실관형 막모듈을 이용한 투과추출의 분리특성에 관한 연구

김우식,이호원,오준택 연세대학교 대학원 1991 延世論叢 Vol.27 No.1

The purpose of this study is to analyze separation characteristics in perstraction using hollow fiber modules. The perstraction experiments of acetic acid have been undertaken under various experimental conditions such as pressure changes, superficial velocity changes in aqueous and organic phases, and potting density changes in two systems with different distribution coefficients. There was no change in overall mass transfer coefficient with a change in the pressure difference between inside and outside hollow fiber. Tortuosity of hollow fibers used was obstained from mass transfer coefficients in membrane phase. The overall mass transfer coefficient increased nonlinearally with increase in organic and aqueous phase velocity where the proportion exponent was obtained to be 0.35 and 0.56 respectively.

대장-직장암에서 Cyclooxygenase-2의 발현

강원경,천준성,장세진,조현민,천성원,안창혁,오승택 대한대장항문학회 2004 Annals of Coloproctolgy Vol.20 No.2

Risk Factors for Rebleeding After Successful Rapid Rhino Packing in Epistaxis Patients

Oh Joon Taek,Bae Mi Rye 대한비과학회 2023 Journal of rhinology Vol.30 No.1

Background and Objectives: Epistaxis is one of the most common emergencies in otolaryngology, and the recently developed Rapid Rhino nasal pack, a balloon-type nasal packing device, is widely used in emergency departments. Rebleeding after initial treatment increases patients’ discomfort and medical costs. The aim of this study was to investigate risk factors for rebleeding in patients treated with Rapid Rhino packing. Methods: In this retrospective study, 93 patients with epistaxis treated with Rapid Rhino from January 2020 to November 2022 were divided into the well-controlled group (39 patients) and the rebleeding group (54 patients), and the baseline characteristics, management methods, and complications were compared between these groups. The rebleeding group was divided according to whether patients experienced a single episode of rebleeding (38 patients) or multiple rebleeding episodes (16 patients), and the differences between these two groups were compared. Results: Oral anticoagulation therapy was associated with a higher risk of rebleeding after Rapid Rhino packing (odds ratio [OR]= 8.41, p=0.047). A history of nasal surgery was associated with multiple rebleeding (OR=22.55, p=0.009). Age, sex, the management method, complications, and the site of bleeding were not found to be related to rebleeding. Conclusion: Patients with rebleeding after Rapid Rhino nasal packing had a higher rate of concurrent oral anticoagulation therapy. A history of nasal surgery was strongly associated with multiple episodes of rebleeding. A detailed medical history can be important for assessing the risk of rebleeding in epistaxis patients treated with Rapid Rhino packing.

Effect of isosecotanapartholide isolated from Artemisia princeps Pampanini on IL-33 production and STAT-1 activation in HaCaT keratinocytes

Oh, Chang Taek,Jang, Yu-Jin,Kwon, Tae-Rin,Im, Songi,Kim, Soon Re,Seok, Joon,Kim, Gun-Yong,Kim, Young-Heui,Mun, Seog Kyun,Kim, Beom Joon SPANDIDOS PUBLICATIONS 2017 MOLECULAR MEDICINE REPORTS Vol.15 No.5

<P>The present study aimed to investigate the anti-inflammatory effect and mechanism of action of isosecotanapartholide (ISTP), isolated from Artemisia princeps Pampanini extract (APE). The effects of ISTP and APE on the proliferation of human keratinocytes following stimulation by tumor necrosis factor-alpha/interferon-gamma were assessed. ISTP and APE downregulated the expression levels of signal transducer and activator of transcription-1 (STAT-1), and reduced interleukin-33 (IL-33) production. ISTP and APE inhibited the mRNA expression levels of thymus and activation-regulated chemokine (TARC/CCL17) in a dose-dependent manner. Western blot analysis demonstrated that ISTP and APE dose-dependently inhibited protein expression levels of intercellular adhesion molecule-1 and phosphorylation of STAT-1. The results of the present study indicate that ISTP may inhibit TARC/CCL17 production in human epidermal keratinocytes via the STAT-1 signaling pathway and may be associated with the inhibition of IL-33 production. The current study indicated that ISTP is an active component in APE and may be a potential therapeutic agent for the treatment of inflammatory skin disorders.</P>

