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Search results for: FRACTIONAL DERIVATIVES AND INTEGRALS
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Approaches Towards Better Immunosuppressive Agents
PublicationSeveral classes of compounds are applied in clinics due to their immunosuppressive properties in transplantology and the treatment of autoimmune diseases. Derivatives of mycophe-nolic acid, corticosteroids and chemotherapeutics bearing heterocyclic moieties like methotrexate, azathioprine, mizoribine, and ruxolitinib are active substances with investigated mechanisms of action. However, improved synthetic approaches of known drugs...
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Recent developmentsinthesynthesisand biological activityofacridine/acridoneanalogues
PublicationMany people in the world struggle with cancer or bacterial, parasitic, viral, Alzheimer's and other diseases. Therefore, many scientists seek new, more effective, more selective and less toxic drugs. Acridine/acridone derivatives constitute a class of compounds with a broad spectrum of biological activity and are of great interest to scientists. Todate, many acridine/acridone analogues have been obtained,which, inter alia, exhibit...
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A new and convenient method for the preparation of functionalized phosphorothioates
PublicationA new and efficient method for the synthesis of alkyl and aryl phosphorothioates in high yields via the reaction of (5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorin-2-yl)disulfanyl derivatives with trimethyl phosphite was developed.
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From tryptophan to novel mitochondria-disruptive agent, synthesis and biological evaluation of 1,2,3,6-tetrasubstituted carbazoles
PublicationMitochondrial targeting plays an important role in anticancer therapy. The Mn(III)-promoted cyclization of 5- (1H-indol-3-yl)-3-oxopentanoic acid allow to obtain novel substituted carbazole derivatives that can act as mitochondria-disruptive agents. The starting materials used for the synthesis of these new aminocarbazoles are oxopentanoate derivatives of tryptophan. The scope and limitation of this method of synthesis are determined...
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Studies on Aminoanthraquinone-Modified Glassy Carbon Electrode: Synthesis and Electrochemical Performance toward Oxygen Reduction
PublicationIn this paper, 9,10-anthraquinone (AQ) derivative-modified glassy carbon (GC) electrodes were studied towards the electrochemical reduction of oxygen in aqueous and non-aqueous solutions. The reaction of 1-chloro-9,10-anthraquinone with aliphatic diamines was applied for the synthesis of amino-9,10-anthraquinone derivatives. The obtained AQ derivatives were grafted onto the surface of glassy carbon electrodes by electropolymerisation...
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Progress in the post weld residual stress evaluation using Barkhausen effect meter with a novel rotating magnetic field probe
PublicationWe report the progress in post weld residual stress evaluation using Barkhausen effect (BE) meter with rotating magnetic field probe. The novel probe of the BE meter contains two C-core electromagnets and searching coil with ferrite antenna. This meter allows automatic measurements of BE intensity envelopes at different angles of magnetizing field. The full process of measurement at given position of the probe takes about only...
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Comparison of simplified sum-over-state expressions to calculate resonance Raman intensities including Franck-Condon and Herzberg-Teller effects
PublicationSum-over-state (SOS) expressions to simulate absorption spectroscopy and resonance Raman (RR) scattering including Franck-Condon (FC) and Herzberg-Teller (HT) effects are described. Starting from the general SOS method, several simplified SOS formulae are derived. In particular, within the so-called independent mode displaced harmonic oscillator model, it is shown that including the vibronic structure in the absorption and RR spectra...
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Structural factors affecting affinity of cytotoxic oxathiole-fused chalcones toward tubulin
PublicationSynthesis, in vitro cytotoxic activity, and interaction with tubulin of (E)-1-(6-alkoxybenzo[d][1,3]oxathiol- 5-yl)-3-phenylprop-2-en-1-one derivatives (2) are described. Some of the compounds demonstrated cytotoxic activity at submicromolar concentrations, and the activity could be related to interaction with tubulin at the colchicine binding site. Interaction of selected derivatives with tubulinwas evaluated using molecular modeling,...
