• Title/Summary/Keyword: Group effect

Search Result 26,897, Processing Time 0.055 seconds

Development of Analytical Methods for Micro Levels of Naphthalene and TNT in Groundwater by HPLC-FLD and MSD (HPLC-FLD와 MSD를 이용한 지하수 중 나프탈렌 및 TNT의 미량 분석법 개발)

  • Park, Jong-Sung;Oh, Je-Ill;Jeong, Sang-Jo;Choi, Yoon-Dae;Her, Nam-Guk
    • Journal of Soil and Groundwater Environment
    • /
    • v.14 no.6
    • /
    • pp.35-44
    • /
    • 2009
  • Naphthalene and TNT (2,4,6-trinitrotoluene) are defined by U.S. EPA as possible carcinogenic compounds known to have detrimental effects on the aquatic ecosystem and human body. There are, however, few researches on methods of analyzing micro-levels of naphthalene and TNT dissolved in groundwater. This study introduces and evaluates the newly developed analytical methods of measuring naphthalene and TNT in groundwater by using HPLC-FLD (Fluorescence detector) and MSD (Mass detector). The MDL, LOQ and salt effect of these methods, respectively, are compared with those of conventional methods which use HPLC-UV. For the analysis of naphthalene, HPLC-FLD was set in the maxima wavelength (Ex: 270 nM, Em: 330 nM) obtained from 3D-Fluorescence to be compared with HPLC-UV in 266 nM wavelength. The MDL ($0.3\;{\mu}g/L$) and LOQ ($2.0\;{\mu}g/L$) of naphthalene by using HPLC-FLD were approximately 80 times lower than those analyzed by HPLC-UV (MDL: $23.3\;{\mu}g/L$, LOQ: $163.1\;{\mu}g/L$). HPLC-MSD were used in comparison with HPLC-UV in 230 and 254 nM wavelength for the analysis of TNT. The MDL ($0.13\;{\mu}g/L$) and LOQ ($0.88\;{\mu}g/L$) of TNT analyzed by using HPLC-MSD were approximately 130 times lower than those obtained by using HPLC-UV in 230 nM (MDL: $16.8\;{\mu}g/L$, LOQ: $117.5\;{\mu}g/L$). The chromatogram of TNT analyzed by using HPLC-UV in 230 nM displayed elevated baseline as the concentration of ${NO_3}^-$ increases beyond 21 mg/L, while the analysis using HPLC-MSD did not demonstrate any change in baseline in presence of ${NO_3}^-$ of 63.7 mg/L which is 3.5 times higher than average concentration in groundwater. In conclusion, HPLC-FLD and HPLC-MSD may be used as suitable methods for the analysis of naphthalene and TNT in groundwater and drinking water. These methods can be applied to the monitoring of naphthalene and TNT concentration in groundwater or drinking water.

Hydrogen Peroxide Modulates Phospholipase $A_2$ Aactivity and Endogenous Oxidative Stress in the Free Radical Induced Acute Lung Injury (과산화수소에 의한 급성폐손상시 염증성 지질분자의 생성기전에 관한 연구)

  • Bae, Chi-Hoon;Kang, Hyung-Seok;Lee, Sub;Jheon, Sang-Hoon;Ahn, Wook-Wu;Kwon, Oh-Choon
    • Journal of Chest Surgery
    • /
    • v.35 no.5
    • /
    • pp.343-349
    • /
    • 2002
  • background: In an attempt to investigate the role of oxidants in the activation of phospholipase $A_2$(PLA$_2$) and endogenous oxidative stress in the lung. acute inflammatory lung injury was induced by the instillation of hydrogen peroxide into the trachea of Sprague-Dawley rats. Material and Method: To prove the hypothesis thats released oxidants from neutrophils activate the PLA$_2$ retrogradely, activities of PLA$_2$ and lysoplatelet activating factor acetyltransferase(lysoPAF AT) were assayed i hours after instillation of hydrogen peroxide. In addition, to confirm the impairing effects of the activation of PLA$_2$ associated with endogenous oxidative stress, lung weight/body weight ratio(L$\times$10$^{-3}$ B), protein contents(mg/two lungs) in bronchoalveolar lavage(BAL) were measured. As neutrophilic respiratory burst has been known to play a pivotal role in the genesis of endogenous oxidative stress associated with acute inflammatory lung injury, BAL neutrophils counts and level of lung myelperoxidase(MPO) were measured after hydorgen peroxide insult. Morphological and histochemical studies were also performed to identify the effect of the endogenous oxidative stress. Result: Five hours after hydrogen peroxide instillation, lungs showed marked infiltration of neutrophils and increased weight. Protein contents in BAL increased significantly compared to those of normal rats. PLA$_2$ activity was enhanced in the hydrogen peroxide instilled group. Interestingly, the accelerated production of platelet activating factor(PAF) was confirmed by the increased activity of lysoPAF AT in the $H_2O$$_2$ employed lung. Morphologically, light microscopic findings of lungs after instillation of hydrogen peroxide showed atelectasis and infiltration of inflammatory cells, which was thought to be caused by lipid mediators produced by PLA$_2$ activation. In cerium chloride cytochemical electron microscopy, dense deposits of cerrous perhydroxide were identified. In contrast, no deposit of cerrous perhydroxide was found in the normal lung.

