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Search results for: schwarzian derivative
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Thermodynamics aspects of interactions between acridine derivatives and DNA
PublicationDNA is a molecular target for many anticancer and antiviral drugs. Therefore, a clear understanding of the interaction of small molecules with DNA is important in the rational design of ligands that can bind to DNA with high affinity and selectivity. There are several methods to investigate interactions between drug and DNA. Some of them measure changing into DNA structures, such as lengthening and untwisting of helix of DNA. Other...
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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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Rhodotorulic Acid and its Derivatives: Synthesis, Properties, and Applications
PublicationSiderophores 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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Antimycobacterial activity of 5-arylidene aromatic derivatives of hydantoin
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Solid phase synthesis of two muramyl pentapeptide derivatives
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Densimetric and ultrasonic characterization of urea and its derivatives in water
PublicationW oparciu o pomiary gęstości dla serii roztworów jak i rozpuszczalnika wykonanych w temperaturach 15, 20, 25, 30 i 35oC wyznaczono pozorne molowe objętości mocznika, N-metylomocznika, N,N'-dimetylomocznika, N,N,N',N'-tetrametylomocznika, N-etylomocznika, N,N'-dietylomocznika jak i N-butylomocznika w wodzie. Dodatkowe pomiary szybkości dźwięku przeprowadzone w temperaturze 25oC pozwoliły obliczyć ściśliwości adiabatyczne, pozorne...
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Microwave-assisted synthesis of zinc derivatives of potato starch
PublicationZincatated potato starch was prepared in a solid-state, microwave-assisted reaction using generated in situ sodium tetrahydroxozincate [Na2Zn(OH)4]. For comparison, zincatation of starch was also carriedout on convectional heating. Depending on the irradiation conditions, the products of either mono- or crosslinking esterification were formed. Higher power applied at shorter exposition offered products ofmonoesterification, and...
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The biological activity of new tuftsin derivatives - induction of phagocytosis
PublicationFagocytoza odgrywa ważną rolę w ochronie organizmu przed różnymi mikroorganizmami. Proces ten może być indukowany przez różne czynniki np. endogenny immunomodulator jakim jest tuftsyna czy muramylo-dipeptyd (MDP), najmniejszy syntetyczny glikopeptyd bakteryjnej ściany komórkowej. Zsyntetyzowano nowe analogi MDP i nor-MDP z tuftsyną i retro-tuftsyną, które są zdolne do indukowania fagocytozy. Najbardziej obiecujące okazały się dwa...
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Functionalization of cysteine derivatives by unsymmetrical disulfide bond formation
PublicationOpracowano metodę funkcjonalizacji pochodnych cysteiny przy pomocy tworzenia niesymetrycznego wiązania disulfidowego. Opracowana metoda okazała się bardzo łagodna, wydajna, i niewrażliwa na obecność dodatkowych grup funkcyjnych.
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Hedging Strategies of Derivatives Instruments for Commodity Trading Entities
PublicationHedging as an outcome of risk management arises to account several questions. Mentioned aspect of size of the hedging is one of them. Latter questioning refers to whether producer of manufacturer are willing to secure entire exposure, when the hedging should start, now or later in the future, what is the vision on market like direction of market, time of interest, magnitude of exposure, what would be the preferred instruments of...
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Acyl Meldrum's acid derivatives: application in organic synthesis
PublicationThis 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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Hydration of urea and its derivatives - Volumetric and compressibility studies
PublicationThe densities and sound velocities at T = (288.15, 293.15, 298.15, 303.15 and 308.15) K have been measured for aqueous solutions of urea, N,N-dimethylurea, N,N-diethylurea, N-propylurea, N-butylurea. From these data the apparent molar volumes, V the apparent molar isentropic compressions, KS,, and the Passynski solvation numbers of solutes have been determined. The concentration dependencies of the calculated quantities, their...
