• Magazine of the Korea Concrete Institute
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• v.10 no.3
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• pp.135-142
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• 1998

본 연구는 초유동 콘크리트용 모르타르의 물/결합재비 및 고성능 감수제 첨가율에 따른 상대플로우 면적비와 상대깔대기 속도비의 상관관계를 실험으로 검토한 것이다. 구속수비 실험결과, C급 플라이애쉬>F급 플라이애쉬 > 석회석분순으로 나타났기 때문에 F급 플라이애쉬 및 석회석분은 유동성 개선에 효과적인 것으로 나타났다. 또한 모르타르 실험결과, 상대플로우 면적비와 상대깔대기 속도비는 고성능 감수제 첨가율이 일정할 경우 물/결합재비의 변화에 따라 원점을 지나는 직선관계로 나타났지만, 물/결합재비가 일정할 경우에는 고성능 감수제 첨가율의 변화에 따라 원점을 지나는 곡선관계로 나타났다. 따라서, 수식화 모델은 Rm= A. m0.4가 합리적이며, 최적값인 ( m .Rm)=(5.1)을 만족하는 배합조건은 플라이애쉬의 경우 치환율 30%, 물/결합재비 83%이며, 석회분의 경우 치환율30%, 물/결합재비 77%로 판명되었다.

• Journal of the Korean Arthroscopy Society
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• v.12 no.2
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• pp.98-101
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• 2008

Purpose: To evaluate the results of arthroscopic removal of calcific deposit depending on the phase-dependent progress of recalcitrant calcific tendinitis of the shoulder. Materials and Methods: From January, 2003 to September, 2007, arthroscopic treatment of calcific tendinitis of the shoulder joint, especially supraspinatus was performed in 27 consecutive patients who had had typical symptoms and failed with the conservative treatment and all patients could be followed up at least 6 months. We evaluated the visual analogue scale at preoperative, postoperative 2 weeks and 6 months. The results were compared according to the arthroscopic findings. Results: 11 cases were chalky calcium deposit of arthroscopic finding and 16 cases were toothpaste-like appearance. The VAS was 8.0 of the group with chalky deposit and 8.3 with toothpaste-like deposit preoperatively, which was not significantly different. However, at postoperative 2 weeks, it was 6.7 with chalky deposit and 2.7 with toothpaste-like, which is significantly different. At postoperative 6 months, the symptoms of all patients were resolved. Conclusion: Resorptive phase is well respond to surgical excision at early postoperative evaluation. The phase of calcific tendinitis is one of important factors for rapid resolution of the shoulder pain and functional improvement after arthroscopic treatment.

• Journal of the Korean Society of Radiology
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• v.10 no.4
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• pp.285-290
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• 2016

The purpose of our study was to retrospectively evaluate the cause of a decreased calcium score of follow-up studies on coronary artery calcium scores (CACs) computed tomography (CT). The subjects were healthy 100 people(85 males $60.6{\pm}6.9$ years, 15 females $67.2{\pm}7.3$ years). The subjects decreased CACs were divided into 4 subgroups depending on Agatston classification, minimal (1-10), mild (11-100), moderate (101-400), severe (400<). As a result of decreased CACs were scan location disagreement 51%, motion artifact 26%, equipment changes 14%, operator mistakes 5%, input miss 2%, image loss 1%, arrhythmia 1%. In the mild group, the most common decreased CACs were 49 people. In the minimal group, the most significant variation reduction has occurred to 6 people. Scan location disagreement was considered a partial volume effects due to the scan starting position. It showed less than 100 CACs a high variation (19.7%) in more than 100 CACs, a lower variation (2.2%), these could be seen that the variation range is different that can be tolerated according to the calcification score. Motion artifact factor was found in 26%, which is so closely related to the preceding tests that affect the higher heart rate like this pulmonary function test, exercise stress test.

• Journal of the Korean Geotechnical Society
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• v.17 no.2
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• pp.59-72
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• 2001

적황색토와 플라이애쉬의 혼합비율에 증가에 따라 건조밀도도 증가하며 최적함수비는 감소하는 경향이고 2차 첨가재인 소석회 및 시멘트 첨가에 의한 건조밀도의 증가는 보이나 처리토의 경량화의 범위는 1:03~1:0.5 정도임을 확인할 수 있었다. 프라이애쉬의 혼합비율이 증가해도 프라이애쉬의 고유산화칼슘(CaO)의 함유량이 적으면 유리산화칼슘의 증가도 크지 않으나, 2차 첨가재인 소석회 및 시멘트 첨가량의 증대에 따라 증가한다. 이는 첨가재에 의한 수화반응의 증가로 확인되며, 본 처리토는 Ion 교환작용과 Pozzolan 반응 생성물인 규산칼슘석회수화물(5CaO.6SiO$_2$.5$H_2O$, Tobermorite)과 알민산유산석회수화물(3CaO.Al$_2$O$_3$.3CaSO$_4$.32$H_2O$, Ettringite)가 주된 반응생성물이며 확인된 알민산유산석회수화물(Ettringite)의 회절 X-선 강도는 2차 첨가재의 첨가에 따른 수화반응으로 수화물은 점차 증가하며 상대적으로 일축압축강도도 상응한 강도발현을 하여 고결화 효과에 기여하고 있음을 보여준다.

