184 research outputs found

    Determination of Cutting Date and Interval on Native Grass Management of Agricultural Waterways in South Korea

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    Agricultural waterways provide a buffer zone between crop fields and adjacent rivers or streams. Waterways are important resource for agriculture water management, water quality and biodiversity conservation. The total linear distance of waterway in Korea is about 180,000 km, and about 40% are concrete and about 60% are grassed waterways. At present, the percentage of concrete waterways is increasing because of their water management efficiency. Some argue that continued expansion of concrete waterways is not sustainable because it leads to potential-degradation of the earth\u27s environment. This concern has led to renewed efforts to use grassed waterways as an alternative to concrete. In addition, grassed waterways enhance the environment-friendly image of agriculture that Korea farmers want to promote. The objective of this experiment was to determine the effect of cutting date and interval of native grasses for water management efficiency of agricultural waterway

    Theta Oscillation Related to the Auditory Discrimination Process in Mismatch Negativity: Oddball versus Control Paradigm

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    Background and Purpose The aim of this study was to identify the mechanism underlying the auditory discriminatory process reflected in mismatch negativity (MMN), using time-frequency analysis of single-trial event-related potentials (ERPs).Methods Two auditory tones of different probabilities (oddball paradigm) and the same probability (control paradigm) were used. The average dynamic changes in amplitude were evaluated, and the in-phase consistency of the EEG spectrum at each frequency and time window across trials, event-related spectral perturbations (ERSPs), and inter-trial phase coherence (ITC) were computed.Results Subtraction of the ERPs of standard stimuli from the ERPs of deviant stimuli revealed a clear MMN component in the oddball paradigm. However, no discernible MMN component was observed in the control paradigm. Statistical tests showed that in the oddball paradigm, deviant tones produced significant increases of theta ERSPs and ITC at around 250 ms as compared with the standard tone, while no significant difference between the two stimuli was observed in the control paradigm.Conclusions Our results confirm that the auditory discriminatory process reflected in MMN is accompanied by phase resetting and power modulation at the theta frequency.OAIID:oai:osos.snu.ac.kr:snu2012-01/102/2014017262/2SEQ:2PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:2014017262ADJUST_YN:YEMP_ID:A079623DEPT_CD:801CITE_RATE:1.892DEPT_NM:의학과SCOPUS_YN:YCONFIRM:

    The Clinical Usefulness of 18F-FDG PET/CT for the Evaluation of Lymph Node Metastasis in Periorbital Malignancies

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    PURPOSE: Surgical treatment of malignancies in the oral cavity and subsequent radiotherapy often result in an oral condition unfavorable for prosthodontic rehabilitation. This study assessed the quality of life related to oral function in edentulous head and neck cancer patients following oncology treatment of malignancies in the lower region of the oral cavity. MATERIALS AND METHODS: Patients treated between 1990 and 2000 with surgery and radiotherapy for a squamous cell carcinoma in the oral cavity who were edentulous in the mandible and had been treated with a conventional, non-implant-retained denture received an invitation for a clinical check-up (clinical assessment, questionnaires regarding oral function and quality of life). RESULTS: Sixty-seven of the 84 patients who fulfilled the inclusion criteria were willing to participate in the study. The mean irradiation dosage that these patients had received in the oral region was 61.8 +/- 5.4 Gy. Half of the patients (n=33) were not very satisfied with their prostheses; they wore their mandibular prostheses at most a few hours per day. It was concluded from the clinical assessment that two thirds of the patients (n 4) could benefit from an implant-retained mandibular denture. Analyses of the questionnaires revealed no significant associations between functional assessments, quality of life, and parameters such as size of the primary tumor, location of the primary tumor, and different treatment regimes. Despite cancer treatment, the patients reported a rather good general quality of life. CONCLUSIONS: Sequelae resulting from radiotherapy probably dominate oral function and quality of life after oncology treatment. In two thirds of the patients, improvement of oral function and related quality of life would be expected with the use of an implant-retained mandibular denture

    The Antitumor Effect and Hepatotoxicity of a Hexokinase II Inhibitor 3-Bromopyruvate: In Vivo Investigation of Intraarterial Administration in a Rabbit VX2 Hepatoma Model

