Model for the Fluorescence Induction Curve of Photoinhibited Thylakoids

AbstractThe fluorescence induction curve of photoinhibited thylakoids measured in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethyl urea was modeled using an extension of the model of Lavergne and Trissl (Biophys. J. 68:2474–2492), which takes into account the reversible exciton trapping by photosystem II (PSII) reaction centers and exciton exchange between PSII units. The model of Trissl and Lavergne was modified by assuming that PSII consists of photosynthetically active and photoinhibited (inactive in oxygen evolution) units and that the inactive PSII units can efficiently dissipate energy even if they still retain the capacity for the charge separation reaction. Comparison of theoretical and experimental fluorescence induction curves of thylakoids, which had been subjected to strong light in the presence of the uncoupler nigericin, suggests connectivity between the photoinhibited and active PSII units. The model predicts that photoinhibition lowers the yield of radical pair formation in the remaining active PSII centers. However, the kinetics of PSII inactivation in nigericin-treated thylakoids upon exposure to photoinhibitory light ranging from 185 to 2650μmol photons m−2 s−1 was strictly exponential. This may suggest that photoinhibition occurs independently of the primary electron transfer reactions of PSII or that increased production of harmful substances by photoinhibited PSII units compensates for the protection afforded by the quenching of excitation energy in photoinhibited centers

Advanced Ion and Plasma Sources for Materials Surface Engineering

The paper presents the results of the authors many year work in the field of ion&plasma sources development. The families of DC and RF ion and plasma sources are described. The results of ion&plasma sources utilization in materials surface modification technologies are discussed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3540

Application of the Hurst index to research the traffic flow intensity

The relevance of the work is due to the predictive properties of the Hurst indicator (index), which make it possible to identify the presence/absence of a trend in the observed stochastic process, which it is advisable to use when regulating and controlling traffic to reduce congestion, traffic accidents based on processing information about traffic flows coming from stationary video recording complexes of traffic violations. The object of investigation is a section of road with intensive one-way traffic, equipped with a software and hardware complex that allows measuring the characteristics of the flow of motor transport. The subject of the study is the daily intensity of the cars flow during the week, from Monday to Sunday. The purpose of this study is to identify the patterns of evolution of the indicators included in the Hurst index, based on the processing of time series of the intensity of motor transport traffic on the road network. As a theoretical and methodological approach, the rescaled range analysis, or the definition of Hurst exponent, is used. The approach developed by the authors allowed us to establish the regularities of the evolution of mean values, standard deviations, accumulated and rescaled range, Hearst exponents, which is the scientific novelty of the performed analysis. Data processing of video surveillance software and hardware complexes made it possible to construct time-dependent indicators of the intensity of car traffic on a road with a consistently high flow of vehicles connecting the central and remote areas of the city of Perm, at various intervals of averaging by days of the week. As a result of the study of time series, dependences on the time of average values, standard deviations, accumulated and rescaled ranges, Hearst exponents were obtained. It is shown that the found characteristics of the traffic flow intensity on a road with a high traffic intensity differ significantly from similar characteristics obtained earlier for roads with a relatively low intensity. The practical significance lies in the use of predictive properties of the Hurst indicator in analyzing the intensity of the flow of vehicles for predicting the movement of vehicles, controlling the operation of traffic lights, monitoring the operation of equipment, etc. The direction of further research is to obtain, process and determine rescaled ranges and Hurst exponents for time series of traffic flow intensity on other sections of the road network

