107 research outputs found
Uticaj prirodnog ekstrakta ruzmarina na oksidativnu stabilnost prženog kukuruznog čipsa
In this paper, the effects of the natural extract of rosemary on oxidative stability and the sensory properties of corn chips without antioxidant, with antioxidant and antioxidant and linseed (4%) was observed. The natural extract of rosemary Synerox HT (antioxidant) was added in an amount of 1250 ppm (0.125%) on the amount of palm oil for frying the corn chips. Corn chips without antioxidant after 3 months of storage in laboratory conditions (30 °C), is already slightly rancid (1.53 mg of malonaldehyde kg-1 of the final product). Corn chips with antioxidant do not show signs of rancidity after 4 months of storage in laboratory conditions (1.05 mg of malonaldehyde kg-1 of the final product).U ovom radu posmatran je uticaj prirodnog ekstrakta ruzmarina na promenu oksidativne stabilnosti i senzornih osobina kukuruznog čipsa bez antioksidansa, sa antioksidansom i antioksidansom i semenkama lana (4%). Prirodni ekstrakt ruzmarina Synerox HT (antioksidans) dodat je u količini od 1250 ppm (0,125%) na količinu palminog ulja za prženje kukuruznog čipsa. Kukuruzni čips bez antioksidansa nakon 3. meseca čuvanja u laboratorijskim uslovima (30 °C), već je blago užegao (1,53 mg malonaldehida kg-1 gotovog proizvoda). Kukuruzni čips sa antioksidansom ne pokazuje znake užeglosti nakon 4. meseca čuvanja u laboratorijskim uslovima (1,05 mg malonaldehida kg-1 gotovog proizvoda)
ASTROCYTE ACTIVITY IN THE CENTRAL NERVOUS SYSTEM AUTOIMMUNITY
Aims: Multiple sclerosis (MS) is an in ammatory autoimmune disorder of the central nervous system (CNS). Complex interactions between inltrating immune cells (IIC) and resident glial cells of the CNS cause myelin loss and neuronal dysfunction in MS. Here we aim to understand how naïve astrocytes functionally respond to the IIC invasion of the CNS.
Methods: We measured calcium activity of naïve astrocytes in culture upon application of IIC. An experimental autoimmune encephalomyelitis (EAE) MS rat model was used to isolate IIC from the spinal cord of animals at the symptomatic stage. Naïve astrocytes were isolated from the spinal cord of WT rats.
Results: We show that IIC and not the lymph node immune cells evoke vigorous increase in the astrocyte calcium activity. This IIC-induced calcium response depends on an autocrine activation of the purinergic P2X7 receptors on the naïve astrocytes.We also show that IIC induce ATP release from astrocytes by a mechanism that involves gap junctions and/or hemichannels activation and not the vesicular pathway. Our data indicate that ATP release and subsequent increase in the astrocytic calcium activity mainly depends on the cell-cell contact between naïve astrocytes and IIC.
