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Wyniki wyszukiwania dla: CARBAMOYL MELDRUM`S ACIDS
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Boron Difluoride Complexes of Carbamoyl Meldrum's Acids
Publikacja5-[Hydroxy(aryl/alkylamino)methylene]-2,2-dimethyl-1,3-dioxane-4,6-diones react with BF3•Et2O in mild conditions leading to the formation of boron difluoride complexes of carbamoyl Meldrum's acids. The X-ray structure has been obtained for one representative complex. The obtained new compounds are fairly stable at standard ambient conditions and easily isolable.
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Peptide modification with thiomalonoamide moiety
PublikacjaAbstract: Meldrum acid derivatives under the thermal decomposition are well known source of ketenes. Recently we investigated chemical properties of thiocarbamolyl meldrum acids. We found that 5-(α-alkylamino- α'-sulfhydryl)methylene Meldrum's acids hated in the presence of amines produce thiomalonamides. We used this reaction to the one pot synthesis of series of short peptides containing thiomalonoamide motif.
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TMSCL as a rate accelerating additive in acylations of amines with 5-(α- amino-α'-hydroxy)methylene meldrum's acids
PublikacjaAspects are presented of the acylation of amines, alcohols and thiols with 5-(α-amino- α'-hydroxy)methylene Meldrum's acids. We placed special emphasis on the acylation reaction of secondary amines with 5-(α-amino- α'-hydroxy)methylene Meldrum's acids, which, due to their basicity, caused problems concerning salt formation with a Meldrum acid derivative. We found that secondary amines, which react at the slowest rate and with a...
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Tmscl as a rate accelerating additive in acylations of amines with 5-(α-amino- α'-hydroxy)methylene meldrum's acids
PublikacjaAspects are presented of the acylation of amines, alcohols and thiols with 5-(α-amino- α'-hydroxy)methylene Meldrum's acids. We placed special emphasis on the acylation reaction of secondary amines with 5-(α-amino- α'-hydroxy)methylene Meldrum's acids, which, due to their basicity, caused problems concerning salt formation with a Meldrum acid derivative. We found that secondary amines, which react at the slowest rate and with a...
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TMSCl Promoted Acylation of Amines with 5-(α-amino- α'-hydroxy)methylene Meldrum's Acids - Elucidation of Mechanism.
PublikacjaRecently we have observed accelerating influence of trimethyl silyl chloride addition on the rate of the reactions of 5-(α-amino- α'-hydroxy)methylene Meldrum's Acids with amines, particularly in the case of highly basic amines. However the nature of the aforementioned process remain unexplained. In proposed communication we wish to report insightful elucidation of this mechanism. The reaction under investigation involves simply...
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Atom-economic thiophosphoroselenenylations of C–H acid esters and amides
PublikacjaThree improved thiophosphoroselenenylation procedures of CHacids, including derivatives of malonic and acetyl-, phosphono-, 4-nitrophenyl- and 3-pyridylacetic acids, have been described and compared to previously reported thiophosphoroselenylation of diethyl malonate using bis(disopropoxyphosphinothioyl)diselenide alone or with the aid of methyl iodide. The use of iodine makes it possible to utilize both equivalents of the selenenylating...
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Thermal Decomposition of Carbamoyl Meldrum’s Acids: A Starting Point for the Preparation of 1,3-Oxazine Derivatives
PublikacjaThe ability to undergo [4 + 2] versus [2 + 2] cycloaddition was under investigation for ketenes thermally generated from carbamoyl Meldrum’s acid. Usually, 1,3-oxazino-5-carbamoylo-4,6-diones are formed when carbamoyl Meldrum’s acid reacts with imine. However, in some cases, a reaction takes an unexpected course, leading to the formation of tetraponerines alkaloids derivatives or cyclic iminoethers.
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A new approach to the stereoselective synthesis of trans-3-carbamoyl-b-lactam moieties†
PublikacjaOne-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,...
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One-step formation of n-alkenyl-malonamides and n-alkenyl-thiomalonamides from carbamoyl meldrum's acids.
PublikacjaA one-pot synthesis for the preparation of N-alkenyl-malonamides and N-alkenyl-thiomalonamides was developed. 5-[Hydroxy/mercapto(aryl/alkylamino)methylene]-2,2-dimethyl-1,3-dioxane-4,6-dione act as a source of ketenes that react with the tautomeric form of alkyl-(2-phenyl-propylidene)-amines. A possible [2+2] or [4+2] cycloaddition product of ketene to imines was not observed.
