Radiolysis of dilute aqueous thiourea solutions

1966 ◽  
Vol 292 (1428) ◽  
pp. 122-133 ◽  
Keyword(s):  
Aqueous Solution ◽  
Dose Rate ◽  
Direct Effect ◽  
Indirect Effect ◽  
Radiation Doses ◽  
Limited Extent ◽  
Γ Radiation ◽  
Low Concentration ◽  
Dose Rates ◽  
Rapid Destruction

Thiourea, when present at low concentration, can act as a radiation protector to macromolecules (biological or polymeric) in aqueous solution. Previous work has shown that much of this protection occurs against the indirect effect. Thiourea can also protect against the direct effect, though to a more limited extent. In this paper the reactions of dilute aqueous thiourea solutions have been followed at a range of γ radiation doses and dose rates, and in the absence and presence of oxygen. The rapid destruction of thiourea confirms that the effect is primarily indirect, and almost independent of concentration, and dose rate over the range 10 to 500 mg/1. The breakdown products of thiourea can react further. In the presence of oxygen the loss of thiourea is more rapid, and different products are formed.

scholarly journals Measurement of the radiation level dose to patient from fluoroscopy device during cardiac catheterization

2020 ◽  
Vol 2 (1) ◽  
pp. 35-41
Author(s):  
Luma Naji Joudha
Keyword(s):  
Dose Rate ◽  
Cardiac Catheterization ◽  
Exposure Dose ◽  
Radiation Doses ◽  
X Ray ◽  
Dose Area Product ◽  
Dose Rates ◽  
Wide Range ◽  
Area Product ◽  
Permissible Dose

Fluoroscopy is a type of medical imaging that shows a continuous X-ray image on a screen, it is used in a wide range of examination and procedures for diagnosis such as in cardiac catheterization. Fluoroscopy can result in relatively high radiation doses, especially for complex interventional procedures that it needed to monitor radiation to reduce exposure. The purpose of this study is to determine the radiation doses for patients during cardiac catheterization exam and compare it with the permissible dose limits. The main parameters which are studied in this work are the time of exposure dose rate, x-ray techniques (milliamper. second), tube voltage (kilovolt) and Dose Area Product (DAP). Twenty-seven patients were included and  absorbed doses were measured and distributed according to Fluoroscopy (Fluo) time, mAs and Dose Area Product (DPA). It was found that the absorbed dose received by the patients has a  linear relationship with the Fluoroscopy time, mAs and DAP. Exposure dose rates were measured and compared with the maximum permissible dose (100 mGy/min), the estimated patient dose rate varied from (12-81.6) mGy/min) for 24 patients as a permissible dose in the safe side, and 3 patients exposed to higher values of the exposure dose rates ) over permissible dose) range (107.4-108) mGy/min

Faktor-Faktor yang Mempengaruhi Minat Beli Produk Makanan Olahan Halal pada Konsumen

2018 ◽  
Vol 8 (3) ◽  
pp. 250
Author(s):  
Saniatun Nurhasah ◽  
Jono M Munandar ◽  
Muhammad Syamsun
Keyword(s):  
Food Safety ◽  
Direct Effect ◽  
Indirect Effect ◽  
Purchase Intention ◽  
Brand Image ◽  
Perceived Value ◽  
Perceived Quality ◽  
Market Potential ◽  
Purchasing Intention ◽  
Positive Direct