Conclusions: These results show that naïve astrocytes functionally respond to the IIC by augmented release of ATP. An increase in ATP release would alter astrocyte-neuron communication and a ect neuronal function in MS.kategorija M3
Seroprevalence of SARS-CoV-2 antibodies among primary healthcare workers in the Republic of Srpska, Bosnia & Herzegovina: A cross-sectional study
Healthcare workers (HCW) in primary healthcare centres in the Republic of Srpska, Bosnia and Herzegovina, are on the first combat line with COVID-19. This study aimed to assess the seroprevalence of SARS-CoV-2 among HCW at the primary healthcare centres and to analyse the risk exposure to COVID-19, clinical signs and vaccination status. A cross-sectional study was conducted among HCW at the selected primary healthcare centres between 19 March and 30 April 2021. Antibodies against the SARS-CoV-2 virus were detected by enzyme-linked immunosorbent assay (ELISA). A total of 1,023 HCW (mean age 45 years; 71% female) were included in the study. The anti-SARS-CoV-2 antibodies were detected in 69.5% of all participants. There was a significant difference in seropositivity among primary healthcare centres from different geographical regions. As many as 432 (42%) of all participants had confirmed COVID-19 symptoms before the study and, 84.8% of them were seropositive. This study showed that 702 primary HCW were vaccinated with any of these vaccines: Sputnik V, Sinopharm, Pfizer/Biontech. High titre of SARS-CoV-2 antibodies was found amongst those who received one (92.6%) or both (97.2%) doses of vaccines. In this study, we report high prevalence of SARS-CoV-2 antibody among HCW in primary healthcare in the Republic of Srpska, Bosnia and Herzegovina during the third pandemic wave
Moisture and ion transport in layered porous building materials : a nuclear magnetic resonance study
Moisture and salt decay processes are amongst the most recurrent causes of damage of built objects and monuments. Although salt damage has been intensively investigated for several decades, the mechanisms and factors that control salt transport, accumulation, and crystallization in porous media and the development of damage are poorly understood. Knowledge about the transport of water and ions and salt crystallization in masonry (in the thesis referred to as substrate) and plasters is needed to explain salt damage and to develop durable materials. In chapter 2 the moisture and ion transport in porous media is reviewed brie°y. The drying behavior of a material is determined by the capillary pressure, and therefore by pore-size distribution. As a consequence the largest pores are emptied ¯rst. In layered systems of di®erent materials the material with larger pores should dry ¯rst. Ions are transported via di®usion and advection with the °ow of the water. These processes are described by a di®usion-advection equation. For high drying rates advection dominates the ion transport, whereas for low drying rates di®usion dominates the ion transport. Chapter 3 reviews the Nuclear Magnetic Resonance (NMR) technique and the ex- perimental set-up, that is used for the investigations described in this thesis. NMR is a non-destructive technique, suitable for probing the transport of water and dissolved ions in porous materials. The time evolution of the hydrogen pro¯les and the pro¯les of dissolved sodium can be measured quasi-simultaneously, which enables monitoring the moisture and salt transport during drying of (layered) porous media. The spatial resolu- tion of the NMR measurements is of the order of one millimeter, which is very accurate compared to conventional destructive techniques (hygroscopic moisture content analysis, chemical methods). It is outlined that using a stimulated echo NMR pulse sequence the self-di®usion of water in porous materials can be measured up to di®usion times exceeding 1 s. In chapter 4 the moisture and salt transport in a two-layer plaster/substrate system is discussed. It is shown experimentally that moisture and salt transport in the plaster layer is in°uenced by the pore-size distribution of the underlying substrate. The same plaster was applied on a Bentheimer sandstone substrate and a calcium-silicate brick sub- strate. In case of the plaster/Bentheimer sandstone system the plaster has pores that are an order of magnitude smaller than those of the substrate. On the other hand, in case of the the plaster/calcium-silicate brick system the plaster has pores that are an order of magnitude larger than the smallest pores of the substrate. The moisture and salt transport and the salt accumulation di®ers signi¯cantly for these two systems. Dur- ing the drying process, air invades ¯rst the layer with the largest pores. Therefore, in the plaster/Bentheimer sandstone system the substrate dries before the plaster, while in the plaster/calcium-silicate brick system the substrate stays wet longer than the plaster. This has important implications for the transport and accumulation of salt. In the plas- ter/Bentheimer sandstone system (the pores of the plaster are smaller than those of the substrate) all salt is removed from the substrate and accumulates in the plaster, because this layer remains wet for a longer time than the substrate. In the plaster/calcium-silicate brick system (the substrate has smaller pores than the plaster) some salt