Filtry
wszystkich: 1242
wybranych: 1058
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: ACYL MELDRUM'S ACID
-
l-ascorbic acid modified poly(ester urethane)s as a suitable candidates for soft tissue engineering applications
PublikacjaIn this paper we created novel poly(ester urethane)s (PESUs) designed specifically for tissue engineering. The PESUs were derived from oligomeric α,ω-dihydroxy(ethylene-butylene adipate) (dHEBA), 1,4-butanediol (BDO) and aliphatic 1,6-hexamethylene diisocyanate (HDI) and modified with l-ascorbic acid to improve their biocompatibility. In addition, we determined their mechanical properties (such as tensile strength, elongation at...
-
Fractional Calculus Evaluation of Hyaluronic Acid Crosslinking in a Nanoscopic Part of Articular Cartilage Model System
PublikacjaThis work presents a study of the mechanism of physical crosslinking of hyaluronic acid in the presence of common phospholipids in synovial joint organ systems. Molecular dynamic simulations have been executed to understand the formation of hyaluronan networks at various phospholipid concentrations. The results of the simulations suggest that the mechanisms exhibit subdiffusion characteristics. Transportation quantities derive...
-
Comparison and Optimization of Saccharification Conditions of Alkaline Pre-Treated Triticale Straw for Acid and Enzymatic Hydrolysis Followed by Ethanol Fermentation
PublikacjaThis paper concerns the comparison of the efficiency of two-stage hydrolysis processes, i.e., alkaline pre-treatment and acid hydrolysis, as well as alkaline pre-treatment followed by enzymatic hydrolysis, carried out in order to obtain reducing sugars from triticale straw. For each of the analyzed systems, the optimization of the processing conditions was carried out with respect to the glucose yield. For the alkaline pre-treatment,...
-
Synthesis of 2-amino-2,6-dideoxy-D-glucitol-6-sulfonic acid as a potential antifungal agent.
PublikacjaGlucosamine-6P (GlcN-6P) synthase catalyzes the first committed step in the biosynthetic pathway leading to the formation of UDP-GlcNAc, a sugar nucleotide precursor providing D-glucosamine for the formation of chitin and manoproteins. 2-Amino-2,6-dideoxy-D-glucitol-6-sulfonic acid is an analog of 2-amino-2-deoxy-D-glucitol 6-phosphate (GlcN-ol-6-P), a known inhibitor of GlcN-6-P synthase, in which the phosphate group of the latter...
-
A spectroscopic study of the cis/trans-isomers of penta-2,4-dienoic acid attached to gold nanoclusters
PublikacjaIn this theoretical work, we present a spectroscopic analysis of the cis/trans-isomers of a molecular switch, penta-2,4-dienoic acid, attached to gold clusters of different size (1, 2 and 20 gold atoms). We have simulated 4 different spectroscopic techniques: Infrared spectroscopy, normal Raman scattering, absorption spectra and resonance Raman scattering. We discuss how the position and the conformation of the molecule determine...
-
Release of potassium from actvated sludge as a resultof use peroxyacetic acid = Uwalnianie potasu z osadu czynnego pod wpływem kwasu nadoctowego
PublikacjaThe phenomenon of potassium efflux (GGKE - glutathione-gated potassium efflux) from the calls of activated sludge bacteria in the result of peroxyacetic acid (CH3CO3H) dosing was investigated. Addition of the strong oxidant to the activated sludge environment caused activation of the defense mechanisms of bacterial cells, related to glutathione transformations, which resulted in the significant increase of potassium ions concentration....
-
Adsorption Kinetics of Acid Dye Acid Red 88 onto Magnetic Multi‐Walled Carbon Nanotubes‐Fe3C Nanocomposite
Publikacja -
Efficient Diethylzinc/Gallic Acid and Diethylzinc/Gallic Acid Ester Catalytic Systems for the Ring-Opening Polymerization of rac-Lactide
Publikacja -
Microstructural behavior of water-in-oil emulsions stabilized by fatty acid esters of propylene glycol and zinc fatty acid salts
PublikacjaZbadano wpływ składu emulgatorów acylopropylenoglikolowych, modyfikowanych mydłami cynku, na charakter przemian strukturalnych jakim ulegają emulsje W/O stabilizowane przez takie emulgatory. Badano zarówno etap emulgowania jak i mikrostrukturę oraz właściwości reologiczne otrzymanych emulsji.
