Ir 전극 계면에서 위상이동 방법 및 상관계수를 이용한 수소의 흡착동온식 결정

전상규,Jeon, Sang-K. 한국전기화학회 2007 한국전기화학회지 Vol.10 No.2

백금족/수용액 계면에서 Langmuir, Frumkin, Temkin 흡착등온식(${\theta}\;vs.\;E$)을 결정하기 위해 최적중간주파수 일 때 위상이동($0^{\circ}{\leq}-{\varphi}{\leq}90^{\circ}$) 거동($-{\varphi}\;vs.\;E$)과 표면피복율($1{\geq}{\theta}{\geq}0$) 거동(${\theta}\;vs.\;E$) 사이의 선형 관계식 연구에 관한 위상이동 방법 및 상관계수를 제안하고 증명하였다. Ir/0.1 M KOH수용액 계면에서 음극 $H_2$ 발생 반응에 관한 수소의 Langmuir 및 Temkin 흡착등온식(${\theta}\;vs.\;E$), 평형상수(Langmuir 흡착등온식: $K=3.3{\times}10^{-4}mol^{-1}$, Temkin 흡착등온식: $K=3.3{\times}10^{-3}{\exp}(-4.6{\theta})\;mol^{-1}$), 상호작용 파라미터(Temkin 흡착등온식: g=4.6), 표준자유에너지($K=3.3{\times}10^{-4}mol^{-1}$ 일 때 ${\Delta}G_{ads}^0=19.9kJ\;mol^{-1},\;K=3.3{\times}10^{-3}{\exp}(-4.6{\theta})\;mol^{-1}$ 및 $0.2<{\theta}<0.8$일 때 $16.5<{\Delta}G_{\theta}^0<23.3kJ\;mol^{-1}$)를 결정한다. 수소 흡착부위의 비균일 및 측 방향 상호작용 효과는 무시할 수 있다. ${\theta}$의 중간값 즉, $0.2<{\theta}<0.8$일 때 Langmuir 또는 Frumkin 흡착등온식과 상관관계에 있는 Temkin 흡착등온식은 상관계수를 이용하여 쉽게 결정할 수 있다. 위상이동 방법 및 상관계수는 흡착동온식(${\theta}\;vs.\;E$) 및 연관된 전극속도론과 열역학 파라미터(K, g, ${\Delta}G_{ads}^0, {\Delta}G_{\theta}^0$)를 결정하기 위한 정확하고 확실한 기술 및 방법이다. The phase-shift method and correlation constants for studying a linear relationship between the behavior ($-{\varphi}\;vs.\;E$) of the phase shift ($0^{\circ}{\leq}-{\varphi}{\leq}90^{\circ}$) for the optimum intermediate frequency and that (${\theta}\;vs.\;E$) of the fractional surface coverage ($1{\geq}\theta{\geq}0$) have been proposed and verified to determine the Langmuir, Frumkin, and Temkin adsorption isotherms (${\theta}\;vs.\;E$) at noble metal/aqueous electrolyte interfaces. At an Ir/0.1 M KOH aqueous electrolyte interface, the Langmuir and Temkin adsorption isotherms (${\theta}\;vs.\;E$), equilibrium constants ($K=3.3{\times}10^{-4}\;mol^{-1}$ for the Langmuir and $K=3.3{\times}10^{-3}{\exp}(-4.6{\theta})\;mol^{-1}$ for the Temkin adsorption isotherm), interaction parameter (g = 4.6 for the Temkin adsorption isotherm), and standard free energies (${\Delta}G_{ads}^0=19.9kJ\;mol^{-1}\;for\;K=3.3{\times}10^{-4}\;mol^{-1}$ and $16.5<{\Delta}G_{\theta}^0<23.3\;kJ\;mol^{-1}\;for\;K=3.3{\times}10^{-3}{\exp}(-4.6{\theta})\;mol^{-1}\;and\;0.2<\theta<0.8$) of H for the cathodic $H_2$ evolution reaction are determined using the phase-shift method and correlation constants. The inhomogeneous and lateral interaction effects on the adsorption of H are negligible. At the intermediate values of ${\theta},\;i.e,\;0.2<{\theta}<0.8$, the Temkin adsorption isotherm (${\theta}\;vs.\;E$) correlating with the Langmuir or the Frumkin adsorption isotherm (${\theta}\;vs.\;E$), and vice versa, is readily determined using the correlation constants. The phase-shift method and correlation constants are accurate and reliable techniques to determine the adsorption isotherms (${\theta}\;vs.\;E$) and related electrode kinetic and thermodynamic parameters(K, g, ${\Delta}G_{ads}^0, {\Delta}G_{\theta}^0$).

