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Chemical dissection of eIF4A-mediated translationBordeleau, Marie-Eve January 2007 (has links)
No description available.
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Method Development for the Application of Vibrational Spectroscopy to Complex Organic-Inorganic Materials in Astrobiology. A Systematic Development of Raman Spectroscopy and Related Analytical Methods to the Structural Chemistry at Organic (Biological) and Inorganic (Mineralogical) Interfaces of Material Assemblies Relevant to Astrobiology and Inter-Planetary Science.Whitaker, Darren A. January 2013 (has links)
In the search for the conformation of extant or extinct life in an
extraterrestrial setting the detection of organic molecular species
which may be considered diagnostic of life is a key objective. These
molecular targets comprise a range of distinct chemical species,
with recognisable spectroscopic features. This project aims to use
these features to develop an in-situ molecular specific Raman spectroscopic
methodology which can provide structural information about
the organic–inorganic interface.
The development of this methodology identified a surface enhanced
Raman spectroscopic technique, that required minimal sample preparation,
allowed for the detection of selected organic species immobilised
on an inorganic matrix and was effective for quantities below
those which conventional dispersive Raman spectroscopy would detect.
For the first time spectral information was gained which allowed
analysis of the organic–inorganic interface to be carried out, this
gave an insight into the orientation with which molecules arrange on
the surfaces of the matrices. Additionally a method for the detection
of organic residues intercalated into the interlamellar space of smectite
type clays was developed. An evaluation of the effectiveness of
uni and multivariate methods for the analysis of large datasets containing
a small number of organic features was also carried out, with a view to develop an unsupervised methodology capable of performing
with minimal user interaction. It has been shown that a novel
use of the Hotellings T2 test when applied to the principal component
analysis of the datasets combined with SERS allows identification
of a small number of organic features in an otherwise inorganic
dominated dataset.
Both the SERS and PCA methods hold relevance for the detection
of organic residues within interplanetary exploration but may also be
applied to terrestrial environmental chemistry.
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Plant Sterol-Poor Diet Is Associated with Pro-Inflammatory Lipid Mediators in the Murine BrainReinicke, Madlen, Leyh, Judith, Zimmermann, Silke, Chey, Soroth, Begcevic Brkovic, Ilijana, Wassermann, Christin, Landmann, Julia, Lütjohann, Dieter, Isermann, Berend, Bechmann, Ingo, Ceglarek, Uta 16 January 2024 (has links)
Plant sterols (PSs) cannot be synthesized in mammals and are exclusively diet-derived.
PSs cross the blood-brain barrier and may have anti-neuroinflammatory effects. Obesity is linked
to lower intestinal uptake and blood levels of PSs, but its effects in terms of neuroinflammation—if
any—remain unknown. We investigated the effect of high-fat diet-induced obesity on PSs in the
brain and the effects of the PSs campesterol and -sitosterol on in vitro microglia activation. Sterols
(cholesterol, precursors, PSs) and polyunsaturated fatty acid-derived lipid mediators were measured
in the food, blood, liver and brain of C57BL/6J mice. Under a PSs-poor high-fat diet, PSs levels
decreased in the blood, liver and brain (>50%). This effect was reversible after 2 weeks upon changing
back to a chow diet. Inflammatory thromboxane B2 and prostaglandin D2 were inversely correlated
to campesterol and -sitosterol levels in all brain regions. PSs content was determined post mortem in
human cortex samples as well. In vitro, PSs accumulate in lipid rafts isolated from SIM-A9 microglia
cell membranes. In summary, PSs levels in the blood, liver and brain were associated directly with
PSs food content and inversely with BMI. PSs dampen pro-inflammatory lipid mediators in the
brain. The identification of PSs in the human cortex in comparable concentration ranges implies the
relevance of our findings for humans.
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Effects of plant sterols and glucomannan on parameters of cholesterol kinetics in hyperlipidemic individuals with and without type 2 diabetesBarake, Roula January 2005 (has links)
No description available.
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Efficacy of plant sterols in novel matrices on blood lipids profiles : medium chain triglycerides and low-fat products consumed with or without a mealRudkowska, Iwona. January 2007 (has links)
No description available.
