• Journal of Periodontal and Implant Science
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• v.47 no.4
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• pp.219-230
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• 2017

Purpose: The purpose of this study was to compare the characteristics of single- and dualspecies in vitro oral biofilms made by static and dynamic methods. Methods: Hydroxyapatite (HA) disks, 12.7 mm in diameter and 3 mm thick, were coated with processed saliva for 4 hours. The disks were divided into a static method group and a dynamic method group. The disks treated with a static method were cultured in 12-well plates, and the disks in the dynamic method group were cultured in a Center for Disease Control and Prevention (CDC) biofilm reactor for 72 hours. In the single- and dual-species biofilms, Fusobacterium nucleatum and Porphyromonas gingivalis were used, and the amount of adhering bacteria, proportions of species, and bacterial reduction of chlorhexidine were examined. Bacterial adhesion was examined with scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Results: Compared with the biofilms made using the static method, the biofilms made using the dynamic method had significantly lower amounts of adhering and looser bacterial accumulation in SEM and CLSM images. The proportion of P. gingivalis was higher in the dynamic method group than in the static method group; however, the difference was not statistically significant. Furthermore, the biofilm thickness and bacterial reduction by chlorhexidine showed no significant differences between the 2 methods. Conclusions: When used to reproduce periodontal biofilms composed of F. nucleatum and P. gingivalis, the dynamic method (CDC biofilm reactor) formed looser biofilms containing fewer bacteria than the well plate. However, this difference did not influence the thickness of the biofilms or the activity of chlorhexidine. Therefore, both methods are useful for mimicking periodontitis-associated oral biofilms.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.4
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• pp.264-276
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• 2010

The objectives of this study were to introduce the methods of soil respiration measurement, to review soil respiration studies conducted in Korea, and to suggest potential issues generated from using various methods for soil respiration measurement. According to the measurement principles, the methods of soil respiration measurements are classified as: alkali absorption method (AA), closed chamber method (CC), closed dynamic chamber method (CDC), and open flow method (OF). Based on the litereaure review on soil respiration studies in Korea, the CDC method was mostly used by the researchers (62%), followed by the AA (17%), OF (13%) and CC (8%) methods. Along with these methods, various instruments were used such as LI-6400-09, EGM-3, EGM-4, and automatic soil respiration chamber. Most of the soil respiration measurements were carried out in forest ecosystems and the reported soil respiration showed a wide range of variations from 130 to 900 mg $CO_2\;m^{-2}h^{-1}$. Continuous monitoring of soil respiration with minimal disturbance and the potential inconsistency in measurements are still the challenges facing the researchers, causing a paucity in quality datasets of sufficient quantity. Few attempts of intercomparison among different methods hinder the data users from synthetic analysis and assessment of the collected datasets. In order to better estimate soil carbon budget and understand their exchange mechanisms in key ecosystems of Korea, it is necessary to measure soil respiration at various plant functional types, soils, and climate conditions over a decadal time scale along with the study on the partitioning of soil respiration into autotrophic and heteorotrophic components.

• Biomedical Science Letters
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• v.15 no.3
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• pp.261-263
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• 2009

