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Topic Review
Degradation and Life Prediction of Polyethylene
Polyethylene is one of the most significant and useful polymers that has been extensively studied for use as a plastic material. The benefits of using polyethylene as a commercial plastic material include its excellent mechanical properties, good flexibility, good chemical resistance, lightweight properties, good thermal stability, and high-cost performance. The piping sector has been impacted by the trend of replacing steel with plastic during the past, resulting in the steady replacement of metal-based pipes with plastic pipes. Polyethylene pipes are the most commonly utilized among them. Consider the case of high-density polyethylene pipes. Its market worth was USD 15.975 billion in 2018, and 9.283 million tons were consumed each year. The service life of polyethylene pipes will not be less than 50 years, and it will continue to grow at a rate of at least 5% annually in the upcoming years.
  • 953
  • 10 Mar 2023
Topic Review
Diketopyrrolopyrrole Fluorescent Probes
Diketopyrrolopyrrole (DPP) organic dyes show an exceptional photophysical features (high-fluorescence quantum yield (FQY), good photochemical and thermal stability) that are essential properties for biological applications. This organic dye pigment of DPP is highly effective as it have shown promising results in various applications of AIE, solid-state emission, bio-imaging, cancer therapy and biorecognition of other essential biological components (biomolecules, proteins, enzymes, mitochondria stains) etc. All these results from the DPPs' high fluorescence quantum yield along with its imperatively low-energy fluorescent probe derivatives. Owing to its outstanding photophysical features, in the last decade numerous research papers have been reported with essentially positive results especially for supramolecular chemistry applications. Therefore in a nutshell, this exciting and attractive research area is presently at its infancy, so great efforts needs to be given to it in order to uncover other potentials which might be hidden that are yet to be known to the scientific communities, especially chemists in order to significantly advance it research horizon higher. 
  • 952
  • 27 Mar 2021
Topic Review
Isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae — that is, same number of atoms of each element — but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Isomers do not necessarily share similar chemical or physical properties. Two main forms of isomerism are structural or constitutional isomerism, in which bonds between the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the same but the relative positions of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different isotopologues. The depth of analysis depends on the field of study or the chemical and physical properties of interest. The English word "isomer" (/ˈaɪsəmər/) is a back-formation from "isomeric", which was borrowed through German isomerisch from Swedish isomerisk; which in turn was coined from Greek ἰσόμερoς isómeros, with roots isos = "equal", méros = "part".
  • 952
  • 20 Oct 2022
Topic Review
Textile Materials for Skin
Textile materials, as a suitable matrix for different active substances facilitating their gradual release, can have an important role in skin topical or transdermal therapy. Characterized by compositional and structural variety, those materials readily meet the requirements for applications in specific therapies.
  • 951
  • 06 Apr 2021
Topic Review
Advances of MXenes
MXenes are synthesized from ‘MAX’ phases by the selective etching of ‘A’ layers. The MAX phases are conductive 2D layers of transition metal carbides/nitrides interconnected by the ‘A’ element with strong ionic, metallic, and covalent bonds.
  • 950
  • 04 Jul 2022
Topic Review
Benchmarking Data Sets
Developing realistic data sets for evaluating virtual screening methods is a task that has been tackled by the cheminformatics community for many years. Numerous artificially constructed data collections were developed, such as DUD, DUD-E, or DEKOIS. However, they all suffer from multiple drawbacks, one of which is the absence of experimental results confirming the impotence of presumably inactive molecules, leading to possible false negatives in the ligand sets. In light of this problem, the PubChem BioAssay database, an open-access repository providing the bioactivity information of compounds that were already tested on a biological target, is now a recommended source for data set construction. Nevertheless, there exist several issues with the use of such data that need to be properly addressed. In this article, an overview of benchmarking data collections built upon experimental PubChem BioAssay input is provided, along with a thorough discussion of noteworthy issues that one must consider during the design of new ligand sets from this database. The points raised in this review are expected to guide future developments in this regard, in hopes of offering better evaluation tools for novel in silico screening procedures.
