Academic literature on the topic 'Supramolecular level'
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Journal articles on the topic "Supramolecular level"
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Credi, Alberto, Belén Ferrer Ribera, and Margherita Venturi. "From supramolecular electrochemistry to molecular-level devices." Electrochimica Acta 49, no. 22-23 (2004): 3865–72. http://dx.doi.org/10.1016/j.electacta.2003.12.063.
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Eckel, Rainer, Robert Ros, Bj�rn Decker, Jochen Mattay, and Dario Anselmetti. "Supramolecular Chemistry at the Single-Molecule Level." Angewandte Chemie International Edition 44, no. 3 (2005): 484–88. http://dx.doi.org/10.1002/anie.200461382.
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Lin, Huirong, Shuang Li, Junqing Wang, et al. "A single-step multi-level supramolecular system for cancer sonotheranostics." Nanoscale Horizons 4, no. 1 (2019): 190–95. http://dx.doi.org/10.1039/c8nh00276b.
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A multi-level supramolecular system produced by single-step Fe<sup>3+</sup>-mediated ionic crosslinking self-assembly can overcome the critical issues of current sonodynamic therapy (SDT) and address the need to monitor therapeutic effects in vivo with a non-invasive approach.
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Schäfer, Christian, Björn Decker, Matthias Letzel, et al. "On the way to supramolecular photochemistry at the single-molecule level." Pure and Applied Chemistry 78, no. 12 (2006): 2247–59. http://dx.doi.org/10.1351/pac200678122247.
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Two examples of artificial supramolecular host-guest systems derived from resorc[4]arenes (calix[n]arenes based on resorcinol) and ammonium ions as guests have been studied by atomic force microscopy (AFM). For the first time, real single-molecule events have been determined for this type of supramolecular complexes and off-rates as well as molecular parameters of single-molecule aggregates such as the depths of the binding pocket (molecular length parameter) could be measured by applying the methods of dynamic force spectroscopy. In addition, this technique was also applied to differentiate between the two states (open and closed) of a photoswitchable resorc[4]arene-anthracene tweezer. An investigation of the exchange rates of various complexes in the gas phase by means of Fourier transform ion cyclotron resonance (FTICR) mass spectrometry confirmed the results of the AFM study.
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Dawn, Arnab. "Supramolecular Gel as the Template for Catalysis, Inorganic Superstructure, and Pharmaceutical Crystallization." International Journal of Molecular Sciences 20, no. 3 (2019): 781. http://dx.doi.org/10.3390/ijms20030781.
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A supramolecular gel is a fascinating combination of flexibility and orderliness. While the supramolecular nature of crosslinking contributes towards the adaptivity and the reversibility of the system, orderliness at the molecular level amplifies the functional output and induces extraordinary selectivity into the system. Therefore, use of supramolecular gels as the soft template is an emerging area of research, which includes but not limited to catalysis of a chemical or a photochemical process, transcription of gel property to a substrate, or even controlling the nucleation of drug molecules. This review aims to highlight the template effect of supramolecular gels in the above-mentioned areas relevant to novel fundamental chemistry, technology, and healthcare.
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Shestimerova, T. A., M. A. Bykov, Z. Wei, E. V. Dikarev, and A. V. Shevelkov. "Crystal structure and two-level supramolecular organization of glycinium triiodide." Russian Chemical Bulletin 68, no. 8 (2019): 1520–24. http://dx.doi.org/10.1007/s11172-019-2586-0.
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Pijper, Dirk, and Ben L. Feringa. "Control of dynamic helicity at the macro- and supramolecular level." Soft Matter 4, no. 7 (2008): 1349. http://dx.doi.org/10.1039/b801886c.
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Yang, Lin, Lan She, Jian-Guo Zhou, Ying Cao, and Xiao-Ming Ma. "Interaction of lysozyme during calcium carbonate precipitation at supramolecular level." Inorganic Chemistry Communications 9, no. 2 (2006): 164–66. http://dx.doi.org/10.1016/j.inoche.2005.05.026.
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Wei, Chengpeng, Mingyang Liu, Yifei Han, Hua Zhong, and Feng Wang. "Supramolecular Chirogenesis Engineered by Pt(II)···Pt(II) Metal–Metal Interactions." Organic Materials 03, no. 02 (2021): 274–80. http://dx.doi.org/10.1055/a-1512-5965.
