• The Journal of Korean Academy of Prosthodontics
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• v.46 no.5
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• pp.528-534
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• 2008

Purpose: Marginal fit is one of the important components for the successful prosthodontic restoration. Poor fitting margin of the restoration causes hypersensitivity, secondary caries, and plaque accumulation, which later result in prosthodontic failure. CAD/CAM zirconia all-ceramic restorations, such as $LAVA^{(R)}$ (3M ESPE, St.Paul, MN) and $EVEREST^{(R)}$ (KaVo Dental GmbH, Biberach, Germany) systems were recently introduced in Korea. It is clinically meaningful to evaluate the changes of the marginal fit of the CAD/CAM zirconia systems before and after build-up. The purposes of this study are to compare the marginal fit of the two CAD/CAM all-ceramic systems with that of the ceramometal restoration, before and after porcelain build-up Material and methods: A maxillary first premolar dentiform tooth was prepared with 2.0 mm occlusal reduction, 1.0 mm axial reduction, chamfer margin, and 6 degree taperness in the axial wall. The prepared dentiform die was duplicated into the metal abutment die. The metal die was placed in the dental study model, and the full arch impressions of the model were made. Twenty four copings of 3 groups which were $LAVA^{(R)}$, $EVEREST^{(R)}$, and ceramometal restorations were fabricated. Each coping was cemented on the metal die with color-mixed Fit-checker $II^{(R)}$ (GC Cor., Tokyo, Japan). The marginal opening of each coping was measured with $Microhiscope^{(R)}$ system (HIROX KH-1000 ING-Plus, Seoul, Korea. X300 magnification). After porcelain build-up, the marginal openings of $LAVA^{(R)}$, $EVEREST^{(R)}$,and ceramometal restorations were also evaluated in the same method. Statistical analysis was done with paired t-test and one-way ANOVA test. Results: In coping states, the mean marginal opening for $EVEREST^{(R)}$ restorations was $52.00{\pm}11.94\;{\mu}m$ for $LAVA^{(R)}$ restorations $56.97{\pm}10.00\;{\mu}m$, and for ceramometal restorations $97.38{\pm}18.54\;{\mu}m$. After porcelain build-up, the mean marginal opening for $EVEREST^{(R)}$ restorations was $61.69{\pm}19.33\;{\mu}m$, for $LAVA^{(R)}$ restorations $70.81{\pm}12.99\;{\mu}m$, and for ceramometal restorations $1115.25{\pm}23.86\;{\mu}m$. Conclusion: 1. $LAVA^{(R)}$ and $EVEREST^{(R)}$ restorations in comparison with ceramometal restorations showed better marginal fit, which had significant differences (P < 0.05) in coping state and also after porcelain build-up . 2. The mean marginal opening values between $LAVA^{(R)}$ and $EVEREST^{(R)}$ restorations did not showed significant differences after porcelain build-up as well as in coping state (P > .05). 3. $EVEREST^{(R)}$, $LAVA^{(R)}$ and ceramometal restorations showed a little increased marginal opening after porcelain build-up, but did not show any statistical significance (P > .05).

• Journal of the Korean Orthopaedic Association
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• v.54 no.3
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• pp.227-236
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• 2019

Purpose: To evaluate the results of tibial lateral plateau fractures using arthroscopic-assisted reduction and internal fixation without cortical window or bone grafts. Materials and Methods: From March 2009 to March 2017, 27 patients with Schatzker type II tibial plateau fractures with articular depression and displacement over 5 mm on a computed tomography (CT) scan, who were treated with arthroscopic reduction and internal fixation and followed-up for at least 18 months, were enrolled in this study. Under arthroscopic guidance, the depressed fracture fragment was reduced using a freer and fixed with 5.0 or 6.5 mm cannulated screws through the inframeniscal portal without a cortical window or bone graft. The clinical and radiological results were evaluated using a Rasmussen system. Second look arthroscopy was performed in thirteen patients during the implant removal operation. Results: All fractures healed completely with a mean union time of 8.7 weeks (range from 8 to 12 weeks). Twenty four patients had good to excellent clinical results and 25 patients had good to excellent radiological results according to the Rasmussen classification. A well-healed articular surface with fibrocartilage was also found in 13 cases with second look arthroscopy. The 8 cases on CT scan at outpatient department follow-up showed bone union without bone grafting. Conclusion: Arthroscopic-assisted fixation of tibial lateral plateau fractures is a useful method without a cortical window or bone graft that produces good clinical results.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.3
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• pp.153-165
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• 2023

