among patients with Rockall scores ≥6, the oral double-dose group had a higher cumulative rebleeding-free proportion than the oral standard-dose group (p=0.02, log-rank test). The proportion of patients free from recurrent bleeding during the 4th-28th day in the oral double-dose group remained lower than that of the group with Rockall scores <6 (p=0.03, log-rank test). Among patients with Rockall scores ≥6, the rebleeding rate was lower in the oral double-dose group than in the oral standard-dose group (4th-28th day: 10.8% vs 28.7%, p=0.002). Double oral esomeprazole at 40 mg twice daily after esomeprazole infusion reduced recurrent peptic ulcer bleeding in high-risk patients with Rockall scores ≥6. NCT01591083. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Changes in the biological activity of heavy metal- and oil-polluted soils in urban recreation territories

NASA Astrophysics Data System (ADS)

Trifonova, T. A.; Zabelina, O. N.

2017-04-01

Urban recreation areas of different sizes were investigated in the city of Vladimir. The degree of their contamination with heavy metals and oil products was revealed. The content of heavy metals exceeded their maximum permissible concentrations by more than 2.5 times. The total content of heavy metals decreased in the sequence: Zn > Pb > Co > Mn > Cr > Ni. The mass fraction of oil products in the studied soils varied within the range of 0.016-0.28 mg/g. The reaction of soils in public gardens and a boulevard was neutral or close to neutral; in some soil samples, it was weakly alkaline. The top layer of all the soils significantly differed from the lower one by the higher alkalinity promoting the deposition of heavy metals there. As the content of Ni, Co, and Mn increased and exceeded the background concentrations, but did not reach the three-fold value of the maximum permissible concentrations, the activity of catalase was intensified. The stimulating effect of nickel on the catalase activity was mostly pronounced at the neutral soil reaction. The urease activity increased when heavy metals and oil products were present together in the concentrations above the background ones, but not higher than the three-fold maximal permissible concentrations for heavy metals and 0.3 mg/g for the content of oil products. The nitrifying activity was inhibited by oil hydrocarbons that were recorded in the soils in different amounts.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Heng, E-mail: hengli@mdanderson.org; Zhu, X. Ronald; Zhang, Xiaodong

Purpose: To develop and validate a novel delivery strategy for reducing the respiratory motion–induced dose uncertainty of spot-scanning proton therapy. Methods and Materials: The spot delivery sequence was optimized to reduce dose uncertainty. The effectiveness of the delivery sequence optimization was evaluated using measurements and patient simulation. One hundred ninety-one 2-dimensional measurements using different delivery sequences of a single-layer uniform pattern were obtained with a detector array on a 1-dimensional moving platform. Intensity modulated proton therapy plans were generated for 10 lung cancer patients, and dose uncertainties for different delivery sequences were evaluated by simulation. Results: Without delivery sequence optimization,more » the maximum absolute dose error can be up to 97.2% in a single measurement, whereas the optimized delivery sequence results in a maximum absolute dose error of ≤11.8%. In patient simulation, the optimized delivery sequence reduces the mean of fractional maximum absolute dose error compared with the regular delivery sequence by 3.3% to 10.6% (32.5-68.0% relative reduction) for different patients. Conclusions: Optimizing the delivery sequence can reduce dose uncertainty due to respiratory motion in spot-scanning proton therapy, assuming the 4-dimensional CT is a true representation of the patients' breathing patterns.« less

A comparison of skin and chest wall dose delivered with multicatheter, Contura multilumen balloon, and MammoSite breast brachytherapy.

PubMed

Cuttino, Laurie W; Todor, Dorin; Rosu, Mihaela; Arthur, Douglas W

2011-01-01

Skin and chest wall doses have been correlated with toxicity in patients treated with breast brachytherapy . This investigation compared the ability to control skin and chest wall doses between patients treated with multicatheter (MC), Contura multilumen balloon (CMLB), and MammoSite (MS) brachytherapy. 43 patients treated with the MC technique, 45 patients treated with the CMLB, and 83 patients treated with the MS were reviewed. The maximum doses delivered to the skin and chest wall were calculated for all patients. The mean maximum skin doses for the MC, CMLB, and MS were 2.3 Gy (67% of prescription dose), 2.8 Gy (82% of prescription dose), and 3.2 Gy per fraction (94% of prescription dose), respectively. Although the skin distances were similar (p = 0.23) for the two balloon techniques, the mean skin dose with the CMLB was significantly lower than with the MS (p = 0.05). The mean maximum rib doses for the MC, CMLB, and MS were 2.3 Gy (67% of prescription dose), 2.8 Gy (82% of prescription dose), and 3.6 Gy per fraction (105% of prescription dose), respectively. Again, the mean rib dose with the CMLB was significantly lower than with the MS (p = 0.002). The MC and CMLB techniques are associated with significantly lower mean skin and rib doses than is the MS. Treatment with the MS was associated with significantly more patients receiving doses to the skin or rib in excess of 125% of the prescription. Treatment with the CMLB may prove to yield less normal tissue toxicity than treatment with the MS. Copyright © 2011 Elsevier Inc. All rights reserved.

A Comparison of Skin and Chest Wall Dose Delivered With Multicatheter, Contura Multilumen Balloon, and MammoSite Breast Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cuttino, Laurie W., E-mail: lcuttino@mcvh-vcu.ed; Todor, Dorin; Rosu, Mihaela

2011-01-01

Purpose: Skin and chest wall doses have been correlated with toxicity in patients treated with breast brachytherapy . This investigation compared the ability to control skin and chest wall doses between patients treated with multicatheter (MC), Contura multilumen balloon (CMLB), and MammoSite (MS) brachytherapy. Methods and Materials: 43 patients treated with the MC technique, 45 patients treated with the CMLB, and 83 patients treated with the MS were reviewed. The maximum doses delivered to the skin and chest wall were calculated for all patients. Results: The mean maximum skin doses for the MC, CMLB, and MS were 2.3 Gy (67%more » of prescription dose), 2.8 Gy (82% of prescription dose), and 3.2 Gy per fraction (94% of prescription dose), respectively. Although the skin distances were similar (p = 0.23) for the two balloon techniques, the mean skin dose with the CMLB was significantly lower than with the MS (p = 0.05). The mean maximum rib doses for the MC, CMLB, and MS were 2.3 Gy (67% of prescription dose), 2.8 Gy (82% of prescription dose), and 3.6 Gy per fraction (105% of prescription dose), respectively. Again, the mean rib dose with the CMLB was significantly lower than with the MS (p = 0.002). Conclusion: The MC and CMLB techniques are associated with significantly lower mean skin and rib doses than is the MS. Treatment with the MS was associated with significantly more patients receiving doses to the skin or rib in excess of 125% of the prescription. Treatment with the CMLB may prove to yield less normal tissue toxicity than treatment with the MS.« less

49 CFR 178.811 - Bottom lift test.

Code of Federal Regulations, 2014 CFR

2014-10-01

... design types designed to be lifted from the base, there may be no permanent deformation which renders the IBC unsafe for transportation and no loss of contents. [Amdt. 178-103, 59 FR 38074, July 26, 1994, as... IBC must be loaded to 1.25 times its maximum permissible gross mass, the load being evenly distributed...

49 CFR 178.811 - Bottom lift test.

Code of Federal Regulations, 2012 CFR

2012-10-01

... design types designed to be lifted from the base, there may be no permanent deformation which renders the IBC unsafe for transportation and no loss of contents. [Amdt. 178-103, 59 FR 38074, July 26, 1994, as... IBC must be loaded to 1.25 times its maximum permissible gross mass, the load being evenly distributed...

49 CFR 178.811 - Bottom lift test.

Code of Federal Regulations, 2011 CFR

2011-10-01

... design types designed to be lifted from the base, there may be no permanent deformation which renders the IBC unsafe for transportation and no loss of contents. [Amdt. 178-103, 59 FR 38074, July 26, 1994, as... IBC must be loaded to 1.25 times its maximum permissible gross mass, the load being evenly distributed...

49 CFR 178.811 - Bottom lift test.

Code of Federal Regulations, 2013 CFR

2013-10-01

... design types designed to be lifted from the base, there may be no permanent deformation which renders the IBC unsafe for transportation and no loss of contents. [Amdt. 178-103, 59 FR 38074, July 26, 1994, as... IBC must be loaded to 1.25 times its maximum permissible gross mass, the load being evenly distributed...

Effects of isoconcentration surface threshold values on the characteristics of needle-shaped precipitates in atom probe tomography data from an aged Al-Mg-Si alloy.

PubMed

Aruga, Yasuhiro; Kozuka, Masaya

2016-04-01

Needle-shaped precipitates in an aged Al-0.62Mg-0.93Si (mass%) alloy were identified using a compositional threshold method, an isoconcentration surface, in atom probe tomography (APT). The influence of thresholds on the morphological and compositional characteristics of the precipitates was investigated. Utilizing optimum parameters for the concentration space, a reliable number density of the precipitates is obtained without dependence on the elemental concentration threshold in comparison with evaluation by transmission electron microscopy (TEM). It is suggested that careful selection of the concentration space in APT can lead to a reasonable average Mg/Si ratio for the precipitates. It was found that the maximum length and maximum diameter of the precipitates are affected by the elemental concentration threshold. Adjustment of the concentration threshold gives better agreement with the precipitate dimensions measured by TEM. © The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Evaluation of Benzo[a]pyrene in Food from China by High-Performance Liquid Chromatography-Fluorescence Detection

PubMed Central

Chen, Yong-Hong; Xia, En-Qin; Xu, Xiang-Rong; Li, Sha; Ling, Wen-Hua; Wu, Shan; Deng, Gui-Fang; Zou, Zhi-Fei; Zhou, Jing; Li, Hua-Bin

2012-01-01

The occurrence and levels of benzo[a]pyrene in various heat-treated foods from China were evaluated by high-performance liquid chromatography-fluorescence detection. In a total of 119 samples, 105 were found to contain benzo[a]pyrene at levels of 0.03 to 19.75 µg/kg. The benzo[a]pyrene contents in 12 animal source foods were higher than the Chinese maximum permissible level in food (5 µg/kg) and the highest level was 19.75 µg/kg, nearly four times the maximum permissible level. The results revealed a widespread carinogenic public health risk from benzo[a]pyrene in heat-treated foods. The highest benzo[a]pyrene levels were found in animal source samples such as charcoal-grilled and smoked meats, especially pork, beef and sausage, while trace levels of benzo[a]pyrene were present in grain food. Charcoal-grilled vegetables were found to also contain certain levels of benzo[a]pyrene. This study provided new information on benzo[a]pyrene content of a variety of heat-treated foods from China. PMID:23202838

Determining the maximum charging currents of lithium-ion cells for small charge quantities

NASA Astrophysics Data System (ADS)

Grimsmann, F.; Gerbert, T.; Brauchle, F.; Gruhle, A.; Parisi, J.; Knipper, M.

2017-10-01

In order to optimize the operating parameters of battery management systems for electric and hybrid vehicles, great interest has been shown in achieving the maximum permissible charging currents during recuperation, without causing a cell damage due to lithium plating, in relation to the temperature, charge quantity and state of charge. One method for determining these recuperation currents is measuring the cell thickness, where excessively high charging currents can be detected by an irreversible increase in thickness. It is not possible to measure particularly small charge quantities by employing mechanic dial indicators, which have a limited resolution of 1 μm. This is why we developed a measuring setup that has a resolution limit of less than 10 nm using a high-resolution contactless inductance sensor. Our results show that the permissible charging current I can be approximated in relation to the charge quantity x by a correlating function I =a /√{(x) } which is compliant with the Arrhenius law. Small charge quantities therefore have an optimization potential for energy recovery during recuperation.

Temporary Blinding Limits versus Maximum Permissible Exposure - A Paradigm Change in Risk Assessment for Visible Optical Radiation

NASA Astrophysics Data System (ADS)

Reidenbach, Hans-Dieter

Safety considerations in the field of laser radiation have traditionally been restricted to maximum permissible exposure levels defined as a function of wavelength and exposure duration. But in Europe according to the European Directive 2006/25/EC on artificial optical radiation the employer has to include in his risk assessment indirect effects from temporary blinding. Whereas sufficient knowledge on various deterministic risks exists, only sparse quantitative data is available for the impairment of visual functions due to temporary blinding from visible optical radiation. The consideration of indirect effects corresponds to a paradigm change in risk assessment when situations have to be treated, where intrabeam viewing of low-power laser radiation is likely or other non-coherent visible radiation might influence certain visual tasks. In order to obtain a sufficient basis for the assessment of certain situations, investigations of the functional relationships between wavelength, exposure time and optical power and the resulting interference on visual functions have been performed and the results are reported. The duration of a visual disturbance is thus predictable. In addition, preliminary information on protective measures is given.

An intelligent maximum permissible exposure meter for safety assessments of laser radiation

NASA Astrophysics Data System (ADS)

Corder, D. A.; Evans, D. R.; Tyrer, J. R.

1996-09-01

There is frequently a need to make laser power or energy density measurements when determining whether radiation from a laser system exceeds the Maximum Permissible Exposure (MPE) as defined in BS EN 60825. This can be achieved using standard commercially available laser power or energy measurement equipment, but some of these have shortcomings when used in this application. Calculations must be performed by the user to compare the measured value to the MPE. The measurement and calculation procedure appears complex to the nonexpert who may be performing the assessment. A novel approach is described which uses purpose designed hardware and software to simplify the process. The hardware is optimized for measuring the relatively low powers associated with MPEs. The software runs on a Psion Series 3a palmtop computer. This reduces the cost and size of the system yet allows graphical and numerical presentation of data. Data output to other software running on PCs is also possible, enabling the instrument to be used as part of a quality system. Throughout the measurement process the opportunity for user error has been minimized by the hardware and software design.

Quantifying the impact of immediate reconstruction in postmastectomy radiation: a large, dose-volume histogram-based analysis.

PubMed

Ohri, Nisha; Cordeiro, Peter G; Keam, Jennifer; Ballangrud, Ase; Shi, Weiji; Zhang, Zhigang; Nerbun, Claire T; Woch, Katherine M; Stein, Nicholas F; Zhou, Ying; McCormick, Beryl; Powell, Simon N; Ho, Alice Y

2012-10-01

To assess the impact of immediate breast reconstruction on postmastectomy radiation (PMRT) using dose-volume histogram (DVH) data. Two hundred forty-seven women underwent PMRT at our center, 196 with implant reconstruction and 51 without reconstruction. Patients with reconstruction were treated with tangential photons, and patients without reconstruction were treated with en-face electron fields and customized bolus. Twenty percent of patients received internal mammary node (IMN) treatment. The DVH data were compared between groups. Ipsilateral lung parameters included V20 (% volume receiving 20 Gy), V40 (% volume receiving 40 Gy), mean dose, and maximum dose. Heart parameters included V25 (% volume receiving 25 Gy), mean dose, and maximum dose. IMN coverage was assessed when applicable. Chest wall coverage was assessed in patients with reconstruction. Propensity-matched analysis adjusted for potential confounders of laterality and IMN treatment. Reconstruction was associated with lower lung V20, mean dose, and maximum dose compared with no reconstruction (all P<.0001). These associations persisted on propensity-matched analysis (all P<.0001). Heart doses were similar between groups (P=NS). Ninety percent of patients with reconstruction had excellent chest wall coverage (D95 >98%). IMN coverage was superior in patients with reconstruction (D95 >92.0 vs 75.7%, P<.001). IMN treatment significantly increased lung and heart parameters in patients with reconstruction (all P<.05) but minimally affected those without reconstruction (all P>.05). Among IMN-treated patients, only lower lung V20 in those without reconstruction persisted (P=.022), and mean and maximum heart doses were higher than in patients without reconstruction (P=.006, P=.015, respectively). Implant reconstruction does not compromise the technical quality of PMRT when the IMNs are untreated. Treatment technique, not reconstruction, is the primary determinant of target coverage and normal tissue doses. Published by Elsevier Inc.

Cosmic Radiation Exposure of Biological Test Systems During the EXPOSE-E Mission

PubMed Central

Hajek, Michael; Bilski, Pawel; Körner, Christine; Vanhavere, Filip; Reitz, Günther

2012-01-01

Abstract In the frame of the EXPOSE-E mission on the Columbus external payload facility EuTEF on board the International Space Station, passive thermoluminescence dosimeters were applied to measure the radiation exposure of biological samples. The detectors were located either as stacks next to biological specimens to determine the depth dose distribution or beneath the sample carriers to determine the dose levels for maximum shielding. The maximum mission dose measured in the upper layer of the depth dose part of the experiment amounted to 238±10 mGy, which relates to an average dose rate of 408±16 μGy/d. In these stacks of about 8 mm height, the dose decreased by 5–12% with depth. The maximum dose measured beneath the sample carriers was 215±16 mGy, which amounts to an average dose rate of 368±27 μGy/d. These values are close to those assessed for the interior of the Columbus module and demonstrate the high shielding of the biological experiments within the EXPOSE-E facility. Besides the shielding by the EXPOSE-E hardware itself, additional shielding was experienced by the external structures adjacent to EXPOSE-E, such as EuTEF and Columbus. This led to a dose gradient over the entire exposure area, from 215±16 mGy for the lowest to 121±6 mGy for maximum shielding. Hence, the doses perceived by the biological samples inside EXPOSE-E varied by 70% (from lowest to highest dose). As a consequence of the high shielding, the biological samples were predominantly exposed to galactic cosmic heavy ions, while electrons and a significant fraction of protons of the radiation belts and solar wind did not reach the samples. Key Words: Space radiation—Dosimetry—Passive radiation detectors—Thermoluminescence—EXPOSE-E. Astrobiology 12, 387–392. PMID:22680685

IDEAL-CRT: A Phase 1/2 Trial of Isotoxic Dose-Escalated Radiation Therapy and Concurrent Chemotherapy in Patients With Stage II/III Non-Small Cell Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Landau, David B., E-mail: david.landau@kcl.ac.uk; Hughes, Laura; Baker, Angela

2016-08-01

Purpose: To report toxicity and early survival data for IDEAL-CRT, a trial of dose-escalated concurrent chemoradiotherapy (CRT) for non-small cell lung cancer. Patients and Methods: Patients received tumor doses of 63 to 73 Gy in 30 once-daily fractions over 6 weeks with 2 concurrent cycles of cisplatin and vinorelbine. They were assigned to 1 of 2 groups according to esophageal dose. In group 1, tumor doses were determined by an experimental constraint on maximum esophageal dose, which was escalated following a 6 + 6 design from 65 Gy through 68 Gy to 71 Gy, allowing an esophageal maximum tolerated dose to be determined from early and late toxicities. Tumormore » doses for group 2 patients were determined by other tissue constraints, often lung. Overall survival, progression-free survival, tumor response, and toxicity were evaluated for both groups combined. Results: Eight centers recruited 84 patients: 13, 12, and 10, respectively, in the 65-Gy, 68-Gy, and 71-Gy cohorts of group 1; and 49 in group 2. The mean prescribed tumor dose was 67.7 Gy. Five grade 3 esophagitis and 3 grade 3 pneumonitis events were observed across both groups. After 1 fatal esophageal perforation in the 71-Gy cohort, 68 Gy was declared the esophageal maximum tolerated dose. With a median follow-up of 35 months, median overall survival was 36.9 months, and overall survival and progression-free survival were 87.8% and 72.0%, respectively, at 1 year and 68.0% and 48.5% at 2 years. Conclusions: IDEAL-CRT achieved significant treatment intensification with acceptable toxicity and promising survival. The isotoxic design allowed the esophageal maximum tolerated dose to be identified from relatively few patients.« less

High Doses of GM-CSF Inhibit Antibody Responses in Rectal Secretions and Diminish Modified Vaccinia Ankara/Simian Immunodeficiency Virus Vaccine Protection in TRIM5α-Restrictive Macaques.