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Supramolecular chirogenesis represents an effective way to induce chirality at the supramolecular level. For the previous host–guest chirogenic systems, metal–ligand coordination, hydrogen bonding, π–π stacking and hydrophobic interactions have been mainly employed as the non-covalent driving forces. In this study, Pt(II)···Pt(II) metal–metal interactions have been engineered to induce supramolecular chirogenesis, by forming non-covalent clipping structures between chiral platinum receptors and achiral platinum guests together. This results in the emergence of Cotton effects in the metal–metal-to-ligand charge transfer region, ascribed to chirality transfer from trans-1,2-diamide cyclohexane unit on chiral receptors to Pt(II)---Pt(II) non-covalent interacting sites. Supramolecular chirogenesis can be further transferred from organic to aqueous solutions, with higher resistance to concentration and temperature variations in the latter medium. Overall, the current study provides new avenues toward supramolecular chirality systems with tailored properties.
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Chen, Miao, Weimin Lin, Le Hong, Ning Ji, and Hang Zhao. "The Development and Lifetime Stability Improvement of Guanosine-Based Supramolecular Hydrogels through Optimized Structure." BioMed Research International 2019 (June 13, 2019): 1–18. http://dx.doi.org/10.1155/2019/6258248.
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Guanosine is an important building block for supramolecular gels owing to the unique self-assembly property that results from the unique hydrogen bond acceptors and donor groups. Guanosine-derived supramolecular hydrogels have promise in the fields of drug delivery, targeted release, tissue engineering applications,etc.However, the property of poor longevity and the need for excess cations hinder the widespread applications of guanosine hydrogels. Although guanosine-derived supramolecular hydrogels have been reviewed previously by Dash et al., the structural framework of this review is different, as the modification of guanosine is described at the molecular level. In this review, we summarize the development and lifetime stability improvement of guanosine-based supramolecular hydrogels through optimized structure and elaborate on three aspects: sugar modification, base modification, and binary gels. Additionally, we introduce the concept and recent research progress of self-healing gels, providing inspiration for the development of guanosine-derived supramolecular hydrogels with longer lifespans, unique physicochemical properties, and biological activities.
Dissertations / Theses on the topic "Supramolecular level"
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Campos, E. Menezes Jorge Ramalhete Susana. "Molecular level understanding of supramolecular gels." Thesis, University of East Anglia, 2017. https://ueaeprints.uea.ac.uk/67676/.
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Supramolecular gels are complex materials which have an expanding scope of industrial and biomedical applications, due to their unique viscoelastic properties, high biocompatibility and possibility of functionalisation. The hierarchical structure of molecular materials combines domains with drastically different degrees of ordering and molecular mobility. This makes their full characterisation a significant methodological and experimental challenge. The focus of this work was therefore the understanding of a variety of supramolecular semicrystalline gels in which very rigid solid components coexist with a dynamic and highly mobile solution phase. Using the examples of amino acid and urea-derivatives gelators, control of the self-assembly processes was successfully gained and tuning of the mechanical properties of the resulting materials by incorporating molecular structure modifications or introducing a variety of structurally diverse additives was achieved. Modification of the structure of the gel fibres was observed, which modulated the dynamic properties of the gel/solution interfaces and dictated the overall behaviour of the system, an aspect which is not commonly investigated in molecular gels. The resulting single and multi-component gels were used as model materials for the development of an NMR-based general strategy capable of probing the several hierarchical levels present. The multiphasic character of molecular gels required the combined use of solid, solution-state and HR-MAS NMR methods. This project has expanded the understanding of saturation transfer difference NMR experiments, with special focus in their applicability and limitations for the study of supramolecular soft systems. This approach was validated using complementary techniques, more specifically, rheology, microscopy, X-ray diffraction and computational methods. By combining molecular level understanding and measurements of the bulk properties, a methodology which can be applied to other soft materials used in pharmaceutical, biomedical and food science applications was developed. Moreover, this approach might have a generic impact in different fields of science and technology, enabling one to direct the recognition and host-guest properties of soft solids, which is essential for their targeted applications.
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Diniz, Ana Marta Correia Alves. "Multiresponsive supramolecular systems for information processing at the molecular level." Doctoral thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/11291.
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Dissertação para obtenção do Grau de Doutor em
Química Sustentável<br>Information processing at the molecular level requires systems able to move between
several states under control of specific inputs. Flavylium salts (2-phenyl-1-benzopyrylium salts)analogues of naturally occurring anthocyanin dyes, are a versatile family of molecules that illustrates the multistate/multiresponsive concept. On the basis of the pH and light dependent network of chemical reactions of the flavylium network, different forms can be obtained by
external stimuli exhibiting different properties.
The research work developed in the framework of this PhD thesis aimed the synthesis and study of multiresponsive covalently linked supramolecular systems, based on a flavylium
unit coupled redox-active and/or metal-complexing moieties. It is intended to increase the number of stimuli in the complex network of flavylium, including electrons and metal ions besides protons and photons (flavylium).
