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Biomedical subjects

T Matsuto

Publications and source records attributed to T Matsuto.

At least 19 recordsLinked to original sources
PubMed2006

Characterization of char derived from various types of solid wastes from the standpoint of fuel recovery and pretreatment before landfilling.

Carbonization is a kind of pyrolysis process to produce char from organic materials under an inert atmosphere. In this work, chars derived from various solid wastes were characterized from the standpoint of fuel recovery and pretreatment of waste before landfilling. Sixteen kinds of municipal and industrial solid wastes such as residential combustible wastes, non-combustible wastes, bulky wastes, construction and demolition wastes, auto shredder residue, and sludges were carbonized at 500 degrees C for 1h under nitrogen atmosphere. In order to evaluate the quality of char as fuel, proximate analysis and heating value were examined. The composition of raw waste had a significant influence on the quality of produced char. The higher the ratio of woody biomass in waste, the higher heating value of char produced. Moreover, an equation to estimate heating value of char was developed by using the weight fraction of fixed carbon and volatile matter in char. De-ashing and chlorine removal were performed to improve the quality of char. The pulverization and sieving method seems to be effective for separation of incombustibles such as metal rather than ash. Most char met a 0.5 wt% chlorine criterion for utilization as fuel in a shaft blast furnace after it was subjected to repeated water-washing. Carbonization could remove a considerable amount of organic matter from raw waste. In addition, the leaching of heavy metals such as chrome, cadmium, and lead appears to be significantly suppressed by carbonization regardless of the type of raw waste. From these results, carbonization could be considered as a pretreatment method for waste before landfilling, as well as for fuel recovery.

Carbon↗
PubMed2006

Recovery of zinc and lead from fly ash from ash-melting and gasification-melting processes of MSW--comparison and applicability of chemical leaching methods.

Fly ash generated from MSW ash-melting and gasification-melting plants, known as Melting Furnace Fly Ash (MFA), contains considerable amounts of heavy metals such as Pb and Zn. These metals can be recovered using a smelting furnace after "pre-treatment" for removal of unnecessary elements such as Cl, Sn and Si. Chemical methods have been studied for pretreatment in the past. However, they have been discussed only with regard to treatment cost and the concentration of Pb and Zn recovered, but neither applicability to various types of MFA nor the environmental impact have been considered. In this study, acid, alkaline and ammonia/chloride leaching methods were compared from the standpoints of: (1) applicability to MFA, (2) concentration of Pb and Zn recovered, (3) treatment cost, and (4) environmental impact. Twenty-three samples of MFAs were collected and classified into 4 types based on element contents. A Pb and Zn recovery experiment was conducted for the representative MFA of those types. The results showed: (1) MFA from gasification-melting plants cannot be treated by chemical methods; (2) the other MFA can be treated to an acceptable quality by existing smelting furnaces; (3) only MFA from electric resistance ash-melting plants can be treated easily by the water washing method; and (4) alkaline and ammonia/chloride leaching methods were more effective than acid leaching.

Carbon↗
PubMed2006

Flow analysis of metals in a municipal solid waste management system.

This study aimed to identify the metal flow in a municipal solid waste (MSW) management system. Outputs of a resource recovery facility, refuse derived fuel (RDF) production facility, carbonization facility, plastics liquefaction facility, composting facility, and bio-gasification facility were analyzed for metal content and leaching concentration. In terms of metal content, bulky and incombustible waste had the highest values. Char from a carbonization facility, which treats household waste, had a higher metal content than MSW incinerator bottom ash. A leaching test revealed that Cd and Pb in char and Pb in RDF production residue exceeded the Japanese regulatory criteria for landfilling, so special attention should be paid to final disposal of these substances. By multiplying metal content and the generation rate of outputs, the metal content of input waste to each facility was estimated. For most metals except Cr, the total contribution ratio of paper/textile/plastics, bulky waste, and incombustible waste was over 80%. Approximately 30% of Cr originated from plastic packaging. Finally, several MSW management scenarios showed that most metals are transferred to landfills and the leaching potential of metals to the environment is quite small.

