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Search results for: ANTIBIOTIC RESIDUE
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Linezolid-resistant Enterococcus faecium strains isolated from one hospital in Poland –commensals or hospital-adapted pathogens?
PublicationOne of the most pressing problems of enterococci infections is occurring resistance to linezolid, which is an antibiotic used in the treatment of infections caused by vancomycin-resistant strains (VRE). The main objective of our research was to investigate the relationship of 19 linezolid-resistant E. faecium isolates from 18 patients hospitalized at Clinical Hospital in Gdansk (Poland). One of the LZDREF was isolated in 2003...
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Antitumor Activity of Triazine Mimic Antibiotics for DNA-binding Implications (Impressive Activity in Vitro Against a Variety of Tumor Types in the NCI-60 Screen): NSC 710607 To Fight HCT-116 Human Colon Carcinoma Cell Lines in Vivo Using the Hollow Fiber Assay and Xenograft Mouse Models
PublicationPurpose Successful clinical applications of DNA-directed selective cytotoxic agents disrupt the vital replication/transcription processes and ultimately lead to cancer cell death. This study aimed to examine the growth screen of two lead triazine compounds in a number of cell lines and xenografts and to develop anticancer agents with noncovalent binding affinity bringing fewer side effects. Methods The NCI initial hollow...
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Biological and mechanical properties of bone cement with nanoarticles - in vitro and in vivo research
PublicationDespite antibiotic preventive treatment both before and after implant implementation, the risks of infection are real. These infections develop at the implant surface a few months after inserting them into the body. To prevent the development of bacteria and reduce the risk of infection, implants coated with nanoparticles are used. The Mechanical Department of the Technical University of Gdansk carries out research into using bone...
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Determining pesticide contamination in honey by LC-ESI-MS/MS - Comparison of pesticide recoveries of two liquid-liquid extraction based approaches
PublicationHoney, a valuable food product, may be contaminated by xenobiotics during its production and/or harvest. The determination of trace levels of contaminants in a complex matrix like honey still presents a challenge to analytical chemists. The aim of this work was to assess and compare the extraction efficiencies of 30 pesticide residues (acaricides, insecticides, herbicides, fungicides), belonging to over 15 different chemical classes....
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Distance between the Basic Group of the Amino Acid Residue's Side Chain in Position P1of Trypsin Inhibitor CMTI-III and Asp189in the Substrate Pocket of Trypsin Has an Essential Influence on the Inhibitory Activity
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Chitosan-Based Membranes as Gentamicin Carriers for Biomedical Applications — Influence of Chitosan Molecular Weight
PublicationOver the past decade, much attention has been paid to chitosan as a potential drug carrier because of its non-toxicity, biocompatibility, biodegradability and antibacterial properties. The effect of various chitosan characteristics on its ability to carry different antibiotics is discussed in the literature. In this work, we evaluated the influence of the different molecular weights of this polymer on its potential as an antibacterial...
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Analysis of the impact of wastewater discharge on recipients: synergistic approach
PublicationThe dissertation presents the analysis of chemical and microbial composition of wastewater and examines the impact of wastewater discharge on the environment. Various case studies were analysed: from small settlements in a pristine European Arctic, to large municipal wastewater treatment plants in areas subjected to greater anthropogenic pressure. In order to comprehensively analyse the impact of wastewater discharge on the receiving...
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Pomiary naprężeń w warstwie wierzchniej stali duplex metodą dyfrakcji promieniowania rentgenowskiego g-sin2Ψ = Residual stress measurements in duplex steel surface layers by g-sin2Ψ x-ray diffraction method
PublicationPrzedstawiono wyniki pomiarów naprężeń w warstwie wierzchniej z wykorzystaniem metody dyfrakcji promieniowania rentgenowskiego g-sin2. Wyjaśniono zasady przeprowadzania pomiarów naprężeń na próbkach walcowych o małej średnicy. Badania prowadzono na próbkach okrągłych ze stali duplex, poddanych procesom nagniatania. Stwierdzono występowanie naprężeń ściskających w warstwach powierzchniowych wszystkich badanych próbek oraz istotne...
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The treatment of wastewater containing pharmaceuticals in microcosm constructed wetlands: the occurrence of integrons (int1–2) and associated resistance genes (sul1–3, qacEΔ1)
PublicationThe aim of this study was to analyze the occurrence of sulfonamide resistance genes (sul1–3) and other genetic elements as antiseptic resistance gene (qacEΔ1) and class 1 and class 2 integrons (int1–2) in the upper layer of substrate and in the effluent of microcosm constructed wetlands (CWs) treating artificial wastewater containing diclofenac and sulfamethoxazole (SMX), which is a sulfonamide antibiotic. The bacteria in the substrate...
