Relevant bibliographies by topics / Proton Glases

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  2. Dissertations / Theses
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Academic literature on the topic 'Proton Glases'

Author: Grafiati
Published: 6 September 2023

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Journal articles on the topic "Proton Glases"

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Kawaguchi, Keiga, Takuya Yamaguchi, Takahisa Omata, Toshiharu Yamashita, Hiroshi Kawazoe, and Junji Nishii. "Phase separation and crystallization in sodium lanthanum phosphate glasses induced by electrochemical substitution of sodium ions with protons." Physical Chemistry Chemical Physics 17, no. 35 (2015): 22855–61. http://dx.doi.org/10.1039/c5cp04132e.

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Phase separation and crystallization forming H3PO4 occurred in sodium lanthanum phosphate glasses after electrochemical substitution of sodium ions with protons, although the glass exhibited significant proton conductivity.
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Ishiyama, Tomohiro, Takuya Yamaguchi, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe, and Takahisa Omata. "Origin of the Temperature Dependence of Proton Conductivity in Phosphate Glass Prepared by Alkali-Proton Substitution Technique." Journal of The Electrochemical Society 169, no. 3 (March 1, 2022): 034517. http://dx.doi.org/10.1149/1945-7111/ac5793.

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The temperature dependence of proton conductivity in 36HO1/2−4NbO5/2−2BaO-4LaO3/2−4GeO2−1BO3/2−49PO5/2 glasses prepared through the alkali-proton substitution method was investigated in this study. The activation energy of proton conduction, E a , was found to exhibit an non-Arrhenius type temperature dependence. The origin of the temperature dependence of the proton conductivity caused by thermal expansion of the glass structure was discussed in terms of the effect of changes in the local environment surrounding the protons. These changes were elucidated using Raman spectroscopy, 1H- and 31P-NMR, infrared spectroscopy, and molecular modeling. Because protons form O-H bonds, they are sensitive to changes in the distance between two oxygen atoms, which affects the strength of the hydrogen bond, and concluded that there is a temperature dependence as observed.
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Hongisto, Mikko, Sylvain Danto, Marian Ghena, Decebal Iancu, Daniel Ighigeanu, Laura Mihai, Véronique Jubera, and Laeticia Petit. "Response of Various Yb3+-Doped Oxide Glasses to Different Radiation Treatments." Materials 15, no. 9 (April 27, 2022): 3162. http://dx.doi.org/10.3390/ma15093162.

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The radiation effects of electrons and protons on the spectroscopic and optical properties of oxide glasses doped with Yb3+ in various glass systems were investigated to understand the impact of the glass composition on the glass photo-response. Changes in the optical and emission properties were seen after the radiation treatment, and the magnitude of the changes depended on the irradiation source and dose. For all the investigated materials, the absorption coefficients in the 200–550 nm range increase post-irradiation, revealing the formation of defects in the glasses during the irradiation. While the spectroscopic properties of the tellurite glass remain unchanged, a small reduction in the Yb3+ emission intensity was seen after irradiating the phosphate, borosilicate, and germanate glasses, indicating that a reduction of Yb3+ to Yb2+ might occur in these glasses during the radiation treatment. The changes in the optical and spectroscopic properties after proton irradiation are small as they are localized at the surface of the glasses due to the shallow penetration depth of the proton in the glass. Even though the doses are small, the electron irradiation produces larger changes in the optical and spectroscopic properties since the electrons penetrate the entire volume of the glasses. All the changes in the optical and spectroscopic properties of the glasses were successfully reversed after a short heat treatment revealing the reversible nature of the photo-response of the investigated glasses.
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Fanara, Sara, Harald Behrens, and Regina Kappes. "Ionic Conductivity of Hydrous Silicate Glasses." Advances in Science and Technology 46 (October 2006): 89–92. http://dx.doi.org/10.4028/www.scientific.net/ast.46.89.

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Hydrous silicate glasses with different compositions (LiAlSi4O10, CaMgSi2O6, CaMgSi2O6 - CaAl2Si2O8 and (Ca,Ba,Sr)O – SiO2) containing up to 3 wt% H2O were synthesized in platinum capsules at high temperature and pressures from 100 to 500 MPa in an internally heated gas pressure vessel. The water content of the glasses was analyzed by Karl-Fischer titration. Using infrared microspectroscopy the homogeneity of water distribution in the samples was checked and concentrations of OH- groups and H2O molecules were estimated. Frequency-dependent ionic conductivity of the glasses was investigated using impedance spectroscopy. It is shown that the proton conductivity is usually orders of magnitude lower than the partial conductivity of alkalis in silicate glasses. Proton conductivity in hydrous barium silicate glass was found to be more than one order of magnitude higher than in an aluminosilicate glass, supporting that the concentration of non-bridging oxygen is crucial for proton conduction in glasses.
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Omata, Takahisa, Takuya Yamaguchi, Satoshi Tsukuda, Tomohiro Ishiyama, Junji Nishii, Toshiharu Yamashita, and Hiroshi Kawazoe. "Proton transport properties of proton-conducting phosphate glasses at their glass transition temperatures." Physical Chemistry Chemical Physics 21, no. 20 (2019): 10744–49. http://dx.doi.org/10.1039/c9cp01502g.

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Proton mobility at the glass transition temperature of 32 proton-conducting phosphate glasses converges between 2 × 10−9 and 2 × 10−7 cm2 V−1 s−1.
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Yamaguchi, Takuya, Yasuhisa Saito, Yasutaka Kuwahara, Hiromi Yamashita, Tomohiro Ishiyama, Junji Nishii, Toshiharu Yamashita, Hiroshi Kawazoe, and Takahisa Omata. "Effect of alkaline-earth species in phosphate glasses on the mobility of proton carriers." Journal of Materials Chemistry A 5, no. 24 (2017): 12385–92. http://dx.doi.org/10.1039/c7ta01475a.

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Karczewski, J., T. Miruszewski, B. Bochentyn, and B. Kusz. "Determination of ionic conductivity in the Bi-Si-O and Pb-Si-O glasses." Materials Science-Poland 35, no. 4 (March 20, 2018): 681–86. http://dx.doi.org/10.1515/msp-2017-0102.

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Abstract Impedance spectroscopy measurements in various gas atmospheres were carried out in order to explain the doubts about the type of carriers and the mechanism of electrical conductivity in Bi-Si-O and Pb-Si-O glasses. In bismuth silicate glass, a typical ionic conductivity with oxygen ions as charge carriers was observed. The level of electrical conductivity of the glass at 400 °C was 5 × 10-8 S·cm-1, with the activation energy of 1.3 eV and was independent of measuring atmosphere. In the case of lead silicate glasses, the conductivity changed with measuring atmosphere. Two types of charge carriers: oxygen ions and proton ions were postulated. Proton conductivity measured in wet argon at temperature 400 °C was estimated at the level of 4 × 10-8 S·cm-1 while the oxygen ions conductivity in such conditions was 78 × 10-8 S·cm-1. We suggest that both types of charge carriers are transported along the same conduction paths using oxygen defects in the glass structure.
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Хасаншин, Р. Х., and Л. С. Новиков. "Влияние протонного облучения на свойства стекла с покрытием ITO." Журнал технической физики 127, no. 11 (2019): 821. http://dx.doi.org/10.21883/os.2019.11.48521.49-19.