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[en] STEROLS AS MOLECULAR MARKERS OF FECAL POLLUTION IN IGUAÇU-SARAPUÍ ESTUARINE SYSTEM, GUANABARA BAY NORTHEAST (RJ) / [pt] ESTERÓIS COMO MARCADORES MOLECULARES DA CONTAMINAÇÃO FECAL NO SISTEMA ESTUARINO IGUAÇU-SARAPUÍ, NOROESTE DA BAÍA DE GUANABARA (RJ)LIVIA GEBARA MURARO SERRATE CORDEIRO 28 August 2006 (has links)
[pt] O presente trabalho tem como objetivo investigar a
contaminação por
esgotos domésticos do sistema estuarino formado pelo rio
Iguaçu e canal de
Sarapuí, localizados na porção noroeste da Baía de
Guanabara, através da
determinação de esteróis e composição elementar (C e N) da
matéria orgânica em
amostras de material particulado em suspensão e
sedimentos, e da caracterização
físico-química e química da água e sedimento. As
amostragens foram realizadas
em março/2004 e setembro/2004, em 7 estações de água e 10
de sedimento,
distribuídas entre 6 km a montante do rio Iguaçu e 4 km
dentro da baía. Também
foi coletada uma amostra composta de esgoto bruto na
Estação de Tratamento da
Ilha do Governador (ETIG). Na determinação dos parâmetros
foram utilizados
métodos analíticos já estabelecidos, tais como
cromatografia a gás/espectrometria
de massa (esteróis) e oxidação a seco (C e N), após
otimização para as condições
específicas de campo e de laboratório. As concentrações
dos principais esteróis
variam em escala temporal e espacial, em função de fatores
climáticos e da
localização de fontes difusas de esgoto. Há gradientes
decrescentes de
concentração de esteróis entre rio e a baía, com
predomínio de esteróis fecais
sobre fitoesteróis. Coprostanona (5b-colestan-3b-ona)
atingindo concentrações de
até 21 mg gC-1, epicolestanol (5a-colestan-5a-ol) e
coprostanol (5b-colestan-3b-
ol) foram os mais abundantes. A detecção de epicolestanol
(inédita para a baía de
Guanabara) em concentrações elevadas no material
particulado e sedimento
(assim como no esgoto bruto), as diferenças na composição
entre esteróis no
esgoto bruto em comparação com o material particulado e
sedimento, e os
resultados das razões entre determinados esteróis, são
resultados que refletem a importância dos processos
bacterianos em alterar a composição original da
matéria orgânica e dos esteróis associados. O conjunto de
informações levantadas
confirma o elevado nível de degradação ambiental da região
estudada. Por outro
lado, a dinâmica do sistema e processos pré- e pós-
deposicionais influenciam na
geoquímica dos esteróis e, portanto, seus efeitos devem
ser levados em
consideração em estudos sobre marcadores moleculares em
estuários com
características semelhantes ao do presente trabalho. / [en] The contamination by domestic sewage of the Iguaçu River
and Sarapuí
channel, located in the north-western sector of Guanabara
Bay, was investigated
by the determination of sterols and elemental composition
(C and N) of organic
matter in suspended matter and superficial sediments.
Physico-chemical and
chemical characterization of water and sediments were
considered as well.
Conventional analytical methods, like gas
chromatography/mass spectrometry
(sterols) and dry chemical oxidation (C and N), were
employed after optimization
for specific field and laboratory conditions. In March and
September/2004
water/suspended particles (7 sample stations) and sediment
(10 stations) were
collected in a transect from 6 km up the river until 4 km
off the river, in the bay.
An additional sample of bulk sewage was also collected at
a sewage treatment
plant close to the studied area. The faecal sterols
predominate over phyto sterols
in suspended matter and sediments. Among the 14 sterols
quantified, higher
concentrations (up to 21 mg gC-1) were measured for
coprostanone (5b-cholestan-
3b-one), epicholestanol (5a-cholestan-3a-ol) and
coprostanol (5b-cholestan-3b-
ol). In general, there is a river-bay decreasing gradient
in sterol concentration,
associated with the location of diffuse sources of sewage.
