Preparation and Characterization of a Propofol-loaded Polymeric Micellar System: Nanoparticular Stability

Cho, Jae-Pyoung,Cho, Jin-Cheol,Oh, Eui-Chaul The Korean Society of Pharmaceutical Sciences and 2008 Journal of Pharmaceutical Investigation Vol.38 No.6

A propofol delivery system was prepared using two biocompatible polymeric surfactants, poloxamer 407 and PEG 400. The nanoparticular stability of the micellar system was evaluated in terms of temperature change, storage time and composition. The particle size of the system was slightly increased with elevating temperature from $4^{\circ}C$ to $25^{\circ}C$, but its distribution was unimodal. At $40^{\circ}C$, the system presented a bimodal particle size distribution and the increase in the fraction of particles larger than 15 nm. This result might be due to the expansion of the nanoparticles through micellar swelling at the high temperature. It was found that propofol was gradually come out of the system, stored for a month at three different temperatures (4, 25 and $40^{\circ}C$). The drug loss was apparently dependent on temperature and the system composition. Increasing temperature induced the acceleration of the drug loss of $7{\sim}10%$ at $4^{\circ}C$ and $14{\sim}16 %$ at $40^{\circ}C$. This may be owing to the high diffusivity resulting from the swelling of the hydrophilic surface of the nanoparticle at high temperature. However, the addition of PEG 400 to the system led to the reduction of the drug loss. This result is associated with the previous investigation that PEG coverage decreased diffusion coefficient because of the formation of the denser structure on the surface of nanoparticulate. Nevertheless, the limited amount of PEG, less than 2% (w/v), should be used to prevent the precipitation and discoloration of the system.

Original Articles : Preparation and Characterization of a Propofol-Loaded Polymeric Micellar System: Nanoparticular Stability

( Jae Pyoung Cho ),( Jin Cheol Cho ),( Eui Chaul Oh ) 한국약제학회 2008 Journal of Pharmaceutical Investigation Vol.38 No.6

Surgical Outcome of a Zero-profile Device Comparing with Stand-alone Cage and Anterior Cervical Plate with Iliac Bone Graft in the Anterior Cervical Discectomy and Fusion

Jae Sik Shin,오성한,Pyoung Goo Cho 대한척추신경외과학회 2014 Neurospine Vol.11 No.3

Objective: A Zero-profile device is a cervical stand-alone cage with integrated segmental fixation device. We characteristically evaluated the radiological changes as well as clinical outcomes in the application of Zero-profile devices compared with stand-alone cages and anterior cervical plates with iliac bone grafts for the cervical disease. Methods: Retrospectively, total 60 patients at least more than one year follow-up were enrolled. Twenty patients were treated with Zero-profile devices (Group A), twenty patients with stand-alone cages (Group B) and twenty patients with anterior cervical plates and iliac bone grafts (Group C) for a single level cervical disease. The clinical outcomes were evaluated by Odom’s criteria and Bazaz-Yoo dysphagia index. The radiologic parameters were by subsidence and the changes of the midpoint interbody height (IBH), the segmental kyphotic angle (SKA), the overall kyphotic angle (OKA) in index level. Results: Although there was no significant clinical difference according to the Odom’s criteria among them(p=0.766), post-operative dysphagia was significantly decreased in the Group A and B compared with the Group C (p=0.04). From the immediate postoperative to the last follow-up time, the mean change of IBH decrement and SKA increment were significant in the Group B compared with the Group A (p=0.025, p=0.033) and the Group C (p=0.001, p=0.000). The subsidence rate was not significant among all groups (p=0.338). Conclusion: This Zero-profile device is a valuable alternative to the anterior cervical discectomy and fusion with a low incidence of postoperative dysphagia and without segmental kyphotic change.

