接觸共形曲率텐서場과 Laplace 演算의 Spectrum

권정환,김운택 대구대학교 부설 과학교육연구소 1991 과학교육 Vol.4 No.-

발열이 있는 호중구 감소증 환자에서의 위험도 예측인자

정중식,권운용,김규석,임용수,이중의,서길준,윤여규 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: Most febrile neutropenic patients are treated in an aggressive manner. However, identification of low-risk patients may enable clinicians to administer risk-based treatment. The object of this study is to certify the factors associated with increased risk at the time of visiting the emergency department. Methods: This is a retrospective study. We reviewed the medical records of 101 febrile neutropenic patients who had visited the emergency department of Seoul National University Hospital from January 1998 to August 1999. We assumed 22 risk prediction factors that could be assessed at admission to the emergency department and 5 factors that could be assessed during treatment course. To find independent risk-prediction factors, we analyzed these factors respectively by using multiple regression analysis. Results: Tachycardia(aOR=136.5), altered mentality(aOR=28.8), decreased renal function(aOR=20.1), and significant comorbidity(aOR=17,2) are the independent factors associated with higher mortality. Altered mentality(aOR=31.6) and decreased renal function(CCr < 75㎖/min, aOR=5.4) are those associated with a higher incidence of septic shock. Independent factors associated with persistent(more than 3 days) fever are the early(within 10 days) onset of fever after last chemotherapy(aOR=8.8) and the existence of new pulmonary infiltrates on a simple chest X-ray(aOR=4.3). Conclusion: The stability of vital signs, the change of mentality, the renal function, the existence of significant comorbidity, the existence of new pulmonary infiltrates, and the rate of neutropenia are clinically useful risk-prediction factors in febrile neutropenia at the time of visiting the emergency department.

박막 크로멜-알루멜 열전퇴형 교류-직류 변환기

정인식,김호운,김진섭,이정희,이종현,신장규,박세일,권성원 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

A planar chromel-alumel multijunction ac-dc converter was fabricated on a LPCVD Si_(3)N_(4)/SiO_(2)/Si_(3)N_(4)-diaphragm, prepared by silicon bulk micromachining, which thermally isolated a bifilar evanohm-heater and the hot junctions of a chromel-alumel thermopile from the silicon substrate. The voltage responsivity, the ac-dc transfer error, and the fluctuation of the output thermoelectric voltage of the converter were investigated. The respective voltage responsivities in air and in a vacuum of the converter were about 3.16 mV/mW and 9.41 mV/mW. The ac-dc voltage and the current transfer errors in air were about ±1.5 ppm and ±0.7 ppm in a frequency range from 10 Hz to 10 kHz, respectively. The fluctuation of the output thermoelectric voltage from 5 seconds to 120 seconds after preheating in air for 5 seconds was about 0.06 % for a heater input of dc 1 V.

만화 과제를 이용한 정신분열병 환자의 사회인지 능력의 측정

오정은,나명현,하태현,신용욱,노규식,홍순범,이경진,신민섭,이영호,권준수 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.3

Objectives : This study is to investigate the hypothesis that schizophrenic patients have difficulty in inferring mental state of others. Methods : Twenty schizophrenic patients and twenty normal subjects were administered to the Cartoon Task required inferring the character's intention in a given context. Results : The schizophrenic patients showed a statistically significant impairment in the Cartoon Task. Both groups chose the card depicting a frequent everyday action significantly more rather than the similar card to the last picture in each story for wrong answers. Conclusion : These preliminary results suggest that schizophrenia is associated with a specific deficit of the cognitive ability referred to as social cognition, and this deficit can be detected not only in the acute phase as found in previous research studies, but also in remission. Also when subjects fail to appreciate what is going on in the minds of other people, they seem to rely on a socially familiar experience.

Streptozotocin-당뇨병 백서에서 당뇨병 이환기간에 따른 대동맥의 이완능 저하 및 Oxygen-Free Radical에 의한 이완능의 손상정도