PHB 합성을 위한 A. eutrophus의 최적 배양 조건 및 부생성물의 영향 고찰

오준택(Joon-Taek Oh),이동건(Dong-Gun Lee),김우식(Woo-Sik Kim) 한국생물공학회 1994 KSBB Journal Vol.9 No.5

연구발표논문초록 ( 분리기술 (Ⅰ) ) : 한외여과에 있어서 용액흐름 방향으로의 농도분극변화에 관한 연구

오준택(Joon Taek Oh),염경호(Kyoung Ho Youm),김우식(Woo Sik Kim) 한국화학공학회 1989 춘계학술발표회 Vol.- No.-

3D Simulation 데이터 기반 인공 신경망을 이용한 Roller Hearth Kiln의 예측 모델 최적화

오준택(Joon Taek Oh),봉현민(Hyun Min Bong),이상철(Sang Chul Lee),안상철(Sang Chul An),김영일(Young Il Kim),장병록(Byoung Lok Jang) 대한설비공학회 2021 대한설비공학회 학술발표대회논문집 Vol.2021 No.6

The current study is conducted to shorten the design time of Roller Hearth Kiln by using the analysis of 3D simulation. A predictive model has been developed by applying a neural networks to the database which is based on the results of 3D simulation of the kiln. The comparion results between the simulation data and the effective values of prediction model shows a good match that the error rate is only 0.88%. Also, the prediction model generated by using neural networks shows similar results with the 3D simulation. Through the prediction model derived through this study, it was confirmed that time can be saved when designing the optimal roller of this type.

Alcaligenes latus 에 의한 PHB 의 생합성에 관한 연구

김우식,오준택,조근도,윤정열 한국화학공학회 1997 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.35 No.3

본 논문은 Alcaligenes latus DSM 1123 균주의 최적 증식조건 및 PHB 생합성을 위한 효과적인 배양방법에 관한 연구이다. 최적 균증식 조건에 대한 실험은 진탕배양기를 이용하였으며, 얻어진 최적 조건 하에서 2.5L 용량의 호기성 배양 장치를 사용하여 회분식 배양과 pH 조절 용액을 달리한 유가식 배양을 행하였다. 배양에 있어 탄소원 및 질소원은 각각 저가의 탄소원인 sucrose및 (NH₄)₂SO₄를 사용한 경우가 가장 효율적이었다. 최적의 C/N비는 탄소원 및 질소원 농도에 비례하여 증가하였으며, sucrose농도 30g/L일 경우 C/N비 30에서 최대의 비증식속도를 보였다. Yeast extract 0.5 g/L와 polypeptone 1.0 g/L를 배지 중에 첨가한 결과 지연시간의 감소 및 2배 이상의 비증식 속도 향상을 보였다. 또 A. latus는 A. eutrophus와 달리 균증식기에도 PHB를 합성하였다. 초기에는 NH₄OH용액을, 균증식기 중반부터는 NaOH용액을 이용하여 2단 유가식 배양을 하였을 경우가 NH₄OH 용액과 NaOH 용액을 각각 이용하여 pH를 조절한 경우에 비하여 비증식속도와 균체량 및 PHB 축적량이 증가하였으며, 이때의 최종균체량, PHB 합성량 및 최종 균체량에 대한 PHB 축적률은 각각 17.6 g/L, 8.04 g/L 및 46%이었다. Culture conditions for the optimum growth and biosynthesis of PHB in Alcaligenes latus DSM 1123 were investigated. Optimum carbon and nitrogen sources and their concentrations for growth were determined, and batch and fed-batch fermentations were performed in a 2.5 L jar type aerobic fermenter with various pH control solutions. Sucrose and (NH₄)₂SO₄ were found to be the most effective carbon and nitrogen sources for the growth of A. latus, respectively. Optimum C/N ratio was found to be varied with the concentrations of carbon and nitrogen sources. The maximum specific growth rate was obtained at the sucrose concentration of 30 g/L and C/N ratio of 30. The specific growth rate increased more than two times and lag time was reduced when yeast extract and polypeptone were added. PHB could be synthesized in the logarithmic growth phase. By using NH₄OH and NaOH solutions in the first and second stage as pH control solution, significant increases in the specific growth rate, biomass and PHB concentrations were observed. Under the optimal conditions, the maximum biomass and PHB accumulation yield(Y_(P/X) attained after 40 hours were 17.6 g/L and 46 %, respectively.