PubMed

Kannanganat, Sunil; Wyatt, Linda S; Gangadhara, Sailaja; Chamcha, Venkatesarlu; Chea, Lynette S; Kozlowski, Pamela A; LaBranche, Celia C; Chennareddi, Lakshmi; Lawson, Benton; Reddy, Pradeep B J; Styles, Tiffany M; Vanderford, Thomas H; Montefiori, David C; Moss, Bernard; Robinson, Harriet L; Amara, Rama Rao

2016-11-01

We tested, in rhesus macaques, the effects of a 500-fold range of an admixed recombinant modified vaccinia Ankara (MVA) expressing rhesus GM-CSF (MVA/GM-CSF) on the immunogenicity and protection elicited by an MVA/SIV macaque 239 vaccine. High doses of MVA/GM-CSF did not affect the levels of systemic envelope (Env)-specific Ab, but it did decrease the expression of the gut-homing receptor α4β7 on plasmacytoid dendritic cells (p < 0.01) and the magnitudes of Env-specific IgA (p = 0.01) and IgG (p < 0.05) in rectal secretions. The protective effect of the vaccine was evaluated using 12 weekly rectal challenges in rhesus macaques subgrouped by tripartite motif-containing protein 5α (TRIM5α) genotypes that are restrictive or permissive for infection by the challenge virus SIVsmE660. Eight of nine TRIM5α-restrictive animals receiving no or the lowest dose (1 × 10 5 PFU) of MVA/GM-CSF resisted all 12 challenges. In the comparable TRIM5α-permissive group, only 1 of 12 animals resisted all 12 challenges. In the TRIM5α-restrictive animals, but not in the TRIM5α-permissive animals, the number of challenges to infection directly correlated with the magnitudes of Env-specific rectal IgG (r = +0.6) and IgA (r = +0.6), the avidity of Env-specific serum IgG (r = +0.5), and Ab dependent cell-mediated virus inhibition (r = +0.6). Titers of neutralizing Ab did not correlate with protection. We conclude that 1) protection elicited by MVA/SIVmac239 is strongly dependent on the presence of TRIM5α restriction, 2) nonneutralizing Ab responses contribute to protection against SIVsmE660 in TRIM5α-restrictive animals, and 3) high doses of codelivered MVA/GM-CSF inhibit mucosal Ab responses and the protection elicited by MVA expressing noninfectious SIV macaque 239 virus-like particles. Copyright © 2016 by The American Association of Immunologists, Inc.

Evaluation of the dependence of the exposure dose on the attenuation correction in brain PET/CT scans using 18F-FDG

NASA Astrophysics Data System (ADS)

Choi, Eun-Jin; Jeong, Moon-Taeg; Jang, Seong-Joo; Choi, Nam-Gil; Han, Jae-Bok; Yang, Nam-Hee; Dong, Kyung-Rae; Chung, Woon-Kwan; Lee, Yun-Jong; Ryu, Young-Hwan; Choi, Sung-Hyun; Seong, Kyeong-Jeong

2014-01-01

This study examined whether scanning could be performed with minimum dose and minimum exposure to the patient after an attenuation correction. A Hoffman 3D Brain Phantom was used in BIO_40 and D_690 PET/CT scanners, and the CT dose for the equipment was classified as a low dose (minimum dose), medium dose (general dose for scanning) and high dose (dose with use of contrast medium) before obtaining the image at a fixed kilo-voltage-peak (kVp) and milliampere (mA) that were adjusted gradually in 17-20 stages. A PET image was then obtained to perform an attenuation correction based on an attenuation map before analyzing the dose difference. Depending on tube current in the range of 33-190 milliampere-second (mAs) when BIO_40 was used, a significant difference in the effective dose was observed between the minimum and the maximum mAs (p < 0.05). According to a Scheffe post-hoc test, the ratio of the minimum to the maximum of the effective dose was increased by approximately 5.26-fold. Depending on the change in the tube current in the range of 10-200 mA when D_690 was used, a significant difference in the effective dose was observed between the minimum and the maximum of mA (p < 0.05). The Scheffe posthoc test revealed a 20.5-fold difference. In conclusion, because effective exposure dose increases with increasing operating current, it is possible to reduce the exposure limit in a brain scan can be reduced if the CT dose can be minimized for a transmission scan.

Implied Maximum Dose Analysis of Standard Values of 25 Pesticides Based on Major Human Exposure Pathways

PubMed Central

Li, Zijian; Jennings, Aaron A.

2017-01-01

Worldwide jurisdictions are making efforts to regulate pesticide standard values in residential soil, drinking water, air, and agricultural commodity to lower the risk of pesticide impacts on human health. Because human may exposure to pesticides from many ways, such as ingestion, inhalation, and dermal contact, it is important to examine pesticide standards by considering all major exposure pathways. Analysis of implied maximum dose limits for commonly historical and current used pesticides was adopted in this study to examine whether worldwide pesticide standard values are enough to prevent human health impact or not. Studies show that only U.S. has regulated pesticides standard in the air. Only 4% of the total number of implied maximum dose limits is based on three major exposures. For Chlorpyrifos, at least 77.5% of the total implied maximum dose limits are above the acceptable daily intake. It also shows that most jurisdictions haven't provided pesticide standards in all major exposures yet, and some of the standards are not good enough to protect human health. PMID:29546224

An exploration of knowledge, attitudes and behaviours of young multiethnic Muslim-majority society in Malaysia in relation to reproductive and premarital sexual practices

PubMed Central

2012-01-01

Background The increasing trend of premarital sexual experience and unintended pregnancies in Malaysia warrants sustained and serious attention. The sensitivities of sex-related issues in a Muslim-majority country create various types of barriers to sexual and reproductive health information, support and practices. This study aims to gain understanding of knowledge, attitudes and behaviours of young women in Malaysia concerning reproductive, contraception and premarital sexual practices. Methods A cross-sectional study was performed, using an anonymous self-administered questionnaire carried out among 1695 female university students in a public university in Malaysia. Results Respondents had low scores for knowledge of reproduction and pregnancy (median=4, of maximum score 10), contraceptive uses (median=6, of maximum score 16) and contraceptive availability (median=3, of maximum score 13). The majority of women surveyed do not have liberal values in relation to premarital sexual behaviour (median=37, of maximum 40); higher scores on this scale corresponded to opposing premarital sex. The multivariate analyses showed that ethnic group was the strongest correlate of knowledge and attitude scores; being of Malay Muslim ethnicity was associated significantly with lower knowledge scores and premarital sex permissiveness. Other significant correlates were year of study, maternal occupational groups, level of religious faith, dating status and urban–rural localities. Level of premarital sex permissiveness was inversely correlated with reproduction and pregnancy knowledge score, and contraceptive knowledge scores. Conclusion Reproductive health knowledge and attitudes were intricately linked to religious values and cultural norms differences surrounding sexual issues. PMID:23057505

An exploration of knowledge, attitudes and behaviours of young multiethnic Muslim-majority society in Malaysia in relation to reproductive and premarital sexual practices.

PubMed

Wong, Li Ping

2012-10-11

The increasing trend of premarital sexual experience and unintended pregnancies in Malaysia warrants sustained and serious attention. The sensitivities of sex-related issues in a Muslim-majority country create various types of barriers to sexual and reproductive health information, support and practices. This study aims to gain understanding of knowledge, attitudes and behaviours of young women in Malaysia concerning reproductive, contraception and premarital sexual practices. A cross-sectional study was performed, using an anonymous self-administered questionnaire carried out among 1695 female university students in a public university in Malaysia. Respondents had low scores for knowledge of reproduction and pregnancy (median=4, of maximum score 10), contraceptive uses (median=6, of maximum score 16) and contraceptive availability (median=3, of maximum score 13). The majority of women surveyed do not have liberal values in relation to premarital sexual behaviour (median=37, of maximum 40); higher scores on this scale corresponded to opposing premarital sex. The multivariate analyses showed that ethnic group was the strongest correlate of knowledge and attitude scores; being of Malay Muslim ethnicity was associated significantly with lower knowledge scores and premarital sex permissiveness. Other significant correlates were year of study, maternal occupational groups, level of religious faith, dating status and urban-rural localities. Level of premarital sex permissiveness was inversely correlated with reproduction and pregnancy knowledge score, and contraceptive knowledge scores. Reproductive health knowledge and attitudes were intricately linked to religious values and cultural norms differences surrounding sexual issues.

Safety and tolerability of the first-in-class agent CPI-613 in combination with modified FOLFIRINOX in patients with metastatic pancreatic cancer: a single-centre, open-label, dose-escalation, phase 1 trial.

PubMed

Alistar, Angela; Morris, Bonny B; Desnoyer, Rodwige; Klepin, Heidi D; Hosseinzadeh, Keyanoosh; Clark, Clancy; Cameron, Amy; Leyendecker, John; D'Agostino, Ralph; Topaloglu, Umit; Boteju, Lakmal W; Boteju, Asela R; Shorr, Rob; Zachar, Zuzana; Bingham, Paul M; Ahmed, Tamjeed; Crane, Sandrine; Shah, Riddhishkumar; Migliano, John J; Pardee, Timothy S; Miller, Lance; Hawkins, Gregory; Jin, Guangxu; Zhang, Wei; Pasche, Boris

2017-06-01

Pancreatic cancer statistics are dismal, with a 5-year survival of less than 10%, and more than 50% of patients presenting with metastatic disease. Metabolic reprogramming is an emerging hallmark of pancreatic adenocarcinoma. CPI-613 is a novel anticancer agent that selectively targets the altered form of mitochondrial energy metabolism in tumour cells, causing changes in mitochondrial enzyme activities and redox status that lead to apoptosis, necrosis, and autophagy of tumour cells. We aimed to establish the maximum tolerated dose of CPI-613 when used in combination with modified FOLFIRINOX chemotherapy (comprising oxaliplatin, leucovorin, irinotecan, and fluorouracil) in patients with metastatic pancreatic cancer. In this single-centre, open-label, dose-escalation phase 1 trial, we recruited adult patients (aged ≥18 years) with newly diagnosed metastatic pancreatic adenocarcinoma from the Comprehensive Cancer Center of Wake Forest Baptist Medical Center (Winston-Salem, NC, USA). Patients had good bone marrow, liver and kidney function, and good performance status (Eastern Cooperative Oncology Group [ECOG] performance status 0-1). We studied CPI-613 in combination with modified FOLFIRINOX (oxaliplatin at 65 mg/m 2 , leucovorin at 400 mg/m 2 , irinotecan at 140 mg/m 2 , and fluorouracil 400 mg/m 2 bolus followed by 2400 mg/m 2 over 46 h). We applied a two-stage dose-escalation scheme (single patient and traditional 3+3 design). In the single-patient stage, one patient was accrued per dose level. The starting dose of CPI-613 was 500 mg/m 2 per day; the dose level was then escalated by doubling the previous dose if there were no adverse events worse than grade 2 within 4 weeks attributed as probably or definitely related to CPI-613. The traditional 3+3 dose-escalation stage was triggered if toxic effects attributed as probably or definitely related to CPI-613 were grade 2 or worse. The dose level for CPI-613 for the first cohort in the traditional dose-escalation stage was the same as that used in the last cohort of the single-patient dose-escalation stage. The primary objective was to establish the maximum tolerated dose of CPI-613 (as assessed by dose-limiting toxicities). This trial is registered with ClinicalTrials.gov, number NCT01835041, and is closed to recruitment. Between April 22, 2013, and Jan 8, 2016, we enrolled 20 patients. The maximum tolerated dose of CPI-613 was 500 mg/m 2 . The median number of treatment cycles given at the maximum tolerated dose was 11 (IQR 4-19). Median follow-up of the 18 patients treated at the maximum tolerated dose was 378 days (IQR 250-602). Two patients enrolled at a higher dose of 1000 mg/m 2 , and both had a dose-limiting toxicity. Two unexpected serious adverse events occurred, both for the first patient enrolled. Expected serious adverse events were: thrombocytopenia, anaemia, and lymphopenia (all for patient number 2; anaemia and lymphopenia were dose-limiting toxicities); hyperglycaemia (in patient number 7); hypokalaemia, hypoalbuminaemia, and sepsis (patient number 11); and neutropenia (patient number 20). No deaths due to adverse events were reported. For the 18 patients given the maximum tolerated dose, the most common grade 3-4 non-haematological adverse events were hyperglycaemia (ten [55%] patients), hypokalaemia (six [33%]), peripheral sensory neuropathy (five [28%]), diarrhoea (five [28%]), and abdominal pain (four [22%]). The most common grade 3-4 haematological adverse events were neutropenia (five [28%] of 18 patients), lymphopenia (five [28%]), anaemia (four [22%], and thrombocytopenia in three [17%]). Sensory neuropathy (all grade 1-3) was recorded in 17 (94%) of the 18 patients and was managed with dose de-escalation or discontinuation per standard of care. No patients died while on active treatment; 11 study participants died, with cause of death as terminal pancreatic cancer. Of the 18 patients given the maximum tolerated dose, 11 (61%) achieved an objective (complete or partial) response. A maximum tolerated dose of CPI-613 was established at 500 mg/m 2 when used in combination with modified FOLFIRINOX in patients with metastatic pancreatic cancer. The findings of clinical activity will require validation in a phase 2 trial. Comprehensive Cancer Center of Wake Forest Baptist Medical Center. Copyright © 2017 Elsevier Ltd. All rights reserved.

Initial Investigation of Factors Influencing Radiation Dose to Patients Undergoing Barium-Based Fluoroscopy Procedures in Tanzania.

PubMed

Ngaile, J E; Msaki, P K; Kazema, R R; Schreiner, L J

2017-04-25

The aim of this study was to investigate the nature and causes of radiation dose imparted to patients undergoing barium-based X-ray fluoroscopy procedures in Tanzania and to compare these doses to those reported in the literature from other regions worldwide. The air kerma area product (KAP) to patient undergoing barium investigations of gastrointestinal tract system was obtained from four consultant hospitals. The KAP was determined using a flat transparent transmission ionization chamber. Mean values of KAP for barium swallow (BS), barium meal (BM) and barium enema (BE) were 2.79, 2.62 and 15.04 Gy cm2, respectively. The mean values of KAP per hospital for the BS, BM and BE procedures varied by factors of up to 7.3, 1.6 and 2.0, respectively. The overall difference between individual patient doses across the four consultant hospitals investigated differed by factors of up to 53, 29.5 and 12 for the BS, BM and BE procedures, respectively. The majority of the mean values of KAP was lower than the reported values for Ghana, Greece, Spain and the UK, while slightly higher than those reported for India. The observed wide variation of KAP values for the same fluoroscopy procedure within and among the hospitals was largely attributed to the dynamic nature of the procedures, the patient characteristics, the skills and experience of personnel, and the different examination protocols employed among hospitals. The observed great variations of procedural protocols and patient doses within and across the hospitals call for the need to standardize examination protocols and optimize barium-based fluoroscopy procedures. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Psychophysical and Vasomotor Responses of the Oral Tissues: A Nicotine Dose-Response and Menthol Interaction Study.

PubMed

Arendt Nielsen, Thomas; Nielsen, Bruno Provstgaard; Wang, Kelun; Arendt-Nielsen, Lars; Boudreau, Shellie A

2016-05-01

This study implemented an intra-oral test-platform to assess the sensory, psychophysical, and vasomotor responses to nicotine and menthol, alone or in combination. Two double-blinded, placebo-controlled, randomized, cross-over studies, including healthy nonsmoking participants were performed. Study I: A dose-response relationship (N = 20) between 0, 2, and 4 mg nicotine gum. Study II: An interaction response (N = 22) to 30 mg menthol and 4 mg nicotine alone or in combination. Heart rate, blood pressure, tactile and thermosensory thresholds, intra-oral blood flow and temperature, pain/irritation intensities/locations, McGill Pain Questionnaire, and taste experience were assessed before, during or after the completion of a standardized chewing regime. A dose-response elevation in heart rate was attenuated when nicotine was combined with menthol. Blood flow, temperature, and warm-detection thresholds, as assessed on the tongue, similarly increased for all gums. Pain intensity and taste experiences were similar between nicotine doses. Nicotine attenuated the sweet, cooling, and freshening sensation of menthol. Within the first 4 minutes, menthol reduced the intensity but not the area of nicotine-induced pain and irritation. The 4-mg nicotine dose led to a continued increase in the intensity and area of irritation in the throat post-chewing. Moreover, one-half of participants responded to menthol as an irritant, and these individuals demonstrated larger areas of nicotine-induced irritation in the throat post-chewing. The intra-oral test platform provides a basis to optimize the assessment of nicotine-related taste and sensory experiences and can be used in future studies for profiling nicotine gum. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A Phase 2 Trial of Oral Solithromycin 1200 mg or 1000 mg as Single-Dose Oral Therapy for Uncomplicated Gonorrhea.

PubMed

Hook, Edward W; Golden, Matthew; Jamieson, Brian D; Dixon, Paula B; Harbison, Hanne S; Lowens, Sylvan; Fernandes, Prabhavathi

2015-10-01

Progressive resistance to antimicrobial agents has reduced options for gonorrhea therapy worldwide. Solithromycin (CEM-101) is a novel oral fluoroketolide antimicrobial with substantial in vitro activity against Neisseria gonorrhoeae. We conducted a phase 2 trial of 2 oral doses of solithromycin (1200 and 1000 mg) for treatment of uncomplicated gonorrhea. A total of 59 participants were enrolled and treated in this trial; 28 participants received 1200 mg of solithromycin and 31 received 1000 mg. Forty-six (78%) participants had positive cultures for N. gonorrhoeae at the time of enrollment: 24 of the 28 persons (86%) who received 1200 mg of oral solithromycin, and 22 of 31 (71%) who received 1000 mg. In addition, 8 participants had positive pharyngeal gonococcal cultures, and 4 had positive rectal cultures. All patients with positive cultures for N. gonorrhoeae were cured at all sites of infection. Chlamydia trachomatis and Mycoplasma genitalium coinfections were evaluated using nucleic acid amplification tests and were negative at 1 week of follow-up in 9 of 11 (82%) participants positive for C. trachomatis and 7 of 10 (70%) participants positive for M. genitalium. Mild dose-related gastrointestinal side effects (nausea, loose stools, vomiting) were common but did not limit therapy. Oral single-dose solithromycin, in doses of 1000 mg and 1200 mg, was 100% effective for treatment of culture-proven gonorrhea at genital, oral, and rectal sites of infection and is a promising new agent for gonorrhea treatment. NCT01591447. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Determining β-lactam exposure threshold to suppress resistance development in Gram-negative bacteria.

