• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.45-53
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• 2000

Enamel microabrasion is a means by which superficial enamel discoloration is removed using hydrochloric acid and fine pumice. As enamel microabrasion alone may not be sufficient in cases of deeper discoloration, composite resin restoration is recommended in areas where there is remaining discoloration. The purpose of this study was to investigate the effects of different methods and number of applications of enamel microabrasion on the shear bond strength of composite resin to enamel. Untreated control was designated as group 1. 5-second applications of a mixture of 18% HCl and fine pumice were performed 5 and 10 times on groups 2 and 3, respectively. A commercially available mixture of 10% HCl and abrasives(PREMA) was applied using a 10 : 1 gear reduction handpiece 5 and 10 times on groups 4 and 5, respectively, with each application lasting 20 seconds. After etching with 37% phosphoric acid, composite resin was bonded. Thermocycling was performed and shear bond strength was measured. The following results were obtained : 1. Group 2 showed the highest bond strength$(24.36{\pm}3.34)$, while group 3 showed the lowest$(19.35{\pm}3.43)$, Shear bond strength decreased in the following order: 2>4>5>1>3. 2. Group 2 showed bond strength significantly higher compared to groups 1 and 3(p<0.05). 3. There were no significant differences between groups 2 and 3, which had been microabraded using HCl and pumice, and groups 4 and 5, to which PREMA had been applied, when bond strengths were compared(p>0.05). 4. When modes of fracture were examined, adhesive failure was observed in groups 3 and 4, while cohesive failure was observed in groups 1, 2, 3 and 4. Only mixed failures were found group 5. 5. When viewed using a SEM, groups 2 and 3, which had been microabraded using HCl and pumice, showed surface appearances similar to that of enamel etched with phosphoric acid. Groups 4 and 5, treated with PREMA, exhibited a smooth surface similar to that of group 1. All oops showed similar, typical surface characteristics following phosphoric acid etching.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.11a
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• pp.27-30
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• 1994

잠재적으로 항감염 약제로 사용될 가능성이 있는 약제들의 초기 연구과정에서 주된 관심사는 이들이 미생물(세균, 바이러스, 기타 기생충)에 대한 작용들이 있는가 하는 점이다. 이러한 작용들이 실험적으로 충분히 연구가 된 후에야 실험동물에서 그 효과를 연구한다. 항 바이러스 제제의 경우에는 세포배양을 통한 연구가 그 약제의 독성과 효용성을 나타내는데 필수적인 것이 된다. 여러 종류의 동물을 이용한 생체실험에서 약제의 일반적인 흡수와 배설, 분포 등에 관한 정보와 약제 자체와 동물 내에서의 대사적 변화에 대한 정보가 제공된다. 여러 가지 미생물로 감염을 시킨 적합한 동물과 여러 가지 용량으로 치료하는 실험을 통하여 약제의 항 감염 능력이 알려지게 된다. 동물에서의 생체실험과 실험관내에서 실험을 하고 나서야 사람에서의 연구가 이루어지게 된다. 소위 전임상시험에서 대표적 병원성 미생물에 대한 생물학적효과, 약리학적 효과와 독성 그리고 동물실험모델에서의 가능한 효과가 결정된 후에 임상시험에 들어가기 마련이다. 항균제의 임상시험에는 각각의 감염질환에 대한 진단 및 치료기준을 반영하는 것이 기본이다. 새로운 항균제의 임상시험에서는 안전성과 효과가 반드시 밝혀져야 한다. 1상에서는 인체에서의 약리효과, 안전성이 주목적이며, 2상과 3상은 겹쳐지는 점도 있으나 하나 또는 그 이상의 적응증에 대한 항균제의 효과와 단기간의 부작용은 2상에서 관찰하여야하며, 다수의 환자에서 제안된 적응질환의 무작위임상시험과 다수에서의 안전성도 3상에서 관찰하여야 한다. 4상에서는 이상에서의 자료로 시판된 후에도 계속해서 감시하는 것으로 지속적으로 안전성을 관찰하는 것이다. 이러한 기본사항외에도 소아, 임산부, 고령자등에서의 임상시험도 넓은 의미에서 포함되어야 할 것이며 또한 질적인 면에서 조절하는 Quality Assurance도 중요하다.양상은 세 용량군 간 차이가 없었으나, 시험기에서 발열의 발현율이 낮았으며, 발열일 수와 항생제 사용일 수가 짧았다. 결론: 골수억제 조절 효과는 용량에 따른 혈액소견에 미치는 영향, 부작용, 감염의 빈도, 감염발생에 따른 항생제 사용기간 등을 고려하여 그 임상 유효성 평가시, 제 3상 시험에 사용할 권장량 (recommended dose) 은 250 ug/$m^2$/d $\times$ 10d 으로 관찰되었다.5주에 부검한 랫드의 간에서 c-myc 종양단백의 발현은 모든 처리군들이 대조군에 비하여 높게 발현되는. 것이 관찰되었으나 시험개시후 26주에 부검한 랫드의 간에서 c-myc 종양단백의 발현은 대조군에 비하여 차이가 거의 없었다. 따라서 랫드에서 화학적으로 유도한 간암발생 과정에서 NK 세포활성이 현저하게 억제되는 것으로 생각되며, c-myc 종양단백의 발현은 시험개시후 15주에 그 발현이 확실한 것으로 사료되어 진다.에 영향을 주는 성분이 있음을 제시하였다.1과 항우울약들의 항혈소판작용은 PKC-기질인 41-43 kD와 20 kD의 인산화를 억제함에 기인되는 것으로 사료된다.다. 것으로 사료된다.다.바와 같이 MCl에서 작은 Dv 값을 갖는데, 이것은 CdCl$_{4}$$^{2-}$ 착이온을 형성하거나 ZnCl$_{4}$$^{2-}$ , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어떠한 용리액에서던지 NH$_{4}$$^{+}$의 경우 Dv값이 제일 작았다. 바. 본 연구의 목적중의 하나인 인체유

