Comparison of changes in retentive force of three stud attachments for implant overdentures

Su-Min Kim,Jae-Won Choi,Young-Chan Jeon,Chang-Mo Jeong,Mi-Jung Yun,So-Hyoun Lee,Jung-Bo Huh 대한치과보철학회 2015 The Journal of Advanced Prosthodontics Vol.7 No.4

PURPOSE The aim of this study was to compare the changes in retentive force of stud attachments for implant overdentures by in vitro 2-year-wear simulation. MATERIALS AND METHODS Three commercially available attachment systems were investigated: Kerator blue, O-ring red, and EZ lock. Two implant fixtures were embedded in parallel in each custom base mounting. Five pairs of each attachment system were tested. A universal testing machine was used to measure the retentive force during 2500 insertion and removal cycles. Surface changes on the components were evaluated by scanning electron microscopy (SEM). A Kruskal-Wallis test, followed by Pairwise comparison, was used to compare the retentive force between the groups, and to determine groups that were significantly different (α<.05). RESULTS A comparison of the initial retentive force revealed the highest value for Kerator, followed by the O-ring and EZ lock attachments. However, no significant difference was detected between Kerator and O-ring (P>.05). After 2500 insertion and removal cycles, the highest retention loss was recorded for O-ring, and no significant difference between Kerator and EZ lock (P>.05). Also, Kerator showed the highest retentive force, followed by EZ lock and O-ring, after 2500 cycles (P<.05). Based on SEM analysis, the polymeric components in O-ring and Kerator were observed to exhibit surface wear and deformation. CONCLUSION After 2500 insertion and removal cycles, all attachments exhibited significant loss in retention. Mechanism of retention loss can only be partially explained by surface changes.

래칭 릴레이의 온도에 따른 동작 특성 변화

류재만,진인영,허창수,Ryu, Jae-Man,Jin, In-Young,Huh, Chang-Su 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.8

Electrical relay in an essential part of smart grids, electrical vehicles, and LED lightning systems. Therefore, studying relay reliability is important. Relays using permanent magnet actuators (PMAs), which are energy efficient, are also in the spotlight. However, most of the permanent magnets used in PMAs have a characteristic wherein the magnetic flux decreases as the temperature increases. When the magnetic flux is reduced, the force acting on the actuator is reduced. Therefore, in this study, we measured the decrease in the relay operating speed with permanent magnet reduction due to temperature rise. In addition, changes in the bouncing phenomena due to magnetic flux reduction were analyzed. As a result, the operating speed of the relay has decreased and the bouncing phenomenon has not significantly changed.

Comparison of changes in retentive force of three stud attachments for implant overdentures

Kim, Su-Min,Choi, Jae-Won,Jeon, Young-Chan,Jeong, Chang-Mo,Yun, Mi-Jung,Lee, So-Hyoun,Huh, Jung-Bo The Korean Academy of Prosthodonitics 2015 The Journal of Advanced Prosthodontics Vol.7 No.4

PURPOSE. The aim of this study was to compare the changes in retentive force of stud attachments for implant overdentures by in vitro 2-year-wear simulation. MATERIALS AND METHODS. Three commercially available attachment systems were investigated: Kerator blue, O-ring red, and EZ lock. Two implant fixtures were embedded in parallel in each custom base mounting. Five pairs of each attachment system were tested. A universal testing machine was used to measure the retentive force during 2500 insertion and removal cycles. Surface changes on the components were evaluated by scanning electron microscopy (SEM). A Kruskal-Wallis test, followed by Pairwise comparison, was used to compare the retentive force between the groups, and to determine groups that were significantly different (${\alpha}$<.05). RESULTS. A comparison of the initial retentive force revealed the highest value for Kerator, followed by the O-ring and EZ lock attachments. However, no significant difference was detected between Kerator and O-ring (P>.05). After 2500 insertion and removal cycles, the highest retention loss was recorded for O-ring, and no significant difference between Kerator and EZ lock (P>.05). Also, Kerator showed the highest retentive force, followed by EZ lock and O-ring, after 2500 cycles (P<.05). Based on SEM analysis, the polymeric components in O-ring and Kerator were observed to exhibit surface wear and deformation. CONCLUSION. After 2500 insertion and removal cycles, all attachments exhibited significant loss in retention. Mechanism of retention loss can only be partially explained by surface changes.

