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Wyniki wyszukiwania dla: Glial Fibrillary Acid
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Impact of imipramine on proteome of rat primary glial cells
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Hyaluronic acid/tannic acid films for wound healing application
PublikacjaIn this study, thin films based on hyaluronic acid (HA) with tannic acid (TA) were investigated in three different weight ratios (80HA/20TA, 50HA/50TA, 20HA/80TA) for their application as materials for wound healing. Surface free energy, as well as their roughness, mechanical properties, water vapor permeability rate, and antioxidant activity were determined. Moreover, their compatibility with blood and osteoblast cells was investigated....
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Anticancer Properties of Amino Acid and Peptide Derivatives of Mycophenolic Acid
PublikacjaBackground: Although Mycophenolic Acid (MPA) is applied as prodrugs in clinic as an immunosuppressant, it also possesses anticancer activity. MPA acts as Inosine-5’-Monophosphate Dehydrogenase (IMPDH) inhibitor, where the carboxylic group at the end of the side chain interacts with Ser 276 of the enzyme via hydrogen bonds. Therefore, MPA derivatives with other polar groups indicated high inhibition too. On the other hand, potent...
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Synthesis and biological activity of mycophenolic acid-amino acid derivatives
PublikacjaIn search of new immunosuppressants, mycophenolic acid (MPA) was coupled with amino acid methyl esters followed by hydrolysis to analogs bearing free carboxylic groups. The obtained compunds were tested in vitro as growth inhibitors of lymphoid cell line (Jurkat) and human peripheral blood mononuclear cells (PBMC) from healthy donors. According to obtained results recovering of free carboxylic group increased their activity. Additionally,...
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Immunosuppressive properties of amino acid and peptide derivatives of mycophenolic acid
PublikacjaMycophenolic acid (MPA) was coupled with amino acids and biologically active peptides including derivatives of tuftsin to modify its immunosuppressive properties. Both amino acid unit in the case of simple MPA amides and modifications within peptide moiety of MPA - tuftsin conjugates influenced the observed activity. Antiproliferative potential of the obtained conjugates was investigated in vitro and MPA amides with threonine methyl...
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Synthesis and antimicrobial activity of amino acid and peptide derivatives of mycophenolic acid
PublikacjaThe series of 16 novel amino acid and peptide mycophenolic acid (MPA) derivatives was obtained as potential antibacterial agents. Coupling of MPA with respective amines was optimized with condensing reagents such as EDCI/DMAP and T3P/TEA. Amino acid analogs were received both as methyl esters and also with the free carboxylic group. The biological activity of the products was tested on five references bacterial strains: Klebsiella...
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Modifications of total synthesis of mycophenolic acid
PublikacjaThe total synthesis of mycophenolic acid (MPA), a potent immunosuppressant, was modified. The obtained mycophenolic acid was suitable for further preparation of new prospective immunosuppressants with improved therapeutic properties.
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Easy formation of acyl-Meldrum's acid anhydride
PublikacjaAcyl Meldrum's acid are usually a good source of ketenes upon definite thermal composition. However we treated acyl-Meldrum's acid with the Lewis acid and we observed formation of 5[[(2,2-dimethyl-4,6-dioxo-1,3-dioxan 5 ylidene)(acyl/arylamino)mathoxy](acyl/arylamino)methylene]-2,2dimethyl-1,3-dioxane-4,6 dione which means acyl-Meldrum's acid anhydride. The chemical properities of acyl-Meldrum's acid anhydride were explored.
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New Analogues of Mycophenolic Acid
PublikacjaMycophenolic acid (MPA) possesses antibacterial, antifungal, antiviral, immunosuppressive and anticancer properties. It is a non-competitive and reversible inhibitor of dehydrogenase inosine-5'-monophosphate (IMPDH). This compound belongs to the immunosuppressive drugs used for the prevention of both acute and chronic transplant rejection. Until now, two derivatives of MPA have been used clinically: mycophenolate mofetil (MMF,...
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Expression-based decision tree model reveals distinct microRNA expression pattern in pediatric neuronal and mixed neuronal-glial tumors
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Amino Acid Based Antimicrobial Agents – Synthesis and Properties
PublikacjaStructures of several dozen of known antibacterial, antifungal or antiprotozoal agents are based on the amino acid scaffold. In most of them, the amino acid skeleton is of a crucial importance for their antimicrobial activity, since very often they are structural analogs of amino acid intermediates of different microbial biosynthetic pathways. Particularly, some aminophosphonate or aminoboronate analogs of protein amino acids are...
