Korea’s technical assistance for better governance

노트 : - Paper for International Conference on U.S.-Korea Dialogue on Strategies for Effective Development Cooperation - Organized by Asia Foundation October 17-18, 2011 Seoul, Korea 행사명 : International Conference on U.S.-Korea Dialogue on Strategies for Effective Development Cooperatio

Cosimulation of MBD (Multi Body Dynamics) and DEM of many spheres using GPU technology

In this paper, dynamic simulation model which have many sphere particles and MBD (Multi Body Dynamics) entities, i.e. bodies, joints, forces, is built and simulated. Many sphere particles are solved with DEM (Discrete Element Method) and simulated with GPU technology. Fast algorithm is applied to calculate hertzian contact forces between many sphere particles (from 100,000 to 1,000,000) and NVIDIA’s CUDA is used to accelerate the calculation. Explicit integration method is applied to solve the many spheres. MBD (Multi Body Dynamics) entities are simulated with recursive formulation. Constraints are reduced by recursive formulation and implicit generalized alpha method is applied to solve dynamic model. Many sphere particles and MBD (Multi Body Dynamics) entities are co-simulated within commercial software RecurDyn. The interaction forces between many sphere particles and rigid body mesh are calculated and applied to each body to simulate two parts simultaneously. These models are built and simulated; fork lifter with sand model, oil in oil tank model, oil filled engine system and water filled washing machine model. All models are simulated with NVIDIA’s GPU and the result is shown

Redak slučaj metastatskog spermatocitnog tumora kod psa bez sarkomatoznih i anaplastičnih promena

Spermatocytic tumor is a rare testicular tumor, which is originated from gonocytes. It is characterized by the histological feature of tripartite which is composed of large, medium, and lymphocyte-like small cells. It is well-known that spematocytic tumor is benign, thus a good prognosis is expected after simple resection. Metastatic spermatocytic tumor is extremely rare and usually accompanied by histological variants including sarcomatous changes and anaplastic variants. In this case, however, we report a canine metastatic spermatocytic tumor without prominent sarcomatous changes and anaplastic variants. The mass was composed of three kinds of cells including large, medium, and small cells with high pleomorphism. The neoplastic cells had an indistinct cytoplasmic border and mitotic figures were frequently observed. The primary spermatocytic tumor metastasized to the abdominal organs one month after the resection, and the dog died 13 months after the surgery. Thus, careful follow-up is recommended after surgical resection of canine spermatocytic tumor even though metastasis in spermatocytic tumors is rare.Spermatocitni tumor je redak tumor testisa, koji potiče od gonocita. Karakteriše ga histološki nalaz tri morfološka tipa ćelija, a sastoji se od velikih, srednjih i limfocitima sličnih malih ć elija. Dobro je poznato da je spermatocitni tumor benignog ponašanja pa se očekuje dobra prognoza nakon jednostavne resekcije. Metastatski spermatocitni tumor izuzetno je redak i obično je prać en histološkim varijacijama, uključujuć i sarkomatozne i anaplastične promene. U ovom slučaju, međutim, opisan je metastatski spermatocitni tumor bez izraženih sarkomatoznih promena i anaplastičnih varijanti. Masa se sastojala od tri vrste ć elija, uključujuć i velike, srednje i male ć elije sa visokim pleomorfi zmom. Neoplastične ć elije su imale nejasnu citoplazmatsku granicu i često su primeć ene mitotičke fi gure. Primarni spermatocitni tumor metastazirao je na trbušne organe mesec dana nakon resekcije, a pas je uginuo 13 meseci nakon operacije. Stoga se preporučuje pažljivo prać enje nakon hirurške resekcije spermatocitnog tumora mada su metastaze u spermatocitnim tumorima retke

Modulation of Skin Collagen Metabolism in Aged and Photoaged Human Skin In Vivo

To the best of our knowledge, no study has been conducted to date to directly compare the collagen metabolism of photoaged and naturally aged human skin. In this study, we compared collagen synthesis, matrix metalloproteinase-1 levels, and gelatinase activity of sun-exposed and sun-protected skin of both young and old subjects. Using northern blot analysis, immunohistochemical stain, and Western blot analysis, we demonstrated that the levels of procollagen type I mRNA and protein in photoaged and naturally aged human skin in vivo are significantly lower than those of young skin. Furthermore, we demonstrated, by northern blot analysis, that the procollagen α1(I) mRNA expression of photoaged skin is much greater than that of sun-protected skin in the same individual. In situ hybridization and immunohistochemical stain were used to show that the expression of type I procollagen mRNA and protein in the fibroblasts of photoaged skin is greater than for naturally aged skin. In addition, it was found, by Western blot analysis using protein extracted from the dermal tissues, that the level of procollagen type I protein in photoaged skin is lower than that of naturally aged skin. The level of matrix metalloproteinase-1 protein and the activity of matrix metalloproteinase-2 were higher in the dermis of photoaged skin than in naturally aged skin. Our results suggest that the natural aging process decreases collagen synthesis and increases the expression of matrix metalloproteinases, whereas photoaging results in an increase of collagen synthesis and greater matrix metalloproteinase expression in human skin in vivo. Thus, the balance between collagen synthesis and degradation leading to collagen deficiency is different in photoaged and naturally aged skin

