고출력 CW Nd:YAG 레이저를 이용한 CSP 1N 박판재 절단시 공정변수의 절단표면특성에 미치는 영향

안동규,김민수,이상훈,유영태,박형준 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-

The objective of this research work is to investigate the influence of process parameters, such as power of laser, travel speed of laser and material thickness, on roughness and striation of the cut surface for the case of cutting of CSP IN sheet using high power Nd:YAG laser with continuous wave (CW). In order to find the practical cutting region and the relationship between process parameters on the roughness and the striation, several laser cutting experiments are carried out. From the results of experiments, the allowable cutting region and an optimal cutting speed for each cutting condition have been obtained to improve the quality of the cut surface. In addition, it has been shown that the surface roughness is related to the number of striation and depth of valley of the cut surface.

랫드에서 인체 재조합 적혈구 조혈인자, rHuEPO의 13주 정맥투여 아만성독성에 관한 연구

김형식,곽승준,천선아,박현선,한하수,임소영,안미영,김원배,김병문,안병옥,홍성렬,이병무 성균관대학교 약학연구소 1998 成均藥硏論文集 Vol.10 No.1

A recombinant human erythropoietin (rHuEPO) was administered intravenously at dosage levels of 0, 100, 500, and 2500 IU/㎏/day for a period of 13 weeks. There were no observed clinical signs and deaths related to treatment in all groups tested. Decreases in body weight gain and food consumption were observed only in males of 2,500 IU/㎏ group after 2 weeks. In hematological parameters, erythrocyte content, hematocrit values and hemoglobin concentration were dose-dependently increased in rHuEPO treated groups. The ratio between kidney weight and whole body weight was significantly increased in females of 500 and 2,500 IU/㎏ groups. The spleen weight was also increased in both sexes of 500 and 2,500 IU/㎏ groups. However, the absolute weight change of other organs was not observed. In histopathological examinations, the renal tubular basophilia was observed only in males and females of 2,500 IU/㎏ groups. From these results, it is concluded that the no-observed adverse effect level(NOAEL) of rHuEPO is 100 IU/㎏ in rats in the present study.

간 세포암에서 VEGF, TGF-β1, b-FGF 발현의 의의

김성용,남충현,주종우,채만규,백무준,이문수,김형철,안현철,김홍수,김창진,김창호 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.1

Purpose: Angiogenesis is important for the proliferation and the metastasis of solid tumors. The growth of a solid tumor is widely recognized to depend on the process of neovascularrozation. Without angiogenesis, tumors cease to grow beyond even a few milimeters in diameter. It has been shown that tumor vascular density is an independent prognostic marker in several types of human tumors and is known to correlate with poor prognosis. To date, many angiogenic factors have been identified, such as transforming growth factor-α(TGF-α), transforming growth factor-β(TGF-β), fibroblast growth factor family(FGF), vascular endothelial growth factor(VEGF), platelet derived endothelial cell growth factor(PD-ECGF), tumor necrosis factor-α(TNF-α), and angiogenin. Hepatocellular carcinoma(HCC) is the second most common tumor in Korean males and is known as a typical hypervascular tumor with frequent portal vein invastion. The authors identified the expreesion of VEGF, TGF-β1, and b-FGF in HCC specimens and evaluated the relationship between these growth factors and the clinicopathologic characteristics of HCC. Method: We reviewed the medical records of 30 patients who were diagnosed as hepatocellular carinoma treated with hepatic resection between January 1994 and December 1998 in Soonchunhyang University Chunan Hospital. The selection of the cases was decided according to the condition of paraffin block fixation. The prognostic factors such as age, sex, tumor size, concentration of serum α-fetoprotein, presence of liver cirrhosis, presence of tumor emboli in portal vein, TMN stage, amount of transfusion during the operation, hepatitis B virus(HBV) infection, and Edmonson-Steiner(E-S) grade were investigated. Relationship between the prognostic factors and the immunopathologic expression of the TGF-β1, b-FGF, and VEGF was examined. Result: Thirty patients (24 males, 6 females) were included in the current study. The patient's mean age was 50.6 years and the age ranged from 36 to 65 years. The mean size of the tumor was found to be 5.2cm. All the patients were follewed up for 7 to 63 months. Child's classification A patients were 23(76.7%)cases, B patients were 7(23.3%)cases, and C was none. Immunohistochemical staining of HCC tumor mass in VEGF expression patients were 17(56.7%), b-FGF expression patients were 10(33.3%), and TGF-β1 expression patients were 10(33.3%). VEGF expression or more than one positive expression among the three factors correlated with tumor size and the stage of HCC but did not correlated with other clinicopathological characteristics. TGF-β1 and b-FGF did not correlate with any clinicopathological characteristics. Conclusion: The results suggest that the expression of VEGF or more than one positive expression among the three factors in HCC cells may be a significant prognostic factor of HCC.

