Characteristics of Throttleable Liquid-Propellant Rocket Injector with Dual Manifold: A Cold Flow Study

( Jung Soo Yoon ),( Sung Hyuk Kim ),( Young Bin Yoon ) 한국액체미립화학회 2010 한국액체미립화학회 학술강연회 논문집 Vol.2010 No.-

Liquid-Propellant Rocket Engines (LPREs) are capable of on-command variable thrust, an operability advantage that has been studied intermittently since the late 1930s. Throttleable LPREs (TLPREs) can be used for docking, orbital maneuvering including orientation and stabilization in space, landing on the atmosphereless planets, and planetary entry. TLPREs can also continuously follow the most economical thrust curve in a given situation, compared to discrete throttling changes over a few select operating points. The effects of variable thrust on the mechanics and dynamics of an LPRE as well as difficulties and issues surrounding the throttling process are important aspects of throttling behavior. There is a many way of LPRE throttling methods, high -pressure-drop systems, dual-manifold injector, gas injection, multiple chambers, pulse modulation, movable injector components, and hydrodynamically dissipative injectors. Especially dual-manifold injector essentially combines two fixed-area injectors into a common structure, with independent feed systems controlling flow to each injector manifold. In this paper provides experimental result of dual-manifold injector. The spray patterns were investigated according to the injection pressure using digital camera and stroboscope. Also, liquid film thickness in orifice tip is investigated with various injection pressure and tangential entry diameter.

The effectiveness of low-fluence fractional CO₂ laser in the treatment of idiopathic guttate hypomelanosis

( Sung Hye Eun ),( Hyun Jung Joo ),( Hyuk Sun Kwon ),( Han Mi Jung ),( Ji Hae Lee ),( Gyong Moon Kim ),( Jung Min Bae ) 대한피부과학회 2017 대한피부과학회 학술발표대회집 Vol.69 No.2

Background: Idiopathic guttate hypomelanosis (IGH) is common acquired leukoderma characterized by discrete, tiny, white macules in the elderly. Until now, there was no definite therapeutic modality for IGH. Objectives: To investigate the effectiveness of low-fluence fractional CO₂ laser in the treatment of IGH Methods: A retrospective review was performed, and a total of 87 lesions on 26 body parts in 17 patients with IGH were included from October, 2016 to June, 2017. A CO₂ fractional laser treatment was performed on all lesions with 2 passes of 2-4 mJ, 400 spots/cm2 with no anesthesia at a 1-week interval. All lesions were classified into three body parts including face, chest, and extremities, and were evaluated according to the body parts. Clinical assessments were evaluated using 6-point scales (0, no; 1, mild; 2, moderate; 3, good; 4, excellent; 5, complete response). Results: Overall, 61.5% (21 out of 26 body parts) showed excellent or complete response after a median of 5.5 treatment sessions (range: 2-9). In the subgroup analysis, 80% (8/10) of face lesions showed excellent response, while 40% (4/10) of extremities reached excellent response. Transient erythema and crust after treatment was common, and one patient stopped treatment because of prolonged hyperpigmentation at irradiation site. Conclusion: Low-fluence fractional CO₂ laser therapy could be an effective option for IGH. It is convenient without need for anesthesia.

Original Article : High Recurrence Rate of Idiopathic Peptic Ulcers in Long-Term Follow-up

( Hyuk Yoon ),( Sang Gyun Kim ),( Hyun Chae Jung ),( In Sung Song ) 대한간학회 2013 Gut and Liver Vol.7 No.2

