초임계 유체를 이용한 두 종류의 항암제가 함유된 고분자 미립자 제조

유종훈 水原大學校 2012 論文集 Vol.26 No.-

Doxorubicin (DOX) is an anthracycline drug commonly used in the treatment of a large spectrum of tumors. It works by interfering with the growth of cancer cells. It binds and intercalates into the DNA strand, thus inhibiting further DNA and RNA biosynthesis, eventually causing cell death. Gemcitabine (GEM) is a synthetic pyrimidine nucleoside analogue with a high antitumor efficacy for ovarian, breast, bladder, and pancreatic cancer. It replaces one of the building blocks of nucleic acids, in this case cytidine, during DNA replication. The process arrests tumor growth, as new nucleosides cannot be attached to the faulty nucleoside, resulting in apoptosis. The purpose of this study is to prepare biodegradable poly(L-lactic acid) microparticles containing two different drugs by a supercritical aerosol solvent extraction system (ASES) process. The effects of operating parameters such as temperature, pressure, and drug composition on the morphology and characteristics of microparticles were studied in detail. The entrapment efficiency and in vitro release profiles of two anticancer drugs from the microparticles were also determined using HPLC. The entrapment efficiency increased with decreasing temperature. The entrapment efficiency of DOX was found to be higher than that of GEM, mainly due to larger molecular weight of DOX. On the other hand, GEM showed higher solubility in aqueous solution, thereby resulting in a faster release compared with DOX.

감염 조절용 차단막의 두께가 광중합기의 중합광에 미치는 영향

장훈상,이석련,홍성옥,류현욱,송창규,민경산 大韓齒科保存學會 2010 Restorative Dentistry & Endodontics Vol.35 No.5

연구목적: 본 연구는 감염 조절용 차단막을 여러 겹으로 사용했을 때 광중합기의 광강도와 파장, light diffusion 등에 미치는 영향에 대해 조사하였다. 연구 재료 및 방법: 감염 조절용 차단막은 투명 랩 (크린랩)을 사용하였고 광중합기는 할로겐 광중합기 (Optilux 360)와 LED 광중합기 (Elipar FreeLight 2)를 사용하였다. 차단막을 1겹, 2겹, 4겹, 8겹으로 광중합기의 광섬유말단을 감싸고 휴대용 광강도 측정기 (Cure Rite)로 광중합기의 광강도를 측정하였다. 광중합기를 주문제작한 optical breadboard에 고정시킨 후 휴대용 spectroradiometer (CS-1000)를 이용하여 광중합기의 파장을 측정하였고, DSLR (Nikon D70s)을 이용하여 광중합기의 light diffusion을 사진 촬영하였다. 결과: 광강도 측정 결과는 차단막의 두께가 증가할수록 광강도가 유의하게 감소하였으나 할로겐 광중합기에서 1겹과 2겹 사이에는 유의차가 없었으며, 4겹 이상의 차단막을 투과할 때 광강도가 더 많이 감소하였다. 여러 겹의 차단막을 투과한 광중합기의 전체적인 파장 형태와 peak wavelength의 변화는 관찰되지 않았다. Light diffusion 사진 촬영 시, LED 광중합기에서는 차단막의 두께가 미치는 영향이 없었으나 할로겐 광중합기에서는 차단막을 4겹 사용했을 때부터 중합광이 조사되는 각도가 감소하기 시작하여 8겹 사용했을 때 통계적으로 유의하게 감소하는 것을 볼 수 있었다 (p < 0.05). 결론: 광중합형 복합레진을 광중합할 경우 감염 조절용 차단막이 찢어지는 경우를 대비하여 1겹으로 사용하기 보다는 2겹으로 사용하는 것이 환자간의 교차감염을 예방하는데 유리할 것으로 사료된다. Objectives: This study investigated the effect of infection control barrier thickness on power density, wavelength, and light diffusion of light curing units. Materials and Methods: Infection control barrier (Cleanwrap) in one-fold, two-fold, four-fold, and eightfold, and a halogen light curing unit (Optilux 360) and a light emitting diode (LED) light curing unit (Elipar FreeLight 2) were used in this study. Power density of light curing units with infection control barriers covering the fiberoptic bundle was measured with a hand held dental radiometer (Cure Rite). Wavelength of light curing units fixed on a custom made optical breadboard was measured with a portable spectroradiometer (CS-1000). Light diffusion of light curing units was photographed with DSLR (Nikon D70s) as above. Results: Power density decreased significantly as the layer thickness of the infection control barrier increased, except the one-fold and two-fold in halogen light curing unit. Especially, when the barrier was four-fold and more in the halogen light curing unit, the decrease of power density was more prominent. The wavelength of light curing units was not affected by the barriers and almost no change was detected in the peak wavelength. Light diffusion of LED light curing unit was not affected by barriers, however, halogen light curing unit showed decrease in light diffusion angle when the barrier was four-fold and statistically different decrease when the barrier was eight-fold (p < 0.05). Conclusions: It could be assumed that the infection control barriers should be used as two-fold rather than one-fold to prevent tearing of the barriers and subsequent cross contamination between the patients.