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Studies on Aminoanthraquinone-Modified Glassy Carbon Electrode: Synthesis and Electrochemical Performance toward Oxygen Reduction
PublicationIn this paper, 9,10-anthraquinone (AQ) derivative-modified glassy carbon (GC) electrodes werestudied towards the electrochemical reduction of oxygen in aqueous and non-aqueous solutions. The reaction of 1-chloro-9,10-anthraquinone with aliphatic diamines was applied for the synthesis of amino-9,10-anthraquinone derivatives. The obtained AQ derivatives were grafted onto the surface of glassy carbon electrodes by electropolymerisation...
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Development of potent and effective SARS-CoV-2 main protease inhibitors based on maleimide analogs for the potential treatment of COVID-19
PublicationIn the present work, we report a new series of potent SARS-CoV-2 Main Protease (Mpro) inhibitors based on maleimide derivatives. The inhibitory activities were tested in an enzymatic assay using recombinant Mpro (3CL Protease from coronavirus SARS-CoV-2). Within the set of new Mpro inhibitors, 6e demonstrated the highest activity in the enzymatic assay with an IC50 value of 8.52 ± 0.44 mM. The IC50 value for Nirmatrelvir (PF-07321332,...
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Numerical Test for Stability Evaluation of Discrete-Time Systems
PublicationIn this paper, a new numerical test for stability evaluation of discrete-time systems is presented. It is based on modern root-finding techniques at the complex plane employing the Delaunay triangulation and Cauchy's Argument Principle. The method evaluates if a system is stable and returns possible values and multiplicities of unstable zeros of the characteristic equation. For state-space discrete-time models, the developed test...
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A convenient and efficient alfa-sulfenylation of carbonyl compounds
PublicationA method for alfa-sulfenylation of carbonyl compounds by a 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-disulfanyl derivatives has been developed. Readily available reagents, mild reaction conditions, and excellent yields with high selectivity makes this method quite simple, convenient and practical.
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Solving Boundary Value Problems for Second Order Singularly Perturbed Delay Differential Equations by ε-Approximate Fixed-Point Method
PublicationIn this paper, the boundary value problem for second order singularly perturbed delay differential equation is reduced to a fixed-point problem v = Av with a properly chosen (generally nonlinear) operator A. The unknown fixed-point v is approximated by cubic spline vh defined by its values vi = vh(ti) at grid points ti, i = 0, 1, ... ,N. The necessary for construction the cubic spline and missing the first derivatives at the boundary...
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Convenient and efficient N-methylation of secondary amines under solvent-free ball milling conditions
PublicationIn the present work, we report the development of a rapid, efcient, and solvent-free procedure for the N-methylation of secondary amines under mechanochemical conditions. After optimization of the milling parameters, a vibrational ball mill was used to synthesize 26 tertiary N-methylated amine derivatives in a short time of 20 min (30 Hz frequency) and high yields ranging from 78 to 95%. An exception was compounds having a hydroxyl...
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Aspects of pollution in Gdansk and gdynia Harbours at the coastal zone of the South Baltic Sea
PublicationOrganotin compounds (OTC), as well as metals, are toxic to many organisms. Even at very low concentrations OTC and metals can have several negative effects. The paper discusses key issues relating to the location of harbours in the coastal zone (including near the river mouths and semi-closed access to the sea) and the pollution of harbour sediments with heavy metals (e.g. zinc, copper, nickel and lead) and organotin derivatives...
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New Analogues of Mycophenolic Acid
PublicationMycophenolic 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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Atom-economic thiophosphoroselenenylations of C–H acid esters and amides
PublicationThree improved thiophosphoroselenenylation procedures of CHacids, including derivatives of malonic and acetyl-, phosphono-, 4-nitrophenyl- and 3-pyridylacetic acids, have been described and compared to previously reported thiophosphoroselenylation of diethyl malonate using bis(disopropoxyphosphinothioyl)diselenide alone or with the aid of methyl iodide. The use of iodine makes it possible to utilize both equivalents of the selenenylating...
