• Title/Summary/Keyword: Reduction Methods

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Effect of the Dose Reduction Applied Low Dose for PET/CT According to CT Attenuation Correction Method (PET/CT 저선량 적용 시 CT 감쇠보정법에 따른 피폭선량 저감효과)

  • Jung, Seung Woo;Kim, Hong Kyun;Kwon, Jae Beom;Park, Sung Wook;Kim, Myeong Jun;Sin, Yeong Man;Kim, Yeong Heon
    • The Korean Journal of Nuclear Medicine Technology
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    • v.18 no.1
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    • pp.127-133
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    • 2014
  • Purpose: Low dose of PET/CT is important because of Patient's X-ray exposure. The aim of this study was to evaluate the effectiveness of low-dose PET/ CT image through the CTAC and QAC of patient study and phantom study. Materials and Methods: We used the discovery 710 PET/CT (GE). We used the NEMA IEC body phantom for evaluating the PET data corrected by ultra-low dose CT attenuation correction method and NU2-94 phantom for uniformity. After injection of 70.78 MBq and 22.2 MBq of 18 F-FDG were done to each of phantom, PET/CT scans were obtained. PET data were reconstructed by using of CTAC of which dose was for the diagnosis CT and Q. AC of which was only for attenuation correction. Quantitative analysis was performed by use of horizontal profile and vertical profile. Reference data which were corrected by CTAC were compared to PET data which was corrected by the ultra-low dose. The relative error was assessed. Patients with over weighted and normal weight also underwent a PET/CT scans according to low dose protocol and standard dose protocol. Relative error and signal to noise ratio of SUV were analyzed. Results: In the results of phantom test, phantom PET data were corrected by CTAC and Q.AC and they were compared each other. The relative error of Q.AC profile was been calculated, and it was shown in graph. In patient studies, PET data for overweight patient and normal weight patient were reconstructed by CTAC and Q.AC under routine dose and ultra-low dose. When routine dose was used, the relative error was small. When high dose was used, the result of overweight patient was effectively corrected by Q.AC. Conclusion: In phantom study, CTAC method with 80 kVp and 10 mA was resulted in bead hardening artifact. PET data corrected by ultra- low dose CTAC was not quantified, but those by the same dose were quantified properly. In patients' cases, PET data of over weighted patient could be quantified by Q.AC method. Its relative difference was not significant. Q.AC method was proper attenuation correction method when ultra-low dose was used. As a result, it is expected that Q.AC is a good method in order to reduce patient's exposure dose.

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Impacts of Climate Change and Follow-up Cropping Season Shift on Growing Period and Temperature in Different Rice Maturity Types (미래 기후변화 및 그에 따른 재배시기 조정이 벼 생태형별 생육기간과 생육온도에 미치는 영향)

  • Lee, Chung-Kuen;Kwak, Kang-Su;Kim, Jun-Hwan;Son, Ji-Young;Yang, Won-Ha
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.3
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    • pp.233-243
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    • 2011
  • This experiment was conducted to investigate the effect of future climate change on growing period and temperature in different rice maturity types as global warming progressed, where Odaebyeo, Hwaseongbyeo, Ilpumbyeo were used as a representative cultivar of early, medium, and medium-late rice maturity type, respectively, and A1B scenario was applied to weather data for future climate change at 57 sites in Korea. When cropping season was not adjusted to climate change, entire growing period and growing temperature were shorten and risen, respectively, as global warming progressed. On the other side, when cropping season was adjusted to climate change, growing period and temperature after heading date were not changed in contrast to growing period and growing temperature before heading which were more seriously shortened and risen as global warming progressed than in not adjusted cropping season. It is supposed that adjusting cropping season to climate change can alleviate rice yield reduction and quality deterioration to some degree by improving growing temperature condition during grain-filling period, but also still have a limit such as seriously shortened growing period indicating that there need to develope actively new rice cultivation methods and varieties for future climate change.

