Skeletal structure of asymmetric mandibular prognathism and retrognathism

Tong Xi,Shankeeth Vinayahalingam,Stefaan Bergé,Thomas Maal,Tae-Geon Kwon 대한악안면성형재건외과학회 2023 Maxillofacial Plastic Reconstructive Surgery Vol.45 No.-

Background This study aimed to compare the skeletal structures between mandibular prognathism and retrognathism among patients with facial asymmetry. Results Patients who had mandibular asymmetry with retrognathism (Group A) in The Netherlands were compared with those with deviated mandibular prognathism (Group B) in Korea. All the data were obtained from 3D-reformatted cone-beam computed tomography images from each institute. The right and left condylar heads were located more posteriorly, inferiorly, and medially in Group B than in Group A. The deviated side of Group A and the contralateral side of Group B showed similar condylar width and height, ramus-proper height, and ramus height. Interestingly, there were no inter-group differences in the ramus-proper heights. Asymmetric mandibular body length was the most significantly correlated with chin asymmetry in retrognathic asymmetry patients whereas asymmetric elongation of condylar process was the most important factor for chin asymmetry in deviated mandibular prognathism. Conclusion Considering the 3D positional difference of gonion and large individual variations of frontal ramal inclination, significant structural deformation in deviated mandibular prognathism need to be considered in asymmetric prognathism patients. Therefore, Individually planned surgical procedures that also correct the malpositioning of the mandibular ramus are recommended especially in patients with asymmetric prognathism.

The Feast of “Culture”

Yu Tong Xi,Yukun Lee 한국콘텐츠학회 2013 ICCC International Digital Design Invitation Exhib Vol.2013 No.-

Trajectory control of tunnel boring machine based on adaptive rectification trajectory planning and multi-cylinders coordinated control

Tong Liu,Guo-fang Gong,Hua-yong Yang,Yu-xi Chen,Yi Zhu 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.10

Trajectory control of tunnel boring machine (TBM) has important implications for excavation efficiency and tunnel quality. A novel rectification trajectory planning method is proposed for TBM with adaptively designed direction and curvature against different attitude deviations and target path, and is comparatively studied with traditional method via numerical simulations. TBM could be fully-actuated by decoupling thrust and torque cylinders in horizontal and vertical planes, respectively. After the tropology analysis of the 4-SPS/PS structure, the real-time expected motions of torque cylinders in vertical plane are derived via reverse kinematics together with synchronous thrust cylinders; so does cylinders in horizontal plane. The proportional direction valves of torque and gripper cylinders are compensated with fixed pressure drop. A compound displacement tracking controller could be established, including flow-speed feed-forward with dead-band compensation and displacement feedback by fuzzy proportional–integral (PI) controller with separated integration. Synchronous controller of integral separated PI structure is also proposed. Experiment results on a Φ 2.5 m scaled TBM indicate that, the displacement tracking performance of cylinders under the compound controller against unbalanced load, which is ± 0.9 mm for high-speed thrust cylinders and ± 0.13 mm for low-speed gripper and torque cylinders, could meet the tolerance of trajectory planning and realize accurate attitude correction.

The Effects of HVOF Coating of WC-CrC-Ni Powder on In718 and of CO2 Laser Heat Treatment on the Coating

Tong-Yul Cho,Jae-Hong Yoon,Yun-Kon Joo,Shihong-Zhang,Wei Fang,권식철,천희곤,Ming-Xi Li 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.3

