• Title/Summary/Keyword: unit groups

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The physico-chemical nature of prepared dextran sulfates

  • Kim, Young-Choong
    • Archives of Pharmacal Research
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    • v.4 no.1
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    • pp.33-41
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    • 1981
  • The prepared dextran sulfates were characterized by measuring the reduced viscosisty at five different concentrations to obtain an intrinsic viscosity in both phosphate and tris buffers, pH 7.4, ionic strength of 0.1 Dextran sulfates having 0.81, 1.06 sulfate groups per hexose unit have reduced viscosity value below 40 ml/g whereas dextran sulfates having 1.21, 1.43, 1.69 sulfate groups per hexose unit have reduced viscosity value over 40 ml/g. Dextran sulfate having 1.21 sulfate groups per hexose unit had highest value of reduced viscosity. The reduced viscosity of dextran sulfate in tris buffer was always higher than that in phosphate buffer regardless of the sulfate content of dextran sulfate. The influence of the sulfation of the dextran sulfate. The influence of the sulfation of the dextran sulfate molecule on the dextran sulfate-LDL interaction was studied with three different dextran sulfate molecules. Dextran sulfate molecules having more than one sulfate group per hexose unit. The dextran sulfate having 0.81 sulfate groups per hexose unit showed considerably different precipitation curves in phosphate and tris buffers. This peculiar behavior of dextran sulfate having 0.81 sulfate groups per hexose unit in the two buffer systems was not noticed with dextran sulfate having more than one noticed with dextran sulfate having more than one sulfate group per hexose unit.

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Marginal and internal discrepancy of 3-unit fixed dental prostheses fabricated by subtractive and additive manufacturing (절삭 및 적층 가공법으로 제작된 3본 고정성 국소의치의 변연 및 내면 적합도에 관한 연구)

  • Choi, Jae-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.58 no.1
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    • pp.7-13
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    • 2020
  • Purpose: This study was to evaluate marginal and internal discrepancy of 3-unit fixed dental prostheses (FDP) fabricated by subtractive manufacturing and additive manufacturing. Materials and methods: 3-unit bridge abutments without the maxillary left second premolar were prepared (reference model) and the reference model scan data was obtained using an intraoral scanner. 3-unit fixed dental prostheses were fabricated in the following three ways: Milled 3-unit FDP (MIL), digital light processing (DLP) 3D printed 3-unit FDP (D3P), stereolithography apparatus (SLA) 3D printed 3-unit FDP (S3P). To evaluate the marginal/internal discrepancy and precision of the prosthesis, scan data were superimposed by the triple-scan protocol and the combinations calculator, respectively. Quantitative and qualitative analysis was performed using root mean square (RMS) value and color difference map in 3D analysis program (Geomagic control X). Statistical analysis was performed using the Kruskal-Wallis test (α=.05), MannWhitney U test and Bonferroni correction (α=.05/3=.017). Results: The marginal discrepancy of S3P group was superior to MIL and D3P groups, and MIL and D3P groups were similar. The D3P and S3P groups showed better internal discrepancy than the MIL group, and there was no significant difference between the D3P and S3P groups. The precision was excellent in the order of MIL, S3P, and D3P groups. Conclusion: Within the limitation of this study, the 3-unit fixed dental prostheses fabricated by additive manufacturing showed better marginal and internal discrepancy than the those of fabricated by subtractive manufacturing, but the precision was poor.

A STUDY ON PERIODONTAL DISEASE SEVERITY AND MYELOPEROXIDASE IN GINGIVAL CREVICULAR FLUID (치주질환 심도와 치은열구액내 Myeloperoxidase에 관한 연구)

  • Choi, Byung-Son;Kwack, Jung-Minn;Kim, Hyung-Seop
    • Journal of Periodontal and Implant Science
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    • v.25 no.3
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    • pp.733-740
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    • 1995
  • This investigation was undertaken to determine the relationship between the amount of polymorphonuclear leukocyte(PMN) enzyme myeloperoxidase(MPO) in gingival crevicular fluid(GCF) collected from active or control site and gingival disease status described by clinical indices(gingival index, papillary bleeding index, pocket depth, periotron unit). The results were as follows : 1. MPO activity/site was greater at active sites than at control sites. 2. According to increasing the clinical parameters, MPO/sites was higher statistically (P<0. 01, P<0.05). 3. High MPO(unit/site) groups was higher statistically than low MPO(unit/site) groups in various clinical parameters. 4. Correlation coefficients between MPO(unit/site) and GI, MPO($unit/{\mu}l$ GCF) and periotron unit were 0.4782, -0.5901, respectively.

