SOME CONDITIONS FOR COMAXIMALITY OF IDEALS

Ahn, Sung Hun The Kangwon-Kyungki Mathematical Society 2000 한국수학논문집 Vol.8 No.1

In this paper, it is shown that if R is a commutative ring with identity and there exists a multiplicatively closed subset S of R such that $S{\cap}Z(R/(I_1I_2{{\cdots}I_n))={\emptyset}$ and $I_1R_s,I_2R_s{\cdots},I_nR_s$ are pairwise comaximal, then $I_1I_2{\cdots}I_n=I_1{\cap}I_2{\cap}{\cdots}{\cap}I_n={\cap}^n_{i=1}(I_i\;:_R\;I_1{\cdots}I_{i-1}I_{i+1}{\cdots}I_n)$.

GO-37 : Ovarian Microcystic Stromal Tumor (MCST): a Novel Extracolonic Tumor in Familial Adenomatous Polyposis

( Sang Hun Lee ),( Soo Jeong Lee ),( Jun Woo Ahn ),( Hyun Jin Roh ),( Yong Soon Kwon ) 대한산부인과학회 2014 대한산부인과학회 학술대회 Vol.100 No.-

Ovarian microcystic stromal tumors (MCSTs) are a very rare cancer, hence even its nomenclature was recently designated as ‘Distinctive morphologic and immunohistochemical feature’ in 2009. Its exact origins and etiological genetic alterations and background are not yet clearly known. Familial adenomatous polyposis (FAP) is autosomal dominant, leading to initial development in the early stage of tumor via germ-line mutations of the APC gene on chromosome 5q21~q22. Cases of APC gene mutations, colon cancers and extra-colonic tumors by germ-line mutations and the second somatic mutations in the wild-type APC allele, respectively, have been found. Rare cases of extra-colonic tumors involving thyroid, liver, bile ducts, central nervous system have been reported, due to the scarcity of disease prevalence. In this study, we reported a 40-year-old female patient with both ovarian MCST and FAP. Collaborative operation involving Gynecology (LSO, ROWR) and Surgery (total colectomy) teams were performed. On sequencing the APC gene of ovarian MSCT, we detected the novel somatic mutation of the APC gene in exon 11, with a heterozygous deletion at nucleotide position c.1540delG (p.Ala514 Profs*9). On mutation analyses, ß-catenin (CTNNB1) and FOXL2 were not detected in ovarian MCST. The result of the analysis revealed that this was the second somatic mutation in the ovary. As far as we know, this is the first report on ovarian MCST with somatic mutation of APC, in a patient with FAP.

High-performance bioelectronic tongue using ligand binding domain T1R1 VFT for umami taste detection

Ahn, Sae Ryun,An, Ji Hyun,Jang, Il Ha,Na, Wonjoo,Yang, Heehong,Cho, Kyung Hee,Lee, Sang Hun,Song, Hyun Seok,Jang, Jyongsik,Park, Tai Hyun Elsevier 2018 Biosensors & Bioelectronics Vol.117 No.-