제 3 대구치 발치시 환자의 호흡 패턴이 스트레스 변화 양상에 미치는 영향

이상명,김형욱,박양호,김진철,박준우,이성준,안재목,Rhee, Sang-Myung,Kim, Hyung-Wook,Park, Yang-Ho,Kim, Jin-Cheol,Park, Jun-Woo,Rhee, Sung-Jun,Nyamdorj, Selenge,Ahn, Jae-Mok 대한구강악안면외과학회 2007 대한구강악안면외과학회지 Vol.33 No.5

Purpose: Heart rate variability(HRV) is the clinical consequence of various influences of the autonomic nervous system(ANS) on heart beat. HRV can estimate the potential physiologic rhythm from the interval between consecutive beats(RR interval or HRV data). It is known as RSA which represents respiration-related HR rhythmic oscillation. Previous studies demonstrated a specific breathing pattern(0.1Hz, 6breaths/min) to improve a physiological body condition related to the stress. In this paper, the level of stress would be evaluated in terms of three phases of the dental treatment, combined with 6breaths/min. Methods: These phases include before, during and after tooth extraction or anesthesia or something.36 patients' stresses were assessed using HRV stress analyzer in each phase in Kangdong Sacred Heart Hospital, and Chuncheon Sacred Heart Hospital, Hallym University Medical Center from Jun. to Sept. of 2007. HRV 5-min data collected were analyzed in time-domain and frequency-domain to evaluate the activity of autonomic nervous system(ANS) which represents the level of stress. Results: All HRV parameters including HF(high frequency), LF(low frequency) and LF/HF ratio showned a significant change affecting the ANS balance. There was a 6.4% difference between R(LF/HF)s on general breathing pattern for balance of Autonomic nervous system, but on controlled breathing pattern, 0.1Hz, was made narrow till 1.4%. The activity of ANS has increased by 1.4% on general breathing pattern, and by 2.9% on controlled breathing pattern, 0.1Hz. Conclusion: After analysis of preoperative stress changes and effect of breathing pattern of 0.1 Hz on the stress in 36 patients who have undergone third molar extraction, following was concluded. In the preoperative stage, the sympathetic change was the greatest?after the?anesthetic injection, and stress was relieved by controlling the breathing pattern to a frequency of 0.1Hz.

쿠싱증후군 환자에서 당 대사 이상 정도에 따른 인슐린 감수성과 인슐린 저항성의 변화

정인경,김성훈,정재훈,민용기,이명식,이문규,유형준,안규정,노정현,김동준,김광원 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.4

