• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.2
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• pp.373-384
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• 2014

The social network service is the bidirectional media that many users can build relations not only friends but also other people. However, a process to approach in the social network is so simple that untrustable information, which malignant users make, is spreaded rapidly in many the social network uses. This causes many users to suffer material or psychological damages. Because of openness in the social network, there will be higher risk of the privacy invasion. Therefore, sensitive information should be transferred or provided only to reliable users. In general, because many users exchange among one hops, many researches have focused on one hop's trust evaluation. However, exchanges between users happen not only one joint bridege but also far nodes more than two nodes on account of dense network and openness. In this paper we propose the efficient scheme combining transitivity and composability for remote users.

• Archives of Plastic Surgery
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• v.34 no.4
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• pp.471-477
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• 2007

Purpose: Hydrofluoric acid(HF) is one of the most dangerous mineral acids with dissociated fluoride ions. As hydrofluoric acid is present in various household products(such as rust removers), a large population of industrials is at the risk of HF exposure. It is a very strong organic acid, used widely in glass etching, metal washing, and in the semiconductor industry. Even when using adequate safety measures, lack of care on the user's part results in chemical burn by HF. Symptoms caused by HF-induced chemical burns shows delayed manifestations resulting in a loss of proper treatment opportunities. We therefore reviewed 20 cases of HF-induced chemical burns and treatment principle. Methods: The objects of this study were 19 male patients and 1 female treated from March 2004 to March 2006. There were 19 cases of injury on digits and 1 on the wrist area. There were 15 cases of immediate treatment after sustaining HF-induced burns, and 5 cases of delayed treatment. As a principle, in the emergency treatment, partial or complete removal of the nail along with copious washing with normal saline was done, depending on the degree of HF invasion of the distal digital extremities. Results: The 15 cases who came to the hospital immediately after the injury were healed completely without sequelae, and those who delayed their treatment needed secondary surgical measures, due to the severity of inflammation and necrosis of the digital tissues. Conclusion: As the industrial sector develops, the use of HF is increasing more and more, leading to increase in incidences of HF-induced chemical burns. When treating chemical burns caused by HF, washing by copious amounts of normal saline, along with early removal of the nails, rather than calcium gluconate, seems to be a available method for preserving the shape and function of the digits and the nail. The education of patients regarding this subject should be empathized accordingly.

• Archives of Reconstructive Microsurgery
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• v.19 no.2
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• pp.81-87
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• 2010

In surgical treatment of the malignant melanoma, radical resection and a sentinel lymph node biopsy are essential procedures to eradicate the tumor and to minimize the risk of local recurrence. For the reconstruction of skin defect after tumor resection, a skin graft has been generally performed procedure. However, if tendon or bone is exposed after tumor resection, simple skin graft is not enough for the coverage of the defect and additional procedure is mandatory. In this study, we reviewed the clinical results of 16 patients, who had been diagnosed with malignant melanoma of the limb and underwent surgical resection and reconstruction of the defect with various methods. The sentinel lymph node dissection was performed in all patients combined with radical excision of the tumor. In 11 cases of positive sentinel lymph nodes, further elective lymph node dissections were performed. The mean tumor invasion depth was 4.54 mm (2~10 mm), and AJCC stage II was most common (9 cases). The pedicled flaps were performed in 10 cases for the reconstruction of defects. All flaps were successfully survived without significant complications until the last follow up. In conclusion, a pedicled flap coverage is very useful reconstruction strategy for the soft tissue defects after radical resection of malignant melanoma.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.4
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• pp.237-244
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• 2020

