• Animal cells and systems
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• 제3권3호
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• pp.311-317
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• 1999

Prolactin (PRL) was reported to be locally synthesized in many brain areas including the hypothalamus, thalamus (TH) and hippocampus (HIP). In the pituitary lactotrophs, PRL synthesis is dependent upon a pituitary-specific transcription factor, Pit-1. In the present study, we attempted to identify Pit-1 or Pit-1-like protein in brain areas known as the synthetic sites of PRL. Reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis showed the same Pit-1 transcripts in brain areas such as the medial basal hypothalamus (MBH), preoptic area (POA), TH, and HIP with the Pit-1 transcripts in the anterior pituitary (AP). Electrophoretic mobility shift assay (EMSA) was run with nuclear protein extracts from brain tissues using a double strand oligomer probe containing a putative Pit-1 binding domain. Shifted bands were found in EMSA results with nuclear proteins from MBH, POA, TH and HIP. Specific binding of the Pit-1-like protein was further confirmed by competition with an unlabeled cold probe. Antisense Pit-1 oligodeoxynucleotide (Pit-1 ODN), which was designed to bind to the Pit-1 translation initiation site and block Pit-1 biosynthesis, was used to test Pit-1 dependent brain PRL transcription. Two nmol of Pit-1 ODN was introduced into the lateral ventricle of a 60-day old male rat brain. RNA blot hybridization and in situ hybridization indicated a decrease of PRL mRNA signals by the treatment of Pit-1 ODN. Taken together, the present study suggests that Pit-1 may play an important role in the transcriptional regulation of local PRL synthesis in the brain.

• 한국가구학회지
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• 제17권3호
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• pp.23-28
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• 2006

An experiment was conducted to investigate the pit structure of four kind of pine wood species grown in Korea. Torus diameter, margo width, margo lattice size, diameter of pit aperture and pit border width were taken under consideration for explaining the pit structure difference among Pinus densiflora, Pinus rigida, Pinus koraiensis and Larix kaempferi. Torus diameter was found highest in Pinus rigida and the lowest in Pinus densiflora. Margo lattice size varied with torus diameter. Wider torus lowered the margo lattice size. Highest margo width was found in Pinus rigida while the lowest one was found in Pinus koraiensis. Pit aperture diameter was found highest in Pinus densiflora and lowest in Pinus koraiensis. In Pinus rigida, pit border was found the highest and the lowest was found in Larix kaempferi. Pit aperture diameter and pit border were increased gradually from pith to bark while there was a decreasing trend in the margo lattice size measuring from the pith to bark.

• 한국환경농학회지
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• 제18권2호
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• pp.191-195
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• 1999

유입폐수의 $BOD_5$가 1차연못에서 88%가 제거되고 있어 Pit의 $BOD_5$ 제거효율이 60%에 달할 것으로 예측된다. 메탄발효 Pit의 환경조건으로 용존산소가 없고, 혐기성 및 중성 pH가 유지되어야 하며, 충분한 체류시간이 확보되어야 하고, 온도변화가 적어야 한다. 분석결과 실험 메탄발효 Pit는 이런 조건들을 만족시키고 있어 Pit설계가 적절함을 알 수 있다. 실험결과 메탄발효 Pit의 설계인자로 폐수체류 기간이 2day, 월류유속은 $1.5m^3m^{-2}day^{-1}$가 적합하며, Pit바닥의 수심은 슬러지층의 온도와 밀접한 관계가 있어 3-3.5m 정도가 적합한 것으로 사료된다. Pit 바닥의 슬러지층 온도가 $16^{\circ}C$ 이상으로 유지되어야 메탈발효가 원활히 일어난다. 우리나라 중부지방과 기후조건이 유사한 지역에 위치한 연못시스템 연구에 의하면, 연못바닥의 온도가 메탄박테리아 활동이 거의 정지하는 $14^{\circ}C$ 이하로 내려가는 기간이 약 7개월이 된다. 온대권의 연못시스템은 연간 슬러지 침전량이 분해량보다 많아 어느 정도 슬러지가 쌓이게 된다. 따라서 여분의 30㎝ 수심을 두어 10-20년에 한번 슬러지를 제거하도록 설계한다. 실험 연못시스템이 설치된 장소는 중부지방보다 평균기온이 약 $3-4^{\circ}C$ 높은 지역으로 연못바닥 지하 1.5m에 위치한 Pit의 수온이 14℃이하가 되는 기간이 Fig.5에서 약 6개월이 된다. 실험 메탄발효 Pit는 좁은 면적의 연못에 설치하기 위해 콘크리트구조로 만들었으나, 1차연못의 규모가 크면 토공만으로 Pit설치가 가능하며 비용이 적게 든다. Pit에서 발생한 가스가 연못상층으로 이용하면서 $CO_2$가 해리되어 정제된 메탄을 회수할 수 있다. 메탄발생이 왕성한 기간에 연못상층에서 포집한 가스는 거의 메탄으로만 구성되어 있어 축산폐수를 처리하면서 메탄가스를 회수하여 연료로 사용하는 것이 가능하다. 메탄발효 Pit가 생태적으로 적응하면 초기보다 처리효율이 증가할 것으로 기대되어 지속적인 실험을 수행할 예정이다.

