• 대한수학회보
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• 제48권3호
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• pp.555-574
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• 2011

It is well known that the mathematical models provide very important information for the research of human immunodeciency virus type. However, the infection rate of almost all mathematical models is linear. The linearity shows the simple interaction between the T-cells and the viral particles. In this paper, a differential equation model of HIV infection of $CD4^+$ T-cells with Crowley-Martin function response is studied. We prove that if the basic reproduction number $R_0$ < 1, the HIV infection is cleared from the T-cell population and the disease dies out; if $R_0$ > 1, the HIV infection persists in the host. We find that the chronic disease steady state is globally asymptotically stable if $R_0$ > 1. Numerical simulations are presented to illustrate the results.

• 한국직업건강간호학회지
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• 제25권1호
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• pp.1-8
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• 2016

Purpose: The 2015 Korean Middle East Respiratory Syndrome Coronavirus (MERS-CoV) outbreaks resulted in 186 cases, with 8% (15 persons) of these being nurses. This study aimed to examine MERS-CoV infection status of clinical nurses and to evaluate perception for infection control. Methods: We investigated the MERS-CoV infection status of nurses using MERS-CoV press release data. We examined and analysed perception for Infection control of 121 nurses of the three MERS intensive therapeutic hospitals in July 2015. Results: One to six nurses per hospital in total 8 health care facilities were infected with MERS-CoV. They mainly had short clinical careers and were unaware of infection possibility. The personal and organizational infection control levels that nurses perceive were low and the relationship between two levels was statistically significant. Conclusion: For promoting health protection and infectious disease management competency of nurses, it is necessary to prepare institutional system for controlling infectious disease.

• Journal of Preventive Medicine and Public Health
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• 제54권4호
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• pp.245-250
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• 2021

Objectives: Jeju Province in Korea reported 627 coronavirus disease 2019 (COVID-19) cases between January 20, 2020, and March 31, 2021. This study analyzed the sources of infection among confirmed cases in Jeju Province, a self-governed island. Methods: The sources of infection were broadly categorized as follows: (1) infections from overseas (confirmed patients who reported travel overseas or contact with overseas travelers); (2) infections from outside Jeju Province (confirmed patients who had visited other provinces or had contact with individuals who had traveled to other provinces in Korea); and (3) unknown sources of infection (confirmed patients who were infected following contact with an infected person whose source of infection was unknown). The chi-square test was used to analyze the differences in the distributions of related variables for each source of infection. Results: Of the 627 confirmed cases, 38 (6.1%) were infections from overseas sources, 199 (31.7%) were from outside of Jeju Province, and 390 (62.2%) were from unknown sources. Jeju Province had no cases with an unknown source of infection during the first and second waves of the nationwide outbreak. Conclusions: Infections from overseas sources could be blocked from spreading to local communities in Jeju Province by conducting screening at the airport, along with the preemptive suspension of visa-free entry. In addition, considering the scale of the nationwide outbreak, measures must be established to delay outbreaks from unknown sources of infection caused by sources outside Jeju Province.

• The Journal of Korean Physical Therapy
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• 제34권6호
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• pp.304-311
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• 2022

Purpose: The purpose of this study was to investigate the knowledge, awareness and performance of COVID-19 infection control among physical therapists and to identify the impact factors on performance Methods: Data were collected from March 16th to March 24th in 2022 from the physical therapist's in Busan. Data analysis was conducted on 170 surveys, after excluding 27 surveys that were found to be unsuitable for data analysis. Results: When correlating the study variables, knowledge and awareness were found to have a positive, meaningful correlation with performance. Performance of COVID-19 personal infection control regression analysis showed that the working department (clinic and long-term care hospital), clinical experience, the more knowledgeable, the awareness (personal), and the more clinical experience had significant positive impacts on the performance of COVID-19 infection control. Performance of COVID-19 treatment room infection control regression analysis showed that the working department (long-term care hospital), educational experience, the awareness (treatment room) had significant positive impacts on the performance of COVID-19 infection control Conclusion: The results of this study may be used as basic data for educating physical therapist's working at the COVID-19 response department. This study suggests that physical therapist's need educational programs to improve their knowledge and awareness and performance of infection control against infectious diseases such as COVID-19. Differentiated physical therapists practice education curricula must be developed and provided after understanding the varying characteristic of physical therapist's with different levels of work experience.

