한국인의 치과의원 내원요인 조사 연구

류영욱,배현숙,성진효,김동기 조선대학교 구강생물학연구소 2003 Oral Biology Research (Oral Biol Res) Vol.27 No.1

According to the increase of the number of dental clinics and the level of the patient's recognition about oral health care, the need for effective clinical management to provide proper oral health care service to the patients has arisen. Many patients has selected the dental clinics based on self estimation or other recommendation. Therefore the main reasons for selecting the dental clinic by the patients needed to analyze, So we conducted the survey which prepared questionnaire were provided to 700 subjects and collected data related to the factors for patients to select the dental clinics. The results were as follows : 1. In the view of access, the place easy of access and parking capacity was important to the degree of 43.0% and 30.8%, respectively. 2. In relation to the dentist, the quality of treatment and the trust was important to the degree of 80.7% and 71.3%, respectively. 3. Modern clinical facility was occupied 65.5% in the basic environment factors. 4. In the basic factors, kindness and cleanliness was 76.6% and 76.7%, respectively, and it showed that these factors were more important than the number of the clinicians and comfort of the waiting room. 5. In relation to the satisfaction of treatment, cheaper treatment cost, decreased waiting tine, the variety of treatment tine and various payment method were important to the degree of 51.8%, 48.4%, 42.8% and 39% in order.

상아질접착제에 대한 광조사가 접착에 미치는 영향

류현옥,김기옥,김성교 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.5

The purpose of this study was to investigate the influence of light irradiation over self-priming adhesive on dentin bonding. After acid etching the exposed dentin, a self-priming adhesive (Prime&Bond□NT dental adhesive system, Dentsply DeTrey, GmbH, Konstanz, Germany) was applied and light irradiation was done for 20 sec with regular intensity (600 mW/㎠) in group I and for 3 sec with ultra-high intensity (1930 mW/㎠) in group III. No light irradiation was done over self-priming adhesive in groups II and IV. Composite resin was added on the self-priming adhesive and irradiated for 40 sec with regular intensity (600 mW/㎠) in groups I and II and for 3 sec with ultra-high intensity (1930 mW/㎠) in groups III and IV. To see the effect of light curing time on dentin bonding, another 3 group specimens were prepared. Without light-irradiation over self-priming adhesive, added composite resin was irradiated for 3, 6, or 12 sec with ultra-high intensity light. After bonded specimens were stored in 37℃ distilled water for 24 hours, shear bond strength were measured using a universal testing machine (4202, Instron, Instron Co., U.S.A.) and fractured surfaces were examined under a stereomicroscope (SZ-PT Olympus, Japan) . Statistical analysis were done with one-way, two-way ANOVA and chi-square test. The results were as follows: 1.The shear bond strengths from the groups irradiated over self-priming adhesive were significantly higher than those from the groups without irradiation (p<0.05). 2.There was no significant shear bond strength difference between regular intensity light irradiation groups and ultra-high intensity ones (p>0.05). 3. There was no significant shear bond strength difference among various irradiation time groups with ultra-high intensity ones (p>0.05). 4.In stereomicroscopic examination of fractured surfaces, adhesive-cohesive mixed failure mode was mostly seen in all groups, and there was no significant difference in failure mode among groups (p>0.05) . Key words : Light irradiation, Self-priming adhesive, Dentin bonding, Shear bond strength

정적 연소기의 단면형상 변화에 따른 플라즈마 제트 점화의 연소특성

김문헌,박정서,류현욱 崇實大學校 2000 論文集 Vol.30 No.1

In this paper, combustion characteristics ignited by single-hole and multi-hole plasma jet igniter and conventional spark plug have been studied by means of schlieren photography and pressure measuring in the Wedge type, Pent-roof type and Toroidal bowl type constant volume vessel which is typical 4-valve SI engine combustion chamber. It is represented that combustion characteristics ignited by conventional spark plug ignition are hardly influenced by configurations of combustion chamber. I contrast in case of plasma jet ignition combustion duration and combustion enhancement rates are effected than spark plug ignition. Consequently, it is important to avoid plasma jet impingement against combustion chamber wall , and to let flame front move toward wide place in the combustion chamber at early stage of combustion.

악성 위궤양의 형태를 보인 원발성 위결핵 1예

한종대,이동욱,심성준,류운석,안현택,박찬욱,김배영,이미선 大韓消化器內視鏡學會 1999 Clinical Endoscopy Vol.19 No.부록2

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.

HDAC6 deacetylates p53 at lysines 381/382 and differentially coordinates p53-induced apoptosis

Ryu, Hyun-Wook,Shin, Dong-Hee,Lee, Dong Hoon,Choi, Junjeong,Han, Gyoonhee,Lee, Kang Young,Kwon, So Hee Elsevier 2017 Cancer letters Vol.391 No.-

