• Title/Summary/Keyword: Dose Rate

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Effect of ionizing radiation on cultured submandibular gland (SG) cells of mouse (전리 방사선 조사에 의한 마우스 배양 악하선 세포의 변화)

  • Lee, Song-Jae
    • The Journal of Korean Society for Radiation Therapy
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    • v.4 no.1
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    • pp.71-77
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    • 1990
  • The present study was undertaken to investigate effects of ionizing radiation on DNA synthesis and chromosomal abnormality in cultured submandibular gland(SG) cells. SG cells from C57BL/6N Crj mice were cultured in Dulbecco's modified Eagle's medium (DME) supplemented with $10\%$ fetal bovine serum, antibiotics and fungizone. The cultured SG cells were irradiated with graded doses of gamma ray ($^{60}Co$) at a dose rate of 58.4rad/min. The effect of irradiation of $^{60}Co$ on DNA synthesis in cultured cells was evaluated by measuring the incorporation of 3H-TdR. Using conventional chromosome techniques and Giemsa staining methods, chromosomal abnormalities in cultured SG cells, induced by irradiation of $^{60}Co$ werw examined. Cytological observations were carried out by a light microscope with high resolving power. The results obtained were as follows : 1. DNA synthesis of SG cells was quantitatively dependent on a radiation dose compare to control. 2. A polyploids and few chromosome-type break, such as single and double breaks, deltions and triradial figures were more predominantly in irradiated SG cells than in control. This increase of chromosomal abnormality was in the proposition to the irradiation doses.

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A study on the reproducibility of blood alcohol concentration - time profile of an individual (음주 후의 혈중알코올농도 변화의 재현성에 관한 연구)

  • Hong, Sungwook
    • Analytical Science and Technology
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    • v.26 no.3
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    • pp.199-204
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    • 2013
  • In this study, the reproducibility of blood alcohol concentration (BAC) - time profile for the same individuals were investigated. Five Korean males were made to drink 55.5 g of ethyl alcohol (neglecting body weight) in the form of undiluted Soju (22% v/v), Korean popular liquor, within 30 min and each drinking sessions were performed for five times. Two kind of side dishes, a sliced raw fish and a sweet and sour pork, were served alternately along with alcohol. The peak BAC reaching time, the maximum BAC and the reduction rate of BAC of an individual varied greatly even though the dose and drinking time interval were not changed. Also, the food taken along with alcohol varies the shape of BAC - time profile. From the repetitive drinking sessions we can know that the BAC - time profile of an individual is not a reproducible one even though the dose, kind of liquer, drinking time and food were maintained constantly. It means that any assumption of blood alcohol concentration of an individual at a previous time stage based on the alcohol dose can not be justified because of large fluctuation of BAC-time profile of an individual.

Influence of the Central Benzodiazepinergic System on Peripheral Cardiovascular Regulation

  • Koh, Jeong-Tae;Ju, Jeong-Min;Shin, Dong-Ho;Cho, Han-Ho;Choi, Bong-Kyu;Kim, Jae-Ha
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.3
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    • pp.287-295
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    • 1998
  • Diazepam is known to have cardiovascular depressive effects through a combined action on benzodiazepinergic receptor and the GABA receptor-chloride ion channel complex. Moreover, it is known that barbiturates also have some cardiovascular regulatory effects mediated by the central GABAergic system. Therefore, this study was undertaken to delineate the regulatory actions and interactions of these systems by measuring the responses of the cardiovascular system and renal nerve activity to muscimol, diazepam and pentobarbital, administered intracerebroventricularly in rabbits. When muscimol $(0.03{\sim}0.3\;{\mu}\;g/kg)$, diazepam $(10{\sim}100\;{\mu}\;g/kg)$ and pentobarbital $(1{\sim}10\;{\mu}\;g/kg)$ were injected into the lateral ventricle of the rabbit brain, there were similar dose-dependent decreases in blood pressure (BP) and renal nerve activity (RNA). The relative potency of the three drugs in decreasing BP and RNA was muscimol > pentobarbital > diazepam. Muscimol and pentobarbital also decreased the heart rate in a dose-dependent manner; however, diazepam produced a trivial, dose-independent decrease in heart rate. Diazepam $(30\;{\mu}g/kg)$ augmented the effect of muscimol $(0.1\;{\mu}g/kg)$ in decreasing blood pressure and renal nerve activity, but pentobarbital $(3\;{\mu}g/kg)$ did not. Bicuculline $(0.5\;{\mu}g/kg)$, a GABAergic receptor blocker, significantly attenuated the effect of muscimol in decreasing BP and RNA, either alone or with diazepam, and that of pentobarbital in decreasing BP and RNA, either alone or with muscimol. We inferred that the central benzodiazepinergic and barbiturate systems help regulate peripheral cardiovascular function by modulating the GABAergic system, which adjusts the output of the vasomotor center and hence controls peripheral sympathetic tone. Benzodiazepines more readily modulate the GABAergic system than barbiturates.