The Phase-Shift Method for the Langmuir Adsorption Isotherms of Electroadsorbed Hydrogens for the Cathodic H₂ Evolution Reactions at the Poly-Pt Electrode Interfaces

천장호,전상규,이재항,Chun, Jang H.,Jeon, Sang K.,Lee, Jae H. The Korean Electrochemical Society 2002 한국전기화학회지 Vol.5 No.3

순환전압전류 및 교류임피던스 기법을 이용하여 다결정 Pt/0.5M $H_2SO_4$ 및 0.5M LiOH수용액 계면에서 저전위 수소흡착(UPD H) 과 전위 수소흡착(OPD H)에 관한 Langmuir 흡착등온식 $({\theta}\;vs.\;E)$ 을 연구조사 하였다. 계면에서 치적중간주파수일 때 위상이동$(0^{\circ}{\leq}{-\phi}{\leq}90^{\circ})$ 거동은 표면피복율$(1{\geq}{\theta}{\geq}0)$ 거동에 정확하게 상응한다. 위상이 동 방법 즉 최적중간주파수일 때 위상이동 변화$({-\phi}\;vs.\;E)$는 계면에서 음극 $H_2$ 발생 반응에 관한 UPD H와 OPDH의 Langmuir흡착등온식을 결정할 수 있는 새로운 전기화학적 방법으로 사용할 수 있다 다결정 Pt/0.5M $H_2SO_4$ 수용액 계면에서 OPD H의 흡착평형상수(K)와 표준자유에너지$({\Delta}G_{ads})$는 각각 $2.1\times10^{-4}$와 21.0kJ/mol 이다. 다결정 Pt/0.5M LiOH 수용액 계면에서 K는 음전위(E)에 따라 2.7 (UPD H)에서 $6.2\times10^{-6}$ (OPD H) 또는 $6.2\times10^{-6}$(OPD H)에서 2.7 (UPD H)로 전이한다. 유사하게 ${\Delta}G_{ads}$는 E에 따라 -2.5kJ/mol (UPD H)에서 29.7kJ/mol (OPD H)또는 29.7kJ/mol (OPD H)에서 -2.5kJ/mol (UPD H)로 전이한다. K와 ${\Delta}G_{ads}$의 전이는 다결정 Pt전극 표면의 상이한 UPD H와 OPD H의 흡착부위에 기인한다. 다결정 Pt전극 계면에서 UPD H와 OPD H는 음극 $H_2$ 발생 반응에 따른 순차적 과정이 아니라, 수소 흡착부위 자체에 따른 독립적 과정이다. UPD H와 OPD H의 기준은 음극 $H_2$발생 반응과 전위가 아니라, 수소 흡착부위와 과정이다. 수용액에서 음극 $H_2$발생 반응에는 다결정 Pt선 전극이 단결정 Pt(100)원반 전극보다 더 효율적이고 유용하다 위상이동 방법은 열역학적 방법과 상충적이 아니라, 보완적이다. The Langmuir adsorption isotherms of the under-potentially deposited hydrogen (UPD H) and the over-potentially deposited hydrogen (OPD H) at the poly-Pt/0.5M $H_2SO_4$ and 0.5 M LiOH aqueous electrolyte interfaces have been studied using cyclic voltammetric and ac impedance techniques. The behavior of the phase shift $(0^{\circ}{\leq}{-\phi}{\leq}90^{\circ})$ for the optimum intermediate frequency corresponds well to that of the fractional surface coverage $(1{\geq}{\theta}{\geq}0)$ at the interfaces. The phase-shift method, i.e., the phase-shift profile $({-\phi}\;vs.\;E)$ for the optimum intermediate frequency, can be used as a new electrochemical method to determine the Langmuir adsorption isotherms $({\theta}\;vs.\;E)$ of the UPD H and the OPD H for the cathodic $H_2$ evolution reactions at the interfaces. At the poly-Pt/0.5M $H_2SO_4$ aqueous electrolyte interface, the equilibrium constant (K) and the standard free energy $({\Delta}G_{ads})$ of the OPD H are $2.1\times10^{-4}$ and 21.0kJ/mol, respectively. At the poly-Pt/0.5M LiOH aqueous electrolyte interface, K transits from 2.7(UPD H) to $6.2\times10^{-6}$ (OPD H) depending on the cathode potential (E) and vice versa. Similarly, ${\Delta}G_{ads}$ transits from -2.5kJ/mol (UPD H) to 29.7kJ/mol (OPD H) depending on I and vice versa. The transition of K and ${\Delta}G_{ads}$ is attributed to the two distinct adsorption sites of the UPD H and the OPD H on the poly-Pt surface. The UPD H and the OPD H on the poly-Pt surface are the independent processes depending on the H adsorption sites themselves rather than the sequential processes for the cathodic $H_2$ evolution reactions. The criterion of the UPD H and the OPD H is the H adsorption sites and processes rather than the $H_2$ evolution reactions and potentials. The poly-Pt wire electrode is more efficient and useful than the Pt(100) disc electrode for the cathodic $H_2$ evolution reactions in the aqueous electrolytes. The phase-shift method is well complementary to the thermodynamic method rather than conflicting.