A Survey on the Effect of Consumer's Social-Economic Status on Beef Purchase Attitude (소비자의 사회 경제적 위치가 쇠고기 구매 태도에 미치는 영향)

  • Lee, Seong-Kap;Yang, Seok-Jin;Kim, Dong-Hoon;Cho, Bong-Jae;Jang, Jung-Young;Lee, Hyo-Ku;Yoon, Bo-Ra;Lee, Young-Jun;Lee, Ok-Hwan
    • The Korean Journal of Food And Nutrition
    • /
    • v.25 no.1
    • /
    • pp.132-141
    • /
    • 2012
  • This current survey was conducted to examine consumer attitudes toward factors determining beef purchasing and improving distribution systems. The frequency of beef purchasing was shown to reflect social and economic status, where inhabitants in large cities, such as Seoul, with higher salaries showed a higher frequency. In addition, consumers that were in their forties bought beef more frequently than consumers that were in their twenties. Consumers in Seoul and the megalopolis with a monthly income of higher than 200 million won preferred to purchase meat from department stores and discount markets. In contrast, people in small cities with lower incomes tended to buy meat from butcher shops and brand shops. In a question regarding unsatisfaction factors of retail beef, individuals that were in their thirties with a high income had concerns associated with packaging problems. For people under thirty with low income, the consistency of quality and price were the prime concerns. In regards to the beef grading system, consumer response varied between inhabitants, monthly income and age group, where consumers from small cities that were in their twenties and forties with a low income had a negative viewpoint. For the differential beef distribution system, housewives between the ages of 30 and 40 from a small city with an income higher than 200 million won had a positive response; however, a large number of consumers were not familiar with this system. The most demanding beef cuts were in the following order: loin, flank and rib. In addition, the most important factors determining purchasing beef were as follows: price, breed and portion.

Studies on the Seroepidemiology of Helminthic Diseases in Korea (우리나라의 주요 기생충질환(寄生蟲疾患)에 대한 혈청역학적(血淸疫學的) 조사(調査))

