[Show abstract][Hide abstract] ABSTRACT: The use of I-Core sandwich panel has increased in cruise ship deck structure since it can provide similar bending strength with conventional stiffened plate while keeping lighter weight and lower web height. However, due to its thin plate thickness, i.e. about 4~6 mm at most, it is assembled by high power laser welding to minimize the welding deformation. This research proposes a volumetric heat source model for T-joint of the I-Core sandwich panel and a method to use shell element model for a thermal elasto-plastic analysis to predict welding deformation. This paper, Part I, focuses on the heat source model. A circular cone type heat source model is newly suggested in heat transfer analysis to realize similar melting zone with that observed in experiment. An additional suggestion is made to consider negative defocus, which is commonly applied in T-joint laser welding since it can provide deeper penetration than zero defocus. The proposed heat source is also verified through 3D thermal elasto-plastic analysis to compare welding deformation with experimental results. A parametric study for different welding speeds, defocus values, and welding powers is performed to investigate the effect on the melting zone and welding deformation. In Part II, focuses on the proposed method to employ shell element model to predict welding deformation in thermal elasto-plastic analysis instead of solid element model.
International Journal of Naval Architecture and Ocean Engineering 09/2013; 5(3). DOI:10.3744/JNAOE.2013.5.3.348 · 0.38 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Welding deformation reduces the dimensional accuracy of ship hull blocks and decreases productivity due to the correction work. Prediction and minimizing of welding distortion at the design stage will lead to higher quality as well as higher productivity. Therefore, it is strongly required to develop an effective method to accurately predict the weld distortion of hull blocks considering the fabrication sequences. In the case of hull block welding work in shipyard, the welding process of curved stiffened plate has large amounts of workload. This paper suggests an efficient method for predicting the welding deformation of stiffened curved plates based on the inherent strain theory combined with the finite element method. The equivalent load was determined by integrating inherent strain components which are calculated in the vicinity of heat affected zone using the highest temperature and the degree of restraint. The welding distortion of curved stiffened panels under equivalent load are calculated by elastic analysis and compared with that by intensive elasto-plastic finite element analysis. It is verified that the proposed method has a high efficiency and accuracy.
Journal of Ship Research 06/2012; 56(2):63-70. DOI:10.5957/JOSR.56.2.090006 · 0.82 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A phase II study was conducted to evaluate S-1 monotherapy in previously untreated elderly or frail metastatic colorectal cancer patients. A total of 48 elderly (70-85 years old) and frail [Eastern Cooperative Oncology Group (ECOG) performance status (PS) 2 and 65-69 years old] patients were eligible for first-line S-1 of 35 mg/m(2) given twice daily for 2 weeks followed by 1 week of rest. The overall response rate (ORR) for all patients was 19%. Similarly, the ORR for frail and elderly patients was 22% and 18%, respectively. Median progression-free survival (PFS) and overall survival (OS) for all patients were 3.9 months (95% CI, 3.0-4.8) and 11.3 months (95% CI, 7.4-15.2), respectively. For frail patients, PFS was 1.4 (95% CI, 0.8-2.0) vs. 4.3 months (95% CI, 3.0-5.4) for the elderly (P = 0.016). OS was significantly longer for elderly patients than for frail patients (13.1 months, 95% CI, 9.5-16.7) vs. (4.1 months, 95% CI, 3.2-5.0; P = 0.01). Toxicity was mild to moderate, as only 29% of patients experienced grade 3 toxicity. Grade 4 toxicity and febrile neutropenia did not occur; however, two frail patients died from grade 5 treatment-related infections. Generally, S-1 monotherapy was well-tolerated and efficacious in the elderly patient group, but not in the frail patient group. Considering performance status and co-morbidities in patients >70 years old, S-1 monotherapy may be a first-line therapeutic option for elderly mCRC patients.
