Relevant bibliographies by topics / Hydrophobic interaction

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Hydrophobic interaction'

Author: Grafiati
Published: 4 June 2021
Last updated: 10 March 2023

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Journal articles on the topic "Hydrophobic interaction"

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Roettger, Belinda F., and Michael R. Ladisch. "Hydrophobic interaction chromatography." Biotechnology Advances 7, no. 1 (1989): 15–29. http://dx.doi.org/10.1016/0734-9750(89)90901-4.

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Kårsnäs, Per, and Tua Lindblom. "Characterization of hydrophobic interaction and hydrophobic interaction chromatography media by multivariate analysis." Journal of Chromatography A 599, no. 1-2 (1992): 131–36. http://dx.doi.org/10.1016/0021-9673(92)85465-6.

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Ohno, Nobumichi, and Shintaro Sugai. "Isotope effects on hydrophobic interaction in hydrophobic polyelectrolytes." Macromolecules 18, no. 6 (1985): 1287–91. http://dx.doi.org/10.1021/ma00148a042.

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Yau, Tak-Yu, William Sander, Christian Eidson, and Albert J. Courey. "SUMO Interacting Motifs: Structure and Function." Cells 10, no. 11 (2021): 2825. http://dx.doi.org/10.3390/cells10112825.

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Small ubiquitin-related modifier (SUMO) is a member of the ubiquitin-related protein family. SUMO modulates protein function through covalent conjugation to lysine residues in a large number of proteins. Once covalently conjugated to a protein, SUMO often regulates that protein’s function by recruiting other cellular proteins. Recruitment frequently involves a non-covalent interaction between SUMO and a SUMO-interacting motif (SIM) in the interacting protein. SIMs generally consist of a four-residue-long hydrophobic stretch of amino acids with aliphatic non-polar side chains flanked on one side by negatively charged amino acid residues. The SIM assumes an extended β-strand-like conformation and binds to a conserved hydrophobic groove in SUMO. In addition to hydrophobic interactions between the SIM non-polar core and hydrophobic residues in the groove, the negatively charged residues in the SIM make favorable electrostatic contacts with positively charged residues in and around the groove. The SIM/SUMO interaction can be regulated by the phosphorylation of residues adjacent to the SIM hydrophobic core, which provide additional negative charges for favorable electrostatic interaction with SUMO. The SUMO interactome consists of hundreds or perhaps thousands of SIM-containing proteins, but we do not fully understand how each SUMOylated protein selects the set of SIM-containing proteins appropriate to its function. SIM/SUMO interactions have critical functions in a large number of essential cellular processes including the formation of membraneless organelles by liquid–liquid phase separation, epigenetic regulation of transcription through histone modification, DNA repair, and a variety of host–pathogen interactions.
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Gao, Dong, Fu-Chun Tan, Wen-Peng Wang, and Li-Li Wang. "Resolution enhancement in hydrophobic interaction chromatography via electrostatic interactions." Chinese Chemical Letters 24, no. 5 (2013): 419–21. http://dx.doi.org/10.1016/j.cclet.2013.03.004.

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Vu, Anh, Xianghong Qian, and S. Ranil Wickramasinghe. "Membrane-based hydrophobic interaction chromatography." Separation Science and Technology 52, no. 2 (2016): 287–98. http://dx.doi.org/10.1080/01496395.2016.1247865.

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Hahn, Rainer, Karin Deinhofer, Christine Machold, and Alois Jungbauer. "Hydrophobic interaction chromatography of proteins." Journal of Chromatography B 790, no. 1-2 (2003): 99–114. http://dx.doi.org/10.1016/s1570-0232(03)00080-1.

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Jungbauer, Alois, Christine Machold, and Rainer Hahn. "Hydrophobic interaction chromatography of proteins." Journal of Chromatography A 1079, no. 1-2 (2005): 221–28. http://dx.doi.org/10.1016/j.chroma.2005.04.002.

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Kolomeisky, A. B., and B. Widom. "Model of the hydrophobic interaction." Faraday Discussions 112 (1999): 81–89. http://dx.doi.org/10.1039/a809308c.

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Machold, Christine, Karin Deinhofer, Rainer Hahn, and Alois Jungbauer. "Hydrophobic interaction chromatography of proteins." Journal of Chromatography A 972, no. 1 (2002): 3–19. http://dx.doi.org/10.1016/s0021-9673(02)01077-4.

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Dissertations / Theses on the topic "Hydrophobic interaction"

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Yang, Fan 1980. "Solvent mediated interaction between hydrophobic spheres." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=84087.

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We develop a coarse grained methodology to study solvent mediated interactions between two or more hydrophobic spheres. The free energy of a configuration of two hydrophobic hard spheres is calculated as a function of their separation to understand the thermodynamic force between them mediated by water. The range of the hydrophobic interaction is found to be of the order of the equilibrium correlation length of water; beyond this range the hydrophobicity induced force is negligible. We also examine the free energy landscape corresponding to the two interacting hydrophobic spheres, and find a new intermediate state between the two states of separate and non-interacting spheres and a weakly bound cluster. The nature of this intermediate state changes depending on the size of the spherical particles, and even disappears beyond a minimum critical radius. Our results are relevant to the understanding of hydrophobic mediated interactions in coarse grained models of protein folding and protein protein interactions which, to date, have only accounted for hydrophobicity in an empirical way.
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To, Chi Shung Brian. "Protein retention and transport in hydrophobic interaction chromatography." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 2.12 Mb., 319 p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3205434.

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Xu, Zhenghe. "A study of hydrophobic interaction in fine particle coagulation." Diss., Virginia Tech, 1990. http://hdl.handle.net/10919/39945.

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Gungunes, H., R. Uzek, L. Uzun, S. Ozkara, S. Senel, and A. Denizli. "Magnetic Nanoparticles for Plasmid DNA Adsorption via Hydrophobic Interaction." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/34946.