In an initial study, two new benzopyrylium salts with directly attached metalcomplexing
groups were synthesized and characterized (Chapter 2). The electrical stimulus was
introduced with a viologen (Chapter 3) and finally redox- and photoactive units such as Ru(II)polypyridyl complexes (Chapter 4) are discussed.
Regarding their possible applications as model compounds to optical memories, it is
expected to achieve with these new systems a larger number of states, which allow increased functionality and versatility.
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Jaabar, Ilhem Lilia. "Surface characterizations to investigate osteoarticular mesenchymal tissues : new insights to monitor the extracellular matrix remodeling at the supramolecular level." Electronic Thesis or Diss., Sorbonne université, 2022. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2022SORUS145.pdf.
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Un tissu conjonctif est un ensemble coopératif de cellules différenciées enchevêtrées dans une matrice extracellulaire (ECM). Cette dernière, particulièrement abondante, se compose principalement de protéines, telles que les collagènes, et d'un gel visqueux constitué d'eau et de protéoglycanes chargés négativement. Tous les tissus conjonctifs subissent un renouvellement constant de leur ECM, préservant ainsi l'intégrité et les propriétés des tissus. Des perturbations dans le remodelage de l'ECM, en termes de composition ou de structure supramoléculaire, peuvent avoir un impact significatif sur l'intégrité du tissu et sur ses propriétés biomécaniques, entraînant ainsi des dysfonctionnements et le développement de pathologies. Cependant, le remodelage de l’ECM est souvent étudié par des techniques biochimiques standards qui ne permettent pas de fournir des informations à l’échelle supramoléculaire. Sonder l’organisation de l’ECM à cette échelle peut contribuer significativement à la compréhension de la nature des processus biologiques et physicochimiques impliqués dans le remodelage pathologique de l’ECM. Dans cette objectif, nous avons développé une approche méthodologie originale permettant la caractérisation de tissus biologiques par des techniques de caractérisation de surface telle que l’AFM et l’XPS. Dans une première étude, l'AFM a été utilisé pour étudier l'effet de la procédure de réticulation UV/riboflavine sur la structure et les propriétés mécaniques de capsules d'épaule malades, qui sont principalement constituées de fibrilles de collagène de type I. Les résultats montrent que la procédure de réticulation a modifié les propriétés biomécaniques des capsules malades, en augmentant la rigidité des tissus sans modification de la structure et de la viabilité cellulaire.Dans une deuxième étude, nous avons étudier le remodelage de l’ECM du cartilage articulaire humain au cours de l’arthrose. Pour ce faire, nous avons caractérisé la composition, la structure et les propriétés mécaniques à différents degrés de sévérité d’arthrose par XPS et AFM. Les résultats ont permis de mettre en évidence deux phases : (1) une tentative de réparation, et (2) une dégradation irréversible du cartilage. Par ailleurs, des modifications structurales similaires à celles observées dans le cartilage arthrosique ont été observé sur des échantillons non arthrosiques traités enzymatiquement. Nos travaux ont donc permis de souligner le rôle central de l'équilibre homéostatique sur la progression de l’arthrose. Dans une troisième, un éventail de techniques de caractérisation moléculaire, biochimique et physicochimique a été utilisé pour déterminer la dynamique de minéralisation et les modifications de l’ECM au cours de la différenciation hypertrophique des chondrocytes. Cette étude a permis de montrer que la différenciation hypertrophique des chondrocytes préhypertrophiques induit un remodelage de l’ECM qui précède la minéralisation. Les analyses chimiques ont, par ailleurs, révélé que les minéraux nouvellement formés sont de l'hydroxyapatite faiblement cristallisée. La cartographie chimique révèle également la présence de débris cellulaires riches en phosphore. Ces derniers semblent être générés par l'apoptose croissante des chondrocytes<br>A connective tissue is a cooperative set of differentiated cells entangled in an extracellular matrix (ECM). The latter, which is particularly abundant, is composed mainly of proteins, such as collagens, and a viscous gel made up of water and negatively charged polysaccharides: proteoglycans. All connective tissues undergo a constant renewal of their ECM, thus preserving the integrity and properties of the tissue. Disturbances in ECM remodeling, in terms of composition or supramolecular structure, can have a significant impact on tissue integrity and biomechanical properties, leading to dysfunction and the development of pathologies. However, ECM remodeling is often studied by standard biochemical techniques that do not provide information at the supramolecular scale. Probing the organization of the ECM at this scale can contribute significantly to the understanding of the nature of the biological and physicochemical processes involved in pathological ECM remodeling. To this end, we have developed an original methodological approach allowing the characterization of biological tissues by surface characterization techniques such as AFM and XPS.In a first study, AFM was used to study the effect of the UV/riboflavin cross-linking procedure on the structure and mechanical properties of diseased shoulder capsules, which are mainly composed of type I collagen