• Development and Reproduction
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• v.5 no.2
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• pp.175-180
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• 2001

The ectopic expression of gonadotropin releasing hormone(GnRH and luteinizing hormone(LH) in several tissues is a quite intriguing phenomenon. Recently, the presence of GnRH and its receptor has been clearly demonstrated in rodents and human mammary gland. In this context, one can postulate that the presence of local circuit composed of GnRH and LH in the gland. The present study was undertaken to elucidate whether there is a correlation between the LH expression in rat mammary gland and physiological status during the process of mammary differentiation. LH contents in mammary gland from cycling to weaning rats were measured by radioimmunoassay(RIA). In cycling rats, changes of the LH level in both serum and mammary gland showed similar pattern as the highest level in proestrus and the lowest level in diestrus II stage. While the serum LH levels were fluctuated from pregnant through involution stage, a sharp decline of mammary LH contents was observed in the lactating rats. This decrement was recovered in involuting rats to the level of proestrus stage. Reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analyses demonstrated that the transcriptional activities of the mammary LH and GnRH were increased from diestrus I stage to estrus stage, and the increased levels were maintained in pregnant, lactation and involution stages. To test the hypothesis that the alteration in mammary LH expression might be steroid-dependant, ovariectomy(OVX) and steroid supplement model was employed. As expected, supplement of estradiol(E$_2$) after OVX remarkably decreased serum LH level compared to that in serum from vehicle-only treated rats. Likewise, administration of E$_2$ significantly reduced the mammary LH content. The present study demonstrated that (i) the LH expression in mammary gland could be altered by some physiological parameters such as estrous cycle, pregnancy, lactation and involution, and (ii) ovarian steroid especially estrogen seems to be one of major endocrine factors which are responsible for regulation of mammary LH expression.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.3
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• pp.18-31
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• 2018

Since accidents of hazardous material transport vehicle on roadways cause severe damage in the form of disaster, foreign countries have long been engaged in systematic management and establishment of relevant laws and policies for the road safety. Recently, over 10-kilometer long tunnel, such as Inje-Yangyang Tunnel and Geumjeongsan Tunnel, has been opened on the expressway and the production of various hazardous materials is increasing with the development of chemical technology. However, road laws related to the safe operation of hazardous materials transport vehicles are still lacking, and policy measures for managing them have not been specified. It is an important task to recognize the risk of accidents of hazardous material transport vehicles and to secure road safety by establishing a management plan for road managers. Therefore, this study analyzed the feasibility of the traffic regulation of expressway tunnel in South Korea and suggested a direction for management. The results of this study can be utilized as the primary data for the revision of law related to hazardous materials transport vehicles on roadways and the derivation of optimal route of hazardous materials transport vehicles.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.482-492
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• 2015

Objectives: Exposure Assessment for workplace hazards where the exposure level is below occupational exposure limits(OELs) has been performed without considering either the degrees of risk or exposure levels and has failed to lead to intervention in many cases. The objective of this study was to suggest and test an application framework for risk assessment methodology under the current exposure assessment system in Korea. Materials: First, we investigated the exposure assessment systems in Korea and other countries. To adopt some risk assessment techniques, we also analyzed risk assessment systems and compared them to exposure assessment systems. A few suggestions were made. We held a public hearing during an industrial hygiene conference and took surveys using a questionnaire. Results: The first suggestion was to implement the risk assessment and exposure assessment through a "one-stop" system. In that case, one expected question would be who has been doing the jobs so far. In most cases, industrial hygiene consulting services or laboratories have been performing exposure assessment for business owners. Business owners are required to perform risk assessment. As two different groups of people will be required to implement two things in a one-stop system, they need to share information. As an information vehicle to share information, commonly filed survey checklists were suggested. The second suggestion was to categorize exposure level into four groups instead of the current binary divisions based on OELs. In the risk assessment system, exposure level is divided into four groups utilizing the cut-points of 10%, 50%, and 100% of OELs. The same schema can be adopted in the exposure assessment system and different levels of requirements can be assigned for each group. The third suggestion was regarding the regulation system. To provide the suggestions some thrust toward being implemented in the field, changes should be made in the legal system. Two different types of new exposure assessment result reporting forms were suggested. Some investigations such as an ergonomic survey are officially accepted as risk assessment under the current legal system. A few items were suggested to be included in the exposure assessment result reporting to be accepted as risk assessment. A pilot study in two small factories was performed and pointed out the strengths and weakness of our suggestions. Conclusions: Discussions and studies on the improvement of the exposure assessment system have been held for decades and no tangible changes have yet been made. We hope this result can help realize healthy lives for workers in Korea.

