• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.114-114
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• 2002

Inhibitors of type IV phosphodiesterase (PDE IV) are currently being developed as new therapeutic agents for asthma, chronic obstructive pulmonary disease(COPD) and arthritis. Unfortunately, the anti-inflammatory effect of PDE IV inhibitors has been considered to be associated to some extent with vomiting as adverse effect. The first generation PDE IV inhibitor, rolipram, was known to induce emesis at clinical trials. (omitted)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.506-512
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• 2004

We analytically estimated the propulsive performance of pulse detonation engines (PDEs) in three cases, which were (1) a fully-fueled simplified PDE, (2) a partially-fueled simplified PDE, and (3) a PDE optimized as a system. The results of the model analyses in the cases of (1) and (2) were in good agreement with published experimental data which were obtained by using simplified PDEs. The comparison between the results of the analyses of simplified PDEs and those of optimized PDE systems showed that specific impulse would become higher by about 10-20% due to PDE-system optimization.

• Korean Journal of Clinical Pharmacy
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• v.30 no.1
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• pp.59-64
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• 2020

The emergence of phosphodiesterase (PDE) 5 inhibitors gave rise to the solution for erectile dysfunction, starting with the development of sildenafil. Although their efficacy in treating erectile dysfunction has been shown, the side effects of PDE5 inhibitors, especially sildenafil, must be taken into consideration. A 64-year-old man received 100 mg of sildenafil and experienced blue vision in both eyes; however, after a day or so, his symptoms improved. The symptoms disappeared when he stopped administering sildenafil, but reappeared when the medication was re-administered. Therefore, he discontinued sildenafil treatment and was prescribed udenafil instead. After that, visual adverse events no longer occurred. Causality assessment showed that in this case, sildenafil-induced cyanopsia was "certain" under the World Health Organization-Uppsala Monitoring Center (WHO-UMC) criteria and Korean causality assessment algorithm (Ver.2), and was "probable" according to the Naranjo scale. In addition, sildenafil also led to abnormal visual reactions in other cases. Sildenafil can also inhibit PDE6, which is present in retinal cells, unlike other PDE5 inhibitors. Thus, visual adverse reactions, such as blue vision, are the unique results of sildenafil, and other PDE5 inhibitors may be used to prevent them.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.419-426
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• 2008

As pulse detonation engine(PDE) does not need compression mechanisms such as compressors because self-sustained detonation waves are able to compress propellant gases by their incident shock waves, the PDE can have a simple straight-tube structure. In this study, we propose an autonomous driving valve system of the PDE, which fill premixed gases into the PDE tubes at high frequency with high mass flow rate. The proposed valve is composed of only three parts: a piston, a cylinder, and a spring. This valve system can produce intermittent flow at high mass flow rate, and also can keep stable reciprocal motion by using the propellant-gas enthalpy. When the cylinder content product is assumed to be constant, experimental results of the mass flow rate were approximately equal to the calculation model. We confirmed the autonomous driving valve performance by experiments, and concluded that this extremely simple valve with no electrical power and controller can be used as the PDE propellant supply system.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.155-155
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• 1993

항우울약인 rolipran(RP)등 phosphodiesterase-억제 약(PDE-1)들이 thrombin(TB: 0.25 U/ml)에 의한 혈소판 응집에 미치는 작용을 가토-혈소판에서 일차 검토하였다. 신 PDE-1인 KR-30075(KR)의 $IC_{50}$/은 sodim nitroprusside의 것보다 낮았고 PDE-1들은 혈소판내 cAMP와 cGMP를 증가시켰으며 특히 KR은 타 PDE-1와 달리 I $P_3$를 감소시켰다. 아울러 rolipram은 cGMP와 I $P_3$를 증가시켰으나, amitriptyline(AT), sertraline(57), chlorpromazine(CP) 및 spermine은 I $P_3$를 증가시켰다. 그러나 이들과 PDE-1들은 강도의 차이는 있으나 모두 TB에 의한 혈소판응집을 모두 억제하였다. 따라서, PDE-1 중 IBMX(2$\times$$10^{-5}$M), KR(5$\times$10$_－7/M), 및 rolipram(10$_{-3}$M) 그 외에 항우울약인 AT(1.5 $\times$10$_－4/M) 와 ST(10$_－4/M) 및 항정신병약인 CP(10$_－4/M)둥이 혈소판내 I $P_3$, [C $a^{＋＋}$], Tx $B_2$, 및 PG $I_2$ 함량과 단백-인산화의 TB에 의한 변동에 미치는 영향을 검토하였다. 그 결과 TB에 의한 혈소판내 I $P_3$, [C $a^{＋＋}$], Tx $B_2$, 및 PG $I_2$ 함량의 증가가 PDE-1들과 항우울약들에 의하여 억제되었다 단, 항우울성약들과 CP는 정상 혈소판 I $P_3$를 증가시켰다. 아울러 혈소판-단백인산학에서 TB는 41-43 kD와 20 kD의 인산화를 현저히 증가시키며 19 kD의 인산화는 감소시켰고, PKC의 기질인 41-43 kD와 20 kD의 단백인산화가 PDE-1들과 항우울약들 뿐 아니라 CP에 의하여 현저히 억제되었다. 단, 20 kD 인산화에 대한 AT의 억제작용은 미약하였고, cAMP와 PDE-1들은 22kD 인산화를 증가시켰다. AT, ST, 및 CP는 A23187에 의한 41-43 kD 인산화는 현저히 억제하나 20 kD 인산화에는 영향을 미치지 않았고, PMA(3.2$\times$$10^{－7}$ M)에 의한 단백인산화에 대하여는 더 미약한 억제-효과를 나타내었다. 이상의 결과는 PDE-1과 항우울약들의 항혈소판작용은 PKC-기질인 41-43 kD와 20 kD의 인산화를 억제함에 기인되는 것으로 사료된다.다. 것으로 사료된다.다.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.1
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• pp.26-30
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• 2016