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Changes in the surface morphology and optical properties of K208 glass samples with an ITO film as a result of exposure to 20-keV protons at a dose of 0.2–1.0 mC/cm2 and a proton current density of 9 nA/cm2 were studied. It has been experimentally shown that the presence of an ITO film affects the nature of the change in morphology and is the main cause of the degradation of the optical properties of samples during proton irradiation.
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Stepanov, Vladimir A., Pavel V. Demenkov, and Olga V. Nikulina. "Radiation hardening and optical properties of materials based on SiO2." Nuclear Energy and Technology 7, no. 2 (June 24, 2021): 145–50. http://dx.doi.org/10.3897/nucet.7.69926.

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Preliminary studies have shown that the optical absorption spectra of radiation-colored glasses correspond to the spectral behavior of the scattering losses of an optically inhomogeneous medium. The reasons for the same optical changes in glasses of different compositions are the radiation-induced electric charge separation in the structurally nano-inhomogeneous glass volume, polarization and formation of nanometer optical inhomogeneities. The authors of this work prove that the radiation changes in the mechanical and optical properties of silicate glasses are of the same nature. The performed estimates indicate that the electric charge separation in the glasses occurs up to absorbed doses of about 1 MGy. The local electric charge separation due to the appearance of Coulomb forces leads to radiation hardening of the glasses. The estimated Coulomb hardening of the quartz glasses was ~ 107 Pa. The theoretical results were experimentally confirmed by measuring the mechanical properties of the glasses under high intensity proton irradiation as well as by testing the mechanical strength of a composite material based on quartz glass. Under proton irradiation with a dose rate of 5×103 Gy/s (energy of 8 MeV) up to threshold doses of ~ (1 – 5) ×106 Gy in the KU-1 quartz glasses, the decrement of acoustic vibrations decreased due to Coulomb hardening. After gamma irradiation with 1.34×105 Gy, the tensile strength of the composite material based on quartz glass increased by up to 20 MPa. This value is in the range of estimates of Coulomb hardening of quartz glasses. It is also shown that ionizing radiation does not affect the elastic modulus of materials based on SiO2.
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Burkhanov, G. S., S. A. Lachenkov, M. A. Kononov, A. U. Bashlakov, V. M. Kirillova, and V. V. Sdobyrev. "Changes in the electrical conductivity of glass, quartz, Au, C, and MoS2 films under influence of continuous proton injection." Perspektivnye Materialy 10 (2021): 37–46. http://dx.doi.org/10.30791/1028-978x-2021-10-37-46.

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Changes in the electrical conductivity of a wide range of materials with different crystal-chemical types and electrophysical properties (quartz, glass, molybdenum disulfide, graphite, gold) under continuous proton injection are studied. Film samples of layered MoS2 and graphite compounds were obtained on rough surfaces of glass or quartz by mechanical rubbing of powder. Gold films are formed on glass substrates by magnetron sputtering of a gold target. To create a continuous stream of protons injected into the test sample, a stationary ion source with a cold cathode and a magnetic field forming an ion beam of relatively low intensity was used. The current in the ion beam is up to 1.2 mA, the pressure of hydrogen in the chamber is ~10 – 2 Pa, the energy of hydrogen ions is from 1 to 4 keV. The experimental results indicate that under conditions of continuous proton injection, the electrical conductivity of thin films with a layered structure (MoS2 and graphite) increases sharply (by 4 – 5 orders of magnitude). This effect increases when the temperature decreases from ~ 293 to ~ 77 K, as well as when the number of charges supplied to the sample increases. In the case of continuous injection of protons into massive dielectrics (glass, quartz) and thin films of gold, no noticeable change in electrical conductivity was detected.
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Dissertations / Theses on the topic "Proton Glases"

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Komarov, F., A. Kamyshan, and P. Grishin. "Micro- and Nanocapillary Structures Based on Dielectric Materials to Focus the Ion Beams." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35219.

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The 255 keV and 150 keV proton beams transmission through tapered glass capillaries with 10 μm and 5 μm outlet diameters, respectively, were studied. The dependence of the output current on input current and the dependence of coefficient of proton beam transmission through capillary on the tilt angle of the capillary with respect to the beam axis were investigated. The focusing and guiding effects for transmitted proton beams were observed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35219
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Charpy, Alexandre. "Etude de la production de muons issus des saveurs lourdes prédite par le modèle de Color Glass Condensate dans les collisions proton-proton et proton-plomb dans l'acceptance du spectromètre à muons de l'expérience ALICE du LHC." Phd thesis, Université Paris Sud - Paris XI, 2007. http://tel.archives-ouvertes.fr/tel-00188303.

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Du fait de son très grand potentiel de découverte, l'entrée en activité du Large Hadron Collider (LHC) au CERN est très attendue par toute la communauté de la physique des particules. En effet, les énergies disponibles ouvrent de nouvelles perspectives dans de nombreuses thématiques. En particulier, elles permettront de tester expérimentalement différents formalismes de la ChromoDynamique Quantique (QCD) élaborés depuis ces dernières années afin d'étudier les collisions hadroniques dans la limite des hautes énergies. La théorie du Color Glass Condensate (CGC) est l'un d'entre eux et prédit un régime de saturation, au sein des noyaux, de la densité
partonique dans le domaine des très petits x, domaine largement accessible au LHC. Le CGC présente un grand intérêt dans l'étude des collisions d'ions lourds ultra-relativistes plomb-plomb puisqu'elle permet d'en décrire les conditions initiales du système qui évoluera vers un état où les quarks et les gluons sont déconfinés : le Plasma de Quarks et de Gluons (PQG). ALICE est l'expérience du LHC dédiée à l'étude du PQG dont l'une des voies d'étude est la mesure de la production des quarkonia lourds à l'aide d'un spectromètre à muons. Couvrant un domaine de rapidité entre −4 < y < −2.5, ce dernier peut s'avérer particulièrement intéressant pour étudier le CGC.
La première partie de ce travail présente les tests de performances des chambres de trajectographie du spectromètre à muons équipées avec l'électronique d'acquisition finale CROCUS. Ils ont conduit à poser les bases du processus de calibration de l'électronique frontale. La seconde partie concerne des simulations effectuées sur
certains paramètres électroniques pouvant affecter les performances du spectromètre à muons. La dernière partie développe les prédictions du modèle du CGC pour la production de quarks lourds et la manifestation des effets de saturation via la mesure des muons issus de ces quarks.
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Osborn, Shawn James. "Morphological and Mechanical Properties of Dispersion-Cast and Extruded Nafion Membranes Subjected to Thermal and Chemical Treatments." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/37517.