High-velocity oxygen-fuel (HVOF) thermal-spray coating (coating) of micron-sized WC-CrC-Ni was carried out on an Inconel718 (In718) surface to improve the surface properties, friction and wear behaviors. During the spraying, binder metals were melted and a small portion of metal carbides, such as WC, Cr7C3 and Ni3C, were melted, partially melted, or decomposed to W2C, Cr, Ni and free carbon. A porous coating was formed by the evolution of carbon oxide gases formed by the reaction of the free carbon and the sprayed oxygen gas. For further improvement, a CO2 laser heat treatment (LH) was performed on the coating. Laser beam (10.6 μm, continuous mode, 400 W) irradiated an oval-shaped focal spot (5 mm × 4 mm) for 0.6 s at a scanning speed 400 mm/min, heating to about 950 - 1200℃ from the edge to the center of the spot. Laser tracks overlap each other 30 %. The porous coating was compacted by the LH, reducing the coating thickness by about 29 % from 280 μm to 200μm and the porosity by about 7 times from 2.6 ± 0.4 % to 0.35±0.06 %. The surface hardness of In718 (410±30 Hv) was increased more than twice to 983±101 Hv by the coating; furthermore, it was increased 45 % (1425±94 Hv) by LH for 0.6 s. The friction coefficient of the In718 surface (0.45±0.08) was reduced 29 % (0.32±0.02) and 9 % (0.29±0.03) by the coating and by the LH, respectively. The wear depth was reduced from 52μm to 30μm and to 12μm by the coating and by the LH, respectively. A HVOF coating of WC-CrC-Ni powder on a metal surface and a LH of the coating are highly recommended for improving the surface properties, the friction behavior and wear resistance.

Laser Heat Treatment of HVOF WC-CrC-Ni Coating

Tong Yul Cho,Jae Hong Yoon,Yun Kon Joo,Wei Fang,Shi Hong Zhang,Hui Gon Chun,Sung Sik Ha,Soon Yong Hwang,Ming-Xi LI 한국표면공학회 2008 한국표면공학회 학술발표회 초록집 Vol.2008 No.-

Mutational Analysis of Key EGFR Pathway Genes in Chinese Breast Cancer Patients

Tong, Lin,Yang, Xue-Xi,Liu, Min-Feng,Yao, Guang-Yu,Dong, Jian-Yu,Ye, Chang-Sheng,Li, Ming Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

Background: The epidermal growth factor receptor (EGFR) is a potential therapeutic target for breast cancer treatment; however, its use does not lead to a marked clinical response. Studies of non-small cell lung cancer and colorectal cancer showed that mutations of genes in the PIK3CA/AKT and RAS/RAF/MEK pathways, two major signalling cascades downstream of EGFR, might predict resistance to EGFR-targeted agents. Therefore, we examined the frequencies of mutations in these key EGFR pathway genes in Chinese breast cancer patients. Methods: We used a high-throughput mass-spectrometric based cancer gene mutation profiling platform to detect 22 mutations of the PIK3CA, AKT1, BRAF, EGFR, HRAS, and KRAS genes in 120 Chinese women with breast cancer. Results: Thirteen mutations were detected in 12 (10%) of the samples, all of which were invasive ductal carcinomas (two stage I, six stage II, three stage III, and one stage IV). These included one mutation (0.83%) in the EGFR gene (rs121913445-rs121913432), three (2.50%) in the KRAS gene (rs121913530, rs112445441), and nine (7.50%) in the PIK3CA gene (rs121913273, rs104886003, and rs121913279). No mutations were found in the AKT1, BRAF, and HRAS genes. Six (27.27%) of the 22 genotyping assays called mutations in at least one sample and three (50%) of the six assays queried were found to be mutated more than once. Conclusions: Mutations in the EGFR pathway occurred in a small fraction of Chinese breast cancers. However, therapeutics targeting these potential predictive markers should be investigated in depth, especially in Oriental populations.

Determining the Optimal Dose Prescription for the Planning Target Volume with Stereotactic Body Radiotherapy for Non-Small Cell Lung Cancer Patients

Liu, Xi-Jun,Lin, Xiu-Tong,Yin, Yong,Chen, Jin-Hu,Xing, Li-Gang,Yu, Jin-Ming Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.5

Objective: The aim of this study was to determine a method of dose prescription that minimizes normal tissue irradiation outside the planning target volume (PTV) during stereotactic body radiotherapy (SBRT) for patients with non-small cell lung cancer. Methods: Previous research and patients with typical T1 lung tumors with peripheral lesions in the lung were selected for analysis. A PTV and several organs at risk (OARs) were constructed for the dose calculated; six treatment plans employing intensity modulated radiotherapy (IMRT) were produced, in which the dose was prescribed to encompass the PTV, with the prescription isodose level (PIL) set at 50, 60, 70, 80, 90 or 95% of the isocenter dose. Additionally, four OARs around the PTV were constructed to evaluate the dose received in adjacent tissues. Results: The use of higher PILs for SBRT resulted in improved sparing of OARs, with the exception of the volume of lung treated with a lower dose. Conclusions: The use of lower PILs is likely to create significant inhomogeneity of the dose delivered to the target, which may be beneficial for the control of tumors with poor conformity indices.