Nonvolatile Memory Effects of NiO Layers Embedded in Al[sub 2]O[sub 3] High-k Dielectrics Using Atomic Layer Deposition

Cho, Wontae,Lee, Sun Sook,Chung, Taek-Mo,Kim, Chang Gyoun,An, Ki-Seok,Ahn, Jae-Pyoung,Lee, Jun-Young,Lee, Jong-Won,Hwang, Jin-Ha The Electrochemical Society 2010 Electrochemical and solid-state letters Vol.13 No.6

Poster Session : PS 0953 ; The Usefulness of Lens Culinaris Agglutinin-A Reactive Alpha-Fetoprotein (AFP-L3) for Hepatocellular Carcinoma

( Pyoung Ahn ),( Jae Young Jang ),( Euiju Park ),( Soung Won Jeong ),( Young Hun Kim ),( Won Young Park ),( Dong Joon Oh ),( Sang Woo Cha ),( Young Deok Cho ),( Sae Hwan Lee ),( Hong Soo Kim ),( Boo S 대한내과학회 2014 대한내과학회 추계학술발표논문집 Vol.2014 No.1

Poster Session Background: The lack of ideal biomarkers for the diagnosis and evaluation of the treatment effect has posed a major challenge to hepatocellular carcinoma (HCC). In the present study, the usefulness of AFP-L3 was analyzed and compared with AFP and protein induced by vitamin K absence or antagonist-II (PIVKA-II) for the detection of HCC. Methods: From July 2013 to March 2014, a retrospective comparison study was conducted at Soonchunhyang University Seoul Hospital. A total of 305 patients were investigated; 165 (54.1%) patients had chronic liver disease and 140 (45.9%) had HCC. Among the patients with HCC, 98 (70%) had newly diagnosed or viable HCC after treatment. We used a current diagnostic cut-off of 20ng/mL for AFP, 10% for AFP-L3 and 40 mAU/mL for PIVKA-II. We analyzed the diagnostic value of these tumor markers for the detection of HCC, respectively. Results: In all patients, the sensitivity and specificity of AFP, AFP-L3 and PIVKA-II were 55.1% and 89.4%, 62.2% and 92.8%, and 46.9% and 87.9%, respectively. The area under curve (AUC) of combination AFP and AFP-L3 showed higher value than the AUCs of other markers and combination (sensitivity of 79.6%, specifi city of 84.1%, and AUC of 0.818). ). In the viable HCC with AFP < 20ng/mL, the proportion with AFP-L3 of =10% was 54.5% (24/44). Conclusions: AFP-L3 was more sensitive and specifi c marker than conventional AFP and PIVKA-II. Additionally, the combination of AFP and AFP-L3 improved diagnostic value for the detection of viable HCC.

Aqueous-phase synthesis of Pd/TiO₂/Fe₃O₄ hybrid nanostructures and their enhanced catalytic properties

Cho, Ahyoung,Han, Geun-Ho,Kim, Jin Soo,Lee, Jae-Chul,Ahn, Jae-Pyoung,Lee, Kwan-Young,Yu, Taekyung Elsevier 2018 Chemical physics letters Vol.712 No.-

<P><B>Abstract</B></P> <P>The development of a new concept of support for catalytic activity is important in the development of catalysts. Dual-supports, composed of a mixture of two metal oxides, can increase catalytic activities by controlling the oxidation state of metal catalysts, as well as give multi-functionality to the catalyst, including photocatalytic properties and reusability. We report an aqueous-phase synthesis of Pd/ and Pt/TiO<SUB>2</SUB>/Fe<SUB>3</SUB>O<SUB>4</SUB> hybrid nanostructures. The synthesized nanostructures had metal nanoparticles with sizes of less than 2.8 nm. The synthesized nanostructures exhibited high H<SUB>2</SUB>O<SUB>2</SUB> selectivity toward the H<SUB>2</SUB>O<SUB>2</SUB> generation and also showed potential as a magnetic separable catalyst for both H<SUB>2</SUB>O<SUB>2</SUB> synthesis and photocatalytic reaction.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Aqueous-phase synthesis of Pd/ and Pt/TiO<SUB>2</SUB>/Fe<SUB>3</SUB>O<SUB>4</SUB> hybrid nanostructures. </LI> <LI> The Pd/TiO<SUB>2</SUB>/Fe<SUB>3</SUB>O<SUB>4</SUB> hybrid nanostructures exhibited high selectivity toward the H<SUB>2</SUB>O<SUB>2</SUB> generation reaction. </LI> <LI> The metal/TiO<SUB>2</SUB>/Fe<SUB>3</SUB>O<SUB>4</SUB> hybrid nanostructures showed magnetic separable reusability toward the photocatalytic reaction. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The metal/TiO<SUB>2</SUB>/Fe<SUB>3</SUB>O<SUB>4</SUB> hybrid nanostructures exhibited not only high selectivity toward the H<SUB>2</SUB>O<SUB>2</SUB> generation reaction but also magnetic separable reusability toward the photocatalytic reaction.</P> <P>[DISPLAY OMISSION]</P>