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Dissociative electron attachment to benzoic acid (C7H6O2)
PublikacjaThe dissociative electron attachment (DEA) to benzoic acid (C6H5COOH) has been studied using an experimental crossed beam setup of a quadrupole mass spectrometer and a trochoidal electron monochromator. Relative partial cross sections for the DEA to produce negative ion fragments show the main channels for dissociation. The comparison of the present results with the ultraviolet photoelectron spectrum of benzoic acid [J. Meeks,...
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Rhodotorulic Acid and its Derivatives: Synthesis, Properties, and Applications
PublikacjaSiderophores are low molecular weight compounds produced by microorganisms to scavenge iron in iron-deficient environments. Rhodotorulic acid, a natural hydroxamate siderophore, plays a vital role in iron acquisition for fungi and bacteria. As the simplest natural hydroxamate siderophore, it exhibits a high affinity for ferric ions, enabling it to form stable complexes that facilitate iron uptake and transport within microorganisms....
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Amino Acid and Peptide‐Based Antiviral Agents
PublikacjaA significant number of antiviral agents used in clinical practice are amino acids, short peptides, or peptidomimetics. Among them, several HIV protease inhibitors (e. g. lopinavir, atazanavir), HCV protease inhibitors (e. g. grazoprevir, glecaprevir), and HCV NS5A protein inhibitors have contributed to a significant decrease in mortality from AIDS and hepatitis. However, there is an ongoing need for the discovery of new antiviral...
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Microwave-assisted preparation of potato starch silicated with silicic acid
PublikacjaApplication of microwave irradiation for the silication of granular potato starch with silicic acid, and the properties of silicated starch were investigated. Potato starch was esterified on 20 min microwave irradiation of starch with silicic acid, applying the power of 450 or 800Wand, for comparison, on 120 min convectional heating of the reagent blend at 100 ◦C. The degree of esterification and the reaction efficiency did not...
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Beeswax And Palmitic Acid Utilization With Heat Pipes For Electronics Cooling
PublikacjaThis paper presents an experimental study of heat pipes supported by phase change materials (PCMs) coated at their adiabatic sections in application for electronics cooling. The PCMs investigated in this research were palmitic acid and beeswax, the latter being considered as a more cost-effective alternative. The study focused on three powers: 20W, 25W, and 30W. The experimental results revealed that the incorporation of palmitic...
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Rhodotorulic Acid and its Derivatives: Synthesis, Properties, and Applications
PublikacjaSiderophores are low molecular weight compounds produced by microorganisms to scavenge iron in iron-deficient environments. Rhodotorulic acid (RA), a natural hydroxamate siderophore, plays a vital role in iron acquisition for fungi and bacteria. As the simplest natural hydroxamate siderophore, RA exhibits a high affinity for ferric ions, enabling it to form stable complexes that facilitate iron uptake and transport within microorganisms....
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New conjugates of mycophenolic acid and their antiproliferative activity
PublikacjaThe new conjugates of mycophenolic acid (MPA) were obtained in the reaction of N6-(ω-aminoalkyl)adenosines with MPA in the presence of EDCI as a coupling reagent. New compounds 4a–h were evaluated on leukemia cell line (Jurkat) and PBMC from healthy donors. Length of the linker influenced observed activity. The compound 4b possessing 1,3-diamine spacer exhibited the most promising results and can be considered to further investigations.
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Thermal and mechanical properties of polyurethanes modified with L-ascorbic acid
PublikacjaIn this study we report the thermal and mechanical properties of polyurethanes modified with ascorbic acid (AA). Ascorbic acid was used as a modifier at concentration of 1 or 2 mass%. The antioxidative properties of AA may improve the biocompatibility of the obtained materials, which were designed for biomedical applications. In this paper we describe characterization of obtained unmodified and ascorbic acid modified polyurethanes...
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Physical crosslinking of hyaluronic acid in the presence of phospholipids in an aqueous nano-environment
PublikacjaHyaluronic acid and phospholipids are two components in the synovial joint cavity that contribute to joint lubrication synergistically. Molecular dynamics simulations were performed and hydrogen bonds in hyaluronic acid were analyzed to identify specific sites that are responsible for its physical cross-linking. Two molecular masses of hyaluronic acid, 10 kDa and 160 kDa, were considered. We use molecular dynamics simulations and...
