3,204 research outputs found
Neuroactive steroids in depression and anxiety disorders: Clinical studies
Get PDFCertain neuroactive steroids modulate ligand-gated ion channels via non-genomic mechanisms. Especially 3 alpha-reduced pregnane steroids are potent positive allosteric modulators of the gamma-aminobutyric acid type A (GABA(A)) receptor. During major depression, there is a disequilibrium of 3 alpha-reduced neuroactive steroids, which is corrected by clinically effective pharmacological treatment. To investigate whether these alterations are a general principle of successful antidepressant treatment, we studied the impact of nonpharmacological treatment options on neuroactive steroid concentrations during major depression. Neither partial sleep deprivation, transcranial magnetic stimulation, nor electroconvulsive therapy affected neuroactive steroid levels irrespectively of the response to these treatments. These studies suggest that the changes in neuroactive steroid concentrations observed after antidepressant pharmacotherapy more likely reflect distinct pharmacological properties of antidepressants rather than the clinical response. In patients with panic disorder, changes in neuroactive steroid composition have been observed opposite to those seen in depression. However, during experimentally induced panic induction either with cholecystokinine-tetrapeptide or sodium lactate, there was a pronounced decline in the concentrations of 3 alpha-reduced neuroactive steroids in patients with panic disorder, which might result in a decreased GABAergic tone. In contrast, no changes in neuroactive steroid concentrations could be observed in healthy controls with the exception of 3 alpha,5 alpha-tetrahydrodeoxycorticosterone. The modulation of GABA(A) receptors by neuroactive steroids might contribute to the pathophysiology of depression and anxiety disorders and might offer new targets for the development of novel anxiolytic compounds. Copyright (c) 2006 S. Karger AG, Basel
GC-FID data of biocatalytic esterification reactions & NMR data of lignin characterization
No full textTabulated chromatographic data (GC-FID) from butyl butyrate esterification reactions. 13C and 31P NMR data from pine kraft lignin (BIOPIVA 100) and cationic pine kraft lignin. A list of sample code identifiers with their descriptions is available upon request from the author.<br
Aplicação da técnica de SPME-GC-MS na determinação dos produtos voláteis gerados na degradação térmica de polímeros
Get PDFTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Quimica.Neste trabalho a técnica de SPME aliada a GC-MS foi aplicada para o estudo da degradação térmica do poli(propileno) e do poli(estireno)-co-poli(metil metacrilato). São discutidos principalmente os produtos formados, mecanismos de formação dos principais produtos e parâmetros cinéticos de degradação. Degradaram-se os polímeros num forno tubular em diversas temperaturas e na saída deste forno acoplou-se uma célula para acomodar a fibra de SPME (polidimetilsiloxano) para a concentração dos produtos da degradação dos polímeros carregados por um gás de arraste. A fibra ficou exposta por 30 min e então foi levada para o injetor aquecido do cromatógrafo a gás acoplado ao detector de massas. Cerca de 41 compostos foram sugeridos para a degradação do PP sendo estes formados por alcanos, alcenos e dienos. Para o copolímero e seus polímeros puros, poli(estireno) (PS) e poli(metil metacrilato) (PMMA) foram sugeridos 76, 26 e 40 compostos, respectivamente. No copolímero foram encontrados compostos provenientes da degradação de seus polímeros puros e ainda compostos provenientes da interação entre estes. Foram propostos mecanismos de formação dos três compostos majoritários do PP e dos quatro compostos majoritários do PS-b-PMMA. Conclui-se que o sistema de SPME-GC-MS é eficaz e promissor para estudos de degradação térmica de polímeros
Meetresultaten Kunststof GC-elementen: Project C2: Oever- en Bodembescherming met GC
No full textAnome BV en het Innovatie Test Centrum van Rijkswaterstaat-DWW zijn samen met verschillende partners aan het onderzoeken in hoeverre Ground Consolidators (GC\u92s) interessant zouden kunnen zijn voor gebruik in Oever- en bodembescherming. De eerste fase van het onderzoek is afgerond en er is besloten om verdergaand onderzoek te doen. In verband met duurzaamheid van het materiaal, is ervoor gekozen om verder onderzoek te verrichten naar GC-elementen van kunststof. Dit onderzoek is gedaan door een drietal studenten van de TU Delft aan de faculteit Civiele Techniek. Voorliggend document bevat de meetresultaten van de kwali- en kwantitatieve experimenten die zijn uitgevoerd om de eigenschappen van kunststoffen GC\u92s en een pakket GC\u92s te bepalen
Meetresultaten Kunststof GC-elementen: Versie 4
