• Journal of Radiation Protection and Research
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• 제44권3호
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• pp.97-102
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• 2019

Background: Dose rate meters are the most widely used, and perhaps one of the most important tools for the measurement of ionising radiation. They are often the first, or only, device available to a user for an instant check of radiation dose at a certain location. Throughout the world, radiation safety practices rely strongly on the output of these dose rate meters. But how well do we know the quality of their output? Materials and Methods: This review is based on the measurements 1,158 commercially available dose rate meters of 116 different makes and models. Expected versus the displayed dose patterns and consistency was checked at various dose rates between $5{\mu}Gy{\cdot}h^{-1}$ and $2mGy{\cdot}h^{-1}$. Samples of these meters were then selected for further investigation and were exposed to radiation sources covering photon energies from 50 keV to 1.5 MeV. The effect of detector orientation on its reading was also investigated. Rather than focusing on the angular response distribution that is often reported by the manufacturer of the device, this study focussed on the design ergonomics i.e. the angles that the operator will realistically use to measure a dose rate. Results and Discussion: This review shows the scope and boundaries of the ionising radiation dose rate estimations that are made using commonly available meters. Observations showed both inter and intra make and model variations, occasional cases of instrument failure, instrument walk away, and erroneous response. Conclusion: The results indicate the significance of selecting and maintaining suitable monitors for specific applications in radiation safety.

• Translational and Clinical Pharmacology
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• 제26권4호
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• pp.150-154
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• 2018

This tutorial reviews the principles of dose individualisation with an emphasis on target concentration intervention (TCI). Once a target effect is chosen then pharmacodynamics can predict the target concentration and pharmacokinetics can predict the target dose to achieve the required response. Dose individualisation can be considered at three levels: population, group and individual. Population dosing, also known as fixed dosing or "one size fits all" is often used but is poor clinical pharmacology; group dosing uses patient features such as weight, organ function and comedication to adjust the dose for a typical patient; individual dosing uses observations of patient response to inform about pharmacokinetic and pharmacodynamics in the individual and use these individual differences to individualise dose.

• 대한예방한의학회지
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• 제20권1호
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• pp.145-159
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• 2016

Objectives : The aim was to investigate the characteristics of low dose effect and non monotonic dose responses(NMDRs) and to predict the influence it might have on the health and medicine, traditional Korean medicine. Methods : By investigating recently published major literatures related to low dose effect and NMDRs, the definition, mechanism, major related fields, and the influence on public health and medicine has been categorized and summarized. Results : Although there are still heated debates about the definition of low dose, it implies the biological responses in environmental exposure level and the NDMDRs means the nonlinear relationship between the dose-response in the slope sign change. Also, it implies the new form of the curve showing a U, reverse U shape, and the slop sign constantly changing showing various forms. This mechanism is because the two acceptor shows opposing effects to toxic materials and the affinity is different along with the numerical value that increase and decrease being different. These characteristics generally appear in endocrine disrupters such as bisphenol A, agricultural pesticides, metal, and radiation. The research field in the public health and medical treatment is obesity, problems in metabolism, growth hormone treatment, climacteric treatment, breast cancer, intake of Korean traditional medicine for pregnancy, menopause and phytoestrogen. Conclusions : As a result of discussing implications, NMDRs is a particular effect in low dose and heated debates surround this response, research is being conducted surrounding the field of obesity, problems in metabolism, growth hormone treatment, climacteric treatment, breast cancer, intake of Korean traditional medicine for pregnancy, menopause, and phytoestrogen. More research and interest in needed as it can have a massive influence in the public health and medicine.

• 방사선산업학회지
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• 제2권3호
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• pp.111-119
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• 2008

Microarrays can measure the expression of thousands of genes to identify the changes in expression between different biological states. To survey the change of whole Salmonella genes after a relatively high dose of gamma radiation (1 kGy), transcriptome dynamics were examined in the cells by using DNA microarrays. At least 75 genes were induced and 89 genes were reduced two-fold or more after irradiation. Several genes located in pSLT plasmid, cyo operon, and Gifsy prophage were induced along with many genes encoding uncharacterized proteins.While, the expression of genes involved in the virulence of Salmonella as well as metabolic functions were decreased. Although the radiation response as a whole could not be illustrated by using DNA microarrays, the data suggest that the response to high dose of irradiation might be more complex than the SOS response.

• Molecules and Cells
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• 제39권2호
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• pp.163-168
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• 2016

Caffeine has both positive and negative effects on physiological functions in a dose-dependent manner. C. elegans has been used as an animal model to investigate the effects of caffeine on development. Caffeine treatment at a high dose (30 mM) showed detrimental effects and caused early larval arrest. We performed a comparative proteomic analysis to investigate the mode of action of high-dose caffeine treatment in C. elegans and found that the stress response proteins, heat shock protein (HSP)-4 (endoplasmic reticulum [ER] chaperone), HSP-6 (mitochondrial chaperone), and HSP-16 (cytosolic chaperone), were induced and their expression was regulated at the transcriptional level. These findings suggest that high-dose caffeine intake causes a strong stress response and activates all three stress-response pathways in the worms, including the ER-, mitochondrial-, and cytosolic pathways. RNA interference of each hsp gene or in triple combination retarded growth. In addition, caffeine treatment stimulated a food-avoidance behavior (aversion phenotype), which was enhanced by RNAi depletion of the hsp-4 gene. Therefore, up-regulation of hsp genes after caffeine treatment appeared to be the major responses to alleviate stress and protect against developmental arrest.