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AMINO ACIDS
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NUCLEIC ACIDS RESEARCH
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Inhibitors of amino acids biosynthesis as antifungal agents
PublikacjaFungal microorganisms, including the human pathogenic yeast and filamentous fungi, are able to synthesize all proteinogenic amino acids, including nine that are essential for humans. A number of enzymes catalyzing particular steps of human-essential amino acid biosynthesis are fungi specific. Numerous studies have shown that auxotrophic mutants of human pathogenic fungi impaired in biosynthesis of particular amino acids exhibit...
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Hydration of amino acids: FTIR spectra and molecular dynamics studies
PublikacjaThe hydration of selected amino acids, alanine, glycine, proline, valine, isoleucine and phenylalanine, has been studied in aqueous solutions by means of FTIR spectra of HDO isotopically diluted in H2O. The difference spectra procedure and the chemometric method have been applied to remove the contribution of bulk water and thus to separate the spectra of solute-affected HDO. To support interpretation of obtained spectral results,...
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Complexation of amino acids derivatives in water by calix[4]arene phosphonic acids
PublikacjaSeries of the calix[4]arene phosphonic acids with various substituents at the lower rim was synthesized. Complexing properties of these receptors towards methyl esters of six amino acids strongly depended on the calix[4]arene conformation flexibility. The complex formation processes were monitored using 1H NMR spectroscopy (deuterated phosphate buffer at pD 7.3, 22 oC) and association constant values were evaluated. Inherently...
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Ion Chromatography in Environmental Analysis of Selected Organic Acids
PublikacjaLow molecular mass carboxylic acids (LCAs) occur in many environmental compartments dueto natural processes and human activity. When volatile and nonvolatile acids are to be monitored then liquidchromatography, including ion chromatography seems a method of choice. At high pH the acids are inionized form and can be separated as carboxylats by means of anion exchange chromatography. LCAs canalso be separated at low pH by ion exclusion...
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Determination and identification of organic acids in wine samples. Problems and challenges.
PublikacjaFor long time, organic acids were underestimated. However, during last two decades there is an increasing interest of natural compounds having antioxidant, antimicrobial and anti-inflammatory properties thus organic acids are very preferable. Wine stands as one of the sources of organic acids since they are responsible for its organoleptic and aestethic character. Nevertheless, it is important to not exceed acceptable level of...
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Propensity of salicylamide and ethenzamide cocrystallization with aromatic carboxylic acids
PublikacjaThe cocrystallization of salicylamide (2-hydroxybenzamide, SMD) and ethenzamide (2-ethoxybenzamide, EMD) with aromatic carboxylic acids was examined both experimentally and theoretically. The supramolecular synthesis taking advantage of the droplet evaporative crystallization (DEC) technique was combined with powder diffraction and vibrational spectroscopy as the analytical tools. This led to identification of eleven new cocrystals...
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Capillary Electrophoresis in Determination of Low Molecular Mass Organic Acids
PublikacjaThis paper presents overviews the capabilities of capillary electrophoretic techniques to determine low molecular mass organic acids in a variety of aqueous, gas and solid samples. It mainly focuses on short - chain carboxylic acids containing one or more carboxylic groups and possibly some other functional groups (hydroxyl, keto-, amino- etc.). Finally the procedures applied to the determine the acids in different matrices are...
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Capillary Electrophoresis in determination of short - chain carboxylic acids in aqueous samples
PublikacjaAnalysis of pollution is extremely important especially in areas directly adjacent tothe residential district. Studies show that short- chain carboxylic acids are a group ofcompounds widespread around sewage treatment plants, landfills, livestock farms. The mostcommon techniques for determination of short - chain carboxylic acids are chromatographictechniques, especially gas chromatography, whose main limitation is that only volatilemonocarboxylic...
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Journal of Amino Acids
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Determination of Selected Organic Acids in Animal Farm Water Samples by Ion Chromatography
PublikacjaLow molecular mass carboxylic acids (LCAs) occur in many environmental compartments due to natural processes and human activity. They are an important group of organic pollutants of waste water that mainly includes, volatile fatty acids, and also dicarboxylic, aromatic, hydroxy- and ketoacids. LCAs are present in the environment at concentrations between 1 to 5000 ppm and different methods have been reported for their determination...