<P><B>Abstract</B></P> <P>Numerous efforts have been made to measure tastes for various purposes. However, most taste information is still obtained by human sensory evaluation. It is difficult to quantify a degree of taste or establish taste standard. Although artificial taste sensors called electronic tongues utilizing synthetic materials such as polymers, semiconductors, or lipid membranes have been developed, they have limited performance due to their low sensitivity and specificity. Recently, bioelectronic tongues fabricated by integrating human taste receptors and nanomaterial-based sensor platforms have been found to have high performance for measuring tastes with human-like taste perception. However, human umami taste receptor is heterodimeric class C GPCR composed of human taste receptor type 1 member 1 (T1R1) and member 3 (T1R3). Such complicated structure makes it difficult to fabricate bioelectronic tongue. The objective of this study was to develop a protein-based bioelectronic tongue for detecting and discriminating umami taste with human-like performance using umami ligand binding domain called venus flytrap (VFT) domain originating from T1R1 instead of using the whole heterodimeric complex of receptors. Such T1R1 VFT was produced from <I>Escherichia coli</I> (<I>E. coli)</I> with purification and refolding process. It was then immobilized onto graphene-based FET. This bioelectronic tongue for umami taste (BTUT) was able to detect monosodium L-glutamate (MSG) with high sensitivity (<I>ca.</I> 1 nM) and specificity in real-time. The intensity of umami taste was enhanced by inosine monophosphate (IMP) that is very similar to the human taste system. In addition, BTUT allowed efficient reusable property and storage stability. It maintained 90% of normalized signal intensity for five weeks. To develop bioelectronic tongue, this approach using the ligand binding domain of human taste receptor rather than the whole heterodimeric GPCRs has advantages in mass production, reusability, and stability. It also has great potential for various industrial applications such as food, beverage, and pharmaceutical fields.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Expression, purification and functional reconstitution of ligand binding domain of umami taste receptor. </LI> <LI> Taste sensor for umami taste detection using T1R1 VFT-functionalized graphene-FET. </LI> <LI> Bioelectronic tongue can detect the taste of umami with high sensitivity and selectivity. </LI> <LI> Bioelectronic tongue can measure the enhancing effect like human taste system. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Continuous Functional Analysis for Axiomatic Design

Ahn, Jeong-Hun,Cha, Sung-Woon 한국정밀공학회 2011 International Journal of Precision Engineering and Vol.12 No.1

Current developments within scientific technologies urge product design toward more sophisticated trends. Recently, axiomatic design has been utilized in order to overcome the difficulties of more sophisticated design requirements. The axiomatic design is a design methodology employing two axioms, the independence axiom and the information axiom, and can be applied in diversified fields. This axiomatic design provides the ability to illustrate the correlations among design factors using matrices, and these matrices also show the correct design direction. Thus, applying these axioms in design often corrects design problems, as shown in the coupled design. Through a new approach termed the "Continuous Functional Analysis," fewer Functional Requirements (FRs) can be used along with Design Parameters (DPs) under given constraints. We can present a simple correction method using the level curve, along with the gradient values.

Living Donor Liver Transplantation for Type II Citrullinemia in the Korean Patient

Sung-Won Jung,Sung-Gyu Lee,Shin Hwang,Ki-Hun Kim,Chul-Soo Ahn,Deok-Bog Moon,Tae-Yong Ha,Gi-Won Song,Dong-Hwan Jung 한국간담췌외과학회 2010 한국간담췌외과학회 학술대회지 Vol.2010 No.4

Ninjurin1 Deficiency Attenuates Susceptibility of Experimental Autoimmune Encephalomyelitis in Mice

Ahn, Bum Ju,Le, Hoang,Shin, Min Wook,Bae, Sung-Jin,Lee, Eun Ji,Wee, Hee-Jun,Cha, Jong-Ho,Lee, Hyo-Jong,Lee, Hye Shin,Kim, Jeong Hun,Kim, Chang-Yeon,Seo, Ji Hae,Lo, Eng H.,Jeon, Sejin,Lee, Mi-Ni,Oh, Go American Society for Biochemistry and Molecular Bi 2014 The Journal of biological chemistry Vol.289 No.6

<P>Ninjurin1 is a homotypic adhesion molecule that contributes to leukocyte trafficking in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. However, <I>in vivo</I> gene deficiency animal studies have not yet been done. Here, we constructed Ninjurin1 knock-out (KO) mice and investigated the role of Ninjurin1 on leukocyte trafficking under inflammation conditions such as EAE and endotoxin-induced uveitis. Ninjurin1 KO mice attenuated EAE susceptibility by reducing leukocyte recruitment into the injury regions of the spinal cord and showed less adhesion of leukocytes on inflamed retinal vessels in endotoxin-induced uveitis mice. Moreover, the administration of a custom-made antibody (Ab<SUB>26–37</SUB>) targeting the Ninjurin1 binding domain ameliorated the EAE symptoms, showing the contribution of its adhesion activity to leukocyte trafficking. In addition, we addressed the transendothelial migration (TEM) activity of bone marrow-derived macrophages and Raw264.7 cells according to the expression level of Ninjurin1. TEM activity was decreased in Ninjurin1 KO bone marrow-derived macrophages and siNinj1 Raw264.7 cells. Consistent with this, GFP-tagged mNinj1-overexpressing Raw264.7 cells increased their TEM activity. Taken together, we have clarified the contribution of Ninjurin1 to leukocyte trafficking <I>in vivo</I> and delineated its direct functions to TEM, emphasizing Ninjurin1 as a beneficial therapeutic target against inflammatory diseases such as multiple sclerosis.</P>

