• Restorative Dentistry and Endodontics
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• v.24 no.2
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• pp.310-321
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• 1999

In this in vitro study, confocal laser scanning microscopic morphology of dentin-resin interface and its relationship to shear bond strength were investigated after the exposed dentin surfaces were treated with 3 different kinds of dentin adhesive systems[three-step; Scotchbond Multi-Purpose Plus(SMPP), self-priming bonding resin; Single Bond(SB), self-etching primer; Clearfil Liner Bond 2(LB2)]. 52 extracted human molar teeth without caries and/or restorations. The experimental teeth were randomly divided into three groups of seventeen teeth each. In five teeth of each group, class V cavities(depth: 1.5mm) with 900 cavosurface angles were prepared at the cementoenamel junction on buccal and lingual surfaces. Bonding resins of each dentin adhesive system were mixed with rhodamine B. Primer of SMPP was mixed with fluorescein. In group 1. the exposed dentin was conditioned with etchant, applied with above primer and bonding resin of SMPP. In group 2, with etchant and self-priming bonding agent of SB. In group 3, with self-etching primer and bonding agent of LB2. After treatment with dentin adhesive systems, composite resin were applied and photocured. The experimental teeth were cut longitudinally through the center line of restoration and grounded so that about $90{\mu}m$-thick wafers of buccolingually orientated dentin were obtained. And, $70{\sim}80{\mu}m$-thick wafers sectioned horizontally, thus presenting a dentinal tubules at 900 to the cut surface of a remaining tooth, were obtained. Primer of SMPP mixed with rhodamine B was applied to these wafers. Confocal laser scanning microscopic investigations of these wafers were done within of 24 hours after treatment. To measure shear bond strength, the remaining twelve teeth of each group were grounded horizontally below the dentinoenamel junction, so that no enamel remained. After applying dentin adhesive systems on the dentin surface, composite was applied in the shape of cylinder. The cylinder was 5mm in diameter, and 2mm in thickness. Shear bond strength was measured using Instron with a cross-head speed of 0.5mm/min. It was concluded as follows ; 1. Hybrid layer of SMPP(mean: $4.56{\mu}m$) was thicker than that of any other groups. This value was not statistically significant thicker than that of SB(mean: $3.41{\mu}m$, p>0.05), and significant thicker than that of LB2(mean: $1.56{\mu}m$, p<0.05). There was a statistical difference between SB and LB2(p<0.05). 2. Although there were variations in the length of resin tag even in a sample, and in a group, most samples in SMPP and SB showed resin tags extending above $20{\mu}m$. But samples in LB2 showed resin tags of $10{\mu}m$ at best. 3. Besides primer's infiltration into demineralized peritubular dentin and dentinal tubules, fluorophore of primer was detected in the lateral branches of dentinal tubules. 4. All groups demonstrated statistically significant differences from one another(p<0.05), with shear bond strengths given in descending order as follows: SMPP(18.3MPa), SB(16.0MPa) and LB2(12.4MPa). 5. LB2 having thinnest hybrid layer($1.56{\mu}m$) showed the lowest shear bond strength(12.4MPa).

• Journal of Chest Surgery
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• v.40 no.6 s.275
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• pp.407-413
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• 2007

