Theoretical Investigation of the Hydrogen-bonded Halide-acetylene Anion Complexes

정병서 대한화학회 2024 대한화학회지 Vol.68 No.2

The halide-acetylene anions, X−–HCCH (X = F, Cl, and Br) have been studied by using several different ab initio and DFT methods to determine structures, hydrogen-bond energies, vibrational frequencies of the anion complexes. Although the halide-acetylene complexes all have linear equilibrium structures, it is found that the fluoride complex is characterized with distinctively different structure and interactions compared to those of the chloride and bromide complexes. The performance of various density functionals on describing ionic hydrogen-bonded complexes is assessed by examining statistical deviations with respect to high level ab initio CCSD(T) results as reference. The density functionals employed in the present work show considerably varying degrees of performance depending on the properties computed. The performances of each density functional on geometrical parameters related with the hydrogen bond, hydrogen-bond energies, and scaled harmonic frequencies of the anion complexes are examined and discussed based on the statistical deviations.

Enhanced Raman Spectrum of Juglone on Ag Surface: Is It a Simile to That of Lawsone?

정병서,조한국 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.1

The surface enhanced Raman spectrum of juglone, a traditional natural dye, has been observed by a custombuilt micro-Raman setup. The spectral features of juglone significantly differ from those of lawsone, a structural isomer of juglone; only small red shifts of the double bond stretching bands are observed, and strong SERS bands are observed in the lower frequency regions as well. The DFT computations reveal that juglone coordinated to an Ag+ adatom with H+ release best correlates with the observed vibrational characteristics in the SERS spectrum among the plausible configurations of juglone coordinated to an adatom on the Ag surface, in line with the previously studied lawsone case. The differences in the SERS spectra of juglone and lawsone are attributed to the different locations of the hydroxyl group in the two isomers.

Ab Initio Studies of Hydrogen Bihalide Anions: Anharmonic Frequencies and Hydrogen-Bond Energies

정병서 대한화학회 2019 대한화학회지 Vol.63 No.4

Hydrogen bihalide anions, XHX− (X = F, Cl, and Br) have been studied by high level ab initio methods to determine the molecular structure, vibrational frequencies, and energetics of the anions. All bihalide anions are found to be of linear and symmetric structures, and the calculated bond lengths are consistent with experimental data. The harmonic frequencies exhibit large deviations from the experimental frequencies, suggesting the vibrations of these anions are very anharmonic. Two different approaches, the VSCF and VPT2 methods, are employed to calculate the anharmonic frequencies, and the results are compared with the experimental frequencies. While the ν1 and ν2 frequencies are in reasonable agreement with the experimental values, the ν3 and ν1 + ν3 frequencies still exhibit large deviations. The hydrogen-bond energies and enthalpies are calculated at various levels including the W1BD and G4 composite methods. The hydrogen-bond enthalpies calculated are in good agreement with the experimental values.

나는 누구인가?자아 성찰 지도를 통한 도덕성 내면화

정병서 한국도덕윤리과교육학회 1996 도덕윤리과교육 Vol.- No.7

운동실조 및 안구진탕으로 발견된 신경아세포종 1예

정병서,한석주,한애리,오정탁,고창준,유철주,황의호 대한외과학회 2001 대한외과학회 학술대회 초록집 Vol.2001 No.5

중국의 과학기술 발전계획

정병서 한국외교협회 2018 계간 외교 Vol.- No.124

외상성 측두골 골절로 인한 안면마비 환자에서 경유양동 접근법을 통한 안면신경 감압술의 효과

정병서,주연희,양호철,곽보경,백주영,이주형 대한이비인후과학회 2013 대한이비인후과학회지 두경부외과학 Vol.56 No.2

Background and Objectives The aim of this study is to evaluate the outcomes and prognosis of traumatic facial paralysis in patients treated with facial nerve decompression via transmastoid approach. Subjects and Method The authors retrospectively reviewed 20 patients who suffered from temporal bone fractures resulting in facial paralysis and received surgical facial nerve decompression treatment via transmastoid approach from 2004 to 2012. Results In 14 patients, the House-Brackmann grade improved to 1, 2, or 3. The preoperative average House-Brackmann grade of 4.95 improved from 4.95 to the postoperative average House-Brackmann grade of 3.15. Statistically significant improvements were found in all groups whether the operation was performed within two weeks, or from two weeks to four weeks, or after four weeks. Conclusion Postoperative results of facial nerve decompression in traumatic temporal bone fracture can be excellent. Surgeons can expect better outcomes with early diagnosis and lesser nerve damage.

우리나라 主要農産物輸入構造變化分析

鄭炳瑞 成均館大學校 科學技術硏究所 1993 論文集 Vol.44 No.1

This study tests the hypothesis that institutional changes in Korea caused structural changes in its import demand for major grains. It used a single equation system approach to estimate Korea's major grain import demand. A chow test method was used to identify structural changes from 1973 to 1991. No significant structural shifts were found to have been caused by instituional changes in the 1970s and 1980s.

