• Asia pacific journal of information systems
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• v.17 no.2
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• pp.97-122
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• 2007

Conventional networking and telecommunications infrastructure characterized by wires, fixed location, and inflexibility is giving way to mobile technologies. Numerous research reports point to the ultimate domination of wireless communication. With the increasing prevalence of advanced cell-phones, various mobile data services (hereafter MDS) are gaining popularity. Although cellular networks were originally introduced for voice communications, statistics indicate that data services are replacing the matured voice service as the growth engine for telecom service providers. For example, SK Telecom, the Korea's largest mobile service provider, reported that 25.6% of revenue and 28.5% of profit came from MDS in 2006 and the share is growing. Statistics also indicate that, in 2006, the average revenue per user (ARPU) for voice didn't change but MDS grew seven percents from the previous year, further highlighting its growth potential. MDS is defined "as an assortment of digital data services that can be accessed using a mobile device over a wide geographic area." A variety of MDS have been deployed, with a few reaching the status of killer applications. Many of them need to access the Internet through the cellular-phone infrastructure. In the past, when the cellular network didn't have acceptable bandwidth for data services, SMS (short messaging service) dominated MDS. Now, Internet-ready, next-generation cell-phones are driving rich digital data services into the fabric of everyday life, These include news on various topics, Internet search, mapping and location-based information, mobile banking and gaming, downloading (i.e., screen savers), multimedia streaming, and various communication services (i.e., email, short messaging, messenger, and chaffing). The huge economic stake MDS has on its stakeholders warrants focused research to understand associated dynamics behind its adoption. Lyytinen and Yoo(2002) pointed out the limitation of traditional adoption models in explaining the rapid diffusion of innovations such as P2P or mobile services. Also, despite the increasing popularity of MDS, unexpected drop in its usage is observed among some people. Intrigued by these observations, an exploratory study was conducted to examine decision factors of MDS usage. Data analysis revealed that the increase and decrease of MDS use was influenced by different forces. The findings of the exploratory study triggered our confirmatory research effort to validate the uni-directionality of studied factors in affecting MDS usage. This differs from extant studies of IS/IT adoption that are largely grounded on the assumption of bi-directionality of explanatory variables in determining the level of dependent variables (i.e., user satisfaction, service usage). The research goal is, therefore, to examine if increase and decrease in the usage of MDS are explained by two separate groups of variables pertaining to information quality and system quality. For this, we investigate following research questions: (1) Does the information quality of MDS increase service usage?; (2) Does the system quality of MDS decrease service usage?; and (3) Does user motivation for subscribing MDS moderate the effect information and system quality have on service usage? The research questions and subsequent analysis are grounded on the two factor theory pioneered by Hertzberg et al(1959). To answer the research questions, in the first, an exploratory study based on 378 survey responses was conducted to learn about important decision factors of MDS usage. It revealed discrepancy between the influencing forces of usage increase and those of usage decrease. Based on the findings from the exploratory study and the two-factor theory, we postulated information quality as the motivator and system quality as the de-motivator (or hygiene) of MDS. Then, a confirmative study was undertaken on their respective role in encouraging and discouraging the usage of mobile data service.

• Korean Chemical Engineering Research
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• v.46 no.5
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• pp.1008-1012
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• 2008

Nanoscale zero-valent iron(nZVI) is famous for its high reactivity originated from its high surface area and it has received considerable attentions as one of the latest innovative technologies for treating contaminated groundwater. Due to its fine powdery form, nZVI has limited filed applications. The efforts to overcome this shortcoming by immobilizing nZVI on a supporting material have been made. This study investigated the differences of resin-supported nZVI's characteristics by changing the preparation methods and evaluated its reactivity. The borohydride reduction of an iron salt was proceeded in ethanol/water solvent containing a dispersant and the synthesis was conducted in the presence of ion-exchange resin. The resulting material was compared to that prepared in a conventional way of using de-ionized water by measuring the phyrical and chemical characteristics. BET surface area and Fe content of nZVI-attached resin was increased from $31.63m^2/g$ and 18.19 mg Fe/g to $38.10m^2/g$ and 22.44 mg Fe/g, respectively, by switching the solution medium from water to ethanol/water with a dispersant. The reactivity of each material was tested using nitrate solution without pH control. The pseudo first-order constant of $0.462h^{-1}$ suggested the reactivity of resin-supported nZVI prepared in ethanol/water was increased 61 % compared to that of the conventional type of supported nZVI. The specific reaction rate constant based on surface area was also increased. The results suggest that this new supported nZVI can be used successfully in on-site remediation for contaminated groundwater.

