• Title/Summary/Keyword: Mineral Density

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Taxonomical Classification of Namweon Series, Black Volcanic Ash Soils (흑색 화산회토인 남원통의 분류)

  • Song, Kwan-Cheol;Hyun, Byung-Geun;Sonn, Yeon-Kyu;Lim, Han-Cheol;Lee, Shin-Chan
    • Korean Journal of Soil Science and Fertilizer
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    • v.42 no.5
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    • pp.385-392
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    • 2009
  • This study was conducted to reclassify Namweon series, black volcanic ash soils, in Jeju Island based on the second edition of Soil Taxonomy : A Basic System of Soil Classification for Making and Interpreting Soil Surveys. Morphological properties of typifying pedon of Namweon series were investigated and physicochemical properties were analyzed according to Soil Survey Laboratory Methods Manual. The typifying pedon of Namweon series has black (10YR 2/1) silt loam Ap horizon (0~11 cm) and black (10YR 2/1) silt loam BA horizon (11~72 cm). Bw horizon (72~100 cm) is very dark brown (10YR 2/2) silt loam. That occurs on lava plain derived from volcanic ash materials. The typifying pedon contains 5.2~6.4% oxalate extractable (Al + 1/2 Fe), over 85% phosphate retention, and lower bulk density than $0.90Mg\;m^{-3}$. Ap, BA, and Bw horizons of the pedon have andic soil properties. That can be classified as Andisol. The typifying pedon has an udic soil moisture regime and has a 1,500 kPa water retention of 15% or more on air-dried samples throughout all horizons, and can be classified as Udand. Ap and BA horizons (0~72 cm) have a color value, moist, and chroma of 2 or less, melanic index of 1.70 or less, and 6% or more organic carbon. That meets the requirements of melanic epipedon. That keys out as Melanudand. That has more than 6.0% organic carbon and the colors of mollic epipedon throughout a layer 50 cm or more thick within 60 cm of the mineral soil surface.. Thus, that keys out as Pachic Melanudand. The pedon has a fine-earth fraction that has a water content at 1,500 kPa tension of 12% or more on air-dried samples and has less than 35% (by volume) rock fragments. Thus, the substitute for particle-size class is medial. That has a sum of 8 times the Si (percnt by weight extracted by acid oxalate) plus 2 times the Fe (percnt by weight extracted by acid oxalate) of 5 or more, and 2 times the Fe is more than 8 times the Si. Thus, the mineralogy class is ferrihydritic. Namweon series can be classified as medial, ferrihydritic, thermic family of Pachic Melanudands, not as ashy, thermic family of Typic Melanudands.

Long-Term Trend Analysis in Nuclear Medicine Examinations (핵의학 영상 검사의 중장기 추세 분석 - 서울 소재 일개 상급 종합병원을 중심으로 -)

  • Jung, Woo-Young;Shim, Dong-Oh;Choi, Jae-Min
    • The Korean Journal of Nuclear Medicine Technology
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    • v.23 no.1
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    • pp.15-28
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    • 2019
  • Purpose Nuclear medicine was initially introduced in Korea in 1969 and widely applied to treat hyperthyroidism with $^{131}I$. Also, gamma camera was adopted in 1969 in the first place and its application has been growing continually in many ways. We analyzed long-term trend in nuclear medicine examinations for the last 2 decades. The purpose of this paper is to make predictions and to set both plans and directions on the development of nuclear medicine. Materials and Methods We analyzed the performance of nuclear medicine examinations and therapies performed in Asan Medical Center from 1998 to 2017. Results Results from the last 20 years regarding Bone scan, Renal scan, MUGA scan and $^{18}F$-FPCIT, Bone Mineral Density were on a increase. And Myocardium perfusion SPECT, Thyroid scan, Lung scan were on a decrease while $^{18}F-FDG$ PET maintained on a steady course. Until 2010 there was a positive performance with the therapy but after the excessive medical care in thyroid examination performance is at status quo. Key events such as a medical strike(2000), Middle-East Respiratory Syndrome (2015) influenced the overall performance of the therapy. Conclusion In order to promote a long-term growth in nuclear medicine examination and therapy, it is inevitable to respond to the changes in current medical environment. Furthermore, it is strongly suggested to put efforts to maintain and develop new examinations and clinical indicators.

