• Title/Summary/Keyword: 기계적이음

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Retrospective study on survival and complication rates of posterior single implant according to the implant diameters, lengths and position (구치부 단일 임플란트의 직경과 길이, 식립 위치에 따른 생존율 및 합병증의 발생률에 대한 후향적 연구)

  • Soo-Young Hong;Seon-Ki Lee;Jin-Han Lee;Jae-In Lee
    • The Journal of Korean Academy of Prosthodontics
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    • v.61 no.2
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    • pp.101-112
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    • 2023
  • Purpose. This retrospective study was to investigate the survival and complication rates of posterior single implant according to the implant diameters, lengths and position. Materials and methods. Patients who had been restored single implant prosthesis in the posterior area by the three prosthodontists in the department of prosthodontics, Daejeon dental hospital of Wonkwang university, in the period from February 2014 to May 2018 were selected for the study. A total of 505 patients with 697 implants were observed. The survival and complications of implants were investigated using electronic medical records and radiographs. Fixture diameters, lengths, position, patient's sex and age were assessed as possible factor affecting the survival and complications of implants. Results. 3-year cumulative survival rates of posterior single implants were 98.5% and 5-year cumulative survival rates were 94.4%. 5-year cumulative survival rates were higher in implants with diameter > 4.0 mm (97.0%) than implants with diameter ≤ 4.0 mm (89.5%), and in females (98.8%) than males (92.4%). There were statistically significant differences (P < .05). The mechanical complication rate was 20.1% and the biological complication rate was 4.7%. Complications occurred in order of abutment screw loosening (7.5%), decementation (6.3%), proximal contact loss (3.7%) and so on. Abutment screw loosening occurred more frequently in the lower molar region (10.5%), in males (9.5%) than females (5.1%), and in patients aged < 65 years (9.4%) than patients aged ≥ 65 years (5.1%). There were statistically significant differences (P < .05). Conclusion. The 5-year cumulative survival rates were higher in implants with diameter > 4.0 mm than implants with diameter ≤ 4.0 mm and in females than males. Abutment screw loosening which was the most commonly occurring complication occurred more frequently in the lower molar region, in males than females, and in patients aged < 65 years than patients aged ≥ 65 years. There were statistically significant differences.

Characteristics of Blood Mixed Cement in Percutaneous Vertebroplasty (경피적 척추 성형술에서 혈액 혼합 시멘트의 특성)

  • Seo, Jin-Hyeok;Woo, Young-Ha;Jeong, Ju-Seon;Kim, Do-Hun;Kim, Ok-Gul;Lee, Sang-Wook;Park, Chan-Ho
    • Journal of the Korean Orthopaedic Association
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    • v.54 no.5
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    • pp.435-439
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    • 2019
  • Purpose: This study evaluated the efficacy of blood mixed cement for osteoporotic vertebral compression fractures in reducing the complications of percutaneous vertebroplasty using conventional cement. Materials and Methods: This study was performed retrospectively in 80 patients, from January 2016 to January 2017. Porous cement was formed by mixing 2, 4, and 6 ml of blood with 20 g of cement used previously. A tube with a diameter and length of 2.8 mm and 215 mm, respectively, was used and the polymerization temperature, setting time, and optimal passing-time were measured and compared with those using only conventional cement. Radiologically, the results were evaluated and compared. Results: The polymerization temperature was 70.3℃, 55.3℃, 52.7℃, and 45.5℃ in the conventional cement (R), 2 ml (B2), 4 ml (B4), and 6 ml (B6), respectively, and the corresponding setting time decreased from 960 seconds (R) to 558 seconds (B2), 533 seconds (B4), and 500 seconds (B6). The optimal passing-time was 45 seconds (B2), 60 seconds (B4), and 78 seconds (B6) at 73 seconds (R), respectively and as the amount of blood increased, it was similar to the cement passing-time. The radiological results showed that the height restoration rates and the vertebral subsidence rates similar among the groups. Two cases of adjacent vertebral compression fractures in the R group and one in the B2 and B4 groups were encountered, and the leakage rate of the cement was approximately two times higher than that in the conventional cement group. Conclusion: In conventional percutaneous vertebroplasty, the procedure of using autologous blood with cement decreased the polymerization temperature, reduced the setting time, and the incidence of cement leakage was low. These properties may contribute to more favorable mechanical properties that can reduce the complications compared to conventional cements alone.