fibrils. The results show that the cross-linking procedure modified the biomechanical properties of the diseased capsules, increasing tissue stiffness without altering the structure and cell viability.In a second study, we investigated the remodeling of human articular cartilage ECM during OA. To do so, we characterized the composition, structure and mechanical properties at different degrees of OA severity by XPS and AFM. The results revealed 2 phases: (1) a repair attempt, and (2) an irreversible degradation of the cartilage. Moreover, structural modifications similar to those observed in osteoarthritic cartilage were observed on non-osteoarthritic samples treated with enzymes. Our work has thus highlighted the central role of homeostatic balance in the progression of OA.In a third study, a range of molecular, biochemical and physicochemical characterization techniques were used to determine the mineralization dynamics and ECM modifications during hypertrophic differentiation of chondrocytes. This study showed that hypertrophic differentiation of prehypertrophic chondrocytes induces ECM remodeling that precedes mineralization. Chemical analyses further revealed that the newly formed minerals are weakly crystallized hydroxyapatite. Chemical mapping also reveals the presence of phosphorus-rich cellular debris. The latter seem to be generated by the increasing apoptosis of chondrocytes
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Afsari, Mamaghani Sepideh. "The Formation of Two Dimensional Supramolecular Structures and Their Use in Studying Charge Transport at the Single Molecule Level at the Liquid-Solid Interface." Diss., Temple University Libraries, 2015. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/350915.
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Chemistry<br>Ph.D.<br>Understanding charge transport through molecular junctions and factors affecting the conductivity at the single molecule level is the first step in designing functional electronic devices using individual molecules. A variety of methods have been developed to fabricate metal-molecule-metal junctions in order to evaluate Single Molecule Conductance (SMC). Single molecule junctions usually are formed by wiring a molecule between two metal electrodes via anchoring groups that provide efficient electronic coupling and bind the organic molecular backbone to the metal electrodes. We demonstrated a novel strategy to fabricate single molecule junctions by employing the stabilization provided by the long range ordered structure of the molecules on the surface. The templates formed by the ordered molecular adlayer immobilize the molecule on the electrode surface and facilitate conductance measurements of single molecule junctions with controlled molecular orientation. This strategy enables the construction of orientation-controlled single molecule junctions, with molecules lacking proper anchoring groups that cannot be formed via conventional SMC methods. Utilizing Scanning Tunneling Microscopy (STM) imaging and STM break junction (STM-BJ) techniques combined, we employed the molecular assembly of mesitylene to create highly conductive molecular junctions with controlled orientation of benzene ring perpendicular to the STM tip as the electrode. The long range ordered structure of mesitylene molecules imaged using STM, supports the hypothesis that mesitylene is initially adsorbed on the Au(111) with the benzene ring lying flat on the surface and perpendicular to the Au tip. Thus, long range ordered structure of mesitylene facilitates formation of Au-π-Au junctions. Mesitylene molecules do not have standard anchoring groups providing enough contact to the gold electrode and the only assumable geometry for the molecules in the junction is via direct contact between Au and the π system of the benzene ring in mesitylene. SMC measurements for Au/mesitylene/Au junctions results in a molecular conductance value around 0.125Go, two orders of magnitude higher than the measured conductance of a benzene ring connected via anchoring groups. We attributed this conductance peak to charge transport perpendicular to the benzene ring due to direct coupling between the π system and the gold electrode that happens in planar orientation. The conductance we measured for planar orientation of benzene ring is two order of magnitude larger than conductance of junctions formed with benzene derivatives with conventional linkers. Thus, altering the orientation of a single benzene-containing molecule between the two electrodes from planar orientation to the upright attached via the linkers, results in altering the conductivity in a large order. Based on these findings, by utilizing STM imaging and STM-BJ in an electrochemical environment including potential induced self-assembly formation of terephthalic acid, we designed an electrochemical single molecule switch. Terephthalic acid forms large domains of ordered structure on negatively charged Au(111) surface under negative electrochemical surface potentials with the benzene ring lying flat on the surface due to hydrogen bonding between carboxylic acid groups of neighboring molecules. Formation of long range ordered structure facilitates direct contact between the π system of the benzene ring and the gold electrodes resulting in the conductance peak. On positively charged Au(111), deprotonation of carboxylic acid groups leads to absence of long range ordered structure of molecules with planar orientation and absence of the conductance peak. In this case alternating the surface (electrode) potential from negative to positive charge densities induces a transition in the adlayer structure on the surface and switches conductance value. Hence, electrochemical surface potential can, in principle, be employed as an external stimulus to switch single molecule arrangement on the surface and the conductance in the junction. The observation of conductance switching due to molecule’s arrangement in the junction lead to the hypothesis that for any benzene derivative, an orientation-dependent conductance in the junction due to the contact geometry (i.e. electrode-anchoring groups versus direct electrode-π contact) should be expected. Conventional techniques in fabricating single molecule junctions enable accessing charge transport along only one direction, i.e., between two anchoring groups. However, molecules such as benzene derivatives are anisotropic objects and we are able to measure an orientation-dependent conductance. In order to systematically study anisotropic conductivity at single molecule level, we need to measure the conductance in different and well-controlled orientations of single molecules in the junction. We employed the same EC-STM-BJ set up for SMC measurements and utilize electrochemical potential of the substrate (electrode) as the tuning source to variate the orientation of the single molecule in the junction. We investigated single molecule conductance of the benzene rings with carboxylic acid functional groups in two orientations: one with the benzene ring bridging between two electrodes using carboxylic acids as anchoring groups (upright); and one with the molecule lying flat on the substrate perpendicular to the STM tip (planar). Physisorption of these species on the Au (111) single crystal electrode surface at negative electrochemical potentials results in an ordered structure with the benzene ring in a planar orientation. Positive electrochemical potentials cause formation of the ordered structure with molecules standing upright due to coordination of a deprotonated carboxyl groups to the electrode surface. Thus, formation of the single molecule junction and consequently conductivity measurements is facilitated in two directions for the same molecule and anisotropic conductivity can be studied. In engineering well-ordered two-dimensional (2-D) molecular structures with controlled assembly of molecular species, pH can be employed as another tuning source for the molecular structures and adsorption in experiments conducted in aqueous solutions. Based on simple chemical principles, amine (NH2) groups are hydrogen bond acceptors and donors. Amines are soluble in water and protonation results in protonated (NH3+) and unprotonated (NH2) amine groups in acidic and moderately acidic/neutral solutions, respectively. Thus, amines are suitable molecular building blocks for fabricating 2-D supramolecular structures where pH is employed as a knob to manipulate intermolecular hydrogen bonding leading to phase transitions. We investigated pH induced structural changes in the 1,3,5–triaminobenzene (TAB) monolayer and the formation/disruption of hydrogen bonds between neighboring molecules. Our STM images indicate that in the concentrated acidic solution, the protonated amine groups of TAB are not able to form H-bonds and long range ordered structure of TAB does not form on the Au(111) surface. However, in moderately acidic solution (pH ~ 5.5) at room temperature, protonation on the ring carbon atom generates species capable of forming H-bonds leading to the formation of the long range ordered structures of TAB molecules. Utilizing EC-STM set up, we investigated the controllable fabrication of a TAB 2-D supramolecular structure based on amine-amine hydrogen bonding and effect of pH in formation of ordered/disordered TAB network.<br>Temple University--Theses
Book chapters on the topic "Supramolecular level"
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Fink, D., V. Hnatowicz, and P. Yu Apel. "Modifications on the Molecular and Supramolecular Level." In Fundamentals of Ion-Irradiated Polymers. Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-07326-1_8.
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Balzani, V., A. Credi, and M. Venturi. "Molecular-Level Devices." In Supramolecular Science: Where It Is and Where It Is Going. Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-011-4554-1_1.
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Chambron, Jean-Claude. "Rotaxanes: From Random to Transition Metal-Templated Threading of Rings at the Molecular Level." In Perspectives in Supramolecular Chemistry. John Wiley & Sons, Ltd., 2007. http://dx.doi.org/10.1002/9780470511510.ch6.
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Rotello, Vincent, Qing Feng, Jong-In Hong, and Julius Rebek. "Competition, Reciprocity and Mutation at the Molecular Level: Irradiation of a Synthetic Replicator Generates a Superior Species." In Self-Production of Supramolecular Structures. Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0754-9_27.
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Şener, Melih K., and Klaus Schulten. "From Atomic-Level Structure to Supramolecular Organization in the Photosynthetic Unit of Purple Bacteria." In The Purple Phototrophic Bacteria. Springer Netherlands, 2009. http://dx.doi.org/10.1007/978-1-4020-8815-5_15.
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Balzani, Vincenzo, and Alberto Credi. "Molecular‐Level Machines." In Encyclopedia of Supramolecular Chemistry. CRC Press, 2004. http://dx.doi.org/10.1081/e-esmc-120012829.