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Influence of a lipid bilayer on the conformational behavior of amphotericin B derivatives - A molecular dynamics study.
PublicationAmphotericin B (AmB) is an effective but very toxic antifungal antibiotic. In our laboratory a series of AmB derivatives of improved selectivity of action was synthesized and tested. To understand molecular basis of this improvement, comparative conformational studies of amphotericin B and its two more selectivederivatives were carried out in an aqueous solution and in a lipid membrane. These molecular simulation studies revealed...
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The mechanism of overcoming multidrug resistance (MDR) of fungi by amphotericin B and its derivatives
PublicationPrzeprowadzono badania porównawcze w celu określenia aktywności i cytotoksyczności amfoterycyny B (AmB) i jej pochodnych wobec standardowego szczepu S. cerevisiae i jego transformantów zawierających geny C. albicans kodujące białka oporności wielolekowej (MDR) typu ABC i MFS. Pochodne AmB: amid 3-dimetyloaminopropylowy amfoterycyny B oraz ester metylowy N-metylo-N-D-fruktopiranozylo-amfoterycyny B wykazały efekt fungistatyczny...
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Anti-Helicobacter pylori activities of selected N-substituted cinnamamide derivatives evaluated on reference and clinical bacterial strains
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Anti-Helicobacter pylori activity of some newly synthesized derivatives of xanthone
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The Antimicrobial Activity of Omiganan Alone and In Combination against Candida Isolated from Vulvovaginal Candidiasis and Bloodstream Infections
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Methods Used for the Eradication of Staphylococcal Biofilms
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Chemical Composition and Antimicrobial Activity of Selected Essential Oils against Staphylococcus spp. Isolated from Human Semen
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Can Immobilized Artificial Membrane Chromatography Support the Characterization of Antimicrobial Peptide Origin Derivatives?
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Synthesis, Antimicrobial and Mutagenic Activity of a New Class of d-Xylopyranosides
PublicationEight N-[2-(2′,3′,4′-tri-O-acetyl-α/β-d-xylopyranosyloxy)ethyl]ammonium bromides, a new class of d-xylopyranosides containing a quaternary ammonium aglycone, were obtained. Their complete structure was confirmed using NMR spectroscopy (1H, 13C, COSY and HSQC) and high-resolution mass spectrometry (HRMS). An antimicrobial activity against fungi (Candida albicans, Candida glabrata) and bacteria (Staphylococcus aureus, Escherichia...
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Ribes nigrum L. Extract-Mediated Green Synthesis and Antibacterial Action Mechanisms of Silver Nanoparticles
PublicationSilver nanoparticles (Ag NPs) represent one of the most widely employed metal-based engineered nanomaterials with a broad range of applications in different areas of science. Plant extracts (PEs) serve as green reducing and coating agents and can be exploited for the generation of Ag NPs. In this study, the phytochemical composition of ethanolic extract of black currant (Ribes nigrum) leaves was determined. The main components...
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Bee Bread Exhibits Higher Antimicrobial Potential Compared to Bee Pollen
PublicationThis study aimed at investigation of the antimicrobial potential of ethanolic extracts of bee bread (BB) and bee pollen (BP) and suspensions of these products in MHB (Mueller Hinton Broth). We covered 30 samples of BP and 19 samples of BB harvested in Polish apiaries. Slightly lower activity was observed against Gram-negative bacteria compared to Gram-positive staphylococci. BB extracts exhibited higher inhibitory potential with...
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Bee Pollen and Bee Bread as a Source of Bacteria Producing Antimicrobials
PublicationThe principal objective of the study was the isolation and identification of bacteria that are present in mature bee bread (BB) and dried (ready for selling and consumption) bee pollen (BP). Obtained isolates were screened for their potential to inhibit select human pathogenic bacteria and their ability to produce enzymes of particular industrial importance. Four and five samples of BP and BB, respectively, were used for the study....