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Composition of fatty acids in selected sorts of biscuits, offered for children
PublikacjaThe fatty acid (FA) composition, especially total trans-fatty acids (TFA) content in 12 assortments of biscuits offered for children, produced by four different companies, were determined by gas chromatography. Total fat content of the biscuit samples ranged from 2.2 to 22.8 g/100 g of product. The major FAs were palmitic C16:0, oleic C18:1, and linoleic C18:2 acids. Depending on the biscuit type, the total saturated fatty acids...
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Occurrence and Determination of Volatile Fatty Acids in Landfill Leachate and Gas
PublikacjaIn landfills containing biological matter volatile fatty acids (VFAs) are generated at high rate at the early stage of waste disposal and their content in leachate is high as compared to the leachate from old parts of landfill since they are converted to methane gas. Monitoring of the leachate for the content of VFAs can help determine the processes occurring in waste and possible effect of the leachate on the environment in the...
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Occurrence and Determination of Volatile Fatty Acids in Landfill Leachate and Gas
PublikacjaIn landfills containing biological matter volatile fatty acids (VFAs) are generated at high rate at the early stage of waste disposal and their content in leachate is high as compared to the leachate from old parts of landfill since they are converted to methane gas. Monitoring of the leachate for the content of VFAs can help determine the processes occurring in waste and possible effect of the leachate on the environment in the...
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X-ray Photoelectron Spectroscopy of Carboxylic Acids as Corrosion Inhibitors of Aluminium Alloys
PublikacjaThe datasets, titled X-ray Photoelectron Spectroscopy studies of citric acid adsorption on aluminium alloy 5754 in alkaline media and X-ray Photoelectron Spectroscopy studies of various carboxylic acids adsorption on aluminium alloys in alkaline media, contain XPS studies of the corrosion inhibitory action of selected dicarboxylic acids towards commercially available aluminium alloy 5754 in alkaline media at pH=11. These datasets...
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Applicability of phenolic acids as effective enhancers of cocrystals solubility of methylxanthines
PublikacjaApplicability of phenolic acids as potential cocrystal formers for methylxanthine derivatives was analyzed both in terms of cocrystallization probabilities and solubility advantage. The cocrystal formation abilities were evaluated using mixing enthalpy estimated within the conductor like screening model for real solvents (COSMO-RS) framework. The solubility improvement of potential cocrystals was estimated by formulation of the...
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Production, Transformation and Determination of Volatile Fatty Acids in Farm Animals and the Environment
PublikacjaThe paper is a critical discussion of the production, transportation and determination of volatile fatty acids in rumens of ruminants. The odor nuisance of the emission of VFAs, often accompanied by volatile nitrogen- and sulfur-organic compounds from animal farming is also discussed.
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Synthesis of 3-Carbamoyl b-Lactams via Manganese(III)-Promoted Cyclization of N-Alkenylmalonamides
PublikacjaManganese(III)-promoted cyclization of N-alkenylmalonamides (¼N-alkenylpropanediamides) gave 3-(aryl/(alkylamino)carbonyl) b-lactams as well as 3-(aryl/(alkylamino)thiocarbonyl) b-lactams. The relative configuration of the obtained products was unambiguously determined by X-ray crystallography. The proposed method is very useful for the one-pot synthesis of a number of 3-(aryl/ (alkylamino)carbonyl) b-lactams, especially those...
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Is the Fatty Acids Profile in Blood a Good Predictor of Liver Changes? Correlation of Fatty Acids Profile with Fatty Acids Content in the Liver
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Determination of short-chain monocarboksylic acids in cattle farm and dairy industry wastewater
PublikacjaThe paper describes application of various techniques to determine short-chain monocarboksylic acids (SCMAs) in samples from the successive steps from milk production: from wastewater from cattle farm to wastewater from dairy industry. Each technique of sample preparation is followed by gas chromatographic analysis.
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The characterization of collagen‑based scaffolds modified with phenolic acids for tissue engineering application
PublikacjaThe aim of the experiment was to study the morphology of collagen-based scaffolds modified by caffeic acid, ferulic acid, and gallic acid, their swelling, and degradation rate, as well as the biological properties of scaffolds, such as antioxidant activity, hemo- and cytocompatibility, histological observation, and antibacterial properties. Scaffolds based on collagen with phenolic acid showed higher swelling rate and enzymatic...
