충돌분무의 액적 거동에 미치는 비등방성 난류특성의 영향에 대한 수치해석 연구

고권현(G. H. Ko),유홍선(H. S. Ryou) 한국전산유체공학회 2003 한국전산유체공학회지 Vol.8 No.4

It is an aim of this study to perform extensive numerical study for analyzing the anisotropic turbulence effects on spatial and temporal behaviors of droplet for impinging sprays. The turbulence model of Durbin is used for comparisons with the k-E model. The turbulence-induced dispersions of droplets are consider to describe the anisotropy of turbulence effectively and spray/wall interactions are simulated using the model of Lee and Ryou. Present study investigates the overall and the internal structures of impinging diesel sprays such as spray shapes, radius and height of wall sprays, Sauter mean diameter (SMD), local droplet velocity, and local gas velocity and compared the results with experimental data by two adopted turbulence models. When the anisotropy effect of turbulence is included, better predictions for both gas and droplet tangential velocities are obtained, compared to the k-ε model. It is concluded that anisotropic effect of turbulence should be considered for simulating impinging diesel sprays.

Host People's Kindness and Migrant Workers' Cultural Adaptation: Evidence from South Korea

Jihyun Ryou(Jihyun Ryou),Sang-Yeon Kim(Sang-Yeon Kim) 한국학술연구원 2022 Korea Observer Vol.53 No.4

This study purports to determine the predictors of migrant workers' cultural adaptation in South Korea. In the main, we examined the extent to which the level of inter-/intracultural socializing, exposure to local/native media, and host culture receptivity affect the level of cultural adaptation in cognitive, affective, behavioral domains. Potential impacts of demographic factors (e.g., age, sex, ethnicity, marital status, living alone vs. with family, education level, residency in years, perceived cultural similarity) were also explored. To find answers to the research questions, a total of 634 migrant workers from 37 different nations were reached using a snowball sampling. Surveys were collected in 12 districts of Seoul, the capital of South Korea, and 21 adjacent metropolitan areas. Results indicate that intercultural interaction with host people and media exposure to local contents tend to help improve their knowledge about South Korea (e.g., language, culture). With all else equal, migrant workers treated kindly by Koreans at the workplace and in service sectors, and those living with family, compared to those who live alone, tended to enjoy a greater satisfaction with work and life in South Korea and were more willing to stay. Practical implications for Korean policymakers include encouraging competent migrant workers to move together with the family, making administrative efforts to further simplify the documentation process, and initiating public campaigns to raise host culture receptivity among Korean citizens.

Development and Application of a New Spray Impingement Model Considering Film Formation in a Diesel Engine

Ryou, Hong-Sun,Lee, Seong-Hyuk,Ko, Gwon-Hyun,Hong, Ki-Bae The Korean Society of Mechanical Engineers 2001 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.15 No.7

The present article presents an extension to the computational model for spray/wall interaction and liquid film processes that has been dealt with in the earlier studies (Lee and Ryou, 2000a). The extensions incorporate film spread due to impingement forces and dynamic motion induced by film inertia to predict the dynamic characteristics of wall films effectively. The film model includes the impingement pressure of droplets, tangential momentum transfer due to the impinging droplets on the film surface and the gas shear force at the film surface. Validation of the spray/wall interaction model and the film model was carried out for non-evaporative diesel sprays against several sources of experimental data. The computational model for spray/wall interactions was in good agreement with experimental data for both spray radius and height. The film model in the present work was better than the previous static film model, indicating that the dynamic effects of film motion should be considered for wall films. On the overall the present film model was acceptable for predication of the film radius and thickness.

