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Search results for: fractional derivatives and integrals
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Chromogenic derivatives of new bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) - synthesis and properties
PublicationDerivatives of bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) with oxygen and sulphur atoms in the structure of aliphatic chains were successfully synthesised. The correlation between the ligand structure and its complexation properties was investigated by absorption spectroscopy. The formation of complexes of presented compounds with metal cations (Cu2+, Ni2+, Zn2+, Co2+, Fe2+ and Pb2+) was studied. Ligands 5-8 were additionally...
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Estimation of interior-permanent-magnet-synchronous-motor rotor position by analysis of phase-current derivatives
PublicationThis paper describes an algorithm for estimation of IPMSM rotor angular position. The algorithm uses derivatives of motor phase currents resulting from PWM modulation to obtain the rotor position. The presented method is designed for medium- and high-speed range, since it is based on determination of the EMF vector. Calculation of the motor position is performed in every PWM cycle. The standard SV-PWM method is used to determine...
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Exposure scenario and risk assessment of infants and newborns to bisphenols and their derivatives from diapers
PublicationNewborns and infants are more sensitive to harmful compounds such as bisphenols and their derivatives because of their not fully developed detoxification mechanism. Exposure to these substances can lead to developmental problems and health consequences in adulthood. Since disposable baby diapers are used from the first days of life and remain in contact with the baby skin, it seems important to monitor the levels of endocrine disrupting chemicals...
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Synthesis and biological evaluation of thiophosphate tricyclic coumarin derivatives as steroid sulfatase inhibitors
PublicationSteroid sulfatase (STS) enzyme inhibition is an important approach to the management of hormone-dependent breast cancer. In this paper, we report convenient methods for the synthesis and biological evaluation of thiophosphate tricyclic coumarin analogs exhibiting STS activity. The described methods are based on the straightforward preparation of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-2-one, 3-hydroxy- 7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one,...
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DFT study of low-energy electron interaction with pyridine, pyrazine and their halo derivatives
PublicationIn this work, the density functional theory with B3LYP hybrid functional was employed to calculate quantities useful for estimating the behavior of pyridine, pyrazine and their derivatives monosubstituted with Cl or Br atom, when exposed to low-energy electron impact. Vertical electron affinities obtained in several Pople basis sets and in aug-cc-pVTZ basis set are reported. Although some of the investigated molecules do not form...
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Electron Transport in Naphthalene Diimide Derivatives
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Graphene and Its Derivatives for Energy Storage
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Novel Azocoumarin Derivatives—Synthesis and Characterization
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Bisphenols and their derivatives in baby diaper samples.
PublicationMany common products contain and leach hazardous chemicals, including endocrine-disrupting chemicals such as bisphenols that are harmful to human health. For toddlers, this dangerousness is higher because of their not fully developed detoxification system. Due to this, bisphenols content in products such as baby diapers, should be monitored. Baby diapers not only remain in close contact with the skin, but are also used from the...
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Synthesis, spectroscopy and computational studies of some biologically important hydroxyhaloquinolines and their novel derivatives
PublicationA series crystalline compounds of methyl and phosphinyl derivatives of 2-methylquinolin-8-ol (1a) and related 5,7-dichloro-2-methylquinolin-8-ol (1b) were quantitatively prepared and characterized by microanalysis, IR, UV-vis and multinuclear NMR spectroscopy. Five of them have been characterized by single crystal X-ray diffraction method. The known compounds, 8-methoxy-2-methylquinoline (2a) and 8-methoxyquinoline (2d), were synthesised...
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O-substituted tetrahydroxamate derivatives of p-tert-butylcalix[4]arene as receptors for transition and heavy metal cations
PublicationTetrasubstituted O-hydroxamate derivatives of p-tert-butylcalix[4]arene were applied as active materials in ion-selective membrane electrodes and were tested towards Pb-selectivity. The electrodes gave near-Nernstian characteristics for Pb2+ cations. The selectivity coefficients were determined. The influence of plasticizer on the electrode behaviour was studied. The dependence of the chemical structure on selectivity coefficients...
