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The Variations of Stratospheric Ozone over the Korean Peninsula 1985~2009 (한반도 상공의 오존층 변화 1985~2009)

  • Park, Sang Seo;Kim, Jhoon;Cho, Nayeong;Lee, Yun Gon;Cho, Hi Ku
    • Atmosphere
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    • 제21권4호
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    • pp.349-359
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    • 2011
  • The climatology in stratospheric ozone over the Korean Peninsula, presented in previous studies (e.g., Cho et al., 2003; Kim et al., 2005), is updated by using daily and monthly data from satellite and ground-based data through December 2009. In addition, long-term satellite data [Total Ozone Mapping Spectrometer (TOMS), Ozone Monitoring Instrument (OMI), 1979~2009] have been also analyzed in order to deduce the spatial distributions and temporal variations of the global total ozone. The global average of total ozone (1979~2009) is 298 DU which shows a minimum of about 244 DU in equatorial latitudes and increases poleward in both hemispheres to a maximum of about 391 DU in Okhotsk region. The recent period, from 2006 to 2009, shows reduction in total ozone by 6% relative to the values for the pre-1980s (1979~1982). The long-term trends were estimated by using a multiple linear regression model (e.g., WMO, 1999; Cho et al., 2003) including explanatory variables for the seasonal variation, Quasi-Biennial Oscillation (QBO) and solar cycle over three different time intervals: a whole interval from 1979 to 2009, the former interval from 1979 to 1992, and the later interval from 1993 to 2009 with a turnaround point of deep minimum in 1993 is related to the effect of Mt. Pinatubo eruption. The global trend shows -0.93% $decade^{-1}$ for the whole interval, whereas the former and the later interval trends amount to -2.59% $decade^{-1}$ and +0.95% $decade^{-1}$, respectively. Therefore, the long-term total ozone variations indicate that there are positive trends showing a recovery sign of the ozone layer in both North/South hemispheres since around 1993. Annual mean total ozone (1985~2009) is distributed from 298 DU for Jeju ($33.52^{\circ}N$) to 352 DU for Unggi ($42.32^{\circ}N$) in almost zonally symmetric pattern over the Korean Peninsula, with the latitudinal gradient of 6 DU $degree^{-1}$. It is apparent that seasonal variability of total ozone increases from Jeju toward Unggi. The annual mean total ozone for Seoul shows 323 DU, with the maximum of 359 DU in March and the minimum of 291 DU in October. It is found that the day to day variability in total ozone exhibits annual mean of 5.7% in increase and -5.2% in decrease. The variability as large as 38.4% in increase and 30.3% in decrease has been observed, respectively. The long-term trend analysis (e.g., WMO, 1999) of monthly total ozone data (1985~2009) merged by satellite and ground-based measurements over the Korean Peninsula shows increase of 1.27% $decade^{-1}$ to 0.80% $decade^{-1}$ from Jeju to Unggi, respectively, showing systematic decrease of the trend magnitude with latitude. This study also presents a new analysis of ozone density and trends in the vertical distribution of ozone for Seoul with data up to the end of 2009. The mean vertical distributions of ozone show that the maximum value of the ozone density is 16.5 DU $km^{-1}$ in the middle stratospheric layer between 24 km and 28 km. About 90.0% and 71.5% of total ozone are found in the troposphere and in the stratosphere between 15 and 33 km, respectively. The trend analysis reconfirms the previous results of significant positive ozone trend, of up to 5% $decade^{-1}$, in the troposphere and the lower stratosphere (0~24 km), with negative trend, of up to -5% $decade^{-1}$, in the stratosphere (24~38 km). In addition, the Umkehr data show a positive trend of about 3% $decade^{-1}$ in the upper stratosphere (38~48 km).

Study on Distribution and Change of Curvature of the Anterior Corneal Surface with each Age in Emmetropia (정시안의 연령별 각막전면곡률 변화와 분포에 관한 연구)

