Czasopisma naukowe PŁ / TUL Scientific Journals
Stały URI zbioruhttp://hdl.handle.net/11652/5575
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Pozycja Safety of workers exposed to harmful airborne bioaerosols – legal status and innovations(Wydawnictwo Politechniki Łódzkiej, 2017) Majchrzycka, Katarzyna; Okrasa, Małgorzata; Szulc, Justyna; Gutarowska, BeataFiltering respiratory protective equipment is commonly used for protection against bioaerosols in industrial workplaces. However, the EU legislation does not specify the requirements for its antimicrobial properties. The result is that in the market there is no equipment available that would ensure complete safety of workers exposed to inhalation of harmful bioaerosols. This is particularly important in the case of equipment intended for multiple and long-term use. The aim of this study was to develop an innovative filtering half mask for the protection of respiratory tract that would have confirmed antimicrobial properties. The half mask was tested for compliance with EN 149:2001+A1:2009, and the survival rate of microorganisms in nonwovens was determined (E. coli bacteria and A. niger moulds). The reduction in the number of E. coli bacteria was 98.69% and the reduction in the number of A. niger moulds was 67.68% after 32 h of storage under conditions simulating the conditions of use of the equipment. It was found that the biocidal activity of the half mask is sufficient to ensure a significant reduction in the number of microorganisms during its long-term use in the workplace. This in turn means that continuous disinfection of respiratory protective equipment would be maintained even without employees’ intervention, which is not possible in case of standard respiratory protective equipment.Pozycja Production of co-immobilized dextransucrase and dextranase preparations and their application in isomalto-oligosaccharides synthesis(Wydawnictwo Politechniki Łódzkiej, 2017) Sikora, Barbara; Kubik, Celina; Bielecki, StanisławDextransucrase (DS) from Leuconostoc mesenteroides and dextranase (DN) from Penicillium funiculosum were co-immobilized by entrapment in calcium alginate and used to produce isomaltooligosaccharides (IMOs) from sucrose. DS convert sucrose into dextran, which is the substrate for DN, so that IMOs are products of dextran hydrolysis. Before the co-immobilization DS was cross-linked with glutardialdehyde (GA), while DN was adsorbed on hydroxyapatite (HAp). Cross-linking was essential for the stability of DS and pre-immobilization of DN to prevent enzyme from leaking out of the alginate beads. Operational stability of co-immobilized preparations of DS and DN was estimated based on amounts of isomaltose and isomaltotriose formed during successive 24h processes of IMOs synthesis, carried out at 30oC, pH 5.4 and 200 rpm in 10% (w/v) sucrose solutions. Preparation characterized by the initial DS/DN activities ratio of 1/14 was found to maintain these activities at least 100 h of IMOs synthesis (5 repeated batch reaction).Pozycja A comparison of two enzymatic methods of clinical dextran production(Wydawnictwo Politechniki Łódzkiej, 2017) Sikora, Barbara; Kubik, Celina; Bielecki, StanisławThe aim of this study was to evaluate and compare of the two enzymatic methods of clinical dextran production were compared. The reactions were performed at 30°C and pH 5.4 in solutions containing different amounts of sucrose, using dextransucrase (DS, in the presence of dextranase (D) (method 1) or acceptor dextrans (method 2). The activity of Leuconostoc mesenteroides L dextransucrase (DS), which converts sucrose to dextran, was 0.4 U ml-1 in both the methods. As much as 53-56% of clinical dextran fractions were obtained for 28 h from 10% sucrose solutions, which contained 1.5% or 2.5% acceptor dextrans with molecular mass of 10 and 15 kDa, respectively. Approximately 50% of these fractions was obtained (also in 28 h) from 10% sucrose solutions by using 0.004 U ml-1 of DN, added to reaction mixtures 5 h later than Our experiments indicate that the clinical dextran can be efficiently produced by using both the compared methods, which employ either acceptor dextrans with definite molecular mass, or the dextranase. Because consumption of the latter enzyme is rather small, and it is easily available, thus this method should be attractive for clinical dextran manufacturers.Pozycja Application