강자성체에서 상전이의 수치적 모의실험

유대영,양해정,양회룡,정진,최승평,장차익 조선대학교 기초과학연구소 2001 自然科學硏究 Vol.24 No.-

It is difficult to explain the magnetic phase transition with classical physics in Curie temperature. We studied qualitatively with the well known Ising model in statistical mechanics. We simulated systems of finite size by Monte Carlo methods with Metropolis algorithm. Thus we could estimate the values of quantities such as the magnetization(m) per spin the specific heat(c) per spin the magnetic susceptibility(χ) per spin, and the mean energy per spin compare with the numerical values in infinitive size. The quantities of c, m, χ, e varied rapidly within 2.3∼2.4 temperature at J/k units. Those values show that the critical temperature can be within the range. The hysteresis loop was obtained with this model.

다공성 펠렛을 포집재로 사용하는 매연여과장치의 배압 및 재생 특성에 관한 연구

金鎭玄,柳鍾植,文學勳,車京玉 明知大學校 産業技術硏究所 2006 産業技術硏究所論文集 Vol.25 No.-

Diesel particulate trap is a core technology for the reduction of PM from diesel vehicles. This study presents the features and the characteristics of DPF system when using pellet type filters. In comparison with wall-flow filter, the pellet filter has the advantages of cracking free during regeneration and shape flexibility. Experiments are conducted in a test bench simulated as diesel engine exhaust condition. Pressure drop and particle loading rate was compared by using two pellet filters having the porosity of 70% and 0%. Also its regeneration was tested.

Reaction of Lithium Cyanoaluminum Hydride with Selected Organic Compounds Containing Representative Functional Groups. Comparison of Reducing Characteristics between Lithium and Sodium Cyanoaluminum Hydrides

Cha, Jin-Soon,Yu, Se-Jin Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.7

Lithium cyanoaluminum hydride (LCAH) was prepared by the metal cation exchange reaction of sodium cyanoaluminum hydride with lithium chloride in tetrahydrofuran. The reducing characteristics of LCAH were explored systematically by the reaction with selected organic compounds containing representative functional groups under the standardized conditions (tetrahydrofuran, 0 ${^{\circ}C}$). The reducing ability of LCAH was also compared with of the sodium derivative, sodium cyanoaluminum hydride (SCAH). Generally, the reducing behavior of LCAH resembles that of SCAH closely, but the reactivity of LCAH toward representative organic functional groups appeared to be stronger than that of SCAH. Thus, the regent reduces carbonyl compounds, epoxides, amides, nitriles, disulfides, carboxylic acids and their acyl derivatives to the corresponding alcohols or amines, at a relatively faster rate than that of SCAH. The cyano substitution, a strong election-withdrawing group, diminishes the reducing power of the parent metal aluminum hydrides and hence effects the alteration of their reducing characteristics.

The Effect of the Sugar-amino Reaction on Reducing Biogenic Amines in the Fermented Fish Sauce

Jin Hyeon Kim,Eunsong Cha,Jin Ha Sim,Changheon Lee,Yong-Jun Cha,Daeung Yu 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

Fish sauce is a traditional fermented condiment popular in Korea and Southeast Asian countries. The fermented fish sauce contains large amounts of biogenic amines, which can cause food toxicity. To improve food quality and safety, effect of sugar-amino reaction on reducing biogenic amines was investigated by increasing heating time (0, 2, 4, and 6 hrs) and adding food additives (glycine, fructose, glucose, xylose, glycerin, and rosemary extract). The contents of biogenic amines (tryptamine, putrescine, cadaverine, histamine, and tyramine) were analyzed by HPLC. Among biogenic amines, histamine contents were decreased with increasing heating time and showed the lowest content at 6 hrs (304.26 mg/kg, 26%), but there was no significant difference at 4 hrs (310.44 mg/kg, 24%) (P<0.05). The glycine and xylose mixture decreased histamine to the most with 263.25 mg/kg (36%), followed by each of xylose and glycine. In color values, L*, a*, and b* values of fermented fish sauce with glycine and xylose mixture and xylose alone were lowered compared to others. The possibility of reducing biogenic amines through sugar-amino reaction has been confirmed, and additional research is needed.