• Journal of radiological science and technology
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• v.36 no.2
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• pp.165-173
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• 2013

This study was the estimation of the dose distribution for proton, prompt gamma rays and proton induced neutron particles, in case of exposing the proton beam to polymer gel dosimeter and water phantom. The polymer gel dosimeter was compositeness material of Gelatin, Methacrylic acid, Hydroquinone, Tetrakis and Distilled water. The density of gel dosimeter was $1.04g/cm^3$ which was similar to water. The 72, 116 and 140 MeV proton beams were used in the simulation. Proton beam interacted with the nuclei of the phantom and the nuclei in excited states emitted prompt gamma rays and proton induced neutron particles during the process of de-excitation. The proton particles, prompt gamma rays, proton induced neutron particles were detected by polymer gel dosimeter and water phantom, respectively. The gap of the axis for gel was 2 mm. The Bragg-peak for proton particles in gel dosimeter was similar to water phantom. The dose distribution for proton and prompt gamma rays in gel dosimeter and water phantom was approximately identical in case of 72, 116 and 140 MeV for proton beam. However, in case of proton induced neutron particles for 72, 116 and 140 MeV proton beam, particles were not detected in gel dosimeter, while the Water phantom absorbed neutron particles. Considering the resulting data, gel dosimeter which was developed in the normoxic state attentively detected the dose distribution for proton beam exposure except proton induced neutron particles.

• Journal of Korean Philosophical Society
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• v.116
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• pp.389-410
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• 2010

Augustin wurde sozusagen von der Rhetorik zum Christentum bekehrt. Der einstmalige Rhetorikprofessor (bis 386) distanziert sich von seiner $fr{\ddot{u}}heren$ Kunst. Aber er $kn{\ddot{u}}pft$ als Bischof im vierten Buch seiner weniger bekannten Schrift "De doctrina Christiana" (DDC; abgef. 427) wieder an die antike Rhetorik, speziell an Cicero, an. So wird die augustinische $Sp{\ddot{a}}tschrift$ $f{\ddot{u}}r$ eine antike Rhetorik in christlicher Verwendung gehalten. Es stellt nun die Frage, was Augustin zur $R{\ddot{u}}ckkehr$ zu seiner $fr{\ddot{u}}heren$ Kunst bewegte. Neuere Forschungen sehen in Augustins Werk eine Grundlage der mittelalterlichen Predigttheorie oder einen $blo{\ss}en$ Versuch, die Rhetorik vom Makel des Sophistischen zu befreien. Gewiss ist seine Einstellung zur "leeren Beredsamkeit" der Sophistik eindeutig, aber dies war eine Haltung, die letztlich von allen seinen christlichen Zeitgenossen geteilt wurde und folglich eines geringen Beweises bedurfte. Die Aufmerksamkeit, die Augustins $sp{\ddot{a}}terem$ Einfluss und seiner Ablehnung der Zweiten Sophistik geschenkt wird, kann den Blick $tr{\ddot{u}}ben$ $f{\ddot{u}}r$ seine Rolle bei der $L{\ddot{o}}sung$ eines christlichen Dilemmas aus dem vierten Jahrhundert. Augustin sah die Gefahren einer entgegengesetzten rhetorischen $H{\ddot{a}}resie$. Die $S{\ddot{u}}nde$ des Sophisten besteht darin, dass er die Notwendigkeit des Inhalts verneint und glaubt, nur die forma alleine sei $w{\ddot{u}}nschenswert$. Der gegenteilige Fehler, dem Geschichtsschreiber der Rhetorik niemals einen Namen gegeben haben, beruht auf dem Glauben, dass derjenige, der im Besitz der Wahrheit ist, auch ipso facto in der Lage ist, die Wahrheit anderen zu ${\ddot{u}}bermitteln$. Es handelt sich um eine $ausschlie{\ss}liche$ $Abh{\ddot{a}}ngigkeit$ von der materia. Augustin erkannte eine Gefahr und benutzte DDC dazu, eine Verbindung von Inhalt und Form in der christlichen Predigt voranzutreiben. Nur wenn man daher das Buch als einen Teil der $gro{\ss}en$ Debatte des vierten Jahrhunderts ansieht, tritt seine historische Bedeutung klar hervor. Der Leser ist beeindruckt davon, dass der Autor darauf insistiert, es sei eine Torheit, dem Feind ein $n{\ddot{u}}tzliches$ Instrument zu ${\ddot{u}}berlassen$. Augustin $erkl{\ddot{a}}rt$, dass die Kunst der Beredsamkeit rege in Gebrauch genommen und nicht kurzerhand abgelehnt werden solle, weil sie mit dem Makel des Heidentums behaftet sei. Kurz gesagt, geplant ist das vierte Buch von DDC als eine ratio eloquentiae Christianae.