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The focus of this research project was to investigate morphological and mechanical properties of both extruded and dispersion-cast Nafion® membranes. The project can be divided into three primary objectives; obtaining a fundamental understanding of the glass transition temperature of Nafion®, determining the effect of thermal annealing treatments on the morphology and mechanical properties of dispersion-cast Nafion®, and examination of dispersion-cast Nafion® subjected to an ex-situ, Fentonâ s chemical degradation test. Nafion®, a perfluorosulfonate ionomer, is considered a commercially successful semi-crystalline ionomer with primary applications in chlor-alkali cells and proton exchange membrane fuel cells. With the aid of dynamic mechanical analysis (DMA) and dielectric spectroscopy (DS), we were able to provide definitive evidence for a genuine glass transition in Nafion®. DMA of Nafion® samples that were partially neutralized with tetrabutylammonium counterions showed a strong compositional dependence suggesting that the β-relaxations of H+-form Nafion® and the neutralized ionomers have the same molecular origin with respect to backbone segmental motions. Building upon our previous studies of the molecular and morphological origins of the dynamic mechanical relaxations of Nafion® neutralized with a series of organic ions, the glass transition temperature of H+-form Nafion® is now confirmed to be the weak β-relaxation centered at -20 °C. Dielectric spectra also showed this transition from the perspective of dipole relaxation. The signature of cooperative long range segmental motions in dielectric spectra was seen here, as with other polymers, mainly through the excellent agreement of the β-relaxation time-temperature dependence with the Vogel-Fulcher-Tammann equation. We have also discovered that new dispersion-cast H+ form Nafion® membranes are susceptible to disintegration/dissolution when subjected to boiling methanol. In this work, we have achieved significant decreases in the percent solubility of H+-form Nafion® by either thermally annealing above 175 °C or solution-processing at 180 °C using a high boiling point solvent. Small Angle X ray Scattering (SAXS) displayed a change in the morphology of H+ form membranes with increasing annealing temperature by a shift in the crystalline scattering peak (q â 0.05 à 1) to lower q values. Counterion exchange of Nafion® from H+ to Na+ form had no influence on the membraneâ s susceptibility to disintegration in boiling methanol. In order to achieve mechanical stability in boiling methanol, Na+ form membranes had to be annealed at 275 °C for at least fifteen minutes. The SAXS data of annealed Na+ form membranes showed a dramatic decrease in crystalline order with annealing temperature, ultimately leading to the disappearance of the crystalline scattering peak after fifteen minutes at 275 °C. The onset of methanol stability with the melting of Nafion® crystallites suggests that chain entanglement is an important parameter in obtaining solvent stability. With respect to chemical stability, we performed studies aimed at examining the effects of Fentonâ s Reagent on the resistance to radical attack of new generation, dispersion-cast Nafion®. Changes in the 19F solid-state NMR spectra of dispersion-cast Nafion® before and after chemical degradation via Fentonâ s Reagent predicts a rather random attack by â ¢OH and â ¢OOH radicals. Several membranes were also thermally annealed between 100-250 °C in an attempt to correlate crystallinity with chemical degradation kinetics of Nafion® via Fentonâ s Reagent. The results indicate that the effect of counterion exchange into the Na+ form was minimal, but the degree of thermal degradation had a tremendous effect on the fluoride release rate and chemical degradation kinetics. By exchanging the membranes into the Na+ form, thermal degradation was avoided, allowing us to study the role of crystallinity as a function of fluoride release. Ultimately, Nafion® crystallinity was deemed an important factor in deterring peroxide radical attack. As the percent crystallinity decreased with annealing temperature, the fluoride concentration in the resulting Fentonâ s media increased accordingly, indicating that the amorphous regions of the polymer are more susceptible to chemical degradation via peroxide radical attack.
Ph. D.
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Bordas, Mariano. "Possibilites offertes par l'utilisation simultanee des methodes pixe (particle induces x-ray emission) et pige (particle induced gamma-ray emission) en analyse elementaire." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13009.

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Lyons, Traci Renae. "Analysis of potential substrates for the pro-survival kinase AKT /." Connect to full text via ProQuest. Limited to UCD Anschutz Medical Campus, 2006.

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Thesis (Ph.D. in Molecular Biology) -- University of Colorado at Denver and Health Sciences Center, 2006.
Typescript. Includes bibliographical references (leaves 194-209). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;
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Cassone, Giuseppe. "Ab initio molecular dynamics simulations of H-bonded systems under an electric field." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066061/document.

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Malgré le mécanisme de base du transport protonique (PT) dans l'eau ait été proposé en 1806, à ce jour il n'existe pas de théorie complète qui décrive la protolyse. Ce phénomène est à la base du fonctionnement des batteries à hydrogène et de nombreux processus biologiques. Grâce à la technique de dynamique moléculaire Car-Parrinello (CPMD) et à l'aide de l'application d'un champ electrique (EF), une partie de cette thèse a été consacrée à l'étude du PT dans deux phase de la glace: la phase Ih et sa contrepartie ferroélectrique, la glace XI. Certains mécanismes ont été révélés: le rôle joué par les oxygènes lorsque se produit le PT et la contribution du (dés)ordre afin d'assister ce processus [1,2]. Le phénomène du PT est aussi à la base de nombreaux convertisseurs d'énergie constitués par le méthanol tels que le Direct Methanol Fuel Cells et les membranes Nafion. Afin de révéler la nature intime du PT dans le méthanol liquide, une série de simulations CPMD ont été menées sous l'effet d'un EF extérieur. De cette façon il a été possible de comparer le rôle joué par les liasons hydrogène afin d'assister le PT [3]. De plus, quand les intensités du champ sont plus élevées que celles qui donnent lieu au PT, certaines réactions chimiques ont été observées dans le même échantillon "numérique" du méthanol. En exploitant des paramètres typique de la "Théorie de la fonctionnelle de la densité conceptuelle", il a été possible de clarifier les conditions qui donnent lieu à ces réactions chimiques. Enfin, afin de quantifier la contribution du EF à la formation de méthane et de formaldéhyde dans le système, des simulations de métadynamique en conjonction à ceux ab initio ont été menées
Although the basic mechanism of the proton transfer (PT) phenomenon in water has been envisaged in 1806, nowadays does not exist a detailed theoretical framework that envelop the protolysis process. This phenomenon is at the base of the operation of hydrogen batteries, as well as of many biological processes. Via the Car-Parrinello Molecular Dynamics (CPMD) technique and by means of the application of an electric field (EF), part of this thesis has been devoted to the detailed study of PT in two ice phases: ice Ih and its ferroelectric counterpart, ice XI. Several previously unknown mechanisms have been shown. As an example, the role played by the oxygens when a PT occurs and the contribution due to (dis)order in assisting this process [1,2]. The PT phenomenon is also at the base of the functioning of some methanol-based energy converters such as Nafion membranes. To the aim of disclosing the intimate nature of PT in liquid methanol, a series of CPMD simulations have been carried out by applying an external EF; the role played by the H-bond network have been also compared with the similar PT mechanism in water [3]. At field strengths higher than those leading to PT, several chemical reactions have been observed in this sample. By exploiting the conceptual Density Functional Theory framework, it has been possible to clarify the circumstances under which a given chemical reaction occurs. Moreover, in order to disclose the role played by the EF in assisting chemical reactions, the mechanism leading to the formation of formaldehyde and methane in the sample has been studied with metadynamics approaches in conjuction with the ab initio ones
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Fonsetti, Matteo. "Modeling the cosmic-ray proton flux on low Earth orbit space telescopes: study of the accuracy with respect to in-flight measurements." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21643/.

