• 제목/요약/키워드: Half Life

검색결과 1,839건 처리시간 0.03초

A Survey on the Awareness of Human Milk Bank in Korean Female Health Care Providers

  • Hahn, Won-Ho;Song, Joon-Hwan;Park, Suyeon;Kang, Nam Mi;Ahn, Sukhee;Song, Seunghyun
    • Perinatology
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    • 제28권1호
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    • pp.11-19
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    • 2017
  • Objective: Human milk bank is known as best alternative option for sick infants. However, only two human milk banks (HMBs) are working in Korea. In the present study, we evaluated the awareness on the HMB in female health care provider to find out the issues that would help facilitating HMB establishment in Korea. Methods: The survey questionnaire was developed by a team composed with neonatologists, obstetricians, nurses, nutritionists, and health care specialists. The survey was performed for female health care workers in Soon Chun Hyang Cheonan Hospital between March and June in 2016. Eighty-eight of 110 questionnaires were collected and the results were analyzed. Results: Most of subjects were found to have correct knowledge on the breast milk feeding. However, only 49% of subjects had awareness of the presence of HMB. Unfortunately, less than half of them could get information about HMB by official way including mass media. In addition, 76% of subjects were found not to want to use HMB. Most important reason was found as a concern on the safety of donor milk including life style of donors, infection controls, and possible nutritional loss of banked milk. Conclusion: The purpose and function of HMB was not widely educated and it seems to be one of most important reasons why women have negative concept about HMB in Korea. Thus, further study is warranted with more numbers of subjects after active public education about the HMB.

Measurement of 137Cs in Ice Core Samples from Antarctica

  • Lim, S.I.;Kim, D.H.;Huh, J.Y.;Lee, J.;Hahn, I.S.;Han, Y.C.;Hur, S.D.;Hwang, H.J.;Kang, W.G.;Kim, Y.D.;Lee, E.K.;Lee, M.H.
    • Journal of the Korean Physical Society
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    • 제73권9호
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    • pp.1263-1268
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    • 2018
  • Three different ice core samples from Antarctica were analyzed to identify activity concentrations of radioactive isotopes. Tracking migration of radioactive isotopes to Antarctica can provide a key clue to understand global environmental changes caused by radiation exposures because the Antarctic ice cores can preserve unique characteristics of various environmental conditions. We are particularly interested in the $^{137}Cs$ nucleus, because it is closely related to radiation exposure from nuclear power plant accidents and nuclear bomb tests. With its half life of $30.17{\pm}0.03$ years, $^{137}Cs$ can also be used to assess the age of sedimentation occurring after around the year 1945. We selected three ice core samples, called Tarn8, Styx27, and H25, from different time periods; the Tarn8 sample is known to be from earlier than ~ 1000 AD, the Styx27 sample is approximately from the year 1945, and the H25 sample is from the year 2012. Radioactive isotope measurements of the ice core samples were performed using a 100% HPGe detector at Cheongpyeong Underground Radiation Laboratory (CURL). We measured the activity of $^{137}Cs$ in the H25 sample to be $0.98{\pm}0.82mBq/kg$. Although the activity has a large uncertainty mainly due to the limited sample quantity, the $^{137}Cs$ isotopes in the Antarctic ice core were measured for the first time in Korea.

카보닐 철-프러시안 블루 합성체를 통한 수중의 세슘 제거 (Removal of Cesium using Carbonyl iron-Prussian blue complex material in water)

