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Search results for: SYNTHETIC REFRIGERANTS
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Synthesis and Characterization of Nitrogen-doped Carbon Nanotubes Derived from g-C3N4
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Silver filled single-wall carbon nanotubes—synthesis, structural and electronic properties
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High Pressure Synthesis versus Calcination – Different Approaches to Crystallization of Zirconium Dioxide
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Bulk synthesis of carbon-filled silicon carbide nanotubes with a narrow diameter distribution
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Surface properties of wustite based iron-cobalt catalysts for ammonia synthesis reaction
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The effect of manganese on the structural and surface properties of nanocrystalline cobalt catalyst for ammonia synthesis
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Method for determination of the chemical composition of phases of the iron catalyst precursor for ammonia synthesis
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Effect of Synthesis Parameters of Graphene/Fe2O3 Nanocomposites on Their Structural and Electrical Conductivity Properties
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Starch-grafted-N-vinylformamide copolymers manufactured by reactive extrusion: synthesis and characterization
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Influence of Magnesium Oxide on the Structure and Catalytic Activity of the Wustite Catalyst for Ammonia Synthesis
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Reduction Process of Iron Catalyst Precursors for Ammonia Synthesis Doped with Lithium Oxide
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Synthesis and characterization of crystalline Fe3O4 nanoparticles Synteza i charakterystyka nanokrystalicznego Fe3O4
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Synthesis and Anticancer Activity of Mitotic-Specific 3,4-Dihydropyridine-2(1H)-thiones
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Synthesis of Fentanyl Triazole Derivatives and their Affinity for Mu-Opioid and Sigma-1 Receptors
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Shape-controllable synthesis of GdVO4 photocatalysts and their tunable properties in photocatalytic hydrogen generation
PublicationNovel visible light responsive materials for water splitting are essential for the efficient conversion of solar energy into hydrogen bond energy. Among other semiconductors, gadolinium orthovanadate has appropriate conduction and valence band edges positioned to split water molecules and a narrow band gap that allows the use of visible light for hydrogen generation. Thus, we present here that hydrogen evolution under visible light...
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Synthesis of bimetallic Co–Pt/cellulose nanocomposites for catalytic reduction of p-nitrophenol
PublicationIn this study, bimetallic nanoparticles (NPs) of Co–Pt anchored on cellulose nanofibers (CNFs) for catalytic applications were synthesized via a sonochemical approach. The electro-spinning technique was employed for the synthesis of CNFs from cellulose acetate. The thorough characterization of synthesised Co–Pt/CNF nanocomposites was performed with the help of scanning electron microscopy (SEM), Fourier transform infra-red (FT-IR)...
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Ladder-Based Synthesis and Design of Low-Frequency Buffer-Based CMOS Filters
PublicationBuffer-based CMOS filters are maximally simplified circuits containing as few transistors as possible. Their applications, among others, include nano to micro watt biomedical sensors that process physiological signals of frequencies from 0.01 Hz to about 3 kHz. The order of a buffer-based filter is not greater than two. Hence, to obtain higher-order filters, a cascade of second-order filters is constructed. In this paper, a more...
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Inhibitors of glucosamine-6-phosphate synthase as potential antimicrobials or antidiabetics – synthesis and properties
PublicationGlucosamine-6-phosphate synthase (GlcN-6-P synthase) is known as a promising target for antimicrobial agents and antidiabetics. Several compounds of natural or synthetic origin have been identified as inhibitors of this enzyme. This set comprises highly selective L-glutamine, amino sugar phosphate or transition state intermediate cis-enolamine analogues. Relatively low antimicrobial activity of these inhibitors, poorly penetrating...
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Computer-assisted pronunciation training—Speech synthesis is almost all you need
PublicationThe research community has long studied computer-assisted pronunciation training (CAPT) methods in non-native speech. Researchers focused on studying various model architectures, such as Bayesian networks and deep learning methods, as well as on the analysis of different representations of the speech signal. Despite significant progress in recent years, existing CAPT methods are not able to detect pronunciation errors with high...
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New synthesis route of highly porous InxCo4Sb12 with strongly reduced thermal conductivity
PublicationHighly porous, In-filled CoSb3 skutterudite materials with an attractive thermoelectric figure of merit (ZT * 1) and corresponding dense samples were fabricated through the cost-effective method of reduction in oxides in dry hydrogen and the pulsed electric current sintering (PECS) method, respectively. The reduction process was described in detail using in situ thermogravimetric analysis of Co2O3, Sb2O3 and In(NO3)35H2O separately...