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Casimiro, Lorenzo. "The butterfly effect of photochromes." In Photochemistry. Royal Society of Chemistry, 2023. http://dx.doi.org/10.1039/bk9781837672301-00509.
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Beyond their application in switchable optical materials, photochromic molecules are also solid building blocks to make nanoscopic objects light-responsive, in order to control molecular motions, convert and store light into chemical energy, or drive chemical reactions. An outstanding quality, in these regards, is the possibility of operating a minor variation on the photochrome structure, such as via covalent or supramolecular strategies, that can ultimately result in a large tuning of the photoresponsivity, both at the molecular and material level. The PhD manuscript here highlighted, titled “Novel Photo- and Electro-responsive Supramolecular Systems and Molecular Machines” and awarded the 2020 European Photochemistry Association PhD Prize, covered several studies on how azobenzene- and terarylene-based photochromes can be employed as photoresponsive components of smart materials and how minor adjustments on their molecular structure can generate drastic changes in their performance, in a sort of butterfly effect fashion.
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Chavan, Rahul B., and Nalini R. Shastri. "Overview of Multicomponent Solid Forms." In Alternative Pain Management. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-1680-5.ch004.
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Multi-drug therapy involves the simultaneous or sequential administration of two or more drugs with similar or different mechanisms of action and is efficient in combating various ailments such as cancer, diabetes, and rheumatoid arthritis. It has emerged advantageous due to larger therapeutic benefits, an increase in patient compliance, lower administrative costs, and reduced number of prescriptions. In the recent past, the clinical success of the Novartis product Entresto (sacubitril, disodium valsartan and water) and Esteve product E-58425 (tramadol and celecoxib) has boosted the development of multi-drug . The present article is hence designed to provide an overview of different multicomponent addicts which provide option of combining the drugs at a supramolecular level (nano-sized level). Key features of multi-drug cocrystal, co-amorphous system and eutectics are described with major emphasis on screening tools, preparation methods, characterization techniques, biopharmaceutical aspects and scale up.
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Desai, Aamod V., Yong-Sheng Wei, Sujit K. Ghosh, and Satoshi Horike. "Structure, Design and Synthesis." In Flexible Metal–Organic Frameworks. Royal Society of Chemistry, 2024. http://dx.doi.org/10.1039/9781839166617-00001.
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Flexible metal–organic frameworks (MOFs) form an attractive class of solid-state materials that exhibit structural softness and a discernible response to external stimulus, physical or chemical. These features make them suitable for several applications for energy, environment and biomedicine, with the ability to tune their characteristics at the molecular level. This chapter provides a detailed analysis of their synthesis and structural properties, with the aim to derive design principles. The flexibility is stated at two levels: one part with the focus on the building blocks of such systems, and the other considering the topological viewpoint in their supramolecular assemblies. The role of metals, ligands and guest molecules in influencing their dynamic nature is discussed with several examples from a range of MOFs. The chapter closes with a perspective on the factors that can enable complete understanding of flexibility in MOFs and thereby lead to a greater understanding in terms of designing such materials.
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Chandra, Girish, Ujala Rani, Birkishore Mahto, and Gopal Kumar Mahato. "Azobenzenes: Photoswitching and Their Chemical Sensor Application." In Dye Chemistry - Exploring Colour From Nature to Lab [Working Title]. IntechOpen, 2024. http://dx.doi.org/10.5772/intechopen.1005351.
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Azobenzene is a well-known dye that undergoes fast trans-cis photoisomerization and has been widely studied and used in the development of organic functional materials. Due to its selective isomeric distribution in the excited state, azobenzene has been used as a photoswitch in the storage of information on a molecular level, photo-controllable catalysis, solar light harvesting, photo-pharmacology, optical-to-mechanical energy conversion, molecular electronic, and photonic devices. Furthermore, the characteristic and distinguishable photoelectronic properties of trans and cis azobenzene have been recently used in the sensing properties of different ions and the recognition of molecules. Here, we are going to review the recent literature where different intermolecular forces show the supramolecular properties under the stimuli of photo-light.
Conference papers on the topic "Supramolecular level"
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Georgakilas, Vasilios. "Control of Supramolecular Shapes at Nanometer Level." In STRUCTURAL AND ELECTRONIC PROPERTIES OF MOLECULAR NANOSTRUCTURES: XVI International Winterschool on Electronic Properties of Novel Materials. AIP, 2002. http://dx.doi.org/10.1063/1.1514163.
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Bräuchle, C. "Bacteriorhodopsin - Optical Processor Molecules from Nature." In Spectral Hole-Burning and Related Spectroscopies: Science and Applications. Optica Publishing Group, 1994. http://dx.doi.org/10.1364/shbs.1994.fa3.
