• Title/Summary/Keyword: Agent Model

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Study on the Appropriate Use of Weapons by Private Security Guards: Focusing on Public Crowded Places (민간 경비원(보안요원)의 정당한 무기사용 방안 연구: 다중이용시설을 중심으로)

  • Hangil Oh;Kyewon Ahn;Ye ji Na
    • Journal of the Society of Disaster Information
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    • v.19 no.4
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    • pp.936-949
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    • 2023
  • On August 3, 2023, a brutal incident of unprovoked violence, termed as "Abnormal motivated crime," occurred in a multi-use facility, where retail and transportation facilities converge, near Seohyeon Station. The assailant drove onto the sidewalk, hitting pedestrians, and then entered a department store where a knife rampage ensued, resulting in a total of 14 victims. In the aftermath of this incident, numerous murder threats were posted on social media, causing widespread anxiety among the public. This fear was further exacerbated by the emergence of a "Terrorless.01ab.net" service. Purpose: This research aims to explore necessary institutional improvements for private security personnel who protect customers and employees in multi-use facilities, to enable them to perform their duties more effectively. Method: To assess the risk of Abnormal motivated crime, a time series analysis using the ARIMA model was conducted to analyze the domestic trends of such crimes. Additionally, Result: the study presents suggestions for improvements in the domestic security service law and emergency manuals for multi-use facilities. Conclusion: This is informed by a legal analysis of the indemnity rights for weapon use by private security guards abroad and their operational authority beyond weapon usage.

Berberine Suppresses Hepatocellular Carcinoma Proliferation via Autophagy-mediated Apoptosis (베르베린을 처리한 간세포암에서 자가포식 경로와 관련된 세포자멸사)

  • Yun Kyu Kim;Myeong Gu Yeo
    • Journal of Life Science
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    • v.34 no.5
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    • pp.287-295
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    • 2024
  • Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide, necessitating novel therapeutic strategies. The chemotherapeutic agents used to treat HCC patients are toxic and have serious side effects. Therefore, we investigated the efficacy of anticancer drugs that reduce side effects by targeting tumor cells without causing cytotoxicity in healthy hepatocytes. Berberine, an isoquinoline alkaloid derived from plant compounds, has emerged as a potential candidate for cancer treatment due to its diverse pharmacological properties. The effect of berberine on HepG2 cell viability was determined using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay. HepG2 cell proliferation was determined through a colony-forming assay. The effects of berberine on HepG2 cell migration were evaluated using a wound-healing assay. Berberine inhibited the proliferation of HepG2 cells, as well as colony formation and migration. Berberine treatment increased the expression of autophagy-related genes and proteins, including Beclin-1 and LC3-II, and elevated the activities and mRNA expression of Caspase-9 and Caspase-3. Additionally, in experiments utilizing the Cell-Derived Xenograft animal model, berberine treatment reduced tumor size and weight in a concentration-dependent manner. These results demonstrate the potential of berberine as a versatile anticancer agent with efficacy in both cellular and animal models of hepatocellular carcinoma. The findings herein shed light on berberine's efficacy against HCC, presenting opportunities for targeted and personalized therapeutic interventions.

A Conceptual Review of the Transaction Costs within a Distribution Channel (유통경로내의 거래비용에 대한 개념적 고찰)