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This study aims the preparation of magnetic poly(2-hydroxyethylmethacrylate-N-methacryloyl-Lphenylalanine), [poly(HEMA-MAPA)] nanoparticles for plasmid DNA separation on the basis of hydrophobic interactions. Magnetic nanoparticles will be produced emulsion polymerization of 2- hydroxyethylmethacrylate (HEMA) and N-methacryloyl-L-phenylalanine (MAPA) monomers. Nanosized particles including hydrophobic groups stemmed from polymerizable derivative of phenylalanine aminoacid were evaluated to offer surface area that is enough for the higher capacity DNA purification than commercial micronsized sorbents for DNA purification. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/34946
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Li, Yuanyuan. "Polymeric Monolithic Stationary Phases for Capillary Hydrophobic Interaction Chromatography." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2796.

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Rigid poly[hydroxyethyl acrylate-co-poly(ethylene glycol) diacrylate] (Poly(HEA-co-PEGDA) monoliths were synthesized inside 75-µm i.d. capillaries by one-step UV-initiated copolymerization using methanol and ethyl ether as porogens. The optimized monolithic column was evaluated for hydrophobic interaction chromatography (HIC) of standard proteins. Six proteins were separated within 20 min with high resolution using a 20 min elution gradient, resulting in a peak capacity of 54. The performance of this monolithic column for HIC was comparable or superior to the performance of columns packed with small particles. Monoliths synthesized solely from PEGDA were also found to show excellent performance in HIC of proteins. Continuing efforts showed that rigid monoliths could be synthesized from PEGDA or poly(ethylene glycol) dimethacrylates (PEGDMA) containing different ethylene glycol chain lengths for HIC of proteins. Effects of PEG chain length, bi-porogen ratio and reaction temperature on monolith morphology and back pressure were investigated. Monoliths prepared from PEGDA 258 were found to provide the best chromatographic performance with respect to peak capacity and resolution. An optimized PEGDA 258 monolithic column was able to separate proteins using a 20-min elution gradient with a peak capacity of 62. The preparation of these in situ polymerized single-monomer monolithic columns was highly reproducible. The single-monomer synthesis approach clearly improves column-to-column reproducibility.The highly crosslinked monolith networks resulting from single crosslinking monomers were found to enhance the surface area of the monolith and concentrations of mesopores. Thus, monolithic columns were developed from four additional crosslinking monomers, i.e., bisphenol A dimethacrylate (BADMA), bisphenol A ethoxylate diacrylate (BAEDA, EO/phenol = 2 or 4) and pentaerythritol diacrylate monostearate (PDAM) for RPLC of small molecules. Gradient elution of alkyl benzenes and alkyl parabens was achieved with high resolution using all monolithic columns. Porogen selection for the BADMA and PDAM was investigated in detail with the intention of obtaining data that could possiblly lead to a rational method for porogen selection.
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Persson, Sebastian. "Screening of Hydrophobic Interaction Chromatography for various Affibody® Molecules." Thesis, Uppsala universitet, Institutionen för biologisk grundutbildning, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-415045.

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Affibody® molecules are small affinity proteins with great opportunities in the application of biotechnological areas. Their popularity as biomolecules in pharmaceutical applications and research entails that the purity of Affibody® molecules is essential for their use as safe medical drugs. Hydrophobic Interaction Chromatography (HIC) is a purification technique that separates molecules based on their inherent difference in hydrophobicity, and the application as a purification strategy for Affibody® molecules may be possible. This thesis investigates the implementation of HIC on Affibody® molecules by screening for differences in binding, recovery, and purity influenced by different parameters, such as resin, pH, salt type, and salt concentration, have on binding, recovery, and purity. HIC presents as a viable purification method where an approximate 97% reduction in Host Cell Proteins was obtained. The yield of the purified product also presented as promising with a recovery of approximately 82%. These results indicate that further investigation and optimization of this technique may benefit the downstream process of the investigated Affibody® molecule.
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Hansson, Petra M. "Hydrophobic surfaces: Effect of surface structure on wetting and interaction forces." Doctoral thesis, KTH, Yt- och korrosionsvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103409.

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The use of hydrophobic surfaces is important for many processes both in nature and industry. Interactions between hydrophobic species play a key role in industrial applications such as water-cleaning procedures and pitch control during papermaking but they also give information on how to design surfaces like hydrophobic mineral pigments. In this thesis, the influence of surface properties on wetting and interaction forces has been studied. Surfaces with close-packed particles, pore arrays, randomly deposited nanoparticles as well as reference surfaces were prepared. The atomic force microscope (AFM) was utilized for force and friction measurements while contact angles and confocal Raman microscopy experiments were mainly used for wetting studies. The deposition of silica particles in the size range of nano- to micrometers using the Langmuir-Blodgett (LB) technique resulted in particle coated surfaces exhibiting hexagonal close-packing and close to Wenzel state wetting after hydrophobization. Force measurements displayed long-range interaction forces assigned to be a consequence of air cavitation. Smaller roughness features provided larger forces and interaction distances interpreted as being due to fewer restrictions of capillary growth. Friction measurements proved both the surface structure and chemistry to be important for the observed forces. On hydrophobic pore array surfaces, the three-phase contact line of water droplets avoided the pores which created a jagged interface. The influence of the pores was evident in the force curves, both in terms of the shape, in which the three-phase contact line movements around the pores could be detected, as well as the depth of the pores providing different access and amount of air. When water/ethanol mixtures were used, the interactions were concluded to be due to ethanol condensation. Confocal Raman microscopy experiments with water and water/ethanol mixtures on superhydrophobic surfaces gave evidence for water depletion and ethanol/air accumulation close to the surface. Force measurements using superhydrophobic surfaces showed extremely long-range interaction distances. This work has provided evidence for air cavitation between hydrophobic surfaces in aqueous solution. It was also shown that the range and magnitude of interaction forces could, to some extent, be predicted by looking at certain surface features like structure,roughness and the overall length scales.<br><p>QC 20121011</p>
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Mukherjee, Manas. "Bubble Solid Interaction." Thesis, Indian Institute of Science, 2004. http://hdl.handle.net/2005/78.