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The field of molecular electronics is characterized by an attempt to engineer and use devices on a molecular level. Supramolecular chemistry is one way to produce such molecular devices. However, long before supramolecular chemists tried to synthesize highly organized artificial systems often employing principles of living nature, nature itself has produced and optimized biological systems on a molecular device level during a long period of evolution.
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Tballad, V. R., S. Brasselet, G. R. Desiraju, and J. Zyss. "Octupolar Crystalline Structures for Quadratic Nonlinear Optics : A Dual Crystal and Propagative Engineering Approach." In The European Conference on Lasers and Electro-Optics. Optica Publishing Group, 1998. http://dx.doi.org/10.1364/cleo_europe.1998.ctuj4.
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Crystal engineering is increasingly turning towards functional materials. Octupolar . NLO active substances are expected to overcome many of the disadvantages posed by dipolar species. While octupolar non-linearity has been demonstrated at the molecular level, its demonstration in supramolecular crystalline systems remains a challenge. Trigonal, non- centrosymmetric assemblies of trigonal molecules lead to supramolecular octupolar networks. However, most trigonal molecules do not assemble into trigonal networks. In this work, the principles of crystal engineering have been used in the carry-over of molecular symmetry into the crystals structures of six related compounds. Supramolecular retrosynthesis of a trigonal network based on herringbone interactions leads to 2,4,6-triaryloxy-l,3,5-triazines as the starting materials. Six triazines are analyzed and their molecular non-linearities are measured by HLS experiments.
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"Stress resistance on the example of supramolecular-genetic level of plant development." In Plant Genetics, Genomics, Bioinformatics, and Biotechnology. Novosibirsk ICG SB RAS 2021, 2021. http://dx.doi.org/10.18699/plantgen2021-082.
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Priimagi, Arri, Stefano Cattaneo, Robin H. A. Ras, Sami Valkama, Olli Ikkala, and Martti Kauranen. "Supramolecular guest-host systems: combining high dye doping level with low aggregation tendency." In SPIE Optics + Photonics, edited by Robert A. Norwood. SPIE, 2006. http://dx.doi.org/10.1117/12.680475.
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Aguiar, Antônio S. N., Jaqueline E. Queiroz, Pollyana P. Firmino, et al. "Experimental and theoretical study of the chalcone molecule (E)-3-(2,6-difluorophenyl)-1-(furan-2-yl)-prop-2-en-1-one." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol202033.
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In this work, we synthesized chalcone (E)-3-(2,6-difluorophenyl)-1-(furan-2-yl)-prop-2-en-1-one (DTP) via Claisen-Schmidt condensation. The supramolecular arrangement of the obtained compound was characterized by X-ray diffraction and Hirshfeld surface, and its crystalline structure was determined. The DTP molecule was studied using the Density Functional Theory, at the theoretical level M06-2X/6-311G ++G, in order to obtain information about its structural and electronic properties. A map of molecular electrostatic potential was obtained to predict the types of interactions and their acid-base behavior.
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Park, Jiyong, Byungnam Kahng та Wonmuk Hwang. "Supramolecular Structure and Stability of the GNNQQNY β-Sheet Bilayer Filament: A Computational Study". У ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-175588.
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Self-assembly of β-sheet forming peptides into filaments has drawn great interests in biomedical applications [1,2]; Hydrogels formed by filaments self-assembled from de novo designed peptides possess potential applications for cell culture scaffolds [3]. On the other hand, peptides derived from amyloidogenic proteins in neurodegenerative diseases such as Alzheimer’s and Parkinson’s also form similar β-sheet filaments in vitro. They share little sequence homology, yet filaments formed by these self-assembling peptides commonly have the cross-β structure, the key signature of the amyloid fibril. Detailed structural information of the self-assembled β-sheet filaments has been limited partly due to the difficulty in preparing ordered filament samples, and it has been only recently that solid-state nuclear magnetic resonance and x-ray techniques have revealed their molecular structure at the atomic level [4,5]. Although molecular structures of amyloid fibrils are becoming available, physical principles governing their self-assembly and the properties of the filaments are not well-understood, for which computational as well as theoretical approaches are desirable [6].
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Corredig, Milena. "Processing plant proteins colloidal structures." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/cyqr3105.