Chromium↗
PubMed2005

Application of a gas-solid fluidized bed separator for shredded municipal bulky solid waste separation.

A laboratory-scale gas-solid fluidized bed separator able to separate fractions of 5.6-50mm was used for separation of shredded municipal bulky waste (SBW) into combustibles and incombustibles. In batch-scale tests, it was found that accumulation of SBW in the bottom of the bed significantly reduced the separation efficiency. In this study, stirring was shown to be effective in preventing this accumulation. Flexible sheet materials such as paper and film plastics also significantly decreased the separation efficiency. In batch-scale tests, an overall efficiency of 90% was obtained when flexible materials such as film plastics and paper were excluded from the feed SBW. In continuous feeding tests, purities of the float and sink fractions attained 95% and 86% efficiencies, respectively, with an overall efficiency of 79%. The effect of feedstock shape on separation efficiency was also investigated. This study revealed that large particles can be properly separated on the basis of density, while the shape of the material significantly influenced behavior in the fluidizing bed.

Incineration↗
PubMed2005

Water-soluble characteristics of chlorine in char derived from municipal solid wastes.

Chlorine in char derived from municipal solid waste (MSW) was characterized and quantified based on its water solubility: easily water-soluble, hardly water-soluble, and non-water-soluble chlorine. For that, a four-cycle process of water-washing, heating or carbonation were carried out. In order to confirm the characteristics of non-water-soluble chlorine, additional thermal treatment and an alkali-acid washing process were applied to washed char. It was found that a large particle size of char (0.5-1.0 mm) significantly contributed to the amount of non-water-soluble chlorine. Pulverization and HNO3-HF digestion were performed to identify a factor to interfere chlorine release from char with a large particle size. Pulverization was proven ineffective for release of non-water-soluble chlorine, whereas approximately 32% of non-water-soluble chlorine was extracted by HNO3-HF digestion. Therefore, the presence of non-water-soluble chlorine is likely to originate from its chemical property rather than simply from its physical one.

Carbon↗
PubMed2005

Influence of residual carbon on the decomposition process of PCDD/Fs in MSWI fly ash.

In heating treatment of fly ash to reduce PCDD/Fs, cooling process is important to inhibit de novo formation of PCDD/Fs. In this study, assuming that residual carbon is the dominant factor of de novo synthesis, the relation between PCDD/Fs and residual carbon was examined. Firstly, by using MSWI fly ash which was treated in an actually operated facility, both the content of PCDD/Fs and residual carbon were decreased as heating temperature increased. At temperatures higher than 400 degrees C, the reduction rate of residual carbon was higher than 20% and more than 95% of PCDD/Fs was decomposed. In order to simulate a heating treatment process, fly ash was heated at different temperatures and gas atmospheres, oxygen or nitrogen. Heated fly ash was placed for 2 h at 300 degrees C in oxygen to promote de novo synthesis, or cooled immediately. As a result, good correlation between PCDD/Fs and residual carbon was found, therefore it was shown experimentally that residual carbon was the main factor for PCDD/Fs formation by de novo synthesis in fly ash.

Atmosphere↗
PubMed2005

Behavior of metals in ash melting and gasification-melting of municipal solid waste (MSW).

In this study, metal behavior in ash-melting and municipal solid waste (MSW) gasification-melting facilities were investigated. Eight ash-melting and three MSW gasification-melting facilities with a variety of melting processes and feedstocks were selected. From each facility, melting furnace fly ash (MFA) and molten slag were sampled, and feedstock of the ash-melting processes was also taken. For the ash melting process, the generation rate of MFA was well correlated with the ratio of incineration fly ash (IFA) in feedstock, and this was because MFA was formed mostly by mass transfer from IFA and a limited amount from bottom ash (BA). Distribution ratios of metal elements to MFA were generally determined by volatility of the metal element, but chlorine content in feedstock had a significant effect on Cu and a marginal effect on Pb. Distribution ratio of Zn to MFA was influenced by the oxidizing atmosphere in the furnace. High MFA generation and distribution ratio of non-volatile metals to MFA in gasification-melting facilities was probably caused by carry-over of fine particles to the air pollution control system due to large gas volume. Finally, dilution effect was shown to have a significant effect on metal concentration in MFA.

