• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.321-331
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• 2005

The purpose of this study was to compare the effectiveness of mechanical and acid treatment on enamel surfaces for the retention of pit and fissure sealants and evaluate the presence of a prismless layer. The etch pattern produced on enamel from immature and mature premolar teeth extracted with varying period of acid etching using 37% phosphoric acid was examined using a scanning electron microscope(SEM). The composition of each groups was evaluated using an energy dispersive x-ray(EDX) spectroscopy. The result of present study can be summarized as follows: 1. Prismless layer was commonly observed on the fissure enamel in young and mature premolar. 2. There were no differences in micro-structure and etching pattern on fissure enamel between the young and the mature premolar. 3. The most effective etching pattern for retention of pit and fissure sealant was observed in 60 seconds of etching time and no apparent difference of etching pattern was found among 15, 30, and 45 seconds of etching time which showed non-retentive etching patterns. 4. The etching pattern obtained by grinding enamel surface with bur followed by 60 seconds of etching was similar to that of 60 seconds of etching without any pretreatment of fissure surface. 5. Type 2 etching pattern was commonly found on fissure enamel in both young and mature premolar. 6. The calcium content and P/Ca ratio in fissure enamel between the young and the mature premolar were significantly different(P<0.05). But content of calcium, phosphate and P/Ca ratio on various regions of fissure enamel in both young and mature premolar did not showed any difference. Based on these results, prismless layer may negatively influence the retention of pit and fissure sealants. Therefore, the mechanical removal of the prismless layer by grinding prior to etching or by prolonged etching time of enamel within the fissure system should result in an improved bonding of a pit and fissure sealant.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.212-222
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• 2004

The application of acidulated phosphate fluoride gel(APF) and fluoride varnishes are the most common topical fluoride therapy. The purpose of this in vitro study was to compare the remineralization effects of two topical fluoride agents, APF gel and fluoride varnish with microtomograph and 3D image analyzer without sample preparation and chemical fixation. For the purpose of the study, the artificial caries lesion was caused on the caries-free permanent pre molar and 48 specimens were divided into three groups each containing 16 specimens No application was performed on group 1, which acted as control group. Group 2 was treated with APF gel and was removed after a minute. Group 3 was treated with the topical application of fluoride varnish and removed after 45 minutes. Each specimen was placed into a closed container with 50ml of a artificial saliva during three months and the 3D images of the remineralization area were taken using the SkyScan each month. Using the density-measuring program in V $works^{TM}$, the density value of the remineralization area was measured. The following results were obtained: 1. All groups demonstrated an increase in the density of artificial caries lesion with time. 2. The density was significantly higher in APF gel and fluoride varnish group than control group at 1 month, 2 months, 3 months after the treatment(P<0.05). 3. The difference of the density between that "prior to treatment" and that "1 month after treatment" in Group 2 and Group 3 was significantly higher than that of Group 1 and, the difference of the density between that "1 month after treatmen" and that "2 month after treatment" in Group 3 was significantly higher than that of Group 1 and 2(P<0.05). 4. The fluoride varnish was more effective after 2 and 3 months and continuous than the APF gel.

• Journal of Chest Surgery
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• v.42 no.4
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• pp.480-486
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• 2009

