• Korean Journal of Radiology
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• v.20 no.5
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• pp.791-800
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• 2019

Objective: To compare various models of diffusion-weighted imaging including monoexponential apparent diffusion coefficient (ADC), biexponential (fast diffusion coefficient [D_f], slow diffusion coefficient [D_s], and fraction of fast diffusion), stretched-exponential (distributed diffusion coefficient and anomalous exponent term [α]), and kurtosis (mean diffusivity and mean kurtosis [MK]) models in the differentiation of renal solid masses. Materials and Methods: A total of 81 patients (56 men and 25 women; mean age, 57 years; age range, 30-69 years) with 18 benign and 63 malignant lesions were imaged using 3T diffusion-weighted MRI. Diffusion model selection was investigated in each lesion using the Akaike information criteria. Mann-Whitney U test and receiver operating characteristic (ROC) analysis were used for statistical evaluations. Results: Goodness-of-fit analysis showed that the stretched-exponential model had the highest voxel percentages in benign and malignant lesions (90.7% and 51.4%, respectively). ADC, D_s, and MK showed significant differences between benign and malignant lesions (p < 0.05) and between low- and high-grade clear cell renal cell carcinoma (ccRCC) (p < 0.05). α was significantly lower in the benign group than in the malignant group (p < 0.05). All diffusion measures showed significant differences between ccRCC and non-ccRCC (p < 0.05) except D_f and α (p = 0.143 and 0.112, respectively). α showed the highest diagnostic accuracy in differentiating benign and malignant lesions with an area under the ROC curve of 0.923, but none of the parameters from these advanced models revealed significantly better performance over ADC in discriminating subtypes or grades of renal cell carcinoma (RCC) (p > 0.05). Conclusion: Compared with conventional diffusion parameters, α may provide additional information for differentiating benign and malignant renal masses, while ADC remains the most valuable parameter for differentiation of RCC subtypes and for ccRCC grading.

• Annals of Hepato-Biliary-Pancreatic Surgery
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• v.27 no.4
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• pp.380-387
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• 2023

Backgrounds/Aims: In 2019, the grading and staging system for neuroendocrine neoplasms (NENs) was significantly changed. In this study, we report the clinicopathological characteristics and surgical outcomes of patients with extrahepatic biliary NENs who underwent curative resection with or without adjuvant treatment. Methods: We retrospectively reviewed a database of 16 patients who developed NENs, neuroendocrine carcinoma (NEC), and mixed endocrine non-endocrine neoplasms (MiNENs) after curative resection. Among them, eight patients had ampulla of Vater (AoV) tumors, and eight patients had non-AoV tumors. Results: G1 and G2 were more frequently observed in the AoV group than in the non-AoV group (12.5% and 62.5%, respectively). In contrast, NEC and MiNEN were more common in the non-AoV group (50.0%). High Ki-67 index (> 20%) and perineural invasion (PNI) were more frequently observed in the non-AoV group. Advanced age (> 65 years), mitotic count > 20 per 2 mm², and Ki-67 index > 20% were strongly correlated with patient survival (p = 0.018, 0.009, and 0.044, respectively). Advanced age (> 65 years) and mitotic count > 20 per 2 mm² were significantly correlated with disease recurrence (p = 0.033 and 0.010, respectively). Conclusions: AoV and non-AoV tumors had significant differences in the histologic grade, Ki67, and PNI. Patients with non-AoV tumors had an increased risk for survival and recurrence than those in the AoV group. For extrahepatic biliary NENs, early detection of tumors, adequate surgery, and aggressive adjuvant treatment for high-risk patients are important to achieve long-term survival and prevent disease recurrence.

• Asia pacific journal of information systems
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• v.18 no.3
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• pp.91-121
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• 2008

