• Journal of applied mathematics & informatics
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• 제28권5_6호
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• pp.1359-1378
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• 2010

The effect of impulse in the ecological models makes them more realistic. Recently, the eco-epidemiological models have become an important field of study from the both mathematical and ecological view points. In this article, we consider some eco-epidemiological systems under the influence of impulsive force. A set of sufficient conditions for the permanence of the system are derived. Stability of the trivial solution and at least one strictly positive periodic solution are obtained. Numerical examples are given in support to our analytical findings. Finally, a short discussion concludes the paper.

• Toxicological Research
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• 제26권2호
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• pp.83-93
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• 2010

Since it was first observed in late 1970s that human cancers often had decreased manganese superoxide dismutase (MnSOD) protein expression and activity, extensive studies have been conducted to verify the association between MnSOD and cancer. Significance of MnSOD as a primary mitochondrial antioxidant enzyme is unquestionable; results from in vitro, in vivo and epidemiological studies are in harmony. On the contrary, studies regarding roles of MnSOD in cancer often report conflicting results. Although putative mechanisms have been proposed to explain how MnSOD regulates cellular proliferation, these mechanisms are not capitulated in epidemiological studies. This review discusses most recent epidemiological and experimental studies that examined the association between MnSOD and cancer, and describes emerging hypotheses of MnSOD as a mitochondrial redox regulatory enzyme and of how altered mitochondrial redox may affect physiology of normal as well as cancer cells.

• 대한수학회논문집
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• 제13권3호
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• pp.643-653
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• 1998

In this paper, we analyze a system for an epidemiological model which has a double zero eigenvalue at certain parameter values.

• 한국빅데이터학회지
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• 제5권2호
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• pp.187-199
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• 2020

WHO는 3월 11일을 기준으로 COVID-19를 유행병으로 선포하였다. 국내에서는 27,000명의 확진자가 발생하였으며, 전세계적으로는 5,000만명이 넘는 확진자가 발생하였다. 이처럼 COVID-19으로 인한 감염이 확산되면서 역학조사의 중요성이 다시 한 번 대두되고 있는 상황이다. 하지만 지난 대구 경북 사례를 시작으로 다수의 확진자가 발생하였고, 현재 역학조사 방식에 한계가 있음을 인지하였다. 이에 질병관리본부는 스마트시티 데이터허브 기술을 활용한 역학조사 지원시스템을 개발하여 역학조사에 활용하였다. 본 논문에서 제안하는 시스템은 역학조사 지원시스템의 일부로 대용량의 이동통신사 데이터를 처리하기 위한 빅데이터 기반 역학조사 지원 시스템이다. 본 시스템을 통해 기존에는 어려웠던 이동통신사 데이터의 이상치 처리나 2명 이상의 접촉자가 발생한 핫스팟 지역 생성 등의 처리가 가능해졌다. 그 결과, 이상치 처리는 요청건당 30초, 핫스팟의 경우 평균 10분 이내에 처리할 수 있게 되었다. 본 연구는 빅데이터 시스템을 역학조사에 접목하고 역학조사를 지원한 첫 사례로써, 빅데이터 시스템의 역학조사에 대한 실용적 활용 가능성을 제시하고 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권6호
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• pp.2997-3004
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• 2012

Background: This cross-sectional observational study was undertaken to identify the epidemiological characteristics of patients with gynecological malignancies in India, in relation to gynecological cancer risk. Methods: In the gynecology out-patient clinic of a tertiary care hospital in Kolkata, India, the patients with suggestive symptoms of gynecological malignancies were screened. One hundred thirteen patients with histopathologically confirmed gynecological malignancies were interviewed. Results: More than two-thirds of the cases (69.0%) occurred in the age range of 35-64 years and the same proportion of patients was from rural areas. Almost all the patients were "ever-married" (96.5%). More than half (54.9%) were illiterate/just literate. Nearly two-thirds (64.6%) were parity 3 or higher. Among the 18 patients with history of multiple sexual partners of the husband, 94.4% (17) were suffering from cervical malignancy, along with all the 3 patients with history of STD syndromes (sexually transmitted diseases) of their husbands. No one had given a history of condom use by her husband. Most of the patients (91.1%) used old / reused cloth pieces during menstruation. Conclusions: There is a need to increase awareness among women and the broader community about different epidemiological factors that may be responsible for increased risk of gynecological malignancies.

• 한국어병학회지
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• 제24권2호
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• pp.95-102
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• 2011

Normalized resistance interpretation (NRI) analysis for tetracycline was applied to generate information on the epidemiological cut-off value for Vibrio ichthyoenteri isolated from diseased olive flounder (Paralichthys olivaceus) larvae. Thus, 42 strains of V. ichthyoenteri were used to determine minimum inhibitory concentration (MIC) values of tetracycline using Etest. Also, 11 tetracycline resistance related genes were investigated by PCR method. Most tetracycline-resistant strains harbored both tetB and tetM with a few exceptions. NRI-derived mean and 2 SD above the mean of theoretical normal distributions of susceptible isolates were 0.33 mg/L and 1.66 mg/L, respectively. The epidemiological cut-off value for V. ichthyoenteri from the calculations could be set to S ${\leq}$ 2 mg/L. Of the 42 strains, 15 were classified as non-wild type (NWT), and MIC values of the NWT strains vary regardless of tetB and tetM detection, suggesting that there may be other mechanisms involved in tetracycline resistance in this Vibrio species.

