Aquatic macrophytes as biomonitors of pollution by textile industry.
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OBJECTIVE: In a factory producing synthetic fibers the hepatotoxic effects of the solvent N,N-dimethylformamide (DMF) were investigated in 126 male employees, especially with regard to the combination effects of DMF exposure and ethyl alcohol consumption. A collective of similar structure from the same factory served as a control collective. METHODS: Reference is made to the results of air measurements and biological monitoring presented in a previous publication. The DMF concentrations in the air ranged from < 0.1 (detection limit) to 37.9 ppm (median 1.2 ppm). Concentrations of the DMF metabolite N-methylformamide (NMF) in urine were 0.05-22.0 mg/l (preshift) and 0.9-100.0 mg/l (postshift), corresponding to 0.02-44.6 mg/g creatinine (preshift) and 0.4-62.3 mg/g creatinine (postshift). A standardized anamnesis was drawn up for relevant previous illnesses and other factors influencing liver function. The laboratory tests included parameters especially relevant to the liver (e.g., AST, ALT, gamma-GT, hepatitis B and C antibodies, and carbohydrate-deficient transferrin). RESULTS: The results indicate a statistically significant toxic influence of DMF on liver function. Alcohol has a synergistic effect. The effects of DMF and those of alcohol are dose-dependent. Under the existing workplace conditions the hepatotoxic effects of alcohol are more severe than those of DMF. In the exposed group there was a statistically significantly greater number of persons who stated that they had drunk less since the beginning of exposure (13% versus 0). This corresponded with the data on symptoms occurring after alcohol consumption (71% versus 4%). In the work areas with lower-level exposure to DMF there was greater alcohol consumption. It corresponded to that of the control collective not exposed to DMF. CONCLUSION: In this study we tried to differentiate and quantify the interaction between DMF exposure and alcohol consumption and the influence of both substances on liver function. The experience gained from former occupational health surveillance in DMF-exposed persons and from the present study show that there are individual differences in tolerance of interactions between DMF and ethyl alcohol. Further studies are necessary for the evaluation of these individual degrees of susceptibilitiy.
The purpose of this present study was to compare the physiological effects of the hydrophilic and hydrophobic properties of the fabrics investigated in exercising and resting subjects at an ambient temperature of 30 degrees C and a relative humidity of 50% with and without wind. Three kinds of clothing ensemble were tested: wool and cotton blend with high moisture regain (A), 100% cotton with intermediate moisture regain (B), 100% polyester clothing with low moisture regain (C). The experiments were performed using seven young adult women as subjects. They comprised six repeated periods of 10-min exercise on a cycle ergometer at an intensity of 40% maximal oxygen uptake followed by 5 min of rest (20 min for the last rest). The experiments comprised two sessions. During session I (first three repetitions of exercise and rest) the subjects were exposed to an indifferent wind velocity and during session II (last three repetitions of exercise and rest) they were exposed to a wind velocity of 1.5 m x s(-1). Rectal temperature and skin temperatures at eight sites, pulse rate and clothing microclimate were recorded throughout the whole period. The main findings can be summarized as follows: rectal temperature during session II was kept at a significantly lower level in A than in B and C. Clothing microclimate humidity at the chest was significantly lower in A than in B and C during session II. Skin and clothing microclimate temperatures at the chest were significantly lower in A than in B and C during session II. Pulse rate was significantly higher in C than in A and B during sessions I and II. It was concluded that the hydrophilic properties of the fabrics studied were of physiological significance for reducing heat strain during exercise and rest especially when influenced by wind.
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Two collagen-coated grafts were studied: Hemashield (bovine collagen cross-linked with formaldehyde vapours and softened by exposure to glycerol) and Tascon (collagen fibres cross-linked with glutaraldehyde solution). The weight of the coating was 310 +/- 5 mg/g for Hemashield and 45 +/- 2.5 mg/g for Tascon. However, notwithstanding these differences, both coatings were efficient in making the walls of the grafts impervious to blood. The water permeabilities for the Hemashield and the Tascon were 8.7 and 5.9 ml.min-1.cm-2 at 120 mmHg respectively. The Hemashield collagen coating was rapidly eroded in vitro (4 h) after exposure to buffer, trypsin or pancreatin solutions, whereas the Tascon collagen coating remained well preserved after 7 d incubation. Both coatings were safe and did not interfere with the physical properties of the graft which was used as a skeleton. The healing properties of the Hemashield were similar to that observed with preclotted polyester prostheses, except in the early hours following graft implantation. On the other hand, the absence of erosion in the coating of the Tascon seemed to contribute to early antithrombogenicity. It also induced marked inflammatory reactions in the surrounding tissues and thus the healing appeared to be delayed.