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Maternal smoking Modulates Fatty Acid Profile of Breast Milk
PublikacjaAIM: We hypothesized that the fatty acid composition of breast milk can be affected by a smoking habit in the mother. Consequently, this study verified whether maternal smoking modulates, and if so to what extent, the breast milk fatty acid profile. METHODS: The study included 20 postpartum women who declared smoking more than five cigarettes daily throughout a period of pregnancy and lactation, and 136 non-smoking postpartum women....
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Cytotoxic and Antioxidant Activities of Benzohydroxamic Acid Analogues
Publikacja20 benzohydroxamic acid analogues were synthesized and evaluated for their in vitro cytotoxicities against mouse mammary tumor cells as well as antioxidant activities against DPPH radical and superoxide anion. It was found that benzothiohydroxamic acids exhibit greater cytotoxicities than benzohydroxamic acids and N-isopropyl derivatives are more active than N-methyl ones. On the other hand, benzothiohydroxamic acids show more...
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An Improved Synthesis of Trisodium (R)-Homocitrate from Citric Acid
PublikacjaA method of synthesis of trisodium (R)-homocitrate starting from citric acid is reported. The procedure affords the final product of high optical purity with satisfactory yield.
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Molecular targets for antifungals in amino acid and protein biosynthetic pathways
PublikacjaFungi cause death of over 1.5 million people every year, while cutaneous mycoses are among the most common infections in the world. Mycoses vary greatly in severity, there are long-term skin (ringworm), nail or hair infections (tinea capitis), recurrent like vaginal candidiasis or severe, life-threatening systemic, multiorgan infections. In the last few years, increasing importance is attached to the health and economic problems...
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Acyl Meldrum's acid derivatives: application in organic synthesis
PublikacjaThis review is focused on one of the most important classes of Meldrum's acid derivatives commonly known as acyl Meldrum's acids. The preparation methods of these compounds are considered including the recently proposed and rather rarely used ones. The chemical properties of acyl Meldrum's acids are described in detail, including thermal stability and reactions with various nucleiophiles. The possible mechanisms of these transformations...
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Dissociation of 2-oxopropanoic acid by low energy electrons
PublikacjaElectron attachment to molecular target can lead to a variety of negative fragment ions. We experimentally probe the main dissociative electron attachment (DEA) channels in 2-oxopropanoic acid (CH3 - CO - COOH) - an important trace component in the Earth's atmosphere. In our studies we utilise nearly mono-energetic electrons at electron energies from 0 eV up to 15 eV.
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Electron attachment and electron iozization of acetic acid clusters embedded in helium nanodroplets
PublikacjaThe effect of incident electrons on acetic acid clusters is explored for the first time. The acetic acid clusters are formed inside liquid helium nanodroplets and both cationic and anionic productsejected in to the gas phase aredetected by mass spectrometry.
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Encapsulation of Amikacin into Microparticles Based on Low-Molecular-Weight Poly(lactic acid) and Poly(lactic acid-co-polyethylene glycol)
PublikacjaThe aim of this study was to fabricate novel microparticles (MPs) for efficient and long-term delivery of amikacin (AMI). The emulsification method proposed for encapsulating AMI employed low-molecular-weight poly(lactic acid) (PLA) and poly(lactic acid-co-polyethylene glycol) (PLA−PEG), both supplemented with poly(vinyl alcohol) (PVA). The diameters of the particles obtained were determined as less than 30 μm. Based on an in-vitro...
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ASCORBIC ACID IN POLYURETHANE SYSTEMS FOR TISSUE ENGINEERING
PublikacjaThe introduction of the paper was devoted to the main items of tissue engineering (TE) and the way of porous structure obtaining as scaffolds. Furthermore, the significant role of the scaffold design in TE was described. It was shown, that properly designed polyurethanes (PURs) find application in TE due to the proper physicochemical, mechanical and biological properties. Then the use of L-ascorbic acid (L-AA) in PUR systems for...
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Interaction of low energy electrons with formic acid monomer, dimer and trimer
PublikacjaConfigurations of the formic acid monomer, dimer and trimer are presented. We have calculated the total energies for these structures. We have considered also the negatively charged clusters and discussed the possible pathways of interaction of low energy electrons with monomers and clusters. Calculations have been executed using 6-311G** and 6-311++G** basis sets. The electron affinities of monomer and clusters are presented....
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Synthesis and biological activity of mycophenolic acid-amino acid derivatives
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CROSS SECTIONS CALCULATIONS FOR ELECTRON SCATTERING FROM RHODANINE AND CYANOACETIC ACID
PublikacjaCross sections for electron-impact ionization and for elastic electron scattering for rhodanine (C3H3NOS2) and cyanoacetic acid (C3H3NO2) have been calculated in wide impinging electron energy range.