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The interaction of a bubble with solid surfaces, hydrophobic and hydrophilic, was investigated. When a bubble approaches towards a solid surface, a thin liquid film forms between them. The liquid in the film drains until an instability forms and film ruptures resulting in a three phase contact (TPC). Following rupture, the TPC line spreads on the solid surface. In the present study, glycerol-water solutions with varying percentages of water were used to investigate the effect of viscosity. Experiments were carried out with varying bubble size. The rupture and TPC line movement were recorded by high-speed digital video camera. The dependence of the TPC line movement on different parameters was investigated. The experimental results were compared with the existing theories for the TPC line movement. An empirical equation was developed to predict the TPC line movement. Formation or rupturing of the intervening film in case of a hydrophilic surfaces, which were glass surface cleaned by six cleaning techniques, was investigated. It was shown that a stable film forms for acid or alkali cleaning.
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Gaudreault, Mathieu. "Collapse transition of SARWs with hydrophobic interaction on a two dimensional lattice." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112623.

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We study the collapse transition of a lattice based protein model including an explicit coarse-grained model of a solvent. This model accounts for explicit hydrophobic interactions, and it is studied by Monte Carlo simulation. The protein is modelled as self-avoiding random walk with nearest neighbor interactions on a two dimensional lattice. Without the solvent, universal quantities of the chain around the collapse transition temperature are well known. Hydrophobicity is then modelled through a lattice of solvent molecules in which each molecule can have Q states depending of an orientation variable. Only one state is energetically favored, when two neighboring solvent molecules are both in the same state of orientation. The monomers are placed in interstitial position of the solvent lattice, and are only allowed to occupy sites surrounded by solvent cells of the same orientation. The potential of mean force between two interstitial solute molecules is calculated, showing a solvent mediated attraction typical of hydrophobic interactions. We then show that this potential increases with the energy of hydrogen bond formation as it appears in the model, while its characteristic range decreases. More importantly, we show that the chain embedded in the solvent undergoes a collapse transition, with the temperature of the transition being shifted relative to that of the chain in isolation. We calculate several critical exponents near the collapse transition, and we observe that their values are not conserved in presence of the explicit solvent.
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Morandi, Mattia. "Disruption of model membranes' phase behavior upon interaction with hydrophilic/hydrophobic molecules." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAE041/document.

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Ce travail concerne l’altération du comportement de phase de membranes lipidiques lors de leur interaction avec des molécules hydrophiles ou hydrophobes. L’utilisation de sondes moléculaires de fluorescence sensibles à leur micro-environnement constitue un aspect majeur de ce travail. Les techniques de spectroscopie de fluorescence et de microscopie confocale ont été mises à profit pour l’étude du comportement de ces sondes, donnant accès au degré de compacité et d’ordre dans les membranes.Nos résultats montrent que le polystyrène, un plastique rencontré de façon commune dans les régions polluées des océans, présente la capacité de modifier le comportement de phase des membranes lipidiques, entrant notamment en compétition avec le cholestérol.Nous avons montré que la présence élevée de sucres, tel que l’on peut le rencontrer dans certaines situations relevant de la bio-préservation, a pour effet de rompre la qualité de compaction des lipides, et nous avons proposé un nouveau modèle thermodynamique pour interpréter nos résultats.Enfin, les effets sur la membrane de l’incorporation d’un polymère amphiphile comportant un cholestérol greffé ont été étudiés, dans le cadre de l’élaboration de nouvelles stratégies thérapeutiques à base de lipides<br>This work focuses on the alterations of lipid membrane phase behavior upon interaction with hydrophobic and hydophilic molecules. One major aspect of this thesis is the employement of environment sensitive probes to obtain information on the lipid bilayer packing by means of confocal spectral imaging and fluorescence spectroscopy. Our results show that polystyrene, a commonly found plastic in ocean wastes, has the ability to disrupt the lipid bilayer phase behavior and has a competitive interaction with cholesterol. The presence of high concentration of sugars, relevant in the field of biopreservation, has been found to alter the lipid bilayer packing and a new thermodynamics model has been proposed to complement the experimental results. Finally, the effects of an amphiphilic cholesterol-grafted polymer on model membrane was investigated, providing insight into potential new lipid therapeutic strategies
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Books on the topic "Hydrophobic interaction"

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Hydrophilic interaction liquid chromatography (HILIC) and advanced applications. Taylor & Francis, 2011.

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Eunice, Li-Chan, ed. Hydrophobic interactions in food systems. CRC Press, 1988.

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Superhydrophobic surfaces. VSP, 2009.

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Tuulmets, Ants. Ultrasound and hydrophobic interactions in solutions. Nova Science Publishers, 2010.

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Riablershirun, Suppanee Kattiyaman. Studies of fountain solution/ Model ink film interactions on hydrophilic and hydrophobic model printing plates. Open University, 1993.

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Wang, Perry G. Hydrophilic Interaction Liquid Chromatography (Hilic) and Advanced Applications. Taylor & Francis Group, 2011.

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Wang, Perry G., and Weixuan He. Hydrophilic Interaction Liquid Chromatography (HILIC) and Advanced Applications. Taylor & Francis Group, 2011.

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Ben-Naim, Arieh Y. Hydrophobic Interactions. Springer London, Limited, 2012.

