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Assesment of Bone Strength Using a New Quantitative Ultrasound Device in Children with Renal Diseases (신질환 환아에서 초음파 골량측정법을 이용한 골상태 평가)

  • Kang Ju-Hyung;Shin Yun-Hye;Cho Nam-Han;Pai Ki-Soo
    • Childhood Kidney Diseases
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    • v.9 no.1
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    • pp.21-30
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    • 2005
  • Purpose : Metabolic bone diseases have been mai or problems in children with renal diseases and steroid treatment is the main precipitating factor reducing bone mineral density(BMD). This study was performed to assess the prevalence of osteoporosis and to evaluate the clinical factors associated with decreased BMD in children with renal diseases. Methods : Forty-four children with renal diseases who were diagnosed at the Pediatric no phrology division of Ajou University hospital since Oct. 1994 were included. Using a new quantitative ultrasound device, BMD and the prevalence of osteoporosis were evaluated. The clinical and serological data were analyzed in association with decreased BMD. Results : A total of 44 patients were evaluated. The age at initial diagnosis was 6.7$\pm$4.2 years. At the time of evaluation, the chronological and bone age was 9.3$\pm$4.2 years and 8.2 $\pm$ 4.6 years, respectively. The renal diseases included nephrotic syndrome 24(54.5%), Henoch Schonlein purpura nephritis 7(15.9%), IgA nephropathy 6(13.9%), reflux nephropathy(RN) 2 (4.5%), and other renal disease 5(%). The prevalence of osteoporosis was 11%. There was no difference in the clinical factors between the long-term and the short-term treated steroid groups. Conclusion : The prevalence of osteoporosis was 12% in 44 children with renal diseases No significant factor was found in association with decreased BMD and there was no relationship between osteoporosis and steroid usage duration or cumulative dose. A new quantitative ultrasound, which is relatively easy to perform, especially in children, is expected to be in common use and will enable clinicians to evaluate metabolic bone disorders with ease.

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Significance of Early Visual Responses to Anti-Vascular Endothelial Growth Factor in Age-related Macular Degeneration (신생혈관 연령관련황반변성에서 항혈관내피세포성장인자 주입술 시행 후 시력 반응의 의의)

  • Song, Hee Jun;Yang, Ji Ho;Kim, Do Gyun
    • Journal of The Korean Ophthalmological Society
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    • v.59 no.11
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    • pp.1030-1038
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    • 2018
  • Purpose: To evaluate whether early visual acuity response at 4 weeks after the first intravitreal anti-vascular endothelial growth factor (VEGF) injection or 4 weeks after the third injection in neovascular age-related macular degeneration (nAMD) is associated with 12-month follow-up outcome. Methods: Thirty treatment-naive patients (30 eyes) with nAMD, treated with intravitreal anti-VEGF, were retrospectively included. Initially, all patients were injected at least three times for three consecutive months and followed up with a pro re nata regimen for at least 12 months. The relationship between 4 weeks after the first and third anti-VEGF injections in visual acuity response was explored, including the mean change from baseline in best-corrected visual acuity (BCVA). The mean change in BCVA was classified into three groups according to visual improvement: <1, 1-<3, or ${\geq}3$ logMAR line(s) in BCVA. The associations among baseline characteristics (gender, age, duration of symptoms, initial BCVA, central macular thickness, and intraocular pressure) and visual acuity responses 4 weeks after the first and third anti-VEGF injections were also assessed. Results: The proportions of eyes with <1, 1-<3, and ${\geq}3-line(s)$ improvement at 4 weeks after the first injection were 6 eyes (20%), 7 eyes (23.3%), and 17 eyes (56.6%), respectively. The proportions of eyes with <1, 1-<3, and ${\geq}3-line(s)$ improvement at 4 weeks after the third injection were 9 eyes (30%), 9 eyes (30%), and 12 eyes (40%), respectively. A BCVA response ${\geq}3-lines$ improvement at 4 weeks after the third injection showed significant associations with ${\geq}3-line(s)$ improvement and BCVA response at 12 months in multiple logistic and linear regression analyses (p = 0.04). Conclusions: In this study, BCVA response ${\geq}3-lines$ improvement at 4 weeks after the third injection showed a significant association with ${\geq}3-line(s)$ improvement and BCVA response at 12 months.