살무사(Agkistrodon blomhoffi brevicaudus)뱀독의 면역학적 성상

전우규,정상인,최철순,양용태 중앙대학교 의과대학 의과학연구소 1991 中央醫大誌 Vol.16 No.3

This study was undertaken to find out main toxic components in venom of Agkistrodon b. brevicaudus and to prepare antiserum to venom. Through the experiment, venom of A. b. brevicaudus was fractionated into 7 fractions through DEAE-Sephadex A-50 and observation were made with toxic reaction of fractioned venom of A. b. brevicaudus, neutralizing effect of antiserum for highly toxic fraction and finally, comparison of neutralizing effect of antisera for fractionated venom and original crude venom. The results ara summarized follows: 1. Fractionation of A. b. brevicaudus venom by DEAE sephadex A-50 column chromatograhpy resulted in seven peaks. The amount of total protein were the highest in 4th fraction. 2. To investigate the toxicity of each fraction, hemorrhagic activity of each fraction were compared. As a result, most strong hemorrhagic activity was shown in 6th fraction. Then 4th, 7th fraction were in that order. 3. Neutralizing effect of rat antisera for 2nd, 4th and 6th fraction were compared. Most effective neutralizing(antilethal) activity was shown in antiserum for 4th fraction and neutralizing effect of antiserum for 4th fraction was similar to that of crude venom.

胸部外傷에 對한 放射線學的 考察

全錫徹,成圭寶,朴永根,朴忠基,徐興錫,咸蒼谷 한양대학교 의과대학 1984 한양의대 학술지 Vol.4 No.1

Radiologic manifestations were analysed in chest injured patients who were admitted and treated at the Department of Thoracic and Cardiovascular Surgery during the period of 5 years from Aug. 1978 to Aug. 1983. The patients were 253 in number and the results were as follows; 1. Nonpenetrating trauma is more frequent (83.8%) than penetrating trauma. 2. The most frequent oause of trauma is traffic accident(60.1%). 3. The frequent radiologic findings in nonpenetrating chest injury were rib fracture, hemothorax and subcutanneous emphysema, and in poetrating chest injury, subcutaneous emphysema, hemothorax and pneumothorx in order of frequency. 4. The most frequently fractured rib was 6th rib, and frequently fractured ribs were from 3rd to 8th ribs(more than 40% of patients). 5. In all cases of hemopneumothorax were associated with rib fracture in nonpenetrating injury. 6. Delayed apperaance of hemothorax, pneumothorax and hemopeumothorax was seen in 9.0% of cases(14 cases).