Air Pollution↗
PubMed2004

Resident's concerns and attitudes towards Solid Waste Management facilities.

Because of limited space, the siting and construction of a new SWM facility is a big challenge in Japan. An SWM facility should be socially accepted as well as environmentally and economically sound. This study aimed to investigate people's concerns about SWM facilities and their attitudes towards such facilities. A questionnaire was designed based on literature reviews and was sent to residents in three municipalities with different backgrounds. The questions covered concerns on the impact of an SWM facility, management aspects, unfairness of facility siting, and attitudes to facility construction. Of the many concerns, "pollution and health effect" had the highest rating, followed by "reliability", "damage to nature" and "cost". The rating was different between municipalities, reflecting their geographic and social backgrounds. Using factor analysis, correlations among concerns were analyzed, and five principal components were extracted, namely "pollution", "nuisance", "facility management", "planning of facility", and "merit/demerit". Although obvious correlations were not found between individual items of concern and attitudes to construction of a facility, the discriminant analysis indicated dominant concerns of attitudes, but the disagreement between actual impact and citizens were found. As for attributes, the "opposed" attitude decreased for residents who had visited an SWM facility, even if they had only seen it from outside.

Cities↗
PubMed2004

Material and heavy metal balance in a recycling facility for home electrical appliances.

Collection and recycling of home electrical appliances was started in Japan in 2001 under a new recycling law. The law is aimed at promoting material recycling and at reducing the amount of waste to be landfilled. End of life products are processed by manual disassembly, shredding, and separation in 38 recycling facilities. The authors conducted a questionnaire survey and interviewed at some facilities to obtain information on process flow and material balance. By using the detailed records offered by one facility and by estimating the composition of recovered components, the material balance in the facilities was determined for four typical recycling processes. The heavy metal content of the recovered components was analyzed, then metal flow in the process was determined for each scenario. As a result, it was concluded that emissions to the environment of most heavy metals have been substantially reduced by the new recycling system, while a modest improvement in the rate of material recovery has been achieved.

Conservation of Natural Resources↗
PubMed2004

Metal distribution in incineration residues of municipal solid waste (MSW) in Japan.

This study aimed to identify distribution of metals and the influential factors on metal concentrations in incineration residues. Bottom ash and fly ash were sampled from 19 stoker and seven fluidized bed incinerators, which were selected to have a variety of furnace capacity, furnace temperature, and input waste. In the results, shredded bulky waste in input waste increased the concentration of some metals, such as Cd and Pb, and the effect was confirmed by analysis of shredded bulky waste. During MSW incineration, lithophilic metals such as Fe, Cu, Cr, and Al remained mainly in the bottom ash while Cd volatilized from the furnace and condensed to the fly ash. About two thirds of Pb and Zn was found in the bottom ash despite their high volatility. Finally, based on the results obtained in this study, the amount of metal in incineration residues of MSW was calculated and the loss of metal was estimated in terms of mass and money. A considerable amount of metal was found to be lost as waste material by landfilling of incineration residues.

Carbon↗
PubMed2001

Effect of electric arc vitrification of bottom ash on the mobility and fate of metals.