  • Kwon, Young-Sik;Mun, Jang-Sil
    • Journal of Distribution Science
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    • v.10 no.2
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    • pp.29-41
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    • 2012
  • This paper undertakes a conceptual review of transaction cost to broaden the understanding of the transaction cost analysis (TCA) approach. More than 40 years have passed since Coase's fundamental insight that transaction, coordination, and contracting costs must be considered explicitly in explaining the extent of vertical integration. Coase (1937) forced economists to identify previously neglected constraints on the trading process to foster efficient intrafirm, rather than interfirm, transactions. The transaction cost approach to economic organization study regards transactions as the basic units of analysis and holds that understanding transaction cost economy is central to organizational study. The approach applies to determining efficient boundaries, as between firms and markets, and to internal transaction organization, including employment relations design. TCA, developed principally by Oliver Williamson (1975,1979,1981a) blends institutional economics, organizational theory, and contract law. Further progress in transaction costs research awaits the identification of critical dimensions in which transaction costs differ and an examination of the economizing properties of alternative institutional modes for organizing transactions. The crucial investment distinction is: To what degree are transaction-specific (non-marketable) expenses incurred? Unspecialized items pose few hazards, since buyers can turn toalternative sources, and suppliers can sell output intended for one order to other buyers. Non-marketability problems arise when specific parties' identities have important cost-bearing consequences. Transactions of this kind are labeled idiosyncratic. The summarized results of the review are as follows. First, firms' distribution decisions often prompt examination of the make-or-buy question: Should a marketing activity be performed within the organization by company employees or contracted to an external agent? Second, manufacturers introducing an industrial product to a foreign market face a difficult decision. Should the product be marketed primarily by captive agents (the company sales force and distribution division) or independent intermediaries (outside sales agents and distribution)? Third, the authors develop a theoretical extension to the basic transaction cost model by combining insights from various theories with the TCA approach. Fourth, other such extensions are likely required for the general model to be applied to different channel situations. It is naive to assume the basic model appliesacross markedly different channel contexts without modifications and extensions. Although this study contributes to scholastic research, it is limited by several factors. First, the theoretical perspective of TCA has attracted considerable recent interest in the area of marketing channels. The analysis aims to match the properties of efficient governance structures with the attributes of the transaction. Second, empirical evidence about TCA's basic propositions is sketchy. Apart from Anderson's (1985) study of the vertical integration of the selling function and John's (1984) study of opportunism by franchised dealers, virtually no marketing studies involving the constructs implicated in the analysis have been reported. We hope, therefore, that further research will clarify distinctions between the different aspects of specific assets. Another important line of future research is the integration of efficiency-oriented TCA with organizational approaches that emphasize specific assets' conceptual definition and industry structure. Finally, research of transaction costs, uncertainty, opportunism, and switching costs is critical to future study.

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The Effect of Dexamethasone on Airway Goblet Cell Hyperplasia and Inflammation in $TiO_2$-Treated Sprague-Dawley Rats ($TiO_2$로 처치된 백서에서 기도내 배상세포 증식과 염증에 대한 Dexamethasone의 효과)

  • Lim, Gune-Il;Kim, Do-Jin;Park, Choon-Sik
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.1
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    • pp.37-48
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    • 2000
  • Backgrounds : The pathophysiology of chronic airflow obstruction, such as bronchial asthma, is characterized by mucus hypersecretion, goblet cell hyperplasia(GCH), smooth muscle hypertrophy, and inflammatory cells infiltration. In fatal asthma patients, one distinct findings is mucus hypersecretion due to GCH. However, the mechanisms of GCH in these hypersecretory diseases remain still unknown. In this study, a rat model was rapidly induced with GCH by instillation of $TiO_2$, intratracheally. We intend to confirm GCH and association of concomitant inflammatory cells infiltration and to observe the effect of potent antiinflammatory agent, that is dexamethasone, on GCH with inflammatory cells. Methods : Twenty-one 8-weeks-old male Sprague-Dawley rats were divided into three groups. Endotoxinfree water was instilled intratracheally in group 1(control) ; $TiO_2$, was instilled in the group 2 ; and dexamethasone was injected intraperitoneally to group 3 before $TiO_2$ instillation. After 120 hours, all rats were sacrificed, and trachea, bronchi, and lungs were resected respectively. These tissues were made as paraffin blocks and stained as PAS for goblet cells and Luna stain for eosinophils. We calculated the ratio of goblet cell to respiratory epithelium and number of infiltrated eosinophils from each tissue. Results : (1) Fraction of goblet cells was significantly increased in group 2 than in group 1 in the trachea and in the main bronchus. (10.19$\pm$11.33% vs 4.09$\pm$8.28%, p<0.01 and 34.09$\pm$23.91% vs 3.61$\pm$4.84%, p<0.01, respectively). (2) Eosinophils were significantly increased in the airway of group 2 than that of group 1. (5.43$\pm$3.84% vs 0.17$\pm$0.47 in trachea and 47.71$\pm$16.91 vs 2.71$\pm$1.96 in main bronchi). (3) There was a positive correlation between goblet cells and eosinophils(r=0.719, p=0.001). (4) There was significant difference in the decrease of goblet cells after dexamethasone injection between group 2 and group 3 (p<0.01). Also, infiltration of eosinophils was suppressed by dexamethasone. Conclusion : We made an animal model of $TiO_2$-induced goblet cell hyperplasia. GCH was observed mainly in the main bronchi with concomitant eosinophilic infiltration. Both goblet cell hyperplasia and eosinophilic infiltration were suppressed by dexamethasone. This animal model may serve as a useful tool in understanding of the mechanism of GCH in chronic airway diseases.