연구배경 당질 코르티코이드는 당 대사에 매우 중요한 호르몬으로 내인성 당질 코르티코이드 과다상태인 쿠싱증후군에서는 말초조직에서 인슐린 저항이 증가하고 이를 보상하고자 인슐린 분비의 증가로 고인슐린혈증이 동반된다고 보고되고 있다. 하지만 생체 내에서와 달리 시험관내에서는 췌도세포에 당질 코르티코이드를 장시간 처리하면, 인슐린 분비 및 생합성이직접적으로 억제됨이 확인된 바 있어 쿠싱증후군 환자에서 당뇨병의 원인으로는 아마도 말초조직에서 증가된 인슐린 저항성 뿐 아니라 이를 충분히 보상하지 못하는 췌장에서의 인슐린 분비 저하가 같이 동반되어있지 않을까 하는 가설을 세우게 되었고, 아직까지 당질코르티코이드가 당대사 이상을 일으키는 기전에 대해 쿠싱증후군을 당대사 정도에 따라 인슐린 감수성과 분비능을 분석한 연구는 없었기에 이를 알아보고자 하였다. 방법: 삼성서울병원에서 쿠싱증후군으로 진단 받은 환자 15명을 대상으로 하였다. 이에 대한 대조군으로는 쿠싱증후군 환자와 같은 성별 그리고 체질량지수를 갖은 15명의 건강한 성인을 대상으로 비교 하였다 쿠싱증후군 환자를 대상으로 경구당부하 검사를 통해 당대사 정도를 정상군, 내당능장애군, 그리고 당뇨병군으로 나눈 후 정맥 당부하 검사를 시행하여 각군의 인슐린 저항성과 인슐린 분비능의 지표를 비교하고, 수술 후 쿠싱증후군이 완치된 상태에서 수술 전후의 당대사 지표의 변화를 조사하였다. 결과: 1) 쿠싱증후군 환자 중 정상인은 20%, 내당능 장애는 27%, 그리고 당뇨병은 53%였다. 체질량지수, 나이, 그리고 발병 기간은 세 군간에 의미 있는 차이가 없었으나, 24시간 소변검사의 코르티솔 농도는 당뇨병군에서 의미있게 높았다. 2) 정맥당부하 검사 결과, 인슐린 감수성 지표인 Sl는쿠싱증추린」서 1.58±0.10[×10^(-4)(min^(-1)(μU/mL)^(-1)]로 정상 대조군의 3.37±0.49[×10^(-4)(min^(-1)(μU/mL)^(-1)]에 비해 의미있게 낮았으나(P=0.024), 쿠싱증후군 환자 중 NGT, IGT, DM 군간에 서로 통계적인 차이는 없었다. 3) SG는 정상 대조군과 쿠싱증후군 환자간에는 의미있는 차이가 없었고, 쿠싱 증후군에 있어서 당대사가 악화될수록 감소하는 경향을 보였으나 의미있는 차이는 없었다. 4) 인슐린 분비능의 지표인 AIRg는 정상인에 비해 전체 쿠싱증후군 환자의 경우 증가하는 경향을 보였으나 의미있는 차이는 없었다. 하지만 쿠싱증후군 환자중에서 당대사 상태에 따라 NGT군은 1299 (1297∼1310)(mu/g/min ×10^(-2))로 정상 대조군(368.9±98.6[mu/g/min ×10^(-2)]) 보다도 의미있게 높았고, DM군{202.2 (91.1~371.4) [mu/g/min ×10^(-2)}은 NGT군에 비해 의미있게 낮았다(P=0.0031). 5) 15명중 현재 완치 상태에 있는 6명에 대해 수술전과 후로 비교하였다. 수술 전 당대사 상태가 1명은정상, 1명은 내당능 장애, 그리고 4명은 당뇨병이었으나 수술 후 시행한 경구 당부하 검사상 모두 정상 당대사 상태를 보였다. 6) 수술 후 완치된 환자 6명에 있어 인슐린 감수성지표인 Sl는 수술전에 중앙값이 1.22[×10^(-4)(min^(-1)(μU/mL)^(-1)]로 대조군에 비해 의미있게 감고』어 있었으나(p.0.05), 수술후 10.95 [×10^(-4)(min^(-1)(μU/mL)^(-1)]로 정상 수준으로 회복되었고(P=0.0022), 인슐린 분비능을 나타내는 AIRg [mu/g/min ×10^(-2)] 값도 정상수준으로 회복되었다. 특히 인슐린 분비능의 회복양상은 혈당농도에 따라 판이하게 나타나서, 정상과 내당능장애 상태에 있던 2명은 수술전에 1201 [mu/g/min ×10^(-2)]로 증가되어 있던 AIRg 값이 수술 후 정상 수준으로 감소하였고, 수술 전에 당뇨병 상태에 있던 4명의 경우 245.9 [mu/g/min ×10^(-2)]로 인슐린 분비능이 감고il어 있었는데 이들은 수술 후 모두 정상 수준으로 증가되었다 (P=0.0286). 결론: 쿠싱증후군 환자에서 당대사 이상은 80%로 높은 유병률을 보였다. 모든 쿠싱증후군환자에서 인슐린 감수성은 정상인에 비해 저하되어 있어 말초조직의 인슐린 저항이 선행됨을 시사하며, 인슐린 분비능은 당대사의 정도에 따라 다르게 나타났는데, 정상 당대사군에서는 인슐린의 저항성을 극복할 만큼 정상 대조군보다 더 많은 양의 인슐린 분비를 하다가 고코르티솔혈증이 심할수록 인슐린 분비능의 감소로 당뇨병으로 진행됨을 확인할 수 있었고, 이런 인슐린 저항성과 인슐린 분비장애는 수술 후 다시 회복되는 가역적인변화를 보였다. Background: Glucocorticoid plays an important role in the control of carbohydrate metabolism. Patients with Cushing's syndrome have been reported to have an increased incidence of carbohydrate intolerance due to peripheral insulin resistance and hyperinsulinemia, although the exact incidence and nature of this disorder have remained unclear. Few results have been published about insulin resistance and insulin secretion according to the level of glucose concentration, or about the reversibility of such defects in patients with Cushing's syndrome. Methods: To assess the effect of glucocorticoid on the insulin sensitivity and insulin secretion in Cushing's syndrome, 15 patients with Cushing's syndrome were classified into 3 groups (normal glucose tolerance: NGT, impaired glucose tolerance: IGT, diabetes: DM) according to the degree of glucose tolerance based on the oral glucose tolerance test (OGTT). Insulin modified, frequently sampled, intravenous glucose tolerance test (FSIGT) was performed before and after curative surgery on these patients and on 15 healthy control subjects. Data were evaluated by non-parametric statistical analysis. Results: 1) Among the 15 patients with Cushing's syndrome, 3 (20%) were NGT, 4 (27%) IGT, and 8 (53%) DM, based on OGTT. Twenty-four hour urinary free cortisol (UFC) was significantly higher in the DM group. 2) Insulin sensitivity index (SI) of Cushing's syndrome was significantly lower than that of the control group p=0.0024), but was not significantly different among the three Cushing's syndrome groups of NGT, IGT and DM. 3) Glucose mediated glucose disposal (SG) (Ed- confirm this abbreviation; it does not seem to match the definition) of Cushing's syndrome was not significantly different from that of the control group. 4) Insulin secretion (AIRg) of Cushing's syndrome tended to be high, but it was not significantly different from that of control. However, according to the level of glucose concentration there was significant difference in AlRg among the three Cushing's syndrome groups p=0.0031); AIRg of DM was significantly lower than that of NGT. 5) After surgical treatment, parameters of insulin sensitivity and insulin secretion were normalized in 6 cured patients; 1 with NGT, 1 with IGT, and 4 with DM, preoperatively. Median SI of all 6 patients was significantly improved up to the normal range postoperatively p=0.0022). Median AIRg of these 6 patients was balanced around that of normal control postoperatively p=0.0286). Conclusion: Eighty percent of patients with Cushing's syndrome had abnormality of carbohydrate metabolism. Insulin sensitivity was significantly decreased in Cushing's syndrome. Insulin secretion was significantly higher only in the NGT and IGT groups of Cushing's syndrome. As the hypercortisolemia is exacerbated, insulin secretion is significantly decreased and causes DM, suggesting that glucocorticoid has a direct or indirect toxic effect on the pancreatic beta cell (J Kor SOC Endocrinol 18:392-403, 2003).