Gold nanoparticle-DNA aptamer composites as a universal carrier for in vivo delivery of biologically functional proteins

Ryou, S.M.,Yeom, J.H.,Kang, H.J.,Won, M.,Kim, J.S.,Lee, B.,Seong, M.J.,Ha, N.C.,Bae, J.,Lee, K. Elsevier Science Publishers 2014 Journal of controlled release Vol.196 No.-

Although the delivery of biologically functional protein(s) into mammalian cells could be of tremendous value to biomedical research, the development of such technology has been hindered by the lack of a safe and effective delivery method. Here, we present a simple, efficient, and versatile gold nanoparticle-DNA aptamer conjugate (AuNP-Apt)-based system, with nanoblock-like properties, that allows any recombinant protein to be loaded without additional modifications and delivered into mammalian living systems. AuNP-Apt-based protein delivery system was able to deliver various proteins into variety of cell types in vitro without showing cytotoxicity. This AuNP-Apt system was also effective for the local and systemic targeted delivery of proteins in vivo. A local injection of the AuNP-Apt loaded with the apoptosis-inducing BIM protein efficiently inhibited the growth of xenograft tumors in mice. Furthermore, an intravenous injection of AuNP-Apt loaded with both epidermal growth factor (EGF) and BIM resulted in the targeted delivery of BIM into a xenograft tumor derived from EGF receptor-overexpressing cancer cells with no detectable systemic toxicity. Our findings show that this system can serve as an innovative platform for the development of protein-based biomedical applications.

Effect of Protease Inhibitors on Degradation of Recombinant Human Epidermal Growth Factor in Skin Tissue

Ryou, Hae-Won,Lee, Jang-Won,Kyung, Kyung-Ae,Park, Eun-Seok,Chi, Sang-Cheol The Pharmaceutical Society of Korea 1997 Archives of Pharmacal Research Vol.20 No.1

Recombinant human epidermal growth factor (rhEGF), a polypeptide of 53 amino acid residues, is subject to degradation by numerous enzymes, especially proteases, when it is applied on the skin for the treatment of open wound. Amastatin, aprotinin, bestatin, EDTA, EGTA, gabexate, gentamicin, leupeptin, and TPCK were investigated for the possible protease inhibitors, which may use to protect rhEGF from degradation by the enzymes in the skin. Skin homogenates containing protease inhibitors and rhEGF were incubated at $37^{\circ}C$ for 30 minutes. After the reaction was stopped with trifluoroacetic acid, the amount of rhEGF remaining in the sample was determined with an HPLC method. The percentages of rhEGF degraded, at the skin/PBS ratio of 0.25, in the mouse, rat, and human skin homogenate were 85%, 70%, and 46%, respectively. The degree of degradation of rhEGF in the cytosolic fraction was higher than that in the membrane fraction and these enzyme reactions were completed in 30 minutes. Bestatin, EGTA, and TPCK showed significant inhibitory effects on the degradation of rhEGF in the two fractions (p<0.05), while the other protease inhibitors had no significant inhibitory effects or, even resulted in deleterious effects. Therefore, the formulation containing one or several inhibitors among these effective inhibitors would be a promising topical preparation of rhEGF for the treatment of open wound.

Shiga-like toxin-based high-efficiency and receptor-specific intracellular delivery system for a protein

Ryou, Jeong-Hyun,Sohn, Yoo-Kyoung,Hwang, Da-Eun,Kim, Hak-Sung Elsevier 2015 Biochemical and biophysical research communication Vol.464 No.4

<P><B>Abstract</B></P> <P>The cell-specific cytosolic delivery of functional macromolecules with high efficiency is of great significance in molecular medicine and biotechnology. Herein, we present a Shiga-like toxin II-based high-efficiency and receptor-specific intracellular delivery system. We designed and constructed the Shiga-like toxin-based carrier (STC) to comprise the targeting and translocation domains, and used it for delivering a protein cargo. The STC was shown to deliver a protein cargo into the cytosol with high efficiency in a receptor-specific manner, exhibiting much higher efficiency than the most widely used cell-penetrating peptide. The general utility of the STC was demonstrated by modulating the targeting domain. The present delivery platform can be widely used for the intracellular delivery of diverse biomolecules in a receptor-specific and genetically encodable manner.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We present a highly efficient and cell-specific intracellular delivery system. </LI> <LI> Shiga-like toxin-based carrier comprises the targeting and translocation domain. </LI> <LI> EGFP was successfully delivered into the cytoplasm of mammalian cells. </LI> <LI> The receptor-specificity was changed by modulating the targeting domain. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The Comparison of The Kitchen Space Reflected on the Rural Living and Social Concerns - Missouri State, U. S and Chonbuk Province, South Korea -