Increasing amounts of municipal solid waste incineration (MSWI) residues are treated prior to landfilling or reuse. In Japan, electric arc melting is used for bottom ash vitrification that generates a glasslike slag. The objective of this paper was to assess this pretreatment technique with respect to its effect on metal mobility and metal content. Both bottom ash and slag were sampled and analyzed on total solids (TS), fixed solids (FS), particle density (pp), specific BET surface area, particle size distribution, and total element content. A six-step wet sequential extraction procedure was used for assessing metal mobility. The results were qualitatively verified by scanning electron microscopy. The major conclusion was that the availability of various metals was affected differently by electric arc vitrification. Metals were solidified, stabilized, and/or separated from the slag. The mobility of Cr, Cu, Zn, Pb, and Ca was reduced. In slag, majorfractions of these elements were found in moderately reducible phases or in the residual slag lattice. The approximately three-fourths of Pb [174 +/- 7 mg (kg of FS)-1] and half of Zn content [676 +/- 352 mg (kg of FS)-1] were most likely removed from bottom ash through evaporation. The total content increases of Al, Cr, Ni, and Cd (51 +/- 3, 621 +/- 27, 138 +/- 19, and 99 +/- 32%, respectively) were probably caused by the wear of furnace refractories.

Adsorption↗
PubMed2000

Accessing endoscopic images for remote conference and diagnosis using WWW server with a secure socket layer.

Out of 137 hospitals in Niigata prefecture, 13 are connected to the Internet. The number of private clinics using the Internet has also increased. It is thought that an endoscopic information exchange over the Internet connection is useful for the cooperation between hospitals, clinics and organizations in related fields. A conventional World Wide Web (WWW) server of endoscopic images has been built around a compressed JPEG (Joint Panel Expert Group) format, for remote conferences and diagnoses. It has been made secure using a proxy server, a firewall server and a Secure Socket Layer (SSL). It is easy to access the server and view these endoscopic images using the usual homepage browsing method. Ordinarily, gastroenterologists would diagnose lesions with endoscopy in most cases. It is suggested that this conventional WWW server will be effective for remote conferences in some cases, even consultation will be possible.

Endoscopy, Gastrointestinal↗
PubMed1998

[The measurement of antioxidant activity in human plasma using cumene hydroperoxide].

We describe a new method using cumene hydroperoxide to determine antioxidant activity (AO) in human plasma. We used a kit (Determiner LPO: Kyowa Medex Co., LTD. Tokyo Japan) for the determination of lipid peroxides in plasma or serum. 30 microliters 1 of sample was mixed with 70 microliters 1 of cumene hydroperoxide (50 nmol/ml) and incubated at 30 degrees C for 120 min before analysis. Samples were mixed with 1.0 ml of reagent-I (Determiner LPO) and incubated at 30 degrees C for 5 min. Then 2.0 ml of reagent-II (Determiner LPO) was added and incubated at 30 degrees C for 10 min, at which time the absorbance at 675 nm was measured. AO were calculated using the following formula: AO nmol/ml = 35 nmol/ml-(Es-Eb)/(Estd-Eb) x 35 nmol/ml (Es = sample abs., Eb = blank abs., Estd = standard abs.). Within-run precision for plasma AO was 2.3%. AO in plasma samples stored for 4 h at 4 degrees C was decreased by 1 nmol/ml. After 3 h at room temperature, AO was decreased by the same amount. Because this method measured ascorbic acid, alpha-tocopherol, glutathione peroxidase and quercetin as antioxidant compounds, we were able to measure antioxidant activity in human plasma. Our reference values were calculated from the volunteers group which consisted of 172 students and 82 soldiers. The reference intervals for plasma AO by this procedure were 15.4-20.9 nmol/ml.

Adult↗
PubMed1998

[Assessment of diabetic cardiovascular autonomic neuropathy by heart rate variability and pulse wave velocity].

Neuropathy is a frequent complication in diabetes mellitus. Since the involvement of the autonomic nervous system indicates a poor prognosis, early detection and subsequent management are important. Analysis of heart rate variability (HRV) provides a quantitative measure of sympathovagal modulation activities on the heart and has been proven to be useful for the early assessment of the diabetic autonomic neuropathy. We recently developed a simple method of measuring pulse wave velocity (PWV) to evaluate sympathetic nervous activity in the vascular system. In this paper, we examined 33 diabetic patients with and without peripheral neuropathy (15 and 18 respectively) using these methods. In time domain analysis, the mean heart rate, standard deviation and coefficient of variation of HRVs significantly differed between these two groups, whereas the indices of PWVs did not show a significant difference. In frequency domain analysis of HRV, both low and high frequency components were decreased, and the low frequency component in normalized unit did not increase after standing in patients with peripheral neuropathy. We previously reported that the mean PWV decreased after standing in patients with diabetic neuropathy. This disagreement suggests that beta sympathetic dysfunction precedes alpha sympathetic dysfunction in diabetic neuropathy.

