• 대한화학회지
• /
• 제31권4호
• /
• pp.295-300
• /
• 1987

고분자전해질인 Chondroitin sulfate A(CSA) 및 Chondroitin sulfate C(CSC) 존재하에서의 methylene blue(MB) 및 acridine orange(AO)의 metachromasy 현상에 관하여 각각 분광학적 방법으로 연구하였다. P/D값의 변화에 따르는 meta-band의 특성적 변화를 stacking 이론에 의하여 설명하였으며, staking 효과의 정량적 고찰에 의하여 고분자의 반복단위당 결합하는 색소분자의 수를 계산한 결과 MB가 AO보다 강한 stacking 효과를 나타냄이 발견되었다. CAS의 안정한 형태의 골격구조와 dimension을 발견하고 평면 방향색소의 free dimer의 모형을 근거로 CSA의 골격표면에 결합한 색소분자의 stacking모형과 dimension을 제안하였다.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (1)
• /
• pp.319-321
• /
• 2004

안전한 그룹 통신은 원격 회의 또는 강의, 네트워크 게임, 그리고 주식정보 제공등 이미 다양한 분야에서 그 필요성을 인식하고 있지만, 그 개념을 망 관리 시스템에 적용하여도 통신망을 효율적으로 관리하데 도움이 될 것으로 기대된다 SNMP는 데이터망 관리를 위한 프로토콜로 일대일 통신에는 안전한 통신을 위한 방안을 제공하지만 안전한 그룹 통신을 위한 방안은 제공하지 않는다. 본 논문에서는 표준 SNMPv3를 확장하여 표준 SNMPv3와 호환이 가능하면서도 안전한 멀티캐스트 서비스를 제공하는 구조를 제안한다. 제안한 구조는 MIB-II를 확장하고, SET 명령과 표준 엔진의 동작을 수정하여 그룹 멤버쉽과 그룹 키를 처리할 수 있도록 하였다.

• Clinical and Experimental Reproductive Medicine
• /
• 제31권1호
• /
• pp.67-74
• /
• 2004

Objective: This study was to examine in vitro neural cell differentiation pattern of the genetically modified human embryonic stem cells expressing tyrosine hydroxylase (TH). Materials and Methods: Human embryonic stem (hES, MB03) cell was transfected with cDNAs cording for TH. Successful transfection was confirmed by western immunoblotting. Newly transfected cell line (TH#2/MB03) was induced to differentiate by two neurogenic factors retinoic acid (RA) and b-FGF. Exp. I) Upon differentiation using RA, embryoid bodies (EB, for 4 days) derived from TH#2/MB03 cells were exposed to RA ($10^{-6}M$)/AA ($5{\times}10^{-2}mM$) for 4 days, and were allowed to differentiate in N2 medium for 7, 14 or 21 days. Exp. II) When b-FGF was used, neuronal precursor cells were expanded at the presence of b-FGF (10 ng/ml) for 6 days followed by a final differentiation in N2 medium for 7, 14 or 21 days. Neuron differentiation was examined by indirect immunocytochemistry using neuron markers (NF160 & NF200). Results: After 7 days in N2 medium, approximately 80% and 20% of the RA or b-FGF induced Th#2/MB03 cells were immunoreactive to anti-NF160 and anti-NF200 antibodies, respectively. As differentiation continued, NF200 in RA treated cells significantly increased to 73.0% on 14 days compared to that in b-FGF treated cells (53.0%, p<0.05), while the proportion of cells expressing NF160 was similarly decreased between two groups. However, throughout the differentiation, expression of TH was maintained ($\sim$90%). HPLC analyses indicated the increased levels of L-DOPA in RA treated genetically modified hES cells with longer differentiation time. Conclusion: These results suggested that a genetically modified hES cells (TH#2/MB03) could be efficiently differentiated in vitro into mature neurons by RA induction method.

• 한국정보과학회논문지:정보통신
• /
• 제29권6호
• /
• pp.613-624
• /
• 2002

최근 들어 TCP/IP 프로토콜을 사용하고 있는 통신망들은 전 세계적으로 엄청나게 증가하고 있다. 특히 인터넷과 WWW(World Wide Web) 서비스의 증가는 통신망에서의 트래픽 증가를 더욱 가속화하고 있다. 본 논문에서는 먼저 네트워크 트래픽 모니터링 및 분석을 위한 요구사항을 조사하고, 웹 기반의 트래픽 모니터링 및 분석 시스템을 설계하고 구현한다. 또한 SNMP 분석 파라미터들을 정의하고 이를 이용하여 네트워크 트래픽 분석을 수행한다. 마지막으로 수집된 트래픽 결과를 기반으로 분석 형태에 따라 GUI(Graphic User Interface)형태로 표현한다. 본 논문에서 제시한 시스템은 웹을 이용하여 플랫폼에 종속되지 않고, 분석 파라미터에 따라 인터넷 트래픽 상황을 분석할 수 있도록 하여 사용자가 자신의 호스트에서 직접 인터넷 트래픽을 관리할 수 있다.

