• Journal of the Korean Ceramic Society
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• v.20 no.2
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• pp.115-122
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• 1983

There has been many controversies about the effects of additive in sintering of SiC But no prior systematic work has been reported about the difference between the effects of B and $B_4C$ as additive. The sintering behavior of SiC and its strength are studied and the optimum concentrations of additives and sintering conditions for SiC are determined. The effects of B and $B_4C$ have same effects on reactive sintering of SiC except the easiness of transport via vapor phase for uniform distribution in case of B. The strength of sintered SiC without exaggerated grain growth is limited by surface flaws and is nearly independent of temperature up to 140$0^{\circ}C$.

• The Journal of the Korean dental association
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• v.52 no.8
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• pp.478-490
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• 2014

Recently, importance of meta-analysis is increasing in the field of dentistry, since it is not easy to settle controversies arising from conflicting studies. Meta-analysis is the statistical method of combining results from two or more individual studies that have been done on the same topic. Merits of meta-analysis include an increase in power, an improvement in precision, and the ability to address solution not provided by individual studies. However, it might mislead researchers when variation across studies and publication bias are not carefully taken into consideration. The purpose of this study is to help understand meta-analysis by making use of individual results in dental research paper.

• Korean Journal of Logic
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• v.14 no.3
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• pp.85-100
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• 2011

Recently Byeong Deok Lee has denied the validity of the so-called uncontested principle, which says that the indicative conditional implies the material conditional. I show that his denial means that modus ponens is not valid and that the truth-conditions of indicative conditionals are weaker than that of material conditionals. It seems that what made him hold this view is related to some misunderstanding of indicative conditionals.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.2
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• pp.132-140
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• 2006

Well-differentiated thyroid cancer is the most common endocrine malignancy with an increasing incidence. Most patients with well-differentiated thyroid caner have a favorable prognosis with high survival rate. While surgery and radioiodine therapy is sufficient treatment for the majority of patients with differentiated thyroid cancer, a minority of these patients experiences progressive, life-threatening growth and metastatic spread of the disease. Because there is no prospective controlled study to evaluate the differences of management of thyroid cancer, it is hard to choose the best treatment option. And there are still lots of controversies about the management of this disease, such as surgical extent, proper use of radioiodine for remnant ablation and therapy, use of rhTSH instead of withdrawal of thyroid hormone, long-term follow-up strategy, thyroglobulin as a tumor marker, etc. In this review, recent data related to these conflicting issues and recent advances in diagnosis, radioiodine therapy and long-term monitoring of well-differentiated thyroid cancer are summarized.

• Journal for History of Mathematics
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• v.25 no.4
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• pp.21-36
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• 2012

It is commonly believed that the model-theoretic account of logical consequence is originated from Tarski' s 1936 paper. But Etchemendy has denied this. This paper discusses and evaluates the recent controversies over whether the definition of logical consequence presented in Tarski' s paper is based on the fixed-domain conception or the variable-domain conception.

• The Korean Journal of Gastroenterology
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• v.72 no.5
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• pp.245-251
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• 2018

Gastric cancer is the most common cancer in Korea and the fifth most common cancer globally. Helicobacter pylori (H. pylori) infection is considered the main etiologic agent for gastric cancer development. Most regional guidelines for H. pylori treatment recommend treating the organism to prevent gastric cancer in the high-risk group. However, evidence that such a strategy can also be applied to the general population, especially in terms of the preventive effect and safety, has not been adequately presented yet. Although a meta-analysis in the general population suggested effectiveness in decreasing gastric cancer incidence, individual studies should be critically reviewed to evaluate the soundness of the evidence. Recently published, long-term, Korean studies on metachronous gastric cancer prevention ended the controversies from previous short-term studies and confirmed the effectiveness. Currently, further prospective, large, randomized studies are ongoing in the general population and will provide more definitive, high-level evidence on this gastric cancer prevention strategy in the next decade.

• BMB Reports
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• v.54 no.3
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• pp.149-156
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• 2021

The well-known second messenger cyclic adenosine monophosphate (cAMP) regulates the morphology and physiology of neurons and thus higher cognitive brain functions. The discovery of exchange protein activated by cAMP (Epac) as a guanine nucleotide exchange factor for Rap GTPases has shed light on protein kinase A (PKA)-independent functions of cAMP signaling in neural tissues. Studies of cAMP-Epac-mediated signaling in neurons under normal and disease conditions also revealed its diverse contributions to neurodevelopment, synaptic remodeling, and neurotransmitter release, as well as learning, memory, and emotion. In this mini-review, the various roles of Epac isoforms, including Epac1 and Epac2, highly expressed in neural tissues are summarized, and controversies or issues are highlighted that need to be resolved to uncover the critical functions of Epac in neural tissues and the potential for a new therapeutic target of mental disorders.

• Archives of Craniofacial Surgery
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• v.22 no.6
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• pp.287-295
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• 2021

Orthognathic surgery has steadily evolved, gradually expanding its scope of application beyond its original purpose of simply correcting malocclusion and the facial profile. For instance, it is now used to treat obstructive sleep apnea and to achieve purely cosmetic outcomes. Recent developments in three-dimensional digital technology are being utilized throughout the entire process of orthognathic surgery, from establishing a surgical plan to printing the surgical splint. These processes have made it possible to perform more sophisticated surgery. The goal of this review article is to introduce current trends in the field of orthognathic surgery and controversies that are under active discussion. The role of a plastic surgeon is not limited to performing orthognathic surgery itself, but also encompasses deep involvement throughout the entire process, including the set-up of surgical occlusion and overall surgical planning. The authors summarize various aspects in the field of orthognathic surgery with the hope of providing helpful information both for plastic surgeons and orthodontists who are interested in orthognathic surgery.

• Acta Via Serica
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• v.8 no.1
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• pp.55-70
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• 2023

Carpets are a useful tool for highlighting the cultural uniqueness of a region because their characteristic usage often reveals distinctive natural features of the place or the unique cultural identity of a group. Investigating anecdotes and associated patterns found in three medieval trans-Eurasian travelogues, this paper focuses on observations made by the Chinese Buddhist monk, Faxian, the Sunni pilgrim and scholar, Ibn Battuta, and Marco Polo, the Venetian merchant examining their thoughts, observations, and perspectives on carpet-related customs in their experienced contexts. In particular, this manuscript touches on the controversies, impacts, and narratives associated with carpet practices observed in each travel writer's context respectively, concluding that each traveler shows several things in common rather than showing different patterns depending on the characteristics of their religion. Overall, they observed the uses of carpets according to their jobs and travel purposes and appropriately detailed related episodes if the intended purpose and context matched the uses.

• Journal of Digestive Cancer Reports
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• v.7 no.2
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• pp.45-50
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• 2019

Incidence of rectal neuroendocrine neoplasms (NEN) has increased tremendously over the decades due to disease awareness and widespread use of screening colonoscopy. Although NEN has been recognized as malignant disease, most rectal NENs are initially found as small mass confined to the submucosa, which can be removed completely through various endoscopic treatments with good prognosis. In this review, we summarize the treatment options focusing on localized T1 rectal NEN by comparing representative international guidelines and discuss current controversies on the management. We also discuss various resection techniques focusing on endoscopic resection.