• Food Engineering Progress
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• v.21 no.4
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• pp.318-325
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• 2017

Alcoholic steatosis is a fundamental metabolic disorder and may precede the onset of more severe forms of alcoholic liver disease. In this study, we isolated enzymatichydrolysate from Semisulcospira libertine by alcalase hydrolysis and investigated the protective effect of Semisulcospira libertine hydrolysate on liver injury induced by alcohol in the mouse model of chronic and binge ethanol feeding (NIAAA). In an in vitro study, the hydrolysate protects HepG2 cells from ethanol toxicity. Liver damage was assessed by histopathological examination, as well as by quantitating activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). After the administration of S. libertina hydrolysate, fat accumulation and infiltration of inflammatory cells in liver tissues were significantly decreased in the NIAAA mouse model. The elevated levels of serum AST, ALT, and ALP activities, along with the lipid contents of a damaged liver, were recovered in experimental mice administrated with S. libertina hydrolysate, suggesting its role in blood enzyme activation and lipid content restoration within damaged liver tissues. Moreover, treatment with S. libertine hydrolysate reduced the expression rate of cyclooxygenase (COX-2), interleukin $(IL)-1{\beta}$, and IL-6, which accelerate inflammation and induces tissue damage. All data showed that S. libertine hydrolysate has a preventive role against alcohol-induced liver damages by improving the activities of blood enzymes and modulating the expression of inflammation factor, suggesting S. libertine hydrolysate could be a commercially potential material for the restoration of hepatotoxicity.

• 한국노년학
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• v.37 no.1
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• pp.55-82
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• 2017

The purpose of this research is to provide implications for the development of age-friendly industry of Korea by analyzing the age-friendly industry activation policy suggested by the Presidential Committee on Ageing Society and Population Policy in response to the population ageing problems. Policy and theoretical implications are derived from an analysis of age-friendly industry activation policy as directly related to the improvement of the three major problems (i.e. health, economy, and loneliness) of Korean older people. This analysis focuses on its specific content, common and core logic, and the validity of the logic. The results show that: 1)the first Plan for Ageing Society and Population suggests a policy for improving poverty, 2)the second Plan for Ageing Society and Population suggests a policy for improving health, and 3)the third Plan for Ageing Society and Population suggests a policy for improving health and loneliness. All policies not only are commonly based on the logically limited concepts of successful ageing and active ageing, but also are characterized by narrow realm, insufficient content, and fragmented policy. The results result in the following policy implications: 1)the age-friendly industry activation policy should be developed with continuity, sufficiency, and diversity, 2)lessons from the limitation related with the de-contextualisation of successful ageing and its elective affinity with consumer capitalism, 3)lessons from the prevention-oriented perspective of active ageing, and 4)lessons from the social characteristics of (non-)psychological resources, limitation of the reablement related with social investment state. The analyses also provide a theoretical implication that a different perspective on the social construct of ageing is needed beyond the dichotomy of ageing based on modelling ageing. Lastly, the paper suggests not only the limitation of the research but also the preferred follow-up studies regarding age-friendly industry activation policy.