Objective: We aimed to investigate the prevalence of erectile dysfunction (ED) and the usage of phosphodiesterase type 5 (PDE5) inhibitors for ED treatment in infertile couples. Methods: A total of 260 male partners in couples reporting infertility lasting at least 1 year were included in this study. In addition to an evaluation of infertility, all participants completed the International Index of Erectile Function (IIEF)-5 questionnaire to evaluate their sexual function. The participants were asked about their use of PDE5 inhibitors while trying to conceive during their partner's ovulatory period and about their concerns regarding the risks of PDE5 inhibitor use to any eventual pregnancy and/or the fetus. Results: Based on the IIEF-5 questionnaire, 41.5% of the participants (108/260) were classified as having mild ED (an IIEF-5 score of 17-21), while 10.4% of the participants (27/260) had greater than mild ED (an IIEF-5 score of 16 or less). The majority (74.2%, 193/260) of male partners of infertile couples had a negative perception of the safety of using a PDE5 inhibitor while trying to conceive. Only 11.1% of men (15/135) with ED in infertile couples had used a PDE5 inhibitor when attempting conception. Conclusion: ED was found to be common in the male partners of infertile couples, but the use of PDE5 inhibitors among these men was found to be very low. The majority of male partners were concerned about the risks of using PDE5 inhibitors when attempting to conceive. Appropriate counseling about this topic and treatment when necessary would likely be beneficial to infertile couples in which the male partner has ED.

• Journal of Physiology & Pathology in Korean Medicine
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• v.31 no.1
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• pp.52-58
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• 2017

This study was aimed to examine relaxing effects of Acanthopanacis cortex(AC) through nitric oxide(NO) production and phosphodiesterase type 5(PDE-5) inhibition in corpus cavernosum. In order to define the relaxation effects of AC extract, rabbit corpus cavernous tissues were prepared in $2{\times}2{\times}8mm$ sized strip. AC extract ($0.01-3.0mg/m{\ell}$) were treated in contracted strips induced by phenylephrine(PE) and $N{\omega}$-nitro-L-arginine (L-NNA) was treated before AC extract-treated. And calcium chloride($Ca^{2+}$) 1 mM was infused into precontracted strips after pretreatment of AC extract in $Ca^{2+}-free$ krebs-ringer solution. When AC extract was applied to human umbilical vein endothelial cell(HUVEC), cell viability was measured by MTT assay, and NO concentration was measured by Griess reagent system. Ratio of smooth muscles to collagen fibers and eNOS, PDE-5 positive reaction were measured by histochemical and immunohistochemical process on mice corpus cavernosum. AC extract significantly affected relaxion of the cavernous strips, and the pretreatment of L-NNA inhibited AC extract-induced relaxation. Contraction induced by the addition of $Ca^{2+}$ was inhibited by treatment with the AC extract in $Ca^{2+}-free$ solution. In AC group, NO concentration, ratio of smooth muscle to collagen fibers, and eNOS positive reaction were increased, PDE-5 positive reaction was decreased compared to PE group. As a result of the above experiment, it was thought that AC extract inhibits the inflow of extracellular $Ca^{2+}$ by activating cGMP through the increase of eNOS / NO and the decrease of PDE-5 which inhibits cGMP activity, in the corpus cavernosum.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.7
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• pp.552-560
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• 2014

Pulse Detonation Engine(PDE) has been investigated as a next generation propulsion system with the advantages of the higher thermal efficiency by the compression effect and the wide operation ranges from zero speed at ground. In the present study, an efficient theoretical PDE performance prediction program was developed for realistic propellants based on the Endo's theory combining the Chapman-Jouguet detonation theory and expansion process of burnt gas in a constant area tube. The program was validated through the comparison with the experimental data obtained by a ballistic pendulum measurement. PDE performance analyses were carried out for various hydrocarbon fuels and oxidizer compositions by changing the mixture equivalence ratio and initial conditions. Theoretical PDE performance database could be established as a result of the analyses.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.3
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• pp.81-89
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• 2018

In this study, the operating characteristics of a small-scale pulse detonation engine (PDE) were investigated experimentally for application as a small thruster and an igniter. The PDE was constructed using commercial gas tubes with an inner diameter of 4.22 mm. The operating and detonation propagation characteristics of the PDE were investigated over the ranges of equivalence ratios and operating frequencies. Measured detonation speed was close to 10% of the theoretical CJ values at 1 Hz and 5 Hz conditions. However, unstable propagation characteristics were shown at 20 Hz and lean conditions, where the velocity deficit was increased by 20~62%.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.6
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• pp.11-18
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• 2018

A pulse detonation engine (PDE) requires high operating frequency greater than 100 Hz to get meaning thrust as a propulsion devise. Thus a PDE needs an ignition circuit operating precisely at high operating frequencies. In this paper AC(alternating current) and DC(direct current) types of ignition circuits were designed and compared. Each circuit was tested at operating frequencies from 16.66 to 100.00 Hz by measuring the input signal of each circuit and the voltage change in the primary coil of the transformer. Results show that the DC power circuit can attain a maximum error rate of 5.15% at higher operating frequencies, whereas the AC power circuit displays a negligible agreement with the operating signal at frequencies greater than 33.33 Hz. Therefore it is confirmed that DC-powered ignition circuit is preferable for the PDE operating at high frequencies.