• Toxicological Research
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• 제15권1호
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• pp.47-53
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• 1999

The effects of methidathion on humoral immune response were studied in BALB/c mice. 0.5 or 5.0 mg/kg/day methidathion were administered orally for 14 days. The parameters examined to assess apparent toxicity of methidathion included changes of body weight, relative weight of spleen, thymus, sidney and liver, and viable spllenic cell numbers. To evaluate the humoral immune response, thymus, kidney and liver, and viable splenic cell numbers. To evaluate the humoral immune resopnse, the plaque forming cell(PFC) responses sheep the red blood cells (SRBC) and the lovels of serum IgG to hen egg lysozyme (HEL) were determined. No alterations were observed in changes of body weights, relative organ weights and the numbers of viable splenocytes by exposure to any dose of methidathion. At the dose of 0.5mg/kg only PFC response was decreased, whereas both PFC response and the level of serum IgG were decreased significantly at the dose of 5.0 mg/kg. These results indicate that exposure to methidathion may cause sup[pression of humoral immune reponse in mice without overt changed in lymphoid organ weight or viability of splenocytes.

• Journal of Radiation Protection and Research
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• 제20권2호
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• pp.97-102
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• 1995

인체 말초 혈액 림프구에서 저선량의 감마선에 의해 유도되는 적응 반응을 관찰하였다. 인체 림프구를 저선량의 감마선(priming dose 0.01Gy) 을 조사한 후 여러 시간 간격 후 고선량 (challenging dose, 1.5Gy) 을 조사하였다. 저선량을 미리 조사한 림프구와 조사하지 않은 림프구에서 발생된 미세핵의 빈도를 계수하였다. 비세핵 발생 빈도는 저선량 조사 4시간 후 고선량을 조사하였을 때 최대 감소치를 보였다. 저선량과 고선량 조사 시간차가 7시간 또는 20시간이었을 때 미세핵 발생 빈도는 약간 감소하였으나 유의성은 없었다. 본 연구에서는 $G_0$상태의 세포주기에서 저선량을 조사하였을 경우 적응 반응이 나타나는 것이 관찰 되었다. 미세핵 분석법은 실험 방법이 비교적 간단하고, 기타 염색체 분석법에 비하여 빠른 시간내 결과를 도출 할 수 있어 추후 방사선에 대한 적응 반응의 연구에 유용한 지표가 될 수 있을 것이다.

• 대한암한의학회지
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• 제20권1호
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• pp.11-21
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• 2015

Objectives : The cancer incidence and cancer burden is increasing. In addition, the use of botanical agents in cancer care is increasing. This article aims to review a research strategy for botanical agents. Methods : The clinical studies of anticancer botanical agents and the papers about clinical research methodology of botanical agents were reviewed. Results : In phase I study, safety confirmation, optimal dose determination and drug interaction study are important. Most botanical agents have low toxicity and some have non-monotone dose response. Therefore, dose-response curve must be evaluated separately from the dose-toxicity curve to determine optimal dose. Although anticancer botanical agents can't shrink tumor size rapidly, they do extend survival. So, in phase II study, response should be evaluated by the survival. Conclusions : Clinical research of botanical agents in cancer is different from traditional methods and strategies. Considering the characteristics of botanical agents and experimental mechanism is necessary in conducting botanical based clinical trials.

• 대한약리학회지
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• 제13권2호
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• pp.49-59
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• 1977

Adrenergic receptors are now classified into alpha type and beta type These adrenergic receptors are distributed in various tissue in different patterns. Therefore, the adrenergic response of a certain tissue may be different from those of the other tissues, and such differences may exist among various species of animals. In this paper, the authors attempt to reevaluate the effect of epinephrine on the isolated atria, aortic strips, and vas deferenses of rabbits preincubated with alpha receptor blockades (ergotamine and dibenamine) and beta receptor blockades (propranolol and dichloroisoproterenol) in Locke-Ringer bathing medium. The results obtained were summarized as follows; 1) The dose dependent responses of isolated atria to epinephrine were significantly inhibited by propranolol and dichloroisoproterenol, and slightly inhibited by dibenamine, but not affected by ergotamine. 2) The dose dependent responses of excised aortic strips to epinephrine were significantly inhibited by ergotamine and dibenamine, but the responses were slightly potentiated by propranolol, and significantly by dichloroisoproterenol. 3) The dose dependent responses of isolated vas deferenses to epinephrine were significantly inhibited by ergotamine and dibenamine, but slightly potentiated by propranolol and dichloroisoproterenol.

• Environmental Engineering Research
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• 제25권4호
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• pp.488-497
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• 2020

The present study investigates the feasibility of nitrogenous heterocyclic compounds (NHCs) (Pyridine-Quinoline) degradation by catalytic wet peroxidation (CWPO) in the presence of nanoscale zerovalent iron supported on granular activated carbon (nFe⁰/GAC) using statistical optimization technique. Response surface methodology (RSM) in combination with Box-Behnken design (BBD) was used to optimize the process parameters of CWPO process such as initial pH, catalyst dose, hydrogen peroxide dose, initial concentration of pyridine (Py) and quinolone (Qn) were chosen as the main variables, and total organic carbon (TOC) removal and total Fe leaching were selected as the investigated response. The optimization of process parameters by desirability function showed the ~85% of TOC removal with process condition of initial solution pH 3.5, catalyst dose of 0.55 g/L, hydrogen peroxide concentration of 0.34 mmol, initial concentration of Py 200 mg/L and initial concentration of Qn 200 mg/L. Further, for TOC removal the analysis of variance results of the RSM revealed that all parameter i.e. initial pH, catalyst dose, hydrogen peroxide dose, initial concentration of Py and initial concentration of Qn were highly significant according to the p values (p < 0.05). The quadratic model was found to be the best fit for experimental data. The present study revealed that BBD was reliable and effective for the determination of the optimum conditions for CWPO of NHCs (Py-Qn).