Anti-stress Effect of Scutellaria baicalensis in SD Rats and ICR Mice

( Jong Hoon Ryu ),( Blendyl Saguan Tan Lee ),( Ji Wook Jung ),( Nam Yoon Ahn ),( Seung Joo Lee ),( Gu Young Yu ),( Shin Ha Han ),( Jeong Hoon Lee ),( Geum Seon Lee ),( Jae Hoon Cheong ) 한국응용약물학회 2004 Biomolecules & Therapeutics(구 응용약물학회지) Vol.12 No.1

N/A Pyroligneous liquid(PL) is produced by carbonizing Oak in 350∼400℃. It is traditionally used for treating stress-related disorder, hepatic disease, immune disorder, G-I disorder and inflammatory disease. The aim of this study is to investigate anti-stress effects of PL. The experiments were performed with the use of young(9 weeks of age) male rats of SD strain and the male ICR mice (20-25g). Animals of the normal group were not exposed to any stress and the control group were exposed to stress. The rats of the Ginseng, diazepam(BZ) and PL supplementary group were orally administered once a day 100g of Ginseng extract-kg body weight, 5 mg of BZ/kg body weight and 1 ml of PL/100 g body weight and then exposed to stress. The mice of the Ginseng, BZ and PL supplementary group were given water containing 100 g of Ginseng extract/100 ml potable water, 5 mg of BZ/kg 100 ml of drinking water and 10 ml of PL/100 ml of drinking water and exposed to stress. Animals were given materials for 7 days after stabilizing them, and then were given supplementary materials for 5 days with stress. They were stressed by immobilization for 30 minutes and then the animals were exposed to electroshocks for 5 minutes. We recorded stress-related behavioral changes of experimental animals by stressing them using the Etho-vision system and measured the levels of corticosterone in blood While stress suppressed locomotor activity of animals, PL-supplementation partially blocked the stress effect of locomotion in rats and mice, and also partially blocked stress-induced behavioral changes such as freezing, burrowing, smelling and rearing activity in rats and in closed area it increased relatively in elevated plus maze test. However, these changes also partially were blocked by PL-supplementation. PL-supplementation decreased levels of blood corticosterone increased by stress in rats. These results suggest that PL protects partially the living organism from stress attack in some cases.

[PG-0007] Identification and Determination of Phenolic compounds in Rapeseed (Brassica napus L.) Mutant Lines Derived from Gamma-ray

Jaihyunk Ryu(Jaihyunk Ryu ),Baul Yang(Baul Yang ),Ye-Jin Lee(Ye-Jin Lee ),Dong-Gun Kim(Dong-Gun Kim ),Sang Hoon Kim(Sang Hoon Kim ),Sang-Il Han(Sang-Il Han ),Bo-Keun Ha(Bo-Keun Ha ),Si-Yong Kang(Si-Yo 한국육종학회 2022 한국육종학회 공동학술발표집 Vol.2022 No.-

A Patient with Pyridoxine-Dependent Epilepsy Who Was Treated with Triple Therapy

Minsun Ryu(Minsun Ryu),Ji-Hoon Na(Ji-Hoon Na),Hyunjoo Lee(Hyunjoo Lee),Young-Mock Lee(Young-Mock Lee) 대한소아신경학회 2022 대한소아신경학회지 Vol.30 No.4

Session G : Immunology : Effects of Qi Training on the Subsets of Lymphocytes in Humans

Hoon Ryu,Chang Duk Jun,Bok Soo Lee,Byung Min Choi,Hyung Min Kim & Hun Taeg Chung 한국생화학분자생물학회 (구 한국생화학회) 1993 추계학술대회집 Vol.- No.-

Feasibility, accuracy, and performance of contact block reduction method for multi-band simulations of ballistic quantum transport

Ryu, Hoon,Park, Hong-Hyun,Shin, Mincheol,Vasileska, Dragica,Klimeck, Gerhard American Institute of Physics 2012 JOURNAL OF APPLIED PHYSICS - Vol.111 No.6