  • 김종규
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2019년도 학술발표회
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    • pp.198-198
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    • 2019
  • 2011년 동일본 지역에서 발생한 지진으로 인하여 후쿠시마 다이이치에 위치한 원자력 발전소에서 다양한 방사성 물질들이 바다, 하천 그리고 대기와 같은 자연환경 속으로 유출되었다. 방사성 세슘(Cesuim, $Cs^{137}$)은 다양한 방사성 물질들 가운데 반감기(Half-life)가 30.17년으로 가장 긴 물질이다. 방사성 세슘이 환경 생태계로 한번 유출될 경우 긴 반감기과 널리 퍼지는 성질로 인하여 오랜 시간동안 넓은 지역에 막심한 피해를 초래하므로 효과적인 처리방법을 통해 안전하게 처리하는 것이 아주 중요하다. 세슘을 제거하기 위하여 물리적, 화학적, 생물학적 등 다양한 방법들을 통해 연구를 진행하고 있으며, 특히 세슘을 제거하는 아주 효과적인 방법 중 하나인 프러시안 블루(Prussian Blue, PB) 흡착제를 적용하는 방법이 많이 주목받고 있다. 그러나 프러시안 블루는 미세한 분말입자로서 수처리에 사용하게 되면 처리 후 발생되는 슬러지들을 수중으로 부터 분리하기 어려운 한계점을 가지고 있다. 최근 연구에서는 프러시안 블루의 적용 한계점를 극복하기 위하여 자성체(Magnetic substance)를 물리적 지지체로 이용하여 외부 자기장을 통해 수중으로 분리하는 방법들이 연구되고 있다. 자성체란 외부 자기장이 주어지게 되면 입자들 표면에 자성력을 띄는 물질들을 말한다. 본 연구에서는 자성체 종류들 가운데 가장 높은 자성력을 지닌 강자성체(Ferromagnetic Substance)를 물리적 지지체로 하여 산화과정, 실란과정, 합성과정을 거쳐 강자성체 입자의 표면에 프러시안 블루를 합성한 새로운 형태에 합성체를 제조하고, 제조된 합성체를 이용하여 수중에 존재하는 세슘 제거 능력을 평가하였다. 제조된 합성체의 물리적 특성을 분석하기 위하여 SEM, XRD를 이용하여 합성체 입자의 표면 분석을 진행하였다. 합성체의 세슘 제거 능력을 평가하기 위하여 임의 제조된 0.5mg/L의 세슘 농도를 가진 원수 100ml에 제조된 새로운 형태의 합성체 1g을 투입한 뒤 1분간의 반응시간 동안 반응한 이후 잔류 세슘을 측정한 결과 수중의 존재하는 세슘에 대해 99.9%의 세슘 제거율을 기록하였다. 자가분리(Magnetic Seperate)의 원리를 이용하여 수중으로부터 회수율을 측정한 결과, 99%의 합성체 회수율을 얻었다. 실험결과를 통해 외부자기장이 주어지게 되면 수중으로부터 합성체를 대부분 분리하여 회수할 수 있다고 판단된다. 본 연구를 통해 개발된 새로운 형태의 합성체는 수중의 세슘 처리 공정에서 사용자가 직접 접촉하지 않고 세슘제거 및 외부자기장을 통해 수중으로부터 분리가 가능한 합성체라고 판단된다.

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Permeability of a Capsaicin Derivative $[{14}^C]DA-5018$ to Blood-Brain Barrier Corrected with HPLC Method

  • Kang, Young-Sook;Kim, Jong-Mi
    • Archives of Pharmacal Research
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    • 제22권2호
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    • pp.165-172
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    • 1999
  • In the present work , the transport mechanism of a capsaicin derivative, DA-5018, through blood-brain barrier (BBB) has been investigated to evaluate the feasibility of potential drug development. The result of pharmacokinetic parameters obtained from the intravenous injection of plasma volume marker,$[3^H]RSA$ and $[{14}^C]DA-5018$, indicated that both AUC, area under the plasma concentration curve and VD, volume of distribution in brain of $[3^H]RSA$ agreed with those reported ($1620{\pm}10 $percentage injected dose minute per milliliter (%IDmin/ml) and $12.0{\pm}0.1{\mu}l/g$, respectively). Elimination half-life and AUC of $[{14}^C]DA-5018$is corrected by the PHLC analysis, 19.6$\pm$1.2 min and 7.69$\pm$0.85% IDmin/ml, respectively. The metabolic rate of $[{14}^C]DA-5018$was very rapid. The blood-brain barrier permeability surface area (PS) product of $[{14}^C]DA-5018$ was calculated to be 0.24$\pm$0.05 $\mu$l/min/g. The result of internal carotid artery perfusion and capillary depletion suggested that [14C]DA-5018 pass through BBB with the time increasingly. Investigation of transport mechanism of $[{14}^C]DA-5018$ using agonist and antagonist suggested that vanilloid (capsaicin) receptor did not exist in the BBB, and nutrient carrier system in the BBB has no effect on the transport of DA-5018. In conclusion, despite the fact that penetration of DA-5018 through BBB is significant, the intact drug found in the brain tissue is small because of a rapid metabolism. Therefore, for the central analgesic effect of DA-5018, the method to increase the metabolic stability in plasma and the brain permeability should be considered.

