^161, ^163Dy의 0.003eV~50keV의 중성자 포획 단면적 측정

민영기,윤정란,노태익,김귀년,이삼열 東亞大學校附設基礎科學硏究所 2002 基礎科學硏究論文集 Vol.19 No.1

교토대학 원자로 연구소의 46MeV 전자선형가속기를 사용하여 중성자 TOF 방법으로, 에너지 영역 0.003eV∼50keV의 ^161, 163Dy sample의 중성자 포획 단면적을 측정하였다. 본 실험에서 사용된 Bi_4Ge_3O_12(BGO) 섬광 검출기는 sample의 핵반응에서 나오는 즉발 포획 감마선 측정에 사용하였다. 이 검출기는 중성자 선원으로부터 거리 12.7±0.02m 위치에 12개의 블록으로 되어 있으며, sample에 포획되는 중성자 flux의 절대치를 구하기 위해 Sm(n, γ) 및 ^10B(n, αγ) 반응을 이용하였다. ^161, 163Dy에 대한 포획 단면적 측정결과는 ENDF/B-VI 결과와 비교하였다. The neutron capture cross sections of ^161, 162Dy has been measured in the energy region from 0.003eV 50keV by using the neutron time-of-flight(TOF) promptγmethod with a 46MeV electron linear accelerator at the Research Reactor Institute, Kyoto University. An assemble of twelve pieces of BGO scintillation detectors, which was placed at a distance of 12.7±0.02mm from the neutron source, was employed as a total energy absorption detector for the prompt capture gamma-ray measurement, to obtain the absolute capture cross section value. The sample of ^161, 163Dy is a form of metallic plate. An enriched boron sample was employed to monitor the neutron flux/spectrum of the TOF beam using the standard reference cross section of the ^10B(n, αγ) reaction. Previous measurements and evaluated data in ENDF/B-VI was compared with the present results.

B_(2)O_(3)를 첨가한 Ni-Cu-Zn Ferrite의 자성에 대한 소결온도 효과

김민경,이명호,고재귀,송승기 명지대학교 자연과학연구소 2005 자연과학논문집 Vol.24 No.-

B_(2)O_(3)가 첨가된 Ni-Cu-Zn 페라이트의 소결온도 변화에 따른 자기적 성질을 연구하였다. 실험에 사용한 시료는 0.1 wt%의 B_(2)O_(3)를 (Ni_(0.204)Cu_(0.204)Zn_(0.612))Fe_(1.198)O_(2.98)에 첨가하여 각각 1000℃, 1100℃ 그리고 1200℃으로 4시간 동안 소결시켜 제작했다. 시료의 자기적 성질은 X-ray 회절 패턴, 자기이력 곡선, 초투자율, 손실계수 그리고 비저항을 측정하여 연구하였다. 자기이력 곡선과 초투자율 측정 결과로부터 세 시료 모두 우수한 연자성체가 되었음을 확인하였고, 소결온도가 높을수록 coercive force(H_(c))의 감소와 초투자율의 증가가 관찰되었다. 특히 가장 높은 온도(1200℃)로 소결한 시료의 Hc는 0.217Oe이었고, 초투자율은 전 영역의 주파수에 걸쳐 가장 큰 값을 유지하였다. 전력손실은 1 ㎑~10 ㎒ 주파수 영역의 교류에 대해 시료 모두 안정된 값을 갖고, 1200℃로 소결된 시료의 전력손실과 비저항은 시료 중 가장 적은 값을 가졌다. We have studied the dependence of B-doped Ni-Cu-Zn ferrite on sintering temperature. The samples were prepared from 0.1 wt% B_(2)O_(3)-doped (Ni_(0.204)Cu_(0.204)Zn_(0.612))Fe_(1.198)O_(2.98) ferrites and sintered at 1000℃, 1100℃ and 1200℃ for 4 hours respectively. The crystal structures of the samples were identified by X-ray diffraction pattern, and the magnetic properties of those were investigated by measuring X-ray diffraction pattern, hysteresis curve, initial permeability and resistivity. The results showed that all of the three samples were good soft magnetic materials, and initial permeability increased with the decreasing of Hc as the sintering temperature became higher. Especially, the sample sintered at 1200℃ showed Hc of 0.217Oe and maintained the highest value of initial permeability through the whole frequency range. The loss factors of the samples showed good frequency stability from 1 ㎑ to 10 ㎒ and both the loss factor and resistivity of the ssample sintered at 1200℃ was the least.