Prevalence of Osteoporosis among Male Adults with Apparently Radiolucent Lumbar Vertebral Bodies on the Plain Radiographs (단순 영상에서 요추체의 음영이 감소된 성인 남성에서의 골다공증 유병률)

  • Kim, Kook Jong;Lim, Sung Joon;Kim, Yong Min;Lee, Hyung Ki;Kim, Geon Jung
    • Journal of the Korean Orthopaedic Association
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    • v.56 no.6
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    • pp.491-497
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    • 2021
  • Purpose: To investigate the prevalence of osteoporosis or osteopenia via dual-energy X-ray absorptiometry bone mineral density (DEXA BMD) in adult males who showed radiolucent lumbar vertebra on the plain radiographs. Materials and Methods: The DEXA BMD values of 98 adult males, who showed radiolucent vertebrae on plain X-rays, were compared with those of the control group (n=168) and osteoporosis-related fracture group (n=113) by statistical analysis. The World Health Organization (WHO) method (lower value between the mean lumbar and femur neck) and the Hansen's method (lowest lumbar vertebra) were used to determine osteoporosis. Results: The mean and standard deviation of the BMD value of each group was -1.4 (±1.2) in the suspicious group, -0.8 (±1.1) in the control group, and -2.4 (±1.0) in the fracture group, respectively; the difference was statistically significant. Using the WHO method, the prevalence ratio of osteoporosis was 17.3% in the suspicious group, 8.3% in the control group, and 45.1% in the fracture group, respectively. Osteopenia was observed in 40.8% of the suspicious group. Hansen's method (lowest lumbar vertebra) revealed the prevalence of osteoporosis in 30.6% of the suspicious group, 17.9% of the control group, and 62.0% of the fracture group. Conclusion: Approximately 17.3% of the suspicious group was diagnosed with osteoporosis, and 40.8% were osteopenic by a confirmative BMD study (WHO criteria) among the adult males showing apparent radiolucency on plain X-rays. The control group also showed an 8% prevalence of osteoporosis. These results suggest that males also are vulnerable to osteoporosis. Therefore, a BMD study should also be used for males, especially for the people showing lumbar vertebrae with radiolucent features.

The Effect of Distal Hooks in Thoracolumbar Fusion Using a Pedicle Screw in Elderly Patients (척추경 나사못을 이용한 고령 환자의 흉요추부 유합에서 원위부 갈고리의 효과)

  • Lee, Dong-Hyun;Kim, Sung-Soo;Kim, Jung-Hoon;Lim, Dong-Ju;Choi, Byung-Wan;Kim, Jin-Hwan;Kim, Jin-Hyok;Park, Byung-Ook
    • Journal of the Korean Orthopaedic Association
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    • v.52 no.1
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    • pp.83-91
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    • 2017
  • Purpose: To investigate the clinical outcomes of distal hook augmentation using a pedicle screw in thoracolumbar fusion in elderly patients. Materials and Methods: This retrospective multicenter study recruited 20 patients aged 65 years or older, who underwent anterior support and long level posterior fusion in the thoracolumbar junction with a follow-up of one year. To assess the effect of distal hook augmentation, the patients were divided into two groups; the pedicle screw with hook group (PH group, n=10) and the pedicle screw alone group (PA group, n=10). Results: The average age was 72.4 years (65-83 years). The average fusion segment was 4.6 segments (3-6 segments). There were no significant differences in age, sex, causative diseases, bone mineral density of lumbar and proximal femur, number of patients with osteoporosis, and number of fused segments between the two groups (p≥0.05). At 1 year follow-up after surgery, parameters related with distal screw pullout were significantly worse in the PA group. No patients in the PH group had distal screw pullout. However, six patients (60%, 6/10) in the PA group had distal screw pullout. There were no significant differences in the progression of distal junctional kyphosis between the two groups. Conclusion: Distal hook augmentation is an effective procedure in protecting distal pedicle screws against the pullout when long level thoracolumbar fusion was performed in elderly patients aged 65 years or older.