김정국,김신우,김수동,서예경,하승우,김보완,백운이,권삼,강승완 경북대학교 병원 1997 경북대학교병원의학연구소논문집 Vol.1 No.1

목적: 당뇨병의 이환기간이 혈관의 내피세포 의존성 및 비의존성 이완능의 저하에 미치는 영향과 이환기간에 따라 oxygen-free radical(OFR)에 의한 동맥이완능의 손상정도에 차이가 있는지를 알아보고자 하였다. 방법: Streptozotocin(STZ)으로 당뇨병이 유도된 3 주 및 10주째의 백서군과 연령이 비슷한 정상 대조백서군의 적출 대동맥환을 norepinephrine으로 수축시킨 상태에서 내피세포 의존성 이완제인 acetylcholine(ACh) 및 비의존성 이완제인 nitroglycerine(NTG)에 대한 이완능을 즉정하여 비교 관찬하였다. 또한 xanthine과 xanthine oxidase의 혼합으로 생성된 H₂O₂에 대동맥환을 노출시킨뒤 역시 ACh과 NTG에 대한 이완능의 손상정도를 비교하였다. 결과: 3주및 10주째 당뇨병 백서의 대동맥환은 모두 대조군 백서의 대동맥환에 비해 ACh에 대한 이완능이 유의하게 감소하였으며 10주째 당뇨병 백서군에서의 ACh에대한 이완능의 저하는 3 주째 당뇨병 백서군에 비해 유의하게 심하였다.H₂O₂에 노출시킨 뒤 ACh에대한 이완능은 3주 및 10주 째 당뇨병 백서군에서 모두 대조군에 비해 유의하게 심한 손상을 보였으나 3주와 10주째 당뇨병 백서군 사이의 손상정도의 차이가 통계학적으로 유의하지는 않았다. 한편 3주 및 10주째 당뇨병 백서군 모두 NTH에 대한 대동맥환의 이완능은 대조 백서군과 별다른 차이가 없었으며 또 H₂O₂에 노출시킨 뒤에도 NTG에 대한 이완능의 손상은 관찰되지 않았다. 결론: STZ-당뇨병백서에서 대동맥의 이완능은 당뇨병에 이환된지 3 주째에 이미 ACh에 대한 내피세포 의존성 이완능이 선택적으로 저하되며 당뇨병의 이환기간이 길수록 이완능의 저하가 심하였고, OFR에 의한 동맥 이완능의 손상도 내피세포 의존성 이완능에만 선택적으로 나타나나 이환기간에 따라 OFR에 의한 이완능 손상정도에는 뚜렷한 차이가 없음을 시사하고 있다. Objectives: Diabetes mellitus produces histological evidence of endothelial as well as changes in vascular function in experimental animal. Oxygen free radicals interfere with of destroy endothelium-dependent relaxation in normal and diabetic blood vessels. The present study was investigated whether the duration of diabetic state can affect the severity of impairment in endothelium-dependent and/or independent relaxation and the sensitivity to oxygen free fadical (OFR)-induced damage in diabetic rat vasculature. Methods: The relaxative responses of aortic ring precontracted with norepinephrine in vitro to cumulative concentrations of acetylcholine (ACh) and nitroglycerine (NTG) were conducted in 3- and 10- week streptozotocin (STZ)-diabetic rats and agematched controls. After exposure to H₂O₂generated by mixing xanthine and xanthine oxidase, the degree of impairment in relaxative responses to ACh and NTG were also compared between 3- and 10-week diabetic rats. Results: The relaxative responses of aortic rings produced by cumulative concentrations of ACh were significantly lower in both 3- and 10-week diabetic rats than in the age-matched controls. The impairments of relaxative responses to ACh in 10-week diabetic rats were significantly greater than those in 3-week ones. After H₂O₂ exposure, the impairments of relaxative responses to ACh in 3- and 10-week diabetic aortas was also significantly greater than those in the control in the control ones. However, the severity of H₂O₂-induced damage in 10-week diabetic aortas was not significantly different than that in 3-week ones. In contrast, aortic rings of 3- and 10-week diabetic rats could still be fully relaxed by NTG, even after exposure to H₂O₂. Conclusion: These findings suggest that in SRZ-diabetic rat aortas selective impairment of endothelium-dependent relaxation to Ach can be found early even over a 3-week period after the induction of diabetes and the impairment may be greater in those with the longer duration of the diabetic state and that the impairment of the vascular relaxation by OFR is also selective to endothelium-dependent response but the sensitivity of OFR-induced damage may not be related to the duration of the diabetic state.

