• Title/Summary/Keyword: Constant potential

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Targeted and sustained delivery of hydrocortisone to normal and stratum corneum-removed skin without enhanced skin absorption using a liposome gel

  • Kim, Moon-Kyoung;Chung, Suk-Jae;Lee, Min-Hwa;Cho, Ae-Ri;Shim, Chang-Koo
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1996.04a
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    • pp.278-278
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    • 1996
  • Judging from hydrocortisone concentration in dosing area, the extent of absorption was reduced in the liposome-gel formulation. However, higher and sustained skin concentrations of hydrocortisone were achieved for the liposome-gel as compared to the ointment. Drug concentration in both viable and deep skin reached its maximum within 0.5 h after application of both formulations to both skin types. Drug concentrations in both skins from the ointment declined with time, while those from the liposome-gel were greatly sustained. The sustainment by the liposome-gel was more remarkable in the viable skin than in the deep skin. Drug concentration in the viable skin could be maintained at a nearly constant level for over 8 h by applying the liposome-gel. As a result, a 5-fold higher viable skin drug concentration was obtained from the liposome-gel than from the ointment at 8 h after the application to the SC-removed skin. However, the plasma concentration of hydrocortisone at 4 h from the liposome-gel was only one-fourth (p<0.01) the value from the ointment when the drug was applied to the SC-removed skin, consistent with. the lower urinary (one-third, p<0.05) and fecal (one-half, p<0.05) excretion. Conclusions : Retarded diffusion of the drug from the skin to the systemic blood stream appears to be a potential factor in the sustained skin concentration of hydrocortisone from the liposome-gel, Interaction of hydrocortisone in the skin with phosphatidylcholine, a component of the liposomes and skin, may well be a factor in retarding the diffusion of the drug in the skin.

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Analysis of Dimension Dependent Subthreshold Swing for FinFET Under 20nm (20nm이하 FinFET의 크기변화에 따른 서브문턱스윙분석)

  • Jung, Hak-Kee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.10
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    • pp.1815-1821
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    • 2006
  • In this paper, the subthreshold swing has been analyzed for FinFET under channel length of 20nm. The analytical current model has been developed , including thermionic current and tunneling current models. The potential distribution by Poisson equation and carrier distribution by Maxwell-Boltzman statistics are used to calculate thermionic emission current and WKB(Wentzel-Kramers-Brillouin) approximation to tunneling current. The cutoff current is obtained by simple adding two currents since two current is independent. The subthreshold swings by this model are compared with those by two dimensional simulation and two values agree well. Since the tunneling current increases especially under channel length of 10nm, the characteristics of subthreshold swing is degraded. The channel and gate oxide thickness have to be fabricated as am as possible to decrease this short channel effects, and this process has to be developed. The subthreshold swings as a function of channel doping concentrations are obtained. Note that subthreshold swings are resultly constant at low doping concentration.

Experimental Study on Air Decomposition By-Product Under Creepage Discharge Fault and Their Impact on Insulating Materials

  • Javed, Hassan;LI, Kang;Zhang, Guoqiang;Plesca, Adrian Traian
    • Journal of Electrical Engineering and Technology
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    • v.13 no.6
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    • pp.2392-2401
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    • 2018
  • Creepage discharge faults in air on solid insulating material play a vital role in degradation and ageing of material which ultimately leads to breakdown of power equipment. And electric discharge decompose air in to its by-products such as Ozone and $NO_x$ gases. By analyzing air decomposition gases is a potential method for fault diagnostic in air. In this paper, experimental research has been conducted to study the effect of creepage discharge on rate of generation of air decomposition by-products using different insulating materials such as RTV, epoxy and fiberglass laminated sheet. Moreover XRF analysis has been done to analyze creepage discharge effect on these insulating materials. All experiments have been done in an open air test cell under constant temperature and pressure conditions. While analysis has been made for low and high humidity conditions. The results show that the overall concentration of air decomposition by-products under creepage discharge in low humidity is 4% higher than concentration measured in high humidity. Based on this study a mathematical relationship is also proposed for the rate of generation of air decomposition by-products under creepage discharge fault. This study leads to indirect way for diagnostic of creepage discharge propagation in air.