Endometrial cancer (EC) in young women tends to be early-stage and low-grade; therefore, such cases have good prognoses. Fertility-sparing treatment with progestin is a potential alternative to definitive treatment (i.e., total hysterectomy, bilateral salpingo-oophorectomy, pelvic washing, and/or lymphadenectomy) for selected patients. However, no evidence-based consensus or guidelines yet exist, and this topic is subject to much debate. Generally, the ideal candidates for fertility-sparing treatment have been suggested to be young women with grade 1 endometrioid adenocarcinoma confined to the endometrium. Magnetic resonance imaging should be performed to rule out myometrial invasion and extrauterine disease before initiating fertility-sparing treatment. Although various fertility-sparing treatment methods exist, including the levonorgestrel-intrauterine system, metformin, gonadotropin-releasing hormone agonists, photodynamic therapy, and hysteroscopic resection, the most common method is high-dose oral progestin (medroxyprogesterone acetate at 500-600 mg daily or megestrol acetate at 160 mg daily). During treatment, re-evaluation of the endometrium with dilation and curettage at 3 months is recommended. Although no consensus exists regarding the ideal duration of maintenance treatment after achieving regression, it is reasonable to consider maintaining the progestin therapy until pregnancy with individualization. According to the literature, the ovarian stimulation drugs used for fertility treatments appear safe. Hysterectomy should be performed after childbearing, and hysterectomy without oophorectomy can also be considered for young women. The available evidence suggests that fertility-sparing treatment is effective and does not appear to worsen the prognosis. If an eligible patient strongly desires fertility despite the risk of recurrence, the clinician should consider fertility-sparing treatment with close follow-up.

• Korean Journal of Clinical Oncology
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• v.14 no.2
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• pp.128-134
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• 2018

Purpose: Previous studies have addressed the role of the hypercoagulable state in the pathogenesis of cancer progression and metastasis. In this study, we investigated the association between coagulation factors, including tissue factor (TF) expression, platelet count, and fibrinogen level, and disease recurrence in patients with non-metastatic colorectal cancer. Methods: Patients who underwent curative resection for stage II or III colorectal cancer between 2000 and 2007 were included in this study. Data from a prospectively maintained database were retrospectively reviewed. TF expression was determined by immunohistochemistry using an anti-TF monoclonal antibody. The Kaplan-Meier method was used to estimate 5-year disease-free survival. Results: TF was highly expressed in 257 of 297 patients (86.5%). TF expression was not significantly associated with the platelet counts (P=0.180) or fibrinogen level (P=0.281). The 5-year disease-free survival rate was lower in patients with high TF expression than in patients with low TF expression (72.3% vs. 83.9%, P=0.074). In Cox hazard analysis, high TF expression was an independent risk factor for tumor recurrence (hazard ratio [HR] 2.446; 95% confidence interval [CI], 1.054-5.674; P=0.037). Undifferentiated histologic type (HR, 2.911; 95% CI, 1.308-6.481; P=0.009), venous invasion (HR, 2.784; 95% CI, 1.431-5.417; P=0.003), and lymph node metastasis (HR, 2.497; 95% CI, 1.499-4.158; P<0.001), were also significantly associated with disease recurrence. Conclusion: TF expression is associated with a recurrence in patients with non-metastatic colorectal cancer. However, further studies are required to clarify the underlying mechanisms relating TF expression with oncologic outcomes and its potential role as a therapeutic target.

• The Korean Journal of Urological Oncology
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• v.16 no.3
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• pp.89-96
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• 2018

Upper tract urothelial carcinoma (UTUC) has a relatively low prevalence rate of about 1.8 per 100,000 people. According to the recent literature, the development of diagnostic techniques has gradually increased the prevalence and diagnosis rate. In the past, when UTUC was diagnosed, more than 60% of the patients were diagnosed as locally advanced or metastatic cancer. However, since 2010, approximately 70% of the patients have been diagnosed as operable stage. Although radical nephroureterectomy is known as the basis of treatment for UTUC, overall survival is poor in patients with lymph node invasion. Especially, the finding that a localized UTUC is associated with a high risk of cancer metastasis in approximately 50% of patients suggests that these patients may not have sufficient treatment through surgery alone. The European Association of Urology and the National Comprehensive Cancer Network guideline 2017 suggested that postoperative adjuvant chemotherapy may be considered in patients with advanced UTUC beyond pT2. Also, recent meta-analyses have reported that cisplatin-based adjuvant chemotherapy can be expected to have a synergistic effect of overall survival and disease-free survival. However, many patients with UTUC undergo postoperative renal failure, which may result in failure to perform cisplatin-based adjuvant chemotherapy with adequate dose. For this reason, several researchers have suggested that it is beneficial to apply neoadjuvant chemotherapy when the preoperative renal function is maintained to a certain extent. But, neoadjuvant chemotherapy has not been used by many clinicians because of the lack of studies and the rarity of the disease. We are currently discussing the outcomes and prospects of perioperative chemotherapy.