Effects of ginsenoside on large-conductance K_Ca channels in human corporal smooth muscle cells

Sung, H H,Chae, M R,So, I,Jeon, J-H,Park, J K,Lee, S W Macmillan Publishers Limited 2011 International journal of impotence research Vol.23 No.5

Ginseng was known to be an effective natural product that enhances penile erection. However, the precise biological function and mechanisms of action of ginseng with regard to erectile function remain unknown. The principal objective of this study was to identify ginsenoside (principal molecular ingredients of ginseng)-induced activation of large-conductance K<SUB>Ca</SUB> channel in human corporal smooth muscle cells, and to determine ginseng's mechanism of action on penile erection. Electrophysiological studies using cultured human corporal smooth muscle cells were conducted. We evaluated the effects of total ginsenosides (TGS) and ginsenoside Rg3 on large-conductance K<SUB>Ca</SUB> channel by determining whole-cell currents and single-channel activities. There was an increase in outward current dependent on TGS concentration (at +60 mV, 1 μg ml<SUP>−1</SUP>; 168.3±59.3%, n=6, P<0.05, 10 μg ml<SUP>−1</SUP>; 173.2±36.8%, n=4, P<0.05, 50 μg ml<SUP>−1</SUP>; 295.3±62.3%, n=19, P<0.001, 100 μg ml<SUP>−1</SUP>; and 462.3±97.1%, n=5, P<0.001) and Rg3 concentration (at +60 mV, 1 μM (0.78 μg ml<SUP>−1</SUP>); 222.8±64.8%, n=11, P<0.0001, 10 μM; 672.6±137.1%, n=10, P<0.0001, 50 μM; and 1713.3±234.7%, n=15, P<0.001) in the solution that was blocked completely by tetraethylammonium (TEA). Channel opening in cell-attached mode and channel activity in the inside-out membrane patches was also increased significantly by 50 μg of TGS or 10 μM of Rg3. The results of this study suggested that the activation of large-conductance K<SUB>Ca</SUB> channels by ginsenoside could be one mechanism of ginsenoside-induced relaxation in corporal smooth muscle.

Constant Correlation Factors between Temkin and Langmuir or Frumkin Adsorption Isotherms at Poly-Pt, Re, and Ni/Aqueous Electrolyte Interfaces

Chun Jang H.,Jeon Sang K.,Chun Jin Y. The Korean Electrochemical Society 2004 한국전기화학회지 Vol.7 No.4

The constant correlation factors between the Temkin and the Langmuir or the Frumkin adsorption isotherms of over-potentially deposited hydrogen (OPD H) for the cathodic H2 evolution reaction (HER) at poly-Pt and Re/0.5M $H_2SO_4$ and poly-Ni/0.05 M KOH aqueous electrolyte interfaces have been experimentally and consistently found using the phase-shift method. At intermediate values of the fractional surface coverage $(\theta),\;i.e.,\;02<{\theta}<0.8$, the Langmuir and Temkin adsorption isotherms of OPD H for the cathodic HER are correlated to each other even though the adsorption conditions or processes are different from each other. At the same range of $\theta$, correspondingly, the Frumkin and Temkin adsorption isotherms of OPD H for the cathodic HER are correlated to each other. The equilibrium constants $(K_o)$ for the Temkin adsorption isotherms $({\theta}\;vs.\; E)$ are consistently ca. 10 times greater than those (K, Ko) for the corresponding Langmuir or Frumkin adsorption isotherms ($({\theta}\;vs.\; E)$. The interaction parameters (g) for the Temkin adsorption isotherms $({\theta}\;vs.\; E)$ are consistently ra. 4.6 greater than those (g) for the corresponding Langmuir or Frumkin adsorption isotherms $({\theta}\;vs.\; E)$. These numbers (10 times and 4.6) can be taken as constant correlation factors between the corresponding adsolftion isotherms (Temkin, Langmuir, Frumkin) at the interfaces. The Temkin adsorption isotherm corresponding to the Langmuir or the Frumkin adsorption isotherm, and vice versa, can be effectively verified or confirmed using the constant correlation factors. Both the phase-shift methodand constant correlation factors are useful and effective for determining or confirming the suitable adsorption isotherms (Temkin, Langmuir, Frumkin) of intermediates for sequential reactions in electrochemical systems.

