• ETRI Journal
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• 제28권5호
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• pp.692-695
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• 2006

Recently, there has been a constant barrage of worms over the Internet. Besides threatening network security, these worms create an enormous economic burden in terms of loss of productivity not only for the victim hosts, but also for other hosts, as these worms create unnecessary network traffic. Further, measures taken to filter these worms at the router level incur additional network delays because of the extra burden placed on the routers. To develop appropriate tools for thwarting the quick spread of worms, researchers are trying to understand the behavior of worm propagation with the aid of epidemiological models. In this study, we present an optimization model that takes into account infection and treatment costs. Using this model we can determine the level of treatment to be applied for a given rate of infection spread.

• Advances in Traditional Medicine
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• 제6권2호
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• pp.69-78
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• 2006

The isoflavonoids comprise a group of phyto-oestrogens that have useful biological activities including oestrogenic, antioxidant and anticancer. As dietary components for humans, they are bioavailable from leguminous vegetables (such as genistein from soybean), and have been well-documented to have numerous health benefits. A wide range of epidemiological studies in humans and limited studies in animals have identified isoflavonoids as potential chemopreventive agents against hormone-dependent cancers. Therefore, an attempt has been made through this review to summarise the information in the mechanisms aspect of isoflavonoid phyto-oestrogens in inhibiting cancer in vitro and in vivo in the models of human cancers.

• Nonlinear Functional Analysis and Applications
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• 제28권2호
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• pp.473-495
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• 2023

The use of mathematical modelling in the study of epidemiological disorders continues to grow substantially. In order to better support global policy initiatives and explain the possible consequence of an outbreak, mathematical models were constructed to forecast how epidemic illnesses spread. In this paper, fractional derivatives and (${\varpi}$ - F_𝓒)-contractions are used to explore the existence and uniqueness solutions of the novel coronavirus-19 model.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6703-6707
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• 2013

Background: Numerous epidemiological studies have been conducted to evaluate the association between variants of the DNA repair gene XRCC3 and cancer risk. Here we focused on one XRCC3 polymorphism and development of cervical cancer, performing a meta-analysis. Methods: The pooled association between the XRCC3 Thr241Met polymorphism and cervical cancer risk was assessed by odds ratios (ORs) and their 95% confidence intervals (95%CIs). Results: A total of 5 case-control studies met the inclusion criteria. The pooled ORs for the total included studies showed no association among homozygotes TT vs. CC: OR=1.93, 95%CI=0.68-5.49, P=0.22; dominant model TT+TC vs. CC: OR=1.37, 95%CI=0.90-2.06, P=0.14; and recessive model TT vs. TC+CC: OR=1.76, 95%CI=0.68-4.55, P=0.25, but might be a slight risk factor for cervical cancer in heterozygote contrast TT vs. CT: OR= 1.33, 95%CI=1.04-1.71, P=0.02. In subgroup analysis, significant associations were found for Asians under all genetic models. Conclusions: Our meta-analysis suggested the XRCC3 Thr241Met polymorphism might not act as a cervical cancer risk factor overall. However, in subgroup analysis, a significant association was found in Asians under all genetic models. The association should be studied with a larger, stratified population, especially for Asians.

• Asian Pacific Journal of Cancer Prevention
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• 제13권1호
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• pp.325-328
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• 2012

Objective: Glutathione S-transferases (GSTs) are important enzymes that are involved in detoxification of environmental carcinogens. Molecular epidemiological studies have been conducted to investigate the association between GSTM1 and GSTT1 homozygous deletion polymorphisms and brain tumours but results have been conflicting. The aim of this study was to clarify this problem using a meta-analysis. Methods: A total of 9 records were identified by searching the PubMed and Embase databases. Fixed- and random-effects models were performed to estimate the pooled odds ratios. Results: No significant association was found between the GSTM1 and GSTT1 homozygous deletion polymorphisms and risk of brain tumours, including glioma and meningioma. Similar negative results were also observed in both population-based and hospital-based studies. Conclusion: These findings indicate that the GSTM1 and GSTT1 polymorphisms may not be related to the development of brain tumours.

• 한국환경보건학회지
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• 제37권6호
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• pp.397-405
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• 2011

Objectives: The impact of climate change on the health has been of increasing concern due to a recent temperature increase and weather abnormality, and the research results of the impact varied depending on regions. We synthesized risk estimates of the overall health effects of low and high temperature taking account of the heterogeneity. Methods: A comprehensive literature search was conducted using PUBMED to identify journal articles of low and/or high temperature effects on mortality. The search was limited to the English language and epidemiological studies using time-series analysis and/or case-crossover design. Random-effect models in meta analysis were used to estimate the percent increase in mortality with $1^{\circ}C$ temperature decrease or increase with 95% confidence intervals (CI) in cold or hot days. Results: Twenty three studies were presented in two tables: 1) low temperature effects; 2) high temperature effects on mortality. The combined effects of low and high temperatures on total mortality were 2% (95% CI, 1-4%) per $1^{\circ}C$ decrease and 4% (95% CI, 2-5%) per $1^{\circ}C$ increase of temperature, respectively. Conclusions: This meta analysis found that both low and high temperatures affected mortality, and the magnitude of high temperature appeared to be stronger than that of low temperature.

