• Title/Summary/Keyword: Resistance Factors

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A Model to Forecast Rice Blast Disease Based on Weather Indexing (기상지수에 의한 벼도열병 예찰의 한 모델)

  • Kim Choong-Hoe;MacKenzie D. R.;Rush M. C.
    • Korean Journal Plant Pathology
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    • v.3 no.3
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    • pp.210-216
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    • 1987
  • A computer program written to predict blast occurrence based on micro climatic events was developed and tested as an on-site microcomputer in field plots in 1984 and 1985. A microcomputer unit operating on alkaline batteries; continuously monitored air temperature, leaf wetness, and relative humidity; interpreted the microclimate information in relation to rice blast development and displayed daily values (0-8) of blast units of severity (BUS). Cumulative daily BUS values (CBUS) were highly correlated with blast development on the two susceptible cultivars, M-201 and Brazos grown in field plots. When CBUS values were used to predict the logit of disease proportions, the average coefficients of determination $(R^2)$ between these two factors were 71 to $91\%$, depending on cultivar and year. This was a significant improvement when compared to 61 to $79\%$ when days were used as a predictor of logit disease severity. The ability of CBUS to predict logit disease severity was slightly less with Brazos than M-201. This is significant inasmuch as Brazos showed field resistance at mid-sea­son. The results in this study indicate that the model has the potential for future use and that the model could be improved by incorporating other variables associated with host plants and pathogen races in addition to the key environmental variables.

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Nasal Carriage of Staphylococcus aureus from Healthy Children Attending Day Care Center (어린이집 소아에서의 황색포도알균의 비강 보균율에 관한 연구)

  • Kim, Young Min;Oh, Chi Eun;Kim, So Hee;Lee, Jina;Choi, Eun Hwa;Lee, Hoan Jong
    • Pediatric Infection and Vaccine
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    • v.17 no.1
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    • pp.9-15
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    • 2010
  • Purpose : This study was performed to investigate the prevalence of Staphylococcus aureus (S. aureus) nasal carriage in Korean children attending day care centers. Methods : During September and October 2009, a survey for nasal carriage of S. aureus and methicillin-resistant S. aureus (MRSA) was conducted among children attending day care centers located in Seoul with questionnaire survey for evaluation of risk factors of acquisition of MRSA was obtained from their guardians. A culture of the anterior nares swabs using enrichment broth was executed for isolating S. aureus and oxacillin susceptibility was assessed by the disk diffusion method. Results : Out of the 428 children enrolled whose mean age was 55 months old, 163 (38.1%) were colonized with S. aureus. Of the 163 isolates, 40 (24.5%) were MRSA. The nasal carriage rate of S. aureus showed an increasing trend with increase of age. Based on the answer to the questionnaire, 9.2% and 3.6% of children had a recent history of hospitalization and surgery, respectively, and approximately 40% of children had a history of prescription of antibiotics within 1 year prior to enrollment. Of the 428 subjects, 40 (9.3%) were MRSA nasal carriers. Conclusion : S. aureus and MRSA carriage rate of children attending day care center in Korea was 38.1% and 9.3%, respectively. Continued surveillance for nasal carriage rate of S. aureus and MRSA (especially community-associated MRSA) is mandatory.

Negative impact of pretreatment anemia on local control after neoadjuvant chemoradiotherapy and surgery for rectal cancer

  • Lee, Hyebin;Park, Hee Chul;Park, Won;Choi, Doo Ho;Kim, Young-Il;Park, Young Suk;Park, Joon Oh;Chun, Ho-Kyung;Lee, Woo-Yong;Kim, Hee Cheol;Yun, Seong Hyeon;Cho, Yong Beom;Park, Yoon Ah
    • Radiation Oncology Journal
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    • v.30 no.3
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    • pp.117-123
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    • 2012
  • Purpose: Although anemia is considered to be a contributor to intra-tumoral hypoxia and tumor resistance to ionizing radiation in cancer patients, the impact of pretreatment anemia on local control after neoadjuvant concurrent chemoradiotherapy (NACRT) and surgery for rectal cancer remains unclear. Materials and Methods: We reviewed the records of 247 patients with locally advanced rectal cancer who were treated with NACRT followed by curative-intent surgery. Results: The patients with anemia before NACRT (36.0%, 89/247) achieved less pathologic complete response (pCR) than those without anemia (p = 0.012). The patients with pretreatment anemia had worse 3-year local control than those without pretreatment anemia (86.0% vs. 95.7%, p = 0.005). Multivariate analysis showed that pretreatment anemia (p = 0.035), pathologic tumor and nodal stage (p = 0.020 and 0.032, respectively) were independently significant factors for local control. Conclusion: Pretreatment anemia had negative impacts on pCR and local control among patients who underwent NACRT and surgery for rectal cancer. Strategies maintaining hemoglobin level within normal range could potentially be used to improve local control in rectal cancer patients.