Reaction of Sodium Cyanoaluminum Hydride with Selected Organic Compounds Containing Representative Functional Groups

Cha, Jin-Soon,Yu, Se-Jin,Roh, Min-Young,Yi, Ja-Eun,Park, Seung-Jin,Kwon, Oh-Oun Korean Chemical Society 2008 Bulletin of the Korean Chemical Society Vol.29 No.12

Power Control for Optimum Channel Estimation of D-TR-STBC-SC System

Yu-Jin Cha(차유진),Jeong-Min Choi(최정민),Jong-Soo Seo(서종수) 한국통신학회 2013 한국통신학회 학술대회논문집 Vol.2013 No.1

장류 및 젓갈 분리 균주 추출물의 비만세포 매개 항염증효과

Yu-Jin Ko(고유진),Hui-Hun Kim(김희훈),Eun-Jung Kim(김은정),Jin-Yong Kim(김진용),Sang-Dong Kang(강상동),Yong-Hwi Son(손용휘),Sin-Yang Choi(최신양),Seong-Kwan Cha(차성관),Jong-Won Kim(김종원),Jeong-Ok Lee(이정옥),Chung-Ho Ryu(류충호) 한국생명과학회 2011 생명과학회지 Vol.21 No.3

본 연구에서 장류 및 젓갈 유래 균체를 각각 sonication, 100℃에서 30 min, 125℃에서 15 min의 조건으로 추출하여 HMC-1에 처리하였을 때, 이 추출방법에 따른 HMC-1매개 염증반응 억제효과를 조사하였다. 추출방법을 달리하여 추출한 장류 및 젓갈 유래 균체 J80, G147이 HMC-1생존율에 미치는 영향은 대조구 B (Not treated)와 비교하였을 때 86~96%로 유의적 차이를 보이지 않아 장류 및 젓갈 유래 균체에 의한 세포 독성은 나타나지 않았다. 장류 및 젓갈 유래 균체의 모든 전처리구에서 histamine 유리 억제효과를 나타내었으며 특히, 100℃에서 30min 동안 가열하였을 때 histamine 억제율이 J80에서 28.86%, G147에서 41.14%으로 가장 높게 나타냈다. IL-8분비량은 J80, G147의 모든 전처리구에서 IL-8 분비억제효과가 나타났으며, J80의 경우 100℃, 30 min에서 처리한구에서 분비량이 0.78 ng/㎖로 대조구 B (Not treated)에 비하여 약 28.45%의 분비억제효과로 가장 높게 나타내었다. G147의 경우 125℃, 15 min에서 처리한 구에서 분비량이 0.73 ng/㎖로 약 36.52%의 분비억제효과로 가장 높게 나타내었다. IL-6 분비량을 측정한 결과 J80, G147의 모든 실험구에서 IL-6 분비억제효과가 나타났으며, J80에서는 100℃, 30 min한 D구의 분비량이 0.40 ng/㎖으로 대조구 B (Not treated)에 비하여 약 38.46%의 분비억제효과로 가장 높았으며, G147 역시 100℃, 30 min 동안 처리한 D구의 분비량이 0.27 ng/㎖으로 대조구 B (Not treated)에 비하여 56.45%의 분비억제효과로 가장 높게 나타냈다. TNF-α 분비량 역시 IL-6와 마찬가지로 J80, G147에서 대조구 B보다 낮은 분비량으로 TNF-α 분비 억제효과가 나타났으며 J80의 경우 100℃, 30 min 처리한 D의 TNF-α 분비량이 0.052 ng/㎖으로 66.67%의 분비억제효과로 가장 높았으며, G147의 경우 sonication을 처리한 C구의 TNF-α 분비량이 0.086 ng/㎖으로 41.1%의 분비억제효과로 다른 구에 비해 높은 억제효과를 나타내었다. 위의 결과를 통해서 장류 및 젓갈 유래 균체의 3가지 전처리 방법 중 100℃, 30 min 처리 시 염증 반응 억제 효과가 가장 높을 것으로 예상된다. 결과를 미루어보아 장류를 섭취하는 대표적인 방법인 가열하여 찌개로 조리과정 중장류 및 젓갈 속의 균체가 열에 가열되면서 염증억제효과 높일 수 있는 가장 좋은 조리 방법으로 사료되며, 이는 대중들이 가장 가깝게 염증반응 억제효과를 볼 수 있는 식품일 것이다. 또한 염장처리과정만을 거친 젓갈을 섭취하는 것보다 열처리과정을 거친 젓갈을 섭취할 경우 염증억제효과를 더 높일 수 있을 것으로 예상된다. The mast cell is one of the major effector cells in inflammatory reactions and can be found in most tissues throughout the body. Activated mast cells can produce histamine, as well as a wide variety of other inflammatory mediators such as eicosanoids, proteoglycans, proteases, and several pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, and interleukins (IL-6), IL-8, IL-4, IL-13. In the present study, we isolated two bacterial strains (J80 and G147) from fermented soybean and Jeotgal,and investigated the inhibitory effects of their extracts which were prepared by several pretreatment methods (sonication for 20 min, heating at 100℃ for 30 min, autoclaving at 121℃ for 15 min) on the mast cell-mediated inflammatory response. The pretreated bacterial extracts had no cytotoxicity against Human Mast Cell (HMC-1). Among various pretreatments, the extracts treated at 100℃ showed highest inhibition of histamine release (J80, 28.46%; G147, 41.14%). The J80 and G147 extracts treated at 100℃ resulted in the inhibition of IL-6 secretion by 38.46% and 56.45%, respectively. The J80 extract treated at 100℃ resulted in the inhibition of TNF-α secretion by 66.67%, but G147 extract showed the highest inhibition effect by 41.1% when treated with sonication. These results suggest that bacterial extracts treated at 100℃ have a higher level of anti-inflammatory effects than other treatments such as sonication or autoclaving.

