• Title/Summary/Keyword: L20 method

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Improvement of an Analytical Method for Methoprene in Livestock Products using LC-MS/MS (LC-MS/MS를 이용한 축산물 중 살충제 메토프렌의 잔류분석법 개선)

  • Park, Eun-Ji;Kim, Nam Young;Park, So-Ra;Lee, Jung Mi;Jung, Yong Hyun;Yoon, Hae Jung
    • Journal of Food Hygiene and Safety
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    • v.37 no.3
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    • pp.136-142
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    • 2022
  • The research aims to develop a rapid and easy analytical method for methoprene using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A simple, highly sensitive, and specific analytical method for the determination of methoprene in livestock products (beef, pork, chicken, milk, eggs, and fat) was developed. Methoprene was effectively extracted with 1% acetic acid in acetonitrile and acetone (1:1), followed by the addition of anhydrous magnesium sulfate (MgSO4) and anhydrous sodium acetate. Subsequently, the lipids in the livestock sample were extracted by freezing them at -20℃. The extracts were cleaned using MgSO4, primary secondary amine (PSA), and octadecyl (C18), which were then centrifuged to separate the supernatant. Nitrogen gas was used to evaporate the supernatant, which was then dissolved in methanol. The matrix-matched calibration curves were constructed using 8 levels (1, 2.5, 5, 10, 25, 50, 100, 150 ng/mL) and the coefficient of determination (R2) was above 0.9964. Average recoveries spiked at three levels (0.01, 0.1, and 0.5 mg/kg), and ranged from 79.5-105.1%, with relative standard deviations (RSDs) smaller than 14.2%, as required by the Codex guideline (CODEX CAC/GL 40). This study could be useful for residue safety management in livestock products.

Monitoring for the Resistance of Botrytis cinerea Causing Gray Mold Against Mepanipyrim (Mepanipyrim에 대한 잿빛곰팡이병균의 저항성 검정)

  • Kim, Ah Hyeong;Kim, Seon Bo;Han, Kee Don;Kim, Heung Tae
    • The Korean Journal of Pesticide Science
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    • v.19 no.3
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    • pp.329-334
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    • 2015
  • With 86 isolates of Botrytis cinerea obtained from diseased fruits of tomato, strawberry and cucumber, it was conducted to detect the fungicide resistance of B. cinerea against mepanipyrim through an agar dilution method. FGA medium was used for monitoring the resistance. Among 86 isolates of B. cinerea, resistant isolates were composed by 23.3%, which was different according to regions isolating the pathogen. In accordance with isolation region, the isolation frequency of resistant isolates was as follows; that of Gyeonggi, Gyeongnam/Pusan and chungnam was 28.6%, 33.3% and 12.8%, respectively. The resistant isolates of B. cinerea showed the cross resistance between mepanipyrim and pyrimethanil. Also the pathogenicity of B. cinerea resistant to mepanipyrim was high as like that of sensitive isolates. Because of them, it should be necessary to manage the spraying system of mepanipyrim and the monitoring for the fungicide resistance.

A Study of the Attitudes of Nurses toward the Geriatric Nursing Care (노인간호에 대한 간호원의 태도조사연구)