Neutrophil Adhesion by Pituitary Growth Hormone Accompanies Tyrosine Phosphorylation of JAK2, pp125^(FAK), and Paxillin and Actin Polymerization : A Role of JAK2 in ppl125^(FAK) Phosphorylation

Ryu, Hoon,Lee, Jung-Hee,Lee, Myeong-Soo,Huh, Hwa-Jeong,Chung, Hun-Taeg 원광대학교 생명공학연구소 1999 생명공학연구소보 Vol.6 No.1

Neutrophil adhesion is fundamentally important during onset of inflammatory responses. The adhesion signaling pathways controls neutrophil arrest and extravasation and influence neutrophil shape and function at sites of inflammation. In the present study, we determined the intracellular signaling pathways for the adhesion of human neutrophils by pituitary growth homone(GH). GH triggered a well-defined signal transduction pathway which involves in JAK2 and STAT3 tyrosine phosphorylation in neutrophils. GH induced the mophological changes, and the tyrosine phosphorylation focal adhesion kinase (pp125^(FAK)), and paxillin in neutrophils. The adhesiveness and the tyrosine phosphorylation of Jak2, STAT3, and pp125^(FAK), and paxillin showed similar bell-shaped response curves. Preincubation with genistein, a tyrosine kinase inhibitor, blocked the GH-stimulated adhesiveness and JAK2, STAT3, pp125^(FAK), and paxillin phosphorylation in neutrophils. Confocal microscopy and flowcytometry showed that GH enhance the focal localization of pp125^(FAK), paxillin, phosphotyrosine and F-actin filament in membrane rufflings and uropod in neutrophils. We further identified that FAK is physically associated with JAK2 and a specific tyrosine residue within pp125^(FAK), tyrosine 925 (Tyr-925), is the principle site of phosphorylation by JAK2 in vitro. GST-pp125^(FAK) containing phenylalanine substitutions at Tyr-925 (Y925F) was not phosphorylated by JAK2 immunoprecipites. Our results indicate that tymsine phosphorylation of pp125^(FAK) and paxillin are necessary events for the GH-induced neutrophil adhesion. Furthermore, the phosphorylation of specific tyrosine residue in pp125^(FAK) by JAK2 imply that JAK2 play a focal adhesion of neutrophils through the direct associatin and phospherylation of pp125^(FAK). This study suggest a model for the non-integrin mediated adhesion signaling pathway in which pituitary GH modulates neutrophil adhesion through the tyrosine phorylation of pp125^(FAK) and paxillin and actin polymerization.

Atomistic Study on Dopant-Distributions in Realistically Sized, Highly P-Doped Si Nanowires

Ryu, Hoon,Kim, Jongseob,Hong, Ki-Ha American Chemical Society 2015 NANO LETTERS Vol.15 No.1

<P>The dependency of dopant-distributions on channel diameters in realistically sized, highly phosphorus-doped silicon nanowires is investigated with an atomistic tight-binding approach coupled to self-consistent Schrödinger–Poisson simulations. By overcoming the limit in channel sizes and doping densities of previous studies, this work examines electronic structures and electrostatics of free-standing circular silicon nanowires that are phosphorus-doped with a high density of ∼2 × 10<SUP>19</SUP> cm<SUP>–3</SUP> and have 12 nm−28 nm cross-sections. Results of analysis on the channel energy indicate that the uniformly distributed dopant profile would be hardly obtained when the nanowire cross-section is smaller than 20 nm. Insufficient room to screen donor ions and shallower impurity bands are the primary reasons of the nonuniform dopant-distributions in smaller nanowires. Being firmly connected to the recent experimental study (<I>Proc. Natl. Acad. Sci. U.S.A.</I> <B>2009</B>, <I>106</I>, 15254–15258), this work establishes the first theoretical framework for understanding dopant-distributions in over-10 nm highly doped silicon nanowires.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2015/nalefd.2015.15.issue-1/nl503770z/production/images/medium/nl-2014-03770z_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl503770z'>ACS Electronic Supporting Info</A></P>

Enhancing Light-emission Stability of Metal-halide Perovskites with Size and Composition Engineering

Hoon Ryu 대한전자공학회 2020 Journal of semiconductor technology and science Vol.20 No.1

Band structures of 10nm-scale metal halide perovskites are examined with atomistic tight-binding simulations. Band gap energies achievable via size and structure engineering is presented for MAPb(IBr)3 to deliver practical design guidelines for lighting sources. Our results also reveal the red-shift, which is induced by phase separation in mixed halides and has served as a deep-seated bottleneck in designs of useful light-emitting devices, can be hugely reduced with size and composition engineering.