랫드에서 쌍화탕의 급성독성에 관한 연구

김수정 ( Su Jeong Kim ),이미영 ( Mee Young Lee ),신인식 ( In Sik Shin ),서창섭 ( Chang Seob Seo ),하혜경 ( Hye Kyung Ha ),허정임 ( Jung Im Huh ),신현규 ( Hyeun Kyoo Shin ) 대한본초학회 2011 大韓本草學會誌 Vol.26 No.2

Objectives: This study was conducted to evaluate the acute toxicity and safety of Ssanghwa-tang (Shuanhetang in Chinese, Sou-wa-to in Japanese) in Crl: CD Sprague-Dawley (SD) rat though the current regulatory guideline. Methods: In this study, 10 rats of each sex were randomly assigned to two groups of 5 rats each and were administrated singly by gavage at dose levels of 0 and 2000 mg/kg/day of ssanghwa-tang water extract (SHT). After single administration of SHT, mortalities, clinical signs, body weight changes, gross findings were observed for the 15-day period. Results: Acute toxicity tests revealed that a single oral administration of SHT at dose levels of 2000 mg/kg did not affect clinical signs, body weight, and gross findings, evaluating the safety of SHT. The SHT treatment did not result in any toxicologically significant changes in mortality, clinical signs, body weight changes. Conclusions: These results showed that the single oral administration of SHT did not cause any toxic effect at the dose levels of 2000 mg/kg/day in rats. In conclusion, the median lethal dose (LD50) of SHT was considered to be over 2000 mg/kg/day body for both sexes.

Treatment of alopecia areata with tofacitinib

( Ji Su Lee ),( Min-woo Kim ),( Hyun-sun Park ),( Jung Yoon Ohn ),( Hyun-sun Yoon ),( Chang-hun Huh ),( Ohsang Kwon ),( Soyun Cho ) 대한피부과학회 2017 대한피부과학회 학술발표대회집 Vol.69 No.2

Background: Treatment of alopecia areata (AA) is often empiric and not yet satisfactory. Recently, Janus kinase inhibitor showed promising results in Caucasians. Objectives: To investigate efficacy, tolerability, and hair growth trajey of oral tofacitinib monotherapy for Korean AA patients over extended period. Methods: This is a retrospective study of adult AA patients treated with tofacitinib monotherapy for least 4 months. Results: Thirty-six Korean patients with median initial SALT score of 98.9 were included; 91.7% had refractory AA. Twenty-nine (80.6%) patients demonstrated more than 5% SALT change. Twenty patients (55.6%) achieved 50% SALT change at median 7.5 months with 5 mg twice dosage. There were significant differences between SALT 50 achievers and non-achievers: duration of current episode (ρ = 0.009), duration of disease since first onset (ρ = 0.026) and age at onset of first episode (ρ = 0.011). Tofacitinib was well tolerated and there was no any serious adverse effect such as malignancy or tuberculosis reactivation. Conclusion: Oral tofacitinib monotherapy may be effective and tolerable in patients with AA. SALT 50 achievement was associated with followings: duration of current episode, duration of disease since first onset, and age at onset of first episode.

절연재에 따른 TEM 안테나의 방사패턴 및 이득 변화

이예나(Ye-Na Lee),최순호(Sun-Ho Choi),허창수(Chang-Su Huh),최진수(Jin-Su Choi),박우철(Woo-Chul Park) 대한전기학회 2014 전기학회논문지 Vol.63 No.5

TEM Horn antenna is typically used in HPEM area. It is necessary to apply a high voltage of the antenna for radiating HPEM. Then, it is necessary to insulate essentially of applying a high voltage to the antenna. At this time, radiation pattern and gain of the TEM Antenna is changed. For this reason, it is necessary to analyze changing characteristics by using simulation. In this paper, I analyzed the radiation pattern of the antenna in accordance with the lens and insulating material. As a result, it was observed that the value of the gain is changed in accordance with the frequency. The lens is used for the antenna, the gain characteristic is improved.