• 공업화학
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• 제5권2호
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• pp.274-284
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• 1994

비이온성 계면활성제 $C_{12}E_5$, 비극성 오일 n-hexadecane, 물을 포함한 계에 oleyl alcohol 혹은 oleic acid 같은 극성 성분을 첨가했을 때의 Phase Inversion Temperature (PIT)를 측정한 결과, 첨가한 극성성분은 친유성 첨가제와 같이 PIT를 급격히 감소시킴을 알 수 있었다. PIT에서의 microemulsion phase의 surfactant film 조성 계산에 의하면 surfactant film에서의 극성 성분/계면활성제 비율이 증가할수록 PIT는 감소하였다. 또한 극성 성분의 첨가는 PIT에서의 microemulsion phase의 부피와 오일, 물의 solubilization parameter에도 큰 영향이 있었다. PIT의 감소에 따라, 예를 들면 극성 성분의 첨가량을 증가시킴에 따라, microemulsion phase의 부피는 급격히 증가하였으며 아울러 오일, 물 모두의 microemulsion phase에 대한 solubilization parameter가 급격히 증가하였다. 본 연구 결과를 비교할 수 있는 세척력 실험결과는 현재 없지만 PIT의 측정은 middle-phase microemulsion phase가 형성되는, 즉 많은 양의 오일을 제거할 수 있는 조건을 예측할 수 있는 유용한 방법임을 알 수 있었다.

• 한국수자원학회논문집
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• 제43권7호
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• pp.657-666
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• 2010

본 연구에서는 하도준설 및 골재채취에 의한 교란하천의 적응과정을 정량적으로 파악하기 위하여 이동상 실내실험을 수행하였으며, 하상경사 및 골재채취를 위한 준설 규모의 변화에 따른 하도의 응답 특성을 분석하였다. 웅덩이의 되메우기가 진행 중일 때에는 웅덩이의 이동속도는 일정하지만, 되메우기가 완료된 후에는 웅덩이(pit)의 이동속도가 빠르게 진행된다. 또한 웅덩이가 되메워지는 동안에 웅덩이의 수중 안식각은 일정하게 유지되었다. 하상경사가 급할 경우에, 웅덩이가 되메워지는 시간과 이동속도가 증가하였다. 골재채취에 의한 하천준설의 규모가 증가하게 되면, 웅덩이의 되메워지는 시간이 증가하게 되며, 웅덩이의 규모가 증가할수록 적응시간이 증가하였다. 무차원 마찰속도가 증가하면 무차원 웅덩이 깊이는 감소하고 무차원 웅덩이 이동속도가 증가하였다. 웅덩이 이동속도가 증가하면 무차원 웅덩이 깊이가 감소하였다. 무차원 사주의 이동속도가 증가하면, 웅덩이의 이동속도가 증가하였다. 상류에서 발달한 사주의 이동이 편향되면, 흐름이 집중되는 사주의 선단부의 위치에 따라 웅덩이의 형상이 변형되어 하류로 이동하였다.

• 대한소아치과학회지
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• 제21권2호
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• pp.429-438
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• 1994

Since the introduction of pit and fissure sealants in the early 1970's, many studies have been published amply documenting the efficacy of these materials as caries-preventive agents. However, the acceptance of the technique by dentist has been questionable. This survey was investigated the attitudes toward and use of pit and fissure sealants by dentist in Chonbuk area. The results were as follows: 1. Utilization of pit and fissure sealants is very high. Only 15% of dentists never use pit and fissure sealants, whereas 85% generally use pit and fissure sealants. 2. Most dentists reported that their knowledge of pit and fissure sealants was gained through dental schools education. 3. Concern about difficult to sell' to patient, poor retention of pit and fissure sealants and unsubstantiated by research were given as the main reasons why pit and fissure sealants was not used. 4. Patient demands and various educate program were given as important factors that would lead to increase use of pit and fissure sealants.

