Certain Aspects of Silver and Silver Nanoparticles in Wound Care: A Minireview

Resistance to antimicrobial agents by pathogenic bacteria has emerged in recent years and is a major health problem. In this context silver and silver nanoparticles (AgNP) have been known to have inhibitory and bactericidal effects and was used throughout history for treatment of skin ulcer, bone fracture, and supporting wound healing. In all of these applications prevention and treatment of bacterial colonized/infected wounds are critical. In this context silver and its derivatives play an important role in health care. Silver is widely used in clinical practice in the form of silver nitrate and/or silver sulfadiazine. In the last few years silver nanoparticles entered into clinical practice as both antimicrobial and antifungal agents. In addition, nanosilver is used in coating medical devices (catheters) and as component of wound dressings. In this paper we present summarized information about silver and nanoparticles made of silver in the context of their useful properties, especially antibacterial ones, being of a great interest for researchers and clinicians

High-Performance Liquid Chromatographic Separation of Stereoisomers of ß-Methyl-Substituted Unusual Amino Acids Utilizing Ion Exchangers Based on Cinchona Alkaloids

Novel peptides based on common amino acid building blocks may serve as possible drug candidates; however, their flexible structures may require stabilization via the incorporation of conformational constraints. The insertion of unusual amino acids is a feasible option that may provide improved pharmacokinetic and pharmacodynamic properties of such peptide-type drugs. The stereochemical purity of these kinds of building blocks must be verified by an efficient separation technique, such as high-performance liquid chromatography. Here, we present and discuss the results of the stereoselective separation mechanism of ß-methylated phenylalanine (ß-MePhe), tyrosine (ß-MeTyr), 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (ß-MeTic), and cyclohexylalanine (ß-MeCha) together with non-methylated Phe, Tyr, Tic, and Cha applying Cinchona alkaloid-based chiral stationary phases (CSPs). The studied zwitterionic CSPs acting as ion exchangers provided optimal performance in the polar ionic mode when methanol or a mixture of methanol and acetonitrile was utilized as the mobile phase together with organic acid and base additives. It was found that the basicity of small amines applied as mobile phase additives did not directly influence the chromatographic ion exchange concept. However, the size of the amines and their concentration led to a reduced retention time following the principles of ion exchange chromatography. On the basis of a systematic study of the effects of the eluent composition on the chromatographic behavior, important structure–retention and enantioselectivity relationships could be revealed. Through a temperature study, it has become evident that the composition of the eluent and the structure of analytes markedly affect the thermodynamic properties

Complementarity of Δ opioid ligand pharmacophore and receptor models

The elaboration of a pharmacophore model for the Δ opioid receptor selective ligand JOM-13 (Tyr–c[ D -Cys–Phe– D -Pen]OH) and the parallel, independent development of a structural model of the Δ receptor are summarized. Although the backbone conformation of JOM-13's tripeptide cycle is well defined, considerable conformational lability is evident in the Tyr 1 residue and in the Phe 3 side chain, key pharmacophore elements of the ligand. Replacement of these flexible features of the ligand by more conformationally restricted analogues and subsequent correlation of receptor binding and conformational properties allowed the number of possible binding conformations of JOM-13 to be reduced to two. Of these, one was chosen as more likely, based on its better superposition with other conformationally constrained Δ receptor ligands. Our model of the Δ opioid receptor, constructed using a general approach that we have developed for all rhodopsin-like G protein-coupled receptors, contains a large cavity within the transmembrane domain that displays excellent complementarity in both shape and polarity to JOM-13 and other Δ ligands. This binding pocket, however, cannot accommodate the conformer of JOM-13 preferred from analysis of ligands, alone. Rather, only the “alternate” allowed conformer, identified from analysis of the ligands but “disfavored” because it does not permit simultaneous superposition of all pharmacophore elements of JOM-13 with other Δ ligands, fits the binding site. These results argue against a simple view of a single, common fit to a receptor binding site and suggest, instead, that at least some binding site interactions of different ligands may differ. © 2000 John Wiley & Sons, Inc. Biopoly 51: 426–439, 1999Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34323/1/5_ftp.pd

Comparing Aquatic Invertebrate Samples Collected from Chicagoland Waterways to Midwest Biodiversity Institute Waterbody Quality Reports.

My project was focused on comparing the field work and research that I completed with Natalia Szklaruk in fall 2021 to the research done by Midwest Biodiversity Institute. The goal was to see if there is a correlation between the health of a waterway, specifically conductivity levels, and the amount of species and taxa present in that area. The process consisted of sampling various waterways in the Chicagoland area, sorting and identifying the species collected, and then researching how our results compared to others and what the implications of this research may be. The results indicated that there is no clear correlation between conductivity levels and the amount of species present in a waterway. Further research could be done to see if other water quality factors are having an effect on native and non-native species health

Sprawozdanie z 49. Międzynarodowej Olimpiady Chemicznej w Nakhon Pathom (Tajlandia)

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