  • 최경옥
    • Journal of Korean Academy of Nursing
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    • v.6 no.2
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    • pp.1-9
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    • 1976
  • Presently, there is increasing demand for geriatric nursing care because of increasing preparation of elderly population due to extended age. Of particular importance in determining the effectiveness of nursing care given to the elderly is the attitude of the nurse toward the elderly patient. Knowledge of the various changes that usually occur with aging will enable the nurse to help an aged Person maximize his potential in illness and in health. The objectives of this study were : 1. To delineate the attitudes of nurses toward the geriatric nursing care. 2. To learn the influencing factors affecting the attitudes of nurses toward the geriatric nursing care. The study population defined and randomly selected is 225 nurses at one general hospital, one private hospital, two national hospitals in Seoul during the period of October l0th -20th, 1975. The questionnaire method was used. Respondents were 140 nurses. X$^2$- test and t- test were employed in analyzing the data. The questionnaire form included 54 statements which concerned the attitudes of nurses to-ward geriatric nursing care. It was divided into five areas : 1) General characteristics of study population. 2) The nurse's concepts of elderly. 3) Care of the geriatric patient. 4) Interpersonal relationship with geriatric patient. 5) Teaching of the geriatric patient. Each of the 54 statements of the questionnaire was considered to be either Positive or Negative. A Positive response was assigned the value of+1 , and a Negative response or no response was assigned the value of O. The results of the study were as follows : 1. The Investigation of attitudes of nurses toward geriatric nursing care. a. Data indicated , respondents have negative attitudes in their. concepts of elderly (74.3%) b. Data indicated respondents have positive attitudes in care of geriatric patient (64.3%). c. Data indicated respondents have positive attitudes in interpersonal relationship with geriatric patient (85% ). 4. Data indicated respondents have positive attitudes in teaching of geriatric patient (89.3%). 2. The results of study regarding the five hypothesis were as follows : a There was significant difference in the mean scores between the attitudes of nurses toward the geriatric nursing care and level of education of the nurse. b. There was no significant difference between the attitudes of nurses toward the geriatric nursing care and clinical experience, but there was significant difference between care of the geriatric patient and clinical experience. c. There was no significant difference between the attitudes of nurses toward the geriatric nursing care and shift most frequently worked, but there was significant difference between care of the geriatric patient and shift most frequently worked. d. There was no significant difference in the mean scores between the attitudes of nurses toward the geriatric nursing care and marital status, but there was significant difference in the mean scores between interpersonal relationship, teaching of geriatric patient and marital status. e, There was no significant difference in the mean scores between the attitudes of nurses toward the geriatric nursing care and experience with elderly, but there was significant difference in the mean scores between care of geriatric patient and experience with elderly.

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Evaluation of Cumulative and Conditional Antibiotic Release from Vancomycin-Embedded Fibrin Sealant and Its Antibacterial Activity : An In Vitro Study

  • Shin, Dong-Won;Sohn, Moon-Jun;Cho, Chong-Rae;Koo, Hae-won;Yoon, Sang Won
    • Journal of Korean Neurosurgical Society
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    • v.63 no.1
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    • pp.45-55
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    • 2020
  • Objective : Fibrin sealants have been used for hemostasis, sealant for cerebrospinal fluid leakage, and adhesive barrier in neurosurgery. Further, as its clinical use and role of an effective drug delivery vehicle have been proposed. This study was performed to measure antibacterial activity and continuous local antibiotic release from different concentrations of vancomycin-impregnated fibrin sealant in vitro. Methods : Antibacterial activity was investigated by disk diffusion test by measuring the diameter of the growth inhibition zone of bacteria (methicillin-resistant Staphylococcus aureus, ATCC29213) from vancomycin-embedded fibrin sealant disc diluted at five different concentrations (C1-C5; 8.33, 4.167, 0.83, 0.083, and 0.0083 mg/disc, respectively). Continuous and conditioned release of vancomycin concentration (for 2 weeks and for 5 days, respectively) were also measured using high-performance liquid chromatography (HPLC) method. To mimic the physiologic wound conditions with in vitro, conditioned vancomycin release in phosphate buffer solution (PBS) was measured and replaced PBS for five consecutive days, half a day or completely daily. Results : In the disk diffusion test, the mean diameters of bacterial inhibition zone were 2.54±0.07 cm, 2.61±0.12 cm, and 2.13±0.15 cm (C1, C2, and C3 respectively) but 1.67±0.06 cm and 1.23±0.15 cm in C4 and C5, respectively. Continuous elution test elicited the peak release of vancomycin from the fibrin sealant at 48 hours, with continued release until 2 weeks. However, conditioned vancomycin release decreased to half or more on day 2, however, the sustainable release was measured over the therapeutic dose (10-20 ㎍/mL) for 5 days and 4 days in assays of half and total exchange of PBS. Conclusion : This study suggests that fibrin sealant can provide an efficient vehicle for antibiotic drug release in a wide range of neurosurgical procedures and the safe and effective therapeutic dose will be at the concentration embedded of 4.167 mg/disc or more of vancomycin.