-
Investigation of an elutable N-propylphosphonic acid chitosan derivative composition with a chitosan matrix prepared from carbonic acid solution
PublikacjaPorous chitosan composites using CO2 dissolution procedure and including water soluble N-propylphosphonic chitosan derivative (p-CHI) were obtained and characterized. In contrast to the control material, composites containing modified chitosan distinguished by a rapid moisture absorption and good adhesion to the skin. The FTIR analysis confirmed the presence of propylphosphonic group in the structure of the polymer. The porosity...
-
Overcoming carboxylic acid inhibition by granular consortia in high-load liquefied food waste fermentation for efficient lactate accumulation
PublikacjaGranular sludge, a self-aggregating spherical biofilm, possesses better stability compared to flocculent sludge under extreme conditions. This study compared the ability of anaerobic granular sludge (AnGS) and flocculent waste activated sludge (WAS) to convert food waste (FW) into highly-valuable optically active lactic acid (LA), a central and versatile intermediate platform molecule. Different loadings (30–60 g volatile suspended...
-
Cold plasma treatment of tannic acid as a green technology for the fabrication of advanced cross-linkers for bioactive collagen/gelatin hydrogels
PublikacjaTannic acid (TA) is a natural compound studied as the cross-linker for biopolymers due to its ability to form hydrogen bonds. There are different methods to improve its reactivity and effectiveness to be used as a modifier for biopolymeric materials. This work employed plasma to modify tannic acid TA, which was then used as a cross-linker for fabricating collagen/gelatin scaffolds. Plasma treatment did not cause any significant...
-
Synthesis and characterization of novel renewable polyesters based on 2,5-furandicarboxylic acid and 2,3-butanediol
PublikacjaNovel polyesters from 2,5-furandicarboxylic acid or 2,5-dimethyl-furandicarboxylate and 2,3-butanediol have been synthesized via bulk polycondensation catalyzed by titanium (IV) n-butoxide, tin (IV) ethylhexanoate, or zirconium (IV) butoxide. The polymers were analyzed by size exclusion chromatography, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy (FTIR), matrix-assisted laser ionization-desorption...
-
Phenazine - 2,6-dihydroxybenzoic acid (1/1)
PublikacjaOtrzymano krystaliczny kompleks fenazyny z kwasem 2,6-dihydroksybenzoesowym o stechiometrii 1:1. Badania struktury kompleksu za pomocą metod rentgenograficznych wykazały, że powiązane wiązaniami wodorowymi typu OH...N cząsteczki fenazyny układają się w stosy, które stabilizowane są poprzez oddziaływania typu π-π pierścieni aromatycznych. Cząsteczki kwasu zajmują przestrzenie kanałów tworzonych pomiędzy kolumnami pierścieni aromatycznych...
-
Glycyrrhetinic acid and its derivatives in infectious diseases
Publikacja -
The Reason Why HAlCl4 Acid Does Not Exist
Publikacja -
(S)-N-Nitrosoazetidine-2-carboxylic acid.
PublikacjaAnaliza rentgenograficzna monokryształów kwasu (S)-N-nitozoazetydyno-2-karboksylowego wykazała, że reszta N-nitrozoaminowa przyjmuje konfigurację E. Azetydynowy atom azotu jest nieznacznie piramidalny. Cząsteczki w sieci krystalicznej oddziałują ze sobą poprzez wiązania wodorowe pomiędzy atomem tlenu grupy nitrozowej i atomem wodoru grupy karboksylowej, tworząc polimeryczny łańcuch.