Usefulness of volumetric BMD measurement by using low dose CT image acquired on L-spine Bone SPECT/CT (L-spine Bone SPECT/CT에서 획득된 저선량 CT 영상을 이용한 용적 골밀도 결과의 유용성)

  • Hyunsoo Ko;Soonki Park;Eunhye Kim;Jongsook Choi;Wooyoung Jung;Dongyun Lee
    • The Korean Journal of Nuclear Medicine Technology
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    • v.27 no.2
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    • pp.99-109
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    • 2023
  • Purpose: CT scan makes up for the weak point of the nuclear medicine image having a low resolution and also were used for attenuation correction on image reconstruction. Recently, many studies try to make use of CT images additionally, one of them is to measure the bone mineral density(BMD) using Quantitative CT(QCT) software. BMD exams are performed to scan lumbar and femur with DXA(Dual-Energy X-Ray Absorptiometry) in order to diagnose bone disease such as osteopenia, osteoporosis. The purpose of this study is to identify the usefulness of QCT_BMD analyzed with low dose CT images on L-spine Bone SPECT/CT comparing with DXA_BMD. Materials and Methods: Fifty five women over 50 years old (mean 66.4 ± 9.1) who took the both examinations(L-spine Bone SPECT/CT with SIEMENS Intevo 16 and DXA scan with GE Lunar prodigy advance) within 90 days from April 2017 to July 2022, BMD, T-score and disease classification were analyzed. Three-dimensional BMD was analyzed with low dose CT images acquired on L-spine Bone SPECT/CT scan on Mindways QCT PROTM software and two-dimensional BMD was analyzed on DXA scan. Basically, Lumbar 1-4 were analyzed and the patients who has lesion or spine implants on L-spine were excluded for this study. Pearson's correlation analysis was performed in BMD and T-score, chi-square test was performed in disease classification between QCT and DXA. Results: On 55 patients, the minimum of QCT_BMD was 18.10, maximum was 166.50, average was 82.71 ± 31.5 mg/cm3. And the minimum of DXA-BMD was 0.540, maximum was 1.302, average was 0.902 ± 0.201 g/cm2, respectively. The result shows a strong statistical correlation between QCT_BMD and DXA_BMD(p<0.001, r=0.76). The minimum of QCT_T-score was -5.7, maximum was -0.1, average was -3.2 ± 1.3 and the minimum of DXA_T-score was -5.0, maximum was 1.7, average was -2.0 ± 1.3, respectively. The result shows a statistical correlation between QCT T-score and DXA T-score (p<0.001, r=0.66). On the disease classification, normal was 5, osteopenia was 25, osteoporosis was 25 in QCT and normal was 10, osteopenia was 25, osteoporosis was 20 in DXA. There was under-estimation of bone decrease relatively on DXA than QCT, but there was no significant differences statistically by chi-square test between QCT and DXA. Conclusion: Through this study, we could identify that the QCT measurement with low dose CT images QCT from L-Spine Bone SPECT/CT was reliable because of a strong statistical correlation between QCT_BMD and DXA_BMD. Bone SPECT/CT scan can provide three-dimensional information also BMD measurement with CT images. In the future, rather than various exams such as CT, BMD, Bone scan are performed, it will be possible to provide multipurpose information via only SPECT/CT scan. In addition, it will be very helpful clinically in the sense that we can provide a diagnosis of potential osteoporosis, especially in middle-aged patients.