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HPLC Determination of Tolperisone in Human Plasma

  • Bae Jung-Woo;Park Young-Seo;Sohn Uy-Dong;Myung Chang-Sun;Ryu Byung-Kwon;Jang Choon-Gon;Lee Seok-Yong
    • Archives of Pharmacal Research
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    • 제29권4호
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    • pp.339-342
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    • 2006
  • A simple high performance liquid chromatographic (HPLC) method was developed for the determination of tolperisone in human plasma. Tolperisone and internal standard (chlorphenesin) were isolated from 1 mL of plasma using 8 mL of dichlormethane. The organic phase was collected and evaporated under nitrogen gas. The residue was then reconstituted with 300 mL aliquot of mobile phase and a 100 mL aliquot was injected onto the $C_{18}$ reverse-phased column. The mobile phase, $45\%$ methanol containing $1\%$ glacial acetic acid and $0.05\%$ 1-hexanesulfonic acid was run at a flow rate of 1 mL/min. The column effluent was monitored using UV detector at 260 nm. The retention times for tolperisone and the internal standard were approximately 7.1 and 8.4 min, respectively. The standard curve was linear with minimal intra-day and inter-day variability. The quantification limit of tolperisone in human plasma was 10 ng/ mL. The proposed method has been applied to the determination of pharmacokinetic profile of tolperisone in Koreans. The T max of tolperisone in Koreans $(0.94{\pm}0.42\;h)$ was not significantly differ from that reported in Europeans (0.5-1 h), but the mean half-life in Koreans $(1.14{\pm}0.27\;h)$ was shorter than that in Europeans $(2.56{\pm}0.2\;h)$. The proposed HPLC method is simple, accurate, reproducible and suitable for pharmacokinetic study of tolperisone.

Transient Neonatal Diabetes Mellitus Managed with Continuous Subcutaneous Insulin Infusion (CSII) and Continuous Glucose Monitoring

  • Kim, Min Soo;Kim, Sung Eun;Lee, Na Yeong;Kim, Seul Ki;Kim, Shin Hee;Cho, Won Kyoung;Cho, Kyoung Soon;Jung, Min Ho;Suh, Byung-Kyu;Ahn, Moon Bae
    • Neonatal Medicine
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    • 제28권1호
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    • pp.41-47
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    • 2021
  • Neonatal diabetes mellitus can be categorized as transient, permanent, or syndromic, and approximately half of the cases are transient. We present a case involving a term newborn who showed overt progression of transient neonatal diabetes mellitus, with complete remission within 6 months. On the second day of life, the patient presented with tachypnea, hyperglycemia, and decreased serum levels of C-peptide and insulin. Continuous subcutaneous infusion of insulin and continuous glucose monitoring were well tolerated. The patient showed a normal growth pattern, with no hyperglycemic or hypoglycemic episodes at 6 months of age. As it is rare and often asymptomatic, hyperglycemia may be attributed to various factors, including intrauterine environment, perinatal stress, and diverse genetic background. Therefore, consistent blood glucose monitoring and prompt early insulin therapy are crucial for any term newborns with persistent hyperglycemia, to prevent further diabetic complications. Moreover, continuous subcutaneous insulin infusion and the utilization of continuous glucose monitoring devices are the most effective and practical management strategies.

한의 암 레지스트리 연구를 위한 암 환자의 한방병원 진료현황에 대한 전문가집단 설문조사 (A Survey on Clinical Practice Patterns of Patients with Cancer at Korean Medical Hospitals for Korean Medicine Cancer Registry)

  • 윤지현;박수빈;김은혜;이지영;윤성우
    • 대한암한의학회지
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    • 제26권1호
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    • pp.17-27
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    • 2021
  • Objective: This study aimed to evaluate which information of cancer patients should be collected for the Korean medicine cancer registry in order to assess the efficacy and safety of Korean medicine (KM) treatment and to identify Korean medical prognostic predictors. Methods: A total of fifteen Korean medical specialists completed an online survey questionnaire including items about general characteristics of cancer patients and clinical practice patterns. Results: The four main types of cancer at Korean medical hospitals were breast, lung, stomach, and colorectal cancer. The majority of patients with cancer at Korean medical hospitals were in the advanced or metastatic stage (50.0%). The prominent purposes of KM treatment were to alleviate cancer-related symptoms, reduce the side effects of conventional therapy, and improve quality of life. The major options for treatment were traditional herbal medicine (THM), acupuncture, moxibustion, thermotherapy, pharmacoacupuncture, and meditation, with THM being the most frequently used (35.7%). Almost all Korean medical specialists (93.9%) used syndrome differentiation in clinical practice and identified over half the cancer patients as deficiency syndrome (57.2%). Conclusion: Physicians considered the primary goal of KM treatment for cancer patients to be symptom management since advanced or metastatic stage patients were the majority at Korean medical hospitals. THM were the most common treatment option and syndrome differentiation was used by almost all physicians. Further research is needed to monitor and ensure optimal KM treatment for patients with cancer.