방광이행상피세포암에서 p53유전자의 변화

김법완,권태균,노기석,정성광,장세국,정운복,김정완 경북대학교 병원 1997 경북대학교병원의학연구소논문집 Vol.1 No.1

The objective of this study was to characterise the pattern of p53 mutations in bladder turmor. In this study, 25 bladder transitional cell carcinomas were analyed by immunohistochemistry (IHC) for p53 nuclear overexpression, and the results were compared with those of polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis in exon 5-8 of the p53 gene and DNA sequencing analysis. 15 out of 20 cases (75%) showed p53 nuclear immunoreactivities on IHC. On PCR-SSCP analysis, 10 out of 25 cases(40%) had abnormal shifts on mobility. 62% of the mutations were in exon 8. Direct DNA sequencing analysis were performed in these 10 cases to confirm the presence of mutated p53 genes and to determine the type of mutations. Sixteen point mutations were detected in 10 cases. Tow specimens had double mutations and another two had triple mutations. G:C→A:T transitions were the most frequent patterns (62.5%). One mutation was a premature stop codon and two were silent mutations. There out of 10 had a point mutation at codon 285 (GAG/Glu→AAG/Lys) and two had at codon 280(GAG/Glu→AAG/Lys). One of 16 mutations was transition at hot spot codon 273 with CpG site. These results suggest that altered expressions and point mutations of p53 occured in all grade of bladder cancer, but are more associated with hight grade bladder tumors. To elucidate the carcinogenesis of bladder cancer, further studies should be carried out.

Deficiency of clusterin exacerbates high-fat diet-induced insulin resistance in male mice.

Kwon, Min Jung,Ju, Tae-Jin,Heo, Jung-Yoon,Kim, Yong-Woon,Kim, Jong-Yeon,Won, Kyu-Chang,Kim, Jae-Ryong,Bae, Young Kyung,Park, In-Sun,Min, Bon-Hong,Lee, In-Kyu,Park, So-Young The Endocrine Society 2014 Endocrinology Vol.155 No.6

<P>The present study examined the role of clusterin in insulin resistance in high fat-fed wild-type and clusterin knockout (KO) mice. The plasma levels of glucose and C-peptide and islet size were increased in clusterin KO mice after an 8-week high-fat diet. In an ip glucose tolerance test, the area under the curve for glucose was not different, whereas the area under the curve for insulin was higher in clusterin KO mice. In a hyperinsulinemic-euglycemic clamp, the clamp insulin levels were higher in clusterin KO mice after the high-fat diet. After adjusting for the clamp insulin levels, the glucose infusion rate, suppression of hepatic glucose production, and glucose uptake were lower in clusterin KO mice in the high fat-fed group. The plasma levels of clusterin and clusterin mRNA levels in the skeletal muscle and liver were increased by the high-fat diet. The mRNA levels of the antioxidant enzymes were lower, and the mRNA levels of nicotinamide adenine dinucleotide phosphate oxidase (NOX) 1 and cytokines and protein carbonylation were higher in the skeletal muscle and liver in clusterin KO mice after the high-fat diet. Palmitate-induced gene expressions of NOX1 and cytokines were higher in the primary cultured hepatocytes of clusterin KO mice compared with the wild-type mice. Clusterin inhibited the gene expression and reactive oxygen species generation by palmitate in the hepatocytes and C2C12. AKT phosphorylation by insulin was reduced in the hepatocytes of clusterin KO mice. These results suggest that clusterin plays a protective role against high-fat diet-induced insulin resistance through the suppression of oxidative stress and inflammation.</P>

Hierarchical multi-level block copolymer patterns by multiple self-assembly

Jung, Hyunsung,Shin, Won Ho,Park, Tae Wan,Choi, Young Joong,Yoon, Young Joon,Park, Sung Heum,Lim, Jae-Hong,Kwon, Jung-Dae,Lee, Jung Woo,Kwon, Se-Hun,Seong, Gi Hun,Kim, Kwang Ho,Park, Woon Ik The Royal Society of Chemistry 2019 Nanoscale Vol.11 No.17

<P>Uniform, well-ordered sub-20 nm patterns can be generated by the templated self-assembly of block copolymers (BCPs) with a high Flory-Huggins interaction parameter (<I>χ</I>). However, the self-assembled BCP monolayers remain limited in the possible structural geometries. Here, we introduce a multiple self-assembly method which uses di-BCPs to produce diverse morphologies, such as dot, dot-in-honeycomb, line-on-dot, double-dot, pondering, dot-in-pondering, and line-on-pondering patterns. To improve the diversity of BCP morphological structures, we employed sphere-forming and cylinder-forming poly(styrene-<I>block</I>-dimethylsiloxane) (PS-<I>b</I>-PDMS) BCPs with a high <I>χ</I>. The self-assembled mono-layer and double-layer SiOx dot patterns were modified at a high temperature (∼800 °C), showing hexagonally arranged (dot) and double-hexagonally arranged (pondering) SiOx patterns, respectively. We successfully obtained additional new nanostructures (big-dot, dot-in-honeycomb, line-on-dot, pondering, dot-in-pondering, and line-on-pondering types) through a second self-assembly of cylinder-forming BCPs using the dot and pondering patterns as guiding templates. This simple approach can likely be extended to the multiple self-assembly of many other BCPs with good functionality, significantly contributing to the development of various nanodevices.</P>