Studies on the Effects of Antler Extract in Osteoporosis-Induced Rats I. Effects of Antler Extract on Hormones, Ca, P and ALP Levels in Osteoporosis-Induced Rats (녹용 추출물 투여가 골다공증 유발 Rat 에 미치는 효과에 관한 연구 I. 녹용 추출물 투여가 골다공증 유발 Rat 의 혈청내 호르몬, Ca, P, ALP 수준에 미치는 영향)

  • Kim, S. K;Kim, S. W.;Kim, M. S.
    • Korean Journal of Animal Reproduction
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    • v.24 no.2
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    • pp.179-188
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    • 2000
  • The present study was carried out in order to investigate the effects of antler extract on hormone concentration, Ca, P and alkaline phosphatase (ALP) levels in ovariectomized rats. Rats were ovariectomized bilaterally and were fed up with Ca- and P-free diet in order to induce osteoporosis. Osteoporosis was determined by the extent of density of bone mineral and lowering the concentrations of serum Ca and P. Male or female antler extract were administrated for 5 weeks to elucidate the protective and therapeutic effects for osteoporosis. The serum concentrations of estradiol, progesterone, calcitonin, osteocalcin, Ca and P, and the activities of ALP of ovariectomized rats were examined for 5 weeks. 1. After administration of female or male antler extract to osteoporosis-induced rats at the doses of 625 mg/kg and 1,250 mg/kg, respectively, the levels of the serum estradiol of the ovariectomized rat significantly decreased from 40.50$\pm$3.34 pg/$m\ell$ to 20.80$\pm$1.86 pg/$m\ell$ for 5 weeks, the levels of serum estradiol were a signigicant lower than those of control group (49.50$\pm$2.70~50.80$\pm$3.l3 pg/$m\ell$). 2. After administration of female or male antler extract to osteoporosis-induced rats at the doses of 625 mg/kg and 1,250 mg/kg, respectively, the levels of serum progesterone were didn't show significant differences. 3. After administration of female or male antler extract to osteoporosis-induced rats at the doses of 625 mg/kg and 1,250 mg/kg, respectively, the levels of serum calcitonin were a little higher than those of control group (0.64$\pm$0.03 ~0.68$\pm$0.04 pg/$m\ell$). 4. After administration of female or male antler extract to osteoporosis-induced rats at the doses of 625 mg/kg and 1,250 mg/kg, respectively, the levels of serum osteocalcin were little higher than those of control groups (0.28$\pm$0.02~0.31$\pm$0.02 ng/$m\ell$). In addition, the levels of serum osteocalcin of female antler extract administered group were little higher than those of male antler extract administered group. 5. The levels of serum Ca and P in osteoporosisinduced rats, administered with male or female antler extract, were little higher than those of control group. However, the levels of serum Ca and P in ovariectomized rats were significantly higher than those of control group (p<0.05). 6. After administration of female or male antler extract to osteoporosis-induced rats, the activities of serum ALP increased compared with those of normal control group. There were significant differences between the serum ALP activities of FA 1,250 and 625 groups (p<0.05). These findings suggest a possible protective and therapeutic effects of female or male antler extract against bone loss in ovariectomized rats, associated with a significant increase of serum estradiol level.

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Sex- and age group-specific associations between intakes of dairy foods and pulses and bone health in Koreans aged 50 years and older: Based on 2008~2011 Korea National Health and Nutrition Examination Survey (50세 이상 한국인의 성·연령군별 우유류와 두류 섭취량과 골 건강과의 관련성 : 2008~2011 국민건강영양조사 자료를 이용하여)

  • Seo, Hyun-Bi;Choi, Young-Sun
    • Journal of Nutrition and Health
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    • v.49 no.3
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    • pp.165-178
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    • 2016
  • Purpose: This study was performed to examine associations of intakes of milk and dairy products, pulses, and soy foods with bone health in Koreans aged 50 yr and older. Methods: A total of 3,201 men and 3,581 women aged 50 yr and older who participated in the 2008~2011 Korea National Health and Nutrition Examination Survey were grouped by sex and age groups of 50~64 yr and 65 yr and older. Subjects within each sex and age group were divided into three bone health groups: normal, osteopenia, and osteoporosis groups based on bone mineral density. Intakes of nutrients and foods derived from 24-hour recall data were compared among three bone health groups. Associations between intake frequencies of foods, including milk, yogurt, tofu, or soy milk, and osteoporosis risk were evaluated based on confounding risk factor-adjusted logistic regression. Results: Calcium intake was in the order of normal, osteopenia, and osteoporosis in men (p < 0.01) and women (p < 0.05) aged 50~64 yr as well as in men aged 65 yr and older (p < 0.001). In women aged 50~64 yr, intake of milk and dairy products was lower in the osteoporosis group (p < 0.01) as compared with the osteopenia group. Intake of pulses or tofu was not significantly different among bone health groups. Odds ratio (OR) for milk intake frequency (${\geq}2$ times/week) compared to intake frequency less than 1 time/month was 0.45 (95% CI 0.24~0.85, p for trend = 0.022) in men aged 65 yr and older. The OR for yogurt intake frequency (1 time/month~1 time/week) was 0.47 (95% CI 0.30~0.73, p for trend = 0.019) in women aged 50~64 yr. Intake frequency of tofu or soy milk was not associated with reduced risk of osteoporosis in all groups. Conclusion: Dairy food intake was significantly associated with bone health, and its effect was sex- and age group-specific, whereas soy food intake was not. Dietary intervention to prevent osteoporosis would be effective for women aged 50~64 yr old and for men aged 65 yr and older.

