• Title/Summary/Keyword: Dispersion effects

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Complexation of Progesterone with Cyclodextrins and Design of Aqueous Parenteral Formulations (프로게스테론과 시클로덱스트린류 간의 복합체 형성 및 수성 주사제 설계)

  • Choi, Hee-Jeong;Chun, In-Koo
    • Journal of Pharmaceutical Investigation
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    • v.31 no.3
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    • pp.151-160
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    • 2001
  • The purpose of this study is to investigate the interaction of progesterone with various cyclodextrins (CDs) in the aqueous solution and in solid state, and finally to formulate a parenteral aqueous formulation. CDs used were ${\alpha}-$, ${\beta}-$, and ${\gamma}-CD$, $2-hydroxypropyl-{\beta}-CD$ (HPCD), sulfobutyl $ether-{\beta}-CD$ (SBCD), $dimethyl-{\beta}-CD$ (DMCD) and $trimethyl-{\beta}-CD$ (TMCD). The solubility studies of progesterone were performed in the presence of various CDs as a function of concentration or temperature. The solubility of progesterone increased in the rank order of ${\alpha}-CD$ < ${\beta}-CD$ < ${\gamma}-CD$ < TMCD$ < HPCD < DMCD < SBCD. Addition of SBCD (200 mg/ml) in water increased the aqueous solubility $(9.36\;{\mu}g/ml)$ about 3,200 times, and lowering the temperature facilitated the solubilization of progesterone. However, the addition of HPCD and SBCD in 20:80 (v/v) polyethylene glycol 300-water and propylene glycol-water cosolvents markedly decreased the solubility of progesterone, compared with solubilizing effects in water. Physical mixtures and solid dispersions of progesterone with HPCD or SBCD were prepared, and evaluated by differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), near IR spectroscopy and dissolution studies. By DSC and IR studies, it was found that progesterone was dispersed in HPCD in monotectic state and dissolved rapidly from both solid dispersions. Based on solubility studies, new aqueous progesterone fonnulations (5 mg/ml) containing SBCD (200 mg/ml) could be prepared and did not form precipitates even after 2 months at $4^{\circ}C$. The solution was transparent when mixed with normal saline and 5% dextrose injection at 1: 1, 1:10 and 1:20 (v/v) even after 7 days. Permeation rates of progesterone through a cellulose membrane from 20% PEG 300 solution $(50\;{\mu}g/ml)$ containing HPCD or SBCD were compared with oily formulation. Permeation of progesterone from oily formulation did not occur up to 8 hr, but aqueous formulations showed fast permeation rates from early stage of permeation study. The addition of HPCD or SBCD retarded the permeation rates of progesterone with the increase of CD concentrations, suggesting the possibility of a controlled absorption from the site administered intramuscularly. These results demonstrate that it is feasible to develop a new progesterone parenteral aqueous injection (5 mg/ml) using SBCD.

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Curcumin Attenuates Hydrogen Peroxide Induced Oxidative Stress on Semen Characteristics during In Vitro Storage of Boar Semen

  • Jang, Hyun-Yong;Kim, Young-Han;Cheong, Hee-Tae;Kim, Jong-Taek;Park, In-Chul;Park, Choon-Keun;Yang, Boo-Keun
    • Reproductive and Developmental Biology
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    • v.33 no.2
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    • pp.99-105
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    • 2009
  • Curcumin is a major active component of the food flovour tumeric. It has been used for the treatment of many diseases such as inflammatory and infectious diseases, cancer and other disease due to its antioxidant properties. Curcumin is a powerful scavenger of many free radicals such as superoxide anion, hydroxyl radical and nitric oxide. The objective of this study was to investigate the antioxidative effects of curcumin against hydrogen peroxide on semen quality during in vitro storage of boar semen. The sperm treated with different concentration of curcumin (1, 5 and 10 ${\mu}M$) in the presence or absence of hydrogen peroxide (250 ${\mu}M\;H_2O_2$) were incubated for 3, 6 and 9 hr at $37^{\circ}C$ and analyzed sperm characteristics such as motility, membrane integrity (MI), lipid peroxidation (LPO), reactive oxygen species (ROS) and DNA fragmentation (DF). The sperm motility and MI in $H_2O_2$ treated group ($47.8%{\pm}6.8$ and $24.8%{\pm}2.2$) were significantly decreased when compare to curcumin treated group ($79.8%{\pm}2.7$ and $34.6%{\pm}1.0$, respectively) irrespective of incubation periods(p<0.05). The LPO of spermatozoal plasma membrane was measured by thiobarbituric acid (TBA) reactions for malondialdehyde (MDA), MDA level in control ($11.6{\pm}0.6\;nmol/L{\times}10^6$) and curcumin groups ($10.7{\pm}0.3\;nmol/L{\times}10^6$) were lower than those of curcumin plus $H_2O_2$ ($17.1{\pm}0.8\;nmol/L{\times}10^6$) or $H_2O_2$ group ($22.5{\pm}1.9\;nmol/L{\times}10^6$) from 3 to 9 hr incubation periods. The DF by sperm chromatin dispersion (SCD) test and ROS production measured by 2',7'-dichlorofluorescein (DCF) fluorescence intensity were no significantly difference through all experimental groups (p>0.05). Correlation among evaluation methods for sperm quality, motility vs MI and DF vs ROS was positively correlated while motility vs DF and ROS vs LPO were negatively correlated in all treatment groups. These results demonstrate that curcumin can effectively improve the sperm quality during in vitro storage of boar semen through its hydrogen peroxide scavenging mechanism as an antioxidant.