<P><B>Abstract</B></P> <P>HDAC6-selective inhibitors represent promising new cancer therapeutic agents, but their precise mechanisms of action are not well understood. In particular, p53's role in HDAC6 inhibitor-induced effects has not been fully elucidated. In this study, we show that an HDAC6-selective inhibitor, A452, increased wild-type p53 levels by destabilizing MDM2, but decreased mutant p53 by inducing MDM2 and inhibiting Hsp90-mutant p53 complex formation. Interestingly, HDAC6 levels inversely correlated with p53 acetylation at lysines 381/382 associated with p53 functional activation. A452 blocked HDAC6 nuclear localization, resulting in increased levels of acetylated p53 at Lys381/382. HDAC6 bound to the C-terminal region of p53 via its deacetylase domain. A452 disrupted the HDAC6-Hsp90 chaperone machinery via Hsp90 acetylation and degradation. Furthermore, it chemosensitized cancer cells to the Hsp90 inhibitor 17-AAG. Overall, silencing of HDAC6 showed similar effects. These findings suggest that the anticancer action of HDAC6 inhibitors requires p53 and Hsp90 and targeting of HDAC6 may represent a new therapeutic strategy for cancers regardless of p53's mutation status.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HDAC6 deacetylates p53 at lysine 381/382. </LI> <LI> A452 increases wild-type p53 levels by destabilizing MDM2. </LI> <LI> A452 decreases mutant p53 levels by inhibiting Hsp90-mutp53 complex formation. </LI> <LI> HDAC6 levels inversely correlate with p53 acetylation. </LI> <LI> A452 disrupts HDAC6-Hsp90 chaperone machinery via Hsp90 acetylation and degradation. </LI> </UL> </P>

Influence of Toxicologically Relevant Metals on Human Epigenetic Regulation

Ryu, Hyun-Wook,Lee, Dong Hoon,Won, Hye-Rim,Kim, Kyeong Hwan,Seong, Yun Jeong,Kwon, So Hee Korean Society of ToxicologyKorea Environmental Mu 2015 Toxicological Research Vol.31 No.1

Environmental toxicants such as toxic metals can alter epigenetic regulatory features such as DNA methylation, histone modification, and non-coding RNA expression. Heavy metals influence gene expression by epigenetic mechanisms and by directly binding to various metal response elements in the target gene promoters. Given the role of epigenetic alterations in regulating genes, there is potential for the integration of toxic metal-induced epigenetic alterations as informative factors in the risk assessment process. Here, we focus on recent advances in understanding epigenetic changes, gene expression, and biological effects induced by toxic metals.

A Comparison of the Efficacy of Cataract Surgery Using Aqualase(R) with Phacoemulsification Using MicroFlow(R) System

( Hyun Wook Ryu ),( Shin Hae Park ),( Choun Ki Joo ) 대한안과학회 2007 Korean Journal of Ophthalmology Vol.21 No.3

Purpose: To compare the outcomes after phacoemulsification performed with the AquaLase(R) and phacoemulsification in MicroFlow(R) system, including surgically induced astigmatism (SIA), corneal endothelial cell damage and postoperative recovery of visual acuity. Methods: The cataracts of Lens Opacities Classification System, version III (LOCS III) nuclear grade below 2 were subjected in this study. Nineteen eyes underwent cataract operation using AquaLase(R) (Alcon Laboratories, Fort Worth, Texas, U.S.A.). A control group (19 eyes) used the MicroFlow(R) system (Millenium, Stortz, U.S.A.) and was selected by matching age, sex, systemic disease, corneal astigmatism and corneal endothelial cell density. All the surgeries were performed by the same operator. SIA, corneal endothelial cell loss, visual acuity, and corneal thickness were evaluated postoperatively. Results: SIA in the group using AquaLase(R) was less than that of the group using MicroFlow(R) system (P=0.022) at 2 months postoperatively. Evaluation of corneal endothelial cell loss, recovery of visual acuity and corneal thickness found no statistically significant differences between the two groups. Conclusions: Cataract surgery using AquaLase(R) induces less surgically induced astigmatism in mild to moderate cataracts. Korean Journal of Ophthalmology 21(3):137-141, 2007

A Case Report of Implant Placement in Distraction-Augmented Alveolar Bone of the Mandible

Hyun Wook Ryu 大韓顎顔面成形再建外科學會 2009 Maxillofacial Plastic Reconstructive Surgery Vol.31 No.2S

Administration of Radioactive Iodine Therapy Within 1 Year After Total Thyroidectomy Does Not Affect Vocal Function

Ryu, Chang Hwan,Ryu, Junsun,Ryu, Youn Mi,Lee, You Jin,Lee, Eun-Kyung,Kim, Seok-Ki,Kim, Tae-Sung,Kim, Tae Hyun,Lee, Chang Yoon,Park, Seog Yun,Chung, Ki Wook,Jung, Yuh-S. Society of Nuclear Medicine 2015 The Journal of nuclear medicine Vol.56 No.10

<P>The purpose of this study was to evaluate the impact of radioactive iodine therapy (RIT) on vocal function during the early follow-up period after total thyroidectomy (TT) using perceptive and objective measurements, questionnaires regarding subjective symptoms, and data on vocal function in a prospectively enrolled and serially followed thyroid cancer cohort. <B>Methods:</B> Of 212 patients who underwent TT and were screened between January and December 2010 at our hospital, 160 were included in the final analysis. Patients with the following histories were excluded: lateral neck dissection, organic vocal fold disease, external radiotherapy, and voice evaluation during thyroxine withdrawal. Patients were stratified into 3 groups: TT, TT with low-dose RIT (1.1–2.2 GBq), and TT with high-dose RIT (≥3.7 GBq). Voice evaluations were performed before surgery and at 1, 6, and 12 mo after TT. <B>Results:</B> Vocal characteristics were altered after TT, including changes on the grade, roughness, and strain scale; increased amplitude perturbation; decreased fundamental frequency; narrowed pitch range; and global disturbances in subjective functional parameters on the voice handicap index. However, the degree of vocal changes among the 3 groups did not significantly differ within the 1-y postoperative follow-up period. According to the results of subgroup analyses of patients who demonstrated good voice outcomes after TT, there were no significant functional differences among the 3 groups. <B>Conclusion:</B> RIT at any dose does not affect vocal function within 1 y of TT.</P>