• International Commerce and Information Review
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• v.7 no.4
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• pp.117-134
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• 2005

B2B transaction was expected to dominate in the global market and thus many e-marketplaces have been built since 1999 in Korea. However, only a few e-marketplaces are thriving and the future of B2B e-marketplaces except MRO area seem to be uncertain. This paper explores why B2B transactions only in MRO area are rapidly increasing and examines the competing structure and business models of MRO e-marketplace. Business models of MRO e-marketplaces are various among different countries. However, they can be classified as three business models:information portal model, purchasing agent model, open market model. It is not easy to answer which business model is most competitive because each models have their own advantages and functions. Information portal model can be easily applied for the e-marketplace which operates off-line enterprises. Purchasing agent model is favorable to the e-marketplaces which has already obtained buyers and sellers. Open market model is desirable to the e-marketplace which has excess to global market.

• Journal of the Korean Mathematical Society
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• v.60 no.5
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• pp.1087-1107
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• 2023

Let E be an elliptic curve defined over ℚ of conductor N, c the Manin constant of E, and m the product of Tamagawa numbers of E at prime divisors of N. Let K be an imaginary quadratic field where all prime divisors of N split in K, P_K the Heegner point in E(K), and III(E/K) the Shafarevich-Tate group of E over K. Let 2u_K be the number of roots of unity contained in K. Gross and Zagier conjectured that if P_K has infinite order in E(K), then the integer c · m · u_K · |III(E/K)| $\frac{1}{2}$ is divisible by |E(ℚ)_tor|. In this paper, we prove that this conjecture is true if E(ℚ)_tor ≅ ℤ/2ℤ or ℤ/4ℤ except for two explicit families of curves. Further, we show these exceptions can be removed under Stein-Watkins conjecture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1936-1942
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• 2010

To examine the effect of overdosed functional food in liver-injured patients, we tried to investigate the dose effect of Allium sativum L. (also called garlic) extract on rats with CCl4-induced liver damage, by comparatively examinating the hepatic function of each group. 42 male Sprague-Dawley rats were selected and divided equally (n=7) into normal, control, positive control, and three experimental subgroups (E1, E2 and E3), respectively. For each kg of body weight, hepatic injury was induced by intraperitoneal administration of $0.5\;m{\ell}$ (0.20 g/kg/day) $CCl_4$, which was diluted in equal amount of olive oil, once a day on every other day for total 5 times. Hot water extraction was performed using domestically cultivated organic garlics, and the obtained extract was injected by sonde, once daily during 4 weeks, to each experimental subgroups by different dosage of 0.35 g/kg(E1), 0.70 g/kg(E2), 1.40 g/kg(E3), respectively. Results showed that the injection of garlic extract positively influenced the physiological activation which lowered the oxidative stress, changed the toxicity, and functionally improved the hepatic condition. Comparing the dose effect between the three experimental subgroups (E1, E2, E3), results of the maximal-dosed subgroup (E3) showed less significance compared with the lower-dosed subgroups(E1 and E2), which seems to resulted from the (increased) toxicity of garlic.

• Honam Mathematical Journal
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• v.43 no.2
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• pp.199-207
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• 2021

In this paper we introduce two classes of modules namely e-symmetric and e-reduced. Also, we study the characterizations of e-symmetric and e-reduced modules and their related properties.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.143-149
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• 2007