• Parasites, Hosts and Diseases
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• 제39권4호
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• pp.267-283
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• 2001

In endemic areas of Taenia tapeworms in Korea, most of the reports showed that T. saginata was dominant over T. solium, but eating pigs is the dominant habit over eating cattle. Why do they have more T saginata despite lower consumption of beef This problem actually has long been recognized but until recently there has been no intensive trial to give a scientific explanation on this epidemiological enigma. By summing up the data published between the years 1963 and 1999, the ratio of armed versus unarmed tapeworms in humans was estimated at approximately 1 :5. The ratio of pig-eaters versus cattle-eaters, however, was approximately 5: 1. This inconsistency could be explained with the recently described T. asiatica, which infects humans through the eating of pig's viscera. We re-evaluate the importance of the consumption of visceral organ of pigs, leading us to an improved epidemiological understanding of the T. asiatica infection together with co-existing T. saginata and T. solium in Korea.

• Journal of Medicine and Life Science
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• 제20권3호
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• pp.107-114
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• 2023

Epidemiological control of coronavirus disease 2019 (COVID-19) is needed to estimate the infection period of confirmed cases and identify potential cases. The present study, targeting confirmed cases for which the time of COVID-19 symptom onset was disclosed, aimed to investigate the relationship between intervals (day) from symptom onset to testing the cycle threshold (CT) values of real-time reverse transcription-polymerase chain reaction. Of the COVID-19 confirmed cases, those for which the date of suspected symptom onset in the epidemiological investigation was specifically disclosed were included in this study. Interval was defined as the number of days from symptom onset (as disclosed by the patient) to specimen collection for testing. A locally weighted regression smoothing (LOWESS) curve was applied, with intervals as explanatory variables and CT values (CTR for RdRp gene and CTE for E gene) as outcome variables. After finding its non-linear relationship, a polynomial regression model was applied to estimate the 95% confidence interval values of CTR and CTE by interval. The application of LOWESS in 331 patients identified a U-shaped curve relationship between the CTR and CTE values according to the number of interval days, and both CTR and CTE satisfied the quadratic model for interval days. Active application of these results to epidemiological investigations would minimize the chance of failing to identify individuals who are in contact with COVID-19 confirmed cases, thereby reducing the potential transmission of the virus to local communities.

• 대한한의학회지
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• 제44권3호
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• pp.47-58
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• 2023

Objectives: This study aimed to investigate the epidemiological characteristics of COVID-19 in Chungju City from July to December 2021. Methods: The authors processed and analyzed the epidemiological analysis report written by researcher. The estimated reproduction rate was analyzed using web-based software that calculates time-varying reproduction numbers. The results were analyzed through univariate multiple regression analysis, with a maximum significance level set at 0.05. Results: During the study period, a total of 1,188 patients were identified, with 7.9% of them progressing to a severe status. The maximum reproduction rate recorded was 3.48. Factors associated with the transition to a severe status included the presence of symptoms at the time of diagnosis, lack of vaccination, and belonging to the age group over 40. Conclusion: Based on the findings of this study, it can be strongly supported that the measures implemented in Chungju City, such as social distancing, vaccination, and preemptive diagnostic tests, were appropriate. Furthermore, it demonstrates that Chungju City effectively managed the impact of COVID-19. Korean Medicine Doctors made significant contributions to the epidemiological investigations of COVID-19. To comprehensively manage infectious diseases, it is crucial to provide administrative and legal support and encourage active research to expand the role of Korean Medicine Doctors in this area.

• Journal of Preventive Medicine and Public Health
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• 제41권5호
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• pp.339-344
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• 2008

Objectives : The objective of this paper is to discuss the importance of obtaining informed consent for conducting epidemiological studies and public health activities, based on the Report of the UNESCO's Working Group on Informed Consent. Methods : The Report of the UNESCO's Working Group on Informed Consent was reviewed and discussed in connection with the ethical considerations of public health activities and epidemiological research. Results : It was at the Nuremberg Trial for the German war criminals of the Second World War that the principle of 'consent' was first stated as a consequence of the medical abuses carried out during the War. As a result of the Trial, the Nuremberg Code came out in 1947. Since then, various international declarations or ethical principles on 'informed consent' have been developed and published. These ethical principles on 'informed consent' have mostly to do with the clinical research that involves human subjects, and not with epidemiological studies and public health activities. However, UNESCO recently issued a comprehensive Report on Informed Consent based on the Universal Declaration on Bioethics and Human Rights adopted in 2005, and this included detailed guidelines on informed consent in epidemiological studies and public health activities. Conclusions : Universal Declaration on Bioethics and Human Rights emphasizes the principle of autonomy to protect the human rights of the human subjects involved in any public health activities and epidemiological research. As a practical guideline, obtaining informed consent is strongly recommended.