Evaluation for Rock Cleavage Using Distribution of Microcrack Spacings (II) (미세균열의 간격 분포를 이용한 결의 평가(II))

  • Park, Deok-Won
    • The Journal of the Petrological Society of Korea
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    • v.25 no.2
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    • pp.151-163
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    • 2016
  • The characteristics of the rock cleavage in Jurassic granite from Geochang were analysed. The evaluation for the three directions of rock cleavages was performed using the parameters such as (1) frequency of microcrack spacing(N), (2) total spacing(${\leq}1mm$), (3) mean spacing($S_{mean}$), (4) difference value($S_{mean}-S_{median}$) between mean spacing($S_{mean}$) and median spacing($S_{median}$), (5) density of spacing(${\rho}$), (6) difference value between two exponents for the whole range of the diagrams(${\lambda}_H-{\lambda}_L$), (7) mean value of exponent(${\lambda}_M$), (8) mean value of exponential constant($a_M$), (9) difference value between two exponents for the section under the initial points of intersection(${\lambda}t_H-{\lambda}t_L$), (10) mean value of exponent(${\lambda}t_M$) and (11) mean value of exponential constant($at_M$). The results of correlation analysis between the values of parameters for three rock cleavages and those for three planes are as follows. The values of (I) parameters(1, 2, 7 and 8) and (II) parameters(3, 4 and 5) are in orders of (I) H(hardway, (H1 + H2)/2) < G(grain, (G1 + G2)/2) < R(rift, (R1 + R2)/2) and (II) R < G < H. On the contrary, the values of the above two groups(I~II) of parameters for three planes show reverse orders. Besides, the values of parameter $6({\lambda}_H-{\lambda}_L)$, parameter $9({\lambda}t_H-{\lambda}t_L)$, parameter $10({\lambda}t_M)$ and parameter $11(at_M)$ for three planes are in orders of R(rift plane, (G1 + H2)/2) < H(hardway plane, (R2 + G2)/2) < G(grain plane, (R1 + H2)/2), H < G < R, H < R < G and R < H < G, respectively. The values of the above four parameters for three rock cleavages show the various orders of R < H < G, R < H < G, H < G < R and H < G < R, respectively. Meanwhile, the spacing values equivalent to the initial points of contact and intersection between the two directions of diagrams were derived. The above spacing values for three rock cleavages are in order of rift(R1 and R2) < grain(G1 and G2) < hardway(H1 and H2). The spacing values for three planes are in order of rift plane(G1 and H1) < hardway plane(R2 and G2) < grain plane(R1 and H2). In particular, the intersection angles for three rock cleavages and three planes are in order of rift and rift plane < hardway and hardway plane < grain and grain plane. Consequently, the two diagrams of rift(R1 and R2) and rift plane(G1 and H1) show higher frequency of the point of contact and intersection. These characteristics of change were derived through the general chart for three planes and three rock cleavages. Lastly, the correlation analysis through the values of parameters along with the distribution pattern is useful for discriminating three quarrying planes.

