• Korean Journal of Soil Science and Fertilizer
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• v.17 no.4
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• pp.389-398
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• 1984

The effect of N forms ($NO_3{^-}-N$, $NH_4{^+}-N$) and concentrations (4, 8, $16meq/{\ell}$) which were changed at head formation stage on the tip-burn incidence of chinese cabbage was studied under the three levels (0, 8, 16 meq/l) of Ca. All of the plants grown on $NH_4{^+}-N$ showed the symptoms of tip-burn and low yields regardless of Ca levels. Roots of plants grown on $NH_4{^+}-N$ were severely damaged. The pH of the leachate from $NH_4{^+}-N$ pot was decreased to below pH 5. Plants which had been grown on $NH_4{^+}-N$ before the head formation stage, but changed to $NO_3{^-}-N$ were recovered from abnormal growth. But, the reverse showed the tip-burn symptoms. $NH_4{^+}-N$ treatments increased the T-N contents, but lowered K and Ca contents of inner leafblades. Icreased applications of Ca did not affect the T-N and K contents of the inner leafblades. $NH_4{^+}-N$ suppressed Ca translocation into the inner leaves from outer leaves after the head formation stage, but $NO_3{^-}-N$ accelarated it. Ca contents were much lower in leaves showing tip-burn symptoms than in healthy leaves. Internal rot which is a tip-burn symptom occuring after head formation were noted in plants applied with high concentration of $NO_3{^-}-N$ both before and after the head formation stage. Ca contents correlated well with the rates of Ca application, but there was no correlation between ca conents and internal rot incidence. Chinese cabbage tip-burn is not caused by Ca deficiency, as is commonly believed, but rather by the water stress (95% water contents in $NO_3{^-}$-fed plants, 91% in $NH_4{^+}$-fed plants) resulting from root damage caused by ammonium toxicity. Internal rot is also caused by excess applications of nitrogen, and is unaffected by calcium levels.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.380-386
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• 2011

Tip burn has been reported as one of the most serious physiological disorder in Chinese chives (Allium tuberosum Rottl.) cultivated in plastic film house. In this study, a physiography and chemical properties of 132 plastic film house soils were investigated to elucidate factors affecting tip burn symptom. Also influence of soil properties on tip burn was statistically determined by path analysis and association analysis including a chi-square test or logistics analysis. Probability distribution of inorganic aqueous species, such as ammonia (g) was calculated using MINTEQ program. Soil order and chemical properties, especially pH, exchangeable calcium and inorganic nitrogen, showed a significant relationship with tip burn of Chinese chives. Tip burn symptoms occur mainly in an alkaline soil classified as Alfisols. Result of linear regression and path analysis exhibited that formation of ammonia (g) from soil solution depend upon soil pH and were associated with ammonium resulting from soil organic matter or nitrate. These results indicate that tip burn symptom of Chinese chives is directly affected by ammonia gas originated from alkaline soil condition.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.549-555
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• 2010

Here we focused on tip-burn and blossom-end rot (BER) symptoms in the tomato plants expressing the constitutively active form of $Ca^{2+}/H^+$ antiporter (sCAX1) and/or a Ca-binding protein (calreticulin, CRT) genes during their whole growth period. Conclusively we demonstrated that CRT is able to suppress the tip-burn and BER symptoms that were induced by sCAX1. Under poor nutrition condition, tomato plants overexpressing sCAX1 showed severe necrotic collapses in both roots and shoot polar tissues, which are in accordance with $Ca^{2+}$ deficient symptoms frequently observed in an agricultural cultivation of tomato. Reciprocal grafting trials using sCAX1 and wild type plants revealed that the tip-burn symptom by sCAX1 overexpression is not caused by hindrance of $Ca^{2+}$ uptake from soil. We constructed CRT overexpressing transgenic tomatoes, and crossed them with sCAX1 transgenic plants to investigate the effects of CRT on the symptoms of sCAX1 transgenic plants. Co-expression of sCAX1 and CRT significantly suppressed the $Ca^{2+}$ deficient symptoms of sCAX1 transgenic plants. Those results suggest the model that $Ca^{2+}$ homeostasis disturbed by the overexpression of sCAX1 may be suppressed by the co-expression of CRT.