Background: The Fogarty thromboembolectomy catheter technique was devised to extract distal arterial emboli and it represents a milestone for the treatment of patients with acute arterial occlusion since the 1960s. The major causes of arterial occlusion have changed from emboli of a heart origin to atherosclerosis over the past 30 years. Accordingly, questions have been raised about the effectiveness of simple Fogarty thromboembolectomy. Material and Method: During the period from March 1990 through August 2008, 156 patients who requiring Fogarty thromboembolectomy were analyzed. The patients were divided into two groups: those with simple Fogarty thromboembolectomy (Group 1, 79 patients) and those with additional vascular bypass graft surgery (Group 2, 77 patients). The duration of symptoms, the cause of thrombi, admission via the emergency room, a history of acupuncture or misdiagnosis, combined diseases, the anatomic occlusion site and the cause of death were analyzed using T-tests, cross tab tests, Chi square tests and Kaplan-Meier tests, respectively. Result: The mean age was 64$\pm$10 years in the 2 groups. The duration of symptoms (pain) in Group 1 vs Group 2 was 12$\pm$4 days vs 71$\pm$14 days (p=0.001). 50 (63%) patients in Group 1 were admitted via the emergency room vs 18 (23%) patients in Group 2 (p=0.005). Misdiagnosis and the treatment for herniated intervertebral disc or acupuncture were given to, 20 (25%) patients in Group 1 vs 30 (39%) patients in Group 2. Anticoagulation treatment before admission was performed in 22 (28%) patients in Group 1 vs 11 (14%) patients in Group 2. The causes of thrombi were heart disease in, 24 (30%) patients in Group 1 vs 6 (8%) patients in Group 2 (p=0.001), atherosclerosis in 46 (58%) patients in Group 1 vs 67 (87%) patients in Group 2 (p=0.001) and trauma in 9 (11%) patients in Group 1 vs 6 (8%) patients in Group 2. The combined diseases were cerebrovascular accident, hypertension and diabetes mellitus in 22 $\sim$ 37% of the total patients. The occlusion sites were mainly in the iliac and femoral arteries. Endarterectomy was performed in 7 (9%) patients in Group 1 vs 18 (23%) patients in Group 2 (p=0.012). Treatment was successful in 27 (34%) patients in Group 1 and in 40 (52%) patients in Group 2 (p=0.019). Reocclusion occurred in 37(47%) patients in Group 1 vs 20 (26%) patients in Group 2 (p=0.000), Amputation was done in 4 (5%) patients in Group 1 vs 12 (16%) patients in Group 2 (p=0.012) and death occurred in 10 (13%) patients (Group 1) vs 3(4%) patients (Group 2) (p=0.044). Conclusion: The recent past has shown a decline in the effectiveness of simple Fogarty thromboembolectomy with a changing pattern of acute arterial occlusion from a rheumatic heart origin to atherosclerosis. Additional bypass procedures play a role for the treatment of arterial occlusion instead of always performing simple Fogarty thromboembolectomy.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.54-61
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• 2000

Amalgam, though a widely used dental material, does not bond to the tooth substrate Therefore, retentive preparation of the cavity is necessary. Such amalgam restorations, until corrosion products form and plug the margin, will show significant marginal leakage. Unless this is prevented early on, saliva and bacteria may enter the cavity causing postoperative hypersensitivity, dissolution and collapse of the restoration, discoloration of the margin and secondary caries, leading to shortened life-span of the restoration and pulpal pathosis. Recently, a method of restoration has been introduced whereby tooth material can be preserved, cavity margin can be sealed and preventive treatment of pit and fissure can be administered while retaining all the advantages of conventional amalgam restorations. Such sealed amalgams involve removing the carious lesion without extending the cavity for prevention and using pit and fissure sealants to seal cavity margins and pit and fissures to reduce microleakage. In this study, finishing of the amalgam and sealant application were performed after different intervals following of amalgam restoration to compare the microleakage of sealed and conventional amalgam restorations. Thirty bicuspids were prepared with Class V cavity preparations on the buccal and lingual surfaces. After amalgam placement, they were divided into the following groups and treated accordingly. Group 1 : Polishing after 24 hours Group 2 : Immediate sealant application without polishing Group 3 : No polishing, but sealant applied after thermocycling 500 times After treatment, the samples were thermocycled 500 times between $5^{\circ}C$ and $55^{\circ}C$ with a dwell time of 30 seconds. After thermocycling, the samples were dipped into 1% methylene blue kept in a $37^{\circ}C$ incubator at 100% humidity for 24 hours. The teeth were then embedded in resin and cut bucco-lingually along the tooth axis and observed with a stereomicroscope to determine the degree of microleakage, The following results were obtained : 1. Group 2 showed the least microleakeage, while group 1 showed the greatest. 2. Group 1 showed significantly greater microleakage compared to group 2 (p<0.05). However, no significant differences were found between group 1 and 3(p>0.05). No significant differences in microleakage were also found between cup 2 and 3(p<0.05).