• Journal of Astronomy and Space Sciences
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• 제31권2호
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• pp.131-140
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• 2014

Lava caves could be useful as outposts for the human exploration of the Moon. Lava caves or lava tubes are formed when the external surface of the lava flows cools more quickly to make a hardened crust over subsurface lava flows. The lava flow eventually ceases and drains out of the tube, leaving an empty space. The frail part of the ceiling of lava tube could collapse to expose the entrance to the lava tubes which is called a pit crater. Several pit craters with the diameter of around 100 meters have been found by analyzing the data of SELENE and LRO lunar missions. It is hard to use these pit craters for outposts since these are too large in scale. In this study, small scale pit craters which are fit for outposts have been investigated using the NAC image data of LROC. Several topographic patterns which are believed to be lunar caves have been found and the similar pit craters of the Earth were compared and analyzed to identify caves. For this analysis, the image data of satellites and aerial photographs are collected and classified to construct a database. Several pit craters analogous to lunar pit craters were derived and a morphological pit crater model was generated using the 3D printer based on this database.

• 대한물리의학회지
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• 제16권1호
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• pp.1-7
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• 2021

PURPOSE: The purpose of this study is to conduct inter-rater and intra-rater reliability tests in patients with low back pain (LBP) using the prone instability test (PIT) and side-lying instability test (SIT). We have analyzed the Korean version Oswestry disability index (K-ODI) correlations and radiograph finding (RF) for validity. METHODS: Individuals (n = 51) (mean age of 40.27 ± 13.28) with LBP for at least over a week were recruited, together with two participating physical therapist examiners. The measurement consisted of PIT, PST, K-ODI, and RF. Sensitivity (Sn), specificity (Sp), positive predictive value, negative predictive value, prevalence index, agreement %, Cohen's kappa, and prevalence-adjusted bias-adjusted kappa (PABAK) were calculated. The PIT and SIT were compared with RF for validity analysis, while PIT, SIT, K-ODI, and RF were calculated for the correlation analysis. RESULTS: The intra-rater reliability test measured for the PIT (kappa = .79, PABAK = .88) and SIT (kappa = .73, PABAK = .84), and inter-rater reliability test measured for the SIT (kappa = .80, PABAK = .88) showed good agreements. The PIT (Sn = .65, Sp = .63) and SIT validities (Sn = .68, Sp = .70) were compared with RF, showing a significant correlation in PIT and RF (r = .69), SIT and RF (r = .73), and PIT and K-ODI (r = .53). CONCLUSION: The SIT is a more comfortable position test than the PIT in patients. Both PIT and SIT have acceptable reliability and validity.

• 한국가구학회지
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• 제17권4호
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• pp.101-107
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• 2006

To know the structural difference between the ray parenchyma and ray tracheid among Pinus densiflora, Pinus rigida, Pinus koraiensis and Larix kaempferi, an observation was carried out under the FE-SEM. The longest ray parenchyma and ray tracheid were found in Pinus koraiensis species while the shortest ray tracheid and ray parenchyma were found in Pinus densiflora and Larix kaempferi. Larix kaempferi had more than one endwall pit in its ray parenchyma. Pinus densiflora was found highest in the pit aperture diameter in ray tracheid and aperture diameter in the cross-field pit. The pit border width in ray tracheid and lumen diameter of ray parenchyma were found highest in Pinus rigida. The cell wall thickness of ray parenchyma and pit aperture diameter in endwall pit of ray tracheid were found highest in Pinus koraiensis compared to other species.

• Corrosion Science and Technology
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• 제22권1호
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• pp.55-63
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• 2023

The aim of this study was to propose a multiple linear regression (MLR) equation to predict ultimate tensile strength (UTS) of 316L stainless steel with unspecified pit corrosion. Tensile specimens with pit corrosion were prepared using a potentiostatic acceleration test method. Pit corrosion was characterized by measuring ten factors using a confocal laser microscope. Data were collected from 22 tensile tests. At 85% confidence level, total pit volume, maximum pit depth, mean ratio of surface area, and mean area were significant factors showing linear relationships with UTS. The MLR equation using these three significant factors at a 85% confidence level showed considerable prediction performance for UTS. Determination coefficient (R²) was 0.903 with training and test data sets. The yield strength ratio of 316L stainless steel was found to be around 0.85. All specimens with a pit corrosion presented a yield ratio of approximately 0.85 with R² of 0.998. Therefore, pit corrosion did not affect the yield ratio.