PubMed

Tam, Vincent H; Chang, Kai-Tai; Zhou, Jian; Ledesma, Kimberly R; Phe, Kady; Gao, Song; Van Bambeke, Françoise; Sánchez-Díaz, Ana María; Zamorano, Laura; Oliver, Antonio; Cantón, Rafael

2017-05-01

β-Lactams are commonly used for nosocomial infections and resistance to these agents among Gram-negative bacteria is increasing rapidly. Optimized dosing is expected to reduce the likelihood of resistance development during antimicrobial therapy, but the target for clinical dose adjustment is not well established. We examined the likelihood that various dosing exposures would suppress resistance development in an in vitro hollow-fibre infection model. Two strains of Klebsiella pneumoniae and two strains of Pseudomonas aeruginosa (baseline inocula of ∼10 8  cfu/mL) were examined. Various dosing exposures of cefepime, ceftazidime and meropenem were simulated in the hollow-fibre infection model. Serial samples were obtained to ascertain the pharmacokinetic simulations and viable bacterial burden for up to 120 h. Drug concentrations were determined by a validated LC-MS/MS assay and the simulated exposures were expressed as C min /MIC ratios. Resistance development was detected by quantitative culture on drug-supplemented media plates (at 3× the corresponding baseline MIC). The C min /MIC breakpoint threshold to prevent bacterial regrowth was identified by classification and regression tree (CART) analysis. For all strains, the bacterial burden declined initially with the simulated exposures, but regrowth was observed in 9 out of 31 experiments. CART analysis revealed that a C min /MIC ratio ≥3.8 was significantly associated with regrowth prevention (100% versus 44%, P  = 0.001). The development of β-lactam resistance during therapy could be suppressed by an optimized dosing exposure. Validation of the proposed target in a well-designed clinical study is warranted. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Single-Dose Hepatitis A Immunization: 7.5-Year Observational Pilot Study in Nicaraguan Children to Assess Protective Effectiveness and Humoral Immune Memory Response.

PubMed

Mayorga, Orlando; Bühler, Silja; Jaeger, Veronika K; Bally, Seraina; Hatz, Christoph; Frösner, Gert; Protzer, Ulrike; Van Damme, Pierre; Egger, Matthias; Herzog, Christian

2016-11-15

 Universal 2-dose hepatitis A virus (HAV) vaccination of toddlers effectively controls hepatitis A. High vaccine costs, however, impede implementation in endemic countries. To test single-dose vaccination as a possible alternative, we initiated an observational, longitudinal study in Nicaragua, to assess protective effectiveness and-through challenge vaccination-humoral immune memory response.  After a 2003 serosurvey, 130 originally seronegative children received one dose of virosomal HAV vaccine in 2005, followed by yearly serological and clinical assessments until 2012. After 7.5 years, a vaccine booster was administered. Concurrent antibody screening of patients presenting with hepatitis symptoms documented persistent HAV circulation in the communities studied.  Between serosurvey and vaccination, 25 children contracted hepatitis A subclinically (>8000 mIU/mL anti-HAV). In the remaining 105 children, immunization resulted in anti-HAV levels of 17-572 mIU/mL. Based on the ≥15% annual infection risk, an estimated 60% of children were exposed to HAV encounters during follow-up. No child presented with hepatitis symptoms. Serological breakthrough infection (7106 mIU/mL) was documented in 1 child, representing an estimated protective effectiveness of 98.3% (95% confidence interval, 87.9-99.8). Boosting elicited an average 29.7-fold increase of anti-HAV levels.  In children living in hyperendemic settings, a single dose of virosomal HAV vaccine is sufficient to activate immune memory and may provide long-term protection. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Analysis of Neutron Production in Passively Scattered Ion-Beam Therapy.

PubMed

Heo, Seunguk; Yoo, Seunghoon; Song, Yongkeun; Kim, Eunho; Shin, Jaeik; Han, Soorim; Jung, Wongyun; Nam, Sanghee; Lee, Rena; Lee, Kitae; Cho, Sungho

2017-07-01

A new treatment facility for heavy ion therapy since 2010 was constructed. In the broad beam, a range shifter, ridge filter and multi leaf collimator (MLC) for the generation of the spread-out Bragg peak is used. In this case, secondary neutrons produced by the interactions of the ion field with beam-modifying devices (e.g. double-scattering system, beam shaping collimators and range compensators) are very important for patient safety. Therefore, these components must be carefully examined in the context of secondary neutron yield and associated secondary cancer risk. In this article, Monte Carlo simulation has been carried out with the FLUktuierende KAskade particle transport code, the fluence and distribution of neutron generation and the neutron dose equivalent from the broad beam components are compared using carbon and proton beams. As a result, it is confirmed that the yield of neutron production using a carbon beam from all components of the broad beam was higher than using a proton beam. The ambient dose by neutrons per heavy ion and proton ion from the MLC surface was 0.12-0.18 and 0.0067-0.0087 pSv, respectively, which shows that heavy ions generate more neutrons than protons. However, ambient dose per treatment 2 Gy, which means physical dose during treatment by ion beam, is higher than carbon beam because proton therapy needs more beam flux to make 2-Gy prescription dose. Therefore, the neutron production from the MLC, which is closed to the patient, is a very important parameter for patient safety. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sustained Antibody Responses 6 Years Following 1, 2, or 3 Doses of Quadrivalent Human Papillomavirus (HPV) Vaccine in Adolescent Fijian Girls, and Subsequent Responses to a Single Dose of Bivalent HPV Vaccine: A Prospective Cohort Study.

PubMed

Toh, Zheng Quan; Russell, Fiona M; Reyburn, Rita; Fong, James; Tuivaga, Evelyn; Ratu, Tupou; Nguyen, Cattram D; Devi, Rachel; Kama, Mike; Matanitobua, Silivia; Tabrizi, Sepehr N; Garland, Suzanne M; Sinha, Rohit; Frazer, Ian; Tikoduadua, Lisi; Kado, Joseph; Rafai, Eric; Mulholland, Edward K; Licciardi, Paul V

2017-04-01

The duration of antibody response following reduced human papillomavirus (HPV) vaccine doses has not been determined. We compared the antibody responses in girls previously vaccinated with zero, 1, 2, or 3 doses of quadrivalent HPV vaccine (4vHPV; Gardasil, Merck) 6 years previously. A prospective cohort study was undertaken in 200 Fijian girls 15-19 years of age. Approximately equal numbers of girls from 2 main ethnic groups (Fijians of Indian descent [FID] and Indigenous Fijians [iTaukei]) in Fiji were recruited for each dosage groups. Blood was drawn before and 28 days following a single dose of bivalent HPV vaccine (2vHPV; Cervarix, GlaxoSmithKline). We measured neutralizing antibodies (NAb) against HPV-6, -11, -16, and -18 using the pseudovirion-based neutralization assay. After 6 years (before a dose of 2vHPV was given), the geometric mean NAb titers for all 4 HPV types were not statistically different between 2-dose (2D) and 3-dose (3D) recipients: HPV-6 (3D: 2216 [95% confidence interval {CI},1695-2896]; 2D: 1476 [95% CI, 1019-2137]; P = .07), HPV-11 (3D: 4431 [95% CI, 3396-5783]; 2D: 2951 [95% CI, 1984-4390]; P = .09), HPV-16 (3D: 3373 [95% CI, 2511-4530]; 2D: 3275 [95% CI, 2452-4373]; P = .89); HPV-18 (3D: 628 [95% CI: 445-888]; 2D: 606 [95% CI, 462-862]; P = .89), and were higher in FID than iTaukei girls. Although 1-dose recipients had significantly lower NAb titers than 2-/3-dose recipients, their NAb titers were 5- to 30-fold higher than unvaccinated girls. Post-2vHPV NAb titers against HPV-16 and -18 were not statistically different between girls who received 1, 2, or 3 doses of 4vHPV previously. Two doses of 4vHPV provide similar NAb titers as 3 doses for 6 years, although the clinical significance is unknown. A single dose of 4vHPV elicits antibodies that persisted for at least 6 years, and induced immune memory, suggesting possible protection against HPV vaccine types after a single dose of 4vHPV. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Dosimetric Evaluation Between Megavoltage Cone-Beam Computed Tomography and Body Mass Index for Intracranial, Thoracic, and Pelvic Localization

DOE Office of Scientific and Technical Information (OSTI.GOV)

VanAntwerp, April E.; Raymond, Sarah M., E-mail: raymons9@ccf.org; Addington, Mark C.

2011-10-01

The aim of this study was to evaluate radiation dose for organs at risk (OAR) within the cranium, thorax, and pelvis from megavoltage cone-beam computed tomography (MV-CBCT). Using a clinical treatment planning system, CBCT doses were calculated from 60 patient datasets using 27.4 x 27.4 cm{sup 2} field size and 200{sup o} arc length. The body mass indices (BMIs) for these patients range from 17.2-48.4 kg/m{sup 2}. A total of 60 CBCT plans were created and calculated with heterogeneity corrections, with monitor units (MU) that varied from 8, 4, and 2 MU per plan. The isocenters of these plans weremore » placed at defined anatomical structures. The maximum dose, dose to the isocenter, and mean dose to the selected critical organs were analyzed. The study found that maximum and isocenter doses were weakly associated with BMI, but linearly associated with the total MU. Average maximum/isocenter doses in the cranium were 10.0 ({+-} 0.18)/7.0 ({+-} 0.08) cGy, 5.0 ({+-} 0.09)/3.5 ({+-} 0.05) cGy, and 2.5 ({+-} .04)/1.8 ({+-} 0.05) cGy for 8, 4, and 2 MU, respectively. Similar trends but slightly larger maximum/isocenter doses were found in the thoracic and pelvic regions. For the cranial region, the average mean doses with a total of 8 MU to the eye, lens, and brain were 9.7 ({+-} 0.12) cGy, 9.1 ({+-} 0.16) cGy, and 7.2 ({+-} 0.10) cGy, respectively. For the thoracic region, the average mean doses to the lung, heart, and spinal cord were 6.6 ({+-} 0.05) cGy, 6.9 ({+-} 1.2) cGy, and 4.7 ({+-} 0.8) cGy, respectively. For the pelvic region, the average mean dose to the femoral heads was 6.4 ({+-} 1.1) cGy. The MV-CBCT doses were linearly associated with the total MU but weakly dependent on patients' BMIs. Daily MV-CBCT has a cumulative effect on the total body dose and critical organs, which should be carefully considered for clinical impacts.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pokhrel, D; Sood, S; Badkul, R

Purpose: To evaluate XVMC computed rib doses for peripherally located non-small-cell-lung tumors treated with SBRT following RTOG-0915 guidelines. Methods: Twenty patients with solitary peripherally located non-small-cell-lung tumors were treated using XVMC-based SBRT to 50–54Gy in 5−3 fractions, respectively, for PTV(V100%)=95%. Based on 4D-CT, ITV was delineated on MaximumIP images and organs-at-risk(OARs) including ribs were contoured on MeanIP images. Mean PTV(ITV+5mm uniform margin) was 46.1±38.7cc (range, 11.1–163.0cc). XVMC SBRT treatment plans were generated with a combination of non-coplanar 3D-conformal arcs/beams, and were delivered by Novalis-TX consisting of HD-MLCs and a 6MV-SRS(1000MU/min) beam, following RTOG-0915 criteria. XVMC rib maximum dose and dosemore » to <1cc, <5cc, <10cc were evaluated as a function of PTV, prescription dose and 3D-distance from tumor isocenter to the most proximal rib contour. Plans were re-computed using heterogeneity-corrected pencil-beam (PB-hete) algorithm utilizing identical beam geometry/MLC positions and MUs and subsequently compared to XVMC. Results: XVMC average maximum rib dose was 50.9±6.4Gy (range, 35.1–59.3Gy). XVMC mean rib dose to <1cc was 41.6±5.6Gy (range, 27.9–47.9Gy), <5cc was 31.2±7.3Gy (range, 10.6–43.1Gy), and <10cc was 21.2±8.7Gy (range, 1.1–36Gy), respectively. For the given prescription, correlation between PTV and rib doses to <5cc (p=0.005) and <10cc (p=0.018) was observed. 3D-distance from the tumor isocenter to the proximal rib contour strongly correlated with maximum rib dose (p=0.0001). PB-hete algorithm overestimated maximum rib dose and dose to <1cc, <5cc, and <10cc of ribs by 5%, 3%, 3%, and 3%, respectively. Conclusion: PB-hete overestimates ribs dose relative to XVMC. Since all the clinical XVMC plans were generated without compromising the target coverage (per RTOG-0915), almost all patient’s ribs doses were higher than the protocol guidelines. As expected, larger tumor size and proximity to ribs received higher absolute dose to ribs. Prospective observation is needed to determine if XVMC delivered rib doses correlates with patient symptoms including chest wall pain and/or rib fractures.« less

First Map of Residential Indoor Radon Measurements in Azerbaijan.

PubMed

Hoffmann, M; Aliyev, C S; Feyzullayev, A A; Baghirli, R J; Veliyeva, F F; Pampuri, L; Valsangiacomo, C; Tollefsen, T; Cinelli, G

2017-06-15

This article describes results of the first measurements of indoor radon concentrations in Azerbaijan, including description of the methodology and the mathematical and statistical processing of the results obtained. Measured radon concentrations varied considerably: from almost radon-free houses to around 1100 Bq m-3. However, only ~7% of the total number of measurements exceeded the maximum permissible concentrations. Based on these data, maps of the distribution of volumetric activity and elevated indoor radon concentrations in Azerbaijan were created. These maps reflect a mosaic character of distribution of radon and enhanced values that are confined to seismically active areas at the intersection of an active West Caspian fault with sub-latitudinal faults along the Great and Lesser Caucasus and the Talysh mountains. Spatial correlation of radon and temperature behavior is also described. The data gathered on residential indoor radon have been integrated into the European Indoor Radon Map. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Emergency department patient knowledge concerning acetaminophen (paracetamol) in over-the-counter and prescription analgesics.

PubMed

Fosnocht, D; Taylor, J R; Caravati, E M

2008-04-01

This study was designed to evaluate patient knowledge of the acetaminophen (paracetamol) content of commonly used pain medications and the maximum daily recommended dose of acetaminophen. A prospective, convenience sample of emergency department patients were enrolled. Data were recorded using a standardised questionnaire over 4 months. 1009 patients were enrolled. 492 patients (49%) did not know if Tylenol contained acetaminophen (paracetamol). The majority (66-90%) of patients did not know if Lortab, Vicodin, Percocet, non-aspirin pain reliever, ibuprofen, Motrin, or Advil contained acetaminophen. 568 patients (56%) reported not knowing the maximum daily dose of acetaminophen and only 71 patients (7%) reported the correct daily dose. Patient knowledge of the acetaminophen content of commonly used analgesic medications and its maximum recommended daily dose is limited. This may contribute to unintentional repeated supratherapeutic ingestion (RSTI) of acetaminophen, or overdose.

Reconstruction of Absorbed Doses to Fibroglandular Tissue of the Breast of Women undergoing Mammography (1960 to the Present)

PubMed Central

Thierry-Chef, Isabelle; Simon, Steven L.; Weinstock, Robert M.; Kwon, Deukwoo; Linet, Martha S.

2013-01-01

The assessment of potential benefits versus harms from mammographic examinations as described in the controversial breast cancer screening recommendations of the U.S. Preventive Task Force included limited consideration of absorbed dose to the fibroglandular tissue of the breast (glandular tissue dose), the tissue at risk for breast cancer. Epidemiological studies on cancer risks associated with diagnostic radiological examinations often lack accurate information on glandular tissue dose, and there is a clear need for better estimates of these doses. Our objective was to develop a quantitative summary of glandular tissue doses from mammography by considering sources of variation over time in key parameters including imaging protocols, x-ray target materials, voltage, filtration, incident air kerma, compressed breast thickness, and breast composition. We estimated the minimum, maximum, and mean values for glandular tissue dose for populations of exposed women within 5-year periods from 1960 to the present, with the minimum to maximum range likely including 90% to 95% of the entirety of the dose range from mammography in North America and Europe. Glandular tissue dose from a single view in mammography is presently about 2 mGy, about one-sixth the dose in the 1960s. The ratio of our estimates of maximum to minimum glandular tissue doses for average-size breasts was about 100 in the 1960s compared to a ratio of about 5 in recent years. Findings from our analysis provide quantitative information on glandular tissue doses from mammographic examinations which can be used in epidemiologic studies of breast cancer. PMID:21988547

Dosimetric verification of IMRT treatment planning using Monte Carlo simulations for prostate cancer

NASA Astrophysics Data System (ADS)

Yang, J.; Li, J.; Chen, L.; Price, R.; McNeeley, S.; Qin, L.; Wang, L.; Xiong, W.; Ma, C.-M.

2005-03-01

The purpose of this work is to investigate the accuracy of dose calculation of a commercial treatment planning system (Corvus, Normos Corp., Sewickley, PA). In this study, 30 prostate intensity-modulated radiotherapy (IMRT) treatment plans from the commercial treatment planning system were recalculated using the Monte Carlo method. Dose-volume histograms and isodose distributions were compared. Other quantities such as minimum dose to the target (Dmin), the dose received by 98% of the target volume (D98), dose at the isocentre (Diso), mean target dose (Dmean) and the maximum critical structure dose (Dmax) were also evaluated based on our clinical criteria. For coplanar plans, the dose differences between Monte Carlo and the commercial treatment planning system with and without heterogeneity correction were not significant. The differences in the isocentre dose between the commercial treatment planning system and Monte Carlo simulations were less than 3% for all coplanar cases. The differences on D98 were less than 2% on average. The differences in the mean dose to the target between the commercial system and Monte Carlo results were within 3%. The differences in the maximum bladder dose were within 3% for most cases. The maximum dose differences for the rectum were less than 4% for all the cases. For non-coplanar plans, the difference in the minimum target dose between the treatment planning system and Monte Carlo calculations was up to 9% if the heterogeneity correction was not applied in Corvus. This was caused by the excessive attenuation of the non-coplanar beams by the femurs. When the heterogeneity correction was applied in Corvus, the differences were reduced significantly. These results suggest that heterogeneity correction should be used in dose calculation for prostate cancer with non-coplanar beam arrangements.

