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Organic residue analysis of Egyptian votive mummies and their research potentialBrettell, Rhea C., Martin, William H.C., Atherton-Woolham, S., Stern, Ben, McKnight, L. 15 June 2016 (has links)
Yes / Vast numbers of votive mummies were produced in Egypt during the Late Pharaonic, Ptolemaic, and Roman
periods. Although millions remain in situ, many were removed and have ultimately entered museum
collections around the world. There they have often languished as uncomfortable reminders of antiquarian
practices with little information available to enhance their value as artefacts worthy of conservation or
display. A multi-disciplinary research project, based at the University of Manchester, is currently
redressing these issues. One recent aspect of this work has been the characterization of natural products
employed in the mummification of votive bundles. Using gas chromatography–mass spectrometry and the
well-established biomarker approach, analysis of 24 samples from 17 mummy bundles has demonstrated
the presence of oils/fats, natural waxes, petroleum products, resinous exudates, and essential oils. These
results confirm the range of organic materials employed in embalming and augment our understanding of
the treatment of votives. In this first systematic initiative of its kind, initial findings point to possible trends in
body treatment practices in relation to chronology, geography, and changes in ideology which will be
investigated as the study progresses. Detailed knowledge of the substances used on individual bundles
has also served to enhance their value as display items and aid in their conservation. / RCB is supported by a PhD studentship from the Art and Humanities Research Council (43019R00209). L.M. and S.A.W. are supported by a Leverhulme Trust Research Project Award (RPG-2013-143).
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Isolierung und Charakterisierung der Chitin-basierten Skelette der marinen Schwämme Aplysina cavernicola und Ianthella bastaUeberlein, Susanne 26 January 2016 (has links) (PDF)
Die Schwammskelette der Ordnung Verongida zeichnen sich durch das Fehlen mineralischer Komponenten aus. Stattdessen bestehen sie aus Spongin, einem kollagenartigen Protein, und Chitin. Im Rahmen der vorliegenden Arbeit wurden die aus solch einem Chitin-Protein-Komplex bestehenden Skelette der Schwammspezies Aplysina cavernicola und Ianthella basta aus der Ordnung Verongida untersucht. Aufgrund ihrer morphologischen Unterschiede wurde für jede Schwammart eine eigene Methode zur Isolierung der Schwammskelette entwickelt. Die isolierten Skelette konnten anschließend mit verschiedenen Methoden wie REM, ATR-FTIR-Spektroskopie und NMR-Spektroskopie charakterisiert werden.
Weiterhin wurde eine Methode zur Extraktion und Analyse der in den Skeletten befindlichen Aminosäuren mittels GC-MS entwickelt. Die Untersuchungen zeigten deutlich, dass es sich bei Spongin um ein kollagenartiges und halogeniertes Protein handelt, welches je nach Schwammart Unterschiede in der Aminosäurezusammensetzung aufweist. Darüber hinaus gelang es zum ersten Mal das Chitin aus dem Chitin-Protein-Komplex mittels Phosphorsäure zu entfernen. Aus den gewonnenen Erkenntnissen konnte abschließend ein Modell zum Aufbau des Chitin-Protein-Komplexes in der Schwammspezies Aplysina cavernicola entwickelt werden.