Fertilizer and Organic Inputs Effects on CO2 and CH4 Emission from a Soil under Changing Water Regimes (토양 수분 변동 조건에서 시비 및 유기물 투입에 따른 CO2와 CH4 방출 특성)

  • Lim, Sang-Sun;Choi, Woo-Jung;Kim, Han-Yong
    • Korean Journal of Environmental Agriculture
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    • v.31 no.2
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    • pp.104-112
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    • 2012
  • BACKGROUND: Agricultural inputs (fertilizer and organic inputs) and water conditions can influence $CH_4$ and $CO_2$ emission from agricultural soils. This study was conducted to investigate the effects of agricultural inputs (fertilizer and organic inputs) under changing water regime on $CH_4$ and $CO_2$ emission from a soil in a laboratory incubation experiment. METHODS AND RESULTS: Four treatments were laid out: control without input and three type of agricultural inputs ($(NH_4)_2SO_4$, AS; pig manure compost, PMC; hairy vetch, HV). Fertilizer and organic inputs were mixed with 25 g of soil at 2.75 mg N/25 g soil (equivalent to 110 kg N/ha) in a bottle with septum, and incubated for 60 days. During the first 30-days incubation, the soil was waterlogged (1 cm of water depth) by adding distilled water weekly, and on 30 days of incubation, excess water was discarded then incubated up to 60 days without addition of water. Based on the redox potential, water regime could be classified into wetting (1 to 30 days), transition (31 to 40 days), and drying periods (41 to 60 days). Across the entire period, $CH_4$ and $CO_2$ flux ranged from 0 to 13.8 mg $CH_4$/m/day and from 0.4~1.9 g $CO_2$/m/day, and both were relatively higher in the early wetting period and the boundary between transition and drying periods. During the entire period, % loss of C relative to the initial was highest in HV (16.4%) followed by AS (8.1%), PMC (7.5%), and control (5.4%), indicating readily decomposability of HV. Accordingly, both $CH_4$ and $CO_2$ fluxes were greatest in HV treatment. Meanwhile, the lower $CH_4$ flux in AS and PMC treatments than the control was ascribed to reduction in $CH_4$ generation due to the presence of oxidized compounds such as ${SO_4}^{2-}$, $Fe^{3+}$, $Mn^{4+}$, and ${NO_3}^-$ that compete with precursors of $CH_4$ for electrons. CONCLUSION: Green manure such as HV can replace synthetic fertilizer in terms of N input, however, it may increase $CH_4$ emission from soils. Therefore, co-application of green manure and livestock manure compost needs to be considered in order to achieve satisfactory N supply and to mitigate $CH_4$ and $CO_2$ emission.

Effect of Octreotide on Patients with Malignant Bowel Obstruction (악성장폐색 환자에서 Octreotide의 치료 효과)

  • Park, Ji-Chan;Jang, Yi-Sun;Jeon, Eun-Kyoung;Kim, Dong-Kyu;Lee, Wook-Hyun;Lee, Guk-Jin;You, Si-Young;Choi, Hyun-Ho;Park, Suk-Young
    • Journal of Hospice and Palliative Care
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    • v.12 no.4
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    • pp.194-198
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    • 2009
  • Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea Purpose: Malignant bowel obstruction causes gastrointestinal symptoms and leads to diminished quality of life in patients with advanced cancer. Several studies have shown the efficacy of octreotide for the relief of malignant bowel obstruction-related symptoms. The aim of this study is to assess the efficacy and safety of octreotide in patients with malignant bowel obstruction. Methods: We retrospectively reviewed medical records of twenty nine patients who had suffered from malignant bowel obstruction without clinical improvement of conservative care and subsequently, received octreotide treatment. Initial dosage of octreotide was 0.1 mg/day, and dose was escalated depending on the clinical effect. For each patient, we assessed visual analogue scale (VAS) of pain, number of vomiting episode, and amount of nasogastric tube drainage. Results: Median dosage of octreotide was 0.2 mg/day (range 0.1~0.6), and median duration from initial medication to death was 20 days (range 2~103). VAS before and after octreotide treatment were 5.6$\pm$1.24, and 2.7$\pm$0.96, respectively. The numbers of vomiting episode before and after octreotide treatment were 3.6/day$\pm$2.5, and 0.4/day$\pm$0.8, respectively. The mean amounts of nasogastric tube drainage before and after octreotide treatment were 975$\pm$1,083 cc/day and 115$\pm$196 cc/day, respectively. Statistically significant reduction in VAS, the number of vomiting episode and the amount of nasogastric tube drainage were observed after octreotide treatment (P<0.05). Conclusion: Administration of octreotide in patients with malignant bowel obstruction, which is uncontrolled by other medication, was effective and safe. In such clinical situations, physicians should consider to add of octreotide for symptomatic control.

