Diarylethene Dyes

2020 ◽  
Vol 5 (7) ◽  
Author(s):  
Andrew Towns
Keyword(s):  
Structural Features ◽  
Photochromic Dye ◽  
Potential Applications

AbstractThis article introduces the general characteristics of the diarylethene class of photochromic dye and the structural features that make photochromism possible. It touches on the methodologies employed to synthesize these compounds as well as the influences that typical substitution patterns exert on photocoloration. A demonstration is then given of the great diversity pertaining to the potential applications in which researchers are seeking to exploit them as functional colorants.

scholarly journals Unusual Structural Features in the Adduct of Dirhodium Tetraacetate with Lysozyme

2021 ◽  
Vol 22 (3) ◽  
pp. 1496
Author(s):  
Domenico Loreto ◽  
Giarita Ferraro ◽  
Antonello Merlino
Keyword(s):  
Anticancer Agents ◽  
Structural Features ◽  
Side Chain ◽  
Side Chains ◽  
Valuable Insight ◽  
Experimental Conditions ◽  
Egg White Lysozyme ◽  
Potential Applications ◽  
Model Protein ◽  
Hen Egg White

The structures of the adducts formed upon reaction of the cytotoxic paddlewheel dirhodium complex [Rh2(μ-O2CCH3)4] with the model protein hen egg white lysozyme (HEWL) under different experimental conditions are reported. Results indicate that [Rh2(μ-O2CCH3)4] extensively reacts with HEWL:it in part breaks down, at variance with what happens in reactions with other proteins. A Rh center coordinates the side chains of Arg14 and His15. Dimeric Rh–Rh units with Rh–Rh distances between 2.3 and 2.5 Å are bound to the side chains of Asp18, Asp101, Asn93, and Lys96, while a dirhodium unit with a Rh–Rh distance of 3.2–3.4 Å binds the C-terminal carboxylate and the side chain of Lys13 at the interface between two symmetry-related molecules. An additional monometallic fragment binds the side chain of Lys33. These data, which are supported by replicated structural determinations, shed light on the reactivity of dirhodium tetracarboxylates with proteins, providing useful information for the design of new Rh-containing biomaterials with an array of potential applications in the field of catalysis or of medicinal chemistry and valuable insight into the mechanism of action of these potential anticancer agents.

scholarly journals Half- and mixed-sandwich metallacarboranes for potential applications in medicine

2019 ◽  
Vol 91 (4) ◽  
pp. 563-573 ◽  
Author(s):  
Marta Gozzi ◽  
Benedikt Schwarze ◽  
Evamarie Hey-Hawkins
Keyword(s):  
Organic Chemistry ◽  
Transition Metal ◽  
Transition Metals ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Structural Features ◽  
Biological Stability ◽  
Potential Applications ◽  
Sandwich Type ◽  
Isolobal Analogy

Abstract Today, medicinal chemistry is still clearly dominated by organic chemistry, and commercially available boron-based drugs are rare. In contrast to hydrocarbons, boranes prefer the formation of polyhedral clusters via delocalized 3c2e bonds, such as polyhedral dicarba-closo-dodecaborane(12) (closo-C2B10H12). These clusters have remarkable biological stability, and the three isomers, 1,2- (ortho), 1,7- (meta), and 1,12-dicarba-closo-dodecaborane(12) (para), have attracted much interest due to their unique structural features. Furthermore, anionic nido clusters ([7,8-C2B9H11]2−), derived from the neutral icosahedral closo cluster 1,2-dicarba-closo-dodecaborane(12) by deboronation followed by deprotonation are suitable ligands for transition metals and offer the possibility to form metallacarboranes, for example via coordination through the upper pentagonal face of the cluster. The isolobal analogy between the cyclopentadienyl(–1) ligand (Cp−) and [C2B9H11]2− clusters (dicarbollide anion, Cb2−) is the motivation in using Cb2− as ligand for coordination to a metal center to design compounds for various applications. This review focuses on potential applications of half- and mixed-sandwich-type transition metal complexes in medicine.

scholarly journals Structural Revisions in Natural Ellagitannins

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1901 ◽  
Author(s):  
Hidetoshi Yamada ◽  
Shinnosuke Wakamori ◽  
Tsukasa Hirokane ◽  
Kazutada Ikeuchi ◽  
Shintaro Matsumoto
Keyword(s):  
Phenolic Compounds ◽  
Biological Activities ◽  
Structural Diversity ◽  
Structural Features ◽  
Complex Structures ◽  
Structural Determination ◽  
Major Focus ◽  
Chebulagic Acid ◽  
Potential Applications

