• Korean Journal of Weed Science
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• v.3 no.1
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• pp.57-68
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• 1983

To estimate the possible amount of weed-crop competitions under the various cropping patterns of two rice cultivars of different type, comparisons between weedy check and weed-free plots in plant height, tillering number, and plant weight were investigated. Fluctuations in Importance Value, competition value, and net productivities were used to discuss the crop-weed competition, respectively. As a result, differences in dominant weed species, competitive crop variety, most effective cropping pattern, and crop yielding characteristics under the different weed competitions were investigated, respectively.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.71-82
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• 2011

Purpose: To evaluate the biochemical control rate and the rate of side effects after performing permanent brachytherapy of localized prostate cancer. Materials and Methods: 67 patients with localized prostate cancer were treated with brachytherapy between April 2007 and December 2008. Of these, 43 patients who were followed up and did not receive external radiotherapy were evaluated for the change in prostate specific antigen (PSA) level and the occurrence of side effects. In total, 18 patients were classified as low risk, 19 patients as intermediate risk, and 6 patients as high risk. The prescription dose was 145 Gy. Results: A PSA increase greater than 2 ng/mL occurred in 2 patients (4.7%). Radiation Therapy Oncology Group (RTOG) grade 1 and 2 acute urologic complications (UC) occurred in 40 and 3 patients, respectively. Further, 5 patients had RTOG grade 1 acute rectal complication (RC). The numbers of RTOG grade 1, 2, and 3 chronic UC were 1, 4, and 1, respectively. The numbers of RTOG grade 1, 2, and 4 chronic RC were 5, 10, and 3, respectively. The statistically significant risk factors (RF) of acute RC were the minimal dose in the most irradiated 0.1 cc volume ($D_{0.1cc}$, p=0.041) and absolute volume receiving 150% of the prescribed dose ($V_{150cc}$, p=0.038) in the entire rectum (ER). The percentage ($V_{100%}$, p=0.019) and absolute volume ($V_{100cc}$, p=0.047) in the involved rectum (IR) were also statistically significant. The RF of chronic RC were $V_{100%}$ (p=0.011) in the ER and the $D_{0.1cc}$ (p=0.049), $V_{100cc}$ (p=0.023) in the IR. The number of used seeds were related with acute UC (p=0.028). Conclusion: Permanent brachytherpy of localized prostate cancer showed a favorable short term biochemical control rate. As such, selective intermediate and high risk patients can be managed with permanent brachytherapy. The effort to reduce rectal complication is also necessary.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.33-45
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• 2011

Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of cancer cell. Inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the cancer cell was reported. However, its role during oocyte maturation and early embryo development is very insufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on meiotic maturation and early embryonic development in pigs. We also investigated several indicators of developmental potential, including structural integrity, gene expression (Hsp90-, cell cycle-, and apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Then, we examined the roles of Hsp90 inhibitor on viability of primary cells in pigs. Porcine oocytes were cultured in the NCSU-23 medium with or without 17-AAG for 44 h. The proportion of GV arrested oocytes was significantly different between the 17-AAG treated and untreated group (78.2 vs 34.8%, p<0.05). After completion of meiotic maturation, the proportion of MII oocytes was lower in the 17-AAG treated group than in the control group (27.9 vs 71.0%, p<0.05). After IVF, the percentage of penetrated oocytes was significantly lower in the 17-AAG treated group (25.2%), resulting in lower normal pronucleus formation (2PN of 14.6%). Therefore, the inhibition of meiotic progression by Hsp90 inhibitor played a critical role in fertilization status. Porcine embryo were cultured in the PZM-3 medium with or without 17-AAG for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (7.5 vs 4.4, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation porcine blastocysts. The mRNA expressions of cell cycle-related genes were down-regulated in the 17-AAG treated group compared with control. Also, the expression of the pro-apoptotic gene Bax increased in 17-AAG treated group, whereas expression of the anti-apoptotic gene Bel-XL decreased. However, the expression of ER stress-related genes did not changed by 17-AAG. Cultured pESF cells were treated with or without 17-AAG and used for MIT assay. The results showed that viability of pESF cells were decreased by treatment of 17-AAG ($2{\mu}M$) for 24 hr. These results indicated that 17-AAG decreased cell proliferation and increased cell death. Expression patterns Hsp90 complex genes (Hsp70 and p23), cell cycle-related genes (cdc2 and cdc25c) and apoptosis-related genes (Bax and Bcl-XL) were significantly changed by using RT-PCR analysis. The spliced form of pXbp-1 product (pXbp-1s) was detected in the tunicamycin (TM) treated cells, but it is not detected in 17-AAG treated cells. In conclusion, Hsp90 appears to play a direct role in porcine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with cell cycle- and apoptosis-related genes expression in developing porcine embryos.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.6
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• pp.465-473
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• 2004