Background/Aims: Our aim was to compare the long-term clinical outcomes of idiopathic peptic ulcer disease (IPUD) with those of Helicobacter pylori-positive and nonsteroidal anti-inflammatory drug (NSAID)-induced peptic ulcer disease (PUD). Methods: Patients with endoscopically diagnosed PUD were retrospectively reviewed. According to their H. pylori-infection status and history of NSAIDs use, patients were categorized into three groups: H. pylori-positive PUD, NSAID-induced PUD, and IPUD. Clinical outcomes were analyzed, and the recurrence rate of PUD was compared among the three groups. Results: A total of 238 patients were enrolled. Those with IPUD, NSAID-induced PUD, and H. pylori-positive PUD comprised of 56, 60, and 122 patients, respectively. The 5-year cumulative incidences of recurrent ulcers were 24.3% (95% confidence interval [CI], 11.6% to 37.0%) in IPUD, 10.9% (95% CI, 2.6% to 19.2%) in NSAID-induced PUD, and 3.8% (95% CI, 0.1% to 7.5%) in H. pylori-positive PUD (IPUD vs NSAID-induced PUD/H. pylori-positive PUD, p=0.43/p<0.001 by log-rank test). In the Cox-proportional hazards model, only IPUD remained as an independent risk factor associated with recurrent ulcers (hazard ratio, 5.97; 95% CI, 1.94 to 18.34; p=0.002). Conclusions: IPUD exhibited a higher recurrence rate than H. pylori-positive and NSAID-induced PUD in long-term follow-up and was an independent risk factor for ulcer recurrence. (Gut Liver 2013;7:175-181)

Expression Patterns of Ki-67, Cyclin A, and Cyclin D1 during Tooth Development

Hyuk-Jae Kwon(권혁제),Kyung-Sik Yoon(윤경식),Han-Sung Jung(정한성) 대한체질인류학회 2013 해부·생물인류학 (Anat Biol Anthropol) Vol.26 No.1

치아발생 및 형태형성 과정에서 치아상피와 치아간엽을 구성하는 세포는 동적인 세포주기의 변화가 일어난다. 현재까지 세포증식은 치아발생에 중요한 현상으로 알려져 있지만, 치아발생 중에 일어나는 복잡한 분자적 기전과 연관해서 세포주기의 각 시기가 어떻게 관여하는지에 대해서는 충분한 연구가 이루어지지 않았다. 그러므로 본 연구는 치아발생 기전과 세포주기의 시기의 변화와의 관계를 밝히고자 하였다. 치아발생 과정에서 일어나는 형태변화를 확인하기 위해 싹시기, 모자시기, 종시기의 쥐 앞니 및 어금니 치배를 헤마톡실린-에오신으로 염색하여 조직학적으로 관찰하였다. 또한 세포주기 시기의 표지자인 Ki-67, 싸이클린 A, 싸이클린 D1의 발현양상을 관찰하기 위해 면역조직화학염색을 시행하였다. 싹시기, 모자시기, 종시기에서 증식하는 세포들은 Ki-67과 싸이클린 A를 발현하는 것을 확인하였다. 싸이클린 D1은 앞니의 상아질모세포 및 모자시기의 사기질결절에서 특이적인 발현을 보였으며, 이곳에서는 Ki-67이나 싸이클린 A가 발현되지 않는다는 것을 발견하였다. 본 연구는 치아발생 중 각 주요 시기에서 세포주기의 변화를 관찰하였으며, 이는 치아발생에 관여하는 기전에 대한 중요한 정보를 제공한다. 또한 본 연구의 결과는 지금까지의 앞니의 사기질모세포 및 사기질결절의 특성에 대한 지식을 이해하는 데에 중요한 자료가 될 것으로 사료된다. Dental epithelial and mesenchymal cells that form the teeth undergo dynamic changes in cell cycle during tooth development and morphogenesis. Although proliferation has been known as a key event during odontogenesis, the cell cycle phases and their relations with the complicated molecular mechanisms of tooth development are not fully understood yet. This study comparatively examined the expression patterns of Ki-67, cyclin A, and cyclin D1 during tooth development in the mouse incisor and molar in order to identify the cellcycle characteristics during odontogenesis. We found that Ki-67 and cyclin A were expressed in the proliferating cells in the dental epithelial and mesenchymal tissues at the bud, cap and bell stages. Cycln D1 showed distinct expression in the incisor odontoblast region and the enamel knot, in which Ki-67 nor cyclin A was expressed. Our results provide specific information on the cell cycle phases during tooth development that may provide clues to relate them with the complex odontogenic mechanisms. Furthermore, we suggest that our findings enlightened the previous studies on the incisor odontoblasts and the enamel knot during tooth development.