Control of Powdery and Downy Mildews of Cucumber by Using Cooking Oils and Yolk Mixture

  • Jee, Hyeong-Jin;Shim, Chang-Ki;Ryu, Kyung-Yul;Park, Jong-Ho;Lee, Byung-Mo;Choi, Du-Hoe;Ryu, Gab-Hee
    • The Plant Pathology Journal
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    • v.25 no.3
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    • pp.280-285
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    • 2009
  • Powdery and downy mildews caused by Sphaerotheca fusca and Pseudoperonospora cubensis are the most common and serious diseases of cucumber worldwide. In spite of the introduction of highly effective systemic fungicides, control of these diseases remains elusive. Hence, this study aimed to develop an alternative method to chemicals in controlling the diseases by using different types of cooking oil. Egg yolk, which contains a natural emulsifier, lecithin, was selected as a surfactant to emulsify the oils. Among the different cooking oils used, soybean, canola (rape seed), safflower, sunflower, olive, and corn oils showed over 95% control values against powdery mildew of cucumber in a greenhouse test. In particular, 0.3% canola oil emulsified with 0.08% yolk (1 yolk and 60 ml canola in 20 l spray) was found to be the most effective. The treatment resulted in 98.9% and 96.3% control efficacies on powdery and downy mildews, respectively, of cucumber in the field. Canola oil exhibited direct and systemic effect, wherein powdery mildew of cucumber was suppressed only on treated leaves but not on non-treated leaves in a plant, while mycelia and conidia of the pathogen were severely distorted or destroyed by the treatment. The prospect of using the canola oil and yolk mixture as a natural fungicide is highly promising because of its effectiveness, availability, low cost, simple preparation, and safety to humans and the environment. The use of the canola oil and yolk mixture is expected to be an effective fungicide for use in organic farming and home gardening.

In vitro Neural Cell Differentiation of Genetically Modified Human Embryonic Stem Cells Expressing Tyrosine Hydroxylase (Tyrosine Hydroxylase 유전자가 주입된 인간 배아줄기세포의 체외 신경세포 분화)

  • Shin, Hyun-Ah;Kim, Eun-Young;Lee, Keum-Sil;Cho, Hwang-Yoon;Kim, Yong-Sik;Lee, Won-Don;Park, Se-Pill;Lim, Jin-Ho
    • Clinical and Experimental Reproductive Medicine
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    • v.31 no.1
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    • pp.67-74
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    • 2004
  • Objective: This study was to examine in vitro neural cell differentiation pattern of the genetically modified human embryonic stem cells expressing tyrosine hydroxylase (TH). Materials and Methods: Human embryonic stem (hES, MB03) cell was transfected with cDNAs cording for TH. Successful transfection was confirmed by western immunoblotting. Newly transfected cell line (TH#2/MB03) was induced to differentiate by two neurogenic factors retinoic acid (RA) and b-FGF. Exp. I) Upon differentiation using RA, embryoid bodies (EB, for 4 days) derived from TH#2/MB03 cells were exposed to RA ($10^{-6}M$)/AA ($5{\times}10^{-2}mM$) for 4 days, and were allowed to differentiate in N2 medium for 7, 14 or 21 days. Exp. II) When b-FGF was used, neuronal precursor cells were expanded at the presence of b-FGF (10 ng/ml) for 6 days followed by a final differentiation in N2 medium for 7, 14 or 21 days. Neuron differentiation was examined by indirect immunocytochemistry using neuron markers (NF160 & NF200). Results: After 7 days in N2 medium, approximately 80% and 20% of the RA or b-FGF induced Th#2/MB03 cells were immunoreactive to anti-NF160 and anti-NF200 antibodies, respectively. As differentiation continued, NF200 in RA treated cells significantly increased to 73.0% on 14 days compared to that in b-FGF treated cells (53.0%, p<0.05), while the proportion of cells expressing NF160 was similarly decreased between two groups. However, throughout the differentiation, expression of TH was maintained ($\sim$90%). HPLC analyses indicated the increased levels of L-DOPA in RA treated genetically modified hES cells with longer differentiation time. Conclusion: These results suggested that a genetically modified hES cells (TH#2/MB03) could be efficiently differentiated in vitro into mature neurons by RA induction method.