Electronic commerce, commonly known as e-commerce or eCommerce, has become a major business trend in these days. The amount of trade conducted electronically has grown extraordinarily by developing the Internet technology. Most electronic commerce has being conducted between businesses to customers; therefore, the researches with respect to e-commerce are to find customer's needs, behaviors through statistical methods. However, the statistical researches, mostly based on a questionnaire, are the static researches, They can tell us the dynamic relationships between initial purchasing and repurchasing. Therefore, this study proposes dynamic research model for analyzing the cause of initial purchasing and repurchasing. This paper is based on the System-Dynamic theory, using the powerful simulation model with some restriction, The restrictions are based on the theory TAM(Technology Acceptance Model), PAM, and TPB(Theory of Planned Behavior). This article investigates not only the customer's purchasing and repurchasing behavior by passing of time but also the interactive effects to one another. This research model has six scenarios and three steps for analyzing customer behaviors. The first step is the research of purchasing situations. The second step is the research of repurchasing situations. Finally, the third step is to study the relationship between initial purchasing and repurchasing. The purpose of six scenarios is to find the customer's purchasing patterns according to the environmental changes. We set six variables in these scenarios by (1) changing the number of products; (2) changing the number of contents in on-line shopping malls; (3) having multimedia files or not in the shopping mall web sites; (4) grading on-line communities; (5) changing the qualities of products; (6) changing the customer's degree of confidence on products. First three variables are applied to study customer's purchasing behavior, and the other variables are applied to repurchasing behavior study. Through the simulation study, this paper presents some inter-relational result about customer purchasing behaviors, For example, Active community actions are not the increasing factor of purchasing but the increasing factor of word of mouth effect, Additionally. The higher products' quality, the more word of mouth effects increase. The number of products and contents on the web sites have same influence on people's buying behaviors. All simulation methods in this paper is not only display the result of each scenario but also find how to affect each other. Hence, electronic commerce firm can make more realistic marketing strategy about consumer behavior through this dynamic simulation research. Moreover, dynamic analysis method can predict the results which help the decision of marketing strategy by using the time-line graph. Consequently, this dynamic simulation analysis could be a useful research model to make firm's competitive advantage. However, this simulation model needs more further study. With respect to reality, this simulation model has some limitations. There are some missing factors which affect customer's buying behaviors in this model. The first missing factor is the customer's degree of recognition of brands. The second factor is the degree of customer satisfaction. The third factor is the power of word of mouth in the specific region. Generally, word of mouth affects significantly on a region's culture, even people's buying behaviors. The last missing factor is the user interface environment in the internet or other on-line shopping tools. In order to get more realistic result, these factors might be essential matters to make better research in the future studies.

• Journal of Chest Surgery
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• v.41 no.3
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• pp.305-312
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• 2008

Background: Anatomic and functional abnormalities of the systemic atrioventricular (AV) valve are common in single ventricle. pathologies and continue to be associated with poor early and late outcomes in surgically palliated single. ventricle patients. We aggressively performed valvuloplasty for atrioventricular valve regurgitation (AVVR) during the course toward a Fontan operation. Material and Method: Between January 1995 and December 2004, 209 patients underwent a Fontan operation in our institution. We retrospectively evaluated the prevalence of AVVR and the influence of AV valve repair on outcome, and we analyzed the progression of AVVR after the Fontan operation for 168 patients where echocardiographic follow up results for more than 6 months after the Fontan operation were available. During the course toward a Fontan operation, 25 patients underwent 30 procedures for AVVR. These procedures. were. carried out during placement of a bidirectional cavopulmonary shunt (BCPS) for nine patients, between the time of placement of a BCPS and the Fontan operation for four patients, and during the Fontan operation for 17 patients. Five patients underwent procedures for AVVR twice. Result: The late mortality rate after the Fontan operation was 4.2% (n=7), with a median follow-up duration of 52 months (range, $6{\sim}123$ months). Seven patients (4%) had unfavorable outcomes such as significant (moderate or severe) AVVR in six patients, and significant AV valve stenosis in one patient was determined at the last follow up after the Fontan operation. Among the seven patients, four patients underwent AV valve repair after the Fontan operation, and one patient underwent subsequent AV valve replacement. Progression to AVVR of equal to or greater than grade 2 was noted in 30 patients (18%) at the last follow up after the Fontan operation, including 12 patients that underwent previous AV valve procedures. Initial grading of AVVR, a previous AV valve operation, and specific AV valve morphology such as a common AV valve or mitral atresia were significant risk factors for the progression of AVVR after the Fontan operation. Conclusion: In our surgical series, a small percentage of patients showed unfavorable outcomes. related to AVVR during the course toward a Fontan operation. However, a closer follow-up is required to evaluate the progression of the AVVR after a Fontan operation, especially for patients showing poor AV valve function at the first presentation and specific AV valve morphology.

• Investigative Magnetic Resonance Imaging
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• v.17 no.2
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• pp.83-90
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• 2013