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Total Ionization Cross Sections of Selected Amino Acids
Dane BadawczeThe data set contains tabulated values of cross-sections for a single electron-impact ionization of selected amino acids (glycine, alanine, phenylalanine, proline and tryptophan) calculated using binary-encouter-Bethe method. The data have been published in graphical form (figure 1) in the following paperA.M. Sheer, P. Mozejko, G.A. Gallup, P.D. Burrow...
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Synthesis of orthogonally protected (3R,4S)- and (3S,4S)-4,5-diamino-3-hy-droxypentanoic acids.
PublikacjaDwa tytułowe aminokwasy otrzymano z odpowiednich kwasów (S)-2,3-diaminopropanowych. Konfigurację absolutną ustalono za pomocą spektroskopii NMR odpowiednich piperydyno-2-onów.
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Carboxylic acids as efficient corrosion inhibitors of aluminium alloys in alkaline media
PublikacjaThe efficiency of AA5754 aluminium alloy corrosion inhibition achieved with maleic, malic, succinic, tartaric, citric, tricarballylic acids and serine in alkaline environment (pH 11) was examined. Selected corrosion inhibitors are characterized by different numbers and distribution of carbonyl and hydroxyl groups within their molecules. We have proposed and verified a novel approach for determining the adsorption isotherms based...
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Studies on applicability of new solid-phase microextraction fibers for the selective extraction and determination of short - chain monocarboksylic acids
PublikacjaShort-chain monocarobxylic acids, sometimes referred to as volatile fatty acids (VFA), are a group of low molecular weight alkyl monocarboxylic acids that are widely distributed within the environment. These molecules contain any from 2 to 8 carbon atoms and originate from the anaerobic biodegradation of organic matter such as carbohydrates, proteins, and fats. These compounds are commonly found in the effluents from animal farming,...
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Study of the influence of medium composition on the motility and aggregation of the recombinant Escherichia coli strain AAEC191A/pACYCpBAD-M9 + 0.5% cassaminic acids, M9 + 0.5% cassaminic acids + 0.2% glucose, M9 + 0.5% cassaminic acids + 0.5% glucose
Dane BadawczeMicrobial motility is a fundamental aspect of many microbial life cycles and is a key survival mechanism that enables microorganisms to navigate diverse and dynamic environmental conditions. This phenomenon becomes particularly important in response to changes in stimuli in time and space. The following experiment aimed to investigate how the composition...
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Study of the influence of medium composition on motility and aggregation of recombinant Escherichia coli strain AAEC191A/pCC90-M9 + 0.5% cassaminic acids, M9 + 0.5% cassaminic acids + 0.2% glucose, M9 + 0.5% cassaminic acids + 0.5% glucose
Dane BadawczeMicrobial motility is a fundamental aspect of many microbial life cycles and is a key survival mechanism that enables microorganisms to navigate diverse and dynamic environmental conditions. This phenomenon becomes particularly important in response to changes in stimuli in time and space. The following experiment aimed to investigate how the composition...
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Study of the influence of medium composition on motility and aggregation of recombinant Escherichia coli strain BL21(DE3)/pCC90-M9 + 0.5% cassaminic acids, M9 + 0.5% cassaminic acids + 0.2% glucose, M9 + 0.5% cassaminic acids + 0.5% glucose
Dane BadawczeMicrobial motility is a fundamental aspect of many microbial life cycles and is a key survival mechanism that enables microorganisms to navigate diverse and dynamic environmental conditions. This phenomenon becomes particularly important in response to changes in stimuli in time and space. The following experiment aimed to investigate how the composition...
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Study of the influence of medium composition on motility and aggregation of recombinant Escherichia coli strain BL21(DE3)/pACYCpBAD-M9 + 0.5% cassaminic acids, M9 + 0.5% cassaminic acids + 0.2% glucose, M9 + 0.5% cassaminic acids + 0.5% glucose
Dane BadawczeMicrobial motility is a fundamental aspect of many microbial life cycles and is a key survival mechanism that enables microorganisms to navigate diverse and dynamic environmental conditions. This phenomenon becomes particularly important in response to changes in stimuli in time and space. The following experiment aimed to investigate how the composition...