Bolus-dependent dosimetric effect of positioning errors for tangential scalp radiotherapy with helical tomotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lobb, Eric, E-mail: eclobb2@gmail.com

2014-04-01

The dosimetric effect of errors in patient position is studied on-phantom as a function of simulated bolus thickness to assess the need for bolus utilization in scalp radiotherapy with tomotherapy. A treatment plan is generated on a cylindrical phantom, mimicking a radiotherapy technique for the scalp utilizing primarily tangential beamlets. A planning target volume with embedded scalplike clinical target volumes (CTVs) is planned to a uniform dose of 200 cGy. Translational errors in phantom position are introduced in 1-mm increments and dose is recomputed from the original sinogram. For each error the maximum dose, minimum dose, clinical target dose homogeneitymore » index (HI), and dose-volume histogram (DVH) are presented for simulated bolus thicknesses from 0 to 10 mm. Baseline HI values for all bolus thicknesses were in the 5.5 to 7.0 range, increasing to a maximum of 18.0 to 30.5 for the largest positioning errors when 0 to 2 mm of bolus is used. Utilizing 5 mm of bolus resulted in a maximum HI value of 9.5 for the largest positioning errors. Using 0 to 2 mm of bolus resulted in minimum and maximum dose values of 85% to 94% and 118% to 125% of the prescription dose, respectively. When using 5 mm of bolus these values were 98.5% and 109.5%. DVHs showed minimal changes in CTV dose coverage when using 5 mm of bolus, even for the largest positioning errors. CTV dose homogeneity becomes increasingly sensitive to errors in patient position as bolus thickness decreases when treating the scalp with primarily tangential beamlets. Performing a radial expansion of the scalp CTV into 5 mm of bolus material minimizes dosimetric sensitivity to errors in patient position as large as 5 mm and is therefore recommended.« less

Impact of head and neck cancer adaptive radiotherapy to spare the parotid glands and decrease the risk of xerostomia.

PubMed

Castelli, Joel; Simon, Antoine; Louvel, Guillaume; Henry, Olivier; Chajon, Enrique; Nassef, Mohamed; Haigron, Pascal; Cazoulat, Guillaume; Ospina, Juan David; Jegoux, Franck; Benezery, Karen; de Crevoisier, Renaud

2015-01-09

Large anatomical variations occur during the course of intensity-modulated radiation therapy (IMRT) for locally advanced head and neck cancer (LAHNC). The risks are therefore a parotid glands (PG) overdose and a xerostomia increase. The purposes of the study were to estimate: - the PG overdose and the xerostomia risk increase during a "standard" IMRT (IMRTstd); - the benefits of an adaptive IMRT (ART) with weekly replanning to spare the PGs and limit the risk of xerostomia. Fifteen patients received radical IMRT (70 Gy) for LAHNC. Weekly CTs were used to estimate the dose distributions delivered during the treatment, corresponding either to the initial planning (IMRTstd) or to weekly replanning (ART). PGs dose were recalculated at the fraction, from the weekly CTs. PG cumulated doses were then estimated using deformable image registration. The following PG doses were compared: pre-treatment planned dose, per-treatment IMRTstd and ART. The corresponding estimated risks of xerostomia were also compared. Correlations between anatomical markers and dose differences were searched. Compared to the initial planning, a PG overdose was observed during IMRTstd for 59% of the PGs, with an average increase of 3.7 Gy (10.0 Gy maximum) for the mean dose, and of 8.2% (23.9% maximum) for the risk of xerostomia. Compared to the initial planning, weekly replanning reduced the PG mean dose for all the patients (p<0.05). In the overirradiated PG group, weekly replanning reduced the mean dose by 5.1 Gy (12.2 Gy maximum) and the absolute risk of xerostomia by 11% (p<0.01) (30% maximum). The PG overdose and the dosimetric benefit of replanning increased with the tumor shrinkage and the neck thickness reduction (p<0.001). During the course of LAHNC IMRT, around 60% of the PGs are overdosed of 4 Gy. Weekly replanning decreased the PG mean dose by 5 Gy, and therefore by 11% the xerostomia risk.

Investigation of biological destruction of benzo[a]pyrene andpolycyclic aromatic hydrocarbons of biochar in soil

NASA Astrophysics Data System (ADS)

Okunev, R. V.; Smirnova, E. V.; Sharipova, A. R.; Gilmutdinova, I. M.; Giniyatullin, K. G.

2018-01-01

The biological decomposition of benzo[a]pyrene in the concentrations exceeding the MAC (maximum permissible concentration) level in soils by 2, 5 and 10 times was studied in laboratory conditions. The gray forest soil samples were contaminated with benzo[a]pyrene and incubated in optimum for bacterial growth soil moisture for 30 and 60 days. The residual amount of contaminant was monitored by HPLC after extraction with acetone-cyclohexane (2:1). Soil microbial activity was evaluated by measuring basal respiration (BR) and substrate-induced respiration (SID) rates of the soil by gas chromatography. The results of the experiment showed that in 60 days the amount of benzo[a]pyrene in contaminated soils decreased; however, this time was not enough for complete decomposition of pollutant. In this case, benzo[a]pyrene has a negative effect on the BR and SIR rates. Soil contamination affected the BR rate only at high doses (10 MPC), whereas the SIR was a more sensitive indicator of the toxic effect of the pollutant and significantly reacts already at concentrations at the level of 2 MPC. The combination of PAHs isolated from biochar has a strong negative effect on the values of BR and SIR.

INDIVIDUAL DOSIMETRY IN DISPOSAL REPOSITORY OF HEAT-GENERATING NUCLEAR WASTE.

PubMed

Pang, Bo; Saurí Suárez, Héctor; Becker, Frank

2016-09-01

Certain working scenarios in a disposal facility of heat-generating nuclear waste might lead to an enhanced level of radiation exposure for workers in such facilities. Hence, a realistic estimation of the personal dose during individual working scenarios is desired. In this study, the general-purpose Monte Carlo N-Particle code MCNP6 (Pelowitz, D. B. (ed). MCNP6 user manual LA-CP-13-00634, Rev. 0 (2013)) was applied to simulate a representative radiation field in a disposal facility. A tool to estimate the personal dose was then proposed by taking into account the influence of individual motion sequences during working scenarios. As basis for this approach, a movable whole-body phantom was developed to describe individual body gestures of the workers during motion sequences. In this study, the proposed method was applied to the German concept of geological disposal in rock salt. The feasibility of the proposed approach was demonstrated with an example of working scenario in an emplacement drift of a rock salt mine. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Intercomparison of Monte Carlo radiation transport codes to model TEPC response in low-energy neutron and gamma-ray fields.

PubMed

Ali, F; Waker, A J; Waller, E J

2014-10-01

Tissue-equivalent proportional counters (TEPC) can potentially be used as a portable and personal dosemeter in mixed neutron and gamma-ray fields, but what hinders this use is their typically large physical size. To formulate compact TEPC designs, the use of a Monte Carlo transport code is necessary to predict the performance of compact designs in these fields. To perform this modelling, three candidate codes were assessed: MCNPX 2.7.E, FLUKA 2011.2 and PHITS 2.24. In each code, benchmark simulations were performed involving the irradiation of a 5-in. TEPC with monoenergetic neutron fields and a 4-in. wall-less TEPC with monoenergetic gamma-ray fields. The frequency and dose mean lineal energies and dose distributions calculated from each code were compared with experimentally determined data. For the neutron benchmark simulations, PHITS produces data closest to the experimental values and for the gamma-ray benchmark simulations, FLUKA yields data closest to the experimentally determined quantities. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

INVESTIGATION OF THE INFLUENCE OF THE POSITION INSIDE A SMALL AIRCRAFT ON THE COSMIC-RADIATION-INDUCED DOSE.

PubMed

Prado, A C M; Pazianotto, M T; Gonçalez, O L; Dos Santos, L R; Caldeira, A D; Pereira, H H C; Hubert, G; Federico, C A

2017-11-01

This article report the measurements on-board a small aircraft at the same altitude and around the same geographic coordinates. The measurements of Ambient Dose Equivalent Rate (H*(10)) were performed in several positions inside the aircraft, close and far from the pilot location and the discrimination between neutron and non-neutron components. The results show that the neutrons are attenuated close to fuel depots and the non-neutron component appears to have the opposite behavior inside the aircraft. These experimental results are also confronted with results from Monte Carlo simulation, obtained with the MCNPX code, using a simplified model of the Learjet-type aircraft and a modeling of the standard atmosphere, which reproduces the real energy and angular distribution of the particles. The Monte Carlo simulation agreed with the experimental measurements and shows that the total H*(10) presents small variation (around 1%) between the positions inside aircraft, although the neutron spectra present significant variations. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Protective, elective lung irradiation in non-metastatic Ewing's sarcoma.

PubMed

Marinova, L; Hristozova, I; Mihaylova, I; Perenovska, P

2015-07-01

Ewing's sarcoma in childhood is a disease from family of the peripheral primitive neuroectodermal tumours. For a period of 16 y (1984-2000), 34 children with Ewing's sarcoma were treated and followed in our department. Twenty-seven of these patients were without distant metastases. Complex treatment was applied to all these patients-chemotherapy VACA (vincristine, actinomycin D, cyclophosphamide, adriamycin), local radiotherapy to a total dose of 50-56 Gy +/- surgery. After, a local tumour control was achieved in 11 children with non-metastatic Ewing's sarcoma, elective whole lung irradiation to a total dose of 12-15 Gy was applied. Our experience in these 11 patients with non-metastatic Ewing's sarcoma, in whom elective lung irradiation was applied, showed significant reduction in the lung metastases, improved free of disease survival and overall survival. The achieved good treatment results necessitate extending this treatment approach through defining the risk groups of patients, suitable for elective lung radiotherapy combined with chemotherapy in non-metastatic Ewing's sarcoma. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Skull counting in late stages after internal contamination by actinides.

PubMed

Tani, Kotaro; Shutt, Arron; Kurihara, Osamu; Kosako, Toshiso

2015-02-01

Monitoring preparation for internal contamination with actinides (e.g. Pu and Am) is required to assess internal doses at nuclear fuel cycle-related facilities. In this paper, the authors focus on skull counting in case of single-incident inhalation of (241)Am and propose an effective procedure for skull counting with an existing system, taking into account the biokinetic behaviour of (241)Am in the human body. The predicted response of the system to skull counting under a certain counting geometry was found to be only ∼1.0 × 10(-5) cps Bq(-1) 1y after intake. However, this disadvantage could be remedied by repeated measurements of the skull during the late stage of the intake due to the predicted response reaching a plateau at about the 1000th day after exposure and exceeding that in the lung counting. Further studies are needed for the development of a new detection system with higher sensitivity to perform reliable internal dose estimations based on direct measurements. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Inter-institutional survival heterogeneity in chemoradiation therapy for esophageal cancer: exploratory analysis of the JCOG0303 study.

PubMed

Hamamoto, Yasuo; Mizusawa, Junki; Katayama, Hiroshi; Nakamura, Kenichi; Kato, Ken; Tsubosa, Yasuhiro; Ishikura, Satoshi; Igaki, Hiroyasu; Shinoda, Masayuki; Fukuda, Haruhiko; Kitagawa, Yuko; Ando, Nobutoshi

2016-04-01

It is important to examine variation in the treatment effects of patients with esophageal cancer in order to generalize treatment outcomes. We aimed to investigate the range of prognostic differences among hospitals in the treatment of locally advanced esophageal cancer. The JCOG0303 study compared the efficacy of radiotherapy plus low-dose cisplatin and 5-fluorouracil with that of high-dose cisplatin and 5-fluorouracil for unresectable esophageal cancer. Of 32 institutions participating in the JCOG0303 study, the 18 institutions that enrolled three or more patients were included in this study. We predicted the 1-year survival in each institution by using a mixed-effect model. We found that the predicted 1-year survival in the 18 institutions with three or more patients was a median of 60.9%, with a range of 60.9-60.9%. This study is the first to investigated heterogeneity of survival in patients who received definitive chemoradiotherapy for locally advanced esophageal squamous cell carcinoma. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Paediatric and maternal schistosomiasis: shifting the paradigms.

PubMed

Bustinduy, Amaya L; Stothard, J Russell; Friedman, Jennifer F

2017-09-01

In endemic areas, schistosomiasis causes both overt and subclinical disease in young children and their mothers, as well as in returned travellers. Key recently published literature. An action plan for paediatric schistosomiasis and female genital schistosomiasis (FGS) is needed with expanded access to praziquantel (PZQ) treatment required. Schistosomiasis-related morbidity is underappreciated. Present and future demand for PZQ treatment is bottlenecked, imbalanced and inequitable. Current dosing, treatment algorithms and access plans are suboptimal with treatment stalled during pregnancy. Raised dosing of PZQ (>40 mg/kg) is being explored in young children. Surveillance of female genital schistosomiasis FGS is increasing. Use of PZQ in pregnancy is safe and preventive chemotherapy guidelines are being revised in morbidity- and transmission-control settings. Shifting focus of population-level control to individual-case management. Detection and prevention of FGS within general health services and integration of PZQ treatment for women and children in antenatal clinics. Feasibility studies assessing alternative and expanded access to PZQ treatment to at-risk children and mothers and pregnant women. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

SU-F-BRE-16: VMAT Commissioning and Quality Assurance (QA) of An Elekta Synergy-STM Linac Using ICOM Test HarnessTM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, A; Ironwood CRC, Phoenix, AZ; Rajaguru, P

2014-06-15

Purpose: To establish a set of tests based on the iCOM software that can be used to commission and perform periodic QA of VMAT delivery on the Elekta Synergy-S, commonly known as the Beam Modulator (BM). Methods: iCOM is used to create and deliver customized treatment fields to characterize the system in terms of 1) MLC positioning accuracy under static and dynamic delivery with full gantry rotation, 2) MLC positioning with known errors, 3) Maximum dose rate, 4) Maximum MLC speed, 5) Maximum gantry speed, 6) Synchronization: gantry speed versus dose rate, and 7) Synchronization: MLC speed versus dose rate.more » The resulting images were captured on the iView GT and exported in DICOM format to Dosimetry Check™ system for visual and quantitative analysis. For the initial commissioning phase, the system tests described should be supplemented with extensive patient QAs covering all clinically relevant treatment sites. Results: The system performance test suite showed that on our Synergy-S, MLC positioning was accurate under both static and dynamic deliveries. Intentional errors of 1 mm were also easily identified on both static and dynamic picket fence tests. Maximum dose rate was verified with stop watch to be consistently between 475-480 MU/min. Maximum gantry speed and MLC speed were 5.5 degree/s and 2.5 cm/s respectively. After accounting for beam flatness, both synchronization tests, gantry versus dose rate and MLC speed versus dose rate, were successful as the fields were uniform across the strips and there were no obvious cold/hot spots. Conclusion: VMAT commissioning and quality assurance should include machine characterization tests in addition to patient QAs. Elekta iCOM is a valuable tool for the design of customized VMAT field with specific MU, MLC leaf positions, dose rate, and indirect control of MLC and gantry speed at each of its control points.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pokharel, S; Rana, S

Purpose: purpose of this study is to evaluate the effect of grid size in Eclipse AcurosXB dose calculation algorithm for SBRT lung. Methods: Five cases of SBRT lung previously treated have been chosen for present study. Four of the plans were 5 fields conventional IMRT and one was Rapid Arc plan. All five cases have been calculated with five grid sizes (1, 1.5, 2, 2.5 and 3mm) available for AXB algorithm with same plan normalization. Dosimetric indices relevant to SBRT along with MUs and time have been recorded for different grid sizes. The maximum difference was calculated as a percentagemore » of mean of all five values. All the plans were IMRT QAed with portal dosimetry. Results: The maximum difference of MUs was within 2%. The time increased was as high as 7 times from highest 3mm to lowest 1mm grid size. The largest difference of PTV minimum, maximum and mean dose were 7.7%, 1.5% and 1.6% respectively. The highest D2-Max difference was 6.1%. The highest difference in ipsilateral lung mean, V5Gy, V10Gy and V20Gy were 2.6%, 2.4%, 1.9% and 3.8% respectively. The maximum difference of heart, cord and esophagus dose were 6.5%, 7.8% and 4.02% respectively. The IMRT Gamma passing rate at 2%/2mm remains within 1.5% with at least 98% points passing with all grid sizes. Conclusion: This work indicates the lowest grid size of 1mm available in AXB is not necessarily required for accurate dose calculation. The IMRT passing rate was insignificant or not observed with the reduction of grid size less than 2mm. Although the maximum percentage difference of some of the dosimetric indices appear large, most of them are clinically insignificant in absolute dose values. So we conclude that 2mm grid size calculation is best compromise in light of dose calculation accuracy and time it takes to calculate dose.« less

[Value of early application of different doses of amino acids in parenteral nutrition among preterm infants].

PubMed

Liu, Zhi-Juan; Liu, Guo-Sheng; Chen, Yong-Ge; Zhang, Hui-Li; Wu, Xue-Fen

2015-01-01

To study the short-term response and tolerance of different doses of amino acids in parenteral nutrition among preterm infants. This study included 86 preterm infants who had a birth weight between 1 000 to 2 000 g and were admitted to the hospital within 24 hours of birth between March 2013 and June 2014. According to the early application of different doses of amino acids, they were randomized into low-dose group (n=29, 1.0 g/kg per day with an increase of 1.0 g/kg daily and a maximum of 3.5 g/kg per day), medium-dose group (n=28, 2.0 g/kg per day with an increase of 1.0 g/kg daily and a maximum of 3.7 g/kg per day), and high-dose group (n=29, 3.0 g/kg per day with an increase of 0.5-1.0 g/kg daily and a maximum of 4.0 g/kg per day). Other routine parenteral nutrition and enteral nutrition support were also applied. The maximum weight loss was lower and the growth rate of head circumference was greater in the high-dose group than in the low-dose group (P<0.05). The infants in the medium- and high-dose groups had faster recovery of birth weight, earlier attainment of 100 kcal/(kg·d) of enteral nutrition, shorter duration of hospital stay, and less hospital cost than those in the low-dose group (P<0.05). Blood urea nitrogen (BUN) levels in the high-dose group increased compared with the other two groups 7 days after birth (P<0.05). The levels of creatinine, pH, bicarbonate, bilirubin, and transaminase and the incidence of complications showed no significant differences between groups (P>0.05). Parenteral administration of high-dose amino acids in preterm infants within 24 hours after birth can improve the short-term nutritional status of preterm infants, but there is a transient increase in BUN level.

26 CFR 31.3402(h)(4)-1 - Other methods.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 15 2013-04-01 2013-04-01 false Other methods. 31.3402(h)(4)-1 Section 31.3402... Collection of Income Tax at Source § 31.3402(h)(4)-1 Other methods. (a) Maximum permissible deviations. An employer may use any other method of withholding under which the employer will deduct and withhold upon...

26 CFR 31.3402(h)(4)-1 - Other methods.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Other methods. 31.3402(h)(4)-1 Section 31.3402... Collection of Income Tax at Source § 31.3402(h)(4)-1 Other methods. (a) Maximum permissible deviations. An employer may use any other method of withholding under which the employer will deduct and withhold upon...

26 CFR 31.3402(h)(4)-1 - Other methods.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 15 2011-04-01 2011-04-01 false Other methods. 31.3402(h)(4)-1 Section 31.3402... Collection of Income Tax at Source § 31.3402(h)(4)-1 Other methods. (a) Maximum permissible deviations. An employer may use any other method of withholding under which the employer will deduct and withhold upon...

26 CFR 31.3402(h)(4)-1 - Other methods.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 26 Internal Revenue 15 2012-04-01 2012-04-01 false Other methods. 31.3402(h)(4)-1 Section 31.3402... Collection of Income Tax at Source § 31.3402(h)(4)-1 Other methods. (a) Maximum permissible deviations. An employer may use any other method of withholding under which the employer will deduct and withhold upon...