Heteroexpression and Functional Characterization of Glucose 6-Phosphate Dehydrogenase from Industrial Aspergillus oryzae

  • Guo, Hongwei;Han, Jinyao;Wu, Jingjing;Chen, Hongwen
    • Journal of Microbiology and Biotechnology
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    • 제29권4호
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    • pp.577-586
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    • 2019
  • The engineered Aspergillus oryzae has a high NADPH demand for xylose utilization and overproduction of target metabolites. Glucose-6-phosphate dehydrogenase (G6PDH, E.C. 1.1.1.49) is one of two key enzymes in the oxidative part of the pentose phosphate pathway, and is also the main enzyme involved in NADPH regeneration. The open reading frame and cDNA of the putative A. oryzae G6PDH (AoG6PDH) were obtained, followed by heterogeneous expression in Escherichia coli and purification as a his6-tagged protein. The purified protein was characterized to be in possession of G6PDH activity with a molecular mass of 118.0 kDa. The enzyme displayed maximal activity at pH 7.5 and the optimal temperature was $50^{\circ}C$. This enzyme also had a half-life of 33.3 min at $40^{\circ}C$. Kinetics assay showed that AoG6PDH was strictly dependent on $NADP^+$ ($K_m=6.3{\mu}M$, $k_{cat}=1000.0s^{-1}$, $k_{cat}/K_m=158.7s^{-1}{\cdot}{\mu}M^{-1}$) as cofactor. The $K_m$ and $k_{cat}/K_m$ values of glucose-6-phosphate were $109.7s^{-1}{\cdot}{\mu}M^{-1}$ and $9.1s^{-1}{\cdot}{\mu}M^{-1}$ respectively. Initial velocity and product inhibition analyses indicated the catalytic reaction followed a two-substrate, steady-state, ordered BiBi mechanism, where $NADP^+$ was the first substrate bound to the enzyme and NADPH was the second product released from the catalytic complex. The established kinetic model could be applied in further regulation of the pentose phosphate pathway and NADPH regeneration of A. oryzae to improve its xylose utilization and yields of valued metabolites.

말기 환자 가족 영적요구 측정도구의 신뢰도 및 타당도 검증 (Reliability and Validity of an Instrument Assessing Spiritual Needs of Families of Terminal Cancer Patients)

  • 강경아;최영심;김예진
    • Journal of Hospice and Palliative Care
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    • 제21권4호
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    • pp.144-151
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    • 2018
  • 목적: 말기암환자 가족의 영적요구도를 측정하기 위한 도구의 신뢰도와 타당도를 검증하기 위한 연구이다. 방법: 본 연구는 1) 예비문항의 작성 2) 내용타당도 검증 3) 신뢰도와 타당도 검증 4) 최종문항 선정 과정에 따른 방법론적 연구이다. 결과: 요인분석을 통해 '신과의 관계/죽음 수용', '관계성 회복/희망과 평화', '삶의 의미와 목적'의 3가지 요인이 추출되었다. 이 요인들은 총 변량의 61.088%를 설명하였으며, Cronbach's alpha 값은 0.944, Guttman 반분 신뢰도 계수는 0.826으로 나타났다. 결론: 본 도구는 신뢰도와 타당도를 지닌 도구임이 확인되었다. 이에 호스피스 완화의료 분야에서 말기암환자 가족의 영적요구도를 사정할 때 활용도가 높은 도구라고 본다.

The exfoliation of irradiated nuclear graphite by treatment with organic solvent: A proposal for its recycling

  • Capone, Mauro;Cherubini, Nadia;Cozzella, Maria Letizia;Dodaro, Alessandro;Guarcini, Tiziana
    • Nuclear Engineering and Technology
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    • 제51권4호
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    • pp.1037-1040
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    • 2019
  • For the past 50 years, graphite has been widely used as a moderator, reflector and fuel matrix in different kinds of gas-cooled reactors. Resulting in approximately 250,000 metric tons of irradiated graphite waste. One of the most significant long-lived radioisotope from graphite reactors is carbon-14 ($^{14}C$) with a half-life of 5730 years, this makes it a huge concern for deep geologic disposal of nuclear graphite (NG). Considering the lifecycle of NG a number of waste management options have been developed, mainly focused on the achievement the radiological requirements for disposal. The existing approaches for recycling depend on the cost to be economically viable. In this new study, an affordable process to remove $^{14}C$ has been proposed using samples taken from the Nuclear Power Plant in Latina (Italy) which have been used to investigate the capability of organic and inorganic solvents in removing $^{14}C$ from exfoliated nuclear graphite, with the aim to design a practicable approach to obtain graphite for recycling or/and safety disposed as L& LLW.