Investigational New Drugs 03/2010; 29(5):1073-80. DOI:10.1007/s10637-010-9418-2 · 2.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We evaluated the efficacy and tolerability of combined paclitaxel and ifosfamide in anthracycline- and docetaxel-pretreated metastatic breast cancer (MBC).
Patients received paclitaxel (175 mg/m(2) i.v. in a 3-h infusion) on day 1 and ifosfamide (1.5 g/m(2) i.v. in a 15-min infusion) on days 1-3, every 3 weeks for a maximum of nine cycles. The tumor response was assessed every two cycles.
We enrolled 34 patients with a median age of 50 years. Thirty patients had visceral metastases. Anthracycline- and docetaxel-based chemotherapy had previously been administered to 18/13 and 13/21 patients, respectively, in (neo)adjuvant/metastatic settings. Three patients had not previously received anthracycline due to abnormal cardiac functions. A total of 174 cycles of chemotherapy were delivered with a median of six cycles. The response rate under the intent-to-treat analysis was 23.5% (all partial responses) with a median response duration of 14 months. The disease control rate was 70.6%. The median progression-free and overall survival were 5.9 and 8.5 months, respectively. There was no apparent relationship between activity and prior docetaxel resistance. The incidence of grade III/IV neutropenia was 46.6% (81 of 174 cycles) with febrile neutropenia of only 1.7%. Major grade III/IV non-hematological toxicities included peripheral neuropathy (6 of 34 patients) and infection (4 of 34 patients). There were no treatment-related deaths.
Paclitaxel combined with ifosfamide was effective and tolerable in anthracycline-/docetaxel-pretreated MBC. Overcoming docetaxel resistance by using paclitaxel in combination with ifosfamide needs to be addressed through further investigation.
Cancer Chemotherapy and Pharmacology 12/2009; 66(3):425-31. DOI:10.1007/s00280-009-1176-5 · 2.77 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Welding deformation reduces the dimensional accuracy of ship hull blocks and decreases the productivity due to the correction work. Prediction and minimizing of welding deformation at the design stage will lead to higher quality as well as higher productivity. Therefore, it is strongly required to develop an effective method to predict accurately the weld deformation of hull blocks considering the fabrication sequences. The welding deformation and residual stress of ship hull block are inevitably arisen from the welding and are accumulated for sequential producing process of trestle, translation and lifting process. But previous studies about inherent strain method were just interested in welding deformation. Therefore welding deformation analysis based on inherent strain method has a great merit about effective analysis time and prediction of accurate welding deformation but has a demerit about prediction of welding residual stress. Because it can't predict welding residual stress, it is hard to apply structural analysis considering welding residual stress. This paper suggests an efficient method for predicting the welding deformation and residual stress of ship hull block based on inherent strain theory combined with the finite element method. The inherent strain chart by using solid-spring model with two dimensional restraints is suggested for calculating the equivalent strain. The equivalent strain was determined by integrating inherent strain components which are calculated in the vicinity of heat affected zone using the highest temperature and the degree of restraint.
[Show abstract][Hide abstract] ABSTRACT: We retrospectively compared adenosine triphosphate-based chemotherapy response assay (ATP-CRA)-guided and empirical chemotherapies for unresectable non-small cell lung cancer (NSCLC) in this case-control study.
Unresectable NSCLC patients receiving ATP-CRA-guided platinum-based doublets as first-line therapy were enrolled as cases (n=27; 14 platinum-sensitive and 13 platinum-resistant patients). Performance status, stage, and chemotherapeutic regimen-matched patients receiving empirical chemotherapy were selected from the retrospective database as controls (n=93) in a case to control ratio of approximately 1:3.
Response rate and survival (progression-free; overall) in both groups were not significantly different. However, the platinum-sensitive subgroup by ATP-CRA showed a higher response rate than the empirical group (71 versus 38%; p=0.023) with a trend toward longer progression-free survival (8.7 versus 4.8 months for platinum-sensitive versus empirical; p=0.223) and overall survival (not reached versus 12.6 months for platinum-sensitive versus empirical for p=0.134).
