• Restorative Dentistry and Endodontics
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• 제38권3호
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• pp.146-153
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• 2013

Objectives: Aluminum step wedge (ASW) equivalent radiodensity (eRD) has been used to quantify restorative material's radiodensity. The aim of this study was to evaluate the effects of image acquisition control (IAC) of a digital X-ray system on the radiodensity quantification under different exposure time settings. Materials and Methods: Three 1-mm thick restorative material samples with various opacities were prepared. Samples were radiographed alongside an ASW using one of three digital radiographic modes (linear mapping (L), nonlinear mapping (N), and nonlinear mapping and automatic exposure control activated (E)) under 3 exposure time settings (underexposure, normal-exposure, and overexposure). The ASW eRD of restorative materials, attenuation coefficients and contrasts of ASW, and the correlation coefficient of linear relationship between logarithms of gray-scale value and thicknesses of ASW were compared under 9 conditions. Results: The ASW eRD measurements of restorative materials by three digital radiographic modes were statistically different (p = 0.049) but clinically similar. The relationship between logarithms of background corrected grey scale value and thickness of ASW was highly linear but attenuation coefficients and contrasts varied significantly among 3 radiographic modes. Varying exposure times did not affect ASW eRD significantly. Conclusions: Even though different digital radiographic modes induced large variation on attenuation of coefficient and contrast of ASW, E mode improved diagnostic quality of the image significantly under the underexposure condition by improving contrasts, while maintaining ASW eRDs of restorative materials similar. Under the condition of this study, underexposure time may be acceptable clinically with digital X-ray system using automatic gain control that reduces radiation exposure for patient.

• Asian-Australasian Journal of Animal Sciences
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• 제29권6호
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• pp.768-774
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• 2016

The present study investigated the impact of parity 1 gilt body weight during late gestation (d 109) on subsequent reproductive performance of sows and performance of suckling pigs. A total of 2,404 farrowing records over 6 parities were divided into six groups on the basis of body weight (190, 200, 210, 220, 230, and 240 kg) at d 109 of gestation of 585 gilts. Significant effects (p<0.05) of body weight on sow retention rate was noticed, with the 210 kg group having the lowest culling rate and highest total number of piglets born alive over the 6 parities. With increase of body weight, a linear increase (p<0.05) in losses of body weight and backfat during the lactation period of parity 1 and a linear decrease (p<0.05) in backfat loss for parities 4 and 6 were found. Compared with light sows, heavy sows had higher (p<0.05) litter weight at birth for parities 1 and 2 and at weaning in parity 1. Sow weaning-to-estrus interval of sows was not influenced (p>0.05) by body weight. In conclusion, maintaining optimal body weight during gestation would be beneficial to sows and suckling piglets.

• 천문학회지
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• 제37권5호
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• pp.605-609
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• 2004

We present a set of high-resolution 3D MHD simulations exploring the evolution of light, supersonic jets in cluster environments. We model sets of high- and low-Mach jets entering both uniform surroundings and King-type atmospheres and propagating distances more than 100 times the initial jet radius. Through complimentary analyses of synthetic observations and energy flow, we explore the detailed interactions between these jets and their environments. We find that jet cocoon morphology is strongly influenced by the structure of the ambient medium. Jets moving into uniform atmospheres have more pronounced backflow than their non-uniform counterparts, and this difference is clearly reflected by morphological differences in the synthetic observations. Additionally, synthetic observations illustrate differences in the appearances of terminal hotspots and the x-ray and radio correlations between the high- and low-Mach runs. Exploration of energy flow in these systems illustrates the general conversion of kinetic to thermal and magnetic energy in all of our simulations. Specifically, we examine conversion of energy type and the spatial transport of energy to the ambient medium. Determination of the evolution of the energy distribution in these objects will enhance our understanding of the role of AGN feedback in cluster environments.