NUMERICAL STUDY ON THE VORTEX STRUCTURES OF AN OSCILLATING CIRCULAR CYLINDER IN UNIFORM FLOWS

Bing Gang Tong,Xie Yuan Yin,Xi Yun Lu 대한기계학회 1992 International Conference on Fluid Machinery Vol.1 No.1

AEROSOL SIZE DISTRIBUTION AND ELEMENTAL COMPOSITION IN URBAN AREAS OF NORTHERN CHINA

ZHONG, LIANG-XI,CHUNG,YONG-SEUNG,NING,DA-TONG 한국교원대학교 환경과학연구소 1996 환경연구논문집 Vol.- No.3

Based on monitoring data collected in the northern cities of China since 1980, the particle size spectra, distribution modes and the elements distribution features are dicussed in this article. It is found that the major aerial contaminant in urban aerosol of northern China is fine dust. It makes up about 70% of the total suspended particulate matter by mass concentration. The spectra of aerosol particles in the range 0.5-15.0㎛ are all unimodal structures. Regardless of narrow or broad profiles, their peak values fall between 0.5 and 1.0㎛, while their surface area spectra present a trimodal structure. The three peaks are in the range 0.5-1.8, 2-8 and 10.20 ㎛, respectively. Of these peaks the surface area concentration of particulates had made a large contribution to the first and the second peaks. The shape of mass distribution also presents a trimodal structure, and the positions of the three peaks are the same as those found in the surface area pattern. Mineral elements mainly exist in large size particles. The anthropogenic pollution elements, however, are contained in corpuscles (<2.0㎛). Compared to the situation in winter, some element concentrations of particulates in summer are found to have generally decreased. Copyright ⓒ 1996 Elsevier Science Ltd.

Role of Centromere Protein H and Ki67 in Relapse-free Survival of Patients after Primary Surgery for Hypopharyngeal Cancer

Wang, Jun-Xi,Zhang, Ying-Yao,Yu, Xue-Min,Jin, Tong,Pan, Xin-Liang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Purpose: Centromere protein H (CENP-H) and Ki67 are overexpressed in some malignancies, but whether they are predictors of survival after primary resection for hypopharyngeal squamous cell carcinoma (HSCC) remains unknown. Methods: We assessed immunohistochemical expression of CENP-H and Ki67 in 112 HSCC specimens collected between March 2003 and March 2005 for analysis by clinical characteristics. The Kaplan-Meier method was used to analyze relapse-free survival and logistic multivariate regression to determine risk factors of relapse-free survival. Cholecystokinin octapeptide assays and flow cytometry were used to examine cell proliferation and apoptosis after siRNA inhibition of CENP-H in HSCC cells. Results: Overall, 50 (44.6%) HSCC specimens showed upregulated CENP-H expression and 69 (61.6%) upregulated Ki67. An increased CENP-H protein level was associated with advanced cancer stage and alcohol history (P=0.012 and P=0.048, respectively) but an increased Ki67 protein level only with advanced cancer stage (P=0.021). Increased CENP-H or Ki67 were associated with short relapse-free survival (P<0.001 or P=0.009, respectively) and were independent predictors of relapse-free survival (P=0.001 and P=0.018, respectively). siRNA knockdown of CENP-H mRNA inhibited cell proliferation and promoted cancer cell apoptosis in vitro. Conclusions: Upregulated CENP-H and Ki67 levels are significantly associated with short relapse-free survival in HSCC. These factors may be predictors of a relapsing phenotype in HSSC cases.