전경대원에서 발생한 결핵의 임상 양상

문창기,박상준,조민구,김영중,김소연,김윤권,정준오,안석진,김은실,서승오,김지훈,최원제,이윤영,박형기,최규영,김현근 대한감염학회 2006 감염과 화학요법 Vol.38 No.6

Background: The purpose of this study was to document the incidence and clinical characteristics of patients with tuberculosis (TB) in combat and auxiliary police, living in a group, in Korea where the incidence rate of active TB in a general population is higher than in Western countries. Materials and Methods:We retrospectively reviewed the medical records of all tuberculosis patients diagnosed at National Police Hospital from January 2002 through December 2004. Results:In 2002-2004, a total of 156 cases of tuberculosis were identified with the mean (Standard deviation) age of 20.6 (±1.0) years. Of these, 134 (85.9%) patients were registered as new cases, 11 (7.1%) as relapse, 2 (1.3%) as failure, 5 (3.1%) as treatment-after-default cases whereas 4 (2.6 %) patients were not included in any categories. Average annual new TB rate and smear-positive TB rate were 86.5/10^(5) and 17.4/10^(5) person-years, respectively. In 12 of 31 smear-positive cases, time from onset of symptoms to diagnosis was more than 30 days. Two multidrug-resistance TB cases were identified and two suspected outbreak episodes of TB had occurred during 3 years. Conclusion:There was no statistically significant difference in the incidence rate of new cases of TB between the general population aged 20 to 29 years and combat and auxiliary police in Korea. 배경 : 국내 결핵의 발생은 감소 추세에 있으나 여전히 후진국형 발생양상을 보이고 있다. 특히 집단생활을 하는 젊은이들에서 발생하는 결핵의 유행이 간헐적으로 알려지고 있어 우려를 낳고 있다. 이에 저자들은 최근 전경대원의 결핵 발병 양상에 대해 알아보고자 본 연구를 시행하였다. 재료 및 방법 : 2002년 1월부터 2004년 12월까지 3년간 경찰병원에서 결핵 진료를 받은 전경대원의 의무기록을 후향적으로 분석하여 연도별 결핵 신환발생률, 도말양성결핵 신환율, 진단 지연, 집단발병, 다제내성결핵을 조사하였다. 결과 : 연도별 결핵 신환자 수(10만명당 발생추정치)는 2002년 50명(83.6명), 2003년 42명(83.7명), 2004년 42명(93.5명)이었고 도말양성 폐결핵 신환자 수는 2002년 10명(16.7명), 2003년 11명(21.9명), 2004년 6명(13.4명)이었다. 3년간 도말양성 폐결핵 환자는 31명이 있었고 그 중 12명은 호흡기 증상 발생 30일이 지나서 진단을 받았다. 다제내성 결핵은 2명이 있었으며 결핵의 집단발병이 의심되는 사례는 2차례 있었다. 결론 : 전경대원과 20-29세 연령군 일반인의 결핵 신환발생률, 도말양성 폐결핵 발생률의 통계적으로 유의한 차이는 없었다.