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Outbreak of Scion Root from 'Shiranuhi Mandarin' Hybrid Tree in Plastic Film House (부지화 감귤에서 자근의 발생)

  • Kang, Seok-Beom;Moon, Young-Eel;Lee, Dong-Hoon;Kim, Yong-Ho;Han, Seung-Gab;Chae, Chi-Won
    • Korean Journal of Environmental Agriculture
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    • v.31 no.4
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    • pp.313-317
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    • 2012
  • BACKGROUND: Citrus is usually propagated by grafting onto a rootstock. In Korea, As trifoliate orange (Poncirus trifoliata) has dwarf and strong cold hardness, it is widely used as the rootstock of satsuma mandarin. Because 'Shiranuhi' ((Citrus unshiu ${\times}$ C. sinensis) ${\times}$ C. reticulata), a kind of citrus, also, generally is grafted onto a trifoliate orange, most of farmer has been recognized that 'Shiranuhi' root is naturally trifoliate orange. Meanwhile, reduction of flowering in 'Shiranuhi' orchard has been issued among the farmers and researchers over past few years and they guessed it was occurred by severe prune, oversupply of fertilization, overfruiting and temperature of growth period. However, a few researchers strongly assumed that it would be caused by scion rooting of 'Shiranuhi'. So, this study was carried out to identify the existence of scion rooting in 'Shiranuhi' tree in Korea. METHODS AND RESULTS: To identify the existence of scion rooting in 'Shiranuhi' tree, we randomly selected six 'Shiranuhi'orchards and we surveyed three to four trees, which flowering was not enough, from six 'Shiranuhi' orchards respectively. We took the root samples of 'Shiranuhi' mandarin, and then separated the two group which were non-scion rooting (Trifoliate orange), and scion rooting ('Shiranuhi' mandarin). To identity the scion rooting, we used primer set of three types which were a F2/R15, F4/R15 and F5/R15 primer set. As a result, when we conducted the DNA analysis, fourteen tree in less bloomed twenty tree was proved as tree with the scion rooting of 'Shiranuhi' mandarin. CONCLUSION(S): Scion roots of 'Shiranuhi'mandarin were usually observed in a deeply planted tree, and xylem of 'Shiranuhi' root indicated more white color than a case of trifoliata orange. 'Shiranuhi' tree by scion rooting was more vigorous but less flowering than trees grafted onto trifoliata orange. When we used F2/R15, F4/R15 and F5/R15 primer set for discriminance of 'Shiranuhi'mandarin root and trifoliate root, we identified the existence of scion rooting in 'Shiranuhi', From our results, it is suggested that the influence of scion root should be reviewed in 'Shiranuhi'orchards.

Optimal Application Rate of Mixed Expeller Cake and Rice Straw and Impacts on Physical Properties of Soil in Organic Cultivation of Tomato (토마토 유기재배에서 혼합유박과 볏짚의 적정시용량 및 토양 물리성에 미치는 영향)

  • Lim, Tae-Jun;Park, Jin-Myeon;Lee, Seong-Eun;Jung, Hyun-Cheol;Jeon, Sang-Ho;Hong, Soon-Dal
    • Korean Journal of Environmental Agriculture
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    • v.30 no.2
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    • pp.105-110
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    • 2011
  • BACKGROUND: In this study, 5 different treatments such as non-treatment, mixed expeller cake 1.0 N (standard nitrogen fertilizer), rice straw, rice straw+mixed expeller cake 0.5 N, rice straw+mixed expeller cake 1.0 N were performed over 4 cropping seasons over 2 years in order to identify the optimal application rate of mixture of rice straw and mixed expeller cake, organic source in organic cultivation of tomatoes. METHODS AND RESULTS: There was no difference in all treatments in case of 200 mg/kg in the nitrate nitrogen content in soil prior to the first cropping season test under the criteria for nitrogen nutrient based on yield of crops, cultivation without fertilizers seems possible. But in the second cropping season, no treatment and rice straw showed the reduction of yield and in the third cropping season, rice-straw+mixed expeller cake 0.5 N treatment showed the significant difference. The content of nitrate nitrogen in soil prior to cropping seasons was evaluated in 160 mg/kg and standard fertilization such as mixed expeller cake, source of nitrogen, are needed due to the deficiency of nitrogen. In terms of application of organic resources, rice straw showed the effects of improvements on physical properties of soil such as bulk density, cation exchange capacity and humus contents, but the mixed expeller cake did not show any significant differences in improvements on physical properties of soil. CONCLUSION(s): Fertilizer management in organic cultivation of tomatoes is thought to produce the reliable quantity of crops as well as keep the high quality of soils by using the optimal application rate of mixed expeller cake according to the contents of nitrate nitrogen in soil and rice straw which improves the physical properties of soil.