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Ben-Naim, Arieh Y. Hydrophobic Interactions. Springer, 2012.

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Nakai, Shuryo, and Eunice Li-Chan. Hydrophobic Interactions in Food Systems. CRC Press, 2018. http://dx.doi.org/10.1201/9781351073318.

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Book chapters on the topic "Hydrophobic interaction"

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O'Farrell, Paul A. "Hydrophobic Interaction Chromatography." In Springer Protocols Handbooks. Humana Press, 2008. http://dx.doi.org/10.1007/978-1-60327-375-6_42.

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Eriksson, Kjell-Ove, and Makonnen Belew. "Hydrophobic Interaction Chromatography." In Methods of Biochemical Analysis. John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9780470939932.ch6.

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Cummins, Philip M., and Brendan F. O’Connor. "Hydrophobic Interaction Chromatography." In Methods in Molecular Biology. Humana Press, 2010. http://dx.doi.org/10.1007/978-1-60761-913-0_24.

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Liu, Fu. "Hydrophobic-Hydrophilic Interaction." In Encyclopedia of Membranes. Springer Berlin Heidelberg, 2016. http://dx.doi.org/10.1007/978-3-662-44324-8_1674.

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O’Farrell, Paul A. "Hydrophobic Interaction Chromatography." In Springer Protocols Handbooks. Humana Press, 1998. http://dx.doi.org/10.1007/978-1-59259-642-3_37.

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O’Connor, Brendan F., and Philip M. Cummins. "Hydrophobic Interaction Chromatography." In Methods in Molecular Biology. Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-6412-3_18.

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Jennissen, Herbert P. "Hydrophobic Interaction Chromatography." In Protein-Ligand Interactions. Humana Press, 2005. http://dx.doi.org/10.1007/978-1-59259-912-7_5.

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Liu, Fu. "Hydrophobic-Hydrophilic Interaction." In Encyclopedia of Membranes. Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-40872-4_1674-1.

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Hjertén, Stellan. "Hydrophobic Interaction Chromatography." In Advances in Chromatography. CRC Press, 2021. http://dx.doi.org/10.1201/9781003209690-4.

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Jennissen, Herbert P. "Hydrophobic Interaction Chromatography." In Protein-Ligand Interactions. Humana Press, 2005. http://dx.doi.org/10.1385/1-59259-912-5_081.

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Conference papers on the topic "Hydrophobic interaction"

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Scott, Graham, Ian Kowalok, Michaela Helble, Scott Lehman, and Brenden Epps. "Poster: Interaction of Water with Hydrophobic and Hydrophilic Surfaces." In 68th Annual Meeting of the APS Division of Fluid Dynamics. American Physical Society, 2015. http://dx.doi.org/10.1103/aps.dfd.2015.gfm.p0009.

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Floryan, Jerzy M., and A. Mohammadi. "Super-Hydrophobic Effect in Single Phase Fluids." In ASME 2012 Fluids Engineering Division Summer Meeting collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/fedsm2012-72422.

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Super-hydrophobic effect involves capture of gas bubbles in pores of a solid wall, which separates liquid from the solid, resulting in the reduction of the shear drag experienced by the liquid. This effect occurs in the presence of two phases. A similar effect might be produced by creating separation bubbles made of the same fluid through proper shaping of the surface. Use of transverse grooves with a sufficiently short wavelength creates the required flow topology. The shear drag decreases by up to 50% compared with the smooth wall but the interaction pressure drag increases, resulting in only minor reduction in the overall drag. Proper shaping of the grooves may reduce the interaction pressure drag.
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Zhang, K. J., and X. F. Peng. "Dynamic Behavior of Nano-Particles on Bubble Interface." In ASME 2008 First International Conference on Micro/Nanoscale Heat Transfer. ASMEDC, 2008. http://dx.doi.org/10.1115/mnht2008-52138.

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The dynamic behavior of particles on a bubble interface contains axial and radial motions and is highly dependent upon the energy of this system. By introducing the concept of particle energy density (the average of the system energy based on particle number), four kinds of energy elements are estimated as critical elements, namely surface energy, line tension (an additive interaction at the contact line), electrostatic interaction and hydrophobic interaction (only for hydrophobic particle whose contact angle is greater than 64°). With consideration of different energy influences, the radial motion, vertical to bubble interface, and circumferential motion, parallel with bubble interface, are theoretically described and discussed.
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Kim, Ki Young, Ki-Taek Byun, and Ho-Young Kwak. "The Mesoscopic Simulation on the Structures of the Surfactant Solution Using Dissipative Particle Dynamics." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-80702.

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With a simple model of surfactant which consists of hydrophilic head group and hydrophobic tail groups connected by harmonic springs, structural change of the association structures of surfactant in an aqueous solution was studied using the dissipative particle dynamics (DPD) simulation. The effect of the hydrophilic interaction between the head and water molecules and the hydrophobic interaction between the tail and water molecules and the head and tail on the structural change of the association structures was studied. Simulations show that proper value of these interaction parameters could yield desirable change of the association structure depending on the concentration of the surfactant. For example, a hexagonal structure appears when the volume fraction of surfactant of SDS (sodium dodecyl sulfate) becomes 25% in aqueous solution, which is in good agreement with observation.
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HWANG, TAEK-SUNG, JIN-WON PARK та CHOUL-HO LEE. "PREPARATION OF HYDROPHOBIC INTERACTION LIGAND-CONTAINING MEMBRANE BY RADIATION AND THEIR ADSORPTION PROPERTIES OF γ-GLOBULINS". У Proceedings of the 4th International Conference. WORLD SCIENTIFIC, 2004. http://dx.doi.org/10.1142/9789812702623_0182.