• Journal of Chest Surgery
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• v.30 no.3
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• pp.282-286
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• 1997

In the era of coronary artery bypass grafting, the intraaortic balloon pump (IABP) is more widely used and its indication has been ex anded. We perf'orbed retrospective clinical analysis on the patients who have received IABP pre andfor postoperatively during the course of CABG. From January 1981 to June 1995, total 322 patients have received CABG at the Seoul National University Hospital and among them 50 patients (15.5%) were supported by IABP during the course of the operation. The mean age at the time. of the operation was 57.2 years (39∼ 75 years) and the male to female ratio was 33 : 17. The preoperative diagnosis was unstable angina in 33 (66%), stable angina in 7 (14%) and postinfarct angina in 8 patients(16%). As for the indications of the IABP, there were 13 cases(26%) with left main disease, 13 (26%) with class IV angina, 12 (24%) with difficulty in CPB weaning, 6 (12%) with postinfarct angina and 3 (6%) with severe LV dysfunction. In the remaining 3 cases, one patient was operated on after PTCA failure in emergency basis, another was a patient with AMI, and the other was one who had postoperative low c rdiac output syndrome. All IABPS were introduced via femoral artery and among them 45 cases (90%) percutaneously. The mean postoperative assist time was 22.3 hours (0.5 ∼ 168 hours) and IABP could be removed within 48 hours in most of them (44150). The operative mortality was 6.1% (3 cases) and postoperative morbidity was only one with lower extremity ischemia. The more general application of the IABP during the course of the CABG ,especially in patients with high preoperative risk factors or difficulty in CPB weaning is a good measure of protecting and recovering myocardial function with minimal risk.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.684-696
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• 1995

A mutant for chalky endosperm and genetic male sterility (GMS) was newly developed in rice. The two characters were found to be controlled by single recessive gene which has pleiotropic effect, indicating that chalky seeds should be GMS seeds in segregating populations. Chalky seeds showed the same shape and size as normal seeds. However, starch composition of central part of endosperm was looser and shape of starch granules was rounder compared with normal endosperm, resulting in significantly lower grain weight, absolute density and grain hardness in chalky grains than in normal ones. Amylose content and gel consistency of chalky grains were much lower and harder, respectively. Male sterile plants showed much shorter plant height, poorer panicle exsertion and lesser panicle number compared with normal plants. Microspore abortion stage in pollen developmental process was observed as before meiosis. Male sterility of the mutant was stable regadless of temperature and day length. A system breeding hybrid rice using this mutant was discussed, comp ring with other systems utilizing cytoplasmic-genic male sterility(CGMS) and environment sensitive GMS(EGMS). Separation of GMS seeds in mixed seed bulks by specific gravity (1.14∼1.16g / cm3) was successful about 85∼90%. But some mixed normal plants were seemed to be easily removed by the apparent difference in growth characters at seedling stage. The highest natural outcrossing rate of this GMS line was as 17.3 % in a plot treated with 2-row pollinator, I-row GMS, and GA3 + cutting of flag leaf + pollen-scattering by rope.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.363-372
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• 1997