Viability of Bifidobacterial Strains against Acid, Bile Acid, and Oxygen Exposure (산, 담즙산, 산소 노출에 대한 비피도박테리아의 생존에 관한 연구)

  • Lim, Kwang-Sei;Huh, Chul-Sung
    • Food Science of Animal Resources
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    • v.26 no.4
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    • pp.503-510
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    • 2006
  • Survival and stability of 19 bifidobacterial strains included 13 isolates from Korean infants against acid, bile acid and oxygen exposure were examined. Acid resistance of selected strains at pH values of 4.0, 3.0 and 2.0 was tested. Among the bifidobacterial strains tested, B. bifidum B3, B. longum D6, and B. adolescentis F1 exhibited higher viable cell counts exposed to acid whereas other strains had various results. The abilities of the strains to grow in the MRS broth containing 0.2% thioglycolic acid and 0.2% oxgall were tested and the tolerance of B. bifidum B3 and B. longum D6 to bile acid were higher than that of others. Even though in same species, the tolerance of tested strains to bile acid were variable. Stabilities of tested strains to oxygen exposure were variable and B. bifidum and B. longum strains showed relatively higher viable cell counts after 48 hours exposure to aerobic incubation. These results demonstrated that the survival and stability of bifidobacterial strains to acid, bile acid, and oxygen exposure were variable and strain-dependent. Due to their tolerant ability to environmental factors like acid, bile acid, and oxygen, B. bifidum B3 and B. longum D6 had good potential properties as probiotic cultures and may be useful for industrial application.

A Linkage between NGOs and Government in Resettlement Assistance for Defecting North Korean Residents (NGO와 정부의 연결관계의 모색: 탈북자 정착지원의 경우)

  • Lee, Ki-Young
    • Korean Journal of Social Welfare
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    • v.37
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    • pp.327-355
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    • 1999
  • This study analyzes the relationship between NGOs and government assisting defecting North Korean residents and seeks a desirable model of a linkage between the two sectors. The factors used in this study for an analysis of the relationship between NGOs and government are frequency and direction of interaction between NGOs and government, government's acceptance or resistance of institutional pluralism. the degree of formality of the relationship, and the relative power balance in the relationship. Also, Coston's typology(l998) of NGO-government relationships is applied for the analysis. Results of the analysis indicates that, in resettlement assistance for defecting North Korean residents, Korean NGOs and government have a cooperative relationship at minimal level, which means that there is a low linkage, informal relationship, and asymmetrical power-relationship between the two sectors. Also, government's acceptance of institutional pluralism seems to be superficial and a tendency of one-way direction of interaction is identified. Based on the findings, this study suggests a more collaborative relationship or partnership between NGOs and the government to arrange more effective assistance programs and activities. Discussion of some controversial issues related to achieving the collaboration and suggestion of a possible model of linking government to the NGOs are followed in conclusion.

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A Study on the Optimal Design of Soft X-ray Ionizer using the Monte Carlo N-Particle Extended Code (Monte Carlo N-Particle Extended 코드를 이용한 연X선 정전기제거장치의 최적설계에 관한 연구)

  • Jeong, Phil hoon;Lee, Dong Hoon
    • Journal of the Korean Society of Safety
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    • v.32 no.2
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    • pp.34-37
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    • 2017
  • In recent emerging industry, Display field becomes bigger and bigger, and also semiconductor technology becomes high density integration. In Flat Panel Display, there is an issue that electrostatic phenomenon results in fine dust adsorption as electrostatic capacity increases due to bigger size. Destruction of high integrated circuit and pattern deterioration occur in semiconductor and this causes the problem of weakening of thermal resistance. In order to solve this sort of electrostatic failure in this process, Soft X-ray ionizer is mainly used. Soft X-ray Ionizer does not only generate electrical noise and minute particle but also is efficient to remove electrostatic as it has a wide range of ionization. X-ray Generating efficiency has an effect on soft X-ray Ionizer affects neutralizing performance. There exist variable factors such as type of anode, thickness, tube voltage etc., and it takes a lot of time and financial resource to find optimal performance by manufacturing with actual X-ray tube source. MCNPX (Monte Carlo N-Particle Extended) is used for simulation to solve this kind of problem, and optimum efficiency of X-ray generation is anticipated. In this study, X-ray generation efficiency was measured according to target material thickness using MCNPX under the conditions that tube voltage is 5 keV, 10 keV, 15 keV and the target Material is Tungsten(W), Gold(Au), Silver(Ag). At the result, Gold(Au) shows optimum efficiency. In Tube voltage 5 keV, optimal target thickness is $0.05{\mu}m$ and Largest energy of Light flux appears $2.22{\times}10^8$ x-ray flux. In Tube voltage 10 keV, optimal target Thickness is $0.18{\mu}m$ and Largest energy of Light flux appears $1.97{\times}10^9$ x-ray flux. In Tube voltage 15 keV, optimal target Thickness is $0.29{\mu}m$ and Largest energy of Light flux appears $4.59{\times}10^9$ x-ray flux.