crystallizes in the plaster layer, but a signi¯cant amount of salt crystallizes within the substrate itself. The e±ciency of the salt transport from substrate to plaster is quanti¯ed in terms of an e±ciency number ², which can be estimated in di®erent ways. It is a simple, practical number, useful for the choice of a compatible plaster for a particular substrate. Based on the results of this study, we have discussed the salt transport for various combinations of plasters and substrates, of which the pore-size distributions have been reported in the literature. In chapter 5 the question is addressed whether a plaster/substrate system which has two plaster layers with di®erent pore sizes, can act as an accumulating system, i.e., a system in which salt crystallizes in the plaster layer and not in the substrate or at the external surface. To this end we have studied the drying behavior of such plasters applied on two di®erent substrates: ¯red-clay brick and Bentheimer sandstone. On the substrate we applied two plaster layers, of which the ¯rst (base) plaster layer has pores that are signi¯cantly smaller than the pores of the second (external) plaster layer. These systems were either saturated with pure water or a NaCl solution. We also studied non-uniformly salt loaded systems, in which the two plaster layers were saturated with pure water, and the substrate with a NaCl solution. The moisture and salt transport during drying were investigated. Among the investigated systems, it is found that only a system consisting of an external gypsum layer and a base lime-cement plaster layer on a Bentheimer sandstone substrate behaves as a salt accumulating system when it is non-uniformly salt loaded. We conclude that it is di±cult to make an accumulating system only based on di®erences in the pore-size distributions of the individual layers, because in practice it is di±cult to prepare plasters with exactly speci¯ed pore-size distributions, in particular, plasters with pores which are larger than the pores of the substrate. Chapter 6 describes NMR measurements of the self-di®usion of water in porous ma- terials containing a large amount of magnetic impurities. These impurities (Fe), which are often present in building materials, hinder the di®usivity measurements by NMR. To investigate the self-di®usion of water in these materials, a stimulated echo NMR technique is applied. A new analytical equation for the long-time stimulated-echo decay in the pres- ence of spatially varying internal ¯eld gradients is derived and experimentally con¯rmed. This equation is used to interpret our NMR di®usion measurements on three materi- als with di®erent amounts of magnetic impurities. It is shown that, using this method, the self-di®usion constant of water in these materials can be determined correctly. The method presented in this chapter may be useful for di®usivity measurements in many classes of materials in which internal magnetic ¯elds interfere with the applied gradients (i.e. susceptibility induced ¯elds in natural stones, inorganic and biologic materials). Verwering ten gevolge van vocht en zout is een van de meest voorkomende oorzaken van schade aan bouwconstructies en monumenten. Hoewel al tientallen jaren lang veel onderzoek is verricht naar zoutschade, zijn de mechanismen en factoren die van invloed zijn op zouttransport, ophoping van zout en kristallisatie nog steeds slecht begrepen. Inzicht in het transport van water en ionen en zoutkistallisatie in metselwerk (in dit proefschrif
Hållbarhetsredovisning : En fallstudie om kommunikation och anställdas insikt i hållbarhetsarbete
Purpose: The purpose of our study is to understand how companies communicate sustainability internally. Furthermore, the study also aims to contribute with increased knowledge of employees’ insight into corporate sustainability reporting. Research questions: ❖How is sustainability communicated internally?❖To what extent are employees aware of corporate sustainability work? Method: In order to achieve the purpose and answer the study's questions, we have chosen to carry out a case study with two types of data collection. The empirical material for the study has been collected using both qualitative and quantitative methods. The qualitative material comes from structured interviews with the sustainability managerand three employees, while the quantitative data is based on a collection of 219 questionnaires that have been answered by employees at Spendrups. Conclusion: The study's results have shown that communication of sustainability work can take place in different ways and that different departments may prefer to absorb information by different sources of information. Knowledge of the sustainability work has been influenced by the employees' attitude towards sustainability. In addition, there are patterns that different departments have relatively more knowledge of sustainability issues related to their daily routines and tasks.Syfte: Syftet med vår studie är att förstå hur företag kommunicerar hållbarhet internt. Vidare syftar studien även till att bidra med ökad kunskap om medarbetaresinsikt i företags hållbarhetsredovisning. Forskningsfrågor: ❖Hur kommuniceras hållbarhet internt?