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Thermodynamic Studies of Interactions between Sertraline Hydrochloride and Randomly Methylated β-Cyclodextrin Molecules Supported by Circular Dichroism Spectroscopy and Molecular Docking Results
PublicationThe interaction between sertraline hydrochloride (SRT) and randomly methylated β-cyclodextrin (RM β CD) molecules have been investigated at 298.15 K under atmospheric pressure. The method used—Isothermal Titration Calorimetry (ITC) enabled to determine values of the thermodynamic functions like the enthalpy (DH), the entropy (DS) and the Gibbs free energy (DG) of binding for the examined system. Moreover, the stoichiometry coefficient...
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Analytical Methods for Causality Evaluation of Photonic Materials
PublicationWe comprehensively review several general methods and analytical tools used for causality evaluation of photonic materials. Our objective is to call to mind and then formulate, on a mathematically rigorous basis, a set of theorems which can answer the question whether a considered material model is causal or not. For this purpose, a set of various distributional theorems presented in literature is collected as the distributional...
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The stereoselective formation of β-lactams with acyl ketenes generated from 5-acyl-Meldrum's acids
PublicationAcyl ketenes formed during thermal decompositions of 5-acyl-2,2-dimethyl-1,3-dioxa-4,6-diones undergo stereoselective [2+2] cycloaddition to chiral aldimines. We report the first example of optically active 3-acyl-β-lactams formation from Meldrum’s acid derivatives.
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Applications of Alkanethiols in Organic Synthesis
PublicationThis manuscript is an update to the earlier Science of Synthesis contribution describing methods for the synthesis of alkanethiols. Thiols can be converted into sulfonic, sulfinic, sulfenic acid and their derivatives, sulfides, disulfides, polysulfides, sulfonium salts, and thiiranes, etc. These transformations are accomplished by nucleophilic displacement or addition, oxidation, condensation, or coupling reactions involving thiol...
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Copper(II) complexes of 7-amino-2-methylchromone and 7-aminoflavone: Magneto-structural, spectroscopic and DFT characterization
PublicationFour new complexes of copper(II) consisting of two different chromone derivatives with carbonyl and amine donor atoms: 7-aminoflavone (L1) and 7-amino-2-methylchromone (L2), were synthesized and characterized by X-ray diffraction, UV–Vis, FT-IR, EPR spectroscopy, MS and elemental analysis. In all four compounds, the chromone derivatives were found to act as monodentate O- or N-ligands. The structural characteristics of 1a and...
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Synthesis of amides under microwave irradiation
PublicationAmides belong to the most important carboxylic acid derivatives. They are constituents of natural compounds like peptides and proteins. They found applications in many branches of science and industry, especially in pharmaceutical and polymer science. Conventional procedures for amide preparation involve reaction between amine and carboxylic acid or their more active derivatives such as acid chlorides, acid anhydrides or esters....
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Arithmetic Loophole in Bell's Theorem: Overlooked Threat to Entangled-State Quantum Cryptography
PublicationBell’s theorem is supposed to exclude all local hidden-variable models of quantum correlations. However,an explicit counterexample shows that a new class of local realistic models, based on generalized arith-metic and calculus, can exactly reconstruct rotationally symmetric quantum probabilities typical oftwo-electron singlet states. Observable probabilities are consistent with the usual arithmetic employedby macroscopic observers...
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TOTAL CROSS SECTIONS FOR ELECTRON SCATTERING FROM SELECTED HYDROCARBONS: THE SUBSTITUTIONAL AND ADDITIVITY EFFECTS
PublicationTotal cross sections (TCS) for electron scattering from selected alkyne molecules, ethylene and its derivatives are compared. All cross sections have been measured in a wide energy range, from about 1 eV up to 370 eV, with the same electrostatic electron spectrometer. The substitutional and additivity effects are indicated and discussed.
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Inline Microstrip Bandpass Filter With Two Transmission Zeros and Increased Order Using Spurious Resonance of Frequency-Dependent Inverter
PublicationA design method for a class of fourth-order inline microstrip bandpass filter with two transmission zeros and 20% fractional bandwidth is presented. The filter consists of two quarter-wavelength transmission-line resonators coupled by a frequency-dependent inverter. The inverter is composed of two open-ended stubs that are connected by an interdigital capacitor and introduces two poles and two transmission zeros in the filter response....