Anti-climacterium Effects of Gagamguibiondam-tang in Ovariectomized Rats (난소적출로 유발된 랫트 갱년기 장애에 대한 가감귀비온담탕의 생리활성 효과 평가)

  • Han, Sang-Gyeom;Kim, Dong-Chul
    • The Journal of Korean Obstetrics and Gynecology
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    • v.30 no.4
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    • pp.18-44
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    • 2017
  • Purpose: The object of this study was to observe the anti-climacterium activity of Gagamguibiondam-tang (GGOT) on ovariectomized (OVX) rats, a well-documented rodent models resembles with women postmenopausal climacterium symptoms, as including cardiovascular diseases, obesity, hyperlipidemia, osteoporosis, organ steatosis and mental disorders. Methods: In this study, anti-climacteric effects were evaluated separated into three categories; 1) anti-obese, 2) anti-uterine atrophy and 3) anti-osteoporotic effects. Five groups were used (8 rats in each group); sham control, OVX control, GGOT 500, 250 and 125 mg/kg administered groups. Twenty-eight days after bilateral OVX surgery, GGOT were orally administered, once a day for 84 days, and then the changes on the body weight and gain during experimental periods, serum estradiol levels, abdominal fat pad and uterus weights with histopathology of abdominal fat pads (total thickness and mean adipocyte diameters) and uterus (total, epithelial and mucosal thickness, percentages of uterine gland regions) for anti-obese and estrogenic effects. In addition, femur, tibia and fourth or fifth lumbar vertebrae (L4 or L5) wet, dry and ash weights, mineral density (BMD), bone strength (failure load), serum osteocalcin and bone specific alkaline phosphatase (bALP) contents, histological and histomorphometrical analyses - bone mass and structure with bone resorption, were monitored for anti-osteoporosis activity. Results: As a result of OVX, noticeable increases of body weight and gains, food and water consumption, weights of abdominal fat pad deposited in dorsal abdominal cavity, serum osteocalcin levels were demonstrated in this experiment with decrease of uterus, femur, tibia and L5 weights, serum bALP and estradiol levels. In addition, marked hypertrophic changes of adipocytes located in deposited abdominal fat pads, uterine disused atrophic changes, decreases of bone mass and structures of femur, tibia and L4 were also observed in OVX control rats with dramatic increases of bone resorption markers, the Ocn and OS/BS at histopathological and histomorphometrical analysis in this study as compared with sham-operated control rats, suggesting the estrogen-deficient climacterium symptoms - obese and osteoporosis were induced by OVX, respectively. However, these estrogen-deficient climacterium symptoms induced by bilateral OVX in rats were significantly inhibited by 84 days of continuous oral treatment of GGOT 500, 250 and 125 mg/kg, respectively. Especially, GGOT 500, 250 and 125 mg/kg showed clear dose-dependent inhibitory activities on the OVX-induced climacterium signs. Conclusion: The results suggest that oral administration of GGOT 500, 250 and 125 mg/kg has clear dose-dependent favorable anti-climacterium effects - estrogenic, anti-obese and anti-osteoporotic activities in OVX rats in this experiment.

Soil Classification of Paddy Soils by Soil Taxonomy (미국신분류법(美國新分類法)에 의(依)한 답토양의 분류(分類)에 관한 연구)