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Synthesis of new antrapyridazone derivatives - a novel group of anticancer agents active on a multidrugresistant(MDR) tumor cell lines
PublicationNovel antrapyridazone derivatives were synthesized and biologically evaluated in order tobroaden the data on structure-activity relationship of this class of cytostatics. Recent literaturedata prove that acetamides react better with aryl chlorides. A new approach based onintroduction of other amides form into aromatic ring in Ullmann was tested. This new methodcould give better yields and make purification step more convenient.
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Novel 1,2,3-Triazole Derivatives as Mimics of Steroidal System—Synthesis, Crystal Structures Determination, Hirshfeld Surfaces Analysis and Molecular Docking
PublicationHerein, we present the synthesis and crystal structures determination of five 4-(1-phenyl-1H-1,2,3-triazol-4-yl)phenol derivatives containing halogen atoms, 6a–e, which may be used as an excellent mimic of steroids in the drug development process. Good quality crystals obtained for all of the synthesized compounds allowed the analysis of their molecular structures. Subsequently, the determined crystal structures were used to calculate...
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Synthesis of functionalized new conjugates of batracylin with tuftsin/ retro-tuftsin derivatives and their biological evaluation
PublicationNew batracylin conjugates with tuftsin/retro-tuftsin derivatives were designed and synthesized using T3P as a coupling agent. The conjugates possess an amide bond formed between the carboxyl group of heterocyclic molecule and the N-termini of the tuftsin/retro-tuftsin chain. The in vitro cytotoxic activity of the new analogues and their precursors was evaluated using a series of human and murine tumor cells. BAT conjugates containing...
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Synthesis of thiol derivatives of azobenzocrown ethers. The preliminary studies on recognition of alkali metal ions by gold nanoparticles functionalized with azobenzocrown and lipoic acid
PublicationThe article presents the synthesis of novel 13- and 16-membered azobenzocrown derivatives with peripheral thiol moieties and preliminary studies assessing their possible application in plasmonic sensors based on gold nanoparticles. The effect of the length of the chain connecting the macrocycle with the thiol group and the effect of the presence of the additional functional compound,...
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New method of fractional order integrator analog modeling for orders 0.5 and 0.25
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<title>Estimation and control of discrete fractional order states-space systems</title>
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Fractional Variable-Order Derivative and Difference Operators and Their Applications to Dynamical Systems Modelling
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Properties of Windows Extracted from Fractional Delay Filters Optimal in Chebyshev Sense
PublicationJedną z najefektywniejszych numerycznie metod projektowania filtrów cyfrowych jest metoda okien. Jednak prostota tego podejścia wiąże się z reguły z niską jakością tak projektowanych filtrów, przede wszystkim ze względu na problemy z doborem odpowiedniego okna. Z tego powodu w zastosowaniach wymagających ciągłej aktualizacji współczynników filtrów, tak jak ma to miejsce w przypadku filtrów ułamkowo-opóźniających o zmiennym opóźnieniu,...
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Versatile Structure for Variable Fractional Delay Filter Based on Extracted Window Method
PublicationW pracy zaproponowano nową strukturę filtru ułamkowoopóźniającego o zmiennym opóźnieniu. Struktura ta umożliwia łatwą zmianę typo oraz długości implementowanego filtru. Zaproponowana struktura jest zmodyfikowaną strukturą Farrowa, której modyfikacje bazują na koncepcji metody okien wyodrębnionych. W metodzie tej filtr prawieoptymalny projektuje się stosując pojedyncze symetryczne okno wyodrębnione z dodatkową korekcją wzmocnienia...