PURPOSE: This study is designed to develop a sealing method for fabric vascular prosthesis with chopped tissue fragments. METHODS: A highly porous fabric vascular prosthesis was invaginated, and a suspension of chopped autologous adipose connective tissue fragments was injected repeatedly until the pores were enmeshed with the fragments. Small tissue fragments oozed out from and firmly anchored within the interstices of the fabric, which made the outer surface smooth. The graft was then invaginated to bring the smooth surface into the luminal side. RESULTS: No blood leakage was observed in an extracorporeal in vivo shunt load test with heparin (total 1400 IU/kg, actinomycin > 1500), whereas a continuous bleeding was seen in a preclotted control graft (400 IU/kg, actinomycin 657 +/- 341). The sealed in a preclotted control graft (400 IU/kg, actinomycin 657 +/- 341). The sealed grafts were implanted in the descending thoracic aorta of 40 dogs, and an equal number of control grafts was used. The grafts were removed at selected time intervals up to 738 days. No bleeding was observed with the sealed grafts, and a thin layer of neointima was observed at 30 postoperative days. Eight (20%) of the control dogs bled to death within 24 hours of implantation. The neointima in the control animals extended from the anastomotic sites slowly with complete healing observed at 217 postoperative days. CONCLUSIONS: The autologous adipose tissue fragments could reliably seal the highly porous fabric prosthesis while allowing rapid and complete neointima healing in dogs.
A two stage anaerobic/aerobic bacterial process was used to decolorize and partially mineralize a reactive vinyl sulfone diazo dye C.I. Reactive Black 5 (RB5) in a synthetic wastewater. Since the anchor group of reactive dyes reacts during the dyeing process, the effect the degree of hydrolysis of the vinyl sulfone dye had on decolorization, mineralization and toxicity in each stage was investigated. An overall color removal of approximately 65% was found for both the fully and partially hydrolyzed dye. Partial mineralization of the fully hydrolyzed RB5 was achieved in the two stage rotating disc reactors. While the anchor group metabolite p-aminobenzene-2-hydroxyethylsulfonic acid (p-ABHES) was mineralized, an oxidized form of the center metabolite (1,2-ketimino-7-amino-8-hydroxynaphthalene-3,6-disulfonic acid) remained in the aerobic stage effluent, causing the effluent to be colored although no RB5 was present. Partially hydrolyzed dye in the influent with vinyl forms of the anchor group caused cessation of biogas production and a reduction in decolorization efficiency in the anaerobic stage. No evidence for mineralization of the partially hydrolyzed dye or its metabolites was found. A method for evaluating dye mineralization using lumped parameters is presented.
Alginate-immobilized Trametes versicolor decolorized Amaranth at similar rates in repeated batch culture when the dye was present in either (i) modified Kirk's medium containing 0.22 gl(-1) ammonium tartrate, (ii) the same buffer, thiamine, trace elements and glucose concentrations as in the modified Kirk's medium, or (iii) glucose alone at either 1, 5 or 10 gl(-1). With glucose alone (0.5 gl(-1)), Amaranth, Reactive Black 5, Reactive Blue 19 and Direct Black 22 had first-order decoloration rate constants of 0.56, 0.76, 0.52, and 0.15 h(-1), respectively. Mixtures of these dyes were also completely decolorized. After four successive decolorations, beads were kept in storage solutions for 48 d at 6 degrees C. CaCl2 (1g l(-1)) was the best storage solution as the beads were easier to handle and had the fastest decoloration rates after storage. Decoloration rates were faster with lower viscosity (less than 2000 cps) alginates and with softer beads which had a lower resistance to compression. Fungal colonization of the beads resulted in higher biomass concentrations with a corresponding higher decoloration rate but the beads became larger, had a lower resistance to compression and a higher percentage of bead breakage in a stirred tank reactor. Biomass, recovered from beads in which there was no growth, could be dispersed while the biomass from colonized beads formed a hollow, spherical shell due to growth on and near the bead surface and no growth in the bead interior. If alginate-immobilized T. versicolor is to be used in a stirred tank reactor, a high biomass loading during the immobilization phase and no fungal growth in the beads is recommended to have high decoloration rates and low bead breakage.
Adsorption isotherms of Direct Red 80 (DR80) and Acid Blue 25 (AB25) on the egg shell membrane (ESM) were performed at 20+/-1 degrees C. Physical characteristics of ESM such as surface area and presence of functional groups were verified. The Fourier transform infra-red (FTIR) spectra proved the presence of functional groups such as hydroxyl, amine and carbonyl groups in ESM. The surface area of ESM was found to be 2.2098 m(2)/g. The effects of operational parameters such as initial dye concentration, pH(0), contact time, particle size and ESM doses were studied. The Langmuir, Freundlich, BET, Redlich-Peterson and Temkin adsorption models were applied to describe the equilibrium isotherms. The pseudo-first-order and pseudo-second-order kinetics models were examined to evaluate the kinetics data at different pH(0) values (2-12) and the rate constants were calculated. Maximum desorption of 81.8% was achieved for both dyes in aqueous solution at pH(0) 12. Also scanning electron micrographs (SEM) of the treated and untreated adsorbent were performed. Results indicate that ESM could be employed as a natural and Eco-Friendly adsorbent material for the removal of trace organics in solutions.
Semiconductor photocatalysis often leads to partial or complete mineralization of organic pollutants. Upon irradiation with UV/visible light, semiconductors catalyze redox reactions in presence of air/O2 and water. Here, the potential of a common semiconductor, ZnO, has been explored as an effective catalyst for the photodegradation of two model dyes: Methylene Blue and Eosin Y. A 16 W lamp was the source of UV-radiation in a batch reactor. The effects of process parameters like, catalyst loading, initial dye concentration, airflow rate, UV-radiation intensity, and pH on the extent of photo degradation have been investigated. Substantial reduction of COD, besides removal of colour, was also achieved. A rate equation for the degradation based on Langmuir-Hinshelwood model has been proposed.