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Détermination du mécanisme d'entrée du rotavirus, impliquant la glycoprotéine VP7 par RMN / Determination of the entry mechanism of rotavirus involving the VP7 glycoprotein by NMRElaid, Sarah 15 February 2013 (has links)
Les Rotavirus appartiennent à la famille des Reoviridae, famille du groupe III des virus à ARN double brin. Identifiés en 1973 par Ruth Bishop, ces virus non enveloppés sont la première cause de diarrhée aiguë sévère du jeune enfant dans le monde. La capside virale icosaédrique est constituée de 3 couches protéiques de structure : la couche externe formée par la glycoprotéine VP7 d’où émergent les spicules de protéine VP4, la couche intermédiaire constituée par la protéine VP6 représentant près de 50 % du poids du virus et enfin, la couche interne appelée core, résultant de l’assemblage des protéines VP2, d’où émergent vers l’intérieur les protéines VP1 et VP3. Cette capside renferme un génome divisé en 11 segments d’ARN bicaténaires. A ces 6 protéines structurales s’ajoutent les protéines non structurales qui interviennent lors de la réplication du virus. Les deux protéines structurales, VP4 et VP7 sont essentielles pour la fixation de la particule triple couche (TLP) aux membranes des cellules hôtes, par interaction aux récepteurs intégrines, elle sont également impliqués dans la déstabilisation des membranes endosomales, indispensable à la libération de la particule double couche (DLP) infectieuse dans le cytoplasme. Actuellement, contrairement au mécanisme d’action de la protéine VP5*, celui de la glycoprotéine VP7 est inconnu. L’objectif de cette thèse, a été de comprendre le mécanisme moléculaire de déstabilisation des membranes par les peptides dérivés de VP7. Dans un premier temps nous avons montré, par des études in silico, l’existence d’un domaine prédit en hélice membranaire bordé de résidus arginine et lysine hautement conservés, situé à l’extrémité C-terminale de la glycoprotéine VP7. Ces résultats ont conduit à la synthèse de quatre peptides avec lesquels des tests de perméabilisation de membranes modèles de larges vésicules unilamellaires (LUVs) ont été menés. Ceux-ci ont permis d’identifier le domaine minimum le plus actif, VP723, parmi les peptides sélectionnés. Dans un second temps nous avons déterminé la structure de ces peptides par RMN, dans des conditions mimant l’environnement hydrophobe de la membrane. Le peptide minimal VP723 s’organise en hélice α-amphipathique, structure souvent impliquée dans la déstabilisation des membranes cellulaires. La comparaison de sa structure obtenue par RMN à celle du domaine correspondant dans la structure cristallographique de la protéine native montre le réarrangement conformationnel de ce segment après maturation par la trypsine. Ces résultats ont été confirmés par deux mutants de synthèse, dont l’un est inactif pour la perméabilisation des membranes modèles. Ces travaux ont été complétés par des expériences de Résonance Plasmonique aux Ondes guidée (PWR). Des études par RMN du solide sont en cours afin de déterminer l’orientation du peptide dans les membranes modèles. En conclusion, nos résultats mettent en évidence l’importance du domaine C-terminal VP723 de la protéine VP7 dans la déstabilisation des membranes, permettant d’assurer la translocation de la particule virale infectieuse (DLP) de l’endosome vers le cytoplasme. Un modèle du mécanisme d’entrée du virus, médié par les peptides dérivés de la maturation par la trypsine de la glycoprotéine VP7 est proposé. / Rotaviruses belong to the Reoviridae family, belonging to the group III of dsRNA viruses. Identified in 1973 by Ruth Bishop, these non-enveloped viruses are the leading cause of severe diarrhea in young children worldwide. The icosahedral capsid is composed of three structural protein layers: the outer one, formed by the glycoprotein VP7, emerges spicules protein VP4, the intermediate one consists of VP6 protein representing nearly 50% of the weight of the virus and finally, the inner one called core, results from the assembly of proteins VP2, emerges towards the inside of proteins VP1 and VP3. The capsid contains a genome divided into 11 segments of dsRNA. To these six structural proteins are added nonstructural proteins involved in virus replication. The two structural proteins, VP4 and VP7, are involved in the interaction of the triple layer particle (TLP) to integrin receptors, necessary for the release of the infectious double layer particle (DLP) into the cytoplasm following the permeabilization of the membrane of the endosome compartments. Currently, unlike the mechanism of action of the protein VP5*, the glycoprotein VP7 remains unknown. The objective of this work was to understand the molecular mechanism involved in the destabilization of membranes by peptides derived from VP7. In a first step, we have shown, by in silico studies, the existence of a helical trans-membrane domain predicted