• 지식경영연구
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• 제21권3호
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• pp.67-87
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• 2020

사용자가 컨텐츠의 소비자에 그치는 것이 아니라 생산자 역할까지 담당하는 웹 2.0 시대에는 사용자의 지속적 컨텐츠 생산이 온라인 사이트의 성공에 핵심 요소가 된다. 온라인 Q&A 사이트는 웹 2.0 트렌드의 대표적 사례로, 고품질의 지식을 반복적으로 공유하는 핵심 사용자들이 지속적으로 지식을 공유하도록 하는 것이 사이트의 성패를 결정짓는다. 본 연구는 핵심 사용자의 지식공유 지속행위를 유발하는 두가지 경로, 즉 지속의도로 대표되는 정교한 의사결정 과정(elaborate decision process)와 과거행위로 대표되는 자동화된 인지적 과정(automated cognitive process)을 제안하였다. 네이버 지식인의 핵심 사용자 337인의 주관적 의도 데이터와 객관적 온라인 행동 데이터를 수집한 뒤, 지속의도와 과거행위의 직접효과 및 둘 간의 조절효과를 검증해 보았다. 종속변수로 이전 연구에서 주로 사용되었던 지식공유 빈도를 측정하는 것과 더불어, 특정 기간 이상 답변활동이 없을 경우 지식공유를 중단한 것으로 판단하는 지식공유 지속여부를 측정하였다. 콕스비례위험 회귀분석과 음이항 회귀분석을 사용하여 지속의도와 과거행위가 지속행위의 두가지 유형에 미치는 효과를 살펴본 결과, 지식공유 지속여부에는 과거행위만 유의한 영향력을 보였으며, 지식공유 빈도에는 지속의도와 과거행위 모두 유의한 영향력을 보였다. 또한, 과거행위가 지속의도의 지식공유 빈도에 대한 영향력을 부정적으로 조절하는 것까지 확인할 수 있었다. 온라인 Q&A 사이트에서 핵심 사용자들의 지식공유 행위를 지속시키기 위해서는 꾸준한 지식공유를 통해 습관화 과정을 거치는 것이 중요하며, 지식공유 빈도를 높이고자 할 경우에는 습관화와 더불어 지식공유 지속의도를 높일 수 있는 적절한 혜택의 마련이 필요하다.

• Korean Journal of Radiology
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• 제25권8호
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• pp.715-725
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• 2024

Objective: To evaluate the outcomes of drug-eluting bead transarterial chemoembolization (DEB-TACE) according to the size of the beads for the treatment of small hepatocellular carcinoma (HCC). Materials and Methods: This retrospective study included 212 patients with a single HCC ≤5 cm from five tertiary institutions. One hundred and nine patients were treated with 70-150-㎛ doxorubicin DEBs (group A), and 103 patients received 100-300-㎛ doxorubicin DEBs (group B). The initial tumor response (assessed between 3 weeks and 2 months after DEB-TACE), time to local tumor progression (TTLTP), restricted mean duration of complete response (RMDCR), rate of complications, incidence of post-embolization syndrome, and length of hospital stay were compared between the two groups. Logistic regression was used to analyze prognostic factors for initial tumor response. Results: The initial objective response rates were 91.7% (100/109) and 84.5% (87/103) for groups A and B, respectively (P = 0.101). In the subgroup analysis of tumors ≤3 cm, the initial objective response rates were 94.6% (53/56) and 78.0% (39/50) for groups A and B, respectively (P = 0.012). There was no significant difference in the TTLTP (median, 23.7 months for group A vs. 19.0 months for group B; P = 0.278 [log-rank], 0.190 [multivariable Cox regression]) or RMDCR at 24 months (11.4 months vs. 8.5 months, respectively; P = 0.088). In the subgroup analysis of tumors >3-cm, the RMDCR at 24 months was significantly longer in group A than in group B (11.8 months vs. 5.7 months, P = 0.024). The incidence of mild bile duct dilatation after DEB-TACE was significantly higher in group B than in group A (5.5% [6/109] vs. 18.4% [19/103], P = 0.003). Conclusion: DEB-TACE using 70-150-㎛ microspheres demonstrated a higher initial objective response rate in ≤3-cm HCCs and a longer RMDCR at 24 months in 3.1-5-cm HCCs compared to larger DEBs (100-300-㎛).