Ellagitannins are literally a class of tannins. Triggered by the oxidation of the phenolic parts on β-pentagalloyl-d-glucose, ellagitannins are generated through various structural conversions, such as the coupling of the phenolic parts, oxidation to highly complex structures, and the formation of dimer and lager analogs, which expand the structural diversity. To date, more than 1000 natural ellagitannins have been identified. Since these phenolic compounds exhibit a variety of biological activities, ellagitannins have potential applications in medicine and health enhancement. Within the context of identifying suitable applications, considerations need to be based on correct structural features. This review describes the structural revisions of 32 natural ellagitannins, namely alnusiin; alnusnin A and B; castalagin; castalin; casuarinin; cercidinin A and B; chebulagic acid; chebulinic acid; corilagin; geraniin; isoterchebin; nobotanin B, C, E, G, H, I, J, and K; punicalagin; punicalin; punigluconin; roxbin B; sanguiin H-2, H-3, and H-6; stachyurin; terchebin; vescalagin; and vescalin. The major focus is on the outline of the initial structural determination, on the processes to find the errors in the structure, and on the methods for the revision of the structure.

scholarly journals Pharmaceutical Properties and Applications of a Natural Polymer from Grewia mollis

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Elijah I. Nep ◽  
Patricia O. Odumosu ◽  
Ndidi C. Ngwuluka ◽  
Patrick O. Olorunfemi ◽  
Nelson A. Ochekpe
Keyword(s):  
Stem Bark ◽  
Structural Features ◽  
Dosage Forms ◽  
Research Activity ◽  
Pharmaceutical Dosage Forms ◽  
Potential Applications ◽  
Controlled Release Formulations ◽  
Ethnobotanical Uses ◽  
Pharmaceutical Properties ◽  
Grewia Gum

The use of naturally occurring biocompatible materials has been the focus of recent research activity in the design of dosage forms for immediate and controlled release formulations. Grewia gum is an intracellular gum obtained by extraction from the inner stem bark of the shrub Grewia mollis (Malvaceae). It grows abundantly (wild or cultivated) in the middle belt region of Nigeria, and the mucilage has been used by indigenes of this belt as thickener in soups. Grewia gum has been investigated for potential applications in pharmaceutical dosage forms. The industrial extrapolation of the applications of the gum has, however, been slowed by the limited structural, toxicological, and stability data available on the gum. This paper highlights ethnobotanical uses of G. mollis shrub and discusses the structural features, functional properties, and applications of grewia gum with emphases on its pharmaceutical potentials.

scholarly journals Tau Seeding Mouse Models with Patient Brain-Derived Aggregates

2021 ◽  
Vol 22 (11) ◽  
pp. 6132
Author(s):  
Aiko Robert ◽  
Michael Schöll ◽  
Thomas Vogels
Keyword(s):  
Cell Types ◽  
Structural Features ◽  
Transgenic Animal ◽  
Tau Proteins ◽  
Tau Pathology ◽  
Cell Type Specificity ◽  
Transgenic Animal Models ◽  
Potential Applications ◽  
Functional Consequences ◽  
Human Brains

Tauopathies are a heterogeneous class of neurodegenerative diseases characterized by intracellular inclusions of aggregated tau proteins. Tau aggregates in different tauopathies have distinct structural features and can be found in different cell types. Transgenic animal models overexpressing human tau have been used for over two decades in the research of tau pathology. However, these models poorly recapitulate the heterogeneity of tauopathies found in human brains. Recent findings demonstrate that injection of purified tau aggregates from the brains of human tauopathy patients recapitulates both the structural features and cell-type specificity of the tau pathology of the donor tauopathy. These models may therefore have unique translational value in the study of functional consequences of tau pathology, tau-based diagnostics, and tau targeting therapeutics. This review provides an update of the literature relating to seeding-based tauopathy and their potential applications.

scholarly journals Graphitic carbon nitride quantum dots: Synthesis and applications

2021 ◽  
pp. 58-73
Author(s):  
Dang Dinh Khoi
Keyword(s):  
Quantum Dots ◽  
Carbon Nitride ◽  
Structural Features ◽  
Graphitic Carbon ◽  
Synthetic Methods ◽  
Graphitic Carbon Nitride ◽  
Vast Number ◽  
Future Challenges ◽  
Potential Applications ◽  
Good Biocompatibility

Graphitic-carbon nitride quantum dots (g-CNQDs), a rising star in the carbon nitride family, has shown great potential in many fields including chemical and biomedical applications due to their good biocompatibility, stable fluorescence, high quantum yield, and nontoxicity. For this reason, enormous efforts have been devoted to optimizing synthetic methods and structures of g-CNQDs to discover the inner properties and structural features in the intriguing system. Also, a vast number of studies have been pursued to discuss the potential applications of g-CNQDs in chemical and biomedical areas. In this review, recent advances in synthesis and applications of g-CNQDs were summarized and the future challenges as well as opportunities of these g-CNQDs in the chemical and biomedical fields will be highlighted.

scholarly journals Application of Stirling Engine Type Alpha Powered by the Recovery Energy on Vessels

2020 ◽  
Vol 27 (1) ◽  
pp. 96-106
Author(s):  
Jacek Kropiwnicki
Keyword(s):  
Thermal Energy ◽  
Mechanical Energy ◽  
Structural Features ◽  
Stirling Engine ◽  
Engine Simulation ◽  
Engine Room ◽  
Stirling Engines ◽  
Potential Applications ◽  
The Impact ◽  
Engine Type

