• Title/Summary/Keyword: internal stability

Search Result 1,118, Processing Time 0.025 seconds

Effect of morphology and diameter of implant fixture-abutment connection on mechanical failure of implants (임플랜트 고정체-지대주 연결부의 형태와 직경이 임플랜트의 기계적 실패에 미치는 영향)

  • Yun, Bo-Hyeok;Shin, Hyon-Mo;Yun, Mi-Jung;Huh, Jung-Bo;Jeong, Chang-Mo;Kang, Eun-Sook
    • The Journal of the Korean dental association
    • /
    • v.53 no.9
    • /
    • pp.644-655
    • /
    • 2015
  • Purpose: This study was conducted to evaluate the effect of the fixture abutment connection type and diameter on the screw joint stability in external butt joint for 2nd surgery and internal cone connected type implant system for 1st and 2nd surgery using ultimate fracture strength. Materials and Methods: USII system, SSII system and GSII system of Osstem Implant were used. Each system used the fixture with two different diameters and cement-retained abutments, and tungsten carbide / carbon coated abutment screws were used. Disc shaped stainless steel metal tube was attached using resin-based temporary cement. The experimental group was divided into seven subgroups, including the platform switching shaped specimen that uses a regular abutment in the fixture with a wide diameter in USII system. A static load was increased to the metal tube at 5mm deviated point from the implant central axis until it reached the compression bending strength at a rate of 1mm/min. Then the deformations and patterns of fracture in threaded connection were compared. Results and Conclusion: 1. In the comparison between the Regular diameter, compression bending strength of SSII system was higher than USII system and GSII system. There was no significant difference between USII system and GSII system. 2. In the comparison between wide diameter, compression bending strength was increased in the order of GSII system, USII system, and SSII system. 3. In comparison between the implant diameter, compression bending strength of the wide diameter was greater than the regular diameter in any system(P<0.05). 4. There was no significant difference between the platform switching (III group) and the regular diameter (I group) in USII system. 5. In USII system, fracture of abutment screw and deformation of both fixture and abutment were observed in I, II and III subgroups. 6. Failure pattern of SSII system, which was the fracture of abutment screw and deformation of the abutment and fixture, was observed in both IV and V subgroups. Fracture of some fixtures was observed in subgroup V. 7. Failure pattern of GSII system, which was the fracture of the abutment screw and deformation of the fixture and the abutment, was observed in both VI and VII subgroups. Apart from other subgroups, subgroup VII demonstrated no bending neither the fracture at the top of the fixture. The compressive deformation of internal slope in the fixture was the only thing observed in subgroup VII.

Translation and Validation of the Activities of Daily Living Scale with Iranian Elderly Cancer Patients Treated in an Oncology Unit

  • Khoei, Mahtab Alizadeh;Akbari, Mohammad Esmail;Sharifi, Farshad;Fakhrzadeh, Hossein;Larijani, Bagher
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.5
    • /
    • pp.2731-2737
    • /
    • 2013
  • Background: This study evaluated the validity and reliability of applying the Katz's Activities of Daily Living (ADL) scale in an Iranian sample of elderly oncologic patients following initial cancer treatment. Materials and Methods: The scale was translated with the forward-backward procedure to give an Iranian version. The ADL scale was then applied in a random sample of 400 oncologic patients aged 60 and older following initial cancer treatment. Assessment of the scale stability was twice, with a 14-days (two weeks) interval, to 30 (of the 400) eligible elderly cancer patients in March 2012. To measure treatment effects, the index was run with 150 patients in a three month recall, following oncology processing. Exploratory and confirmatory factor analysis was performed for assessment of construct validity of the Katz's ADL. Reliability was measured with internal consistency (Cronbach's alpha co-efficient), and test/retest (Spearman's r value) of the instrument. Criterion validity was evaluated by comparing the Katz with Physical Function (PF) subscale of SF 36. Known-group validity was approved by comparing of Katz' ADL between quartile groups of PF subscale of SF 36. Results: In our study the ADL demonstrated a high degree of internal homogeneity (Cronbach's alpha 0.923). There was a high correlation between scores of two time measurement of Katz's ADL (p value of two- related- samples test was 0.3). Construct validity showed a correlation coefficient of 0.572 between the ADL and PF scores. In factor analysis, 2 factors were extracted. Evidence for the reliability of the questionnaire was good and known group validity was approved by significant differences of ADL score between quartiles of the PF subscale of SF36. Conclusions: The results suggest that the Iranian version of ADL applied for oncologic older adult patients following initial cancer treatment is a reliable and a valid clinical instrument and comparable to those reported in other studies.