  • Joo, Yeong-Hee;Shin, Yong-Hwa
    • Korean Journal of Soil Science and Fertilizer
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    • v.11 no.2
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    • pp.97-104
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    • 1979
  • According to Soil Taxonomy which has been developed over the past 20 years in the soil conservation service of the U. S. D. A, Soils in Korea are classified. This system is well suited for the classification of the most of soils. But paddy field soils have some difficulties in classification because Soil Taxonomy states no proposals have yet been developed for classifying artificially irrigated soils. This paper discusses some problems in the application of Taxonomy and suggestes the classification of paddy field soils in Korea. Following is the summary of the paper. 1. Anthro aquic, Aquic Udipsamments : The top soils of these soils are saturated with irrigated water at some time of year and have mottles of low chroma(2 or less) more than 50cm of the soil surface. (Ex. Sadu, Geumcheon series) 2. Anthroaquic Udipsamments : These sails are like Anthroaquic, Aquic Udipsamments except for the mottles of low chroma within 50cm of the soil surface. (Ex. Baegsu series) 3. Halic Psammaquents : These soils contain enough salts as distributed in the profile that they interfere with the growth of most crop plants and located on the coastal dunes. The water table fluctuates with the tides. (Ex. Nagcheon series) 4. Anthroaquic, Aquic Udifluvents : They have some mottles that have chroma of 2 or less in more than 50cm of the surface. The upper horizon is saturated with irrigated water at sometime. (Ex. Maryeong series) 5. Anthro aquic Udifluvents : These soils are saturated with irrigated water at some time of year and have mottles of low chroma(2 or less) within 50cm of the surface soils. (Ex. Haenggog series) 6. Fluventic Haplaquepts : These soils have a content of organic carbon that decreases irregularly with depth and do not have an argillic horizon in any part of the pedon. Since ground water occur on the surface or near the surface, they are dominantly gray soils in a thick mineral regolith. (Ex Baeggu, Hagseong series) 7. Fluventic Thapto-Histic Haplaquepts : These soils have a buried organic matter layer and the upper boundary is within 1m of the surface. Other properties are same as Fluventic Haplaquepts. (Ex. Gongdeog, Seotan series) 8. Fluventic Aeric Haplaquepts : These soils have a horizon that has chroma too high for Fluventic Haplaquepts. The higher chroma is thought to indicate either a shorter period of saturation of the whole soils with water or some what deeper ground water than in the Fluventic Haplaquepts. The correlation of color with soil drainage classes is imperfect. (Ex. Mangyeong, Jeonbug series) 9. Fluventic Thapto-Histic Aeric Haplaquepts : These soils are similar to Fluventic Thapto Histic Haplaquepts except for the deeper ground water. (Ex. Bongnam series) 10. Fluventic Aeric Sulfic Haplaquepts : These soils are similar to Fluventic Aeric Haplaquepts except for the yellow mottles and low pH (<4.0) in some part between 50 and 150cm of the surface. (Ex. Deunggu series) 11. Fluventic Sulfaquepts : These soils are extremely acid and toxic to most plant. Their horizons are mostly dark gray and have yellow mottles of iron sulfate with in 50cm of the soil surface. They occur mainly in coastal marshes near the mouth of rivers. (Ex. Bongrim, Haecheog series) 12. Fluventic Aeric Sulfaquepts : They have a horizon that has chroma too high for Fluventic Sulfaquepts. Other properties are same as Fluventic Sulfaquepts. (Ex. Gimhae series) 13. Anthroaquic Fluvaquentic Eutrochrepts : These soils have mottles of low chroma in more than 50cm of the surface due to irrigated water. The base saturation is 60 percent or more in some subhroizon that is between depth of 25 and 75cm below the surface. (Ex. Jangyu, Chilgog series) 14. Anthroaquic Dystric Fluventic Eutrochrepts : These soils are similar to Anthroaquic Fluvaquentic Eutrochrepts except for the low chroma within 50cm of the surface. (Ex. Weolgog, Gyeongsan series) 15. Anthroaquic Fluventic Dystrochrepts : These soils have mottles that have chroma of 2 or less within 50cm of the soil surface due to artificial irrigation. They have lower base saturation (<60 percert) in all subhorizons between depths of 25 and 75cm below the soil surface. (Ex. Gocheon, Bigog series) 16. Anthro aquic Eutrandepts : These soils are similar to Anthroaquic Dystric Fluventic Eutrochrepts except for lower bulk density in the horizon. (Ex. Daejeong series) 17. Anthroaquic Hapludalfs : These soils' have a surface that is saturated with irrigated water at some time and have chroma of 2 or less in the matrix and higher chroma of mottles within 50cm of the surface. (Ex. Hwadong, Yongsu series) 18. Anthro aquic, Aquic Hapludalfs : These soils are similar to Anthro aquic Hapludalfs except for the matrix that has chroma 2 or less and higher chroma of mottles in more than 50cm of the surface. (Ex. Geugrag, Deogpyeong se ries)

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