• Title/Summary/Keyword: Incidence density

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Bone Mineral Density and Factors influencing Bone Mineral Density in College Women (일 대학 여대생의 골밀도와 골밀도에 영향을 주는 요인)

  • Chon, Mi-Young;Jeon, Hye-Won;Kim, Myoung-Hee
    • Women's Health Nursing
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    • v.18 no.3
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    • pp.190-199
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    • 2012
  • Purpose: The purpose of this study was to identify the levels of bone mineral density (BMD) and to explain the factors influencing BMD among female college students in Korea. Methods: A cross-sectional study was conducted with 144 college women. Lifestyle factors were determined by self-report questionnaire. Body composition was measured by body composition analyzer and bone mineral density was measured by ultrasound bone densitometry. Data were analyzed using SPSS for windows, version 19.0. Results: The mean BMD at calcaneus site was 0.56$g/cm^2$ (mean T-score=-0.22). The incidence of osteopenia was 21.5%. Factors predicting BMD were menarche age (r=-.22, p=.009) and height (r=-.18, p=.030) with 7% of explained variance. Conclusion: These results suggest that health care professionals need to provide young women with program that is intended to affect their intention toward osteoporosis preventive behavior change.

An Improved Theoretical Model to Explain Electronic and Optical Properties of p-Type GaAs/AlGaAs Superlattices for Multi-Wavelength Normal Incidence Photodetectors

  • Kim, Byoung-Whi;Choi, Eun-Chang;Park, Kwon-Chul;Kang, Seok-Youl
    • ETRI Journal
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    • v.18 no.4
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    • pp.315-338
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    • 1997
  • We extend our previous theoretical analysis of electronic and optical properties of p-type quantum well structures based on the two heavy- and light-hole system to include all the three valence bands. These theories are then used to clarify the origin of the normal incidence absorption and photo current at photon wavelengths of 2 - 3 ${\mu}m$, which was observed in addition to the absorption around 8 ${\mu}m$ by a recent experimental investigation with heavily doped p-type GaAs/AlGaAs multi-quantum well (MQW) structures. In the theoretical analysis, the Hartree and exchange-correlation many-body interactions are taken into account within one-particle local density approximation, and it is shown that normal incidence absorption occurs in two wavelength regions over the transition energy range higher than barrier height for p-type GaAs/AlGaAs superlattices with well doping of $2{\times}10^{19}\;cm^{-3}$; one region has broad absorption peaks with coefficients of about 5000 $cm^{-1}$ around 8 ${\mu}m$, and the other has two rather sharp peaks at 2.7 ${\mu}m$ and 3.4 ${\mu}m$ with 1800 $cm^{-1}$ and 1300 $cm^{-1}$, respectively. The result indicates that the theory explains the experimental observation well, as the theoretical and experimental results are in close agreement in general absorption features.

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Incidence, and Identification of Three Root-Knot Nematode species Occurring in the Medicinal Herbs (약용식물의 뿌리혹선충 발생과 분류동정)

  • Park, So-Deuk;Kahn, Zakaullah;Kim, Jae-Cheol;Choi, Boo-Sull;Kim, Tak
    • Korean Journal Plant Pathology
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    • v.14 no.6
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    • pp.603-605
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    • 1998
  • Soil and root samples were collected form the rhizoshpere of 11 different medicinal plants to determine the incidence, density and identification of root-knot nematode species associated with medicinal herbs. About 55% of medicinal herbs examined was found to be infested with root-knot nematodes. As a result of infection casued by three root-knot nematodes, M. hapla recorded 43.3% in medicinal herba whereas M. incognita and M. arenaria showed 7.9% and 3.7%, repectively. Forsythia koreana, Hemerocalis fulva, Hibuscus mutabilis and Petasites japonicus were the most severely infested herbs whereas Acanthopanax sessilflorus was least infested. Population of the second stage younger plants. Meloidogyne hapla, M. incognita and M. arenaria were the species associated with the medicinal herbs. The most abundant nematode observed in medicinal herbs was M. hapla and followed by M. incognita and M. arenaria. M. arenaria was observed firstly on Ficus carica, one of medicinal plant.

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Planarization of Diamond Films Using KrF Excimer Laser Processing (KrF 엑사이머 레이저 법을 이용한 다이아몬드 박막의 평탄화)

  • Lee, Dong-Gu
    • Journal of the Korean Society for Heat Treatment
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    • v.13 no.5
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    • pp.318-323
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    • 2000
  • The planarization of rough polycrystalline diamond films synthesized by DC arc discharge plasma jet CVD (chemical vapor deposition) was attempted using KrF excimer laser pulses. The effects of laser incidence angle and reaction gases (ozone and oxygen) on etching rate of diamond were studied. The temperature change of diamond and graphite with different laser fluences was calculated by computer simulation to explain the etching behavior of diamond films. The threshold energy density from the experiment for etching of pure crystalline diamond was about $1.7J/cm^2$ and fairly matched the simulation value. Preferential etching of a particular crystallographic plane was observed through scanning electron microscopy. The etching rate of diamond with ozone was lower than that with oxygen. When the angle of incidence was $80^{\circ}$ to the diamond surface normal, the peak-to-valley surface roughness was Significantly reduced from $20{\mu}m$ to $0.5{\mu}m$.