Mechanical and Electrical Properties of Electrospun CNT/PVDF Nanofiber for Micro-Actuator (미세-작동기를 위한 전기방사 CNT/PVDF 나노섬유 기반의 탄소 복합재의 기계적 및 전기적 특성 평가)

  • Gu, Ga-Young;Wang, Zuo-Jia;Kwon, Dong-Jun;Park, Joung-Man
    • Composites Research
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    • v.26 no.1
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    • pp.14-20
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    • 2013
  • The electrospun PVDF containing CNT was made for fabricating materials of the actuator. The electrochemical and their actuating movement were evaluated for the actuator performance in the electrochemical environment. The actuator (which was fabricated by electrospinning) had some advantages, i.e., good dispersion and flexible properties. In the electrospinning process, the final product would have different forms based on different essential factors. In this work, electrospun nanofibers were aligned by using the drum-type collector, and the morphology was identified via the field emission-scanning electron microscope (FE-SEM). The uniform dispersion of CNT in PVDF nanofiber was observed by electron probe X-ray micro-analysis (EPMA) test. The results of tensile strength and electrical resistivity provided the aligned state. The electrospun CNT/PVDF nanofiber sheet on the aligned direction showed better mechanical and electrical properties than the case of the vertically-aligned direction. The efficiency and electrical capacities of electrospun CNT/PVDF nanofiber sheets were compared with the cast PVDF sheet for actuator application. Electrospun CNT/PVDF nanofiber sheet exhibited much better the case of actuator performance than cast neat PVDF actuator, due to the excellent electrical connecting areas.

Sensitivity of Gastric Cancer Cells to Chemotherapy Drugs in Elderly Patients and Its Correlation with Cyclooxygenase-2 Expression

  • Qiu, Zhen-Qin;Qiu, Zhen-Rong
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3447-3450
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    • 2015
  • Objective: To explore the sensitivity of gastric cancer cells to chemotherapy drugs in elderly patients and its correlation with cyclooxygenase-2 (COX-2) expression in cancer tissue. Materials and Methods: Forty-three elderly patients with gastric cancer (observation group) and 31 young patients with gastrointestinal tumors (control group) who were all diagnosed by pathology and underwent surgery in the 89th Hospital of Chinese People's Liberation Army were selected. Drug sensitivity testing of tumor cells in primary culture was carried out in both groups using a methyl thiazolyl tetrazolium (MTT) method, and the expression of COX-2 and the factors related to multi-drug resistance (MDR) in cancer tissue were assessed by immunohistochemistry. Results: The inhibition rates (IR) of vincristine (VCR), 5-fluorouracil (5-FU), oxaliplatin (L-OHP), mitomycin (MMC) and epirubicin (eADM) on tumor cells in the observation group were dramatically lower than in the control group, with statistical significance (P<0.05 or P<0.01). The positive rates of COX-2, glutathione s-transferase-${\pi}$ (GST-${\pi}$) and P glycoprotein (P-gp) expression in cancer tissue in the observation group were all higher than in control group (P<0.05), while that of DNA topoisomerase $II{\alpha}$ ($TopoII{\alpha}$) expression lower than in the control group (P<0.01). In the observation group, COX-2 expression in cancer tissue had a significantly-positive correlation with GST-${\pi}$ and P-gp (r=0.855, P=0.000; r=0.240, P=0.026), but a negative correlation with $TopoII{\alpha}$ (r=-0.328, P=0.002). In the control group, COX-2 expression in cancer tissue was only correlated with P-gp positively (r=0.320, P=0.011). Bivariate correlation analysis displayed that COX-2 expression in cancer tissue in the observation group had a significantly-negative correlation with the IRs of 5-FU, L-OHP, paclitaxel (PTX) and eADM in tumor cells (r=-0.723, P=0.000; r=-0.570, P=0.000; r=-0.919, P=0.000; r=-0.781, P=0.000), but with hydroxycamptothecine (HCPT), VCR and 5-FU in the control group (r=-0.915, P=0.000; r=-0.890, P=0.000; r=-0.949, P=0.000). Conclusions: Gastric cancer cells in elderly patients feature stronger MDR, which may be related to high COX-2 expression.