containing a highly conserved arginine and lysine residues, located at the C-terminus of the VP7 glycoprotein. These results led to the synthesis of four peptides with which permeabilizing tests of model membranes were conducted. We have identified the minimum of the most active domain, named VP723, among the selected peptides. In a second step, we determined the structure of these peptides by NMR under conditions mimicking the hydrophobic environment of the membrane. The VP723 peptide is organized like an α-helical amphipathic structure often involved in the destabilization of cell membranes. The comparison of the structure obtained by NMR to that of the corresponding domain in the crystallographic structure of the native protein shows a conformational rearrangement of the segment after trypsin maturation. These results were confirmed by two synthetic mutants, one of which is inactive for the permeabilization of model membranes. These studies were complemented by experiments Plasmon Resonance guided the Waves (PWR). Studies by solid state NMR are in progress to determine the orientation of the peptide in model of membranes. In conclusion, our results highlight the importance of the C-terminal domain of the VP7 protein, named VP723, in the destabilization of membranes, to ensure the translocation of the infectious viral particle (DLP) from the endosome into the cytoplasm compartments. A mechanism of virus entry mediated by peptides derived from trypsin maturation of the VP7 glycoprotein is proposed in this study.
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Degradation Mechanisms in Small-Molecule Organic Electronic DevicesWölzl, Florian 04 February 2016 (has links)
Over the last decades organic light-emitting diodes (OLEDs) and organic solar cells (OSCs) have gained considerable attention as efficient, flexible, lightweight, and potentially low-cost technology for lighting and display applications or as a renewable energy source, respectively. However, achieving long-term stability remains challenging. Revealing and understanding aging processes is therefore of great interest. This work presents fundamental investigations to understand and circumvent organic device degradation.
In the first part, single materials used in organic devices were investigated. By tailoring an attenuated total reflection infrared (ATR-IR) spectrometer to the specific needs and subsequent measurements, it is shown that the tris(8-hydroxyquinoline)aluminum (Alq3) molecule, a well known fluorescent green emitter, degrades during air exposure by the formation of carbonyl groups. By using a laser desorption/ionization time of flight mass spectrometer (LDI-TOF-MS) it was shown that a,w-bis-(dicyanovinylen)-sexithiophen (DCV6T-Bu4), a well known small-molecule material which is used as part of the active layer, reacts with oxygen during ultraviolet (UV) irradiation.
By using climate boxes and a sun simulator the impact of dry and humid air as well as sunlight on C60, a widely-used acceptor molecule in organic solar cells, was investigated. The breaking of the C60 cage to C58 and C56 and the further reaction of these components with oxygen as well as the dimerization of C58 and C56 molecules were found. The degradation products such as C58O increase with air exposure time but they are independent of the humidity level of the ambient air as well as sunlight irradiation. Subsequent annealing leads to a decrease of the C58O concentration.
Many efficient n-dopants are prone to degradation in air, due to the low ionization potentials, thereby limiting the processing conditions. It was found that the air exposure of the highly efficient n-dopant tetrakis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidinato)ditungsten(II) (W2(hpp)4) leads to oxidation reactions of the molecule to [W(hpp)2 + O] and other degradation products. The decay constant of W2(hpp)4 and the matching mean growth time of the [W(hpp)2 + O] degradation as well as a second very quick degradation of the dopant could be determined. The two decay constants can be explained by the assumption that W2(hpp)4 molecules, which are involved in the charge transfer, do degrade slower due to the fact that the charge transfer leads to a downshift of the energy levels of the W2(hpp)4 molecule.
Apart from the properties of the organic materials, other effects such as the impact of different purification systems on the material purity as well as the dependence of material purity on the OLED lifetime has been investigated. No correlations between the purification grade and the amount of impurities were found. OLEDs which contain N,N\'-di(naphthalen-1-yl)-N,N\'-diphenyl-benzidine (alpha-NPD) purified in a vertically interlaced stainless steel sublimation systems shows slightly higher external quantum efficiencies compared to tube-based vacuum sublimation systems. The devices which contain alpha-NPD purified by a sublimation system have an extended lifetime.