Background: The brain natriuretic peptide (BNP) level has been reported in some studies to be associated with the occurrence of atrial fbrillation (AF). The aim of this study is to evaluate the potential usefulness of the BNP level as a predictor of the occurrence of postoperative (postop) AF and to assess the relationship of the BNP level with the onset of AF and the restoration of sinus rhythm. Material and Method: From January 1, 2005 to February 28, 2006, 82 patients without a history of atrial arrhythmia that had undergone cardiac surgery were enrolled in the study. Blood samples for plasma BNP were drawn daily for all these patients from the preoperative (preop) day to the 7th postop day. The patient records were reviewed and postop EKGs were checked daily for AF until the time of discharge. Result: Patients were divided into two groups based on development of postop AF. Postoperative AF developed in 26 patients (31.7%). There was no significant statistical difference in age, sex distribution, preop left ventricle ejection fraction, hypertension, left ventricular hypertrophy, or the use of beta blockers between the non-postop AF and postop AF group. More patients in the AF group had undergone valve surgery (39.3% versus 76.9%, p=0.002). The preop left atrium size was significantly larger in the AF patients ($43.8{\pm}10.3 mm$ versus $49.8{\pm}11.5 mm$, p=0.029). The preop plasma BNP levels were higher in the postop AF patients ($144.1{\pm}20.8 pg/mL$ versus $267.5{\pm}68 pg/mL$, p=0.034). In the postop AF group, the plasma BNP level was the highest on the 3rd postop day. Postop AF developed in most patients by the 3rd postop day; restored sinus rhythm developed by the 7th postop day. Conclusion: Elevated plasma BNP levels may lead to the occurrence of postop AF in patients undergoing cardiac surgery. Patients who have a high risk of postop AF should be considered for aggressive prophylactic antiarrhythmic therapy.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1129-1136
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• 2018

Purpose: To compare the postoperative clinical outcomes after cataract surgery and implantation using the BunnyLens $MF^{(R)}$ and $ReSTOR^{(R)}$ multifocal intraocular lenses. Methods: Sixty-five eyes implanted with multifocal intraocular lenses were divided into two groups involving either $ReSTOR^{(R)}$ (39 eyes) or BunnyLens $MF^{(R)}$ (26 eyes) lenses. In these two groups, the distant and near visual acuity, astigmatism, spherical equivalent, and contrast sensitivity test were examined at preoperative and postoperative 1 week, 8 weeks, and 24 weeks. We compared the clinical efficacy between the two groups before and after cataract surgery using statistical analysis. Results: The mean value of distant and near visual acuity, and spherical equivalent of both groups after intraocular lens implantation were significantly improved, compared with the preoperative values (p < 0.05), while there was no significant differences between the two groups (p > 0.05). The means of postoperative distant and near visual acuity, astigmatism, and contrast sensitivity test were not significantly different between $ReSTOR^{(R)}$ and BunnyLens $MF^{(R)}$ lenses (p > 0.05). The mean numeric error of spherical equivalent at the final postoperative 24 weeks was $-0.17{\pm}0.50$ diopters (D) for the $ReSTOR^{(R)}$ lenses and $-0.34{\pm}0.52D$ for the BunnyLens $MF^{(R)}$ lenses (p > 0.05). Conclusions: BunnyLens $MF^{(R)}$ and $ReSTOR^{(R)}$ lenses showed no significant difference in clinical efficacy, including distance and near vision, spherical equivalent error, and contrast sensitivity test after cataract surgery. However, it should be noted that BunnyLens $MF^{(R)}$ lenses had a tendency toward myopic shift compared with $ReSTOR^{(R)}$ lenses.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.5
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• pp.1-11
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• 2021

The purpose of this study is to find out the main factors affecting air quality in urban physical space factors, and provide clues for environmental improvement. Nine monitoring stations in China's industrial city, Changchun, collected AQI concentration data from January 1, 2018 to December 31, 2019. This paper analyzes the types and distribution characteristics of urban physical facilities within a radius of 300m with the detection station as the center. The monitoring station is divided into three groups, and the difference in floating dust concentration among the three groups in different seasons is analyzed. The results show that AQI concentration is the highest in spring and winter, followed by summer, and the lowest in autumn. The place with the highest concentrations of AQI in spring are F (93.00), D (91.10), I (89.20), in summer are D (69.05), A (67.89), B (84.44), in autumn are I (62.80), G (60.84), D (53.27), D (53.27), in winter are I (95.82), H (95.60), f (94.04). Through SPSS analysis, it shows that the air index in a space with a diameter of 600 meters is related to forest land, grassland, bare land, water space, tree height, building area (average value), and building volume (average value). According to the statistical analysis results of spring and winter with the most serious pollution, forest land area (43,637m², 15.44%) and water surface area (18,736m², 6.63%) accounted for the majority, and group 1 (A, B, C) with the least average building area (448m², 0.17%) and average building volume (10,201m²) had the lowest pollution concentration. On the contrary, group 2 (D, E, F) had the highest AQI concentration, with less or no woodland (1,917m², 0.68%) and water surface area (0m², 0%), and the highest average building area (1,056m², 0.37%) and average building volume (17,470m³). It is confirmed that the characteristics of the area with the highest AQI concentration are that the more the site ratio of tree height above 12m, the smaller the site ratio of bare land, and the lower the pollution degree. On the contrary, the larger the area of bare land, the higher the pollution degree. By analyzing the characteristics of nine monitoring stations in Changchun, it can be seen that the air quality brought by the physical characteristics of urban space is closely related to the above factors.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.143-151
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• 2022