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Gain Correction for Nearly Optimal Variable Fractional Sample Delay Filter Design
PublicationJedną z najbardziej efektywną numerycznie metodą projektowania filtrów jest metoda okien. Sprawia to, że takie podejście bardzo dobrze nadaje się do implementacji filtrów ułamkowoopóźniających o zmiennym opóźnieniu, gdzie wymagana jest częsta aktualizacja współczynników takiego filtru. Z drugiej strony, jeżeli wymagane są filtry wysokiej jakości wybór okna jest najczęściej problematyczny. Z tego powodu w pracy rozpatrzono użycie...
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Computational analysis of substituent effects on proton affinity and gas-phase basicity of TEMPO derivatives and their hydrogen bonding interactions with water molecules
PublicationThe study investigates the molecular structure of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and its derivatives in the gas phase using B3LYP and M06-2X functional methods. Intermolecular interactions are analyzed using natural bond orbital (NBO) and atoms in molecules (AIM) techniques. NO2-substituted TEMPO displays high reactivity, less stability, and softer properties. The study reveals that the stability of TEMPO derivatives...
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Assessing ecotoxicity and the endocrine potential of selected phthalates, BADGE and BFDGE derivatives in relation to environmentally detectable levels
PublicationThere is no doubt that the subject area of plasticmaterials (e.g., production of epoxy resins or polyesters) is inherently connected to issues concerning bisphenol A (BPA) and its analogues. Unfortunately, much less attention has been given to other compounds, which are also used for the production of these materials. Bisphenol A diglycidyl ether (BADGE) is a synthetic industrial compound obtained by a condensation reaction between...
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Novel N-(aryl/heteroaryl)-2-chlorobenzenesulfonamide derivatives: synthesis and anticancer activity evaluation
PublicationA new series of N-(aryl/heteroaryl)-2-chlorobenzenesulfonamide derivatives 4-21 have been synthesized, and evaluated at the National Cancer Institute (USA) for their in vitro activities against a panel of 60 different human cancer cell lines. Among them, compounds 16, 20 and 21 exhibited remarkable cytotoxic activity against numerous human cancer cell lines. We found that sulfonamide derivative 21 appeared to be more selective...
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Elucidating the impact of enzymatic modifications on the structure, properties, and applications of cellulose, chitosan, starch and their derivatives: a review
PublicationPolysaccharides, as one of the most prominent natural biopolymers, display numerous biological activities and industrial applications. Nevertheless, some polysaccharides lack biological properties or display weak biological activities. Besides, practical usages of polysaccharides still remain challenging because of their poor solubility and inappropriate hydrophilic/hydrophobic balance. Hence, enzymatic or chemical modifications...
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Novel 2-(2-alkylthiobenzenesulfonyl)-3-(phenylprop-2-ynylideneamino)guanidine derivatives as potent anticancer agents – Synthesis, molecular structure, QSAR studies and metabolic stability
PublicationA series of new 2-(2-alkylthiobenzenesulfonyl)-3-(phenylprop-2-ynylideneamino)guanidine derivatives have been synthesized and evaluated in vitro by MTT assays for their antiproliferative activity against cell lines of colon cancer HCT-116, cervical cancer HeLa and breast cancer MCF-7. The obtained results indicated that these compounds display prominent cytotoxic effect. The best anticancer properties have been observed for derivatives...
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Design, synthesis and biological evaluation of novel N-phosphorylated and O-phosphorylated tacrine derivatives as potential drugs against Alzheimer’s disease
PublicationIn this work, we designed, synthesised and biologically investigated a novel series of 14N- and O-phosphorylated tacrine derivatives as potential anti-Alzheimer’s disease agents. In the reaction of 9-chlorotacrine and corresponding diamines/aminoalkylalcohol we obtained diamino and aminoalkylhydroxy tacrine derivatives. Next, the compounds were acid to give final products 6–13 and 16–21 that were characterised by 1H, 13 C, 31P...
