• 분석과학
• /
• 제17권5호
• /
• pp.393-400
• /
• 2004

페놀 (POH) 용액에 염산과 아질산나트륨을 가하고 이 혼합물 용액의 온도를 상승시키면서 POH의 나이트로소화 반응의 최적조건을 발견하였다. 염산과 아질산나트륨 농도, 반응온도, 그리고 반응시간 변화가 나이트로소페놀 생성에 미치는 효과를 관찰함으로서 발견한 것이다. 결과, POH의 나이트로소화의 최적조건은 0.10 M 이상의 HCl 농도, $5.0{\times}10^{-4}{\sim}2.0{\times}10^{-3}M$ 범위의 $NO{_2}^-$ 농도, $80^{\circ}C$의 반응온도, 그리고 3시간의 반응시간이었다. POH 이외의 10종 미국환경청 분류 상위환경오염페놀들의 나이트로소화 반응도 이 조건에서 진행시켰다. 나이트로소화 반응을 받는 페놀은 POH, 2-클롤로페놀 (2ClPOH), 2,4-다이클롤로페놀 (24diClPOH), 2,4-다이메틸페놀(24diMPOH), 4-클롤로-3-메틸페놀 (4Cl3MPOH), 그리고 적은 양의 2-나이트로페놀 (2NPOH)이었다. 산성 용액에서 나이트로소화된 페놀이나 되지 않은 페놀 여러 종의 최대흡광파장(${\lambda}_{max}$)은 300 nm 부근이었고, 염기성 용액에서는 2,4,6-트리클롤로페놀 (246triClPOH)과 펜타클롤로페놀 (pentaClPOH)을 제외하고, 그 외 모든 페놀들의 ${\lambda}_{max}$는 400 nm부근이었다. 염기성 용액에서 나이트로소화된 POH 및 그 유도체들의 400 nm에서의 몰흡광계수 (${\varepsilon}$)는 이들의 산성 용액 300 nm에서의 ${\varepsilon}$보다 1.5~2.0배 정도였다. 모세관-고성능액체크로마토그래피 (Capillary-HPLC)의 크로마토그램에 의하여 반응용액 중 $NO{_2}^-$ 농도가 0.003 M 이상일 때는 과량의 $NO{_2}^-$가 나이트로소 페놀의 생성을 방해함도 발견하였다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2023년도 봄 학술논문 발표대회
• /
• pp.255-256
• /
• 2023

The development of corrosion inhibitors with outstanding performance is a never-ending and complex process engaged in by researchers, engineers and practitioners. Computational assessment of organic corrosion inhibitors performance is a crucial step towards the design of new task-pecific materials. Herein, electronic features, adsorption characteristics and bonding mechanisms of two pyridine oximes, namely 2-pyridylaldoxime (2POH) and 3-pyridylaldoxime (3POH) with the iron surface were investigated using molecular dynamics (MD), and self-consistent-charge density-unctional tight-binding (SCC-DFTB) simulations. SCC-DFTB simulations revealed that 3POH molecule can form covalent bonds with iron atoms in its neutral and protonated states, while 2POH molecule can only bond with iron through its protonated form, resulting in interaction energies of -2.534, -2.007, -1.897, and -0.007 eV for 3POH, 3POH+, 2POH+, and 2POH, respectively. Projected density of states (PDOSs) analysis of pyridines-Fe(110) interactions indicated that pyridine molecules chemically adsorbed on the iron surface.