The inference about the cause of death of Korean Fir in Mt. Halla through the analysis of spatial dying pattern - Proposing the possibility of excess soil moisture by climate changes - (한라산 구상나무 공간적 고사패턴 분석을 통한 고사원인 추정 - 기후변화에 따른 토양수분 과다 가능성 제안 -)

  • Ahn, Ung San;Kim, Dae Sin;Yun, Young Seok;Ko, Suk Hyung;Kim, Kwon Su;Cho, In Sook
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.21 no.1
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    • pp.1-28
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    • 2019
  • This study analyzed the density and mortality rate of Korean fir at 9 sites where individuals of Korean firs were marked into the live and dead trees with coordinates on orthorectified aerial images by digital photogrammetric system. As a result of the analysis, Korean fir in each site showed considerable heterogeneity in density and mortality rate depending on the location within site. This make it possible to assume that death of Korean fir can occur by specific factors that vary depending on the location. Based on the analyzed densities and mortality rates of Korea fir, we investigated the correlation between topographic factors such as altitude, terrain slope, drainage network, solar radiation, aspect and the death of Korean fir. The density of Korean fir increases with altitude, and the mortality rate also increases. A negative correlation is found between the terrain slope and the mortality rate, and the mortality rate is higher in the gentle slope where the drainage network is less developed. In addition, it is recognized that depending on the aspect, the mortality rate varies greatly, and the mean solar radiation is higher in live Korean fir-dominant area than in dead Korean fir-dominant area. Overall, the mortality rate of Korean fir in Mt. Halla area is relatively higher in areas with relatively low terrain slope and low solar radiation. Considering the results of previous studies that the terrain slope has a strong negative correlation with soil moisture and the relationship between solar radiation and evaporation, these results lead us to infer that excess soil moisture is the cause of Korean fir mortality. These inferences are supported by a series of climate change phenomena such as precipitation increase, evaporation decrease, and reduced sunshine duration in the Korean peninsula including Jeju Island, increase in mortality rate along with increased precipitation according to the elevation of Mt. Halla and the vegetation change in the mountain. It is expected that the spatial patterns in the density and mortality rate of Korean fir, which are controlled by topography such as altitude, slope, aspect, solar radiation, drainage network, can be used as spatial variables in future numerical modeling studies on the death or decline of Korean fir. In addition, the method of forest distribution survey using the orthorectified aerial images can be widely used as a numerical monitoring technique in long - term vegetation change research.

Immune Cells Are Differentially Affected by SARS-CoV-2 Viral Loads in K18-hACE2 Mice

  • Jung Ah Kim;Sung-Hee Kim;Jeong Jin Kim;Hyuna Noh;Su-bin Lee;Haengdueng Jeong;Jiseon Kim;Donghun Jeon;Jung Seon Seo;Dain On;Suhyeon Yoon;Sang Gyu Lee;Youn Woo Lee;Hui Jeong Jang;In Ho Park;Jooyeon Oh;Sang-Hyuk Seok;Yu Jin Lee;Seung-Min Hong;Se-Hee An;Joon-Yong Bae;Jung-ah Choi;Seo Yeon Kim;Young Been Kim;Ji-Yeon Hwang;Hyo-Jung Lee;Hong Bin Kim;Dae Gwin Jeong;Daesub Song;Manki Song;Man-Seong Park;Kang-Seuk Choi;Jun Won Park;Jun-Won Yun;Jeon-Soo Shin;Ho-Young Lee;Ho-Keun Kwon;Jun-Young Seo;Ki Taek Nam;Heon Yung Gee;Je Kyung Seong
    • IMMUNE NETWORK
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    • v.24 no.2
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    • pp.7.1-7.19
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    • 2024
  • Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019. In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virus-infected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105 PFU; however, 1×12 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Studies on the Varietal Difference in the Physiology of Ripening in Rice with Special Reference to Raising the Percentage of Ripened Grains (수도 등숙의 품종간차이와 그 향상에 관한 연구)

