Today, structural adhesives are found extensively in load-bearing engineering applications, as their use can be advantageous compared to other fastening methods. However, the characteristics of adhesives are far more complex, making it challenging to predict their behavior in different service conditions. In addition, environmental factors like temperature and water can affect the performance of an adhesive bond both physically and chemically. This work was initiated by MuoviTech AB and aims to evaluate the performance of structural methyl methacrylate adhesives cured in different environmental conditions. The study began with a literature review to find relevant research and literature about structural adhesives, their material characteristics, and the effects of temperature and water on the performance of adhesive bonds. A market survey was conducted to find products suitable for the experiment, and Araldite 2050, Araldite 2051, Permabond TA4200, 3M DP8810NS, LoctiteHY 4070, and Acralock SA 10-05 were selected together with MuoviTech AB. The laboratory work began with sample preparation in terms of abrasion and cleaning of the surface. The adhesives were applied to the samples, and single-lap joints were prepared and cured in room temperature and normal humidity, as well at 5 °C and underwater, for 24 hours. Single-lap shear tests were performed according to American standard ASTM D3163. Lastly, differential scanning calorimetry (DSC) was utilized for the thermal analysis of the samples cured at 5 °C and underwater. The results showed that neither of the adhesives performed in the range specified in the manufacturers’ technical data sheets (TDS). Lower failure strength and elongation was observed for the samples cured at 5 °C and underwater, compared to the samples cured in the optimal condition. However, Loctite HY 4070 showed an increase in failure strength. The DSC analysis revealed various degrees of post-curing. Further investigation with prolonged curing time and more environmental conditions are recommended. New tests for Loctite HY 4070 is also recommended to confirm the results. / Idag finns strukturella lim i stor utsträckning i bärande tekniska applikationer, eftersom deras användning kan vara fördelaktig jämfört med andra fästmetoder. Limmens egenskaper är dock mycket mer komplexa, vilket gör det svårt att förutsäga deras beteende under olika serviceförhållanden. Dessutom kan miljöfaktorer som temperatur och vatten påverka en limbindnings prestanda både fysiskt och kemiskt. Detta arbete initierades av MuoviTech AB och syftar till att utvärdera prestanda för strukturella metylmetakrylatlim härdade under olika miljöförhållanden. Studien inleddes med en litteraturöversikt för att hitta relevant forskning och litteratur om strukturella lim, deras materialegenskaper och effekterna av temperatur och vatten på limförbandens prestanda. En marknadsundersökning genomfördes för att hitta produkter som var lämpliga för experimentet, och Araldite 2050, Araldite 2051, Permabond TA4200, 3MDP8810NS, Loctite HY 4070 och Acralock SA 10-05 valdes tillsammans med MuoviTech AB. Arbetet i laboratoriet inleddes med provförberedelse genom slipning och rengöring av provens yta. Lim applicerades på proverna och förband med enkla överlapp (single-lap) bereddes och härdades i rumstemperatur och normal fuktighet, liksom vid 5 ° C och under vatten, under 24 timmar. Skjuvtester utfördes enligt den amerikanska standarden ASTM D3163. Slutligen användes differentiell svepkalorimetri (DSC) för termisk analys av proverna som härdades vid 5 ° C och under vatten. Resultaten visade att inget av limmen presterade i enlighet med det som beskrevs i tillverkarnas tekniska datablad (TDS). Däremot så observerades en lägre brottstyrka och töjning för proverna som härdades vid 5 ° C och under vatten, jämfört med de prover som härdades i det optimala tillståndet. Loctite HY 4070 visade emellertid en ökning av brottstyrka. DSC-analysen gav indikation på att olika grader av efterhärdning. Ytterligare undersökningar med längre härdningstid och med flera miljöförhållanden rekommenderas. Nya tester för Loctite HY 4070 rekommenderas också för att bekräfta resultaten.

