• The Pure and Applied Mathematics
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• v.30 no.2
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• pp.203-220
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• 2023

A new modification of the SIS epidemic model incorporating the adaptive host behavior is proposed. Unlike the common situation in most epidemic models, this system has two disease-free equilibrium points, and we were able to prove that as the basic reproduction number approaches the threshold of 1, these two points merge and a Bogdanov-Takens bifurcation of codimension three occurs. The occurrence of this bifurcation is a sign of the complexity of the dynamics of the system near the value 1 of basic reproduction number. Both local and global stability of disease-free and endemic equilibrium point are studied.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.6
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• pp.803-811
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• 2012

Oriental Medicine always attach great importance to the damp diseases. Dampness is related with many organs and many clinical diseases. The cause and the location of the damp disease, nature of the symptoms, combination with other pathogenic factors are very diverse. This article analyzed the concept, cause of disease, pathogenesis, characteristic of symptoms, treatment method and prescriptions of Epidemic Warm Diseases of dampness syndrome and cases of dampness-heat diseases based on the theories of Epidemic Warm Diseases and found that theories of Epidemic Warm Diseases have very wide area of application. Dampness is classified into cold-dampness and dampness-heat by combination of heat or cold. The dampness syndrome is related with organs such as lung, spleen, kidney, triple energizers and bladder, and affects liver and heart. The basic treatment methods are dispelling dampness turbidity and diffusing qi movement. The detail treatment methods are spreading lung qi with lightness and resolving dampness and excreting turbidity in upper energizer, opening and dipping down with pungent-bitter and diffusing qi movement and strengthening the spleen and stomach in the middle energizer, draining dampness with bland in the lower energizer. Warming Yang is the main method of treatment for cold-dampness and clearing heat is for dampness-heat with the assistant methods such as resolving dampness and promoting the flow of qi. 5. Acute fever, virus diseases, epidemic diseases among modern diseases are much related with the dampness-heat syndrome.

• International Journal of Contents
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• v.18 no.2
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• pp.1-17
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• 2022

As of September 2021, COVID-19 is still seriously impacting people globally. To better control the epidemic, the Chinese government adopted a nationwide quarantine policy at the early stage of the discovery of COVID-19, which has significantly changed people's production and life. China's Douyin app (International version: TikTok) is an extremely influential entertainment and social tool. During COVID-19, a large number of short videos about COVID-19 appeared. Publishers included government agencies, professionals, and self-media. The content released has made Douyin a tool for people to receive COVID-19 information in addition to entertainment and social functions. This is a quantitative study. By exploring the impact of the Douyin app on Chinese college students during COVID-19, this study provides suggestions from the level of social media such as TikTok to enable Korea's epidemic prevention to be more effective. This study established variable questions such as Douyin's information perceived value, information usage channels, information awareness, anti-epidemic policy attitude, trust of public institution and preventive behavioral intention, and conducted a questionnaire survey. Using SPSS to analyze the obtained data, this study found that: 1. The short video information usage channels about COVID-19 in Douyin have a positive impact on the audience's information awareness; 2. The information perceived value in Douyin has a positive impact on the audience's information awareness; 3. Information awareness and trust of public institution in Douyin have a positive impact on the audience's anti-epidemic policy attitude; 4. Information awareness and trust of public institutions in Douyin have a positive impact on the audience's preventive behavioral intention; 5. The audience's anti-epidemic policy attitude has a positive effect on preventive behavioral intention.

• Journal of Preventive Medicine and Public Health
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• v.34 no.2
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• pp.131-140
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• 2001