  • Su-Bong Ahn
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.14
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    • pp.1-40
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    • 1973
  • There is a general tendency to increase nitrogen level in rice production to insure an increased yield. On the other hand, percentage of ripened grains is getting decreased with such an increased fertilizer level. Decreasing of the percentage is one of the important yield limiting factors. Especially the newly developed rice variety, 'Tongil' is characterized by a relatively low percentage of ripened grains as compared with the other leading varieties. Therefore, these studies were aimed to finding out of some measures for the improvement of ripening in rice. The studies had been carried out in the field and in the phytotron during the period of three years from 1970 to 1972 at the Crop Experiment Station in Suwon. The results obtained from the experiments could be summarized as follows: 1. The spikelet of Tongil was longer in length, more narrow in width, thinner in thickness, smaller in the volume of grains and lighter in grain weight than those of Jinheung. The specific gravity of grain was closely correlated with grain weight and the relationship with thickness, width and length was getting smaller in Jinheung. On the other hand, Tongil showed a different pattern from Jinheung. The relationship of the specific gravity with grain weight was the greatest and followed by that with the width, thickness and length, in order. 2. The distribution of grain weight selected by specific gravity was different from one variety to another. Most of grains of Jinheung were distributed over the specific gravity of 1.12 with its peak at 1.18, but many of grains of Tongil were distributed below 1.12 with its peak at 1.16. The brown/rough rice ratio was sharply declined below the specific gravity of 1.06 in Jinheung, but that of Tongil was not declined from the 1.20 to the 0.96. Accordingly, it seemed to be unfair to make the specific gravity criterion for ripened grains at 1.06 in the Tongil variety. 3. The increasing tendency of grain weight after flowering was different depending on varieties. Generally speaking, rice varieties originated from cold area showed a slow grain weight increase while Tongil was rapid except at lower temperature in late ripening stage. 4. In the late-tillered culms or weak culms, the number of spikelets was small and the percentage of ripened grains was low. Tongil produced more late-tillered culms and had a longer flowering duration especially at lower temperature, resulting in a lower percentage of ripened grains. 5. The leaf blade of Tongil was short, broad and errect, having light receiving status for photosynthesis was better. The photosynthetic activity of Tongil per unit leaf area was higher than that of Jinheung at higher temperature, but lower at lower temperature. 6. Tongil was highly resistant to lodging because of short culm length, and thick lower-internodes. Before flowering, Tongil had a relatively higher amount of sugars, phosphate, silicate, calcium, manganese and magnesium. 7. The number of spikelets of Tongil was much more than that of Jinheung. The negative correlation was observed between the number of spikelets and percentage of ripened grains in Jinheung, but no correlation was found in Tongil grown at higher temperature. Therefore, grain yield was increased with increased number of spikelets in Tongil. Anthesis was not occurred below 21$^{\circ}C$ in Tongil, so sterile spikelets were increased at lower temperature during flowering stage. 8. The root distribution of Jinheung was deeper than that of Tongil. The root activity of Tongil evaluated by $\alpha$-naphthylamine oxidation method, was higher than that of Jinheung at higher temperature, but lower at lower temperature. It is seemed to be related with discoloration of leaf blades. 9. Tongil had a better light receiving status for photosynthesis and a better productive structure with balance between photosynthesis and respiration, so it is seemed that tongil has more ideal plant type for getting of a higher grain yield as compared with Jinheung. 10. Solar radiation during the 10 days before to 30 days after flowering seemed enough for ripening in suwon, but the air temperature dropped down below 22$^{\circ}C$ beyond August 25. Therefore, it was believed that air temperature is one of ripening limiting factors in this case. 11. The optimum temperature for ripening in Jinheung was relatively lower than that of Tongil requriing more than $25^{\circ}C$. Air temperature below 21$^{\circ}C$ was one of limiting factors for ripening in Tongil. 12. It seemed that Jinheung has relatively high photosensitivity and moderate thermosensitivity, while Tongil has a low photosensitivity, high thermosensitivity and longer basic vegetative phase. 13. Under a condition of higher nitrogen application at late growing stage, the grain yield of Jinheung was increased with improvement of percentage of ripened grains, while grain yield of Tongil decreased due to decreasing the number of spikelets although photosynthetic activity after flowering was. increased. 14. The grain yield of Jinheung was decreased slightly in the late transplanting culture since its photosynthetic activity was relatively high at lower temperature, but that of Tonil was decreased due to its inactive photosynthetic activity at lower temperature. The highest yield of Tongil was obtained in the early transplanting culture. 15. Tongil was adapted to a higher fertilizer and dense transplanting, and the percentage of ripened grains was improved by shortening of the flowering duration with increased number of seedlings per hill. 16. The percentage of vigorous tillers was increased with a denser transplanting and increasing in number of seedlings per hill. 17. The possibility to improve percentage of ripened grains was shown with phosphate application at lower temperature. The above mentioned results are again summarized below. The Japonica type leading varieties should be flowered before August 20 to insure a satisfactory ripening of grains. Nitrogen applied should not be more than 7.5kg/10a as the basal-dressing and the remained nitrogen should be applied at the later growing stage to increase their photosynthetic activity. The morphological and physiological characteristics of Tongil, a semi-dwarf, Indica $\times$ Japonica hybrid variety, are very different from those of other leading rice varieties, requring changes in seed selection by specific gravity method, in milling and in the cultural practices. Considering the peculiar distribution of grains selected by the method and the brown/rough rice ratio, the specific gravity criterion for seed selection should be changed from the currently employed 1.06 to about 0.96 for Tongil. In milling process, it would be advisable to bear in mind the specific traits of Tongil grain appearance. Tongil is a variety with many weak tillers and under lower temperature condition flowering is delayed. Such characteristics result in inactivation of roots and leaf blades which affects substantially lowering of the percentage of ripened grains due to increased unfertilized spikelets. In addition, Tongil is adapted well to higher nitrogen application. Therefore, it would be recommended to transplant Tongil variety earlier in season under the condition of higer nitrogen, phosphate and silicate. A dense planting-space with three vigorous seedlings per hill should be practiced in this case. In order to manifest fully the capability of Tongil, several aspects such as the varietal improvement, culural practices and milling process should be more intensively considered in the future.he future.

