• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.889-892
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• 2006

In this study, we compared and analysed the early strength properties of mortar according to the kinds and replacement ratio of mineral admixture to select the kinds and replacement ratio of mineral admixture of high early strength concrete. For this purpose, mortar mixtures according to the kinds(FA, MK, ZR, BFS, DM) and replacement ratio(0, 2, 4% by volume of sand) of mineral admixture were selected. From our test data, early-age compressive strength decreased in accordance with the increase of replacement ratio of fly-ash(FA) & blast furnace slag powder(BSF) and, in case of addintion admixture, early-age compressive strength of with containing ZR & BFS appeared higher compared with containing other mineral admixture.

• BMB Reports
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• v.56 no.9
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• pp.469-481
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• 2023

The gut microbiome is widely recognized as a dynamic organ with a profound influence on human physiology and pathology. Extensive epidemiological and longitudinal cohort studies have provided compelling evidence that disruptions in the early-life microbiome can have long-lasting health implications. Various factors before, during, and after birth contribute to shaping the composition and function of the neonatal and infant microbiome. While these alterations can be partially restored over time, metabolic phenotypes may persist, necessitating research to identify the critical period for early intervention to achieve phenotypic recovery beyond microbiome composition. In this review, we provide current understanding of changes in the gut microbiota throughout life and the various factors affecting these changes. Specifically, we highlight the profound impact of early-life gut microbiota disruption on the development of diseases later in life and discuss perspectives on efforts to recover from such disruptions.

• Advances in nano research
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• v.14 no.1
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• pp.93-101
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• 2023

This research aims to explore the influence of early entrepreneurial education on cognitive and non-cognitive abilities of male sixth-grade primary school pupils using a randomized pretest-posttest control group design. A total of 45 students were randomly allocated to experimental, active-control, and control groups using a multi-stage random selection procedure. The experimental group was taught entrepreneurship using the Bizworld entrepreneurship education package. The active control group did not get entrepreneurship education but was instructed on a non-entrepreneurship-related issue (hygiene). The Control group received no instruction. The findings revealed that early entrepreneurial education skills impacted noncognitive abilities (such as risk-taking propensity, creativity, self-efficacy, persistence, and need for achievement). Early entrepreneurship education seems to be an effective technique for developing children's non-cognitive abilities in the late years of primary school. As a result, entrepreneurship education may be taught in primary schools, emphasizing the development of non-cognitive abilities, which will affect children's individual, educational, social, and vocational futures and can have long-term advantages for students, families, and society.

• Natural Product Sciences
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• v.16 no.4
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• pp.271-279
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• 2010

Systemic lupus erythematosus (SLE) is characterized by systemic inflammation through production of inflammatory mediators and signaling abnormalities between T- and B- cells, leading to autoantibody production and multiorgan injuries. This study was investigated whether bamboo culm extract (BC) attenuates development of lupus systemic inflammation in the early stage in pristane-induced lupus mice. The pristane-induced lupus mice were administrated with BC 0.5 ml/kg or PBS and healthy mice with PBS orally once a day for 14 days. Our results showed that BC remarkably attenuated levels of serum TNF-$\alpha$, IL-6, IL-10, IFN-$\gamma$, $PGE_2$, and VEGF, production of macrophages IL-6 and $PGE_2$ and expression of macrophages IL-6 and COX-2 mRNA in the presence or absence of LPS in pristane-induced lupus mice. Also, BC remarkably reduced expression of CD40L on the splenic T cells and CD80 on the splenic B cells and upregulated the reduced apoptosis of splenic T cells and CD4+ T cells in pristane-induced lupus mice. Therefore, these findings suggest that BC may attenuate early development of lupus systemic inflammation via downregulation of inflammatory mediators and amelioration of abnormal signaling between T cells and B cells.

• Environmental Analysis Health and Toxicology
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• v.25 no.1
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• pp.19-26
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• 2010

Discharged materials from the point or non-point source are released into the sea, and as the results, marine environment is directly affected. We must estimate the impacts of contaminants to marine pollution rapidly and accurately. Therefore, it is needed on early warning system for appreciating marine environmental impacts, and required a bioassay to evaluate abnormal changes. A bioassay test was developed to examine the effects of heavy metal contaminants on the early life stages of the marine annimals. We have studied the effects of metals on early development of a sea urchin species, Strongylocentrotus intermedius. S. intermedius embryos were tested with six metals (Cu, Ag, Zn, Cd, Cr, Ni) and showed the highest sensitivity to Cu as well as the lowest sensitivity to Cd. The order of biological impact for metals was Cu>Ag>Ni>Zn>Cr>Cd. In accordance with the results, sea urchins embryos can provide biological criteria for seawater quality assessment. The sensitivity of developmental bioassay whith S. intermedius is at intermediate level among marine organisms commonly used in aquatic bioassays. And this sea urchin can be routinely employed as a test organism for ecotoxicity assays.