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Exploring the Reactivity of Unsymmetrical Diphosphanes toward Heterocumulenes: Access to Phosphanyl and Phosphoryl Derivatives of Amides, Imines, and Iminoamides
PublicationWe present a comprehensive study on the diphosphanation of iso(thio)cyanates by unsymmetrical diphosphanes. The reactions involving unsymmetrical diphosphanes and phenyl isocyanate or phenyl thioisocyanate gave rise to phosphanyl, phosphoryl, and thiophosphoryl derivatives of amides, imines, and iminoamides. The structures of the diphosphanation products were confirmed through NMR spectroscopy, IR spectroscopy, and single-crystal...
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Effect of temperature and ionic strength on volumetric and acoustic properties of solutions of urea alkil derivatives in aqueous NaCl
PublicationThe present work was undertaken to study volumetric and acoustic properties for diluted solutions of tetramethylurea in pure water and for urea, n-propylurea, n-butylurea and tetramethylurea in 0.5 or 1 moldm3 aqueous solutions of sodium chloride. This paper presents measured values of densities and sound velocities at T = (288.15, 298.15 and 308.15) K. From these data the apparent molar volumes, , adiabatic compressibilities,...
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Synthetic genistein derivatives as modulators of glycosaminoglycan storage
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Imidazoacridinone Derivatives as Efficient Sensitizers in Photoantimicrobial Chemotherapy
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Chlorophylls and their Derivatives Used in Food Industry and Medicine
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Glycyrrhetinic acid and its derivatives in infectious diseases
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Chromogenic macrocyclic derivatives of azoles - synthesis and properties,
PublicationNew azocrown ethers comprising imidazoles in the macrocycle have been synthesized. Imidazole, 2-methyl-, 4-methyl-, and 4-phenylimidazole were incorporated to form macrocyclic units by coupling with the appropriate bis-diazonium salts. The syntheseswere performed under high dilution conditions. The X-ray structure of a water adduct of the 21-membered crown ether derivative of 4-methylimidazole 8 has been solved. Metal...
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Affinity of fentanyl and its derivatives for the σ1-receptor
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Thermodynamics of new piroxicam derivatives in terahertz light
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Chromogenic Macrocyclic Derivatives of Azoles - Synthesis and Properties
PublicationOpisano syntezę makrocyklicznych azokoron zawierających resztę pirolu i imi-dazolu w makropierścieniu. Zbadano zdolność kompleksowania kationów metaliprzez otrzymane związki makrocykliczne przy pomocy spektrofotometrii UV-Visw acetonitrylu. Zbadano także właściwości jonoforowe związków w membranowychelektrodach jonoselektywnych. Ustalono strukturę krystalograficzną 18-czło-nowej pochodnej pirolu.
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Novel 1,2,4-Oxadiazole Derivatives in Drug Discovery
PublicationAbstract: Five-membered 1,2,4-oxadiazole heterocyclic ring has received considerable attention because of its unique bioisosteric properties and an unusually wide spectrum of biological activities. Thus, it is a perfect framework for the novel drug development. After a century since the 1,2,4-oxadiazole have been discovered, the uncommon potential attracted medicinal chemists’ attention, leading to the discovery of a few presently...
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Synthesis of phosphono and phosphate derivatives of hydroxyimino-D-alditols as new potential antifungal agents
PublicationIn search for new effective we antyfungals we focus on two enzymes involved in biosynthesis of the fungal cell wall. The first enzyme is glucosamine-6-phosphate (GlmS), which catalyzes transformation of D-fructose-6-phosphate (Fru-6P) to D-glucosamine-6-phodphate (GlcN-6P) in the chitin biosynthesis pathway. The second enzyme is phosphomannose isomerase (PMI) repored to play a crucial role in biosynthesis of many mannosylated structures,...
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Photoresponsive Amide-Based Derivatives of Azobenzene-4,4′-Dicarboxylic Acid—Experimental and Theoretical Studies
PublicationAzobenzene derivatives are one of the most important molecular switches for biological and material science applications. Although these systems represent a well-known group of compounds, there remains a need to identify the factors influencing their photochemical properties in order to design azobenzene-based technologies in a rational way. In this contribution, we describe the synthesis and characterization of two novel amides...