Purpose : The essential triad for nerve regeneration is nerve conduit, supporting cell and neurotrophic factor. In order to improve the peripheral nerve regeneration, we used polyglycolic acid(PGA) tube and brain-derived neurotrophic factor(BDNF) gene transfected Schwann cells in sciatic nerve defects of SD rat. Materials and methods : Nerve conduits were made with PGA sheet and outer surface was coated with poly(lactic-co-glycolic acid) for mechanical strength and control the resorption rate. The diameter of conduit was 1.8mm and the length was 17mm Schwann cells were harvested from dorsal root ganglion(DRG) of SD rat aged 1 day. Schwann cells were cultured on the PGA sheet to test the biocompatibility adhesion of Schwann cell. Human BDNF gene was obtained from cDNA library and amplified using PCR. BDNF gene was inserted into E1 deleted region of adenovirus shuttle vector, pAACCMVpARS. BDNF-adenovirus was multiplied in 293 cells and purified. The BDNF-Adenovirus was then infected to the cultured Schwann cells. Left sciatic nerve of SD rat (250g weighing) was exposed and 14mm defects were made. After bridging the defect with PGA conduit, culture medium(MEM), Schwann cells or BDNF-Adenovirus infected Schwann cells were injected into the lumen of conduit, respectively. 12 weeks after operation, gait analysis for sciatic function index, electrophysiology and histomorphometry was performed. Results : Cultured Schwann cells were well adhered to PGA sheet. Sciatic index of BDNF transfected group was $-53.66{\pm}13.43$ which was the best among three groups. The threshold of compound action potential was between 800 to $1000{\mu}A$ in experimental groups which is about 10 times higher than normal sciatic nerve. Conduction velocity and peak voltage of action potential of BDNF group was the highest among experimental groups. The myelin thickness and axonal density of BDNF group was significantly greater than the other groups. Conclusion : BDNF gene transfected Schwann cells could regenerate the sciatic nerve gap(14mm) of rat successfully.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 1997.06b
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• pp.8-10
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• 1997