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Hepatoprotective Effects of Oyster Hydrolysate on Lipopolysaccharide/D-Galactosamine-Induced Acute Liver Injury in Mice (Lipopolysaccharide/D-Galactosamine에 의해 유도된 급성 간 손상 생쥐모델에서 굴가수분해물의 간 보호 효과)

  • Ryu, Ji Hyeon;Kim, Eun-Jin;Xie, Chengliang;Nyiramana, Marie Merci;Siregar, Adrian S.;Park, Si-Hyang;Cho, Soo Buem;Song, Dae Hyun;Kim, Nam-Gil;Choi, Yeung Joon;Kang, Sang Soo;Kang, Dawon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.6
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    • pp.659-670
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    • 2017
  • Oxidative stress and inflammation are key factors responsible for progression of liver injury. A variety of functions of oyster hydrolysate (OH) are affected by their antioxidant and anti-inflammatory activities. However, little is known regarding the effects of OH on a liver injury model. This study was performed to evaluate the effects of OH on acute liver injury induced by lipopolysaccharide/D-galactosamine (LPS/D-GalN) in mice. Experimental groups were divided into six groups as follows (each group, n=10): control (saline), LPS/D-GalN, LPS/D-GalN+OH (100 mg/kg), LPS/D-GalN+OH (200 mg/kg), LPS/D-GalN+OH (400 mg/kg), and LPS/D-GalN+silymarin (25 mg/kg, positive control). The experimental acute liver injury model was induced with LPS ($1{\mu}g/kg$) and D-GalN (400 mg/kg). We first analyzed antioxidant and anti-inflammatory activities in OH. OH showed high DPPH and ABTS radical scavenging activities and reduced ROS generation in Chang cells in a dose-dependent manner. In addition, OH showed anti-inflammatory activities, such as inhibition of cyclooxygenase-2 and 5-lipooxygenase. Treatment with OH down-regulated tumor necrosis factor $(TNF)-{\alpha}$, interleukin (IL)-6, and $IL-1{\alpha}$ expression levels in LPS-stimulated RAW264.7 cells. OH significantly reduced LPS/D-GalN-induced increases in the concentrations of alanine transaminase and aspartate aminotransferase in serum. In the LPS/D-GalN group, liver tissues exhibited apoptosis of hepatocytes with hemorrhages. These pathological alterations were ameliorated by OH treatment. Consistently, hepatic catalase activity was low in the LPS/D-GalN group compared to the control group, and catalase activity was significantly restored by OH treatment (P<0.05). Furthermore, OH markedly reduced the LPS/D-GalN-induced increase in $TNF-{\alpha}$, $IL-1{\beta}$, and IL-6 levels in liver tissue. Taken together, these results show that OH has hepatoprotective effects on LPS/D-GalN-induced acute liver injury via inhibition of oxidative stress and inflammation, suggesting that OH could be used as a health functional food and potential therapeutic agent for acute liver injury.

