• Journal of the Korean Chemical Society
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• v.36 no.4
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• pp.598-602
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• 1992

2-Piperidylglycine will be a model compound for the synthesis of antitumor agent 593A. 2-Piperidylglycine may be synthesized by alkylation of glycine equivalent to C-2 position of piperidine ring. ${\delta}$-Valerolactam was reacted with trimethyl oxonium tetrafluoroborate to give 2-methoxy-1-piperideine. The imino ether was not condensed with ethyl phthalimidoacetate, one of glycine equivalents, but with ethyl nitroacetate to afford ethyl nitro-2-piperidylene acetate. The subsequent hydrogenation over Pt/C gave ethyl 2-piperidyl glycinate. Because the Z-configuration of the condensed product was assigned by nmr, the stereochemistry of ethyl 2-piperidyl glycinate different from that of Agent 593A.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.39-45
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• 1998

Kojic acid, antimelanogenic agent, has been widely used in cosmetics to lighten the skin color. However, it has skin irritancy and instability against pH, temperature and light. To overcome these problems and optimize the molecular structure of kojic acid (KA), a prodrug, kojic acid monostearate(KMS), has been synthesized to modify the topical drug delivery in the point of sustained release of the parent drug via enzymatic hydrolysis during skin absorption. The prodrug was tested for enzymatic hydrolysis with cytosolic fraction of hairless mouse, skin. From the in vitro skin permeation study through hairless mouse skin, we found that KMS was retained in the skin and generated KA continuously by the skin esterase cleavage. In addition, topical formulations of o/w type creams and polyolprepolymer-containing cream were further tested for whitening effects using in vivo yellow skin guinea pig model.

• Korean Journal of Materials Research
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• v.31 no.6
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• pp.367-374
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• 2021

This paper presents the characteristics of gentamicin-loaded into cetyl trimethyl ammonium intercalated montmorillonite (GtM/CTMA/Mt) as a hybrid composite for a slow-released antibacterial delivery systems. The work describes the successful immobilization of gentamicin into the interlayers of surfactant-modified montmorillonite. Physicochemical characterization of the material is carried out by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy. The kinetics of the gentamicin release is investigated by in vitro study and analyzed based on UV-Vis spectrometry. In addition, antibacterial study is performed towards Klebsiella pneumoniae Staphylococcus aureus, Escherichia coli, and Streptococcus pyogenes. The results show that the gentamicin loading into CTMA/Mt increases the effectiveness of the antibacterial activity, as shown by the higher inhibition zone for all tested bacteria, compared to gentamicin as a positive control. The kinetics study suggests that the gentamicin release obeys the modified Korsmeyer-Peppas model. The physicochemical study and activity test demonstrate the feasibility of the GtM/CTMA/Mt for practical applications.

• International Journal of Computer Science & Network Security
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• v.22 no.8
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• pp.404-412
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• 2022

The development in the field of the internet of things (IoT) have improved the quality of the life and also strengthened different areas in the society. All cities across the world are seeking to become smarter. The creation of a smart parking system is the essential use case in smart cities. In recent couple of years, the number of vehicles has increased significantly. As a result, it is critical to make the use of technology that enables hassle-free parking in both public and private spaces. In conventional parking systems, drivers are not able to find free parking space. Conventional systems requires more human interference in a parking lots. To manage these circumstances there is an intense need of IoT enabled parking solution that includes the well defined architecture that will contain the following components such as smart sensors, communication agreement and software solution. For implementing such a smart parking system in this paper we proposed a design of smart parking system and also compare it with convetional system. The proposed design utilizes sensors based on IoT and Data Mining techniques to handle real time management of the parking system. IoT enabled smart parking solution minimizes the human interference and also saves energy, money and time.