Dissolution and Duodenal Permeation Characteristics of Lovastatin from Bile Salt Solid Dispersions (담즙산염과의 고체분산체로부터 로바스타틴의 용출 및 십이지장 점막 투과 특성)

  • Chun, In-Koo
    • Journal of Pharmaceutical Investigation
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    • v.39 no.2
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    • pp.97-106
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    • 2009
  • Although lovastatin (LS) is widely used in the treatment of hypercholesterolemia, its bioavailability is known to be around 5%. This study was aimed to increase the solubility and dissolution-permeation rates of LS using solid dispersions (SDs) with bile salts. The solubilities of LS in water, aqueous bile salt solutions and non-aqueous vehicles were determined, and effects of bile salts on the cellulose or duodenal permeation of LS from SDs were evaluated using a horizontal permeation system. SDs were prepared at various ratios of LS to carriers, such as sodium deoxycholate (SDC), sodium glycocholate (SGC) and/or 2-hydroxypropyl-$\beta$-cyclodextrin (HPCD). The addition of bile salts (25 mM) in water increased markedly the solubility of LS by the micellar solubilization. Some non-aqueous vehicles were effective in solubilizing LS. From differential scanning calorimetric studies, it was found that the crystallinity of LS in SDs disappeared, indicating a formation of amorphous state. The SDs showed markedly enhanced dissolution compared with those of their physical mixtures (PMs) and drug alone. In the dissolution-permeation studies using a cellulose membrane, the donor and receptor solutions were maintained as a sink condition using pH 7.0 phosphate buffer containing 0.05% sodium lauryl sulfate (SLS). The flux of LS alone was nearly same as that of LS-SDC-HPCD (1:3:6) PM. However, the flux of LS-SDC-HPCD (1:3:6) SD slightly increased compared with drug alone and PM, suggesting that entrapment of LS in micelles does not significantly hinder the permeation across cellulose membrane. In the dissolution-duodenal permeation studies using a LS-HPCD-SDC (1:3:6) SD, the addition of various bile salts in donor solutions (25 mM) enhanced the permeation of LS markedly, and the fluxes were found to be $0.69{\pm}0.41$, $0.87{\pm}0.51$, $0.84{\pm}0.46$, $0.47{\pm}0.17$ and $0.68{\pm}0.32{\mu}g/cm^2/hr$ for sodium cholate (SC), SDC, SGC, sodium taurodeoxycholate (STDC) and sodium taurocholate (STC), respectively. The stepwise increase of donor SGC concentration increased the flux dose-dependently. From the relationship of donor SGC concentration and flux, the concentration of SGC initiating the permeation across the duodenal mucosa was calculated to be 11.1 mM, which is nearly same as the critical micelle concentration (CMC, 11.6 mM) of SGC. However, with no addition of bile salts and below CMC, the permeation was very limited and irratic, indicating that LS itself is very poor permeable. Higher protions of bile salt in SD such as LS-SDC or LS-SGC (1 : 49 and 1 : 69) showed highly promoted fluxes. In conclusion, SD systems with bile salts, which may form their micelles in intestinal fluids, might be a promising means for providing enhanced dissolution and intestinal permeation of practically insoluble and non-absorbable LS.