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Ren, Jun, Zhiqian Pi, Xue Lin, Li Xu, Jian Xie, and Lingyun Jia. "Effect of Structural Properties of Both Proteins and Stationary Phases to Adsorption Behavior of Proteins in Hydrophobic Interaction Chromatography." In 2010 4th International Conference on Bioinformatics and Biomedical Engineering (iCBBE). IEEE, 2010. http://dx.doi.org/10.1109/icbbe.2010.5517033.

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Rossi, M. Pi´a, Haihui Ye, and Yury Gogotsi. "In Situ ESEM Study of Liquid Interactions With Carbon Nanopipes." In ASME 2004 Heat Transfer/Fluids Engineering Summer Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/ht-fed2004-56275.

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The wetting and fluidic properties of various types of carbon nanotubes (CNT) are currently being studied for various applications, including their use as nanopipes for the controlled transport of fluids to well-defined locations, such as a cell. While numerous studies on the modeling of the behavior of liquids in nanotubes and nanopores have already been reported, very few experimental observations have been published. In this research, the field emission Environmental Scanning Electron Microscope (ESEM) has proved to be a powerful tool in the in situ analysis of the wetting of CNT with diverse liquids at high magnification. Additionally, the ability of the ESEM to condense and evaporate liquids within the chamber has enabled the dynamic study of CNT/liquid interactions. As a result, hydrophilic and hydrophobic behavior of diverse types of commercial carbon nanofibers (CNF) and CNT has been observed. The fluidic behavior of CNF depends largely on surface chemistry and structure. The presence of defects and end groups may cause partial wetting, while graphitized CNF are extremely hydrophobic. Nevertheless, water still becomes drawn into hydrophobic CNF due to surface tension and capillary forces. CNT fabricated by chemical vapor deposition (CVD) with straight, thin walls appear transparent under the electron beam of the ESEM. When studying the interaction of these CNT with water, it was possible to see liquid menisci inside the CNT. From the measured contact angles, it is clear that these CNT are hydrophilic. Furthermore, the wetting behavior observed is very similar to that of closed hydrothermal CNT under high pressures in TEM. Finally, rupture of these thin-walled CNT was observed inside the ESEM chamber as a result of rapid changes in pressure at constant temperatures.
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Ruiz, Gustavo, and Dora Medina. "Triborheological Analysis of Reconstituted Gastrointestinal Porcine Mucus / Polymeric Nanoparticles System for Studying Mucoadhesion." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/khsf3022.

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The project analyses the interaction between pig gastrointestinal mucus and chitosan nanoparticles from a rheological point of view. Considering that mucus protective, hydrating and lubricating properties must be preserved as much as possible for avoiding side effects or diseases. Viscoelastic and protective properties of mucus are mainly produced by a mucin network, which is stabilized through electrostatic, hydrophobic and hydrogen bonding interactions that are also related with the interaction with chitosan nanoparticles. Mainly, because mucin is a glycoprotein with a polyanionic nature at physiological pH, while chitosan is a cationic polymer under physiological conditions. So, the interaction is determinant in mucus rheological properties, because mucus should behave as a polymeric solution under neutral pH conditions, and as a viscoelastic gel under acidic conditions. Therefore, a rheological analysis is important to visualize how the interaction with chitosan nanoparticles could produce changes in viscosity, friction coefficient, resistance to different shear stresses and oscillatory stress to which the gastrointestinal mucus is subjected under natural conditions, since the different pH values of the tract.
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9

Guan, Yingxue, Aili Zhang, and Lisa X. Xu. "Study of Interaction Energy Between Nanoparticles and Cell Membrane." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-23187.

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Applications of nanoparticles in the bio-medical field like nano-medicine, molecular imaging probes, fluorescence marker, gene carriers, are developing quickly owing to the unique characteristics of nanoparticles. Among these applications, the interaction of nano-particles with the living cells is of critical importance. The complex chemical properties and biological activities of the particles bring about undesirable cytotoxic potentials and special cell internalization. According to previous studies, the cell uptake kinetics of nanoparticles mainly depend on the concentration difference between extracellular and intracellular nanoparticles, the surface electric charge of the nanoparticle, and the active transport of the cell. For example, Ginzburg’s thermodynamic simulation and Park’s three-dimensional phase-field model quantitatively explain the transitions in membrane morphology after exposure to nanoparticles with different surface charge, respectively. However, recent studies have shown that the gold nanoparticles coated with hydrophilic and hydrophobic functional groups with the same concentration but in different orders, completely exhibit quite different intrusion ability at 4°C when the active transport of the cell is greatly inhibited. The results suggest that the interaction energy of nanoparticles and cell membranes may be another driving force for the nanopartcles’ mass transfer across the cell membrane. Thus, in this paper, the interaction energy of the differently coated nanoparticles (P) with cell membrane (M) in water (W) is studied theoretically and results are used to explain the former experimental findings.
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Liu, Runkeng, Zhenyu Liu, and Huiying Wu. "Study of Pool Boiling Heat Transfer on Concave Nanostructured Surface With Molecular Dynamics Simulation." In ASME 2019 Heat Transfer Summer Conference collocated with the ASME 2019 13th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/ht2019-3528.

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Abstract The nanoscale boiling phenomena on solid surface is significantly distinct from that at macroscale. In this work, the pool boiling process of liquid argon thin film on smooth/concave aluminum surfaces were simulated using non-equilibrium molecular dynamics (NEMD) simulation, in which the nonuniform hydrophilic/hydrophobic surfaces were considered. For each surface, the superheat degree was progressively increased and the MD simulations were carried out to record the variation of atomic motion trajectory, mass density, the number of vapor and liquid atoms, kinetic energy and internal energy as time elapses. The predictions show that heat flux can reach critical heat flux (CHF) with increasing of wall superheat degree. Under the same superheat degree, the hydrophilic surface has the higher heat flux value than the hydrophobic surface, but it is earlier to reach CHF compared to the hydrophobic one. In addition, it also demonstrates that, with the same surface morphology, liquid-solid interaction strength has a significant influence on the heat transfer transition from nucleate boiling to film boiling. The surface morphology has more favorable effect on the pool boiling compared to the surface wettability at nanoscale. The obtained results in this work can guide the design and fabrication of enhanced heat transfer surface with nanostructured modification.
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Reports on the topic "Hydrophobic interaction"

1

Chefetz, Benny, and Jon Chorover. Sorption and Mobility of Pharmaceutical Compounds in Soils Irrigated with Treated Wastewater. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7592117.bard.