• International Journal of Automotive Technology
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• 제5권2호
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• pp.77-88
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• 2004

Narrow commuter vehicles can address many congestion, parking and pollution issues associated with urban transportation. In making narrow vehicles safe, comfortable and acceptable to the public, active tilt control systems are likely to playa crucial role. This paper focuses on the development of an active direct tilt control system for a narrow vehicle that utilizes an actuator in the vehicle suspension. A simple PD controller can stabilize the tilt dynamics of the vehicle to any desired tilt angle. However, the challenges in the tilt control system design arise in determining the desired lean angle in real-time and in minimizing tilt actuator torque requirements. Minimizing torque requirements requires the tilting and turning of the vehicle to be synchronized as closely as possible. This paper explores two different control design approaches to meet these challenges. A Receding Horizon Controller (RHC) is first developed so as to systematically incorporate preview on road curvature and synchronize tilting with driver initiated turning. Second, a nonlinear control system that utilizes feedback linearization is developed and found to be effective in reducing torque. A close analysis of the complex feedback linearization controller provides insight into which terms are important for reducing actuator effort. This is used to reduce controller complexity and obtain a simple nonlinear controller that provides good performance.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.8-13
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• 1998

Animal cells in culture typically convert most of the glucose they consume into lactate. The accumulation of lactate, however, is commonly cited as one of the factors that inhibit cell growth and limit the maximum cell concentration that can be achieved in culture. The specific production of lactate and the amount of glucose converted to lactate can be reduced when cells are grown in a fed-batch culture in which the residual glucose concentration is maintained at low levels. Such a fed-batch culture was used to grow and adapt hybridoma cells into a low-lactate-producing state before changing into continuous culture. The cells reached and maintained a high viable cell concentration at steady state. In a similar manner, cells that were initially grown in batch culture and a glucose-rich environment reached a steady state with a cell concentration that is much lower. The feed composition and dilution rates for both cultures were similar, suggesting steady state multiplicity. From a processing perspective the desired steady state among those is the one with the least metabolite production. At such seady state nutrient concentration in the feed can be further increased to increase cell and product concentrations without causing the metabolite inhibitory effect typically seen in a cell culture. Controlling cell metabolism in a continuous culture to reduce or eliminate waste metabolite production may significantly improve the productivity of mammalian cell culture processes.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1978년도 학술대회지
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• pp.55-66
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• 1978

Five ginsenosides $(A_1,\;A_2,\;B_1,\;B_2,\;C)$ and a yellow pigment were isolated from American ginseng stems and leaves. Ginsenoside $A_2,\;B_1,\;B_2$ and C were proven to be identical with Korean ginseng root ginsenoside $Rg_1,$ Rd, Re and $Rb_2,$ respectively. The yellow pigment proved identical with panasenoside isolated from Korean ginseng leaves. Ginsenoside $A_1$, which was also present in American ginseng roots, was not identical to any of the known root (ginsenoside $R_{0}-Rg_{2}$) and leaf (ginsenoside $F_{1}-F_{3}$) Korean ginseng saponins. A gas-liquid chromatographic method was developed to analyze ginsenosides and sapogenins in rabbit plasma and urine samples. Panasenoside and stigmasterol were found to be the best internal standards for ginsenosides and sapogenihs, respectively. Ginsenoside C had a significantly longer half-life, higher plasma protein binding, lower metabolic and renal clearance than ginsenoside $A_1,\;A_2\;and\;B_2$. Ginsenosides were not found in rabbit plasma and urine samples after oral administration. Ginsenoside C had a higher toxicity than ginsenoside $A_2$ after intraperitoneal administration to mice. Toxicity was not observed after oral administration of the ginsenosides.

• 간호행정학회지
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• 제20권4호
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• pp.405-413
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• 2014

Purpose: The purpose of this study was to review articles on Nursing Management Minimum Data Sets (NMMDS) and to suggest strategies to improve practical use of NMMDS in nursing management. Methods: A systematic search for articles published until 2013 was undertaken using the following biomedical databases: CINAHL, PubMed, and Google scholar. Seventeen articles were fully reviewed. Results: The results showed that studies were related to updating NMMDS reflecting current EHR use, mapping NMMDS to standardized national databases, and validating, translating and evaluating NMMDS for international uses. NMMDS has three dimensions and was developed reflecting the needs of nurse managers. Conclusion: The study findings provide a summary of recent trends in NMMDS. These results can serve as basic information to promote practical use of NMMDS in the healthcare organization to provide nursing management data for nurse managers.