AbstractThe Stirling engine is a device in which thermal energy is transformed into mechanical energy without any contact between the heat carrier and the working gas enclosed in the engine. The mentioned feature makes this type of engine very attractive for the use of the recovery energy taken from other heat devices. One of the potential applications of Stirling engines is the use of thermal energy generated in the ship’s engine room for producing electricity. The work presents the concept of the Stirling engine type alpha powered by the recovery energy. The model of Stirling engine developed in this work allows a quantitative assessment of the impact of the design features of the engine, primarily the heat exchange surfaces and the volume of control spaces, on the achieved efficiency and power of the engine. Using an iterative procedure, Stirling engine simulation tests were carried out taking into account the variable structural features of the system. The influence of the size of the heater and the cooler, as well as the effectiveness of the regenerator and the temperature of the heat source on the efficiency and power produced by the Stirling engine have been presented.

Molecular modeling of porphyrin-based conjugates and subphthalocyanine aggregates

2009 ◽  
Vol 13 (04n05) ◽  
pp. 494-508 ◽  
Author(s):  
Víctor R. Ferro ◽  
Luis A. Poveda ◽  
Rafael Lopez ◽  
José M. García de la Vega
Keyword(s):  
Charge Separation ◽  
Theoretical Study ◽  
Theoretical Models ◽  
Structural Features ◽  
New Materials ◽  
Potential Applications ◽  
Donor Acceptor ◽  
The Stability ◽  
Porphyrin Dimers

A theoretical study was carried out on both porphyrin-based conjugates (with interest in the so-called artificial photosynthesis) and subphthalocyanine aggregates (with potential applications as new materials for optoelectronics, solar energy and other uses). A simple molecular orbital model for studying the role of the spacer groups in the electron transfer in porphyrin-quinone conjugates was developed. The influence of the π-π interaction, hydrogen association and covalent linkage on the stability and structural features in porphyrin-porphyrin complexes as well as the charge separation in donor-acceptor porphyrin dimers, were reproduced. Theoretical models suggest the potential feasibility of SubPc's aggregative processes leading to nanometer-sized fully aromatic fullerene-like molecular architectures.

Structural Properties and ELNES of Polycrystalline and Nanoporous Mg3N2

2020 ◽  
Vol 26 (1) ◽  
pp. 102-111
Author(s):  
Olivia Wenzel ◽  
Viktor Rein ◽  
Radian Popescu ◽  
Claus Feldmann ◽  
Dagmar Gerthsen
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Crystal Size ◽  
Bulk Material ◽  
Structural Features ◽  
Edge Structure ◽  
Transmission Electron ◽  
Potential Applications ◽  
Magnesium Nitride ◽  
Electron Energy Loss

AbstractNanoporous, high-purity magnesium nitride (Mg3N2) was synthesized with a liquid ammonia-based process, for potential applications in optoelectronics, gas separation and catalysis, since these applications require high material purity and crystallinity, which has seldom been demonstrated in the past. One way to evaluate the degree of crystalline near-range order and atomic environment is electron energy-loss spectroscopy (EELS) in a transmission electron microscope. However, there are hardly any data on Mg3N2, which makes identification of electron energy-loss near-edge structure (ELNES) features difficult. Therefore, we have studied nanoporous Mg3N2 with EELS in detail in comparison to EELS spectra of bulk Mg3N2, which was analyzed as a reference material. The N-K and Mg-K edges of both materials are similar. Despite having the same crystal structure, however, there are differences in fine-structural features, such as shifts and absences of peaks in the N-K and Mg-K edges of nanoporous Mg3N2. These differences in ELNES are attributed to coordination changes in nanoporous Mg3N2 caused by the significantly smaller crystallite size of 2–6 nm compared to the larger (25–125 nm) crystal size in a bulk material.

scholarly journals Aerogels as Promising Thermal Insulating Materials: An Overview

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Prakash C. Thapliyal ◽  
Kirti Singh
Keyword(s):  
Thermal Insulation ◽  
Energy Efficient ◽  
Structural Features ◽  
Primary Energy ◽  
Building Envelope ◽  
High Porosity ◽  
Thermal Insulating ◽  
Wide Range ◽  
Potential Applications ◽  
Insulation Systems

Aerogels are solids with high porosity (<100 nm) and hence possess extremely low density (∼0.003 g/cm3) and very low conductivity (∼10 mW/mK). In recent years, aerogels have attracted more and more attention due to their surprising properties and their existing and potential applications in wide range of technological areas. An overview of aerogels and their applications as the building envelope components and respective improvements from an energy efficiency perspective including performance is given here. This overview covers thermal insulation properties of aerogels and studies regarding structural features which will be helpful in buildings envelope. The improvements of thermal insulation systems have future prospects of large savings in primary energy consumption. It can be concluded that aerogels have great potential in a wide range of applications as energy efficient insulation, windows, acoustics, and so forth.

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