Purpose : To report our clinical experience with cardiac 3.0 T MRI in patients compared with 1.5 T using individually optimized imaging protocols. Materials and Methods: We retrospectively reviewed 30 consecutive patients and 20 consecutive patients who underwent 1.5 T and 3 T cardiac MRI within 10 months. A comparison study was performed by measuring the signal-to-noise ratio (SNR), the contrast-to-noise ratio (CNR) and the image quality (by grading each sequence on a 5-point scale, regarding the presence of artifacts). Results: In morphologic and viability studies, the use of 3.0 T provided increase of the baseline SNRs and CNRs, respectively (T1: SNR 29%, p < 0.001, CNR 37%, p < 0.001; T2-SPAIR: SNR 13%, p = 0.068, CNR 18%, p = 0.059; viability imaging: SNR 45%, p = 0.017, CNR 37%, p = 0.135) without significant impairment of the image quality (T1: $3.8{\pm}0.9$ vs. $3.9{\pm}0.7$, p = 0.438; T2-SPAIR: $3.8{\pm}0.9$ vs. $3.9{\pm}0.5$, p = 0.744; viability imaging: $4.5{\pm}0.8$ vs. $4.7{\pm}0.6$, p = 0.254). Although the image qualities of 3.0 T functional cine images were slightly lower than those of 1.5 T images ($3.6{\pm}0.7$ vs. $4.2{\pm}0.6$, p < 0.001), the mean SNR and CNR at 3.0 T were significantly improved (SNR 143% increase, CNR 108% increase, p < 0.001). With our imaging protocol for 3.0 T perfusion imaging, there was an insignificant decrease in the SNR (11% decrease, p = 0.172) and CNR (7% decrease, p = 0.638). However, the overall image quality was significantly improved ($4.6{\pm}0.5$ vs. $4.0{\pm}0.8$, p = 0.006). Conclusion: With our experience, 3.0 T MRI was shown to be feasible for the routine assessment of cardiac imaging.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.366-370
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• 2013

The effects of the early tree shapes with renewal by top-working on Y-shaped peach tree, and the influence on the maintaining fruit quantity with gradual renewal of interstock cultivar were determined. In the comparison of the places of top-working tree, top working tree on the inside of the main branch of interstock cultivar had higher graft union rate and branch growth than those of top working tree on the outside. Tree width, basal diameter of shoot, and number of bearing shoots were smaller in top working tree than in replanted tree. Although labor time was not different to control top working tree and replanted tree, labor time was much required to manage top working tree with interstock cultivar. Accumulated fruit production was 2,384 kg/10a in top working tree and 2,025 kg/10a in replanted tree for three years. However, top working tree had no loss of fruits because interstock cultivar of top-working tree had 3,727 kg/10a of fruits. No variation on fruit quality was observed between top working tree and replanting tree. In terms of economic value of top-working tree, labor to manage interstock cultivar, fertilizer price, fruit bagging, and grading and packing price increased. However, fruit production increased, and price of seedling, rental equipment, pulling-out trees, and repairing supporting system decreased. Therefore, gradual renewal of topworking tree has effects on the maintaining fruit quantity, supplementation on fruit loss, and renewal cultivar.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.6 no.1
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• pp.1-9
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• 2003

Purpose: To investigate the relation of the gastric epithelial cell proliferation, apoptosis and genotypes of H. pylori in children. Methods: Histologic grading by updated Sydney system, PCNA immunostaining, TUNEL method and the genotypes (cagA, picB and iceA) by PCR were performed in H. pylori positive (N=20) and negative (N=20) gastric biopsy specimens. Results: PCNA index was significantly different between H. pylori positive children ($77.4{\pm}13.12$) and H. pylori negative children ($52.3{\pm}12.20$) (p=0.000). There were positive correlations between PCNA index and H. pylori density (r=0.624, p=0.000), polymorphonuclear neutrophil activity (r=0.460, p=0.005) and chronic inflammation (r=0.433, p=0.009). Apoptosis index of H. pylori positive children ($0.70{\pm}0.411$) was significantly higher than of H. pylori negative children ($0.14{\pm}0.201$) (p=0.000). Positive correlations between apoptosis index and H. pylori density (r=0.691, p=0.000), polymorphonuclear neutrophil activity (r=0.585, p=0.000) and chronic inflammation (r=0.535, p=0.001) were noted. As PCNA index increased, apoptosis index significantly increased (r=0.527, p=0.001). The positive rates of genotypes were cagA 90%, picB 75%, iceA1 60% and iceA2 15%, respectively. There were no significant correlations between the status of the genotypes and PCNA index, apoptosis index, the endoscopic findings and the histologic findings. Conclusion: PCNA index and apoptosis index in H. pylori positive children were higher than in H. pylori negative children but were not related to H. pylori genotypes. This study suggested that correlatively increased gastric epithelial cell proliferation and apoptosis are important to pathogenesis of H. pylori infection in children.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.9
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• pp.4777-4781
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• 2012