• 한국의류학회지
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• 제25권6호
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• pp.1167-1178
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• 2001

본 연구의 목적은 최근 미국 내에서 교육 개혁의 한 방편으로 공립학교 학생들에게 교복을 착용하도록 하는 도시가 증가함에 따라 교복 정책에 대한 여론은 찬반론이 교차하고 있고, 이를 뒷받침 할 연구는 부족하여 교복 착용에 관련된 요인들간의 관계를 알아보아 교육정책에 제안하기 위하여 시도되었다. 연구 대상자는 미국 미네소타 주, 도심 지역의 세 남녀 공학 고등학교를 대상으로 조사되었다. 세 고등학교는 학교 의복 착용에 대한 서로 다른 규율을 갖고 있었다. School R은 학교에서 지정한 교복만을 착용 해야 하는 규율을 갖고 있고 School F는 학생들에게 학교가 선정한 색상에 일치하는 의복을 통학복 으로 입을 수 있도록 한 매우 유동적인 교복 정책을 갖고 있었다. School N은 특정한 학교 교복은 없고 학생들에게 통학복 착용에 대한 규율은 있었다. 세 학교의 학부모, 교사, 학생을 대상으로 한 연구 결과는 부모, 교사는 교복 착용이 학생들의 행동에 영향을 미칠 것이라고 인지한 반면 학생들은 전체적으로 그렇지 않다는 태도를 보였다. 학생들에게 선호도가 높은 교복은 School F의 교복처럼 통학복에 색상 제한을 하는 약간은 자유로운 형태로 나타났으며 해당 학교 학생들의 교복에 대한 만족도 또한 높게 나타났다. 교복을 입지 않는 School N의 학부모들은 학생들 통학복에 대한 지출이 다른 두 학교 부모 보다 많은 것으로 나타났다. 또한 교복을 착용한 경험이 오래된 학생일수록 교복 착용에 더 긍정적인 관점을 보인 것으로 보아 미국 내에서의 교복 정책은 초등학교부터 실시하는 것이 바람직한 것으로 받아 들여 진다.

• 한국동물학회지
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• 제24권2호
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• pp.59-64
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• 1981

SCK 腫瘍細胞에 대한 溫熱處理의 細胞致死效果는 in vitro의 경우보다 in vivo의 경우에 顯著하게 컸다. In vivo에서 溫熱處理한 후, 腫瘍을 그대로 放置해두면 腫瘍細胞는 어느 期間동안 계속해서 죽게 되며 腫瘍의 機能的인 血管容積도 마찬가지로 減少한다. In vivo에서 X線을 照射하기 前과 後 30分에 溫熱處理한 腫瘍細胞의 放射線生殘曲線은 溫熱處理하지 않은 對照群의 그것에 比해 기울기가 컸다. 結論的으로 腫瘍細胞에 대한 溫熱處理의 細胞致死效果가 in vitro에 비해서 in vivo의 경우에 크게 되는 것은 腫瘍의 內部環境에 연유하는 것으로 생각된다.

• Restorative Dentistry and Endodontics
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• 제46권1호
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• pp.14.1-14.7
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• 2021

Objectives: The aim of this study was to evaluate the apical pressure generated by 2 endodontic irrigation needles and the GentleWave system in mandibular molars. Materials and Methods: The mesial and distal root canals of 12 mandibular molars were irrigated with a 30-gauge close-end needle or with a 30-gauge open-end needle. Procedures were performed in the mesial and distal canals. The GentleWave procedure and irrigation at 1 mm from the apex in the distal roots using an open-end needle were used, respectively, as negative and positive controls. The apical pressure was measured using a data acquisition pressure setup. Apical pressure exerted by the different needles in the 2 different canal types was statistically compared using 2-way analysis of variance. Results: Significant differences were found in the apical pressure for both needles and the canal type. The lowest values were obtained with close-end needles and in mesial canals. Negative apical pressure values were obtained using GentleWave. Conclusions: The needle and the canal type influenced the apical pressure. The GentleWave procedure produced negative apical pressure.