Competitive Models of Organizational Commitment, Work Values and Job Satisfaction of the Middle Management in Hotel Enterprises (호텔기업 중간관리자의 조직몰입-직무가치-직무만족 경합모델)

  • Park, Suk-Jin;Kim, Tae-Heon
    • The Journal of the Korea Contents Association
    • /
    • v.11 no.8
    • /
    • pp.388-398
    • /
    • 2011
  • This study analyzes a correlation between organizational commitment, work values, job satisfaction and loyalty of the middle management in hotel enterprises. In other words, this research aims at drawing up theoretical and working-level implication through establishing the competition model of parameters and independent variables, which have an effect on loyalty of the middle management in hotels. Analysis showed that work values of the middle management play not a key role to mediate between organizational commitment and job satisfaction, and that internal values are higher than external values in route analysis of work values. Meanwhile, it was analyzed that the middle management of hotels make a long-service commitment with great satisfaction on the job. But there was no connection between their job satisfaction and loyalty. Consequently, it was confirmed through the analysis of the competition model that they rather attach significance to internal values and specificity of the hotelier than their satisfaction with work because of economic stability, and the loyalty of the middle management responds sensitively to the organizational commitment variables as a permanent job, sense of belonging, self-esteem.

Interlaboratory Study for Cryptosporidium and Giardia Test Methods in Water (정수장 원생동물 분석방법의 국내 실험실간 교차시험 연구)

  • Chung, Hyenmi;Park, Sangjung;Kim, Daekyun;Park, Sanghee;Kim, Reeho;Lee, Sangho;Cho, Joorae;Lee, Kyeunghee;Park, Jonggeun;Lee, Mokyoung;Byun, Seungheon;Cho, Eunju;Rhim, Yeontaek
    • Journal of Korean Society on Water Environment
    • /
    • v.22 no.2
    • /
    • pp.321-327
    • /
    • 2006
  • This interlaboratory study was designed to evaluate protozoan test methods in water and to predict the major causes of deviation of the methods. Each of four laboratories with previous experience of protozoa analysis in water participated, and met the initial performance criteria of EPA 1623 method provided. The protozoan analysis procedure consists of filtrations, concentration, immunomagnetic separation, dyeing (staining) and counting with observation. We tested three different filtration equipments: capsule filter for 10 L of surface water, and high volume (HV) capsule filter and membrane filter for 100 L of finished water. When the recovery of each step of the procedure was evaluated with EasySeed, the commercial stock of each 100 Cryptosporidium and Giardia, immunomagnetic separation and filtration step were the most crucial steps affecting the stability of the recovery, especially for Cryptosporidium. There was no significant difference of recovery among the filtration methods. Recovery of protozoa from source water were evaluated with spiked EasySeed as matrix tests. The recoveries of Giardia increased significantly in the matrix tests compared those in the deionized water. We also applied red stained mixture stocks of Cryptosporidium and Giardia called ColorSeed as internal standards of water sample tests. The recoveries of both EasySeed and ColorSeed in samples tested were within the range of the criteria, however, the Giardia recoveries using ColorSeed decreased significantly. Further optimization study with ColorSeed will be necessary, considering the convenience of using the internal standard without additional sample analysis. The significant factors of the recovery variation were identified as the differences of laboratories as well as water quality and type of the stock for spiking. The results of this study emphasize the importance of the quality assurance program for protozoan analysis lab in water.

Full validation of high-throughput bioanalytical method for the new drug in plasma by LC-MS/MS and its applicability to toxicokinetic analysis