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Theoretical and computational analysis of nonlinear fractional integro-differential equations via collocation method
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Initial value problems for neutral fractional differential equations involving a Riemann-Liouville derivative
PublicationBadano równania neutralne typu ułamkowego z odchylonym argumentem. Podano warunki dostateczne na istnienie jednego rozwiązania.
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Passive Variable Fractional Delay Filter Design using Distributed Maximal Flatness Method
PublicationW pracy przedstawiono nową metodę projektowania pasywnych filtrów ułakowoopóźniających opartą na metodzie rozproszonej maksymalnej płaskości. W zaproponowane podejście jest uogólnieniem najbardziej popularnej metody projektowania filtrów maksymalnie płaskich - metody projektowania filtrów maksymalnie płaskich. Filtr maksymalnie płaski cechuje bardzo dobra jakość jedynie w wąskim paśmie wokół częstotliwości zerowej, ale jego istotną...
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Analysis of the influence of polystyrene microplastics and their derivatives on the DNA of human colon epithelial cells HT29 with the comet assay
PublicationWe have been using plastic for almost a century and nowadays a lot of them circulates as pollutants in the environment and still defragmenting to micro and nanoscale. The exposition through the food chain and its precise impact on human health is still not clear. In our study, we tested real food packaging after contact with food products and real thermoinsulation and environmental samples of polystyrene in different model liquids,...
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Spectroscopic studies on physicochemical properties of selected unsymmetrical bisacridine derivatives and NMR analysis of their interactions with the model sequence Pu22 aided by molecular dynamics
PublicationIn recent years, new promising acridine derivatives have appeared, belonging to the unsymmetrical bisacridines (UAs) family with high anticancer activity. Both their physicochemical properties and their mechanism of action at the molecular level have not been thoroughly analyzed so far. Four derivatives were selected for the study, termed as: C-2028, C-2041, C-2045 and C-2053. The first aim of this work was to determine the protonation...
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Meldrum’s acid assisted formation of tetrahydroquinolin‑2‑one derivatives a short synthetic pathway to the biologically useful scaffold
PublicationA new method for the preparation of tetrahydroquinolin-2-one derivatives is presented. This approach involves a two-step reaction between enaminones and acylating agents, immediately followed by electrophilic cyclization, all within a single synthesis procedure, eliminating the need to isolate intermediates. The entire process is facilitated by the use of acyl Meldrum’s acids which not only shortens the preparation time of the...
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Indole-Acrylonitrile Derivatives as Potential Antitumor and Antimicrobial Agents—Synthesis, In Vitro and In Silico Studies
PublicationA series of 2-(1H-indol-2-yl)-3-acrylonitrile derivatives, 2a–x, 3, 4a–b, 5a–d, 6a–b, and 7, were synthesized as potential antitumor and antimicrobial agents. The structures of the prepared compounds were evaluated based on elemental analysis, IR, 1H- and 13NMR, as well as MS spectra. X-ray crystal analysis of the representative 2-(1H-indol-2-yl)-3-acrylonitrile 2l showed that the acrylonitrile double bond was Z-configured. All...
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Structural Factors Affecting Cytotoxic Activity of (E)-1-(Benzo[d ][1,3]oxathiol-6-yl)-3-phenylprop-2-en-1-one Derivatives
PublicationDerivatives of (E)-1-(5-alkoxybenzo[d][1,3]oxathiol-6-yl)-3-phenylprop-2-en-1-one (1) demonstrated exceptionally high in vitro cytotoxic activity, with IC50 values of the most active derivatives in the nanomolar range. To identify structural fragments necessary for the activity, several analogs deprived of selected fragments were prepared, and their cytotoxic activity was tested. It was found that the activity depends on combined effects...
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Hydrophilic Films Based on Carboxymethylated Derivatives of Starch and Cellulose
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Emulsion-Based Gel Loaded with Ibuprofen and Its Derivatives
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