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Studies on applicability of new solid-phase microextraction and determination of short - chain monocarboxylic acids
PublikacjaA convenient approach to monitor the short-chain monocaroboksylic acids (SCAMs) in different samples is gas chromatography (GC) preceded by sample preparation based on solid-phase microextraction (SPME). The fiber with polar coatings were used to extract the SCAMs from headspace of liquid and solid samples. Recently polimeric ionic liquid (PIL) fiber coatings have been proposed to extract volatile organic compounds, minly polar...
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Study of the influence of medium composition on motility and aggregation of recombinant Escherichia coli strain AAEC191A/pCC90 D54-STOP-M9 + 0.5% cassaminic acids, M9 + 0.5% cassaminic acids + 0.2% glucose, M9 + 0.5% cassaminic acids + 0.5% glucose
Dane BadawczeMicrobial motility is a fundamental aspect of many microbial life cycles and is a key survival mechanism that enables microorganisms to navigate diverse and dynamic environmental conditions. This phenomenon becomes particularly important in response to changes in stimuli in time and space. The following experiment aimed to investigate how the composition...
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Study of the process of biofilm formation by UPEC IH11128 in the M9+0,5% casamino acids medium
Dane BadawczeBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of IH11128 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 +...
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Study of the process of biofilm formation by UPEC DR14 in the M9+0,5% casamino acids medium
Dane BadawczeBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...
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Study of the influence of medium composition on motility and aggregation of recombinant Escherichia coli strain AAEC191A/pCC90 Dra D-mut-M9 + 0.5% cassaminic acids, M9 + 0.5% cassaminic acids + 0.2% glucose, M9 + 0.5% cassaminic acids + 0.5% glucose
Dane BadawczeMicrobial motility is a fundamental aspect of many microbial life cycles and is a key survival mechanism that enables microorganisms to navigate diverse and dynamic environmental conditions. This phenomenon becomes particularly important in response to changes in stimuli in time and space. The following experiment aimed to investigate how the composition...
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Study of the influence of medium composition on motility and aggregation of recombinant Escherichia coli strain BL21(DE3)/pCC90 D54-STOP-M9 + 0.5% cassaminic acids, M9 + 0.5% cassaminic acids + 0.2% glucose, M9 + 0.5% cassaminic acids + 0.5% glucose
Dane BadawczeMicrobial motility is a fundamental aspect of many microbial life cycles and is a key survival mechanism that enables microorganisms to navigate diverse and dynamic environmental conditions. This phenomenon becomes particularly important in response to changes in stimuli in time and space. The following experiment aimed to investigate how the composition...
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Study of the influence of medium composition on motility and aggregation of recombinant Escherichia coli strain BL21(DE3)/pCC90 Dra D-mut-M9 + 0.5% cassaminic acids, M9 + 0.5% cassaminic acids + 0.2% glucose, M9 + 0.5% cassaminic acids + 0.5% glucose
Dane BadawczeMicrobial motility is a fundamental aspect of many microbial life cycles and is a key survival mechanism that enables microorganisms to navigate diverse and dynamic environmental conditions. This phenomenon becomes particularly important in response to changes in stimuli in time and space. The following experiment aimed to investigate how the composition...
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Study on the concentration of acids by membrane distillation
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Chlorogenic acids – their properties, occurrence and analysis
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Multivariate Statistical Analysis for Mutual Dependence Assessment of Selected Polyphenols, Organic Acids and Metals in Cool-Climate Wines
PublikacjaPolyphenols, organic acids and metal ions are an important group of compounds that affect the human health and quality of food and beverage products, including wines. It is known that a specific correlation between these groups exist. While wines coming from the New World and the Old World countries are extensively studied, wines coming from cool-climate countries are rarely discussed in the literature. One of the goals of this...
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Study of the process of biofilm formation by UPEC DR14 in the M9+0,5% casamino acids+0,2% glycerol medium
Dane BadawczeBiofilm formation is a direct reaction of bacteria to environmental factors. In order to determine the influence of the medium composition on the ability of DR14 on biofilm production, we cultured bacteria under the following conditions: LB medium, M9 medium + 0,2% glucose, M9 + 0,5% casamino acids, M9 + 0,5% casamino acids + 0,2% glycerol, M9 + 0,5%...