<p><em>ABSTRACT</em></p><p><em>Indonesia is one of the largest Moslem population countries in the world. It leads to the increasing of halal product demand in Indonesia. The awareness to consume halal product becomes a large market potential for producers to produce their halal products. Nowadays, halal is not only purely about religion matter, but also about business and trade. The objective of this study is to investigate the factors affecting customers on purchasing halal buying interest on processed food. We use a purposive sampling method with 109 respondents who are customers of the supermarkets and minimarkets in Bogor City/District, Indonesia. While data analysis is done by SEM-PLS method, this study uses brand image, perceived quality, perceived value, halal certification, health reason, halal awareness, and halal marketing as the factors which are affecting the halal purchase intention of the customers. The result showed that health reason, halal awareness, and perceived value have a significant and positive direct effect on purchasing intention. Halal marketing also shows a significant and positive effect on purchasing intention. While halal marketing shows a negative and significant effect on purchasing intention. The food safety, halal certification, brand image, and perceived quality show the same effect which has no direct effect on purchasing intention. Furthermore, food safety has an indirect effect on purchasing intention through health reason. Halal certification has an indirect effect on minat beli through brand image variable. Meanwhile, brand image and perceived quality have an indirect effect through perceived value variable on purchasing intention.</em></p><p><em><br /></em></p><p>ABSTRAK</p><p>Indonesia adalah salah satu negara dengan populasi Muslim terbesar di dunia. Hal ini menyebabkan meningkatnya permintaan produk halal di Indonesia. Kesadaran untuk mengkonsumsi produk halal menjadi potensi pasar yang besar bagi produsen untuk memproduksi produk halal mereka. Saat ini, halal tidak hanya murni soal agama, tapi juga soal bisnis dan perdagangan. Tujuan dari penelitian ini adalah untuk mengetahui faktor-faktor yang mempengaruhi minat pelanggan dalam membeli pada makanan olahan halal. Kami menggunakan metode voluntery sampling dengan 109 responden yang merupakan pelanggan supermarket dan minimarket di Kota/Kabupaten Bogor, Indonesia. Sedangkan analisis data dilakukan dengan metode SEM-PLS. Penelitian ini menggunakan citra merek, persepsi kualitas, persepsi nilai, sertifikasi halal, kesehatan, kesadaran halal, dan Pemasaran halal sebagai faktor yang mempengaruhi niat pembelian halal pelanggan. Hasil penelitian menunjukkan bahwa kesadaran halal, alasan kesehatan, dan persepsi nilai berpengaruh positif dan signifikan terhadap niat beli. Pemasaran halal juga menunjukkan efek positif dan signifikan terhadap niat beli. Sedangkan pemasaran halal menunjukkan efek negatif dan signifikan terhadap niat beli. Keamanan pangan, sertifikasi halal, citra merek, dan kualitas yang dirasakan menunjukkan efek yang sama yang tidak berpengaruh langsung pada niat beli. Selanjutnya, keamanan pangan berpengaruh tidak langsung terhadap niat beli melalui alasan kesehatan. Sertifikasi halal memiliki efek tidak langsung terhadap niat beli melalui variabel citra merek. Sedangkan citra merek dan persepsi kualitasmemiliki pengaruh tidak langsung melalui persepsi nilai variable terhadap niat beli.</p>

scholarly journals Radiation Awareness for Endovascular Abdominal Aortic Aneurysm Repair in the Hybrid Operating Room: An Instant Operator Risk Chart for Daily Practice

2021 ◽  
pp. 152660282110074
Author(s):  
Quirina M. B. de Ruiter ◽  
Frans L. Moll ◽  
Constantijn E. V. B. Hazenberg ◽  
Joost A. van Herwaarden
Keyword(s):  
Radiation Dose ◽  
Dose Rate ◽  
Effect Size ◽  
Radiation Risk ◽  
Dose Limit ◽  
Access Site ◽  
Femoral Access ◽  
Dose Rates ◽  
Rate Prediction ◽  
Operator Dose

Introduction: While the operator radiation dose rates are correlated to patient radiation dose rates, discrepancies may exist in the effect size of each individual radiation dose predictors. An operator dose rate prediction model was developed, compared with the patient dose rate prediction model, and converted to an instant operator risk chart. Materials and Methods: The radiation dose rates (DRoperator for the operator and DRpatient for the patient) from 12,865 abdomen X-ray acquisitions were selected from 50 unique patients undergoing standard or complex endovascular aortic repair (EVAR) in the hybrid operating room with a fixed C-arm. The radiation dose rates were analyzed using a log-linear multivariable mixed model (with the patient as the random effect) and incorporated varying (patient and C-arm) radiation dose predictors combined with the vascular access site. The operator dose rate models were used to predict the expected radiation exposure duration until an operator may be at risk to reach the 20 mSv year dose limit. The dose rate prediction models were translated into an instant operator radiation risk chart. Results: In the multivariate patient and operator fluoroscopy dose rate models, lower DRoperator than DRpatient effect size was found for radiation protocol (2.06 for patient vs 1.4 for operator changing from low to medium protocol) and C-arm angulation. Comparable effect sizes for both DRoperator and DRpatient were found for body mass index (1.25 for patient and 1.27 for the operator) and irradiated field. A higher effect size for the DRoperator than DRpatient was found for C-arm rotation (1.24 for the patient vs 1.69 for the operator) and exchanging from femoral access site to brachial access (1.05 for patient vs 2.5 for the operator). Operators may reach their yearly 20 mSv year dose limit after 941 minutes from the femoral access vs 358 minutes of digital subtraction angiography radiation from the brachial access. Conclusion: The operator dose rates were correlated to patient dose rate; however, C-arm angulation and changing from femoral to brachial vascular access site may disproportionally increase the operator radiation risk compared with the patient radiation risk. An instant risk chart may improve operator dose awareness during EVAR.