Immobilization of Layered Double Hydroxide into Polyvinyl Alcohol/Alginate Hydrogel Beads for Phosphate Removal

  • Han, Yong-Un;Lee, Chang-Gu;Park, Jeong-Ann;Kang, Jin-Kyu;Lee, In;Kim, Song-Bae
    • Environmental Engineering Research
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    • v.17 no.3
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    • pp.133-138
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    • 2012
  • Polyvinyl alcohol/alginate hydrogel beads containing Mg-Al layered double hydroxide (LDH-PVA/alginate beads) were synthesized for phosphate removal. Results showed that blending PVA with the LDH-alginate beads significantly improved their stability in a phosphate solution. The kinetic reaction in LDH-PVA/alginate beads reached equilibrium at 12 hr-post reaction with 99.2% removal. The amount of phosphate removed at equilibrium ($q_e$) was determined to be 0.389 mgP/g. The equilibrium data were described well by the Freundlich isotherm with the distribution coefficient ($K_F$, 0.638) and the constant (n, 0.396). Phosphate removal in LDH-PVA/alginate beads was not sensitive to solution pH. Also, the removal capacity of LDH-PVA/alginate beads ($q_e$, 1.543 mgP/g) was two orders of magnitude greater than that of PVA/alginate beads ($q_e$, 0.016 mgP/g) in column experiments. This study demonstrates that LDH-PVA/alginate beads with a higher chemical stability against phosphate compared to LDH-alginate beads have the potential for phosphate removal as adsorptive media.

Formation of Functional Cardiomyocytes Derived from Mouse Embryonic Stem Cells

  • 신현아;김은영;이영재;이금실;조황윤;박세필;임진호
    • Proceedings of the KSAR Conference
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    • 2003.06a
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    • pp.76-76
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    • 2003
  • Pluripotent embryonic stem cells can differentiate into beating cardiomyocytes with proper culture conditions and stimulants via embryo-like aggregates. We describe here the use of mouse embryonic stem (mES03) cells as a reproducible differentiation system for cardiomyocyte. mES03 cells growing in colonies were dissociated and allowed to re-aggregated in suspension [embryoid body (EB) formation〕. To induce cardiomyocytic differentiation, cells were exposed to 0.75% dimethyl sulfoxide (DMSO) during EB formation for 4 days and then another 4 days without DMSO (4+/4-). Thus treated EB was plated onto gelatin-coated dishes for differentiation. Spontaneously contracting colonies which appeared in approximately 4~5 days upon differentiation were mechanically dissected, enzymatically dispersed, plated onto coverslips, and then incubated for another 48~72 hrs. By RT-PCR, robust expression of cardiac myosin heavy chain $\alpha$, cardiac muscle heavy polypeptide 7 $\beta$($\beta$-MHC), cardiac transcription factor GATA4, and skeletal muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel ($\alpha$$_1$CaC $h_{sm}$ ) were detected as early as 8 days after EB formation, but message of cardiac muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel ($\alpha$$_1$CaCh) were reveled at a low level. In contrast, expression of myosin light chain (MLC-2V) and atrial natriuretic factor (ANF) were not detected during EB formation for 8 days. However, a strong expression of the atrial-specific ANF gene was expressed from day 8 onward, which were remained constant in EB. (cardiac specialization and terminal differentiation stage). Electrophysiological examination of spontaneously contracting cells showed ventricle-like action potential 17 days after the EB formation. This study indicates that mES03 cell-derived cardiomyocytes via 4+/4- protocol displayed biochemical and electrophysiological properties of subpopulation of cardiomyocytes.

