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Zone refining is a technology of deeply purifying metals. Its essence is to use the difference in solubility of impurity elements in the solid and molten state of the main metal to precipitate the impurities or change the distribution of the impurity elements. It provides an effective and easy method for preparing high-purity metals.
18 May 2021
ZnO Photocatalysts for the Treatment of Wastewater
The presence of contaminants in wastewater, surface water, groundwater, and drinking water is a serious threat to human and environmental health. Their toxic effects and resistance towards conventional water treatment methods have compelled the scientific community to search for an environmentally friendly method that could efficiently degrade toxic contaminants. In this regard, visible light active photocatalysts have proved to be efficient in eliminating a wide variety of water toxins. A plethora of research activities have been carried out and significant amounts of funds are spent on the monitoring and removal of water contaminants, but relatively little attention has been paid to the degradation of persistent water pollutants. In this regard, nanoparticles of doped ZnO are preferred options owing to their low recombination rate and excellent photocatalytic and antimicrobial activity under irradiation of solar light.
18 Feb 2022
Zinc-Based Metal-Organic Frameworks
The design and structural frameworks for targeted drug delivery of medicinal compounds and improved cell imaging have been developed with several advantages. However, metal-organic frameworks (MOFs) are supplemented tremendously for medical uses with efficient efficacy. These MOFs are considered as an absolutely new class of porous materials, extensively used in drug delivery systems, cell imaging, and detecting the analytes, especially for cancer biomarkers, due to their excellent biocompatibility, easy functionalization, high storage capacity, and excellent biodegradability. While Zn-metal centers in MOFs have been found by enhanced efficient detection and improved drug delivery, these Zn-based MOFs have appeared to be safe as elucidated by different cytotoxicity assays for targeted drug delivery. On the other hand, the MOF-based heterogeneous catalyst is durable and can regenerate multiple times without losing activity. Therefore, as functional carriers for drug delivery, cell imaging, and chemosensory, MOFs’ chemical composition and flexible porous structure allowed engineering to improve their medical formulation and functionality.
16 Feb 2022
Willardiine and Its Analogues
Willardiine was first identified by Rolf Gimelin in 1959 from the extracts of seeds of Acacia willardiana. Structurally it corresponds to (2S)-2-amino-3-(2,4-dioxopyrimidin-1-yl)propanoic acid (1) and carrying an uracil moiety it can be ascribed to the category of nucleoamino acids. Willardiine is synthesized by the single specific enzyme uracilylalanine synthase, and the N–heterocyclic moiety uracil obtained by the orotate pathway proved to be an effective bioisostere for the distal carboxyl group of L-glutamate. Different aspects on both chemistry and biotechnological applications of willardine/willardine-analogues and nucleopeptides will be reviewed herein.
18 Oct 2022
Voltammetric Techniques in Assessing the Food Quality
Generally, the detection of analytes or molecules present in food materials interferes with the chromophore moieties in the food. Some of the common problems with the use of conventional methods in determining food quality are low sensitivity to redox changes, turbidity, low spectrum resolution, and scattering issues related to the sample. Moreover, the miniaturization and portability of detectors are the biggest disadvantages of conventional methods. Therefore, there is a huge demand for quick, robust, selective, and easy methods, such as voltammetric methods, for determining the food’s quality. They exhibit a higher level of selectivity for the redox reactions, and a faster response. They are very simple, economical, and their portability with unlimited miniaturization has made them an ideal and popular choice for assessing the food quality compared with other analytical methods.
23 Dec 2022
Vitamin E is a common compound used for tocopherols and tocotrienols (α, β, γ, δ); it is the component of many natural products of both plant and animal origin.
12 Jul 2021
Visual pH Sensors
The pH sensors are gaining widespread attention as non-destructive tools, visible to the human eye, and are capable of real-time and in-situ response.
31 May 2021
Vancomycin with Muramyl Pentapeptide
Vancomycin and a native muramyl pentapeptide ended with D-alanine (MPP-D-Ala), and vancomycin and a modified muramyl pentapeptide ended with D-serine (MPP-D-Ser) form complexes in a very specific way. This complexes provide a basis for characterizing the type and stability of the connection. The type of experimentally measured and computer-simulated interactions opens the field for discussion on possible modifications to the structure of vancomycin or muramyl pentapeptide to obtain their desired characteristics.
07 Feb 2022
Valence-shell Electron-pair Repulsion Model
There are the following main assumptions of the Valence-shell Electron-pair Repulsion (VSEPR) model. - The arrangement of covalent bonds of the atom centre analyzed depends on the number of electron pairs in its valence shell: bonds and nonbonding pairs as lone electron pairs. - The arrangement of valence electron pairs around the centre considered is to maximize their distances apart. - The non-valence electrons - inner electrons with nucleus (i.e. the core) possess the spherical symmetry (or at least it is in force for the main groups elements). It is worth to note that the intra- and intermolecular interactions influence on electronic and molecular structures in accordance with this VSEPR model.
06 Sep 2021
Using CNSL for the Synthesis of Surfactants
Cashew Nut Shell Liquid (CNSL) is a promising non-edible renewable resource, directly extracted from the shell of the cashew nut. The interesting structure of CNSL and its components (cardanol, anacardic acid and cardol) lead to the synthesis of biobased surfactants.
10 Mar 2022
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