• Journal of Korea Entertainment Industry Association
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• v.15 no.2
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• pp.169-178
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• 2021

The Korean girl group "Kara" has suffered the trilemma of its de facto failure to debut, the crisis of team breakup, and the CEO crisis of the agency. But the group has made an outstanding achievement in the history of Korean pop music after overcoming all odds. Their success strategy has never been disclosed by insiders involved in Kara's total music projects. This study has been carried out in the analysis of the strategy to provide academic implications and to honor the contribution of the late CEO Ho-yeon Lee and Kara's key member Ha-ra Gu. Therefore, between Nov. and Dec. 2020, we conducted in-depth interviews with managers, composers, stylists and Ha-ra Gu(Only in 2019, before her death) who took part in the project. The research model is set up by combining Porter's Competitive Advantage Strategy and the music value chain model into categories of "Product Innovation Differentiation (PD)" (producing, album production, performance activities) and "Marketing Differentiation (MD)" (market targeting, image specialization, promotion and communication). The analysis showed that the PD focused on complete rediscovered harmonization and revalued members' personality and sincerity with peppy songs and dainty dances as well as emission of "bright energy" which caused healing effects instead of mimicking other star singers recklessly. In terms of MD, they selected Japan's 10-20s as their main market, increasing intimacy with fans and media with the image of cute+pretty+classy+sexy. The result suggests that Poter's differentiation can function as a meaningful strategy frame in the fostering, hit, and revival of idol groups. In addition, it reaffirmed that spontaneous and passionate activities of early-stage or celebrity fan may serve as a valid catalyst for realizing differentiation, as Kara's caller of Japanese actor Gekidan Hitori caused a strong "priming effect" that drove Kara's unexpected wonderful success in Japan.

• Korean Journal of Environmental Agriculture
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• v.7 no.1
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• pp.43-51
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• 1988