Any interaction of plants with phytopathogens involves the generation of various chemical molecules that are critical for activation of their defense machinery. One of the chemicals, salicylic acid (SA)induces systemic acquired resistance (SAR)in plants. The activation of SAR provides a broad-spectrum resistance against a wide range of related or unrelated pathogens. There has been considerable progress in the biochemical and molecular understanding of SAR activation in various plants. In addition, several chemicals including SA and its analogs are known to provide a direct or indirect defense against pathogens when applied to plants. Molecular mechanism of plant defense induced by synthetic chemical inducers is not very well understood. This review highlights the importance of salicylic acid and its most studied analog, Acibenzolar-S-methyl in inducing SAR and it also provides a description of other major chemical elicitors of plant defenses and their possible molecular mechanism.

Doctor Educationis / The fungus Botrytis cinerea is an opportunistic pathogen on a wide variety of crops, causing a disease known as grey mould through infections via wounds or dead plant parts. Synthetic fungicides for controlling this disease are fast becoming ineffective due to the development of resistance. This, coupled with consumers' world wide becoming increasingly conscious of potential environmental and health problems associated with the build-up of toxic chemicals, (particularly in food products), have resulted in pressure to reduce the use of chemical pesticide volumes as well as its residues. An emerging alternative to random chemical synthesis is the study and exploitation of naturally occurring products with fungicidal properties. One group of compounds known as strobilurins produced by Strobilurus species, woodland basidiomycete fungi, is a good example of this phenomenon. Plants produce an enormous array of secondary metabolites, and it is commonly reasoned that a significant part of this chemical diversity serves to protect plants against plant pathogens. A problem with plant-produced compounds as potential fungicides is that in the natural state, they are generally only weakly active compared to synthetic fungicides. There have been reports on the uses of mixtures of synthetic fungicides for the control of plant pathogenic fungi. When utilized in two-way mixtures, such fungicides may maintain or enhance the level of control of a pathogen at reduced rates for both components utilized in combinations, or alone at normal rates. These studies provide an important precedent for the idea of synergism. For this study, we hypothesize that the addition of plant extracts may enhance the antifungal efficacy of the synthetic strobilurin fungicide, kresoxim-rnethyl against B. cinerea. We selected South African medicinal plant species such as Artemesia afra, Elyptropappus rhinocerotis, Galenia africana, Hypoxis hemerocallidea, Siphonochilus aetheopicus, Sutherlundia frutescence, Tulbaghia violacea and Tulbaghia alliaceae for this study. For the in vitro study, indigenous medicinal plant extracts were prepared at twofold dilution concentrations and combined with kresoxim-rnethyl at concentrations of 0.25 and 0.5% (w/v). The B. cinerea mycelial plug assays showed potent antifungal inhibitory effects with the plant extract and kresoxim-rnethyl mixtures. Further analyses of the mixtures indicate synergistic effects between the fungicide and plant extracts. I surmise that these in vitro effects are also achievable in vivo. Combinations of these agents represent an attractive avenue for the development of new management strategies for controlling B. cinerea in the future. A second study was conducted to analyse the final dose rates for synergistic reactions for combinations of kresoxim-methyl and medicinal plant extracts against B. cinerea in vivo. A series of two-fold concentrations of medicinal plant extracts were combined with kresoxim-methyl to conduct decay inhibition studies on Granny Smith apples. Synergistic effects were observed for many of the kresoxim-methyl and plant extract combinations. I, therefore, came to the conclusion that indigenous South African plant species produce modulators that potentiate the activity of fungicides. Whether these synergistic effects are due to the inhibition of fungal multi-drug resistant pumps require further studies at the molecular level. However, these inhibitory effects are likely to be advantageous for developing fungicide formulations and application strategies with low toxicity effects on the environment. This approach not only makes it possible to reduce fungicide concentrations while maintaining adequate decay control, but also ensures a reduction of the chemical residue on the fruit.

