• The Korean Journal of Pain
• /
• 제27권2호
• /
• pp.162-167
• /
• 2014

Background: Although a physician may be the nearest to the radiation source during C-arm fluoroscope-guided interventions, the radiographer is also near the fluoroscope. We prospectively investigated the radiation exposure of radiographers relative to their location. Methods: The effective dose (ED) was measured with a digital dosimeter on the radiographers' left chest and the side of the table. We observed the location of the radiographers in each procedure related to the mobile support structure of the fluoroscope (Groups A, M and P). Data about age, height, weight, sex, exposure time, radiation absorbed dose (RAD), and the ED at the radiographer's chest and the side of the table was collected. Results: There were 51 cases for Group A, 116 cases for Group M and 144 cases for Group P. No significant differences were noted in the demographic data such as age, height, weight, and male to female ratio, and exposure time, RAD and ED at the side of the table. Group P had the lowest ED ($0.5{\pm}0.8{\mu}Sv$) of all the groups (Group A, $1.6{\pm}2.3{\mu}Sv$; Group M, $1.3{\pm}1.9{\mu}Sv$; P < 0.001). The ED ratio (ED on the radiographer's chest/ED at the side of the table) of Group A was the highest, and the ED radio of Group P was the lowest of all the groups (Group A, $12.2{\pm}21.5%$; Group M, $5.7{\pm}6.5%$; Group P, $2.5{\pm}6.7%$; P < 0.001). Conclusions: Radiographers can easily reduce their radiation exposure by changing their position. Two steps behind the mobile support structure can effectively decrease the exposure of radiographers by about 80%.

• Journal of Radiation Protection and Research
• /
• 제43권1호
• /
• pp.29-38
• /
• 2018

Background: Radon contributing about 42% of annual average dose, mainly comes from soil. In this paper, standard measurement procedures for soil radon exhalation rate are suggested and their measurement uncertainties are analyzed. Materials and Methods: We used accumulation method for estimating surface exhalation rate. The closed-loop measurement system was made up with a RAD7 detector and a surface chamber. Radon activity concentrations in the system were observed as a function of time, with data collection of 5 and 15-minute and the measurement time of 4 hours. Linear and exponential fittings were used to obtain radon exhalation rates from observed data. Standard deviations of measurement uncertainties for two approaches were estimated using usual propagation rules. Results and Discussion: The exhalation rates (E) from linear approach, with 30 minutes measurement time were $44.8-48.6mBq{\cdot}m^{-2} {\cdot}s^{-1}$ or $2.14-2.32atom{\cdot}cm^{-2}{\cdot}s^{-1}$ with relative measurement uncertainty of about 10%. The contributions of fitting parameter A, volume (V) and surface (S) to the estimated measurement uncertainty of E were 59.8%, 30.1% and 10.1%, in average respectively. In exponential fitting, at 3-hour measurement we had E ranged of $51.6-69.2mBq{\cdot}m^{-2} {\cdot}s^{-1}$ or $2.46-3.30atom{\cdot}cm^{-2}{\cdot}s^{-1}$ with about 15% relative uncertainty. Fitting with 4-hour measurement resulted E about $51.3-68.2mBq{\cdot}m^{-2} {\cdot}s^{-1}$ or $2.45-3.25atom{\cdot}cm^{-2}{\cdot}s^{-1}$ with 10% relative uncertainty. The uncertainty contributions in exponential approach were 75.1%, 13.4%, 8.7%, and 2.9% for total decay constant k, fitting parameter B, V, and S, respectively. Conclusion: In obtaining exhalation rates, the linear approach is easy to apply, but by saturation feature of radon concentrations, the slope tends to decrease away from the expected slope for extended measurement time. For linear approach, measurement time of 1-hour or less was suggested. For exponential approach, the obtained exhalation rates showed similar values for any measurement time, but measurement time of 3-hour or more was suggested for about 10% relative uncertainty.