Seasonal variation in
climatic factor also influenced in the sterols
distribution. The presence of
epicholestanol (reported here for the first time in
Guanabara Bay) in relatively
high concentrations in suspended matter and sediments (as
well as in raw sewage),
the differences in sterol composition between raw sewage
and suspended
matter/sediments, and the values obtained for selected
sterols source-diagnostic
ratios, suggested the occurrence of significant microbial
alteration of organic
matter, with implications on the geochemistry of sterols.
The elevated degradation
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Estudio global del metabolismo lipídico de saccharomyces spp. En fermentaciones a bajas temperaturasRedón Miralles, Maria Antonia 19 November 2010 (has links)
El objetivo global de esta tesis consiste en mejorar el control de las fermentaciones a bajas
temperaturas a partir de los cambios en el metabolismo lipídico. En el primer capítulo, observamos
que el almacenamiento en condiciones inadecuadas de una levadura seca activa tenía como
consecuencias una menor vitalidad y contenido lipídico. Estos efectos desaparecían tras una
recuperación en medio de cultivo óptimo. En el segundo capítulo, la cepa híbrida S. cerevisiae/S.
bayanus presentó la mejor cinética fermentativa sin necesidad de aclimatación. Sin embargo, el
resto de especies analizadas mostraron una modificación en la composición lipídica y una mejora de
su actividad fermentativa a 13 ºC al hacer coincidir la temperatura de fermentación con la de
precultivo. En el tercer trabajo, nos centramos en la nutrición lipídica de la levadura consiguiendo
una reducción del tiempo de fermentación a bajas temperaturas mediante la adición de ácido
palmitoleico en el medio de precultivo. Finalmente, en el último capítulo se analizó el efecto de la
supresión de genes del metabolismo de los fosfolípidos sobre la vitalidad a bajas temperaturas y la
composición en fosfolípidos. / The global aim of this thesis consists in improving the control of low temperature fermentations by
considering the changes in lipid metabolism. In the first chapter, we reported that poor ADWY
storage conditions resulted in an impairment of the vitality and a decrease in the lipid content.
These effects disappeared after a recovery in optimal medium. In the second chapter, we analysed
the strain and specific-response to fermentation temperature, showing that the hybrid S.
cerevisiae/S. bayanus presented the highest sugar consumption whatever the preculture temperature
used. The rest of the species needed a preadaptation at low temperature involving a change in their
lipid composition to improve their fermentation rate at 13 ºC. In the third chapter, we focused on
the lipid nutrition of yeast and we saw that palmitoleic acid supplementation reduced significantly
the fermentation length at low temperature. In the last chapter various phospholipid mutants were
tested to ascertain whether the suppression of some genes could modify the vitality at low
temperature and the phospholipid composition.
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Evaluation of a functional oil composed of medium chain triacylglycerols, phytosterols and n-3 fatty acids on the cardiovascular risk profile of overweight womenBourque, Christine. January 2002 (has links)
We examined the effect of a functional oil (FctO), with potential weight-controlling and blood lipid-lowering attributes, vs beef tallow as control (C), on the cardiovascular risk profile of overweight women. The FctO comprised energy expenditure-enhancing medium chain triacylglycerols, cholesterol-lowering phytosterols and triacylglycerol-suppressing n-3 fatty acids. In a randomized, single-blind, crossover design, inpatient trial, 17 women consumed each oil as part of a controlled, supervised, energy-adjusted diet for 27 days. Body weight decreased similarly during both dietary periods. Plasma total and LDL cholesterol levels decreased by 4.8% and 10.4% following FctO, and were lower by 9.0% and 16.4% respectively, after FctO vs C. HDL cholesterol and circulating triacylglycerol levels were unaffected by treatment, though HDL:LDL and HDL:total cholesterol ratios increased by 19.5% and 9.4% on FctO. Plasma total homocysteine levels were higher on FctO vs C. Plasma glutathione increased with FctO supplementation. / We conclude that consumption of FctO improves the overall cardiovascular risk profile of overweight women.
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The TRC8 hereditary kidney cancer gene product is regulated by sterols and modulates SREBP levels /Lee, Jason Philip. January 2007 (has links)
Thesis (Ph.D. in Human Medical Genetics) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 117-126). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;
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Establishment of a Drosophila model of Niemann-Pick type C disease /Fluegel, Megan L. January 2006 (has links)
Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 88-101).
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