• Biomolecules & Therapeutics
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• v.30 no.3
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• pp.284-290
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• 2022

Oral squamous cell carcinoma (OSCC) is mostly diagnosed at an advanced stage, with local and/or distal metastasis. Thus, locoregional and/or local control of the primary tumor is crucial for a better prognosis in patients with OSCC. Platelets have long been considered major players in cancer metastasis. Traditional antiplatelet agents, such as aspirin, are thought to be potential chemotherapeutics, but they need to be used with caution because of the increased bleeding risk. Podoplanin (PDPN)-expressing cancer cells can activate platelets and promote OSCC metastasis. However, the reciprocal effect of platelets on PDPN expression in OSCC has not been investigated. In this study, we found that direct contact with platelets upregulated PDPN and integrin β1 at the protein level and promoted invasiveness of human OSCC Ca9.22 cells that express low levels of PDPN. In another human OSCC HSC3 cell line that express PDPN at an abundant level, silencing of the PDPN gene reduced cell invasiveness. Analysis of the public database further supported the co-expression of PDPN and integrin β1 and their increased expression in metastatic tissues compared to normal and tumor tissues of the oral cavity. Taken together, these data suggest that PDPN is a potential target to regulate platelet-tumor interaction and metastasis for OSCC treatment, which can overcome the limitations of traditional antiplatelet drugs.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.297-306
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• 2022

Objective : Intracranial atypical meningiomas have a poor prognosis and high rates of recurrence. Moreover, up to one-third of the recurrences undergo high-grade transformation into malignant meningiomas. We aimed to investigate the clinical factors that can predict the propensity of malignant transformation from atypical to anaplastic meningiomas. Methods : Between 2001 and 2018, all patients with atypical meningioma, in whom the tumors had undergone malignant transformation to anaplastic meningioma, were included. The patients' medical records documenting the diagnosis of atypical meningioma prior to malignant transformation were reviewed to identify the predictors of transformation. The control group comprised 56 patients with atypical meningiomas who were first diagnosed between January 2017 and December 2018 and had no malignant transformation. Results : Nine patients in whom the atypical meningiomas underwent malignant transformation were included. The median time interval from diagnosis of atypical meningioma to malignant transformation was 19 months (range, 7-78). The study group showed a significant difference in heterogeneous enhancement (77.8% vs. 33.9%), bone invasion (55.6% vs. 12.5%), mitotic index (MI; 14.8±4.9 vs. 3.5±3.9), and Ki-67 index (20.7±13.9 vs. 9.5±7.1) compared with the control group. In multivariate analysis, increased MI (odds ratio, 1.436; 95% confidence interval, 1.127-1.900; p=0.004) was the only significant factor for predicting malignant transformation. Conclusion : An increased MI within atypical meningiomas might be used as a predictor of malignant transformation. Tumors at high risk for malignant transformation might require more attentive surveillance and management than other atypical meningiomas.

• Journal of the Korea Society of Computer and Information
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• v.28 no.1
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• pp.171-178
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• 2023

As the risk of privacy invasion due to self-disclosure increases in SNS environment, many studies have tried to discover the influencing factors of self-disclosure. This study is an extension of this research stream and pays attention to the role of interaction privacy controls(friend list and privacy settings) as a new influencing factor. Specifically, the study theorizes and test the logic that the ability to effectively control interactions between individuals using IPC(called IPC usefulness) satisfies the three psychological needs(autonomy, relationship, and competency needs) suggested by the Self-Determination Theory, and in turn increase the amount of self-disclosure. As a result of data analysis, it was found that IPC usefulness has a very strong influence on the satisfaction of psychological needs and is a major factor in increasing the degree of self-disclosure by users. Based on these findings, the study discusses the theoretical and practical implications as well as future research directions.

• Smart Media Journal
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• v.11 no.10
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• pp.76-88
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• 2022

Personal information leakage is very harmful as it can lead to additional attacks using leaked information as well as privacy invasion, and it is primarily caused by hacking server databases of institutions that collect and store personal information. We propose a scheme that allows a service-requesting user to authorize a secure delegated transfer of his personal information to the service provider via a reliable authority and enables only the two parties of the service to retrieve the provided information stored on a blockchain ensuring data confidentiality. It thus eliminates the necessity of storing customer information in the service provider's own database. As a result, the service provider can serve customers without requiring membership registration or storing personal information in the database, so that information leakage through the server database can be completely blocked. In addition, the scheme is free from the risk of information leakage and subsequent attacks through smartphones because it does not require a user's smartphone to store any authentication credential or personal information of its owner.