Kriging Analysis for Spatio-temporal Variations of Ground Level Ozone Concentration

  • Gorai, Amit Kumar;Jain, Kumar Gourav;Shaw, Neha;Tuluri, Francis;Tchounwou, Paul B.
    • Asian Journal of Atmospheric Environment
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    • v.9 no.4
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    • pp.247-258
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    • 2015
  • Exposure of high concentration of ground-level ozone (GLO) can trigger a variety of health problems including chest pain, coughing, throat irritation, asthma, bronchitis and congestion. There are substantial human and animal toxicological data that support health effects associated with exposure to ozone and associations have been observed with a wide range of outcomes in epidemiological studies. The aim of the present study is to estimate the spatial distributions of GLO using geostatistical method (ordinary kriging) for assessing the exposure level of ozone in the eastern part of Texas, U.S.A. GLO data were obtained from 63 U.S. EPA's monitoring stations distributed in the region of study during the period January, 2012 to December, 2012. The descriptive statistics indicate that the spatial monthly mean of daily maximum 8 hour ozone concentrations ranged from 30.33 ppb (in January) to 48.05 (in June). The monthly mean of daily maximum 8 hour ozone concentrations was relatively low during the winter months (December, January, and February) and the higher values observed during the summer months (April, May, and June). The higher level of spatial variations observed in the months of July (Standard Deviation: 10.33) and August (Standard Deviation: 10.02). This indicates the existence of regional variations in climatic conditions in the study area. The range of the semivariogram models varied from 0.372 (in November) to 15.59 (in April). The value of the range represents the spatial patterns of ozone concentrations. Kriging maps revealed that the spatial patterns of ozone concentration were not uniform in each month. This may be due to uneven fluctuation in the local climatic conditions from one region to another. Thus, the formation and dispersion processes of ozone also change unevenly from one region to another. The ozone maps clearly indicate that the concentration values found maximum in the north-east region of the study area in most of the months. Part of the coastal area also showed maximum concentrations during the months of October, November, December, and January.

A Study on the Antioxidative Effects of Zostera marina and its Application in Cosmatics (잘피(Zostera marina)의 항산화 효능과 화장품 응용에 관한 연구)

  • Lee, So-Yeon;Yang, Jae-Chan;Kim, Bo-Ae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.3
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    • pp.534-544
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    • 2017
  • In order to use the sea flowering plant, Zostera marina, as a cosmetic ingredient, this study was conducted to evaluate its antioxidant effect. We confirmed the formulation stability of the emulsion containing Zostera marina extracts. We studied the antioxidant activity of the dissolved Zostera marina extracts through the DPPH (1,1-Diphenyl-2-picrylhydrazy) radical scavenging activity assay and SOD (superoxide dismutase)-like activity assay. Also, the pH, viscosity and particle dispersion of the emulsion containing Zostera marina extracts were measured using a Turbiscan LAB. The emulsions were measured at one-week intervals in a thermostat chamber ($25^{\circ}C{\pm}1^{\circ}C$, $40^{\circ}C{\pm}1^{\circ}C$) for 28 days. The extracts of Zostera marina showed a DPPH radical scavenging rate of 86.21% and SOD-like activity of 99.24% at 5.00 mg/ml and exhibited a dose-dependent increase in their antioxidant activity. We measured the stability of the pH, viscosity and emulsion particles using the Turbiscan LAB in a thermostat chamber for 28 days. The formulations to which the Zostera marina extracts were added were considered to be stable, due to their negligible physical property changes over time during storage. The results suggest that the Zostera marina extracts with 70% ethanol (v/v) could be used in cosmetics as an antioxidant for the anti-aging of skin.

Effects of Oxyfluorinated Graphene Oxide Flake on Mechanical Properties of PMMA Artificial Marbles (함산소불소화 처리된 그래핀 산화물 플레이크가 PMMA 인조대리석의 기계적 물성에 미치는 영향)

  • Kim, Hyo-Chul;Jeon, Son-Yeo;Kim, Hyung-Il;Lee, Young-Seak;Hong, Min-Hyuk;Choi, Ki-Seop
    • Polymer(Korea)
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    • v.36 no.3
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    • pp.251-261
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    • 2012
  • The nanocomposites containing graphene oxide flakes were prepared in order to improve the mechanical properties of artificial marbles based on poly(methyl methacrylate)(PMMA) matrix. Graphene oxide flakes were prepared from graphite by oxidation with Hummers method followed by exfoliation with thermal treatment. Surface of graphene oxide flakes were modified with oxyfluorination in various oxygene:fluorine compositions to improve the interfacial compatibility. The nanocomposites containing graphenes modified with oxyfluorination in the oxygen content of 50% and higher showed the significant increase in flexural strength, flexural modulus, Rockwell hardness, Barcol hardness, and Izod impact strength. The morphology of fractured surface showed the improved interfacial adhesion between PMMA matrix and the graphenes which were properly treated with oxyfluorination. The mechanical properties of nanocomposite were deteriorated by increasing the content of graphene above 0.07 phr due to the nonuniform dispersion of graphenes.