• Clinics in Orthopedic Surgery
• /
• 제10권4호
• /
• pp.455-461
• /
• 2018

Background: Surgical-site, multimodal drug injection has recently evolved to be a safe and useful method for multimodal pain management even in patients with musculoskeletal trauma. Methods: Fifty consecutive patients who underwent plating for mid-shaft and distal clavicular fractures were included in the study. To evaluate whether surgical-site injections (SIs) have pain management benefits, the patients were divided into two groups (SI and no-SI groups). The injection was administered between the deep and superficial tissues prior to wound closure. The mixture of anesthetics consisted of epinephrine hydrochloride (HCL), morphine sulfate, ropivacaine HCL, and normal saline. The visual analogue scale (VAS) pain scores were measured at 6-hour intervals until postoperative hour (POH) 72; stress biomarkers (dehydroepiandrosterone sulfate [DHEA-S], insulin, and fibrinogen) were measured preoperatively and at POH 24, 48, and 72. In patients who wanted further pain control or had a VAS pain score of 7 points until POH 72, 75 mg of intravenous tramadol was administered, and the intravenous tramadol requirements were also recorded. Other medications were not used for pain management. Results: The SI group showed significantly lower VAS pain scores until POH 24, except for POH 18. Tramadol requirement was significantly lower in the SI group until POH 24, except for POH 12 and 18. The mean DHEA-S level significantly decreased in the no-SI group ($74.2{\pm}47.0{\mu}g/dL$) at POH 72 compared to that in the SI group ($110.1{\pm}87.1{\mu}g/dL$; p = 0.046). There was no significant difference in the insulin and fibrinogen levels between the groups. The correlation values between all the biomarkers and VAS pain scores were not significantly different between the two groups (p > 0.05). Conclusions: After internal fixation of the clavicular fracture, the surgical-site, multimodal drug injection effectively relieved pain on the day of the surgery without any complications. Therefore, we believe that SI is a safe and effective method for pain management after internal fixation of a clavicular fracture.

• KSBB Journal
• /
• 제13권2호
• /
• pp.119-124
• /
• 1998

Twelve bacterial strains capable of growing on phenol minimal medium were isolated from iron foundry activated sludge by enrichment culture, and amount them, one isolate which was the best in cell growth and phenol degradation was selected and identified as Acinetobacter junii POH. The optimal temperature, initial pH and phenol concentration in the above medium were 3$0^{\circ}C$, 7.5 and 1000 ppm, respectively. Cell growth of Acinetobacter junii POH dramatically increased 20 hrs cultivation-time and reached a almost stationary phsae 40 hrs cultivation-time then phenol was degraded about 98%. Cell growth was inhibited y phenol at concentrations over 1500 ppm. The isolate was resistant to several antibiotics as well as various heavy metal ions. The growth-limiting log P value of Acinetobacter junii POH on organic solvents was 2.9 in the LB medium. Therefore, it is suggested that Acinetobacter junii POH could be effectively used for the biological treatment of wastewater containing the presence of heavy metal ions and organic solvents.

• 정보통신설비학회논문지
• /
• 제10권1호
• /
• pp.14-26
• /
• 2011

광 가입자용 송신 장치는 가입자 접속부의 ATM(Asynchronous Transfer Mode) 계층으로부터 ATM 셀을 비동기적인 방법으로 FIFO(First In, First Out)를 통해 수신하여 Idle/Unasigned 셀의 삽입, 셀에 대한 HEC(Header Error Correction) 계산, 그리고 셀 페이로드에 대한 스크램블링을 통해 VC4 신호 페이로드에 사상한다. 이때 VC4 POH(Path Over Head)상의 H4 바이트에 의해 셀의 시작점을 지시하고 동시에 POH 오버헤드에 대한 생성, 삽입을 통해 VC4 신호를 형성한다. 이 신호는 AU4 포인터 생성부에서 VC4의 시작점 J1을 생성하여 AUG버스를 통해 STM-1 신호 생성 부에서 프레임 형태로 출력된 후 155Mbps 속도로 광 신호로 변환되어 송신된다.

