• Toxicological Research
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• v.35 no.4
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• pp.343-351
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• 2019

Many in vitro developmental toxicity assays have been proposed over several decades. Since the late 1980s, we have made intermittent attempts to introduce in vitro assays as screening tests for developmental toxicity of inhouse candidate products. Two cell-based assays which were developed two decades apart were intensively studied. One was an assay of inhibitory effects on mouse ascites tumor cell attachment to a concanavalin A-coated plastic sheet surface (MOT assay), which we studied in the early days of assay development. The other was an assay of inhibitory effects on the differentiation of mouse embryonic stem cell to beating heart cells (EST assay), which we assessed more recently. We evaluated the suitability of the assays for screening in-house candidates. The concordance rates with in vivo developmental toxicity were at the 60% level. The EST assay classified chemicals that inhibited cell proliferation as embryo-toxic. Both assays had a significant false positive rate. The assays were generally considered unsuitable for screening the developmental toxicity of our candidate compounds. Recent test systems adopt advanced technologies. Despite such evolution of materials and methods, the concordance rates of the EST and MOT systems were similar. This may suggest that the fundamental predictivity of in vitro developmental toxicity assays has remained basically unchanged for decades. To improve their predictivity, in vitro developmental toxicity assays should be strictly based on elucidated pathogenetic mechanisms of developmental toxicity.

• Asia-Pacific Journal of Business
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• v.13 no.4
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• pp.11-24
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• 2022

Purpose - The purpose of this study was to examine how job seekers' spec influence their actual employment especially focusing on the differentiating effects of applicants' specs depending on whether general or decent job employment. Design/methodology/approach - This study conducted analyses on 54,443 samples that incorporated data from the Graduates Occupational Mobility Survey for three years (2017-2019) collected by the Korea Employment Information Service. The linear probability model and logit model were used to examine the research questions. Findings - The results analyzed with the hierarchical regression model showed that most job seekers' specs were statistically significant in predicting employment status. Interestingly, there is a difference between the factors predicting employment for a general job and a decent job. This study suggests academic and practical implications for future research in the selection/ recruitment field by clarifying the critical factors to influence applicants' employment. Research implications or Originality The results of this study follow the screening hypothesis which explains that the applicants' specs have significant impacts on actual employment. Also, the dual labor market theory, which explains that applicants' specs differently affect actual employment between general and decent jobs, was reaffirmed.

• BMB Reports
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• v.56 no.11
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• pp.594-599
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• 2023

A number of therapeutic drugs have been developed from functional chemicals found in plants. Knowledge of plants used for medicinal purposes has historically been transmitted by word of mouth or through literature. The aim of the present study is to provide a systemic platform for the development of lead compounds against breast cancer based on a traditional medical text. To verify our systematic approach, integrating processes consisted of text mining of traditional medical texts, 3-D virtual docking screening, and in vitro and in vivo experimental validations were demonstrated. Our text analysis system identified rutin as a specific phytochemical traditionally used for cancer treatment. 3-D virtual screening predicted that rutin could block EGFR signaling. Thus, we validated significant anti-cancer effects of rutin against breast cancer cells through blockade of EGFR signaling pathway in vitro. We also demonstrated in vivo anti-cancer effects of rutin using the breast cancer recurrence in vivo models. In summary, our innovative approach might be proper for discovering new phytochemical lead compounds designing for blockade of malignant neoplasm including breast cancer.

• YAKHAK HOEJI
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• v.43 no.3
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• pp.342-350
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• 1999

The antibacterial activity against Propionibacterium acnes (P. acnes), $5{\alpha}-reductase$ inhibition and comedolytic effects are the important pharmacological target sites of antiacne drughs. We previously reported on the antibacterial activities against P. acnes by natural products. In the present study the screening of $5{\alpha}-reductase$ inhibition and comedolytic effects from natural products were performed. Seven natural products such as Angelica koreana, Sophora flavescens, Prunus persica, Bombyx mori, Areca catechu, Galla rhois and Gleditschia koraiensis perfectly inhibited the activity of $5{\alpha}-reductase$ at the concentration of 0.01% (w/v). Sixteen natural products which were shown to have the potent antibacterial activities against P.acnes or $5{\alpha}-reductase$ inhibition activities were assayed for the comedolytic test. In the results of comedolytic effects on experimentally-induced comedones (EIC), Sophora flavescens showed the strongest comedolytic effect on EIC, and Polygonum cuspidatum and Angelica koreana showed stronger comedolytic effects on EIC than azelaic acid used for a positive control at the concentration of 3% (w/v). These results suggest that several natural products including Sophora flavescens can be developed as noble antiacne agents.

