• Title/Summary/Keyword: Kinetic studies

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Correlations of Cerebellar Function with Psychotic Symptoms and Cognitive Function in Schizophrenic Patients (남자 정신분열병 환자의 소뇌기능과 정신증상 및 인지기능간의 연관성)

  • Kim, Seo Young;Jun, Yong Ho;Kwon, Young Joon;Jeong, Hee Yeon;Hwang, Bo Young;Shim, Se Hoon
    • Korean Journal of Biological Psychiatry
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    • v.14 no.3
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    • pp.184-193
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    • 2007
  • Objectives:There is increasing evidence that the cerebellum plays an important role in cognition and psychiatric symptoms as well as motor coordination. The concept of cognitive dysmetria has been making cerebellar function in schizophrenia the focus of current studies. In other words, disruption in the corticocerebellum-thalamic -cortical circuit could lead to disordered cognition and clinical symptoms of schizophrenia. The purposes of this study were to determine cerebellar dysfunction in male schizophrenic patients semiquantitatively with ICARS and to investigate the clinical and cognitive correlates of ICARS in patients. Methods:We compared the scores of cerebellar neurologic sign using ICARS in 47 male patients with a DSM-IV-TR diagnosis of schizophrenia with 30 gender and age-matched healthy control subjects. The semiquantitative 100-point ICARS consists of 19 items divided into 4 unequally weighted subscores:posture and gait disturbances, kinetic functions, speech disorders and oculomotor disorders. All subjects were also assessed with cognitive function test. Cognitive functions were evaluated by Korean-Mini Mental Status Examination (K-MMSE), Verbal fluency test, and Clock drawing test. The patients were administered Korea version of Positive and Negative Symptom Scale(K-PANSS) to assess the symptom severity. Results:Schizophrenic patients had significantly higher scores on the ICARS than control subjects with posture and gait disturbances, kinetic functions, and oculomotor disorders. They also showed more significant impairments in cognitive function tests than control subjects. There was a significant correlation between ICARS and negative symptoms of patients. In cognitive function test, Clock drawing test was significantly associated with negative symptoms. In addition, Clock drawing test was negatively correlated with the total score of ICARS. Conclusion:In this study, we confirmed that schizophrenic patients have significant impairments in cognitive and cerebellar function, and that those were related with negative symptoms of schizophrenic patients. These results support a role of the cerebellum in schizophrenia. It is meaningful that we used a structured, and reliable procedure for rating neurological soft signs, ICARS. We hope that future prospective studies using a similar design help that rate of neurological sign should have been visible with the progression of illness.

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Rat Liver $AT_1$ Receptor Binding Analysis for Drug Screening

  • Lee, Sunghou;Lee, Buyean;Hwasup Shin;Jaeyang Kong
    • Biomolecules & Therapeutics
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    • v.3 no.1
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    • pp.21-27
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    • 1995
  • The only compounds with antagonistic activity via AT$_1$receptor, one of two subtypes of angiotensin II (AII) receptor, have been demonstrated to block the vasoconstriction effects of AII and thereby provide therapeutic potential. This initiated the search for compounds with high specific affinity to AT$_1$receptor and their effective screening methods. The radioligand binding assay for the AII receptor is regarded as the primary method for the evaluation of AT$_1$receptor antagonists for their activity. In this paper, we characterized the liver AT$_1$receptor and describe the efficient method of the radioligand binding assay using rat liver as a source of AT$_1$receptor. Equilibrium binding studies with rat adrenal cortex, adrenal medulla, liver and bovine adrenal showed that the specific bindings of [$^3$H] AII were saturable in all tissues and the Scatchard plots of those data were linear, suggesting a single population of binding sites. Hill slopes were very near to the unity in all tissues. Kinetic studies of [$^3$H) AII binding in rat liver homogenates yielded two association rate constants, 4.10$\times$10$^{7}$ M$^{-1}$ min$^{-1}$ and 4.02$\times$10$^{9}$ M$^{-1}$ min$^{-1}$ , with a single dissociation rate constant, 7.07$\times$10$^{-3}$ min-$^{-1}$ , possibly due to the partial dissociation phenomenon. The rank order of inhibition potencies of [$^3$H] AII binding in rat liver was AII>Sarile>Losartan>PD 123177. Rat liver homogenates revealed to have very high density of homogeneous population of the AT$_1$receptor subtype, as the specifically bound [$^3$H] AII was not inhibited by PD 123177, the nonpeptide antagonist of AT$_2$. The results of this study demonstrated that the liver homogenates from rats could be the best receptor preparation for the AT$_1$receptor binding assay and provide an efficient system for the screening of newly synthesized candidate compounds of AT$_1$receptor antagonist.