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Research into the fate of pharmaceutical compounds (PCs) in the environment has focused on aspects of removal efficiency during sewage treatment, degradation in surface water and accumulation in soils and sediments. However, very little information is available on the binding interactions of pharmaceuticals with dissolved organic matter (DOM) originating from wastewater treatment. Such interactions can significantly affect the transport potential of PCs in soils by altering compound affinity for soil particle surfaces. Our primary hypothesis is that the transport potential of PCs in soils is strongly impacted by the type and strength of interaction with DOM and the stability of resulting DOM-PC complexes. The overarching goal of the proposed work is to develop a better understanding of the risk associated with introduction of PCs into the environment with treated wastewater. This goal has been achieved by elucidating the mechanisms of the interaction of selected pharmaceuticals (that have shown to be widespread wastewater contaminants) with DOM constituents; by determining the stability and fate of DOM-PC complexes introduced to soils and soil constituents; and by evaluating the potential uptake of these compounds by plants. Based on the results obtained in this study (column and batch sorption-desorption experiments), we suggest that PCs can be classified as slow-mobile compounds in SOM-rich soil layers. When these compounds pass this layer and/or are introduced into SOM-poor soils, their mobility increases significantly. Our data suggest that in semiarid soils (consisting of low SOM), PCs can potentially be transported to the groundwater in fields irrigated with reclaimed wastewater. Moreover, the higher mobility of the acid PCs (i.e., naproxen and diclofenac) in freshwater column systems suggests that their residues in soils irrigated with reclaimed wastewater can leach from the root zone and be transported to the groundwater after rain events. Our data obtained from the binding experiments of PCs with DOM demonstrate that the hydrophobic DOM fractions were more efficient at sorbing PCs than the more polar hydrophilic fractions at a pH near the pKa of the analytes. At the pH of natural semiarid water and soil systems, including that of reclaimed wastewater and biosolids, the role of the hydrophobic fractions as sorption domains is less important than the contribution of the hydrophilic fractions. We also hypothesize that the DOM fractions interact with each other at the molecular level and do not act as independent sorption domains. In summary, our data collected in the BARD project demonstrate that the sorption abilities of the DOM fractions can also significantly affect the mobility of pharmaceutical compounds in soils influenced by intensive irrigation with treated wastewater or amended with biosolids.
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2

Chefetz, Benny, and Jon Chorover. Sorption and Mobility of Pharmaceutical Compounds in Soils Irrigated with Treated Wastewater. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7709883.bard.

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Research into the fate of pharmaceutical compounds (PCs) in the environment has focused on aspects of removal efficiency during sewage treatment, degradation in surface water and accumulation in soils and sediments. However, very little information is available on the binding interactions of pharmaceuticals with dissolved organic matter (DOM) originating from wastewater treatment. Such interactions can significantly affect the transport potential of PCs in soils by altering compound affinity for soil particle surfaces. Our primary hypothesis is that the transport potential of PCs in soils is strongly impacted by the type and strength of interaction with DOM and the stability of resulting DOM-PC complexes. The overarching goal of the proposed work is to develop a better understanding of the risk associated with introduction of PCs into the environment with treated wastewater. This goal has been achieved by elucidating the mechanisms of the interaction of selected pharmaceuticals (that have shown to be widespread wastewater contaminants) with DOM constituents; by determining the stability and fate of DOM-PC complexes introduced to soils and soil constituents; and by evaluating the potential uptake of these compounds by plants. Based on the results obtained in this study (column and batch sorption-desorption experiments), we suggest that PCs can be classified as slow-mobile compounds in SOM-rich soil layers. When these compounds pass this layer and/or are introduced into SOM-poor soils, their mobility increases significantly. Our data suggest that in semiarid soils (consisting of low SOM), PCs can potentially be transported to the groundwater in fields irrigated with reclaimed wastewater. Moreover, the higher mobility of the acid PCs (i.e., naproxen and diclofenac) in freshwater column systems suggests that their residues in soils irrigated with reclaimed wastewater can leach from the root zone and be transported to the groundwater after rain events. Our data obtained from the binding experiments of PCs with DOM demonstrate that the hydrophobic DOM fractions were more efficient at sorbing PCs than the more polar hydrophilic fractions at a pH near the pKa of the analytes. At the pH of natural semiarid water and soil systems, including that of reclaimed wastewater and biosolids, the role of the hydrophobic fractions as sorption domains is less important than the contribution of the hydrophilic fractions. We also hypothesize that the DOM fractions interact with each other at the molecular level and do not act as independent sorption domains. In summary, our data collected in the BARD project demonstrate that the sorption abilities of the DOM fractions can also significantly affect the mobility of pharmaceutical compounds in soils influenced by intensive irrigation with treated wastewater or amended with biosolids.
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3

Chefetz, Benny, and Baoshan Xing. Sorption of hydrophobic pesticides to aliphatic components of soil organic matter. United States Department of Agriculture, 2003. http://dx.doi.org/10.32747/2003.7587241.bard.