• Journal of Preventive Medicine and Public Health
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• 제48권5호
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• pp.225-230
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• 2015

Objectives: The epidemiological characteristics of breast cancer incidence by age group in Korean women are unique. This systematic review aimed to investigate the association between hormone replacement therapy (HRT) and breast cancer risk in Korean women. Methods: We searched electronic databases such as KoreaMed, KMbase, KISS, and RISS4U as well as PubMed for publications on Korean breast cancer patients. We also conducted manual searching based on references and citations in potential papers. All of the analytically epidemiologic studies that obtained individual data on HRT exposure and breast cancer occurrence in Korean women were selected. We restricted the inclusion of case-control studies to those that included age-matched controls. Estimates of summary odds ratio (SOR) with 95% confidence intervals (CIs) were calculated using random effect models. Results: One cohort and five case-control studies were finally selected. Based on the heterogeneity that existed among the six studies (I-squared=70.2%), a random effect model was applied. The summary effect size of HRT history from the six articles indicated no statistical significance in breast cancer risk (SOR, 0.983; 95% CI, 0.620 to 1.556). Conclusions: These facts support no significant effect of HRT history in the risk of breast cancer in Korean women. It is necessary to conduct a pooled analysis.

• 대한수의학회지
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• 제44권3호
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• pp.463-467
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• 2004

To identify risk factors of canine distemper, which is one of the most important disease of dogs in Korea, a case-control study was performed with 2,507 cases and 4,121 controls from 630 veterinary clinics throughout Korea. In multivariate logistic regression models, the sampling period (Mars and April) and the age of the dogs (7-12 months old) were associated with an increased risk of canine distemper. Sex, body size and residential region showed no significant relationship. The epidemiological evidences of canine distemper in Korea agree to the risk factors observed in foreign countries.

• Journal of Cancer Prevention
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• 제22권1호
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• pp.1-5
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• 2017

Pancreatic cancer is a highly aggressive malignant tumor of the digestive system and radical resection, which is available to very few patients, might be the only possibility for cure. Since therapeutic choices are limited at the advanced stage, prevention is more important for reducing incidence in high-risk individuals with family history of pancreatic cancer. Epidemiological studies have shown that a high consumption of fish oil or ${\omega}3-polyunsaturated$ fatty acids reduces the risk of pancreatic cancers. Dietary fish oil supplementation has shown to suppress pancreatic cancer development in animal models. Previous experimental studies revealed that several hallmarks of cancer involved in the pathogenesis of pancreatic cancer, such as the resistance to apoptosis, hyper-proliferation with abnormal $Wnt/{\beta}-catenin$ signaling, expression of pro-angiogenic growth factors, and invasion. Docosahexaenoic acid (DHA) is a ${\omega}3-polyunsaturated$ fatty acid and rich in cold oceanic fish oil. DHA shows anti-cancer activity by inducing oxidative stress and apoptosis, inhibiting $Wnt/{\beta}-catenin$ signaling, and decreasing extracellular matrix degradation and expression of pro-angiogenic factors in pancreatic cancer cells. This review will summarize anti-cancer mechanism of DHA in pancreatic carcinogenesis based on the recent studies.

• 한국기후변화학회지
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• 제9권2호
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• pp.133-142
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• 2018

Climate change will affect not only the crop productivity but also the pattern of rice disease epidemics in Korea. Impact assessments for the climate change are conducted using various climate change scenarios from many global climate models (GCM), such as a scenario from a best GCM or scenarios from multiple GCMs, or a combination of both. Here, we evaluated the feasibility of using a climate change scenario from the best GCM for the impact assessment on the potential epidemics of a rice leaf blast disease in Korea, in comparison to a multi?model ensemble (MME) scenario from multiple GCMs. For this, this study involves analyses of disease simulation using an epidemiological model, EPIRICE?LB, which was validated for Korean rice paddy fields. We then assessed likely changes in disease epidemics using the best GCM selected for individual agro?climatic zones and MME scenarios constructed by running 11 GCMs. As a result, the simulated incidence of leaf blast epidemics gradually decreased over the future periods both from the best GCM and MME. The results from this study emphasized that the best GCM selection approach resulted in comparable performance to the MME approach for the climate change impact assessment on rice leaf blast epidemic in Korea.