Finally, the impact of residual gases during device fabrication on OLED lifetime and electrical characteristics was investigated. It was found that water vapor introduces an additional series resistance to the OLED, while the other gases do not influence the electric characteristics. The presence of nitrogen or oxygen impacts the lifetime of the OLEDs by the same amount. Nitrogen is non-reactive, this leads to the conclusion that the influence of nitrogen and oxygen on the OLED lifetime is of non-chemical nature, such as changes in the morphology of the organic layers. Water vapor introduces an additional, even faster degradation process within the first hours of OLED operation. As major sources of device degradation, the dimerization of 4,7-diphenyl-1,10-phenanthroline (BPhen) as well as the complexation reaction of alpha-NPD with a bis(1-phenylisoquinoline)iridium(III) (Ir(piq)2) fragment was identified.
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Meeting at the Membrane – Confined Water at Cationic Lipids & Neuronal Growth on Fluid Lipid Bilayers: Meeting at the Membrane – Confined Water at Cationic Lipids &Neuronal Growth on Fluid Lipid BilayersWoiterski, Lydia 05 December 2013 (has links)
Die Zellmembran dient der Zelle nicht nur als äußere Hülle, sondern ist auch an einer Vielzahl von lebenswichtigen Prozessen wie Signaltransduktion oder Zelladhäsion beteiligt. Wasser als integraler Bestandteil von Zellen und der extrazellulären Matrix hat sowohl einen großen Einfluss auf die Struktur von Biomolekülen, als auch selbst besondere Merkmale in eingschränkter Geometrie. Im Rahmen dieser Arbeit wurden zwei Effekte an Modellmembranen untersucht: Erstens der Einfluss des Gegenions an kationischen Lipiden (DODAX, X = F, Cl, Br, I) auf die Eigenschaften des Grenzflächenwassers und zweitens das Vermögen durch Viskositätsänderungen das Wachstum von Nervenzellen anzuregen sowie die einzelnen Stadien der Bildung von neuronalen Netzwerken und deren Optimierung zu charakterisieren.
Lipidmultischichten und darin adsorbiertes Grenzflächenwasser wurden mittels Infrarotspektroskopie mit abgeschwächter Totalreflexion untersucht. Nach Charakterisierung von Phasenverhalten und Wasserkapazität der Lipide wurden die Eigenschaften des Wassers durch kontrollierte Hydratisierung bei einem Wassergehalt von einem Wassermolekül pro Lipid verglichen. Durch die geringe Wasserkapazität können in diesem besonderen System direkte Wechselwirkungen zwischen Lipiden und Wasser aus der ersten Hydratationsschale beobachtet werden. Bemerkenswert strukturierte OH-Streckschwingungsbanden in Abhängigkeit des Anions und niedrige IR-Ordnungsparameter zeigen, dass stark geordnete, in ihrer Mobilität eingeschränkte Wassermoleküle an DODAX in verschiedenen Populationen mit unterschiedlich starken Wasserstoffbrückenbindungen
existieren und sich vermutlich in kleinen Clustern anordnen.
Die zweite Fragestellung hatte zum Ziel, das Wachstum von Nervenzellen auf Membranen zu beleuchten. Auf der Ebene einzelner Zellen wurde untersucht, ob sich in Analogie zu den bisher verwendeten elastischen Substraten, die Viskosität von Membranen
als neuartiger physikalischer Stimulus dafür eignet, das mechanosensitive Verhalten von Neuronen zu modulieren. Das Wachstum der Neuronen wurde auf substrat- und
polymergestützten Lipiddoppelschichten mittels Phasenkontrastmikroskopie beobachtet. Die Quantifizierung der Neuritenlängen, -auswuchsgeschwindigkeiten und
-verzweigungen zeigten kaum signifikante Unterschiede. Diffusionsmessungen (FRAP) ergaben, dass entgegen der Erwartungen, die Substrate sehr ähnliche Fluiditäten aufweisen.