26 CFR 31.3402(h)(4)-1 - Other methods.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 15 2014-04-01 2014-04-01 false Other methods. 31.3402(h)(4)-1 Section 31.3402... Collection of Income Tax at Source § 31.3402(h)(4)-1 Other methods. (a) Maximum permissible deviations. An employer may use any other method of withholding under which the employer will deduct and withhold upon...

12 CFR Appendix A to Part 205 - Model Disclosure Clauses and Forms

Code of Federal Regulations, 2011 CFR

2011-01-01

... maximum overdraft line of credit). If you tell us within 2 business days after you learn of the loss or... your permission.) If you do NOT tell us within 2 business days after you learn of the loss or theft of... [automated teller machines] [telephone bill-payment service] [point-of-sale transfer service]. (2) Fixed...

49 CFR 178.811 - Bottom lift test.

Code of Federal Regulations, 2010 CFR

2010-10-01

... passing the test. For all IBC design types designed to be lifted from the base, there may be no permanent deformation which renders the IBC unsafe for transportation and no loss of contents. [Amdt. 178-103, 59 FR... bottom lift test. The IBC must be loaded to 1.25 times its maximum permissible gross mass, the load being...

77 FR 8741 - Spirotetramat; Pesticide Tolerances for Emergency Exemptions

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-15

... on onion, dry bulb under section 408(l)(6) of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 U... pesticide on dry bulb onions. This regulation establishes a maximum permissible level for residues of... degradates, in or on onion, dry bulb at 0.3 parts per million (ppm). This time-limited tolerance expires on...

12 CFR Appendix A to Part 205 - Model Disclosure Clauses and Forms

Code of Federal Regulations, 2012 CFR

2012-01-01

... maximum overdraft line of credit). If you tell us within 2 business days after you learn of the loss or... your permission.) If you do NOT tell us within 2 business days after you learn of the loss or theft of... [automated teller machines] [telephone bill-payment service] [point-of-sale transfer service]. (2) Fixed...

12 CFR Appendix A to Part 205 - Model Disclosure Clauses and Forms

Code of Federal Regulations, 2013 CFR

2013-01-01

... maximum overdraft line of credit). If you tell us within 2 business days after you learn of the loss or... your permission.) If you do NOT tell us within 2 business days after you learn of the loss or theft of... [automated teller machines] [telephone bill-payment service] [point-of-sale transfer service]. (2) Fixed...

12 CFR Appendix A to Part 205 - Model Disclosure Clauses and Forms

Code of Federal Regulations, 2014 CFR

2014-01-01

... maximum overdraft line of credit). If you tell us within 2 business days after you learn of the loss or... your permission.) If you do NOT tell us within 2 business days after you learn of the loss or theft of... [automated teller machines] [telephone bill-payment service] [point-of-sale transfer service]. (2) Fixed...

A Phase I Study of the Safety and Pharmacokinetics of Higher-Dose Icotinib in Patients With Advanced Non-Small Cell Lung Cancer

PubMed Central

Liu, Jian; Wu, Lihua; Wu, Guolan; Hu, Xingjiang; Zhou, Huili; Chen, Junchun; Zhu, Meixiang; Xu, Wei; Tan, Fenlai; Ding, Lieming; Wang, Yinxiang

2016-01-01

Lessons Learned This phase I study evaluated the maximum tolerated dose, dose-limiting toxicities, safety, pharmacokinetics, and efficacy of icotinib with a starting dose of 250 mg in pretreated, advanced non-small cell lung cancer patients. We observed a maximum tolerated dose of 500 mg with a favorable pharmacokinetics profile and antitumor activity. These findings provide clinicians with evidence for application of higher-dose icotinib. Background. Icotinib, an oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has shown favorable tolerability and antitumor activity at 100–200 mg in previous studies without reaching the maximum tolerated dose (MTD). In July 2011, icotinib was approved by the China Food and Drug Administration at a dose of 125 mg three times daily for the treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) after failure of at least one platinum-based chemotherapy regimen. This study investigated the MTD, tolerability, and pharmacokinetics of higher-dose icotinib in patients with advanced NSCLC. Methods. Twenty-six patients with advanced NSCLC were treated at doses of 250–625 mg three times daily The EGFR mutation test was not mandatory in this study. Results. Twenty-four (92.3%) of 26 patients experienced at least one adverse event (AE); rash (61.5%), diarrhea (23.1%), and oral ulceration (11.5%) were most frequent AEs. Dose-limiting toxicities were seen in 2 of 6 patients in the 625-mg group, and the MTD was established at 500 mg. Icotinib was rapidly absorbed and eliminated. The amount of time that the drug was present at the maximum concentration in serum (Tmax) ranged from 1 to 3 hours (1.5–4 hours) after multiple doses. The t1/2 was similar after single- and multiple-dose administration (7.11 and 6.39 hours, respectively). A nonlinear relationship was observed between dose and drug exposure. Responses were seen in 6 (23.1%) patients, and 8 (30.8%) patients had stable disease. Conclusion. This study demonstrated that higher-dose icotinib was well-tolerated, with a MTD of 500 mg. Favorable antitumor activity and pharmacokinetic profile were observed in patients with heavily pretreated, advanced NSCLC. PMID:27789778

A Phase I Study of the Safety and Pharmacokinetics of Higher-Dose Icotinib in Patients With Advanced Non-Small Cell Lung Cancer.

PubMed

Liu, Jian; Wu, Lihua; Wu, Guolan; Hu, Xingjiang; Zhou, Huili; Chen, Junchun; Zhu, Meixiang; Xu, Wei; Tan, Fenlai; Ding, Lieming; Wang, Yinxiang; Shentu, Jianzhong

2016-11-01

This phase I study evaluated the maximum tolerated dose, dose-limiting toxicities, safety, pharmacokinetics, and efficacy of icotinib with a starting dose of 250 mg in pretreated, advanced non-small cell lung cancer patients. We observed a maximum tolerated dose of 500 mg with a favorable pharmacokinetics profile and antitumor activity.These findings provide clinicians with evidence for application of higher-dose icotinib. Icotinib, an oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has shown favorable tolerability and antitumor activity at 100-200 mg in previous studies without reaching the maximum tolerated dose (MTD). In July 2011, icotinib was approved by the China Food and Drug Administration at a dose of 125 mg three times daily for the treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) after failure of at least one platinum-based chemotherapy regimen. This study investigated the MTD, tolerability, and pharmacokinetics of higher-dose icotinib in patients with advanced NSCLC. Twenty-six patients with advanced NSCLC were treated at doses of 250-625 mg three times daily The EGFR mutation test was not mandatory in this study. Twenty-four (92.3%) of 26 patients experienced at least one adverse event (AE); rash (61.5%), diarrhea (23.1%), and oral ulceration (11.5%) were most frequent AEs. Dose-limiting toxicities were seen in 2 of 6 patients in the 625-mg group, and the MTD was established at 500 mg. Icotinib was rapidly absorbed and eliminated. The amount of time that the drug was present at the maximum concentration in serum (T max ) ranged from 1 to 3 hours (1.5-4 hours) after multiple doses. The t 1/2 was similar after single- and multiple-dose administration (7.11 and 6.39 hours, respectively). A nonlinear relationship was observed between dose and drug exposure. Responses were seen in 6 (23.1%) patients, and 8 (30.8%) patients had stable disease. This study demonstrated that higher-dose icotinib was well-tolerated, with a MTD of 500 mg. Favorable antitumor activity and pharmacokinetic profile were observed in patients with heavily pretreated, advanced NSCLC. ©AlphaMed Press; the data published online to support this summary is the property of the authors.

Effective chemotherapy of heterogeneous and drug-resistant early colon cancers by intermittent dose schedules: a computer simulation study.

PubMed

Axelrod, David E; Vedula, Sudeepti; Obaniyi, James

2017-05-01

The effectiveness of cancer chemotherapy is limited by intra-tumor heterogeneity, the emergence of spontaneous and induced drug-resistant mutant subclones, and the maximum dose to which normal tissues can be exposed without adverse side effects. The goal of this project was to determine if intermittent schedules of the maximum dose that allows colon crypt maintenance could overcome these limitations, specifically by eliminating mixtures of drug-resistant mutants from heterogeneous early colon adenomas while maintaining colon crypt function. A computer model of cell dynamics in human colon crypts was calibrated with measurements of human biopsy specimens. The model allowed simulation of continuous and intermittent dose schedules of a cytotoxic chemotherapeutic drug, as well as the drug's effect on the elimination of mutant cells and the maintenance of crypt function. Colon crypts can tolerate a tenfold greater intermittent dose than constant dose. This allows elimination of a mixture of relatively drug-sensitive and drug-resistant mutant subclones from heterogeneous colon crypts. Mutants can be eliminated whether they arise spontaneously or are induced by the cytotoxic drug. An intermittent dose, at the maximum that allows colon crypt maintenance, can be effective in eliminating a heterogeneous mixture of mutant subclones before they fill the crypt and form an adenoma.

SU-E-T-365: Dosimetric Impact of Dental Amalgam CT Image Artifacts On IMRT and VMAT Head and Neck Plans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, N; Young, L; Parvathaneni, U

Purpose: The presence of high density dental amalgam in patient CT image data sets causes dose calculation errors for head and neck (HN) treatment planning. This study assesses and compares dosimetric variations in IMRT and VMAT treatment plans due to dental artifacts. Methods: Sixteen HN patients with similar treatment sites (oropharynx), tumor volume and extensive dental artifacts were divided into two groups: IMRT (n=8, 6 to 9 beams) and VMAT (n=8, 2 arcs with 352° rotation). All cases were planned with the Pinnacle 9.2 treatment planning software using the collapsed cone convolution superposition algorithm and a range of prescription dosemore » from 60 to 72Gy. Two different treatment plans were produced, each based on one of two image sets: (a)uncorrected; (b)dental artifacts density overridden (set to 1.0g/cm{sup 3}). Differences between the two treatment plans for each of the IMRT and VMAT techniques were quantified by the following dosimetric parameters: maximum point dose, maximum spinal cord and brainstem dose, mean left and right parotid dose, and PTV coverage (V95%Rx). Average differences generated for these dosimetric parameters were compared between IMRT and VMAT plans. Results: The average absolute dose differences (plan a minus plan b) for the VMAT and IMRT techniques, respectively, caused by dental artifacts were: 2.2±3.3cGy vs. 37.6±57.5cGy (maximum point dose, P=0.15); 1.2±0.9cGy vs. 7.9±6.7cGy (maximum spinal cord dose, P=0.026); 2.2±2.4cGy vs. 12.1±13.0cGy (maximum brainstem dose, P=0.077); 0.9±1.1cGy vs. 4.1±3.5cGy (mean left parotid dose, P=0.038); 0.9±0.8cGy vs. 7.8±11.9cGy (mean right parotid dose, P=0.136); 0.021%±0.014% vs. 0.803%±1.44% (PTV coverage, P=0.17). Conclusion: For the HN plans studied, dental artifacts demonstrated a greater dose calculation error for IMRT plans compared to VMAT plans. Rotational arcs appear on the average to compensate dose calculation errors induced by dental artifacts. Thus, compared to VMAT, density overrides for dental artifacts are more important when planning IMRT of HN.« less

Dose Trends of Aripiprazole from 2004 to 2014 in Psychiatric Inpatients in Korea.

PubMed

Woo, Young Sup; Shim, In Hee; Lee, Sang-Yeol; Lee, Dae-Bo; Kim, Moon-Doo; Jung, Young-Eun; Lee, Jonghun; Won, Seunghee; Jon, Duk-In; Bahk, Won-Myong

2017-05-31

Although aripiprazole has been widely used to treat various psychiatric disorders, little is known about the adequate dosage for Asian patients in clinical practice. Hence, we evaluated the initial and maximum doses of aripiprazole from 2004 to 2014 to estimate the appropriate dosage for Korean psychiatric inpatients in clinical practice. In this retrospective study, we reviewed the medical records of patients who were hospitalized in five university hospitals in Korea from March 2004 to December 2014. The psychiatric diagnosis according to the text revision of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition during index hospitalization and the initial and maximum doses of aripiprazole were evaluated. There were 74 patients in Wave 1 (2004-2006), 201 patients in Wave 2 (2007-2010), and 353 patients in Wave 3 (2011-2014). The initial doses of aripiprazole in all diagnostic groups were significantly lower in Wave 3 than in Wave 2. The maximum doses of aripiprazole in each diagnostic group were not significantly different among Waves 1, 2, and 3. The relatively low initial doses of aripiprazole documented in our study may reflect a strategy by clinicians to minimize the side effects associated with aripiprazole use, such as akathisia.

Regulatory Forum Opinion Piece*: Retrospective Evaluation of Doses in the 26-week Tg.rasH2 Mice Carcinogenicity Studies: Recommendation to Eliminate High Doses at Maximum Tolerated Dose in Future Studies. A Response to the Counterpoints.

PubMed

Paranjpe, Madhav G; Denton, Melissa D; Vidmar, Tom J; Elbekai, Reem H

2016-01-01

We recently conducted a retrospective analysis of data collected from 29 Tg.rasH2 carcinogenicity studies conducted at our facility to determine how successful was the strategy of choosing the high dose of the 26-week studies based on an estimated maximum tolerated dose (MTD). As a result of our publication, 2 counterviews were expressed. Both counterviews illustrate very valid points in their interpretation of our data. In this article, we would like to highlight clarifications based on several points and issues they have raised in their papers, namely, the dose-level selection, determining if MTD was exceeded in 26-week studies, and a discussion on the number of dose groups to be used in the studies. © The Author(s) 2015.

SU-E-T-169: Characterization of Pacemaker/ICD Dose in SAVI HDR Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalavagunta, C; Lasio, G; Yi, B

2015-06-15

Purpose: It is important to estimate dose to pacemaker (PM)/Implantable Cardioverter Defibrillator (ICD) before undertaking Accelerated Partial Breast Treatment using High Dose Rate (HDR) brachytherapy. Kim et al. have reported HDR PM/ICD dose using a single-source balloon applicator. To the authors knowledge, there have so far not been any published PM/ICD dosimetry literature for the Strut Adjusted Volume Implant (SAVI, Cianna Medical, Aliso Viejo, CA). This study aims to fill this gap by generating a dose look up table (LUT) to predict maximum dose to the PM/ICD in SAVI HDR brachytherapy. Methods: CT scans for 3D dosimetric planning were acquiredmore » for four SAVI applicators (6−1-mini, 6−1, 8−1 and 10−1) expanded to their maximum diameter in air. The CT datasets were imported into the Elekta Oncentra TPS for planning and each applicator was digitized in a multiplanar reconstruction window. A dose of 340 cGy was prescribed to the surface of a 1 cm expansion of the SAVI applicator cavity. Cartesian coordinates of the digitized applicator were determined in the treatment leading to the generation of a dose distribution and corresponding distance-dose prediction look up table (LUT) for distances from 2 to 15 cm (6-mini) and 2 to 20 cm (10–1).The deviation between the LUT doses and the dose to the cardiac device in a clinical case was evaluated. Results: Distance-dose look up table were compared to clinical SAVI plan and the discrepancy between the max dose predicted by the LUT and the clinical plan was found to be in the range (−0.44%, 0.74%) of the prescription dose. Conclusion: The distance-dose look up tables for SAVI applicators can be used to estimate the maximum dose to the ICD/PM, with a potential usefulness for quick assessment of dose to the cardiac device prior to applicator placement.« less

A cytogenetic biomonitoring of industrial radiographers occupationally exposed to low levels of ionizing radiation by using cbmn assay.

PubMed

Shakeri, Mahsa; Zakeri, Farideh; Changizi, Vahid; Rajabpour, Mohammad Reza; Farshidpour, Mohammad Reza

2017-06-15

Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. The average annual effective dose in industrial radiography is one of the highest among radiation workers. The aim of this study was to investigate the cytogenetic effects of ionizing radiation in the peripheral blood lymphocytes of 60 industrial radiographers and 40 non-exposed individuals as the control group by using cytokinesis-block micronucleus (CBMN) assay. Totally, the frequencies of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) were significantly higher in the industrial radiographers than in the controls (p = 0.000). The mean MN frequency per 1000 binucleated cells in the industrial radiographers with last 5-y radiation dose of >100 mSv was significantly higher than those with ≤100 mSv (34.81 ± 12.7‰ vs. 26.33 ± 7.94‰, p = 0.024). The effect of age was observed in the control group and subjects with the age of >30 y showed significantly higher MN frequency compared with the subjects with the age of ≤30 y (9.45 ± 3.71‰ vs. 6.81 ± 3.05‰, p = 0.02). No obvious trend of increased MN as a function of either duration of employment or age or smoking status was observed in the industrial radiographers. The results show the increased levels of cytogenetic damages in the industrial radiographers. Even the workers exposed to the permissible doses are subjected to elevated frequencies of DNA damages. These findings confirm the importance of cytogenetic biomonitoring program beside physical dosimetry, surveying radiation safety of equipment and periodic training of workers for improvement of safety and radiation protection. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparative total and unbound pharmacokinetics of cefazolin administered by bolus versus continuous infusion in patients undergoing major surgery: a randomized controlled trial.

PubMed

Naik, B I; Roger, C; Ikeda, K; Todorovic, M S; Wallis, S C; Lipman, J; Roberts, J A

2017-06-01

Perioperative administration of cefazolin reduces the incidence of perioperative infections. Intraoperative re-dosing of cefazolin is commonly given between 2 and 5 h after the initial dose. This study was undertaken to determine whether intraoperative continuous infusions of cefazolin achieve better probability of target attainment (PTA) and fractional target attainment (FTA) than intermittent dosing. Patients undergoing major surgery received cefazolin 2 g before surgical incision. They were subsequently randomized to receive either an intermittent bolus (2 g every 4 h) or continuous infusion (500 mg h -1 ) of cefazolin until skin closure. Blood samples were analysed for total and unbound cefazolin concentrations using a validated chromatographic method. Population pharmacokinetic modelling was performed using Pmetrics ® software. Calculations of PTA and FTA were performed for common pathogens. Ten patients were enrolled in each arm. A two-compartment linear model best described the time course of the total plasma cefazolin concentrations. The covariates that improved the model were body weight and creatinine clearance. Protein binding varied with time [mean (range) 69 (44-80)%] with a fixed 21% unbound value of cefazolin used for the simulations (120 min post-initial dosing). Mean ( sd ) central volume of distribution was 5.73 (2.42) litres, and total cefazolin clearance was 4.72 (1.1) litres h -1 . Continuous infusions of cefazolin consistently achieved better drug exposures and FTA for different weight and creatinine clearances, particularly for less susceptible pathogens. Our study demonstrates that intraoperative continuous infusions of cefazolin increase the achievement of target plasma concentrations, even with lower infusion doses. Renal function and body weight are important when considering the need for alternative dosing regimens. NCT02058979. © The Author 2017. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Dose- and Time-Dependent Transcriptional Response of Ishikawa Cells Exposed to Genistein.