Purpose. The purpose of this study was to evaluate the performance efficiency of two different drill combinations according to the heat generated and drilling time. Materials and methods. In this study, cow ribs were used as research materials. To test the specimen, cow bones were rid of fascia and muscles, and a temperature sensor was mounted around the drilling area. The experimental group was divided into a group using a guide drill and a group using a Lindmann drill according to the drill used before the initial drilling. The drilling sequence of the guide drilling group is as follows; guide drill (ø 2.25), initial drill (ø 2.25), twist drill (ø 2.80), and twist drill (ø 3.20). The drilling sequence of the Lindmann drilling group is as follows; Lindmann drill (ø 2.10), initial drill (ø 2.25), twist drill (ø 2.80), and twist drill (ø 3.20). The temperature was measured after drilling. For statistical analysis, the difference between the groups was analyzed using the Mann-Whitney U test and the Friedman test was used (α = .05). Results. The average performance efficiency for each specimen of guide drilling group ranged from 0.3861 to 1.1385 mm³/s and that of Lindmann drilling group ranged from 0.1700 to 0.4199 mm³/s. The two drill combinations contained a guide drill and Lindmann drill as their first drills. The combination using the guide drill demonstrated excellent performance efficiency when calculated using the drilling time (P < .001). Conclusion. Since the guide drill group showed better performance efficiency than the Lindmann drill group, the use of the guide drill was more suitable for the primary drilling process.

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.137-144
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• 2021

Purpose : The usability of X-Jaw split VMAT was evaluated by comparative analysis of the dose distribution between the treatment plan divided by X-Jaw and Full field VMAT treatment plan in left breast cancer treatment including supraclavicular lymph nodes. Materials and Methods : 10 patients with left breast cancer, including supraclavicular lymph nodes, were simulated using vacuum cushion, and 2 Full field Arc VMAT and 4 X-Jaw split Arc VMAT were planned The treatment plan was designed to include more than 95% of the Planning Target Volume (PTV) and to be minimally irradiated in the surrounding Organ at risk (OAR). Dose analysis of PTV and OAR was performed through dose volume histogram (DVH). Results : The Full field VMAT treatment plan and the X-Jaw split VMAT treatment plan of 10 patients were expressed as average values and compared. The difference between the two treatment plans was not large, with a Conformity index (CI) of 1.05±0.04, 1.04±0.03, and a Homogeneity index (HI) of 1.07±0.008, 1.07±0.009. For OAR, V5 in the left lung is 56.1±6.50%, 50.4±6.30%, and V20 is 20.0±4.15%, 13.52±3.61%. Compared to Full field VMAT, V5 decreased by 10.0% V20 by 32.6% in X-Jaw split VMAT. The V30 of the heart is 3.68±1.85%, 2.23±1.52%, and the Mean dose is 8.93±1.65 Gy, 7.67±1.52 Gy. In the X-Jaw split VMAT, V30 decreased by 39.3% and the Mean dose decreased by 14.1%. The left lung and heart, which are normal tissues, were found to have a statistical significance of that p-value is less than 0.05. Conclusion : In the case of left breast cancer treatment, which includes Supraclavicular lymph nodes with a large PTV volume and a length of X Jaw of 15 cm or more, the X-Jaw split VMAT shows improved dose distribution, which can reduce radiation dose of OAR such as lungs and heart, while maintaining similar PTV coverage with HI and CI equivalent to Full field VMAT. It is thought to be effective in reducing radiation complications.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.1
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• pp.18-25
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• 2022