Limb Salvage Using a Combined Distal Femur and Proximal Tibia Replacement in the Sequelae of an Infected Reconstruction on Either Side of the Knee Joint (슬관절 주위 재건물 감염 후유증 시 슬관절 상하부 종양인공관절을 이용한 사지 구제술)

  • Jeon, Dae-Geun;Cho, Wan Hyeong;Park, Hwanseong;Nam, Heeseung
    • Journal of the Korean Orthopaedic Association
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    • v.54 no.1
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    • pp.37-44
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    • 2019
  • Purpose: Tumor infiltration around the knee joint or skip metastasis, repeated infection sequelae after tumor prosthesis implantation, regional recurrence, and mechanical failure of the megaprosthesis might require combined distal femur and proximal tibia replacement (CFTR). Among the aforementioned situations, there are few reports on the indication, complications, and implant survival of CFTR in temporarily arthrodesed patients who had a massive bony defect on either side of the knee joint to control infection. Materials and Methods: Thirty-four CFTR patients were reviewed retrospectively and 13 temporary arthrodesed cases switched to CFTR were extracted. All 13 cases had undergone a massive bony resection on either side of the knee joint and temporary arthrodesis state to control the repeated infection. This paper describes the diagnosis, tumor location, number of operations until CFTR, duration from the index operation to CFTR, survival of CFTR, complications, and Musculoskeletal Tumor Society (MSTS) score. Results: According to Kaplan-Meier plot, the 5- and 10-year survival of CFTR was 69.0%±12.8%, 46.0%±20.7%, respectively. Six (46.2%) of the 13 cases had major complications. Three cases underwent removal of the prosthesis and were converted to arthrodesis due to infection. Two cases underwent partial change of the implant due to loosening and periprosthetic fracture. The remaining case with a deep infection was resolved after extensive debridement. At the final follow-up, the average MSTS score of 10 cases with CFTR was 24.6 (21-27). In contrast, the MSTS score of 3 arthrodesis cases with failed CFTR was 12.3 (12-13). The average range of motion of the 10 CFTR cases was 67° (0°-100°). The mean extension lag of 10 cases was 48° (20°-80°). Conclusion: Although the complication rates is substantial, conversion of an arthrodesed knee to a mobile joint using CFTR in a patient who had a massive bony defect on either side of the knee joint to control infection should be considered. The patient's functional outcome was different from the arthrodesed one. For successful conversion to a mobile joint, thorough the eradication of scar tissue and creating sufficient space for the tumor prosthesis to flex the knee joint up to 60° to 70° without soft tissue tension.

Quality Characteristics and Shelf-life of Tofu Coagulated by Furie Juice of Pomegranate (석류 농축액 첨가 두부의 품질특성 및 저장성)

  • Kim, Ji-Young;Park, Geum-Soon
    • Journal of the Korean Society of Food Culture
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    • v.21 no.6
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    • pp.644-652
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    • 2006
  • This study was investigated the utilization of pomegranate(P) as coagulants for 새려 manufacture, the quality characteristics and shelf-life on tofu made by P1(fruit juice of pomegranate 1%) and P2(fruit juice of pomegranate 2%) and P3(fruit juice of pomegranate 3%) and P4(fruit juice of pomegranate 4%) and P5(fruit juice of pomegranate 5%) were investigated and compared to G.D.L(C). And also, total microbe and tatal acid of the tofu were determined during storage at $0^{\circ}C^$. The results are summarized as follow P3(493.3g/500ml) compared to C(485g/500ml) showed the highest yield. Turbidity of tofu was increased as the proportion of pomegranate was increased, while pH of tofu was increased as the proportion of pomegranate was decreased. $L^{\ast}^{\ast}^{\ast}$ value of C tofu was highest, $a^{\ast}^{\ast}^{\ast}$ value of tofu was increased as the proportion of pomegranate was increased and $b^{\ast}^{\ast}^{\ast}$ value of C tofu was higher than those of other tofus. The hardness of tofu coagulated with pomegranate showed higher than that of coagulated G.D.L. The cohesiveness of P4, P5 showed higher than C tofu, but those of other tofus showed lower than C tofu. The springiness of tofu showed in the order of P4>P5>P3>P2>P1, gumminess of P5 tofu was highest. The Brittleness of tofu was increased as the proportion of pomegranate increased. The pH value of tofu coagulated with pomegranate increased during storage at $0^{\circ}C^$. During the storage period of tofu, pH and total acid showed a maximum change in C tofu. Generally the total plate counts of bacteria of all tofu increased during storage at $0^{\circ}C^$, and those of tofu with added pomegranate were shown to be lower than C tofu. The results of S.E.M(scanning electron microscopes), the lower hardness showed the more soft and the smaller particle, The particle of C tofu was small and uniformity but the size of P4, P5 tofu showed coarse. In the sensory evaluation of all tofu, sleekness, nutty, chewiness and smoothness, appearance and overall quality was the highest in C tofu. In the sensory evaluation of tofus coagulated with pomegranate. overall quality was the highest in P2.