저비중 척추마취시 국소마취제의 용적이 마취 높이에 미치는 영향

김승준,한동우,남용택,배선준,오경미 대한마취과학회 2001 Korean Journal of Anesthesiology Vol.41 No.2

The Effect of the Injected Volume on the Spread of Spinal Anesthesia with Hypobaric Tetracaine Dong Woo Han, M.D., Seung Jun Kim, M.D., Sun Joon Bai, M.D. Kyeong Mee Oh, M.D., and Yong Taek Nam, M.D. Department of Anesthesiology, Yonsei University College of Medicine, Seoul, Korea Background: The properties of hypobaric spinal anesthesia are excellent in sensory and motor block with low concentration solutions, increased venous return, and hemodynamic stability. Much volume is needed with hypobaric spinal anesthesia because low concentration solutions are used. The purpose of this study was to examine the effects of the injected volume on the level of anesthesia in hypobaric spinal anesthesia during a total hip replacement. Methods: Twenty-seven adult patients scheduled for a total hip replacement were assigned randomly to two groups, one with 0.1% (n = 14), and the other with 0.2% (n = 13) hypobaric tetracaine spinal anesthesia. 8 mg of tetracaine was used for male patients and 7 mg for female patients. Hence the injected volumes were 8 ml for male and 7 ml for female patients in 0.1% solution and 4 ml for male and 3.5 ml for female patients in 0.2% solution, respectively. Epinephrine was mixed to either solution in concentrations of 1 : 200,000. The speed of injection was fixed at the rate of 0.2 ml/sec. Results: The height of sensory block with the 0.1% was one dermatome higher (T5.7) than with the 0.2% tetracaine solution (T6.7). The time for sensory block (11.4 min vs 12.3 min) and the time for motor block (10.0 min vs 15.0 min) with 0.1% was shorter than that with the 0.2% tetracaine solution. The duration of sensory block and the duration of motor bllock were not significantly different in either groups. Complete motor block was achieved in all patients. Conclusions: Both 0.1% and 0.2% hypobaric tetracaine spinal anesthesia are suitable for a total hip replacement. However we got better results with 0.1% than with 0.2% retracaine such as rapid and high sensory block with rapid motor block. (Korean J Anesthesiol 2001; 41: 159~164)

High intensity focused ultrasound as a potential new modality for the treatment of pigmentary skin disorder

( Joon Seok ),( Yeon A No ),( Chang Taek Oh ),( Eun Ja Choi ),( Sun Young Choi ),( Beom Joon Kim ),( Myeung Nam Kim ) 대한피부과학회 2015 대한피부과학회 학술발표대회집 Vol.67 No.2

Background: The clinical skin tightening benefits of high intensity focused ultrasound (HIFU) have been established, but its mechanisms of action in pigmented skin disorders remain unknown. Objectives: We aim to investigate macroscopic andhistopathological changes after HIFU at different exposure doses in hyperpigmentation. Methods: We applied HIFU irradiation at 0.1 and 0.2 J/cm2 to UVB-induced hyperpigmentation in guinea pig skin. The therapeutic effects of HIFU were judged based on gross appearance using photography, dermoscopy and chromametry during a period of 3 weeks after HIFU irradiation. Histological assessments were performed using H&E and Fontana-Masson staining 1 day before and 3 weeks after HIFU irradiation. Results: Macroscopically, UVB-induced hyperpigmentation was significantly reduced 3 weeks after HIFU with 0.1 and 0.2 J/cm2. Histopathologically, the heavy deposition of melanin in the epidermis induced by UVB exposure was reduced 3 weeks after HIFU irradiation. Conclusion: We confirmed that HIFU decreases UVB-induced hyperpigmentation as well as mechanical destructive activity. We suggest that HIFU may be useful as an alternative modality for patients suffering from skin pigmentary conditions.