The purpose of this study is to propose effective scenarios for green areas in apartment complexes that can improve the connection between green spaces considering wind flow, thermal comfort, and mitigation of the urban heat island effect. The study site was an apartment complex in Godeok-dong, Gangdong-gu, Seoul, Korea. The site selection was based on comparing temperatures and discomfort index data collected from June to August 2020. Initially, the thermal and wind environment of the current site was analyzed. Based on the findings, three scenarios were proposed, taking into account both green patches and corridor elements: Scenario 1 (green patch), Scenario 2 (green corridor), and Scenario 3 (green patch & corridor). Subsequently, each scenario's wind speed, wind flow, and thermal comfort were analyzed using ENVI-met to compare their effectiveness in mitigating the urban heat island effect. The study results demonstrated that green patches contributed to increased wind speed and improved wind flow, leading to a reduction of 31..20% in the predicted mean vote (PMV) and 68.59% in the predicted percentage of dissatisfied (PET). On the other hand, green corridors facilitated the connection of wind paths and further increased wind speed compared to green patches. They proved to be more effective than green patches in mitigating the urban heat island, resulting in a reduction of 92.47% in PMV and 90.14% in PET. The combination of green patches and green corridors demonstrated the greatest increase in wind speed and strong connectivity within the apartment complex, resulting in a reduction of 95.75% in PMV and 95.35% in PET. However, patches in narrow areas were found to be more effective in improving thermal comfort than green corridors. Therefore, to effectively mitigate the urban heat island effect, enhancing green areas by incorporating green corridors in conjunction with green patches is recommended. This study can serve as fundamental data for planning green areas to mitigate future urban heat island effects in apartment complexes. Additionally, it can be considered a method to improve urban resilience in response to the challenges posed by the urban heat island effect.

• Journal of Korean Academy of Nursing
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• v.12 no.2
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• pp.1-26
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• 1982