Die Betrachtung der zeitlichen Entwicklung des kollektiven Neuronenwachstums, also der Bildung von komplexen Netzwerken, offenbarte robuste „Kleine-Welt“-Eigenschaften und darüber hinaus unterschiedliche Stadien. Diese wurden durch graphentheoretische
Analyse beschrieben, um anhand typischer Größen wie dem Clusterkoeffizienten und der kürzesten Pfadlänge zu zeigen, wie sich die Neuronen in einem frühen Stadium vernetzen, im Verlauf eine maximale Komplexität erreichen und letztlich das Netzwerk durch effiziente Umstrukturierung hinsichtlich kurzer Pfadlängen
optimiert wird.
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Corrélation entre le comportement électrique et les propriétés physico-chimiques des fils émaillés : vers l'origine de la défaillance de machines tournantes en conditions extrêmes / Origin of the failure occurring in high temperature electrical machines : a route to improve the electrical behavior of enamel wiresPetitgas, Benoit 26 June 2013 (has links)
Le sujet de cette thèse concerne les applications hautes températures, où les moteurs doivent être capables de fonctionner à 400°C pendant 2 heures, selon la norme en vigueur. Il convient dans ce type d’applications de disposer de matériaux assez stables pour que leurs propriétés isolantes restent inchangées, ce qui est le cas du fil émaillé PolyImide (PI). Ce fil émaillé pose néanmoins des problèmes économiques et de fournisseurs, d’où la nécessité de trouver d’autres alternatives. Ce travail de thèse a eu pour but de mettre au point et valider des techniques d’analyses (ATG / ATM / ATR-FTIR / DRS) adaptées au fil émaillé, et ce jusqu’à 400°C. Le PEI présente des propriétés insuffisantes pour ce type d’application car il se dégrade avant 350°C et perd ses propriétés d’isolation électrique. Le PAI est un matériau qui ne se dégrade que peu avant 400°C, et présente des caractéristiques électriques (propriétés diélectriques et de conduction) déjà plus proche du PolyImide. Nous avons pu établir la comparaison de deux PAI dont l’un est conventionnel et l’autre est un nanocomposite à base d’alumine. Ce dernier PAI est plus stable en température mais ne semble pas avoir de propriétés électriques très supérieures. Pour confronter les résultats expérimentaux obtenus dans des conditions particulières aux conditions réelles d’utilisation, des moteurs avec ces fils émaillés ont été fabriqués. Les moteurs équipés des fils PEI/PAI (fil standard) et PAI sont défaillants après 40 minutes au lieu de 2h, contrairement aux moteurs équipés de fil PI. La dégradation du PEI et le fluage du PAI, caractérisé au-delà de sa Tg (280°C), peuvent être la cause des dysfonctionnements de ces moteurs / This work is related to the high temperature application where motors have to withstand severe conditions - 400°C during 2 hours - according to the standard. Electrical insulation becomes a serious challenge for such application where materials have to remain stable, which is the case of PolyImide enameled wire. Other alternatives have to be found because this is a very expensive material with a small number of suppliers. The thermal, structural, mechanical and electrical properties of these systems have been investigated in-situ until 400°C by thermogravimetric analysis, ATR-FTIR microscopy, thermomechanical analysis, dielectric spectroscopy and DC voltage experiments. Dielectric spectroscopy has indicated a loss of insulating properties during the thermal cycle especially for PEI-containing enamels that degrades before 350°C. PAI enameled wires degrade just before 400°C, and electrical properties (dielectric properties and conductivity) are closer to PI‘s in this temperature range. A comparison between a conventional PAI and a PAI filled with nanoparticules of aluminium oxide has been made. The nanocomposite is thermally more stable but does not show better electrical behavior. To correlate all these results to the real test conditions (combined thermal, electrical and mechanical stresses), electrical motors have been fabricated using the enameled wires said before. They all breakdown after 40 minutes running, except motors made with PI enameled wires. The degradation of PEI ad the creeping of PAI up to its Tg (280°C) can explain the breakdown of these motors