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Iso-Partricin, an Aromatic Analogue of Amphotericin B: How Shining Light on Old Drugs Might Help Create New Ones
PublicationPartricin is a heptaene macrolide antibiotic complex that exhibits exceptional antifungal activity, yet poor selective toxicity, in the pathogen/host system. It consists of two compounds, namely partricin A and B, and both of these molecules incorporate two cis-type bonds within their heptaenic chromophores: 28Z and 30Z. In this contribution, we have proven that partricins are susceptible to a chromophore-straightening photoisomerization...
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The stereostructure of candicidin D.
PublicationThe candicidin D stereostructure was established based on NMR studies including DQF-COSY, ROESY, HSQC and HMBC experiments. The relative configurations of the candicidin D stereogenic centers were assigned as the following: 9R*, 11S*, 13S*, 15R*, 17S*, 18R*, 19S*, 21R*, 36S*, 37R*, 38S*, 40S* and 41S*. The geometry of the heptaene chromophore was defined as 22E, 24E, 26Z, 28Z, 30E, 32E and 34E.
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Review on Current Status of Echinocandins Use
PublicationFungal infections are rising all over the world every year. There are only five medical compound classes for treatment: triazoles, echinocandins, polyenes, flucytosine and allylamine. Currently, echinocandins are the most important compounds, because of their wide activity spectrum and much lower sides effects that may occur during therapy with other drugs. Echinocandins are secondary metabolites of fungi, which can inhibit the...
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Phage therapy as a novel strategy in the treatment of urinary tract infections caused by E. coli
PublicationUrinary tract infections (UTIs) are regarded as one of the most common bacterial infections affecting millions of people, in all age groups, annually in the world. The major causative agent of complicated and uncomplicated UTIs are uropathogenic E. coli strains (UPECs). Huge problems with infections of this type are their chronicity and periodic recurrences. Other disadvantages that are associated with UTIs are accompanying complications...
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Stereostructure of mycoheptin A2
PublicationThe absolute configurations of all the stereogenic centers of the antibiotic mycoheptin A2 were established upon previouslyelaborated general procedure, consisting of DQF-COSY, NOESY, ROESY, HSQC and HMBC experiments as major tools. Thestructure of mycoheptin A2 without stereochemistry of its aglycone has been reported before.
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Crystal structures of the DsbG disulfide isomerase reveal an unstable disulfide
PublicationDsb proteins control the formation and rearrangement of disulfide bonds during the folding of secreted and membrane proteins in bacteria. DsbG, a member of this family, has disulfide bond isomerase and chaperone activity. Here, we present two crystal structures of DsbG at 1.7- and 2.0-Angstrom resolution that are meant to represent the reduced and oxidized forms, respectively. The oxidized structure, however, reveals a mixture...
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Stereostructure of mycoheptin A2
PublicationThe absolute configurations of all the stereogenic centers of the antibiotic mycoheptin A2 were established upon previously elaborated general procedure, consisting of DQF-COSY, NOESY, ROESY, HSQC and HMBC experiments as major tools. The structure of mycoheptin A2 without stereochemistry of its aglycone has been reported before.
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Amphotericin B and Its New Derivatives - Mode of Action
PublicationAmphotericin B (AmB) is a well known antifungal and antiprotozoal antibiotic used in the clinic for several decades. Clinicalapplications of AmB, however, are limited by its nephrotoxicity and many other acute side effects which are not acceptable by patientswhen their life is not threaten. In order to improve the therapeutic index of this drug, lipid formulations have been introduced and manyefforts have been made to obtain less...
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A new assay for simultaneous identification and differentiation of Klebsiella oxytoca strains
PublicationBacterial strain typing, or identifying bacteria at the strain level, is particularly important for diagnosis, treatment, and epidemiological surveillance of bacterial infections. This is especially the case for bacteria exhibiting high levels of antibiotic resistance or virulence, and those involved in nosocomial or pandemic infections. Strain typing also has applications in studying bacterial population dynamics.
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Alternative treatment approaches of urinary tract infections caused by uropathogenic Escherichia coli strains
PublicationUrinary tract infections (UTIs) are the most widespread and annoying infections affecting millions of people every year annually. The biggest problem of urinary diseases are recurrences, the increasing resistance of uropathogens to commonly used antibiotics, as well as the high health care costs of afflicted persons. Uropathogenic Escherichia coli strains (UPECs) are the most dominant etiologic agent of community-acquired infections...
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Challenges in determination of pesticides from various chemical groups in fruits and vegetables applying QuEChERS method
PublicationPesticides are a large group of compounds with different physical and chemical properties, which place some of them among the most toxic, environmentally stable, and mobile substances. Nevertheless, their number, use, and application are continuously expanding. A consequence of their use is the possible presence of residues in treated food products. To protect consumers from exposure to unacceptable levels of pesticides Maximum...