$SO_2$ gas injuries for 19 varieties of 10 species of plants were investigated within a environmentally controlled growth chamber. Visible injuries were observed when exposing the plants either 0, 0.2, 0.4, 0.7 or 1.5ppm of $SO_2$ gas for 5 days from 9 : 00 to 17 : 00 everyday. The results obtained were as follows: 1. Light brown spots were shown on Raphanus sativus(Chunchu, Taeback, Jinjudaepyung), Brassica campestris(Manchun, Josaengmiho, Seoul, Jeonseung), and Capsicum annum(Searona, Hongsanho, Hongilpum); brown spots on Sesamum indicum(Pungnyun, Kwangsan); reddish brown shades on Cleosia cristata; and black brown spots on Perilla frutescens, Calendula officinalis, Chrysanthemum morifolium, and Salvia splendens, respectively. 2. The spotty injuries induced by $SO_2$ gas injuries for 19 varieties of 10 species of plants were investigated within a environmentally controlled growth chamber. Visible injuries were observed when exposing the plants either 0, 0.2, 0.4, 0.7 or 1.5ppm of $SO_2$ gas for 5 days from 9 : 00 to 17 : 00 everyday. The results obtained were as follows: 1. Light brown spots were shown on Raphanus sativus(Chunchu, Taeback, Jinjudaepyung), Brassica campestris(Manchun, Josaengmiho, Seoul, Jeonseung), and Capsicum annum(Searona, Hongsanho, Hongilpum); brown spots on Sesamum indicum(Pungnyun, Kwangsan); reddish brown shades on Cleosia cristata; and black brown spots on Perilla frutescens, Calendula officinalis, Chrysanthemum morifolium, and Salvia splendens, respectively. 2. The spotty injuries induced by SO₂ gas on Raphanus sativus, Callistephus chinensis, Capsicum annum, Perilla frutescens, Calendula officinalis, Salvia splendens, and Sesamum indicum; the many small spots on Chrysanthemum morifolium; and the brown shade on Celosia cristata appeared on the upper surface of the intervein, on the leaf apex area and on the entire upper surface of leaves, respectively. 3. Visual injuries of Capsicum annum(Chunchu), Perilla frutescens, Sesamum indicum(Pungnyun, Kwangsan), and Salvia splendens were developed at 0.4ppm of SO₂ gas fumigation. Brassica campestris(Jeonseung), Capsicum annum(Searona, Hongilpum), and Cleosia cristata, however, showed the injury at 1.5ppm of $SO_2$ gas concentration. 4. Based on the tolerance grade(time when the 1st injury appeared), Raphanus sativus, Perilla frutescens, Sesamum indicum, and Salvia splendens were the most sensitive plants and Chrysanthemum morifolium, Callistephus chinensis, Cleosia cristata, and Calendula officinalis were the plants most tolerant of $SO_2$ gas. gas on Raphanus sativus, Callistephus chinensis, Capsicum annum, Perilla frutescens, Calendula officinalis, Salvia splendens, and Sesamum indicum; the many small spots on Chrysanthemum morifolium; and the brown shade on Celosia cristata appeared on the upper surface of the intervein, on the leaf apex area and on the entire upper surface of leaves, respectively. 3. Visual injuries of Capsicum annum(Chunchu), Perilla frutescens, Sesamum indicum(Pungnyun, Kwangsan), and Salvia splendens were developed at 0.4ppm of $SO_2$ gas injuries for 19 varieties of 10 species of plants were investigated within a environmentally controlled growth chamber. Visible injuries were observed when exposing the plants either 0, 0.2, 0.4, 0.7 or 1.5ppm of $SO_2$ gas for 5 days from 9 : 00 to 17 : 00 everyday. The results obtained were as follows: 1. Light brown spots were shown on Raphanus sativus(Chunchu, Taeback, Jinjudaepyung), Brassica campestris(Manchun, Josaengmiho, Seoul, Jeonseung), and Capsicum annum(Searona, Hongsanho, Hongilpum); brown spots on Sesamum indicum(Pungnyun, Kwangsan); reddish brown shades on Cleosia cristata; and black brown spots on Perilla frutescens, Calendula officinalis, Chrysanthemum morifolium, and Salvia splendens, respectively. 2. The spotty injuries induced by SO₂ gas on Raphanus sativus, Callistephus chinensis, Capsicum annum, Perilla frutescens, Calendula officinalis, Salvia splendens, and Sesamum indicum; the many small spots on Chrysanthemum morifolium; and the brown shade on Celosia cristata appeared on the upper surface of the intervein, on the leaf apex area and on the entire upper surface of leaves, respectively. 3. Visual injuries of Capsicum annum(Chunchu), Perilla frutescens, Sesamum indicum(Pungnyun, Kwangsan), and Salvia splendens were developed at 0.4ppm of SO₂ gas fumigation. Brassica campestris(Jeonseung), Capsicum annum(Searona, Hongilpum), and Cleosia cristata, however, showed the injury at 1.5ppm of $SO_2$ gas concentration. 4. Based on the tolerance grade(time when the 1st injury appeared), Raphanus sativus, Perilla frutescens, Sesamum indicum, and Salvia splendens were the most sensitive plants and Chrysanthemum morifolium, Callistephus chinensis, Cleosia cristata, and Calendula officinalis were the plants most tolerant of $SO_2$ gas. gas fumigation. Brassica campestris(Jeonseung), Capsicum annum(Searona, Hongilpum), and Cleosia cristata, however, showed the injury at 1.5ppm of $SO_2$ gas concentration. 4. Based on the tolerance grade(time when the 1st injury appeared), Raphanus sativus, Perilla frutescens, Sesamum indicum, and Salvia splendens were the most sensitive plants and Chrysanthemum morifolium, Callistephus chinensis, Cleosia cristata, and Calendula officinalis were the plants most tolerant of $SO_2$ gas.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.418-428
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• 2007

