• Journal of Gastric Cancer
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• v.7 no.2
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• pp.97-101
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• 2007

We report our experience with a case of performing laparoscopy-assisted total gastrectomy along with pancreas-preserving splenectomy for treating early gastric cancer. laparoscopy-assisted total gastrectomy was planned for a 62-year-old male patient with a double early gastric cancer located in the upper and lower third of the stomach. Five trocars were placed and we used a harmonic scalpel to dissect the greater curvature. Enlarged splenic hilar lymph node was encountered and they were proved to be metastasis by frozen section biopsy. We then performed total gastrectomy with pancreas-preserving splenectomy for the purpose of completely dissecting the lymph nodes along the splenic artery and splenic hilum. We created a 4 cm sized longitudinal mini-laparotomy below the xiphoid process to remove the specimen, and anastomosis was done via the Roux-en-Y method. The patient was discharged on the 9th postoperative days after an uneventful recovery. Our experience shows that laparoscopy-assisted total gastrectomy with pancreas-preserving splenectomy is a relatively safe procedure for treating upper third early gastric cancer with metastatic splenic hilar lymph nodes.

• Journal of Gastric Cancer
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• v.8 no.4
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• pp.198-203
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• 2008

Purpose: Multiple early gastric cancer (MEGC) accounts for between 4.5% and 11.7% of all early gastric cancers (EGC). We investigated the treatment of MEGC from the viewpoint of the clinicopathologic features of the disease. Materials and Methods: 2,281 patients with EGC underwent gastric resection at the Department of Surgery, Severance Hospital during the 11 years between January 1994 and December 2004 and we carried out a retrospective analysis of these patients. Results: There were 91 cases of synchronous MEGC (4.0%) according to the diagnostic criteria of Moertel: there were 81 double, 9 triple and 1 quadruple lesions. Of the 102 accessory lesions, 64 (62.7%) were less than 10 mm in diameter and 83 (81.4%) were located in the same region as the main lesion. The most frequent histologic type of main lesion was a well differentiated adenocarcinoma, which was found in 52 cases (57.1%). There were 49 mucosal main lesions and 42 submucosal main lesions. Lymph node metastasis was detected in 6 cases (6.6%): 1 in mucosal lesions and 5 in submucosal main lesions Conclusion: Solitary EGC and MEGC had very similar clinopathological features and a similar prognosis. Therefore, we believe that the general EGC treatment guidelines can be applied for multiple EGC. It is important to evaluate the whole stomach before and during the operation and then after examining the resected specimen.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.205-212
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• 2018

In order to overcome shortcomings of commercial analysis program for solving certain geotechnical problems, finite element method adopting isoparametric quadrilateral element was selected as a tool for analyzing soil behavior and calculating process was programmed. Two examples were considered in order to verify reliability of the developed program. One of the two examples is the case of acting isotropic confining pressure on finite element and the other is the case of acting shear stress on the sides of the finite element. Isoparametric quadrilateral element was considered as the finite element and displacements in the element can be expressed by node displacements and shape functions in the considered element. Calculating process for determining strain which is defined by derivatives using global coordinates was coded using the Jacobian and the natural coordinates. Four point Gauss rule was adopted to convert double integral which defines stiffness of the element into numerical integration. As a result of executing analysis of the finite element under isotropic confining pressure, calculated stress corresponding to four Gauss points and center of the element were equal to the confining pressure. In addition, according to the analyzed results for the element under shear stress, horizontal stresses and vertical stresses were varied with positions in the element and the magnitudes and distribution pattern of the stresses were thought to be rational.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.5
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• pp.719-730
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• 2021

We have demonstrated a sandwich-type ZnO-based piezoelectric energy harvesting nanogenerator, namely ZCZ-NG device, composed of symmetrically stacked layers of ZnO/carbon tape/ZnO structure. Especially, we have adopted a conductive double-sided adhesive carbon tape in an effort to fabricate a high-quality ZCZ-NG device, leading to its superior output performance in terms of the peak-to-peak output voltage. Effects of the device size, ZnO layer thickness, and bending strain rate on the device performance have been investigated by measuring the output voltage. Moreover, to evaluate the effectiveness of the fabricated ZCZ-NG devices, we have experimentally implemented a sensor network testbed which can utilize the output voltages of ZCZ-NG devices. This sensor network testbed consists of several components such as Arduino-based transmitter and receiver nodes, wirelessly transmitting the sensed information of each node. We hope that this research combining the ZnO-based energy harvesting devices and IoT sensor networks will contribute to the development of more advanced energy harvester-driven IoT sensor networks in the future.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.6
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• pp.309-315
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• 2006

Purpose: Accurate evaluation of cervical lymph node (LN) metastasis of head and neck squamous cell canter (SCC) is important to treatment planning. We evaluated the diagnostic accuracy of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for the detection of cervical LN metastasis of head and neck SCC and performed a retrospective comparison with CT/MRI findings. Materials & Methods: Seventeen patients with pathologically proven head and neck SCC underwent F-18 FDG PET/CT and CT/MRI within 4 week before surgery. We recorded lymph node metastases according to the neck level system of imaging-based nodal classification. F-18 FDG PET/CT images were analyzed visually for assessment of regional tracer uptake in LN. We analyzed the differences in sensitivity and specificity between F-18 FDG PET/CT and CT/MRI using the Chi-square test. Results: Among the 17 patients, a total of 123 LN levels were dissected, 29 of which showed metastatic involvement. The sensitivity and specificity of F-18 FDG PET/CT for detecting cervical LN metastasis on a level-by-level basis were 69% (20/29) and 99% (93/94). The sensitivity and specificity of CT/MRI were 62% (18/29) and 96% (90/94). There was no significant difference in diagnostic accuracy between F-18 FDG PET/CT and CT/MRI. Interestingly, F-18 FDG PET/CT detected double primary tumor (hepatocellular carcinoma) and rib metastasis, respectively. Conclusion: There was not statistically significant difference of diagnostic accuracy between F-18 FDG PET/CT and CT/MRI for the detection of cervical LN metastasis of head and neck SCC. The low sensitivity of F-18 FDG PET/CT was due to limited resolution for small metastatic deposits.