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Air Pollution and Its Effects on E.N.T. Field (대기오염과 이비인후과)

  • 박인용
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1972.03a
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    • pp.6-7
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    • 1972
  • The air pollutants can be classified into the irritant gas and the asphixation gas, and the irritant gas is closely related to the otorhinolaryngological diseases. The common irritant gases are nitrogen oxides, sulfur oxides, hydrogen carbon compounds, and the potent and irritating PAN (peroxy acyl nitrate) which is secondarily liberated from photosynthesis. Those gases adhers to the mucous membrane to result in ulceration and secondary infection due to their potent oxidizing power. 1. Sulfur dioxide gas Sulfur dioxide gas has the typical characteristics of the air pollutants. Because of its high solubility it gets easily absorbed in the respiratory tract, when the symptoms and signs by irritation become manifested initially and later the resistance in the respiratory tract brings central about pulmonary edema and respiratory paralysis of origin. Chronic exposure to the gas leads to rhinitis, pharyngitis, laryngitis, and olfactory or gustatory disturbances. 2. Carbon monoxide Toxicity of carbon monoxide is due to its deprivation of the oxygen carrying capacity of the hemoglobin. The degree of the carbon monoxide intoxication varies according to its concentration and the duration of inhalation. It starts with headache, vertigo, nausea, vomiting and tinnitus, which can progress to respiratory difficulty, muscular laxity, syncope, and coma leading to death. 3. Nitrogen dioxide Nitrogen dioxide causes respiratory disturbances by formation of methemoglobin. In acute poisoning, it can cause pulmonary congestion, pulmonary edema, bronchitis, and pneumonia due to its strong irritation on the eyes and the nose. In chronic poisoning, it causes chronic pulmonary fibrosis and pulmonary edema. 4. Ozone It has offending irritating odor, and causes dryness of na sopharyngolaryngeal mucosa, headache and depressed pulmonary function which may eventually lead to pulmonary congestion or edema. 5. Smog The most outstanding incident of the smog occurred in London from December 5 through 8, 1952, because of which the mortality of the respiratory diseases increased fourfold. The smog was thought to be due to the smoke produced by incomplete combustion and its byproduct the sulfur oxides, and the dust was thought to play the secondary role. In new sense, hazardous is the photochemical smog which is produced by combination of light energy and the hydrocarbons and oxidant in the air. The Yonsei University Institute for Environmental :pollution Research launched a project to determine the relationship between the pollution and the medical, ophthalmological and rhinopharyngological disorders. The students (469) of the "S" Technical School in the most heavily polluted area in Pusan (Uham Dong district) were compared with those (345) of "K" High School in the less polluted area. The investigated group had those with subjective symptoms twice as much as the control group, 22.6% (106) in investigated group and 11.3% (39) in the control group. Among those symptomatic students of the investigated group. There were 29 with respiratory symptoms (29%), 22 with eye symptoms (21%), 50 with stuffy nose and rhinorrhea (47%), and 5 with sore thorat (5%), which revealed that more than half the students (52%) had subjective symptoms of the rhinopharyngological aspects. Physical examination revealed that the investigated group had more number of students with signs than those of the control group by 10%, 180 (38.4%) versus 99 (28.8%). Among the preceding 180 students of the investigated group, there were 8 with eye diseases (44%), 1 with respiratory disease (0.6%), 97 with rhinitis (54%), and 74 with pharyngotonsillitis (41%) which means that 95% of them had rharygoical diseases. The preceding data revealed that the otolaryngological diseases are conspicuously outnumbered in the heavily polluted area, and that there must be very close relationship between the air pollution and the otolaryngological diseases, and the anti-pollution measure is urgently needed.