• The Korean Journal of Pain
• /
• 제26권1호
• /
• pp.51-56
• /
• 2013

Background: The C-arm fluoroscope is an essential tool for the intervention of pain. The aim of this study was to investigate the radiation exposure experienced by the hand and chest of pain physicians during C-arm fluoroscopy-guided procedures. Methods: This is a prospective study about radiation exposure to physicians during transforaminal epidural steroid injection (TFESI) and medial branch block (MBB). Four pain physicians were involved in this study. Data about effective dose (ED) at each physician's right hand and left side of the chest, exposure time, radiation absorbed dose (RAD), and the distance from the center of the X-ray field to the physician during X-ray scanning were collected. Results: Three hundred and fifteen cases were included for this study. Demographic data showed no significant differences among the physicians in the TFESIs and MBBs. In the TFESI group, there was a significant difference between the ED at the hand and chest in all the physicians. In physician A, B and C, the ED at the chest was more than the ED at the hand. The distance from the center of the X-ray field to physician A was more than that of the other physicians, and for the exposure time, the ED and RAD in physician A was less than that of the other physicians. In the MBB group, there was no difference in the ED at the hand and chest, except for physician D. The distance from the center of the X-ray field to physician A was more than that of the other physicians and the exposure time in physician A was less than that of the other physicians. Conclusions: In conclusion, the distance from the radiation source, position of the hand, experience and technique can correlate with the radiation dose.

• Radiation Oncology Journal
• /
• 제8권2호
• /
• pp.219-223
• /
• 1990

1985년 1월부터 1989년 12월까지 연세대학교 의과대학 치료방사선과 및 연세암센터에서 치료받은 33명의 대세포 폐암 환자에 대한 후향적 분석을 시행하였다. 이중 28명 이 남자로 대부분을 차지했으며 평균 연령은 59세였다. 대세포 미분화폐암이 가장 많았으며 종양의 위치는 우측 폐에 19명, 좌측 폐에 14명에서 발견되었다. 일반적으로 대세포 폐암은 상당수가 폐의 주변부에 종양이 위치해 있는 것으로 알려져 있지만 본 조사에서는 중심부에 위치해 있는 경우가 주변부 만큼 많이 관찰되었다($51.5\%$와 $48.5\%$). 33명의 환자중 21명이 IIIB기 이상의 상당히 진행된 병변을 갖고 진단되어 졌다. 총 15명의 환자에서 원격전이가 관찰되었는데 이중 11명이 진단당시부터 원격전이를 갖고 있었고 나머지 4명은 치료 도중이나 치료 후 발견된 경우였다. 원격전이 부위는 다양하였는데, 연부조직, 피부, 췌장 및 충수돌기등 다른 폐암에서는 흔치 않는 부위에서의 원격전이가 관찰되었다. 치료는 개인별로 차이가 많았는데, 초기에 진행된 병변을 가진 환자가 많았으므로 19명 만이 근치적 목적의 치료를 받았으며 나머지 14명은 고식적인 방법으로 치료를 받았는데 치료후 2명의 환자에서 완전 관해를 얻었다. 4명의 환자가 24개월에서 54개월까지 장기 생존하였으며 2년 생존율은 $14.3\%$였고 중앙생존 기간은 6개월 이었다. 생존율에 영향을 주는 인자들을 분석해 본 결과 늑막 유출액이 없었던 환자군과 치료후 완전 관해를 보였던 환자군에서 통계학적으로 유의하게 생존율이 좋았다 (p<0.01).서만이 방사선 치료에 의해 완전관해를 얻을 수 있었던바($25\%$) (p<0.001), 모두 통계적으로 유의한 차이를 보였다. 한편 이를 원발부위, T-병기 그리고 N-병기에 따라 분석해본 결과, 특히 T-병기중 T3, 4에서는 유의한 차이가 관찰되었으나(p<0.0005), T1, 2에서는 유의한 차이가 관찰 되지 않았다(0.3, 수술이 필요하였던 환자는 $1\%$로 합병증의 증가 없이 A점에 8900cGy, 직장에 7300cGy정도의 국소치료가 가능함을 보여 주었으나 생존율에 대한 추후 분석이 따라야 할 것으로 사료된다.보면 6,000rad이하에서 20/63$(34.9\%)$의 실패율에 비하여 6,000rad이상일 때는 10/49$(20.4\%)$의 실패율이었다. 연령 벨로는 $40\~49$세에서 실패율(14/41 $24.1\%$)이 많았다. 본 성적으로 보아서 생존율은 여러 저자들과 큰 차이가 없음을 알 수 있었고 A점 선량은 8,000rad 이상, B점은 6,000rad이상이 조사되어야 적정선량이 됨을 시사해 주고 있다.\%$가 대부분이