• The Journal of the Convergence on Culture Technology
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• v.10 no.4
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• pp.443-449
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• 2024

This study aims to analyze the complex impact of technological changes in the Fourth Industrial Revolution era and demographic shifts in Korea on military personnel management, and to explore innovative strategies for the Korean military's workforce operations. The research findings indicate that changes in future battlefield environments and the introduction of advanced technologies necessitate a fundamental restructuring of military personnel, emphasizing a shift towards a highly specialized and elite workforce. Key research findings are as follows: First, the military application of cutting-edge technologies, such as unmanned systems, autonomous weapon systems, and AI-based decision support systems, is expanding. Second, this technological advancement requires a restructuring of personnel to foster a technology-intensive elite force, including optimizing troop size, reorganizing unit structures, and increasing the utilization of civilian expertise. Third, strategies for securing high-tech talent include strengthening internal technology talent development programs, establishing systems to attract civilian experts, and building a talent development system through industry-academia-research cooperation. The significance of this study lies in providing a theoretical and practical foundation for building a future-oriented and efficient Korean military organization by presenting innovative measures for military human resource management systems suitable for the Fourth Industrial Revolution era. For these changes to be successfully implemented, cooperation among relevant stakeholders, including the military, government, academia, and industry, is essential, supported by comprehensive national-level planning and support.

• Defense and Technology
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• no.4 s.218
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• pp.36-47
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• 1997

미국의 민군겸용 정책은 겸용기술 연구개발, 겸용생산, 상용능력 활용 등의 3가지 전략으로 구성되며, 획득 개혁안이 제도, 조직, 경영 측면에서 이를 실천할 수있는 실질적인 지원을 하고 있다. 미국과 비슷한 상황에 직면해 있는 우리나라도 새로운 국방기술정책이 요구되고 있으며, 과거의 소극적인 정책에서 벗어나 민과 군의 역량을 최대한 활용할 수 있도록 다각적인 형태의 정책을 추진해야 할 것이다

• Convergence Security Journal
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• v.17 no.2
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• pp.145-151
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• 2017

The Cyberspace of the Republic of Korea Army is continuously threatened by enemies. Means for responding to such cyber threats are ultimately Military information security professional personnel. Currently, however, there are only a handful of advanced information security professional persons in Republic of Korea Army, and a lack of systematic training is inadequate. Therefore, in this thesis, we surveyed the information security professional human resource policies of USA, UK, Israel, and Japan. In addition, the policy to train professional human resources specialized in defense cyber security, we proposed training of specialist talent of 4 steps and medium and long term plan, step-by-step training system sizing, introduction of certification system.