Application of the wavelet analysis to research the traffic flow intensity

The relevance of the work is the specific properties of the wavelet analysis, which make it possible to identify not only the amplitude-scale (frequency) characteristics of the time series under consideration, but also the evolution of these characteristics during the observation time. As a result of the study, it is advisable to identify those indicators of the intensity of traffic flow that may turn out to be indicators of possible problematic situations (congestion, traffic accidents, etc.). It is advisable to use them in the future when regulating and controlling traffic on the basis of processing information about traffic flows that comes from stationary video recording complexes of traffic violations. The object of study is a road with intensive one-way traffic, equipped with a software and hardware complex that allows measuring the characteristics of the flow of motor transport. The subject of the study is the daily intensity of the flow of cars. The purpose of this study is to identify patterns in the indicators evolution obtained using wavelet analysis as a result of processing of the time series of the car traffic intensity on the road network. As a theoretical and methodological approach, the wavelet transforms using the MHat wavelet, and the Morlet wavelet is used. The approach used by the authors allowed us to establish the correspondence of some characteristics obtained during the wavelet analysis with the evolution of the traffic flow intensity function during the daily observation time, which is the scientific novelty of the study. The wavelet analysis of the data of the video surveillance software and hardware complexes obtained during the day allowed us to construct time dependences of amplitude-scale (frequency) indicators of the car traffic intensity on the road connecting the central and rear areas of the city of Perm. As a result of the study of time series, experimental three-dimensional distributions of wavelet images, scalograms, skeletons and scalegrams of the function of the daily intensity of the traffic flow were obtained. An explanation of the characteristic features of the obtained dependencies and their relationship with the initial function of the traffic flow intensity is proposed. The practical significance lies in obtaining amplitude-scale (frequency) characteristics as a result of wavelet analysis of the traffic intensity using MHat and Morlet wavelets, which is of practical interest from the point of view of predicting the movement of vehicles, controlling the operation of traffic lights, monitoring the operation of equipment, etc. The direction of further research is to obtain, process, analyze and generalize the results of performing amplitude-scale wavelet analysis for time series of traffic flow intensity on parts of the road network with different vehicle traffic intensity

Evolution of chemical composition and gas emissions from aged pig slurry during outdoor storage with and without prior solid separation

Chemical composition and gas emissions from two types of pig slurry were evaluated: the liquid fraction of mechanical solid-liquid separated slurry (SS), and raw slurry (RS). The slurry was obtained at the end of a pig fattening period and was stored in 100 l vessels for 15 weeks simulating outdoor storage conditions. During this period, representative samples were taken and analysed for chemical composition. Methane, carbon dioxide, ammonia, water vapour and nitrous oxide emissions were recorded. The results showed a high biological degradation during the first five weeks of outdoor storage in SS and RS slurries, as a result of an increase in the dissolved chemical oxygen demand, volatile fatty acids and carbon dioxide emission observed in this period. However, methanogenic activity was not evident until week 6 of storage in both slurries, confirmed by the volatile fatty acids accumulation and the negligible methane emissions during the first five weeks of storage. The results showed that differences in the initial slurry organic matter content, influenced by solid separation process affects the evolution pattern of the organic matter degradation. Storage time can considerably affect the biodegradability of organic matter in pig slurry. © 2011 IAgrE.This work was supported by the Agrobiogas project financed by the Agroalimed Foundation of the Conselleria de Agricultura, Pesca, Alimentacion y Agua of Valencia, Spain.Moset, V.; Cambra López, M.; Estellés, F.; Torres Salvador, AG.; Cerisuelo, A. (2012). Evolution of chemical composition and gas emissions from aged pig slurry during outdoor storage with and without prior solid separation. Biosystems Engineering. 111(1):2-10. doi:10.1016/j.biosystemseng.2011.10.001S210111

Modulating effect of Cu(II) complexes with enamine and tetrazole derivatives on CYP2C and CYP3A and their cytotoxic and antiproliferative properties in HepG2 spheroids