External Ventricular Drainage before Endovascular Treatment in Patients with Aneurysmal Subarachnoid Hemorrhage in Acute Period: Its Relation to Hemorrhagic Complications

Purpose The purpose of this study was to report the authors’ experience with external ventricular drainage (EVD) before endovascular treatment (EVT) in patients with acute aneurysmal subarachnoid hemorrhage (aSAH) and to investigate its relation to hemorrhagic complications.Materials and Methods Between March 2010 and December 2017, a total of 122 patients were recruited who had an aSAH, underwent EVT to secure the ruptured aneurysm, and had EVD performed within 72 hours of rupture. The pre-embo EVD group (n=67) comprised patients who underwent EVD before EVT, and the post-embo EVD group (n=55) comprised those who underwent EVD after EVT. Results Overall, EVD-related hemorrhage occurred in 18 patients (14.8%): six (8.9%) in the pre-embo EVD group and 12 (21.8%) in the post-embo EVD group (P=0.065). No rebleeding occurred between EVD and EVT in the pre-embo EVD group. Clinical outcomes at discharge did not differ significantly between groups (P=0.384). At discharge, the final modified Rankin Scale score in patients who experienced pre-embo rebleeding was better in the pre-embo EVD group than in the post-embo EVD group (P=0.041). Current use of an antiplatelet agent or anticoagulant on admission (odds ratio [OR], 2.928; 95% confidence interval [CI], 1.234–7.439; P=0.042) and stent use (OR, 2.430; 95% CI, 1.524–7.613; P=0.047) remained independent risk factors for EVD-related hemorrhagic complications. Conclusion EVD before EVT in patients with aSAH in acute period did not increase the rate of rebleeding as well as EVD-related hemorrhagic complications. Thus, performing EVD before EVT may be beneficial by normalizing increased intracranial pressure. Especially in patients with rebleeding before the ruptured aneurysm is secured, pre-embo EVD may improve clinical outcomes at discharge

Estrogen receptor-α gene haplotype is associated with primary knee osteoarthritis in Korean population

Estrogen and estrogen receptors (ERs) are known to play important roles in the pathophysiology of osteoarthritis (OA). To investigate ER-α gene polymorphisms for its associations with primary knee OA, we conducted a case–control association study in patients with primary knee OA (n = 151) and healthy individuals (n = 397) in the Korean population. Haplotyping analysis was used to determine the relationship between three polymorphisms in the ER-α gene (intron 1 T/C, intron 1 A/G and exon 8 G/A) and primary knee OA. Genotypes of the ER-α gene polymorphism were determined by PCR followed by restriction enzyme digestion (PvuII for intron 1 T/C, XbaI for intron 1 A/G, and BtgI for exon 8 G/A polymorphism). There was no significant difference between primary knee OA patients and healthy control individuals in the distribution of any of the genotypes evaluated. However, we found that the allele frequency for the exon 8 G/A BtgI polymorphism (codon 594) was significantly different between primary knee OA patients and control individuals (odds ratio = 1.38, 95% confidence interval = 1.01–1.88; P = 0.044). In haplotype frequency estimation analysis, there was a significant difference between primary knee OA patients and control individuals (degrees of freedom = 7, χ(2 )= 21.48; P = 0.003). Although the number OA patients studied is small, the present study shows that ER-α gene haplotype may be associated with primary knee OA, and genetic variations in the ER-α gene may be involved in OA

Development of tricuspid regurgitation late after left-sided valve surgery: a single-center experience with long-term echocardiographic examinations

OBJECTIVES: This study sought to investigate the incidence and identify the predictors of significant tricuspid regurgitation (TR) development long after left-sided valve surgery. METHODS: Of 615 patients who underwent surgery for left-sided valve disease between 1992 and 1995, 335 patients without significant TR who completed at least 5 years of clinical and echocardiographic follow-up were enrolled. Late significant TR development was assessed by echocardiography with a mean follow-up duration of 11.6 +/- 2.1 years. RESULTS: Significant late TR was found in 90 patients (26.9%). Patients with late TR showed an advanced age (47.6 +/- 13.4 vs 44.3 +/- 13.2 years, P = .04), a higher prevalence of preoperative atrial fibrillation (83.3 vs 46.5%, P < .001), a greater left atrial dimension (56.9 +/- 13.2 vs 52.4 +/- 11.5 mm, P = .006), and a higher prevalence of prior valve surgery (40.0 vs 25.3%, P = .01). In addition, late TR occurred more frequently in patients who had undergone mitral valve surgery than in those who did not (93.3 vs 72.2%, P < .001). However, multivariate analysis showed that the presence of preoperative atrial fibrillation (odds ratio 5.37; 95% CI 2.71-10.65; P < .001) was the only independent factor of late TR development. Patients who developed late TR had a lower event-free survival rate than those who did not (P = .03). CONCLUSIONS: The development of significant TR long after left-sided valve surgery is not uncommon with an estimated incidence of 27% and is closely associated with a poor prognosis. The presence of preoperative atrial fibrillation was identified as the only independent predictor of the development of late TR