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    Objective: The purpose of this study was to compare the antitumor effect and hepatotoxicity of an intraarterial delivery of low-dose and high-dose 3-bromopyruvate (3-BrPA) and those of a conventional Lipiodol-doxorubicin emulsion in a rabbit VX2 hepatoma model. Materials and Methods: This experiment was approved by the animal care committee at our institution. VX2 carcinoma was implanted in the livers of 36 rabbits. Transcatheter intraarterial administration was performed using low dose 3-BrPA (25 mL in a 1 mM concentration, n = 10), high dose 3-BrPA (25 mL in a 5 mM concentration, n = 10) and Lipiodol-doxorubicin emulsion (1.6 mg doxorubicin/0.4 mL Lipiodol, n = 10), and six rabbits were treated with normal saline alone as a control group. One week later, the proportion of tumor necrosis was calculated based on histopathologic examination. The hepatotoxicity was evaluated by biochemical analysis. The differences between these groups were statistically assessed with using Mann-Whitney U tests and Kruskal-Wallis tests. Results: The tumor necrosis rate was significantly higher in the high dose group (93% +/- 7.6 [mean +/- SD]) than that in the control group (48% +/- 21.7) (p = 0.0002), but the tumor necrosis rate was not significantly higher in the low dose group (62% +/- 20.0) (p = 0.2780). However, the tumor necrosis rate of the high dose group was significantly lower than that of the Lipiodol-doxorubicin treatment group (99% +/- 2.7) (p = 0.0015). The hepatotoxicity observed in the 3-BrPA groups was comparable to that of the Lipiodol-doxorubicin group. Conclusion: Even though intraarterial delivery of 3-BrPA shows a dose-related antitumor effect, single session treatment seems to have limited efficacy when compared with the conventional method.Vali M, 2008, J PHARMACOL EXP THER, V327, P32, DOI 10.1124/jpet.108.141093Park HS, 2007, KOREAN J RADIOL, V8, P216Vali M, 2007, J VASC INTERV RADIOL, V18, P95, DOI 10.1016/j.jvir.2006.10.019Shin SW, 2006, ACTA RADIOL, V47, P1036, DOI 10.1080/02841850600977752Gwak GY, 2005, J HEPATOL, V42, P358, DOI 10.1016/j.jhep.2004.11.020Ko YH, 2004, BIOCHEM BIOPH RES CO, V324, P269, DOI 10.1016/j.bbrc.2004.09.047Llovet JM, 2003, LANCET, V362, P1907Yoon CJ, 2003, RADIOLOGY, V229, P126, DOI 10.1148/radio.2291021029Pedersen PL, 2002, BBA-BIOENERGETICS, V1555, P14Geschwind JFH, 2002, CANCER RES, V62, P3909Ko YH, 2001, CANCER LETT, V173, P83Smith TAD, 2000, BRIT J BIOMED SCI, V57, P170Pedersen PL, 1999, J BIOENERG BIOMEMBR, V31, P291Dang CV, 1999, TRENDS BIOCHEM SCI, V24, P68Bosch FX, 1999, SEMIN LIVER DIS, V19, P271Bruix J, 1997, HEPATOLOGY, V25, P259Rempel A, 1996, CANCER RES, V56, P2468Stuart KE, 1996, CANCER, V77, P2217MATHUPALA SP, 1995, J BIOL CHEM, V270, P16918OKADA M, 1995, BRIT J CANCER, V71, P518WATANABE D, 1995, ONCOLOGY, V52, P76REMPEL A, 1994, BBA-GENE STRUCT EXPR, V1219, P660BRUIX J, 1992, J HEPATOL, V15, P350OKUDA K, 1992, HEPATOLOGY, V15, P948SHINOHARA Y, 1991, FEBS LETT, V291, P55KO YH, 1990, ARCH BIOCHEM BIOPHYS, V278, P373BISMUTH H, 1986, WORLD J SURG, V10, P311JOHANSSON T, 1985, BIOCHEM BIOPH RES CO, V133, P608VIITANEN PV, 1984, J BIOL CHEM, V259, P9679BUSTAMANTE E, 1981, J BIOL CHEM, V256, P8699PEDERSEN PL, 1978, PROGR EXPT TUMOR RES, V22, P190WEINHOUS.S, 1972, CANCER RES, V32, P2007