No full textAnome BV en het Innovatie Test Centrum van Rijkswaterstaat-DWW zijn samen met verschillende partners aan het onderzoeken in hoeverre Ground Consilidators (GC\u92s) interessant zouden kunnen zijn voor gebruik in Oever- en bodembescherming. De eerste fase van het onderzoek is afgerond en er is besloten om verdergaand onderzoek te doen. In verband met duurzaamheid van het materiaal, is ervoor gekozen om verder onderzoek te verrichten naar GC-elementen van kunststof. Dit onderzoek is gedaan door een drietal studenten van de TU Delft aan de faculteit Civiele Techniek. Voorliggend document bevat de meetresultaten van de kwali- en kwantitatieve experimenten die zijn uitgevoerd om de eigenschappen van kunststoffen GC\u92s en een pakket GC\u92s te bepalen
The Private Cost of Long-Term Care in Canada: Where You Live Matters
Get PDFCanadians expect the same access to health care whether they are rich or poor, and wherever they live, often without direct charge at the point of service. However, we find that the private cost of long-term care differs greatly across the country, and within provinces, we find substantial variation, depending on income level, marital status, and, in Quebec alone, on assets owned. A non-married person with average income would pay more than twice as much in the Atlantic provinces as in Quebec, while a couple with one in care would pay almost four times as much in Newfoundland as in Alberta.long-term care, private cost
Meetresultaten \u93extra proef\u94 Kunststof GC-elementen: Stabiliteit, soortelijk gewicht en elasticiteit
No full textDit rapport is een aanvulling op het eindverslag van het onderzoek naar het gedrag van kunststof GC elementen voor oever- en bodembescherming. Conclusies van dat (schaal-) onderzoek waren dat een structuur van GC elementen verrassend sterke hydraulische eigenschappen bezit en daarmee interessant is als erosiebeschermer bij bodem en oeverconstructies. Beperking in het gebruik lag bij \u93stabiliteit\u94. Onder sterke stroming of golfslag was het pakket onvoldoende stabiel. Zo werden er onder zeer sterke stroming flarden uit getrokken, of bewoog het pakket enigszins onder golfslag op een talud. Er werden verschillende kunststoffen gebruikt, met verschillende soortelijke gewichten. Uit extrapolatie en precieze bestudering van het bezwijken kon verwacht worden dat gebruik van sterkere GC\u92s (minder elastisch) en zwaardere GC\u92s (stabieler) het bereik waarin de GC gebruikt kan worden aanzienlijk zou moeten kunnen vergroten
Oblique derivative problems for second order equations of mixed type in multiply connected domains
No full textIn this paper, oblique derivative boundary value problems for second order equations of mixed (elliptic-hyperbolic) type in multiply connected domains is discussed. Firstly the representation of solutions for the above boundary value problem is given, afterwards the uniqueness and existence of solutions of the above problem are stated. In book [1], the author proposed the Dirichlet boundary value problem (Tricomi problem) for second order equations of mixed type in multiply connected domains. In [2, 3], the author only discussed the Dirichlet problem (Tricomi T-2 for the equation u(xx) + sgny u(yy) = 0 in a special doubly connected domain. Up to now we have not seen that other authors have solved it in multiply connected domains. In the present paper, we try to discuss the oblique derivative problem for second order equations of mixed type in multiply connected domains, which includes the Dirichlet problem (Problem T-2) as a special case.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000169505000164&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Mathematics, AppliedMathematicsCPCI-S(ISTP)
Semi-automated non-target processing in GC × GC–MS metabolomics analysis: applicability for biomedical studies
Get PDFDue to the complexity of typical metabolomics samples and the many steps required to obtain quantitative data in GC × GC-MS consisting of deconvolution, peak picking, peak merging, and integration, the unbiased non-target quantification of GC × GC-MS data still poses a major challenge in metabolomics analysis. The feasibility of using commercially available software for non-target processing of GC × GC-MS data was assessed. For this purpose a set of mouse liver samples (24 study samples and five quality control (QC) samples prepared from the study samples) were measured with GC × GC-MS and GC-MS to study the development and progression of insulin resistance, a primary characteristic of diabetes type 2. A total of 170 and 691 peaks were quantified in, respectively, the GC-MS and GC × GC-MS data for all study and QC samples. The quantitative results for the QC samples were compared to assess the quality of semi-automated GC × GC-MS processing compared to targeted GC-MS processing which involved time-consuming manual correction of all wrongly integrated metabolites and was considered as golden standard. The relative standard deviations (RSDs) obtained with GC × GC-MS were somewhat higher than with GC-MS, due to less accurate processing. Still, the biological information in the study samples was preserved and the added value of GC × GC-MS was demonstrated; many additional candidate biomarkers were found with GC × GC-MS compared to GC-MS. © 2010 The Author(s)
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