• Clinical and Experimental Pediatrics
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• v.53 no.1
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• pp.56-66
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• 2010

Purpose : Although oseltamivir is widely used for treatment of influenza, few clinical studies of its efficacy and resistance have been performed in Korea. We evaluated the safety, side effects, and efficacy of oseltamivir treatment in Korean pediatric patients. Methods : We analyzed 321 children diagnosed with influenza at Busan St. Mary's Medical Center, Korea, between January 2008 and June 2008 (first study period) and November 2008 and January 2009 (second study period). Patients were divided into two groups: those receiving oseltamivir treatment for 5 days and those receiving only symptomatic treatment. We investigated clinical symptoms, side effects, and resistance to oseltamivir. We also identified influenza strains and evaluated resistance to oseltamivir using an influenza virus culture. Results : One hundred eighty-six patients were assigned to the treatment group, and 135 were assigned to the control group. The treatment group showed shorter admission duration (4.4 days) compared with controls (5.0 days) (P =0.000) and had fewer lower respiratory tract complications compared with controls (P <0.05). No significant statistical difference in the virus antigenic type was observed between the groups. In the first study period, virus culture showed influenza B (41.7% vs. 49.6%), A/H3N2 (7.9% vs. 8.4%), and A/H1N1 (9.4% vs. 6.5%). In the second study period, only A/H1N1 (55.3% vs. 50.0%) was isolated, except for one case of A (H3N2) in the treatment group. No differences in short- and long-term side effects, including neuropsychologic side effects, were noted between groups. There was no resistance to oseltamivir before or after treatment in the first study period. Conclusion : Based on our results, we suggest that osetalmivir therapy in pediatric patients is effective.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.3
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• pp.241-251
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• 2010

This study aims at contributing to the restorative dentistry by examining results in the vertical load test of four different low invasive fixed partial dentures. Based on a hypothesis on the right upper first molar is missing, three units of FPDs were made for the second premolar and the second molar abutment. that is, twelve metal dies and FPDs were made for resin bonded FPD and Two Key Bridges and Human Bridge without occlusal rest and Human Bridge with occlusal rest. By using universal test machine, the numerical maximum value were recorded during the vertical load test of each FPDs after the bonding process treated by Maxcem which is resin cement. The failure process and its result of prosthesis were also observed. The maximum load was 7,295 N, 4,729 N, 2,190 N, 3,073 N from groups of resin bonded FPD, Two Key Bridge, Human Bridge without occlusal rest and Human Bridge with occlusal rest respectively. There was a statistical significance among the groups of resin bonded FPD, Two Key Bridge and Human Brides. However, there was no significant difference between Human Bridge without occlusal rest and Human Bridge with occlusal rest. Regarding the failure of prosthesis, the groups of Resin Bonded FPD and Two Key Bridge showed that one of the abutment teeth in the both side of retention part was highly failed earlier than the other one (83.2% and 66.6% respectively). While, Human Bridge without occlusal rest and Human Bridge with occlusal rest showed high percentage of failure in the abutment teeth in the both side of retention part at the same time (91.6% and 58.3% respectively). This study demonstrates that the group of Human Bridges has low resistance to the vertical loads of low invasive FPDs in comparison with the groups of resin bonded FPD and Two Key Bridge. Nevertheless, the maximum occlusal load of the restorative position, resistance to diverse restoration failure, amount of tooth reduction and patients' cooperation should be considered when they are applied in the clinic in order to choose an appropriate restoration for each patient.

• Radiation Oncology Journal
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• v.17 no.4
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• pp.314-320
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• 1999