• Journal of the Korean Society of Radiology
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• v.10 no.3
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• pp.201-206
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• 2016

Social interest in breast cancer has increased. The most basic exams for diagnosis include breast X-ray and breast ultrasound. In particular, breast microcalcification requires histological diagnosis, and breast microcalcification biopsy is commonly performed. Therefore, this study aimed to analyze and assess X-ray guided biopsy (needle localized open biopsy) and ultrasound guided biopsy (sono guided core needle biopsy), which are basics in diagnosis of microcalcification. Targeting 241 cases in which magnification mammography was performed for patients who visited the hospital due to breast microcalcification, age distribution and the location of lesions were analyzed in X-ray guided biopsy and ultrasound guided biopsy. By classifying exams performed after magnification mammography, the frequencies of X-ray guided biopsy and ultrasound guided biopsy were analyzed, and malignant and benign results were confirmed. The results showed that 64 cases(26.6%) were X-ray guided biopsy, which was 5.4 times higher than 12 cases(4.9%) of ultrasound guided biopsy. Due to development of ultrasound equipments, stereotactic vacuum-assisted biopsy, etc. the methods of histological diagnosis of microcalcification have become diverse, but when considering characteristics and limitations of each exam, X-ray guided biopsy is thought to be most accurate and useful.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.245-253
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• 2014

BACKGROUND: Oyster shell(OS) is alkaline with pH 9.8, porous, and has high concentration of $CaCO_3$. It could be used as an alternative of lime fertilizer to immobilize cadmium(Cd) in heavy metal contaminated arable soil. Therefore, this study has been conducted to compare effects of calcium(Ca) materials [OS and $Ca(OH)_2$] on Cd extractability in contaminated soil and determined mechanisms of Cd immobilization with OS. METHODS AND RESULTS: Both Ca materials were added at the rates of 0, 0.1, 0.2, 0.4, and 0.8% (wt Ca wt-1) in Cd contaminated soil and the mixtures were incubated at $25^{\circ}C$ for 4 weeks. Both Ca materials increased pH and negative charge of soil with increasing Ca addition and decreased 1N $NH_4OAc$ extractable Cd concentration. 0.1 N HCl extractable Cd concentration markedly decreased with addition of OS. 1 N $NH_4OAc$ extractable Cd concentration was related with pH and net negative charge of soil, but not with 0.1 N HCl extractable Cd concentration. We assumed that Cd immobilization with $Ca(OH)_2$ was mainly attributed to Cd adsorption resulted from increase in pH-induced negative charge of soil. Scanning electron microscope (SEM) images and energy dispersive spectroscopy(EDS) analyses were conducted to determine mechanism of Cd immobilization with OS. There was no visible precipitation on surface of both Ca materials. However, Cd was detected in innerlayer of OS by EDS analyses but not in that of $Ca(OH)_2$. CONCLUSION: We concluded that Cd immobilization with OS was different from that with $Ca(OH)_2$. OS might adsorbed interlayer of oyster shell or have other chemical reactions.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1266-1271
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• 2020

We report herein a 46-year-old woman who presented with mucinous breast carcinoma that appeared as a coarse and densely calcified mass on mammography. The lesion was a 4.6-cm-sized palpable, hyperechoic, calcified mass with posterior shadowing on ultrasonography. This finding is a unique feature of mucinous breast carcinoma and is also observed in unusual breast cancer variants such as metaplastic breast cancer with chondroid differentiation, extraosseous osteosarcoma, and breast chondrosarcoma. The lesion showed a slow-growing pattern throughout the 4-year observation period. Mammography performed 4 years ago revealed faint, grouped microcalcifications; the lesion increased in size over 2 years, presenting as a well-circumscribed, calcified mass, mimicking dystrophic calcification. As several unusual variants of breast cancer, including mucinous carcinoma, may present as coarse and densely calcified masses on mammography, immediate biopsy should be considered when they are observed.