• Journal of Korean Society of Transportation
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• v.22 no.5
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• pp.89-97
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• 2004

The Korea Air Force(KAF) has operated freight flights based on the prefixed time and route schedule, which is adjusted once in a month. The major purpose of the operation of freight flights in the KAF is to distribute necessary supplies from the home air base to other air bases. The secondary purpose is to train the young pilots to get more experiences in navigation. Each freight flight starts from and returned to the home air base everyday except holidays, while it visits several other air bases to accomplish its missions. The study aims to forecast freight demand at each base by using time series analysis, and then it tried to optimize the cost of operating flights by solving vehicle routing problem. For more specifically, first, several constraints in operating cargos were defined by reviewing the Korea Air Force manuals and regulation. With such constraints, an integer programming problem was formulated for this specific routing problem allowing several visits in a tour with limitation of maximum number of visits. Then, an algorithm to solve the routing problem was developed. Second, the time series analysis method was applied to find out the freight demand at each air base from the mother air base in the next month. With the forecasted demands and the developed solution algorithm, the oprimum routes are calculated for each flight. Finally, the study compared the solved routing system by the developed algorithm with the existing routing system of the Korea Air Force. Through this comparison, the study proved that the proposed method can provide more (economically) efficient routing system than the existing system in terms of computing and monetary cost. In summary, the study suggested objective criteria for air routing plan in the KAF. It also developed the methods which could forecast properly the freight demands at each bases by using time series analysis and which could find the optimum routing which minimizes number of cargo needed. Finally, the study showed the economical savings with the optimized routing system by using real case example.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.500-504
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• 2006

Haptoglobin (Hp) is an acute phase protein, and its plasma level increases consistently in response to inflammation. To investigate the biological role of Hp in lung epithelial cells, the gene expressions of cyclooxygenase-2 (COX-2) and inflammatory cytokines were analyzed using human Hp gene-transfected A549 cells. Western blot analysis showed that COX-2 expression was markedly increased in Hp DNA-transfected cells (stable transfection and transient transfection) compared with that in vehicle DNA-transfected cells. When the Hp-expressing cells were treated with $1{\mu}g/ml$ of LPS or 100 U/ml of $IL-1{\beta}$ for 24 hr, the COX-2 expression was synergistically up-regulated. ACP-based PCR data demonstrated the Hp decreased SPARC expression, but increased IL-4 and S100AI expressions. These findings suggest that the Hp acts as a pro-inflammatory mediator in lung inflammation.

• Nutrition Research and Practice
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• v.9 no.2
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• pp.129-136
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• 2015