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Relationship between Glycated Hemoglobin and Depression, Anxiety, Alexithymia, Stress Response in Diabetic Patients - A Preliminary Study - (당뇨환자에서 당화혈색소와 관련된 우울, 불안, 감정표현불능, 스트레스반응 - 예비적 연구 -)

  • Jeong, Jong-Hyun;Ko, Seung-Hyun;Hong, Seung-Chul;Han, Jin-Hee;Lee, Sung-Pil;Ahn, Yoo-Bae;Song, Ki-Ho
    • Korean Journal of Psychosomatic Medicine
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    • v.12 no.2
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    • pp.157-164
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    • 2004
  • Objectives : This study was designed to investigate depression, anxiety, alexithymia, stress responses between well-controlled and poorly-controlled diabetic patients by glycated hemoglobin levels. Methods : The subjects were 55 diabetic patients(mean age : $49.9{\pm}9.9$, 27 men and 28 women) who were confirmed to have diabetes depending on the laboratory findings as well as clinical symptoms at the St. Vincent Hospital Diabetes Clinic, from Mar. 2004 to Aug. 2004. Korean version of Beck Depression Inventory(BDI), State and Trait Anxiety Inventory(STAI), Toronto Alexithymia Scale(TAS) and Stress Response Inventory(SRI) were used for assessment. Based on glycated hemoglobin levels, the patients were divided into 10 well-controlled group(below 7%) and 45 poorly-controlled group(above 7%). We compared BDI, STAI, TAS and SRI scores between two groups by independent t-test. Results 1) Well-controlled diabetics, compared with poorly controlled group, manifested decreased illness duration($12.2{\pm}55.4$months vs. $55.4{\pm}66.6 months)(p=0.000), but other demographic data showed no difference between two groups. 2) The STAI scores of poorly-controlled group were significantly higher in both state anxiety sores $(38.7{\pm}3.8 \;vs.\;43.7{\pm}6.7)(p=0.29)$ and trait anxiety scores$(36.9{\pm}5.7\;vs.\;41.5{\pm}6.4)(p=0.43)$ than well-controlled groups. 3) No significant differences were found in the score of BDI, TAS, SRI between well and poorly-controlled diabetic groups. Conclusion : The above results suggest that poorly-controlled diabetic patients are more likely to have higher anxiety level than well-controlled diabetic patients. However, there were no differences in depression, alexithymia, stress responses between two group. We suggest that physicians should consider integrated approaches for psychiatric problems in the management of diabetic patients.