PubMed

Naciff, Jorge M; Khambatta, Zubin S; Carr, Gregory J; Tiesman, Jay P; Singleton, David W; Khan, Sohaib A; Daston, George P

2016-05-01

To further define the utility of the Ishikawa cells as a reliable in vitro model to determine the potential estrogenic activity of chemicals of interest, transcriptional changes induced by genistein (GES) in Ishikawa cells at various doses (10 pM, 1 nM, 100 nM, and 10 μM) and time points (8, 24, and 48 h) were identified using a comprehensive microarray approach. Trend analysis indicated that the expression of 5342 unique genes was modified by GES in a dose- and time-dependent manner (P ≤ 0.0001). However, the majority of gene expression changes induced in Ishikawa cells were elicited by the highest dose of GES evaluated (10 μM). The GES' estrogenic activity was identified by comparing the Ishikawa cells' response to GES versus 17 α-ethynyl estradiol (EE, at equipotent doses, ie, 10 μM vs 1 μM, respectively) and was defined by changes in the expression of 284 unique genes elicited by GES and EE in the same direction, although the magnitude of the change for some genes was different. Further, comparing the response of the Ishikawa cells exposed to high doses of GES and EE versus the response of the juvenile rat uterus exposed to EE, we identified 66 unique genes which were up- or down regulated in a similar manner in vivo as well as in vitro Genistein elicits changes in multiple molecular pathways affecting various biological processes particularly associated with cell organization and biogenesis, regulation of translation, cell proliferation, and intracellular transport; processes also affected by estrogen exposure in the uterus of the rat. These results indicate that Ishikawa cells are capable of generating a biologically relevant estrogenic response and offer an in vitro model to assess this mode of action. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Colistin-associated Acute Kidney Injury in Severely Ill Patients: A Step Toward a Better Renal Care? A Prospective Cohort Study.

PubMed

Dalfino, Lidia; Puntillo, Filomena; Ondok, Maria Josephine Mura; Mosca, Adriana; Monno, Rosa; Coppolecchia, Sara; Spada, Maria Luigia; Bruno, Francesco; Brienza, Nicola

2015-12-15

Critically ill patients with severe sepsis or septic shock may need relatively high colistin daily doses for efficacy against multidrug-resistant and extensively drug-resistant gram-negative rods. However, acute kidney injury (AKI) may represent a major dose-limiting adverse effect of colistin. We sought to determine AKI occurrence and to identify factors influencing AKI risk in severely ill patients receiving colistin according to a recently proposed dosing strategy. A prospective, observational, cohort study involving patients with severe sepsis or septic shock who received colistin was performed. AKI was defined according to Acute Kidney Injury Network criteria. Colistin administration was driven by a modified pharmacokinetics-pharmacodynamics (PK/PD)-based dosing approach. Of 70 patients who received colistin at a median daily dose of 9 million IU (MIU; interquartile range, 5.87-11.1 MIU), 31 (44%) developed AKI. In univariate analysis, age, Acute Physiology and Chronic Health Evaluation (APACHE) II score, Sequential Organ Failure Assessment (SOFA), score and baseline renal impairment were significantly associated with AKI. Moreover, patients with AKI were less frequently treated with adjuvant ascorbic acid (P = .003). In multivariate analysis, independent predictors of AKI were baseline renal impairment (adjusted hazard ratio, 4.15; 95% confidence interval, 1.9-9.2; P < .001) and age (1.03; 1.0-1.05; P = .028), whereas a strong independent renal-protective role emerged for ascorbic acid (0.27; .12-.57; P < .001). In severely ill patients receiving colistin according to a PK/PD-driven dosing approach, baseline renal impairment and older age strongly predict AKI occurrence, but concomitant administration of ascorbic acid markedly reduces AKI risk, allowing safer use of colistin. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Non-linear absorption pharmacokinetics of amoxicillin: consequences for dosing regimens and clinical breakpoints.

PubMed

de Velde, Femke; de Winter, Brenda C M; Koch, Birgit C P; van Gelder, Teun; Mouton, Johan W

2016-10-01

To describe the population pharmacokinetics of oral amoxicillin and to compare the PTA of current dosing regimens. Two groups, each with 14 healthy male volunteers, received oral amoxicillin/clavulanic acid tablets on two separate days 1 week apart. One group received 875/125 mg twice daily and 500/125 mg three times daily and the other group 500/125 mg twice daily and 250/125 mg three times daily. A total of 1428 amoxicillin blood samples were collected before and after administration. We analysed the concentration-time profiles using a non-compartmental pharmacokinetic method (PKSolver) and a population pharmacokinetic method (NONMEM). The PTA was computed using Monte Carlo simulations for several dosing regimens. AUC0-24 and Cmax increased non-linearly with dose. The final model included the following components: Savic's transit compartment model, Michaelis-Menten absorption, two distribution compartments and first-order elimination. The mean central volume of distribution was 27.7 L and mean clearance was 21.3 L/h. We included variability for the central volume of distribution (34.4%), clearance (25.8%), transit compartment model parameters and Michaelis-Menten absorption parameters. For 40% fT>MIC and >97.5% PTA, the breakpoints were 0.125 mg/L (500 mg twice daily), 0.25 mg/L (250 mg three times daily and 875 mg twice daily), 0.5 mg/L (500 mg three times daily) and 1 mg/L (750, 875 or 1000 mg three times daily and 500 mg four times daily). The amoxicillin absorption rate appears to be saturable. The PTAs of high-dose as well as twice-daily regimens are less favourable than regimens with lower doses and higher frequency. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

3,3',4,4',5-Pentachlorobiphenyl (PCB 126) Decreases Hepatic and Systemic Ratios of Epoxide to Diol Metabolites of Unsaturated Fatty Acids in Male Rats.

PubMed

Wu, Xianai; Yang, Jun; Morisseau, Christophe; Robertson, Larry W; Hammock, Bruce; Lehmler, Hans-Joachim

2016-08-01

Disruption of the homeostasis of oxygenated regulatory lipid mediators (oxylipins), potential markers of exposure to aryl hydrocarbon receptor (AhR) agonists, such as 3,3',4,4',5-pentachlorobiphenyl (PCB 126), is associated with a range of diseases, including nonalcoholic fatty liver disease and nonalcoholic steatohepatitis. Here we test the hypothesis that PCB 126 exposure alters the levels of oxylipins in rats. Male Sprague-Dawley rats (5-weeks old) were treated over a 3-month period every 2 weeks with intraperitoneal injections of PCB 126 in corn oil (cumulative doses of 0, 19.8, 97.8, and 390 µg/kg b.w.; 6 injections total). PCB 126 treatment caused a reduction in growth rates at the highest dose investigated, a dose-dependent decrease in thymus weights, and a dose-dependent increase in liver weights. Liver PCB 126 levels increased in a dose-dependent manner, while levels in plasma were below or close to the detection limit. The ratios of several epoxides to diol metabolites formed via the cytochrome P450 (P450) monooxygenase/soluble epoxide hydrolase (sEH) pathway from polyunsaturated fatty acids displayed a dose-dependent decrease in the liver and plasma, whereas levels of oxylipins formed by other metabolic pathways were generally not altered by PCB 126 treatment. The effects of PCB 126 on epoxide-to-diol ratios were associated with an increased CYP1A activity in liver microsomes and an increased sEH activity in liver cytosol and peroxisomes. These results suggest that oxylipins are potential biomarkers of exposure to PCB 126 and that the P450/sEH pathway is a therapeutic target for PCB 126-mediated hepatotoxicity that warrants further attention. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. for Permissions, please e-mail: journals.permissions@oup.com.

Dosimetric study of mandible examinations performed with three cone-beam computed tomography scanners.

PubMed

Khoury, Helen J; Andrade, Marcos E; Araujo, Max Well; Brasileiro, Izabela V; Kramer, Richard; Huda, Amir

2015-07-01

The objective of this work was to evaluate the air kerma-area product (PKA) and the skin absorbed dose in the region of the eyes, salivary glands and thyroid of the patient from mandible examinations performed with three cone-beam computed tomography (CBCT) scanners, i.e. i-CAT classic, Gendex CB-500 and PreXion 3D. For the dosimetric evaluation, an anthropomorphic head phantom (model RS-250) was used to simulate an adult patient. The CBCT examinations were performed using standard and high-resolution protocols for mandible acquisitions for adult patients. During the phantom's exposure, the PKA was measured using an ionising chamber and the absorbed doses to the skin in the region of the eyes, thyroid and salivary glands were estimated using thermoluminescence dosemeters (TLDs) positioned on the phantom's surface. The PKA values estimated with the CBCT scanners varied from 26 to 138 µGy m(2). Skin absorbed doses in the region of the eyes varied from 0.07 to 0.34 mGy; at the parotid glands, from 1.31 to 5.93 mGy; at the submandibular glands, from 1.41 to 6.86 mGy; and at the thyroid, from 0.18 to 2.45 mGy. PKA and absorbed doses showed the highest values for the PreXion 3D scanner due to the use of the continuous exposure mode and a high current-time product. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Non-destructive determination of uranium, thorium and 40K in tobacco and their implication on radiation dose levels to the human body.

PubMed

Landsberger, S; Lara, R; Landsberger, S G

2015-11-01

The naturally occurring radionuclides of (235)U, (238)U and (232)Th and their daughter products are a potential major source of anthropogenic radiation to tobacco smokers. Often overlooked is the presence of (40)K in tobacco and its implication to radiation dose accumulation in the human body. In this study, these three radiation sources have been determined in four typical US cigarettes using neutron activation analysis (NAA). The NAA reactions of (238)U(n,γ)(239)U, (232)Th(n,γ)(233)Th and (41)K(n,γ)(42)K were used to determine (235)U, (238)U and (232)Th and (40)K, respectively. The activity of (238)U can easily be determined by epithermal NAA of the (238)U(n,γ)(239)U reaction, and the activity of (235, 234)U can easily be deduced. Using isotopic ratios, the activity due to (40)K was found by the determined concentrations of (41)K (also by epithermal neutrons) in the bulk material. Each gram of total potassium yields 30 Bq of (40)K. The annual effective dose for smokers using 20 cigarettes per day was calculate to be 14.6, 137 and 9 μSv y(-1) for (238,235,) (234)U, (232)Th and (40)K, respectively. These values are significantly lower that the dose received from (210)Po except for (232)Th. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Hispanic mothers' beliefs regarding HPV vaccine series completion in their adolescent daughters.

PubMed

Roncancio, A M; Ward, K K; Carmack, C C; Muñoz, B T; Cribbs, F L

2017-02-01

Rates of human papillomavirus (HPV) vaccine series completion among adolescent Hispanic females in Texas in 2014 (∼39%) lag behind the Healthy People 2020 goal (80%). This qualitative study identifies Hispanic mothers' salient behavioral, normative and control beliefs regarding having their adolescent daughters complete the vaccine series. Thirty-two mothers of girls (aged 11-17) that had received at least one dose of the HPV vaccine, completed in-depth interviews. Six girls had received one dose of the HPV vaccine, 10 girls had received two doses, and 16 girls had received all three doses. The questions elicited salient: (i) experiential and instrumental attitudes (behavioral beliefs); (ii) supporters and non-supporters (normative beliefs) and (iii) facilitators and barriers (control beliefs). Directed content analysis was employed to select the most salient beliefs. Mothers: (i) expressed salient positive feelings (e.g. good, secure, happy and satisfied); (ii) believed that completing the series resulted in positive effects (e.g. protection, prevention); (iii) believed that the main supporters were themselves, their daughter's father and doctor with some of their friends not supporting series completion and (iv) believed that vaccine affordability, information, transportation, ease of scheduling and keeping vaccination appointments and taking their daughter's immunization card to appointments were facilitators. This study represents the first step in building theory-based framework of vaccine series completion for this population. The beliefs identified provide guidance for health care providers and intervention developers. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Dose escalation of definitive radiation is not associated with improved survival for cervical esophageal cancer: a National Cancer Data Base (NCDB) analysis.

PubMed

De, B; Rhome, R; Doucette, J; Buckstein, M

2017-04-01

For cervical esophageal cancer (CEC), National Comprehensive Cancer Network guidelines support RT to 50-50.4 Gy with chemotherapy but acknowledge higher doses may be appropriate. This study uses the National Cancer Database (NCDB) to characterize RT practices and identify if a dose-response relationship exists for overall survival (OS) for definitive treatment of CEC. We queried the NCDB for patients diagnosed with Stage I-III CEC from 2004 to 2013, and selected patients receiving definitive RT with doses between 50 and 74 Gy. Using multivariate logistic regression, the database was analyzed to determine factors associated with use of RT > 50.4 Gy. Patients were then stratified into three dose categories. Predictors of OS were analyzed with univariate and multivariate methods using the Kaplan-Meier curves, the log-rank test, and the Cox proportional hazards analysis. We stratified 789 patients with CEC who were treated with definitive radiation ± chemotherapy: 50-50.4 Gy ('standard'), >50.4 and <66 Gy ('medium'), and 66-74 Gy ('high'). Of these patients, 215 (27%) received standard doses, 375 (48%) received medium doses, and 199 (25%) received high doses. Patients with Medicaid insurance and those with Stage II disease were less likely (P < 0.05) to receive >50.4 Gy. Sex, histology, distance to treatment facility, and academic/community facility type were not significantly associated with receipt of >50.4 Gy. There was no association between dose and OS for the medium or high groups when using univariate analysis or analysis adjusted for demographic, facility, and clinical attributes. Stage III disease and the Charlson-Deyo scores of 1 or 2 were associated with higher mortality (P < 0.05), while female sex and use of chemotherapy were associated with lower mortality (P < 0.01). Nearly three-fourths of CEC patients in the United States are treated with RT > 50.4 Gy. Higher radiation doses were not associated with increased OS in CEC patients in the NCDB. © The Authors 2017. Published by Oxford University Press on behalf of International Society for Diseases of the Esophagus. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Monte Carlo and Phantom Study of the Radiation Dose to the Body from Dedicated Computed Tomography of the Breast

PubMed Central

Sechopoulos, Ioannis; Vedantham, Srinivasan; Suryanarayanan, Sankararaman; D’Orsi, Carl J.; Karellas, Andrew

2008-01-01

Purpose To prospectively determine the radiation dose absorbed by the organs and tissues of the body during a dedicated computed tomography of the breast (DBCT) study using Monte Carlo methods and a phantom. Materials and Methods Using the Geant4 Monte Carlo toolkit, the Cristy anthropomorphic phantom and the geometry of a prototype DBCT was simulated. The simulation was used to track x-rays emitted from the source until their complete absorption or exit from the simulation limits. The interactions of the x-rays with the 65 different volumes representing organs, bones and other tissues of the anthropomorphic phantom that resulted in energy deposition were recorded. These data were used to compute the radiation dose to the organs and tissues during a complete DBCT acquisition relative to the average glandular dose to the imaged breast (ROD, relative organ dose), using the x-ray spectra proposed for DBCT imaging. The effectiveness of a lead shield for reducing the dose to the organs was investigated. Results The maximum ROD among the organs was for the ipsilateral lung with a maximum of 3.25%, followed by the heart and the thymus. Of the skeletal tissues, the sternum received the highest dose with a maximum ROD to the bone marrow of 2.24%, and to the bone surface of 7.74%. The maximum ROD to the uterus, representative of that of an early-stage fetus, was 0.026%. These maxima occurred for the highest energy x-ray spectrum (80 kVp) analyzed. A lead shield does not protect substantially the organs that receive the highest dose from DBCT. Discussion Although the dose to the organs from DBCT is substantially higher than that from planar mammography, they are comparable or considerably lower than those reached by other radiographic procedures and much lower than other CT examinations. PMID:18292479

Impact of cardiosynchronous brain pulsations on Monte Carlo calculated doses for synchrotron micro- and minibeam radiation therapy.

PubMed

Manchado de Sola, Francisco; Vilches, Manuel; Prezado, Yolanda; Lallena, Antonio M

2018-05-15

The purpose of this study was to assess the effects of brain movements induced by heartbeat on dose distributions in synchrotron micro- and minibeam radiation therapy and to develop a model to help guide decisions and planning for future clinical trials. The Monte Carlo code PENELOPE was used to simulate the irradiation of a human head phantom with a variety of micro- and minibeam arrays, with beams narrower than 100 μm and above 500 μm, respectively, and with radiation fields of 1 × 2 cm and 2 × 2 cm. The dose in the phantom due to these beams was calculated by superposing the dose profiles obtained for a single beam of 1 μm × 2 cm. A parameter δ, accounting for the total displacement of the brain during the irradiation and due to the cardiosynchronous pulsation, was used to quantify the impact on peak-to-valley dose ratios and the full width at half maximum. The difference between the maximum (at the phantom entrance) and the minimum (at the phantom exit) values of the peak-to-valley dose ratio reduces when the parameter δ increases. The full width at half maximum remains almost constant with depth for any δ value. Sudden changes in the two quantities are observed at the interfaces between the various tissues (brain, skull, and skin) present in the head phantom. The peak-to-valley dose ratio at the center of the head phantom reduces when δ increases, remaining above 70% of the static value only for minibeams and δ smaller than ∼200 μm. Optimal setups for brain treatments with synchrotron radiation micro- and minibeam combs depend on the brain displacement due to cardiosynchronous pulsation. Peak-to-valley dose ratios larger than 90% of the maximum values obtained in the static case occur only for minibeams and relatively large dose rates. © 2018 American Association of Physicists in Medicine.

Successful pharmacogenetics-based optimization of unboosted atazanavir plasma exposure in HIV-positive patients: a randomized, controlled, pilot study (the REYAGEN study).

PubMed

Bonora, S; Rusconi, S; Calcagno, A; Bracchi, M; Viganò, O; Cusato, J; Lanzafame, M; Trentalange, A; Marinaro, L; Siccardi, M; D'Avolio, A; Galli, M; Di Perri, G

2015-11-01

Atazanavir without ritonavir, despite efficacy and tolerability, shows low plasma concentrations that warrant optimization. In a randomized, controlled, pilot trial, stable HIV-positive patients on atazanavir/ritonavir (with tenofovir/emtricitabine) were switched to atazanavir. In the standard-dose arm, atazanavir was administered as 400 mg once daily, while according to patients' genetics (PXR, ABCB1 and SLCO1B1), in the pharmacogenetic arm: patients with unfavourable genotypes received 200 mg of atazanavir twice daily. EudraCT number: 2009-014216-35. Eighty patients were enrolled with balanced baseline characteristics. The average atazanavir exposure was 253 ng/mL (150-542) in the pharmacogenetic arm versus 111 ng/mL (64-190) in the standard-dose arm (P < 0.001); 28 patients in the pharmacogenetic arm (75.7%) had atazanavir exposure >150 ng/mL versus 14 patients (38.9%) in the standard-dose arm (P = 0.001). Immunovirological and laboratory parameters had a favourable outcome throughout the study with non-significant differences between study arms. Atazanavir plasma exposure is higher when the schedule is chosen according to the patient's genetic profile. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Immune Serum From Sabin Inactivated Poliovirus Vaccine Immunization Neutralizes Multiple Individual Wild and Vaccine-Derived Polioviruses.