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Free volume in physical absorption of carbon dioxide in ionic liquids: Molecular dynamics supported modeling
PublicationUnderstanding the mechanisms underlying the carbon dioxide (CO2) absorption in ionic liquids (ILs) is the key to their efficient utilization in industrial flue gas treatment. One of the parameters considered substantially important in the process is the Free Volume. In this study, the Fractional Free Volume (FFV) of 73 ILs was calculated using Molecular Dynamics (MD). A quantitative Structure-Property Relationship (QSPR) study...
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Wideband Highly-Selective Bandpass Filtering Branch-Line Coupler
PublicationThis paper presents a novel design of a wideband highly-selective bandpass filtering branch-line coupler (FBLC). By integrating a coupled microstrip line, and an open-ended stub at each port of a single-section BLC, bandpass filtering characteristics with excellent selectivity and broad operating bandwidth have been achieved. The proposed circuit has been verified through EM simulations and physical measurements of the fabricated...
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Unusual behavior of secondary amine group as a leaving group
PublicationIn our recent project we focused on reactivity of2,2-dimethyl-4,6-dioxane-1,3-dione carbamoilo- and thiocarbamoylo- derivatives as a ketenesource. Meldrum`s acid derivatives after thermal decomposition gives substituted keteneswith stoichiometric yield, that can be trapped with various spectrum of nucleophiles likealcohols, thiols, amine, imines etc. In case of5-[3-(dimethylamino)-sulfanyl-propyliden]-2,2-dimethyl-1,3-dioxane-4,6-dione...
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Teloxantron inhibits the processivity of telomerase with preferential DNA damage on telomeres
PublicationTelomerase reactivation is one of the hallmarks of cancer, which plays an important role in cellular immortalization and the development and progression of the tumor. Chemical telomerase inhibitors have been shown to trigger replicative senescence and apoptotic cell death both in vitro and in vivo. Due to its upregulation in various cancers, telomerase is considered a potential target in cancer therapy. In this study, we identified...
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Convenient and efficient synthesis of functionalized unsymmetrical alkynyl sulfides
PublicationWe developed a simple and efficient method for the synthesis of functionalized unsymmetrical alkynyl sulfides under mild conditions in good yields. The designed method is based on the reaction of 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-disulfanyl derivatives with lithium acetylides. The developed method allows the preparation of unsymmetrical alkynyl sulfides bearing additional hydroxyl, carboxyl, or amino functionalities.
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Calix[4]arenes appended with thioamide moieties as powerful tool for heavy metals recognition
PublicationSelectivity of new thioamide derivatives was assessed using those ligands as sensor materials in ion-selective membrane electrodes and tested towards Pb2+ - selectivity. The influence of the nature of the thioamide function (linear, branched or cyclic substituents) on their ionophoric properties was investigated. Electrodes based on cyclic thioamide moieties are promising analytical tools for monitoring Pb2+ concentration in natural...
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Enhanced Toxicity of Bisphenols Together with UV Filters in Water: Identification of Synergy and Antagonism in Three-Component Mixtures
PublicationContaminants of emerging concern (CEC) localize in the biome in variable combinations of complex mixtures that are often environmentally persistent, bioaccumulate and biomagnify, prompting a need for extensive monitoring. Many cosmetics include UV filters that are listed as CECs, such as benzophenone derivatives (oxybenzone, OXYB), cinnamates (2-ethylhexyl 4-methoxycinnamate, EMC) and camphor derivatives (4-methylbenzylidene-camphor,...
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Impact of dyes isomerization effect on the charge transfer phenomenon occurring on the dye/nanosemiconductor interface
PublicationThe present work aimed to find the answer how does the isomerization of the Ru based dyes affect the overall photon-to-current efficiency of the DSSCs and to explain the charge transfer phenomenon occurring on the dye/ nanosemiconductor interface. Therefore, electronic and optical properties of three bipyridine derivatives anchored on the TiO2 electrode were investigated by computational simulations based on quantum chemistry codes...