우유및 우유 성분내의 주요 광물질의 함량

정근희,전우민,이상업,김영교,박동준 ( Keun H . Chung,Woo M . Jeon,Sang U . Lee,Young K . Kim,Dong J . Park ) 한국축산학회 1989 한국축산학회지 Vol.31 No.10

In order to study the level of the selected elements(Ca, Zn and Cd, etc.) in milk and their interrelationships with milk protein, raw milk samples in the vicinity of Seoul and market milk samples were collected in the summer, winter and early spring. The average Ca and Zn content of milk from different areas and different products varied between 0.06∼0.13% and 2∼5ppm, respectively, and the Cu content is below 0.lppm. Cd(regarded as a toxic element) content in milk is not detected and the Hg content is below the detection limit of AAS instrument in the milk produced in Korea. The interrelationship of these elements with milk components(specially with casein) is also studied. Generally, inorganic elements(Ca, Mg and Zn) are contained in the portion of casein and whey. The fraction of α_s -casein contains higher Ca amounts than that of β- or k-casein does, but we have not found out that these elements are combined with milk component or not.

수요자 참여형으로 육성된 최고품질 벼 ‘알찬미’

현웅조(Ung-Jo Hyun),원용재(Yong-Jae Won),정응기(Eung-Gi Jeong),안억근(Eok-Keun Ahn),이정희(Jeong-Heui Lee),정국현(Kuk-Hyun Jung),박향미(Hyang-Mi Park),전용희(Yong-Hee Jeon),곽지은(Jieun Kwak),성낙식(Nak-Sig Sung),김정천(Jeong-Cheon K 한국육종학회 2021 한국육종학회지 Vol.53 No.2

Alchanmi’, a japonica rice variety, was developed from a cross between ‘Junam’ and ‘Chilbo’ by a rice breeding team at the NationalInstitute of Crop Science and Icheon, Agricultural Technology Center in 2018. The heading date of ‘Alchanmi’ was August 10 in the middleplain area-two days later than that of ‘Hwaseong’. ‘Alchanmi’ had a culm length of 69 cm, 16 cm shorter than that of ‘Hwaseong’, and 103spikelets per panicle. The viviparous germination rate of ‘Alchanmi’ was 24.4%. It showed resistance to blast, bacterial blight (K1, K2, K3race), and stripe virus, but was susceptible to the K3a race of bacterial blight, dwarf and black streak dwarf viruses, and plant hoppers. Themilled rice of this variety exhibited a translucent and medium short grain shape. The cooked rice grains of ‘Alchanmi’ had an excellent palatabilityindex (0.7) and showed lower amylose content (18.6%) than that of ‘Hwaseong’. The grain milling characteristics of ‘Alchanmi’ were betterthan those of ‘Hwaseong’, especially the head rice milling recovery ratio and head rice ratio (96.2%). ‘Alchanmi’ showed 5.83 MT/ha of milledrice productivity at 6 sites under ordinary cultivation (Registration No. 8132).

Analysis on the Frumkin Adsorption Isotherm of the Over-Potentially Deposited Hydrogen (OPD H) at the Polycrystalline Ni | Alkaline Aqueous Electrolyte Interface Using the Phase-Shift Method

Chun Jang H.,Jeon Sang K. The Korean Electrochemical Society 2001 한국전기화학회지 Vol.4 No.4

