• Journal of applied mathematics & informatics
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• v.41 no.2
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• pp.287-293
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• 2023

In this paper, the Augmented graph Es(τ) of the inverse graph Gs(τ) of a cyclic group (τ,◦) was studied. The Augmented inverse graph was constructed by applying the method of Mycielski's construction. The dimension of Augmented inverse graph and different properties of the graph were investigated. Later the chromatic number of Augmented inverse graph was discussed and the relation between the maximum degree of the graph and the chromatic number was established. In the Mycielski's construction, the properties of the key node 'u' in Es (τ) were established based on cardinality of the cyclic group (τ,◦) and also proved that the Augmented inverse graph Es(τ) was a triangle free graph.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.4
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• pp.525-535
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• 2001

In this paper, a new adaptive analysis scheme for element-free Galerkin method(EFGM) is proposed. The novel point of this scheme is that the triangular cell structure based on the Delaunay triangulation is used in the numerical integration and the node adding/removing process. In adaptive analysis with this scheme, there is no need to divide the integration cell and the memory cell structure. For the adaptive analysis of crack propagation, the reconstruction of cell structure by adding and removing the nodes on integration cells based the estimated error should be carried out at every iteration step by the Delaunay triangulation technique. This feature provides more convenient user interface that is closer to the real mesh-free nature of EFGM. The analysis error is obtained basically by calculating the difference between the values of the projected stresses and the original EFG stresses. To evaluate the performance of proposed adaptive procedure, the crack propagation behavior is investigated for several examples.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.3
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• pp.321-328
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• 2000

An improved formulation of thin-wailed curved beams with variable curvatures based on displacement field considering the second order terms of finite semitangential rotations is presented. From linearized virtual work principle by Vlasov's assumptions, the total potential energy is derived and all displacement parameters and the warping functions are defined at cendtroid axis. In developing the thin-walled curved beam element having eight degrees of freedom per a node, the cubic Hermitian polynomials are used as shape functions. In order to verify the accuracy and practical usefulness of this study, free vibrations and buckling analyses of parabolic and elliptic arche shapes with mono-symmetric sections are carried out and compared with the results analyzed by ABAQUS' shell element.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4739-4743
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• 2012

Background: Predictive biomarkers for lung cancer recurrence after curative tumor resection remain unclear. This study set out to assess the role of FoxM1 in the recurrence of non-small cell lung cancer. Methods: Immunohistochemistry for FoxM1 expression was performed on paraffin-embedded tumor tissues from 165 NSCLC patients. Association of FoxM1 expression with clinicopathological parameters and disease free survival were evaluated. Results: Our results indicated FoxM1 expression to be significantly associated with poorer tissue differentiation (P =0.03), higher TNM stage (P <0.01), lymph node metastasis (P <0.01), advanced tumor stage (P <0.01), and poorer disease free survival (P <0.01). Multivariable analysis showed that FoxM1 expression increased the hazard of recurrence (hazard ratio= 1.96, 95% CI, 1.04-3.17, P <0.05), indicating that FoxM1 is an independent and significant predictor of lung cancer recurrence. Conclusion: Therefore, FoxM1 is an independent risk factor for recurrence of NSCLC. Elevated FoxM1 expression could be used as an indicator of poor disease free survival.

• Korean Journal of Head & Neck Oncology
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• v.18 no.2
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• pp.179-183
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• 2002

Objective: A comparison of American Joint Committee on Cancer (AJCC) 1988 and 1997 nasopharyngeal carcinoma (NPC) classifications was made in terms of patient distribution and efficacy in predicting prognosis. Materials and Methods: Between Jan. 1981 and Dec. 1998, 60 cases of node negative nasopharyngeal carcinoma were retrospectively reviewed. The extent of disease each patients restaged according to the 4th and 5th AJCC system and Ho system, respectively. Results: The overall and disease free 5-year survival rates were 61.1% and 62.6%, respectively. Among T classifications of 4th AJCC, 5th AJCC and Ho staging system were not observed significantly different in disease-free survival rates, respectively. Conclusion: We observed a better patient distribution with AJCC 1997 comparing to AJCC 1988. The new classification also attained better statistical significances among stages in the overall survival and disease free survival rates was needed.

• Interaction and multiscale mechanics
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• v.6 no.2
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• pp.237-255
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• 2013

In this paper, a meshfree-enriched finite element method (ME-FEM) is introduced for the large deformation analysis of nonlinear path-dependent problems involving contact. In linear ME-FEM, the element formulation is established by introducing a meshfree convex approximation into the linear triangular element in 2D and linear tetrahedron element in 3D along with an enriched meshfree node. In nonlinear formulation, the area-weighted smoothing scheme for deformation gradient is then developed in conjunction with the meshfree-enriched element interpolation functions to yield a discrete divergence-free property at the integration points, which is essential to enhance the stress calculation in the stage of plastic deformation. A modified variational formulation using the smoothed deformation gradient is developed for path-dependent material analysis. In the industrial metal forming problems, the mortar contact algorithm is implemented in the explicit formulation. Since the meshfree-enriched element shape functions are constructed using the meshfree convex approximation, they pose the desired Kronecker-delta property at the element edge thus requires no special treatments in the enforcement of essential boundary condition as well as the contact conditions. As a result, this approach can be easily incorporated into a conventional displacement-based finite element code. Two elasto-plastic problems are studied and the numerical results indicated that ME-FEM is capable of delivering a volumetric locking-free and pressure oscillation-free solutions for the large deformation problems in metal forming analysis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10231-10236
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• 2015