Methylprednisolone is a synthetic glucocorticoid which is usually taken intravenously for many neurosurgical diseases which cause edema including brain tumor, and trauma including spinal cord injury. Methylprednisolone reduces swelling and decreases the body's immune response. It is also used to treat many immune and allergic disorders, such as arthritis, lupus, psoriasis, asthma, ulcerative colitis, and Crohn's disease. To identify genes expressed during methylprednisolone treatment against neurons of rats (PC12 cells), DNA microarray method was used. We have isolated 2 gene groups (up- or down-regulated genes) which are methylprednisolone differentially expressed in neurons. Lipocalin 3 is the gene most significantly increased among 772 up-regulated genes (more than 2 fold over-expression) and Aristaless 3 is the gene most dramatically decreased among 959 down-regulated genes (more than 2 fold down-expression). The gene increased expression of Fgb, Thbd, Cfi, F3, Kngl, Serpinel, C3, Tnfrsf4 and Il8rb are involved stress-response gene, and Nfkbia, Casp7, Pik3rl, I11b, Unc5a, Tgfb2, Kitl and Fgf15 are strongly associated with development. Cell cycle associated genes (Mcm6, Ccnb2, Plk1, Ccnd1, E2f1, Cdc2a, Tgfa, Dusp6, Id3) and cell proliferation associated genes (Ccl2, Tnfsf13, Csf2, Kit, Pim1, Nr3c1, Chrm4, Fosl1, Spp1) are down-regulated more than 2 times by methylprednisolone treatment. Among the genes described above, 4 up-regulated genes are confirmed those expression by RT-PCR. We found that methylprednisolone is related to expression of many genes associated with stress response, development, cell cycle, and cell proliferation by DNA microarray analysis. However, We think further experimental molecular studies will be needed to figure out the exact biological function of various genes described above and the physiological change of neuronal cells by methylprednisolone. The resulting data will give the one of the good clues for understanding of methylprednisolone under molecular level in the neurons.

• Journal of Auto-vehicle Safety Association
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• v.10 no.1
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• pp.20-26
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• 2018

The fatality of rollover accidents in motor vehicle crashes is high despite their low incidence. Through the investigation of a 12-passenger van rollover accident in which 10 passengers were involved, we intend to analyze the correlation between the severity of the injury and the position of the occupants. We collected accident information from medical records, interviews, photo-images of the damaged van, field surveys, and the results of the Korean New Car Assessment Program (KNCAP). Based on the occupants' position, we classified injury sites and estimated injury severity. Passenger injury severity was evaluated by trauma score calculation. The initiation type of the rollover accident was passenger side 'fall-over' and the Collision Deformation Classification (CDC) code for the damaged van was 00TDZO3. The crash of the van involved 10 passengers, with an average age of $16.3{\pm}4.2years$. Few of the occupants had fastened seat belts at the time of the incident, and there was no airbag installed. One patient sustained severe liver injury and another was diagnosed with a fracture of the right humerus. The most common injuries were at the upper extremities and the neck. The average of Injury Severity Score (ISS) was $4.8{\pm}5.9$, and the average ISS of right-seated, mid-seated and left-seated occupants was $7.5{\pm}9.3$, $1.5{\pm}0.7$, and $3.3{\pm}2.1$ respectively (p>0.05). In the rollover (to-passenger side) accident of occupant unfastened, the average ISS of right-seated occupants (near side) was higher, but there was no statistically significant difference.

• Journal of Nutrition and Health
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• v.33 no.5
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• pp.532-539
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• 2000

The purpose of this research is to assess th iron nutritional status of pregnant women and to evaluate the appropriateness of the present cut off levels of hemoglobin(Hgb), hematocrit(Hct) and total iron binding capacity(TIBC) for assessing iron deficiency status. Pregnant women who were visiting public helath centers in Ulsan were interviewed and agreed to attend the study. Blood sample was taken and biochemical analysis of blood was performed. The collected data were classified into 3 trimesters by gestational age and then statistical analysis was performed. The prevalence of anemia in all subjects was 32.3% by WHO criteria(Hgb < 11.0g/dl) and 17.8% of all subjects was iron deficient anemia by CDC criteria(Hgb < 11.0/dl and serum ferritin < 12.0ug/l). Since the iron deficient anemia generally occures at the last stage of iron deficiency, it is not efficient to diagnose and prevent the iron deficient anemia in pregnant women by using the present cut off level of Hgb. Therefore, the new cut off level of iron status indices is necessary for assessing iron deficiency in early pregnancy before manifestation of anemia and for reducing the prevalence of anemia in later pregnancy. For this reason, the present cut off levels of iron status indices were estimated and compared by assessing the iron deficiency judged by serum ferritin level (<12.0ug/l)as true iron deficiency. It follows from the results of this research that present cut off levels of Hgb, Hct and TIBC were very insensitive in identifying the subjection with iron deficiency. The appropriate cut off levels of Hgb were 11.5g/dl for total period of pregnancy, 12.0g/dl for 1st and 3rd trimester, and 11.5g/dl for 2nd trimester. The cut off level of Hct was 34.0% for total period for pregnancy, 35.0% for 1st trimester, and 34.0% for 2nd and 3rd trimester. The cut off level of TIBC was 400ug/dl for total period, 360ug/dl for 1st 2nd trimester, and 450ug/dl for 3rd trimester.