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L'avvento dell'era spaziale ha consentito alla civiltà umana di fare notevoli passi avanti nello studio dei fenomeni celesti. I grandi telescopi di terra sono oggi affiancati da sofisticati telescopi spaziali in grado di operare oltre l'atmosfera terrestre in un ambiente estremo e fortemente proibitivo costantemente spazzato dagli intensi venti provenienti dal Sole e pervaso da flussi di particelle, i raggi cosmici, che si estendono per oltre 20 ordini di grandezza in energia. Quando i raggi cosmici interagiscono con il campo magnetico terrestre, con l'atmosfera o con i venti solari, danno luogo a complessi fenomeni che, da un lato, rappresentano un banco di prova prezioso per l'astrofisica delle particelle, dall'altro costituiscono una fonte di disturbo per le missioni di osservazione X e gamma poiché interagendo con la strumentazione di bordo incrementano il cosiddetto rumore di fondo strumentale. Appare allora evidente quanto una conoscenza il più possibile dettagliata di come stimare (e prevedere) tale rumore di fondo sia sempre più necessaria per la buona riuscita di una missione spaziale. In questo lavoro di tesi mi sono focalizzato sullo studio del modello che rappresenta l'attuale stato dell'arte nella modellizzazione del flusso di protoni di raggi cosmici in orbita bassa; dopo una presentazione preliminare di tale modello, l'ho messo all'opera confrontandone le previsioni con i dati ottenuti da alcuni esperimenti notevoli con l'obiettivo di valutare la precisione del modello rispetto alle misure. Quanto ottenuto è stato infine rielaborato allo scopo di effettuare una stima del flusso di protoni primari a cui sarà sottoposta una missione operante in orbita bassa nell’immediato futuro, la missione XRISM, il cui lancio è previsto per gennaio 2022, considerando come finestra temporale il periodo nominale di lancio e come latitudine geomagnetica la regione equatoriale.
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PEREIRA, Kleber Fernando. "Procyon cancrivorus (mão-pelada): aspectos morfológicos das glândulas salivares e distribuição do nervo isquiático." Universidade Federal de Goiás, 2012. http://repositorio.bc.ufg.br/tede/handle/tde/1146.

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Made available in DSpace on 2014-07-29T15:13:46Z (GMT). No. of bitstreams: 1 Dissertacao Kleber Fernando Pereira.pdf: 1118848 bytes, checksum: 4671bfd9ffd403997392e07dda224e2d (MD5) Previous issue date: 2012-03-02
The raccoon (Procyon cancrivorus) is a wild carnivore, reaching one meter in length including the tail, and weigh up to 10 kg. Known as raccoon or mouse naked hand washer has the peculiarity to dive in the water everything she eats. It has nocturnal and crepuscular, terrestrial and arboreal climber, a resident of shrub areas, preferably near water courses, is a good swimmer with great ability to dig, climb and is living alone. This thesis has generated the production of two articles. In the first article, entitled "Origin and anatomical distribution of the ischiatic nerve of raccoon", it was proposed to study the anatomy of the ischiatic nerve of raccoon in order to build morphological basis of this nerve with the aim of comparative neurology, and thus provide necessary support especially for the practices used in clinical medicine and surgery. The ischiatic nerve of the raccoon comes from the ventral ramus of the sixth and seventh nerves lumbar and first sacral nerve, resembling the origin of the guinea pig. Leaves the pelvic cavity through the greater ischiatic foramen, presenting themselves surrounded by the superficial gluteal muscles, biceps femoris and caudal crural abductor, this path similar to the dog and is distributed to the gluteus biceps, gluteus medius, gluteus deep, as well as observed in goats Saanen, and quadratus femoris muscles twin, resembling in dog, cat and pig, biceps femoris, semitendinosus, semimembranosus, observed in all specimens analyzed and adductor magnus, only observed raccoon. In all specimens are compared, the ischiatic nerve ends by bifurcating into the tibial and common peroneal nerve. In the second article, entitled "Morphological Aspects of the salivary glands of crab-eating raccoon (Procyon cancrivorus)" were described morphological aspects of salivary glands and their ducts located in Procyon cancrivorus and compare with literature data on the morphology of domestic and wild animals such as dogs, cats, skunks and raccoons. The salivary glands of the raccoon are formed by the parotid, mandibular, sublingual and zygomatic. The parotid gland shows irregular triangular shape and mandibular rounded contour is observed surrounded by a fibrous capsule. The sublingual is divided into two parts: a caudal part which lies in the region occiptomandibular the digastric muscle and the rostral part lies between the mucous membrane of the mouth and mylohyoid muscle with its respective duct. The zygomatic gland is small and rounded, situated in the rostral part of the pterygopalatine fossa. The anatomical knowledge of the origin and distribution of the ischiatic nerve and the morphology of the salivary glands when compared with bare hand domestic and wild animals, provides contributions to medicine and surgery in wild animals and for future studies on the general biology of the species.
O mão-pelada (Procyon cancrivorus) é um carnívoro silvestre, podendo chegar a 1 metro de comprimento incluindo a cauda, e pesar até 10 kg. Conhecido como guaxinim, mão-pelada ou rato lavador têm a peculiaridade de mergulhar na água tudo o que come. Possui hábito noturno e crepuscular, escalador arborícola e terrícola, habitante de áreas arbustivas, preferencialmente próximas a cursos de água, é um bom nadador com ótimas habilidades para cavar, escalar e tem vida solitária. A presente tese gerou a produção de dois artigos. No primeiro artigo, Origem e distribuição anatômica do nervo isquiático de mão-pelada , propôs-se estudar a anatomia do nervo isquiático de mão-pelada, a fim de assentar bases morfológicas deste nervo visando à neurologia comparativa, e assim fornecer subsídios necessários especialmente para as práticas utilizadas nas clínicas médica e cirúrgica. O nervo isquiático do mão-pelada origina-se do ramo ventral do sexto e sétimo nervos lombares e primeiro nervo sacral, assemelhando-se com a origem em preá. Deixa a cavidade pélvica através do forame isquiático maior, apresentando-se envolvido pelos músculos glúteo superficial, bíceps femoral e abdutor caudal crural, trajeto este semelhante com o cão e distribui-se para os músculos glúteo bíceps, glúteo médio, glúteo profundo, assim como observado em caprinos da raça Saanen, músculos quadrado femoral e gêmeo, assemelhando-se em cão, gato e suíno, músculos bíceps femoral, semitendíneo, semimembranáceo, observado em todos os espécimes analisadas e adutor magno, verificado apenas em mão-pelada. Em todos os espécimes comparados, o nervo isquiático termina bifurcando-se em nervo tibial e fibular comum. No segundo artigo, Morphological aspects of the salivary glands of crab-eating racoon (Procyon cancrivorus) foram descritos os aspectos morfológicos das glândulas salivares e a localização dos seus ductos em Procyon cancrivorus, e comparar com dados literários sobre a morfologia de animais domésticos e silvestres, como cão, gato, gambás e quatis. As glândulas salivares do mão-pelada são formadas pelas glândulas parótida, mandibular, sublingual e zigomática. A glândula parótida apresenta formato irregularmente triangular e a mandibular observa-se contorno arredondado circundada por uma cápsula fibrosa. A sublingual se divide em duas partes: uma parte caudal que se situa na região occiptomandibular do músculo digástrico e a parte rostral situa-se entre a túnica mucosa da boca e o músculo milo-hióideo com seu respectivo ducto. A glândula zigomática é pequena e arredondada, situada na parte rostral da fossa pterigopalatina. O conhecimento anatômico da origem e distribuição do nervo isquiático e da morfologia das glândulas salivares do mão-pelada, quando comparado com animais domésticos e silvestres, oferece contribuições para a clínica médica e cirúrgica em animais silvestres e para futuros estudos sobre a biologia geral da espécie.
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Fanara, Sara [Verfasser]. "Proton conduction and water diffusion in silicate glasses and melts / von Sara Fanara." 2009. http://d-nb.info/998088528/34.

