• Korean Journal of Microbiology
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• v.52 no.4
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• pp.428-436
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• 2016

The emergence of antibiotic-resistant bacteria has been increased and become a public health concern worldwide. Many bacterial infections can be sequentially treated with different types of antibiotics. Thus, this study was designed to evaluate the changes in survival, antibiotic susceptibility, mutant frequency, ${\beta}$-lactamase activity, biofilm formation, and gene expression in Klebsiella pneumoniae after exposure to sequential antibiotic treatments of ciprofloxacin and meropenem. Treatments include control (CON; no addition), 1/2 MIC ciprofloxacin addition (1/2CIP), 2 MIC ciprofloxacin addition (2CIP), initial 1/2 MIC ciprofloxacin addition followed by 1/2 MIC meropenem (8 h-incubation) and 2 MIC ciprofloxacin (16 h-incubation) (1/2CIP-1/2MER-2CIP), initial 1/2 MIC ciprofloxacin addition followed by 1/2 MIC meropenem (8 h-incubation) and 2 MIC meropenem (16 h-incubation) (1/2CIP-1/2MER-2MER), and initial 1/2 MIC ciprofloxacin addition followed by 2 MIC ciprofloxacin(8 h-incubation) and 2 MIC meropenem(16 h-incubation) (1/2CIP-2CIP-2MER). No growth of K. pneumoniae was observed for the 2CIP throughout the incubation period. The numbers of planktonic cells varied with the treatments (7~10 log CFU/ml), while those of biofilm cells were not significantly different among treatments after 24-h incubation, showing approximately 7 log CFU/ml. Among the sequential treatments, the least mutant frequency was observed at the 1/2CIP-1/2MER-2CIP (14%). Compared to the CON, 1/2CIP-2CIP-2MER decreased the sensitivity of K. pneumoniae to piperacillin, cefotaxime, and nalidixic acid. The highest ${\beta}$-lactamase activity was 22 nmol/min/ml for 1/2CIP-1/2MER-2CIP, while the least ${\beta}$-lactamase activity was 6 nmol/min/ml for 1/2CIP-2CIP-2MER. The relative expression levels of multidrug efflux pump-related genes (acrA, acrB, and ramA) were increased more than 2-fold in K. pneumoniae exposed to 1/2CIP-1/2MER-2MER and 1/2CIP-2CIP-2MER. The results suggest that the sequential antibiotic treatments could change the antibiotic resistance profiles in K. pneumoniae.

• Journal of Gastric Cancer
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• v.9 no.4
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• pp.231-237
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• 2009

Purpose: The aim of this study was to evaluate the significance of palliative gastrojejunostomy for treating patients with unresectable stage IV gastric cancer, and as compared with laparotomy for treating patients with incurable gastric cancer. Materials and Methods: We retrospectively studied 167 patients who could not undergo resection without obstruction at Korea University Hospital from 1984 to 2007. They were classified into two groups, one that underwent palliative gastrojejnostomy (the bypass group, n=62) and one that underwent explo-laparotomy (the O&C group, n=105), and the clinical data and operative outcomes were compared according to the groups. Results: For the clinical characteristics, there were no differences of age, gender and liver metastasis between the bypass group and the explo-laparotomy group, but there was a significant different for the presence of peritoneal metastasis (P=0.001). There was no difference between two groups for the postoperative mortality and morbidity. For the postoperative outcomes, the duration of the hospital stay (29.25 vs 16.67) and the frequency of re-admission were not different, but the median overall survival (4.3 months vs. 3.4 months, respectively) was significantly different. By multivariate analysis, the presence of peritoneal metastasis was identified as the independent prognostic factor for incurable gastric cancer. Conclusion: A prophylactic bypass procedure is not effective for improving the quality of life and prolonging the life expectancy of unresectable stage IV gastric cancer patients without obstruction.

• Korean journal of applied entomology
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• v.57 no.2
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• pp.77-85
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• 2018

