• Journal of the Korean Statistical Society
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• v.22 no.1
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• pp.133-138
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• 1993

We consider two estimators of the infection rate in the simple stochastic epidemic model. It is shown that the maximum likelihood estimator of teh infection rate under the discrete time observation does not have the moment of any positive order. Some properties of the Choi-Severo estimator, an approximation to the maximum likelihood estimator, are also investigated.

• Korean Journal of Veterinary Service
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• v.15 no.1
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• pp.1-6
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• 1992

A survey on the dosage optimal time for the bovine fascioliasis was carried out from Jan. 1987 to Dec. 1990. The results were summarized as follows ; 1. The mean infection rate was 27.7% (1,662 heads were infected out of 3,247 heads In 205 herds). A seasonal infection rate was winter (34.6%) >spring(32.5%) >summer(24.7%) > autumn(22.8%) 2. In the density of the fasciola spp. egg of infected bovine feces remarks 79.6% on the range below 10. 3. The density of fasciola spp. egg is not directly proportinal to the infection rate, and remarks on the range from 5 to 20. 4. In the herds dosed vermifuge the appearance of the fasciola spp. egg is as follows ; 1∼3 months show 3.8% and 4∼6 months 8.5% 5. The dosage optimal time for the bovine fasciliasis is as follows ; 1) According to the monthly infection rate the first dosage optimal time is Dec and Feb and the second-Jun and Aug. 2) In the herd dosed vermifuge the dosage optimal time is to dose twice by 60 days interval after 3∼4 months from previous dosage.

• KSBB Journal
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• v.10 no.3
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• pp.317-322
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• 1995

Insect cells were grown and infected with baculovirus for the production of recombinant protein. Later infection gave the lower expression of recombinant protein. This indicates that the expression rate is lower at higher cell concentration. This phenomena provides a well-posed optimization problem with respect to the infection time. The optimal infection time was experimentally shown to exist for the maximum productivity of recombinant protein. Also, the expression increased with the addition of 5% silkworm hemolymph. This is considered to be due to the increase of intracellular viruses and the longevity of viable cells after the infection. The production of ${\beta}$-galaclosidase increased about ten-fold with the addition of yeastolate and silkworm hemolymph for high cell density and high expression, respectively.

• Journal of Mushroom
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• v.17 no.3
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• pp.93-98
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• 2019

We investigated the correlation between density of air and the infection rate of airborne microorganisms in mushroom cultivation facilities and found that the correlation was low in places where the infection rate during cultivation was less than 1%. The farms with an infection rate of 2~5% showed a high infection rate in the inoculation room in spring and summer seasons, and in the incubation room in autumn, and the farms with an infection rate of more than 6% showed infection in all the rooms regardless of the season. The farms where the Trichoderma sp. was investigated at the time of the mushroom cultivation showed the highest infection rates of 3.17%, 2.74%, and 2.64% in summer, spring, and autumn, respectively. The farms infected with Neurospora tetrasperma showed a lesser rate of infection than the ones infected with Trichoderma sp., and the highest infection rate of 0.56% was observed in summer. Based on these results, the type of infection could be classified into five groups, where type I was farms where the infection rate is less than 1% in all seasons. Three farms belonged to this type, and the infection rate in this type was lower than that in the other types.

• Childhood Kidney Diseases
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• v.21 no.2
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• pp.75-80
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• 2017