Effect of Dispersant Contents on the Dispersity of Conductive Carbon-black and Properties of Screen-printed Source-drain Electrodes for OTFTs (분산제 함량에 따른 전도성 카본블랙의 분산 특성 및 스크린 인쇄된 OTFTs용 소스-드레인 전극 물성)

  • Lee, Mi-Young;Bae, Kyung-Eun;Kim, Seong-Hyun;Lim, Sang-Chul;Nam, Su-Yong
    • Polymer(Korea)
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    • v.33 no.5
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    • pp.397-406
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    • 2009
  • We have fabricated source-drain electrodes for OTFTs using a screen-printing technique with carbon-black pastes as conductive paste. And effects of dispersants contents (SOP 10-40%) on the dispersity of carbon-black pastes and characteristics of screen-printed source-drain electrodes for OTFTs using two types of dispersants (DB-2150, DB-9077) were investigated. As contents of both dispersants were increased the dispersity of carbon-black mill-bases was improved, whereas the carbon-black pastes exhibited different dispersion characteristics. For the case of DB-2150, the dispersity of the pastes was improved with increasing dispersant content and the storage modulus G' in their rheology characteristics were reduced. But, for the DB-9077, the storage modulus G' of pastes were increased with dispersant content due to the flocculated network structure formed by interactions among carbon-black powders and dispersants. But, since this flocculated network structure of the pastes using DB-9077 resulted in the conduction path of carbon-black structures, the conductivities of screen-printed electrodes and mobilities of the OTFTs with them were better than those using pastes with DB-2150.

Effects of Silane Structure on Composite Interaction Parameter (αC)) of Silica Filled Rubber Compounds (실란 구조가 실리카 복합소재 내 구조발달 상호계수(αC)에 미치는 영향)

  • Kim, Sung Min;Kim, Kwang Jea
    • Polymer(Korea)
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    • v.38 no.4
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    • pp.411-416
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    • 2014
  • Due to the polar characteristics of silica compared to carbon black, the degree of silica dispersion, which affects the mechanical properties of rubber compounds, is an important issue. Wolff first introduced the in-rubber structure of particles (${\alpha}_F$) to express the structure development in the compounds; however, with the introduction of bifunctional silanes, his theory could not explain the 3-dimensional network structure of the compounds. Later his theory was expanded to express the composite interaction parameter (in-rubber structure of the compound) (${\alpha}_C$), which included Wolff's filler-filler interaction parameter (${\alpha}_F$), however, there was no reported experimental result proving the theory. This research first experimentally expressed the in-rubber structure of the compound ${\alpha}_C$ (= ${\alpha}_F+{\alpha}_{FP}$(filler-silane-rubber interaction parameter) + ${\alpha}_P$ (rubber-rubber interaction parameter)) upon mono- and bifunctional silane treated silica filled natural rubber (NR) compounds. Using different structure silanes, i.e. PTES, OTES, TESPD, and TESPT, the ${\alpha}_C$ value of each compound was measured and calculated. The ${\alpha}_C$ value of TESPT treated silica filled compound was 1.64, which composed of ${\alpha}_F$ (0.99), ${\alpha}_{FP}$ (0.31), and ${\alpha}_P$ (0.34).