위암 환자에서 절제된 림프절 수의 차이와 관련이 있는 인자

정귀애,박정희,변익건,김경종,장정환,김권천,민영돈 朝鮮大學校 附設 醫學硏究所 2004 The Medical Journal of Chosun University Vol.29 No.1

Purpose: By the definition of UICC TNM classification (fifth edition), the nodal stage of gastric cancer is based on the number of metastatic lymph nodes, which is influenced by the number of resected lymph nodes. And individual differences in the number of resected lymph nodes had been observed in patients with gastric cancer. The aim of this study is to verify the factors which are associated with the difference in the number of resected lymph nodes in patients with gastric cancer. Methods: We reviewed 613 patients with gastric cancer who underwent curative resection and D2 lymph node dissection with 15 or more resected lymph nodes. The number of resected lymph nodes was analyzed according to the characteristics of patients, the types of operation and prognostic factors of gastric cancer. Results: The mean number of resected lymph nodes per patient was 33.0 (median: 31.0, range: 15-88). The number of resected lymph nodes was significantly associated with the types of operation, the location and size of tumor, macroscopic types, depth of tumor invasion and the number of metastatic lymph nodes. Patient's age, gender and the histopathological finding's had no relationship with the number of resected lymph nodes. Conclusions: The number of resected lymph nodes from gastric cancer was different in each patient despite of same D2 lymph node dissection and it was associated with several prognostic factors of gastric cancer.

첨가제가 Mn-Zn 페라이트의 자기적 성질에 미치는 효과

이명호,김민경,고재귀,송승기 명지대학교 자연과학연구소 2004 자연과학논문집 Vol.23 No.-

우리 연구는 첨가제가 페라이트에 미치는 효과를 연구하기 위해 두 종류의 서로 다른 금속이온을 첨가제로 한 Mn-Zn 페라이트 시료를 제작하여 이들의 자기적 성질을 비교 분석하였다. 시료 제작에 사용된 Mn-Zn 페라이트의 주 원료 조성비는 31 mol% MnO, 16 mol% ZnO 그리고 53 mol% Fe_(2)O_(3)이다. 볼밀 작업을 통해 주 원료를 잘 혼합한 후 950℃에서 3시간 동안 하소하였다. 하소된 재료에 실험에 필요한 첨가물을 혼합한 뒤 성형과정을 거쳐 1300℃에서 3시간 동안 소결하였다. 첨가물은 0.1 wt% Na_(2)SiO_(3)만을 사용한 경우 (Sample 1)와 0.05 wt% Na_(2)SiO_(3), 0.1 wt% CaO와 0.05 wt% Al_(2)O_(3)를 첨가한 (Sample 2) 두 종류의 첨가제를 이용하였다. 두 시료에 대한 자성 특성을 측정한 결과 Sample 2 시료가 Sample 1에 비해 포화자속밀도(saturation flux density) B_(8)는 더 커진 반면 잔류자속밀도(residual flux density) B_(1)과 보자력(coercive force) H_(6)는 더 적어졌음을 확인하였다. 또한 고주파 측정에서도 0.05 wt% Na_(2)SiO_(3), 0.1 wt% CaO와 0.05 wt% Al_(2)O_(3)가 첨가된 시료에서 주파수 증가에 따르는 자기손실이, 다른 시료에 비해, 매우 완만하게 증가하는 것을 관찰하였다. 이들 자기 측정으로부터 0.05 wt% Na_(2)SiO_(3), 0.1 wt% CaO와 0.05 wt% Al_(2)O_(3)의 첨가제가 Mn-Zn 페라이트의 연자성 특성을 향상시켯음을 확인하였고, 이 결과는 이들 첨가물이 소결(sintering)과정에 관하여 Mn-Zn 페라이트 미세구조의 치밀화와 입자성장을 촉진시키는 효과가 있음을 보인다. We prepared two kinds of Mn-Zn ferrites composed of 31 mol% MnO, 16 mol% ZnO and 53 mol% Fe_(2)O_(3) as a main material. These were well mixed in a ball-milling machine and calcinated at 950℃ for 3 hours. After being mixed with two kinds of additives of 0.1 wt% Na_(2)SiO_(3) (Sample 1) and 0.05 wt% Na_(2)SiO_(3), 0.1 wt% CaO and 0.05 wt% Al_(2)O_(3) (Sample 2) respectively, the materials were molded and sintered at 1300℃ for 3 hours. The sample 2 was found to have more saturation flux density, and less residual flux density and coercive force than the other one, which means that the sample 2 is more suitable for soft-magnetic material. When the samples were applied by AC magnetic field in the frequency range of 10 kMz~1 MHz, both have shown relatively stable initial permeabilities up to 1 MHz. On the other hand, the loss factof of sample 2 became less than that of sample 1 in the high frequency range above 100 kHz although there was no much difference in the resistivity of both samples through the frequency change, which suggests the additives in the sample 2 has suppressed the viscosity loss in the high frequency range. We conclude that the 0.05 wt% Na_(2)SiO_(3), 0.1 wt% CaO and 0.05 wt% Al_(2)O_(3) additives has promoted coarsening and densification of the microstructure of the Mn-Zn ferrite and resulted in the better quality of the Mn-Zn ferrite