and properties of selected flavanones(Wydawnictwo Politechniki Łódzkiej, 2018) Błazińska, Paulina; Sykuła, AnnaFlavanones, secondary plant metabolites, are one of the main group of flavanoids. They are widely spread in nature in many plants. The large diversity of structural structure of flavanones and controlled methods of modifying their molecules have a huge impact on biological activity. The present review will summarize the current knowledge about occurrence, obtaining by chemical synthesis, application and bioactivity of flavanones. Also, they are received from specific chemical synthesis. Flavanones have a great biological activity. Derivatives of flavanone have many different properties such as anti-inflammatory, anticancer, antioxidant, antimicrobial or hepatoprotective activities. These natural polyphenolic compounds are used in cosmetology, pharmacy and medicine. The demand and usage on them increases.Pozycja Analysis of the selected antioxidant compounds n ice cream supplemented with Spirulina (Arthrospira platensis) extract(Wydawnictwo Politechniki Łódzkiej, 2018) Szmejda, Klaudia; Duliński, Robert; Byczyński, Łukasz; Karbowski, Adrian; Florczyk, Tomasz; Żyła, KrzysztofThe research is aimed at evidencing that ice-cream formulations incorporating algae can have health-benefiting effects on human body. The main task of the project is to design ice-cream product line that distinguish itself from regular ice-cream by increased anti-oxidant activity resulted from inclusion of the algae extract. The currently known research evidences that ice-cream can be effective as carriers of health-promoting probiotic bacteria, which in turn encourages also application of other microorganisms in particular algae of specific strains (e.g. Spirulina platensis) as a supplement to ice-cream. In submitted research, the level of polyphenols and antioxidant activity expressed as degree of inhibiting generation of cationo-free radical from DPPH•+ solution were analyzed. Preliminary results based on antioxidative activity tests measured with potential to quench free radicals have shown that ice-cream formulations enriched with algae extract exhibit significantly higher potential achieving inhibition level of 39.7% in the mint ice cream samples as compared to 32.8% inhibition for the control sample without algae. Furthermore, each of the examined samples (dairy, pistachio, mint) ice creams versions supplemented with Spirulina were characterized by enhanced antioxidant activities expressed as potential to quench free radicals and the carotenoids content.Pozycja The DFT study on the electronic structure of boronic acid derivatives and its esters with fructose(Wydawnictwo Politechniki Łódzkiej, 2018) Kur, Katarzyna; Kowalska-Baron, Agnieszka; Miller, EwaTheoretical investigations are carried out to examine the geometrical structure and parameters of electron transitions to the lowest excited states of two boronic acid derivatives: 3-aminophenylboronic acid and 3-(acetamidomethyl)phenyl boronic acid and its cycling esters with fructose, using the DFT based 6-31 G(d,p) method. The most stable ester isomer of each acid has been selected. Predicted excitation wavelength are shorter (less than 0.5 eV) than experimental ones, what is in a good agreement considering limitations of the DFT method. In case of almost every calculated molecule the analysis of electronic transitions shows that transition S0→S1 involves electron transfer mainly from the HOMO to LUMO orbital.Pozycja Optical properties of (3-(acetamidomethyl)phenyl) boronic acid and its interactions with selected sugars(Wydawnictwo Politechniki Łódzkiej, 2018) Kur, Katarzyna; Przybyt, Małgorzata; Miller, Ewa(3-(Acetamidomethyl)phenyl)boronic acid (3AAPBA)has at pH 7 absorbance maximum at 270 nm with molar absorbance coefficient 516 M-1cm-1. 