Quality Characteristics of Cuttlefish Inky Tofu Prepared with Various Coagulants (응고제에 따른 오징어 먹물 두부의 품질 특성)

  • Park, Eo-Jin;An, Sang-Hee
    • Journal of the Korean Society of Food Culture
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    • v.21 no.6
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    • pp.653-660
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    • 2006
  • Some quality characteristics of tofu prepared with cuttlefish ink were investigated to study the effects of various of coagulants. Each concentration of coagulant was determined as 0.2% of GDL, 0.3# of $MgCl_2$, 1%^ of $CaCl_2$, 1.5% of $CaSO_4$ and 0.6% D-gluconic acid calcium by pre-experiment. Also, the optimum concentration of added cuttlefish ink was chosen as 3%(diluted in twenty times). The yield of inky tofu prepared with GDL as coagulant was the highest. According to prepared with $MgCl_2$ was the highest. The result of microstructure was examined by SEM, the particles of inky tofu coagulated with GDL and D-gluconic acid calcium were small and uniformity. In overall acceptability of sensory properties, inky tofu coagulated with GDL was the highest in score. In the color of inky tofu, L value and a value were the highest coagulated with GDL, but that coagulated with $CaCl_2$ had the highest b value. In the texture properties of inky tofu, hardness, gumminess and brittleness were the highest coagulated with D-gluconic acid calcium. A positive correlation was observed between the pH of tofu whey and acidity. Sensory properties of roasted nutty flavor, hardness, cohesiveness and springiness were positively correlated with the acceptability.

Effect of various surface treatment methods of highly translucent zirconia on the shear bond strength with resin cement (고투명도 지르코니아의 다양한 표면처리 방법이 레진시멘트와의 전단결합강도에 미치는 영향)

  • Yu-Seong Kim;Jin-Woo Choi;Hee-Kyung Kim
    • The Journal of Korean Academy of Prosthodontics
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    • v.61 no.3
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    • pp.179-188
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    • 2023
  • Purpose. The purpose of this study was to evaluate the effect of surface treatments on the shear bond strength of two types of zirconia (3-TZP and 5Y-PSZ) with resin cement. Materials and methods. Two different types of zirconia specimens with a fully sintered size of 14.0×14.0×2.0 mm3 were prepared, polished with 400, 600, and 800 grit silicon carbide paper, and buried in epoxy resin. They were classified into four groups each control, sandblasting, primer, and sandblasting & primer. Cylindrical resin adhered to the surface-treated zirconia with resin cement. It was stored in distilled water (37℃) for 24 hours, and a shear bond strength test was performed. The normality of the experimental group was confirmed with the Kolmogorov-Smirnov & Shapiro-Wilk test. The interaction and statistical difference were analyzed using a two-way ANOVA. A post-hoc analysis was performed using Dunnett T3. Results. As a result of two-way ANOVA, there was no significant difference in shear bonding strength between zirconia types (P > .05), but there was a significant correlation in the sandblasting, primer, and alumina sandblasting & primer group (P < .05). Dunnett T3 post-test showed that, regardless of the type of zirconia, shear bonding strength was sandblasting & primer > Primer > sandblasting > control group (P < .05). Conclusion. There was no difference in shear bond strength between the types of zirconia. The highest shear bond strength was shown when the mechanical and chemical treatments of the zirconia surface was performed simultaneously.