• Journal of Chest Surgery
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• v.36 no.3
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• pp.131-135
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• 2003

Bovine pericardium fixed in glutaraldehyde solution (GA) has been one of the most popular surgical bioprosthesis, however, late calcific degeneration after implantation remains to be solved. To mitigate calcific degeneration, we posttreated the bovine pericardium with amino acids after GA fixation. Material and Method: 40 small pieces of bovine pericardia were fixed in 0.625% GA solution with 4 g/L $MgCl_26H_2O$as a control group (group 1). 40 pieces fixed in the same GA solution were posttreated with 2% chitosan solution (group 2) and the other 40 pieces posttreated with 8% glutamate (group 3). These were implanted into the belly of forty Fisher 344 rats subdermally and extracted at f month, 2 months, 3 months and 4 months after implantation. Result: With atomic absorption spectrophotometry we measured the deposited calcium amount and the results were as follows; 2.01 $\pm$0.13 mg/g in group 1, 2.34$\pm$0.73 mg/g in group 2, 2.49$\pm$0.15 mg/g in group 3 at 1 month after implantation, and 3.57$\pm$0.15 mg/g in group 1, 3.52$\pm$0.92 mg/g in group 2, 3.46$\pm$0.12 mg/g in group 3 at the second month. But 5.45$\pm$0.42 mg/g in group 1, 3.22 $\pm$1.31 mg/g in group 2 and 4.20$\pm$0.55 mg/g in group 3 at the 3rd month, which have statistical significance in group 2 (p<0.05). Finally at 4th month, 6.01$\pm$1.21 mg/g in group 1, 3.78$\pm$1.82 mg/g in group 2, 3.92$\pm$0.92 mg/g in group 3, which also have statistical significance (p < 0.05). Conclusion: This means posttreatment with 2% chitosan shows meaningful calcium mitigation effects after 3rd month on subcutaneously implanted bovine pericardium in the rat models but 8% glutamate shows mitigation effect after 4months in this experiment.

• Journal of Periodontal and Implant Science
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• v.32 no.3
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• pp.589-602
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• 2002

Hyaluronic acid (HA)는 중요한 glycosaminoglycan 중 하나로서 단백질과 화학적 결합을 하지 않기 때문에 분리가 쉽고 결합조직의 세포간 기질의 주요 성분이다. 우리는 점탄성 고분자 hyaluronic acid를 실험실상에서 사람 태아 골모세포의 골 형성 과정에 미치는 영향을 알아보고자 하였다. 우리는 여러 농도의 HA에 대한 사람 태아 골모세포에서의 세포증식, 염기성 인산분해효소 활성, 석회화 결절 형성능, 교원질 합성능 그리고 bone sialoprotein (BSP)의 발현 정도를 검사하였다. 세포증식에서 각 농도의 HA 처리군과 대조군 간에 2일과 4일간의 결과에서 유의한 차이를 보이지 않았다. 염기성 인산분해효소 활성에서는 0.063% HA 처리군에서 음성 대조군에 비해 가장 유의한 염기성 인산분해효소 활성을 보였다 (p<0.05). 0.063% HA 처리군은 교원질 합성능에서도 가장 높은 수준을 보였다 (p<0.05). 석회화 결절 형성능에서는 0.063% HA 처리군에서 대조군에 비해 많은 염색된 석회화 결절을 보였다. BSP의 발현 정도를 분석한 Western blot에서는 대조군에 비해 0.063% HA 처리군에서 증가된 단백질 발현을 나타났다. 본 연구 결과 고분자 HA가 실험실상에서 사람 태아 골모세포의 분화를 통해 새로운 골 형성을 유도할 수 있는 능력이 있음을 시사하였다.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.343-350
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• 2023

Based on Lung CT Screening Reporting and Data System (Lung-RADS), which has been used to standardize reading for lung cancer screening since November 2016, the types and frequency of "S" modifier findings other than lung cancer were analyzed. As a result of this study, 360 cases (35.19%) of "S" modifier were found in 1,023 subjects, and the most frequent diseases were coronary calcification and emphysema, 145 (14.17%) of coronary calcification and 138 (13.49%) of emphysema, indicating that the discovery rate was very high compared to other findings. In addition, it was found to be highly associated with the duration of smoking, and in the case of coronary calcification, 9 cases (5.73%) were found in the non-smokers group A, 23 cases (11.44%) within 10 years of smoking, 39 cases (13.68%) in the C group within 20 years of smoking, and 31% of the E group over 30 years of smoking. In addition to coronary calcification and emphysema, abnormal findings of pneumonia, lung epilepsy, and mediastinal disease were also found to be p<0.05 as a result of the analysis of the association with the smoking period, indicating that the smoking period was affected.