• Tuberculosis and Respiratory Diseases
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• 제68권1호
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• pp.22-28
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• 2010

Background: Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis. VEGF production is regulated by HIF-$1{\alpha}$ and EGFR. This study examined the relationship between the clinicopathological factors and VEGF, HIF-$1{\alpha}$ and EGFR protein overexpression, and evaluated their prognostic value in patients with a surgically resected non-small cell lung cancer (NSCLC). Methods: Patients who underwent a surgical resection at Kangnam St. Mary's hospital were reviewed retrospectively. The core biopsy samples from 54 patients with NSCLC were assembled on a tissue microarray (TMA), and immunohistochemical staining for the VEGF, HIF-$1{\alpha}$ and EGFR proteins was performed. The overexpression of these proteins was evaluated in relation to age, gender, histology and staging by univariate analysis. The clinicopathological prognostic factors were analyzed. Results: Multivariate analysis performed by Cox regression (odds ratio 2.8, 95% CI 1.0~8.2, p=0.046) revealed HIF-$1{\alpha}$ overexpression to be an unfavorable factor. There was no correlation between the overexpression of these proteins and the clinicopathological factors. VEGF showed a positive relationship with EGFR, but there was no statistical significance [$p(x^2)=0.06$]. Conclusion: HIF-$1{\alpha}$ overexpression predicts shorter survival in patients with a surgically resected NSCLC. Therefore, HIF-$1{\alpha}$ may be a poor prognostic factor in NSCLC.

• Tuberculosis and Respiratory Diseases
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• 제79권4호
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• pp.274-281
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• 2016

Background: Factors associated with the prognosis of patients with small cell lung cancer (SCLC) is relatively unknown, than of those with non-small cell lung cancer. This study was undertaken to identify the prognostic factors of SCLC. Methods: The medical records of 333 patients diagnosed with SCLC at tertiary hospital from January 1, 2008, to December 31, 2012 were retrospectively reviewed. Patients were categorized by age (${\leq}65$ years vs. >65 years) and by extent of disease (limited disease [LD] vs extensive disease [ED]). Overall survival and progression free survival rates were determined. Factors associated with prognosis were calculated using Cox's proportional hazard regression model. Results: Most baseline characteristics were similar in the LD and ED groups. Eastern Cooperative Oncology Group (ECOG) performance status (PS), first chemotherapy regimen, and prophylactic cranial irradiation (PCI) differed significantly in patients with LD and ED. Mean ECOG PS was significantly lower (p<0.001), first-line chemotherapy with etoposide-cisplatin was more frequent than with etoposide-carboplatin (p<0.001), and PCI was performed more frequently (p=0.019) in LD-SCLC than in ED-SCLC. Prognosis in the LD group was better in younger (${\leq}65$ years) than in older (>65 years) patients, but prognosis in the ED group was unrelated to age. Conclusion: This study showed that overall survival (OS) was significantly improved in younger than in older patients with LD-SCLC. Univariate and multivariate analyses showed that age, PCI and the sum of cycles were significant predictors of OS in patients with LD-SCLC. However, prognosis in the ED group was unrelated to age.

• Journal of Korean Neurosurgical Society
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• 제61권1호
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• pp.19-27
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• 2018