The main purpose of this study was to test the effect of the structured information on the sleep amount of the patients undergoing open heart surgery. This study has specifically addressed to the Following two basic research questions: (1) Would the structed in formation influence in the reduction of sleep disturbance related to anxiety and Physical stress before and after the operation? and (2) that would be the effects of the structured information on the level of preoperative state anxiety, the hormonal change, and the degree of behavioral change in the patients undergoing an open heart surgery? A Quasi-experimental research was designed to answer these questions with one experimental group and one control group. Subjects in both groups were matched as closely as possible to avoid the effect of the differences inherent to the group characteristics, Baseline data were also. collected on both groups for 7 days prior to the experiment and found that subjects in both groups had comparable sleep patterns, trait anxiety, hormonal levels and behavioral level. A structured information as an experimental input was given to the subjects in the experimental group only. Data were collected and compared between the experimental group and the control group on the sleep amount of the consecutive pre and post operative days, on preoperative state anxiety level, and on hormonal and behavioral changes. To test the effectiveness of the structured information, two main hypotheses and three sub-hypotheses were formulated as follows; Main hypothesis 1: Experimental group which received structured information will have more sleep amount than control group without structured information in the night before the open heart surgery. Main hypothesis 2: Experimental group with structured information will have more sleep, amount than control group without structured information during the week following the open heart surgery Sub-hypothesis 1: Experimental group with structured information will be lower in the level of State anxiety than control group without structured information in the night before the open heart surgery. Sub-hypothesis 2 : Experimental group with structured information will have lower hormonal level than control group without stuctured information on the 5th day after the open heart surgery Sub-hypothesis 3: Experimental group with structured information will be lower in the behavioral change level than control group without structured information during the week after the open heart surgery. The research was conducted in a national university hospital in Seoul, Korea. The 53 Subjects who participated in the study were systematically divided into experimental group and control group which was decided by random sampling method. Among 53 subjects, 26 were placed in the experimental group and 27 in the control group. Instruments; (1) Structed information: Structured information as an independent variable was constructed by the researcher on the basis of Roy's adaptation model consisting of physiologic needs, self-concept, role function and interdependence needs as related to the sleep and of operational procedures. (2) Sleep amount measure: Sleep amount as main dependent variable was measured by trained nurses through observation on the basis of the established criteria, such as closed or open eyes, regular or irregular respiration, body movement, posture, responses to the light and question, facial expressions and self report after sleep. (3) State anxiety measure: State Anxiety as a sub-dependent variable was measured by Spi-elberger's STAI Anxiety scale, (4) Hormornal change measure: Hormone as a sub-dependent variable was measured by the cortisol level in plasma. (5) Behavior change measure: Behavior as a sub-dependent variable was measured by the Behavior and Mood Rating Scale by Wyatt. The data were collected over a period of four months, from June to October 1981, after the pretest period of two months. For the analysis of the data and test for the hypotheses, the t-test with mean differences and analysis of covariance was used. The result of the test for instruments show as follows: (1) STAI measurement for trait and state anxiety as analyzed by Cronbachs alpha coefficient analysis for item analysis and reliability showed the reliability level at r= .90 r= .91 respectively. (2) Behavior and Mood Rating Scale measurement was analyzed by means of Principal Component Analysis technique. Seven factors retained were anger, anxiety, hyperactivity, depression, bizarre behavior, suspicious behavior and emotional withdrawal. Cumulative percentage of each factor was 71.3%. The result of the test for hypotheses show as follows; (1) Main hypothesis, was not supported. The experimental group has 282 minutes of sleep as compared to the 255 minutes of sleep by the control group. Thus the sleep amount was higher in experimental group than in control group, however, the difference was not statistically significant at .05 level. (2) Main hypothesis 2 was not supported. The mean sleep amount of the experimental group and control group were 297 minutes and 278 minutes respectively Therefore, the experimental group had more sleep amount as compared to the control group, however, the difference was not statistically significant at .05 level. Thus, the main hypothesis 2 was not supported. (3) Sub-hypothesis 1 was not supported. The mean state anxiety of the experimental group and control group were 42.3, 43.9 in scores. Thus, the experimental group had slightly lower state anxiety level than control group, howe-ver, the difference was not statistically significant at .05 level. (4) Sub-hypothesis 2 was not supported. . The mean hormonal level of the experimental group and control group were 338 ㎍ and 440 ㎍ respectively. Thus, the experimental group showed decreased hormonal level than the control group, however, the difference was not statistically significant at .05 level. (5) Sub-hypothesis 3 was supported. The mean behavioral level of the experimental group and control group were 29.60 and 32.00 respectively in score. Thus, the experimental group showed lower behavioral change level than the control group. The difference was statistically significant at .05 level. In summary, the structured information did not influence the sleep amount, state anxiety or hormonal level of the subjects undergoing an open heart surgery at a statistically significant level, however, it showed a definite trends in their relationships, not least to mention its significant effect shown on behavioral change level. It can further be speculated that a great degree of individual differences in the variables such as sleep amount, state anxiety and fluctuation in hormonal level may partly be responsible for the statistical insensitivity to the experimentation.

• Journal of Chest Surgery
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• v.35 no.4
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• pp.261-266
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• 2002