• Korean Journal of Clinical Pharmacy
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• v.12 no.2
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• pp.55-64
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• 2002

Infection is one of the main causes of death in severe burn cases. Treatment of burn patient includes fluid therapy, wound care, complication care and antibiotic therapy for infection. The objective of this study was to evaluate the characteristics of burn patients, the type of isolated microorganisms and their susceptibility, and the systemic antibiotics used. This is a retrospective study of 126 burn patients treated in the Hanil General Hospital from January to December 2001. Total 126 patients were assessed with 103 males and 23 females (4.5:1). The average age was $34.8\pm17.6$ years and extent of burn $(TBSA\;\%)\;was\;24.5\pm18.5\%$. The burn was caused by electric accident $(47.6\%),\;flame\;(29.4\%),\;scalding\;(21.4\%),\;and\;chemical\;accident\;(1.6\%)$. The overall mortality rate was $7.14\%$ (9/126) and all expired patients were males. The average age (n=9) was $48.8\pm15.6$ yrs and the extent of burn was $65.0\pm19.0\%$. The causes of death were due to flame burns $(13.5\%)$ and electric burns $(6.7\%)$. The culture sites of the isolated microorganisms were wound $(85.3\%),\;sputum\;(9.3\%),\;urine\;(2.7\%),\;blood\;(1.3\%)\;and\;catheter\;tip\;(1.3\%)$. Pseudomonas aeruginosa was the most commonly isolated organism $(35\%)$, followed by Staphylococcus aureus $(30.1\%)$, Acinetobacter baumannii $(21.4\%)$, and Enterococcus spp. $(3.9\%)$. The number of systemic antibiotics administered was 4.5. The classes of the antibiotics were cephalosporines $(38.5\%)$, aminoglycosides $(31\%)$, quinolones $(13.3\%)$, penicillins $(12.4\%)$, carbapenems $(2.4\%)$, glycopeptides $(1.9\%)$ and others $(0.6\%)$. In conclusion, most of burn patients had wound infection and Pseudomonas aeruginosa was the most commonly isolated organism. Cephalosporins were administered the most frequently among antibiotics.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.115-122
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• 2019

Foliar fertilization of carbonated water during lettuce hydroponic cultivation was increased photosynthetic rate and stomatal conductance as higher carbon dioxide concentration of carbonated water The higher the carbon dioxide concentration in the carbonated water was better growth of lettuce. However, the carbon dioxide concentration of 500 ppm and 700 ppm in the carbonated water was increased the tip-burn occurrence, and the yield was higher in the 300 ppm. the carbon dioxide concentration of 300 ppm in the carbonated water was lower in the fresh weight but increased yield resulted in the lower of the tip-burn occurrence The high temperature limits for growth were 32℃ in the control, 33℃ in the 300ppm and 34℃ in the 500 ppm according to analyze chlorophyll fluorescent Fo. The high temperature tolerance in lettuce increased approximately 4℃ by foliar fertilization treatments of carbonated water under this experiment conditions. Also the activity of SOD(superoxide dismutase), the antioxidant enzyme, was higher with high carbon dioxide concentration of the carbonated water.

• Journal of Bio-Environment Control
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• v.8 no.2
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• pp.115-124
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• 1999

This study was conducted to determine the optimum root zone environment condition and proper nutrient management system for lettuce in hydroponics. For the root zone environment condition, several level of pH and electrical conductivity (EC) were treated respectively. Though all the level of pH 4 to pH 8, except pH 3, performed better growth without any visible physiological disorder, the optimum pH of the nutrient solution for lettuce production was pH 5.5 to 6.0. The optimum ionic strength of the solution was EC 1.2 to 1.6 mS $cm^{-1}$ / because higher nutrient level caused tip burn symptom by calcium deficiency. Considering the above results, it is concluded that lettuce can be efficiently mass-produced through the optimum root zone environment.