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Distinction of clenbuterol intake from drug or contaminated food of animal origin in a controlled administration trial – the potential of enantiomeric separation for doping control analysis
PublicationThe differentiation of clenbuterol abuse and unintentional ingestion by contaminated meat is crucial with respect to the valuation of an adverse analytical finding in human sports doping control. The proportion of the two enantiomers of clenbuterol may serve as potential discriminating parameter. For the determination of the individual enantiomers, specific methods were developed and validated for the different matrices under investigation...
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Structure-based design and evaluation of novel N-phenyl-1H-indol-2-amine derivatives for fat mass and obesity-associated (FTO) protein inhibition
PublicationFat mass and obesity-associated (FTO) protein contributes to non-syndromic human obesity which refers to excessive fat accumulation in human body and results in health risk. FTO protein has become a promising target for anti-obesity medicines as there is an immense need for the rational design of potent inhibitors to treat obesity. In our study, a new scaffold N-phenyl-1H-indol-2-amine was selected as a base for FTO protein inhibitors...
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Interaction of the conserved region 4.2 of sigma(E) with the RseA anti-sigma factor
PublicationEo-E RNA polymerase transcribes a regulon of folding factors for the bacterial envelope and is induced by physical and chemical stresses. The RseA anti-sigma factor inhibits the activity of Esigma(E) RNA, polymerase. It is shown here that the N-terminal portion of sigma(E), residues 1-153, binds core RNA polymerase. RseA interacts with residues 154-191 of sigma(E), a site that is homologous to region 4, the sigma factor binding...
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Effect of Ethanol Extracts of Propolis (EEPs) against Staphylococcal Biofilm—Microscopic Studies
PublicationStaphylococci growing in the form of biofilm exhibit high resistance to a plethora of antibiotics. The aim of the study was to assess the influence of ethanolic extract of propolis (EEPs) on S. epidermidis ATCC 35984 biofilm using fluorescent microscopy. Propidium iodide (PI) and SYTO 9 were used for differentiation of live and dead cells, and calcofluor white was used to stain the extracellular matrix, the self-produced extracellular...
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Biological and mechanical properties of bone cement with nanoparticles - in vivo and in vitro research
PublicationDespite antibiotics preventive treatment, before and after an implant implementation, risk of infection are real. These infections at the implant surface develop in a few months after applying them into the body. To prevent the development of bacteria and to reduce the risk of infection, implants coated with nanoparticles come into use. The Mechanical Department of the Technical University of Gdańsk carried out a research with...
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Peptidoglycan hydrolases - potential weapons against Staphylococcus aureus
PublicationBacteria of the genus Staphylococcus are common pathogens responsible for a broad spectrum of human and animal infections and belong to most important etiological factors causing food poisoning. Because of rapid increase in prevalence of isolation of staphylococci resistant to many antibiotics, there is an urgent need for development of new alternative chemotherapeutics. A number of studies have recently demonstrated the strong...
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Przegląd rodzajów chiralnych faz stacjonarnych oraz możliwości ich zastosowań w chromatografii cieczowej
PublicationChromatograficzne rozdzielanie związków optycznie czynnych ma ogromne znaczenie nie tylko w przemyśle farmaceutycznym, ale i agrochemicznym, a także w badaniach naukowych różnego rodzaju. W niniejszym opracowaniu scharakteryzowano komercyjnie dostępne chiralne fazy stacjonarne na bazie, cyklodekstryn, polisacharydów, makrocyklicznych antybiotyków, eterów koronowych, a także fazy proteinowe, ligandowymienne, jonowymienne oraz fazy...
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Aryl and N-arylamide carbon nanotubes for electrical coupling of laccase to electrodes in biofuel cells and biobatteries
PublicationSingle walled carbon nanotubes (SWCNTs) were equipped with aryl residues by chemical reactions. These insoluble materials were used to substitute classical soluble mediators, which help to transfer electrical charge between the conducting electrode and the redox active center of enzyme molecules. The effect of different aryl residues on the efficiency of the catalytic reduction of dioxygen in the presence of laccase was systematically...