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Studies on Screening and Iolation of ${\alpha}-Amylase$ Inhibitors of Soil Microorganisms( II ) -Isolation and Activities of the Inhibitor of Streptomyces Strain DMC-72- (토양균의 ${\alpha}-Amylase$ 저해제 검색 및 분리에 관한 연주(제2보) -스트렙토마이세스속 DMC-72 균주의 저해 성분의 분리 및 작용-)

  • Kim, Kyung-Jae;Lee, Shung-Hee;Kim, Jung-Woo;Kim, Ha-Won;Shim, Mi-Ja;Choi, Eung-Chil;Kim, Byong-Kak
    • The Korean Journal of Mycology
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    • v.13 no.4
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    • pp.203-212
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    • 1985
  • Of 450 strains isolated from the soil microbes collected in various locations in Korea, a strain had a strong inhibitory activity against bacterial ${\alpha}-amylase$ and was named strain DMC-72 of the genus Streptomyces. The amylase inhibitory metabolite produced by this strain was purified by means of acetone precipitation, adsorption on Amberlite IRC-50 and SP-Sephadex C-25. The inhibitor was found to be a derivative of oligosaccharides by spectral and chemical data. The inhibitor was stable at the pH range of $1{\sim}13$ and at $100^{\circ}C$ for half an hour, also inhibited other amylases such as salivary ${\alpha}-amylase$, pancreatic ${\alpha}-amylase$, fungal ${\alpha}-amylase$ and glucoamylase. However, it showed no inhibitory activity against ${\alpha}-glucosidase$, ${\beta}-glucosidase$, dextranase, and ${\beta}-amylase$. The kinetic studies of the inhibitor showed that its inhibitory effects on starch hydrolysis by ${\alpha}-amylase$ were noncompetitive.

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TPH, $CO_2$ and VOCs Variation Characteristics of Diesel Contaminated Aquifer by In-situ Air Sparging (공기분사공정에 의한 유류오염대수층의 TPH, $CO_2$, VOCs 변화 특성)

  • Lee, Jun-Ho;Park, Kap-Song
    • Journal of Soil and Groundwater Environment
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    • v.11 no.6
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    • pp.18-27
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    • 2006
  • Air Sparging (IAS, AS) is a ground-water remediation technique, in which organic contaminants are volatilized into air as they rise from saturated to vadose soil zone. This study was conducted to investigate the variation characteristics of TPH, VOCs and $CO_2$ for air sparging of diesel contaminated saturated soil. Initial TPH concentration was 10,000 mg/kg for saturated soil phase and 1,001 mg/L for soil aquifer phase. After 36 days of air sparging, the equilibrium temperature of 2-Dimension experiment system was $24.9{\pm}1.5^{\circ}C$. The saturated soil TPH concentration (in the C10 port close to air diffuser) was reduced to 66.0% of the initial value. The mass amount of $CO_2$ was 3,800 mg and 3,200 mg in air space (C70 port) and in unsaturated soil zone (C50 port), respectively. The VOCs production kinetic parameter was 0.164/day in the air space (C70 port) and 0.182/day in the unsaturated soils (C50 port).

Isotherms, Kinetics and Thermodynamic Parameters Studies of New Fuchsin Dye Adsorption on Granular Activated Carbon (입상 활성탄에 대한 New Fuchsin 염료흡착의 등온선, 동력학 및 열역학 파라미터에 관한 연구)

  • Lee, Jong-Jib
    • Applied Chemistry for Engineering
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    • v.25 no.6
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    • pp.632-638
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    • 2014
  • Batch adsorption studies including equilibrium, kinetics and thermodynamic parameters for the adsorption of new fuchsin dye using granular activated carbon were investigated with varying the operating variables such as initial concentration, contact time and temperature. Equilibrium adsorption data were fitted into Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherms. Adsorption equilibrium was mostly well described by Langmuir Isotherm. From the estimated separation factor of Langmuir ($R_L$ = 0.023), and Freundlich (1/n = 0.198), this process could be employed as an effective treatment for the adsorption of new fuchsin dye. Also based on the adsorption energy (E = 0.002 kJ/mol) from Dubinin-Radushkevich isotherm and the adsorption heat constant (B = 1.920 J/mol) from Temkin isotherm, this adsorption is physical adsorption. From kinetic experiments, the adsorption reaction processes were confirmed following the pseudo second order model with good correlation. The intraparticle diffusion was a rate controlling step. Thermodynamic parameters including changes of free energy, enthalpy, and entropy were also calculated to predict the nature of adsorption. The change of enthalpy (92.49 kJ/mol) and activation energy (11.79 kJ/mol) indicated the endothermic nature of adsorption processes. The change of entropy (313.7 J/mol K) showed an increasing disorder in the adsorption process. The change of free energy found that the spontaneity of process increased with increasing the adsorption temperature.