종양은 아직 그 발생 원인과 기작이 정확히 밝혀져 있지 않으므로 정확한 정의를 내리는 것은 어려우나 일반적으로 종양이란 정상 세포가 갖고 있는 세포 분열의 특이성을 상실하여 일어나는 조직의 자율적인 과잉 성장을 말한다. 이와 같은 세포의 비정상적인 증식에 의한 종양을 임상 및 병리 형태학적으로 양서 종양과 악성종양으로 분류한다. 양성 종양을 일으키는 종양 세포는 정상 세포와 비슷할 뿐 아니라 그 주변 세포들과 확실한 경계를 이루고 있으며 증식도 느리며 다른 부위로의 전이가 없다. 이에 반해 악성종양은 일반적으로 증식도 빠르고 이형의 세포로서 주변의 조직으로 확산, 전이될 뿐만 아니라 최종적으로 숙주인 개체를 사망시킨다. 악성종양은 다시 상피 조직에서 유례한 암, 비상피 조직에서 유래된 육종, 백혈구에서 유래된 백혈병 등으로 구별하지만 그의 본질은 거의 같으며 모든 악성종양은 통속적으로 암이라고 불리운다. 종양의 발생원인으로 크게 3가지로 나눌 수 있는데 화학물질, 바이러스 및 유전적 요인에 의한 것으로 알려졌다. 최초의 발암물질로 알려진 benzopyrene에 의한 발암 등 연구에 의해 화학적 발암원들은 직접 발암 물질로 작용하는 것이 아니라, 일단 체내에서 대사된 후 이들 대사 산물일 DNA 등에 작용함으로써 발암이 유도 되는 것으로 밝혀졌다. 이와 같이 화학적 변화를 거친 후에야 DNA에 영향을 미치는 것외에 다른 화학물질들은 또 다른 기작을 통해 암을 유발하는데 쥐의 피부에 benzopyrene을 한 번 처리하면 암을 유발하지 않으나 여기에 phorbol ester를 처리하면 높은 빈도로 암이 형성된다. 여기서 benzopyrene과 같이 세포의 DNA에 돌연변이를 일으키는 작용을 하는 발암물질을 발암개시제라 하고 phorbol ester처럼 그 자체로는 발암능이 없으나 발암개시제에 노출된 세포에 영향을 미쳐 발암능을 크게 강화시켜 주는 것을 발암촉진제라고 한다. 암은 세포증식 제어계에 DNA가 이상을 일으킨 현상을 말하는 데 이와 같은 DNA의 변형된 유전정보에 의해 암과 관련된 단백질을 합성하므로 이 DNA를 암유전자라 부르며 바이러스에서 유래된 것을 V-one 그리고 세포에서 유래된 것을 c-one이라 한다. 암유전자는 본래 암을 형성하기 위한 것이 아니라 증식제어 유전자로서 변이나 비정상으로 활성화 됨으로써 암을 유발시키므로 proto-oncogene이라 부른다. 또한 고등동물의 유전자 중에는 세포성장을 억제하는 유전자들이 있으며 이들은 세포의 성장 생존 분화를 조절하는 것으로 생각되고 있다. 따라서 이들 유전자는 세포의 암변형을 억제하는 기능을 가지고 있다. 이들 유전자의 이상으로 세포성장 억제기능이 상실되면 세포의 과잉 성장이 초래되면 결과적으로 암으로 유발하는 것으로 추측되고 있다. 최근의 연구에 의하면 암세포에서 암억제 유전자의 이상과 암유전자의 활성화가 함께 발견 되면서 정상세포가 암으로 변형되는 과정에는 암억제 유전자의 이상과 암유전자의 활성화가 동시에 관여한 가능성이 높은 것으로 알려져 있다. 정상 세포가 암을 유발하기 위해서는 발암의 다단계설에서와 같이 여러 단계의 변과가 필요한데 여러 가지 요인에 의해 정상세포의 염색체가 변화되어 정상세포들이 가지고 있는 세포분열의 특이성을 상실하고 증식이 빠르고 저항력이 강한 세포가 선택 되어지고 비정상 서ㅔ포으 과잉 분여러에 의해 종양이 형성되며 이어서 혈관의 신생을 촉진하는 맥관형성, 전이 등이 과정을 거쳐 신체의 다른 부위로 전이된다. 20세기 초까지는 암은 노화와 함께 자연발생적으로 일어나는 피할 수 없는 질병으로 여겨졌으며 그 치료도 조기에 발견된 암환자에게 외과적인 치료를 하는 것이 최선의 방법 이었다. 그러나 현재에는 암환자의 80% 이상이 환경적 요인에 의해 암이 발생 된다고 믿어지고 있다. 과거 치료에 중점을 둔 것에서 점차 예방의 가능성과 그 방법의 모색에 관심을 갖게 되었으며 치료적인 면에서도 외과적 수술 이외에 방사선 치료, 항암제의 투여 등 약물요법, 면역요법의 이용 이외에 더 나아가 gene theraph 및 tumor vaccines 개발에 대한 관심도 증가되고 있다. 국제암연구협회에서는 인간에게 발암이 가능한 물질의 종류를 정기적으로 발표하고 있는데 지금까지 발암 가능성이 높다고 널리 알려진 위험요인을 크게 나누어 보면 다음과 같다. 흡연, 음주, 식이요인, 호르몬 및 기타 요인으로 약물, 자외선 등을 들 수 있는데 현재까지 이들 요인에 의한 발암 기작이 완전히 규명된 것은 아니지만 이들에 의한 발암의 확률이 높다는 것은 사실이므로 이 위험요인에 노출되는 것을 방지함으로써 암발생을 예방할 수 있을 것이다. 암발생의 예방법으로는 암발생 자체를 예방하는 것과 이미 발생한 암환자를 조기 발견하고 치료하는 방법이 있을 수 있다. 현재까지의 여러 연구 결과들을 보면 유전적인 요인을 제외한 대부분의 발암 위험인자들은 개개인의 생활습관과 밀접히 관련되어 있음을 알 수 있다. 이를 바탕으로 1992년 대한 암협회에서는 '암 예방 14개 권장 사항'을 발표하여 국민 홍보활동을 하고 있는데 그 내용의 반 이상이 식생활 습관과 관련되어 있을 정도이므로 암예방에 있어서의 식품의 역할이 매우 크다 할 수 있다. 따라서 건전한 생활습관과 더불어 적절한 식품의 섭취는 암예방을 위한 기본이 될 것이다.