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HSU, CHEN-HAO, and 徐振皓. "Studies on Low Temperature Decal Transfer Method in high glass transition for Polymer Proton Exchange Membrane Electrode Assembly." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/35176542562153433580.

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Books on the topic "Proton Glases"

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Menaa, Bouzid. Bioencapsulation in silica-based nanoporous sol-gel glasses. New York: Nova Science Publishers, 2010.

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Bouzid, Menaa, ed. Bioencapsulation in silica-based nanoporous sol-gel glasses. Hauppauge, N.Y: Nova Science Publishers, 2009.

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Bodovitz, Steven. Market opportunities and challenges for antibody arrays and beads: A market research study. Westborough, MA: D&MD Publications, 2005.

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W, Janke, ed. Rugged free energy landscapes: Common computational approaches in spin glasses, structural glasses, and biological macromolecules. Berlin: Springer, 2008.

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P, Bilezikian John, Marcus Robert 1940-, and Levine Michael A. 1950-, eds. The parathyroids: Basic and clinical concepts. 2nd ed. San Diego, CA: Academic Press, 2001.

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Robert, Marcus, and Michael A. Levine. The parathyroids: Basic and clinical concepts. San Diego, Calif: Academic, 2015.

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P, Halloran Bernard, and Nissenson Robert A, eds. Parathyroid hormone-related protein: Normal physiology and its role in cancer. Boca Raton: CRC Press, 1992.

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P, Bilezikian John, Marcus Robert 1940-, and Levine Michael A. 1950-, eds. The Parathyroids: Basic and clinical concepts. New York: Raven Press, 1994.

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Janke, Wolfhard. Rugged Free Energy Landscapes: Common Computational Approaches to Spin Glasses, Structural Glasses and Biological Macromolecules. Springer London, Limited, 2007.

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Rugged Free Energy Landscapes Common Computational Approaches To Spin Glasses. Springer, 2010.

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Book chapters on the topic "Proton Glases"

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Matsumura, Midori, Yusuke Daiko, and Masayuki Nogami. "Hydrogen-Sensor Prepared Using Proton-Conducting Glass Films." In Solid State Phenomena, 627–30. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/3-908451-31-0.627.

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Daiko, Y., and Y. Iwamoto. "Proton Conduction in Sol-Gel-Derived Glasses and Thin Films." In Handbook of Sol-Gel Science and Technology, 1–13. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-19454-7_118-1.

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Daiko, Yusuke, and Yuji Iwamoto. "Proton Conduction in Sol-Gel-Derived Glasses and Thin Films." In Handbook of Sol-Gel Science and Technology, 2649–61. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-32101-1_118.

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Roehl, Holger, Philippe Lam, and Dominique Ditter. "Chemical Durability of Glass—Delamination." In Challenges in Protein Product Development, 291–304. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-90603-4_13.

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Thomas, Roger C. "Proton Channels in Snail Neurons Studied with Surface pH Glass Microelectrodes." In Novartis Foundation Symposia, 168–86. Chichester, UK: John Wiley & Sons, Ltd., 2007. http://dx.doi.org/10.1002/9780470513699.ch10.

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Akamatsu, T., Toshihiro Kasuga, and Masayuki Nogami. "Preparation of Fast Proton-Conducting Phosphate Glass-Derived Hydrogels and their Electrochemical Properties." In THERMEC 2006 Supplement, 327–32. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-429-4.327.

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Lottspeich, Friedrich, Christoph Eckerskorn, and Werner Mewes. "Evaluation of Siliconized Glass Fiber Membrane for Protein Chemical Analysis." In Methods in Protein Sequence Analysis, 240–47. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-73834-0_31.

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Vandekerckhove, Joel, Guy Bauw, Magda Puype, Jozef van Damme, and Marc van Montagu. "Protein Blotting from Polyacrylamide Gels on Glass Microfiber Sheets: Acid Hydrolysis and Gas-Phase Sequencing of Glass-Fiber Immobilized Proteins." In Advanced Methods in Protein Microsequence Analysis, 179–93. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-71534-1_15.

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Michelangeli, Fabián, José Francisco Pérez, and Marie Christine Ruiz. "Kinetics of Activation of H+ Secretion by Secretagogues in Relation to Changes in [Ca2+]i in Isolated Gastric Glands." In Mechanisms and Consequences of Proton Transport, 265–73. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0971-4_30.

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Frank, Rainer, and Keith Ashman. "Application of Covalently Modified Glass Fibre Supports to Microsequence Analysis." In Methods in Protein Sequence Analysis · 1986, 403–7. Totowa, NJ: Humana Press, 1987. http://dx.doi.org/10.1007/978-1-59259-480-1_31.

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Conference papers on the topic "Proton Glases"

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Wilkinson, C. J., L. Ruane, W. Miller, A. Gunsch, A. Zieser, I. J. Tillman, Z. Thune, D. Wang, and U. Akgun. "CARNA - A Compact Glass Proton Imager." In 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC). IEEE, 2017. http://dx.doi.org/10.1109/nssmic.2017.8533076.

