Search results for "asma"
showing 10 items of 4204 documents
Production of titanium ion beams in an ECR ion source
2002
Abstract Intensive highly charged Ti ion beams were successfully produced in the 14 GHz ECR ion source at the Accelerator Laboratory, University of Jyvaskyla (JYFL). The Ti beams were produced using the MIVOC technique, i.e. by allowing the vapor of an organic compound containing titanium to diffuse into the ion source at room temperature. After optimizing the source parameters the intensity of the 48 Ti 11+ ion beam reached a value of 45 μA.
Photoinduced and Self‐Activated Nuclease Activity of Copper(II) Complexes with N ‐(Quinolin‐8‐yl)quinolin‐8‐sulfonamide – DNA and Bovine Serum Album…
2016
Two CuII complexes with a new quinoline sulfonamide derivative and phenanthroline (phen), [Cu(QSQ)(phen)]ClO4·0.5H2O (1) and [Cu(QSQ)(phen)(H2O)]ClO4 (2) [HQSQ = N-(quinolin-8-yl)quinolin-8-sulfonamide], have been synthesized and physicochemically characterized. Single-crystal X-ray diffraction studies have revealed a highly distorted trigonal-bipyramidal structure for 1 (τ = 0.68) and an almost perfect trigonal-bipyramidal geometry for 2 (τ = 0.92). DNA binding studies, which were performed by thermal denaturation, viscometry, fluorescence spectroscopy, and cyclic voltammetry, indicated a partial intercalation of 1 with Kapp = 2.45 × 106 M–1. The nuclease activity of 1 was investigated upo…
Effects of Pentachlorophenol and Biotic Interactions on Soil Fauna and Decomposition in Humus Soil
1995
In a laboratory experiment, effects of chemical stress (pentachlorophenol, PCP, at concentrations of 0, 50, and 500 mg/kg) and biotic interactions (nematodes in the presence or absence of collembolas and enchytraeids) on the community structure of soil animals and decomposition processes were studied. PCP was strongly adsorbed to humus that contained 65% organic matter. Numbers of fungal-feeding nematodes decreased significantly at the highest PCP concentration, while no effects were found in bacterial feeders. There were differences in the numbers of nematodes between different animal combinations, but at the highest PCP concentration, collembolas and enchytraeids had no effect on them. Nu…
Citrate Sensing by the C 4 -Dicarboxylate/Citrate Sensor Kinase DcuS of Escherichia coli : Binding Site and Conversion of DcuS to a C 4 -Dicarboxylat…
2007
ABSTRACT The histidine protein kinase DcuS of Escherichia coli senses C 4 -dicarboxylates and citrate by a periplasmic domain. The closely related sensor kinase CitA binds citrate, but no C 4 -dicarboxylates, by a homologous periplasmic domain. CitA is known to bind the three carboxylate and the hydroxyl groups of citrate by sites C1, C2, C3, and H. DcuS requires the same sites for C 4 -dicarboxylate sensing, but only C2 and C3 are highly conserved. It is shown here that sensing of citrate by DcuS required the same sites. Binding of citrate to DcuS, therefore, was similar to binding of C 4 -dicarboxylates but different from that of citrate binding in CitA. DcuS could be converted to a C 4 -…
Determination of zirconium traces in polymers by ICP-IDMS - a powerful and fast method for routine testing of zirconium residues in polyolefins
1999
Zirconium trace analyses play an important role for polyolefins produced by modern catalytic processes with zirconium metallocenes. A reliable and fast routine testing method by inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) was therefore developed, which allows the determination of zirconium in polymers down to the low ng/g level. With respect to its precision, accuracy, and time-consumption this method is suitable for routine testing of production processes. A spike solution, enriched in the stable isotope 91Zr, was prepared and used for the isotope dilution procedure, which has the advantage of being an internal “one point” calibration method. The polyolefin sam…
Wood coated with plasma-polymer for water repellence
2008
The effects of cold HMDSO and HMDSO + SF6 plasma treatments on spruce, chestnut and poplar wood were investigated in order to obtain a hydrophobic surface evaluated by microscopic, spectroscopic (FT-IR and LIBS) and contact angle analyses. Cold plasma treatments can increase the surface hydro-repellence without modifying the external aspect and bulk properties of different woods.
Trace element determination in sediments: a comparative study between neutron activation analysis (NAA) and inductively coupled plasma-mass spectrome…
2000
An inductively coupled plasma-mass spectrometry (ICP-MS) method has been employed for trace element determination in five real sediment samples and a standard reference material. These samples were mineralized by dry ashing at 550°C and fused at 1100°C for 30 min with lithium metaborate. Dissolved samples were measured by a semiquantitative methodology with external calibration and with Rh as an internal standard. More than 50 elements have been measured. As a reference technique, a direct analysis of the solid samples was carried out by neutron activation analysis. Results obtained by ICP-MS have been compared with those obtained by neutron activation analysis (NAA) by applying the paired …
Nano‐Powdered Calcium Carbonate Reference Materials: Significant Progress for Microanalysis?
2019
Validation of Methylmercury Determinations in Aquatic Systems by Alkyl Derivatization Methods for GC Analysis Using ICP-IDMS
2001
Isotope dilution mass spectrometry (IDMS), using an inductively coupled plasma quadrupole mass spectrometer (ICPMS) and a species-specific methylmercury spike was applied to validate the commonly used GC method for methylmercury (MeHg+) determination, which is based on the formation of volatile methylethylmercury by derivatization with NaBEt4. The spike compound, Me201Hg+, was synthesized by reaction of 201Hg-enriched mercury chloride with methylcobalamin. By analyzing different environmental aquatic samples, it was found that in most cases, transformation of MeHg+ into elemental mercury (Hg0) took place. From investigations of synthetic solutions, it could be followed that halide ions are …
Bestimmung von Tri-n-butylphosphat in Plasmapräparaten nach Festphasenextraktion und Kapillar-Gaschromatographie
1988
A simple method for the quantitative determination of tri-n-butylphosphate in blood plasma preparations is described. The sample is passed through an octadecyl extraction column from which tri-n-butylphosphate is eluted with chloroform. By capillary GC 50 micrograms/l tri-n-butylphosphate can be detected with a recovery of more than 90%.