This study aimed to evaluate the prevalence of preoperative thrombocytosis and its prognostic significance in Thai patients with endometrial cancer. We retrospectively reviewed the medical records of 238 cases who had undergone surgical staging procedures between January 2005 and December 2008. Associations between clinicopathological variables and preoperative platelet counts were analyzed using Pearson's chi square or two-tailed Fisher's exact tests. Survival analysis was performed with Kaplan-Meier estimates. Univariate and Cox-regression models were used to evaluate the prognostic impact of various factors including platelet count in terms of disease-free survival and overall survival. The mean preoperative platelet count was $315,437/{\mu}L$ (SD $100,167/{\mu}L$). Patients who had advanced stage, adnexal involvement, lymph node metastasis, and positive peritoneal cytology had significantly higher mean preoperative platelet counts when compared with those who had not. We found thrombocytosis (platelet count greater than $400,000/{\mu}L$) in 18.1% of our patients with endometrial cancer. These had significant higher rates of advanced stage, cervical involvement, adnexal involvement, positive peritoneal cytology, and lymph node involvement than patients with a normal pretreatment platelet count. The 5-year disease-free survival and overall survival were significantly lower in patients who had thrombocytosis compared with those who had not (67.4% vs. 85.1%, p=0.001 and 86.0% vs. 94.9%, p=0.034, respectively). Thrombocytosis was shown to be a prognostic factor in the univariate but not the multivariate analysis. In conclusion, presence of thrombocytosis is not uncommon in endometrial cancer and may reflect unfavorable prognostic factors but its prognostic impact on survival needs to be clarified in further studies.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1381-1385
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• 2014

Background: The prognostic value of the Ki67 expression level is yet unclear in breast cancer. The aim of this study was to investigate the association between Ki67 expression levels and prognostic factors such as grade, Her2 and hormone receptor expression status in breast cancers. Materials and Methods: Clinical and pathological features of the patients with breast cancer were retreived from the hospital records. Results: In this study, 163 patients with breast cancer were analyzed, with a mean age of $53.4{\pm}12.2$ years. Median Ki67 positivity was 20% and Ki67-high tumors were significantly associated with high grade (p<0.001), lymphovascular invasion (p=0.001), estrogen receptor (ER) negativity (p=0.035), Her2 positivity (p=0.001), advanced stage (p<0.001) and lymph node positivity (p<0.003). Lower Ki67 levels were significantly associated with longer median relapse-free and overall survival compared to those of higher Ki67 levels. Conclusions: High Ki67 expression is associated with ER negativity, Her2 positivity, higher grade and axillary lymph node involvement in breast cancers. The level of Ki67 expression is a prognostic factor predicting relapse-free and overall survival in breast cancer patients.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3187-3190
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• 2012

This study evaluated the relationship between pretreatment hemoglobin (Hb) and prognostic factors in Thai patients with endometrial cancer. Medical records of 228 patients who had undergone surgery between January 2005 and December 2007 were retrospectively reviewed. Associations between clinicopathological variables and pretreatment Hb levels were described using Pearson's chi square test or two-tailed Fisher's exact test. Survival analysis was performed with Kaplan-Meier estimates. Univariate and Cox-regression models were used to evaluate the prognostic impact of various factors, including Hb levels, in term of disease-free survival. The median duration of follow-up was 38.2 months. Eighty-nine patients (39%) had a preoperative Hb level of <12 g/dL, these having significantly higher rates of non-endometrioid histology, advanced FIGO stage, lymphovascular space invasion, cervical involvement, adnexal involvement, positive peritoneal cytology, and lymph node involvement than patients with Hb ${\geq}12$ g/dL. The 5-year disease-free and overall survival were significantly lower in patients with pretreatment Hb levels <12 g/dL compared with those with Hb ${\geq}12$ g/dL (79.3% vs. 89.2%, p=0.044 and 87.6% vs. 99.3%, p<0.001, respectively). In the multivariate analysis only histology, myometrial invasion, and lymphovascular invasion proved to be independent prognostic factors, whereas tumor grading, stage, cervical involvement, adnexal involvement, positive peritoneal cytology, lymph node involvement, and low Hb were not. In conclusion, presence of anemia before treatment may reflect poor prognostic factors in patients with endometrial cancer and low pretreatment hemoglobin level may have a prognostic impact on clinical outcome.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.991-996
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• 2015

Side population (SP) cells have stem cell-like properties with a capacity for self-renewal and are resistant to chemotherapy and radiotherapy. Therefore the presence of SP cells in human breast cancer probably has prognostic value. Objective: To investigate the characteristics of SP cells and identify the relationship between the SP cells levels and clinico-pathological parameters of the breast tumor and disease-free survival (DFS) in breast cancer patients. Materials and Methods: A total of 122 eligible breast cancer patients were consecutively recruited from January 1, 2006 to December 31, 2007 at Yunnan Tumor Hospital. All eligible subjects received conventional treatment and were followed up for seven years. Predictors of recurrence and/or metastasis and DFS were analyzed using Cox regression analysis. Human breast cancer cells were also obtained from fresh human breast cancer tissue and cultured by the nucleic acid dye Hoechst33342 with Verapami. Flow cytometry (FCM) was employed to isolate the cells of SP and non-SP types. Results: In this study, SP cells were identified using flow cytometric analysis with Hoechst 33342 dye efflux. Adjusted for age, tumor size, lymph nodal status, histological grade, the Cox model showed a higher risk of recurrence and/or metastasis positively associated with the SP cell level (1.75, 1.02-2.98), as well as with axillary lymph node metastasis (2.99, 1.76-5.09), pathology invasiveness type (1.7, 1.14-2.55), and tumor volume doubling time (TVDT) (1.54, 1.01-2.36). Conclusions: The SP cell level is independently associated with tumor progression and clinical outcome after controlling for other pathological factors. The axillary lymph node status, TVDT and the status of non-invasive or invasive tumor independently predict the prognosis of breast cancer.