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Watanabe, Yuichi, Naoyuki Takeshita, Toshio Tsuchiya, Hideo Hosono, and Hiroshi Kawazoe. "A large second-order nonlinearity in poled phosphate glass containing mobile protons." In Photosensitivity and Quadratic Nonlinearity in Glass Waveguides. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/pqn.1995.sub.1.

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Recently, Myers et al. reported that a large second-order nonlinearity [χ(2)~1pm/V] was induced in the near surface region (~4μm) of commercial fused silica by electric-field (5× 104V/cm) poling process at 300°C1. Since the large nonlinearity that they observed were remarkable in the glass containing a small amount of alkali (Na+) impurity, they proposed a model, based on the formation of space-charge layer due to drift of Na+ during poling process, that could explain the nonlinearity. Here we report second-order nonlinearity in poled phosphate glass. The observed nonlinearity is explained tentatively by considering the drift of protons in the poled glasses.
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Silverglate, Peter R., Edward F. Zalewski, and Peter Petrone III. "Proton-induced radiation effects on optical glasses." In San Diego '92, edited by James B. Breckinridge and Alexander J. Marker III. SPIE, 1993. http://dx.doi.org/10.1117/12.138944.

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Henry, Leanne J., Thomas G. Alley, Dennis S. Rand, and John J. Kester. "Second Harmonic Generation in Low-Water Fused Silica by Proton Implantation." In Photosensitivity and Quadratic Nonlinearity in Glass Waveguides. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/pqn.1995.sud.3.

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Second harmonic generation (SHG) in poled fused silica, which was first reported by Myers, Mukherjee and Brueck(1) in 1991, has increased in importance because of a multitude of potential device applications. Such applications include electro-optic switching, frequency doubling crystals, parametric amplification, parametric oscillation, and linear electro-optic modulation/frequency conversion which can be monolithically integrated into optical fibers and planar integrated circuit geometries. Because of these potential applications, much work has been done to understand the phenomenon of SHG in poled fused silica.
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Wilkinson, C. J., K. Goranson, A. Turney, Q. Xie, I. J. Tillman, Z. L. Thune, A. Dong, et al. "High density scintillating glass proton imaging detector." In SPIE Medical Imaging, edited by Thomas G. Flohr, Joseph Y. Lo, and Taly Gilat Schmidt. SPIE, 2017. http://dx.doi.org/10.1117/12.2252777.

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Karlsson, Niklas, Johann Cohen-Tanugi, Tuneyoshi Kamae, and Hiroyasu Tajima. "Simulation of Gamma Rays from Proton Interaction in Local Galaxies." In THE FIRST GLAST SYMPOSIUM. AIP, 2007. http://dx.doi.org/10.1063/1.2757414.

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Schmidt, V. Hugo. "Dynamical model for phase coexistence in proton glass." In The 5th Williamsburg workshop on first-principles calculations for ferroelectrics. AIP, 1998. http://dx.doi.org/10.1063/1.56272.

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BLAIZOT, J. P., F. GELIS, and R. VENUGOPALAN. "PROTON-NUCLEUS COLLISIONS IN THE COLOR GLASS CONDENSATE FRAMEWORK." In Proceedings of the SEWM2004 Meeting. WORLD SCIENTIFIC, 2005. http://dx.doi.org/10.1142/9789812702159_0015.

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Darafsheh, Arash, Reza Taleei, Alireza Kassaee, and Jarod C. Finlay. "Proton therapy dosimetry by using silica glass optical fiber microprobes." In SPIE BiOS, edited by Israel Gannot. SPIE, 2017. http://dx.doi.org/10.1117/12.2252583.

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Daiko, Y., S. Mizutani, K. Segawa, S. Honda, and Y. Iwamoto. "Development of H+emission gun using a proton conducting glass fiber." In 2016 IEEE 16th International Conference on Nanotechnology (IEEE-NANO). IEEE, 2016. http://dx.doi.org/10.1109/nano.2016.7751521.

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Reports on the topic "Proton Glases"

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Martin, Steve W. Development of New Fast Proton Conducting Chalcogenide Glassy Electrolytes. Fort Belvoir, VA: Defense Technical Information Center, March 2005. http://dx.doi.org/10.21236/ada430645.

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Asenath-Smith, Emily, Emily Jeng, Emma Ambrogi, Garrett Hoch, and Jason Olivier. Investigations into the ice crystallization and freezing properties of the antifreeze protein ApAFP752. Engineer Research and Development Center (U.S.), September 2022. http://dx.doi.org/10.21079/11681/45620.

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Antifreeze proteins (AFPs) allow biological organisms, including insects, fish, and plants, to survive in freezing temperatures. While in solution, AFPs impart cryoprotection by creating a thermal hysteresis (TH), imparting ice recrystallization inhibition (IRI), and providing dynamic ice shaping (DIS). To leverage these ice-modulating effects of AFPs in other scenarios, a range of icing assays were performed with AFPs to investigate how AFPs interact with ice formation when tethered to a surface. In this work, we studied ApAFP752, an AFP from the beetle Anatolica polita, and first investigated whether removing the fusion protein attached during protein expression would result in a difference in freezing behavior. We performed optical microscopy to examine ice-crystal shape, micro-structure, and the recrystallization behavior of frozen droplets of AFP solutions. We developed a surface chemistry approach to tether these proteins to glass surfaces and conducted droplet-freezing experiments to probe the interactions of these proteins with ice formed on those surfaces. In solution, ApAFP752 did not show any DIS or TH, but it did show IRI capabilities. In surface studies, the freezing of AFP droplets on clean glass surfaces showed no dependence on concentration, and the results from freezing water droplets on AFP-decorated surfaces were inconclusive.
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Choudhary, Ruplal, Victor Rodov, Punit Kohli, John D. Haddock, and Samir Droby. Antimicrobial and antioxidant functionalized nanoparticles for enhancing food safety and quality: proof of concept. United States Department of Agriculture, September 2012. http://dx.doi.org/10.32747/2012.7597912.bard.

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General concept. The reported 1-year study tested the feasibility ofpreparing antimicrobial and antioxidant nanoparticlesfunctionalized with natural phenolic compounds, as a first step to reach the ultimate goal - improving safely and quality of foods by developing novel antimicrobial and antioxidant food-contacting materials. The secondary objectives of the study were (a) selecting the most promising phenoliccompounds, (b) building nanoparticles with the selected phenolicgrafted on their Surface, and (c) testing antimicrobial and antioxidant properties of these particles. The study was expected to provide a " go/no go" decision as concerning the prospects of phenolic- bound nanoparticles as antimicrobial and antioxidant agents. Results. In course of the feasibility study, curucminwas chosen as the most promising phenoliccompound due to its high antibacterial activity exceeding other tested compounds by at leas one order of magnitude. Lipsome-typephospholipid/polydiacetylene(PDA) nanoparticlesfunctionalizedwith curcuminwere successfully built. The pitfall of limited curcumin amount that could be covalently bound to theparticle surface was circumvented by inclusion of curcunun in the liposome body. It was suggested onthe basis of fluorescence spectroscopy that curcuminwas bound by hydrophobic forces in the bi1ayer periphery of the Liposomesand therefore mightexert a contact effect on microorganisms. The curcumin­ functionalizednanoparticles(CFN) were shown to have a strong bactericidal activity towards both Gram-negative (E. coli) and Gram-positive (B. ce,·e11s) bacteria, but only limited effect against yeast. Furthermore, beyond the originallyplanned objectives, preliminary trials showed that CFN could be bound to silanized glass surface rendering aנבtiנnicrobial activity to the glass. Tnaddition, the particles showed antioxidantcapacity. Tberefore, it ,vas co11cluded tlוattlוeaims of tlוefeasibility study bad been successfully reached an
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Hansen, E. Pilot Scale Testing - Transport of HLW Glass Former Chemicals Proof of Principle Test Results. Office of Scientific and Technical Information (OSTI), August 2003. http://dx.doi.org/10.2172/818266.