췌십이지장절제술 후 결과에 영향을 미치는 인자

정희석,정귀애,장정환,김권천,민영돈,김성환 조선대학교 2003 The Medical Journal of Chosun University Vol.28 No.1

`Background : Pancreatoduodenectomy is a widely used technique in the treatment of periampullary, duodenal and cephalic pancreatic disease. Although many improvements have been made in operative technique and posmiddleerative care, pancreatoduodenectomy remains a technically difficult procedure attended by relatively high morbidity and mortality rates. Materials and methods : The hospital records of 51 patients who underwent pancreatoduodenectomy at the Chosun University Hospital between 1994 and 2001 were reviewed. Clinical data and the following morbidity and mortality were recorded The risk factors were analyzed by a Chi-square test. Results : Fifth decade was the most prevalent ages (43.1%) The mean age was 59 years (ranging from 29 to 78) and the male to female ratio was 26 to 1. The periampullary cancer was the most reason to operation (86%) and injury due to trauma, adenocarcinoma of stomach, colon cancer, chronic pancreatitis in order Posmiddleerative complications were developed in seventeen patients and anastomotic leakage was the most common complication Death within a month after operation was 3 (5.8%) and the one of the cause of death was leakage in two patients, the other cause was intraadbominal bleeding in one patients. The cardiovascular disease, pulomnary problem, diabetes, level of bilirubin were checked preoperatively and showed no statistical difference in the posmiddleerative morbidity. The other factors such as amount of bleeding, operation time were not influencing posmiddleerative complications. The occurrence of leakage in eight cases of drainage tuve inserted into the pancreaticojejunostomy site was not different from no tuve insertion statistically Conclusion: old age of the patients, diabetes mellitus and massive intraoperative hemorrhage are the risk factors influencing the results after pancreatoduodenectomy. Morbidity and mortality after pancreatoduodenctomy can be devreased if a prudent selection of paients is made and the operation is performed by accomplushed surgeon.

한국 정상인과 제2형 당뇨병 환자에서 췌도베타세포의 정량

김병기,이광우,이정민,문인성,김용귀,이교영,손호영,차봉연,강무일,윤건호,강성구,고승현,김성래,서선희,김동구,이명덕,강찬석 대한당뇨병학회 2000 Diabetes and Metabolism Journal Vol.24 No.5

Background: There have been several reports about insulin secretory impairment in non-obese type 2 diabetic patients and even in impaired glucose tolerant subjects in Korea. Insulin secretory impairment might be induced by insufficient beta-cell mass, functional defects of beta-cells or both. To clarify the cause of impaired insulin secretion in type 2 non-obese diabetic patients in Korea, betacell masses were quantified in normal and type 2 diabetic subjects. Method: Normal pancreases were procured by 6 heart-beating non-diabetic donors under informed consent from relatives and approval of the university ethical committee. To quantify the beta cell mass and insulin content in various part of the pancreas, first we divided it into 3 parts: head, body and tail, and then each three parts were weighed and subdivided again into 8 segments equally. For diabetic patients, tissue sections were obtained from 15 partial or total pancreatectomized type 2 diabetic patients of any causes. After being fixed, tissues were immunostained using the Streptavidin-biotin-peroxidase method with anti-insulin antibody. Beta cells were counted by point count method. Results: The mean value of total pancreas weight of normal subjects (n=b) was 77.1±14.6 g, that of mean relative volume of beta cells in the pancreas was 2.1±0.9%, ranging from 1.4% to 3.1%(head 2.3±0.6%, body 1.8±0.2%, tail 2.2±0.4%). Mean value of total beta cell mass which was calculated from relative volume of beta-cells and weight of each portions was 1.3±0.3 g, ranging from 1.2 g to 1.9 g (head 0.6±0.3 g, body 0.4±0.2 g, tail 0.4±0.2 g). Mean insulin content per pancreas was 63.6±46.6 ㎍, ranging from 27.8 to 137.2 ㎍/pancreas (head 25.1±19.1 ㎍, body 20.8±15.5 ㎍, tail 17.7±14.9 ㎍). In diabetic patients, relative volume of beta cells in tissues were variable from 0.4% to 2.8% and there was good correlation between beta-cell mass and body mass index of the diabetic patients. However we can't find the correlation among relative volume of beta-cell, (r²=0.55, p$lt;0.05) duration of diabetes and age. Remarkable heterogeneity for loss of beta-cells in the islets of diabetic patients was observed even in the same lobe of pancreas. There were no evidence of lymphocytic infiltration in the islets. Conclusion: Insufficient beta cell mass seems to be a main cause for insulin secretory impairment in non-obese type 2 diabetic patients in Korea.