• The Plant Pathology Journal
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• 제36권5호
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• pp.398-405
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• 2020

Nutrient manipulation is a promising strategy for controlling plant diseases in sustainable agriculture. Although many studies have investigated the relationships between certain elements and plant diseases, few have comprehensively explored how differing mineral nutrition levels might affect plant-fungal pathogen interactions, namely plant susceptibility and resistance. Here, we systematically explored the effects of the seven mineral elements that plants require in the greatest amounts for normal development on the susceptibility of soybean plants (Glycine max) to Fusarium oxysporum infection in controlled greenhouse conditions. Nitrogen (N) negligibly affected plant susceptibility to infection in the range 4 to 24 mM for both tested soybean cultivars. At relatively high concentrations, phosphorus (P) increased plant susceptibility to infection, which led to severely reduced shoot and root dry weights. Potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), and iron (Fe) induced plant resistance to infection as their concentrations were increased. For K and Ca, moderate concentrations had a positive effect on plant resistance to the pathogen, whereas relatively high doses of either element adversely affected plant growth and promoted disease symptoms. Further experiments were conducted, assessing disease suppression by selected combinations of macro-elements and Fe at screened concentrations, i.e., K (9 mM) plus Fe (0.2 mM), and S (4 mM) plus Fe (0.2 mM). The disease index was significantly reduced by the combination of K plus Fe. In conclusion, this systematic investigation of soybean plant responses to F. oxysporum infection provides a solid basis for future environmentally-friendly choices for application in soybean disease control programs.

• Journal of Medicine and Life Science
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• 제20권2호
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• pp.67-72
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• 2023

Carbapenem-resistant Enterobacteriaceae (CRE) infections have increased rapidly over the past decade and are recognized as a severe health threat in Korea and worldwide. This study aimed to identify the status and characteristics of CRE infection in Jeju province and provide important basic data for the prevention and management of CRE infection. A descriptive epidemiological analysis was performed on reported cases of CRE infection in Jeju Province between 2018 and 2021 using the integrated management system for disease, an infectious disease reporting system from the Korea Disease Control and Prevention Agency. The annual difference and distribution trends of CRE infection were analyzed using CRE isolates, carbapenemase-producing CREs (CP-CRE) and their genotypes, and the type of medical institution in Jeju Province. CRE infections steadily increased in Jeju from 2018 to 2021, and the proportion of CP-CRE among the CREs also showed a statistically significant increase each year. Among the CRE isolates, Klebsiella pneumoniae (KPC, 62.13%) was the most common, and among the CP-CRE genotypes, KPC (81.62%) showed the highest distribution and increased each year. As the distribution of CP-CRE in have increased over the past 4 years, measures to prevent the spread and outbreak of CRE infections are warranted. The results of this study are expected to be used as basic data for prevention and management of CRE infections in the province.

• Tuberculosis and Respiratory Diseases
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• 제87권4호
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• pp.473-482
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• 2024

Background: Chronic airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), are increasingly being treated with inhaled corticosteroid (ICS). However, ICSs carry potential infection risks, particularly nontuberculous mycobacteria (NTM). This study investigated the association between ICS use and NTM infection risk using national insurance data, particularly for individuals with chronic airway diseases. Methods: We conducted a nationwide population-based study using data from the National Health Insurance Service-National Sample Cohort in South Korea from 2002 to 2019. The cohort included 57,553 patients diagnosed with COPD or asthma. To assess the risk of NTM infection, we used Cox proportional hazards models and propensity score-based inverse probability of treatment weighting (IPTW) to ensure a balanced analysis of covariates. Results: Of the 57,553 patients (mean age 56.0 years, 43.2% male), 16.5% used ICS and 83.5% did not. We identified 63 NTM infection cases, including nine among ICS users and 54 among non-users. Before and after IPTW, ICS use was associated with a higher risk of NTM infection (adjusted hazard ratio [HR], 4.01; 95% confidence interval [CI], 1.48 to 15.58). Higher risks were significant for patients ≥65 years (adjusted HR, 6.40; 95% CI, 1.28 to 31.94), females (adjusted HR, 10.91; 95% CI, 2.24 to 53.20), never-smokers (adjusted HR, 6.31; 95% CI, 1.49 to 26.64), systemic steroid users (adjusted HR, 50.19; 95% CI, 8.07 to 312.19), and those with higher comorbidity scores (adjusted HR, 6.64; 95% CI, 1.19 to 37.03). Conclusion: ICS use in patients with chronic airway diseases might increase the risk of NTM infection, particularly in older females, never-smokers, and systemic steroid users.