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Histopathological observation of spontaneous testicular atrophy in Sprague-Dawley rat (Sprague-Dawley 랫트에 자연발생한 고환위축의 병리조직학적 관찰)

  • Son, Hwa-Young;Kim, Yong-Bum;Ha, Chang-Su;Kang, Boo-Hyon
    • Korean Journal of Veterinary Pathology
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    • v.2 no.1
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    • pp.47-52
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    • 1998
  • The incidence of spontaneous testicular atrophy and its morphological changes during stage-specific spermatogenesis were investigated in male Sprague-Dawley rats at 10, 19, and 32 weeks of age. The incidence of testicular atrophy was 0.2%(2/90) 7.9%(9/114) and 10%(4/40) in 4, 13 and 26 weeks respectively. The epididymis with testicular atrophy had low sperm density. In the minimally affected tests scattered tubules showed complete depletion of germ cells without stage specificity. Testes with moderate to severe testicular atrophy showed seminiferous tubules lined with dense Sertoli cell population. While Leydig cells in the interstitium appeared hypertrophy they were immunohistochemically negative for proliferating cell nuclear antigen a marker of cell proliferation.

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Effects of different stocking density in lairage of fattening pigs in high temperatures

  • Dongcheol Song;Seyeon Chang;Jaewoo An;Sehyun Park;Kyeongho Jeon;Hyuck Kim;Jinho Cho
    • Korean Journal of Agricultural Science
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    • v.50 no.4
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    • pp.861-867
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    • 2023
  • Lairages serve several functions, such as providing post-mortal inspections and providing a reservoir of animals to ensure the slaughter line runs efficiently. High stress lairage conditions can contribute to the accumulation of transport stress in pigs, causing poor pork quality and still stressed pigs at slaughter. The objective of this study was to investigate meat quality, blood profile and behavior changes according to lairage stocking density in in high temperature. Density treatments were as follows: LD, low density (lower than 0.5 m2/100 kg); ND, normal density (0.5 m2/100 kg to 0.83 m2/100 kg); HD, high density (higher than 0.83 m2/100 kg). Air temperature treatment was as follows: HT, high temperature (higher than 24℃). Pigs stocked with LD showed lower pH, WHC (water holding capacity), and higher DL (drip loss) and CL (cooking loss) than those stocked with HD. Pigs stocked with LD showed lower cortisol level than those stocked with HD. Therefore, Pigs exposed to high stock density (lower than 0.5 m2/100 kg) in high air temperature during pre-slaughter caused acute stress and lead to PSE (pale, soft, exudative) pork incidence. Based on obtained results, stocking of too high (lower than 0.5 m2/100 kg) density is generally not good for meat quality and animal welfare at high temperatures.

Osteoporotic Ankle Fracture (골다공증성 족관절 골절)

  • Hyobeom Lee;Cheolhyun Kim;Gab-Lae Kim
    • Journal of Korean Foot and Ankle Society
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    • v.27 no.2
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    • pp.43-48
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    • 2023
  • The incidence of osteoporotic ankle fractures is increasing as the population ages. These fractures are becoming more common in clinical practice and require careful management because of the higher likelihood of developing complications than typical ankle fractures. The introduction of a method for measuring the ankle joint bone mineral density is a valuable tool for assessing the bone quality of the ankle joint. By evaluating the bone mineral density, healthcare professionals can better understand the extent of osteoporosis and the overall strength of the ankle joint. This information is crucial for determining the appropriate treatment for individual fractures. Several factors must be considered when deciding on the treatment for osteoporotic ankle fractures. These include the ankle joint bone mineral density, skin condition, any comorbidities the patient may have, and the patient's functional demands. Taking these factors into consideration allows healthcare providers to tailor the treatment plan to the specific needs and the circumstances of each patient. By applying the appropriate treatment, it is expected that the complications associated with osteoporotic ankle fractures can be minimized, and the prognosis for patients can be improved.