• Journal of Korean Public Health Nursing
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• v.5 no.2
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• pp.5-25
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• 1991

This study was conducted from July to December 1990, in order to diagnose nurses' educational need for home care. The study subjects consisted of 145 nursing educators, and the 3 groups of nurses, namely 250 senior nursing students of diploma and collegiate program, 235 health center nurses, 521 university' hospital nurses in Seoul. Four types of questionaires were formulated by Delphi method. Two questionaires for the nursing educators were designed to measure their expectations of nurses' knowledge and of their skill for home care, and another two questionaires for the nurses to measure their actual home care knowledge and skill. The results of the study were as follows : 1) The mean scores of educators' expectation for home care knowledge were 17.68 for the care of dependence on medical equipment, 17.44 for the care of mobility impairment patient, 16.56 for the care of cardiopulmonary impairment patient, 16.40 for the care of nutrition and elimination impairment patient, '1.20 for the care of psychiatric disorder patient and 9.03 for the care of cancer and terminally ill patient,. 2) The mean scores of nurses' home care knowledge tested by 20 items were 14.36 for the care of mobility impairment patient, 13.28 for the c8;re of dependence on medical equipment, 13.78 for the care of cardiopulmonary impairment patient, 12.92 for the care of nutrition and elimination impairment patient, and those of tested by 10 items were 7.08 for the care of psychologic disorder patient, 7.80 for the care of cancer and terminally ill patient. The sum of means marked 69.23. As for the nurses' home care knowledge categorized by tasks in terms of the group, significant difference were shown in the care of mobility impairment(P=0.00), cancer and terminally ill(P=0.03), nutrition and elimination impairment(P=0.00) and psychologic disorder patient(P=0.00). No significant difference were shown in the care of dependence on medical equipment and cardiopulmonary impairment patient. 3) Regard to educational need of nurses' home care knowledge categorized by task according to the group it was found that all sampled nurses had educational need in the care of mobility impairment, dependence on medical equipment, cardiopulmonary impairment, cancer and terminally ill patient. It was found that health center nurses had educational need in the care of psychologic disorder. No educational need were found in the health center nurses whose career less than 2 years, in the care of mobility impairment, cardiopulmonary impairment and psychologic disorder patient, and in those of career with 2-5 year in the care of psychologic disorder patient. No educational need were found in the hospital nurses whose career more than 15 years, in the care of cardiopulmonary impairment patient and in those of career with 11-15 year, in the care of cancer and terminally ill patient. 4) The mean scores of educators' expectation for home care skill measured by Likert 5 points scale were 4. 21 for assessing, 4.49 for planning, 4.29 for basic care, 4.42 for curative care, 4.40 for rehabilitative care, 4.36 for emergency care, 4.53 for medication, 4.31 for nutritional care, 4.32 for other means for care, and 4.38 for evaluation. 5) Regard to nurses' home care skill measured by Likert 5 points scale of self evaluation, there was a significant difference between the nurses' home care skill and group(P=0.00l). The higher scores reported by students were vital sign checking and basic care while the scores of below medium were curative care and emergency care. The higher scores reported by health center nurses were vital sign checking, other means for care and care of specimen while the scores below medium were curative, emergency and nutritional care. The higher scores reported by hospital nurses were vital sign checking, care of specimen and basic care, while the score below medium was emergency care. 6) Regard to educational need of nurses' home care skill by nursing process activity according to the group it was found that health center nurses had educational need in all nursing skills including vital sign checking, care of specimen, health assessment, socioeconomic assessment, nursing diagnosis, care plan, basic care, curative care, rehabiitative care, psychological care, emergency care, medication, nutritional care, other means for care and evaluation. And students had educational need in all nursing skills except vital sign checking, and hospital nurses had educational need in all nursing skills except vital sign checking, care of specimen and basic care. 7) In short, the result of this study suggests that the curriculum should be organized in accordence with nurses' educational background and their career for the education of nurses for home care. It should be considered to develop the short term educational program focused on curative and rehabilitative care for health center nurse or community health nurse practitioner and which was focused on family care for hospital nurse. Concerning about this field practice for home care nurse, they are required not only community practice but also . clinical practice including emergency, curative and rehabilitative care.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.3
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• pp.58-69
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• 2018