The Effect of pH Control by Organic and Inorganic acid/base on Reducing Biogenic Amines in the Fermented Fish Sauce

Jin Ha Sim,Eunsong Cha,Jin Hyeon Kim,Changheon Lee,Yong-Jun Cha,Daeung Yu 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

Biogenic amines are nitrogenous compounds formed by amino acid decarboxylation, that might effect allergic reactions, headaches, and vomiting. Even though fish sauce has high amount biogenic amines, fish sauce is still used as condiment in Korea. So in this study, the pH of fish sauce was adjusted to 3.0∼7.0 with 1 N HCl (or NaOH) and citric acid (or NaHCO₃) as organic/inorganic acids/bases to reduce biogenic amines in fish sauces fermented over 1 year (pH 5.3). The contents of biogenic amines in fish sauces with pH adjusting and heating for 2 hour at 92℃ were analyzed by HPLC. Among the biogenic amines, histamine content was decreased with increasing pH. The fish sauces adjusted pH by organic base at 6.0 and 7.0 smelled like dried shrimp, roasted shrimp, and nutty. However, an ammonia odor was generated at pH 7.0. In spite of showing second highest reduction rate, the pH 6.0 was selected as the optimal condition. Although there was an effect of organic and inorganic base on reducing histamine content in fermented fish sauce, additional studies are needed for further reduction.

Stereotactic body radiation therapy for liver oligo-recurrence and oligo-progression from various tumors

Cha, Yu Jin,Kim, Mi-Sook,Jang, Won-Il,Seo, Young Seok,Cho, Chul Koo,Yoo, Hyung Jun,Paik, Eun Kyung The Korean Society for Radiation Oncology 2017 Radiation Oncology Journal Vol.35 No.2

Purpose: To evaluate the outcomes of stereotactic body radiation therapy (SBRT) for patients with liver oligo-recurrence and oligo-progression from various primary tumors. Materials and Methods: Between 2002 and 2013, 72 patients with liver oligo-recurrence (oligo-metastasis with a controlled primary tumor) and oligo-progression (contradictory progression of a few sites of disease despite an overall tumor burden response to therapy) underwent SBRT. Of these, 9 and 8 patients with uncontrollable distant metastases and patients immediate loss to follow-up, respectively, were excluded. The total planning target volume was used to select the SBRT dose (median, 48 Gy; range, 30 to 60 Gy, 3-4 fractions). Toxicity was evaluated using the Common Toxicity Criteria for Adverse Events v4.0. Results: We evaluated 55 patients (77 lesions) treated with SBRT for liver metastases. All patients had controlled primary lesions, and 28 patients had stable lesions at another site (oligo-progression). The most common primary site was the colon (36 patients), followed by the stomach (6 patients) and other sites (13 patients). The 2-year local control and progression-free survival rates were 68% and 22%, respectively. The 2- and 5-year overall survival rates were 56% and 20%, respectively. The most common adverse events were grade 1-2 fatigue, nausea, and vomiting; no grade ${\geq}3$ toxicities were observed. Univariate analysis revealed that oligo-progression associated with poor survival. Conclusion: SBRT for liver oligo-recurrence and oligo-progression appears safe, with similar local control rates. For liver oligo-progression, criteria are needed to select patients in whom improved overall survival can be expected through SBRT.

HER2 induces expression of Leptin in human breast epithelial cells

( Yu Jin Cha ),( You Jin Kang ),( Aree Moon ) 생화학분자생물학회(구 한국생화학분자생물학회) 2012 BMB Reports Vol.45 No.12

A close association between the obesity hormone leptin and breast cancer progression has been suggested. The present study investigated the molecular mechanism for enhanced leptin expression in breast cancer cells and its functional significance in breast cancer aggressiveness. We examined whether leptin expression level is affected by the oncoprotein human epidermal growth factor receptor2 (HER2), which is overexpressed in ∼30% of breast tumors. Here, we report, for the first time, that HER2 induces transcriptional activation of leptin in MCF10A human breast epithelial cells. We also showed that p38 mitogen-activated protein kinase signaling was involved in leptin expression induced by HER2. We showed a crucial role of leptin in the invasiveness of HER2-MCF10A cells using an siRNA molecule targeting leptin. Taken together, the results indicate a molecular link between HER2 and leptin, providing supporting evidence that leptin represents a target for breast cancer therapy. [BMB Reports 2012; 45(12): 719-723]