Objectives : During March-May, 2000, a measles outbreak occurred at Youngduk, Korea. This county is divided into two areas with different historical and socioeconomic background. The outbreak occurred in one of these areas. We conducted a comparative epidemiologic study on the two areas in order to evaluate the factors related to the epidemic. Materials and Methods : We selected two groups, grades 3 and 5 in a primary schools in each area. We investigated outbreak-related factors using parent-questionnaires, the vaccination history from the student's health record and the records concerning the recent measles-outbreak from the local health center. Serologic test on measles-IgG and -IgM antibody was done. Results : The infection rate was 31.5% for the epidemic area and 3.7% for non-the epidemic area according to clinical or serological criteria (p<0.001). No difference was seen in the measles vaccination rate, residence at the time of vaccination or past measles infection history between the two areas. In the epidemic area, the attack rate for the 4-6 year-old MMR booster group(20.5%) was higher than the non-booster group(32.4%), but was not found significantly. Vaccine efficacy was 29.6% in the epidemic area and 87.0% in the non-epidemic area (p<0.001). The IgG level and positive rate were significantly different between the two areas (median 10727 IU/ml, 98.9% in epidemic area; median 346 IU/ml, 85.9% in the non-epidemic area, p<0.001). However, the IgG level and positive rate between the measles-cases and non-cases were not significantly different. Conclusions : This outbreak took place in mostly vaccinated children. These results suggest that a reduction of herd immunity for immunity failure after vaccination may be one of the feasible factors related to the outbreak pattern in the two areas. The results of the IgG level and positive rate suggest that re-establishment of a normal value for IgG level and of a qualitative method for IgG are needed.

• Journal of Preventive Medicine and Public Health
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• v.7 no.2
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• pp.403-415
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• 1974

The author has investigated epidemiological features of human cases of epidemic encephalitis (E. E.) in the Republic of Korea and the status of antibody requisition in pre-and post-epidemic time. And virological and serological studies with regarding the relationship of E. E. infection between human and piglet, and field survey against its vector by means of virus isolation from mosquitoes were carried out. Finally, vaccine field trial against human population has also been evaluated in order to confirm its effectiveness. The results of the studies are summarized as follows : 1. The annual incidence of reported cases during the past 25 years (1949-1973) in the Republic of Korea has shown two patterns, one was typical cyclic incidence and the other one was irregular. Annual average morbidity and mortality rate per 100,000 population were 5.7 and 2.1 and fatality rate was 34.6% in typical cyclic years. 2. With regard to the geographical distribution of E. E., the province of Jeolla-Bug-Do illustrated the highest incidence regardless of the epidemic size. 3. The main epidemic period was between mid-August and mid-September (above 90% of the total number of cases). The first case was reported in middle of July and the epidemic ceased in late of October. 4. An analysis of the age distribution of cases of E. E., has shown that above 90% of the total cases occurred in the age groups under 14 years and it was noted that about its 54% were occurred in the age groups between 5-9 years group. 5. Through the Haemagglutination Inhibition (H-I) test for the laboratory diagnosis of E. E., it was found that higher H-I antibody titer was usually detected in the convalescent phase, 15 days after onset. 6. The H-I antibody survey against 563 healthy population by age groups during the pre-epidemic season showed that 422(75%) were less than H-I titer, 1:20 and 122(21.7%) were positive H-I titer, 1:20. Among the 94 American in Seoul who had not been in E. E. endemic area previously only one person had appeared sero-conversion as a H-I titer of 1:80 after post-epidemic season. 7. The E. E. virus could be isolated from the mosquitos pools-C, tritaeniorhyncus which were caught between late July and middle August. 8. E.E. Virus was also isolated from piglet blood on early August and H-I antibody conversion was occurred mostly on middle of August. 9. H-I antibody sero-conversion rate reached to high level when vaccine purified by mouse brain tissue inoculated, showing 98.9%. Higher antibody titer was acquired when booster inoculation was performed, Four fold rise of H-I add N-T antibodies was confirmed with 93.2% and 82.1% respectively.

• Journal of Veterinary Science
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• v.23 no.1
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• pp.2.1-2.18
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• 2022

Background: Co-infections of the porcine reproductive and respiratory syndrome virus (PRRSV) and the Haemophilus parasuis (HPS) are severe in Chinese pigs, but the immune response genes against co-infected with 2 pathogens in the lungs have not been reported. Objectives: To understand the effect of PRRSV and/or HPS infection on the genes expression associated with lung immune function. Methods: The expression of the immune-related genes was analyzed using RNA-sequencing and bioinformatics. Differentially expressed genes (DEGs) were detected and identified by quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC) and western blotting assays. Results: All experimental pigs showed clinical symptoms and lung lesions. RNA-seq analysis showed that 922 DEGs in co-challenged pigs were more than in the HPS group (709 DEGs) and the PRRSV group (676 DEGs). Eleven DEGs validated by qRT-PCR were consistent with the RNA sequencing results. Eleven common Kyoto Encyclopedia of Genes and Genomes pathways related to infection and immune were found in single-infected and co-challenged pigs, including autophagy, cytokine-cytokine receptor interaction, and antigen processing and presentation, involving different DEGs. A model of immune response to infection with PRRSV and HPS was predicted among the DEGs in the co-challenged pigs. Dual oxidase 1 (DUOX1) and interleukin-21 (IL21) were detected by IHC and western blot and showed significant differences between the co-challenged pigs and the controls. Conclusions: These findings elucidated the transcriptome changes in the lungs after PRRSV and/or HPS infections, providing ideas for further study to inhibit ROS production and promote pulmonary fibrosis caused by co-challenging with PRRSV and HPS.