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Impact of Comorbid Obsessive Compulsive Symptoms on Quality of Life in Stable Patients with Chronic Schizophrenia (안정화된 만성 조현병 환자에서 강박장애 증상이 삶의 질에 미치는 영향)

  • Moon, Jung Yoon;Kang, Sukhoon;Seok, Jung-Ho;Kim, Chan-Hyoung;Kim, Tae Yong;Choi, Jin Hee;So, Hyong Seok
    • Anxiety and mood
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    • v.13 no.2
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    • pp.141-147
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    • 2017
  • Objective : This study aimed to evaluate the relationship between comorbid obsessive compulsive disorder (OCD) and quality of life in stable patients with schizophrenia. Methods : We interviewed 162 symptom-stable inpatients who have been on a constant dose of antipsychotics for at least 3 months prior and diagnosed as chronic schizophrenia. Subsequently, patients were classified according to the existence of OCD as evaluated using the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV). Further, all clinical and demographic data were collected and evaluated. To investigate potential interrelationships, the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Korea-Positive and Negative Symptom Scale (K-PANSS), Korean Modification of the Scale to Measure Subjective Well-Being under Neuroleptic Treatment (KmSWN) and Korean Version Quality of Life Scale (K-QOLS) were performed. Independent t-test and Chi-square test were used to compare groups and regression analysis was done to assess the relationship between the Y-BOCS and quality of life. Results : Schizophrenia patients with OCD showed significantly earlier onset of schizophrenia, more severe psychiatric symptoms and lower quality of life, compared to those without comorbid OCD. OCD might be associated with lower quality of life in schizophrenia. Conclusion : Schizophrenia patients with OCD showed lower quality of life than those without OCD. In the treatment for schizophrenia, evaluation of OCD might be needed to improve their quality of life and social function.

Computational Study of Unsteady Three Dimensional Wing in Pitching Motion Utilizing Linear Vortex Panel Method (VORTEX 패널법을 이용한 비정상 3차원 날개의 피칭 운동에 관한 연구)

  • Jeong,Bong-Gu;Cho,Tae-Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.6
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    • pp.1-7
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    • 2003
  • In this study, steady/unsteady aerodynamic characteristic for three dimensional symmetric wing was investigated numerically using Vortex Panel Method. This program utilized linearly varying vortices in x and y directions distributed on the wing surface and was applied to the incompressible potential. flow around a three dimensional wing Separation and deformation of the wake are not considered. The comparison between NACA Airfoil Data and the computed results showed excellent agreement. πus method was applied to unsteady wings undergoing both sudden pitch-up and constant rate pitching motion. In the unsteady flow analysis, a formation and a time-dependent locations of Starting Vortices are considered and the effect of Starting Vortices on aerodynamic characteristic of the wing was calculated. The present method can be extended to apply for more complicated cases such as pitching, flapping and rotating wing analysis.

The Development of Phasic and Tonic Inhibition in the Rat Visual Cortex

  • Jang, Hyun-Jong;Cho, Kwang-Hyun;Park, Sung-Won;Kim, Myung-Jun;Yoon, Shin-Hee;Rhie, Duck-Joo
    • The Korean Journal of Physiology and Pharmacology
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    • v.14 no.6
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    • pp.399-405
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    • 2010
  • Gamma-aminobutyric acid (GABA)-ergic inhibition is important in the function of the visual cortex. In a previous study, we reported a developmental increase in $GABA_A$ receptor-mediated inhibition in the rat visual cortex from 3 to 5 weeks of age. Because this developmental increase is crucial to the regulation of the induction of long-term synaptic plasticity, in the present study we investigated in detail the postnatal development of phasic and tonic inhibition. The amplitude of phasic inhibition evoked by electrical stimulation increased during development from 3 to 8 weeks of age, and the peak time and decay kinetics of inhibitory postsynaptic potential (IPSP) and current (IPSC) slowed progressively. Since the membrane time constant decreased during this period, passive membrane properties might not be involved in the kinetic changes of IPSP and IPSC. Tonic inhibition, another mode of $GABA_A$ receptor-mediated inhibition, also increased developmentally and reached a plateau at 5 weeks of age. These results indicate that the time course of the postnatal development of GABAergic inhibition matched well that of the functional maturation of the visual cortex. Thus, the present study provides significant insight into the roles of inhibitory development in the functional maturation of the visual cortical circuits.

