Search results for "sensitive"
showing 10 items of 210 documents
Organometal(loid) species in geochemical exploration : preliminary qualitative results
1998
Abstract Organic and other volatile metal(loid) species (e.g. hydrides) in environmental gases can be determined with high sensitivity and selectivity by low-temperature gas chromatography coupled on-line to plasma mass spectrometry (LTGC/ICP–MS). A standard reference solution is analysed simultaneously for calibration of the results as well as for monitoring the excitation conditions in the plasma. This highly sensitive analytical method was applied in field screening tests at Cu and Hg deposits in Germany. In some of the soil gas and soil samples investigated, organic compounds of several elements (e.g. As, Hg) could clearly be identified. The implications of these results with respect to…
Determination of thallium in water samples
2007
Abstract This article illustrates the developments of effective preconcentration techniques and highly sensitive detection methods for accurate measurements of Tl species at extremely low concentration in aqueous solutions. The literature on this topic was taken from the Analytical Abstracts in the period 1990–2005.
Selective hydrogenation of 2-methyl-butyn-2-ol on Pd catalysts
2013
PVA Hydrogel Electrolyte and Porous Polyisoprene Carbon Nanostructure Composite Based Pressure Sensitive Supercapacitor
2019
Special gratitude is in order to Raimonds Orlovs for temperature dependent resistance measurements. Financial support of project 1.1.1.1/16/A/013, “Hybrid energy harvesting systems” is greatly appreciated.
Optimalization of doubletone polarography
1977
Abstract Through the application of coherent fundamental frequencies, the synchronization of measuring frequency and dropping frequency, which facilitate the use of phase sensitive techniques, doubletone polarography could be developed into a highly sensitive polarographic method with a high resolution in common with all derivative methods.
In human endothelial cells rapamycin causes mTORC2 inhibition and impairs cell viability and function.
2008
Aim Drug-eluting stents are widely used to prevent restenosis but are associated with late endothelial damage. To understand the basis for this effect, we have studied the consequences of a prolonged incubation with rapamycin on the viability and functions of endothelial cells. Methods and results Human umbilical vein or aorta endothelial cells were exposed to rapamycin in the absence or in the presence of tumour necrosis factor α (TNFα). After a 24 h-incubation, rapamycin (100 nM) caused a significant cell loss associated with the increase of both apoptosis and necrosis, as quantified by propidium iodide staining, caspase 3 activity, and lactate dehydrogenase release. Rapamycin also impair…
Proteasome comprising a beta1 inducible subunit acts as a negative regulator of NADPH oxidase during elicitation of plant defense reactions.
2005
Elicitation of defense reactions in tobacco by cryptogein, triggered a production of active oxygen species (AOS) via the NADPH oxidase, NtrbohD, and an accumulation of beta1din, a defense induced beta-type subunit of 20S proteasome. The proteasome inhibitor, MG132, stimulated this AOS production. Tobacco cells transformed with sense constructs of beta1din showed an inhibition of the AOS production following elicitin treatment, whereas the antisense transformed cells showed a strongly enhanced AOS production. In cells transformed with sense construct of beta1din, the NtrbohD transcripts failed to be induced by cryptogein as observed in control and antisense transformed cells. Conversely, in …
Comparison of total-reflection X-ray fluorescence, static and portable energy dispersive X-ray fluorescence spectrometers for art and archeometry stu…
2004
Abstract In this paper, a Total-reflection X-ray Fluorescence (TXRF), a static and a portable Energy Dispersive X-ray Fluorescence (EDXRF) spectrometers are described. Both the equipments and the techniques employed in the field of the art and archeometry are compared. Some applications in this area are presented as well. The aim of the work is to know which spectrometer is the best suited depending on the work of art and the problem treated. The conclusion reached from the experience is that the portable EDXRF spectrometer is advisable to make “in situ” and online analysis in a multidisciplinary environment, the static EDXRF equipment is good to perform analysis on paper and metal pieces a…
Chromatin structure of the yeast FBP1 gene: transcription-dependent changes in the regulatory and coding regions.
1993
We have studied the chromatin structure of the Saccharomyces cerevisiae FBP1 gene, which codes for fructose-1,6-bisphosphatase. A strong, constitutive, DNase I, micrococcal nuclease and S1 nuclease hypersensitive site is present close to the 3′ end of the coding region. In the repressed state, positioned nucleosomes exist around this site, and subtle changes occur in this nucleosomal organization upon derepression. A DNase I hypersensitive region is located within the promoter between positions −540 and −400 and it extends towards the gene in the derepressed state, leading to an alteration of nucleosomal positioning. Psoralen crosslinking of chromatin, which is used for the first time to st…