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CLINICAL CHARACTERISTICS OF CHRONIC MOTOR TIC DISORDER AND TOURETTE'S DISORDER (만성 틱 장애 뚜렛씨 장애의 임상 특성)

  • Shin, Sung-Woong;Lim, Myung-Ho;Hyun, Tae-Young;Seong, Yang-Sook;Cho, Soo-Churl
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.12 no.1
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    • pp.103-114
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    • 2001
  • Tourette's disorder is a disease which manifests one or more motor tics and vocal tics for more than a year. Chronic motor tic or vocal tic disorders are characterized by only one kind of tics for more than a year. We intended to investigate the clinical characteristics of the patients with chronic motor tic disorders or Tourette's disorders who had admitted from May 1, 1998 to May 1, 1999 to Seoul National University Hospital Child and Adolescent Psychiatry ward. In addition, we compared the clinical characteristics of the patients in order to elucidate the relationship between the two disorders. The patients with learning disabilities were selected as controls. There was no statistically significant difference between the onsets of the patients with chronic motor tic disorders(n=13, $7.3{\pm}2.5$ years), and Tourette's disorder(n=39, $7.2{\pm}2.2$ years), but with learning disability($4.2{\pm}1.9$ years). Also, the patients with chronic motor tic disorder and Tourette's disorder showed similar age at admission($11.7{\pm}2.7$ versus $11.5{\pm}2.6$ years), duration of admission($5.7{\pm}5.4$ versus $11.0{\pm}8.7$ weeks), mothers' ages at child birth($27.3{\pm}2.9$ versus $28.3{\pm}6.7$ years old),and fathers' age at child birth($32.2{\pm}3.2$ versus $33.3{\pm}5.2$ years old). We observed that those who had learning disabilities were alike in those aspects, except for age at visit to clinic($9.8{\pm}3.2$ years old). Family history of psychiatric illnesses(24.1% versus 46.2%), recognized precipitating factors(11.1% versus 35.7%) and response to pharmacological treatments(77.8% versus 76.9%) of the patients with chronic motor tic disorders and Tourette's disorders were observed and no differences were found. Comorbid patterns of diseases were noted. Intrafamilial conflicts were more common in the patients with learning disabilities than those with chronic tic disorders or Tourette's disorders. Precipitating factors were observed more frequent in chronic tic disorder and Tourette's disorder than learning disability. Neurocognitive profiles were investigated, and verbal IQs of the patients with chronic motor tic disorder, Tourette's disorder and learning disability were $92.3{\pm}10.7$, $94.7{\pm}14.9$, $94.3{\pm}13.8$, performance IQs $93.0{\pm}20.5$, $97.5{\pm}13.0$, $95.0{\pm}16.9$ and full-scale IQs $91.9{\pm}20.1$, $95.8{\pm}14.5$, $93.9{\pm}15.1$, respectively, which were found to be not significantly different. No difference was found in structural neurological abnormalities and EEG profiles. The patients with learning disabilities showed more common Bender-Gestalt test abnormalities. In conclusion, we have not found any affirmative clues for the division of chronic motor tic disorder and Tourette's disorder in clinical perspective.

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A Study on the Leakage Protection with Polypropylene Mat in Irrigation Canal (Polypropylene Mat에 의(依)한 용수로(用水路)의 누수방지(漏水防止)에 관(關)한 연구(硏究))

  • Kang, Sin-Up;Kang, Yea-Mook;Cho, Seung-Seup
    • Korean Journal of Agricultural Science
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    • v.6 no.2
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    • pp.166-184
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    • 1979
  • In order to prevent the water loss in the irrigation canal constructed on the sandy gravel layer or on the other highly permeable ground layer, lining has been practiced. Many studies have been done so far on the lining method to prevent the water loss in the irrigation canal and recently studies on the lining with plastic film or polyethylene film were also reported. However, the plastic film or polyethylene film has low strength and is liable to break, and water loss from pin hole caused by contacting with sand or gravel is highly predicted. This study was then conducted to find proper lining and buring method in canal construction of polypropylene mat after coated with vinyl, as one way to overcome the shortcoming frequently observed when plastic or usual polyehtylene film were used. Eventhough rather longer periods of experiments are needed to attain reliable and accurate results on the variation of durability, the durability of asphalt coated area, or on the damage due to freeze after burial or exposure of polypropylene mat, the experiemental results obtained during one year of period are summarized as follows: 1. The curvature at the area between canal bottom and side slope had increased stability and saved consruction cost. The relationship among the variation of curvature, the reduction of polypropylene mat and the reduced amount of soil cutting at each side slope was presented in Fig. 7 through 9. 2. The depth of covering material to protect polypropylene mat was desired to be over 30cm, considering the water depth, side slope, canal cleaning practices, traffic, or back pressure of irrigation period. 3. In order to increase the canal stability and to prevent slope erosion, sandy soil was required, to be placed under ground, and coarse gravel should cover the surface area of canal. 4. The studies on the stability of side slope in the canal should consider the passive area on the bottom and the slope should be about 1 to 2, considering the slope stability, allowable velocity and tractive force. 5. When compared with earth lining, the lining with polypropylene mat coated with vinyl was responsible to save 28% and 37% of canal lining cost, when the soil carrying distances were 500 and 700m. respectively. 6. The water interception was almost completely attained when the polypropylene mat coated with vinyl was used for lining. But further studies were assumed to be necessary for the use of asphalt since the strength of polypropylene mat connected with asphalt will vary with duration.