Lung Volumes and Diffusing Capacity in Bronchiectasis: Correlation with the Findings of High Resolutional CT (기관지확장증의 흉부고해상전산화단층촬영소견과 폐기량 및 폐확산능과의 관계)

  • Kim, Yeon-Jae;Park, Jae-Yong;Won, Jun-Hee;Kim, Chang-Ho;Kang, Duk-Sik;Jung, Tae-Hoon
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.4
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    • pp.489-499
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    • 1999
  • Background: The patient with bronchiectasis may have obstructive ventilatory impairment combined with mild restrictive ventilatory impairment due to fibrosis of surrounding lung parenchyme and pleural adhesions caused by chronic recurrent pulmonary infections. Since hyperinflation or emphysematous change can be occured in bronchiectasis, pulmonary functions such as lung volumes and diffusing capacity may also vary with associated emphysema. Methods: For the evaluation of lung volumes and diffusing capacity in bronchiectasis with respect to the anatomic types and severity of bronchiectasis, a total of 40 cases comprising 24 cases of tubular, and 16 cystic type of bronchiectasis were analyzed retrospectively. Correlation between lung functions and extent of bronchiectasis or associated emphysema detected in HRCT were also evaluated. Results: Vital capacity(VC) tended to decrease in cystic type than in tubular type. As the severity of bronchiectasis became serious, the VC were significantly reduced, whereas the total lung capacity(TLC), residual volume(RV) and its ratio to the total lung capacity(RV/TLC) had no significant difference. Lung clearance index(LCI) was significantly increased in cystic type than in tubular type, whereas the slope of phase III in single breath nitrogen curve($\triangle$N2/L) was not significantly changed regard to the type and severity of bronchiectasis. DLCO and DLCO/VA reflecting diffusing capacity were significantly decreased in cystic type and also as the severity of bronchiectasis became serious. The correlation coefficient of VC, DLCO and LCI with the extent of bronchiectasis were -0.322, -0.339 and 0.487, respectively, whereas other parameters were not significantly correlated with the extent of bronchiectasis. VC and DLCO correlated negatively with the extent of emphysema while RV, RV/TLC, LCI and $\triangle$N2/L correlated positively. Conclusion: These findings suggest that the reduction of VC and diffusing capacity or uneven distribution of inspired gas in bronchiectasis are related to both the extent of bronchiectasis and associated emphysema while increased residual volume be related to the extent of associated emphysema alone.

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Cytosolic Phospholipase A2 Activity in Neutrophilic Oxidative Stress of Platelet-activating Factor-induced Acute Lung Injury (Platelet-activating Factor에 의한 급성폐손상에서 호중구성 산화성 스트레스에 관여하는 Cytosolic Phospholipase A2 활성도의 변화)

  • Kwon, Young Shik;Hyun, Dae Sung;Lee, Young Man
    • Tuberculosis and Respiratory Diseases
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    • v.63 no.6
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    • pp.497-506
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    • 2007
  • Background: The present investigation was performed in rats and isolated human neutrophils in order to confirm the presumptive role of the positive feedback loop of cytosolic phospholipase $A_2$ ($cPLA_2$) activation by plateletactivating factor (PAF). Methods: The possible formation of the positive feedback loop of the $cPLA_2$ activation and neutrophilic respiratory burst was investigated in vivo and in vitro by measurement of the parameters denoting acute lung injury. In addition, morphological examinations and electron microscopic cytochemistry were performed for the detection of free radicals in the lung. Results: Five hours after intratracheal instillation of PAF ($5{\mu}g/rat$), the lung leak index, lung myeloperoxidase (MPO) activity, the number of neutrophils and the concentration of cytokine-induced neutrophil chemoattractant (CINC) in bronchoalveolar lavage fluid were increased by PAF as compared with those of control rats. The NBT assay and cytochrome-c reduction assay revealed an increased neutrophilic respiratory burst in isolated human neutrophils following exposure to PAF. Lung and neutrophilic $cPLA_2$ activity were increased following PAF exposure and exposure to hydrogen peroxide increased $cPLA_2$ activity in the lung. Histologically, inflammatory findings of the lung were observed after PAF treatment. Remarkably, as determined by $CeCl_3$ cytochemical electron microscopy, increased production of hydrogen peroxide was identified in the lung after PAF treatment. Conclusion: PAF mediates acute oxidative lung injury by the activation of $cPLA_2$, which may provoke the generation of free radicals in neutrophils.