3AAPBA exhibits weak fluorescence with maximum at 297 nm and quantum yield 0.062 ± 0.001. Fluorescence decay is monoexponential and the lifetime is 2.05 ± 0.01 ns. Interactions of 3AAPBA with selected sugars were studied by absorbance, steady-state and time-resolved fluorescence measurements. At pH 7 fluorescence of 3AAPBA is quenched only by fructose (with quenching constant 67.9 M-1) and to some extend by galactose. Addition of these two monosaccharides causes also changes of absorbance spectra of 3AAPBA. Acid-base dissociation of free 3AAPBA and its esters with sugars was studied by absorbance and steady-state fluorescence measurements in pH range from 4.5 to 11.00. Esterification of phenylboronic acid derivatives by sugars leads to increased acidity of them. In case of 3AAPBA the obtained values of pK indicate that affinity of studied sugars towards it can be ordered as follows: fructose > galactose > glucose > maltose > lactose > sucrose. At pHs higher than pK the fluorescence decays turn to biexponential with additional shorter component in lifetime which we propose to attribute to anionic form of 3AAPBA or its esters.Pozycja Antioxidant Potential and Phytochemical Content of Selected Fruits and Vegetables Consumed in Cyprus(Wydawnictwo Politechniki Łódzkiej, 2018) Georgiadou, Egli C; Goulas, Vlasios; Majak, Iwona; Ioannou, Antigoni; Leszczyńska, Joanna; Fotopoulos, VasileiosConsuming a diet high in fruits and vegetables can lower the risk of developing numerous chronic diseases, including cancer and cardiovascular disease, due to the presence of multiple antioxidants. Horticultural produce consumed in Cyprus include a large variety of fruits and vegetables, most of which are common components of a Mediterranean-style diet due to the island’s localization. The aim of the present study was to evaluate the antioxidant composition and activity of the edible portion of ten fruits and ten vegetables commonly consumed in Cyprus. Total phenolics, anthocyanins, ascorbic acid and carotenoids contents were determined, while the in vitro antioxidant activity was evaluated by three assays. Antioxidant activity showed great variation, with the highest values found in green olives, capers and red chili peppers and in correlation with total phenolic content. Ascorbic acid was detected in large quantities in parsley, coriander, red guavas and red chili peppers, while red chili peppers, capers and coriander had high levels of carotenoids. Furthermore, sweet cherries, red grapes, and red apples contained significant amounts of anthocyanins. Statistical analysis revealed that phenolic compounds are the most potent antioxidants in fruit and vegetables, while total anthocyanins had a weak contribution to their antioxidant activity. The present study could be a guide for Cypriot as well as Mediterranean diet health-conscious consumers to select specific fruits and vegetables as dietary components. To the best of our knowledge, this is the first study thoroughly describing the antioxidant composition and activity of a wide array of important Cypriot horticultural products.Pozycja In vitro study of hesperetin Schiff bases antioxidant activity on rat liver mitochondria(Wydawnictwo Politechniki Łódzkiej, 2018) Sykuła, Anna; Cheshchevik, Vitali T.; Cheshchevik, Nina G.; Dzeikala, Aliaksandr; Łodyga-Chruścińska, ElżbietaThree hesperetin Schiff bases: hesperetin thiosemicarbazone (HTSC), hesperetin isoniazone (HIN) and hesperetin benzhydrazone (HHSB) have been synthesized and characterized by using analytical and spectral techniques. The influence of substituents on hesperetin antioxidant activity has been studied in vitro using mitochondrial assays. The studied compounds have been found to exhibit both antioxidant and pro-oxidant activity.Pozycja Biofilms – a danger for food industry(Wydawnictwo Politechniki Łódzkiej, 2018) Plucińska, Aleksandra; Kunicka-Styczyńska, AlinaBacterial biofilm is a complex structure of microorganisms with variable qualitative composition depending on the raw materials used, parameters of the production process and localization in hardly accessible places for antimicrobial agents. At the same time, the life of bacteria in the biofilm structure increases the resistance of pathogens and the probability of their survival in adverse conditions. However, the effectiveness of biofilm removal is still not satisfactory, despite the constant improvement of the cleaning and disinfection procedures of industrial surfaces. The methods of biofilm eradication used so far can be divided into three groups (physical, biological, chemical). Numerous in vitro studies indicate that alternatives to commonly used disinfectants may be natural substances such as essential oils that have bactericidal and bacteriostatic activity. The present review will focus on describing biofilm formation and performance. In addition, the paper describes an overview of the methods used to prevent and eradicate biofilms.