PubMed

Sun, Mingbo; Li, Changgui; Xu, Wenbo; Liao, Guoyang; Li, Rongcheng; Zhou, Jian; Li, Yanping; Cai, Wei; Yan, Dongmei; Che, Yanchun; Ying, Zhifang; Wang, Jianfeng; Yang, Huijuan; Ma, Yan; Ma, Lei; Ji, Guang; Shi, Li; Jiang, Shude; Li, Qihan

2017-05-15

A Sabin strain-based inactivated poliomyelitis vaccine (Sabin-IPV) is the rational option for completely eradicating poliovirus transmission. The neutralizing capacity of Sabin-IPV immune serum to different strains of poliovirus is a key indicator of the clinical protective efficacy of this vaccine. Sera collected from 500 infants enrolled in a randomized, blinded, positive control, phase 2 clinical trial were randomly divided into 5 groups: Groups A, B, and C received high, medium, and low doses, respectively, of Sabin-IPV, while groups D and E received trivalent oral polio vaccine and Salk strain-based IPV, respectively, all on the same schedule. Immune sera were collected after the third dose of primary immunization, and tested in cross-neutralization assays against 19 poliovirus strains of all 3 types. All immune sera from all 5 groups interacted with the 19 poliovirus strains with various titers and in a dose-dependent manner. One type 2 immunodeficiency-associated vaccine-derived poliovirus strain was not recognized by these immune sera. Sabin-IPV vaccine can induce protective antibodies against currently circulating and reference wild poliovirus strains and most vaccine-derived poliovirus strains, with rare exceptions. NCT01056705. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Simultaneous Determination of Formoterol Fumarate and Budesonide Epimers in Metered Dose Inhaler Using Ion-Pair Chromatography.

PubMed

Salem, Y A; Shaldam, M A; El-Sherbiny, D T; El-Wasseef, D R; El-Ashry, S M

2017-11-01

A simple, accurate and valid ion-pairing chromatographic method was developed for the simultaneous determination of formoterol fumarate (FF) and budesonide (BUD) epimers in metered dose inhaler. The separation was performed on C-18 column using mobile phase consisting of acetonitrile:0.05 M sodium acetate buffer (40:60% v/v) containing 0.03% sodium dodecyl sulfate adjusted to pH 3.1 using increasing volumes of either TEA or orthophosphoric acid isocratically eluted at 1.0 mL/min. Quantitation was achieved with UV detection at 214 nm. The retention times were 3.22, 6.41 and 6.91 min for formoterol fumarate, budesonide epimers B and A, respectively. The linearity range was 0.05-5.0 μg/mL for formoterol fumarate and 0.5-50.0 μg/mL for budesonide. The method was validated for, linearity; lower limit of quantification, lower limit of detection accuracy and precision. The proposed method is rapid (7 min), reproducible (RSD < 2.0%) and achieves satisfactory resolution between FF and BUD B (resolution factor = 12.07). The mean recoveries of the analytes in metered dose inhaler (99.97 and 99.83% for FF and BUD, respectively) were satisfactory. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Combination chemotherapy with methotrexate and vinblastine for surgically unresectable, aggressive fibromatosis.

PubMed

Park, Kyong-Hwa; Choi, Yoon Ji; Kim, Kwan-Woo; Ro, Kyung-Han; Kang, Chang Ho; Song, Sang-Heon; Park, Jong Hoon

2016-09-01

To elucidate the clinical benefit and safety of low-dose chemotherapy using methotrexate and vinblastine in patients (mostly adults) with progressive and/or symptomatic fibromatosis. Patients were enrolled if they were treated with methotrexate and vinblastine chemotherapy for recurrences after surgical excision or newly diagnosed aggressive fibromatosis that was not amenable to surgical resection at the Korea University Medical Center from May 2008 to February 2016. Twenty-two patients were treated with this regimen, and 21 were eligible for safety and efficacy analysis. Eleven (52%) of 21 patients showed a documented partial response (PR), and 11 showed stable disease (SD) by the end of treatment. All the patients who achieved PR reported a significant reduction in pain and improvement in the function of the affected lesions. Median progression-free survival was not reached at the time of analysis. The most common adverse event was abnormalities of the liver transaminases (overall 84.2%). The most common grade 3 or higher toxicity was neutropenia (36.8%), but no febrile neutropenic event was observed. The elevated levels of transaminases were normalized by reducing the dose of methotrexate or delaying treatment. Low-dose chemotherapy with methotrexate and vinblastine for 1 year was effective and well tolerated by adult patients with aggressive, recurrent fibromatosis. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Use of iodine for water disinfection: iodine toxicity and maximum recommended dose.

PubMed Central

Backer, H; Hollowell, J

2000-01-01

Iodine is an effective, simple, and cost-efficient means of water disinfection for people who vacation, travel, or work in areas where municipal water treatment is not reliable. However, there is considerable controversy about the maximum safe iodine dose and duration of use when iodine is ingested in excess of the recommended daily dietary amount. The major health effect of concern with excess iodine ingestion is thyroid disorders, primarily hypothyroidism with or without iodine-induced goiter. A review of the human trials on the safety of iodine ingestion indicates that neither the maximum recommended dietary dose (2 mg/day) nor the maximum recommended duration of use (3 weeks) has a firm basis. Rather than a clear threshold response level or a linear and temporal dose-response relationship between iodine intake and thyroid function, there appears to be marked individual sensitivity, often resulting from unmasking of underlying thyroid disease. The use of iodine for water disinfection requires a risk-benefit decision based on iodine's benefit as a disinfectant and the changes it induces in thyroid physiology. By using appropriate disinfection techniques and monitoring thyroid function, most people can use iodine for water treatment over a prolonged period of time. PMID:10964787

Is it possible to avoid hypopituitarism after irradiation of pituitary adenomas by the Leksell gamma knife?

PubMed

Marek, Josef; Jezková, Jana; Hána, Václav; Krsek, Michal; Bandúrová, L'ubomíra; Pecen, Ladislav; Vladyka, Vilibald; Liscák, Roman

2011-02-01

Radiation therapy is one of the treatment options for pituitary adenomas. The most common side effect associated with Leksell gamma knife (LGK) irradiation is the development of hypopituitarism. The aim of this study was to verify that hypopituitarism does not develop if the maximum mean dose to pituitary is kept under 15 Gy and to evaluate the influence of maximum distal infundibulum dose on the development of hypopituitarism. We followed the incidence of hypopituitarism in 85 patients irradiated with LGK in 1993-2003. The patients were divided in two subgroups: the first subgroup followed prospectively (45 patients), irradiated with a mean dose to pituitary <15 Gy; the second subgroup followed retrospectively 1993-2001 and prospectively 2001-2009 (40 patients), irradiated with a mean dose to pituitary >15 Gy. Serum TSH, free thyroxine, testosterone or 17β-oestradiol, IGF1, prolactin and cortisol levels were evaluated before and every 6 months after LGK irradiation. Hypopituitarism after LGK irradiation developed only in 1 out of 45 (2.2%) patients irradiated with a mean dose to pituitary <15 Gy, in contrast to 72.5% patients irradiated with a mean dose to pituitary >15 Gy. The radiation dose to the distal infundibulum was found as an independent factor of hypopituitarism with calculated maximum safe dose of 17 Gy. Keeping the mean radiation dose to pituitary under 15 Gy and the dose to the distal infundibulum under 17 Gy prevents the development of hypopituitarism following LGK irradiation.

DOSIMETRIC CONSEQUENCES OF USING CONTRAST-ENHANCED COMPUTED TOMOGRAPHIC IMAGES FOR INTENSITY-MODULATED STEREOTACTIC BODY RADIOTHERAPY PLANNING.

PubMed

Yoshikawa, Hiroto; Roback, Donald M; Larue, Susan M; Nolan, Michael W

2015-01-01

Potential benefits of planning radiation therapy on a contrast-enhanced computed tomography scan (ceCT) should be weighed against the possibility that this practice may be associated with an inadvertent risk of overdosing nearby normal tissues. This study investigated the influence of ceCT on intensity-modulated stereotactic body radiotherapy (IM-SBRT) planning. Dogs with head and neck, pelvic, or appendicular tumors were included in this retrospective cross-sectional study. All IM-SBRT plans were constructed on a pre- or ceCT. Contours for tumor and organs at risk (OAR) were manually constructed and copied onto both CT's; IM-SBRT plans were calculated on each CT in a manner that resulted in equal radiation fluence. The maximum and mean doses for OAR, and minimum, maximum, and mean doses for targets were compared. Data were collected from 40 dogs per anatomic site (head and neck, pelvis, and limbs). The average dose difference between minimum, maximum, and mean doses as calculated on pre- and ceCT plans for the gross tumor volume was less than 1% for all anatomic sites. Similarly, the differences between mean and maximum doses for OAR were less than 1%. The difference in dose distribution between plans made on CTs with and without contrast enhancement was tolerable at all treatment sites. Therefore, although caution would be recommended when planning IM-SBRT for tumors near "reservoirs" for contrast media (such as the heart and urinary bladder), findings supported the use of ceCT with this dose calculation algorithm for both target delineation and IM-SBRT treatment planning. © 2015 American College of Veterinary Radiology.

Effects of Bleaching by Nitrogen Deficiency on the Quantum Yield of Photosystem II in Synechocystis sp. PCC 6803 Revealed by Chl Fluorescence Measurements.

PubMed

Ogawa, Takako; Sonoike, Kintake

2016-03-01

Estimation of photosynthesis by Chl fluorescence measurement of cyanobacteria is always problematic due to the interference from respiratory electron transfer and from phycocyanin fluorescence. The interference from respiratory electron transfer could be avoided by the use of DCMU or background illumination by blue light, which oxidizes the plastoquinone pool that tends to be reduced by respiration. On the other hand, the precise estimation of photosynthesis in cells with a different phycobilisome content by Chl fluorescence measurement is difficult. By subtracting the basal fluorescence due to the phycobilisome and PSI, it becomes possible to estimate the precise maximum quantum yield of PSII in cyanobacteria. Estimated basal fluorescence accounted for 60% of the minimum fluorescence, resulting in a large difference between the 'apparent' yield and 'true' yield under high phycocyanin conditions. The calculated value of the 'true' maximum quantum yield of PSII was around 0.8, which was similar to the value observed in land plants. The results suggest that the cause of the apparent low yield reported in cyanobacteria is mainly ascribed to the interference from phycocyanin fluorescence. We also found that the 'true' maximum quantum yield of PSII decreased under nitrogen-deficient conditions, suggesting the impairment of the PSII reaction center, while the 'apparent' maximum quantum yield showed a marginal change under the same conditions. Due to the high contribution of phycocyanin fluorescence in cyanobacteria, it is essential to eliminate the influence of the change in phycocyanin content on Chl fluorescence measurement and to evaluate the 'true' photosynthetic condition. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Self-tapping ability of carbon fibre reinforced polyetheretherketone suture anchors.

PubMed

Feerick, Emer M; Wilson, Joanne; Jarman-Smith, Marcus; Ó'Brádaigh, Conchur M; McGarry, J Patrick

2014-10-01

An experimental and computational investigation of the self-tapping ability of carbon fibre reinforced polyetheretherketone (CFR-PEEK) has been conducted. Six CFR-PEEK suture anchor designs were investigated using PEEK-OPTIMA® Reinforced, a medical grade of CFR-PEEK. Experimental tests were conducted to investigate the maximum axial force and torque required for self-taping insertion of each anchor design. Additional experimental tests were conducted for some anchor designs using pilot holes. Computational simulations were conducted to determine the maximum stress in each anchor design at various stages of insertion. Simulations also were performed to investigate the effect of wall thickness in the anchor head. The maximum axial force required to insert a self-tapping CFR-PEEK suture anchor did not exceed 150 N for any anchor design. The maximum torque required to insert a self-tapping CFR-PEEK suture anchor did not exceed 0.8 Nm. Computational simulations reveal significant stress concentrations in the region of the anchor tip, demonstrating that a re-design of the tip geometry should be performed to avoid fracture during self-tapping, as observed in the experimental component of this study. This study demonstrates the ability of PEEK-OPTIMA Reinforced suture anchors to self-tap polyurethane foam bone analogue. This provides motivation to further investigate the self-tapping ability of CFR-PEEK suture anchors in animal/cadaveric bone. An optimised design for CFR-PEEK suture anchors offers the advantages of radiolucency, and mechanical properties similar to bone with the ability to self-tap. This may have positive implications for reducing surgery times and the associated costs with the procedure. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

RADIOACTIVE CONTAMINATION OF FOODS. PROBLEMS IN THE FOOD CONSUMPTION OF THE ITALIAN POPULATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferro-Luzzi, A.; Mariani, A.

The aspects of health physics that are basically applications of physics are reviewed. Units of radiation measurement, RBE, permissible doses, personnel monitoring, applications of radiation spectrometry, and measurement of body activity are considered, as well as the release, dispersion, and deposition of radioactive material in reactor accidents. 140 references. (D.C.W.)

Volumetric tumor burden and its effect on brachial plexus dosimetry in head and neck intensity-modulated radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romesser, Paul B.; Qureshi, Muhammad M.; Kovalchuk, Nataliya

2014-07-01

To determine the effect of gross tumor volume of the primary (GTV-P) and nodal (GTV-N) disease on planned radiation dose to the brachial plexus (BP) in head and neck intensity-modulated radiotherapy (IMRT). Overall, 75 patients underwent definitive IMRT to a median total dose of 69.96 Gy in 33 fractions. The right BP and left BP were prospectively contoured as separate organs at risk. The GTV was related to BP dose using the unpaired t-test. Receiver operating characteristics curves were constructed to determine optimized volumetric thresholds of GTV-P and GTV-N corresponding to a maximum BP dose cutoff of > 66 Gy.more » Multivariate analyses were performed to account for factors associated with a higher maximal BP dose. A higher maximum BP dose (> 66 vs ≤ 66 Gy) correlated with a greater mean GTV-P (79.5 vs 30.8 cc; p = 0.001) and ipsilateral GTV-N (60.6 vs 19.8 cc; p = 0.014). When dichotomized by the optimized nodal volume, patients with an ipsilateral GTV-N ≥ 4.9 vs < 4.9 cc had a significant difference in maximum BP dose (64.2 vs 59.4 Gy; p = 0.001). Multivariate analysis confirmed that an ipsilateral GTV-N ≥ 4.9 cc was an independent predictor for the BP to receive a maximal dose of > 66 Gy when adjusted individually for BP volume, GTV-P, the use of a low anterior neck field technique, total planned radiation dose, and tumor category. Although both the primary and the nodal tumor volumes affected the BP maximal dose, the ipsilateral nodal tumor volume (GTV-N ≥ 4.9 cc) was an independent predictor for high maximal BP dose constraints in head and neck IMRT.« less

Stereotactic body radiation therapy of early-stage non-small-cell lung carcinoma: Phase I study

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGarry, Ronald C.; Papiez, Lech; Williams, Mark

Purpose: A Phase I dose escalation study of stereotactic body radiation therapy to assess toxicity and local control rates for patients with medically inoperable Stage I lung cancer. Methods and Materials: All patients had non-small-cell lung carcinoma, Stage T1a or T1b N0, M0. Patients were immobilized in a stereotactic body frame and treated in escalating doses of radiotherapy beginning at 24 Gy total (3 x 8 Gy fractions) using 7-10 beams. Cohorts were dose escalated by 6.0 Gy total with appropriate observation periods. Results: The maximum tolerated dose was not achieved in the T1 stratum (maximum dose = 60 Gy),more » but within the T2 stratum, the maximum tolerated dose was realized at 72 Gy for tumors larger than 5 cm. Dose-limiting toxicity included predominantly bronchitis, pericardial effusion, hypoxia, and pneumonitis. Local failure occurred in 4/19 T1 and 6/28 T2 patients. Nine local failures occurred at doses {<=}16 Gy and only 1 at higher doses. Local failures occurred between 3 and 31 months from treatment. Within the T1 group, 5 patients had distant or regional recurrence as an isolated event, whereas 3 patients had both distant and regional recurrence. Within the T2 group, 2 patients had solitary regional recurrences, and the 4 patients who failed distantly also failed regionally. Conclusions: Stereotactic body radiation therapy seems to be a safe, effective means of treating early-stage lung cancer in medically inoperable patients. Excellent local control was achieved at higher dose cohorts with apparent dose-limiting toxicities in patients with larger tumors.« less

76 FR 37806 - Ashton Hydro, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-28

... DEPARTMENT OF ENERGY [Project No. 14213-000] Ashton Hydro, LLC; Notice of Preliminary Permit... lands or waters owned by others without the owners' express permission. The proposed run-of-the-river... level and a maximum storage capacity of about 200 ac-ft; (3) a new intake on the upstream face of the...

24 CFR 245.315 - Materials to be submitted to HUD.

Code of Federal Regulations, 2010 CFR

2010-04-01

... local HUD office: (a) Documents to be submitted under profit and loss approach: (1) A copy of the notice... Increase in Maximum Permissible Rents § 245.315 Materials to be submitted to HUD. When the notice referred to in § 245.310 is served on the tenants, the mortgagor must send to the local HUD office copies of...

24 CFR 245.315 - Materials to be submitted to HUD.

Code of Federal Regulations, 2011 CFR

2011-04-01

... local HUD office: (a) Documents to be submitted under profit and loss approach: (1) A copy of the notice... Increase in Maximum Permissible Rents § 245.315 Materials to be submitted to HUD. When the notice referred to in § 245.310 is served on the tenants, the mortgagor must send to the local HUD office copies of...

75 FR 35027 - Notice of Public Information Collection Approved By the Office of Management and Budget

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-21

... must file an informal request for any increase in the station's FM Digital ERP). (2) Licensees to... Digital ERP beyond 6 dB. (3) Licensees submitting such a request must use a simplified method set forth in the Order to determine the proponent station's maximum permissible FM Digital ERP. (4) In situations...

Prevention of unorganized emissions of ammonia in installations of dewaxing of oils

NASA Astrophysics Data System (ADS)

Rehovskaya, E. O.; Nagibina, I. Yu; Ivanov, A. Yu

2018-01-01

The problem of lack of automation devices in oil dewaxing units is considered in this work. As a result, fugitive ammonia emissions that exceed the maximum permissible concentration, which adversely affect the health of personnel and the environment, can occur in the atmospheric air. The device and the operating principle of the automatic air separator are shown.

Zinc, nickel and cadmium in carambolas marketed in Guangzhou and Hong Kong, China: implication for human health.

PubMed

Li, J T; Liao, B; Lan, C Y; Qiu, J W; Shu, W S

2007-12-15

Carambola (Averrhoa carambola L.) is a popular juicy fruit throughout the tropical and subtropical world. This study was designed to quantify the levels of zinc (Zn), nickel (Ni) and cadmium (Cd) in carambolas marketed in southern China, and further to evaluate the potential health risk of human consumption of carambola. Zinc concentrations, ranging from 1.471 to 2.875 mg/kg (on fresh weight basis), were below the maximum permissible concentration for Zn in fruit of China (5 mg/kg). However, Ni concentrations (0.134-0.676 mg/kg) were considerably higher than the related recommendation values. Furthermore, Cd concentrations in 51% of the carambolas purchased from Guangzhou exceeded the maximum permissible concentration for Cd in fruit of China (0.03 mg/kg). Our results implicated that the consumption of 0.385 kg carambola contaminated by Cd per day would cause the tolerable daily intake (TDI) of Cd by the consumer to be exceeded. In addition, the remarkably high Ni concentrations in carambolas should also be of concern. The status of heavy metal contamination of carambola products marketed in the other regions and their implications for human health should be identified urgently by in-depth studies.