This study investigated root damage characteristics and correlations between roadside trees and street furniture through the investigation of the root damage conditions and the current status of roadside trees and street furniture in Seo-gu, Daejeon City where the occurrence of pavement uplift is frequent. The study area was divided into six areas by species of trees as Metasequoia glyptostroboides and Platanus occidentalis focusing on the streets that were installed with trees chest height and 8cm round planted at the time of the development of the Dunsan-dong Housing Site Development in Seo-gu, Daejeon metropolitan city (1990~1994). The damage rate of roadside protection frames (95.3%) was higher than that of curbstones (19.7%) at the study site. Streets without a protective frame were more likely to have damaged pavement. In addition, the frequency of breakage of protective frames was lowered when a drinking water area was increased to more than a certain level. The frequency of the type of uplift in the sidewalk pavement surfaces is in the order of tail type > mounding type > irregular type, and the frequency of the uplift direction is the highest in Direction 1 ($0{\sim}44^{\circ}C$), Direction 2 ($45{\sim}89^{\circ}$), and Direction 3 ($95{\sim}134^{\circ}$) when $180^{\circ}$ of the street direction is based on $90^{\circ}$ parallel to the curbstone. The uplift length is about 31~60cm and it is most often at a height of 3~6cm. When comparing the results of uplift deformation, Metasequoia glyptostroboides was found to be higher than the deformation of Platanus occidentalis. In addition, it can be seen that the larger the length, width and height of the ridge, the larger the deformation becomes. The relationship between the diameter at breast height, the dimension of the pavement width, the frequency of the ridge phenomenon and the deformation amount is not necessarily proportional, and there seems to be a gap due to external factors such as soil humidity and planting base. Therefore there is a need for a multi-directional approach in reducing uplift.

• Herbal Formula Science
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• v.22 no.1
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• pp.167-176
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• 2014

Objectives : This study investigated the improvement effects of Gangjihwan (DF) and combination of Gangjihwan and Gamisochehwan (GSH) on nonalcoholic fatty liver disease in a high fat diet-induced obese mouse model. Methods : Eight-week-old C57BL/6N mice were divided into five groups: a normal lean group given a standard diet, an obese control group given a high fat diet, and atorvastatin, DF, and DF+GSH groups given a high fat diet with atorvastatin (10 mg/kg), DF (40 mg/kg), and DF+GSH (80 mg/kg), respectively. After 8 weeks of treatment, body weight gain, blood lipid markers, ALT concentrations, liver weight and histology were examined. Results : 1. Body weight gain was significantly decreased in DF, DF+GSH and atorvastatin groups compared with control. The extent of decreases was eminent in DF+GSH group. 2. Circulating concentrations of total cholesterol, HDL-cholesterol and LDL-cholesterol were decreased in DF, DF+GSH and atorvastatin groups compared with control. The decreases were significant in DF+GSH and atorvastatin groups. 3. Liver weights were decreased in DF, DF+GSH and atorvastatin groups compared with control. In particular, liver weight was significantly reduced only in DF+GSH group. 4. Hepatic lipid accumulation was significantly decreased in DF, DF+GSH and atorvastatin groups compared with control, and the magnitude of which was more effective in DF+GSH group than in DF-only group. 5. Circulating ALT concentrations were decreased in DF, DF+GSH and atorvastatin compared with control, but ALS levels were significantly reduced only in DF+GSH group. Conclusions : In conclusion, these results suggest that DF decreases body weight gain, improves blood lipid metabolism, and reduces liver weight and hepatic lipid accumulation, contributing to the improvement of nonalcoholic fatty liver disease. In addition, these effects were more effective in DF+GSH combination group than in DF-only group.