Objective : The objectives of this study were to evaluate the immediate and long-term efficacy and safety of coil embolization for large or giant aneurysms. Methods : One hundred and fifty large or giant aneurysm cases treated with endovascular coil embolization between January 2005 and February 2014 at a single institute were included in this study. Medical records and imaging findings were reviewed. Statistical analysis was performed to evaluate prognostic factors associated with major recurrence (major recanalization or rupture) and delayed thromboembolism after selective coil embolization. Results : Procedure-related symptomatic complications occurred in five (3.3%) patients. The mean clinical and radiological follow-up periods were 38 months (range, 2-110) and 26 months (range, 6-108), respectively. During the follow-up period, the estimated recurrence rate was 4.6% per year. Multivariate analysis using Cox regression showed the degree of occlusion to be the only factor associated with recurrence (p=0.008, hazard ratio 3.15, 95% confidence interval 1.34-7.41). The patient's history of rupture in addition to the size and location of the aneurysm were not associated with recurrence in this study. Delayed infarction occurred in eight cases, and all were incompletely occluded. Conclusion : Although immediate postprocedural safety profiles were reasonable, longterm results showed recanalization and thromboembolic events to occur continuously, especially in patients with incomplete occlusion. In addition, incomplete occlusion was associated with delayed thromboembolic complications. Patients with incomplete occlusions should be followed carefully for delayed recurrence or delayed thromboembolic events.

• 보건행정학회지
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• 제14권4호
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• pp.1-20
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• 2004

This study is to examine relationships of several socioeconomic position indicators with mortality risk in a nationwide longitudinal study of South Korea. The Korea Labor & Income Panel Study, conducted on a probability sample of urban South Korean households by Korea Labor Institute, contains date of death information for the decedents which were used to estimate relative risks of mortality and their $95\%$ confidence intervals (CI) with Cox regression analysis. A total of 125 men and women among 8,415 subjects died between 1998 and 2002. Socioeconomic differentials in mortality were observed after adjustment for sex and age. Those with less than 12-year education had 1.90 times $(95\%\;CI=1.25-2.91)$ greater mortality risk than those with 12-year education or more. Greater mortality risks were also found among those with low occupational class and manual occupation. The magnitude of differentials in mortality risks between occupational class were similar in two different approaches to measuring women's occupational class: (1) approach 1 where women, married or not, retain their own occupational class, and (2) approach 2 where married women are assigned their husbands' occupational class. Relative risks of dying among those with low household Income were 1.62 $(95\%\; CI=1.08-2.42)$ compared with the counterparts. Those who reported economic hardship at the time of survey in 1998 had greater risk of mortality $(RR=1.83,\;95\%\;CI=1.21-2.78)$ than those who did not. In conclusion, increased social discourse and policy discussions about these health inequalities are needed in Korean society. Future studies should explore the causes and mechanisms of socioeconomic mortality inequalities.

• Asian Pacific Journal of Cancer Prevention
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• 제15권4호
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• pp.1585-1588
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• 2014

Background: Data regarding childhood and adolescent non Hodgkin lymphomas in Iran are limited. The aim of this study was to assess the epidemiological and histomorphological features and survival of affected patients in our center. Materials and Methods: The clinicopathologic features and outcome of 44 children and adolescents with non Hodgkin lymphoma diagnosed during 2004-2012, were investigated retrospectively. The influence of potential prognostic parameters in overall survival was investigated by log-rank test and Cox regression analysis. Results: The mean age at presentation was $13.8{\pm}6.16$ years with a male predilection (M: F=3:1). Malignant lymphoma, not otherwise specified, diffuse large cell lymphoma and Burkitt lymphoma were the three most common histological types observed. The tumors were 36.4% intermediate grade, 27.3% high grade and 34.1% belonged to the malignant lymphoma not otherwise specified group. Immunohistochemistry findings were available in 39 cases. Out of these cases 33 (84.6%) had B cell lineage, 4 (10.25%) T cell lineage and 2 (5.12%) of the cases belonged to miscellaneous group. 3 year and 5 year survivals were 48% and 30% respectively and median survival was 36 months (95%CI=21.7-50.3 months). Overall survival in patients with high grade tumors was 19.5 months, in the intermediate group,79 months, and for malignant lymphomas not otherwise specified it was 33.6 months (p value=0.000). Conclusions: The survival rate for children and adolescents with non Hodgkin lymphomas at our center during 2004-2012 was at a low level.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4527-4531
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• 2016