  • Rim, Han-Jong;Lee, Joon-Sang;Joo, Kyoung-Hwan;Chung, Myung-Sook
    • Journal of agricultural medicine and community health
    • /
    • v.16 no.1
    • /
    • pp.48-60
    • /
    • 1991
  • In a seroepidemiological study in several areas of Korea, the ELISA technique was performed to determine prevalence of some important helminthic diseases in our nation during March $15^{th}$ to June $30^{th}$. 1991. In this survey the serum antibody positive rates of anisakiasis, toxocariasis, clonorchiasis, paragonimiasis, cysticercosis, and sparganosis were measured. Among, 6,704 cases examined, 19.7% showed positive antibody titer at least one of the six items studied. Overall positive antibody rate was 8.1% in anisakiasis, 5.6% in toxocariasis, 3.6% in clonorchiasis, 1.7% in paragonimiasis, 4.5% in cysticercosis, and 2.6% in sparganosis respectively. In Pusan port southeastern part of Korea, antibody positive rate of anisakiasis was 2.9%, and clonorchiasis was 2.8% among 450 examine. In TaeJ$\check{o}$n city, central part of Korea. toxocariasis(6.7%) and anisakiasis(3.7%) showed high serologic positive rate. Of the 875 persons in Chunche$\check{o}$n gun(=province), northern central rural area of South Korea, anisakiasis was revealed as 3.4% seropositivity. In Tonghae port, eastern coast of South Korea. 9.9% of population examined showed positive antibody titer in anisakiasis. Of the 1,122 persons examined in Southern part of Cholla-Namdo(Southwestern coastal area of Korea), anisakiasis was 16.9%, cysticerocosis was 12.7% and the paragonimiasis was 3.3% respectively. In some localized area of Cholla-Pukdo, anisakiasis was 9.3% and cysticekosis was 4.3% among 702 cases examined. In some localized area of Kyungsang-Pukdo, anisakiasis was 10.6%. and toxocariasis was 16.1% among 900 cases examined. And finally, in Cheju-do, southern island of Korea, anisakiasis showed high positive rate(6.7%). Because cross reactions between related helminth group may disturb the analysis of these data, use of further developed techniques such as EITB(enzyme-linked immunoelectrotransfer blot) was considered as a essential tools for the study. We thought that probably most of the positive cases of cysticerosis were taeniasis cases. We can't rule out taeniasis even though EITB was employed as far as crude worm extract or cystic fluid of cysticercus was used as antigen. It was well Known that toxocariasis and anisakiasis also showed cross reactivity. However, the data presented here focus on seropositive rate of several helminthic diseases in Korea, not true prevalence rate of helminthiases, and to wait for more expensive purified antigen in sufficient amount for epidemiologic use is not necessary because increased immunologic sensitivity had little effect on epidemiologic sensitivity. We, here, suggest that ELISA should be applied as soon as possible to the evaluation of prevalence of tissue invading parasitic diseases, and a review of the antibody positive rate obtained in this study would be a basic data for controlling program of parasitic diseases in Korea.

  • PDF

An in vitro study of mesenchymal stem cell proliferation on titanium discs coated with rhTGF-β2/PLGA by electrospray (Electrospray법으로 rhTGF-β2/PLGA 복합체를 코팅한 티타늄에서의 간엽줄기세포 증식에 관한 연구)

  • Kim, Joohyung;Kim, Seong-Kyun;Heo, Seong-Joo;Koak, Jai-Young;Lee, Woo-Sung;Lee, Joo-Hee;Park, Ji-Man
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.54 no.2
    • /
    • pp.120-125
    • /
    • 2016
  • Purpose: The purpose of this study is to identify the effect of mesenchymal stem cell proliferation on recombinant human transforming growth factor-beta (rhTGF-${\beta}2$) / poly (D,L-lactide-co-glycolide) (PLGA) treated titanium discs by electrospray. Materials and methods: Anodized titanium surface coated with PLGA was used for a control group to compare anodized titanium surface coated with 125 ng/ml and 500 ng/ml rhTGF-${\beta}2$ as test groups. Atomic force microscope (AFM) test was utilized to determine the difference in coating surface roughness, and field-emission scanning electron microscopy (FE-SEM) was taken to visualize even distribution of coating particles on titanium discs. The mesenchymal stem cell proliferation was tested by using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl-tetrazolium bromide) assay on 1st, 4th, 7th days. Results: According to AFM results, there was no statistically significant difference in titanium discs treated with PLGA and with rhTGF-${\beta}2$/PLGA (P>.05). MTT assay test results showed that there was statistically significant difference in mesenchymal stem cell proliferation on test groups compared to control groups at 7th day, and cell viability on discs coated with rhTGF-${\beta}2$ was significantly higher than control groups (P<.05). Conclusion: Titanium surface coated with rhTGF-${\beta}2$/PLGA shows statistically significant higher cell proliferation and the titanium surface coated with the higher concentration of rhTGF-${\beta}2$ presents faster cell growth activity.