In an attempt to avoid the adverse effects of the cardiopulmonary bypass, off pump coronary artery bypass grafting(Off pump CABG) that has recently been rediscovered and refined. We compared the preoperative risk factors and in-hospital outcomes of patients done Off pump with those done On pump CABG. Material na Method: One hundred seventy eight patients was underwent CABG between January 2001 and July 2001 12 patients whom underwent associated valvular or left ventricular volume reduction surgery were excluded in this study Data were collected for 52 Off pump CABG and 114 On pump CABG for patient and disease risk factors, extent of coronary disease, and in-hospital outcomes. Result: Off pump CABG and On pump CABG groups did not show any differences in their patient and disease risk factors, and extent of coronary disease. Off pump CABG group had significantly lower mean operation time(234 $\pm$ 37 min vs 290 $\pm$ 48 min, p<0.001), lower mean CK-MB level(10.1 $\pm$ 13.5 IU/L vs 33.1 $\pm$ 18.2 IU/L, p<0.001) and mean ventilation time(14.8 $\pm$ 3.5 hours vs 16.2 $\pm$ 4.9 hours, p=0.048) than On pump CABG groups. On pump CABG group had significantly more distal grafts(3.4 $\pm$ 0.9 vs 2.6 $\pm$ 0.8, p<0.001) than Off pump CABG groups. There were no operative mortality in two groups. Off pump) CABG and On pump CABG groups did not show any differences in their postoperative complications and outcomes including perioperative myocardial infarction, stroke, respiratory failure, renal failure, reoperation, the amount of bleeding, the need of intraaortic balloon pump, the need of inotropics, and the stay of intensive care unit and hospital. Two patients were converted to On pump CABG. Conclusion: This study showed that patients having Off pump CABG are not exposed to a greater risks of adverse outcomes and also provided evidence that patients having Off pump CABG have significantly lower operation time, CK-MB, ventilation time and less distal grafts. Although there may be potential benefits to Off pump CABG, further studies must be directed to determine those patients who would benefit from Off pump CABG.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.1
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• pp.9-14
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• 2009

Purpose: Nowadays in the nuclear medicine, many studies and efforts are being made to reduce the scan time, as well as the waiting time to be needed to execute exams after injection of radionuclide medicines. Several methods are being used in clinic, such as developing new radionuclide compounds that enable to be absorbed into target organs more quickly and reducing acquisition scan time by increase the number of Gamma Camera detectors to examine. Each medical equipment manufacturer has improved the imaging process techniques to reduce scan time. In this paper, we tried to analyze the difference of image quality between FBP, 3D OSEM reconstruction methods that commercialized and being clinically applied, and Astonish reconstruction method (A kind of Iterative fast reconstruction method of Philips), also difference of image quality on scan time. Material and Methods: We investigated in 32 patients that examined the Bone SPECT from June to July 2008 at department of nuclear medicine, ASAN Medical Center in Seoul. 40sec/frame and 20sec/frame images were acquired that using Philips‘ PRECEDENCE 16 Gamma Camera and then reconstructed those images by using the Astonish (Philips’ Reconstruction Method), 3D OSEM and FBP methods. The blinded test was performed to the clinical interpreting physicians with all images analyzed by each reconstruction method for qualitative analysis. And we analyzed target to non target ratio by draws lesions as the center of disease for quantitative analysis. At this time, each image was analyzed with same location and size of ROI. Results: In a qualitative analysis, there was no significant difference by acquisition time changes in image quality. In a quantitative analysis, the images reconstructed Astonish method showed good quality due to better sharpness and distinguish sharply between lesions and peripheral lesions. After measuring each mean value and standard deviation value of target to non target ratio with 40 sec/frame and 20sec/frame images, those values are Astonish (40 sec-$13.91{\pm}5.62$ : 20 sec-$13.88{\pm}5.92$), 3D OSEM (40 sec-$10.60{\pm}3.55$ : 20 sec-$10.55{\pm}3.64$), FBP (40 sec-$8.30{\pm}4.44$ : 20 sec-$8.19{\pm}4.20$). We analyzed target to non target ratio from 20 sec and 40 sec images. And we analyzed the result, In Astonish (t=0.16, p=0.872), 3D OSEM (t=0.51, p=0.610), FBP (t=0.73, p=0.469) methods, there was no significant difference statistically by acquisition time change in image quality. But FBP indicates no statistical differences while some images indicate difference between 40 sec/frame and 20 sec/frame images by various factors. Conclusions: In the circumstance, try to find a solution to reduce nuclear medicine scan time, the development of nuclear medicine equipment hardware has decreased while software has marched forward at a relentless. Due to development of computer hardware, the image reconstruction time was reduced and the expanded capacity to restore enables iterative methods that couldn't be performed before due to technical limits. As imaging process technique developed, it reduced scan time and we could observe that image quality keep similar level. While keeping exam quality and reducing scan time can induce the reduction of patient's pain and sensory waiting time, also accessibility of nuclear medicine exam will be improved and it provide better service to patients and clinical physician who order exams. Consequently, those things make the image of department of nuclear medicine be improved. Concurrent Imaging - A new function that setting up each image acquisition parameter and enables to acquire images simultaneously with various parameters to once examine.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.49-61
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• 2014