A Study on Occupational Hydrofluoric Acid Burns in a Hydrofluoric Acid Manufacturing Factory (불산제조업체에서 발생한 불산화상에 관한 조사연구)

  • Lim, Hyun-Sul;Cheong, Hae-Kwan;Kim, Ji-Young
    • Journal of Preventive Medicine and Public Health
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    • v.26 no.4 s.44
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    • pp.587-598
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    • 1993
  • Hydrofluoric acid is one of the strongest irritating, corrosive and poisonous inorganic chemicals. Hydrofluoric acid burns are occurring with ever-increasing frequency due to the wide use of this acid in industries. Hydrofluoric acid burns are characterized by severe progressive tissue destruction and excruciating pain due to the unique properties of the freely dissolvable fluoride ion. The authors reviewed medical records of 32 cases (36 spells) of hydrofluoric acid burns which occurred in a hydrofluoric acid manufacturing factory from Sep. 1, 1990 to June 30, 1993. The results are as follows; 1. Eleven measurements of air concentrations of hydrofluoric acid by detection tube method from 1990 to 1992 were all below TLV (Department of Labor, R.O. K). 2. There were 19 cases (22 spells) of hydrofluoric acid burns which occurred during the study period among regular employees. The overall incidence density of hydrofluoric acid was 17.8 cases (20.6 spells) per 100 person-year. Incidence density was 19.0 cases (22.0 spells) per 100 person-year among male workers and there were no female cases. Incidence density was 32.9 cases (38.3 spells) per 100 person-year among production workers and 1.9 cases (1.9 spells) per 100 person-years among management workers with the difference being statistically significant (P<0.01). 3. Of 32 cases (36 spells) of hydrofluoric acid burns among workers who were regularly employed or temporarily employed, 26 spells (81.2%) were between age 20 to 39. In 15 spells(41.7%) burns occurred between 12:00 and 17:59 with 16 spells(44.3%) having arrived at hospital within 2 hours after the accident. 4. Of 36 spells, the main cause of hydrofluoric acid burns were by splashes (8 spells, 22.2 %). The most frequent site of burns were fingers and pain was the most frequent symptom. Thirty spells (83.3%) of the hydrofluoric acid burns were treated with local injection of antidote (calcium gluconate). Complete recovery without scarring were observed in most of the cases (34 out of 36 cases, 94.4%). The study results suggest that to prevent hydrofluoric acid burns, environmental control and the wearing of hydrofluoric acid resistant protective clothes and gloves are important. It is also stressed that establishment of an emergency management and a transfer system for hydrofluoric acid burn victims is necessary.

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Optimum Stand Density Control Considering Stability in Larix kaempferi Forests (임분 안정성을 고려한 일본잎갈나무 임분밀도 관리의 적정 수준)

  • Park, Joon Hyung;Chung, Sang Hoon;Kim, Sun Hee;Lee, Sang Tae
    • Journal of Korean Society of Forest Science
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    • v.109 no.2
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    • pp.202-210
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    • 2020
  • This study investigated the optimal levels of stand density control considering the stability of Larix kaempferi stands. A stand density management diagram was developed from 259 sample plots. Based on these data, we determined an optimal level of the stand density control by identifying the relationship between the relative yield index (Ry) and height-to-diameter ratio. The estimated r-square (R2) of the stand density management diagram is 0.600. The analysis of the relationship between Ry and the slender tree incidence showed that when the stand density exceeded a certain threshold and the ratio of slender trees rapidly increased. The critical value of Ry was 0.63. The results of this study are expected to contribute to the establishment of stand management strategies that can reduce damage from natural causes, such as wind and snow, and to develop stand practice systems for the improved productivity of commercial forests.

Effect of light intensity on first feeding of the chub mackerel Scomber japonicus larvae

  • Yoon, Ho-Seop;Hwang, Jae-Ho;Choi, Sang-Duk
    • Animal cells and systems
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    • v.14 no.2
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    • pp.125-128
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    • 2010
  • This study investigated the effect of different light intensities on first feeding of chub mackerel Scomber japonicus larvae. Fertilized eggs, obtained from LHRHa-induced spawning of captive broodstock, were stocked (60 larvae/l) into twelve 30-1 aquaria under light intensities of 0, 100, 200, 500 and 1000 lx, with three replicate aquaria per treatment. Temperature was maintained at $20^{\circ}C$ and salinity was 35 psu. Larvae were fed the rotifer Brachionus rotundiformis at a density of five rotifers/ml. Feeding incidence was measured as the percentage of larvae with prey in the digestive tract. Feeding intensity was evaluated as the number of prey in the digestive tract of the larvae. Larvae fed in darkness (0 lx) had significantly lower (P < 0.05) feeding incidence ($13{\pm}0.05%$ larvae with prey) and feeding intensity ($1.00{\pm}0.05$ rotifers per larva) than those larvae fed at 100 ($30{\pm}0.07%$, $1.17{\pm}0.09$ rotifers per larva), 200 ($43{\pm}0.08%$, $1.24{\pm}0.11$ rotifers larvae$^{-1}$), 500 ($53{\pm}0.08%$, $1.48{\pm}0.14$ rotifers per larva) and 1000 lx ($60{\pm}0.08%$, $1.38{\pm}0.13$ rotifers per larva). The feeding incidence of S. japonicus larvae increased with light intensity while feeding intensity showed no significant difference (P > 0.05) between light treatments.