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Rafaeli, Ada, Russell Jurenka, and Daniel Segal. Isolation, Purification and Sequence Determination of Pheromonotropic-Receptors. United States Department of Agriculture, July 2003. http://dx.doi.org/10.32747/2003.7695850.bard.

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Moths constitute a major group of pest insects in agriculture. Pheromone blends are utilised by a variety of moth species to attract conspecific mates, which is under circadian control by the neurohormone, PBAN (pheromone-biosynthesis-activating neuropeptide). Our working hypothesis was that, since the emission of sex-pheromone is necessary to attract a mate, then failure to produce and emit pheromone is a potential strategy for manipulating adult moth behavior. The project aimed at identifying, characterising and determining the sequence of specific receptors responsible for the interaction with pheromonotropic neuropeptide/s using two related moth species: Helicoverpa armigera and H. lea as model insects. We established specific binding to a membrane protein estimated at 50 kDa in mature adult females using a photoaffinity-biotin probe for PBAN. We showed that JH is required for the up-regulation of this putative receptor protein. In vitro studies established that the binding initiates a cascade of second messengers including channel opening for calcium ions and intracellular cAMP production. Pharmacological studies (using sodium fluoride) established that the receptor is coupled to a G-protein, that is, the pheromone-biosynthesis-activating neuropeptide receptor (PBAN-R) belongs to the family of G protein-coupled receptor (GPCR)'s. We showed that PBAN-like peptides are present in Drosophila melanogaster based on bioassay and immunocytochemical data. Using the annotated genome of D. melanogaster to search for a GPCR, we found that some were similar to neuromedin U- receptors of vertebrates, which contain a similar C-terminal ending as PBAN. We established that neuromedin U does indeed induce pheromone biosynthesis and cAMP production. Using a PCR based cloning strategy and mRNA isolated from pheromone glands of H. zea, we successfully identified a gene encoding a GPCR from pheromone glands. The full-length PBAN-R was subsequently cloned and expressed in Sf9 insect cells and was shown to mobilize calcium in response to PBAN in a dose-dependent manner. The successful progress in the identification of a gene, encoding a GPCR for the neurohormone, PBAN, provides a basis for the design of a novel battery of compounds that will specifically antagonize pheromone production. Furthermore, since PBAN belongs to a family of insect neuropeptides with more than one function in different life stages, this rationale may be extended to other physiological key-regulatory processes in different insects.
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Rafaeli, Ada, and Russell Jurenka. Molecular Characterization of PBAN G-protein Coupled Receptors in Moth Pest Species: Design of Antagonists. United States Department of Agriculture, December 2012. http://dx.doi.org/10.32747/2012.7593390.bard.

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The proposed research was directed at determining the activation/binding domains and gene regulation of the PBAN-R’s thereby providing information for the design and screening of potential PBAN-R-blockers and to indicate possible ways of preventing the process from proceeding to its completion. Our specific aims included: (1) The identification of the PBAN-R binding domain by a combination of: (a) in silico modeling studies for identifying specific amino-acid side chains that are likely to be involved in binding PBAN with the receptor and; (b) bioassays to verify the modeling studies using mutant receptors, cell lines and pheromone glands (at tissue and organism levels) against selected, designed compounds to confirm if compounds are agonists or antagonists. (2) The elucidation ofthemolecular regulationmechanisms of PBAN-R by:(a) age-dependence of gene expression; (b) the effect of hormones and; (c) PBAN-R characterization in male hair-pencil complexes. Background to the topic Insects have several closely related G protein-coupled receptors (GPCRs) belonging to the pyrokinin/PBAN family, one with the ligand pheromone biosynthesis activating neuropeptide or pyrokinin-2 and another with diapause hormone or pyrokinin-1 as a ligand. We were unable to identify the diapause hormone receptor from Helicoverpa zea despite considerable effort. A third, related receptor is activated by a product of the capa gene, periviscerokinins. The pyrokinin/PBAN family of GPCRs and their ligands has been identified in various insects, such as Drosophila, several moth species, mosquitoes, Triboliumcastaneum, Apis mellifera, Nasoniavitripennis, and Acyrthosiphon pisum. Physiological functions of pyrokinin peptides include muscle contraction, whereas PBAN regulates pheromone production in moths plus other functions indicating the pleiotropic nature of these ligands. Based on the alignment of annotated genomic sequences, the primary and secondary structures of the pyrokinin/PBAN family of receptors have similarity with the corresponding structures of the capa or periviscerokinin receptors of insects and the neuromedin U receptors found in vertebrates. Major conclusions, solutions, achievements Evolutionary trace analysisof receptor extracellular domains exhibited several class-specific amino acid residues, which could indicate putative domains for activation of these receptors by ligand recognition and binding. Through site-directed point mutations, the 3rd extracellular domain of PBAN-R was shown to be critical for ligand selection. We identified three receptors that belong to the PBAN family of GPCRs and a partial sequence for the periviscerokinin receptor from the European corn borer, Ostrinianubilalis. Functional expression studies confirmed that only the C-variant of the PBAN-R is active. We identified a non-peptide agonist that will activate the PBAN-receptor from H. zea. We determined that there is transcriptional control of the PBAN-R in two moth species during the development of the pupa to adult, and we demonstrated that this transcriptional regulation is independent of juvenile hormone biosynthesis. This transcriptional control also occurs in male hair-pencil gland complexes of both moth species indicating a regulatory role for PBAN in males. Ultimate confirmation for PBAN's function in the male tissue was revealed through knockdown of the PBAN-R using RNAi-mediated gene-silencing. Implications, both scientific and agricultural The identification of a non-peptide agonist can be exploited in the future for the design of additional compounds that will activate the receptor and to elucidate the binding properties of this receptor. The increase in expression levels of the PBAN-R transcript was delineated to occur at a critical period of 5 hours post-eclosion and its regulation can now be studied. The mysterious role of PBAN in the males was elucidated by using a combination of physiological, biochemical and molecular genetics techniques.
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Rafaeli, Ada, Russell Jurenka, and Chris Sander. Molecular characterisation of PBAN-receptors: a basis for the development and screening of antagonists against Pheromone biosynthesis in moth pest species. United States Department of Agriculture, January 2008. http://dx.doi.org/10.32747/2008.7695862.bard.