BACKGROUND/OBJECTIVES: A variety of immunomodulators can improve the efficacy of low-dose chemotherapeutics. Active hexose correlated compound (AHCC), a mushroom mycelia extract, has been shown to be a strong immunomodulator. Whether AHCC could enhance the antitumor effect of low-dose 5-fluorouracil (5-FU) via regulation of host immunity is unknown. MATERIALS/METHODS: In the current study Hepatoma 22 (H22) tumor-bearing mice were treated with PBS, 5-FU ($10mg{\cdot}kg^{-1}{\cdot}d^{-1}$, i.p), or AHCC ($360mg{\cdot}kg^{-1}{\cdot}d^{-1}$, i.g) plus 5-FU, respectively, for 5 d. $CD^{3+}$, $CD^{4+}$, $CD^{8+}$, and NK in peripheral blood were detected by flow cytometry. ALT, AST, BUN, and Cr levels were measured by biochemical assay. IL-2 and $TNF{\alpha}$ in serum were measured using the RIA kit and apoptosis of tumor was detected by TUNEL staining. Bax, Bcl-2, and TS protein levels were measured by immunohistochemical staining and mRNA level was evaluated by RT-PCR. RESULTS: Diet consumption and body weight showed that AHCC had no apparent toxicity. AHCC could reverse liver injury and myelosuppression induced by 5-FU (P < 0.05). Compared to mice treated with 5-FU, mice treated with AHCC plus 5-FU had higher thymus index, percentages of $CD^{3+}$, $CD^{4+}$, and NK cells (P < 0.01), and ratio of $CD^{4+}$/$CD^{8+}$ (P < 0.01) in peripheral blood. Radioimmunoassay showed that mice treated with AHCC plus 5-FU had the highest serum levels of IL-2 and $TNF{\alpha}$ compared with the vehicle group and 5-FU group. More importantly, the combination of AHCC and 5-FU produced a more potent antitumor effect (P < 0.05) and caused more severe apoptosis in tumor tissue (P < 0.05) compared with the 5-FU group. In addition, the combination of AHCC and 5-FU further up-regulated the expression of Bcl-2 associated X protein (Bax) (P < 0.01), while it down-regulated the expression of B cell lymphoma 2 (Bcl-2) (P < 0.01). CONCLUSIONS: These results support the claim that AHCC might be beneficial for cancer patients receiving chemotherapy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.618-624
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• 2017

In Seoul and most metropolitan cities, urban trains are delayed due to high congestion during commute times. The delay effect of passengers boarding and disembarking is also significant. In this study, a wide passenger door system was developed as a way to improve the scheduled speed of urban trains by decreasing the passengers' flow time. The door size was defined experimentally to shorten the entrance time. The optimum door size was also determined to improve the stop precision performance of the train while considering the interference effect with peripheral devices. Because the change in door size changes the structural characteristics of the vehicle, the structural stability of a train was analyzed numerically. A prototype of the wide door system was made, and the proposed design was verified using functional and endurance tests. The systematic development process can be used as design data for door size definition and system production when applying a wide door to improve the scheduled speed.

• Journal of Distribution Science
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• v.9 no.2
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• pp.97-109
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• 2011

As a marketing vehicle to survive in intensified retailing competition, retailer brand development has been adopted by retailers in Korea. As evidence, the retailer brand share of a major retailer, Tesco Korea, has grown from 20% in 2007 to 22.8% in the first half of 2008. It means that retailers have provided more and more retailer brand foods for customers. With the growing accessibility to retailer brand foods, it would be expected that the number of retailer brand food claims will increase. Customers have increasingly exposed to a variety of marketing activities conducted by retailers. When buying the retailer brand foods, customers tend to be affected by marketing activities of retailers. Despite the fact that customers trust retailers and then, buy their brand foods, in case of food accidents caused by production process, customers have to seek compensation from a retailer brand supplier. Of course, a retailer tends to shift its responsibility to its suppliers. Accordingly, it is not easy for customers to solve food claims. The research, therefore, aims at exploring the relationship between the buying-decision processes of retailer brand customers and which side takes legal responsibility for food claims. To effectively achieve the research aim, the author adopted a quantitative and a qualitative research technique, in order to supplement the disadvantages of each method. Before field research, based on the developed research model, the author pre-tested questionnaire with 10 samples, amended, and handed out to 400 samples. Amongst them, 316 questionnaires are available. For a focus group interview, 9 participants were recruited, who are students, housewives, and full-time workers, aged from 20s to 40s. Through the focus group interview as well as the questionnaire results, it was found that most customers were influenced by a retailer or store image in a customer's mind, retailer reputation and promotional activities. Surprisingly, customers think that the name of a retailer is a more important factor than who produces retailer brand foods, even though many customers check a retailer brand supplier, when making a buying-decision. Rather than retailer brand suppliers, customers trust retailers. That is why they purchase retailer brands. Nevertheless, production-related food claims is not involved with retailers. In fact, it would be difficult for customers to distinguish whether a food claim is related to selling or manufacturing processes. Based on research results, from a customer perspective, the research suggests that the government should require retailers to take the whole responsibility for retailer brand food claims, preventing retailers from passing the buck to retailer brand suppliers. In case of food claims, in order for customers to easily get the compensation, it is necessary to reconsider the current system. If so, retailers have to fully get involved in retailer brand production stage, and further, the customer awareness of retailer brands will be improved than ever before. Retailers cannot help taking care of the whole processes of retailer brand development, because of responsibility. As a result, the process to seek compensation for food claims might become easier, and further, the protection of customer right might be improved.