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Food systems need to be designed to better fit within planetary boundaries. It is not only important to find more sustainable protein sources, but also to create fully circular, robust supply chains. But this is only the beginning: new formulations will need to fit common dietary expectations. The utilization of plant-based protein ingredients present significant challenges in relation to their nutritional and technological functionalities. Today these proteins do not measure up when used as ingredients in conventional processes. Plant protein streams contain polydisperse colloids, and detailed studies of their behaviour during processing is only at their infancy. To predict their structure-function, their physical and chemical changes need to be followed at various length scales. Furthermore, for each food matrix, depending on the final product needs, it will be required to find the appropriate level of refinement and processing history, to reach the right balance between sustainability and processing/nutritional functionality. This is currently a significant knowledge gap. This talk will outline how processing dynamics at the molecular and supramolecular level, affect the interactions occurring with the various components in mixed matrices, and will aim to inspire researchers to find new processing and formulation approaches that will better fit plant-based ingredients utilization, and with this accelerate progress towards a shift to more sustainable diets.
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Bourne, Jonathan W., and Peter A. Torzilli. "Collagen Molecular Conformation Exhibits Strain-Rate Dependent Response to Axial Deformation in Silico." In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-205534.
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Fibrillar collagens are a group of structural proteins that self assemble into a complex ordered structure of interconnected molecules to form supramolecular fibril structures. These collagens have three subgroups based on sequence similarity, of which clade A includes the most abundant fibrillar collagens, types I, II, and III. The fibrous hierarchical structures starts with individual collagen molecules that are crosslinked by enzymes to other collagen molecules to form micro fibrils, which aggregate and link to form sub fibrils, then larger fibrils and in some tissues continuing to assemble into larger levels of fascicles and above.
Reports on the topic "Supramolecular level"
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Kirchhoff, Helmut, and Ziv Reich. Protection of the photosynthetic apparatus during desiccation in resurrection plants. United States Department of Agriculture, 2014. http://dx.doi.org/10.32747/2014.7699861.bard.
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In this project, we studied the photosynthetic apparatus during dehydration and rehydration of the homoiochlorophyllous resurrection plant Craterostigmapumilum (retains most of the photosynthetic components during desiccation). Resurrection plants have the remarkable capability to withstand desiccation, being able to revive after prolonged severe water deficit in a few days upon rehydration. Homoiochlorophyllous resurrection plants are very efficient in protecting the photosynthetic machinery against damage by reactive oxygen production under drought. The main purpose of this BARD project was to unravel these largely unknown protection strategies for C. pumilum. In detail, the specific objectives were: (1) To determine the distribution and local organization of photosynthetic protein complexes and formation of inverted hexagonal phases within the thylakoid membranes at different dehydration/rehydration states. (2) To determine the 3D structure and characterize the geometry, topology, and mechanics of the thylakoid network at the different states. (3) Generation of molecular models for thylakoids at the different states and study the implications for diffusion within the thylakoid lumen. (4) Characterization of inter-system electron transport, quantum efficiencies, photosystem antenna sizes and distribution, NPQ, and photoinhibition at different hydration states. (5) Measuring the partition of photosynthetic reducing equivalents between the Calvin cycle, photorespiration, and the water-water cycle. At the beginning of the project, we decided to use C. pumilum instead of C. wilmsii because the former species was available from our collaborator Dr. Farrant. In addition to the original two dehydration states (40 relative water content=RWC and 5% RWC), we characterized a third state (15-20%) because some interesting changes occurs at this RWC. Furthermore, it was not possible to detect D1 protein levels by Western blot analysis because antibodies against other higher plants failed to detect D1 in C. pumilum. We developed growth conditions that allow reproducible generation of different dehydration and rehydration states for C. pumilum. Furthermore, advanced spectroscopy and microscopy for C. pumilum were established to obtain a detailed picture of structural and functional changes of the photosynthetic apparatus in different hydrated states. Main findings of our study are: 1. Anthocyan accumulation during desiccation alleviates the light pressure within the leaves (Fig. 1). 2. During desiccation, stomatal closure leads to drastic reductions in CO2 fixation and photorespiration. We could not identify alternative electron sinks as a solution to reduce ROS production. 3. On the supramolecular level, semicrystalline protein arrays were identified in thylakoid membranes in the desiccated state (see Fig. 3). On the electron transport level, a specific series of shut downs occur (summarized in Fig. 2). The main events include: Early shutdown of the ATPase activity, cessation of electron transport between cyt. bf complex and PSI (can reduce ROS formation at PSI); at higher dehydration levels uncoupling of LHCII from PSII and cessation of electron flow from PSII accompanied by crystal formation. The later could severe as a swift PSII reservoir during rehydration. The specific order of events in the course of dehydration and rehydration discovered in this project is indicative for regulated structural transitions specifically realized in resurrection plants. This detailed knowledge can serve as an interesting starting point for rationale genetic engineering of drought-tolerant crops.