Port site infiltration of local anesthetic after laparoendoscopic single site surgery for benign adnexal disease

( Jung Eun Kim ),( Seung-hyuk Shim ),( Meari Dong ),( Hyojin Lee ),( Han Sung Hwang ),( Han Sung Kwon ),( Sun Joo Lee ),( Ji Young Lee ),( In Sook Sohn ),( Soo-nyung Kim ),( Soon-beom Kang ) 대한산부인과학회 2017 Obstetrics & Gynecology Science Vol.60 No.5

Objective To determine whether local bupivacaine injection into the incision site after gynecologic laparoendoscopic single site surgery (LESS) improves postoperative pain. Methods This prospective cohort study included consecutive 158 patients who had LESS for benign adnexal disease from March 2013 to December 2015. Chronologically, 82 patients (March 2013 to August 2014) received no bupivacaine (group 1) and 76 (August 2014 to December 2015) received a bupivacaine block (group 2). For group 2, 10 mL 0.25% bupivacaine was injected into the 20 mm-incision site through all preperitoneal layers after LESS completion. Primary outcome is postoperative pain score using the visual analog scale (VAS). Results There was no difference in clinicopathological characteristics between the groups. Operating time (expressed as median [range], 92 [55-222] vs. 100 [50-185] minutes, P=0.137) and estimated blood loss (50 [30-1,500] vs. 125 [30- 1,000] mL, P=0.482) were similar between the groups. Post-surgical VAS pain scores after 3 hours (3.5 [2-6] vs. 3.5 [2-5], P=0.478), 6 to 8 hours (3.5 [2-6] vs. 3 [1-8], P=0.478), and 16 to 24 hours (3 [2-4] vs. 3 [1-7], P=0.664) did not differ between groups. Conclusion Bupivacaine injection into the trocar site did not improve postoperative pain after LESS. Randomized trials are needed to evaluate the benefits of local bupivacaine anesthetic for postoperative pain reduction.

Self-assembled nanoparticles containing hydrophobically modified glycol chitosan for gene delivery

Sang Yoo, Hyuk,Eun Lee, Jung,Chung, Hesson,Chan Kwon, Ick,Young Jeong, Seo Elsevier 2005 Journal of controlled release Vol.103 No.1

<P><B>Abstract</B></P><P>A self-assembled nanoparticle was prepared using a hydrophobically modified glycol chitosan for gene delivery. A primary amine of glycol chitosan was modified with 5β-cholanic acid to prepare a hydrophobically modified glycol chitosan (HGC). The modified chitosan spontaneously formed DNA nanoparticles by a hydrophobic interaction between HGC and hydrophobized DNA. As the HGC content increased, the encapsulation efficiencies of DNA increased while the size of HGC nanoparticles decreased. Upon increasing HGC contents, HGC nanoparticle became less cytotoxic. The increased HGC contents also facilitated endocytic uptakes of HGC nanoparticles by COS-1 cells, which were confirmed by a confocal microscopy. The HGC nanoparticles showed increasing in vitro transfection efficiencies in the presence serum. In vivo results also showed that the HGC nanoparticles had superior transfection efficiencies to naked DNA and a commercialized transfection agent. The HGC nanoparticles composed of hydrophobized DNA and hydrophobically modified glycol chitosan played a significant role in enhancing transfection efficiencies in vitro as well as in vivo.</P>

Screening and identification of bioorganic light-emitting substances from marine macrophytes

Sang Mok Jung,Han Seong Lee,Han Joo Lee,Seul Gi Kang,Ji Su Son,Jae Hyuk Jeon,Hee Baik Chae,Hyun Woung Shin 한국조류학회I 2015 ALGAE Vol.30 No.2

Organic light-emitting materials in marine macrophytes from various coastal environments were identified. Twentyeight species from the solvent fractions were examined and identified as candidates for bioorganic light-emitting materials using photoluminescence (PL) spectra and gas chromatography-mass spectrometry. We selected 16 solvent fractions from a total of 1,221 prepared from Ishige okamurae, Sargassum confusum, Grateloupia elliptica, Chondracanthus intermedius, Porphyra yezoensis, Meristotheca papulosa, Gelidium amansii, and Scytosiphon lomentaria. The maximum light-emitting PL spectra appeared at various colors, mainly between blue and green, based on chromaticity coordinates, from solvent fractions of M. papulosa, G. amansii, G. elliptica, P. yezoensis, S. lomentaria, I. okamurae, and C. intermedius. These results will contribute to the development of novel organic light-emitting materials.