  • Kim, Chan-Soo;Sung, A-Young
    • Journal of Korean Ophthalmic Optics Society
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    • 제9권2호
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    • pp.211-221
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    • 2004
  • The purpose of this study is to evaluate the distribution and change of curvature of the anterior corneal surface with age in emmetropia. 504 subjects who have emmetroia with good naked vision of at least 0.6-1.0 (spherical equivalent: +0.75D- -0.75D) participated in this study. The 504 subjects into 8 groups with 10 year interval from 3-year to 83-year, and their corneal curvatures were analyzed using manual keratometry. The results are as follows. In individual analysis: First, regression analysis of corneal curvature radius with age has given an equation: Y = -0.003x + 7.796 (r = -0.26). The average corneal curvature radii was measured to be $7.68{\pm}0.25mm$ at 38.3-year and range was 6.98-8.54 mm. Second, frequency of corneal curvature radius were obtained in 36% between 7.61 and 7.80 mm, 78% between 7.41 and 8.00 mm, 96% between 7.21 and 8.20 mm, 100% between 6.98 and 8.54 mm. Third, as for the comparison of corneal curvature radius with respect to sex, The mean value of male (n = 304, mean: 37.6-year $7.72{\pm}0.24mm$, Range: 7.09-8.54 mm) is larger than that of female (n = 200, mean: 39.3-year $7.62{\pm}0.24mm$, Range: 6.98-8.42 mm) by 0.1mm (p<0.01). In groups analysis: First, regression analysis of corneal curvature radius with age has given an equation: $Y=-0.0066x^2+0.0227x+7.7282$ (r = -0.90). Second, vertical and horizontal curvature radius decreased with age (p < 0.01). Especially the decrease of horizontal curvature radius were more pronounced than the decrease of vertical (horizontal:10-70 age group: 0.38 mm decrease, vertical:10-70 age group: 0.20 mm decrease). Third, difference between steep and flat meridian (astigmatism) progressively decreased with age. (low age group:0.18 mm difference, high age group: 0.08 mm difference). Fourth, the corneal curvature radius of male was larger than female's in total groups(p < 0.01). Consequently, the change of corneal curvature radius with age progressively decreased in all conditions (mean, vertical, horizontal, male, and female) and this change was more outstanding in horizontal rather than in vertical.

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Tibial Torsion in Children of the Jeju Area (제주지역 소아의 경골 염전)

  • Song, Dong Ho;Eun, Baik-Lin;Park, Sang Hee;Lee, Joon Young;Tockgo, Young Chang
    • Clinical and Experimental Pediatrics
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    • 제48권1호
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    • pp.75-80
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    • 2005
  • Purpose : Internal tibial torsion is prevalent in East Asian countries such as Korea and Japan, where sitting on the floor is common behavior. Internal tibial torsion or excessive lateral tibial torsion may cause esthetical, functional, or psychological problems and also may induce degenerative arthritis in older age. The purpose of this study is to measure the tibial torsion in children of the Jeju area. Methods : Tibial torsion was measured in 1,042 lower extremities of 521 children from one to 12 years of age. The values of transmalleolar angles were analyzed for each age group divided by 6 months. Quadratic and linear regression models were used to fit patterns of changes in mean values of transmalleolar angles. The age at seven, which provides the highest coefficient of determination for quadratic regression analysis, was used as a cut-off point to fit different statistical models. Results : The mean transmalleolar angle was $0.10{\pm}5.79^{\circ}$ in all children,$ 0.90{\pm}5.49^{\circ}$ in males, and $-0.80{\pm}5.97^{\circ}$ in females. The value was $4.25{\pm}4.04$ in 1 year of age, gradually decreased to the lowest level of $-1.98^{\circ}$ in four years and seven months of age, increased again with age until it reached $0.67{\pm}1.10^{\circ}$ at seven years of age, and stayed at that level thereafter. Conclusion : Internal tibial torsion in infancy is known to correct spontaneously in the normal developing process. But in this study, the mean transmalleolar angle in children of Jeju area annually decreased after one year of age; to the lowest angle at four years and seven months of age; increased again gradually to the age of seven; and persisted in that level, about $10^{\circ}$ less than western children, not correcting further thereafter. These findings suggest tibial torsion might be caused by lifestyle, especially sitting on feet. To prevent abnormalities of joints and gaits, early diagnosis of tibial torsion in childhood and posture correction or early treatment when needed, seems to be necessary.