Streptozotocin으로 유발된 당뇨병쥐의 신경전도속도에 대한 Evening primrose oil (EPO), Vit.C, Vit.E의 약물효과

신창열,류정수,김학림,강봉수,손의동,허인회 중앙대학교 약학연구소 1997 약학 논총 Vol.11 No.-

The effects of evening primrose oil (EPO). Vit.C and Vit.E on nerve conduction velocity (NCV) in streptozotocin -induced diabetic rats were investigated. 5 weeks- diabetes caused 27±0.5 % reduction in sciatic motor conduction velocity as compared with normal control. Dietary supplement of 5% EPO. 125mg/kg Vit.C. and lg/kg Vit.E prevented significantly the development of the motor nerve conduction velocity deficit about 21±0.5, 21±0.5, 26±0.5% respectively. The total serum cholesterol and triglyceride were decreased by administration 5% EPO. Vit.C, and Vit.E as compared with diabetic control. However, the serum glucose was not decreased by administration 5% EPO. 125mg/kg Vit.C but the serum glucose was decreased by administration lg/kg Vit.E as compared with diabetic control.

A comparison of the treatment outcome of oral tofacitinib with other conventional therapies in refractory alopecia totalis and universalis: A retrospective study

( Ye Eun Kim ),( Jung-won Shin ),( Chang-hun Huh ),( Min-woo Kim ),( Ji-su Lee ),( Ohsang Kwon ),( Soyun Cho ),( Hyun-sun Park ) 대한피부과학회 2018 대한피부과학회 학술발표대회집 Vol.70 No.2

Background: Treatment of alopecia totalis and alopecia universalis is often challenging and unsatisfactory. Recently, Janus kinase inhibitor has shown promising results. Objectives: The aim of this study is to compare the efficacy and tolerability between oral tofacitinib and conventional modalities for treating refractory alopecia totalis/universalis. Methods: A total 74 patients (18, treated with tofacitinib; 26, treated with conventional oral treatment (steroid ± cyclosporine); 30, treated with diphenylcyclopropenone) were included and their medical records were reviewed retrospectively. Results: After 6 months, 44.4% of patients in the tofacitinib group, 37.5% in the conventional oral treatment group, and 11.1% in the diphenylcyclopropenone group achieved 50% SALT change. During the treatment, 10% of patients in the tofacitinib group, 73.1% in the conventional oral treatment group, and 10% in diphenylcyclopropenone group experienced adverse drug reactions. Conclusion: In conclusion, oral tofacitinib was more effective than diphenylcyclopropenone immunotherapy and more tolerable than conventional oral treatment after 6 months of treatment.

교반기 매개변수에 따른 교반형 전자파 잔향실의 특성 및 유용성 평가

김광용(Kwang-Yong Kim),홍주일(Joo-Il Hong),허창수(Chang-Su Huh) 대한전기학회 2010 전기학회논문지 Vol.59 No.9

This paper analyzes optimal stirrer parameter to improve field uniformity in a mode-stirred reverberation chamber. Stirrer parameter is varied about stirrer height and stirrer angle. Also we analyze quality factor, number of excited modes and stirrer efficiency that affect field uniformity. The results show good performance as higher as stirrer height. Isotropic field distribution is formed at 45 ° stirrer angle. When stirrer angle varies, scattering characteristic of incident wave are changed. So electric field distribution in a mode-stirred reverberation chamber is also changed. Therefore, it affect field uniformity. The results expect to help that designs stirrer for get better field uniformity. Immunity test performed designed mode-stirred reverberation chamber for semiconductor that categorized by technology. Test result shows that good recurrence compared wave-guide immunity test.

열화된 광유와 식물성절연유에서 온도, 벤조트리아졸의 유동대전 영향

최순호(Sun-Ho Choi),정중일(Jung-Il Jeong),허창수(Chang-Su Huh) 대한전기학회 2011 전기학회논문지 Vol.60 No.2

In this paper, the FT-IR, conductivity and flow electrification phenomena of Vegetable oils were discussed. Vegetable oil has high flash point and eco-friendly properties compared to conventional mineral oil. Accelerated aging transformer oil samples produced in the oven at 140[℃] for 500 hours, 1000 hours, 1500 hours, 2000 hours. Serial device to measure the flow electrification phenomena was designed and fabricated. Pico ammeter and the Labview data measurements were utilized. The effects of Temperature and antistatic agent on fluid flow electrification were investigated. Both Mineral and vegetable oil showed similar trends for temperature change. The polarity reversal occurred in mineral oil with antistatic agent above 10 ~ 30[ppm] and in vegetable oil with antistatic agent above 5[ppm].