• International conference on construction engineering and project management
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• 2024.07a
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• pp.1230-1237
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• 2024

Personalized learning is a critical factor in optimizing performance on construction sites. Traditional pedagogical methods often adhere to a one-size-fits-all approach, failing to provide the nuanced adaptation required to cater to diverse knowledge needs, roles, and learning preferences. While advancements in technology have led to improvements in personalized learning within construction education, the crucial connection between instructors' roles and training enviornment to personalized learning success remains largely unexplored. To address these gaps, this research proposes a novel learning approach utilizing multi-agent, context-specific AI agents within construction virtual environments. This study aims to pioneer an innovative approach leveraging the Large Language Model's capabilities with prompt engineering to make domain-specific conversations. Through the integration of AI-driven conversations in a realistic 3D environment, users will interact with domain-specific agents, receiving personalized safety guidance and information. The system's performance is assessed using the five evaluation criteria including learnability, interaction, communication, relevancy and visualization. The results revealed that the proposed approach has the potential to significantly enhance safety learning in the construction industry, which may lead to improve practices and reduction in accidents on diverse construction sites.

• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.32-41
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• 2004

Purpose : To measure the NMR relaxation properties of MnPC, to observe the characteristics of liver enhancement patterns on MR images in experimentally implanted rabbit VX2 tumor model, and to estimate the possibility of tissue specific contrast agent for MnPC in comparison with the hepatobiliary agent. Materials and Methods : Phthalocyanine (PC) was chelated with paramagnetic ions, manganese (Mn). 2.01 g (5.2 mmol) of phthalocyanine was mixed with 0.37 g (1.4 nlmol) of Mn chloride at $310^{\circ}C$ for 36 hours and then purified by chromatography ($CHCl_3:\;CH_3OH=98:2$, volume ratio) to obtain 1.04 g $(46\%)$ of MnPC (molecular weight = 2000 daltons). The T1/T2 relaxivity (R1/R2) for MnPC were determined at a 1.5 T (64 MHz) MR spectrometer. VX2 tumor model was experimentally implanted in the liver parenchyma of rabbits. All MR studies were performed on 1.5 T. The human extremity radio frequency coil of a bird cage type was employed. MR images were acquired at 17 to 24 days after VX2 carcinoma implantation.4 mmol/kg MnPC and 0.01 mmol/kg Mn-DPDP were injected via the ear vein of rabbits. T1-weighted images were obtained with spin-echo (TR/TE=516/14 msec) and fast multiplanar spoiled gradient recalled (TR/TE : 80/4 msec, $60^{\circ}$ flip angle) pulse sequence. Fast spin-echo (TR/TE=1200/85 msec) was used to obtain the T2-weighted images. Results : The value of T1/T2 relaxivity (R1/R2) of MnPC was $7.28\;mM^{-1}S^{-1}$ and $55.56\;mM^{-1}S^{-1}$ respectively at 1.5 T (64 MHz). Because the T2 relaxivity of MnPC that bonded strongly, covalently manganese with phthalocyanine was very high, the signal intensity of liver parenchyma was decreased on postcontrast T2-weighted images and we could easily distinguish the VX2 carcinoma within the liver parenchyma. When MnPC was administrated intravenously, the tumor margin delineation was more remarkable than Mn-DPDP-enhanced images. The enhancement of liver parenchyma with MnPC persisted at relatively high levels over at least one hour after injection of the contrast agents. Conclusion : The hepatic uptake and biliary excretion of MnPC, which are similar to Mn-DPDP, suggest that this agent is a new liver-specific agent. Also, MnPC seems to be used as a dual contrast agent (T1 and T2) with high T2 relaxivity. However, it is warranted that MnPC needs further investigation as a potential contrast agent for MR imaging of the liver. That is, further characterizations of MnPC are needed in vivo and in vitro before clinical trials. The diagnostic potential of MnPC will also have to be examined more in the animal models of additional types.

• Biomolecules & Therapeutics
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• v.28 no.6
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• pp.569-575
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• 2020