ATP-CRA may be helpful in selecting platinum-responsive patients in unresectable NSCLC. We consider that nonplatinum doublets in platinum-resistant patients by ATP-CRA may be a more adapted approach than platinum-based doublets in future clinical trials.
Anticancer research 10/2009; 29(10):4243-9. · 1.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Epithelioid hemangioendothelioma (EHE) is a rare tumor of vascular origin. While it can be found in any tissue, it is most often found in lung and liver and usually has an intermediate behavior. EHEs originating from pleural tissue have been less frequently described than those from other sites. Furthermore, to date, all of the cited pleural EHEs were described as highly aggressive. In the present report, we describe a rare case of pleural EHE extending to lung and bone in a 31-year-old woman. The histological diagnosis was confirmed by both conventional examination and immunohistochemistry. Her disease stabilized during the 4th course of adriamycin (45 mg/m(2), day 1-3), dacarbazine (300 mg/m(2), day 1-3) and ifosfamide (2,500 mg/m(2), day 1-3) with mesna, and she survived for 10 months after the diagnosis.
Yonsei Medical Journal 01/2009; 49(6):1036-40. DOI:10.3349/ymj.2008.49.6.1036 · 1.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Gastric cancer is one of the most common cancers worldwide, and there are clinical caveats in predicting tumor response to chemotherapy. This study describes the construction of an in vitro pharmacogenomic database, and the selection of genes associated with chemosensitivity in gastric cancer cell lines. Gene expression and chemosensitivity databases were integrated using the Pearson correlation coefficient to give the GC-matrix. The 85 genes were selected that were commonly associated with chemosensitivity of the major anticancer drugs. We then focused on the genes that were highly correlated with each specific drug. Classification of cell lines based on the set of genes associated with each drug was consistent with the division into resistant or sensitive groups according to the chemosensitivity results. The GC-matrix of the gastric cancer cell line database was used to identify different sets of chemosensitivity-related genes for specific drugs or multiple drugs.
[Show abstract][Hide abstract] ABSTRACT: When conventional treatments of malignant pleural effusion, such as repeated thoracentesis, closed thoracotomy and pleurodesis by instilled sclerosing agents, are ineffective, there are few alternative therapies available. Our case involves a 47-year-old woman with uterine cervical carcinoma suffering from malignant pleural effusion. She presented with a chief complaint of severe dyspnea, and was classified as an Eastern Cooperative Oncology Group (ECOG) performance status of 4. Her underlying cervical carcinoma progressed despite various systemic chemotherapy regimens. In addition, pleural effusion persisted in spite of 4 weeks of drainage through the thoracotomy tube and talc pleurodesis. Under such circumstances, we attempted intrapleural chemotherapy with cisplatin plus cytarabine, which resulted in significant decrease of the pleural effusion. No serious systemic toxicities, including myelosuppression, were observed. As a result, the patient's dyspnea was relieved, and her ECOG performance status improved from 4 to 2. However, the thoracotomy tube was not removed due to subsequent iatrogenic pneumothorax. Pleural effusion did not recur for the 4 weeks leading up to her death.
Yonsei Medical Journal 01/2008; 48(6):1035-8. DOI:10.3349/ymj.2007.48.6.1035 · 1.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Lemierre syndrome is a rare disease that's characterized by internal jugular vein thrombosis and septic emboli. These symptoms typically develop after acute oropharyngeal infection by Fusobacterium necrophorum. Although this syndrome is less frequently seen in modern times due to the availability of antibiotics, physicians must be aware of the syndrome in order to initiate prompt antibiotics therapy, including coverage of the anerobic organisms. We discuss here the case of an 18-year-old female with Lemierre syndrome and we review the relevant literature on this syndrome.
The Korean Journal of Internal Medicine 10/2007; 22(3):211-4. DOI:10.3904/kjim.2007.22.3.211 · 1.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The study investigated correlations between adenosine triphosphate / chemotherapy response assay (ATP-CRA) and clinical outcomes after ATP-CRA-guided platinum-based chemotherapy for unresectable nonsmall-cell lung cancer (NSCLC).