Background: PTEN protein is one of the most important tumour suppressor factors which is detectable by immunohistochemistry. The goal of the present study was to investigate the prognostic role of PTEN gene expression in breast cancer patients. Materials and Methods: This descriptive-analytical study was conducted on 100 breast cancer patients referred to Sabzevar hospitals in the north-east of Iran between 2010 and 2011, who were followed up to 2015. PTEN gene expression in tissue samples was determined using specific monoclonal antibodies and data were analyzed using Chi-square test and Fisher's exact test. Patient survival was analyzed after 4 years of follow-up using the Cox regression model. Results: PTEN gene expression was evident in 70 of 100 cnacer samples but was found at high levels in all non-cancer samples. There was an inverse significant relationship between PTEN gene expression and tumour stage or tumour grade (p<0.001). The expression of PTEN in invasive ductal tumours was lower than in non-invasive tumours. There was also an inverse significant relationship between the hazard of death and PTEN gene expression (p<0.001). In addition, there was an inverse significant relationship between tumour stage and hazard of death (p<0.001). Conclusion: These findings indicate that lack of PTEN gene expression can be a sign of a worse prognosis and poor survival in breast cancer cases.

• Genomics & Informatics
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• 제8권1호
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• pp.9-18
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• 2010

Integrins are transmembrane receptor proteins that mediate cell-cell adhesion and cell-extracellular matrix (ECM) adhesion. The deregulation of cell-ECM adhesion and the abnormal expression of beta1 (${\beta}1$) integrins (ITGB1s) are involved in tumor development and metastasis. In the liver, the expression of integrins and ECM proteins can be a cause of hepatocellular carcinoma (HCC) development. We performed direct DNA sequencing of 24 individuals, and identified 23 sequence variants of ITGB1 polymorphisms. Among these 23 variants, 7 common variants were selected based on frequencies and linkage disequilibrium, and then genotyped in a larger-scale group of subjects (n=1,103). The genetic associations of ITGB1 polymorphisms with the clearance of HBV and HCC outcome of HBV patients were analyzed using logistic regression models and Cox relative hazard models. Although there was no significant association observed between the polymorphisms and the HCC outcome of HBV patients, the second most common haplotype (ITGB1 haplotype-2 [C-C-C-C-T-C-T]) was putatively associated with HBV clearance (OR=0.75, p=0.008 and $P^{corr}=0.05$). The minor allele frequency (MAF) of ITGB1 haplotype -2 of the spontaneously recovered (SR) group was significantly higher than that of the chronic carrier group (CC) (freq. = 0.248 vs. 0.199). The information derived from this study could be valuable for understanding the genetic factors involved in the clearance of HBV.

• Asian Pacific Journal of Cancer Prevention
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• 제16권12호
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• pp.4853-4858
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• 2015

Background: Colorectal cancer is the most common gastrointestinal cancer in Oman with an increasing incidence. We here report the presenting features, treatment outcomes and survival in a University hospital in Oman and compare our data with regional and international studies. Materials and Methods: Medical records of patients with colorectal cancer were reviewed retrospectively between June 2000 and December 2013 and were followed until June 2014. Results: A total of 162 patients were diagnosed with colorectal cancer. The majority were males (58.6%), with a median age of 56 years. Rectum was involved in 29.6% of patients, followed by ascending and sigmoid colon. The majority of patients had stage III (42.6%) and stage IV (32.7%) disease at presentation. K-Ras status was checked for 79 patients, and 41 (51.9%) featured the wild type. Median relapse free survival was 22 months. Median overall survival for all patients was 43 months. Observed 5 year overall survival (OS) for stages I, II and III was 100%, 60% and 60% respectively. On Log rank univariate analysis, age, BMI, diabetes, hypertension, metformin use, stage, clinical nodal status for rectal cancer, pathological T and nodal status, site of metastasis, surgical intervention, chemotherapy, radiotherapy, chemotherapy regimen, no of cycles of chemotherapy, response, RFS, site of recurrence and administration of $2^{nd}$ line chemotherapy were significant factors affecting OS. On Cox regression multivariate analysis none of the factors independently affected the OS. Conclusions: The majority of patients present with advanced disease and at young age. The survival rates are comparable to the published regional and international literature.