• Development and Reproduction
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• v.16 no.1
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• pp.69-75
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• 2012

Hatching occurred in the time dependent manners and strictly controlled. Although, the hatching processes are under the control of muti-embryotrophic factors and the expressed G proteins of cell generate integrated activation, the knowledge which GPCRs are expressed during hatching stage embryos are very limited. In the present study, which G proteins are involved was examined during blastocyst development to the hatching stage. The early-, expanded-, and lobe-stage blastocysts were treated with various $G_{\alpha}$ activators and H series inhibitors, and examined developmental patterns. Pertusis toxin (PTX) improved the hatching rate of the early-stage blastocyst and lobe-formed embryos. Cholera toxin (CTX) suppressed the hatching of the early-stage blastocyst and expanded embryos. The effects of toxins on hatching and embryo development were changed by the H7 and H8. These results mean that PTX mediated GPCRs activation is signaling generator in the nick or pore formation in the ZP. In addition, PTX mediated GPCR activation induces the locomotion of trophectoderm for the escaping. CTX mediate GPCRs activation is the cause of suppression of hatching processes. Based on these data, it is suggested that various GPCRs are expressed in the periimplantation stage embryos and the integration of the multiple signals decoding of various signals in a spatial and temporal manner regulate the hatching process.

• Korean Journal of Ichthyology
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• v.18 no.3
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• pp.266-272
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• 2006

The egg development and early life history of Korean endemic bitterling Rhodeus pseudosericeus were observed under the controlled water temperature, $17.0{\pm}0.5^{\circ}C$. Fertilized eggs are opaque yellow in color, measuring 2.9~3.1 mm in length and 1.6~1.9 mm in breadth. The eggs of this species began to hatch about seventy hours after insemination and the range of total length of larvae were 3.2~3.4 mm. The larvae reached at the heterotrophic stage about twenty-five days after hatching. R. pseudosericeus had a pair of wing-shaped yolk projection during the prelarval stage that is a common character of the genus Rhodeus.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.605-618
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• 2021

The use of human resources determines the success of enterprises. This study applies the questionnaire design method to analyze the relationship between job stress, job satisfaction, and job performance, noting that few studies have comparatively examined these variables between industries, especially between high-tech and traditional industries. The proposed assessment model in this study can facilitate decision-makers' ability to make the optimal business decisions through their personnel systems, thereby improving employee satisfaction and increasing job performance. This study found that in the traditional and high-tech industries, some demographic variables have significant differences in the job stress, job satisfaction and job performance, but the demographic variables that can significantly affect the differences in these job's variables are differences between industries. This study acknowledges that job stress and performance have a significantly negative correlation, and traditional industries will have more stress factors than high-tech industries. In addition, support for traditional industries exist in job satisfaction and performance has a significantly positive correlation, but not in high-tech industries. Job stress for performance has a significantly negative correlation in two industries. This study reconfirmed the relationship between job stress, satisfaction and performance, found some differences in this relationship and the respective industrial characteristics.

• Journal of the Korea Concrete Institute
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• v.15 no.5
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• pp.662-669
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• 2003

Recently, the serviceability and durability of concrete structures under thermal load have received great attention. The thermal stress and clacking behavior of concrete at early ages are one of the important factors that affect such serviceability and durability of concrete structures. Nevertheless, most studies on the behavior of early-age concrete have been confined to the temperature and strain development itself in the laboratory. The desirable efforts to explore the material properties of concrete at early-ages have not been made extensively so far. The purpose of the present study is, therefore, to identify some important material properties that affect the stress behavior of concrete at early-ages. To this end, full-scale concrete base-restrained wall members have been fabricated, and many sensors including thermocouples, strain meters and stress meters were installed inside of the wall members. These sensors were to measure the development of temperatures, strains and stresses at several location in concrete walls during the hardening and curing phase of early-age concrete. By using these measured values of strain and stress, the compliance function at early-age was identified. The basic form of compliance function derived in this study follows the double-power law. However, the results of present study indicate that the values of existing compliance functions are much lower than actual values, especially at very early-ages. It can be seen that the prediction of stresses of early-age concrete based on the proposed compliance function agrees very well with test data. The present study allows more realistic evaluation of varying stresses in early-age concrete under thermal load.

• Journal of Practical Engineering Education
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• v.13 no.2
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• pp.251-259
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• 2021

Due to the characteristic that early childhood education is a process of nurturing children's senses by a leader rather than the transfer of knowledge, even in the era of with Corona, early childhood distance education is not one-to-one non-face-to-face education, but rather through distributed materials such as early childhood education packages or media such as TV. Distance education was conducted in a self-care method. Through a review of prior research and intensive parent interviews, the researcher identified the requirements for distance education, such as the expansion and accessibility of educational contents, understanding of basic knowledge of early childhood distance education, and the need to increase children's social skills through real-time distance education. It was identified that the current distance education-related solutions are not suitable for early childhood education. Accordingly, the researcher presents the basic direction (VERI) of the early childhood distance education solution of diversity, ease, real-time communication, and integration, and provides a Web/App platform that allows children, parents, and teachers to share content and communicate in real time and in non-real time. The development of a solution was proposed. This distance education solution is expected to effectively support early childhood distance education in the era of With Corona as infants, parents, and teachers communicate and share the current situation, which is only presenting guidelines and materials.