We surveyed 281 sites of tropical plants and 666 sites of fruit plants for three years (2015~2017) on Pseudococcus longispinus and Pseudococcus orchidicola which have not been surveyed domestically. In tropical plants, P. longispinus were found at 34 sites, while P. orchidicola were found at 87 sites. However, both species were not found in fruit plants. The developmental characteristics of P. longispinus and P. orchidicola were investigated under various temperatures. The female nymph of P. longispinus did not develop at $14^{\circ}C$ and the developmental period was the longest at $16^{\circ}C$ for 361.4 days and the shortest at $32^{\circ}C$ for 39.0 days. The longevity of female adult of P. longispinus was the shortest at $28^{\circ}C$ as 71.7 days. The number of offspring was highest at 177.7 at $32^{\circ}C$. The female nymph of P. orchidicola did not develop at $12^{\circ}C$. However, the developmental period was the longest at $14^{\circ}C$ for 184.9 days and the shortest at $28^{\circ}C$ for 21.5 days. The longevity of female adult of P. orchidicola was the shortest at 51.5 days at $28^{\circ}C$. The number of offspring was highest at 143.8 at $28^{\circ}C$. The net reproductive rate ($R_0$) and intrinsic rate of increase ($r_m$) of P. longispinus were 162.3 and 0.127 at $32^{\circ}C$, respectively. The $R_0$ and $r_m$ of P. orchidicola were 98.3 and 0.139 at $28^{\circ}C$, respectively. These results suggest that the optimum temperature of P. longispinus and P. orchidicola was $32^{\circ}C$ and $28^{\circ}C$, respectively. Therefore, we guess that they can never be able to survive the winter of Korea.

• Korean journal of applied entomology
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• v.57 no.3
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• pp.127-135
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• 2018

Climate change can affect variables related to the life cycle of insects, including growth, development, survival, reproduction and distribution. As it encourages alien insects to rapidly spread and settle, climate change is regarded as one of the direct causes of decreased biodiversity because it disturbed ecosystems and reduces the population of native species. Hypera postica caused a great deal of damage in the southern provinces of Korea after it was first identified on Jeju lsland in the 1990s. In recent years, the number of individuals moving to estivation sites has concerned scientists due to the crop damage and national proliferation. In this study, we examine how climate change could affect inhabitation of H. postica. The MaxEnt model was applied to estimate potential distributions of H. postica using future climate change scenarios, namely, representative concentration pathway (RCP) 4.5 and RCP 8.5. As variables of the model, this study used six bio-climates (bio3, bio6, bio10, bio12, bio14, and bio16) in consideration of the ecological characteristics of 66 areas where inhabitation of H. postica was confirmed from 2015 to 2017, and in consideration of the interrelation between prediction variables. The fitness of the model was measured at a considered potentially useful level of 0.765 on average, and the warmest quarter has a high contribution rate of 60-70%. Prediction models (RCP 4.5 and RCP 8.5) results for the year 2050 and 2070 indicated that H. postica habitats are projected to expand across the Korean peninsula due to increasing temperatures.

• Tuberculosis and Respiratory Diseases
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• v.40 no.3
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• pp.283-291
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• 1993

Background: Long-term low flow oxygen therapy not only increases survival, but also improves the quality of life in patients with chronic obstructive pulmonary disease (COPD) with chronic hypoxemia. For the assessment and improvement of the status of home oxygen therapy, we analyzed clinical experience of 26 patients who have been administered low flow oxygen at home. Method: Twenty-six patients (18 men and 8 women) who have been received long-term oxygen therapy (LTOT) at home were examined. We reviewed physical characteristics, clinical history, pulmonary function test, ECG, arterial blood gas analysis, hemoglobin and hematocrit, types of oxygen devices, inhalation time per day, concentration of administered $O_2$, duration of $O_2$ therapy, and problems in the home oxygen therapy. Results: The underlying diseases of patients were COPD 14 cases, far advanced old pulmonary tuberculosis 9 cases, bronchiectasis 2 cases, and idiopathic pulmonary fibrosis 1 case. The reasons for LTOT at home were noted for cor pulmonale 21 cases, for dyspnea on exertion and severe ventilatory impairment 4 cases, and for oxygen desaturation during sleep 1 case. The mean values of aterial blood gas analysis before home oxygen therapy were $PaO_2$ 57.7 mmHg, $PaCO_2$ 48.2 mmHg, and $SaO_2$ 87.7%. And the mean values of each parameters in the pulmonary function test were VC 2.05 L, $FEV_1$ 0.92 L, and $FEV_1$/FVC% 51.9%. Nineteen patients have used oxygen tanks as oxygen devices, 1 patient oxygen concentrator, 2 patients oxygen tank and liquid oxygen, and other 4 patients oxygen tank together with portable oxygen. The duration of oxygen therapy was below 1 year in 3 cases, 1~2 years in 15 cases, 3~5 years in 6 cases, 9 years in 1 case, and 10 years in 1 case. All patients have inhalated oxygen with flow rate less than 2.5 L/min. And only 10 patients have inhalated oxygen more than 15 hours per day, but most of them short time per day. Conclusion: For the effective oxygen administration, it is necessary that education for long-term low flow oxygen therapy to patients, their family and neighbor should be done, and also the institutional backup for getting convenient oxygen devices is required.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.329-336
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• 2014