하인두식도절제술 후 위를 이용한 재건술

정병서(Byung Seo Jung),김종관(Jong Kwan Kim),최은창(Eun Chang Choi),김충배(Choong Bai Kim) 대한외과학회 2001 Annals of Surgical Treatment and Research Vol.61 No.4

엉겅퀴 발효 추출물을 통한 남성 갱년기 증상 개선 효과

정병서(Byung Seo Jeong),김성훈(Seong Hoon Kim),김현표(Hyun Pyo Kim) 한국식품영양과학회 2017 한국식품영양과학회지 Vol.46 No.7

본 연구에서는 엉겅퀴 추출물(CE) 및 엉겅퀴 발효추출물(FCE)이 남성 갱년기 증상의 개선에 미치는 영향을 알아보기 위해 25주령 된 흰쥐에 추출물을 6주간 투여한 후, 간독성, 테스토스테론, SHBG, 정자수 및 정자 운동성, PSA, 복부지방, 근육량, 혈중지질, 운동수행능력 등에 미치는 영향을 조사하였고 세포 실험을 통해 그 기작을 확인하였다. 천연 추출물에서 있을 수 있는 간독성을 측정하기 위해 간 손상의 지표인 AST와 ALT를 측정한 결과 대조군과 차이를 보이지 않았다. CE 및 FCE 투여 후 남성 갱년기에서 감소하는 테스토스테론의 혈중 농도가 증가하였고, 테스토스테론의 생체 내 활성을 저하시키는 SHBG의 농도는 반대로 감소하였다. 총 정자수와 정자 운동성을 측정한 결과에서도 CE 및 FCE 투여군에서 증가한 양상을 나타냈고, 이는 정자 형성과 활동성에 영향을 주는 테스토스테론 농도의 증가와 관련이 있을 것으로 생각된다. 또한, 전립선에 대한 부작용을 알아보기 위해 PSA를 측정하였으나 대조군과 별다른 차이를 나타내지 않았다. 지방조직과 근육에 대한 영향을 측정한 결과 지방조직량은 줄이고 근육량은 늘려 남성 갱년기에서 흔히 나타나는 체지방 증가 및 근육량 감소를 완화시키는 효과가 있는 것으로 생각된다. 또한, 남성 갱년기에서 흔히 동반되는 혈중지질대사 이상에 있어서도 CE 및 FCE 투여군이 총 콜레스테롤과 중성지방은 감소시킨 반면 고밀도 콜레스테롤은 증가시켜 긍정적인 효과가 있는 것을 관찰하였다. 운동수행능력 측정 결과에서는 CE 및 FCE 투여군이 대조군보다 수영시간이 증가하였고, 이는 CE 및 FCE의 투여가 남성 갱년기에서 나타나는 활력의 저하를 회복시킬 수 있음을 시사한다. 끝으로 CE 및 FCE의 테스토스테론 증가기작을 알아보기 위해 세포실험을 통해 테스토스테론 생합성 과정에 관여하는 효소 유전자의 변화를 측정한 결과 처리군에서 합성관련 효소는 모두 증가함을 나타내었고, 전환관련 효소는 감소함을 나타내었으므로 엉겅퀴 추출물이 테스토스테론 합성을 직접 촉진시킬 수 있음을 알 수 있었다. 또한, CE와 FCE를 비교해 봤을 때 전반적으로 FCE가 더 좋은 효과를 나타내었고, 이는 발효 과정을 통해 엉겅퀴 유효 성분의 증가에 따른 것으로 여겨진다. 결론적으로 본 연구에서는 CE 및 FCE가 남성 갱년기 개선에 도움을 줄 수 있는 좋은 소재로 활용될 수 있다는 가능성을 제시하였다. As men get older, total testosterone levels decline gradually, and concentrations of free and bioavailable testosterone decline sharply with each decade beyond their 30s. Andropause or testosterone deficiency syndrome (TDS) is defined as a decrease in sexual satisfaction or decline in general well-being accompanied by low levels of testosterone in older men. This male climacteric is characterized by nervousness, reduced potency, decreased libido, irritability, fatigue, depression, memory problems, sleep disturbances, and hot flushes. Cirsium japonicum (CJ) is used as a traditional medicine for hemorrhage, blood congestion, and inflammation in Korea. However, there is no report on the efficacy of CJ treatment for TDS. In this study, we observed the mitigating effect of CJ extract (CE) and fermented CJ extract (FCE) on symptoms of TDS. In elderly male rats, total and testosterone levels, hind limbs muscles, forced swimming time, and total and motile sperm counts significantly increased after daily intake of CE and FCE for 6 weeks. In contrast, sex hormone binding globulin, retroperitoneal fat, total serum cholesterol, and triglyceride levels were significantly reduced in CE and FCE groups. However, there was no difference in prostate specific antigen, aspartate aminotransferase, and alanine aminotransferase levels among all groups, which means CE and FCE did not have putative adverse effects. In a cell experiment, we also observed that CE and FCE enhanced expression of genes related to testosterone biosynthesis but reduced genes involved in testosterone conversion. On the whole, these positive effects on TDS were greater in FCE compared to CE. Thus, these results suggest the potential of FCE as a promising natural product for recovering testosterone levels and alleviating TDS.