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Optical recognition elements: macrocyclic imidazole chromoionophores entrapped in silica xerogel
PublicationMaterials containing new chromoionophores consisting of crown residue and azole moiety as partsof macrocycles were encapsulated by the sol-gel procedure in silica xerogel matrices and proposed aschemical recognition elements especially for such metal ions as Li+, Cs+ and Cu2+. Action of these recognition elements is in principle based on changes of reflectance. The recognition elements containing 21-membered chromogenic...
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Badanie wybranych właściwości wyłączników różnicowoprądowych typu F
PublicationW instalacjach elektrycznych niskiego napięcia instaluje się coraz więcej przekształtników energoelektronicznych (systemy fotowoltaiczne, instalacje ładowania pojazdów elektrycznych, układy napędowe o regulowanej prędkości obrotowej silnika), a mają one wpływ na dobór typu wyzwalania wyłączników różnicowoprądowych (AC, A, F lub B). W obwodach, w których pojawia się prąd różnicowy zawierający składowe o częstotliwości innej niż...
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Correlation between the number of Pro-Ala repeats in the EmrA homologue of Acinetobacter baumannii and resistance to netilmicin, tobramycin, imipenem and ceftazidime
PublicationAcinetobacter baumannii coccobacilli are dangerous to patients in intensive care units because of their multidrug resistance to antibiotics, developed mainly in the past decade. This study aimed to examine whether there is a significant correlation between the number of Pro-Ala repeats in the CAP01997 protein, the EmrA homologue of A. baumannii, and resistance to antibiotics. A total of 79 multidrug-resistant A. baumannii strains...
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The PRNS butterfly in the FPGA technology
PublicationW publikcaji zaprezentowano koncepcję realizacji motylka konwesji wejściowej w Wielomianowym Systemie Resztowym (Polynoamil Residue Number System, PRNS). Omówiono wykorzystanie reprezentacji liczb w systemie diminished-1 w prezentowanym rozwiązaniu oraz przedstawiono wynik syntezy ukłądu w środowisku Xilinx ISE.
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(1H-Pyrazole-[kappa]N)bis(tri-tert-butoxysilanethiolato-[kappa]2O,S)cadmium
PublicationThe CdII atom in the title complex, [Cd(C12H27O3SSi)2-(C3H4N2)], is penta-coordinated by two O and two S atoms from the O,S-chelating silanethiolate residue and one pyrazole N atom in a distorted trigonal-bipyramidal geometry. The pyrazole ligand forms an intramolecular N-H---O hydrogen bond.
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Pesticides in the Environment
PublicationApplied all over the world, pesticides are some of the most dangerous pollutants of the environment becauseof their mobility and ability to accumulate in the environment and their consequent long-term adverseeffects on living organisms in general and human health in particular. For these reasons, it is essential tomonitor and analyze pesticide residues in the environment. This entry discusses the classification of pesticidesas...
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Fatty acids as molecular carriers in cleavable antifungal conjugates
PublicationConjugates composed of C2-18 fatty acid (FA) residues as a molecular carrier and 5-fluorocytosine (5-FC) as an active agent, released upon the action of intracellular esterases on the ester bond between FA and “trimethyl lock” intramolecular linker, demonstrate good in vitro activity against human pathogenic yeasts of Candida spp. The minimal inhibitory concentrations (MIC) values for the most active conjugates containing caprylic...
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Macrocyclic derivatives of imidazole as chromoionophores for bismuth(III)/lead(II) pair
Publication18-membered diazomacrocycles with imidazole or 4-methylimidazole residue as a part of macrocycle were used as chromoionophores in bismuth(III) and lead(II) dual selective optodes for the first time. Cellulose triacetate membranes doped with macrocyclic chromoionophores are bismuth(III) and lead(II) selective with color change from orange/red to different shades of blue and violet, respectively. Results obtained for model and real...
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Characteristics of volatile organic compounds emission profiles from hot road bitumens
PublicationA procedure for the investigation and comparison of volatile organic compounds (VOCs) emission profiles to the atmosphere from road bitumens with various degrees of oxidation is proposed. The procedure makes use of headspace analysis and gas chromatography with universal as well as selective detection, including gas chromatography–mass spectrometry (GC–MS). The studies revealed that so-called vacuum residue, which is the main component...
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The influence of biological environment on the appearance of silver-coated implants
PublicationDespite antibiotics preventive treatment before and after implantation, risk of infection is real. The infections at the implant surface developein a few months after applying them into the body. To prevent the development of bacteria and to reduce the risk of infection, implants coated with silver layer come into use. The paper presents the research results in biological environment on vein and orthopaedicimplants covered with...