• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.14-30
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• 1998

Manganese is an essential element in the body. It is mainly deposited in the liver and to a lesser degree in the basal ganglia of the brain and eliminated through the bile duct. Rapid turnover of managanese in the body makes it difficult to evaluate the manganese exposure in workers, esecially in those with irregular or intermittent exposure, like welders. Therefore, conventional biomarkers, including blood and urine manganese can provide only a limited information about the long-tern or cumulative exposure to manganese. Introduction of magnetic resonance imaging (MRI) made a progress in the assessment of manganese exposure in the medical conditions related to manganese accumulation, e. g. hepatic failure and long-term total parenteral nutrition. Manganese shortens spin-lattice(T1) relaxation time on MRI due to its paramagnetic property, resulting in high signal intensity (HSI) on T1-weighted image(T1W1) of MRI. Manganese deposition in the brain, therefore, can be visualizedas an HSI in the globus pallidus, the substantia nigra, the putamen and the pituitary. clinical and epidemiologic studies regarding the MRI findings in the cases of occupational and non-occupational manganese exposure were reviewed. relationships between HSI on T1W1 of MRI and age, gender, occupational manganese exposure, and neurological dysfunction were analysed. Relationships betwen biological exposure indices and HSI on MRE werealso reviewed. Literatures were reviewed to establish the relationships between HSI, Manganese deposition in the brain, pathologic findings, and neurological dysfunction. HSI on T1W1 of MRI reflects regional manganese deposition in the brain. This relationship enables an estimation of regional manganese deposition in the brain by analysing MR signal intensity. Manganese deposition in the brain can induce a neuronal loss in the basal ganglia but functional abnormality is supposed to be related to the cumulative exposure of manganese in the brain, use of brain MRI for the assessment of exposure in a group of workers seems to be hardly rationalized, while ti can be a useful adjunct for the evaluation of manganese exposure int he cases with suspected manganese-related health problems.

• Journal of Chest Surgery
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• v.35 no.5
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• pp.387-391
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• 2002

Background: Postoperative morbidity and mortality in destroyed lung are relatively high. We tried to identify the prognostic factors affecting postoperative morbidity and mortality in destroyed lung through a retrospective study. Material and method: The retrospective study was undertaken in 112 patients who had undergone pneumonectomy or pleuropneumonectomy for destroyed lung at Severance Hospital from 1970 to 2000. We analyzed the correlation between postoperative morbidity and mortality and etiology, duration of disease, preoperative FEV1, presence or absence of peroperative empyema, operation timing, the side of operation, duration of operation, and operation type. Result: There were 55 men and 57 women, aged 20 to 81 years (mean 44 years). Etiologic diseases were tuberculosis in 86 patients(76.8%) including tuberculos empyema in 20 and tuberculous bronchiectasis in 4, pyogenic empyema in 12(10,7%), bronchiectasis in 12(10.7%), and lung abscess in 2(1.8%). Postoperative morbidity were 25%(n=28) and postoperative mortality was 6%(n=7). The presence of preoperative empyema(p=0.016), pleuropneumonectomy(p=0.037) and preoperative FEV1 of less than 1.75 L(P=0.048) significantly increased the postoperative morbidity, If operation time was less than 300min, postoperative morbidity(p=0.002) and mortality(p=0.03) were significantly low. Conclusion: Postoperative morbidity and mortality in destroyed lung were acceptable. Postoperative morbidity and mortality were significantly low when operation time was less than 300 min. Preoperative existence of empyema, pleuropneumonectomy and preoperative FEV1 of less than 1.75 L significantly increased postoperative morbidity.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.5
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• pp.499-506
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• 2005

This study was performed to investigate the effects of influent C/N ratio on the removal of organic and nitrogenous compounds by two nonwoven fabric filter bioreactors. The reactors were alternately aerated at an aeration/nonaeration period ratio of 60 min/60 min, and fed with wastewater only during nonaeration period. The influent C/N ratio (COD/TKN) was gradually reduced from 10 to 2. The influent was prepared by diluting the leachate from a foodwaste treatment facility in I city so that the COD concentration could be about 2,500 mg/L. The C/N ratio of the wastewater was adjusted by adding ammonium chloride. The results of the experiment showed that the COD and BOD concentration of the effluent was $40{\sim}54\;mg/L$ and $1{\sim}4\;mg/L$, respectively at the C/N ratios of $10{\sim}3$, and the effluent SS concentration was always below 2.0 mg/L. The T-N removal efficiencies were 96% or higher at C/N ratios of $10{\sim}5$, but decreased to 83% and 81%, respectively at the C/N ratios of 3 and 2.8. At the C/N ratios of 2.6 and 2, the effluent quality deteriorated due to ammonia toxicity. The fraction of nitrifying microorganism in the reactors increased from 10% to 20% as the C/N ratio decreased from 5 to 2.6. Alkalinity consumed were $3.12{\sim}3.49\;g$ alkalinity/g T-N removed at the C/N ratios of $10{\sim}5$, which are lower than the theoretical value of 3.57. However, the ratio increased to 4.63 and 4.87 g alkalinity/g T-N removed, respectively at the C/N ratios of 3 and 2.8.