• International Journal of Oral Biology
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• v.39 no.1
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• pp.49-56
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• 2014

We investigated the role of central P2X receptors in inflammatory pain transmission in the orofacial area in rats. Experiments were carried out using male Sprague-Dawley rats weighing 230-280g. Complete Freund's adjuvant (CFA, $40{\mu}L$) was applied subcutaneously to the vibrissa pad to produce inflammatory pain. The intracisternal administration of iso-PPADS tetrasodium salt, a non-selective P2X receptor antagonist, A317491 sodium salt hydrate, a $P2X_{2/3}$ receptor antagonist, 5-BDBD, a $P2X_4$ receptor antagonist, or A438079 hydrochloride, a $P2X_7$ receptor antagonist, was performed 5 days after CFA injection. Subcutaneous injections of CFA produced increases in thermal hypersensitivity. Intracisternal injections of iso-PPADS ($25{\mu}g$) or A438079 (25 or $50{\mu}g$) produced significant anti-hyperalgesic effects against thermal stimuli compared to the vehicle group. A317491 or 5-BDBD did not affect the head withdrawal latency times in rats showing an inflammatory response. Subcutaneous injections of CFA resulted in the up-regulation of OX-42, a microglia marker, and GFAP, an astrocyte marker, in the medullary dorsal horn. The intracisternal administration of A438079 reduced the numbers of activated microglia and astrocytes in the medullary dorsal horn. These results suggest that a blockade of the central $P2X_7$ receptor produces antinociceptive effects, mediated by inhibition of glial cell function in the medullary dorsal horn. These data also indicate that central $P2X_7$ receptors are potential targets for future therapeutic approaches to inflammatory pain in the orofacial area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.197-205
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• 2020

Compared to aerial photogrammetry, UAV photogrammetry has advantages in acquiring and utilizing high-resolution images more quickly. The production of 3D models using UAV photogrammetry has become an important issue at a time when the applications of 3D spatial information are proliferating. Therefore, this study assessed the feasibility of utilizing 3D models produced by UAV photogrammetry through quantitative and qualitative analyses. The qualitative analysis was performed in accordance with the LODs (Level of Details) specified in the 3D Land Spatial Information Construction Regulation. The results showed that the features on planes have a high LoD while features with elevation differences have a low LoD due to the occlusion area and parallax. Quantitative analysis was performed using the 3D coordinates obtained from the CPs (Checkpoints) and edges of nearby structures. The mean errors for residuals at CPs were 0.042 m to 0.059 m in the horizontal and 0.050 m to 0.161 m in the vertical coordinates while the mean errors in the structure's edges were 0.068 m and 0.071 m in horizontal and vertical coordinates, respectively. Therefore, this study confirmed the potential of 3D models from UAV photogrammetry for analyzing the digital twin and slope as well as BIM (Building Information Modeling).