Shade comparative analysis of natural tooth measured by visual and spectrophotometric methods (육안과 분광 측정기를 이용한 자연 치아의 색조비교분석)

  • Kim, Bum-Suk;Shin, Soo-Yeon;Lee, Jong-Hyuk
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.46 no.5
    • /
    • pp.443-454
    • /
    • 2008
  • Statement of problem: A clinically successful color match is one of the important factor to get an esthetic dental restoration. Dental shade guides are commonly used to evaluate tooth color in restorative procedure. But numerous reports have indicated that common shade guides do not provide sufficient spectral coverage of the natural tooth colors. To address issues associated with the shade guide, distinct avenues have been pursued objective spectrophotometric / colorimetric assessment. Purpose: This study compared the accuracy of tooth color selection of spectrophotometer with that of human visual determination. Three main factors were investigated, namely, the effect of light, the individual variation and the experience of the observer. Material and methods: At the first experiment, on ten patients, one operator independently selected the best matching shade to the unrestored maxillary central incisor, using a Vita Classical Shade Guide in the morning, at noon and in the afternoon. The same teeth were measured by means of a reflectance spectrophotometer. At the second experiment, on ten patients, ten operators (5 experts, 5 novices) selected and measured by the same method above at noon. At the third experiment, the results of the second experiment were divided into two groups, expert and novice, and analyzed. Results: 1. There was significant difference between visual and spectrophotometric assessment (mean ${\Delta}E$ values) in experiment 1, 2, 3 (P < .05). 2. There was no significant difference between experts and novices group, when comparing with each visual and spectrophotometric assessment (mean ${\Delta}E$ values). Conclusion: Spectrophotometer could be used to analyze the shade of natural tooth objectively. Thereby, this method offers the potential tominimize considerably the need for corrections or even remakesafter intraoral try-in of restoration. Furthermore, to achieve its advantage, both the shade-matching environment and communication between dentist and technician should be optimized with use of visual and instrumental shade-matching systems.

Physicochemical Quality Characteristics of Tomato Sauce Added with Pimpinella brachycarpa (참나물을 첨가한 토마토소스의 이화학적 품질특성)

  • Jang, Sang-Jun
    • Culinary science and hospitality research
    • /
    • v.20 no.4
    • /
    • pp.169-182
    • /
    • 2014
  • This study investigates the physicochemical quality characteristics of tomato sauce added with different kinds of pimpinella brachycarpa. The results are as follows. The pH of tomato sauce added with freeze-dried pimpinella brachycarpa, in contrast to the tomato sauce with raw pimpinella brachycarpa, decreased as the addition quantity of the sample increased. As for sugar content, PBP0 with Pimpinella brachycarpa contained was shown to be the highest with 10.83. For chromaticity, all values (e.g, L, A and B) of tomato sauce added with pimpinella brachycarpa and with freeze-dried pimpinella brachycarpa decreased showing significant differences among the samples as the addition quantity of the samples increased. With increased addition quantity of the sample with freeze-dried Pimpinella brachycarpa, its water content decreased. PBP4, addition group with 4% of freeze-dried Pimpinella brachycarpa, was shown to be the highest DPPH free radical scavenging activity as 29.58. When adding Pimpinella brachycarpa to tomato sauce, a total number of micro-organisms decreased. In case of adding raw Pimpinella brachycarpa rather than freeze-dried Pimpinella brachycarpa, it created a further effect on an inhibitive action of growing and developing micro-organisms. In the preference of tomato sauce with Pimpinella brachycarpa, PBF2 with 2% of Pimpinella brachycarpa had the highest score as 5.1 for the color. For taste, 3.7, the lowest taste score, was shown in PBF1with 1% of Pimpinella brachycarpa. The overall preference revealed that PBF2 was the highest scoring 5.8.. PBF3 was scored highest with 5.9 for overall preference. From the comprehensive findings, 2~3% of the addition ratio between raw Pimpinella brachycarpa and freeze-dried Pimpinella brachycarpa in the production of tomato sauce is considered the most preferable.

Germination Dependency of Antioxidative Activities in Brown Rice (현미의 발아정도에 의한 항산화활성의 변화)

