Filters
total: 2122
displaying 1000 best results Help
Search results for: SYNTHETIC REFRIGERANTS
-
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,...
-
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.
-
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,...
-
Mechanochemical synthesis of nanophotocatalysts SiO2/TiO2/Fe2O3: their structural, thermal and photocatalytic properties
Publication -
Synthesis, crystal structure and electrical properties of A-site cation ordered BaErMn2O5 and BaErMn2O6
Publication -
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,...
-
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...
-
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.
-
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.
-
Hydrothermal reactions: From the synthesis of ligand to new lanthanide 3D-coordination polymers
PublicationThe organic ligand 2,5-piperazinedione-1,4-diaceticacid (H2PDA) was synthesized under hydrothermal conditions starting from the iminodiacetic acid and catalyzed by oxalic acid. The X-ray powder diffraction data indicates that the compound crystallizes in the P21/c space group as reported in the literature. The ligand was also characterized by elemental analysis, magnetic nuclear resonance, infrared spectroscopy and thermogravimetric...
-
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...
-
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...
-
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....
-
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.
-
Amine-Catalyzed Direct Aldol Reactions of Hydroxy- and Dihydroxyacetone: Biomimetic Synthesis of Carbohydrates
Publication -
Cyclic Dipeptides as Building Units of Nano- and Microdevices: Synthesis, Properties, and Structural Studies
Publication -
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....
-
Synthesis of carbon nanotubes and nanospheres with controlled morphology using different catalyst precursors
Publication -
Insights into the synthesis and application of biochar assisted graphene-based materials in antibiotic remediation
Publication -
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...
-
Rearrangement of azoxybenzocrowns into chromophoric hydroxyazobenzocrowns and the use of hydroxyazobenzocrowns for the synthesis of ionophoric biscrown compounds
PublicationThe Wallach rearrangement was used as a method for preparing p-hydroxyazobenzocrown ethers starting from different azoxybenzocrowns as substrates. Synthesis of a series of p-hydroxyazobenzocrowns under modified conditions and characterization of the obtained products are presented. o-Hydroxyazobenzocrowns were identified among the products of the photochemical rearrangement of azoxybenzocrowns. Novel biscrowns were synthesized...
-
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...
-
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.
-
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...
-
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...
-
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...
-
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...
-
Synthesis and properties of HoT2Al20 (T = Ti, V, Cr) intermetallic cage compounds
PublicationPolycrystalline samples of HoT2Al20 (T = Ti, V, Cr) intermetallics were synthesized using a step-wise arc-melting technique. All three compounds adopt the CeCr2Al20-type crystal structure with Ho atoms positioned inside oversized icosahedral cages formed by Al atoms. The structure of HoV2Al20 compound is reported. The materials properties were studied by means of electrical resistivity, magnetic susceptibility, and specific heat...
-
Comprehensive study on graphene hydrogels and aerogels synthesis and their ability of gold nanoparticles adsorption
PublicationGraphene hydrogels were prepared by ascorbic acid-assisted gelation of graphene oxide (GO) aqueous suspensions both in acidic and basic conditions. Different mass ratio of ascorbic acid (AA) to GO was used (namely 20:1 and 10:1). In order to eliminate the influence of AA on the final structure of hydrogels, samples without AA were prepared by a hydrothermal gelation of GO in an autoclave. An in-depth structural characterization...
-
A new approach to the stereoselective synthesis of trans-3-carbamoyl-b-lactam moieties†
PublicationOne-pot synthesis of optically active 1,4-disubstituted-3-carbamoyl-azetidinones from 5-[(N-arylamino)- (hydroxyl)methylene]-2,2-dimethyl-1,3-dioxa-4,6-diones and chiral aldimines is achieved via thermal generation of carbamoyl ketenes and subsequent [2+2] cycloaddition. Three possible chiral induction approaches were tested and (R)-(+)-1-phenylethylamine was confirmed as the best chiral auxiliary. Among the four possible diastereoisomers,...
-
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...
-
Synthesis and properties of AxV2Al20 (A = Th, U, Np, Pu) ternary actinide aluminides
PublicationPolycrystalline samples of AxV2Al20 (A = Ce, Th, U, Np, Pu; 0.7 ≤ x ≤ 1.0) actinide intermetallics were synthesized using the arc-melting method. Crystal structure studies were performed by means of powder x-ray diffraction and the Rietveld refinement method. All studied compounds crystallize in the CeCr2Al20-type structure (space group Fd-3m, no. 227) with the actinoid and Ce atom located in the oversized icosahedral cage formed...
-
Bulk synthesis of carbon-filled silicon carbide nanotubes with a narrow diameter distribution
Publication -
Surface properties of wustite based iron-cobalt catalysts for ammonia synthesis reaction
Publication -
The effect of manganese on the structural and surface properties of nanocrystalline cobalt catalyst for ammonia synthesis
Publication -
Method for determination of the chemical composition of phases of the iron catalyst precursor for ammonia synthesis
Publication -
Effect of Synthesis Parameters of Graphene/Fe2O3 Nanocomposites on Their Structural and Electrical Conductivity Properties
Publication -
Starch-grafted-N-vinylformamide copolymers manufactured by reactive extrusion: synthesis and characterization
Publication -
Influence of Magnesium Oxide on the Structure and Catalytic Activity of the Wustite Catalyst for Ammonia Synthesis
Publication -
Reduction Process of Iron Catalyst Precursors for Ammonia Synthesis Doped with Lithium Oxide
Publication -
Synthesis and characterization of crystalline Fe3O4 nanoparticles Synteza i charakterystyka nanokrystalicznego Fe3O4
Publication -
Synthesis and Anticancer Activity of Mitotic-Specific 3,4-Dihydropyridine-2(1H)-thiones
Publication -
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...
-
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
-
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...
-
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...
-
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)...
-
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...
-
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,...
-
The new diphosphanylphosphido complexes of tungsten(VI) and molybdenum(VI). Their synthesis, structures and properties
PublicationWe report on the reactivity of R2P–P(Li)–PR’2 (R = tBu, iPr, R’ = NEt2, iPr) towards diimido complexes [(dippN)2MCl2·dme] (M = Mo, W and dipp = 2,6-iPr2C6H3). A series of new complexes with diphosphanylphosphido ligands R2P–P–PR’2 were isolated. The solid-state structures of [(dippN)2M(Cl)(1,2-η-iPr2P–P– PiPr2)] (2Mo and 2W) and [(dippN)2M(Cl){1,2-η-tBu2P–P–P(NEt2)2}] (3Mo and 3W) were established by single-crystal X-ray diffraction...