위상이동 방법을 이용하여 다결정 Ni|0.05M KOH수용액 계면에서 음극 $H_2$발생 반응을 위한 과전위 전착(흡착)된 수소의 Frumkin 흡착등온식을 연구조사 하였다. 다결정 Ni|0.05M KOH수용액 계면에서, 최적중간주파수일 때 위상이동$(0^{\circ}\leq{\phi}\leq90^{\circ})$ 거동은 표면피복율 $(1\geq{\theta}\geq0)$ 거동에 정확하게 상응한다. 최적중간주파수일 때 위상이동 변화 $(-{\phi}\;vs.\;E)$즉 위상이동 방법은 다결정 Ni|0.05M KOH수용액 계면에서 음극 $H_2$발생 반응을 위한 과전위 전착(흡착)된 수소의 Frumkin흡착등온식$(\theta\;vs.\;E)$을 추정할 수 있는 새로운 방법으로 사용될 수 있다. 다결정 Ni|0.05M KOH 수용액 계면에서, 표면피복율에 따른 과전위 전착(흡착)된 수소의 표준자유에너지 변화율(r), Frumkin 흡착등온식의 상호작용 파라미터(g), 표면피복율$(\theta)$에 따른 과전위 전착(흡착)된 수소의 흡착평형상수(K)와 표준자유에너지$({\Delta}G_{\theta})$는 각각 $24.8kJ mol^{-1},\;10,\;5.9\times10^{-6}{\leq}K{\leq}0.13,\;and\;5.1\leq{\Delta}G_{\theta}\leq29.8kJ\;mol^{-1}$이다. 전극속도론적 파라미터$(r,\;g,\;K,\;{\Delta}G_{\theta})$는 표면피복율${\theta}에 따른다. The Frumkin adsorption isotherm of the over-potentially deposited hydrogen (OPD H) for the cathodic $H_2$ evolution reaction (HER) at the poly-Ni|0.05M KOH aqueous electrolyte interface has been studied using the phase-shift method. The behavior of the phase shift $(0^{\circ}\leq{\phi}\leq90^{\circ})$ for the optimum intermediate frequency corresponds well to that of the fractional surface coverage $(1\geq{\theta}\geq0)$ at the interface. The phase-shift method, i.e., the Phase-shift profile $(-{\phi}\;vs.\;E)$ for the optimum intermediate frequency, can be used as a new method to estimate the Frumkin adsorption isotherm $(\theta\;vs.\;E)$ of the OPD H for the cathodic HER at the interface. At the poly-Ni|0.05M KOH aqueous electrolyte interface, the rate (r) of change of the standard free energy of the OPD H with $\theta$, the interaction parameter (g) for the Frumkin adsorption isotherm, the equilibrium constant (K) for the OPD H with $\theta$, and the standard free energy $({\Delta}G_{\theta})$ of the OPD H with ${\theta}$ are $24.8kJ mol^{-1},\;10,\;5.9\times10^{-6}{\leq}K{\leq}0.13,\;and\;5.1\leq{\Delta}G_{\theta}\leq29.8kJ\;mol^{-1}$. The electrode kinetic parameters $(r,\;g,\;K,\;{\Delta}G_{\theta})$ depend strongly on ${\theta} (0{\leq}{\theta}{\leq}1)$.

A cell‐free extract from human adipose stem cells protects mice against epilepsy

Jeon, Daejong,Chu, Kon,Lee, Soon‐,Tae,Jung, Keun‐,Hwa,Kang, Kyung‐,Mook,Ban, Jae‐,Joon,Kim, Soyun,Seo, Jin Soo,Won, Chong‐,Hyun,Kim, Manho,Lee, Sang Kun,Roh, Jae‐,K Blackwell Publishing Ltd 2011 Epilepsia Vol.52 No.9

<P><B>Summary</B></P><P><B>Purpose: </B> Stem cell–based therapies are being considered for various neurologic diseases, such as epilepsy. Recent studies have suggested that some effects of transplanted stem cells are due to bystander effects that modulate the host environment, rather than direct effects of cell replacement. The extract from human adipose stem cells (ASCs) that secrete multiple growth factors including cytokines and chemokines may be a potential source of bystander effects for the treatment of epilepsy, in which inflammation is thought to play an important role. Here, we investigated the effects of a cytosolic extract of human ASCs (ASCs‐E) in a mouse model of epilepsy.</P><P><B>Methods: </B> Human ASCs‐E, boiled ASCs‐E, or fibroblast‐extract (fibroblast‐E) was intraperitoneally administrated to C57BL/6 mice 15 min before pilocarpine‐induced status epilepticus (SE) or during chronic epileptic stage. Blood–brain barrier (BBB) leakage was evaluated by measuring Evans blue dye extravasation. Spontaneous recurrent seizure (SRS) was investigated by long‐term video–electroencephalography (EEG) monitoring. The mice performed elevated plus maze, open‐field, light/dark transition, and novel object recognition tasks.</P><P><B>Key Findings: </B> Acute application of human ASCs‐E before SE led to earlier attenuation of seizure spike activities after treatment with diazepam, reduction of BBB leakage, and inhibition of the development of epilepsy. Human ASCs‐E treatment (for 7 days) during the chronic epileptic stage suppressed SRS and reduced abnormal epileptic behavioral phenotypes. However, neither boiled ASCs‐E nor fibroblast‐E had any effects in the experimental epilepsy model.</P><P><B>Significance: </B> Our results demonstrate that human ASCs‐E prevents or inhibits epileptogenesis and SRS in mice. They also suggest a stem cell–based, noninvasive therapy for the treatment of epilepsy.</P>