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Sorption of hydrophobic compounds to aliphatic components of soil organic matter (SOM) is poorly understood even though these aliphatic carbons are a major fraction of SOM. The main source of aliphatic compounds in SOM is above- and below-ground plant cuticular materials (cutin, cutan and suberin). As decomposition proceeds, these aliphatic moieties tend to accumulate in soils. Therefore, if we consider that cuticular material contributes significantly to SOM, we can hypothesize that the cuticular materials play an important role in the sorption processes of hydrophobic compounds (including pesticides) in soils, which has not yet been studied. The overall goal of this research was to illustrate the mechanism and significance of the refractory aliphatic structures of SOM in sorbing hydrophobic compounds (nonionic and weakly polar pesticides). The importance of this study is related to our ability to demonstrate the sorption relationship between key pesticides and an important fraction of SOM. The specific objectives of the project were: (1) To isolate and characterize cuticular fractions from selected plants; (2) To investigate the sorption mechanism of key hydrophobic pesticides and model compounds to cuticular plant materials; (3) To examine the sorption mechanisms at the molecular level using spectroscopic techniques; (4) To investigate the sorption of key hydrophobic pesticides to synthetic polymers; (5) To evaluate the content of cuticular materials in agricultural soils; and (6) To study the effect of incubation of plant cuticular materials in soils on their sorptive capabilities. This project demonstrates the markedly high sorption capacity of various plant cuticular fractions for hydrophobic organic compounds (HOCs) and polar organic pollutants. Both cutin (the main polymer of the cuticle) and cutan biopolymers exhibit high sorption capability even though both sorbents are highly aliphatic in nature. Sorption by plant cuticular matter occurs via hydrophobic interactions and H-bonding interactions with polar sorbates. The cutin biopolymer seems to facilitate reversible and noncompetitive sorption, probably due to its rubbery nature. On the other hand, the epicuticular waxes facilitate enhance desorption in a bi-solute system. These processes are possibly related to phase transition (melting) of the waxes that occur in the presence of high solute loading. Moreover, our data highlight the significance of polarity and accessibility of organic matter in the uptake of nonpolar and polar organic pollutants by regulating the compatibility of sorbate to sorbent. In summary, our data collected in the BARD project suggest that both cutin and cutan play important roles in the sorption of HOCs in soils; however, with decomposition the more condensed structure of the cutin and mainly the cutan biopolymer dominated sorption to the cuticle residues. Since cutin and cutan have been identified as part of SOM and humic substances, it is suggested that retention of HOCs in soils is also controlled by these aliphatic domains and not only by the aromaticrich fractions of SOM.
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4

Altstein, Miriam, and Ronald J. Nachman. Rational Design of Insect Control Agent Prototypes Based on Pyrokinin/PBAN Neuropeptide Antagonists. United States Department of Agriculture, 2013. http://dx.doi.org/10.32747/2013.7593398.bard.

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The general objective of this study was to develop rationally designed mimetic antagonists (and agonists) of the PK/PBAN Np class with enhanced bio-stability and bioavailability as prototypes for effective and environmentally friendly pest insect management agents. The PK/PBAN family is a multifunctional group of Nps that mediates key functions in insects (sex pheromone biosynthesis, cuticular melanization, myotropic activity, diapause and pupal development) and is, therefore, of high scientific and applied interest. The objectives of the current study were: (i) to identify an antagonist biophores (ii) to develop an arsenal of amphiphilic topically active PK/PBAN antagonists with an array of different time-release profiles based on the previously developed prototype analog; (iii) to develop rationally designed non-peptide SMLs based on the antagonist biophore determined in (i) and evaluate them in cloned receptor microplate binding assays and by pheromonotropic, melanotropic and pupariation in vivo assays. (iv) to clone PK/PBAN receptors (PK/PBAN-Rs) for further understanding of receptor-ligand interactions; (v) to develop microplate binding assays for screening the above SMLs. In the course of the granting period A series of amphiphilic PK/PBAN analogs based on a linear lead antagonist from the previous BARD grant was synthesized that incorporated a diverse array of hydrophobic groups (HR-Suc-A[dF]PRLa). Others were synthesized via the attachment of polyethylene glycol (PEG) polymers. A hydrophobic, biostablePK/PBAN/DH analog DH-2Abf-K prevented the onset of the protective state of diapause in H. zea pupae [EC50=7 pmol/larva] following injection into the preceding larval stage. It effectively induces the crop pest to commit a form of ‘ecological suicide’. Evaluation of a set of amphiphilic PK analogs with a diverse array of hydrophobic groups of the formula HR-Suc-FTPRLa led to the identification of analog T-63 (HR=Decyl) that increased the extent of diapause termination by a factor of 70% when applied topically to newly emerged pupae. Another biostablePK analog PK-Oic-1 featured anti-feedant and aphicidal properties that matched the potency of some commercial aphicides. Native PK showed no significant activity. The aphicidal effects were blocked by a new PEGylated PK antagonist analog PK-dF-PEG4, suggesting that the activity is mediated by a PK/PBAN receptor and therefore indicative of a novel and selective mode-of-action. Using a novel transPro mimetic motif (dihydroimidazole; ‘Jones’) developed in previous BARD-sponsored work, the first antagonist for the diapause hormone (DH), DH-Jo, was developed and shown to block over 50% of H. zea pupal diapause termination activity of native DH. This novel antagonist development strategy may be applicable to other invertebrate and vertebrate hormones that feature a transPro in the active core. The research identifies a critical component of the antagonist biophore for this PK/PBAN receptor subtype, i.e. a trans-oriented Pro. Additional work led to the molecular cloning and functional characterization of the DH receptor from H. zea, allowing for the discovery of three other DH antagonist analogs: Drosophila ETH, a β-AA analog, and a dF analog. The receptor experiments identified an agonist (DH-2Abf-dA) with a maximal response greater than native DH. ‘Deconvolution’ of a rationally-designed nonpeptide heterocyclic combinatorial library with a cyclic bis-guanidino (BG) scaffold led to discovery of several members that elicited activity in a pupariation acceleration assay, and one that also showed activity in an H. zea diapause termination assay, eliciting a maximal response of 90%. Molecular cloning and functional characterization of a CAP2b antidiuretic receptor from the kissing bug (R. prolixus) as well as the first CAP2b and PK receptors from a tick was also achieved. Notably, the PK/PBAN-like receptor from the cattle fever tick is unique among known PK/PBAN and CAP2b receptors in that it can interact with both ligand types, providing further evidence for an evolutionary relationship between these two NP families. In the course of the granting period we also managed to clone the PK/PBAN-R of H. peltigera, to express it and the S. littoralis-R Sf-9 cells and to evaluate their interaction with a variety of PK/PBAN ligands. In addition, three functional microplate assays in a HTS format have been developed: a cell-membrane competitive ligand binding assay; a Ca flux assay and a whole cell cAMP ELISA. The Ca flux assay has been used for receptor characterization due to its extremely high sensitivity. Computer homology studies were carried out to predict both receptor’s SAR and based on this analysis 8 mutants have been generated. The bioavailability of small linear antagonistic peptides has been evaluated and was found to be highly effective as sex pheromone biosynthesis inhibitors. The activity of 11 new amphiphilic analogs has also been evaluated. Unfortunately, due to a problem with the Heliothis moth colony we were unable to select those with pheromonotropic antagonistic activity and further check their bioavailability. Six peptides exhibited some melanotropic antagonistic activity but due to the low inhibitory effect the peptides were not further tested for bioavailability in S. littoralis larvae. Despite the fact that no new antagonistic peptides were discovered in the course of this granting period the results contribute to a better understanding of the interaction of the PK/PBAN family of Nps with their receptors, provided several HT assays for screening of libraries of various origin for presence of PK/PBAN-Ragonists and antagonists and provided important practical information for the further design of new, peptide-based insecticide prototypes aimed at the disruption of key neuroendocrine physiological functions in pest insects.
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5

