Long-term results of both fixed and mobile-bearing total knee arthroplasties were encouraging in patients who were younger than fifty-one years of age with osteoarthritis. However, we found no superiority of the mobile-bearing total knee prosthesis over the fixed-bearing total knee prosthesis.

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Hanji paper, the paper material traditionally used in Korea, is in the focus of the present aging and mechanistic study. As raw materials and historic recipes for paper making are still available for Hanji today, specimen resembling historical material at the point of production can be prepared. While from that starting point, historical material had taken the path of natural aging, newly prepared samples-prepared according to both historic and current recipes-were artificially aged, and both aging modes can be compared. For the first time, an in-depth chemical and mathematical analysis of the aging processes for Hanji is presented. The aging of Hanji paper, resulting in hydrolysis and oxidation processes, was addressed by means of selective fluorescene labeling of oxidized groups in combination with gel permeation chromatography, providing profiles of carbonyl and carboxyl groups relative to the molar mass distribution. Starting Hanji showed the highest molecular weight ([1,400 kDa) ever reported for paper. We have defined two critical parameters for comparison of the paper samples: half-life DP (the time until every chain is split once on average) and life expectancy (the time until an average DP of failure is reached and no further mechanical stress can be tolerated). The two values were determined to be approximately 500 and 4,000 years, respectively, for the Hanji samples, provided there is no UV radiation. The rate of cellulose chain scission under accelerated aging (80°C, RH 65 %), was about 600 times faster than under natural conditions. In addition, cellulose degradation of Hanji paper under accelerated aging condition was about 2-3 times slower than that of historical rag paper as those used in medieval Europe.

The effects of plasma damages on the organic gate dielectric of the organic thin film transistor (OTFT) during the fabrication process are investigated; metal deposition process on the organic gate insulator by the plasma sputtering mainly generates the process induced damage of bottom contact structured OTFT. For this study, two different deposition methods (thermal evaporation and plasma sputtering) have been tested for their damage effects onto poly(4-vinyl phenol) (PVP) as organic gate dielectric. Unlike thermal evaporation, conventional plasma sputtering process induces serious damages onto the organic layer as increasing the surface energy, changing the surface morphology and degrading OTFT performances.

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Study DesignA retrospective review was carried out on 23 patients with rigid fixed kyphosis who underwent surgical correction for their deformity.PurposeTo report the results of surgical correction of fixed kyphosis according to the surgical approaches or methods.Overview of LiteratureSurgical correction of fixed kyphosis is more dangerous than the correction of any other spinal deformity because of the high incidence of paraplegia.MethodsThere were 12 cases of acute angular kyphosis (6 congenital, 6 healed tuberculosis) and 11 cases of round kyphosis (10 ankylosing spondylitis, 1 Scheuermann's kyphosis). Patients were excluded if their kyphosis was due to active tuberculosis, fractures, or degenerative lumbar changes. Operative procedures consisted of anterior, posterior and combined approaches with or without total vertebrectomy. Anterior procedure only was performed in 2 cases, while posterior procedure only was performed in 8 cases. Combined procedures were used in 13 cases, including 4 total vertebrectomies.ResultsThe average kyphotic angle was 71.8° preoperatively, 31.0° postoperatively, and the average final angle was 39.2°. Thus, the correction rate was 57% and the correction loss rate was 12%. In acute angular kyphosis, correction rate of an anterior procedure only was 71%, correction rate of the combined procedures without total vertebrectomy was 49% and correction rate of the combined procedures with total vertebrectomy was 60%. In round kyphosis, correction rate of posterior procedure only was 65% and correction rate of combined procedures was 59%. The clinical results according to the Kirkaldy-Willis scale demonstrated 17 excellent outcomes, 5 good outcomes and one poor outcome.ConclusionsOur data indicates that the combined approach and especially the total vertebrectomy showed the safety and the greatest correction rate if acute angular kyphosis was greater than 60 degrees.

For efficient aerodynamic design optimization, a discrete adjoint code is developed from an unstructured hybrid mesh Navier-Stokes solver. The adjoint code is verified by comparison of flux Jacobian and objective function gradient with a finite difference method. An aerodynamic design tool is developed utilizing the flow solver, adjoint code and a gradientbased optimizer and applied to a design example of a high-lift device. Use of prism layer grid sensitivities is suggested for more efficient gradient calculation from the adjoint analysis of Navier-Stokes equations with unstructured hybrid mesh.