P��ij��nteen yhteenvetotutkimus III : Tilan tuleva kehitys

English summary: Lake P��ij��nne research III

Oxidation of catechol in plants : III. Purification and properties of the diphenylene dioxide 2,3-quinone-forming enzyme system from Tecoma leaves

In attempting to determine the nature of the enzyme system mediating the conversion of catechol to diphenylenedioxide 2,3-quinone, in Tecoma leaves, further purification of the enzyme was undertaken. The crude enzyme from Tecoma leaves was processed further by protamine sulfate precipitation, positive adsorption on tricalcium phosphate gel, and elution and chromatography on DEAE-Sephadex. This procedure yielded a 120-fold purified enzyme which stoichiometrically converted catechol to diphenylenedioxide 2,3-quinone. The purity of the enzyme system was assessed by polyacrylamide gel electrophoresis. The approximate molecular weight of the enzyme was assessed as 200,000 by gel filtration on Sephadex G-150. The enzyme functioned optimally at pH 7.1 and at 35 ��C. The Km for catechol was determined as 4 �� 10���4 Image . The enzyme did not oxidize o-dihydric phenols other than catechol and it did not exhibit any activity toward monohydric and trihydric phenols and flavonoids. Copper-chelating agents did not inhibit the enzyme activity. Copper could not be detected in the purified enzyme preparations. The purified enzyme was not affected by extensive dialysis against copper-complexing agents. It did not show any peroxidase activity and it was not inhibited by catalase. Hydrogen peroxide formation could not be detected during the catalytic reaction. The enzymatic conversion of catechol to diphenylenedioxide 2,3-quinone by the purified Tecoma leaf enzyme was suppressed by such reducing agents as GSH and cysteamine. The purified enzyme was not sensitive to carbon monoxide. It was not inhibited by thiol inhibitors. The Tecoma leaf was found to be localized in the soluble fraction of the cell. Treatment of the purified enzyme with acid, alkali, and urea led to the progressive denaturation of the enzyme.

Synthesis, characterisation and thermal analysis of copper (II) and chromium (II, III) hydrazine carboxylates

Copper(II) hydrazine carboxylate monohydrate, Cu(N2H3COO)2��H2O and chromium (II, III) hydrazine carboxylate hydrates, Cu(N2H3COO)2��H2O and Cu(N2H3COO)2��3H2O have been prepared and characterised by chemical analysis, IR, visible spectra and magnetic measurements. Thermal analysis of the copper complex yields a mixture of copper metal and copper oxide. Chromium complexes on thermal decomposition yield Cr2O3 as residue. Decomposition of chromium(HI) complex under hydrothermal conditions yield CrOOH, a precursor to CrO2.

Dom��nnamnstvister och ond tro - En r��ttslig analys av UDRP, s��rskilt med tanke p�� begreppet ond tro i artikel 4.a.iii

Internets ��kade betydelse gjorde att f��retagen b��rjade inse vilka problem som kan uppst�� av att en webbsida med ett dom��nnamn i form av deras varum��rke olovligen handhas av en utomst��ende part. Konflikterna blev d��rf��r fler medan existerande tvistl��sningsmekanismer ans��gs dyra, tungrodda och ineffektiva. Ur detta behov f��ddes sedermera Uniform Domain Name Dispute Resolution Policy (UDRP). Detta internationella tvistl��sningsf��rfarande skapades f��r att till��mpas p�� s.k. cybersquatting, dvs. situationer d��r dom��nnamn, som inkr��ktar p�� andras varu- eller servicem��rken, registreras i ond tro t.ex. f��r framtida f��rs��ljning. Jag granskar i denna avhandling huvudsakligen f��ruts��ttningarna f��r ��verf��ring eller upph��vning av dom��nnamnsregistreringar i enlighet med UDRP, varf��r jag fokuserar p�� artikel 4.a och d�� i synnerhet p�� inneb��rden av begreppet ���registrering och anv��ndning i ond tro���. Arbetet bygger huvudsakligen p�� en analys av de avg��randen som fattats inom ramen f��r UDRP. Syftet ��r att genom en systematisk unders��kning av till��mpningen av begreppet ond tro beskriva och utv��rdera r��ttstill��mpningen inom UDRP. De granskade avg��randena ��r 396 st. till antalet och har meddelats under tidsperioden 14.1.2000-15.8.2001.

Rare-earth chromium citrates as precursors for rare-earth chromites: lanthanum biscitrato chromium(III) dihydrate, La[Cr(C6H5O7)2]��2H

The thermal decomposition of lanthanum biscitrato chromium(III) dihydrate has been studied in static air and dynamic argon atmospheres. The complex decomposes in four steps: dehydration, decomposition of the citrate to an intermediate oxycarbonate, formation of LaCrO4(V) from oxycarbonate, and finally decomposition of LaCrO4(V) to LaCrO3. Formation of LaCrCrO4(V) requires the presence of oxygen The decomposition behaviour of a mechanical mixture of lanthanum citrate hydrate and chromium citrate hydrate was compared with that of the citrato complex. Both the starting material and the intermediates were characterized by X-ray diffraction, IR electronic and ESR spectroscopy, surface area and magnetic susceptibility measurements, as well as by chemical analysis. A scheme is proposed for the decomposition of lanthanum biscitrato chromium(III) dihydrate in air. LaCrO3 can be obtained at temperatures as low as 875 K by isothermal decomposition of the complex.