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Diastereoselective Synthesis of Z‐Alkenyl Disulfides from α‐Thiophosphorylated Ketones and Thiosulfonates
PublicationWe developed a simple and efficient method for the synthesis of functionalized unsymmetrical Z‐alkenyl disulfides under mild conditions in moderate to good yields. The designed method is based on the reaction of α‐thiophosphorylated carbonyl compounds with thiotosylates in the presence of a base. The developed method allows the preparation of unsymmetrical Z‐alkenyl disulfides bearing additional hydroxy, carboxy, or ester functionalities
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Application of Syntactic Pattern Recognition Approach in Design and Optimisation of Group Machining Systems
PublicationRozwinięto koncepcję budowy zoptymalizowanych struktur systemów wytwarzania grupowego spektrum części z wykorzystaniem modelu analizy syntaktycznej sekwencji operacji ich procesów technologicznych. Określono formułę metryki odległościowej opisu stopnia zróżnicowania marszrut indywidualnych procesów oraz testowano jej skuteczność w aspekcie eksploracji wielowymiarowych danych i klasteryzacji obiektów wg cech wymagań technologicznych....
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Phosphate tricyclic coumarin analogs as steroid sulfatase inhibitors: synthesis and biological activity.
PublicationIn the present work, we report convenient methods for the synthesis and biological evaluation of phosphate tricyclic coumarin derivatives as potential steroid sulfatase inhibitors. The described synthesis includes the straightforward preparation 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 modified...
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Design and synthesis of new analogues of batracylin linked to tuftsin and retro-tuftsin derivatives
PublicationThe synthesis of derivatives of batracylin with several peptides was elaborated followed by their cytotoxic activity investigation.
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Developments in the synthesis and biological activity of Glycyl-L-Histydyl-L-Lysine derivatives
PublicationWe emphasize on the methods of the synthesis described in the literature and present the aspects of Gly-His-Lys structure modifications that played a key role in scientific research.
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Beta-Galactosidases of Pseudoalteromonas sp. – Characteristics and application for lactose hydrolysis and galactopyranosides synthesis
PublicationBeta-galactosidase [EC 3.2.1.23] is an enzyme that catalyzes the hydrolysis of O-glycosidic linkages in galactosides. It has biotechnological applications in the dairy industry for the production of milk with a low content of lactose and galactooligosacharides for use in healthy food. The transgalactosylation activity of beta-galactosidase can be used in the synthesis of alkyl galactopyranosides. Due to the fact that conditions of...
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Simple and novel synthesis of 3-(thio)phosphoryl-β-lactams by radical cyclization
PublicationRadical cyclization of phosphono-acetenamides promoted by manganese(III) acetate leads exclusively to the formation of 3-phosphoryl-β-lactams. The thiophosphoryl analogues were also prepared using this method. In particular, the presented protocol does not require the use of noble metals, while comparable methods do.
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Synthesis and application of tetrazole di and triamide derivatives in ion-selective membrane electrodes
PublicationA number of tetrazole diamides and triamides have been synthesized and applied as ion carries in ion-selective membrane electrodes. Their selectivity and sensitivity were studied towards alkali, alkaline earth, transition and heavy metal cations. it was found that membranes doped with 3 and 2-nitrophenyl octyl ether exhibit an almost theoretial Nernstian response for NH+ over relatively wide concentration range. Elestrodes with...
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A Green Chemistry "environmentally friendly" approach to the synthesis of chloro-intermediates of ephedrine/pseudoephedrine
PublicationMethylamphetamine is an addictive stimulant drug that strongly activates certain systems in the brain. It is closely related chemically to amphetamine, but the central nervous system effects of methamphetamine are greater. There is much interest in methylamphetamine among scientists and therefore the synthesizes of methylamphetamine and its metabolites are carried out on a large scale in chemical laboratories. Globally, ephedrine...
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Solid-phase synthesis and characterization of N-acetylated Gly-His-Lys analogues
PublicationZaprezentowano nowe analogi tripeptydu Gly-His-Lys (GHK), stanowiącego sekwencję naturalnie występującą w -II-łańuchu kolagenu, skąd jest uwalniany w stanach zapalnych i w procesach gojenia się ran. Gly-His-Lys jest szeroko stosowany na rynku kosmetycznym w połączeniu z kwasem palmitynowym, który ułatwia jego wnikanie w głąb skóry. Zaplanowane modyfikacje zawierały fragment Gly-X-Y (X=Met, Hyp, Hyp-Met, Gly-Hyp; Y=Lys, D-Lys) i...