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Prophylactic extended-field irradiation with concurrent chemotherapy for pelvic lymph node-positive cervical cancer

  • Oh, Jinju;Seol, Ki Ho;Lee, Hyun Joo;Choi, Youn Seok;Park, Ji Y.;Bae, Jin Young
    • Radiation Oncology Journal
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    • v.35 no.4
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    • pp.349-358
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    • 2017
  • Purpose: This study aimed to evaluate whether prophylactic extended-field pelvic radiotherapy (EF-PRT) yields better results than standard whole pelvic radiotherapy (WPRT) in patients with pelvic lymph node-positive cervical cancer treated with concurrent chemoradiotherapy (CCRT). Materials and Methods: A total of 126 cases of stage IB-IVA cervical cancer that had pelvic lymph node involvement in magnetic resonance imaging and were treated with CCRT between 2000 and 2016 were reviewed. None of the patients had para-aortic lymph node (PALN) metastases. The patients were classified to two groups, namely, those treated with EF-PRT, including prophylactic para-aortic radiotherapy, and those treated only with WPRT. The median dose to the PALN area in patients treated with EF-PRT was 45 Gy. All patients received concurrent cisplatin-based chemotherapy. Results: Overall, 52 and 74 patients underwent EF-PRT and WPRT, respectively. Patient characteristics and irradiated dose were not significantly different, except the dose to the para-aortic area, between the two groups. The median follow-up period was 75.5 months (range, 5 to 195 months). The 10-year cumulative recurrence rate of PALN for EF-PRT vs. WPRT was 6.9% and 10.1% (p = 0.421), respectively. The 10-year disease-free survival and overall survival for EF-PRT vs. WPRT were 69.7% vs. 66.1% (p = 0.748) and 71.7% vs. 72.3% (p = 0.845), respectively. Acute gastrointestinal complications were significantly higher in EF-PRT (n = 21; 40.4%) than WPRT (n = 26; 35.1%) (p = 0.046). Late toxicities were not significantly different in both groups. Conclusion: In this study, prophylactic radiotherapy for PALN does not have an additional benefit in patients with pelvic lymph node-positive cervical cancer treated with CCRT.

General Pharmacology of Erythropoietin Produced by a New Recombinant DNA Technique (새로운 유전자 재조합 기술에 의하여 생산된 Erythropoietin의 일반약리작용)

  • 김영훈;정성목;임동문;조효진;정재경;김달현;박관하;이동억;김현수
    • Biomolecules & Therapeutics
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    • v.2 no.4
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    • pp.336-342
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    • 1994
  • The general pharmacological properties of EPO were investigated in various animals administering intravenously and in vitro system. The results were as follows. 1. Central nervous system: EPO at doses of 70, 700, 7000 U/kg showed no effect In mice on general behavior, on strychnine- and pentetrazol-induced convulsion and on acetic acid-induced writhing syndrome. The hexobarbital-induced sleeping time in mice was slightly reduced by EPO at a dose of 7000 U/kg but did not change at doses of 70, 700 U/kg. The body temperature in rats was slightly decreased by EPO at doses of 700, 7,000 U/kg but the change was in normal physiological range. 2. Respiratory and cardiovascular system: EPO showed no effect on respiratory rate, blood pressure, heart rate, femoral blood flow, and electrocardiogram in anesthetized dogs at doses of 70, 700, 7000 U/kg. 3. Smooth muscle: EPO at concentrations of 70, 700 U/ml had no effect on the contractile response of isolated guinea pig ileum to histamine and acetylcholine. 4. Water and electrolytes excretion: EPO at dose above 700 U/kg increased urine volume in rats but did not affect the concentrations of $Na^{+},\;K^{+},\;Cl^{-}$ in urine. 5. Gastrointestinal system: EPO(70, 700, 7000 U/kg) had no effect on the intestinal charcoal meal propulsion 6. Blood coagulation system: The administration of EPO(70, 700, 7000 U/kg) had no effect on the plasma prothrombin time(PT) and activated partial thromboplastin time(APTT) in mice. Platelet aggregation induced by ADP and collagen was not influenced by EPO(70 U/ml, 700 U/ml). The overall results obtained indicated that EPO exerts almost no serious pharmacological effect even at a 100-fold clinical dose(7000 U/kg).