Physical and chemical properties of the aggregate by-products including sludge and crushed dust samples collected from the 21 private companies throughout the country were analyzed to evaluate possible usage of the by-products as artificial soil materials for plantation. The pH of the materials ranged from 8.0 to 11.0. The organic matter content was $2.85g\;kg^{-1}$, and the total nitrogen content and available phosphate content were low as 0.7 percents and $12.98mg\;kg^{-1}$, respectively. Exchangeable $Ca^{2+}$, $Mg^{2+}$, $K^+$, and $Na^+$ were 2.29, 0.47, 0.02 and $0.05cmol\;kg^{-1}$, respectively. Heavy metal contents were lower than the limits regulated by environmental law of Korea. Textural analysis showed that most of the materials were silt loam with low water holding capacity ranged from 0.67 to 7.41 percents, and with low hydraulic conductivity ranged from 0.4 to $2.8m\;s^{-1}$. Mineralogical analysis showed that the aggregate by product materials were mostly composed of silicate, alumina and ferric oxides except calcium oxide dominant materials derived from limestones. The primary minerals were quartz, feldspars and dolomites derived from granite and granitic gneiss materials. Some samples derived from limestone material showed calcite and graphite together with the above minerals. According to the result, it can be concluded that the materials could be used as the artificial soil material for plantation after proper improvement of the physico-chemical properties and fertility.

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.783-794
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• 1996

It has been suggested that ion transport systems are intimately involved in mediating the effects of growth regulatory factors on the growth of a number of different types of animal cells in vivo. The functional importance of the apical membrane $Na^+/H^+$ antiporter in the renal proximal tubule is evidenced by estimates that this transporter mediates the reabsorption of approximately one third of the filtered load of sodium and the bulk of the secretion of hydrogen ions. This study was designed to investigate the pathway utilized by IGF-I in regulating sodium transport in primary cultured renal proximal tubule cells. Results were as follows : 1. $Na^+$ was observed to accumulate in the primary cells as a function of time. Raising the concentration of extracellular NaCl induced an decrease in $Na^+$ uptake compared with control cells in a dose dependent manner. The rate of $Na^+$ uptake into the primary cells was about two times higher in the absence of NaCl($40.11{\pm}1.76pmole\;Na^+/mg\;protein/min$) than in the presence of 140mM NaCl($17.82{\pm}0.94pmole\;Na^+/mg\;protein/min$) at the 30 minute uptake. 2. $Na^+$ uptake was inhibited by IAA($1{\times}10^{-4}M$) or valinomycin($5{\times}10^{-6}M$) treatment($50.51{\pm}4.04$ and $57.65{\pm}2.27$ of that of control, respectively). $Na^+$ uptake by the primary proximal tubule cells was significantly increased by ouabain($5{\times}10^{-5}M$) treatment($140.23{\pm}3.37%$ of that of control). When actinomycin D($1{\times}10^{-7}M$) or cycloheximide($4{\times}10^{-5}M$) was applied, $Na^+$ uptake was decreased to $90.21{\pm}2.39%$ or $89.64{\pm}3.69%$ of control in IGF-I($1{\times}10^{-5}M$) treated cells, respectively. 3. Extracellular cAMP decreased $Na^+$ uptake in a dose-dependent manner($10^{-8}-10^{-4}M$). IBMX($5{\times}10^{-5}M$) also inhibited $Na^+$ uptake. Treatment of cells with pertussis toxin(50pg/ml) or cholera toxin($1{\mu}g/ml$) inhibited $Na^+$ uptake. Extracellular PMA decreased $Na^+$ uptake in a dose-dependent manner(1-100ng/ml). 100 ng/ml PMA concentration significantly inhibited $Na^+$ uptake in IGF-I treated cells. However, staurosporine($1{\times}10^{-7}M$) had no effect on $Na^+$ uptake. When PMA and staurosporine were added together, the inhibition of $Na^+$ uptake was not observed. In conclusion, sodium uptake in primary cultured rabbit renal proximal tubule cells was dependent on membrane potentials and intracellular energy levels. IGF-I stimulates sodium uptake through mechanisms that involve some degree of de novo protein and/or RNA synthesis, and cAMP and/or PKC pathway mediating the action mechanisms of IGF-I.