Quinone studies. Part III. Metal ion-catalysed oxidation of halophenols and halonaphthols by peroxidisulphate

Oxidation of representative halophenols and halonaphthols by peroxidisulphate has been examined. The influence of metallic ions, viz. Cu2+, Fe3+, Ag+, on the above reaction has been studied. Cu2+ ion-catalyzed oxidation gives halo-1, 4-quinones in excellent yield. Potassium bis(biureto)cuprate(III) complex also oxidises halophenols to halo-1, 4-quinones.

Biosorption of iron(III) from aqueous solutions using the husk of Cicer arientinum

Iron is a major pollutant released as a by-product during several industrial operations especially during acid mining of metal ores. In this paper, the use of Bengal gram husk (husk of channa dal, Cicer arientinum) in the biosorption of Fe(III) from aqueous solutions is discussed. Parameters like agitation time, adsorbent dosage and pH were studied at different Fe(Ill) concentrations. The adsorption data fit well with Langmuir and Freundlich isotherm models. The adsorption capacity (q(max)) calculated from the Langmuir isotherm was 72.16 mg of Fe(III)/g of the biosorbent at an initial pH of 2.5. Desorption Studies were performed at different concentrations of hydrochloric acid showing that quantitative recovery of the metal ion is possible. The infrared spectra of the biomass before and after treatment with Fe(III), revealed that hydroxyl, carboxyl and amide bonds are involved in the uptake of Fe(III) ions.

Tris(tert-butyl 3-oxobutanoato-kappa O-2(1),O- )-aluminium(III) at 153 K

In the title complex, [Al(C8H13O3)(3)], a potential metal-organic chemical vapour deposition (MOCVD) precursor, three bidentate ligand molecules are bound to the metal atom, forming an octahedral geometry. Two non-planar six-membered chelate rings adopt screw-boat conformations, while the third ring has a conformation that lies about halfway between an envelope and a screw-boat.

Gauge theory of a group of diffeomorphisms. III. The fiber bundle description

A new fiber bundle approach to the gauge theory of a group G that involves space���time symmetries as well as internal symmetries is presented. The ungauged group G is regarded as the group of left translations on a fiber bundle G(G/H,H), where H is a closed subgroup and G/H is space���time. The Yang���Mills potential is the pullback of the Maurer���Cartan form and the Yang���Mills fields are zero. More general diffeomorphisms on the bundle space are then identified as the appropriate gauged generalizations of the left translations, and the Yang���Mills potential is identified as the pullback of the dual of a certain kind of vielbein on the group manifold. The Yang���Mills fields include a torsion on space���time.

Generalized Burgers equations and Euler���Painlev�� transcendents. III

It was proposed earlier [P. L. Sachdev, K. R. C. Nair, and V. G. Tikekar, J. Math. Phys. 27, 1506 (1986); P. L. Sachdev and K. R. C. Nair, ibid. 28, 977 (1987)] that the Euler���Painlev�� equations ���y(d2y/d��2)+a(dy/d��)2 +f(��)y(dy/d��)+g(��)y2+b(dy/d��) +c=0 represent generalized Burgers equations (GBE���s) in the same way as Painlev�� equations represent the Korteweg���de Vries type of equations. The earlier studies were carried out in the context of GBE���s with damping and those with spherical and cylindrical symmetry. In the present paper, GBE���s with variable coefficients of viscosity and those with inhomogeneous terms are considered for their possible connection to Euler���Painlev�� equations. It is found that the Euler���Painlev�� equation, which represents the GBE ut+u��ux=(��/2)g(t)uxx, g(t)=(1+t)n, ��>0, has solutions, which either decay or oscillate at ��=�����, only when ���1<n<1. The solutions are shocklike when n=1. On the other hand, they oscillate over the whole real line when n=���1. Furthermore, the solutions monotonically decay both at ��=+��� and ��=������, that is, they have a single hump form if �������n=(1���n)/(1+n). For ��<��n, the solutions have an oscillatory behavior either at ��=+��� or at ��=������, or at ��=+��� and ��=������. For ��=��n, there exists a single parameter family of exact single hump solutions, similar to those found for the nonplanar Burgers equations in Paper II. Thus the parametric value ��=��n seems to bifurcate the families of solutions, which remain bounded at ��=�����. Other GBE���s considered here are also found to be reducible to Euler���Painlev�� equations.