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Modelling and packed bed column studies on adsorptive removal of phosphate from aqueous solutions by a mixture of ground burnt patties and red soil

  • Rout, Prangya R.;Dash, Rajesh R.;Bhunia, Puspendu
    • Advances in environmental research
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    • v.3 no.3
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    • pp.231-251
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    • 2014
  • The present study examines the phosphate adsorption potential and behavior of mixture of Ground Burnt Patties (GBP), a solid waste generated from cooking fuel used in earthen stoves and Red Soil (RS), a natural substance in fixed bed column mode operation. The characterization of adsorbent was done by Proton Induced X-ray Emission (PIXE), and Proton Induced ${\gamma}$-ray Emission (PIGE) methods. The FTIR spectroscopy of spent adsorbent reveals the presence of absorbance peak at $1127cm^{-1}$ which appears due to P = O stretching, thus confirming phosphate adsorption. The effects of bed height (10, 15 and 20 cm), flow rate (2.5, 5 and 7.5 mL/min) and initial phosphate concentration (5 and 15 mg/L) on breakthrough curves were explored. Both the breakthrough and exhaustion time increased with increase in bed depth, decrease in flow rate and influent concentration. Thomas model, Yoon-Nelson model and Modified Dose Response model were used to fit the column adsorption data using nonlinear regression analysis while Bed Depth Service Time model followed linear regression analysis under different experimental condition to evaluate model parameters that are useful in scale up of the process. The values of correlation coefficient ($R^2$) and the Sum of Square Error (SSE) revealed the Modified Dose Response model as the best fitted model to the experimental data. The adsorbent mixture responded effectively to the desorption and reusability experiment. The results of this finding advocated that mixture of GBP and RS can be used as a low cost, highly efficient adsorbent for phosphate removal from aqueous solution.

Effects of Aged Platycodon grandiflorum on Cyclophosphamide-induced Immunosuppression in Mice (홍도라지 추출물이 마우스 모델에서 Cyclophosphamide에 의한 면역력 저하 억제에 미치는 영향)

  • Lee, Eun Byeol;Choi, Ji-Hye;Jang, Hwan-Hee;Hong, Ha-Cheol;Lee, Hae-Jeung;Jeong, Hyun Cheol;Lee, Sung-Jin;Lee, Sung Hyen
    • Korean Journal of Pharmacognosy
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    • v.51 no.4
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    • pp.340-348
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    • 2020
  • This study was conducted to evaluate the immunomodulatory effects of red doraji (Platycodon grandiflorum, RD) prepared by repeated steaming and drying process in the immune-suppressed mice induced by pre (RD-A) or post-treatment (RD-B) with cyclophosphamide. The immune-stimulating effects of ethanol RD extract in in vivo at 150 (RD-1) and 300 mg/kg body weight (RD-2) for RD-A and RD-B groups were measured and compared to the NC group supplied with distilled water only or positive control group. After 14 days of oral supplement, serum IgA, IgG, and cytokine levels, splenocytes proliferation rate, NK cell activity, and gene expression of cytokines were measured as immune related biomarkers. Serum IgA, IgG, IL-1β, and IL-12 levels increased in both RD-A and RD-B groups while serum TNF-α level decreased in RD-A group compared to the NC group. Splenocytes proliferation rate, NK cell activity, and cytokine (IL-1β, IL-6, IFN-γ) expression levels were also improved by RD supplement in the both groups. The RD showed more significant immunomodulatory effects at higher dose (RD-2) rather than the lower dose (RD-1). Thus, RD has an immune efficacy in a dose dependent manner and can be used as an immune stimulating source to improve immunity.

Comparative optimization of Be/Zr(BH4)4 and Be/Be(BH4)2 as 252Cf source shielding assemblies: Effect on landmine detection by neutron backscattering technique

  • Elsheikh, Nassreldeen A.A.
    • Nuclear Engineering and Technology
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    • v.54 no.7
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    • pp.2614-2624
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    • 2022
  • Monte Carlo simulations were used to model a portable Neutron backscattering (NBT) sensor suitable for detecting plastic anti-personnel mines (APMs) buried in dry and moist soils. The model consists of a 100 MBq 252Cf source encapsulated in a neutron reflector/shield assembly and centered between two 3He detectors. Multi-parameter optimization was performed to investigate the efficiency of Be/Zr(BH4)4 and Be/Be(BH4)2 assemblies in terms of increasing the signal-to-background (S/B) ratio and reducing the total dose equivalent rate. The MCNP results showed that 2 cm Be/3 cm Zr(BH4)4 and 2 cm Be/3 cm Be(BH4)2 are the optimal configurations. However, due to portability requirements and abundance of Be, the 252Cf-2 cm Be/3 cm Be(BH4)2 NBT model was selected to scan the center of APM buried 3 cm deep in dry and moist soils. The selected NBT model has positively identified the APM with a S/B ratio of 886 for dry soils of 1 wt% hydrogen content and with S/B ratios of 615, 398, 86, and 12 for the moist soils containing 4, 6, 10, and 14 wt% hydrogen, respectively. The total dose equivalent rate reached 0.0031 mSv/h, suggesting a work load of 8 h/day for 806 days within the permissible annual dose limit of 20 mSv.