• Herbal Formula Science
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• v.22 no.1
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• pp.113-122
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• 2014

Objectives : This study investigated the improvement effects of Pakistani (DF-a) and Chinese Ephedra herba-containing Gangjihwan (DF-b) on nonalcoholic fatty liver disease in a high fat diet-induced obese mouse model. Methods : Eight-week-old C57BL/6N mice were divided into five groups: a normal lean group given a standard diet, an obese control group given a high fat diet, and atorvastatin, DF-a, and DF-b groups given a high fat diet with atorvastatin (10 mg/kg), DF-a (80 mg/kg), and DF-b (80 mg/kg), respectively. After 8 weeks of treatment, body weight gain, blood lipid markers, ALT concentrations, liver weight and histology were examined. Results : 1. Body weight gain was significantly decreased in DF-a, DF-b, and atorvastatin groups compared with control. The extent of decreases was eminent in DF-a group. 2. Circulating concentrations of total cholesterol and LDL-cholesterol were significantly decreased in DF-a, DF-b, and atorvastatin groups compared with control. The decreases were most effective in atorvastatin group. 3. Liver weights were decreased in DF-a, DF-b, and atorvastatin groups compared with control. In particular, liver weight was significantly reduced in DF-b group. 4. Hepatic lipid accumulation was significantly decreased in DF-a, DF-b, and atorvastatin groups compared with control, and the magnitude of which was most effective in DF-b group. 5. Circulating ALT concentrations were decreased in DF-a, DF-b, and atorvastatin groups compared with control, but ALS levels were significantly reduced only in DF-b group. Conclusions : In conclusion, these results suggest that DF-a and DF-b decrease body weight gain, improve blood lipid metabolism, and reduce liver weight and hepatic lipid accumulation, contributing to the improvement of nonalcoholic fatty liver disease. In addition, these effects were similar between Pakistani and Chinese Ephedra herba-containing Gangjihwan.

• Investigative Magnetic Resonance Imaging
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• v.8 no.1
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• pp.42-49
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• 2004

Purpose : The quantization noise in magnetic resonance imaging (MRI) systems is analyzed. The signal-to-quantization noise ratio (SQNR) in the reconstructed image is derived from the level of quantization in the signal in spatial frequency domain. Based on the derived formula, the SQNRs in various main magnetic fields with different receiver systems are evaluated. From the evaluation, the quantization noise could be a major noise source determining overall system signal-to-noise ratio (SNR) in high field MRI system. A few methods to reduce the quantization noise are suggested. Materials and methods : In Fourier imaging methods, spin density distribution is encoded by phase and frequency encoding gradients in such a way that it becomes a distribution in the spatial frequency domain. Thus the quantization noise in the spatial frequency domain is expressed in terms of the SQNR in the reconstructed image. The validity of the derived formula is confirmed by experiments and computer simulation. Results : Using the derived formula, the SQNRs in various main magnetic fields with various receiver systems are evaluated. Since the quantization noise is proportional to the signal amplitude, yet it cannot be reduced by simple signal averaging, it could be a serious problem in high field imaging. In many receiver systems employing analog-to-digital converters (ADC) of 16 bits/sample, the quantization noise could be a major noise source limiting overall system SNR, especially in a high field imaging. Conclusion : The field strength of MRI system keeps going higher for functional imaging and spectroscopy. In high field MRI system, signal amplitude becomes larger with more susceptibility effect and wider spectral separation. Since the quantization noise is proportional to the signal amplitude, if the conversion bits of the ADCs in the receiver system are not large enough, the increase of signal amplitude may not be fully utilized for the SNR enhancement due to the increase of the quantization noise. Evaluation of the SQNR for various systems using the formula shows that the quantization noise could be a major noise source limiting overall system SNR, especially in three dimensional imaging in a high field imaging. Oversampling and off-center sampling would be an alternative solution to reduce the quantization noise without replacement of the receiver system.