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The synthesis and structure of a potential immunosuppressant: N-mycophenoyl malonic acid dimethyl ester
PublikacjaThe synthesis of a potential immunosuppressant, i.e. dimethyl ester of N-mycophenoyl malonic acid was optimized in the reaction of mycophenolic acid (MPA) with amino malonic dimethyl ester in the presence of propanephosphonic anhydride (T3P) as a coupling reagent. The structural properties of the obtained MPA derivative were investigated by NMR, MS and single crystal X-ray diffraction methods. Theoretical considerations of conformational...
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Thermal energy storage using stearic acid as PCM material
PublikacjaThis work presents an experimental study of thermal energy storage by use of PCM. The aim of the study was to establish the influence of different inlet temperature of heat transfer fluid (HTF) and different Reynolds number of HTF on intensity of charging process. The PCM used in this study was stearic acid and water was used as HTF. A copper helical coil mounted in cylindrical container served as a heat transfer surface.
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Collagen and hyaluronic acid hydrogel in water-in-oil microemulsion delivery systems
PublikacjaThe efficacy of microemul-sion in dermal and transdermal delivery of active ingredients. Here, we assessed the water-in-oilmicroemulsion capacity to incorporate two natural polymers, i.e. collagen and hyaluronic acid withlow and high molecular weight. Systems were extensively characterized in terms of conductivity, phaseinversion studies, droplet diameter, polydispersity index and rheological properties. The results of thisresearch...
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Photoresponsive, amide-based derivative of embonic acid for anion recognition
PublikacjaThe synthesis and ion-binding properties of amide-based derivative of embonic acid andp-aminoazobenzenewere described. The new compound was characterized by X-ray structural analysis and spectroscopic methods.Ligand interacts in acetonitrile with Y-shaped anions (benzoates and acetates) and dihydrogen phosphatesforming complexes of 1:1 stoichiometry. In more polar DMSO the complexes stoichiometry changes to 2:1(L:anion). Light-inducedtranstocisisomerization...
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Electron-impact ionization cross section of formic acid
PublikacjaExperimental electron-impact ionization cross sections of one of the simplest carboxylic acids, formic acid, are presented. The molecular target was studied in two independent experimental setups applying different methods: the total ion collection and the electron–impact mass spectrometry methods. Experimental data were taken at incident electron energies ranging from ionization threshold [11.31 eV; J.C. Traeger, Int. J. Mass...
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Investigations on the immunosuppressive activity of derivatives of mycophenolic acid in immature dendritic cell
PublikacjaThe main activity of mycophenolic acid (MPA) and its analogs is the inhibition of proliferation of T cells. Here, we hypothesized that MPA and its conjugates inhibits also the activity of antigen-presenting cells (APC) including dendritic cells (DCs). We tested the effect of novel amino acid derivatives of MPA and conjugates of MPA with acridines/acridones on DCs by flow cytometry, ELISA and MLR assay. Both acridines/acridone derivatives...
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Characterization of fatty acid composition in Eurasian badger (Meles meles)
PublikacjaPolyunsaturated fatty acids (PUFAs, LA and ALA) are not synthesized in mammals in the absence of their essential fatty acid precursors. However, hibernating animals and animals sleeping through the winter need sufficiently high amounts of these acids. The Eurasian badger does not hibernate, but sleeps over winter. In the autumn the body weight of adult badgers increases even twofold, since they put on fat before the winter. Fat...
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Novel amides of mycophenolic acid and some heterocyclic derivatives as immunosuppressive agents
PublikacjaThe group of new amide derivatives of mycophenolic acid (MPA) and selected heterocyclic amines was synthesised as potential immunosuppressive agents functioning as inosine-5'-monophosphate dehydrogenase (IMPDH) uncompetitive inhibitors. The synthesis employed uronium-type activating system (TBTU/HOBt/DIPEA) while or phosphonic acid anhydride method (T3P/Py) facilitating amides to be obtained in moderate to excellent yields without...
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Improvement of derivatized amino acid detection sensitivity in micellar electrokinetic capillary chromatography by means of acid-induced pH-mediated stacking technique
PublikacjaDerivatization is a frequently used sample prepara-tion procedure applicable to the enhancement of analyte de-tection sensitivity. Amino acids mostly require derivatization prior to electrophoretic or chromatographic analysis, especial-ly if spectrophotometric detection is used. This study presents an on-line preconcentration technique for derivatized amino acids. The sensitivity of the method was improved by the utilization of...