Purpose: With the aging of the population, the attack rate of osteoporotic vertebral compression fracture is in the increasing trend, and percutaneous vertebroplasty (PVP) is the most commonly performed standardized treatment. Although there is a research report of the excellence of usefulness of the SPECT/CT examination in terns of the exact diagnosis before and after the procedure, the bone cement material used in the procedure influences the image quality by forming an artifact in the CT image. Therefore, the objective of the research lies on evaluating the effect the bone cement gives to a SPECT/CT image. Materials and Methods: The images were acquired by inserting a model cement to each cylinder, after setting the background (3.6 kBq/mL), hot cylinder (29.6 kBq/mL) and cold cylinder (water) to the NEMA-1994 phantom. It was reconstructed with Astonish (Iterative: 4 Subset: 16), and non attenuation correction (NAC), attenuation correction (AC+SC-) and attenuation and scatter correction (AC+SC+) were used for the CT correction method. The mean count by each correction method and the count change ratio by the existence of the cement material were compared and the contrast recovery coefficient (CRC) was obtained. Additionally, the bone/soft tissue ratio (B/S ratio) was obtained after measuring the mean count of the 4 places including the soft tissue(spine erector muscle) after dividing the vertebral body into fracture region, normal region and cement by selecting the 20 patients those have performed PVP from the 107 patients diagnosed of compression fracture. Results: The mean count by the existence of a cement material showed the rate of increase of 12.4%, 6.5%, 1.5% at the hot cylinder of the phantom by NAC, AC+SC- and AC+SC+ when cement existed, 75.2%, 85.4%, 102.9% at the cold cylinder, 13.6%, 18.2%, 9.1% at the background, 33.1%, 41.4%, 63.5% at the fracture region of the clinical image, 53.1%, 61.6%, 67.7% at the normal region and 10.0%, 4.7%, 3.6% at the soft tissue. Meanwhile, a relative count reduction could be verified at the cement adjacent part at the inside of the cylinder, and the phantom image on the lesion and the count increase ratio of the clinical image showed a contrary phase. CRC implying the contrast ratio and B/S ratio was improved in the order of NAC, AC+SC-, AC+SC+, and was constant without a big change in the cold cylinder of the phantom. AC+SC- for the quantitative count, and AC+SC+ for the contrast ratio was analyzed to be the highest. Conclusion: It is considered to be useful in a clinical diagnosis if the application of AC+SC+ that improves the contrast ratio is combined, as it increases the noise count of the soft tissue and the scatter region as well along with the effect of the bone cement in contrast to the fact that the use of AC+SC- in the spine SPECT/CT examination of a PVP performed patient drastically increases the image count and enables a high density of image of the lesion(fracture).

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.30-35
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• 2013