Moral Disengagement About Cyberbullying and Parental Monitoring: Effects on Traditional Bullying and Victimization via Cyberbullying Involvement

2016 ◽  
Vol 38 (3) ◽  
pp. 303-326 ◽  
Author(s):  
Diana J. Meter ◽  
Sheri Bauman
Keyword(s):  
Direct Effect ◽  
Indirect Effect ◽  
Indirect Effects ◽  
Parental Monitoring ◽  
Moral Disengagement ◽  
Traditional Bullying ◽  
Traditional Victimization ◽  
And Gender

The indirect effects of moral disengagement about cyberbullying and parental monitoring on traditional victimization and bullying via cyberbullying involvement were examined in a diverse sample of 800 youth in Grades 3 to 8. After controlling for grade and gender, moral disengagement about cyberbullying and parental monitoring had an indirect effect on traditional victimization and bullying through cyberbullying involvement. Moral disengagement about cyberbullying and parental monitoring had a direct effect on traditional bullying. Results suggest that moral disengagement about cyberbullying and parental monitoring affect cyberbullying involvement and additionally impact experiences beyond the cyber context.

Kinetics of DNA Repair Under Chronic Irradiation at Low and Medium Dose Rates in Repair Proficient and Repair Compromised Normal Fibroblasts

2021 ◽  
Author(s):  
Elena K. Zaharieva ◽  
Megumi Sasatani ◽  
Kenji Kamiya
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dose Rate ◽  
Dose Response ◽  
Chronic Irradiation ◽  
Dose Rates ◽  
Chronic Radiation ◽  
Damage Repair ◽  
Kinetics Of ◽  
Medium Dose

We present time and dose dependencies for the formation of 53BP1 and γH2AX DNA damage repair foci after chronic radiation exposure at dose rates of 140, 250 and 450 mGy/day from 3 to 96 h, in human and mouse repair proficient and ATM or DNA-PK deficient repair compromised cell models. We describe the time/dose-response curves using a mathematical equation which contains a linear component for the induction of DNA damage repair foci after irradiation, and an exponential component for their resolution. We show that under conditions of chronic irradiation at low and medium dose rates, the processes of DNA double-strand breaks (DSBs) induction and repair establish an equilibrium, which in repair proficient cells manifests as a plateau-shaped dose-response where the plateau is reached within the first 24 h postirradiation, and its height is proportionate to the radiation dose rate. In contrast, in repair compromised cells, where the rate of repair may be exceeded by the DSB induction rate, DNA damage accumulates with time of exposure and total absorbed dose. In addition, we discuss the biological meaning of the observed dependencies by presenting the frequency of micronuclei formation under the same irradiation conditions as a marker of radiation-induced genomic instability. We believe that the data and analysis presented here shed light on the kinetics of DNA repair under chronic radiation and are useful for future studies in the low-to-medium dose rate range.

THE EFFECT OF EXOGENOUS HORMONES ON AGGRESSIVE AND DEFENSIVE BEHAVIOUR IN THE RING DOVE (STREPTOPELIA RISORIA)

1966 ◽  
Vol 36 (1) ◽  
pp. 35-51 ◽  
Author(s):  
D. M. VOWLES ◽  
D. HARWOOD
Keyword(s):  
Direct Effect ◽  
Indirect Effect ◽  
Aggressive Behaviour ◽  
Breeding Cycle ◽  
Defensive Behaviour ◽  
Hormonal Effects ◽  
Streptopelia Risoria ◽  
Ring Dove ◽  
Second Peak ◽  
Model Predator

SUMMARY The aggressive and defensive behaviour of the ring dove was studied in response to a model predator and to another member of the same species. During a single breeding cycle defensive behaviour increased rapidly just before laying, reached a second peak at the time of hatching, and declined as the squabs became independent. Cocks showed aggressive behaviour to other doves throughout the cycle, but this response reached a peak soon after laying, and declined at the time of hatching. The effects of seven daily injections of oestrogen, progesterone, progesterone plus oestrogen, testosterone, and prolactin were studied. In both sexes prolactin and progesterone (with and without oestrogen) increased defensive behaviour towards a predator; in hens these hormones also increased defensive behaviour towards other birds. In cocks, however, prolactin had no effect on the response to other doves; progesterone (with and without oestrogen) increased aggressiveness, and oestrogen increased nest-cooing. Single injections of the same hormones produced similar effects, with the exception that testosterone and oestrogen in hens caused a temporary (1–5 hr.) increase in defensive behaviour. The latency of most hormonal effects was 30 min. to 2 hr., although the injections were intramuscular. This suggests a direct effect on central nervous mechanisms. Progesterone had a latency of 12–18 hr., suggesting an indirect effect.