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Experimental investigation on heat pipes supported by soy wax and lauric acid for electronics cooling
PublikacjaThis paper presents an experimental study of heat pipes for electronics cooling that were supported by energy storage materials (i.e. phase change materials - PCMs) coated at the adiabatic section. The PCMs utilized included two materials, namely lauric acid and soy wax, the latter being considered as a more cost-effective alternative. The study focused on three different powers: 20 W, 25 W, and 30 W. Both heating, cooling, and...
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Recovery of Pure Lead-Tin Alloy from Recycling Spent Lead-Acid Batteries
PublikacjaSpent lead–acid batteries have become the primary raw material for global lead production. In the current lead refining process, the tin oxidizes to slag, making its recovery problematic and expensive. This paper aims to present an innovative method for the fire refining of lead, which enables the retention of tin contained in lead from recycled lead–acid batteries. The proposed method uses aluminium scrap to remove impurities...
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The mechanical properties and bactericidal degradation effectiveness of tannic acid-based thin films for wound care
PublikacjaThe surface area is the most important aspect when considering the interactions between a material and the surrounding environment. Chitosan (CTS) and tannic acid (TA) were previously successfully tested by us to obtain thin films to serve as wound dressings or food packaging materials. However, surface properties as well as the antimicrobial activity of the material were not considered. They are important if the material is likely...
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Dissociative electron attachment and anion-induced dimerization in pyruvic acid
PublikacjaWe report partial cross sections for the dissociative electron attachment to pyruvic acid. A rich fragmentation dynamics is observed. Electronic structure calculations facilitate the identification of complex rearrangement reactions that occur during the dissociation. Furthermore, a number of fragment anions produced at electron energies close to 0 eV are observed, that cannot originate from single electron-molecule collisions....
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Dissociation of furan-2-carboxylic acid by low energy electrons
PublikacjaElectron attachment to molecular target can lead to a variety of negative fragment ions. We experi- mentally probe the main dissociative electron attachment channels in furan-2-carboxylic acid (C3H3O2 − COOH) - a molecular target composed of two important structural units: a furan ring and a carboxylic group. In our studies we utilise nearly mono-energetic electrons at electron energies from 0 eV up to 15 eV. Our detection setup...
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Preparation of Pseudopeptides Building Blocks with Retro-Thioamide Bond Mediated via Thiocarbamoyl Meldrum's Acid
PublikacjaAn easy and efficient synthesis of pseudo tripeptide containing a thiomalonamide moiety was developed. Isothiocyanate derivatives of amino acids react smoothly with 2,2-dimethyl-1,3-dioxane-4,6-dione yielding new thiocarbamoyl Meldrum's acids. Thermal decomposition of this new Meldrum's acid derivatives generate thiocarbamoyl ketenes, which acylate amino acid esters to give pseudo tripeptides.
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Bioactivation of Konjac Glucomannan Films by Tannic Acid and Gluconolactone Addition
PublikacjaWound healing is a dynamic process that requires an optimal extracellular environment, as well as an accurate synchronization between various cell types. Over the past few years, great efforts have been devoted to developing novel approaches for treating and managing burn injuries, sepsis, and chronic or accidental skin injuries. Multifunctional smart-polymer-based dressings represent a promising approach to support natural healing...
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The content of conjugated linoleic acid and vaccenic acid in the breast milk of women from Gdansk and the surrounding district, as well as in, infant formulas and follow-up formulas. Nutritional recommendation for nursing women
PublikacjaFatty acids are some of the most important components of human milk. Polyunsaturated fatty acids (PUFAs) are essential nutrients required for the optimal growth and development of infants, especially the central nervous system, brain and retina. AIM: To determine the conjugated linolenic acid (CLA) and vaccenic acid (VA) content of human breast milk from mothers consuming different diets, and to compare the results with CLA and...
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Chromogenic amides of pyridine-2,6-dicarboxylic acid as anion receptors
PublikacjaThe synthesis of simple, chromogenic pyridine-2,6-dicarboxylic acid amides, derivates of isomeric nitroanilines and aminonitrophenols, and their ion binding properties are described. The ligands' response to ionic species was examined by naked eye and was studied with the use of UV-Vis spectroscopy in DMSO and its mixture with water. The effect of the localisation and the type of the substituents in aromatic rings were discussed....