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Marginal fit of anterior 3-unit fixed partial zirconia restorations using different CAD/CAM systems

  • Song, Tae-Jin;Kwon, Taek-Ka;Yang, Jae-Ho;Han, Jung-Suk;Lee, Jai-Bong;Kim, Sung-Hun;Yeo, In-Sung
    • The Journal of Advanced Prosthodontics
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    • v.5 no.3
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    • pp.219-225
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    • 2013
  • PURPOSE. Few studies have investigated the marginal accuracy of 3-unit zirconia fixed partial dentures (FPDs) fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM) system. The purpose of this study was to compare the marginal fit of zirconia FPDs made using two CAD/CAM systems with that of metal-ceramic FPDs. MATERIALS AND METHODS. Artificial resin maxillary central and lateral incisors were prepared for 3-unit FPDs and fixed in yellow stone. This model was duplicated to epoxy resin die. On the resin die, 15 three-unit FPDs were fabricated per group (45 in total): Group A, zirconia 3-unit FPDs made with the Everest system; Group B, zirconia 3-unit FPDs made with the Lava system; and Group C, metal-ceramic 3-unit FPDs. They were cemented to resin dies with resin cement. After removal of pontic, each retainer was separated and observed under a microscope (Presize 440C). Marginal gaps of experimental groups were analyzed using one-way ANOVA and Duncan test. RESULTS. Mean marginal gaps of 3-unit FPDs were $60.46{\mu}m$ for the Everest group, $78.71{\mu}m$ for the Lava group, and $81.32{\mu}m$ for the metal-ceramic group. The Everest group demonstrated significantly smaller marginal gap than the Lava and the metal-ceramic groups (P<.05). The marginal gap did not significantly differ between the Lava and the metal-ceramic groups (P>.05). CONCLUSION. The marginal gaps of anterior 3-unit zirconia FPD differed according to CAD/CAM systems, but still fell within clinically acceptable ranges compared with conventional metal-ceramic restoration.

Comparison of the bonding strengths of second- and third-generation light-emitting diode light-curing units

  • Lee, Hee-Min;Kim, Sang-Cheol;Kang, Kyung-Hwa;Chang, Na-Young
    • The korean journal of orthodontics
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    • v.46 no.6
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    • pp.364-371
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    • 2016
  • Objective: With the introduction of third-generation light-emitting diodes (LEDs) in dental practice, it is necessary to compare their bracket-bonding effects, safety, and efficacy with those of the second-generation units. Methods: In this study, 80 extracted human premolars were randomly divided into eight groups of 10 samples each. Metal or polycrystalline ceramic brackets were bonded on the teeth using second- or third-generation LED light-curing units (LCUs), according to the manufacturers' instructions. The shear bond strengths were measured using the universal testing machine, and the adhesive remnant index (ARI) was scored by assessing the residual resin on the surfaces of debonded teeth using a scanning electron microscope. In addition, curing times were also measured. Results: The shear bond strengths in all experimental groups were higher than the acceptable clinical shear bond strengths, regardless of the curing unit used. In both LED LCU groups, all ceramic bracket groups showed significantly higher shear bond strengths than did the metal bracket groups except the plasma emulation group which showed no significant difference. When comparing units within the same bracket type, no differences in shear bond strength were observed between the second- and third-generation unit groups. Additionally, no significant differences were observed among the groups for the ARI. Conclusions: The bracket-bonding effects and ARIs of second- and third-generation LED LCUs showed few differences, and most were without statistical significance; however, the curing time was shorter for the second-generation unit.

SUBPERMUTABLE SUBGROUPS OF SKEW LINEAR GROUPS AND UNIT GROUPS OF REAL GROUP ALGEBRAS

  • Le, Qui Danh;Nguyen, Trung Nghia;Nguyen, Kim Ngoc
    • Bulletin of the Korean Mathematical Society
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    • v.58 no.1
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    • pp.225-234
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    • 2021
  • Let D be a division ring and n > 1 be an integer. In this paper, it is shown that if D ≠ ��3, then every subpermutable subgroup of the general skew linear group GLn(D) is normal. By applying this result, we show that every subpermutable subgroup of the unit group (ℝG)∗ of the real group algebras RG of finite groups G is normal in (ℝG)∗.

Meropenem Versus Piperacillin-Tazobactam as Empiric Therapy for Febrile Neutropenia in Pediatric Oncology Patients

  • Sezgin, Gulay;Acipayam, Can;Ozkan, Ayse;Bayram, Ibrahim;Tanyeli, Atila
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.11
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    • pp.4549-4553
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    • 2014
  • Background: Infection is a serious cause of mortality in febrile neutropenia of pediatric cancer patients. Recently, monotherapy has replaced the combination therapy in empirical treatment of febrile neutropenia. Since there has been no reported trial comparing the efficacy of meropenem and piperacillin-tazobactam (PIP/TAZ) monotherapies, the present retrospective study was conducted to compare safety and efficacy in febrile neutropenic children with cancer. Materials and Methods: Charts of febrile, neutropenic children hospitalized at our center between March 2008 and April 2011 for hemato-oncological malignancies were reviewed. Patients received PIP/TAZ 360 mg/kg/day or meropenem 60 mg/kg/day intravenously in three divided doses. Duration of fever and neutropenia, absolute neutrophil count, modification, and success rate were compared between the two groups. Resolution of fever without antibiotic change was defined as success and resolution of fever with antibiotic change or death of a patient was defined as failure. Modification was defined as changing the empirical antimicrobial agent during a febrile episode. Results: Two hundred eighty four febrile neutropenic episodes were documented in 136 patients with a median age of 5 years. In 198 episodes meropenem and in 86 episodes PIP/TAZ were used. Duration of fever and neutropenia, neutrophil count, sex, and primary disease were not different between two groups. Success rates and modification rate between two groups showed no significant differences (p>0.05). Overall success rate in the meropenem and PIP/TAZ groups were 92.4% and 91.9% respectively. No serious adverse effects occurred in either of the groups. Conclusions: Meropenem and PIP/TAZ monotherapy are equally safe and effective in the initial treatment of febrile neutropenia in children with cancer.