-
Hydrogen charging of nitrided steel in acid solution
PublikacjaKonstrukcyjną stal, azotowaną w wyładowaniu jarzeniowym w mieszaninie gazów o różnej zawartości N2, H2 i Ar, poddawano katodowemu nawodorowaniu w kwaśnym roztworze, imitującym przepracowany olej maszynowy. W pomiarach szybkości przenikania wodoru i ekstrakcji próżniowej określano wpływ azotowanych warstw, odpowiednio, na transport wodoru i na jego nieodwracalne pułapkowanie. W obecności niezdefektowanej warstwy kompaktowych azotków...
-
The 2:1 cocrystal of benzamide and pentafluororbenzoic acid
PublikacjaKrystaliczna struktura centrosymetrycznej supermolekuły składa się z czterech cząsteczek benzamidu oraz dwóch kwasu karboksylowego, które powiązane są ze sobą za pomocą wiązań wodorowych typu O-H...O oraz N-H...O.
-
May dithiophosphoric acid participate in the set process?
PublikacjaZastosowano otrzymane S-tioacyloditiofosforany jako odczynniki tioacylujące do syntezy kwasów tiohydroksamowych. Dla większości N-alkilohydroksyloamin produktem tej reakcji były żądane kwasy tiohydroksamowe. Natomiast gdy substratem jest hydroksyloamina zawierająca duży objętościowo podstawnik na atomie azotu lub gdy posiada dwa podstawniki na atomie azotu w reakcji tej tworzą się wyłącznie odpowiednie O-tioacylohydroksyloaminy....
-
Mass spectrometric identification of 13C-Labeled metaboloites during anaerobic propanoic acid oxidation
PublikacjaBiowaste digestion is a possibility to gain biogas as a renewable fuel source. However, the anaerobic food chain may be disrupted by, e.g., substrate overload or by inhibitors, leading to the accumulation of volatile fatty acids (VFAs), predominantly of propanoic acid (PA). VFA Accumulation may cause a rapid pH decrease, less biogas production, or even a total inhibition. To maintain high biogas productivity or to prevent a collapse...
-
Mass Spectrometric Identification of 13C-labeled Metabolites During anaerobic Propanoic Acid Oxidation
PublikacjaBiowaste digestion is a possibility to gain biogas as a renewable fuel source. However, the anaerobic food chain may be disrupted by, e.g., substrate overload or by inhibitors, leading to the accumulation of volatile fatty acids (VFAs), predominantly of propanoic acid (PA). VFA Accumulation may cause a rapid pH decrease, less biogas production, or even a total inhibition. To maintain high biogas productivity or to prevent a collapse...
-
Mechanism of the Reaction of Amines with 5-[(Aryl- or Alkylamino)hydroxymethylene]-2,2-dimethyl-1,3-dioxane-4,6-diones in the Presence of Chlorotrimethylsilane (Me3SiCl);
PublikacjaAddition of chlorotrimethylsilane (Me3SiCl) to the mixture of a carbamoyl‐substituted Meldrum's acid, i.e., a 5‐[(arylamino)hydroxymethylene]‐2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione of type 1 and a secondary amine as nucleophile strongly accelerated the rate of their reaction. The reason for this phenomenon observed, during our previous research, remained, however, unclear. To elucidate the mechanism of this reaction, we assumed and...
-
Influence of temperature and anion type on thermophysical properties of aqueous solutions of morpholine based amino acid ionic liquids
PublikacjaDensities and sound velocities of aqueous solutions of N-butyl-N-methylmorpholine based amino acid ionic liquids (AAILs), including N-acetyl-L-alanine, N-acetyl-Lvalinate, N-acetyl-L-leucinate, and N-acetyl-L-izoleucinate anions were measured at a temperature from 293.15 to 313.15 K at 5 K intervals and atmospheric pressure. These data were used to calculate the apparent molar volumes and the apparent molar compressibilities in...
-
Optimization of Trans-esterification Process and Characterization of Biodiesel from Soapstock Using Silica Sulfuric Acid as a Heterogeneous Solid Acid Catalyst
Publikacja -
Screening stability, thermochemistry, and chemical kinetics of 3-hydroxybutanoic acid as a bifunctional biodiesel additive
PublikacjaThe thermo-kinetic aspects of 3-hydroxybutyric acid (3-HBA) pyrolysis in the gas phase were investigated using density functional theory (DFT), specifically the M06-2X theoretical level in conjunction with the cc-pVTZ basis set. The obtained data were compared with benchmark CBS-QB3 results. The degradation mechanism was divided into 16 pathways, comprising 6 complex fissions and 10 barrierless reactions. Energy profiles were calculated...