A study of neuropeptides related to headaches in children with meningeal irritation signs (수막 자극 증상으로 내원한 환자에서 두통과 관련된 신경 펩타이드에 대한 연구)

  • Seo, Bo Gil;Yoo, Myung Hwan;Shim, Jae Won;Shim, Jung Yeon;Jung, Hye Lim;Park, Moon Soo;Kim, Deok-Soo
    • Clinical and Experimental Pediatrics
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    • 제49권5호
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    • pp.533-538
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    • 2006
  • Purpose : The headache, one of the symptoms of meningitis, is related to abrupt elevation of intracranial pressure(ICP) or stimulation of intracranial nociceptive structure. However, in cases of mild elevation of ICP or normal findings of cerebrospinal fluid(CSF) analysis, patients sometimes complain of headaches. Therefore, other pathways may contribute to the occurrence of headaches in aseptic meningitis or meningismus. We intend to investigate the role of substance P(SP) and calcitonin gene-related peptide(CGRP) in aseptic meningitis or meningismus. Methods : We measured leukocyte count, the concentration of protein and glucose in CSF and ICP of patients with meningeal irritation sign. We also measured SP and CGRP levels by using immunoassay. We analyzed the relationship between the presence of headache and the value of SP and CGRP. Results : The concentrations of CGRP($18.8{\pm}10.5ng/mL$) in CSF and ICP($14.8{\pm}4.5cmH_2O$) in aseptic meningitis group were significantly higher than in those($14.1{\pm}7.4ng/mL$ and $12.0{\pm}5.1cmH_2O$, respectively) of the meningismus group(P<0.05). There was no significant difference in the SP levels between the two groups. In the aseptic meningitis group, the concentrations of SP and CGRP were significantly higher in the normal ICP group than in the elevated ICP group(P<0.05). Conclusion : Headaches in children with aseptic meningitis or meningismus is considered to be related to the elevation of the CSF levels of SP and CGRP.

The Effect of Washing of Carcasses with Sodium Hypochlorite Solution and Vacuum Packaging on the Microbiological and Physiochemical Quality of the Breast Meat from Old Hen during Storage at 4℃ (차아염소산나트륨 세척 및 진공 포장이 노계 가슴육의 냉장 저장 중 미생물학적 및 이화학적 품질에 미치는 영향)

  • Na, Jae Cheon;Kim, Sun Hyo;Jung, Samooel;Lee, Soo Kee;Kang, Hwan Gu;Choi, Hee Cheol;Jo, Cheorun
    • Korean Journal of Poultry Science
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    • 제40권4호
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    • pp.327-336
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    • 2013
  • This study was conducted to examine the effect of spray-washing old hens (old laying hens, old molting hens and old breeder hens) carcasses with sodium hypochlorite (50 ppm) solution and vacuum packaging on the microbiological and physiochemical quality of breast meat during storage at $4^{\circ}C$. There were no significant differences of cooking loss and texture among breast meats from different birds with spray-washing by water or sodium hypochlorite solution before storage. The numbers of total aerobic bacteria of aerobically packaged and only water-washed breast meat were higher than 7 Log CFU/g (the limitation population for spoilage of meat) after 7 days of storage. However, the numbers of total aerobic bacteria of vacuum packaged breast meat washed by sodium hypochlorite solution were lower than 7 Log CFU/g even after 14 days of storage. The volatile basic nitrogen content of vacuum packaged breast meat were lower than 20 mg% (the limitation value for spoilage of meat) regardless of the washing method, while those of aerobically packaged breast meat washed by tap water and sodium hypochlorite solution were 41.1 and 20.1 mg%, respectively. In addition, lipid oxidation and change of pH in breast meat was inhibited by vacuum packaging when compared with that of aerobic packaged breast meat during storage. Therefore, the results indicated that the washing old hen's carcasses with sodium hypochlorite (50 ppm) solution and vacuum packaging could improve the shelf-life of meat from old birds. This result can provide the basic information for industry, which are seeking for export market.

A Study on the Impact of Competency of Technology: Based Startups on Performance Using ETRI Technology (ETRI 기술을 활용한 기술창업기업의 역량이 경영성과에 미치는 영향에 관한 연구)

  • Bae, Hongbeom;Song, Minkyung;Kim, Seokyun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • 제13권1호
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    • pp.61-72
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    • 2018
  • In a rapidly changing environment, such as globalization, technology-based startups are attracting attention as a new growth engine that creates jobs and added value and promotes national competitiveness. At present, countries around the world recognize the development of technology-based start-up companies as a major policy task and strive to make policy efforts to revitalize start-ups and strengthen innovation capabilities of companies. Especially, in order to secure superiority in the fierce market competition, it is becoming more and more important for the growth and development of technological start-up companies that pioneer new markets and energize the economy based on original and innovative technologies. Therefore, it is necessary to study systematically and plan for survival and growth of technology start-up companies. The purpose of this study is to investigate the entrepreneurial spirit of Innovation, Entrepreneurship, Risk Sensibility and Technology Innovation Capacity, R&D ability, Technology Accumulation Capacity, Technology Innovation System, The results of this study are as follows. the effects of marketing ability on technical performance and financial performance are examined. First, the CEO 's entrepreneurial spirit has an effect on the technical performance and financial performance of the management performance. Second, the technology accumulation ability and the R & D capability have a positive effect on the technical performance. Finally, it was found that the ability to commercialize the technology commercialization capacity affects both technical performance and financial performance. The policy implications that can be gained through this are as follows. First, by strengthening cooperation between universities and research institutes, related technology entrepreneurship education programs should be upgraded so that technology entrepreneurs or preliminary entrepreneurs can capture business opportunities and secure market price competitiveness. Secondly, R & D for the purpose of start-up should be developed and marketable technology should be developed and linked to direct start-up. Third, it is necessary to activate the program to match the company with the honorary retirement manpower of large enterprises and SMEs, which have more experience in field experience than the founders.