• Mycobiology
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• 제31권3호
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• pp.173-178
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• 2003

India has maximum genetic materials in early cauliflower, which grow in subtropical conditions. Different disease parameters like linear growth, maximum growth rate per day, AUDPC, apparent infection rate and percent diseased area were calculated in artificially inoculated plants. Apparent infection rate is not co-related with the black rot disease incidence and should never be considered during characterization of disease resistance and varietal screening. Based on the above disease parameters Kunwari-18, Phool Gobhi Kunwari, Kataki-7 and BT-10-2 were selected as moderately resistance to black rot in early cauliflower. These lines can be used for black rot prone area and also for black rot disease improvement programme. Considering the qualitative and quantitative parameters, slow rotting resistance cauliflower lines are selected as such for cultivation and would be best suited in integrated disease programme.

• 농촌의학ㆍ지역보건
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• 제16권2호
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• pp.172-176
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• 1991

Lyme disease, or Lyme borreliosis. is an infection caused by spirohete Borrellia burgdorferi. This disease was recognized in Lyme, Conneticut U.S.A. in 1975. The onset of the disease is usually heralded by the appearance of a pathognomic skin lesion, known as erythema chronicum migrans, and accompanied by flue like or meningitis like symptoms. Unless treatment is initiated early, the disease usually disseminated, often resulting carduac, neurologic, or joint manifestations. All stages of the disease are usually curable by appropriate antibiotic therapy, and can prevent severe late cardiac, neurologic, and joint complications. Lyme disease is typically defined by clinical evidence supported by serologic test. The diagnosis require serologic confirmantion of erythema chronicum migrans, occurring in patient in nonendemic countries. Determination of antibody titer against B. burgdorferi by enzyme linked immunosorbent assay(ELISA) currently the most practical diagnostic test. Currently Lyme disease occurs in U.S.A. Europe, and Australia. It has recently recognized in China, Japan, and Soviet Union also. In United States, Lyme disease is most common vector borne infection. There is no reported case of patients with this disease in Korea. But the vector of this disease, -Ixodes ticks- had been identified in Korea. And Korea is geographically closely related to China and Japan where Lyme disease is already reported. We expect first case of Lyme disease could he reported in near future. We review the clinical manifestations and diagnostic method of Lyme disease.

• 기본간호학회지
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• 제23권2호
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• pp.136-148
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• 2016

Purpose: This study was done to investigate the level of nursing students' awareness, attitude, safety climate, and performance of infection control, and to identify factors influencing performance. Methods: The sample consisted of 239 nursing students from 5 nursing schools. Data were collected from November 15 to December 11, 2013 and analyzed by frequency, t-test, ANOVA, Pearson correlation coefficients, and multiple stepwise regression with SPSS/WIN 21.0. Results: Of the participants, 216 (90.4%) had experienced contact with infectious diseases. The performance of personal hygiene was scored the highest followed by standard precautions, transmission precautions, and vaccination. There were significant correlations between awareness, attitude, safety-climate and performance. Awareness, safety-climate, attitude, contents of infection control education, and direct exposure to infectious disease collectively explained 30% of the variance in performance, and awareness was the most influential factor. Conclusion: The results indicate that performance of infection control by nursing students can be increased if awareness, safety climate, attitude, and contents of infection control education are improved, and exposure to infectious disease is decreased. These findings can be utilized to improve performance by developing education programs for infection control.