Purpose : Paclitaxel is a chemotherapeutic agent with potent microtubule stabilizing activity that arrests cells in $G_2$-M phase. Because $G_2$ and M are the most radiosensitive phase of the cell cycle, paclitaxel has potential role as a cell-cycle specific radiosensitizer. This study was peformed to see the effects of paclitaxel on the radiation-induced damage of gastric mucosa of the rat. Materials and Methods : The rats were divided into the three groups i.e., paclitaxel alone group, radiation alone group and, a combination of paclitaxel and radiation in combined group. A single intraperitoneal infusion of paclitaxel (10 mg/kg) was done in paclitaxel alone group. In radiation alone group, a single fraction of irradiation (8 Gy, x-ray) to the whole abdomen and, a combination of a single fraction of irradiation (8 Gy, x-ray) to the whole abdomen was given 24 hrs after paclitaxel infusion In combined group of paclitaxel and radiation. The incidence of mitosis and apoptosis as well as histologic changes of the gastric mucosa were evaluated at 6 hrs, 24 hrs, 3 days and 5 days after treatment. Results : The number of the mitosis was not increased by paclitaxel infusion. The incidence of the apoptosis was similar from 6 hrs to 3 days after paclitaxel infusion and was decreased at 5 days. Paclitaxel induced minimal glandular dilatation and cellular atypia of gastric mucosa at 24 hrs and 3 days. In irradiation group, the incidence of apoptosis was $6.0\%$ in 6 hrs and $1.25\%$ in 24 hrs after irradiation and minimal glandular dilatation and cellular atypia were noted throughout the experimental period. The incidence of apoptosis in the combined group of paclitaxel and irradiation ($4.5\%$) was significantly higher than irradiation alone group ($1.25\%$) at 3 days (p<0.05). Conclusion : Paclitaxel had no mitotic on mitotic arrest in gastric mucosa of the rat. Increased number of apoptosis in combined paclitaxel and irradiation group suggested the additive effects of paclitaxel on irradiation.

• Journal of Yeungnam Medical Science
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• v.20 no.1
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• pp.62-70
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• 2003

Background: Most of all studies about the relation between the health risk and obesity are based on the European and American data. The purpose of this study is to examine the relation between adiposity and risk factors for cardiovacular disease (CVD) in normal weight individuals. Materials and Methods: Normal weight subjects with a body mass index (BMI) between 18.5 and $23kg/m^2$ (76 subjects) and overweight subjects with a BMI between 23 and $25kg/m^2$ (53 subjects) were retained for this study. Normal weight subjects were divided into three group of each adiposity variable, then three group and the overweight group were evaluated for the presence of CVD risk factors and analyze the correlation coefficients between adiposity variables and risk factors controlled for age in normal weight, overweight groups. Using logistic regression analysis, the odds ratio (OR) for the prevalence of risk factors for each group of adiposity variables and the overweight group was estimated relative to the first group in normal weight subjects. Results: Systolic BP, diastolic BP, LDL cholestrol, HDL cholesterol, triglycerides in normal weight subjects were significantly correlated with all adiposity variables (P<0.01). Third group (3.7 for %fat and 4.7 for fat mass)of adiposity variables in the normal weight group and the overweight group (6.6 for %fat and 11.5 for fat mass) tended to have higher ORs compared to first group for risk factor variables. Conclusion: Normal weight subjects with elevated adiposity had higher prevalence of risk factors than normal weights subjects with less adiposity. Measuring of adiposity added additional information of cardiovascular disease risk factors in normal weight subjects.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.1
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• pp.63-70
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• 2009

Objective: This study was performed to investigate the effectiveness of minimal stimulation using rhFSH and GnRH antagonist compared with GnRH antagonist multidose protocol (MDP) in IVF treated patients with aged 40 and above. Methods: Seventy-five patients with aged 40 and above were equally randomized to minimal stimulation group (n=37) or GnRH antagonist MDP group (n=38). For minimal stimulation group, ultrasound monitoring was started on cycle day 7 or 8. Daily injections of 0.25 mg cetrorelix together with 150 IU rhFSH were started from the day at 13${\sim}$14 mm of a leading follicle diameter. For GnRH antagonist MDP group, daily injections of 225 IU rhFSH were initiated from cycle day 2 and GnRH antagonist was started at a dose of 0.25 mg/day on rhFSH stimulation day 6 or the day at 13${\sim}$14 mm of leading follicle diameter. In both groups, transvaginal ultrasound-guided oocyte retrieval was performed. According to cleavage and morphologic characteristics of embryos, embryos were transferred 3 to 5 days after oocyte retrieval. Results: There were no differences in patients' characteristics and cycle cancellation rate between the two groups. Total dose and duration of rhFSH used were significantly fewer and shorter in minimal stimulation group than those in GnRH antagonist MDP group. The numbers of oocytes retrieved, mature oocytes and transferred embryos were also lower in minimal stimulation group. However, there were no significant differences in the clinical pregnancy rate and miscarriage rate between the two groups. Conclusions: This study demonstrates that minimal stimulation protocol provides comparable pregnancy rates to GnRH antagonist MDP with fewer dose and days of rhFSH used, and thus can be a cost-effective alternative in women aged 40 and above.