Pharmacokinetics of amoxicillin after intramuscular injection at different temperatures to cultured olive flounder, Paralichthys olivaceus (Amoxicillin의 근육투여에 따른 수온별 넙치 체내 약동학적 특성)

  • Kim, Ji-Soo;Lee, Ji-Hoon;Lee, Soo-Jin;Park, Kwan-Ha
    • Journal of fish pathology
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    • v.28 no.1
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    • pp.43-51
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    • 2015
  • The pharmacokinetic properties and residue levels of amoxicillin (AMOX) were studied after intramuscular injection to cultured olive flounders ($100{\pm}50g$), Paralichthys olivaceus. For pharmacokinetic studies, AMOX of 20 to 80 mg/kg body weight was administered at $17{\pm}2^{\circ}C$ or $22{\pm}2^{\circ}C$ and AMOX concentrations were determined in plasma, the liver, and the kidney by HPLC-UVD. Plasma samples were assessed at 0.25, 0.5, 1, 3, 6, 12, 24, 48, 72, 96, 168 hours post-dose, whereas liver and kidney concentrations were measured at 0.25 to 48 hours post-dose. The kinetic profiles of AMOX were analyzed by fitting to a 2-compartmental model with PKSolver program. The following parameters were obtained for a single dosage of 20, 40 and 80 mg/kg of body weight at $22^{\circ}C$ and 20 and 40 mg/kg of body weight at $17^{\circ}C$ in plasma, liver and kidney, respectively: $C_{max}$ (the peak concentration)= $27.23-257.36{\mu}g/m{\ell}$, $5.49-41.65{\mu}g/g$, $16.75-129.31{\mu}g/g$; $t_{max}$ (the time for peak concentration)= 0.05-0.91, 1.36-3.28, 1.95-4.49 h. For residue studies, AMOX of 40 and 400mg/kg was administered, and muscle samples were taken at 2, 5, 7, 14 and 21 days post-dose. The residueof AMOX in the muscle were found under the MRLs (maximum residue levels) within 7 days for the two doses.

Equilibrium, Kinetic and Thermodynamic Parameter Studies on Adsorption of Allura Red from Aqueous Solution by Granular Activated Carbon (입상활성탄에 의한 수용액으로부터 오로라 레드의 흡착에 대한 평형, 동력학 및 열역학 파라미터에 관한 연구)

  • Lee, Jong-Jib
    • Applied Chemistry for Engineering
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    • v.25 no.4
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    • pp.430-436
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    • 2014
  • Allura Red (AR) is a water-soluble harmful tar-based food colorant (FD & C Red 40). Batch adsorption studies were performed for the removal of AR using bituminous coal based granular activated carbon as adsorbent by varying the operation parameters such as adsorbent dosage, initial concentration, contact time and temperature. Experimental equilibrium adsorption data were analyzed by Langmuir, Freundlich and Temkin isotherms. The equilibrium process was described well by Freundlich isotherm. From determined separation factor ($R_L$), adsorption of AR by granular activated carbon could be employed as effective treatment method. Temkin parameter, B was determined to 1.62~3.288 J/mol indicating a physical adsorption process. By estimation of adsorption rate experimental data, the value of intraparticle diffusion rate constant ($k_m$) increased with the increasing adsorption temperature. The adsorption process were found to confirm to the pseudo second order model with good correlation. Thermodynamic parameters like change of free energy, enthalpy, and entropy were also calculated to predict the nature adsorption in the temperature range of 298~318 K. The negative Gibbs free energy change (${\Delta}G$ = -2.16~-6.55 kJ/mol) and the positive enthalpy change (${\Delta}H$ = + 23.29 kJ/mol) indicated the spontaneous and endothermic nature of the adsorption process, respectively.