Prediction of the Land-surface Environment Changes in the Anmyeon-do Using Fuzzy Logic Operation (퍼지논리연산을 이용한 안면도 지표환경 변화 예측)

  • 장동호;지광훈;이현영
    • Journal of the Korean Geographical Society
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    • v.37 no.4
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    • pp.371-384
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    • 2002
  • It is very important to predict the environmental changes in the land-surface as a way of prevention of sustainable nature. This study investigated the difference between the predicted and actual data of Anmyeon-do from 1981 to 2000 through a fuzzy logic operation using multi-spectral image. According to literature survey, maps, and ground truth data, the types of land-use have changed due primarily to shore reclamation or wild land and grassland fostering before the eighties. After the mid-eighties, however, a number of private residents and commercial stores quickly have spreaded throughout beach resorts and quasi-agricultural and forest areas. Moreover, shore and community regions were severely damaged in the nineties with increased farmland, due to the development of tour places and expansion of city area. The predicted result of the environmental changes in the land-surface using the fuzzy logic operation was almost similar to the state of Anmyeon-do obtained through the satellite image. Particularly, the flat lands near the shore was predicted to change slightly. This area is largely under development, thereby raising concerns on the shore environment. Thus, this method is applicable to conducting research on the change in the land-surface.

Evaluation of Relative Bioavailability of 25-Hydroxycholecalciferol to Cholecalciferol for Broiler Chickens

  • Han, J.C.;Chen, G.H.;Wang, J.G.;Zhang, J.L.;Qu, H.X.;Zhang, C.M.;Yan, Y.F.;Cheng, Y.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.8
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    • pp.1145-1151
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    • 2016
  • This study was conducted to evaluate the relative bioavailability (RBV) of 25-hydroxycholecalciferol (25-OH-$D_3$) to cholecalciferol (vitamin $D_3$) in 1- to 21-d-old broiler chickens fed with calcium (Ca)- and phosphorus (P)-deficient diets. On the day of hatch, 450 female Ross 308 broiler chickens were assigned to nine treatments, with five replicates of ten birds each. The basal diet contained 0.50% Ca and 0.25% non-phytate phosphorus (NPP) and was not supplemented with vitamin D. Vitamin $D_3$ was fed at 0, 2.5, 5.0, 10.0, and $20.0{\mu}g/kg$, and 25-OH-$D_3$ was fed at 1.25, 2.5, 5.0, and $10.0{\mu}g/kg$. The RBV of 25-OH-$D_3$ was determined using vitamin $D_3$ as the standard source by the slope ratio method. Vitamin $D_3$ and 25-OH-$D_3$ intake was used as the independent variable for regression analysis. The linear relationships between the level of vitamin $D_3$ or 25-OH-$D_3$ and body weight gain (BWG) and the weight, length, ash weight, and the percentage of ash, Ca, and P in femur, tibia, and metatarsus of broiler chickens were observed. Using BWG as the criterion, the RBV value of 25-OH-$D_3$ to vitamin $D_3$ was 1.85. Using the mineralization of the femur, tibia, and metatarsus as criteria, the RBV of 25-OH-$D_3$ to vitamin $D_3$ ranged from 1.82 to 2.45, 1.86 to 2.52, and 1.65 to 2.05, respectively. These data indicate that 25-OH-$D_3$ is approximately 2.03 times as active as vitamin $D_3$ in promoting growth performance and bone mineralization in broiler chicken diets.

