• Restorative Dentistry and Endodontics
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• v.44 no.4
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• pp.45.1-45.10
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• 2019

Objectives: Self-adhesive resin cements contain functional monomers that enable them to adhere to the tooth structure without a separate adhesive or etchant. One of the most stable functional monomers used for chemical bonding to calcium in hydroxyapatite is 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP). The aim of this study was to evaluate the influence of the10-MDP concentration on the bond strength and physical properties of self-adhesive resin cements. Materials and Methods: We used experimental resin cements containing 3 different concentrations of 10-MDP: 3.3 wt% (RC1), 6.6 wt% (RC2), or 9.9 wt% (RC3). The micro-tensile bond strength of each resin cement to dentin and a hybrid resin block (Estenia C&B, Kuraray Noritake Dental) was measured, and the fractured surface morphology was analyzed. Further, the flexural strength of the resin cements was measured using the three-point bending test. The water sorption and solubility of the cements following 30 days of immersion in water were measured. Results: The bond strength of RC2 was significantly higher than that of RC1. There was no significant difference between the bond strength of RC2 and that of RC3. The water sorption of RC3 was higher than that of any other cement. There were no significant differences in the three-point bending strength or water solubility among all three types of cements. Conclusions: Within the limitations of this study, it is suggested that 6.6 wt% 10-MDP showed superior properties than 3.3 wt% or 9.9 wt% 10-MDP in self-adhesive resin cement.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.293-299
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• 1999

Bone scintigraphy with $^{99m}Tc-methylene$ diphosphonate(MDP) performed for 20 weeks per two weeks interval respectively after fracture in seven(male 3 heads, female 4 heads) canine radius were analysed. All of bone scans performed 2 weeks to 20 weeks after fracture showed increase in generalized tracer uptake and showed localized increase in tracer uptake at the fracture site. Bone scans and ratio performed 6 weeks after fracture showed the most outstanding increase in generalized and localized tracer uptake. New bone formation had been observed from 2 weeks and they were incorporated completely on 18 weeks, they showed most activity during 6-10 weeks after fracture. It was recognized that the bone scan with $^{99m}Tc-methylene$ was quite sensitivity but low specificity on the fracture healing in canine radius.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.3
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• pp.63-72
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• 2015

This paper presents the issue that is predicting the movement of an agent in an enclosed space by using the MDP (Markov Decision Process). Recent researches on the optimal path finding are confined to derive the shortest path with the use of deterministic algorithm such as $A^*$ or Dijkstra. On the other hand, this study focuses in predicting the path that the agent chooses to escape the limited space as time passes, with the stochastic method. The MDP reward structure from GIS (Geographic Information System) data contributed this model to a feasible model. This model has been approved to have the high predictability after applied to the route of previous armed red guerilla.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.518-525
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• 1995

목적 : 안구제거술 후에 삽입한 hydroxyapatite 안구보충물내로 혈관신생이 완전하게 일어 나는 시기를 알아보기 위함이다. 방법 : 안구제거술을 받은 43예의 환자(남자 33예, 여자 10예, 14-56세)에게 대부분 변경되지 않은 방법으로 hydroxyapatite 안구보충물을 삽입한 후 10-23주 사이에 다양한 간격(10-12 주 2예, 13-16주 18예, 17-20주 20예, 21-23주 3예)을 두고 $^{99m}Tc-MDP$ 골주사를 시행하여 보충물내로의 혈관신생 정도를 전향적으로 측정하였다. 정면 및 측면촬영의 정적영상에서 안구보충물의 방사능섭취가 비교(nasal bridge)의 방사능섭취보다 약할 경우를 grade 1, 같을 경을 grade 2, 강할 경우를 grade 3로 나누었으며 grade 2와 3을 혈관신생이 완전하다고 정의하였다. 또한 43예 모두에서 방사능섭취 정도와 관계없이 안구보충물 삽입후 평균 21주되는 시기에 안구보충물에 구멍을 내어 이 구멍으로부터의 출혈여부를 확인한 후 운동성나사(motility peg)를 끼워 의안(prosthesis)과 연결하였다. 43예중 7예에서는 $^{99m}Tc-MDP$ 골주사와 조영제주입후의 자기공명영상(Gd-DTPA T1-weighted images)을 같은 날짜에 시행하여 각각의 예에서 방사능섭취 정도와 조영제증강 정도를 비교하였다. 결과 : 안구보충물내로 완전하게 혈관신생이 일어났던 grade 2와 3의 비율은 안구보충물삽입후 10-12주에서는 0%, 13-16주 33%, 17-20주 50%, 21-23주 67%로써 시간경과에 따라 점차 증가하였다. 골주사소견에 관계없이 안구보충물 삽입후 평균 21주되는 시기에 보충물 앞쪽에 구멍을 내었을 때 43예 모두에서 완전한 혈관신생을 의미하는 출혈을 볼 수 있었다. $^{99m}Tc-MDP$ 골주사와 조영제주입후의 자기공명영상을 둘 다 시행한 7예 각각에서 방사능섭취의 정도와 조영제증강의 정도가 거의 일치하였다. 결론 : 본 예비연구의 결과로써 hydroryapatite 안구보충물 삽입후 21주째에 $^{99m}Tc-MDP$ 골주사를 시행하는 것이 좋을 것으로 생각되며, hydroxyapatite 안구보충물내로의 완전한 혈관신생 여부를 보는 데에는 $^{99m}Tc-MDP$ 골주사가 조영제주입후의 자기공명영상보다 더 경제적이라고 할 수 있겠다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3394-3408
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• 2014