❖I vilken utsträckning är medarbeterna medvetna om företags hållbarhetsarbete? Metod: För att uppnå syftet och svara på studiens frågeställningar har vi valt att utföra en fallstudie med två typer av datainsamlingar. Det empiriska materialet för studien har samlats in med hjälp av både kvalitativ och kvantitativ metod. Det kvalitativa materialet kommer från strukturerade intervjuer med en hållbarhetsansvarig och tre medarbetare, medan det kvantitativa underlaget i studien bygger på en insamling av 219 enkäter som har besvarats av medarbetare på Spendrups. Slutsatser: Studiens resultat visar att kommunikationen av hållbarhetsarbetet kan ske på olika sätt samt att olika avdelningar kan preferera att ta till sig informationen via olika informationskällor. Kännedom om hållbarhetsarbetet har påverkats av medarbetarnas attityder gentemot hållbarhet. Dessutom finns det mönster om att olika avdelningar har relativt mer kännedom om hållbarhetsfrågor som rör deras dagliga rutiner och arbetsuppgifter
Bioavailability of Nutritional Resources From Cells Killed by Oxidation Supports Expansion of Survivors in Ustilago maydis Populations
After heavy exposure of Ustilago maydis cells to clastogens, a great increase in viability was observed if the treated cells were kept under starvation conditions. This restitution of viability is based on cell multiplication at the expense of the intracellular compounds freed from the damaged cells. Analysis of the effect of the leaked material on the growth of undamaged cells revealed opposing biological activity, indicating that U. maydis must possess cellular mechanisms involved not only in reabsorption of the released compounds from external environment but also in contending with their treatment-induced toxicity. From a screen for mutants defective in the restitution of viability, we identified four genes (adr1, did4, kel1, and tbp1) that contribute to the process. The mutants in did4, kel1, and tbp1 exhibited sensitivity to different genotoxic agents implying that the gene products are in some overlapping fashion involved in the protection of genome integrity. The genetic determinants identified by our analysis have already been known to play roles in growth regulation, protein turnover, cytoskeleton structure, and transcription. We discuss ecological and evolutionary implications of these results
Novel kinetics model for adsorption of pollutant from wastewaters onto zeolites. Kinetics of phenol adsorption on zeolite-type silicalite
The kinetics of isothermal adsorption of phenol from an aqueous solution onto the zeolite-type silicalite was investigated. Zeolite-type silicalite was synthesized and its basic physico-chemical properties were determined. Isothermal adsorption kinetics curves of phenol on zeolite-type silicalite were measured at temperature range from 283 to 313 K. By applying Friedman’s differential isoconversional method it was found that the adsorption of phenol on silicalite has one rate determining step. By using the ‘model-fitting’ method it was established that the kinetic of adsorption can be described with theoretical kinetic model of the two-dimensional phase-boundary controlled reaction (model R2). The kinetic parameters, activation energy ( E a = 45 kJ mol − 1 ) and preexponetial factor ( lnA = 14.1 min −1 ) of phenol adsorption were calculated. The thermodynamic parameters, standard enthalpy (Δ H *), standard entropy (Δ S *) and standard free Gibbs energy of adsorption (Δ G *) were calculated and discussed. A novel model for the kinetics of pollutant adsorption from wastewaters onto zeolites based on the following: zeolite pores have cylindrical shape with average radius r 0 , pores in zeolite are filled simultaneously by the model ‘layer by layer’, the rate of phenol adsorption is higher than the rate of the growth of the thickness of the adsorption layer was suggested. It has been found that the adsorption kinetics can be completely described by this kinetic model
Data_Sheet_1_Bioavailability of Nutritional Resources From Cells Killed by Oxidation Supports Expansion of Survivors in Ustilago maydis Populations.DOCX
<p>After heavy exposure of Ustilago maydis cells to clastogens, a great increase in viability was observed if the treated cells were kept under starvation conditions. This restitution of viability is based on cell multiplication at the expense of the intracellular compounds freed from the damaged cells. Analysis of the effect of the leaked material on the growth of undamaged cells revealed opposing biological activity, indicating that U. maydis must possess cellular mechanisms involved not only in reabsorption of the released compounds from external environment but also in contending with their treatment-induced toxicity. From a screen for mutants defective in the restitution of viability, we identified four genes (adr1, did4, kel1, and tbp1) that contribute to the process. The mutants in did4, kel1, and tbp1 exhibited sensitivity to different genotoxic agents implying that the gene products are in some overlapping fashion involved in the protection of genome integrity. The genetic determinants identified by our analysis have already been known to play roles in growth regulation, protein turnover, cytoskeleton structure, and transcription. We discuss ecological and evolutionary implications of these results.</p
Spectrophotometric investigation of famotidine-Pd(II) complex and its analytical application in drug analysis
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