Purpose: This study aimed to evaluate the color stability and antibacterial properties of the surface of polyethyl methacrylate (PEMA) resin with zirconia nanoparticles added. Materials and Methods: The control group was pure PEMA resin, and the experiment group was PEMA resin 15 mm in diameter and 2.5 mm in thickness disk-shaped specimens with 2, 4 and 8 w/v% of zirconia nanoparticles added, which were respectively divided into Group Z2, Group Z4, and Group Z8. After analyzing the surface roughness and color stability of the specimens, their antibacterial properties were evaluated using Porphyromonas gingivalis (P. gingivalis). The Statistical analysis was performed using when normality was met in the Shapiro-Wilk test, one-way ANOVA was used to test parameters, and Tukey's test was used as a post hoc test. When normality was not met, the Kruskal-Wallis test, a non-parametric test was used (P < 0.05). Results: The surface roughness measurement found that there was no significant difference between the experimental and control groups. The color stability evaluation showed that the Z2, Z4, and Z8 groups were within the color range of natural teeth. The adhesion of P. gingivalis was evaluated to be significantly reduced in Group Z2 compared to the control group (P < 0.05). In the Z2 group, Z4 group, and Z8 group, dead cells bacteria than the control group were observed. Conclusion: In conclusion, PEMA resin with zirconia nanoparticles added was within the range of natural teeth in color and reduced the adhesion of P. gingivalis.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.2
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• pp.55-63
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• 2024

Purpose: This study aimed to assess the antimicrobial efficacy of an 810-nm infrared diode laser with indocyanine green (ICG) against Staphylococcus aureus on sandblasted, large grit, and acid-etched (SLA) titanium surfaces, comparing its effectiveness with alternative chemical decontamination modalities. Materials and Methods: Biofilms of S. aureus ATCC 25923 were cultured on SLA titanium disks for 48 hours. The biofilms were divided into five treatment groups: control, chlorhexidine gluconate (CHX), tetracycline (TC), ICG, and 810-nm infrared diode laser with ICG (ICG-PDT). After treatment, colony-forming units were quantified to assess surviving bacteria, and viability was confirmed through confocal laser-scanning microscope (CLSM) imaging. Results: All treated groups exhibited a statistically significant reduction in S. aureus (P < 0.05), with notable efficacy in the CHX, TC, and ICG-PDT groups (P < 0.01). While no statistical difference was observed between TC and CHX, the ICG-PDT group demonstrated superior bacterial reduction. CLSM images revealed a higher proportion of dead bacteria stained in red within the ICG-PDT groups. Conclusion: Within the limitations, ICG-PDT effectively reduced S. aureus biofilms on SLA titanium surfaces. Further investigations into alternative decontamination methods and the clinical impact of ICG-PDT on peri-implant diseases are warranted.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.3
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• pp.149-158
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• 2024

Purpose: This study aims to investigate the effects of provisional restoration fabrication methods and surface polishing on surface roughness and microbial adhesion through in vitro experiments. Materials and Methods: 120 cylindrical provisional restoration resin blocks (10 × 10 × 2.5 mm) were manufactured according to four fabrication methods, and 30 specimens were assigned to each group. Afterwards, they were divided into non-polishing group, #400 grit SiC polishing group, and #800 grit SiC polishing group and polished to a 10 × 10 × 2 mm specimen size (n = 10). The surface roughness Ra and Ry of the specimen was measured using a Surface Roughness Tester. Three specimens were extracted from each group and were coated with artificial saliva, and then Streptococcus mutans were cultured on the specimens at 37℃ for 4 hours. The cultured specimens were fixed to fixatives and photographed using a scanning electron microscope. For statistical analysis, the two way of ANOVA was performed for surface roughness Ra and Ry, respectively, and the surface roughness was tested post-mortem with a Scheffe test. Results: The fabrication method and the degree of surface polishing of the provisional restorations had a significant effect on both surface roughness Ra and Ry, and had an interaction effect. There was no significant difference in Ra and Ry values in all polishing groups in DLP and LCD groups. Conclusion: The fabrication method and surface polishing of the provisional restoration had a significant effect on surface roughness and showed different adhesion patterns for S. mutans adhesion.