One hundred forty-four patients underwent operation for coarctation of the aorta at Seoul National University Children's Hospital between June 1986 and Decembsr 1995. Age ranged 0.1 to 191 months. Of these 78.5%(113) were infants. We classified the patients in terms of the anatomic location of coarctatiln and the associatCd anomalies(I[401= primary coarctation, 11(741=isthmic hypoplasia, lIIf30)=tubular hypoplasia involving transverse arch, Ar63 =with ventricular septal defect, B(28)=with other major cardiac defects). Subcalvian flap coarctoplasty(60), resection & anastomosis(44), extended aortoplasty(26), and onlay patch(14) were used as surgical methods. Overall operative mortality was 16.0(23/144)%. The hospital mortality was signific'antly higher in patheints with type 111, subtype B, younger age(under 3 months), extended aortoplasty(p(0.01). However, one-stage total repair in patients with subtype A or B were not found to be a predictor of hospital death. Restenosis had occured in 18 patients among 121 survivals(14. 9%). The mean follow-up period was 29.1 $\pm$28.8(0~129.2) months. Preoperative, immediate postoperative(within 3 months after operation) and postoperative(later than 6 months after operation) echocardiographic data on the dimensions of ascending aorta(AA), transverse arch(TA), an4 aortic isthmus(Al) were available in 77 patients(I=20, ll=42, 111= 15). Preoperative and postoperative aortic isthmus(All) and tra sverse arch indices(TAI), defined as TAIAA & AIIAA respectively, were compared. Immediate postoperative All in type 1, II and TAI in type 111 were significantly smaller in stenotic than non-stenotic group suggesting incomplete relieves of stenotic segment Younger age, subclavian coarctoplasty in patient under 3 months of age were round to be the risk factors for restenosis in this series. In conclusion, We found that aortic arch index and transverse arch index can be a useful tool to figure out the anatomic and clinical characteristics of the patients with aortic coarctation, and that anatomy, associated anomalies, age, and surgical methods may influence the surgical outcome of the coarctation repair.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.91-91
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• 1995

에탄올에 의한 급성독성은 에탄올, 아세트알데히드 및 에탄을 대사산물의 변형생성물질 등에 기인하므로 알콜 섭취 후 혈중 에탄을 농도 및 아세트알데히드의 농도를 낮추는 것은 음주에 의한 급성 중독상태에 머무는 시간을 단축시키는데 중요하다. 본 실험에서는 Bacillus subtilis natto sp.를 식물 추출액을 배지로 하여 배양한 후 단백 분해효소로 고분자물질을 절단하여 얻은 발효액인 바이오짐(상품명: Biozyme)을 주성분으로 한 '비지니스(조선무약합자회사)' 의 인체 혈중 알콜대사 촉진작용을 검색하였으며, 비지니스 및 바이오짐이 랫드의 에탄을 대사에 미치는 효과를 검토하여 다음과 같은 결과를 얻었다. 인체 혈중 알콜대사 촉진작용을 검색하기 위해 알콜 섭취 전과 후의 혈중 에탄올 농도를 비교하였는데, 대조군에 비해 비지니스 투여군이 30분 후부터 2시간 후까지 혈청 알콜농도가 낮게 나타났다. 대조군의 혈청 알콜농도를 100으로 하였을 때 알콜 투여 30분, 60분, 90분, 120분 경과 후 시험군은 각각 대조군의 84.3%, 89,0%, 85.9%, 75.8%를 나타내어 평균 16% 정도 낮았다. 시험군의 AUC는 대조군의 AUC의 89%로 비지니스 투여군에서 혈액내 알콜의 제거가 빠르게 진전된다는 것을 보여주었다. 또한, 랫드의 에탄을 대사에 미치는 효과를 알아보고자 바이오짐 및 비지니스 투여 후 채혈하여 혈중 에탄을 및 아세트알데히드 농도를 측정하였다. 비즈니스 투여시 혈중 알콜 농도는 알콜 투여 60분 경과후 가장 큰 감소 효과(대조군:83.70$\pm$11.80mg/이, 시험군:45.12$\pm$6.63mg/d1, 47% 감소)를 나타내었으며, 시험군의 AUC는 대조군에 비해 30% 감소하였다. 혈중 아세트알데히드 농도는 투여 60분 후 비지니스 투여군(4.56$\pm$0.51nmol/$m\ell$)이 대조군(6.45$\pm$0.64nmo1/$m\ell$)에 비해 유의성 있는 감소(29%)를 나타내었으며, 시험군의 AUC는 대조군에 비해 35% 감소하였다. 바이오짐 투여시 혈중 에탄을 농도가 알콜 투여 2시간 경과 후 가장 큰 감소 효과(대조군:49.10$\pm$5.20mg/dl, 시험군:25.90$\pm$7.16mg/d1, 47% 감소)를 나타내었으며, 시험군의 AUC는 대조군에 비해 39% 감소하였고, 혈중 아세트알데히드의 농도는 투여 60분후 시험군(3.96$\pm$0.07nmo1/$m\ell$)이 대조군(6.45$\pm$0,64nmo1/$m\ell$)에 비해 유의성 있는 감소(39%)를 나타내었으며, 시험군의 AUC는 대조군에 비해 48% 감소하였다 한편, 시험관내 에탄올 대사 효소에 대한 바이오짐의 효과를 검색해본 결과 바이오짐(2.0 $\mu\textrm{g}$/assay)에 의해 Aldehyde dehydrogenase(1.5unit/assay)의 활성이 14% 증가되었다. 본 연구의 결과로 볼 때, 비지니스 및 바이오짐은 음주 후 상승된 혈중 에탄을 농도 및 아세트알데히드의 농도를 현저히 감소시키는 효과가 있었다.