Purpose: One of the current services, providing information to the patients and their guardians by using promotion materials induces positive responses and contributes to the improvement of the hospital reliability. Therefore, the objective of this study is to evaluate the effectiveness of audio visual materials, one of the means of promotion, as a way to give accurate medical information to resolve patient's curiosity about purpose and procedure of their examination and deplete complains about waiting which attributes negative effect to service quality assessment. Materials and Methods: 60 patients(mean age $53.97{\pm}12.24$, male : female = 26 : 34) who had $^{18}F-FDG PET/CT$ scan from July 2012 to August 2012 in Seoul Asan Medical Center were referred to the study. All of the patients having PET/CT scan were asked to watch an informative video material before the injection of radiopharmaceutical ($^{18}F-FDG$) and to fill in a questionnaire. Results: As a result of analyzing the contents of questionnaire, 52% of 60 patients had PET/CT scan for the first time and 72.4% of the patients read the PET/CT guidebook offered from their outpatient department or inpatient wards before their scan. After we searched the level of previous knowledge of the purpose and method of PET/CT scan, the patients answered 25.1% "know well", 34% "not sure", 40.9% "don't know" respectively. And 84.7% of the patients answered that watching the PET/CT guide video before the injection helps understanding what exam they were having and 15.3% of the patients did not. For the question asking ever the patients have experienced using our homepage or smart phone QR code to see the guide video before they visit out PET center, only 3.3% of them answered "yes". Lastly, the patients answered 60.1% "yes", 31.4% "so so" and 8.5% "no" respectively for the question asking whether watching the video makes the patients to fill the waiting time short. Conclusion: It is found that understanding of objective and method of the PET/CT scan and level of satisfaction was improved after the patients watched the guide video whether they had PET/CT scan before and read the PET/CT guidebook or not. Also, watching the video was effective for the reduction of perceptible waiting time. But while displaying the PET/CT guide video is useful for providing information about the scan and shortening the waiting time as one of the medical service, utilization of service was actually very poor because of the passive promotion and indifference of the patients about their examination. Therefore, from now on, it is necessary to construct the healthcare system which can be offered to more patients through the active promotion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.106-112
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• 2016

The purpose of this study was to examine the differences in the direct medical expenditure of community residents according to their physical activity level. The quota sampling method was used to select samples from a youth community center, senior center, community cultural center, and community recreational sports center in G city in Gyeongbuk-do. Of the 773 questionnaires distributed, 716 were completed. The questionnaires consisted of the demographic characteristics, regular exercise and physical activity levels, health status and medical costs. While the beneficial effect of regular exercise and physical activity on dental costs was not (significant), its effect on the costs of visiting hospital services was (significant). The mean differences in the total monthly direct medical expenditures on outpatient services and medicine for those with very high, high, moderate, low, and very low levels of physical activity were 7,500, 26,299, 47,517, 9,314, and 9,9978 won, respectively. The result of this study supported the findings of previous studies that regular exercise and physical activity. are not associated with the reduction of medical expenditure.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.6
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• pp.707-716
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• 2005

Statement of problem. Collarless metal ceramic fixed partial dentures(FPDs) had an esthetic problem such as opaque reflection in cervical region. To overcome this, modified coping which removed its facial cervical metal could be used. The marginal quality could be worsen according to the amount of its facial metal reduction. Purpose. The purpose of this study was to evaluate marginal fits of collarless metal ceramic FPDs with retainers of modified copings. Material and method. Dentoform maxillary left central incisor and right lateral incisor were prepared for 3-unit collarless metal ceramic FPD and fixed in yellow stone. This model was duplicated to PBT resin dies via CAD/CAM and injection molding. Four different facial margin design groups were investigated. Group A was a coping with a thin facial metal collar, group B was a collarless coping with its facial metal to the shoulder, group C was a collarless coping with its facial metal 1 mm short of the shoulder, and group D was a collarless coping with its facial metal 2 mm short of the shoulder. Seven collarless metal ceramic FPDs per group were fabricated. They were cemented to PBT resin dies with resin cement. After removal of pontics, each retainers were separated and observed under Accura 2000 optical microscope. Then, retainers were embeded in orthodontic resin and cross sectioned faciopalatally. Internal marginal fits of midfacial porcelain margins were observed under FE-SEM. Result and conclusion. Within the limitations of this in vitro study. The following conclusions were drawn. 1. Mean marginal gaps of collarless FPDs were in the $50-60{\mu}m$ range. 2. In midfacial margin, marginal discrepancies were greater in group A than in the experimental groups(p<0.05). 3. In midpalatal margin, marginal gaps were greater in group C and D than in group A and B(p<0.05). 4. Marginal fits of porcelain margins were better than those of metal margins in collarless metal ceramic FPDs. 5. In both teeth, internal marginal gaps of group C and D were greater than those of group A and B(p<0.05).