The authors performed an in vitro chemosensitivity test, ATP-CRA, to evaluate the chemosensitivities of anticancer drugs such as cisplatin, carboplatin, paclitaxel, docetaxel, gemcitabine, and vinorelbine for chemonaive, unresectable NSCLC. The cell death rate was determined by measuring the intracellular ATP levels of drug-exposed cells compared with untreated controls. A sensitive drug was defined as a drug producing 30% or more reduction in ATP compared with untreated controls. Assay-guided platinum-based 2-drug chemotherapy was given to patients with pathologically confirmed NSCLC.
Thirty-four patients were enrolled. Thirty tumor specimens were obtained by bronchoscopic biopsies and 4 obtained surgically. The median age was 61 years and 27 patients had an Eastern Cooperative Oncology Group (ECOG) performance status of 0–1. The response rate was 43.8%. At a median follow-up period of 16.9 months, the median progression-free and overall survivals were 3.6 and 11.2 months, respectively. Patients were dichotomized into the platinum-sensitive (S; 20 patients) and resistant (R; 14 patients) groups. The positive/negative predictive values were 61.1% and 78.6% with a predictive accuracy of 68.8%. Although without significant differences in pretreatment parameters, the S-group showed better clinical response (P = .036), longer progression-free survival (P = .060), and longer overall survival (P = .025).
Despite using bronchoscopic biopsied specimens, ATP-CRA and clinical outcomes correlated well after assay-guided platinum-based 2-drug chemotherapy for unresectable NSCLC. There was a favorable response and survival in the platinum-sensitive vs resistant groups. Cancer 2007.
Cancer 05/2007; 109(9):1829 - 1835. DOI:10.1002/cncr.22601 · 4.89 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We investigated the association of survivin expression with the prognosis in advanced rectal cancer with preoperative chemoradiotherapy for pathological analysis.
Journal of the Korean Society of Coloproctology 01/2007; 23(6). DOI:10.3393/jksc.2007.23.6.511
[Show abstract][Hide abstract] ABSTRACT: Nephrotic syndrome is a rare manifestation of malignancy associated with paraneoplastic syndrome. Paraneoplastic nephrotic syndrome has been reported in various malignancies: malignant lymphoma, colon cancer, lung cancer and prostate cancer. However, an ovarian carcinoma associated with nephrotic syndrome has rarely been reported. Only six cases of ovarian carcinoma associated paraneoplastic nephrotic syndrome has been reported worldwide, but no cases have been reported in Korea. Here, we report a case of paraneoplastic nephrotic syndrome in a patient with an ovarian carcinoma. The patient presented with ascites, proteinuria and hypoalbuminemia. An initial computed tomography (CT) scan and ultrasonography evaluations showed no specific findings suggestive of an ovarian tumor. Despite treatment for nephrotic syndrome, the symptoms became more aggravated. There after, follow up evaluation at Yonsei University Medical Center, including serum CA 125, pelvis MRI and peritoneal fluid examination were performed. On the pelvis MRI, a left ovarian mass was detected with an ascitic fluid collection. The serum CA 125 level was elevated to 2211 U/ml. The peritoneal fluid cytological examination showed malignant cells suggestive of an ovarian carcinoma. Combination chemotherapies including paclitaxel plus carboplatin, topotecan plus gemcitabine and oxaliplatin plus capecitabine were administered to the patient, and complete remission was achieved on image and tumor marker studies. There was complete recovery from the nephrotic syndrome with no evidence of ascites and proteinuria. These findings suggest that nephrotic syndrome caused by paraneoplastic syndrome can be resolved only after the complete control of the underlying malignancy.
Yonsei Medical Journal 07/2003; 44(3):539-43. DOI:10.3349/ymj.2003.44.3.539 · 1.29 Impact Factor