Superficial layers of the dorsal horn receive a dense plexus of nerve fibers immunoreactive to pituitary adenylate cyclase activating polypeptide (PACAP). In vivo experiments were conducted in the mice to evaluate the effects of PACAP-38, herein referred to as PACAP, PACAP receptor antagonist PACAP(6-38) and PACAP-antiserum on nociceptive behaviors induced by radiant heat, intrathecally administered N-methyl-D-aspartate (NMDA) or intraplantarly administered formalin. PACAP (0.05-0.5μg) dose-dependently decreased the paw-withdrawal latencies induced by thermal stimulation and enhanced the aversive licking and biting behaviors induced by intrathecally injected NMDA. Pretreatment with the PACAP receptor antagonist PACAP(6-38) (0.5-2μg) or PACAP-antiserum (1:500-2000 dilution) dose-dependently attenuated the second phase, but not the first phase, of nociceptive responses to formalin. Next, the effects of PACAP on NMDA- and kainate-induced currents evoked in single dorsal horn neurons were studied. Whole-cell patch recordings were made from superficial dorsal horn neurons of spinal cord slices from 14- to 20-day-old mice. PACAP at the concentrations of 100 and 200nM, which caused no significant change of holding currents, increased NMDA-but not kainate-induced currents in superficial dorsal horn neurons. Our results suggest that exogenously applied PACAP sensitizes the dorsal horn neurons to formalin stimulation, and facilitates NMDA receptor-mediated nociceptive response. As a corollary, PACAP, which may be released from primary afferent fibers potentiates nociceptive transmission to the dorsal horn by interacting primarily with NMDA receptors.

Final publication is available at http://www.tandfonline.com/doi/full/10.1080/19393210.2014.968808 / 京都大学 / 0048 / 新制・課程博士 / 博士(社会健康医学) / 甲第19637号 / 社医博第70号 / 新制||社医||9(附属図書館) / 32673 / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 木原 正博, 教授 小杉 眞司, 教授 YOUSSEFIAN Shohab / 学位規則第4条第1項該当 / Doctor of Public Health / Kyoto University / DFAM

Clinically relevant concentrations of ethanol modulate the function of a number of ion channel proteins. A fundamental question regarding the effects of alcohol is whether the drug modifies ion channels by directly binding to the protein, indirectly by perturbing the surrounding membrane lipid, or some combination of both. This thesis further characterized ethanol's site of action by examining the effects of ethanol on N-methyl-D-aspartate (NMDA) receptor/channels and large conductance Ca2+-activated K+ (BK) channels at a number of levels using direct electrophysiological methods. In Chapter One, the magnitude of ethanol's inhibition of a number of cloned heteromeric NMDA receptor/channels in the absence or presence of a number of modulators was compared. The rank order of ethanol sensitivity for the subunit combinations studied was NR1b/NR2A > NR1b/NR2B > NR1b/NR2C > NR1b/NR2D. Modulation of the receptor with Mg2+, Zn2+, the glycine antagonist 7-Chlorokynurenic Acid, or after reduction or oxidation of the redox regulatory site did not alter the ethanol sensitivity of heteromeric NMDA receptors. Therefore, the ethanol sensitivity of NMDA receptor/channels is dependent upon which NR2 subunit is present, and ethanol's site of action is unrelated to these modulatory sites on the receptor/channel protein. In Chapter Two, ethanol's site of action at cloned BK channels was characterized using of a number of 1-alkanols. Ethanol, butanol, hexanol, and heptanol reversibly and dose-dependently increased the current carried through BK channels. Longer chain 1-alkanols, such as octanol had no effect on channels. In Chapter Three, the action of ethanol on BK channels reconstituted in a number of model planar bilayers was studied. Ethanol increased the activity of BK channels incorporated in bilayers composed of phosphatidylethanolamine (PE) and phosphatidylserine (PS) or PE alone by decreasing the average amount of time channels dwelled in the closed state. There was no significant effect of alcohol on either channel conductance or unitary current. Taken together, these data suggest that ethanol action on BK channels does not require the complex membrane architecture found in native membranes, and does not require freely diffusible cytoplasmic factors or proteins.