The tuned mass-damper-inerter for harmonic vibrations suppression, attached mass reduction, and energy harvesting

  • Marian, Laurentiu;Giaralis, Agathoklis
    • Smart Structures and Systems
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    • v.19 no.6
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    • pp.665-678
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    • 2017
  • In this paper the tuned mass-damper-inerter (TMDI) is considered for passive vibration control and energy harvesting in harmonically excited structures. The TMDI couples the classical tuned mass-damper (TMD) with a grounded inerter: a two-terminal linear device resisting the relative acceleration of its terminals by a constant of proportionality termed inertance. In this manner, the TMD is endowed with additional inertia, beyond the one offered by the attached mass, without any substantial increase to the overall weight. Closed-form analytical expressions for optimal TMDI parameters, stiffness and damping, given attached mass and inertance are derived by application of Den Hartog's tuning approach to suppress the response amplitude of force and base-acceleration excited single-degree-of-freedom structures. It is analytically shown that the TMDI is more effective from a same mass/weight TMD to suppress vibrations close to the natural frequency of the uncontrolled structure, while it is more robust to detuning effects. Moreover, it is shown that the mass amplification effect of the inerter achieves significant weight reduction for a target/predefined level of vibration suppression in a performance-based oriented design approach compared to the classical TMD. Lastly, the potential of using the TMDI for energy harvesting is explored by substituting the dissipative damper with an electromagnetic motor and assuming that the inertance can vary through the use of a flywheel-based inerter device. It is analytically shown that by reducing the inertance, treated as a mass/inertia-related design parameter not considered in conventional TMD-based energy harvesters, the available power for electric generation increases for fixed attached mass/weight, electromechanical damping, and stiffness properties.

Comparative Rumen Degradability of Some Legume Forages between Wet and Dry Season in West Sumatra, Indonesia

  • Evitayani, Evitayani;Warly, L.;Fariani, A.;Ichinohe, T.;Abdulrazak, S.A.;Fujihara, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.8
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    • pp.1107-1111
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    • 2004
  • An experiment was conducted to evaluate the potential nutritive value of five legume forages (leaves and twigs) in West Sumatra during wet and dry seasons. The chemical composition, in vitro dry matter (IVDMD), organic matter (IVOMD) and crude protein digestibility (IVCPD), in vitro gas characteristics and estimated metabolizable energy (ME) showed variation among legume forages and between different seasons. Crude protein (CP) ranged from 14.2 to 27.8% DM in the wet season, with a significant (p<0.05) reduction in dry season. C. pubescens, G. maculata, L. leucocephala and P. phaseloides showed the least reduction in CP content. The NDF, ADF and lignin were about 39.0, 26.5 and 6.1% DM, respectively in the wet season, and significantly (p<0.05) increased in the dry season, except for NDF of C. mucunoides and C. pubescens. For IVDMD, IVOMD and IVCPD significantly increased in the wet season, but values remained as high as over 50.0% of DM. The in vitro gas characteristics and metabolizable energy were significantly (p<0.05) higher in wet season than the dry season. During both seasons, the rate of constant (c) for G. maculata and ME content for C. pubescens and P. phaseloides were not significantly (p<0.05). Results demonstrated that P. phaseloides and L. leucocephala have a good nutritive value during both wet and dry seasons. Further studies on feeding trials are needed to quantify the animal responses when offered these legume forages.