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The original objectives of the approved proposal included: (a) The determination of species- and tissue-specificity of the PBAN-R; (b) the elucidation of the role of juvenile hormone in gene regulation of the PBAN-R; (c) the identificationof the ligand binding domains in the PBAN-R and (d) the development of efficient screening assays in order to screen potential antagonists that will block the PBAN-R. Background to the topic: Moths constitute one of the major groups of pest insects in agriculture and their reproductive behavior is dependent on chemical communication. Sex-pheromone blends are utilised by a variety of moth species to attract conspecific mates. In most of the moth species sex-pheromone biosynthesis is under circadian control by the neurohormone, PBAN (pheromone-biosynthesis-activating neuropeptide). In order to devise ideal strategies for mating disruption/prevention, we proposed to study the interactions between PBAN and its membrane-bound receptor in order to devise potential antagonists. Major conclusions: Within the framework of the planned objectives we have confirmed the similarities between the two Helicoverpa species: armigera and zea. Receptor sequences of the two Helicoverpa spp. are 98% identical with most changes taking place in the C-terminal. Our findings indicate that PBAN or PBAN-like receptors are also present in the neural tissues and may represent a neurotransmitter-like function for PBAN-like peptides. Surprisingly the gene encoding the PBAN-receptor was also present in the male homologous tissue, but it is absent at the protein level. The presence of the receptor (at the gene- and protein-levels), and the subsequent pheromonotropic activity are age-dependent and up-regulated by Juvenile Hormone in pharate females but down-regulated by Juvenile Hormone in adult females. Lower levels of pheromonotropic activity were observed when challenged with pyrokinin-like peptides than with HezPBAN as ligand. A model of the 3D structure of the receptor was created using the X-ray structure of rhodopsin as a template after sequence alignment of the HezPBAN-R with several other GPCRs and computer simulated docking with the model predicted putative binding sites. Using in silico mutagenesis the predicted docking model was validated with experimental data obtained from expressed chimera receptors in Sf9 cells created by exchanging between the three extracellular loops of the HezPBAN-R and the Drosophila Pyrokinin-R (CG9918). The chimera receptors also indicated that the 3ʳᵈ extracellular loop is important for recognition of PBAN or Diapause hormone ligands. Implications: The project has successfully completed all the objectives and we are now in a position to be able to design and screen potential antagonists for pheromone production. The successful docking simulation-experiments encourage the use of in silico experiments for initial (high-throughput) screening of potential antagonists. However, the differential responses between the expressed receptor (Sf9 cells) and the endogenous receptor (pheromone glands) emphasize the importance of assaying lead compounds using several alternative bioassays (at the cellular, tissue and organism levels). The surprising discovery of the presence of the gene encoding the PBAN-R in the male homologous tissue, but its absence at the protein level, launches opportunities for studying molecular regulation pathways and the evolution of these GPCRs. Overall this research will advance research towards the goal of finding antagonists for this important class of receptors that might encompass a variety of essential insect functions.
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8

Fridman, Eyal, and Eran Pichersky. Tomato Natural Insecticides: Elucidation of the Complex Pathway of Methylketone Biosynthesis. United States Department of Agriculture, December 2009. http://dx.doi.org/10.32747/2009.7696543.bard.

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Plant species synthesize a multitude of specialized compounds 10 help ward off pests. and these in turn may well serve as an alternative to synthetic pesticides to reduce environmental damage and health risks to humans. The general goal of this research was to perform a genetic and biochemical dissection of the natural-insecticides methylketone pathway that is specific to the glandular trichomes of the wild species of tomato, Solanumhabrochaites f. glabratum (accession PI126449). Previous study conducted by us have demonstrated that these compounds are synthesized de novo as a derivate pathway of the fatty acid biosynthesis, and that a key enzyme. designated MethylketoneSynthase 1 (MKS 1). catalyzes conversion of the intermediate B-ketoacyl- ACPs to the corresponding Cn-1 methylketones. The approach taken in this proposed project was to use an interspecific F2 population. derived from the cross between the cultivated lV182 and the wild species PIl26449. for three objectives: (i) Analyze the association between allelic status of candidate genes from the fatty acid biosynthesis pathway with the methylketone content in the leaves (ii) Perform bulk segregant analysis of genetic markers along the tomato genome for identifying genomic regions that harbor QTLs for 2TD content (iii) Apply differential gene expression analysis using the isolated glands of bulk segregant for identifying new genes that are involved in the pathway. The genetic mapping in the interspecific F2 population included app. 60 genetic markers, including the candidate genes from the FAS pathway and SSR markers spread evenly across the genome. This initial; screening identified 5 loci associated with MK content including the candidate genes MKS1, ACC and MaCoA:ACP trans. Interesting observation in this genetic analysis was the connection between shape and content of the glands, i.e. the globularity of the four cells, typical to the wild species. was associated with increased MK in the segregating population. In the next step of the research transcriptomic analysis of trichomes from high- and 10w-MK plants was conducted. This analysis identified a new gene, Methy1ketone synthase 2 (MKS2), whose protein product share sequence similarity to the thioesterase super family of hot-dog enzymes. Genetic analysis in the segregating population confirmed its association with MK content, as well as its overexpression in E. coli that led to formation of MK in the media. There are several conclusions drawn from this research project: (i) the genetic control of MK accumulation in the trichomes is composed of biochemical components in the FAS pathway and its vicinity (MKS 1 and MKS2). as well as genetic factors that mediate the morphology of these specialized cells. (ii) the biochemical pathway is now realized different from what was hypothesized before with MKS2 working upstream to I\1KS 1 and serves as the interface between primary (fatty acids) and secondary (MK) metabolism. We are currently testing the possible physical interactions between these two proteins in vitro after the genetic analysis showed clear epistatic interactions. (iii) the regulation of the pathway that lead to specialized metabolism in the wild species is largely mediated by transcription and one of the achievements of this project is that we were able to isolate and verify the specificity of the MKS1 promoter to the trichomes which allows manipulation of the pathways in these cells (currently in progress). The scientific implications of this research project is the advancement in our knowledge of hitherto unknown biochemical pathway in plants and new leads for studying a new family in plants (hot dog thioesterase). The agricultural and biotechnological implication are : (i) generation of new genetic markers that could assist in importing this pathway to cultivated tomato hence enhancing its natural resistance to insecticides, (ii) the discovery of MKS2 adds a new gene for genetic engineering of plants for making new fatty acid derived compounds. This could be assisted with the use of the isolated and verified MKS1 promoter. The results of this research were summarized to a manuscript that was published in Plant Physiology (cover paper). to a chapter in a proceeding book. and one patent was submitted in the US.
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