Crotamiton is an anti-scabies drug, but it was recently found that crotamiton also suppresses non-scabietic itching in mice. However, the underlying mechanism is largely unclear. Therefore, aim of the study is to investigate mechanisms of the anti-pruritic effect of crotamiton for non-scabietic itching. Histamine and chloroquine are used as non-scabietic pruritogens. The effect of crotamiton was identified using fluorometric intracellular calcium assays in HEK293T cells and primary cultured dorsal root ganglion (DRG) neurons. Further in vivo effect was evaluated by scratching behavior tests. Crotamiton strongly inhibited histamine-induced calcium influx in HEK293T cells, expressing both histamine receptor 1 (H1R) and transient receptor potential vanilloid 1 (TRPV1), as a model of histamine-induced itching. Similarly, it also blocked chloroquine-induced calcium influx in HEK293T cells, expressing both Mas-related G-protein-coupled receptor A3 (MRGPRA3) and transient receptor potential A1 (TRPA1), as a model of histamine-independent itching. Furthermore, crotamiton also suppressed both histamine- and chloroquine-induced calcium influx in primary cultures of mouse DRG. Additionally, crotamiton strongly suppressed histamine- and chloroquine-induced scratching in mice. Overall, it was found that crotamiton has an anti-pruritic effect against non-scabietic itching by histamine and chloroquine. Therefore, crotamiton may be used as a general anti-pruritic agent, irrespective of the presence of scabies.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.3
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• pp.249-254
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• 2014

The purpose of this study is to characterize the effects of KHG26792 (3-(naphthalen-2-yl(propoxy)methyl)azetidine hydrochloride), a potential skin whitening agent, on melanin synthesis and identify the underlying mechanism of action. Our data showed that KHG26792 significantly reduced melanin synthesis in a dose-dependent manner. Additionally, KHG26792 downregulated microphthalmia-associated transcription factor (MITF) and tyrosinase, the rate-limiting enzyme in melanogenesis, although tyrosinase was not inhibited directly. KHG26792 activated extracellular signal-regulated kinase (ERK), whereas an ERK pathway inhibitor, PD98059, rescued KHG26792-induced hypopigmentation. These results suggest that KHG26792 decreases melanin production via ERK activation. Moreover, the hypopigmentary effects of KHG26792 were confirmed in a pigmented skin equivalent model using Cervi cornus Colla (deer antler glue), in which the color of the pigmented artificial skin became lighter after treatment with KHG26792. In summary, our findings suggest that KHG26792 is a novel skin whitening agent.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.12 no.20
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• pp.123-138
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• 1989

The primary objective of the agency research in the game theory lives in the maintenance of Pareto is optimal condition for the optimal incentive contract. The basic concepts which are related to this objective are reviewed in connection with the general assumptions to model it, the moral hazard and adverse selection which arised from the information asymmetry, and finally the problem of risk distribution. The demand for auditing and the role of auditor have been addressed by ASOBAC. Issues which an auditor is explicitly introduced in a principal-agent framework have been addressed in this paper. These issues must be confronted to appropriately with the auditor, and to achieve an adequate understanding of optimal confronting arrangement with the auditor. The first step in introducing an auditor into this analysis is to examine the game-theoretic foundation of such a expended agency model. The Mathematical program formulated may not yield solution that are resonable. This arises because the program may call for the auditor and manager to play dominated Nash equilibra in some subgame. The nontrivial natures of the subgame implies that randomized strategies by the auditor and manager nay be of crucial importance. The possibilities for overcoming the randomized strategy problem were suggested; change the rule of the game and or impose covexity condition. The former seems unjustifiable in on auditing context, and the latter promising but difficult to achieve. The discussion ended with an extension of the revelation principle to the owner manager-auditor game, assuming strategies. An examination of the restriction and improvement direction of the basic concept of agency theory was addressed in the later part of this paper. Many important aspects of auditor incentives are inherently multiple-agent, multiple-period, multiple-objectine, phenomena and require further analyses and researches.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12B
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• pp.2233-2248
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• 1999

The TMN that appears to operate the various communication networks generally and efficiently is developed under the different platform environment such as the different hardware and the different operating system. One of the main problems is that all the agents of the TMN system must be duplicated and maintain the software and the data blocks that perform the identical function. Therefore, the standard of the Q3 interface development cannot be defined and the multi-platform cannot be supported in the development of the TMN agent. In order to overcome these problems, the Farming methodology that is based on the Farmer model has been suggested. With the Farming methodology, the software and the data components which are duplicated and stored in each distributed object are saved in the platform independent class repository(PICR) by converting into the format of the independent componentware in the platform, so that the componentwares that are essential for the execution can be loaded and used statically or dynamically from PICR as described in the framework of each distributed object. The distributed TMN agent of the personal communication network is designed and developed by using the Farmer model.