• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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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.

• 한국임상약학회지
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• 제30권1호
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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.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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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.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1993년도 제2회 신약개발 연구발표회 초록집
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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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• 제43권1호
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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.

• 동의생리병리학회지
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• 제31권1호
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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.

• 한국항공우주학회지
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• 제42권7호
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• pp.552-560
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• 2014

Pulse Detonation Engine (PDE)는 압축 효과에 따른 효율 증가와 정지 상태로부터 높은 초음속구간까지 작동가능하다는 등의 장점으로 인해 차세대 고속추진기관으로 많은 연구가 진행되고 있다. 본 연구에서는 Chapman-Jouguet 데토네이션 이론과 일정 단면적의 관내 압축성 기연 가스 팽창과정을 연계한 Endo 이론을 바탕으로 실제 추진제에 대한 효율적인 PDE 이론 성능 예측 프로그램을 개발하였다. 성능 예측 프로그램은 탄도진자 측정을 통하여 얻은 실험 결과와 비교를 통하여 검증하였다. 이 프로그램을 이용하여 당량비, 초기압력 및 초기 온도 및 압력에 대한 성능 특성을 살펴보았고 다양한 탄화수소 연료, 산화제 조성에 대한 성능을 해석하여 PDE 이론 성능 데이터베이스를 구축하였다.

• 한국추진공학회지
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• 제22권3호
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• pp.81-89
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• 2018

본 연구에서는 소형 추력기 및 점화기로 활용 가능한 소형 PDE의 작동특성을 실험적으로 알아보았다. 4.22 mm의 내경을 갖는 상용 가스 튜브를 이용하여 소형 PDE를 구성하였으며, 당량비 및 작동 주파수 변화에 따른 PDE의 작동 및 데토네이션 전파 특성을 알아보았다. 측정된 데토네이션 속도는 1 Hz와 5 Hz 작동 조건에서는 희박 영역을 제외한 당량비 조건에 이론값과 10%이내의 오차를 가지는 비교적 정확한 값을 보였다. 그러나 20 Hz 조건의 희박 영역에서는 불안정한 전파 특성을 보였으며, 20~62%의 큰 속도 결손이 발생하였다.

• 한국추진공학회지
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• 제22권6호
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• pp.11-18
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• 2018

펄스 데토네이션 엔진 (PDE는) 추진기관으로서 의미 있는 추력을 얻기 위해 100 Hz 이상의 높은 작동 주파수를 요구한다. 따라서 PDE는 높은 작동 주파수에서 정확하게 작동하는 점화 회로 필요로 한다. 이번 논문에서는 교류와 직류 전원을 이용하는 두 종류의 점화 회로를 설계하여 비교하였다. 두 회로는 16.66 에서 100.00 Hz 작동 주파수에서 입력 신호와 변압기의 1 차 코일에 인가되는 전압 변화를 측정하여 시험하였다. 실험 결과 직류 전원의 회로의 경우 증가된 작동 주파수에서 최대 5.15%의 작동 주파수 오차를 보였으나 교류 전원의 회로의 경우 33.33 Hz 이상부터는 거의 맞지 않는 결과를 보였다. 이를 통해 고주파 작동의 PDE에서는 직류 전원의 점화 회로가 선호됨을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제34권3호
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• pp.644-653
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• 2024

Considering the emergence of various infectious diseases, including the coronavirus disease 2019 (COVID-19), people's attention has shifted towards immune health. Consequently, immune-enhancing functional foods have been increasingly consumed. Hence, developing new immune-enhancing functional food products is needed. Pinus densiflora pollen can be collected from the male red pine tree, which is commonly found in Korea. P. densiflora pollen extract (PDE), obtained by water extraction, contained polyphenols (216.29 ± 0.22 mg GAE/100 g) and flavonoids (35.14 ± 0.04 mg CE/100 g). PDE significantly increased the production of nitric oxide (NO) and reactive oxygen species (ROS) but, did not exhibit cytotoxicity in RAW 264.7 cells. Western blot results indicated that PDE induced the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2. PDE also significantly increased the mRNA and protein levels of cytokines and the phosphorylation of IKKα/β and p65, as well as the activation and degradation of IκBα. Additionally, western blot analysis of cytosolic and nuclear fractions and immunofluorescence assay confirmed that the translocation of p65 to the nucleus after PDE treatment. These results confirmed that PDE increases the production of cytokines, NO, and ROS by activating NF-κB. Therefore, PDE is a promising nutraceutical candidate for immune-enhancing functional foods.