Conventional mobile state (MS) and base station (BS) association based on average signal strength often results in imbalance of cell load which may require more powerful processor at BSs and degrades the perceived transmission rate of MSs. To deal with this problem, a Markov decision process (MDP) for load balancing in a multi-cell system with multi-carriers is formulated. To solve the problem, exploiting Sarsa algorithm of on-line learning type [12], ${\alpha}$-controllable load balancing algorithm is proposed. It is designed to control tradeoff between the cell load deviation of BSs and the perceived transmission rates of MSs. We also propose an ${\varepsilon}$-differential soft greedy policy for on-line learning which is proven to be asymptotically convergent to the optimal greedy policy under some condition. Simulation results verify that the ${\alpha}$-controllable load balancing algorithm controls the behavior of the algorithm depending on the choice of ${\alpha}$. It is shown to be very efficient in balancing cell loads of BSs with low ${\alpha}$.

• The Korean Journal of Nuclear Medicine
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• v.33 no.2
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• pp.172-177
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• 1999

Purpose: The purpose of this study was to ascertain whether radiation adaptive response could be induced by Tc-99m-methylene diphosphonate (Tc-99m-MDP) in peripheral lymphocytes of patients undergoing bone scintigraphy. Materials and Methods: Lymphocytes from 22 patients (6 males, 16 females, mean age $50{\pm}14$ years) were collected before and after bone scintigraphy using 740 MBq Tc-99m-MDP Lymphocytes from 10 controls (6 males, 4 females, mean age $43{\pm}7$ years) were also collected. They were exposed to challenge dose of 2 Gy gamma rays using a cell irradiator. Number of ring-form and dicentric chromosomes per 600 cells (chromosomal aberrations) was counted under the light microscope. Results: Chromosomal aberrations in patients before bone scintigraphy ($385.1{\pm}30.5$) was not different from that of controls ($367.8{\pm}36.6$). However, chromosomal aberrations in patients after bone scintigraphy was significantly decreased to $192.6{\pm}22.1$ (p=0.0001). Conclusion: Low dose gamma-irradiation by Tc-99m-MDP used for bone scintigraphy induces a cytogenetic adaptive response in peripheral lymphocytes.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.5
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• pp.640-650
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• 1998

Pumping performances of a helical molecular drag dump(MDP) and of a radial MDPs are numerically analyzed by using the direct simulation Monte Carlo (DSMC) method. A helical- and radial-MDP have rotating pumping channels cut on a cylinder and on a disk, respectively. For a helical MDP, the present results agree quantitatively with the previously known numerical results. For radial MDPs, both of the Type 1 (having pumping channels cut on the stationary disk) and of the Type 2 (having pumping channels cut on the rotating disk) are analyzed to predict their performances for various parameters, i.e., the radius of curvature center of the channel wall, the depth of the channel, the clearance between housing and disk, and the rotating speed. The results show that the performance of the Type 2 is superior to that of the Type 1, and that for all types the pumping efficiency decreases as the clearance increases. Also, the radial type MDP has larger leakage losses in the direction of pumping channel than does the helical one.