• Journal of Plant Biotechnology
• /
• 제42권3호
• /
• pp.154-160
• /
• 2015

The plant breeding technology was developed with genetic engineering. Many researchers and breeders have turned from traditional breeding to molecular breeding. Genetically modified organisms (GMO) were developed via molecular breeding technology. Currently, molecular breeding technologies facilitate efficient plant breeding without introducing foreign genes, in virtue by of gene editing technology. Gene targeting (GT) via homologous recombination (HR) is one of the best gene editing methods available to modify specific DNA sequences in genomes. GT utilizes DNA repair pathways. Thus, DNA repair systems are controlled to enhance HR processing. Engineered sequence specific endonucleases were applied to improve GT efficiency. Engineered sequence specific endonucleases like the zinc finger nuclease (ZFN), TAL effector nuclease (TALEN), and CRISPR-Cas9 create DNA double-strand breaks (DSB) that can stimulate HR at a target site. RecQl4, Exo1 and Rad51 are effectors that enhance DSB repair via the HR pathway. This review focuses on recent developments in engineered sequence specific endonucleases and ways to improve the efficiency of GT via HR effectors in plants.

• Plant Resources
• /
• 제1권1호
• /
• pp.13-21
• /
• 1998

A cDNA Fragment encoding iron storage protrin generated by polymerase chain reaction(PCR) using highly conserved regions of ferritin related genes were used to sereen a red pepper cDNA library. cDNA clone was designated as Fp1. Fp1 clone contatines a 5' nontranslated region of 51dp containing stop conds. Down stream from 5' UTP. an open reading frame of 750bp was observed. followed by a 3' UTR of 272bp. The deduces amino acid sequence of red pepper protein(Fp1) showed 84%, 48% and 36% identity with soybean(SolC). human(HuL H) and horse spleen(HoS-L) ferritin mRNA accumulation in response to iron. Ferritin mRNA accumulation was transient and particularly abundant in leaves. reaching a maxmum at 12h. The level of ferritin mRNA in roots was affected to a lesser extent than in leaves.

• 한국공작기계학회논문집
• /
• 제17권4호
• /
• pp.51-58
• /
• 2008

This paper presents a new design of the precision stage for the reticle in lithography process and a low hunting control method for the stage. The stage has three axes for X, Y, ${\theta}_z$ those actuated by three voice coil motors individually. The designed reticle stage system has three gap sensors and voice coil motors, and supported by four air bearings and the forward/inverse kinematics of the stage were solved to get an accurate reference position. When a stage is in regulating control mode, there always exist small fluctuations(stage hunting) in the stage movement. Because the low stage hunting characteristic is very important in recent lithography and nano-level applications, a special regulating controller for ultra low hunting is proposed in this paper. Also this research proposed the 2-step transmission system for preventing the noise infection from environmental devices. The experimental results showed the proposed regulating control system reduced hunting noise as 35nm(rms) when a conventional PID generates 77nm(rms) in the same mechanical system. Besides the reticle stage has 100nm linear accuracy and $1{\mu}rad$ rotation accuracy at the control frequency of 8kHz.

• Journal of Animal Science and Technology
• /
• 제63권5호
• /
• pp.984-997
• /
• 2021

This study sought to evaluate DNA damage and repair in porcine postovulatory aged oocytes. The DNA damage response, which was assessed by H2A.X expression, increased in porcine aged oocytes over time. However, the aged oocytes exhibited a significant decrease in the expression of RAD51, which reflects the DNA damage repair capacity. Further experiments suggested that the DNA repair ability was suppressed by the downregulation of genes involved in the homologous recombination (HR) and nonhomologous end-joining (NHEJ) pathways. The expression levels of the cell cycle checkpoint genes, CHEK1 and CHEK2, were upregulated in porcine aged oocytes in response to induced DNA damage. Immunofluorescence results revealed that the expression level of H3K79me2 was significantly lower in porcine aged oocytes than in control oocytes. In addition, embryo quality was significantly reduced in aged oocytes, as assessed by measuring the cell proliferation capacity. Our results provide evidence that DNA damage is increased and the DNA repair ability is suppressed in porcine aged oocytes. These findings increase our understanding of the events that occur during postovulatory oocyte aging.