Development of Optimal Seed Production Methods Using Domestic Rye Cultivar in Central and North Area of Korea (중·북부지역에서 국내육성 호밀품종의 채종방법)

  • Han, Ouk-Kyu;Song, Ju-Hee;Ku, Ja-Hwan;Kim, Dea-Wook;Kwon, Young-Up;Lee, Yu-Young;Park, Chang-Hwan;Kweon, Soon-Jong;Ahn, Jong-Woong
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.38 no.1
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    • pp.44-52
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    • 2018
  • This experiment was conducted at Suwon, Korea from 2013 to 2015. The objective of this study was to establish the optimum seeding rate, and to clarify the nitrogen fertilizer level for rye seed production in central and north area of Korea. We used Korean rye cultivar 'Gogu' for this test. We employed a split-plot design with three replications. The main plots were designed by three seeding levels (3, 5 and $7kg\;10a^{-1}$), but other sub-plots were randomly seeded. The plots were treated with three different nitrogen fertilizer levels (3, 6 and $9kg\;10a^{-1}$). The percentage of productive tiller, number of grain per spike, fertility rate, 1 liter weight, and 1000-grain weight decreased as seeding rate increased from $3kg\;10a^{-1}$ to $7kg\;10a^{-1}$, whereas the number of spike per $m^2$ increased. Therefore the grain yields of rye had less of an effect by increasing seeding rate. There was an increase in number of spike per $m^2$, number of grain per spike, and fertility rate as nitrogen fertilizer level increased from $3kg\;10a^{-1}$ to $9kg\;10a^{-1}$, but grain yields significantly not affected by the interaction of seeding rate ${\times}$ nitrogen fertilizer levels. However, the best seeding rate and nitrogen fertilizer level for rye seed production were 5 kg and $5{\sim}6kg\;10a^{-1}$, respectively, considering seed and fertilizer reduction and the prevention of pollution by excess fertilization.

Change of FDG Uptake According to Radiation Dose on Squamous Cell Carcinoma of the Head and Neck (두경부종양에서 방사선조사량에 타른 FDG-PET의 변화양상)

  • Lee Sang-wook;Kim Jae-Seung;Im Ki Chun;Ryu Jin Sook;Lee Hee Kwan;Kim Jong Hoon;Ahn Seung Do;Shin Seong Soo;Yoon Sang Min;Song Siyeol;Park Jin-hong;Moon Dae Hyuk;Choi Eun Kyung
    • Radiation Oncology Journal
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    • v.22 no.2
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    • pp.98-105
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    • 2004
  • Purpose : To evaluate whether positron omission tomography (PET) with 2-[F-18]fluoro-2-deoxy-D-giucose(FDG) can be used to predict of early response to definitive aim radlotherapy (RT) in squamous cell carcinoma of the head and neck using response rate and locoreglonal control as study endpoints. Materials and Methods : Twenty-two patients with head and neck cancer underwent a FDG-PET study before RT, after a flrst dose of 45 Gy, and after a second dose on more 4han 70 Gy. Standard uptake value (SUV) was calculated for primary tumor (n=22) and neck lymph node (n:10). Attenuation corrected PET scans acquired 60 min after tracer injection were used for evaluation of FDG uptake In tumors. A quantitative FDG uptake index was expressed as Suvlean (corrected for iean body mass). The follow-up time was at least 5 months (range S-1 S months). Results : A total of 22 primary tumors and 10 metastatic lymph nodes were analyzed In FDG-PET. In the first PET study the mean SUVlean the primary tumors and nodes were 5.4 (SD, 2.5) and 4.6 (SD, 2.3), respectively. In the second PET, study peformed after 46 Gy RT the mean SUV in primary tumor and node decreased to 2.9 (SD, 1.9, p<0.001) and 1.7 (SD, 1.3) respectively. in the third PET study peformed at the full dose (more than 70 Gy), RT the mean SUV In the primary tumors and nodes decreased to 2.3 (SD, 1.5, p<0.001) and 1.5 (SD, 1 .1) respectively. Conclusions: FDG uptake In tumors showed a significant decrease after the 45 Gy and more than 70 Gy of RT for squamous cell carcinoma of the head and neck. Reduction of metabolic activity after 46 Gy of radiotherapy Is closely correlated with radiation response.