The fluorometric method using the aqueous sodium hydroxide solution as the trapping solution possesses a sufficient sensitivity to determine hydrogen sulfide of background levels in the atmosphere. But the sulfide ion collected in the trapping solution is unstable, so the samples must be analyzed soon after sampling. The authors modified the trapping solution by adding a small amount of EDTA for better stability of the sulfide ion in the solution. The EDTA added into the solution masks the metallic ions such as ferrous, ferric and manganse ions, and it lowers the rate of oxidation of sulfide ion as a result of decrease of these ions in the solution which are considered to work as catalysts of oxidation. In case of 1.0×10-5 M of sodium sulfide in 0.1 N NaOH, the concentration decreased at a rate of about 20% in a day at room temperature, but it became more stable by the presence of 0.01 M EDTA and the sulfide solution was stable at least for one week if the solution was kept in a dark room. The sulfide solution containing EDTA was also quite stable to aeration; 5×10-6 M of sodium sulfide in 0.1 N NaOH in the presence of 0.01 M EDTA was stable even after passing air through the solution at a flow rate of 0.5 1/min for 2 hours. The modified trapping solution containing EDTA enables the fluorometric method to be more practical in the determination of hydrogen sulfide of background levels in the atmosphere.
Presently, 6 cases of IgG4-related pleuritis have been reported. We encountered a patient who developed chylothorax due to IgG4-related disease. To our knowledge, such patients have not been reported. This patient developed right-sided chylothorax and left-sided non-chylothorax lymphocyte-predominant pleuritis. Elevated serum and pleural IgG4 concentrations and histopathological analysis of pleural biopsy confirmed the diagnosis of IgG4-related pleuritis. Left-sided pleuritis improved with corticosteroid therapy, but right-sided chylothorax persists. IgG4-related disease can be one cause of chylothorax.
Human parechoviruses (HPeV) are mainly isolated from upper respiratory tract infection and gastroenteritis in children. HPeV has not been screened for in the past studies of community-acquired pneumonia (CAP) in adults, and its association with CAP is unknown. We present two cases that HPeV was detected by multiplex polymerase chain reaction for respiratory viruses using bronchoalveolar lavage fluid and diagnosed as pneumonia caused by HPeV.
Many traditional researches on the debris flow are based on the continuum mechanics, which handled with water and particles as one body. But this method can not describe particle/particle interaction based on dynamical mechanism of particle motions. This study takes an approach method for considering particles motion and motion of water current individually by using the distinct element method (DEM) coupled with a model for water-flow. Present method is applied to collect the basic information of collision and repulsion process in the equilibrium state on debris flow. Calculated velocity profiles and the concentration profiles are compared with the reported experimental results. And the role of particle/particle interaction in constitutive relation have been investigated from the present numerical model.
The role of vegetation on water balance in mountainous region has been discussed for long time, however, the quantitative evaluation of the role has not been clearly. Meantime, erosion control works have been extensively carried out since the end of the War, for recovery of ruined country. Now, it becomes necessary to evaluate the effects of erosion control works quantitatively. We have started observations of rainfall, discharge and sediment runoff at 5 experimental basins located in upper Watarase River, in order to evaluate the effects of erosion control works carried out in the basins. This paper is a result of preliminary study concerned to change of runoff characteristics of Watarase River at Kusaki Dam site, which includes 5 experimental basins and is 254km2 in area.The results obtained are as follows: The long term runoff characteristics has been changing inthe direction of becoming lower runoff ratio. Intensities of flood peak are becoming mild. These results are obtained using the data during 1977 to 1995, so, it seems too short to judge correctly. We must confirm these results using the data of experimental basins in future.