Objective: To investigate the relationship between the efficacy and safety of different doses of thalidomide (Thal) plus dexamethasone (Dex) as the initial therapy in elderly patients with newly diagnosed multiple myeloma (MM). Methods: Clinical data of 28 elderly patients with newly diagnosed MM who underwent the TD regimen as the initial therapy were analyzed retrospectively. The patients were divided into two groups according to the maximal sustained dose of Thal: lower dose (group A) and higher dose (group B). The overall response rate (ORR), progression free survival (PFS), overall survival (OS), and adverse events (AES) were compared between the two groups. Results: A total of 28 patients were followed up with a median of 18 months. The ORR was 60.1%. The median response time and PFS were 2.0 and 17.0 months, respectively. The mean sustained dose of Thal in group B was significantly higher than group A (292.9 mg v 180.4 mg, P=0.01). There was no significantly difference in ORR (57.1% v 64.3%, P=1.00) and PFS (9.63months v 17.66 months, P=0.73) between groups A and B. During the follow up, only five patients died (<40%) and, therefore, median OS values were not available. It is estimated, however, that the mean survival time in the two groups was 35.6 and 33.4 months (P>0.05), respectively. All of the patients tolerated the treatment well. The incidence of AES in patients with a grading above 3 in group B was significantly higher than in group A (P=0.033). Conclusions: The TD regimen results in a high response rate and manageable AES as the initial therapy in elderly patients with MM. TD should be considered as the front line regimen for the treatment of elderly patients with MM in areas with financial constraints. The clinical response can be achieved at a low dose Thal with minimal toxicity.

• Korean Journal of Poultry Science
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• v.45 no.1
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• pp.63-71
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• 2018

This study was conducted to evaluate the effect of age of laying hens on egg internal and external qualities. A total of 8,300 eggs were randomly collected from 15 grading & packaging (GP) centers, and 50 eggs per farm during April to May in 2015. Age of laying hens ranged from 18 to 65 weeks of age and they were classified into 5 age groups (18~25, 26~35, 36~45, 46~55, and 56~65 weeks). Egg weight increased, but the Haugh unit decreased as the age of laying hens increased. Yolk color was higher in eggs laid from 25~35 weeks of laying hens compared with that of 18~25-weeks-old chickens. The incidence of dirty eggs was highest (P<0.05) in 18~25 week group and remained constant after 26 weeks. Among eggshell defects, speckled and pimpled eggs increased as the age of laying hens increased. The incidence of calcium deposits and misshapen eggs was highest during 18~25 weeks of age and remained constant after 26 weeks. The percentage of total eggshell cracks increased as the age of laying hens increased. Among eggshell cracks, star- and hair-like cracks were frequently noted. The percentage of meat spot was higher than that of blood spot and their incidence was highest among the 56~65 week group. Age of laying hens significantly increased egg weight, incidence of pimpled or speckled eggs, star- or hair-like cracks, and meat spot. On the other hand, a significant negative interaction between age of laying hens and the Haugh unit was noted. In conclusion, our study revealed that the age of laying hens affected internal and external egg qualities.

• The Journal of the Korean bone and joint tumor society
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• v.10 no.2
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• pp.96-106
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• 2004

Purpose: To determine the usefulness of limb salvage operation with recycled autogenous bone graft in musculoskeletal malignant tumors. Materials and Methods: Twenty nine cases, who underwent limb salvage operation with recycled autogenous bone graft for the treatment of musculoskeletal malignant tumor between February 1990 and January 2003, were included. There were 18 males and 11 females and the mean age was 33 years (range, 10 to 65 years). The mean follow-up period was 51.8 months (range, 18 to 117 months). The Enneking stage was IIA in 10 cases and IIB in 19 cases. The recycling method of autogenous bone was deep freezing in 6 cases, autoclaving in 11 cases, pasteurization in 7 cases and the composite of autoclaving and vascularized fibular graft in 5 cases. The union of junctional site was evaluated radiologically and the functional results was analyzed by the grading systems of the International Symposium On Limb Salvages (ISOLS). Results: The mean union time was 7.2 months (range, 3 to 15 months). The union took 5.8 months (range, 4 to 8 months) in deep freezing, 9.7 months (range, 6 to 15 months) in autoclaving, 5.9 months (range, 4 to 8 months) in pasteurization, and 5 months (range, 4 to 8 months) in the composite of autoclaving and vascularized fibular graft. The mean functional evaluation percentage was 76.8% (range, 40 to 90%). It was 65.8% (range, 40 to 85%) in deep freezing, 76.6% (range, 40 to 90%) in autoclaving, 81.6% (range, 70 to 90%) in pasteurization, and 83.4% (range, 75 to 90%) in the composite of autoclaving and vascularized fibular graft. There were 6 cases of complications including 1 case of local recurrence, lung metastasis, infection, fracture, respectively and 2 cases of nonunion. Conclusion: The limb salvage operation with recycled autogenous bone graft is a useful treatment method for the musculoskeletal malignant tumors. Particularly, autoclaving is the most reliable sterilization method. The vascularized fibular graft can compensate decreased osteoinductivity and mechanical strength of recycled bone. So, the composite of autoclaving and vascularized bone graft seems to be a favorable treatment method for high grade malignant musculoskeletal tumors.