• The Korean Journal of Nuclear Medicine
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• v.33 no.6
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• pp.484-492
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• 1999

Purpose: This study was to evaluate the clinical usefulness of $^{99m}Tc$-MDP bone scintigraphy for assessing vascular ingrowth into the ocular implants after enucleation or evisceration. Materials and Methods: Twenty-four patients (M:F=7:17, mean age: 36 years), who buried a coralline hydroxyapatite after uncomplicated enucleation or evisceration surgery were studied. Dynamic and static scintigraphy on the orbit fossa were obtained after injection of 740 MBq $^{99m}Tc$-MDP to evaluate the status of vascularization. The study was performed from the 3 to 33 weeks after surgery. According to the visual analysis, activity greater than nasal bridge was graded as 4, equal to the nasal bridge as 3, less than nasal bridge but greater than normal orbit as 2, greater than normal orbit but less than grade 2 as 1. Uptake ratio was also calculated by measuring the implants activity (H) and contralateral orbit activity (N). Grading score and uptake ratio were compared with clinical outcome of vascularization. Additionally, we also analyzed the vascularization status as time lapse between primary surgery and scintigraphic study and surgical methods. Results: Twenty-one patients who had bone scintigraphy at 11 weeks after surgery showed increased uptake above grade 2 and greater H/N ratio than 1.16. Of these, 19 patients who had drilling surgery for permanent peg application showed adequate bleeding during the procedure. The activity grade and uptake ratio were inversely correlated with vascular ingrowth. Higher than grade 2 or greater than 1.56 in H/N ratio seemed to be an indicator for better prognosis. Accomplishment of vascularization was not affected by the surgical way such as enucleation or evisceration. Conclusion: $^{99m}Tc$-MDP bone scintigraphy can be a useful method to evaluate the vascularized status of implants. Adequate time for $^{99m}Tc$-MDP bone scintigraphy may be 11-20 weeks after enucleation or evisceration.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.2
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• pp.201-208
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• 1997

It is becoming increasingly clear that the inflammatory reaction can be ascribed to a complex array of mediators generated and released from activated phagocytes. In this study, the effect of PAF on interleukin-1(IL-1) activity by rat alveolar macrophages(AM) was examined using thymocyte proliferation assay in the supernate of sample obtained after 24 hr culture. When AM were cultured with PAF alone, no change in IL-1 activity was observed. However, the combined addition of PAF and muramyl dipeptide(MDP) or lipopolysaccharide(LPS) to AM cultures markedly enhanced IL-1 activity by 2-3 fold compared with AM cultures with the stimulant alone in a concentration dependent fashion. The peack effect was found at $10^{-8}$ M PAF with MDP and $10^{-14}$ M PAF with LPS. the effect of PAF was also tested in silica, toxic respirable dust, -added AM cultures as well as in the cultures containing bacterial compounds. Although silica did not stimulate the IL-1 activity, PAF could enhance IL-1 activity by 2 fold above the value of the silica-treated AM cultures with the peak response at $10^{-12}$ M PAF. Optimal enhancement of IL-1 activity occured when MDP and PAF were present together at the initiation of the 24 hr AM cultures. Additionaly, the biologically inactive precursor/metabolite of PAF, lyso-PAF failed to induce enhancement of IL-1 activity. When the specific, but structurally different PAF receptor antagonists, BN 52021($10^{-5}$ M) and CV 3988($10^{-5}$ M) was treated 15 min before addition of PAF($10^{-8}$ M) and MDP$(10\;{\mu}g/ml)$ to the AM cultures, it markedly inhibited the enhancement of IL-1 activity induced by PAF. The effects of these PAF antagonists were also observed in LPS$(10\;{\mu}g/ml)$-stimulated cells. Collectively, these data suggest that PAF enhances IL-1 activity by interaction with a specific receptor.

• Journal of the Korean Society of Systems Engineering
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• v.15 no.2
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• pp.39-46
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• 2019

The purpose of this paper is to present the results of the study, applying Systems Engineering(SE) method, on the feasibility of developing a Melt-down Proof Modular Micro Reactor(MDP-MMR) for its future deployment in Korea. The reactor is being developed by NCSU (North Carolina State University) due to its advantage of melt-down proof nature of the reactor core. For this paper, the characteristics of the MDP-MMR has been studied in terms of fuel characteristics, inherent safety features and passive safety system. The NCSU's development process has been reviewed applying the SE method, and further research is recommended for the feasibility study on deploying such a modular micro reactor in Korea.