Effect of Hormone Therapy on Long-term Outcomes of Patients with Human Epidermal Growth Factor Receptor 2-and Hormone Receptor-Positive Metastatic Breast Cancer: Real World Experience in China

  • Du, Feng;Yuan, Peng;Wang, Jia-Yu;Ma, Fei;Fan, Ying;Luo, Yang;Xu, Bing-He
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.3
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    • pp.903-907
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    • 2015
  • Background: Among human epidermal growth factor receptor 2 (HER2)-positive breast cancer, more than half are also hormone receptor (HR)-positive. Although HR is a predictive factor for the efficacy of hormone therapy, there are still some uncertainties in regard to the effects on patients with HR-positive and HER2-positive metastatic breast cancers due to the potential resistance to hormone therapy caused by co-expression of HR and HER2. There are no clinical trials directly comparing the efficacy of hormonal therapy with chemotherapy. Materials and Methods: To examine the real-world effect of hormone therapy on patients with HR-positive and HER2-positive metastatic breast cancers, a cross-sectional study of a representative sample of the Chinese population was conducted. The study included 113 patients who received first-line and second-line palliative treatment between 2005 and 2010 in the Cancer Institute and Hospital, Chinese Academy of Medical Science. The effect of hormone therapy on overall survival (OS) was studied. Results: The patients who received hormone therapy (n=51) had better overall survival in contrast to those who received chemotherapy with anti-HER2 therapy (n=62) in first- or second-line treatment. The difference was of borderline statistical significance (51.8m vs 31.9m, p=0.065). In addition, the effect of hormone therapy did not differ significantly with other prognostic factors, including age (${\leq}50$ years or >50 years), disease free survival (${\geq}2$ years or < 2 years) and site of metastasis (visceral or bone/soft tissue). On multivariate analysis, administration of hormone therapy was associated with a trend toward a favorable prognosis (p=0.148, HR=0.693, 95%CI 0.422-1.139). Age more than 50 years was the sole independent harmful prognostic factor (p<0.001, HR=2.797, 95%CI 1.676-4.668). Conclusions: Our data suggest that hormonel therapy may improve outcomes of the patients with ER-positive and HER2-positive metastatic breast cancer.

Study on inhibition effects on metastasis and recurrence of Traditional Herb Medicine(THM) (한약의 전이재발억제 효과에 관한 연구)

  • Lee, Sang-Seob;Yoo, Hwa-Seung;Cho, Jung-Hyo;Son, Chang-Kyu;Lee, Yeon-Weol;Cho, Chong-Kwan
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.9 no.1
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    • pp.75-87
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    • 2003
  • Recently, the occurrence and death rates of cancer have increased rapidly. Metastasis and recurrence is the most important factor of death from cancer. So inhibition of recurrence and metastasis can increase the cure rate of cancer disease. At the basic chinese traditional medicine(TCM), there are a lot of theory related to neoplasm treatment. The metastasis and recurrence of neoplasm was the basis of yudu(餘毒) on remained neoplasm cell and stagnation of blood, thermotoxo, phlegm, asthenia of healthy enerngy and stagnation of vital energy. The principles therapy of neoplasm on metastasis and recurrence was based on knowledge of the method of support the healthy energy and strengthen the body resistance, promote blood circulation to remove blood stasis, clear away heat and toxic materials, dissipate phlegm and disperse the accumulation of evils. But the major clinical features of neoplasm was to be considered in developing a treatment plan include (1) distinguish between clinical and pathologic staging - acute and chronic, (2) classification of pathologic pattern, and (3) distingction of body situation : for examples asthenia - sthenia etc. It was most important to distinguish between supporting the healthy and eliminating the evil factors and to treat differently at the root and the branch cause of a neoplasm. This paper's results indicate that identification and effective use of THM can inhibite netastasis and recurrence and then it will help increasing survival rate. Also as BioTechnology(BT) has developed rapidly nowadays, as genes related to cancer have revealed. So it will give rise to the development of searching the mechanism of herb medicines which have inhibition effects of metastasis and recurrence.

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