  • Han, Sang-Beom
    • Proceedings of the Korean Society of Toxicology Conference
    • /
    • 2006.11a
    • /
    • pp.65-74
    • /
    • 2006
  • Modem drug discovery requires rapid pharmacokinetic evaluation of chemically diverse compounds for early candidate selection. This demands the development of analytical methods that offer high-throughput of samples. Naturally, liquid chromatography / tandem mass spectrometry (LC-MS/MS) is choice of the analytical method because of its superior sensitivity and selectivity. As a result of the short analysis time(typically 3-5min) by LC-MS/MS, sample preparation has become the rate- determining step in the whole analytical cycle. Consequently tremendous efforts are being made to speed up and automate this step. In a typical automated 96-well SPE(solid-phase extraction) procedure, plasma samples are transferred to the 96-well SPE plate, internal standard and aqueous buffer solutions are added and then vacuum is applied using the robotic liquid handling system. It takes only 20-90 min to process 96 samples by automated SPE and the analyst is physically occupied for only approximately 10 min. Recently, the ultra-high flow rate liquid chromatography (turbulent-flow chromatography)has sparked a huge interest for rapid and direct quantitation of drugs in plasma. There is no sample preparation except for sample aliquotting, internal standard addition and centrifugation. This type of analysis is achieved by using a small diameter column with a large particle size(30-5O ${\mu}$m) and a high flow rate, typically between 3-5 ml/min. Silica-based monolithic HPLC columns contain a novel chromatographic support in which the traditional particulate packing has been replaced with a single, continuous network (monolith) of pcrous silica. The main advantage of such a network is decreased backpressure due to macropores (2 ${\mu}$m) throughout the network. This allows high flow rates, and hence fast analyses that are unattainable with traditional particulate columns. The reduction of particle diameter in HPLC results in increased column efficiency. use of small particles (<2 urn), however, requires p.essu.es beyond the traditional 6,000 psi of conventional pumping devices. Instrumental development in recent years has resulted in pumping devices capable of handling the requirements of columns packed with small particles. The staggered parallel HPLC system consists of four fully independent binary HPLC pumps, a modified auto sampler, and a series of switching and selector valves all controlled by a single computer program. The system improves sample throughput without sacrificing chromatographic separation or data quality. Sample throughput can be increased nearly four-fold without requiring significant changes in current analytical procedures. The process of Bioanalytical Method Validation is required by the FDA to assess and verify the performance of a chronlatographic method prior to its application in sample analysis. The validation should address the selectivity, linearity, accuracy, precision and stability of the method. This presentation will provide all overview of the work required to accomplish a full validation and show how a chromatographic method is suitable for toxirokinetic sample analysis. A liquid chromatography/tandem mass spectrometry (LC-MS/MS) method developed to quantitate drug levels in dog plasma will be used as an example of tile process.

  • PDF

Distraction osteogenesis in patients with complete cleft lip and palate (완전 구순구개열을 가진 환자에서의 골신장술)

  • Yi, J.K.;Park, C.H.;Na, J.I.;Jeong, J.S.;Koo, H.M.;Eom, M.Y.;Song, M.S.
    • Korean Journal of Cleft Lip And Palate
    • /
    • v.8 no.2
    • /
    • pp.63-70
    • /
    • 2005
  • Patients with cleft lip and palate usually show up maxillary hypoplasia. In these cases, a large amount of maxillary advancement is often needed to correct the severe deformity, but local soft-tissue scars around the maxilla restrict maxillary advancement and increase the relapse rate. Maxillary distraction osteogenesis is an effective method for facial and occlusal improvement in these patients. By gradually lengthening both the bones and the soft tissues, distracted midface can greatly increase postoperative stability and decrease the relapse rate. However, the maxillary extraoral appliances of the early days used were esthetically unappealing as well as difficult for the patient to manage. Recently, more inconspicuous intraoral distraction appliances have been developed and used with success. We acquired favorable result in two patients(bilateral 1 patient and unilateral 1 patient) with severe maxillary hypoplasia secondary to complete cleft lip and palate were treated with midface distraction using internal distractor (Zurich Pediatric Maxillary Distractor, KLS Martin, Tuttlingen, Germany). So, we report our experience with literatures.

  • PDF

Validated HPLC Method for the Pharmacokinetic Study of Atenolol and Chlorthalidone Combination Therapy in Korean Subjects

  • Kang, Hyun-Ah;Kim, Hwan-Ho;Kim, Se-Mi;Yoon, Hwa;Cho, Hea-Young;Oh, Seaung-Youl;Choi, Hoo-Kyun;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
    • /
    • v.36 no.5
    • /
    • pp.331-338
    • /
    • 2006
  • A rapid, selective and sensitive reverse-phase HPLC methods for the determination of atenolol and chlorthalidone in human serum and whole blood were validated, and applied to the pharmacokinetic study of atenolol and chlorthalidone combination therapy. Atenolol and an internal standard, pindolol, were extracted from human serum by liquid-liquid extraction, and analyzed on a $\mu$-Bondapak C18 $10-{\mu}$ column in a mobile phase of methanol-0.01 M potassium dihydrogenphosphate(30:70, v/v, adjusted to pH 3.5) and fluorescence detection(emission: 300 nm, excitation: 224 nm). Chlorthalidone and an internal standard, probenecid, were extracted form human whole blood by liquid-liquid extraction, and analyzed on a Luna C18 $5-{\mu}$ column in a mobile phase of acetonitrile containing 77% 0.01 M sodium acetate and UV detection at 214 nm. These analysis were performed at three different laboratories using the same quality control(QC) samples. The chromatograms showed good resolution, sensitivity, and no interference by human serum and whole blood, respectively. The methods showed linear responses over a concentration range of 10-1,000 ng/mL for atenolol and 0.05-20 ${\mu}g/mL$ for chlorthalidone, with correlation coefficients of greater than 0.999 at all the three laboratories. Intra- and inter-day assay precision and accuracy fulfilled international requirements. Stability studies(freeze-thaw, short-, long-term, extracted sample and stock solution) showed that atenolol and chlorthalidone were stable. The lower limit of quantitation of atenolol and chlorthalidone were 10 ng/mL and 0.05 ${\mu}g/mL$, respectively, which was sensitive enough for pharmacokinetic studies. These methods were applied to the pharmacokinetic study of atenolol and chlorthalidone in human volunteers following a single oral administration of Hyundai $Tenoretic^{\circledR}$ tablet(atenolol 50 mg and chlorthalidone 12.5 mg) at three different laboratories.