Effect of Ethane 1,2-Dimethane Sulfonate (EDS) on the Accessory Sex Organs in Adult Rats : A Histological Study (Ethane 1,2-Dimethane Sulfonate(EDS)가 성체 흰쥐의 부속 생식기관에 미치는 효과 : 조직학적 연구)

  • Lee, Won-Yong;Lee, Sung-Ho
    • Development and Reproduction
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    • v.13 no.2
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    • pp.105-114
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    • 2009
  • Ethane 1,2-dimethane sulfonate (EDS) is a well-known alkylating agent used as selective Leydig cell (LC) toxicant to create a testicular dysfunction model. Previous studies including our own clearly demonstrated the dramatic weight loss of the androgen dependent accessory sex organs such as epididymis, seminal vesicle and prostate gland in this 'LC knock-out' rats. The present study was performed to evaluate the effect of EDS administration on histological changes of the epididymis, seminal vesicle and prostate in adult rats. Adult male Sprague-Dawley rats (350$\sim$400 g B.W.) were injected with a single dose of EDS (75 mg/kg, i.p.) and sacrificed on weeks 0, 1, 2, 3, 4, 5, 6 and 7. Tissue weights (testis, epididymis, seminal vesicle and prostate gland) were measured. The histological changes of tissue were observed by a light microscopy using hematoxylin & eosin staining. Weights of the reproductive and accessory organs progressively declined after the EDS treatments (weeks 1, 2 and 3). After this, the decrease was stopped, then gradually returned to the normal levels. There was a partial (about 60%) recovery of the epididymis weight during weeks $6{\sim}7$. The cross section of epididymis revealed an increase in thickness of the epithelium during weeks $1{\sim}3$. In contrast, considerable reduction of epithelial thickness in seminal vesicle was observed during same period. Similarly, a reduction in thickness of prostate epithelial layer was found during weeks $1{\sim}3$, then it was back to normal thickness after week 4. Taken together, the present study demonstrated that the temporally induced androgen-deficiency by EDS treatment could result the prominent alterations in histology of the accessory sex organs. Further studies on the physiological and molecular regulation of these androgen-sensitive organs using EDS model will be helpful to understand the normal and pathological development and differentiation mechanism of these organs.

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Effects of Cyclosporin A, FK506, and 3-Deazaadenosine on Acute Graft-versus-host Disease and Survival in Allogeneic Murine Hematopoietic Stem Cell Transplantation (마우스 동종 조혈모세포 이식모델에서 Cyclosporin A, FK506, 3-Deazaadenosine 등의 약제가 급성 이식편대 숙주병과 생존에 미치는 영향)

  • Jin, Jong Youl;Jeong, Dae Chul;Eom, Hyeon Seok;Chung, Nak Gyun;Park, Soo Jeong;Choi, Byung Ock;Min, Woo Sung;Kim, Hack Ki;Kim, Chun Choo;Han, Chi Wha
    • IMMUNE NETWORK
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    • v.3 no.2
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    • pp.150-155
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    • 2003
  • Background: We investigated the effect of donor marrow T cell depletion, administration of FK506, cyclosporin A (CSA), and 3-deazaadenosine (DZA) on graft versus host disease (GVHD) after allogeneic murine hematopoietic stem cell transplantation (HSCT). Methods: We used 4 to 6 week old Balb/c ($H-2^d$, recipient), and C3H/He ($H-2^k$, donor) mice. Total body irradiated recipients received $1{\times}10^7$ bone marrow cells (BM) and $0.5{\times}10^7$ splenocytes of donor under FK506 (36 mg/kg/day), CSA (5 mg/kg/day, 20 mg/kg/day), and DZA (45 mg/kg/day), which were injected intraperitoneally from day 1 to day 14 daily and then three times a week for another 2 weeks. To prevent the GVHD, irradiated Balb/c mice were transplanted with $1{\times}10^7$ rotor-off (R/O) cells of donor BM. The severity of GVHD was assessed daily by clinical scoring method. Results: All experimental groups were well grafted after HSCT. Mice in experimental group showed higher GVHD score and more rapid progression of GVHD than the mice with R/O cells (R/O group) (p<0.01). There were relatively low GVHD scores and slow progressions in FK506 and low dose CSAgroups than high dose CSA group (p<0.01). The survival was better in FK506 group than low dose CSA group. All mice treated with CSA died within 12 days after HSCT. The GVHD score in DZA group was low and slow in comparison with control group (p<0.05), but severity and progression were similar with low dose CSA group (p=0.11). All mice without immunosuppressive treatment died within 8 days, but all survived in R/O group (p<0.01). Survival in low dose CSA group was longer than in control group (p<0.05), but in high dose CSA group, survival was similar to control group. The survival benefit in DZA group was similar with low dose CSA group. FK506 group has the best survival benefit than other groups (p<0.01), comparable with R/O group (p=0.18), although probability of survival was 60%. Conclusion: We developed lethal GVHD model after allogeneic murine HSCT. In this model, immunosuppressive agents showed survival benefits in prevention of GVHD. DZA showed similar survival benefits to low dose CSA. We propose that DZA can be used as a new immunosuppressive agent to prevent GVHD after allogeneic HSCT.