• Journal of Korean Neurosurgical Society
• /
• 제56권3호
• /
• pp.194-199
• /
• 2014

Objective : Meningioma is the second most common primary central nervous system neoplasm. In contrast, chordoid meningioma is rare; due to the paucity of cases, little is known about its clinical features or treatment outcomes. The objectives of this study were to describe the clinical characteristics and outcomes for patients with chordoid meningioma. Methods : In total, 16 patients, with newly diagnosed chordoid meningioma who underwent surgical excision between 1999 and 2012 were included. We retrospectively evaluated the medical records, radiological findings, and pathological findings. The median follow-up period was 56.5 (range, 3-170) months. The MIB-1 labeling index ranged from 1 to 26.60% (median, 5.04). Results : Simpson grade I, II, and III resections were performed in four, nine, and three patients, respectively. The overall recurrence rate was 37.5%. Overall progression-free survival (PFS) after resection was 94.7 months (95% CI=62.9-126.6). Of the 4 patients with Simpson grade I resection, recurrence occurred in one patient. Among the Simpson grade II and III resection groups, eight patients underwent adjuvant radiation therapy and they showed significantly longer PFS (121 months, 95% CI=82.1-159.9) than the patients who underwent surgery alone (40.5 months, 95% CI=9.6-71.3) by the log-rank test (p<0.05). Conclusion : Chordoid meningiomas are difficult to manage and have a high rate of recurrence. Complete resection of the tumor is a key determinant of better outcomes. Adjuvant radiation therapy is recommended, eparticulary when Simpson grade I resection was not achieved.

• 한국정보통신학회논문지
• /
• 제12권12호
• /
• pp.2140-2145
• /
• 2008

UWB 초고속 무선통신 시스템을 위한 MB-OFDM용 128-포인트 FFT 프로세서를 설계하였다. 128-포인트 FFT 프로세서는 Radix-2 FFT 알고리듬과 R2SDF 파이프라인 구조에 기초하고 있으며, VHDL을 이용하여 구현되었다. 그 결과는 Modelsim을 이용하여 검증되었으며, Xilinx Vertex-II FPGA를 이용하여 합성된 결과 18.7MHz의 동작주파수를 얻을 수 있었다. 제안된 128-포인트 FFT 프로세서는 병렬처리 되는 FFT 프로세서의 한 블록으로 이용될 수 있으며, 이를 이용하여 고속의 병렬처리 FFT 모듈이 구현될 수 있게 된다. 따라서 본 논문은 4개의 128-포인트 FFT 프로세서를 병렬로 연결하여 4배의 동작주파수를 얻을 수 있었으며, 결과적으로 MB-OFDM에서 요구되는 동작주파수 이상의 성능을 얻게 되었다.

• 대한임상독성학회지
• /
• 제15권1호
• /
• pp.1-10
• /
• 2017

Purpose: This study was conducted to identify predictors of serious poisoning in patients with snake bite based on initial findings. Methods: We conducted a retrospective study of patients with snake bite who were treated at the emergency department between January 2010 and December 2016. The patients were divided into two groups according to the severity of symptoms based on the traditional snakebite severity grading scale. The mild poisoning group (MP) was classified as those who had a grade I snakebite severity during the hospital stay, and the severe poisoning group (SP) was classified as patients who had grade I at the time of admission, but progressed to grade II-IV during hospitalization. Initial clinical manifestations and laboratory findings of the two groups were compared. Results: Bite to hospital time intervals of SP were longer than those of MP (p=0.034), and the local effect score (LES) was higher in SP (p<0.001). Laboratory analyses revealed that creatine phosphokinase (p=0.044), creatine phosphokinase MB isoenzyme (CK-MB, p=0.011) and serum amylase (p=0.008) were significantly higher in SP. LES, CK-MB and serum amylase were significant prognostic predictors as indicated by univariate logistic regression analysis. Multivariate analysis revealed the following two significant predictors: LES (odds ratio=3.983, p<0.001) and serum amylase (odds ratio=1.020, p=0.017). Conclusion: In managing cases of snake bites, clinical manifestations and laboratory findings must be carefully evaluated. LES and serum amylase are predictive factors for severe poisoning, which is especially important to rapid determination of the intensive care of the patient.