Radionuclide concentrations in agricultural soil and lifetime cancer risk due to gamma radioactivity in district Swabi, KPK, Pakistan

  • Umair Azeem;Hannan Younis;Niamat ullah;Khurram Mehboob;Muhammad Ajaz;Mushtaq Ali;Abdullah Hidayat;Wazir Muhammad
    • Nuclear Engineering and Technology
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    • v.56 no.1
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    • pp.207-215
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    • 2024
  • This study focuses on measuring the levels of naturally occurring radioactivity in the soil of Swabi, Khyber Pakhtunkhwa, Pakistan, as well as the associated health hazard. Thirty (30) soil samples were collected from various locations and analyzed for 226Ra, 232Th, and 40K radioactivity levels using a High Purity Germanium detector (HPGe) gamma-ray spectrometer with a photo-peak efficiency of approximately 52.3%. The average values obtained for these radionuclides are 35.6 ± 5.7 Bqkg-1, 47 ± 12.5 Bqkg-1, and 877 ± 153 Bqkg-1, respectively. The level of 232Th is slightly higher and 40K is 2.2 times higher than the internationally recommended limit of 30 Bqkg-1 and 400 Bqkg-1, respectively. Various parameters were calculated based on the results obtained, including Radium Equivalent (Raeq), External Hazard (Hex), Absorbed Dose Rate (D), Annual Gonadal Equivalent Dose (AGDE), Annual Effective Dose Rate, and Excess Lifetime Cancer Risk (ELCR), which are 170.3 ± 24 Bqkg-1, 0.46 ± 0.06 Bqkg-1, 81.4 ± 2.04 nGy h-1, 582 ± 78.08 µSvy-1, 99.8 ± 13.5 µSv Gy-1, and 0.349 ± 0.04, respectively. These values are below the limits recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in 2002. This study highlights the potential radiation threats associated with natural radioactivity levels in the soil of Swabi and provides valuable information for public health and safety.

A Study on Absorbed Dose in the Breast Tissue using Geant4 simulation for Mammography (유방촬영에서 Geant4 시뮬레이션를 이용한 유방조직내 흡수선량에 관한 연구)

  • Lee, Sang-Ho;Lee, Jong-Seok;Han, Sang-Hyun
    • Journal of radiological science and technology
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    • v.35 no.4
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    • pp.345-352
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    • 2012
  • As the breast cancer rate is increasing fast in Korean women, people pay more attention to mammography and number of mammography have been increasing dramatically over the last few years. Mammography is the only means to diagnose breast cancer early, but harms caused by radiation exposure shouldn't be overlooked. Therefore, it is important to calculate the radiation dose being absorbed into the breast tissue during the process of mammography for a protective measure against radiation exposure. Because it is impossible to directly measure the radiation dose being absorbed into the human body, statistical calculation methods are commonly used, and most of them are supposed to simulate the interaction between radiation and matter by describing the human body internal structure with anthropomorphic phantoms. However, a simulation using Geant4 Code of Monte Carlo Method, which is well-known as most accurate in calculating the absorbed dose inside the human body, helps calculate exact dose by recreating the anatomical human body structure as it is through the DICOM file of CT. To calculate the absorbed dose in the breast tissue, therefore, this study carried out a simulation using Geant4 Code, and by using the DICOM converted file provided by Geant4, this study changed the human body structure expressed on the CT image data into geometry needed for this simulation. Besides, this study attempted to verify if the dose calculation of Geant4 interlocking with the DICOM file is useful, by comparing the calculated dose provided by this simulation and the measured dose provided by the PTW ion chamber. As a result, under the condition of 28kVp/190mAs, the Difference(%) between the measured dose and the calculated dose was found to be 0.08 %~0.33 %, and at 28 kVp/70 mAs, the Difference(%) of dose was 0.01 %~0.16 %, both of which showed results within 2%, the effective difference range. Therefore, this study found out that calculation of the absorbed dose using Geant4 Simulation is useful in measuring the absorbed dose in the breast tissue for mammography.