Evaluation on the Marginal Fitness of Zirconia Core fabricated with CAD/CAM System (CAD/CAM 시스템으로 제작한 지로코니아 코어의 변연 적합도 평가)

  • Noh, Hyeongrok;Sun, Gumju;Joo, Kyuji
    • The Journal of the Korea Contents Association
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    • v.13 no.11
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    • pp.800-806
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    • 2013
  • The purpose of this study was to evaluate the marginal fitnesses on the effect of span length of bridge and the marginal gaps within the clinically allowed range. The samples were fabricated with zirconia core using CAD/CAM system. The test groups were divided by four groups, single crown, 2-units bridge, 3-units bridge and 4-units bridge and 10 zirconia cores per each group. The results of mean marginal gaps were $42.95{\pm}6.93{\mu}m$ in the single crown, $43.53{\pm}5.27{\mu}m$ in 2-unit, $53.43{\pm}13.38{\mu}m$ in 3-unit, and $50.85{\pm}8.25{\mu}m$ in 4-unit on each. The marginal gap of mesial and distal surfaces were statistically significant differences between single, 2-unit group and 3-unit, 4-unit group (p<.05) and this results was effected by the span length. The buccal and lingual surfaces were no statistically significant differences within all groups(p>.05). From this results the span length of the zirconia core may have influence on marginal fitness and the marginal gaps were within the clinically allowed range.

AN EVALUATION OF PRECISION FIT OF IMPLANT-SUPPORTED PROSTHESIS USING THE PERIOTEST ($Periotest^{(R)}$를 이용한 임프란트지지 보철물의 적합도 평가에 관한 연구)

  • Kim, Young-Min;Bae, Jeong-Sik
    • The Journal of Korean Academy of Prosthodontics
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    • v.36 no.4
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    • pp.587-597
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    • 1998
  • In this study, the Periotest value was measured with Periotest to evaluate precision fit of the 2-unit and 3-unit implant-supported prosthesis by modifying the size and location of ill-fitted conditions. The 2-unit prosthesis was fabricated with the right implant fitted incorrectly and the 3-unit prosthesis with the right and center implant fitted incorrectly. To evaluate the effects of the ill-fitted sizes, 4 groups were divided.:The control group being the accurately fabricated sample group fitted properly. Group 1 was constructed with $40{\mu}m$ ill-fitted conditions, group 2 with $70{\mu}m$ and group 3 with $100{\mu}m$ ill-fitted conditions. The Periotest value was measured at each implant site after tightening 10Ncm. The result was follows : 1. The PTV on the ill-fitted area in the 2-unit implant-supported prosthesis increased as the ill-fitted conditions increased. There was a statistically significant difference among groups(p<0.05). In the same ill-fitted sample, the PTV depending on the measured location demonstrated a statistically significant difference (p<0.05) 2. The PTV on the ill-fitted area of the 3-unit implant-supported with an ill-fitted condition in the right implant increased as the ill-fitted conditions increased. There was a significant difference among groups (p<0.05). In the same ill-fitted sample, the PTV depending on the measured location demonstrated a statistically significant difference (p<0.05). 3. In the 3-unit implant-supported prosthesis with ill fitting conditions in the center implant, the PTV on the ill-fitted area demonstrated a statistically significant difference between the control group, group 1 and group 2 (p<0.05). In the same ill-fitted sample, the PTV depending on the measured location demonstrated significant difference between the gap side and the adjacent side with over $70{\mu}m$ ill-fitted conditions (p<0.05). The results suggest that Periotest is a valuable objective method for evaluating the precision fit of an implant superstructure.

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UNIT KILLING VECTORS AND HOMOGENEOUS GEODESICS ON SOME LIE GROUPS

  • Yi, Seunghun
    • Journal of the Chungcheong Mathematical Society
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    • v.19 no.3
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    • pp.291-297
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    • 2006
  • We find unit Killing vectors and homogeneous geodesics on the Lie group with Lie algebra $\mathbf{a}{\oplus}_p\mathbf{r}$, where $\mathbf{a}$ and $\mathbf{r}$ are abelian Lie algebra of dimension n and 1, respectively.

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