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Collage d'hydrogels par des nanoparticules de silice / Adhesion of hydrogels by silica nanoparticlesGracia, Marie 27 February 2017 (has links)
Il est difficile de réaliser une forte adhésion entre deux hydrogels par un procédé simple. Récemment, un nouveau concept a été proposé par Leibler et ses collaborateurs pour coller des hydrogels ou des tissus biologiques. Il consiste à utiliser des nanoparticules sur lesquels s'adsorbent les chaînes de polymère et qui jouent ainsi le rôle de connecteurs. L'objectif principal de la thèse est d'identifier et de contrôler les mécanismes à l'origine de l'adhésion de deux hydrogels par des nanoparticules. De nombreuses questions sont abordées : la nature des nanoparticules de silice (taille, charge, concentration, état de dispersion), l'influence de la structure de l'hydrogel et son état de gonflement, la répartition des nanoparticules sur les interfaces. Les expériences sont menées avec plusieurs catégories d'hydrogels: le Poly(N,N diméthyl-acrylamide) (PDMA), le Polyacrylamide (PAAm), des gels nanocomposites (PDMA renforcé par des nanoparticules de silice), ou encore des gels à double-réseaux. Nous mesurons les propriétés adhésives à l'aide de tests de joints de recouvrement, de pelage à 90°, et de pelage en Y, que nous avons mis au point. Nous avons utilisé des expériences d'ATR-FTIR, de microcopie confocale à fluorescence et de microscopie électronique à balayage pour mettre en évidence l'adsorption des chaînes polymères à la surface des hydrogels, évaluer la quantité de particules de silice à la surface du gel, et caractériser leur distribution. Les résultats nous permettent de proposer un mécanisme d'adhésion et de définir les conditions qui permettent de réaliser une adhésion optimale. / It is very challenging to achieve strong adhesion between two soft and wet materials like hydrogels. Recently Leibler and his collaborators invented a new concept to assemble hydrogels or biological tissues using nanoparticles. The principle relies on the adsorption of gel chains at the surface of nanoparticles, which act as connectors, and on the ability of the adsorbed gel chains to reorganize under stress. The main objective of this work is to identify and control the physical mechanisms fundamental to gel adhesion by silica nanoparticles. Many questions are investigated: the nature of the nanoparticles (size, surface chemistry, concentration, state of dispersion), the gel structure and its state of swelling, the distribution of the nanoparticles at the gel surface. Experiments are conducted using several types of gels: Poly(N,N dimethylacrylamide) (PDMA), Poly(acrylamide) (PAAm), nanocomposite gels (PDMA reinforces with silica nanoparticles), or double-network (DN) gels. We quantify the adhesive properties using lap-shear experiments, peeling tests at 90°, and Y-peeling tests that we developed. We use ATR-FTIR experiments, confocal microscopy and scanning electron microscopy to demonstrate the adsorption of polymers onto the silica nanoparticles and characterize their spatial repartition. The results allow us to propose a mechanism explaining the adhesion and to define conditions for optimal adhesion.
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The Molecular Investigation Of The Effects Of Simvastatin, A Cholesterol Reducing Drug, On Different Rat Skeletal Muscle TissuesSimsek Ozek, Nihal 01 September 2007 (has links) (PDF)
In the present study Fourier Transform Infrared (FTIR) and Attenuated Total Reflectance FTIR (ATR-FTIR) Spectroscopy were used to examine the effects of simvastatin on structure, composition and function of macromolecules of three different rat skeletal muscles EDL (Extensor Digitorium Longus), DIA (Diaphragm) and SOL (Soleus) containing different amount of slow and fast twitch fibers, at molecular level.