As an abiotic stress, chilling stress is one of the major factors limiting plant growth and increasing susceptibility to pathogens. Therefore, enhancing stress tolerance in plants is an important strategy for their survival under unfavorable environmental conditions. The objective of this study was to determine the effects of the exogenous application of salicylic acid (SA) or nitric oxide (NO) on chilling tolerance in pepper seedlings. Pepper (Capsicum annuum L. 'kidaemanbal') seedlings were grown under normal growing conditions ($20/25^{\circ}C$, 15 hours photoperiod, $145{\pm}5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, fluorescence lamps) for 23 days after transplanting. The solution (3 mL) of 1 mM SA and 0.3 mM NO with surfactant triton 0.1% were sprayed two times a week, respectively. Right after the completion of chemical application, seedlings were subjected to chilling condition at $4^{\circ}C$ for 6 hours under dark condition and then the seedlings were recovered at the normal growing conditions for 2 days. In order to assess plant tolerance against chilling stress, growth characteristics, chlorophyll fluorescence (Fv/Fm), and membrane permeability were determined after chilling stress imposition. Total phenolic concentration and antioxidant capacity were measured during the whole experimental period. Disease incidence for pepper bacterial spot and wilt was also analyzed. Pepper seedlings treated with SA or NO were maintained similar dry mass ratio, while the value in control increased caused by chilling stress suggesting relatively more water loss in control plants. Electrolyte leakage of pepper seedlings treated with SA or NO was lower than that of control 2 days after chilling treatment. Fv/Fm rapidly decreased after chilling stress in control while the value of SA or NO was maintained about 0.8. SA increased higher total phenolic concentration and antioxidant capacity than NO and control during chemical treatment. In addition, increase in total phenolic concentration was observed after chilling stress in control and NO treatment. SA had an effect on the reduction of bacterial wilt in pepper seedlings. The results from this study revealed that pre-treatment with SA or NO using foliar spray was effective in chilling tolerance and the reduction of disease incidence in pepper seedlings.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.210-218
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• 2012

This study was carried out to analyze the vegetation properties, soil characteristics and ordination of Bletilla striata population in South Korea. The $Bletilla$ $striata$ population was classified into $Juniperus$ $rigida$ dominant population, $Rhododendron$ $yedoense$ var. $poukhanense$ dominant population, $Rhus$ $javanica$ dominant population, $Bletilla$ $striata$ typical population. $Bletilla$ $striata$ were mainly distributed along the coast of south-western regions of the Korean penninsula and it's population was located at an elevation of 4m to 40m. In the study sites, soil organic matter, total nitrogen, available phosphate, exchangeable potassium, exchangeable calcium, exchangeable magnesium, cation exchange capacity and soil pH were 2.38-6.70%, 0.09-0.27%, 1.81-6.85mg/kg, 1.08-1.72$cmol^+/kg$, 3.56-7.71$cmol^+/kg$, 1.52-3.21$cmol^+/kg$, 5.28-16.95$cmol^+/kg$ and 4.60-6.01 respectively. $Rhododendron$ $yedoense$ var. $poukhanense$ dominant population was found in the steep sloped area that has high percentage of organic matter, total nitrogen, cation exchange capacity and pH than other populations. $Rhus$ $javanica$ dominant population was found in the gentle sloped area that has less percentage of organic matter, total nitrogen, cation exchange capacity and pH. $Juniperus$ $rigida$ dominant population and $Bletilla$ $striata$ typical population were found in the medium sloped area that has medium percentage of organic matter, total nitrogen, cation exchange capacity and pH. Current status of $Bletilla$ $striata$ habitats is very vulnerable with local development constantly threatening the species' survival. Thus, concrete conservation plans to protect natural habitats should be set up as soon as possible.