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Copper(I) iodide ribbons coordinated with thiourea derivatives
PublicationTwo products of the reactions of CuI with 1-benzoyl-3-(4-bromophenyl)thiourea and with 1-benzoyl-3-(2-iodophenyl)thiourea have been obtained and characterized, namely poly[[[1-benzoyl-3-(4-bromophenyl)thiourea-κS]-µ3-iodidocopper(I)] acetone hemisolvate], {[CuI(C₁₄H₁₁BrN₂OS)]‧0.5C₃H₆O}ₙ, and poly-[µ₄-iodido-µ₃-iodido-[N-(benzo[d]thiazol-2-yl)benzamide-κN]dicopper(I)], [Cu₂I₂(C₁₄H₁₀N₂OS)]ₙ. Their structures, determined by single-crystal...
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Synthesis of bicoumarin thiophosphate derivatives as steroid sulfatase inhibitors
PublicationBased on the frameworks of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-4-one, 3-hydroxy- 7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one and 3-hydroxy-8,9,10,11-tetrahydro-7H-cyclohepta[c] chromen-6-one, a series of bicoumarin thiophosphate analogs have been synthesized and biologically evaluated. Additionally, their binding modes have been modeled using docking techniques. The inhibitory properties of the synthesized compounds...
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Apoptosis of human leukemia cells induced by imidazoacridinone derivative C-1311 (Symadex)
PublicationPraca dotyczy różnej wrażliwości komórek białaczek ludzkich do ulegania apoptozie pod wpływem pochodnej imidazoakrydonu C-1311, co jest zgodne z aktywnością cytotoksyczną tego związku (EC90) wobec badanych komórek.
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The Effect of Conjugation with Octaarginine, a Cell-Penetrating Peptide on Antifungal Activity of Imidazoacridinone Derivative
PublicationAcridine cell-penetrating peptide conjugates are an extremely important family of compounds in antitumor chemotherapy. These conjugates are not so widely analysed in antimicrobial therapy, although bioactive peptides could be used as nanocarriers to smuggle antimicrobial compounds. An octaarginine conjugate of an imidazoacridinone derivative (Compound 1-R8) synthetized by us exhibited high antifungal activity against reference...
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Multiple Solutions to Third-Order Differential Equations with Derivative Dependence and Deviating Arguments
PublicationIn this paper, we give some new results for multiplicity of positive (nonnegative) solutions for third-order differential equations with derivative dependence, deviating arguments and Stieltjes integral boundary conditions. We discuss our problem with advanced argument α and arbitrary β ∈ C([0,1],[0,1]), see problem (2). It means that argument β can change the character on [0,1], so β can be delayed in some set J ⊂ [0,1] and advanced...
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Enantioselective sensing of (S)-Thalidomide in blood plasma with a chiral naphthalene diimide derivative
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Fractional Variable-Order Derivative and Difference Operators and Their Applications to Dynamical Systems Modelling
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Synthesis and biological activity of mycophenolic acid-amino acid derivatives
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Anticancer Properties of Amino Acid and Peptide Derivatives of Mycophenolic Acid
PublicationBackground: 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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Fractional Problems with Right-Handed Riemann-Liouville Fractional Derivatives
PublicationIn this paper, we investigate the existence of solutions for advanced fractional differential equations containing the right-handed Riemann-Liouville fractional derivative both with nonlinear boundary conditions and also with initial conditions given at the end point T of interval [0,T ]. We use both the method of successive approximations, the Banach fixed point theorem and the monotone iterative technique, as well. Linear problems...
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NUMERICAL ESTIMATION OF HULL HYDRODYNAMIC DERIVATIVES IN SHIP MANOUVERING PREDICTION
PublicationOperating in crowded waterways pose a risk of accidents and disasters due to maneuvering limitations of the ship. In order to predict ship’s maneuvering characteristics at the design stage, model tests are often executed as the most accurate prediction tool. Two approaches can be distinguished here: free running model tests and numerical simulations based on planar motion model with the use of hydrodynamic derivatives obtained...
