Search results for " Chemistry"
showing 10 items of 41321 documents
Sähköpostin avulla perustelevaan keskusteluun?
1997
Vuorovaikutus muiden ihmisten kanssa edistää argumentointitaitojen ja kriittisen ajattelun kehittymistä. Entä kun vuorovaikutus tapahtuu sähköpostin avulla? – Kirjoittaja väitteli kasvatustieteiden tohtoriksi 7.6.1997 Jyväskylän yliopistossa. Väitöskirjan aiheena oli Studying argumentation in higher education by electronic mail.
The causal representation of outpatients with Crohn's disease: is there a link between psychological distress and clinical disease activity?
2013
Objectives: Because of the fluctuating and occasional character of Crohn’s disease (CD), patients have to cope with a changeable condition of health. Personal perceived control is known to be an important element of adaptation to their medical condition. The objectives of this work are to determine if perceived personal control is predictive of the clinical activity of the disease and of psychological distress (depression, anxiety). Methods: The Hospital Anxiety Depression Scale (HADS), the causal dimension scale and the Clinical Global Impression (CGI; assessing perceived severity) were administered to 160 patients affected by Crohn’s disease. Indicators of inflammation (CRP), disease dura…
Pringle maneuver during open partial nephrectomy for renal tumors
2017
Introduction. Sparing kidney tissue is important because studies show that patients who have their entire kidney removed are more likely to suffer from chronic kidney disease after surgery than patients who received a kidney-sparing partial nephrectomy. The aim of study is to show the effectives of Pringle maneuver for clamping renal pedicle in order to minimize warm ischemia during open partial nephrectomy. Material and method. We retrospectively analyzed 34 patients diagnosed with cT1 renal tumors between 2012 and 2016 and underwent open partial nephrectomy in Sibiu Urology Department. During the surgery we perform clamping of renal pedicle with Satinsky clamp or with the Pringle maneuver…
Waste heat recovery from a marine waste incinerator using a thermoelectric generator
2012
Published version of an article published in the journal: Journal of Electronic Materials. Also available from the publisher at: http://dx.doi.org/10.1007/s11664-012-2009-6 A marine waste incinerator has been evaluated for waste heat harvesting using thermoelectric generators (TEG). The application has been evaluated using mathematical modeling to optimize the heat exchanger and some vital design parameters of the TEG. The calculation shows that it is possible to extract 58 kW el at a price of 6.6 US$/W from an 850-kW th incinerator when optimizing for maximum power. However, minimizing the cost, it is possible to get 25 kW el at a price of 2.5 US$/W. A trade-off between the two targets lea…
Levels and Potential Health Hazards of Chlorinated Pesticidesin Surface Water Samples of Charsadda Area of Pakistan Using SPME-GC-ECD Technique
2021
In the present study, we determined the levels of chlorinated pesticide residues in surface water samples collected from the Charsadda district (KPK, Pakistan). SPME-GC-ECD with COMBI PAL CTC autosampler was used for extraction and analysis of 20 organochlorine pesticides in the collected water samples. For maximum efficiency of the SPME procedure, several parameters were studied, including the extraction and desorption time of the fiber, solution pH, agitation of samples, and stirring speed, etc. This method showed good liner response, with R2 values in the range of 0.9887 to 0.9999 for all pesticides. This method also provided good percent recoveries at 1 µg L−1 (87.5 to 106.0%) and at 2 …
Diallyldimethylammonium Chloride (DADMAC) in Water Treated with Poly-Diallyldimethylammonium Chloride (PDADMAC) by Reversed-Phase Ion-Pair Chromatogr…
2023
Poly-diallyldimethylammonium (PDADMAC) chloride is a flocculant agent extensively used in water clarification treatments. Commercial polyelectrolyte formulations often contain residual monomer (DADMAC), reaction by-products and other reactants as contaminants that could potentially affect human health. In the present study, we optimized an analytical method based on reversed-phase ion-pair chromatography coupled with mass spectrometry for quantifying ultra-trace levels of DADMAC, without preliminary treatments, in drinking water distributed by the Palermo aqueduct. The method was validated in terms of accuracy (recovery between 80 to 120%), precision (RSD < 10%), linearity range (from 0.…
Mechanisms of irreversible aquaporin-10 inhibition by organogold compounds studied by combined biophysical methods and atomistic simulations
2021
Abstract The inhibition of glycerol permeation via human aquaporin-10 (hAQP10) by organometallic gold complexes has been studied by stopped-flow fluorescence spectroscopy, and its mechanism has been described using molecular modelling and atomistic simulations. The most effective hAQP10 inhibitors are cyclometalated Au(III) C^N compounds known to efficiently react with cysteine residues leading to the formation of irreversible C–S bonds. Functional assays also demonstrate the irreversibility of the binding to hAQP10 by the organometallic complexes. The obtained computational results by metadynamics show that the local arylation of Cys209 in hAQP10 by one of the gold inhibitors is mapped int…
On the convergence of zero-point vibrational corrections to nuclear shieldings and shielding anisotropies towards the complete basis set limit in wat…
2016
The method and basis set dependence of zero-point vibrational corrections (ZPVCs) to nuclear magnetic resonance shielding constants and anisotropies has been investigated using water as a test system. A systematic comparison has been made using the Hartree–Fock, second-order Møller–Plesset perturbation theory (MP2), coupled cluster singles and doubles (CCSD), coupled cluster singles and doubles with perturbative triples corrections (CCSD(T)) and Kohn–Sham density functional theory with the B3LYP exchange-correlation functional methods in combination with the second-order vibrational perturbation theory (VPT2) approach for the vibrational corrections. As basis sets, the correlation consisten…
Water in stereoselective organocatalytic reactions
2009
In this review, recent advances in asymmetric organocatalytic reactions carried out with variable amounts of water, from substoichiometric to a large excess (reaction medium), are discussed. We also summarize several proposed mechanisms for the different possibilities of the action of water both in the increased activity of the catalyst and in the asymmetric induction. Finally, the application of this catalytic methodology to the enantioselective synthesis of valuable compounds through enamine or iminium catalysis is presented.
Ortho -Functionalized Aryltetrazines by Direct Palladium-Catalyzed C−H Halogenation: Application to Fast Electrophilic Fluorination Reactions
2016
International audience; A general catalyzed direct C-H functionalization of s-tetrazines is reported. Under mild reaction conditions, N-directed ortho-C-H activation of tetrazines allows the introduction of various functional groups, thus forming carbon-heteroatom bonds: C-X (X=I, Br, Cl) and C-O. Based on this methodology, we developed electrophilic mono- and poly-ortho-fluorination of tetrazines. Microwave irradiation was optimized to afford fluorinated s-aryltetrazines, with satisfactory selectivity, within only ten minutes. This work provides an efficient and practical entry for further accessing highly substituted tetrazine derivatives (iodo, bromo, chloro, fluoro, and acetate precurso…