    A Comparative Study on the Efficacy of Covered Metal Stent and Plastic Stent in Unresectable Malignant Biliary Obstruction

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    Background/AimsThe placement of self expandable metal stent (SEMS) is one of the palliative therapeutic options for patients with unresectable malignant biliary obstruction. The aim of this study was to compare the effectiveness of a covered SEMS versus the conventional plastic stent.MethodsWe retrospectively evaluated 44 patients with unresectable malignant biliary obstruction who were treated with a covered SEMS (21 patients) or a plastic stent (10 Fr, 23 patients). We analyzed the technical success rate, functional success rate, early complications, late complications, stent patency and survival rate.ResultsThere was one case in the covered SEMS group that had failed technically, but was corrected successfully using lasso. Functional success rates were 90.5% in the covered SEMS group and 91.3% in the plastic stent group. There was no difference in early complications between the two groups. Median patency of the stent was significantly prolonged in patients who had a covered SEMS (233.6 days) compared with those who had a plastic stent (94.6 days) (p=0.006). During the follow-up period, stent occlusion occurred in 11 patients of the covered SEMS group. Mean survival showed no significant difference between the two groups (covered SEMS group, 236.9 days; plastic stent group, 222.3 days; p=0.182).ConclusionsThe patency of the covered SEMS was longer than that of the plastic stent and the lasso of the covered SEMS was available for repositioning of the stent

    Different contribution of extent of myocardial injury to left ventricular systolic and diastolic function in early reperfused acute myocardial infarction

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    BACKGROUND: We sought to investigate the influence of the extent of myocardial injury on left ventricular (LV) systolic and diastolic function in patients after reperfused acute myocardial infarction (AMI). METHODS: Thirty-eight reperfused AMI patients underwent cardiac magnetic resonance (CMR) imaging after percutaneous coronary revascularization. The extent of myocardial edema and scarring were assessed by T2 weighted imaging and late gadolinium enhancement (LGE) imaging, respectively. Within a day of CMR, echocardiography was done. Using 2D speckle tracking analysis, LV longitudinal, circumferential strain, and twist were measured. RESULTS: Extent of LGE were significantly correlated with LV systolic functional indices such as ejection fraction (r��=��-0.57, p��<��0.001), regional wall motion score index (r��=��0.52, p��=��0.001), and global longitudinal strain (r��=��0.56, p��<��0.001). The diastolic functional indices significantly correlated with age (r��=��-0.64, p��<��0.001), LV twist (r��=��-0.39, p��=��0.02), average non-infarcted myocardial circumferential strain (r��=��-0.52, p��=��0.001), and LV end-diastolic wall stress index (r��=��-0.47, p��=��0.003 with e') but not or weakly with extent of LGE. In multivariate analysis, age and non-infarcted myocardial circumferential strain independently correlated with diastolic functional indices rather than extent of injury. CONCLUSIONS: In patients with timely reperfused AMI, not only extent of myocardial injury but also age and non-infarcted myocardial function were more significantly related to LV chamber diastolic function.ope

    Sentinel Lymph Node Radiolocalization with 99mTc Filtered Tin Colloid in Clinically Node-Negative Squamous Cell Carcinomas of the Oral Cavity

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    The objective of this study was to evaluate the feasibility of sentinel lymph node biopsy by using a radiotracer lymphatic mapping technique in patients with squamous cell carcinoma of the oral cavity, and the diagnostic value of this technique. We studied twenty patients with previously untreated squamous cell carcinomas of the oral cavity and N0 necks. After the peritumoral injection of 99mTc filtered tin colloid preop-eratively, lymphoscintigraphy and intraoperative mapping using a gamma detector were performed to localize sentinel nodes. An open biopsy of the sentinel node was followed by complete neck dissection. We identified the sentinel nodes in 19 of 20 patients (95.0%) by lymphoscintigraphy and in all (100%) by intraoperative gamma detector. In all cases, the status of the sentinel node accurately predicted the pathologic status of the neck with the false negative rate being 0%. The negative predictive value for the absence of cervical metastases was 100%. In conclusion, our radio-localization technique of sentinel nodes using 99mTc filtered tin colloid in N0 squamous cell carcinomas of the oral cavity is technically feasible and appears to accurately predict the presence of the occult metastatic disease
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