INTEGRAL DEPENDENCE ON MODULES

AHN, SUNG-HUN 동국대학교 자연과학연구원 1994 자연과학연구 논문집 Vol.14 No.-

In this paper, we define an integral dependence and integral closure on modules and prove some result about these operations. In particular, we show that, for any q ∈ AssR(M/Nd), there is a prime ideal p ∈ AssR(M/N) with p ∩R = q and ht(p) = 1 and that the module M is a finite R-module if and only if R is a finite R-module. Finally, we show that M is a finitely generated module over the restricted Rees ring R[It] with respect to I if and only if so is R.

Clinicopathological features and post-resection outcomes of hepatocellular adenoma

Sung-Min Kim,Shin Hwang,Chul-Soo Ahn,Ki-Hun Kim,Deok-Bog Moon,Tae-Yong Ha,Gi-Won Song,Dong-Hwan Jung,Gil-Chun Park,Seung-Mo Hong 한국간담췌외과학회 2021 Annals of hepato-biliary-pancreatic surgery Vol.25 No.1

Backgrounds/Aims: Hepatocellular adenomas (HCA) are rare benign liver tumors with the potential of malignant transformation and risk of bleeding. We investigated the clinicopathological features and outcomes of HCA in 19 patients who underwent surgical resection. Methods: This retrospective observational study included 19 patients who underwent hepatic resection during a 9-year period from 2011 to 2019. Results: The incidence of HCA was 0.18% of all hepatic resection cases during the study period. The mean age of the patients was 34.3±9.6 years, and 12 patients (63.2%) were female. Abdominal pain was present as initial clinical manifestation in 5 patients and the other 14 patients had no specific symptoms. HCA was diagnosed in 7 out of 8 patients who underwent liver biopsy. R0 resection was performed in 18 patients (94.7%) and laparoscopic liver resection was performed in 11 patients (57.9%). The mean tumor size was 5.6±3.6 cm and 17 patients had a single tumor. Immunohistochemical analysis of the resected tumor specimens revealed hepatocyte-nuclear-factor-1 mutated HCA in 2 (10.5%), β-catenin-mutated HCA in 2 (10.5%), inflammatory HCA in 12 (63.2%) and unclassified HCA in 3 (15.8%). There were no pathognomonic findings in the preoperative liver imaging studies among these four groups. Currently, all patients are alive with a mean follow-up period of 40.1±26.3 months. One patient showed residual tumors after incomplete resection. Conclusions: Surgical resection may be indicated if imaging studies show diagnostic ambiguity, growing tumor or symptomatic mass. Because of the risk of tumor recurrence and malignant transformation, long-term follow-up is necessary.

TECHNO-ECONOMIC COMPARISON ON SOFC HYBRID SYSTEMS

Sung Ho PARK,Young Duk LEE,Kang Hun LEE,Kook Young AHN 한국신재생에너지학회 2012 AFORE Vol.2012 No.-

INTEGRAL CLOSURE OF A GRADED TORSION FREE MODULE OVER A GRADED DOMAIN

Ahn, Sung-Hun 東國大學校 1996 東國論叢 Vol.35 No.-

graded domain R 상의 graded torsion free module M의 integral dependence를 정의하고 M 의 integral closure M￣가 V의 graded R￣-submodule이라는 것과 M￣ = ??_n∈z(M￣ ∩V_n)임을 보였다.