Analysis for Case Study of Quality Management System to Solve Corporate Problems (기업의 문제해결을 위한 품질경영시스템 적용사례 분석)

  • Seo, Suwon;Jeong, Jongpil
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.18 no.4
    • /
    • pp.191-203
    • /
    • 2018
  • Identify the effects of ISO quality management system on the durability of the enterprise by applying it to early startups and small - and medium-sized enterprises. In particular, the quality management system of a technology start-up small and medium sized companies is important in applying the management system to the financial, management and quality control services rather than to research and development. The quality management system is applied to the medical equipment manufacturers, mobile phone brokers, foreign Chinese companies, and components manufacturers for diesel engines.Try it. Check the case where the quality management system has been applied to the company concerned and the nonconformities have been improved. In addition, the success of the project was determined by applying the quality control system to maintain the stability and perpetuation of the company through the case of the failed selection. The company explains that recently, it must appoint internal auditors to carry out continuous improvement activities and that those who want the development and continuity of the company must reflect the quality management system.

An Empirical Study on the Strategy and Implications of M&A in Korea IT companies (한국 IT 기업의 M&A 전략과 시사점)

  • Son, Myung-Sub;Seo, Yong-Mo;Hyun, Byung-Hwan
    • Journal of the Korea Convergence Society
    • /
    • v.8 no.3
    • /
    • pp.245-252
    • /
    • 2017
  • The purpose of this study is to analyze the effects of mergers and acquisitions of domestic IT companies on strategic aspects of internal capacity enhancement. Empirical analysis applied to this study analyzed the business performance in the market through the merger of Daum Communications and Kakao Group. After Daum pursued the merger with Kakao, it showed that the platform business of kakao is expanding to the domain of the existing portal site. The merger was completed, and the total value of the stocks went up to the highest level, but soon its value declined. The merger shows that the growth potential of the enterprise is temporarily declining, which seems to be the internal cost of the merger. Even in the case of profitability, the merger did not show positive results. In the case of stability, the expectation due to the merger was reflected and slightly increased. The following two companies were interested in the kakao when they viewed the merger through a chronological analysis. However, after the merger, the interest of the next kakao was similar. This is seen as a result of the expansion of kakao's diverse platform business rather than the following search sites. From the results of this study, it is suggested that domestic IT companies should approach by analyzing the strategic factors that generate synergy when pursuing M & A to strengthen their resources or capabilities.

Precision evaluation of crown prosthesis manufactured by two bur and three bur (2종류의 버와 3종류의 버를 이용해 제작된 크라운 보철물의 정밀도 평가)

  • Kim, Chong-Myeong;Jeon, Jin-Hun;Lee, Jae-jun;Kim, Ji-Hwan;Kim, Woong-Chul
    • Journal of Technologic Dentistry
    • /
    • v.38 no.2
    • /
    • pp.57-62
    • /
    • 2016
  • Purpose: The purpose of this study was to assess precision of crown prostheses that were fabricated by using 2 kinds of bur or 3 kinds of bur. Methods: The crowns were fabricated by using the first molar of the right maxillary in this study. The abutments that were prepared were scanned by using a scanner and designed by using CAD software. Based on the crown design, NC data were created with CAM software. The created NC data were used while fabricating the crown prostheses by using 5-axis milling machine. Scanning was done for the internal and external surface of the completed crown prostheses and 3-dimensional measurement was conducted for precision assessment. Results: The $RMS{\pm}SD$ value for the external surface of the crown prostheses that was fabricated by using two burs and three burs were $28.5{\pm}4.1{\mu}m$ and $19.1{\pm}2.8{\mu}m$, respectively; and the value for two burs were bigger than that for three burs with statistical significance (p<0.001). The $RMS{\pm}SD$ value for the internal surface of the crown prostheses that was fabricated by using two burs and three burs were $14.9{\pm}1.9{\mu}m$ and $13.3{\pm}2.5{\mu}m$, respectively; and the value for two burs were bigger than that for three burs but with no statistical significance. Conclusion: Based on this study, the prostheses that were fabricated by using 3 bur presented better stability compared to those that were fabricated by using 2 bur and statistically significant difference was found only in the external surface.