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Phage-Directed Synthesis of Photoluminescent Zinc Oxide Nanoparticles under Benign Conditions
PublicationBiological systems, especially bacteriophages and peptides, are an attractive green alternative to other known methods of nanoparticle synthesis. In this work, for the first time, bacteriophages were employed to synthesize a specific peptide, capable of producing nanoparticles (NPs). Derivatives of M13 bacteriophage exposing a ZnO-binding peptide (TMGA-LGLKWPV) on either pIII or pVIII phage coat protein were constructed and used...
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Comparison of Optimization Techniques for Coupling Matrix Synthesis Using Eigenvalue Based Approach
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Synthesis of 5-Substituted 1H-Tetrazoles from Nitriles in the Presence of Heterogeneous Catalyst
PublicationTetrazoles are five-membered heterocyclic compounds containing in their rings four nitrogen atoms. They have wide applications as corrosion inhibitors, analytical reagents, high-energy materials and gas generating compositions. Tetrazoles also play important role in coordination chemistry as ligands and in medicinal chemistry as metabolically stable surrogates for carboxylic acids. In recent years, investigation of new method of...
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Synthesis and steroid sulfatase inhibitory activities of N-alkanoyl tyramine phosphates and thiophosphates
PublicationA series of phosphate and thiophosphate analogs based on the frameworks of N-alkanoyl tyramines have been synthesized and biologically evaluated. Their binding modes have been modeled using docking techniques. The inhibitory effects of the synthesized compounds were tested on STS isolated from the human placenta as well as the MCF-7, MDA-MB-231 and SkBr3 cancer cell lines. Most of the new STS inhibitors possessed potent activity...
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Rational design, synthesis and biological evaluation of thiadiazinoacridines: a new class of antitumor agents.
PublicationZsyntetyzowano serię związków o potencjalnej zdolności do wiązania się z DNA z grupy tiadiazinoakrydyn poprzez cyklizację odpowiednich pochodnych 9-imino-4-nitro-9,10-dihydroakrydyny. Zbadano ich zdolność do wiązania się z DNA oraz cytotoksyczność względem kilku linii komórek nowotworwych. Badania aktywności przeciwnowotworowej wobec białaczki P388 wskazały na zgodność tych wyników z wynikami cytotoksyczności in vitro. Wykazano,...
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Synthesis and ionophoric properties of functionalized p-tert-butyl-calix[4]arenes
PublicationProjektowanie struktury związków o właściwościach jonoforowych stanowi ważny element chemii supramolekularnej. W pracy przedstawiono wyniki badań nad funkcjonalizacją makrocyklicznych kaliks[4]arenów prowadzacą do nowych związków o zróżnicowanych właściwościach kompleksujących. Syntezowane przez nas jonofory badane były w membranowych elektrodach jonoselektywnych. Wyznaczono potencjometryczne współczynniki selektywności oraz stałe...
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A convenient synthesis of (S)-O-benzyl-N-tert-butoxycarbonyl-beta-tyrosine.
PublicationOpracowano dogodną metodę syntezy tytułowego aminokwasu z aldehydu 4-benzyloksybenzoesowego, kwasu malonowego i octanu amonu. Otrzymany aminokwasu rozdzielono na enancjomery poprzez krystalizację soli diastereoizomerycznej z kwasem L-winowym.
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The synthesis of 1,4,7,10-tetraazacyclododecanes with acetylsalicylic side arm as potential cobalt(II) fluorophores.
PublicationMonoacylowe pochodne 1,4,7,10-tetraazacyklododekanu otrzymano w bezpośredniej reakcji cyklenu z chlorkiem kwasu salicylowego, jak również przy użyciu trichronionego cyklenu. Monoacylową pochodną wykorzystano następnie w reakcji z fosforynem etylu otrzymując difunkcyjny związek. Otrzymane ligandy zbadano spektrofotometrycznie. Obydwa ligandy oddziaływują selektywnie z jonami Co(II), tworząc kompleksy o stechiometrii 2:1 i 1:1 (ligand:metal).
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Catalysts for advanced oxidation processes: Deep eutectic solvents-assisted synthesis – A review
PublicationNew catalyst synthesis techniques, including green materials, are extensively studied for heterogeneous photocatalytic advanced oxidation processes (AOPs) on spotlight of sustainable development. Deep eutectic solvents (DESs) started to be used in this field as environmentally friendly alternative to ionic liquids (ILs). During the catalyst synthesis, DESs can act as stabilizers, capping agents, structure directing agents, templates,...
