Search results for "sulfide"
showing 10 items of 388 documents
Verwertbarkeit verschiedener Cysteinderivate bei langfristiger parenteraler Ernährung
1989
Utilization of cysteine derivatives for parenteral nutrition was established by means of nitrogen balance of growing rats. N,N-bis-acetylcystine and bisacetyl-glycyl-cystine were not utilized as substrates. N-acetylcysteine, glutathione disulfide, and L-thiazolidine-(4)-carboxylic acid gave evidence as suitable cysteine sources for parenteral nutrition.
A crucial role of adamantanoid Cu(II) complexes in the redox systems: CuCl–diallylsulfoxide–O2 and CuCl2–diallylsulfide–O2
2014
Abstract The hypothetically reversible [Cu(I)(diallylsulfoxide)] ↔ O 2 [Cu(II)(diallylsulfide)] system was examined by FTIR spectroscopy and X-ray diffraction. It is stated that the Cu4OCl6 body centered adamantanoid cages, appearing at both the substrate and product sites, act as a template to promote the oxidation of diallylsulfide to diallylsulfoxide or Cu(I) to Cu(II), thus making the reaction irreversible. Each of these two adamantanoid cores possesses a different point symmetry as well as self assembly mode to form two polymorphs of the [Cu4OCl6(diallylsulfoxide)4] complex. Their polymorphic relationships based on the symmetry homology S4 ← Td → C3, as well as the distortion in the Cu…
A putative social chemosignal elicits faster cortical responses than perceptually similar odorants.
2006
Social chemosignals, so-called pheromones, have recently attracted much attention in that effects on women's psychophysiology and cortical processing have been reported. We here tested the hypothesis that the human brain would process a putative social chemosignal, the endogenous steroid endrostadienone, faster than other odorants with perceptually matched intensity and hedonic characteristics. Chemosensory event-related potentials (ERP) were recorded in healthy women. ERP analyses indicate that androstadienone was processed significantly faster than the control odorants. Androstadienone elicited shorter latencies for all recorded ERP components but most so for the late positivity. This fin…
Absorption Properties of Metal–Semiconductor Hybrid Nanoparticles
2011
The optical response of hybrid metal-semiconductor nanoparticles exhibits different behaviors due to the proximity between the disparate materials. For some hybrid systems, such as CdS-Au matchstick-shaped hybrids, the particles essentially retain the optical properties of their original components, with minor changes. Other systems, such as CdSe-Au dumbbell-shaped nanoparticles, exhibit significant change in the optical properties due to strong coupling between the two materials. Here, we study the absorption of these hybrids by comparing experimental results with simulations using the discrete dipole approximation method (DDA) employing dielectric functions of the bare components as input…
Optical, Structural and Paramagnetic Properties of Eu-Doped Ternary Sulfides ALnS2 (A = Na, K, Rb; Ln = La, Gd, Lu, Y)
2015
Eu-doped ternary sulfides of general formula ALnS2 (A = Na, K, Rb; Ln = La, Gd, Lu, Y) are presented as a novel interesting material family which may find usage as X-ray phosphors or solid state white light emitting diode (LED) lighting. Samples were synthesized in the form of transparent crystalline hexagonal platelets by chemical reaction under the flow of hydrogen sulfide. Their physical properties were investigated by means of X-ray diffraction, time-resolved photoluminescence spectroscopy, electron paramagnetic resonance, and X-ray excited fluorescence. Corresponding characteristics, including absorption, radioluminescence, photoluminescence excitation and emission spectra, and decay k…
Photoluminescence Enhancement of CdSe Quantum Dots: A Case of Organogel–Nanoparticle Symbiosis
2012
Highly fluorescent organogels (QD-organogel), prepared by combining a pseudopeptidic macrocycle and different types of CdSe quantum dots (QDs), have been characterized using a battery of optical and microscopic techniques. The results indicate that the presence of the QDs not only does not disrupt the supramolecular organization of the internal fibrillar network of the organogel to a significant extent, but it also decreases the critical concentration of gelator needed to form stable and thermoreversible organogels. Regarding the photophysical properties of the QDs, different trends were observed depending on the presence of a ZnS inorganic shell around the CdSe core. Thus, while the core-s…
Rare isotopic species of hydrogen sulfide: the rotational spectrum of H236S
2014
The rotational spectrum of the 36 S-bearing isotopologue of hydrogen sulfide (H2S) has been investigated for the first time in the 167 GHz−1.6 THz frequency range, thus providing an accurate and reliable set of spectroscopic parameters. The experimental investigation was backed up by state-of-the-art quantum-chemical calculations, which also allowed us to demonstrate the incorrectness of the previously reported spectroscopic constants. The present results are of suitable accuracy to attempt the astrophysical detection of the isotopic species under consideration. Finally, reliable predictions for the spectroscopic constants of other rare isotopologues of H2S, namely the mono- and bi-deuterat…
POPs and organic polysufides in sediments of Lake Ladoga
2007
Abstract The study included one station close to a pollution source (depth 59 m) and another far from polluted areas (depth 40 m). Samples were analysed for organic chlorine, bromine and sulfur compounds. Samples taken with a corer were sliced to the layers of 0–1, 1–4, 4–7 cm etc. down to the depth of 34 cm. The dating was made with two independent methods, the 210Po method and with the soot particle counting method. The analyses were made with a multiresidue method. Gas chromatography was connected to low resolution mass spectrometry (LRMS) or to high resolution mass spectrometry (HRMS). A different extraction was applied to screen the possible occurrence of polysulfides. Typical chloroph…
Hydrogen sulfide measurements in air by passive/diffusive samplers and high-frequency analyzer: A critical comparison
2016
In this study, hydrogen sulfide (H2S) measurements in air carried out using (a) passive/diffusive samplers (Radiello® traps) and (b) a high-frequency (60 s) real-time analyzer (Thermo® 450i) were compared in order to evaluate advantages and limitations of the two techniques. Four different sites in urban environments (Florence, Italy) and two volcanic areas characterized by intense degassing of H2S-rich fluids (Campi Flegrei and Vulcano Island, Italy) were selected for such measurements. The concentrations of H2S generally varied over 5 orders of magnitude (from 101e103 mg/m3), the H2S values measured with the Radiello® traps (H2SR) being significantly higher than the average values measure…
Regulation of tumour cell sensitivity to TNF-induced oxidative stress and cytotoxicity: Role of glutathione
1998
Glutathione (GSH) and the rate of cellular proliferation determine tumour cell sensitivity to tumour necrosis factor (TNF). Buthionine sulphoximine (BSO), a selective inhibitor of GSH synthesis, inhibits tumour growth and increases recombinant human TNF (rhTNF)-alpha cytoxicity in vitro. Administration of sublethal doses of rhTNF-alpha to Ehrlich ascites-tumour (EAT)-bearing mice induces oxidative stress (as measured by increases in intracellular peroxide levels, O2.- generation and mitochondrial GSSG). ATP-induced selective GSH depletion, when combined with rhTNF-alpha administration, affords a 61% inhibition of tumour growth and results in a significant extent of host survival. Administra…