The experiment was conducted to examine the effects of dietary organic selenium and vitamin E on weight gain, feed intake, feed conversion, and selenium retention in meat of broiler chickens. For each growth phase, the basal diet was supplemented with 0 (control), vitamin E 150 IU/kg and the combination of 1.2 ppm Se from selenium yeast (SY) and vitamin E 100, 150, 200 and 300 IU/kg. Weight gain was significantly higher in supplemental control and vitamin E 150 compared to the combination of 1.2 ppm SY and vitamin E 150 IU during day 1 to 21. Feed intake significantly(P<0.05) increased in supplemental vitamin E 150 compared to the combination of 1.2 ppm SY and vitamin E 150 and 200 IU during day 1 to 21. Feed intake was significantly(P<0.05) higher in control compared to that of combination of 1.2 ppm SY and vitamin E 200 IU during day 21 to 35. However feed conversion was not affected in supplemental vitamin E and SY during day 1 to 35. Selenium concentrations of breast muscle and liver tissue significantly increased (P<0.05) in supplemental combination of 1.2 ppm SY and vitamin E compared to the control and vitamin E 150 IU. TBARS of control and vitamin E 150 IU were significantly (P<0.05) higher in day 3 than day 1, but the combination of Se 1.2 ppm and vitamin E of TBARS had no difference during day 1 to 3. TBARS in day 3 was significantly (P<0.05) lower in supplemental combination of Se 1.2 ppm and vitamin E than control and vitamin E 150 IU.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.719-723
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• 2007

It is very active that existing companies of providing e-Learning contents try to differentiate themselves through a business model based on Web 2.0. For instance, Etoos, online education website (www.etoos.com) run by SK Communications has made more space where students can participate in the Web 2.0 era and overhauled its website completely, turning into an open-ended one, which strengthens learning and fun in 2007. This study is to analyze the present state of e-Learning contents with representative e-learning sites for middle and high school students, to find that the development direction for next generation e-Learning lies in developing contents focusing on learners that can get effective feedback and drawing collective intelligence grounded on the essence of Web 2.0, and to suggest 'the project to form virtual private tutor community in e-Learning contents.'

• Molecules and Cells
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• v.20 no.3
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• pp.378-384
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• 2005

Estrogen metabolites are carcinogenic. The comparative mitogenic activities of $17{\beta}$-estradiol (E2) and four metabolites, 2-hydroxyestradiol (2-OHE2), 4-hydroxyestradiol (4-OHE2), $16{\alpha}$-hydroxyestrone ($16{\alpha}$-OHE1) and 2-methoxyestradiol (2-ME), were determined in estrogen receptor(ER)-positive MCF-7 human breast cancer cells. Each of the E2 metabolites caused proliferation of the MCF-7 cells, but only E2 and $16{\alpha}$-OHE1 induced a greater than 20-fold increases in transcripts of the progesterone receptor (PR) gene, a classical ER-mediated gene. This suggests that the mitogenic action of E2 and $16{\alpha}$-OHE1 could result from their effects on gene expression via the ER. E2 metabolites altered the expression of E2-regulated proteins including heat shock proteins (Hsps). $16{\alpha}$-OHE1 and 2-ME as well as E2 increased levels of Hsp56, Hsp60, $Hsp90{\alpha}$ and Hsp110 transcripts, and the patterns of these inductions resembled that of PR. Hsp56 and Hsp60 protein levels were increased by all the E2 metabolites. Levels of the transcripts of 3 E2-upregulated proteins (XTP3-transactivated protein A, protein disulfide isomerase-associated 4 protein and stathmin 1) and an E2-downregulated protein (aminoacylase 1) were also affected by the E2 metabolites. These results suggest that the altered expression of Hsps (especially Hsp56 and Hsp60) by E2 metabolites such as E2, $16{\alpha}$-OHE1 and 2-ME could be closely linked to their mitogenic action.