Adult↗
PubMed1998

[Communications between hospital laboratory personnel and physicians].

The availability of internet facilities have been spreading rapidly and widely over the past several years. We publish a laboratory data handbook every year and distribute this to physicians in our hospital. Recently we have moved the information to our web site of the Internet. Using the web site, physicians can refer to the information on a 24-hour basis. This information includes: reference ranges; correlation of data obtained by previous and new methods; procedures for ordering each type of laboratory test. Furthermore, anyone can send questions and opinions by E-mail through the web page. The graphs which show the average values of patient results for each day can be obtained by using our database. These graphs are useful for long-range quality management of precision. Another important application is displaying histograms showing the distribution of test results between patients with a specific disease and healthy subjects. The application is expected to facilitate progress in laboratory medicine.

Clinical Laboratory Information Systems↗
PubMed1997

Structural changes in oxidative modification of low-density lipoprotein: investigation using lipid peroxidation products, surface charge, and spectrophotometric patterns.

It is well recognized that oxidative modification of low-density lipoprotein (LDL) accelerates atherogenesis of the arterial vascular wall. In this study, we examined the relationship between various methods of measuring the extent of oxidation, namely lipid peroxidation products, surface charge, and spectrophotometric patterns. LDL was isolated from fresh human normal plasma by centrifugation and was oxidized by incubating with copper ions. Apolipoprotein B was isolated from the LDL solution. We also prepared artificial lipid particles composed of cholesterol linolenate, triolein, and phosphatidylcholine. Our results suggest that lipid peroxidation begins drastically in 30-60 min, while the abolition of the positive charge on apoliproproteins is accelerated after 60 min. We found a characteristic change in the spectrophotometric pattern during the process and conclude that the spectrophotometric absorption ration at 232 and 203 nm is a useful measure of in vitro oxidation of LDL.

Electrophoresis, Polyacrylamide Gel↗
PubMed1997

Differences in the effects of cytokines on the expression of adhesion molecules in endothelial cells.

OBJECTIVES: Expressions of adhesion molecules on arterial endothelial cells are crucial events in initiation of atherosclerosis. Our recent study has shown that endothelial cells express endothelial leukocyte adhesion molecule-1 (ELAM-1) significantly due to stimulation with oxidized LDL, H2O2, or hypoxia. This current study is aimed at investigating temporal relations of the induction of ELAM-1, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) in cultured endothelial cells of the human thoracic aorta. METHODS: The activators examined were interleukin 1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF alpha), and interferon gamma (IFN gamma). Cells were incubated with each of the cytokines at 10 ng/ml for 0.5-48 hours. The adhesion molecules were determined by enzyme immunoassay. RESULTS: ELAM-1 appeared after stimulations by IL-1 and TNF alpha; ELAM-1 was induced by IL-1 after one hour, while it rose sharply after a 30-min stimulation by TNF alpha. The ICAM-1 expression was observed even in non-stimulated cells and further increased in proportion to duration of stimulation. No significant difference occurred between the effects of IL-1 and TNF alpha on the ICAM-1 expression. Weak expression of VCAM-1 was observed only by TNF alpha after 4-through 24-h stimulation. IFN gamma did not cause any changes in the expression of ELAM-1, VCAM-1, and ICAM-1. CONCLUSIONS: The present data indicate a specific time course for each induction of ELAM-1 and VCAM-1, but not ICAM-1. Therefore, the combination of molecules may play a role for endothelial cells to discriminate monocytes from such other cells as neutrophils and lymphocytes.

Aorta↗