Eiwei?, Aminos?uren

Ohne Zusammenfassung     

Ueber die Untersuchung von Balsamen und Harzen

Ohne Zusammenfassung     

Analyses of radionuclides in soil,water, and agriculture products near the Urgeiriça uranium mine in Portugal

Analyses of soils, irrigation waters, agriculture products (lettuce), green pasture, and cheese were performed in samples collected in the area of the old Urgeiriça uranium mine and milling facilities, Centre-North of Portugal, in order to assess the transfer of uranium series radionuclides in the environment and to man. Soils close to milling tailings display an enhancement of radioactivity. In the drainage basin of the stream Ribeira da Pantanha, receiving drainage from the tailings piles and discharges from the acid mine water treatment plant, there was enhancement of uranium series radionuclide concentrations in water and suspended matter. Agriculture products from kitchen gardens irrigated with water from the Ribeira da Pantanha show an increase of radioactivity, mainly due to uranium isotopes. Agriculture products from other kitchen gardens in this area, irrigated with groundwater, as well pasture and cheese produced locally from sheep milk did not show enhanced radionuclide concentrations. In the Urgeiriça area, some soils display radionuclide concentrations higher than soils in reference areas and, in agriculture products grown there, ²²⁶Ra was the radionuclide more concentrated by vegetables. Through ingestion of these products ²²⁶Ra may be the main contributor to the increment of radiation dose received by local population.     

SENSITIVITY TO PHOTOADDITION OF MONO-AND BIFUNCTIONAL FUROCOUMARINS OF X-RAY SENSITIVE MUTANTS OF SACCHAROMYCES CEREVISIAE

Abstract— With the exception of rad53 , seven other X-ray sensitive mutants of the rad50 serie of Saccharomyces cerevisiae were found to be more sensitive than the wild type to photoaddition of Afunctional (3-methoxypsoralen) and monofunctional (3-carbethoxypsoralen) furocoumarins. The magnitude of sensitivity to killing is dependent upon the locus and the phase of growth.
This means that in addition to the two repair pathways (excision-resynthesis and mutagenic pathways) previously shown to be involved in repair of furocoumarins photo-induced lesions, a third pathway is implicated in the repair of such lesions.     

The structure and energetics of pyrrolidinones, tetrahydrofuranones, piperidinones, and tetrahydropyranones: a computational study

We have performed high level ab initio quantum chemical calculations for 2- and 3-pyrrolidinone; tetrahydro-2- and -3-furanone; 2-, 3-, and 4-piperidinone; and tetrahydro-2-, -3-, and -4-pyranone. The most stable molecular structures were obtained from DFT calculations using the B3LYP density functional and the 6-31G(d) and 6-311+G(3df,2p) basis sets. The respective enthalpies of formation have been computed by the G3(MP2)//B3LYP composite method and appropriately chosen reactions. The calculated results are in excellent agreement with experimental data reported in the literature.     

Spektrophotometrische Bestimmung von Mikromengen Mangan mit Salicyl- und Acetylsalicylsäure

Zusammenfassung Eine spektrophotometrische Methode zur Bestimmung von Mangan in Submikrogrammengen wurde beschrieben. 1 bis 2,5 ml Probelösung werden mit 3 ml 0,58-m Salicylsäure oder Acetylsalicylsäure in 10%igem Ammoniak und 1 ml 5%igem Perhydrol versetzt. Nach 2 1/2 Stunden wird mit 10%igem Ammoniak auf 100 ml aufgefüllt und bei 385 nm spektrophotometrisch gemessen. Das Lambert-Beersche Gesetz wird für Konzentration von 0,005 bis 0,0125g/ml befolgt.

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Spectrophotometric determination of microamounts of manganese with salicylic and acetylsalicylic acid

Summary A method of spectrophotometric determination of Mn is described. 1 to 2.5 ml of the test solution was treated with 3 ml of 0.58-m solution of salicylic acid or acetylsalicylic acid in 10% amonia and 1 ml of 5% perhydrol are added. After 2 1/2 hours the volume is completed to 100 ml with 10% amonia. Extinction is measured at 385 nm. The law of Lambert-Beer is obeyed between 0.005g and 0.0125g/ml.

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Wir danken an dieser Stelle dem Banco Nacional de Desenvolvimento und dem Conselho Nacional de Pesquisas yon Brasilien, die uns diese Arbeiten erm6glicht haben.     

Quality assurance program for the chemical characterization of soils

A quality assurance program has been developed both to assess and to demonstrate the quality of the results produced by an analytical diagram applied to the chemical characterization of soils. The composition of several soils was determined following procedures based on the methods that are applied to silicate materials. A combination of acid decomposition followed by fusion allows the determination of SiO₂, Al, Fe, Ca, Mg, Ti, P, Mn, Cd, Co, Cr, Cu, Ni, Pb and Zn; a specific acid attack was used for Hg analysis and an acid mixture decomposition to analyse Na, K, Li and Sr. Several quality control parameters, namely calibration function characteristics, limits of detection, limits of quantification, quality control standards, duplicate analysis, spike recoveries and certified reference materials analysis, are introduced, evaluated and discussed. The results obtained for the certified reference materials show that the analytical diagram gave acceptable accurate values for the elements applying the quality assurance program proposed.     

Gold complexes with dithiothiophene ligands: a metal based on a neutral molecule

The gold complexes n-Bu4N[Au(alpha-tpdt)2] (5), n-Bu4N[Au(dtpdt)2] (4) and n-Bu4N[Au(tpdt)2] (6) based on new dithiothiophene ligands (alpha-tpdt= 2,3-thiophenedithiolate, dtpdt=2,3-dihydro-5,6-thiophenedithiolate and tpdt = 3,4-thiophenedithiolate) have been prepared and characterised. These gold(III) complexes are diamagnetic, but they can be oxidised with iodine to the paramagnetic compounds [Au(alpha-tpdt)2] (8), [Au(dtpdt)2] (7) and n-Bu4N[[Au(tpdt)2]n-2] (9), which were isolated as fine powders and which exhibit paramagnetic susceptibilities that are almost temperature independent with room temperature values of 2.5 x 10(-4), 2.0 x 10(-4) and 5 x 10(-4) emu x mol(-1), respectively. Interestingly, the neutral complex [Au(alpha-tpdt)2] (8) as a polycrystalline sample displays the properties of a metallic system with a room temperature electrical conductivity of 6 S x cm(-1) and a thermoelectric power of 5.5 microVK(-1); this is the first time that this metallic property has been observed in a molecular system based on a neutral species.