Reporter genes are often used to observe expression of promoters, which may change from its natural behaviour as a result of stress or disease states. Reporter genes are useful because they are easily detectable by a variety of imaging methods, including fluorescence microscopy techniques, magnetic resonance imaging, and positron emission tomography. Previously, methyl 5-MeO-N-aminoanthranilate (MMNA) had been synthesized as an aldehyde-conditional fluorophore and was tested in physiological conditions to identify the Aldehydic Load of cells. Thus, it was hypothesized that a reporter protein displaying an aldehyde on the cell surface can be identified by MMNA. This reporter protein would contain a substrate recognition site for formylglycine generating enzyme (FGE) that converts a specific cysteine residue into a formylglycine residue. This will result in production of an aldehyde at the N-terminal of the transmembrane domain of platelet derived growth factor receptor . In this way, the protein product, Aldehyde-presenting FGE-dependent Readout (Alfred), would display an aldehyde on the extracellular surface of the cell. Alfred was expressed in A549 human lung cancer cells using the Tet-On® Inducible System, which allows expression of a gene of interest by use of doxycyclin (dox) as a chemical trigger. Microscopy of Alfred-transfected cells, induced by dox and probed with MMNA, showed no difference in fluorescence between non-transfected and Alfred-transfected cells. The overexpression of FGE to increase thiol-to-aldehyde conversion, and the imaging of cells at longer timepoints (48 and 72 hours) to allow localization of the protein to the cell surface, were attempted. In addition, Alfred was constitutively expressed in another transfection experiment in efforts to increase gene expression. However, these efforts to evaluate Alfred did not improve the microscopy results. Western blotting confirmed FGE overexpression in transgenic cells. Blotting against the Myc-tag in Alfred showed no detected proteins in Alfred-transfected cells. In conjunction with the microscopy images, these results suggest that Alfred is not expressed and cannot be detected as a reporter gene. Comparison to previous works allows the identification of potential approaches to improve Alfred functionality, including the absence of the hemagglutinin epitope, the choice of aldehyde probe used, the choice of cell line used, and the method of analyzing microscopy. Future directives are postulated to identify sources that hinder Alfred expression, and to improve visualization of Alfred over homeostatic aldehydes.

Durant ma thèse, j'ai étudié cinq molécules d'intérêt astrophysique et atmosphérique en utilisant la spectroscopie à haute résolution dans les régions spectrales microonde, millimétrique et infrarouge lointain. Il s'agit du thioformate de méthyleCH3SCH(O), de sulfure de diméthyle (CH3)2S, de méthacroléine CH3C(CHO)CH2, d'acétate de vinyle CH3C(O)OCHCH2 et d'acétate de butadiènyle CH3C(O)O(CH)3CH2. Tous les spectres de ces molécules étudiées possèdent comme point en commun un mouvement de grande amplitude de rotation interne de un ou deux groupes méthyles CH3 qui aboutit à un dédoublement des raies. Ainsi, une modélisation spectrale spécifique pour chaque molécule est nécessaire afin de reproduire leurs spectres à la précision expérimentale et déterminer un ensemble de paramètres spectroscopiques à trés haute précision.Les molécules de thioformate de méthyle et de sulfure de diméthyle sont potentiellement détectables dans le milieu interstellaire (MIS) étant donné qu'elles sont les analogues soufrés du formiate de méthyle CH3OCH(O) et du diméthyle éther (CH3)2O, deux molécules relativement abondantes dans le MIS. Nous avons effectué pour la première fois une étude spectroscopique complète au laboratoire pour ces molécules, étude qui est indispensable pour fournir aux astrophysiciens des listes de fréquences et d'intensités de raies qui leur permettront dans le futur de détecter ces espèces et d'exploiter les spectres observés dans le MIS avec les radiotélescopes au sol et/ou embarqués. La méthacroléine est l'un des composés de l'oxydation des isoprènes émis dans la troposphère et elle joue un rôle important dans la chimie de l'atmosphère terrestre. Notre travail dans le domaine microonde a permis de mieux comprendre sa structure moléculaire et sa stabilité.Enfin, deux molécules d'esters carboxyliques ont été étudiées pendant ma thèse dans les régions spectrales des microondes comprises entre 2 et 40 GHz. J'ai complété l'étude du spectre microonde de l'acétate de vinyle CH3COOCHCH2 et j'ai étudié pour la première fois le spectre de deux isomères d'acétate de butadiènyle CH3COO (CH)3CH2. Outre que la validation des calculs de chimie quantiques effectués, cette étude a permis une meilleure compréhension de l'évolution des valeurs de barrières de potentielles entravant la rotation interne en fonction de la structure chimique. / During my thesis, I studied five molecules of astrophysical and atmospheric interest using high-resolution spectroscopy in the spectral regions of microwave, millimeterwave and far infrared. These molecules are methyl thioformate CH3SCH(O), dimethyl sulfide(CH3)2S, methacrolein CH3C(CHO)CH2, vinyl acetate CH3C(O)OCHCH2 and butadienylacetate CH3C(O)O(CH)3CH2. All of their spectra have in common a large amplitude motion,the internal rotation of the methyl group(s) CH3 leading to a splitting of the lines. Then, iused a specific theoretical modeling for each molecule in order to reproduce their spectra at experimental accuracy and to determine a set of spectroscopic parameters with very highprecision.Methyl thioformate and dimethyl sulfide are potentially detectable in the interstellar medium(MIS) as they represent the sulfur analogues of methyl formate CH3OCH(O) and dimethylether (CH3)2O, two molecules relatively abundant in the MIS. I performed a complete spectroscopic study in laboratory in order to provide astrophysicists with lists of frequencies and intensities of lines, which enable them to exploit the observed spectra in the MIS.Methacrolein is one of the compounds of the oxidation of isoprene emitted in the troposphereand plays an important role in the chemistry of the earth's atmosphere. Our studies in themicrowave range enables us to better determine its molecular structure which is useful inorder to better understand its stability. Finally, two ester molecules have been studied in the microwave spectral regions between2 and 40 GHz. The study of the microwave spectrum of vinyl acetate CH3COOCHCH2 is completed and the spectrum of two isomers of butadienyl acetate CH3COO(CH)3CH2 is studied for the first time.In addition to the validation of quantum chemistry calculations, this study allowed a better under standing of the evolution of potential barrier values du to internal rotation as a function of chemical structure.