Purpose: To investigate the frequency, presentation, management, and outcome of cytomegalovirus (CMV) infection in pediatric patients who underwent renal transplantation. Methods: We performed a retrospective chart review of 70 patients under the age of 18, who underwent renal transplantation between January 1990 and November 2014. A diagnosis of CMV infection was based on serology, molecular assays, antigenemia assays, and culture. CMV infection was defined as detection of virus and CMV disease was diagnosed when clinical signs and symptoms were present. Results: The number of patients with CMV infection was 18 (25.7% of renal transplant recipients). Twelve were male (66.7%), and the $mean{\pm}standard$ deviation (SD) age at infection was $13.3{\pm}3.9$ years. Median time of infection after renal transplantation was 4 months (range 1.0-31.0 months). Pretransplantation CMV status in the infected group was as follows: donor (D)+/recipient (R)+, 11 (61.1%); D+/R-, 7 (38.9%); D-/R+, 0; and D-/R- 0. Nine patients had CMV disease with fever, leukopenia, thrombocytopenia, or organ involvement such as enteritis, hepatitis, and pneumonitis. The age of disease occurrence was $13.1{\pm}3.9$ years and the median time to disease onset after renal transplantation was 8 months (range 1.0-31.0). Immunosuppressive agents were reduced or discontinued in 14 patients (77.8%), antiviral agents were used in 11 patients (61.1%), and all patients with CMV infection were controlled. Conclusions: A quarter of the patients had CMV infection about 4 months after renal transplantation. CMV infection was successfully treated with reduction of immunosuppressants or with antiviral agents.

• Biomedical Science Letters
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• v.18 no.3
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• pp.201-209
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• 2012

Apoptosis is a physiological programmed cell death process. Tubercle bacilli inhibit apoptosis of alveolar macrophages and phagolysosome fusion. We investigated whether the Bcl-2 family anti-apoptotic member, Bfl-1/A1, plays an important role in the anti-apoptotic process during mycobacterial infection. PMA-treated human monocytoid THP-1 cells were infected with mycobacteria (H37Rv, BCG, and K-strain) at a multiplicity of infection (MOI) of 10 for 0, 1.5, 3, 6, 9, 12, 18, 24, 48, or 72 h. In addition, PMA-treated THP-1 cells were pretreated with specific inhibitors for 45 min before stimulation with mycobacteria at an MOI of 10 for 4 h. After the indicated time, the cells were subject to reverse transcription-polymerase chain reaction (RT-PCR) analysis, and a Bfl-1/A1-specific Western blot was performed. In PMA-differentiated THP-1 cells, the expression level of Bfl-1/A1 mRNA was increased by Mycobacterium tuberculosis (MTB) H37Rv infection. The mRNA level of Bfl-1/A1 peaked 3 h after MTB infection, then declined gradually until 9 h. However, Bfl-1/A1 mRNA induction gradually re-increased from 24 h to 72 h after MTB infection. No difference in Bfl-1/A1 expression was detected following infection with MTB H37Rv, K-strain, or M. bovis BCG. These results were not dependent on mycobacterial virulence. Moreover, mRNA levels of other anti-apoptotic molecules (Mcl-1, Bcl-2, and Bcl-xL) were not increased after MTB H37Rv or K-strain infection. These results suggest that mycobacteria induce the innate immune host defense mechanisms that utilize Bfl-1/A1 molecules at early time points, regardless of virulence.

• KSBB Journal
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• v.26 no.2
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• pp.107-111
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• 2011

The essential operating parameters in virus vaccine production are multiplicity of infection (MOI), harvest time, and infection time. Stimulating agents also can be applied in order to improve vaccine productivity further. We investigated the optimum operating conditions in porcine transmissible gastroenteritis virus (TGEV) vaccine production and the applicability of sodium butyrate (NaBu) as a stimulating agents for the improvement of vaccine productivity. The optimum MOI, infection time, and harvest time for high production of TGEV by swine testicle (ST) cells were found to be 0.0001 pfu/cell, 3 day after cell inoculation, and 24 hpi, respectively. NaBu is known as a histone deacetylase inhibitor that has been widely used for the high expression of recombinant protein using mammalian cells and for the enhancement of virus propagation. So we tried to examine the potential of NaBu as a stimulating agent and to determine the optimum concentration by comparing TGEV titers with different range of NaBu concentration. TGEV titer with 5 mM NaBu was 1.5 times higher than control. Therefore, we concluded that NaBu can be a promising agent for stimulating various vaccine production including TGEV and the optimum NaBu concentration for TGEV production was determined to be 5 mM.