• Restorative Dentistry and Endodontics
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• v.36 no.5
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• pp.419-424
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• 2011

Objectives: This study was aimed to determine the effects of temporary sealing materials on microtensile bond strength between resin-coated dentin and resin inlay and to compare the bonding effectiveness of delayed dentin sealing and that of immediate dentin sealing. Materials and Methods: The teeth were divided into 4 groups: group 1, specimens were prepared using delayed dentin sealing after temporary sealing with zinc oxide eugenol (ZOE); group 2, specimens were prepared using immediate dentin sealing and ZOE sealing; group 3, specimens were prepared using immediate dentin sealing and Dycal (Dentsply) sealing; group 4, specimens were prepared using immediately sealed, and then temporarily sealed with a resin-based temporary sealing material. After removing the temporary sealing material, we applied resin adhesive and light-cured. Then the resin inlays were applied and bonded to the cavity with a resin-based cement. The microtensile bond strength of the sectioned specimens were measured with a micro-tensile tester (Bisco Inc.). Significance between the specimen groups were tested by means of one-way ANOVA and multiple Duncan's test. Results: Group 1 showed the lowest bond strength, and group 4 showed the highest bond strength (p < 0.01). When temporary sealing was performed with ZOE, immediate dentin sealing showed a higher bonding strength than delayed dentin sealing (p < 0.01). Conclusions: Based on these results, immediate dentin sealing is more recommended than delayed dentin sealing in bonding a resin inlay to dentin. Also, resin-based temporary sealing materials have shown the best result.

• Economic and Environmental Geology
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• v.46 no.6
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• pp.485-494
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• 2013

$CO_2$ Monitoring, Mitigation and Verification (MMV) is the essential part in the Carbon Capture and Storage (CCS) project in order to assure the storage permanence economically and environmentally. In large-scale CCS projects in the world, the seismic time-lapse survey is a key technology for monitoring the behavior of injected $CO_2$. In this study, we developed a basic process procedure for 3-D seismic baseline data from the Aquistore project, Estevan, Canada. Major target formations of Aquistore CCS project are the Winnipeg and the Deadwood sandstone formations located between 1,800 and 1,900 ms in traveltime. The analysis of trace energy and similarity attributes of seismic data followed by spectral decomposition are carried out for the characterization of $CO_2$ injection zone. High trace energies are concentrated in the northern part of the survey area at 1,800 ms and in the southern part at 1,850 ms in traveltime. The sandstone dominant regions are well recognized with high reflectivity by the trace energy analysis. Similarity attributes show two structural discontinuities trending the NW-SE direction at the target depth. Spectral decomposition of 5, 20 and 40 Hz frequency contents discriminated the successive E-W depositional events at the center of the research area. Additional noise rejection and stratigraphic interpretation on the baseline data followed by applying appropriate imaging technique will be helpful to investigate the differences between baseline data and multi-vintage monitor data.