Simvastatin, a lipophilic statin, is widely used in the treatment of hypercholesterolemia and cardiovascular diseases due to its higher efficacy. However, long term usage of statins give rise to many adverse effects on different tissues and organs. Skeletal muscle accounts for around 45 % of the total body weight and has a high metabolic rate and blood flow. As a consequence, it is highly exposed to drugs within the circulation. Therefore, it is one of the target tissues of statins. The two main types of muscle fibers are type I (slow-twitch) and type II (fast-twitch) fibers / having different structural organization and metabolic features. EDL is a fast twitch muscle while SOL is slow twitch muscle. On the other hand, DIA shows intermediate properties between slow and fast twitch muscle.
The results of ATR-FTIR and FTIR spectra revealed a considerable decrease in protein and lipid content of simvastatin treated skeletal muscles, indicating protein breakdown or decreased protein synthesis and increased lipolysis. Moreover changes in protein structure and conformation were observed. In simvastatin treatment, muscle membrane lipids were more ordered and the amount of unsaturated lipids was decreased possibly due to lipid peroxidation. The drug treatment caused a decrease in the content of nucleic acids, especially RNA, and hydrogen and non-hydrogen bonded phospholipids in the membrane structures of skeletal muscles.
In all of the spectral parameters investigated EDL muscle was more severely affected from statin treatments while SOL was less affected from the drug treatments. Thus, FTIR and ATR-FTIR spectroscopy appear to be useful methods to evaluate the effects of statin on skeletal muscle tissues at molecular level.
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Flocculation Behavior Of Two Different Clay Samples From Kirka Tincal DepositCirak, Mustafa 01 September 2010 (has links) (PDF)
Kirka Boron Plant in Eski
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Characterization Of Yellow Rust And Stem Rust Resistant And Sensitive Durum Wheat Lines At Molecular Level By Using Biophysical MethodsKansu, Cigdem 01 September 2011 (has links) (PDF)
Stem rust and Yellow rust diseases are the two major wheat fungal diseases causing
considerable yield losses in Turkey and all around the world. There are studies which
are carried out to identify and utilize resistance sources in order to obtain resistant
lines of wheat. However, virulent pathotypes are continuously being important
threats to wheat production and yield. For that reason, new approaches for rapid
identification are needed.
The aim of this study was to investigate and to understand the structural and
functional differences between the resistant and sensitive durum wheat cultivars to
the plant fungal diseases of stem and yellow (stripe) rusts. To aim this, forty durum
wheat recombinant inbred lines (RILs), which were previously determined to be
resistant or sensitive to stem and yellow rust diseases, were investigated by the noninvasive
Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR)
Spectroscopy. Also, classification of the resistant and sensitive lines depending on
the structural and functional differences has been attempted. The FTIR spectra for stem rust disease showed that, resistant durum wheat lines had
a significant increase in the population of unsaturation in acyl chains of lipid
molecules, an increase in lipid and in total protein content and also an increase in
carboxylic acids and alcohols. For yellow rust disease, resistant lines had a
significant increase in hydrogen bonding and they had also a more ordered
membrane structure.
In Principal Component Analysis for stem rust disease, according to 3700-650 cm-1
region, amide III band (1213-1273 cm-1 region) and C-H stretching region (3020-
2800 cm-1), the resistant and sensitive groups were separated successfully. For
yellow rust disease, according to 3700-650 cm-1 region, Amide A and Amide III
bands, the resistant and sensitive lines were grouped distinctly.
FTIR spectroscopy provides a useful approach to determine the differences in
molecular structure of durum wheat RILs regarding resistance of lines to fungal
diseases. However, further research is still needed to ensure if the structural and
functional differences in biomolecules of the samples could be used as molecular
markers for discrimination of rust resistant materials from rust sensitive ones.
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