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Chiral-based optical and electrochemical biosensors: Synthesis, classification, mechanisms, nanostructures, and applications
PublicationThis review seeks to collect, summarize, classify and discuss the latest advances in chiral-based optical biosensors. Starting from the identification of chiral molecules, photoluminescence, and electrochemical sensors, applications of chiral structures in biosensing molecules are reviewed. Then, biosensors working on the basis of chirality are classified, followed by summarizing the outcomes of research works on design, synthesis,...
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Efficient synthesis of N-benzyloxycarbonyl- and N-tert-butoxycarbonyl-(S)-isoserine and their derivatives
PublicationOpisano wydajną metodę syntezy N-benzyloksykarbonylo- i N-tert-butoksykarbo-nylo-(S)-izoseryny i jej pochodnych z kwasu L-jabłkowego poprzez odpowiednie oksazolidinony i hydrolizę tych połączeń za pomocą wodorotlenku benzylowo-trimetyloamoniowego.
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The synthesis and structure of a potential immunosuppressant: N-mycophenoyl malonic acid dimethyl ester
PublicationThe synthesis of a potential immunosuppressant, i.e. dimethyl ester of N-mycophenoyl malonic acid was optimized in the reaction of mycophenolic acid (MPA) with amino malonic dimethyl ester in the presence of propanephosphonic anhydride (T3P) as a coupling reagent. The structural properties of the obtained MPA derivative were investigated by NMR, MS and single crystal X-ray diffraction methods. Theoretical considerations of conformational...
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Voiceless Stop Consonant Modelling and Synthesis Framework Based on MISO Dynamic System
PublicationA voiceless stop consonant phoneme modelling and synthesis framework based on a phoneme modelling in low-frequency range and high-frequency range separately is proposed. The phoneme signal is decomposed into the sums of simpler basic components and described as the output of a linear multiple-input and single-output (MISO) system. The impulse response of each channel is a third order quasi-polynomial. Using this framework, the...
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A New Approach to Chemical Recycling of Polyamide 6.6 and Synthesis of Polyurethanes with Recovered Intermediates
PublicationA new efficient method for the chemical decomposition of polyamide 6.6 by the glycolysis and amino-glycolysis processes was proposed. The glycolysis was conducted using the mass excess of ethylene glycol (EG) as a decomposing agent in the presence of a catalyst. Also, a mixture of EG and triethylenetetramine was used as another decomposing agent in the amino- glycolysis process. The described process of decomposition did not...
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Synthesis, spectroscopy and computational studies of some novelphosphorylated derivatives of quinoline-5,8-diones
PublicationThe neutral phosphorus nucleophiles such as R2P(=Y)M allowed the radical addition to 2-methyl-5,8-dioxo-5,8-dihydroquinoline-7-amine and N-(2-methyl-5,8-dioxo-5,8-dihydroquinolin-7-yl)acetamide giving exclusively O-phosphorylated products. All products were quantitatively prepared and characterized by microanalysis, and multinuclear NMR spectroscopy. Seven of them, have been characterized by single crystal X-ray diffraction method....
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Anion recognition by phosphonium calix[4]arens: synthesis and physico-chemical studies
Publicationp-tert-butylcalix[4]arenes in the cone conformation, di-and tetra substituted at the narrow rim with charged phosphonium groups have been synthesies and characterised.
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Synthesis and characterisation of polyurethane elastomers with semi-products obtained from polyurethane recycling
PublicationIn this work polyurethane elastomers were synthesised by using different mixtures of a petrochemical and glycerolysate polyols and 4,4-diphenylmethane diisocyanate (MDI). Glycerolysate polyol was produced from polyurethane foam decomposition using crude glycerine as a decomposition agent. The structure and thermal properties of obtained semi-product were similar to the polyol used in the synthesis of original foam. Glycerolysate...
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Investigation of the Effects of Primary Structure Modifications within the RRE Motif on the Conformation of Synthetic Bovine Herpesvirus 1‐Encoded UL49.5 Protein Fragments
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Reversed-phase and normal-phase thin-layer chromatography and their application to the lipophilicity prediction of synthetic pyrethroids based on quantitative structure–retention relationships
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Analogues of trypsin inhibitor SFTI-1 modified in the conserved P1′ position by synthetic or non-proteinogenic amino acids retain their inhibitory activity
PublicationA series of linear and monocyclic (with a disulfide bridge only) analogues of trypsin inhibitor SFTI-1 modified in the P-1 and/or P-1' positions were synthesized by the solid-phase method. In the substrate specificity P-1 position, Phe or N-benzylglycine (Nphe) were introduced, whereas the conserved Ser6 in Bownam-Birk (BBI) inhibitors was replaced by Hse (L-homoserine), Nhse [N-(2-hydroxyethyl)glycine], Sar, and Ala. Kinetic studies...