Matthew, Gray. Data from "Winter is Coming – Temperature Affects Immune Defenses and Susceptibility to Batrachochytrium salamandrivorans". University of Tennessee, Knoxville Libraries, 2021. http://dx.doi.org/10.7290/t7sallfxxe.

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Environmental temperature is a key factor driving various biological processes, including immune defenses and host-pathogen interactions. Here, we evaluated the effects of environmental temperature on the pathogenicity of the emerging fungus, Batrachochytrium salamandrivorans (Bsal), using controlled laboratory experiments, and measured components of host immune defense to identify regulating mechanisms. We found that adult and juvenile Notophthalmus viridescens died faster due to Bsal chytridiomycosis at 14 ºC than at 6 and 22 ºC. Pathogen replication rates, total available proteins on the skin, and microbiome composition likely drove these relationships. Temperature-dependent skin microbiome composition in our laboratory experiments matched seasonal trends in wild N. viridescens, adding validity to these results. We also found that hydrophobic peptide production after two months post-exposure to Bsal was reduced in infected animals compared to controls, perhaps due to peptide release earlier in infection or impaired granular gland function in diseased animals. Using our temperature-dependent infection results, we performed a geographic analysis that suggested that N. viridescens populations in the northeastern United States and southeastern Canada are at greatest risk for Bsal invasion. Our results indicate that environmental temperature will play a key role in the epidemiology of Bsal and provide evidence that temperature manipulations may be a viable Bsal management strategy.
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6

Barefoot, Susan, Benjamin Juven, Thomas Hughes, et al. Characterization of Bacteriocins Produced by Food Bioprocessing Propionobacteria. United States Department of Agriculture, 1992. http://dx.doi.org/10.32747/1992.7561061.bard.

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Objectives were to further characterize activity spectra of dairy propionibacteria bacteriocins, jenseniin G and propionicin PLG-1, purify them, examine the role of cell walls in resistance, examine their interactions with cytoplasmic membrane, explain producer immunity, and clone the responsible genes. Inhibitory spectra of both bacteriocins were further characterized. Propionicin was most effective in controlling Gram-positive, rather than Gram-negative organisms; it controlled growth of sensitive cells both in a culture medium and a model food system. Jenseniin inhibited yogurt cultures and may help prevent yogurt over-acidification. Both were active against botulinal spores; jenseniin was sporostatic; propionicin was sporicidal. Jenseniin was produced in broth culture, was stable to pH and temperature extremes, and was purified. Its molecular mass (3649 Da) and partial amino acid composition (74%) were determined. A blocked jenseniin N-terminus prevented sequencing. Methods to produce propionicin in liquid culture were improved, and large scale culture protocols to yield high titers were developed. Methods to detect and quantify propionicin activity were optimized and standardized. Stability of partially purified propionicin was demonstrated and an improved purification scheme was developed. Purified propionicin had a 9328-Da molecular mass, contained 99 amino acids, and was significantly hydrophobic; ten N-terminal amino acids were identified. Propionicin and Jenseniin interacted with cytoplasmic membranes; resistance of insensitive species was cell wall-related. Propionicin and jenseniin acted similarly; their mode of action appeared to differ from nisin. Spontaneous jenseniin-resistant mutants were resistant to propionicin but nisin-sensitive. The basis for producer immunity was not resolved. Although bacteriocin genes were not cloned, a jenseniin producer DNA clone bank and three possible vectors for cloning genes in propionibacteria were constructed. In addition, transposon Tn916 was conjugatively transferred to the propionicin producer from chromosomal and plasmid locations at transfer frequencies high enough to permit use of Tn916 for insertional mutagenesis or targeting genes in propionibacteria. The results provide information about the bacteriocins that further supports their usefulness as adjuncts to increase food safety and/or quality.
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