• Journal of Korean Neurosurgical Society
• /
• 제29권11호
• /
• pp.1445-1450
• /
• 2000

Objectives : The Objective of this study was to analyze the prognostic factors affecting survival in the patients with glioblastomas. Methods : We retrospectively studied 55 consecutive patients with glioblastomas who were admitted to neurosurgery department from January 1988 to March 1998. Fifteen pateients were excluded from the analysis because of follow-up loss and surgical motality. There were 24 male and 16 female patients, with a mean age of 51 years. Surgery consisted of biopsy in 4(10.0%) patients, subtotal resection in 9(22.5%) patients and gross total resection in 27(67.5%) patients. Nine(22.5%) patients received second operation. Twenty-eight(70%) received postoperative radiation therapy. Various levels of radiation dose were used, 6,000 rad over 7 weeks in most cases. The variable factors were examined for their relationship with survival ; age at the time of diagnosis, gender, duration of neurological symptoms, preoperative neurological state(Karnofsky performance score), extent of surgical resection, location of tumor, reoperation, and postoperative radiotherapy and chemotherapy. Result : The mean survival time was 55 weeks, three(7.5%) of the 40 patients survived more than two years. Survival time with biopsy only cases was 24 weeks, for those with subtotal resection 43 weeks, and for those with gross total resection 67 weeks. A mean survival time from the time of reoperation was 42 weeks. Statistically significant survival factors in glioblastoma were extent of surgical resection, postoperative radiotherapy and reoperation. Summary : Results of our series support the views that the extent of surgery, reoperation and postoperative radiation are important prognostic factors. We also recommend radical tumor removal, postoperative radiotherapy and reoperation, if possible.

• 한국연초학회:학술대회논문집
• /
• 한국연초학회 2001년도 제45회 학술발표회 및 심포지움:담배산업의 환경변화와 최근의 연구동향
• /
• pp.72-78
• /
• 2001

농업 유전공학 기술은 생산성 향상, 환경보전, 식품의 안정성 및 품질향상에 기여함은 물론 농업의 경쟁력을 높일 수 있는 유일한 대안으로 인식되고 있다. 전 세계적으로 유전자 재조합 작물의 경작지는 2000년 한해동안 지난해 같은 기간에 비해 11% 증가하였으며 이는 1996년 대비 25배 증가하였고, 선진국과 개발도상국은 각각 2%, 51% 1999년 대비 증가하였다. 1983년 유전자 재조합에 의한 식물의 형질전환이 성공한 뒤 종묘업계는 형질전환 종자개발과 보급에 열중하고 있으며 종자시장에 형질전화 품종이 차지하는 비율은 2000년 30억 달러에서 2010년이면 전체의 60%인 200억 달러에 이를 것으로 전망된다. 1995년 제초제 저항성 콩(라운드업레디콩)이 농가에 보급된 이후 2000년 형질전환품종 재배면적이 3990만 ha에 이르렀고 1997년 미국과 캐나다는 옥수수, 대두, 면화, 감자, 유채 등의 형질전환 품종 재배로 각각 3억1400만 달러, 5300만 달러를 벌어들였음. 형질전환 품종의 보급 증가속도는 소비자들의 GMO에 대한 거부반응으로 다소 주춤한 상태이다. 그러나 최근 종자회사들은 생태계 위해성 논란을 피해갈 수 있는 연구로 이러한 상황을 돌파하려 하고 있다. 우리나라에서도 유전자변형 생물체에 관한 법률이 제정되었으며 많은 대학과 연구소에서 형질전환 연구가 꾸준히 이루어지고 있고 최근 제초제 저항성 벼와 바이러스 저항성 감자가 개발돼 GMO 안정성 점검에 들어가 있고, 살충성 배추, 혈압강하 토마토, 지방산 강화 들깨, 병저항성 고추 등도 실험실과 포장에서 재배되고 있다. 이르면 4-5년 뒤 형질전환 작물들이 농가에 보급될 전망이다. 이처럼 체크 툴은 Firewall의 수비능력을 보강하는 위치에 있다고 생각할 수 있다.다. 4 장에서는 3장에서 제기한 각각의 문제점에 대해 RAD 의 관점에 비추어 e-business 시스템의 단기개발을 실현하기 위한 고려사항이나 조건 해결책을 제안한다. 본 논문이 지금부터 e-business 를 시작하려고 하는 분, e-business 시스템의 개발을 시작하려고 하는 분께 단기간의 e-business 실현을 위한 하나의 지침이 된다면 다행이겠다.formable template is used to optimize the matching. Then, clustering the similar shapes by the distance between each centroid, papaya can be completely detected from the background.uage ("Association of research for algorithm of calculating machine (1992)"). As a result, conventional NN and CNN were available for interpolation of sampling data. Moreover, when nonlinear intensity is not so large under the field condition of small slope, interpolation performance of CNN was a little not so better than NN. However, when nonlinear intensity is large under the field condition of