Analysis of Contrast Medium Dilution Rate for changes in Tube Current and SOD, which are Parameters of Lower Limb Angiography Examination (하지 혈관조영검사 시 매개변수인 관전류와 SOD에 변화에 대한 조영제 희석률 분석)

  • Kong, Chang gi;Han, Jae Bok
    • Journal of the Korean Society of Radiology
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    • v.14 no.5
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    • pp.603-612
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    • 2020
  • This study has a purpose to look into the effect of the relationship between the Tube current (mA) and SOD(Source to Object Distance), which is a parameter of lower limb angiography examination, and the dilution rate of the contrast medium concentration (300, 320, 350) on the image. To that end, using 3 mm vessel model water phantom, a vessel model custom made in the size of peripheral vessel diameter, this study measured relationships between change of parameters, such as tube current (mA), SOD and varying concentrations (300, 320, 350) of contrast medium dilution into SNR and CNR values while analyzing the coefficients of variance(cv<10). The software used to measure SNR and CNR values was Image J 1.50i from NIH (National Institutes of Health, USA). MPV (mean pixel value) and SD (standard deviation) were used after verifying numerically the image signal for region of interest (ROI) and background on phantom from the DICOM (digital imaging and communications in medicine) 3.0 file transmitted to PACS. As to contrast medium dilution by the change of tube current, when 146 mA and 102 mA were compared, For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ~ 30% : 70%) but CM: N/S dilution rate (20%: 80% ~ 10% : 90%) the coefficient of variation was 10 or more. As to contrast medium dilution by concentration for SOD change, when SOD's (32.5 cm and 22.5 cm) were compared,For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ~ 30% : 70%) but CM: N/S dilution rate (20%: 80% ~ 10% : 90%) the coefficient of variation was 10 or more. As to contrast medium dilution by concentration for SOD change, when SOD's (32.5 cm and 12.5 cm) were compared,For both SNR and CNR, the coefficient of variation value was less than 10 until the section of CM: N/S dilution (100% ~ 30% : 70%) but CM: N/S dilution rate (20%: 80% ~ 10% : 90%) the coefficient of variation was 10 or more. As a result, set a low tube current value in other tests or procedures including peripheral angiography of the lower extremities in the intervention, and make the table as close as possible to the image receiver, and adjust the contrast agent concentration (300) to CM: N/S dilution (30%: 70%). ) Is suggested as the most efficient way to obtain images with an appropriate concentration while simultaneously reducing the burden on the kidney and the burden on exposure.

Development of $^{99m}Tc$-Transferrin as an Imaging Agent of Infectious Foci (감염병소 영상을 위한 $^{99m}Tc$-Transferrin 개발)