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Synthesis and Cholinesterase Inhibitory Activity of N-Phosphorylated /N-Tiophosphorylated Tacrine
PublicationNovel phosphorus and thiophosphorus tacrine derivatives were designed, synthesized and their biological activity and molecular modeling was investigated as a new potential anti-Alzheimer's disease (AD) agents. All new synthesized compound exhibited lower toxicity against neuroblastoma cell line (SH-SY5Y) in comparison with tacrine. Two analogues in the series, 7 and 9, demonstrated lack of cytotoxicity against hepatocellular cells...
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SYNTHESIS OF PHOSPHORUS TACRINE ANALOGUES AS A NEW POTENTIAL ANTI-ALZHEIMER’S DISEASE AGENTS
PublicationA series of novel phosphorus tacrine derivatives was obtained in three steps, including synthesis of 9-chlorotacrine, connection of 9-chlorotacrine with hexamethylenediamine, 1,8-diaminooctane and 1,12-diaminododecane linkers and reaction of obtained tacrine diamine analogues with corresponding acid ester to give nine tacrine organophosphorus compounds. All of the obtained final structures were characterized by 1H NMR, 13C NMR,...
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Peptide modification with thiomalonoamide moiety
PublicationAbstract: Meldrum acid derivatives under the thermal decomposition are well known source of ketenes. Recently we investigated chemical properties of thiocarbamolyl meldrum acids. We found that 5-(α-alkylamino- α'-sulfhydryl)methylene Meldrum's acids hated in the presence of amines produce thiomalonamides. We used this reaction to the one pot synthesis of series of short peptides containing thiomalonoamide motif.
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Implementation of the FOPID Algorithm in the PLC Controller - PWR Thermal Power Control Case Study
PublicationIn the paper authors describe proposition of design and verification procedures of the discrete Fractional Order PID (FOPID) algorithm for control of the Pressurized Water Reactor (PWR) thermal power near its nominal operating point. The FOPID algorithm synthesis consists of: off-line optimal tunning of its parameters in continuous time-domain with LQ (Linear Quadratic) performance index and simplified models of nuclear reactor...
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Role of distillation in determination of SCFAs in samples of different origin
PublicationShort-chain fatty acids (SCFAs) are very volatile compounds and choosing an appropriate isolation and enrichement technique is a key to their determination. Distillation is one of methods which can be applied. There are many types of distillation. The simplest ones are direct, steam and fractional distillation, but they are not used very often and have some drawbacks. However, many modifications of basic distillation have been...
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Necessary and Sufficient Condition for State-Independent Contextual Measurement Scenarios
PublicationThe problem of identifying measurement scenarios capable of revealing state-independent contextuality in a given Hilbert space dimension is considered. We begin by showing that for any given dimension d and any measurement scenario consisting of projective measurements, (i) the measure of contextuality of a quantum state is entirely determined by its spectrum, so that pure and maximally mixed states represent the two extremes...
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Assessment of the devulcanization process of EPDM waste from roofing systems by combined thermomechanical/microwave procedures
PublicationEthylene-propylene-diene rubber (EPDM) is a elastomer widely used in common industrial applications. EPDM can be shaped into sheets and employed as isolating material for roofing systems. In this study, scraps of EPDM from commercial, industrial and residential roofing systems were treated by combined thermo-mechanical and microwave devulcanization processes including peroxide of benzoyl (BPO). The devulcanized EPDM (Dev-EPDM)...
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A new 1-nitro-9-aminoacridine derivative targeting yeast topoisomerase II able to overcome fluconazole-resistance
PublicationFungal resistance remains a significant threat and a leading cause of death worldwide. Thus, overcoming microbial infections have again become a serious clinical problem. Although acridine derivatives are widely analyzed as anticancer agents, only a few reports have demonstrated their antifungal activity. In an effort to develop biologically active antifungals, twelve novel C-857 (9-(2′ -hydroxyethylamino)-1-nitroacridine) and...