scholarly journals Intraoperative 2D C-arm and 3D O-arm in children: a comparative phantom study

2018 ◽  
Vol 12 (5) ◽  
pp. 550-557 ◽  
Author(s):  
M. Prod’homme ◽  
M. Sans-Merce ◽  
N. Pitteloud ◽  
J. Damet ◽  
P. Lascombes
Keyword(s):  
Radiation Exposure ◽  
Scattered Radiation ◽  
Intraoperative Imaging ◽  
Radiation Doses ◽  
Organ Doses ◽  
Thermoluminescent Dosimeters ◽  
Dose Rates ◽  
Absorbed Doses ◽  
Entrance Dose ◽  
Student’S T

Purpose Exposure to ionizing radiation is a concern for children during intraoperative imaging. We aimed to assess the radiation exposure to the paediatric patient with 2D and 3D imaging. Methods To evaluate the radiation exposure, patient absorbed doses to the organs were measured in an anthropomorphic phantom representing a five-year-old child, using thermoluminescent dosimeters. For comparative purposes, organ doses were measured using a C-arm for one minute of fluoroscopy and one acquisition with an O-arm. The cone-beam was centred on the pelvis. Direct and scattered irradiations were measured and compared (Student’s t-test). Skin entrance dose rates were also evaluated. Results All radiation doses were expressed in µGy. Direct radiation doses of pelvic organs were between 631.22 and 1691.87 for the O-arm and between 214.08 and 737.51 for the C-arm, and were not significant (p = 0.07). Close scattered radiation on abdominal organs were between 25.11 and 114.85 for the O-arm and between 8.03 and 55.34 for the C-arm, and were not significant (p = 0.07). Far scattered radiation doses on thorax, neck and head varied from 0.86 to 6.42 for the O-arm and from 0.04 to 3.08 for the C-arm, and were significant (p = 0.02). The dose rate at the skin entrance was 328.58 µGy.s−1 for the O-arm and 1.90 with the C-arm. Conclusion During imaging of the pelvis, absorbed doses for a 3D O-arm acquisition were higher than with one minute fluoroscopy with the C-arm. Further clinical studies comparing effective doses are needed to assess ionizing risks of the intraoperative imaging systems in children.

scholarly journals Serum Metabolomic Alterations Associated with Cesium-137 Internal Emitter Delivered in Various Dose Rates

Metabolites ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 270
Author(s):  
Heng-Hong Li ◽  
Yun-Tien Lin ◽  
Evagelia C. Laiakis ◽  
Maryam Goudarzi ◽  
Waylon Weber ◽  
...  
Keyword(s):  
Dose Rate ◽  
Cumulative Dose ◽  
Low Dose ◽  
Biological Effects ◽  
Serum Samples ◽  
Dose Rates ◽  
Sphingosine 1 Phosphate ◽  
Cesium 137 ◽  
Dose Rate Effect ◽  
Medium Dose

Our laboratory and others have use radiation metabolomics to assess responses in order to develop biomarkers reflecting exposure and level of injury. To expand the types of exposure and compare to previously published results, metabolomic analysis has been carried out using serum samples from mice exposed to 137Cs internal emitters. Animals were injected intraperitoneally with 137CsCl solutions of varying radioactivity, and the absorbed doses were calculated. To determine the dose rate effect, serum samples were collected at 2, 3, 5, 7, and 14 days after injection. Based on the time for each group receiving the cumulative dose of 4 Gy, the dose rate for each group was determined. The dose rates analyzed were 0.16 Gy/day (low), 0.69 Gy/day (medium), and 1.25 Gy/day (high). The results indicated that at a cumulative dose of 4 Gy, the low dose rate group had the least number of statistically significantly differential spectral features. Some identified metabolites showed common changes for different dose rates. For example, significantly altered levels of oleamide and sphingosine 1-phosphate were seen in all three groups. On the other hand, the intensity of three amino acids, Isoleucine, Phenylalanine and Arginine, significantly decreased only in the medium dose rate group. These findings have the potential to be used in assessing the exposure and the biological effects of internal emitters.

Sign in / Sign up

Export Citation Format

Share Document