-
An influence of molecular weight, deacetylation degree of chitosan xerogels on their antimicrobial activity and cytotoxicity. Comparison of chitosan materials obtained using lactic acid and CO2 saturation.
PublikacjaThis paper presents a comparison of the antimicrobial activity and cytotoxicity against L929 cells of chitosan xerogels prepared by dissolving the polymer in a solution of lactic acid (LA) or carbonic acid (CO2) and then freeze-drying. There was no simple relationship between the antimicrobial activity and cytotoxicity of the samples obtained using both techniques (LA and CO2). Chitosan materials obtained by the LA method in a...
-
Curing epoxy with ethylenediaminetetraacetic acid (EDTA) surface-functionalized Co Fe3-O4 magnetic nanoparticles
PublikacjaIn this work, the bulk and surface composition of Fe3O4 supermagnetic nanoparticles were modified for efficient epoxy curing. The bare, ethylenediaminetetraacetic acid (EDTA) capped, and cobalt (Co)-doped EDTA capped Fe3O4 nanoparticles were synthesized electrochemically. The crystalline structure and phase information, surface capping, morphology and magnetization behavior of nanoparticles were studied by X-Ray diffraction (XRD),...
-
Plasma free amino acid profiling as metabolomic diagnostic and prognostic biomarker in paediatric cancer patients: a follow‑up study
PublikacjaAmino acids (AAs) play a crucial role in cancer cell metabolism. Levels of 22 plasma AAs at the time of diagnosis and after treatment were established among 39 pediatric cancer patients and 33 healthy children. Glutamic acid levels decreased and tryptophan levels increased during treatment. Cancer patients presented significantly lower levels of glutamine and leucine post-treatment while levels of 12 other AAs were higher comparing...
-
Acid–base properties of the crosslinked polysaccharide–polyimine layer deposited on the surface of siliceous material (acid–base properties of the polysaccharide–polyimine layer)
Publikacja -
A comprehensive evaluation of mimosa extract as a corrosion inhibitor on AA6060 alloy in acid rain solution: part I. Electrochemical AC methods
PublikacjaThe inhibition effect of mimosa extract on the corrosion of AA6060 aluminum alloy in acid rain solution was investigated by electrochemical impedance spectroscopy and dynamic electrochemical impedance spectroscopy (DEIS). All the studied electrochemical parameters showed good corrosion inhibitive characteristics with respect to the aluminum alloy in the tested solution. Inhibitor efficiency increased with the concentration and...
-
Simulation of Force Spectroscopy Experiments on Galacturonic Acid Oligomers
Publikacja -
Synthesis of 2,6-diaminopimelic acid (DAP) and its analogues
PublikacjaKwas 2,6-diaminopimelinowy jest ważnym aminokwasem biosyntetyzowanym przez bakterie i wyższe rośliny. Liczne fragmenty peptydoglikanu zawierające reszty kwasu diaminopimelinowego wykazują aktywność przeciwnowotworową i/lub immunostymulacyjną. W artykule opisano sposoby syntezy kwasu 2,6-diaminopimelinowego i jego analogi.
-
Serum fatty acid profile in psoriasis and its comorbidity
Publikacja -
Chlorogenic Acid Stability in Pressurized Liquid Extraction Conditions
Publikacja -
Magnetization enhancement in magnetite nanoparticles capped with alginic acid
Publikacja -
Sweet surfactants I: Fatty acid esters of sucralose
Publikacja -
The Characterization of Scaffolds Based on Dialdehyde Chitosan/Hyaluronic Acid
Publikacja -
Peroxidative metabolism of arachidonic acid in the course of Lyme arthritis
Publikacja -
Developing nucleic acid-based electrical detection systems
Publikacja -
The Acid Strength of the Lewis‐Brønsted Superacids – A QSPR Study
Publikacja -
Therapy with acetylsalicylic acid does not interfere with oral surgery
Publikacja -
Structured triacylglicerols containing behenic acid: preparation and properties
PublikacjaNiskokaloryczne lipidy strukturyzowane otrzymano na drodze przeestryfikowania właściwego oleju oliwkowego całkowicie uwodornionym wysokoerukowym olejem rzepakowym (TAG/SLHE) oraz na drodze acydolizy oleju oliwkowego kwasem behenowym (TAG/SLB). Reakcje były katalizowane Lipozyme RM IM. Tłuszcz (TAG/SLHE) charakteryzował się wysoką temperaturą topnienia - 45,5 st. C, natomiast tłuszcz (TAG/SLB) miał temperaturę topnienia 37,5 st.C...