CYP2C and CYP3A cytochromes are induced by a variety of compounds and affect the pharmacokinetics and pharmacodynamics of a large number of drugs. Currently, the possibility of using copper coordination compounds in antitumor therapy is being actively studied. Evaluation of potential interactions between new molecules and P450 cytochromes is necessary at an early stage of drug design.The aim. To study the modulating effect of Cu(II) complexes with enamine and tetrazole derivatives on CYP2C9, CYP2C19 and CYP3A4 and their cytotoxic and antiproliferative properties on normal human lung fibroblasts MRC-5 and a 3D model of hepatocellular carcinoma HepG2.Materials and methods. Cytotoxic and antiproliferative activities of copper(II) complexes – [CuL2] (1), [Cu2(bipy)2(PT)4] (2), [Cu2(phen)2(PT)4] (3), {[Cu(phen)(MT)2]∙H2O}n (4) (L – anion of 2-anilinomethylidene-5,5-dimethylcyclohexane-1,3-dione; PT – 5-phenyltetrazolate anion; MT – 5-methyltetrazolate anion; bipy – 2,2’-bipyridine; phen – 1,10-phenanthroline) – were examined in 2D and 3D models using fluorescence-based phenotypic screening. The modulating effect on CYP2C9, CYP2C19 and CYP3A4 was studied using fluorescence-based targeted screening. The results of CYP3A4 expression were confirmed by real-time reverse transcription polymerase chain reaction (RT-PCR).Results. Complex (1) increases the CYP3A4 expression and does not affect CYP2C9 and CYP2C19 expression. Complex (2) has no modulating effect on CYP2C and CYP3A. Complexes with 1,10-phenatrolin (3) and (4) induce CYP3A4, inhibit CYP2C9 and do not affect CYP2C19 expression. All compounds have a dose-dependent cytotoxic effect on HepG2 and MRC-5: the compound with 5-methyltetrazolate anion (4) has the same effect on cell lines, compounds with 5-phenyltetrazolate anion (2) and (3) have selective effect. Complexes with 1,10-phenatrolin are effective on both 2D and 3D models.Conclusion. The [Cu2(phen)2(FT)4] complex (3) can be used as a basis for creating an antitumor compound, but further modification of the structure is required to increase the selectivity to tumor cells

EXPRESSION OF mRNA FOR CYTOKINES COMPARED TO THEIR CONCENTRATIONS IN CULTURE SUPERNATES OF U937 CELLS EXPOSED TO POLYCLONAL ACTIVATORS

Investigation of the cytokine expression dynamics as well as the cytokine-producing potential of immune-competent cells allows extensive studies of their functional characteristics. mRNAs encoding a number of cytokine genes are relatively stable, thus their level may be used as a marker for assessing the levels of activation and proliferation of immunocompetent cells as well as for evaluating the cytokine-producing potential of immunocompetent cells.In our work, we assessed correlations between the levels of mRNA expression specific for IL-10, TNF-α, GM-CSF cytokines determined in a culture of differentiated macrophage U937 cells, and protein concentrations of the same cytokines as measured in supernates of U937 cell cultures, without and after exposure to polyclonal activators. The IL-10, TNF-α, GM-CSF mRNA expression was determined by real-time quantitative polymerase chain reaction. Protein concentrations of IL-10, TNF-α, GM-CSF cytokines in the culture supernatant of U937 cells were measured by an enzyme immunoassay. The use of an initially homogeneous cell culture in the study is convenient due to the identical conditions in all experimental variants.The most pronounced effect of polyclonal activators is exerted upon production of GM-CSF mRNA, as well as protein concentration of this cytokine in the cell culture supernatants, thus actually coinciding with RT-qPCR results.  The TNF-α mRNA level decreased under the influence of polyclonal activators, whereas concentration of this cytokine was decreased in the cell supernate. The TNF-α protein in a culture medium did not reflect temporal changes in the cellular TNF-α mRNA expression, probably, due to potential decrease of cellular mRNA occurring by the feedback inhibitory mechanism. While the cytokines can accumulate and remain in the supernatant, the mRNA-related events leading to cytokine formation may be completed earlier. Therefore, the signalling pathways and cytokine release kinetics should be studied after establishing the time dependence at short time intervals, which may be individual for each cytokine.Thus, the results of a study using polyclonal activators suggest that polyclonal activators applied as mitogens, have a significant effect upon the concentration of secreted IL-10, TNFα and GM-CSF. In this case, polyclonal activators affect the levels of mRNA encoded by cytokine genes, thus indicating transcriptional mechanisms of its action. But, in view of the fact that the data are ambiguous, in order to achieve greater correspondence between the changes in the studied proteins and specific mRNAs, a detailed description of the time dependence is required for the changes in mRNA contents