A Study on the Toxicity Assessment of Plating Wastewater using Aquatic Microcosm (수계 Microcosm을 이용한 도금폐수의 독성평가)

  • 위성욱;도삼유평;조경;나명석;이종빈
    • Korean Journal of Environmental Biology
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    • v.20 no.3
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    • pp.256-262
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    • 2002
  • This research investigated experimentally on the population growth in the aquatic microcosm with the wastewater of plating factory. The purpose of this study was to evaluate the effect of culture conditions of the characteristic growth pattern of the examined species. Population of the system is consists of three organisms; Chlorella vulgaris as a producer, Cyclidium glaucoma as a consumer and Pseudomonas putida as a decomposer. The different growth patterns of each population are followed by surfactant type; Especially C. glaucoma was sensitive, Ch. uvlgaris was maintained population size stably even at high level of surfactant and p. putida was not significantly affected. After treatment of waste water from plating factory, it began to be affected at 1.0% solution treatment to Ch. vulgaris which the cell number was decreased prominently after 2 days, and C. glaucoma was disappeared at 2.5% solution treatment. P. putida was showed increasing pattern according to treatment concentration, at 2.5% solution and population size grew double. The result from current microcosm study indicates that this model system can be applied to environmental assessment method for various pollutants.

Menu Development and Evaluation through Eating Behavior and Food Preference of Preschool Children in Day-Care Centers (보육시설 유아들의 식행동과 식품기호도 조사를 통한 식단개발 및 평가)

  • Sin, Eun-Kyung;Lee, Yeon-Kyung
    • Journal of the Korean Society of Food Culture
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    • v.20 no.1
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    • pp.1-14
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    • 2005
  • This study was conducted to develop and evaluate food menus after investigating eating behaviors and food preferences of preschool children. Parents of the preschool children In 2 Gumi City day-care centers completed questionnaires in July 2003, which were used to assess eating behaviors and food preferences of their preschool children. Analysis of the questionnaires led to the development of the menus. Menus (n=10) were developed for five different categories (two menus were developed for each category) including general menu, unbalanced menu, anemia menu, obese menu, and traditional menu. The preschool children(n=656) evaluated the menus as they were provided with each them throughout October 2003. The five score scale method was used to evaluate taste, smell, looks, texture and general preference of each menu. Results in eating behaviors showed that 70.7% of preschool children had unbalanced eating behaviors. No gender based differences in eating behaviors were found, but in regard to food preferences boys tended to prefer carbonated drinks more than girls. Results indicated that among all menus, fruit ranked highest $(3.97{\pm}0.65)$ for food preference, and vegetables ranked lowest for food preference $(2.46{\pm}0.68)$. Food preference in regard to cooking process indicated the highest preference was for fried foods $(3.80{\pm}0.68)$ and the lowest preference was for raw vegetables $(2.61{\pm}1.27)$ and namul $(2.85{\pm}1.13)$. Preference for taste ranked the highest $(4.30{\pm}0.91)$ but preference for looks recorded the lowest $(3.95{\pm}0.89)$. Of all the foods in the menus, steamed tofu rated the highest for individual food item preference, while tuna sesame leaf rice rated the lowest preference. Statistical analysis of interrelationships among food taste, smell, looks, texture and general preference were significant (p<0.0l). Results from this study suggest that various factors including food taste, smell, looks, and texture influence the food preferences of preschool children. Therefore, it is concluded that by developing a variety of appetizing menus for use at home and in day-care centers, containing varied food items and cooking methods, preschool children will be encouraged to increase their food preferences and to establish appropriate eating behaviors.