A Study on Trade Automation in Korea (한국의 무역자동화에 관한 고찰)

  • 전재경;이재승
    • Journal of the Korea Society of Computer and Information
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    • v.3 no.3
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    • pp.139-150
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    • 1998
  • Due to development of science and telecommunication with wide-spread computer supply, it could be done through computer automatically instead of manpower-work for paper transportation & paper approval. It is developed to so-called Factory Automation. Further, it is developed to Office Automation. Trading companies & concerned trade authorities are interested in Trade Automation that such technique is applied to trade work. Generally, Trade Automation means to realize paperless trade by exchanging electronic papers through inter-computers after concerned trade operators transformed various papers to electronic papers that computer could read. In case Trade Automation fix in the trade business, it is expected one of innovations among traditional paper work of trade business, namely without going import-export authorities, Customs office, Banks. Shipping companies, Marine insurance companies on hand-carrying papers, it could be fast, simple, correct to finish every trade procedures such as commercial business, foreign currency, customs clearance, transportations, insurance. terms of payment, etc., with Electronic Data Interchange through computer facilities. Especially, telecommunication for trade form could be helpful to proceed trade paper with one-run-method Further we can anticipate 6 effects for Trade Automation as belows : First, as explained just above articles, with completion for Trade Automation, every trade procedures can be done by computer. so, time to work can be diminished. namely. logistics cost including accessory costs for trade procedures can be saved much. Second, viewing to private enterprise, effect of Office Automation can be maximized and rapid, correct exchange for various trade informations could raise efficiency of enterprise management establishing rational production, storage, transportation and could raise competition improving standard for consumers's service. Third, establishing Trade Automation systems makes it easier piling-up of harbor cargo by pre-transmission of electronic paper & trade informations make it possible to finish customs clearance in advance and can be dispatched upon cargo arrival. Fourth, most of concerned trade authorities such as import-export approval office. financial authorities, transport & insurance companies concentrated in Metropolitan area(Seoul, In -Cheon, Kyung-Ki). Therefore, in case Trade Automation could be realized. it is possible to proceed trade business instantly in every country area by computer facilities. Also. it contribute well-balanced development for suburb. region area by suburb dispersion of trading companies. Fifth, on the way to Trade Automation establishment & its enlargement process. producing enormous demand for over-all telecommunication such as hardware. software. network makes opportunity to progress telecommunication industry & concerned industries. Finally. Trade Automation accelerate change of employment structure leading unnecessary labors on the industries of office & logistics to manufacturing area.

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The Influences of a Team System's Introduction to Hospital Organization, Regarding Job Satisfaction and Organization Commitment (병원조직에 팀제 도입이 팀직무만족과 팀조직 몰입에 미치는 영향)

  • Choi, Soon-Yeon;Nam, Eun-Woo
    • Korea Journal of Hospital Management
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    • v.5 no.1
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    • pp.232-271
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    • 2000
  • The introduction of a team system to any organization is usually to improve that organizations dynamics, by increasing the proper adaptation to rapidly changing environments, by reducing approval procedures, and by promoting power authorization. In this regard, this study was carried out in an attempt to determine (1) whether or not the introduction of a team system can be as effective in hospital organizations as it has been in business organizations, and (2) what behavior factors influence such effectiveness. For the current study, questionnaires were distributed to the employees of a university hospital in Pusan. Four hundred eighty three of them(94.7%) were retrieved and analyzed through statistical processes. The three types of variables that were found to influence team effectiveness were: (1) independent variables of team organization characteristics, such as communication, organizational atmosphere, leadership and team knowledge, (2) intervening variables of team organization characteristics. such as job autonomy, technological variety, task subjectivity, task feedback and task importance, and(3) the dependent variables of team level effectiveness, such as job satisfaction and commitment to team organization. The gathered data were processed by using the 6.12 version of the statistical program SAS(Statistical Analysis System), and the reliance coefficient of those measured variables was then evaluated as an average of 0.78. The influence of team level effectiveness was analyzed by using multiple regression analysis. These differences in effectiveness were then analyzed on the basis of related mean values, while the differences among demo-sociological characteristics were analyzed by using the dispersion analysis(ANOVA) and the t-test. The results of the study can be summarized by the following. First, regarding the relationship between team organization characteristics and team level effectiveness, all of the factors including communication, organizational atmosphere, leadership and team knowledge were found to have a significant influence on effectiveness. Second, the factors of team job characteristics, such as technological variety, task importance and job autonomy, had significant effects on job satisfaction and organizational commitment among the teams members. Team level effectiveness was generally high, while team job satisfaction was higher the teams organizational commitment. Third, regarding the demo-sociological characteristics, team level effectiveness was found to be higher among those who were older, who had more job experience, and who had a higher position. Comparing the differences among job types, the effectiveness was relatively higher in the fields of nursing and administration/management then in other fields. Further study should be done towards the setting of variables for characteristics of hospital organization, developing suitable methods of measurement, and researching individual level effectiveness.

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