• Korean Journal of Plant Resources
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• v.35 no.6
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• pp.796-804
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• 2022

The demand for Chelidonium majus L. subsp. asiaticum H. Hara is expected to increase due to its pharmacological properties such as antibacterial, antioxidant, and anti-inflammatory effects. However, an effective propagation system for this species has not yet been established. This study was conducted to analyze the seed dormancy and germination characteristics of C. majus L. subsp. asiaticum H. Hara native to Korea and establish a mass propagation system. The dormancy type was primarily classified by analyzing the general information of the collected seeds. The seed dormancy breaking was investigated by comparing the effects of cold stratification (0, 2, 4, 8, 10, or 12 weeks) with warm stratification (S, summer temperature, 25/15℃) and intermediate temperature stratification (A, autumn temperature, 15/10℃) of alternating temperature stratification (S12-A4 or S12-A8 weeks). After dormancy break, 500 mg/L GA₃ and GA₄₊₇ treatment replaced cold stratification and improved seed germination. The results of this study are expected to provide basic data for future seed propagation and mass propagation by analyzing the dormancy and germination characteristics of C. majus L. subsp. asiaticum H. Hara seeds.

• The Journal of the Korean dental association
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• v.39 no.12 s.391
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• pp.1039-1055
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• 2001

불소의 적절한 활용을 통하여 미국인들의 구강건강이 확실하게 증진되었으며 수돗물의 인공적인 불소참가 사업은 지난 2000년 동안에 건강과학이 이룩한 가장 획기적인 건강관리 예방사업으로 인정되었다. 음료수에 불소를 적정량 첨가하여 치아우식증을 퇴치하기 위하여 적극적 예방책을 마련함으로써 치과의학의 과학적인 연구의 기틀을 확고히 하여 치과의학이 현대 건강과학의 지도적 위치를 확보하는 과정에 중요한 임무를 담당했다. 그러므로 미국의 중앙건강관리 및 예방 연구소는 정기적으로 불소사용과 관련된 연구 업적들에 대하여 관련 분야의 세계적인 학자들로 하여금 조리 정연하게 주기적으로 분석 검토하여 구강건강을 향상시킬수 있는 방안을 제시하기 위하여 불소사용법에 대한 안내서를 마련하고 있다. 미국 중앙 질병 관리 및 예방연구소는 평생을 불소에 관한 연구를 하고 있는 11명의 전문가들과 긴밀한 연락을 취하면서 22명의 과학자들과 함께 그 동안에 발표된 관계문헌 270개를 분석 검토하여 2년동안에 걸쳐 작성한 최근의 불소 사용 안내서를 지난 2001년 8월 17일 발표했다. 그 내용이 중요하고 한국의 치과의사들에게 큰 도움이 되리라고 확신하기 때문이다. CDC의 허락을 받고 한글판을 작성하게 되었다. 한국의 관심 있는 독자들의 이해를 돕기 위하여 더욱 자세한 내용을 알고자 하는 분들이 실무진에 참여한 연구자들 및 과학자들과 직접 접촉할 수 있도록 그들의 직책과 현재의 소속을 밝혔으며 이 안내서에 사용된 문헌 270개 참고문헌 전체를 소개한다

• Research in Community and Public Health Nursing
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• v.12 no.2
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• pp.468-481
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• 2001