Clinical outcomes of surveillance colonoscopy for patients with sessile serrated adenoma

Sung Jae Park,Hyuk Yoon,In Sub Jung,Cheol Min Shin,Young Soo Park,Na Young Kim,Dong Ho Lee 대한장연구학회 2018 Intestinal Research Vol.16 No.1

Background/Aims: Sessile serrated adenomas (SSAs) are known to be precursors of colorectal cancer (CRC). The properinterval of follow-up colonoscopy for SSAs is still being debated. We sought to determine the proper interval of colonoscopy surveillance in patients diagnosed with SSAs in South Korea. Methods: We retrospectively reviewed the medical records of patientsdiagnosed with SSAs who received 1 or more follow-up colonoscopies. The information reviewed included patient baselinecharacteristics, SSA characteristics, and colonoscopy information. Results: From January 2007 to December 2011, 152SSAs and 8 synchronous adenocarcinomas were identified in 138 patients. The mean age of the patients was 62.2 years and 60.1% patients were men. SSAs were located in the right colon (i.e., from the cecum to the hepatic flexure) in 68.4% patients. Atthe first follow-up, 27 SSAs were identified in 138 patients (right colon, 66.7%). At the second follow-up, 6 SSAs were identifiedin 65 patients (right colon, 66.7%). At the 3rd and 4th follow-up, 21 and 11 patients underwent colonoscopy, respectively, andno SSAs were detected. The total mean follow-up duration was 33.9 months. The mean size of SSAs was 8.1±5.0 mm. SSAs weremost commonly found in the right colon (126/185, 68.1%). During annual follow-up colonoscopy surveillance, no cancer wasdetected. Conclusions: Annual colonoscopy surveillance is not necessary for identifying new CRCs in all patients diagnosedwith SSAs. In addition, the right colon should be examined more carefully because SSAs occur more frequently in the right colonduring initial and follow-up colonoscopies.

Recurred case of malignant eccrine poroma on the ear after 10 years (초)

( Sang Seok Kim ),( Chul Woo Kim ),( Ju Hyuk Park ),( Min Seong Kil ),( Chang Sun Yoo ),( Soo Jung Shin ) 대한피부과학회 2011 초록집 Vol.49 No.10

Fermented Colostrum Whey Upregulates Aquaporin-3 Expression in, and Proliferation of, Keratinocytes via p38/c-Jun N-Terminal Kinase Activation

Sang-Ah Seo,Hyun-Jung Park,Min-Gi Han,Ran Lee,Ji-Soo Kim,Ji-Hoo Park,Won-Young Lee,Hyuk Song 한국축산식품학회 2021 한국축산식품학회지 Vol.41 No.5

Colostrum, which contains various immune and growth factors, aids wound healing by promoting keratinocyte proliferation. Aquaporins (AQPs) are small, hydrophobic membrane proteins that regulate cellular water retention. However, few studies have examined the effect of processed colostrum whey on AQP-3 expression in human skin cells. Here, we investigated the effect of milk, colostrum, fermented milk, and fermented colostrum whey on AQP-3 expression in keratinocyte HaCaT cells. Concentrations of 100– 400 μg/mL of fermented colostrum whey were found to induce HaCaT cell proliferation. AQP-3 was found to be expressed exclusively in HaCaT cells. AQP-3 expression was significantly increased in 100 μg/mL fermented colostrum whey-treated cells compared with that in controls. Moreover, fermented colostrum increased p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) phosphorylation, but not ERK1/2 phosphorylation. Thus, our results suggest that fermented colostrum whey increased AQP-3 expression in, and the proliferation of, keratinocytes via JNK and p38 MAPK activation.