• Plant Biotechnology Reports
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• v.4 no.1
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• pp.15-21
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• 2010

The over-expression of Arabidopsis CAX1 and CAX2 causes transgenic tomato plants to reveal severe $Ca^{2+}$ deficiency-like symptoms such as tip-burn and/or blossom end rot, despite there being sufficient $Ca^{2+}$ in each plant part. To correct the symptoms and to moderately enhance the calcium level, a worldwide vegetable tomato was genetically engineered using a modified Arabidopsis cation/$H^+$ antiporter sCAX2A, a mutant form of Arabidopsis CAX2. Compared with the wild-type, the sCAX2A-expressing tomato plants demonstrated elevated $Ca^{2+}$ levels in the fruits with almost no changes in the levels of $Mn^{2+}$, $Cu^{2+}$, and $Fe^{2+}$. Moreover, expression of sCAX2A in tomato plants did not show any significant alterations in their morphological phenotypes. Unlike 35S::sCAX1 construct, sCAX2A antiporter gene driven by 35S promoter can be a valuable tool for enriching $Ca^{2+}$ contents in the tomato fruit without additional accumulation of the undesirable cations.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.761-771
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• 2014

The study was conducted to evaluate effects of weed managements after false seedbed on the weed control and growth of spring and fall cabbages (Brassica oleracea L.) in an organic upland in 2013. Weed managements included rake, flame, PE mulch, and none treatment. The weed occurrence was not effectively controlled by rake treatment but controlled by flame treatment in spring and fall cultivation. PE mulch plots had 30% of tip-burn in spring cultivation. Weed managements after false seedbed were similar fresh weight, leaf number, and cabbage yield to the conventional PE mulch. Head of cabbage was the lowest on the none treatment. Fall cultivation reduced the weed density and increased yield of cabbage compared to those of spring in all treatment plots. In conclusion, rake or flame treatment after false seedbed markedly decreased weed occurrence, which was expected to use for management of environmentally-friendly vegetation as a substitute of PE mulch.

• Journal of Korean Society for Quality Management
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• v.45 no.4
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• pp.1003-1020
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• 2017

Purpose: The purpose of this study is to find the optimum working conditions for spot welding of wire Cu alloys to achieve high-level quality. The parts subject to spot welding are brush card assemblies, which are the main module of the electric movement method of the car seat. Methods: In this study, the signal-to-noise ratio(SN ratio) and the loss function [L(y)] are used as Taguchi method for dynamic characteristics. Results: The results of the study are as follows. First, the analysis of variance using SN ratio showed 6 significant factors(p = 0.1% or less) among 7 factors except press force. Second, the optimal design of the dynamic characteristics is the tip exchange cycle: 50,000 ea., the welding time is 110 ms, the pressing force is 11 kgf/cm2, the rise time is 40 ms, and the tip dressing is 3,000 ea., Tip angle is 12o and electric current is 1,800 A. Conclusion: The validity of the spot welding process of the manufacturer's brush card assembly was verified and proved to be consistent with the study results. The results of this study are expected to standardize the welding conditions and guarantee the quality level required by the customers.

• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.146-151
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• 2008

Purpose : Multidrug-resistant Acinetobacter baumannii (A. baumannii) is recognized to be the most difficult pathogen to control and treat in pediatric burn centers. We analyzed the antibiotic susceptibility pattern of A. baumannii in our pediatric burn intensive care unit during the past 7 years. Methods : We retrospectively evaluated 56 patients (105 samples) under the age 15 years and who were infected with A. baumannii between January 1999 and December 2005. Results : Fot the 56 patients, the ratio of males to females was 1.15:1 and the median age was 48.3 months. The sites of 105 isolates were wounds (65%), sputum (20%), blood (6 %), cutdown tips (5%), endo-tip tubes (2%) and urine (2%). A. baumannii presented yearround. The annual antimicrobial resistance rate increased and the multidrug resistant rate for two or more antibiotics was 93.33%. For 3 patients in whom resistance emerged, the interval period between the susceptible and resistant strains after antibiotic use was a mean of 10 days. The A. baumannii isolated from blood were all multi-drug resistant pathogens. Conclusion : Multidrug resistance of A. baumannii is increasing. Strict infection control guidelines and active surveillance are needed for the prevention and treatment of A. baumannii in hospitals.