Fundamental Studies on the Equilibrium and Kinetics for the fractional Distillation Reaction of Waste Organic Solvent (폐용제 분별증류 회수 반응의 평형 및 속도론적 기초연구)

  • Noh Hyun-Sook;Kim Dong-Su
    • Resources Recycling
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    • v.11 no.6
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    • pp.38-46
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    • 2002
  • Fundamental investigations were conducted far the recovery process of waste organic solvent by fractional distillation in the aspects of equilibrium and kinetics. Mixture of toluene and xylene, which were both being used in the largest amount as industrial organic solvent, was taken as the artificial waste organic solvent and their distillation behaviors were studied. The purity of recovered solvent was investigated by Cir Chromatography and shown to be in the range of 94~98%. Based upon equilibrium calculations, the changes in the Gibbs free energy, standard enthalpy, and standard entropy for distillation reaction have been estimated. The standard enthalpy changes for toluene and xylene were shown to be 44.833 and 47.044 kJ $mol^{-1}$ respectively, which were similar to their molar heats of evaporation. The activation energies of distillation fur toluene and xylene obtained from kinetic studies were 3.281 and 2.699 kJ $mol^{-1}$ and they were about one tenths of the standard enthalpy changes of distillation reaction. The highness of the purity of recovered organic solvents suggested the possibility that the recovered waste organic sol-vent could partly replace the original solvent.

Adsorption Equilibrium, Kinetics and Thermodynamics Studies of Malachite Green Using Zeolite (제올라이트를 이용한 말라카이트 그린의 흡착평형, 동력학 및 열역학 연구)

  • Lee, Jong-Jib
    • Clean Technology
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    • v.18 no.1
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    • pp.76-82
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    • 2012
  • The paper includes utlization of zeolite as potential adsorbent to remove a hazardous malachite green from waste water. The adsorption studies were carried out at 298, 308 and 318 K and effects of temperature, contact time, initial concentration on the adsorption were measured. On the basis of adsorption data Langmuir and Freundlich adsorption isotherm model were also confirmed. The equilibrium process was described well by Freundlich isotherm model, showing a selective adsorption by irregular energy of zeolite surface. From determined isotherm constants, zeolite could be employed as effective treatment for removal of malachite green. From kinetic experiments, the adsorption process followed the pseudo second order model, and the adsorption rate constant ($k_2$) decreased with increasing initial concentration of malachite green. Thermodynamic parameters like activation energy, change of free energy, enthalpy, and entropy were also calculated to predict the nature adsorption. The activation energy calculated from Arrhenius equation indicated that the adsorption of malachite green on the zeolite was physical process. The negative free energy change (${\Delta}G^{\circ}$ =-6.47~-9.07 kJ/mol) and the positive enthalpy change (${\Delta}H^{\circ}$ = +32.414 kJ/mol) indicated the spontaneous and endothermic nature of the adsorption in the temperature range 298~318 K.

Synthesis, Spectral and Thermal Studies of Lanthanide(III) Complexes of Phenylbutazone (Phenylbutazone의 란탄(III) 착물에 대한 합성, 스펙트럼 및 열적 연구)

  • Anoop, M.R.;Binil, P.S.;Jisha, K.R.;Suma, S.;Sudarsanakumar, M.R.
    • Journal of the Korean Chemical Society
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    • v.55 no.4
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    • pp.612-619
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    • 2011
  • Lanthanide(III) complexes of 1,2-diphenyl-4-butyl-3,5-pyrazolidinedione(phenylbutazone, PB) have been synthesized and characterized by elemental analyses, molar conductance measurements, IR, UV-Vis. and NMR spectra. The spectral data reveal that the PB acts as a bidentate and mono-ionic ligand coordinating through both the carbonyl oxygens of the pyrazolidinedione ring. The molar conductance data suggest that the complexes are non-electrolytes. The thermal behaviour of the complexes was studied by TG and DTG in air atmosphere and the results provide information about dehydration, thermal stability and thermal decomposition. The final products are found to be the corresponding metal oxides. The thermodynamic parameters and kinetic parameters were evaluated for the dehydration and decomposition stages. The negative entropy values of the decomposition stages indicate that the activated complexes have a more ordered structure than the reactants and that the reactions are slower than normal. Based on these studies, the complexes have been formulated as $[Ln(PB)_3]{\cdot}5H_2O$(Ln=La and Ce) and $[Ln(PB)_3(H_2O)_2]{\cdot}2H_2O$(Ln=Pr, Nd and Sm).