Evaluation of Image Quality by Using a Tungsten Edge Block in a Megavoltage (MV) X-ray Imaging (텅스텐 엣지 블록을 이용하여 Megavoltage (MV) 영상의 질 평가)

  • Min, Jung-Whan;Son, Jin-Hyun;Kim, Ki-Won;Lee, Jung-Woo;Son, Soon-Yong;Back, Geum-Mun;Kim, Jung-Min;Kim, Yeon-Rae;Jung, Jae-Yong;Kim, Sang-Young;Lee, Do-Wan;Choe, Bo-Young
    • Progress in Medical Physics
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    • 제23권3호
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    • pp.154-161
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    • 2012
  • Digital Radiography (DR) has rapidly developed in megavoltage X-ray imaging (MVI). Thus, a very simple and general quality assurance (QA) method is required. The purpose of this study was to evaluate the modulation transfer function (MTF), the noise power spectrum (NPS) and the detective quantum efficiency (DQE) for MVI using general QA method and computed radiography (CR) device. We used tungsten edge block with $19{\times}10{\times}1cm^3$ thickness and 6MV energy. For detector, CR-IP (image plate), CR-IP-lead, the CR-IP-back (lanex TM fast back screen), CR-IP-front (lanex TM fast front screen) were used and pre-sampling MTF was calculated. The MTF of CR-IP-front showed the highest value with 1.10 lp/mm although the CR-IP showed the only 0.70 lp/mm. The best NPS was observed in CR-IP front screen. According to the increase in spatial frequency, our results showed that DQE was approximately 1.0 cycles/mm. The present study demonstrates that the QA method with our home-made edge block can be used to evaluate MTF, NPS and DQE for MVI.

Studies on Change of Physico-chemical Properties due to Ripening degrees in the Reclaimed Tidle Deposits I. With reference to Munpo and Pori series (간척지토양(干拓地土壤)의 숙성화정도별(熟成化程度別) 이화학성(理化學性) 변화연구(變化硏究) I. 문포(文浦) 및 포이통(浦里統)에 관(關)하여)

  • Yoo, Chul-Hyun;Cho, Guk-Hyun;Choi, Jeong-Weon;Park, Keon-Ho;Kim, Yeong-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • 제22권3호
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    • pp.180-190
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    • 1989
  • In order to obtain basic information on soil inprovement and management of two reclaimed paddy soils, Munpo and Pori series, this study was carried out by investigating the change of physico-chemical and soil mechanical properties. 1. In the Munpo series, the contents of salt in the soil and ground water before paddy rice transplanting at 6 years after reclamation were 0.60 and 1.84%, respectively, and the safty cultivation of paddy rice was possible after 20 years, while that of the Pori series was after 12 years. 2. In the Munpo series, the change of the soil particle size according to the ages after reclamation showed negative correlation with sandy contents, but clay contents had positive correlation both in the surface and subsurface soils. The pori series showed reverse tendency. 3. Between the N-value and Atterberg limits and the ages showed negative correlation in both Munpo and Pori series, but clay-activity showed positive. Arid the cole values showed positive correlation in the Munpo series, but negative in the Pori series. 4. Cone penetrating resistance in the surface of the Munpo series after 6 years of reclamation was 62.9, after 20 years 24.5 and $16.7kg/cm^2$ in 15cm of soil depth at depth of 22.5cm after 27 years. In the Pori series, it was $3kg/cm^2$ at 15-20cm of soil depth after 12 years and it used after being creation of hard pan layer after 23 years. 5. Change of the clay minerals by the different year after accomplishment of tidal reclamation did not show. The major clay minerals were illite and kaolinite, and accessory clay minerals were montmorillonite and vermiculite in both Munpo and Pori series.