The purpose of this study was to collect basic data to develop school health policy and health promotion program. This survey measured the levels of risk behaviors in six categories in a middle school students in Kyungju(n=490). The data was collected from November to December 2000. It was done using a 1999 version of the Youth Risk Behavior Survey of CDC, which was translated and make a partial modification. The major results were as follows. Many middle school students engaged in behaviors that will increase the likelihood of death or illness. 1) A high percentage of middle school students engaged in behaviors that contribute to unintentional injuries and school-related violence (42.1 -78%) 2) Students who perceived their school life are happy experienced more depression(p=.000) and Students who perceived their school and family life are so-and-so seriously considered attempting suicide(p = .000) than other subgroup. 3) In spite of they were normal weight, 14.5% of students considered themselves overweight. 4) There was significantly difference or correlation between health risk behaviors and grade, parents educational level perception of school life and performance, perception of family life and religion. Based on this results of study, it is necessary to develop school health program and school health policy to prevent health risk behaviors and improve health promotion especially considering characteristics of middle school students.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.12 no.1
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• pp.113-120
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• 2005

Purpose: To identify risk factors for surgical site infections in patients undergoing general surgery, to analyze the prolonged hospital stay and extra cost for antibiotics, and to provide basic data for control of surgical site infections. Method: Surgical site infection was defined using the definition of the CDC and the data were analyzed by $x^2$-test and unpaired t-test. Results: The prevalence of surgical site infections was 9.7%, and it was related to wound class, duration of operation, number of operations, whether the operation was an emergency, trauma, drains, preoperative stays, presence of remote infection during operative period, and previous history of recent surgery. The mean duration for post-operative stay when a surgical site infection occurred was 9.5 days and in 56.9 % of the patients the surgical site infection appeared 7 days after the operation. Post-operative stays for infected patients were 20.3 days longer than that of uninfected patients. The mean cost of antibiotics for infected patients was higher than that for uninfected patients by 561,067 won per person. Conclusion: Surgical site infection results in an increased length of stay and extra-cost, thus, hospitals need to create strategies to reduce nosocomial infections through effective infection surveillance and by considering factors related to surgical site infections.

• Journal of Microbiology and Biotechnology
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• v.10 no.1
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• pp.27-34
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• 2000

The chloroform and methanol (2;1, v/v) extract from an edible plant, Actinidia arguta Planchon, appeared to possess antitumor activity against human leukemias Jurkat T and U937 cells through inducing apoptosis. The substance in the solvent extract was purified by silica gel column chromatography, preparative TLC, and Sephadex LH-20 column chromatography. Characteristics of the substance analyzed by UV scanning analysis, $^1H$ and $^{13}C$ NMR spectra suggested that the substance belongs to the chlorophyll derivatives-like group. The $IC_{50}$ value of the chlorophyll derivative (Cp-D) determined by MTT assay was $15\mu\textrm{g}/ml$ for Jurkat, $10\mu\textrm{g}/ml$ for U937, and $11.4\mu\textrm{g}/ml$ for HL-60m and was more toxic to these leukemias than to solid tumors or normal fibroblast. In order to elucidate cellular mechanisms underlying the cytotoxicity, the effect of the Cp-D on Jurkat T cells was investigated. When cells were treated with the Cp-D at a concentration of $15\mu\textrm{g}/ml$, [3H]thymidine incorporation declined rapidly and wa undetectable in 1h. However, no significant changes were made in the cell cycle distribution of the cells by 24h. The sub-Gl peak representing apoptotic cells began to be detectable in 36h, at which time apoptotic DNA fragmentation was also detected on agarose gel electrophoresis, demonstrating that the cytotoxic effect of the Cp-D is attributable to the induced apoptosis. Under the same conditions, although the protein level of cyclin-dependent kinases such as cdc4, csk6, cdk2, and cdc2 was not significantly changed until 24h, the kinase activity of all c안 rapidly declined and reached a minimum level within 1-6h and then recovered to the initial level by 12h and sustained until 24h. These results suggest that inactivation of cdks at an inappropriate time during the cell cycle progression in jurkat T cells following a treatment with the Cp-D leads to induction of apoptotic cell death.