• Journal of Sericultural and Entomological Science
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• no.11
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• pp.31-44
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• 1970

This experiment is conducted fer method cf bring to perfectly from defective cutting sapling 25 a production method of sapling which is to substitute for conventional graf ting. 1. In green wood cutting root comes out after 15 days of cutting with nearly straight development of root system; after 40 days of cutting, roots with total length of 1119 mms 43 roots, and 5.4 grs a root in total weight obtained. 2. Survival percentage of green wood cutting ranges between 56％ and 90％, average 73％ of that and it varies with natural characteristics of varietes. The results show variety of Gaeryang-Suban and Iljiroe with 80％ as a best ones in contrast with the variety of Shipyung. 3. The varietics or Gaeryang-Suban. Iljiroe, Suwon-Sang No.4, Rosang makes of much more roots than Yongchonchuwoo and Shipyung do. 4. Root ability made good number of roots commercially, when cutting is conducted soaking in 0.01 ％ NAA solution or 0.02％ NAA solution for 2 or 3 seconds as a chemical promoter. 5. Economical measures for increase of scion adapted 1) 2 scions from a green wood 50 cm long should be taken and basal pan of scion at its middle portion should be cut right under the node. 2) Scions below 50cm long may be used. Small scions or growthceased shoots h3ve also considerable root ability enough to be used. 3) Thus far, up 100,000 scions might be produced in 10 a. 6. We can find number of root increased, when cutting the opposite side in obliquity manner at 450. 7. When 110,000 saplings in 10 a. for the production of bring to perfectly from defective cutting sapling planted, quality of stocks does not go to bad condition without any obstacles in practical use. 8. Although the times or grafting delayed until middle of July, quality of sapling goes just a little down. Grafting may be conducted from early June to middle of July separately in several times, and the green wood of prunned mulberry in spring is available for a scion after end of June. 9. 10 grs weight of defective cutting sapling makes 95％ of complete sapling, otherwise 5 or 10 grs in weight of one becomes 80％ of complete sapling with its quality as similar as grafted one. 10. When the sapling planted, its branches should be cut, leaving 3 or 4 buds at the bottom of new branches. 11. In view of economical stand point, production cost of bring to perfectly from defective cutting sapling obtains 52％ of grafting cost.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.1
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• pp.8-15
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• 1992

An experiment was conducted to find out effect of soil water condition on shoot and root growth and P, K uptake by soybean plants. Soybean plants were grown under different soil water table levels, 20cm, 40cm and 60cm below the soil surface using minirhizotron with 20cm in diameter, and well irrigated and water stressed conditions using 1/2000a Waganer pots. Three soybean plants, Paldal culfivar, were grown and sampled at the early growing period, 37 days after planting, and at the harvesing period, 115 days after planting. Shoot and root growth were restricted by water stresed condition and by excessive soil water condition with the 20cm water table. Little difference in shoot and root growth were found between well irrigated condition and 40cm or 60cm water table conditions. The P and K contents in shoot under water stressed condition were higher than well irrigated condition at the early growing period but reversed at later harvesting period. The dry weight and length of roots were more severely restricted by water stress than those of shoots. Root morphological difference was found by anatomical observation. Normal cortex was developed under the well irrigated condition, while abnormal cortex with aerenchyma formed by lysis under excessive water conditions of 20 or 40cm water talbes. Aerenchyma was formed at outer skirt of pericycle. Role of formation of aerenchyma of soybean roots might be an adaptation to excessive soil water condition and possibly related to survival of soybean roots growing under near flooding condition on dikes of paddy lands.

• Journal of Chest Surgery
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• v.43 no.5
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• pp.475-481
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• 2010

Background: We evaluated mid-term results of mitral annuloplasty using a flexible band and a completely rigid ring for mitral valve repair in patients with degenerative mitral regurgitation (MR). Material and Method: From January 2004 to September 2008, 71 patients (M:F=36:35, $55{\pm}13$ years) underwent mitral valve repair with mitral annuloplasty for degenerative MR. Ring annuloplasty was done using a Cosgrove-Edwards flexible band (Group I, n=43) or a Carpentier-Edwards classic ring (Group II, n=28). There were no differences in preoperative characteristics of the participants. Average duration of follow-up was 36 months (range: 2~69 mos). Result: There was no in-hospital mortality. Postoperative morbidity, which included atrial fibrillation (n=7) and low cardiac output syndrome (n=5) in groups I and II were similar. There was one late death in group II. The proportion exhibiting freedom from recurrent mitral regurgitation ($\geq$moderate) at 4 years in Groups I and II were, respectively, 94.5 and 91.8%, (p=0.695). Left ventricular ejection fraction decreased in the early postoperative period ($7{\pm}2$ days) and recovered by last follow-up ($25{\pm}16$ mos; p=0.002). The pattern was similar in groups I and II (p=0.905). Re-operation was performed in 3 patients (1 in Group I and 2 in Group II, p=0.316). Four-year event-free survival (free of adverse valve-related events) was 95.2% for Group I and 92.6% for Group II; this difference was not significant, p=0.646). Conclusion: The type of technique used in mitral annuloplasty to repair the mitral valve repair after degenerative MR did not affect mid-term clinical and functional results.