Ryou, Ok-Soo,Choi, Byoung-Sook The Korean Housing Association 1999 한국주거학회 논문집 Vol.10 No.3

Reproducibility of cardiopulmonary exercise testing between one after and 1–3 weeks after elective percutaneous coronary intervention

Ryou Tanaka,Isao Waki,Shigeshi Kamikawa,Daiki Yamashita,Natsumi Tabita,Saori Nishimura,Shunich Higashiya,Hirosuke Yamaji,Takashi Murakami,Shozo Kusachi 한국운동재활학회 2023 JER Vol.19 No.5

Prompt prescription and early initiation of exercise training are essential for patients undergoing elective percutaneous coronary intervention (PCI). We hypothesized that cardiopulmonary exercise testing (CPET) parameters determined the day after elective PCI during hospitalization would not differ from those obtained 1–3 weeks post-PCI in patients with stable coronary heart disease (CHD). CPET was performed the day after and 1–3 weeks (13±4.6; 7–21 days) after PCI. CPET was performed with a bicycle ergometer up to the ventilatory aerobic threshold (VAT) on the day after PCI. Symptom-limited CPET was conducted 1–3 weeks after PCI. No complications arose from the tests. There were no significant differences in %VAT (next day: 88.6± 16.7 vs. 1–3 weeks later: 91.4%±18.7%), the workload at the VAT (51.8±11.0 W vs. 52.9± 11.6 W), heart rate (HR) at the VAT (95.3±105 beats/min vs. 94.1±11.3 beats/min), or metabolic equivalent (METs) at the VAT (3.69±0.69 vs. 3.84±0.78) between the two sessions. The slope of linear regression for two repeated measurements was close to 1 (%VAT, 1.02; workload at the VAT, 0.95; METs at the VAT, 1.03), except for HR (0.70). Bland–Altman plots revealed the reproducibility of all four CPET measurements between the two sessions. In conclusion, CPET up to the VAT can be performed safely 1-day post-PCI in patients with stable CHD. CPET parameters do not significantly differ between testing performed the day after and 1–3 weeks after PCI. Next-day CPET during hospitalization after PCI may enable prompt exercise prescription without the need for another CPET 1–3 weeks later.

Lithium-Ion Batteries: Excellent Cycle Life of Lithium-Metal Anodes in Lithium-Ion Batteries with Mussel-Inspired Polydopamine-Coated Separators (Adv. Energy Mater. 6/2012)

Ryou, Myung-Hyun,Lee, Dong Jin,Lee, Je-Nam,Lee, Yong Min,Park, Jung-Ki,Choi, Jang Wook Wiley (John WileySons) 2012 ADVANCED ENERGY MATERIALS Vol.2 No.6

Immunochemical Studies on Expression of Quinoproteins in Escherichia coli

RYOU, CHONGSUK,KIM, JAE-BEOM,KWON, MOOSIK 한국미생물 · 생명공학회 2000 Journal of microbiology and biotechnology Vol.10 No.1

An immunochemical method has been developed as the most sensitive tool for studying the expression of quinoproteins containing pyrroloquinoline quinone (PQQ) in E. coli. The PQQ was conjugated to bovine serum albumin (BSA), and the conjugant was purified by using a KwikSep^™ dextran desalting column chromatography. The PQQ-BSA conjugant was immunized to rabbits, and the IgG fractions of the antisera were purified. The most sensitive antibody againt PQQ-BSA conjugant recognized some nanogram quantity of the antigen on the blot, but had little cross reactivity with BSA. Using this batch of the antibody, all the immunochemical assays of quinoproteins in E. coli were performed. Some six different PQQ-specific spots were detected by Western blot analysis of the soluble proteins in E. coli after two-dimensional gel electrophoresis. Their molecular weights on the blot were estimated to be about 100-, 90-, 72-, 58-, 52-, and 50-kDa. Their pI values fell in the range from 4.8 to 5.5. These results strongly suggest that quinoproteins are present in E. coli, and that the protein moieties were covalently bound to PQQ.