Design of a Work Process and Implementation of a Prototype for the Development of an Automation Tool for Android Application Vulnerability Inspection

Da-Woon Leem,Hyun-Ju Jung,Moon-Sung Hwang,Jung-Ah Shim,Hyun-Jung Kwon 보안공학연구지원센터 2016 International Journal of Software Engineering and Vol.10 No.3

As a variety of services are provided through mobile devices, there have been increasing security threats to mobile platforms and applications. Many mobile application security check methodologies are proposed to deal with such threats, but it is not clear exactly how the security vulnerabilities are inspected, and there is no correct methodology for such. One way to increase the execution rate of vulnerability check is to develop an automation tool that simplifies the process. Therefore, in this study, a work process of Android application vulnerability inspection was designed and a prototype of the automation tool for vulnerability inspection was implemented. Furthermore, the effectiveness of the implemented prototype was assessed through an actual application using the prototype.

수도권매립지 바이오가스를 이용한 수소생산 및 활용방안 마련

권기운 ( Gi-woon Kwon ),김재형 ( Jae-hyung Kim ),장재용 ( Jae-yong Jang ),이경호 ( Kyeong-ho Lee ),박철형 ( Cheal-hyang Park ),유재관 ( Jai-kwan Ryou ),김유정 ( You-jung Kim ),박혜옥 ( Hye-ok Park ),박정현 ( Jung-hyun Park ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 한국폐기물자원순환학회 추계학술발표논문집 Vol.2019 No.-

최근 우리나라는 수소경제 활성화를 위해 수소생산 단계부터 활용단계, 안전분야까지 정부주도로 추진중에 있다. 현재까지 수소모빌리티, 연료전지 등 활용분야에 대해서는 많은 기술개발과 글로벌 경쟁력을 확보하고 있으나, 공급부분에 있어서는 부생수소를 통해 일부 지역에 국한되어 활용되고 있는 실정에 있다. 이에 그린수소 확대·전환 등 원활한 수소공급을 위해 수소추출 등 대규모 수소생산에 집중이 필요한 상황에 있다. 이에 본 연구에서는 수도권매립지로 반입되는 음식물류폐수의 혐기성소화 후 생산된 바이오가스를 활용한 수소추출 방법 및 이때 생산된 수소를 활용하기 위한 비즈니스모델을 제시하고자 하였다. 바이오가스 조성 대부분은 메탄과 이산화탄소로 구성되어 있으며, 일부 불순물이 포함되어 있어 수소생산으로 활용하기 위해서는 전처리 공정이 필연적이다. 본 연구에서는 수소추출 원료로 사용된 바이오가스를 시간당 약 600 m³_{(인입 바이오가스 기준)}로 활용하는 것으로 가정하고, 바이오가스 전처리 공정은 기존에 운영 중인 불순물제거·고질화 공정 일부를 개선하여 활용하는 방안으로 검토하였다. 이때 생산된 수소는 수소추출설비의 초기투자비 등을 고려하여 일일 약 640 kg으로 산정하였다. 수소충전설비는 디스펜서 1기를 포함한 일반적인 수소충전시스템을 고려하였으며, 수소충전소의 운영시간은 인건비 등을 감안하여 12시간을 기준으로 하였다. 수소 수요예측은 수도권매립지 주변의 거주지역 등을 고려하였다. 이를 통한 비즈니스 모델로는 수소충전소 운영을 통한 소매판매 및 유통사를 통한 수소판매 등으로 검토되었으며, 이를 활용한 경제성은 수소 수요량 증대에 따라 판매형태 비율 조정, 디스펜서 신규구축 및 수소추출설비 확대 등에 따라 다르게 나타나는 것으로 확인되었다. 추후 수도권매립지의 바이오가스 활용량 증대, 수소추출 기술 적용 등을 통해 수도권 북부권역의 수소생산기지로서 수소공급을 위한 중요한 역할을 나타낼 것으로 사료된다.