  • Kim, Seong-Min;Song, Ho-Chun
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.3
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    • pp.177-185
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    • 2006
  • Purpose: Purpose of this study is to synthesize $^{99m}Tc$-labeled transferrin for injection imaging and to compare it with $^{67}Ga$-titrate for the detection of infectious foci. Materials and methods: Succinimidyl 6-hydrazino-nicotinate hydrochloride-chitosan-transferrin (Transferrin) was synthesized and radiolabeled with $^{99m}Tc$. Labeling efficiencies of $^{99m}Tc$-Transferrin were determined at 10 min, 30 min, 1 hr, 2 hr, 4 hr and 8 hr. Biodistribution and imaging studies with $^{99m}Tc$-Transferrin and $^{67}Ga$-citrate were performed in a rat abscess model induced with approximately $2{\times}10^8$ colony forming unit of Staphylococcus aureus ATCC 25923. Results: Successful synthesis of Transferrin was confirmed by mass spectrometry. Labeling efficiency of $^{99m}Tc$-Transferrin was $96.2{\pm}0.7%,\;96.4{\pm}0.5%,\;96.6{\pm}1.0%,\;96.9{\pm}0.5%,\;97.0{\pm}0.7%\;and\;95.5{\pm}0.7%$ at 10 min, 30 min, 1 hr, 2 hr, 4 hr and 8 hr, respectively. The injected dose per tissue gram of $^{99m}Tc$-Transferrin was $0.18{\pm}0.01\;and\;0.18{\pm}0.01$ in the lesion and $0.05{\pm}0.01\;and\;0.04{\pm}0.01$ in the normal muscle, and lesion-to-normal muscle uptake ratio was $3.7{\pm}0.6\;and\;4.7{\pm}0.4$ at 30 min and 3 hr, respectively. On image, lesion-to-background ratio of $^{99m}Tc$-Transferrin was $2.18{\pm}0.03,\;2.56{\pm}0.11,\;3.08{\pm}0.18,\;3.77{\pm}0.17,\;4.70{\pm}0.45\;and\;5.59{\pm}0.40$ at 10 min, 30 min, 1 hr, 2 hr, 4 hr and 10 hr and those of $^{67}Ga$-citrate was $3.06{\pm}0.84,\;4.12{\pm}0.54\;and\;4.55{\pm}0.74 $ at 2 hr, 24 hr and 48 hr, respectively. Conclusion: Transferrin is successfully labeled with $^{99m}Tc$, and its labeling efficiency was higher than 95% and stable for 8 hours. $^{99m}Tc$-Transferrin scintigraphy showed higher image quality in shorter time compared to $^{67}Ga$-citrate image. $^{99m}Tc$-transferrin is supposed to be useful in the detection of the infectious foci.

A Comparative Study on Travelers' Online Travel Agency(OTA) selection attributes and revisit selection attributes (여행자의 온라인여행사(OTA) 선택속성과 재방문 시 선택속성에 관한 비교연구)

  • Yang, Chan-Yeol
    • Management & Information Systems Review
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    • v.37 no.4
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    • pp.175-193
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    • 2018
  • As a new type of business model in the market competition situation of tour companies, this study has developed to the online form of the travel industry to the business form which is the combination of the electronic commerce function and the mobile service process in the provision of the simple web-site, This study explores the difficulties of change for the development of the travel industry from the point of view that recognition is not a simple marketing strategy diversification means but a change of recognition as a business model for expanding new markets or creating new markets. The factors affecting the choice of online travel agent (OTA) and the factors that influence the choice of online travel agency were analyzed. Were used for the empirical survey. The purpose of this study is to investigate the factors influencing the choice of online travel agents who have experience with or experience using online travel agency (OTA), what factors are important to them, and how they differ in importance when visiting again. The results of this study are as follows: First, there was a significant difference between the first and second visitors of online travel agencies. The results of this study were as follows: Attitude toward resolving complaints, convenience of change and cancellation, delivery of tickets and documents, convenience of complaints, The emphasis should be on establishing and strengthening service environments such as the speed of updating the latest information, the simplicity of the booking procedure, the degree of satisfaction of the past, the ability of employees to handle their work, the safety of various payment methods and settlement, The results of this study are as follows: First, the satisfaction of the online travel agency is influenced by the selection factors of the selected online tour agency, and the A/S such as the convenience of prompt delivery, Environmental factors contributed to satisfaction. It is suggested that the systematic service structure such as customer satisfaction and ease of use is a necessary marketing strategy for survival and development of online travel agencies. It is suggested that the marketing concentration strategy with the first visitors as the target market is effective and this is a part of the marketing strategy for the survival of online travel agencies.