A case of Papillary Thyroid Carcinoma Associated with TSH/GH co-secreting Pituitary Adenoma

( Min Gui Han ),( Jee Hee Yoon ),( Soo Jeong Kim ),( Hee Kyung Kim ),( Ho Cheol Kang ) 대한내과학회 2013 대한내과학회 추계학술발표논문집 Vol.2013 No.1

A thyrotrophin (TSH) producing pituitary adenoma (TSHoma) could induce thyroid cancer by chronically stimulating thyroid follicular epithelial cells. Only few cases of thyroid cancer associated with TSHoma were reported and this is the first reported case in Korea, as far as we know. A 59-year-old man was referred for the evaluation of inappropriate TSH level. His serum free T4 was 3.21 ng/dL and TSH 5.41 mU/L. Sellar MRI revealed a 7 cm-sized huge pituitary adenoma with suprasellar extension. Multiple calcified hypoechoic nodules found on thyroid ultrasonography (US) were documented papillary carcinomas (PTC) by fine-needle aspiration cytology. Increased basal IGF-1 level (478.6 ng/ml) and non-suppressible GH levels (GH nadir, 1.3 ng/ml) during 75g OGTT were demonstrated. Monthly octreotide-LAR therapy for a TSH/GH co-secreting pituitary adenoma and a wait-and-see policy for multifocal PTC were planned due to the impossibility of curative resection. The octreotide-LAR therapy improved free T4, TSH, GH, and IGF-1 levels with some shrinkages of TSHoma. However, follow-up thyroid US done 1 year later showed progression of the thyroid cancer, so the patient underwent total thyroidectomy and remnant thyroid ablation with 131I. Maximal TSH level obtained during thyroid hormone withdrawal was suboptimal (16.67 mU/L), and TSH levels were not suppressed on up to 300 ug/day levothyroxine dose. After the thyroidectomy, the TSHoma showed gradual growing despite octreotide therapy and additional bromocriptine therapy. The patient needed a debulking operation for pituitary macroadenoma and survived the operation although postoperative course was complicated with infection and panhypopituitarism. We need to be very careful in decision making of total thyroidectomy in the setting of TSHoma, because it could promote the growth of TSHoma by dampening the normal negative feedback mechanism. Furthermore, endogenous TSH level suitable for remnant ablation could not be obtainable by thyroid hormone withdrawal and high dose of levothyroxine could not suppress TSH levels, due to autonomy of TSHoma.

Preparation of TiB₂/C Composites in a CVI Reactor

Kim, Min Ki,Kim, Dong Phil,Chung, Gui Yung Trans Tech Publications, Ltd. 2007 Key Engineering Materials Vol.334-335 No.1

<P>Titanium diboride (TiB2) appears to be an attractive candidate for a high-temperature fiber reinforced composites. Chemical Vapor Infiltration (CVI) has been carried out for the preparation of TiB2/C composites. Titanium diboride has been deposited from the gas mixtures of TiCl4, BCl3, and H2 in the furnace at the reaction temperatures between 850 to 950 °C and about 20 torr. Effects of infiltration parameters such as temperature, reaction time, and concentrations of BCl3 and H2 have been studied. Analyses with SEM, TGA and XPS were carried out. The amount of deposition in the preform increased with the increases of the reaction time, temperature and the flow rate of BCl3. The activation energy of the whole deposition reaction could be estimated from the Arrhenius plot.</P>

선천성 자궁 기형의 산과적 영향에 대한 연구

김민정 ( Min Joung Kim ),임시연 ( Si Yeon Lim ),최예훈 ( Ye Hoon Choi ),박철훈 ( Chul Hoon Park ),허수영 ( Soo Young Hur ),이귀세라 ( Gui Sera Lee ),김은중 ( Eun Joung Kim ),신종철 ( Jong Chul Shin ),김사진 ( Sa Jin Kim ) 대한산부인과학회 2005 Obstetrics & Gynecology Science Vol.48 No.9

이융모막 이양막-융합된 태반의 혈관문합에 의한 가성 태아 수혈 증후군

김민정 ( Min Joung Kim ),임시연 ( Si Yeon Lim ),허수영 ( Soo Young Hur ),이귀세라 ( Gui Se Ra Lee ),신종철 ( Jong Chul Shin ),김수평 ( Soo Pyung Kim ),나종구 ( Jong Gu Rha ),김사진 ( Sa Jin Kim ) 대한산부인과학회 2005 Obstetrics & Gynecology Science Vol.48 No.8