• Journal of Microbiology and Biotechnology
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• v.25 no.10
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• pp.1728-1733
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• 2015

This study was done to establish a mouse model for catheter-related biofilm infection suitable to bioluminescence imaging (BLI). Biofilm formation of Pseudomonas aeruginosa (P. aeruginosa) Xen5 grown on catheter disks in vitro and in an implanted mouse model was real-time monitored during a 7-day study period using BLI. The numbers of integrated brightness (IB) and viable bacterial count (VBC) in the biofilm disks in vitro were highest at 24 h after inoculation; the IB of biofilm in vivo was increased until 24 h after implantation. A statistical correlation was observed between IB and VBC in vitro by linear regression analysis. The actual VBC value in vivo can be estimated accurately by IB without sacrifice. In addition, we monitored the change in white blood cells (WBCs) during infection. The number of WBCs on day 7 was significantly higher in the infection group than in the control group. This study indicates that BLI is a simple, fast, and sensitive method to measure catheter biofilm infection in mice.

• Journal of Korean Academy of Nursing
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• v.17 no.3
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• pp.227-240
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• 1987

Infection has assumed increased importance as a cause of death among thermally injured individuals. Decreased treatment effectiveness and an increase in mortality are the hallmarks of nosocomial infection. Infection control is a monumental task that must be achieved to reduce mortalities. This was a retrospective study to survey the epidemiological features of nosocomial infections in a burn unit and to identify the possibilities for infection control. During the past 6 year 2 month period from July, 1981 to August, 1987, 306 burn patients were treated in the burn unit of university hospital. Among of these, 290 cases were the subjects of this study. The data were collected from the patients' records after discharge. All data collected were analyzed using percent, x$^2$-test, t-test with SPSS program. The results of this study are summariged as follows: 1) Infection rate was 40%. According to site, there were 67 cases of wound infection, 60 cases of post-operative skin graft infection, 20 cases of septicemia and 20 cases of donor site infection. As far as the burn size was concerned, the infection rate for patients whose burn size ranged 61 to 70%, was shown to be 100%, followed by the infection rate of 93.8%, for patients whose burn size ranged from 41~50%. As far as the period of time over which the infection developed, 5 to 7 days showed the highest frequency. Further infection was the main cause of deaths and complications. 2) Based upon the results obained by comparing the general characteristics, between a hospital infection-group and non-hospital infection group, there was a significant defference according to age, the time of the year when the accident happened, the place of accident or length of hospital-admission. And according to the result obtained by comparing the general characteristics of the burn, there was a significant difference according to burn size, burn depth, burn type, and burn site. And also based upon the result obtained by comparing the two groups according to method of treatment, there was a significant difference according to the use of antibiotics and to the type of wound-treatment, and for the 8 different binds of treatment related to infection, there was a significant difference for all. In conclusion, age, length of hospital-admission, burn size, burn type, burn site, burn depth, type of woundtreatment and the 8 different binds of treatment, which are related to burns, were shown to be the factors which affect the infection rate in burn patients.

• Journal of Korean society of Dental Hygiene
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• v.11 no.1
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• pp.137-148
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• 2011

Objectives : The objectives of this study were to investigate the infection control practices of practicing dental hygienists. Methods : This research was based on self-filling survey which 149 dental hygienists in dental clinic and dental hospital on October 2009. For the data analysis, an SPSS WIN 11.5 program was used and its signification level was 0.05. The following shows the results of this study. Results : 1. There was significant difference in there practice about sterilization and disinfection of dental instrument depending upon the respondent' career(p<0.05). 2. There was significant difference to were gloves and a apron according to type of service(p<0.05). 3. There was significant difference in the time to change the gown according to experience of education factors infection control(p<0.05). Conclusions : The majority of dental hygienists surveyed reported altering infection control practices and treatment techniques. While there has been an improvement in compliance with recommended infection control guidelines. Even though there is a need for continuing infection control education for dental hygienists.