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Numerical Estimation of Hull Hydrodynamic Derivatives in Ship Maneuvering Prediction
PublicationPrediction of the maneuvering characteristics of the ship at the design stage can be done by means of model tests, computational simulations or a combination of both. The model tests can be realized as direct simulation of the standard maneuvers with the free running model, which gives the most accurate results, but is also the least affordable as it requires very large tank or natural lake, as well as complex equipment of the...
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Immunosuppressive properties of amino acid and peptide derivatives of mycophenolic acid
PublicationMycophenolic 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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Expedited antenna optimization with numerical derivatives and gradient change tracking
PublicationDesign automation has been playing an increasing role in the development of novel antenna structures for various applications. One of its aspects is electromagnetic (EM)-driven design closure, typically applied upon establishing the antenna topology, and aiming at adjustment of geometry parameters to boost the performance figures as much as possible. Parametric optimization is often realized using local methods given usually reasonable...
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Therapeutic Potential of Carnosine and Its Derivatives in the Treatment of Human Diseases
PublicationDespite significant progress in the pathogenesis, diagnosis, treatment, and prevention of cancer and neurodegenerative diseases, their occurrence and mortality are still high around theworld. The resistance of cancer cells to the drugs remains a significant problem in oncology today,while in the case of neuro-degenerative diseases, therapies reversing the process are still yet to be found. Furthermore, it is important to seek new...
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New Chalcones Derivatives With Potent Antitumor Activity And Their Metabolism In Vitro
PublicationChalcone derivatives exhibit a broad range of biological activities, with antioxidant and cytotoxic properties among the most studied. Despite numerous reports on chalcones as cytotoxic, and potentially anticancer agents, very little is know on their actual mechanism of activity. Generally, chalcones are considered as antimitotic agents, which interfere with tubulin assembly.We have recently developed a new class of chalcones with...
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Antimicrobial and surface activity of 1-alkyl-3-methylimidazolium derivatives
PublicationWiedza na temat zależności struktura-aktywność umożliwia projektowanie i syntezę nowych kationowych związków amfifilowych ze zoptymalizowaną aktywnością antymikrobową na rzecz przyszłego rozwoju nowych środków dezynfekujących, sanityzujących czy konserwujących. Potrzeba projektowania i identyfikowania nowych związków posiadających właściwości przeciwbakteryjne jest rezultatem pojawienia się bardziej odpornych mikroorganizmów w...
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Supramolecular Interactions between β-Cyclodextrin and the Nucleobase Derivatives of Ferrocene
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Conjugation of polyethylenimine and its derivatives to carbon-encapsulated iron nanoparticles
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Natural composites based on polysaccharide derivatives: preparation and physicochemical properties
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Prediction of antimicrobial activity of imidazole derivatives by artificial neural networks
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Studies on the influence of β-cyclodextrin derivatives on the physical stability of famotidine
PublicationThe usage of Fourier transform infrared spectroscopy, near infrared spectroscopy, differential scanning calorimetry and microscopy is presented in this work focused on the exploration of the effect of CD on the physical stability of famotidine (FAM). The most significant information was achieved by analysis of the second derivatives ofnear infrared (NIR) spectra recorded. Changes in the shape of spectra derivatives allow...
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Photophysics of 7-Hydroxytetrahydroisoquinoline-3-carboxylic Acid and Its Derivatives
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Alkylation of 9-substituted guanine derivatives with α,ω-dihaloalkanes
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Indirect Measurement of Motor Current Derivatives in PMSM Sensorless Drives
PublicationMotor current derivatives contain useful information for control algorithms, especially in sensorless electric drives. The measurement of motor current derivatives in electric motors supplied by voltage source inverter can be performed using di/dt transducers. However, in such a solution additional sensors have to be installed, e.g. Rogowski coils. Another approach is to measure current derivatives indirectly – by oversampling...