Estimates of auditory risk from outdoor impulse noise. II: Civilian firearms.

PubMed

Flamme, Gregory A; Wong, Adam; Liebe, Kevin; Lynd, James

2009-01-01

Firearm impulses are common noise exposures in the United States. This study records, describes and analyzes impulses produced outdoors by civilian firearms with respect to the amount of auditory risk they pose to the unprotected listener under various listening conditions. Risk estimates were obtained using three contemporary damage risk criteria (DRC) including a waveform parameter-based approach (peak SPL and B-duration), an energy-based criterion (A-weighted SEL and equivalent continuous level) and a physiological model (AHAAH). Results from these DRC were converted into a number of maximum permissible unprotected exposures to facilitate interpretation. Acoustic characteristics of firearm impulses differed substantially across guns, ammunition, and microphone location. The type of gun, ammunition and the microphone location all significantly affected estimates of auditory risk from firearms. Vast differences in maximum permissible exposures were observed; the rank order of the differences varied with the source of the impulse. Unprotected exposure to firearm noise is not recommended, but people electing to fire a gun without hearing protection should be advised to minimize auditory risk through careful selection of ammunition and shooting environment. Small-caliber guns with long barrels and guns loaded with the least powerful ammunition tend to be associated with the least auditory risk.

FADING EFFECT OF LiF:Mg,Ti AND LiF:Mg,Cu,P Ext-Rad AND WHOLE-BODY DETECTORS.

PubMed

Pereira, J; Pereira, M F; Rangel, S; Saraiva, M; Santos, L M; Cardoso, J V; Alves, J G

2016-09-01

Thermoluminescence dosemeters are widely used in individual and environmental monitoring. The aim of this work was to compare the thermal stability of dosemeters of the Ext-Rad and whole-body card types with LiF:Mg,Ti and LiF:Mg,Cu,P detectors stored at different temperatures and periods. The dosemeters were stored at 0°C, room temperature and 40°C for periods that lasted 8, 30, 45, 90 and 120 d. In general, TLD-100H detectors present higher TL signal stability than TLD-100 detectors. The intensity of the signal remained constant for both materials for storage periods at 0°C. At RT the same results was observed for TLD-100H. For TLD-100 detectors, a maximum variation of 22 % was registered for the longest period. At 40°C the TL signal decreased with storage time for both detectors. The TL signal of TLD-100H detectors presented maximum variations of 12 % whereas for TLD-100 detectors, larger variations of 25 % were observed. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Fetal radiation dose estimates for I-131 sodium iodide in cases where conception occurs after administration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sparks, R.B.; Stabin, M.G.

1999-01-01

After administration of I-131 to the female patient, the possibility of radiation exposure of the embryo/fetus exists if the patient becomes pregnant while radioiodine remains in the body. Fetal radiation dose estimates for such cases were calculated. Doses were calculated for various maternal thyroid uptakes and time intervals between administration and conception, including euthyroid and hyperthyroid cases. The maximum fetal dose calculating was about 9.8E-03 mGy/MBq, which occurred with 100% maternal thyroid uptake and a 1 week interval between administration and conception. Placental crossover of the small amount of radioiodine remaining 90 days after conception was also considered. Such crossovermore » could result in an additional fetal dose of 9.8E-05 mGy/MBq and a maximum fetal thyroid self dose of 3.5E-04 mGy/MBq.« less

In vivo dosimetry for external photon treatments of head and neck cancers by diodes and TLDS.

PubMed

Tung, C J; Wang, H C; Lo, S H; Wu, J M; Wang, C J

2004-01-01

In vivo dosimetry was implemented for treatments of head and neck cancers in the large fields. Diode and thermoluminescence dosemeter (TLD) measurements were carried out for the linear accelerators of 6 MV photon beams. ESTRO in vivo dosimetry protocols were followed in the determination of midline doses from measurements of entrance and exit doses. Of the fields monitored by diodes, the maximum absolute deviation of measured midline doses from planned target doses was 8%, with the mean value and the standard deviation of -1.0 and 2.7%. If planned target doses were calculated using radiological water equivalent thicknesses rather than patient geometric thicknesses, the maximum absolute deviation dropped to 4%, with the mean and the standard deviation of 0.7 and 1.8%. For in vivo dosimetry monitored by TLDs, the shift in mean dose remained small but the statistical precision became poor.

Whole-remnant and maximum-voxel SPECT/CT dosimetry in {sup 131}I-NaI treatments of differentiated thyroid cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mínguez, Pablo, E-mail: pablo.minguezgabina@osakid

Purpose: To investigate the possible differences between SPECT/CT based whole-remnant and maximum-voxel dosimetry in patients receiving radio-iodine ablation treatment of differentiated thyroid cancer (DTC). Methods: Eighteen DTC patients were administered 1.11 GBq of {sup 131}I-NaI after near-total thyroidectomy and rhTSH stimulation. Two patients had two remnants, so in total dosimetry was performed for 20 sites. Three SPECT/CT scans were performed for each patient at 1, 2, and 3–7 days after administration. The activity, the remnant mass, and the maximum-voxel activity were determined from these images and from a recovery-coefficient curve derived from experimental phantom measurements. The cumulated activity was estimatedmore » using trapezoidal-exponential integration. Finally, the absorbed dose was calculated using S-values for unit-density spheres in whole-remnant dosimetry and S-values for voxels in maximum-voxel dosimetry. Results: The mean absorbed dose obtained from whole-remnant dosimetry was 40 Gy (range 2–176 Gy) and from maximum-voxel dosimetry 34 Gy (range 2–145 Gy). For any given patient, the activity concentrations for each of the three time-points were approximately the same for the two methods. The effective half-lives varied (R = 0.865), mainly due to discrepancies in estimation of the longer effective half-lives. On average, absorbed doses obtained from whole-remnant dosimetry were 1.2 ± 0.2 (1 SD) higher than for maximum-voxel dosimetry, mainly due to differences in the S-values. The method-related differences were however small in comparison to the wide range of absorbed doses obtained in patients. Conclusions: Simple and consistent procedures for SPECT/CT based whole-volume and maximum-voxel dosimetry have been described, both based on experimentally determined recovery coefficients. Generally the results from the two approaches are consistent, although there is a small, systematic difference in the absorbed dose due to differences in the S-values, and some variability due to differences in the estimated effective half-lives, especially when the effective half-life is long. Irrespective of the method used, the patient absorbed doses obtained span over two orders of magnitude.« less

CT Fluoroscopy Shielding: Decreases in Scattered Radiation for the Patient and Operator

PubMed Central

Neeman, Ziv; Dromi, Sergio A.; Sarin, Shawn; Wood, Bradford J.

2008-01-01

PURPOSE High-radiation exposure occurs during computed tomographic (CT) fluoroscopy. Patient and operator doses during thoracic and abdominal interventional procedures were studied in the present experiment, and a novel shielding device to reduce exposure to the patient and operator was evaluated. MATERIALS AND METHODS With a 16-slice CT scanner in CT fluoroscopy mode (120 kVp, 30 mA), surface dosimetry was performed on adult and pediatric phantoms. The shielding was composed of tungsten antimony in the form of a lightweight polymer sheet. Doses to the patient were measured with and without shielding for thoracic and abdominal procedures. Doses to the operator were recorded with and without phantom, gantry, and table shielding in place. Double-layer lead-free gloves were used by the operator during the procedures. RESULTS Tungsten antimony shielding adjacent to the scan plane resulted in a maximum dose reduction of 92.3% to the patient. Maximum 85.6%, 93.3%, and 85.1% dose reductions were observed for the operator’s torso, gonads, and hands, respectively. The use of double-layer lead-free gloves resulted in a maximum radiation dose reduction of 97%. CONCLUSIONS Methods to reduce exposure during CT fluoroscopy are effective and should be searched for. Significant reduction in radiation doses to the patient and operator can be accomplished with tungsten antimony shielding. PMID:17185699

MEASUREMENT OF RADON, THORON AND THEIR PROGENY CONCENTRATIONS IN THE DWELLINGS OF PAURI GARHWAL, UTTARAKHAND, INDIA.

PubMed

Joshi, Veena; Dutt, Sanjay; Yadav, Manjulata; Mishra, Rosaline; Ramola, R C

2016-10-01

It is well known that inhalation of radon, thoron and their progeny contributes more than 50 % of natural background radiation dose to human being. The time-integrated passive measurements of radon, thoron and their progeny concentrations were carried out in the dwellings of Pauri Garhwal, Uttarakhand, India. The measurements of radon and thoron concentrations were performed by LR-115 detector-based single-entry pin-hole dosemeter, while for the measurement of progeny concentrations, LR-115 deposition-based direct radon and thoron progeny sensors technique was used. The experimental techniques and results obtained are discussed in detail. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Using quality of life measures in a Phase I clinical trial of noni in patients with advanced cancer to select a Phase II dose.

PubMed

Issell, Brian F; Gotay, Carolyn C; Pagano, Ian; Franke, Adrian A

2009-01-01

ABSTRACT. The purpose of this study was to determine a maximum tolerated dose of noni in cancer patients and whether an optimal quality of life-sustaining dose could be identified as an alternative way to select a dose for subsequent Phase II efficacy trials. Dose levels started at two capsules twice daily (2 g), the suggested dose for the marketed product, and were escalated by 2 g daily in cohorts of at least five patients until a maximum tolerated dose was found. Patients completed subscales of the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 quality of life (physical functioning, pain, and fatigue) the brief fatigue inventory (BFI), questionnaires at baseline and at approximately 4-week intervals. Blood and urine were collected at baseline and at approximately 4-week intervals for measurement of scopoletin. Fifty-one patients were enrolled at seven dose levels. The maximum tolerated dose was six capsules four times daily (12 g). Although no dose-limiting toxicity was found, seven of eight patients at the next level (14 g), withdrew due to the challenges of ingesting so many capsules. There were dose-related differences in self-reported physical functioning and pain and fatigue control. Overall, patients taking three or four capsules four times daily experienced better outcomes than patients taking lower or higher doses. Blood and urinary scopoletin concentrations related to noni dose. We concluded that it is feasible to use quality of life measures to select a Phase II dose. Three or four capsules four times daily (6-8 g) is recommended when controlling fatigue, pain, and maintaining physical function are the efficacies of interest. Scopoletin, a bioactive component of noni fruit extract, is measurable in blood and urine following noni ingestion and can be used to study the pharmacokinetics of noni in cancer patients.

A short-term risk-benefit analysis of occasional and regular use of low-dose aspirin in primary prevention of vascular diseases: a nationwide population-based study.

PubMed

Wu, I-Chen; Hsieh, Hui-Min; Wu, Ming-Tsang

2015-01-09

To calculate the short-term risk-benefit effect of occasional and regular use of low-dose aspirin (≤100 mg/day) in primary prevention. Two retrospective cohort studies. Taiwan. 63 788 and 24 910 patients of two nationwide population-based studies were examined. Two databases of 1 000 000 patients were randomly sampled from data of Taiwan's National Health Insurance (NHI) for years 1997-2000 (NHI 2000) and 2005 (NHI 2005). In NHI 2000, 63 788 patients 30-95 years of age were found not to have previously been prescribed aspirin before 1 January 2000, but to have first been prescribed low-dose aspirin after that date. They were also found to be at risk of first hospitalisation for any major vascular diseases including haemorrhage (major gastrointestinal haemorrhage or cerebral haemorrhage) and ischaemia (acute myocardial infarction or ischaemic stroke) after their first prescription. We also applied it to NHI 2005, and the number of eligible patients was 24 910. Patients prescribed low-dose aspirin for <20% of the days of a 60-day follow-up period were considered to be occasional users, and those prescribed low-dose aspirin for ≥80% of the days were considered to be regular users. Differences in rate of haemorrhage and ischaemia between these users were used to calculate their net clinical risk. Vascular diseases. In NHI 2000, the overall unadjusted rates of haemorrhage and ischaemia were 0.09% and 0.21%, respectively, for occasional users and 0.32% and 2.30%, respectively, for regular users. Adjusted net clinical risk of low-dose aspirin use between the two groups was 2.24% (95% CI 2.03% to 2.48%; p<0.001). Similar results were also found in NHI 2005. Short-term regular use of low-dose aspirin might not be better than occasional use for preventing major vascular diseases in primary prevention. Prescribing regular low-dose aspirin for primary prevention should be done with caution. Future studies should explore the risk-benefit effect of long-term low-dose aspirin use in primary prevention. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

TCDD, FICZ, and Other High Affinity AhR Ligands Dose-Dependently Determine the Fate of CD4+ T Cell Differentiation.

PubMed

Ehrlich, Allison K; Pennington, Jamie M; Bisson, William H; Kolluri, Siva K; Kerkvliet, Nancy I

2018-02-01

FICZ and TCDD, two high-affinity AhR ligands, are reported to have opposite effects on T cell differentiation with TCDD inducing regulatory T cells and FICZ inducing Th17 cells. This dichotomy has been attributed to ligand-intrinsic differences in AhR activation, although differences in sensitivity to metabolism complicate the issue. TCDD is resistant to AhR-induced metabolism and produces sustained AhR activation following a single dose in the μg/kg range, whereas FICZ is rapidly metabolized and AhR activation is transient. Nonetheless, prior studies comparing FICZ with TCDD have generally used the same 10-50 μg/kg dose range, and thus the two ligands would not equivalently activate AhR. We hypothesized that high-affinity AhR ligands can promote CD4+ T cell differentiation into both Th17 cells and Tregs, with fate depending on the extent and duration of AhR activation. We compared the immunosuppressive effects of TCDD and FICZ, along with two other rapidly metabolized ligands (ITE and 11-Cl-BBQ) in an acute alloresponse mouse model. The dose and timing of administration of each ligand was optimized for TCDD-equivalent Cyp1a1 induction. When optimized, all of the ligands suppressed the alloresponse in conjunction with the induction of Foxp3- Tr1 cells on day 2 and the expansion of natural Foxp3+ Tregs on day 10. In contrast, a low dose of FICZ induced transient expression of Cyp1a1 and did not induce Tregs or suppress the alloresponse but enhanced IL-17 production. Interestingly, low doses of the other ligands, including TCDD, also increased IL-17 production on day 10. These findings support the conclusion that the dose and the duration of AhR activation by high-affinity AhR ligands are the primary factors driving the fate of T cell differentiation. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Six-Month Safety Data of Recombinant Vesicular Stomatitis Virus-Zaire Ebola Virus Envelope Glycoprotein Vaccine in a Phase 3 Double-Blind, Placebo-Controlled Randomized Study in Healthy Adults.

PubMed

Halperin, Scott A; Arribas, Jose R; Rupp, Richard; Andrews, Charles P; Chu, Laurence; Das, Rituparna; Simon, Jakub K; Onorato, Matthew T; Liu, Kenneth; Martin, Jason; Helmond, Frans A

2017-06-15

This study (NCT02503202) evaluated the safety of recombinant vesicular stomatitis virus-Zaire Ebola virus envelope glycoprotein vaccine (rVSVΔG-ZEBOV-GP). Overall, 1197 subjects were randomized 2:2:2:2:1; 1194 were vaccinated with 1 dose of 1 of 3 lots of rVSVΔG- ZEBOV-GP (2 × 107 plaque-forming units [pfu], n = 797; combined-lots group), a single high-dose lot of rVSVΔG-ZEBOV-GP (1 × 108 pfu, n = 264; high-dose group), or placebo (n = 133). Daily temperatures and adverse events (AEs) were recorded days 1 to 42 postvaccination. Solicited AEs included injection-site AEs from days 1 to 5, and joint pain, joint swelling, vesicular lesions (blisters), and rashes from days 1 to 42. Serious AEs (SAEs) were recorded through 6 months postvaccination. Fever (≥38.0°C) was observed in 20.2% of combined lots (3.2% with ≥39.0°C), 32.2% of high-dose (4.3% with ≥39.0°C), and 0.8% of placebo (0.8% with ≥39.0°C). Incidences of AEs of interest (days 1-42) were arthralgia (17.1% combined lots, 20.4% high-dose, 3.0% placebo), arthritis (5.1% combined lots, 4.2% high-dose, 0.0% placebo), and rash (3.8% combined lots, 3.8% high-dose, 1.5% placebo). Twenty-one SAEs and 2 deaths were reported, all assessed by investigators as unrelated to vaccine. rVSVΔG-ZEBOV-GP was generally well-tolerated, with increased rates of injection-site and systemic AEs compared to placebo, and no vaccine-related SAEs or deaths. These findings support the use of rVSVΔG-ZEBOV-GP vaccine in persons at risk for Ebola virus disease. NCT02503202. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Determinants and clinical outcome of uptitration of ACE-inhibitors and beta-blockers in patients with heart failure: a prospective European study.

PubMed

Ouwerkerk, W; Voors, A A; Anker, S D; Cleland, J G; Dickstein, K; Filippatos, G; van der Harst, P; Hillege, H L; Lang, C C; Ter Maaten, J M; Ng, L L; Ponikowski, P; Samani, N J; van Veldhuisen, D J; Zannad, F; Metra, M; Zwinderman, A H

2017-06-21

Despite clear guidelines recommendations, most patients with heart failure and reduced ejection-fraction (HFrEF) do not attain guideline-recommended target doses. We aimed to investigate characteristics and for treatment-indication-bias corrected clinical outcome of patients with HFrEF that did not reach recommended treatment doses of ACE-inhibitors/Angiotensin receptor blockers (ARBs) and/or beta-blockers. BIOSTAT-CHF was specifically designed to study uptitration of ACE-inhibitors/ARBs and/or beta-blockers in 2516 heart failure patients from 69 centres in 11 European countries who were selected if they were suboptimally treated while initiation or uptitration was anticipated and encouraged. Patients who died during the uptitration period (n = 151) and patients with a LVEF > 40% (n = 242) were excluded. Median follow up was 21 months. We studied 2100 HFrEF patients (76% male; mean age 68 ±12), of which 22% achieved the recommended treatment dose for ACE-inhibitor/ARB and 12% of beta-blocker. There were marked differences between European countries. Reaching <50% of the recommended ACE-inhibitor/ARB and beta-blocker dose was associated with an increased risk of death and/or heart failure hospitalization. Patients reaching 50-99% of the recommended ACE-inhibitor/ARB and/or beta-blocker dose had comparable risk of death and/or heart failure hospitalization to those reaching ≥100%. Patients not reaching recommended dose because of symptoms, side effects and non-cardiac organ dysfunction had the highest mortality rate (for ACE-inhibitor/ARB: HR 1.72; 95% CI 1.43-2.01; for beta-blocker: HR 1.70; 95% CI 1.36-2.05). Patients with HFrEF who were treated with less than 50% of recommended dose of ACE-inhibitors/ARBs and beta-blockers seemed to have a greater risk of death and/or heart failure hospitalization compared with patients reaching ≥100%. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.