시화호 표층퇴적물의 특성과 오염도 평가

주재식(Jae Sik Ju),손문호(Moonho Son),조현서(Hyeon-Seo Cho),김평중(Pyoung-Joong Kim) 한국산학기술학회 2016 한국산학기술학회논문지 Vol.17 No.12

시화호 표층퇴적물 중 지구화학적 특성과 미량금속의 오염도 평가를 위해 입도, 강열감량(IL), 화학적산소요구량(COD) 및 미량금속(As, Pb, Cd, Cu, Cr, Zn, Ni, Mn, Hg, Fe, Li)을 분석 하였다. 시화호 표층퇴적물의 평균입도는 2.94~6.35Ø 의 범위로 분포하였으며, 퇴적상은 전반적으로 sandy silt(sZ)를 나타내었고, 이러한 표층퇴적물의 성상은 유기물 및 미량금속의 농도와 상관관계를 나타내었다 (p<0.05). 특히, 표층퇴적물 중 As, Pb, Cd, Cu, Cr, Zn, Fe, Hg은 평균입도와 상관성을 보일 뿐만 아니라, IL(Ignition Loss)과도 높은 상관성을 보여 이들 원소의 농도가 입도와 유기물의 영향을 받고 있는 것으로 나타났다. 이에 시화호의 표층퇴적물 관리에 있어서 미량금속의 유입 뿐 만 아니라 유기물의 유입을 병행하여 조사되어야 할 것으로 판단되었다. 오염도 평가에 있어서 표층퇴적물 중 미량금속 함량의 농축계수와 농집지수는 대부분 약간 오염된 상태를 나타낸 가운데, As의 경우 농축계수와 농집지수 가 오염된 상태를 보였다. 이는 특정 중금속에 의한 농축이 여전히 해결되지 않은 것으로 나타나, 이를 해결할 수 있는 방안마련이 시급할 것으로 사료되었다. 아울러 비교적 공단지역 및 배수갑문에 근접한 지역은 오염도가 높은 반면, 시화호 중앙부분은 오염도가 낮은 경향을 보여, 지역적 편차를 고려한 지속적인 모니터링시 이 필요할 것으로 판단되었다. The purpose of this study was to understand the pollution level of the surface sediment of Sihwa Lake by assessing its geochemical characteristics and investigating the spatial distribution of trace metals and organic matter. In the surface sediment of Sihwa lake, the mean grain size was between 2.94 and 6.35 Ø and the main type of sediment was sandy silt. The concentrations of As, Co, Cr, Ni, V and Li among the metal elements in the surface sediment were correlated with the mean crust concentration (p<0.05). Based on the strong correlation between the metals (Cd, Cu, Pb and Zn) and organic matter (Ignition Loss), the concentrations of these metal elements seem to be controlled by the organic matter dilution effect. The trace metal pollution level, determined by applying the Republic of Korea Marine environmental standard and the US National Oceanic and Atmospheric Administration"s sediment quality guidelines, showed the pollution level of As to be either close to or in excess of the above-mentioned standards at almost all levels. The enrichment factor and geoaccumulation index of As showed that there was an incremental increase of pollution by elements other than V, Cr, Co, Fe, Al and Mn. Moreover, the nearby industrial area and dike were more polluted than the other areas, so the surface sediments in Sihwa lake should be monitored by taking into consideration the geological variations.