-
Methods for quantifying lysophosphatidic acid in body fluids: A review
Publikacja -
VOLTAMMETRIC DETERMINATION OF DEOXYRIBONUCLEIC ACID PRESENCE ON A CARBON ELECTRODE
PublikacjaThis paper presents a voltammetry as a useful method to analyse DNA from different species. This electrochemical method is well know and used in different analyses. The influence of an area of working electrode and the capacity component, is shown at equals and the measurement. In voltammetry DNA measurement the capacity component is very important and must be taken into consideration. All mathematical analyses were verify at laboratory.
-
No Evidence for Sex-specificity in Vitamin C, E and Fatty Acid Content of Human Milk from Healthy Polish Mothers
PublikacjaHuman milk (HM) is a complex fluid that meets the nutritional needs of infants. Its composition idrfs associated with environmental, maternal, and foetal variables. It provides nutrients and bioactive substances, including cytokines, immunoglobulins, and constituents with antioxidative properties. Boys are reportedly more susceptible to oxidative stress. This study aimed to determine the relationship between infant sex and the...
-
Synthesis, characterization and Luminescent Properties of New Coordination Polymers Based on p-tert Butylcalix[4]arene-tetracarboxylic acid and Lanthanine cations
PublikacjaA series of new coordination polymers based on p-tert-butylcalix[4]arene-tetracarboxylic acid with Eu3+, Tb3+wrer prepared by hydro and solvothermal methods. the obtained solid compounds were characterized by infrared and luminescence spectroscopy, powder X-ray diffraction, scianning electron microscopy and thermogravimetric anylisis. The infrared curves and the x-ray diffraction patterns indicate that the same crystalline structure...
-
Simultaneous impedance and volumetric studies and additionally potentiodynamic polarization measurements of molasses as a carbon steel corrosion inhibitor in 1M hydrochloric acid solution
PublikacjaThe inhibition effect of molasses on the corrosion of low carbon steel in 1M hydrochloric acid solution was investigated by volumetric and electrochemical measurements. Potentiodynamic polarization and dynamic electrochemical impedance spectroscopy (DEIS) results were obtained and compared with to those, obtained with the hydrogen evolution technique. All results indicate that molasses functioned as a good inhibitor in 1M hydrochloric...
-
Poly(ε-Caprolactone)/Poly(Lactic Acid) Blends Compatibilized by Peroxide Initiators: Comparison of Two Strategies
PublikacjaPoly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA) blends were compatibilized by reactive blending and by copolymers formed during reaction in the solution. The reactive blending of PCL/PLA was performed using di-(2-tert-butyl-peroxyisopropyl)benzene (BIB) or dicumyl peroxide (DCP) as radical initiator. PCL-g-PLA copolymers were prepared using 1.0 wt. % of DCP or BIB via reaction in solution, which was investigated through...
-
Sensitive method for determination of benzoic acid in beverages and food samples using air–assisted hydrophobic deep eutectic solvent-based dispersive liquid-liquid microextraction
PublikacjaA simple, reliable and rapid air–assisted hydrophobic deep eutectic solvent-based dispersive liquid–liquid microextraction (AA-HDES-DLLME) was developed for analysis of benzoic acid in various beverages and food samples. The final determination stage was performed via UV–visible spectrophotometry. The key parameters (extraction time, HDES type and volume, dispersant volume, pH and sample volume) of the AA-HDES-DLLME method were...