• Korean Journal of Clinical Laboratory Science
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• v.53 no.1
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• pp.32-40
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• 2021

This study examined the association between hypertension (HTN), estimated glomerular filtration rate (eGFR), and urine microalbumin/creatinine ratio (ACR) in Korean adults. Data for 8,922 adults (3,941 men and 4,981 women) aged ≥20 years from the Sixth Korean National Health and Nutrition Examination Survey VI (2013~2014) were analyzed. In men, after adjusting for the related variables, the odds ratios (ORs) of HTN [systolic blood pressure (SBP) ≥140 mmHg, diastolic blood pressure (DBP) ≥90 mmHg, or use of HTN medications] were significantly higher in the decreased eGFR group [eGFR <60 mL/min/1.73 ㎡, 1.98 (95% CI, 1.21~3.24)], elevated ACR group [ACR ≥30 mg/g, 2.03 (95% CI, 1.54~2.69)], and decreased eGFR plus elevated ACR group [eGFR <60 mL/min/1.73 ㎡ and ACR ≥30 mg/g, 6.03 (95% CI, 2.82~12.92)] than in the normal group (eGFR ≥60 mL/min/1.73 ㎡ and ACR <30 mg/g). In women, after adjusting for the related variables, the ORs of HTN were significantly higher in the decreased eGFR group (2.29, 95% CI, 1.27~4.13), elevated ACR group (2.22, 95% CI, 1.68~2.94), and decreased eGFR plus elevated ACR group (10.77, 95% CI, 3.89~29.82) than the normal group. In conclusion, HTN was associated with a decreased eGFR and elevated ACR in Korean men and women. In addition, the prevalence of HTN increased greatly when a decreased eGFR and elevated ACR occurred simultaneously.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.2
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• pp.125-134
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• 2024

The present study was conducted to explore relationships between anemia and estimated glomerular filtration rate (eGFR) and urine microalbumin/creatinine ratio (uACR) in Korean adults with or without metabolic syndrome (MetS). The data of 4,943 adults aged ≥20 years who participated in KNHNES V-3 (2012) were analyzed. In the non-MetS group, the odds ratio (OR) for anemia of those with a decreased eGFR {eGFR<60 mL/min/1.73 m², 3.85 (95% confidence interval [CI], 2.03~7.30)} was significant as was the OR of those with decreased eGFR plus elevated uACR (eGFR<60 mL/min/1.73 m² and uACR≥30 mg/g, 5.81 [95% CI, 2.60~13.02]). In the MetS group, ORs for anemia for those with an elevated uACR (2.18 [95% CI, 1.11~4.27]), a decreased eGFR (3.74 [95% CI, 1.11~12.55]), or a decreased eGFR plus an elevated uACR (16.79 [95% CI, 5.93~47.57]) were significant. In conclusion, in non-MetS, anemia was associated with a low eGFR, whereas in MetS, anemia was associated with a low eGFR and an elevated uACR. In addition, the OR for anemia was greatly increased when eGFR was diminished and uACR was elevated regardless of MetS and MetS status.

• Korean Journal of Veterinary Research
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• v.12 no.2
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• pp.185-190
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• 1972

A preliminary survey for classification of coccidia isolated from domestic animals and poultry was broadly conducted by the morphological aspects of the $o{\ddot{o}}cysts$. The number of animals and birds used in this survey were 762 chickens, 30 rabbits, 37 goats, 18 swine, 39 cattle, 8 dogs, 132 ducks, 23 deer and 15 horses. The species classified in each animal and bird were six species in chicken, nine in rabbits, nine in goats, six in swine, six in cattle, one in dogs and negative in ducks, deer and horses. The coccidial species in each animal and bird were as follows: In chicken: Eimeria acervulina, E.maxima, E. mitis, E. necatrix, E. praecox, and E. tenella. In rabbits: Eimeria irresidua, E. magna, E. media, E. neolepolis, E. perforans, E. piriformis and E. stiedae. In goats: Eimeria ahsata, E. arloingi, E. crandalis, E. faurei, E. granulosa, E. intricata, E. ninakohlyakimovae, E. pallida, E. perva. In Swine: Eimeria deblieki, E. perminuta, E. palita, E. scabra, E. scrofae and Isospora suis. In Cattle : Eimeria bovis, E. bukidonensis, E. cylindrica, E ellipsoidalis, E subspherica and E. Zurnii. In dogs: Isospora bigemina.