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Use of partially immobilized membrane ATPase in heavy metals determination
1998
Nikezic, G. (Institut za nuklearne nauke Vinca, Beograd (Yugoslavia). Laboratorija za molekularnu biologiju i endokrinologiju) | Horvat, A. | Jovanovic, D. | Vasic, V. | Vujisic, Lj. | Nedeljkovic, N. | Radak, B. | Kopecni, M.
Previous studies clearly indicated that membrane enzymes - ATPases i.e. Na, K-ATPase and Mg-ATPase, responded to presence of various organic and inorganic pollutants. In this work effect of mercury and cadmium on these enzymes activities was investigated in synaptic plasma membranes partially immobilized on microliter plate. Comparing those activities with the control enzyme activities obtained with native and partially immobilized mambranes it was concluded that: a. both metals exerted a concentration-dependent inhibition of investigated enzymes, b. for partially immobilized membranes estimated half maximum inhibition (IC50) values for Na, K-ATPase were IC50 (Hg) = 0.9 micromol/cubic cm, IC50 (cd) = 35 micromol/cubic cm and for Mg - ATPase IC50 (Hg) = 3.5 micromol/cubic cm, IC50 (Cd) = 36 micromol/cubic cm; for native membranes IC50 for Na,K-ATPase were IC50 (Hg) =3.3 micromol/cubic cm, IC50 (Cd) = 2 micromol/cubic cm and for Mg ATPase IC50 (Hg) = 2.3 micromol/cubic cm, IC50 (Cd) = 0.2 mmol/cubic cm. Obtained results indicate avaibility of microtitar plates for partially immobilization of membranes with aim to form a new biosensor for heavy metals detection.
Afficher plus [+] Moins [-]Trace metal content in fish as possible environment indicator in DTD [Danube-Tisza-Danube] channel [Yugoslavia]
1998
Djukic, N. (Poljoprivredni fakultet, Novi Sad (Yugoslavia)) | Maletin, S. | Teodorovic, I. | Miljanovic, B.
During the period 1990-1997, the content of 11 trace metals (Fe, Cr, Co, Al, Mn, Cd, Cu, Ni, Pb, Zn, Sr) was studied in muscle and other organs of fish from DTD (Danube-Tisza-Danube) channel system (Yugoslavia). According to obtained and analysed data, the trace metal bioaccumulation can possibly act as enviromental indicator in biomonitoring. DTD (Danube-Tisza-Danube) Channel System can, therefore, be classified as the 3rd class, concerning analysed trace metal content.
Afficher plus [+] Moins [-]Competitive sorption of heavy metal by soils. Isotherms and fractional factorial experiments
1998
Echevarria, Guillaume | Morera, M.T. | Mazkiaran, C. | Garrido, J.J. | Laboratoire Sols et Environnement (LSE) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | Universidad Pública de Navarra [Espagne] = Public University of Navarra (UPNA)
Competing ions strongly affect heavy metal sorption onto the solid surfaces of soil. This study evaluated competitive sorption of Cd, Cu, Ni, Pb and Zn on three soils: Calcixerollic Xerochrept, Paralithic Xerorthent and Lithic Haplumbrept. Monometal and competitive sorption isotherms were obtained at 25°C. The individual effect of ions on retention of the others was ascertained by a fractional factorial analysis design. Most of the sorption isotherms belonged to type L subtype 2 in the classification of Giles. In competitive sorption the initial linear part was shorter and the knee sharper when compared with monometal sorption isotherms. Parameters related to sorptive capacity, such as Point B, Langmuir monolayer and Freundlich distribution coefficient, were higher in monometal than in competitive sorption, and in basic soils than in acidic soil. Calcium desorbed at different points of the sorption isotherms indicated that cationic exchange with Ca was the main retention mechanism in calcareous soils. For Pb, the ratio Ca desorbed/Pb sorbed was close to one; for Cu, Ni and Zn the ratio ranged from 1.20 to 1.37, probably due to partial dissolution of calcium carbonates by hydrolytic processes during retention. On the other hand, Cd had a ratio around 0.6 reflecting another additional retention mechanism, probably surface complexation. Fractional factorial design confirmed that the presence of the cations investigated reduced the amount of the five metals retained, but the presence of Cu and Pb in the system depressed Ni, Cd and Zn sorption more than the inverse. Cation mobility was enhanced when equilibrium concentration increased and the effect was higher in Ca-saturated soils.
Afficher plus [+] Moins [-]Structural-functional rearrangements in chromosome G in Chironomus riparius (Diptera, Chironomidae) collected from a heavy metal-polluted area near Turin, Italy
1998
Michailova, P. | Petrova, N. | Sella, G. | Ramella, L. | Bovero, S. (Institute of Zoology, Bulgarian Academy of Sciences, 1 Tzar Osvoboditel boulv. Sofia 1000, Bulgaria)
Heavy metal concentrations in consecutive saturation extracts of dredged sediment derived surface soils
1998
Tack, F.M.G. | Singh, S.P. | Verloo, M.G. (Laboratory for Analytical Chemistry and Applied Ecochemistry, University of Ghent, Coupure Links 653, B-9000 Gent (Belgium))
Competitive sorption of heavy metal by soils. Isotherms and fractional factorial experiments
1998
Echeverria, J.C. | Morera, M.T. | Mazkiaran, C. | Garrido, J.J. (Universidad Publica de Navarra, Departamento de Quimica Aplicada, Campus Arrosadia, 31006 Pamplona (Spain))
Evaluation of heavy metal lability in polluted soils by a cation exchange batch procedure
1998
Esnaola, M.V. | Millan, E. (Departamento de Quimica Aplicada Facultad de Quimica, Universidad del Pais Vasco, Apdo. 1072, 20080 San Sebastian (Spain))
Experience with the replication of regional survey of soil pollution
1998
Meuli, R. | Schulin, R. | Webster, R. (ETH Zurich, Institute for Terrestrial Ecology, Grabenstrasse 3, 8952 Schlieren (Switzerland))
Changes in tree ring chemistry in sugar maple (Acer saccharum) along an urban-rural gradient in southern Ontario
1998
Watmough, S.A. | Hutchinson, T.C. | Sager, E.P.S. (Environmental Resource Studies Program, Trent University, Peterborough, Ontario, K9J 7B8 (Canada))
The manure model: manure, minerals (N, P and K), ammonia emission, heavy metals and the use of fertiliser in Dutch agriculture
1998
Oudendag, D.A. | Luesink, H.H. (Agricultural Economics Research Institute [LEI-DLO], The Hague (Netherlands))