Surface Organometallic Chemistry (SOMC) is an excellent approach to erase the gap between homogeneous and heterogeneous catalysis by grafting the molecular organometallic complex on various oxide surfaces, forming well-defined and single-site catalysts. This strategy allows for better characterization as well as the improvement and development of existing and new catalysts. These surface species could promote a wide range of catalytic applications (i.e., metathesis of hydrocarbons, hydrogenolysis of alkanes, and olefin polymerization reactions) depending on the metal center and its coordination sphere. In particular, the grafting of alkylated organometallic complexes of groups 4, 5, and 6 metals on the surface oxide is a thermodynamically favored reaction generally leading to strongly bonded well-defined surface species, which are highly reactive catalysts. This thesis has focused on the preparation, characterization, and catalytic investigation of different supported complexes that contain methyl, alkyl, and alkylidyne ligands. The first part compares the catalytic activity of [(≡Si−O−)W(-CH3)5] and [(≡Si-O-)Mo(≡CtBu)(-CH2tBu)2] surface species experimentally and by DFT calculations in the metathesis reactions of linear classical and functionalized olefins. Both pre-catalysts perform almost equally in the α-olefin metathesis reaction. However, in the functionalized olefin metathesis reaction, W pre-catalyst provides selective metathesis products and performs much better than Mo that gives a range of isomerization products. The second part deals with the synthesis and characterization of [(THF)2Zr(-CH3)4] and its grafting on silica support for the first time. The generated surface species [(≡Si−O−)Zr(CH3)3(THF)2] and [(≡Si−O−)2Zr(CH3)2(THF)2] are used for the conversion of CO2 and propylene oxide to cyclic propylene carbonates achieving a TON of 4227. The third part describes the first synthesis and characterization of the highly unstable homoleptic [Ti(-CH3)4] without any coordinating solvent. This complex was stabilized by grafting on SiO2-700, yielding two fully characterized surface species [(≡Si-O-)TiMe3] and [(≡Si-O-Si≡)(≡Si-O-)TiMe3], which were used in the hydrogenolysis reaction of propane and n-butane, with TONs of 419 and 578, respectively. Finally, the fourth part reports the immobilization and characterization of [TiMe2Cl2], an intermediate in the synthesis of [Ti(-CH3)4], on SiO2-700 resulting in [(≡Si-O-)TiMeCl2] and [(≡Si-O-)TiMe2Cl] surface species. These complexes reacted with a demethylating Lewis acid agent (BARF), forming the corresponding cationic Ti species [(≡Si-O-)TiMeCl]+ and [(≡Si-O-)TiCl2]+. Both neutral and cationic complexes were tested in the ethylene polymerization reaction affording linear HDPE with high molecular weights of 500,367 and 486,612 g/mol.

No description available.