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Synthesis and biological activity of mycophenolic acid-amino acid derivatives
PublicationIn 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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The content of butyl- and phenyltin derivatives in the sediment from the Port of Gdansk
PublicationPróbki osadów portowych były pobierane dwukrotnie (2003 i 2005)z różnych nabrzeży w Porcie Gdańsk. Rdzenie o długości 25 cm były dzielone na warstwy o grubości 2 i 5cm i po odpowiednim przygotowaniu (w tym także analizie sitowej) były poddawane analizie na zawartość związkow cynoorganicznych.W analizowanych póbkach (o różnej granulacji cząstek osadu) wykryto i oznaczono względnie duże stężenie TBT, DBT, MBT oraz MPhT. Osady portowe...
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Synthesis of ester derivatives of propylene glycol in the presence of zinc carboxylates.
PublicationZbadano wpływ temperatury i stężenia karboksylanów cynku na przebieg estryfikacji glikolu propylenowego kwasami tłuszczowymi. Otrzymano emulgatory, w których maksymalne stężenie monoestru wynosiło 55-57%.
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CYP3A4 overexpression enhances the cytotoxicity of the antitumor triazoloacridinone derivative C-1305 in CHO cells
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Induction of apoptosis by triazoloacridinone derivative - C-1533 in HL60 and MOLT4 human leukemia cells.
PublicationPrzeprowadzone badania miały na celu określenie zdolności triazoloakrydonu C-1533 do indukcji śmierci komórek nowotworowych MOLT4 i HL60 na drodze apoptozy. Badanie zjawiska apoptozy przeprowadzono z wykorzystaniem techniki cytofluorymetrii przepływowej, mikroskopii fluorescencyjnej i elektroforezy agarozowej. Badania wykazały, że zarówno w komórkach MOLT4 jak i HL60, spadek mitochondrialnego potencjału błonowego oraz translokacja...
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On the Fenchel–Moreau conjugate of G-function and the second derivative of the modular in anisotropic Orlicz spaces
PublicationIn this paper, we investigate the properties of the Fenchel–Moreau conjugate of G-function with respect to the coupling function c(x, A) = |A[x]2 |. We provide conditions that guarantee that the conjugate is also a G-function. We also show that if a G-function G is twice differentiable and its second derivative belongs to the Orlicz space generated by the Fenchel–Moreau conjugate of G then the modular generated by G is twice differentiable...
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Time fractional analysis of Casson fluid with application of novel hybrid fractional derivative operator
PublicationA new approach is used to investigate the analytical solutions of the mathematical fractional Casson fluid model that is described by the Constant Proportional Caputo fractional operator having non-local and singular kernel near an infinitely vertical plate. The phenomenon has been expressed in terms of partial differential equations, and the governing equations were then transformed in non-dimensional form. For the sake of generalized...
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CYP3A4 overexpressin enhances the cytotoxicity of the antitumor triazoloacridinone derivative C-1305 in CHO cells
PublicationW pracy badano wpływ nadekspresji izoenzymu CYP3A4 na cytotoksyczność i odpowiedź komórkową indukowaną przez przeciwnowotworową pochodną triazoloakrydonu w modelowym układzie komórek CHO: dzikego typu, z nadekspresją reduktazy cytochromu P450 (CHO-HR) oraz z koekspresją reduktazy i izoenzymu CYP3A4 (CHO-HR-3A4). Wykazano, że komórki CHO wykazywały różną wrażliwość na badany związek, a linia CHO-HR okazała się najbardziej wrażliwa,...
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Solvent-Free Synthesis of Phosphonic Graphene Derivative and Its Application in Mercury Ions Adsorption
PublicationFunctionalized graphene was efficiently prepared through ball-milling of graphite in the presence of dry ice. In this way, oxygen functional groups were introduced into material. The material was further chemically functionalized to produce graphene derivative with phosphonic groups. The obtained materials were characterized by spectroscopic and microscopic methods, along with thermogravimetric analysis. The newly developed material...
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Polymeric bisphosphonate derivative of ciprofloxacin – synthesis, structural analysis and antibacterial activity of the prospective conjugate
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In vitro photodynamic activity of lipid vesicles with zinc phthalocyanine derivative against Enterococcus faecalis
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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.