• Tuberculosis and Respiratory Diseases
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• v.44 no.2
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• pp.379-390
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• 1997

Background : It has long been suggested that neutrophils and their products are implicated as the central mediators of the acute lung injuries. Contrary to the dominant role of neutrophils in ARDS, many cases of ARDS has occurred in the setting of severe neutropenia without pulmonary neutrophil infiltration. Therefore it is certain that effector cell(s) other than neutrophil play an important role in the pathogenesis of ARDS. This experiment was performed to define the mechanism of ARDS in the setting of neutropenia, 1) by comparing the severity of endotoxin-induced lung injury, 2) by measurement of hydrogen peroxide production and cytokine concentration in the bronchoalveolar lavage cells and fluids obtained from different rats with and without cyclophosphamide-pretreatment. Method : The male Sprague-Dawleys were divided into the normal control (NC)-, endotoxin (ETX)-, and cyclophosphamide (CPA)-group in which neutropenia was induced by injecting cyclophosphamide intraperitoneally. Acute lung injury was evoked by injecting lipopolysaccharide (LPS) into a tail vein. The bronchoalveolar lavage (BAL) was performed at 3 and 6 hour after administration of LPS to measure the change of cell counts and concentrations of protein and cytokines, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). Hydrogen peroxide (HPO) production from BAL cells was measured at 6 hour after LPS administration by phenol red microassay with and without zymosan stimulation. Results : The results were as follows. A change of leukocyte counts in the peripheral blood after treatment with CPA : More than 95% of total leukocytes and neutrophils were reduced after CPA administration, resulting in severe neutropenia. A change of BAL cells : In the ETX-group, the number of total cells (p < 0.01) and of macrophage and neutrophil (p < 0.05) were increased at 3 and 6 hour after LPS administration compared to those of NC-group. In the CPA-group, the number of total leukocyte and macrophage were not changed after LPS administration, but neutrophil counts were significantly reduced and it took part in less than 0.1% of total BAL cells (p < 0.01 vs NC-group). BAL cells in this group were almost all macrophages (99.7%). A change of protein concentration in the BALF : In the ETX-group, protein concentration was increased at 3 hour and was more increased at 6 hour after LPS administration (p < 0.05 and < 0.01 vs NC-group, respectively). In the CPA-group, it was also significantly elevated at 3 hour after LPS administration (p < 0.05 vs NC-group), but the value was statistically not different from that of ETX-group. The value measured at 6 hour after LPS administration in the CPA-group became lower than that of ETX-group (p < 0.05), but showed still a higher value compared to that of NC-group (p < 0.05). A change of cytokine concentration in the BALF : TNF -alpha and IL-6 were elevated in the ETX - and CPA-group compared to those of NC-group at both time intervals. There was no statistical difference in the values of both cytokines between the ETX- and CPA-groups. Measurement of hydrogen peroxide production from BAL cells : There was no intergroup difference of HPO production from resting cells. HPO production after incubation with opsonized zymosan was significantly elevated in all groups. The percent increment of HPO production was highest in the ETX-group (89.0%, p < 0.0008 vs NC-group), and was 42.85 in the CPA-group (p = 0.003 vs NC-group ). Conclusion : Acute lung injury in the setting of neutropenia might be caused by functional activation of resident alveolar macrophages.