• Journal of Chest Surgery
• /
• 제56권3호
• /
• pp.179-185
• /
• 2023

Background: Assessments of air leaks are usually performed subjectively, precluding the use of air leaks as an evaluation factor. We aimed to identify objective parameters as predictive factors for prolonged air leak (PAL) and air leak cessation (ALC) from air flow data produced by a digital drainage system. Methods: Flow data records of 352 patients who underwent lung lobectomy were reviewed, and flow data at designated intervals (1, 2, and 3 hours postoperatively [POH] and 3 times a day thereafter [06:00, 13:00, 19:00]) were extracted. ALC was defined by flow less than 20 mL/min over 12 hours, and PAL was defined as ALC after 5 days. Cumulative incidence curves were obtained using Kaplan-Meier estimates of time to ALC. Cox regression analysis was performed to determine the effects of variables on the rate of ALC. Results: The incidence of PAL was 18.2% (64/352). Receiver operating characteristic curve analysis showed cut-off values of 180 mL/min for the flow at 3 POH and 73.3 mL/min for the flow on postoperative day 1; the sensitivity and specificity of these values were 88.9% and 82.5%, respectively. The rates of ALC by Kaplan-Meier analysis were 56.8% at 48 POH and 65.6% at 72 POH. Multivariate Cox regression analysis revealed that the flow at 3 POH (≤80 mL/min), operation time (≤220 minutes), and right middle lobectomy independently predicted ALC. Conclusion: Air flow measured by a digital drainage system is a useful predictor of PAL and ALC and may help optimize the hospital course.

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
• /
• pp.122-122
• /
• 1998

Propentofylline (PPF), a xanthine derivative, has been reported to be effective for the treatment of both vascular dementia and Alzheimer's disease. The elimination half-life of PPF was ranged from 15 to 45 min in rabbit and human, and PPF was rapidly disappeared from the blood. The objective of this experiment is to investigate whether xanthine analogues have effects on the profile of plasma concentration and metabolism of PPF. Caffeine (50 mg/kg, ip) was treated to Sprague-Dawley rats for consecutive 7 days and PPF was intravenously administered to rats 2 hr after the last dose of caffeine. In the other group, PPF was intravenously administered to rats 1 hr after a single dose of pentoxifylline (50 mg/kg, iv). Control group was treated with saline vehicle for the same period as in treatment groups. Blood was withdrawn at specific time intervals. PPF and one of its metabolite (POH) in plasma were determined by gas chromatography/nitrogen phosphorus detector. Plasma concentrations and pharmacokinetic parameters were compared between groups. The area under the curve (AUC) of PPF in rats treated sub chronically with caffeine was significantly decreased compared to control rats. Caffeine treatment results in a significant increase of total body clearance. The AUC of POH was significantly decreased in the caffeine-treated group. A single dose of pentoxifylline has no effect on the phramacokinetics of PPF. Reduction of the AUCs of PPF and POH both suggests that caffeine may increase the excretion of PPF with no affecting the metabolism of PPF to POH.

• KSBB Journal
• /
• 제17권1호
• /
• pp.88-92
• /
• 2002

모세관 기체 크로마토그래피에서 HETP에 영향을 미치는 인자를 고찰하기 위해서 이동상의 유량에 대한 체류분포곡선을 측정하였다. 상관도($r^2$)를 기준으로 측정된 분포곡선으로부터 1, 2차 모멘트와 HETP를 계산하여, 실험식의 매개변수를 추산하였다. 실험식은 이동상의 유속에 대한 함수로서 표시되었으며 이론적인 Golay 식도 고려하였다. 실험에 사용된 시료는 글 표피에 많이 포함된 항암제인 d-limonene와 POH이었다. 실험결과에 의하면, 유속이 증가함에 따라 d-limonene과 POH의 HETP가 증가하였다. d-limonene의 상관도는 0.8265에서 0.8465이었고, POH에서는 0.9353에서 0.9374범위를 나타내었다. $H_g$, $H_{l}$ 및 $H_{c}$를 각각 계산하여 전체 HETP에 미치는 영향을 고찰한 결과, d-limonene과 POH의 $H_{g}$가 HETP에 가장 큰 영향을 주었지만, $H_{l}$는 거의 영향을 미치지 않았다. HETP에 관하여 최적 이동상의 유속이 존재하였다.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2008년도 12th Asian Congress of Fluid Mechanics
• /
• pp.77.2-77.2
• /
• 2008

• Journal of Digestive Cancer Research
• /
• 제5권1호
• /
• pp.1-4
• /
• 2017