• The Journal of the Korea Contents Association
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• v.17 no.12
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• pp.357-367
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• 2017

The study investigated information about the effects of message framing on colorectal cancer(CRC) screening related health beliefs and compliance with the CRC screening test within the theoretical framework of the prospect theory and the Health belief model (HBM). This study was using a non-randomized controlled quasi-experimental design. One hundred and sixty-four in the industrial workers who were currently nonadherent to guidelines for receiving screening were assigned to one of three experimental conditions: (a) gain-framed message, (b) loss-framed message, and (c) general-framed message. CRC screening-related health beliefs was self-reported after the intervention. And the immunoassay Fecal Occult Blood Test (iFOBT) kit was collected at 1 week. The research finding were analyzed by $x^2$ test and one-way ANOVA using SPSS 21.0. The loss-framed message group had higher perceived susceptibility, severity and benefit than the gain-framed message and general message. The participation rate for the immunoassay Fecal Occult Blood Test(iFOBT) was highest in the loss-framed message group. The loss framed messages more effective to enhance screening behavior. The present results provide a theoretical basis for developing educational guidelines for CRC testing and could be used for performing comprehensive approach by predicting and suggesting the practical effects according to message type in advance.

• The Journal of Korean Medicine
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• v.32 no.3
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• pp.35-43
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• 2011

Objectives: This study was performed to screen target-specific inhibitors of ${\beta}$-catenin/TCF signaling whose functional activation plays an important role in early events in carcinogenesis. Methods: To investigate the activation or suppression of ${\beta}$-catenin/TCF transcription, we established a transiently transfected cell line with a constitutively active ${\beta}$-catenin mutant gene whose product is not degraded. This cell line was also co-transfected with luciferase reporter gene constructs containing either an optimized (TOPflash) or mutant (FOPflash) TCF-binding element. We investigated cytotoxic effects using a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt (MTS) assay. To find effective inhibitors of ${\beta}$-catenin/TCF signaling from medicinal herbs, the crude extracts of 99 types of medicinal herbs were screened using a luciferase assay system in HEK-293 and SH-SY5y cells. Results: At a concentration of $50{\mu}g$/ml, extracts of Angelica koreanae radix, Cannabis sativa semen, Ephedrae intermedia Schrenk radix, and Vitis rotundifolia fruit showed the following inhibitory effects on ${\beta}$-catenin/TCF signaling: $40{\pm}5.6%$, $23{\pm}6.1%$, $8{\pm}5.1%$, and $22{\pm}9.8%$ in ${\beta}$-catenin-activated HEK-293 cells and $9{\pm}4.7%$, $39{\pm}8.1%$, $39{\pm}6.4%$, and $42{\pm}10.1%$ in ${\beta}$-catenin-activated SH-SY5y cells, respectively. Crude extracts of E. radix were isolated by silica gel column chromatography, and two non-polar fractions of these extracts showed inhibitory effects on ${\beta}$-catenin/TCF signaling. Conclusions: In this study, we established a transiently transfected cell line as a screening system and found that various medicinal herb extracts had inhibitory effects on ${\beta}$signaling.

• Environmental Analysis Health and Toxicology
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• v.11 no.3_4
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• pp.65-68
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• 1996

Selaginellae Herba has been used as folk medicine for antineoplastics, coagulants, antidotes and invigorants. To find an in vitro screening method for liver protective effect of Selaginellae Herba in benzo(a)pyrene intoxicated injury were examined in primary cultured rat hepatocytes. Using MTT assay, herba concentration showed dose dependently viability. The lowest concentration of benzo(a)pyrene giving cytotoxicity revealed around 50gM. The hepatoprotective effect of Selaginellae Herba in both water and chloroform extracts was also increased dose dependently.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.6
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• pp.987-996
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• 2003

The structural integrity of the reactor vessel with the approaching end of life must be assured for pressurized thermal shock. The regulation specifies the screening criteria for this and requires that specific analysis be performed for the reactor vessel which is anticipated to exceed the screening criteria at the end of plant life. In case the screening criteria is exceeded by the deterministic analysis, probabilistic analysis must be performed to show that failure probability Is within the limit. In this study, probabilistic fracture mechanics analysis of the reactor vessel for pressurized thermal shock is performed and the effects of residual stress and master curve on the failure probability are investigated.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.2
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• pp.33-38
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• 2004

Toner particles used in laser and xerographic printing process is fused on paper surface so strongly that they tend not to detach easily from the recylced paper surface during pulping. Furthermore, the removal efficiency of detached toner particles by conventional screening and flotation process has limitation due to the platy shape and large size of detached toner particles. It has been shown that the removal efficiency of toners in the screening process can be increased by agglomerating the toner particles with fatty alcohol. It is not possible, however, to remove small and platy toner particles by screening process. These small and platy toner particles should be removed by flotation process. In this study the effect of fatty alcohol that used for toner agglomeration on flotation efficiency has been examined. It was shown that flotation efficiency decreased when fatty alcohol was used most probably due to its effect of reducing hydrophobicity of toner particles.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.4
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• pp.112-120
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• 1996

With the MOsES (mask oxide sidewall etch scheme)process which uses the conventional i-line stepper and isotropic wet etching, CMOSFET's with fine gate pattern of 0.1.mu.m CMOSFET device, the screening oxide is deposited before the low energy ion implantation for source/drain extensions and two step sidewall scheme is adopted. Through the characterization of 0.1.mu.m CMOSFET device, it is found that the screening oxide deposition sheme has larger capability of suppressing the short channel effects than two step sidewall schem. In cse of 200.angs.-thick screening oxide deposition, both NMOSFET and PMOSFET maintain good subthreshold characteristics down to 0.1.mu.m effective channel lengths, and show affordable drain saturation current reduction and low impact ionization rates.