  • 949
  • 26 Oct 2020
Topic Review
Magnetic Iron Oxide Nanoparticle Synthesis
Iron oxides are chemical compounds which havedifferent polymorphic forms, including γ-Fe2O3 (maghemite), Fe3O4(magnetite), and FeO (wustite). Among them, the most studiedare γ-Fe2O3 and Fe3O4,as they possess extraordinary properties at the nanoscale (such as superparamagnetism, high specific surface area, biocompatible etc.),because at this size scale, the quantum effectsaffect matter behavior and optical, electrical and magnetic properties.Therefore, in the nanoscale, these materials become ideal for surface functionalization and modification in various applications such as separation techniques, magnetic sorting (cells and other biomolecules etc.), drug delivery, cancer hyperthermia, sensing etc., and also for increased surface area-to-volume ratio, which allows for excellent dispersibility in the solution form.The current methods used are partially and passively mixed reactants, and,thus, every reaction has a different proportion of all factors which causes further difficulties in reproducibility.Direct active and complete mixing and automated approaches could be solutions to thissize- and shape-controlled synthesis, playing a key role in its exploitation for scientific or technological purposes. An ideal synthesis method should be able to allow reliable adjustment of parameters andcontrol over the following: fluctuation in temperature;pH, stirring rate;particle distribution; size control;concentration; and control over nanoparticle shape andcomposition i.e., crystallinity, purity, and rapid screening. Iron oxide nanoparticle (IONP)-based available clinical applications are RNA/DNAextraction and detection of infectious bacteria andviruses. Such technologies are important at POC (point of care) diagnosis.IONPs can play a key role in these perspectives.Although there are various methods for synthesis of IONPs,one of the most crucial goals is to control size and properties with high reproducibility to accomplish successful applications.Using multiple characterization techniques to identify and confirm the oxide phase of iron can provide better characterization capability. It is very important to understand the in-depth IONP formation mechanism, enabling better control over parameters and overall reaction and, by extension, properties of IONPs.This workprovides an in-depth overview ofdifferent properties, synthesis methods, and mechanisms of iron oxide nanoparticles (IONPs) formation, and the diverse range of theirapplications. Differentcharacterization factors and strategiesto confirm phase purity in the IONP synthesis field are reviewed.First, properties of IONPs and various synthesis routes with their merits and demerits are described. We also describe different synthesis strategies and formation mechanisms for IONPs such as for: wustite (FeO), hematite(α-Fe2O3), maghemite(ɤ-Fe2O3) and magnetite(Fe3O4). We also describe characterization of these nanoparticles and various applications in detail. In conclusion, we present a detailed overview on the properties, size-controlled synthesis, formation mechanisms and applications of IONPs.
  • 949
  • 30 Oct 2020
Topic Review
Different Schiff Bases
Schiff bases are a vast group of compounds characterized by the presence of a double bond linking carbon and nitrogen atoms, the versatility of which is generated in the many ways to combine a variety of alkyl or aryl substituents.
  • 948
  • 18 Feb 2022
Topic Review
AIE-Active Photosensitizers
Photodynamic therapy (PDT) is a non-invasive approach for tumor elimination that is attracting more and more attention due to the advantages of minimal side effects and high precision. In typical PDT, reactive oxygen species (ROS) generated from photosensitizers play the pivotal role, determining the efficiency of PDT. However, applications of traditional PDT were usually limited by the aggregation-caused quenching (ACQ) effect of the photosensitizers employed. Fortunately, photosensitizers with aggregation-induced emission (AIE-active photosensitizers) have been developed with biocompatibility, effective ROS generation, and superior absorption, bringing about great interest for applications in oncotherapy.
  • 948
  • 27 May 2022
Topic Review
Smart Contrast Agents in MRI
Zinc and copper are essential cations involved in numerous biological processes; and variations in their concentrations can cause diseases; such as neurodegenerative diseases; diabetes and cancers. Hence, the detection and quantification of these cations is of utmost importance for the early diagnosis of disease. MRI responsive contrast agents (mainly Lanthanide 3+ complexes), relying on a change in state of the MRI active part upon interaction with the cation of interest e.g. switch ON/OFF or vice versa, have been successfully utilized to detect zinc and are now being developed to detect Copper(II). These paramagnetic probes mainly exploit the relaxation-based properties (T1-based contrast agents), but also the paramagnetic induced hyperfine shift properties (paraCEST and parashift probes) of the contrast agents. The challenges encountered going from zinc to copper(II) detection are discussed. Depending on the response mechanism, the use of fast-field cycling MRI seems promising to increase the detection field while keeping a good response. In vivo applications of cation responsive MRI probes are only at their infancy and the recent developments are described, along with the associated quantification problems.
  • 948
  • 08 Jan 2021
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