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A Study on Farmer's Syndrome and Its Risk Factors of Vinyl House Worker and Farmer in a Rural Area (일부 농촌지역 비닐하우스 재배자들의 농부증 실태와 관련요인)

  • Lee, In-Bae;Lee, Yeon-Kyeong;Chang, Sung-Sil;Lee, Sok-Goo;Cho, Young-Che;Lee, Dong-Bae;Lee, Tae-Yong
    • Journal of agricultural medicine and community health
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    • v.24 no.1
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    • pp.13-33
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    • 1999
  • The aim of this study was to investigate fatigue scores, physical complaints, farmer's syndrome and to find out its risk factors among farmers. The questionnaire survey was conducted to 177 vinyl house workers and 213 farmers who lived in Chongyang gun of Chungnam province from February 24 to March 15, 1998. The obtained main results were followings; 1. The fatigue scores were not significantly different between vinyl house workers and farmers. The fatigue scores were higher in female group, lower education group, shorter sleep hours group(under 8 hours), nonsmoker, nondrinker group than otherwise groups. There was not statistically significant difference between the mean fatigue scores and age, eating habit and body mass index. Duration of farming years in vinyl house and farming area and number of farming workers in farmers family showed a slight relationship with the fatigue score. 2. Health scores were not different between vinyl house workers and farmers. The health states was poorer in female group, lower education group, shorter sleep hours group(under 8 hours), nonsmoker group, and nondrinker group than otherwise groups by health scores. Health scores were not related with age, eating habit and body mass index. 3. The proportion of farmer's syndrome was 49.1% in vinyl house workers and 52.1% in farmers. That was higher in female than in male and the higher proportion was found in the lower education group of vinyl house workers and farmers. The proportion of farmer's syndrome was higher in the group of smoker, alcohol drinkers and over or under weight in vinyl house workers, but did not differ in those of farmers. 4. By multiple logistic regression, sex and sleep hours were risk factors affecting to farmer's syndrome. Odds ration for female group was 2.53 (reference group was male) and that for over 8 sleep hours group was 0.74 (reference group was under 8 sleep hours group). 5. The chief complaints by CMI were "I am difficult to work due to aching the back and the limbs", "I feel prickle pain in the limbs", "I sometimes have a twinge in the limbs", "I am not quite well as having a pain in the limbs", "I feel weaker grasping power than before" in both of vinyl house workers and farmers. Vinyl house workers more frequently pointed out skin darkening, skin disease and hemorrhoids than farmers. 6. According to correspondence analysis, skin disease of vinyl house workers was related to vinyl house farmers and digestive and general symptom was associated with male and endocrinological and muscular symptom was associated with female in vinyl house workers. And it revealed that farmer's syndrome was highly related with female and farmers relatively. By the above results, the fatigue scores, perceive health and farmer's syndrome did not much differ in two groups, but aged female farmers should be considered as female farmers represented higher fatigue score, farmers syndrome and poorer perceive health than male farmers in addition to farmer's syndrome was increased with ageing process. Also feeble but distinguished symptoms which might be due to working environment were observed especially in vinyl house workers and that should be considered and investigated continuously.

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