• Asian Pacific Journal of Cancer Prevention
• /
• 제15권16호
• /
• pp.6781-6785
• /
• 2014

Purpose: This study used receiver operating characteristic curves to analyze Surveillance, Epidemiology and End Results (SEER) medulloblastoma (MB) and primitive neuroectodermal tumor (PNET) outcome data. The aim of this study was to identify and optimize predictive outcome models. Materials and Methods: Patients diagnosed from 1973 to 2009 were selected for analysis of socio-economic, staging and treatment factors available in the SEER database for MB and PNET. For the risk modeling, each factor was fitted by a generalized linear model to predict the outcome (brain cancer specific death, yes/no). The area under the receiver operating characteristic curve (ROC) was computed. Similar strata were combined to construct the most parsimonious models. A Monte Carlo algorithm was used to estimate the modeling errors. Results: There were 3,702 patients included in this study. The mean follow up time (S.D.) was 73.7 (86.2) months. Some 40% of the patients were female and the mean (S.D.) age was 16.5 (16.6) years. There were more adult MB/PNET patients listed from SEER data than pediatric and young adult patients. Only 12% of patients were staged. The SEER staging has the highest ROC (S.D.) area of 0.55 (0.05) among the factors tested. We simplified the 3-layered risk levels (local, regional, distant) to a simpler non-metastatic (I and II) versus metastatic (III) model. The ROC area (S.D.) of the 2-tiered model was 0.57 (0.04). Conclusions: ROC analysis optimized the most predictive SEER staging model. The high under staging rate may have prevented patients from selecting definitive radiotherapy after surgery.

• The Korean Journal of Physiology and Pharmacology
• /
• 제24권4호
• /
• pp.311-317
• /
• 2020

In the present experimental study, cecal ligation and puncture significantly increased the myocardial injury assessed in terms of excess release of creative kinase-MB (CK-MB), cardiac troponin I (cTnI), interleukin (IL)-6 and decrease of IL-10 in the blood following 12 h of laparotomy procedure as compared to normal control. Also, a significant increase in protein expression levels of high-mobility group box 1 (HMGB1) and decreased phosphorylation of glycogen synthase kinase-3β (GSK-3β) was observed in the myocardial tissue as compared to normal control. A single independent administration of telmisartan (2 and 4 mg/kg) and AR-A014418 (1 and 2 mg/kg) substantially reduced sepsis-induced myocardial injury in terms of decrease levels of CK-MB, cTnI and IL-6, HMGB1, GSK-3β and increase in IL-10 and p-GSK-3β in the blood in sepsis- subjected rats. The effects of telmisartan at dose 4 mg/kg and AR-A014418 at a dose of 2 mg/kg were significantly higher than the telmisartan at a dose of 2 mg/kg and AR-A014418 1 mg/kg respectively. Further, no significant effects on different parameters were observed in the sham control group in comparison to normal. Therefore it is plausible to suggest that sepsis may increase the levels of angiotensin II to trigger GSK-3β-dependent signaling to activate the HMGB1/receptors for advanced glycation end products, which may promote inflammation and myocardial injury in sepsis-subjected rats.

• The Korean Journal of Ceramics
• /
• 제4권4호
• /
• pp.297-303
• /
• 1998

The effect of aliovalent dopants, $ Nb_2O_5$ and MnO, on the phase stability of 12 mol% ceria partially-stabilized zirconia (Ce-TZP) polycrystals was studied. Both dopants (MnO and $ Nb_2O_5$) significantly increased the stability of the tetragonal zirconia phase (Mb temperature lower than liquid nitrogen temperature). The enhancement of the stability of the tetragonal phase in Ce-TZP doped with 1 mol% of Mno(Ce-TZP/MnO) andCe-TZP doped with 1 mol% of $ Nb_2O_5$(Ce-TZP/$ Nb_2O_5$) were explained by the significant reduction of the driving force, -${\Delta}$Gchem, for the tetragonal-to-mono-clinic phase transformation caused by the addition of MnO and $ Nb_2O_5$. The enhanced stability of the tetragonal phase in the Ce-TZP and Al2O3 composite (Ce-TZP/$Al_2O_3$) is believed to be caused by smaller grain size, moderate reduction in the chemical driving force and increase in the strain energy barrier to the transformation. Mechanical properties of the Ce-TZP and the Ce-TZP/$Al_2O_3$ with (i) the same grain size and (ii) the same Mb temperature were examined by measuring stress-strain behavior in 3 point bending. The Ce-TZP/$Al_2O_3$ composite doped with 1.3w% MnO (Ce-TZP/$Al_2O_3$/MnO), which had the same grain size as the Ce-TZP and De-TZP/$Al_2O_3$ showed more transformation plasticity than either the Ce-TZP or the Ce-TZP/$Al_2O_3$ composite. The Ce-TZP wihch had the same Mb temperature as that of the Ce-TZP/$Al_2O_3$/MnO did not show any transformation plasticity.