<i>In vivo</i> corrosion mechanism by elemental interdiffusion of biodegradable Mg–Ca alloy

Jung, Jae‐,Young,Kwon, Sang‐,Jun,Han, Hyung‐,Seop,Lee, Ji‐,Young,Ahn, Jae‐,Pyoung,Yang, Seok‐,Jo,Cho, Sung‐,Youn,Cha, Pil‐,Ryung,Kim, Yu‐,Chan,Seo Wiley Subscription Services, Inc., A Wiley Company 2012 Journal of biomedical materials research. Part B, Vol.b100 No.8

<P><B>Abstract</B></P><P>We elucidated the <I>in vivo</I> corrosion mechanism of the biodegradable alloy Mg–10 wt % Ca in rat femoral condyle through transmission electron microscope observations assisted by focused ion beam technique. The alloy consists of a primary Mg phase and a three‐dimensional lamellar network of Mg and Mg<SUB>2</SUB>Ca. We found that the Mg<SUB>2</SUB>Ca is rapidly corroded by interdiffusion of Ca and O, leading to a structural change from lamellar network to nanocrystalline MgO. In contrast to the fast corrosion rate of the lamellar structure, the primary Mg phase slowly changes into nanocrystalline MgO through surface corrosion by O supplied along the lamellar networks. The rapid interdiffusion induces an inhomogeneous Ca distribution and interestingly leads to the formation of a transient CaO phase, which acts as a selective leaching path for Ca. In addition, the outgoing Ca with P from body fluids forms needle‐type calcium phosphates similar to hydroxyl apatite at interior and surface of the implant, providing an active biological environment for bone mineralization. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.</P>

Rapid <i>In Vitro</i> Corrosion Induced by Crack-Like Pathway in Biodegradable Mg-10% Ca Alloy

Jung, Jae-Young,Kwon, Sang-Jun,Han, Hyung-Seop,Yang, Gui Fu,Lee, Ji-Young,Yang, Seok-Jo,Cho, Sung-Youn,Cha, Pil-Ryung,Kim, Young-Yul,Kim, Yu-Chan,Seok, Hyun-Kwang,Ahn, Jae-Pyoung Cambridge University Press 2013 Microscopy and Microanalysis Vol.19 No.5

<B>Abstract</B><P>The <I>in vitro</I> corrosion mechanism of the biodegradable cast Mg-10% Ca binary alloy in Hanks' solution was evaluated through transmission electron microscopy observations. The corrosion behavior depends strongly on the microstructural peculiarity of Mg2Ca phase surrounding the island-like primary Mg phase and the fast corrosion induced by the interdiffusion of O and Ca via the Mg2Ca phase of lamellar structure. At the corrosion front, we found that a nanosized crack-like pathway was formed along the interface between the Mg2Ca phase and the primary Mg phase. Through the crack-like pathway, O and Ca are atomically exchanged each other and then the corroded Mg2Ca phase was transformed to Mg oxides. The <I>in vitro</I> corrosion by the exchange of Ca and O at the nanosized pathway led to the rapid bulk corrosion in the Mg-Ca alloys.</P>

Community Characteristics of Waterbirds in Junam Reservoir, Changwon-si, Korea

Yu, Jae-Pyoung,Choi, Jong-Su,Kim, Tae-Jwa,Paik, In-Hwan,Jin, Seon-Deok,Kim, In-Kyu,Hong, Gil-Pyo,Cho, Hae-Jin,Shin, Yong-Un,Kang, Chang-Wan,Ko, Gyeong-Nam,Paek, Woon-Kee National Science Museum of Korea 2012 Journal of Korean nature Vol.5 No.1

The study was performed for birds living around Junam Reservoir, a representing place for migrant birds in Korea for 10 times from February to December (except November) in 2011. The result states that a total of 11,742 individuals, 102 species, 41 families and 13 orders of birds were found around the reservoir and anseriformes including Anser albifrons (16.42%), Anser fabalis (14.44%), Fulica atra (14.08%), Anas platyrhynchos (10.01%), Anas clypeata (7.70%), Aythya ferina (6.88%) and Anas poecilorhyncha (6.59%) are dominant species. By seasons, winter shows high frequencies of types, number of species, number of individuals and diversity. The result of comparing individuals of swans from 1989 to 2011 shows large fluctuation of individuals, irregular repetition and the number of individuals gradually decreases. The number of geese, dabbling ducks and diving ducks between 1999 and 2011 shows gradual increase. Number of species and individuals of birds in the Junam Reservoir have increased and it is estimated that about between 12,000 and 14,000 individuals of 60~65 species spend winter. The reservoir is important as a habitat for migratory birds, as well as ecological study. It requires administrative supports to provide stable environment for birds to spend winter.