The regulatory role of cystatin C in autophagy and neurodegeneration

Autophagy is a dynamic cellular process involved in the turnover of proteins, protein complexes, and organelles through lysosomal degradation. It is particularly important in neurons, which do not have a proliferative option for cellular repair. Autophagy has been shown to be suppressed in the striatum of a transgenic mouse model of Parkinson’s disease. Cystatin C is one of the potent regulators of autophagy. Changes in the expression and secretion of cystatin C in the brain have been shown in amyotrophic lateral sclerosis, Alzheimer’s and Parkinson’s diseases, and in some animal models of neurodegeneration, thus proving a protective function of cystatin C. It has been suggested that cystatin C plays the primary role in amyloidogenesis and shows promise as a therapeutic agent for neurodegenerative diseases (Alzheimer’s and Parkinson’s diseases). Cystatin C colocalizes with the amyloid β-protein in the brain during Alzheimer’s disease. Controlled expression of a cystatin C peptide has been proposed as a new approach to therapy for Alzheimer’s disease. In Parkinson’s disease, serum cystatin C levels can predict disease severity and cognitive dysfunction, although the exact involvement of cystatin C remains unclear. The aim: to study the role of cystatin C in neurodegeneration and evaluate the results in relation to the mechanism of autophagy. In our study on humans, a higher concentration of cystatin C was noted in cerebrospinal fluid than in serum; much lower concentrations were observed in other biological fluids (intraocular fluid, bile, and sweat). In elderly persons (61–80 years old compared to practically healthy people at 40–60 years of age), we revealed increased cystatin C levels both in serum and intraocular fluid. In an experiment on C57Bl/6J mice, cystatin C concentration was significantly higher in brain tissue than in the liver and spleen: an indication of an important function of this cysteine protease inhibitor in the brain. Using a transgenic mouse model of Parkinson’s disease (5 months old), we demonstrated a significant increase in osmotic susceptibility of brain lysosomes, depending on autophagy, while in a murine model of Alzheimer’s disease, this parameter did not differ from that in the appropriate control

Anaerobic digestion of screenings for biogas recovery

Screenings comprise untreatable solid materials that have found their way into the sewer. They are removed during preliminary treatment at the inlet work of any wastewater treatment process using a unit operation termed as a screen and at present are disposed of to landfill. These materials, if not removed, will damage mechanical equipment due to its heterogeneity and reduce overall treatment process, reliability and effectiveness. That is why this material is retained and prevented from entering the treatment system before finally being disposed of. The amount of biodegradable organic matter in screenings often exceeds the upper limit and emits a significant amount of greenhouse gases during biodegradation on landfill. Nutrient release can cause a serious problem of eutrophication phenomena in receiving waters and a deterioration of water quality. Disposal of screenings on landfill also can cause odour problem due to putrescible nature of some of the solid material. In view of the high organic content of screenings, anaerobic digestion method may not only offer the potential for energy recovery but also nutrient. In this study, the anaerobic digestion was performed for 30,days, at controlled pH and temperature, using different dry solids concentrations of screenings to study the potential of biogas recovery in the form of methane. It was found screenings have physical characteristics of 30% total solids and 93% volatile solids, suggesting screenings are a type of waste with high dry solids and organic contents. Consistent pH around pH 6.22 indicates anaerobic digestion of screenings needs minimum pH correction. The biomethane potential tests demonstrated screenings were amenable to anaerobic digestion with methane yield of 355,m3/kg VS, which is comparable to the previous results. This study shows that anaerobic digestion is not only beneficial for waste treatment but also to turn waste into useful resources