  • Kang, Bo-Ra;Park, Mi-Jung;Lee, Heum-Sook
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.35 no.4
    • /
    • pp.389-394
    • /
    • 2006
  • The change of antioxidative character by germination of brown rice was evaluated. From the total methanolic extract of brown rice, 2.5 mm-germinated brown rice, and 5 mm-germinated brown rice, SOD-like activity and nitrite scavenging ability were identified as antioxidative character. SOD-like activities and nitrite scavenging abilities of all samples were changed dose-dependently and germination-dependently. After successive partitioning with hexane, ethyl acetate (EtOAc) and water, each fraction was tested for these activities. SOD-like activities of all fractions were increased by germination, and especially hexane fraction and EtOAc fraction of 5 mm-germinated brown rice had more strong activities than 50 ppm vitamin C. The $EC_{50}$ values of SOD-like activity showed a gradual decrease by germination and that of EtOAc fraction of 5 mm-germinated brown rice was 17 ppm, which was lower concentration than that of 50 ppm vitamin C. The $IC_{50}$ values of nitrite scavenging ability at PH 1.5 also underwent a great decrease by germination and germinated brown rice had the nitrite scavenging ability at lower concentration than brown rice. The results suggest that SOD-like activity and nitrite scavenging ability are thought to be enhanced by the germination effect.

Effect of Dietary Intake of Salicornia herbacea L. Hot Water Extract on Anti-obesity in Diet-induced Obese Rats (함초 열수추출물의 섭취가 비만유도 흰쥐의 항비만 효과에 미치는 영향)

  • Lee, Hye-Sung;Choi, Jun-Hyeok;Kim, Youn-Geon;Lee, Chang-Ho
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.41 no.7
    • /
    • pp.950-956
    • /
    • 2012
  • Salicornia herbacea L. is an annual herb that grows in salt marshes and salt fields along the seashores. It is also commonly used as a folk remedy in Korea. The objective of this study was to investigate the beneficial effects of Salicorrnia herbacea L. (SH) hot water extract on obesity. Five-week old male Sprague-Dawley rats (n=36) were divided into two groups and provided either a normal fat diet (11.5% fat from kcal) or a high fat diet (40.5% fat from kcal) for 6 weeks to induce obesity. Then, rats were blocked into six groups of six mice each and provided either a diet containing SH (0.5% of diet; g/kg) or a normal diet for another 6 weeks. Final body weights were significantly reduced when rats were fed SH among the high fat diet groups (HNS and HHS). Serum triglyceride concentrations significantly decreased in every group provided SH. HDL-cholesterol concentrations significantly increased in SH-fed groups among the high fat diet groups. Further, atherogenic index significantly decreased when rats were fed SH diet (HHS). There were no differences in LDL-cholesterol between the high fat diet groups, and glucose concentrations decreased when rats were fed SH diet (HNS). These results indicate that dietary intake of Salicornia herbacea L. hot water extract might have beneficial effects on obesity by reducing body weight, fat weights, and improving blood lipid profile.

A Human Resources Study of the Landscape Architecture Industry in Korea (국내 조경산업의 기술인력 현황과 수급 예측)

  • Byeon, Jae-Sang;Shin, Sang-Hyun
    • Journal of the Korean Institute of Landscape Architecture
    • /
    • v.37 no.3
    • /
    • pp.33-45
    • /
    • 2009
  • In the industry of landscape architecture, in which the core of production is manpower, the management of manpower is of utmost importance. The industry of landscape architecture, however, is highly sensitive to economic shifts and policy changes; this sensitivity renders the management of manpower-maintaining the balance between supply and demand-often times difficult. Currently, this vicious circle appears to persist in the sense that the industry suffers from a lack of skilled employees, and a new body of skilled laborers from the paucity of jobs. This study, in analyzing current manpower management as well as the prospective supply and demand in the field, looks forward to the stability of the supply and demand in landscape architecture in the nation. According to this study, the number of new skilled laborers-those who have a higher credential than that of "landscape architect-engineer"-is expected to increase by 10% per year. The number of new skilled laborers being 1,137 in 2008, it can be inferred that there will be a new group of 1,251 skilled laborers in the field in 2009. Meanwhile, estimating that the number of current skilled laborers in the field of landscape architecture is 14,783, the demand for new skilled laborers remains approximately 540. The supply of 1,251 skilled laborers outnumbers the demand of 540 by nearly 230%. Hence, the educational institutions of landscape architecture must be prepared to deal with this imbalance between the excessive supply and the lesser demand of skilled laborers. The issue of the excessive supply of manpower is particularly critical, because it may well undermine the competitiveness of the industry as a whole: compared to other related industries such as architecture and civil engineering, for instance. With the customary validation of long work experience no longer in effect, the need for an engineer's license will keep on increasing. It is time that educational institutions took this issue into full account and helped their students to be better qualified and more competent.