• Communications for Statistical Applications and Methods
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• v.4 no.2
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• pp.427-434
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• 1997

The purpose of this paper is to discuss distribution-free tests of hypothesis that the random samples are identically distributed against the epidemic alternative. But most tests that have been considered are depended only on specific null distribution. Two nonparametric tests are considered and compared with a likelihood ratio test by the empirical powers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.353-362
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• 2018

The national loss caused by the periodic livestock epidemic is very large. In addition, vehicle movement is the main cause of livestock epidemics in Korea. In this context, this study analyzed the relationship between the degree centrality of livestock facilities and the outbreak of infectious diseases. For this purpose, a livestock vehicle movement network was constructed using the facility entrance data provided by KAHIS. Afterwards, the centrality index was derived for each facility in the vehicle movement network and the mean centrality index of the epidemic and non-epidemic facilities were compared. The analysis results are summarized as follows. First, the degree centrality of epidemic facilities is significantly greater than non-epidemic facilities. As a result of the analysis of the entire period data and the period-based data, in most data, the degree centrality of facilities where livestock infectious diseases occurred was significantly greater than most non-occurrence facilities. Second, in the entire period data, the difference in degree centrality between the epidemic and non-epidemic facilities was smaller for HPAI than for FMD. On the other hand, no significant difference was found in the results of the analysis according to the divided period. The policy implications of the results are as follows. First, proactive management of facilities based on centrality is needed. Second, in the case of cloven-hoofed animal facilities, it is more urgent to introduce a management policy based on the degree centrality.

• The Journal of Korean Medical History
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• v.30 no.2
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• pp.133-143
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• 2017

Objectives : This paper summarizes results from review of 36 cases and medical records extracted from Yeoksimanpil, involving treatment of exogenous disease in the last Joseon dynasty, and considers significance of treatment protocols. Methods : About 130 medical records from Yeoksimanpil related to exogenous disease were reviewed, and 36 cases were extracted for closer investigation. The author examined the characteristics of exogenous diseases treated in Yeoksimanpil during the Joseon dynasty, employing Yi Suki's theory about exogenous febrile disease, and analyzed the theory from the viewpoint of epidemic febrile disease (溫病學). Results : The majority of exogenous diseases recorded in Yeoksimanpil include Sanghan (傷寒); Seo (暑); Ryeohwan (厲患); and Hongjin (紅疹). Sanghan was found to be prevalent among the exogenous diseases, but diseases caused by warmth and epidemic are recognized separately from Sanghan. Yi Suki's theory about exogenous febrile disease is similar to the basic theory of modern epidemic febrile disease, although his theory was developed independently during the last Joseon dynasty. Conclusions : Although some exogenous diseases in Yeoksimanpil were recognized separately, Yi Suki did not specify each feature nor did he focus on each symptom. Instead, the author's research suggests that Yi Suki was able to identify and treat a variety of various exogenous diseases due to his accumulation of medical knowledge and skill.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.477-483
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• 2003

Molecular diagnostic techniques have been used to identify porcine epidemic diarrhea virus (PEDV), a causative agent of acute enteritis in swine, but they were difficult to be petformed and time-consuming. To detect PEDV in a rapid and easy way, we developed biotinylated cDNA probe for N gene encoding the nucleoproteins of PEDV. Formalin-fixed and paraffin-embedded tissues from 24 naturally infected pigs were used for the experiment. The ISH produced a positive reaction in all cases. When intestinal tissues were hybridized with PEDV probe, strong signals were seen in the villus enterocytes of the jejunum and ileum. Hybridization signals were also found in the duodenum from one pig and in colon from dnother. In conclusion, ISH with a biotinylated cDNA probe was provided to be a useful diagnostic method for detecting PEDV effectively in routinely processed tissue sections.