An Unthinking Sage? Plotinus' Model of Non-Deliberative Action (생각하지 않는 현자(賢者)? 플로티누스의 비-숙고적 행동 모델)

  • Song, Euree
    • Journal of Korean Philosophical Society
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    • no.125
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    • pp.63-89
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    • 2019
  • The aim of this paper is to examine the so-called theory of automatic action attributed to Plotinus, according to which the sage can act automatically without deliberation or reasoning. Concerns were raised that such a theory runs the risk of turning the agent into an automaton by reducing action to mechanical reflexes to external stimuli. I attempt to show that Plotinus does not hold a theory of automatic action by arguing that the Plotinian sage's non-deliberative action is not automatic at all. For this purpose, I first draw attention to the non-deliberative action of the World-Reason (i.e. the reason of the World-Soul), which is supposed to present an ideal model of action. Indeed, Plotinus mentions that the World-Reason rules the world "as if automatically". This is, however, meant to indicate the spontaneous and natural manner in which the World-Reason rules. In this respect, the way the World-Reason works is compared to the way nature (i.e. the productive power of the World-Soul) works. But Plotinus points out that the World-Reason knows what to do, whereas nature works without knowing. In this connection, Plotinus makes it clear that the World-Reason does not calculate or deliberate about what to do because it already knows it. To clarify this point, I turn to Plotinus' analogy of practical wisdom (phronêsis) and skill, according to which the World-Reason is compared to an accomplished craftsman or artist, who confidently works without any doubt, hesitation or difficulty, thereby expressing her intelligence, unmediated by deliberation. From this perspective, non-deliberative action according to practical wisdom turns out to be superior to deliberative action. Plotinus admits that there are difficult circumstances in which even the skilled craftsman, unlike the World-Reason who always controls the whole situation, needs to deliberate or calculate, but he is nevertheless confident that the craftsman easily finds the solution. This suggests that the sage, who possesses practical wisdom, can act normally like a great master or virtuoso without deliberation, but in an emergency situation he also employs deliberation, but resourcefully and creatively responds to challenge. The attempt is made to elucidate the Plotinian model of sage's action with the help of Csikzentmihalyi's concept of 'flow' and Annas' application of it to the analogy of virtue and skill. Finally, it is shown that the sage's virtuous action, in spite of being a habituated action, is not a passive, routinized, automatic action, but an active, flexible, intelligent action.

Development of Elite Lines with Improved Eating Quality Using RIL Population Derived from the Korean Weedy Rice, Wandoaengmi6 (국내 잡초벼(완도앵미6) 유래 RILs 집단의 식미 관련 특성분석 및 우량계통 선발)

  • Kim, Suk-Man;Park, Seul-Gi;Park, Hyun-Su;Baek, Man-Kee;Jeong, Jong-Min;Cho, Young-Chan;Suh, Jung-Pil;Lee, Keon-Mi;Lee, Chang-Min;Kim, Choon-Song
    • Journal of the Korean Society of International Agriculture
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    • v.31 no.4
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    • pp.428-436
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    • 2019
  • As the main objective of rice breeding programs, rice eating quality is one of critical factors directly determining the market price and the consumer preference. However, the genetic complexity of eating quality and the difficulty in accurate evaluation often constrain improvement of the eating quality in rice breeding programs. In addition, given that the rice eating quality of current cultivars has already reached some high-level, diversifying of genetic resources are demanded more than ever to improve the rice eating quality. In this study, we developed a recombinant inbred lines (RILs) population derive from Wandoaengmi6, a japonica-type Korean weedy rice with high eating quality and a high degree of glossiness of cooked rice. Year-to-year correlations between the traits in three years were shown normal distribution for major agronomic traits and physicochemical characteristics. After evaluating tested traits related to eating quality procedure, a total of ten lines were ultimately selected from the population. Increasement of the taste of cooked rice (TA) and the overall eating quality (OE) were confirmed in the selected lines, which are caused by alleles derived from Wandoaengmi6 without any linkage drag. These results indicate that the utility of wide genomic resources in Korean landrace could be of application in various rice breeding programs and countermeasure to contribute to properly response to climate change.