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Novel Functionalization of Boron-Doped Diamond by Microwave Pulsed-Plasma Polymerized Allylamine Film
PublicationWe report the novel modification of a hydrogen-terminated polycrystalline boron-doped electrode with a microwave pulsed-plasma polymerized allylamine. Boron-doped diamond (BDD) was coated with a very thin layer of adherent cross-linked, pinhole- and additive-free allylamine plasma polymer (PPAAm) resistant to hydrolysis and delamination and characterized by a high density of positively charged amino groups. The pulsed microwave...
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‘Acridines’ as New Horizons in Antifungal Treatment
PublicationFrequent fungal infections in immunocompromised patients and mortality due to invasive mycosis are important clinical problems. Opportunistic pathogenic Candida species remain one of the leading causes of systemic mycosis worldwide. The repertoire of antifungal chemotherapeutic agents is very limited. Although new antifungal drugs such as lanosterol 14α-demethylase and β-glucan synthase inhibitors have been introduced into clinical...
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A convenient method for the preparation of functionalized N-acylsulfenamides from primary amides.
PublicationWe have developed a convenient method for the synthesis of functionalized N-acylsulfenamides under mild conditions and in moderate to good yields. The designed method is based on the reaction of (5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl)-disulfanyl derivatives with nitrogen nucleophiles generated from primary amides or imides and sodium hydride. The developed method allows for the preparation of N-acylsulfenamides bearing...
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Access to Side-On Bonded Tungsten Phosphanylphosphinidene Complexes
PublicationMetathesis reactions between diimido complexes of tungsten(VI)[(ArN)2WCl2] (Ar = 2,6-iPr2C6H3) and lithium derivatives of diphosphanes R2P-P(SiMe3)Li (R = tBu and iPr) yield two anionic diimido complexes of tungsten with side-on bonded phosphanylphosphinidene ligands, [(ArN)2WCl(η2-R2P-P)]-. Both complexes are structurally characterized. A possible reaction mechanism and the role of donor solvents are discussed on the basis of...
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On existence and uniqueness of weak solutions for linear pantographic beam lattices models
PublicationIn this paper, we discuss well-posedness of the boundary-value problems arising in some “gradientincomplete” strain-gradient elasticity models, which appear in the study of homogenized models for a large class ofmetamaterials whosemicrostructures can be regarded as beam lattices constrained with internal pivots. We use the attribute “gradient-incomplete” strain-gradient elasticity for a model in which the considered strain energy...
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Escherichia coli K-12 suppressor-free mutants lacking early glycosyltransferases and late acyltransferases. Minimal lipopolysaccharide structure and induction of envelope stress response.
PublicationTo elucidate the minimal lipopolysaccharide (LPS) structure needed for the viability of Escherichia coli, suppressor-free strains lacking either the 3-deoxy-d-manno-oct-2-ulosonic acid transferase waaA gene or derivatives of the heptosyltransferase I waaC deletion with lack of one or all late acyltransferases (lpxL/M/P) and/or various outer membrane biogenesis factors were constructed. Δ(waaC lpxL lpxM lpxP) and waaA mutants exhibited...
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Coplanar Waveguide-Fed Broadband Microwave Devices with (or without) a Thin Dielectric Substrate for Use in Flexible Electronic Systems
PublicationTwo examples of microwave devices, fed by a coplanar waveguide and realized on a thin substrate (or without such a substrate), are employed to investigate the influence of devices’ curvatures and the proximity of different materials on their parameters. To perform the tests, a broadband antenna and a low-pass filter are chosen. A feeding coplanar waveguide is realized on a dielectric material brick attached to an SMA connector...
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Chemical Aspects of Biological Activity of Isothiocyanates and Indoles, the Products of Glucosinolate Decomposition
PublicationThere is growing evidence that cancer chemoprevention employing natural, bioactive compounds may halt or at least slow down the different stages of carcinogenesis. A particularly advantageous effect is attributed to derivatives of sulfur-organic phytochemicals, such as glucosinolates (GLs) synthesized mainly in Brassicaceae plant family. GLs are hydrolysed enzymatically to bioactive isothiocyanates (ITC) and indoles, which exhibit strong...