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Effects of Supplementation of Mixed Methanogens and Rumen Cellulolytic Bacteria on Biochemical Methane Potential (혼합 메탄균과 반추위 섬유소 분해균 첨가가 메탄발생에 미치는 영향)

  • Kim, Ji-Ae;Yoon, Young-Man;Kim, Chang-Hyun
    • Korean Journal of Soil Science and Fertilizer
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    • 제45권4호
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    • pp.515-523
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    • 2012
  • The study investigated the biochemical methane potential (BMP) assay of cellulose supplementing with mixed methanogens and cellulolytic bacteria to improve anaerobic digestion for methane production. For the BMP assay, 7 different microbial supplementation groups were consisted of the cultures of mixed methanogens (M), Fibrobacter succinogenes (FS), Ruminococcus flavefaciensn (RF), R. albus (RA), RA+FS and M+RA+FS including control. The cultures were added in the batch reactors with the increasing dose levels of 1% (0.5 mL), 3% (1.5 mL) and 5% (2.5 mL). Incubation for the BMP assay was carried out for 40 days at $38^{\circ}C$ and anaerobic digestate obtained from an anaerobic digester with pig slurry as inoculum was used. In results, 5% FS increased total biogas and methane production up to 10.4~22.7% and 17.4~27.5%, respectively, compared to other groups (p<0.05). Total solid (TS) digestion efficiency showed a similar trend to the total biogas and methane productions. Generally the TS digestion efficiency of the FS group was higher than that of other groups showing at the highest value of 64.2% in the 5% FS group. Volatile solid (VS) digestion efficiencies of 68.4 and 71.0% in the 5% FS and the 5% RF were higher than other groups. After incubation, pH values in all treatment groups were over 6.4 indicating that methanogensis was not inhibited during the incubation. In conclusion, the results indicated that the hydrolysis stage for methane production in anaerobic batch reactors was the late-limiting stage compared with the methanogenesis stage, and especially, as the supplementation levels of F. succinogenes supplementation increased, the methane production was increased in the BMP assay compared with other microbial culture addition.

The Role of Video-Assisted Thoracic Surgery in the Diagnosis and the Treatment of a Mediastinal Mass (종격동 병변의 진단 및 치료와 비디오 흉강경의 역할 -흉강경에 의한 종격동 병변 진단 치료-)

  • Baek, Hyo-Chae;Park, Han-Gi;Bae, Gi-Man;Lee, Du-Yeon
    • Journal of Chest Surgery
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    • 제29권7호
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    • pp.769-776
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    • 1996
  • The application of video-assisted thoracic surgery (VATS) in the examination of the thoracic cavity can be a new option in patients with mediastinal tumor because it provides outstanding visibility of the structures of the mediastinum. By clear viewing through the thoracoscope, a mediastinal tumor can be biopsied or resected, depending on the findings during an operation. We reviewed all patients who underwent curative or diagnostic operations from March 1990 to August 1995 under the impression of a mediastinal mass. The total number of patients were 113 with 59 males and 54 females. Group A underwent resection of tu or by thoracotomy(38 patients: 18 males, 20 females), and group B underwent resection of tumor by VATS (36 patients : 20 males and 16 females). Seven patients in group B were excluded because they underwent thoracotomy due to pleural adhesion or intra-operative bleeding ; therefore, the true VATS group numbered 29 cases. Group C underwent Iymph node biopsy by VATS(33 patients'16 males, 17 females), and group D(6 patients: 5 males, 1 female) underwent Iymph node biopsy through anterior mediastinotomy. The mean age in group A was 36.2 years compared to 41.3 years In group B. We compared operation time, frequency of injection for pain control, duration of chest tube insertion, postoperative hospital stay, and diagnostic yield. In group A, they were 164 minutes, 3.4 times, 5.2 days, and 11.3 days, respectively, in comparison to 152 minutes, 2 times, 4.7 days, and 8.3 days, respectively, in group B. These data revealed that the day of discharge was significantly shorter in group B (p valu : 0.03). In group C, the mean age was 45.8 years (range 1 ∼70). The operation time was from 30 to 335 minutes (mean 105), pain control was required from 0 to 15 times(mean 3.2), and a chest tube was needed for 1 to 36 days (mean 6.1). In group D, mean age was 53.3 years, operation time 121 minutes, pall control injec- tion frequency 2.6 times, and mean chest tube duration 10.5 days. The diagnostic yield in group C was 8 oyo compared to 100 oyo in group D although the number of patients in group D is small.

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