An Alternative Evaluation of the Item-based Collaborative Filtering Using Simulated Online Shopping

Ahn, Hyung-Jun Korea Data Strategy Society 2009 Journal of information technology applications & m Vol.16 No.3

This paper presents a novel method for evaluating the usefulness of online product recommendation. Previous studies on evaluating recommendation systems have mostly relied on two methods : testing the accuracy of estimating user preferences by recommendation systems, or empirically testing the effectiveness with lab experiments involving human participants. The former does not measure the usefulness directly and hence can be misleading; the latter is expensive in that it requires a working online store System and test participants. In order to address the problems, the proposed approach uses simulation to imitate customer behavior and evaluate the usefulness of recommendation. Models for user behavior and an abstract Internet store are developed for simulation. Actual simulation experiments are performed to illustrate the use of the approach.

CHARACTERISTICS OF BISMUTH-BASED THIN FILMS DEPOSITED DIRECTLY ON POLYMER SUBSTRATES FOR EMBEDDED CAPACITOR APPLICATION

Ahn, Jun-Ku,Kim, Hae-Won,Ahn, Kyung-Chan,Yoon, Soon-Gil,Son, Seung-Hyun,Jung, Hyung-Mi,Moon, Jin-Suck,Jin, Hyun-Joo,Lee, Seung-Eun,Lee, Jeong-Won,Chung, Yeoul-Kyo,Oh, Yong-Soo Taylor Francis 2007 Integrated ferroelectrics Vol.95 No.1

<P> B2Mg2/3Nb4/3O7 (BMN) thin films were deposited at low temperature (< 200°C) on Copper Clad Laminates (CCL) with various Ar/O2 flow ratios and film thicknesses by sputtering system. 200 nm-thick BMN thin films were deposited at Ar/O2 = 10: 10 had rms roughness of 54.3 ÅA, capacitance density of 155 nF/cm2 at 100 kHz, dissipation factor of 0.017 and leakage current density of ∼10- 5 at 3 V. Surface roughness of the BMN thin films increased a little with increasing the film thickness. However leakage current density decreased and the dielectric constant of that was maintained at 40.</P>

Fabrication of a Wheatstone-Bridge Integrated SU-8 Cantilever

Ahn, Jun-Hyung,Park, Chang-Sin,Lee, Dong-Weon IOP Publishing 2010 Japanese journal of applied physics Vol.49 No.6

Apicidin inhibits cell growth by downregulating IGF-1R in salivary mucoepidermoid carcinoma cells

AHN, MEE-YOUNG,AHN, JI-WEE,KIM, HYUNG-SIK,LEE, JUN,YOON, JUNG-HOON Spandidos Publications 2015 ONCOLOGY REPORTS Vol.33 No.4

<P>Inhibition of histone deacetylases (HDACs) has emerged as a new target for cancer therapies. The present study examined the antitumor effect and molecular mechanism of the HDAC inhibitor apicidin in YD-15 human salivary mucoepidermoid carcinoma (MEC) cells. The cells were treated with apicidin and cell death was quantified using an MTT assay. Apoptosis and autophagy were measured using flow cytometry, immunoblot analysis and cell staining. Regulation of the signaling pathways was monitored using immunoblot analysis and co-treatment with specific inhibitors. Insulin-like growth factor 1 receptor (IGF-1R) was knocked down using specific siRNA. Apicidin significantly inhibited the proliferation of MEC cells. Apicidin also induced apoptosis through the inactivation of extracellular signal-regulated kinase (ERK) and AKT/mTOR signaling and activation of c-Jun NH2-terminal kinase (JNK), whereas apicidin promoted autophagy through inactivation of the AKT/mTOR signaling. These effects may be mediated by the inhibition of IGF-1R, an upstream regulator of MAPK and AKT/mTOR pathways. These results suggested that apicidin is an attractive chemotherapeutic agent against salivary MEC and may be a good candidate for targeting IGF-1R for cancer therapies.</P>