Development and Utilization of Evaluation Methods for Offshore Wind Farm Landscape Quality Assessment (해상풍력발전단지 경관의 질 평가를 위한 평가기법의 개발 및 활용방안)

  • Jin-Oh Kim;Byoungwook Min;Kyung-Sook Woo;Jin-Pyo Kim
    • Journal of Environmental Impact Assessment
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    • v.32 no.6
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    • pp.577-589
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    • 2023
  • In Korea, the technical techniques for assessing visual impacts are standardized, but the methods for assessing the marine landscape itself are not standardized and need to be improved. In particular, in the landscape impact assessment of offshore wind power generation in Korea, it is necessary to recognize the landscape itself as a receptor and prepare a system that can evaluate the characteristics and sensitivity of the landscape. In this study, we propose an evaluation method for preparing a marine landscape quality assessment document that reflects the project characteristics of offshore wind power projects, and examine the possibility of utilization by applying it to actual project sites as an example. To evaluate the quality of marine scenery in offshore wind power projects, evaluation items of landscape characteristics, physical characteristics, and socio-cultural characteristics were evaluated based on the preliminary survey contents, and the quality of marine scenery was divided into five grades. Next, the evaluation criteria of the evaluation items were synthesized and the quality of the marine landscape was classified into preservation grade (grade 5), semi-preservation grade (grade 4), buffer grade (grade 3), semi-improvement grade (grade 2), and improvement grade (grade 1). In addition, the Sinan-Ui Offshore Wind Farm, an actual project site, was randomly selected to conduct the evaluation process and examine its utilization. This study aims to complement the existing method of visual impact assessment in offshore wind power projects and evaluate the quality of the marine landscape itself to effectively conserve marine landscape resources during offshore wind power projects. Rather than relying on mechanical and quantitative evaluation, this study is expected to be used as a basis for comprehensive understanding of the location and socio-cultural characteristics of the project site and for communication and cooperation with stakeholders.

The Evaluation of the Packaging Properties and Recyclability with Modified Acrylic Emulsion for Flexible Food Paper Coating (유연 종이 식품 포장재의 개질 아크릴 에멀젼 코팅 특성 및 재활용성 평가)

  • Myungho Lee;In Seok Cho;Dong Cheol Lee;Youn Suk Lee
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.29 no.3
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    • pp.153-161
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    • 2023
  • The worldwide effects of COVID-19 have led to a surge in online shopping and contactless services. The consumption pattern has caused the issues such as the environmental pollution together with the increase of plastic waste. Reducing the reliance on the petroleum based plastic use for the package and replacing it with environmentally friendly material are the simple ways in order to solve those problems. Paper is an eco-friendly product with high recyclability as the food packaging materials but has still poor barrier properties. A barrier coating on surface of the paper can be achieved with the proper packaging materials featuring water, gas and grease barrier. Polyethylene (PE) or polypropylene (PP) coatings which are generally laminated or coated to paper are widely used in food packaging applications to protect products from moisture and provide water or grease resistance. However, recycling of packaging containing PE or PP matrix is limited and costly because those films are difficult to degrade in the environment. This study investigated the recyclability of modified acrylic emulsion coating papers compared to PE and PP polymer matrixes as well as their mechanical and gas barrier properties. The results showed that PE or modified acrylic emulsion coated papers had better mechanical properties compared to the uncoated paper as a control. PE or PP coating papers showed strong oil resistance property, achieving a kit rating of 12. Those papers also had a significantly higher percentage of screen reject during the recycling process than modified acrylic coated paper which had a screen rejection rate of 6.25%. In addition an uncoated paper had similar value of a screen rejection rate. It may suggest that modified acrylic emulsion coating paper can be more easily recycled than PE or PP coating papers. The overall results of the study found that modified acrylic emulsion coating paper would be a viable alternative to suggest a possible solution to an environmental problem as well as enhancing the weak mechanical and poor gas barrier properties of the paper against moisture.