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When less water is available, hydropower turbines are less efficient, or have to stop altogether. This reality is often neglected in recent work on the planning and operations of hydropower systems, despite widespread expected increases in drought intensity, frequency and duration. This paper is the first to integrate variable‐efficiency turbines into a hydropower plant design framework that accounts for design optimization as well as deep uncertainty in climatic and socio‐economic variables. Specifically, this framework focuses on leveraging multi‐objective robust decision making for the financially robust design of run‐of‐river hydropower plants, whose output is highly sensitive to flow variability. Application to five plants in Türkiye challenges two key design assumptions, use of net present value as a design objective and use of identical turbines. Instead, maximizing the benefit‐cost ratio yields plants with better financial viability over a range of plausible futures. They tend to have smaller capacity, and feature a small turbine that is well‐adapted to low‐flow periods. Another key insight is that socio‐economic uncertainties have as much or even more impact on robustness than climate conditions. In fact, these uncertainties have the potential to make many small hydropower projects too risky to build. Our findings are of considerable practical relevance at a time where 140 GW of unexploited small hydropower potential could help power the energy transition. They also highlight the need for similar research in reservoir‐based plants, considering over 3,000 such plants planned or in construction worldwide. Key Points: Traditional approaches to hydropower planning need to be revisited to account for the impact of a variable climate on turbine efficiencyMaximizing the benefit cost ratio rather than the net present value promotes smaller designs, better adapted to a drought‐prone worldSocio‐economic and climatic factors are both crucial to design financial robustness [ABSTRACT FROM AUTHOR]

IntroductionHyperkyphosis commonly affects older people but is not widely acknowledged as a clinically actionable problem, especially in men. There are several techniques to quantify kyphosis including the blocks and Cobb angle measurements. This study includes both kyphosis measures to investigate whether older men with accentuated kyphosis may be at increased mortality risk.MethodsMen aged ≥65 years (N = 5994) were recruited to participate in the MrOS prospective cohort study from 2000 to 2002 (baseline). Our primary cohort included 2931 enrollees (mean age 79.3 years; SD 5.2) who underwent blocks-measured kyphosis from 2006 to 2009. Our secondary cohort included 2351 participants who underwent radiographic Cobb angle measurements at baseline. Cox proportional hazards analyses were used to determine association between kyphosis and all-cause mortality while adjusting for prevalent radiographic vertebral fractures, bone mineral density, incident fractures, gait speed, timed chair stands, self-reported health, alcohol use, medical co-morbidities, and physical activity.ResultsDuring a mean follow-up of 8.3 (SD 3.2) years, 1393 participants died in the primary cohort. In this group, compared to men with 0-1 block kyphosis, increasing blocks-measured kyphosis was associated with increased mortality (HR: 1.26-1.53, p trend

In the period following World War II, a postmodern period in which cultural activity increased and the creation of new characteristics and patterns of form in social and economic life and is no longer the old artistic pressure is dominant, but the media, technology and the market and called the community the term consumer or multinational capitalism emerged new movements, including the art of hyperrealism subject of research has included the first chapter of the research problem, which ended with the following question:(what is the property of technical renewal brought by excessive realism)The aim of the study was to know the renewal in the art of hyperrealism and the techniques used in the works of art, the limits of the research included models of the art of hyperrealism for the period(1969/1979) in Europe/ America. The second chapter included two sections, the first dealt with intellectual and cultural transformations and their impact on postmodern arts and the second came on two axes, the first; the points of difference between the original image and the imaginary image and its relationship to the art of hyperrealism, and the second: the artistic characteristics of hyperrealism and its artists. In the third chapter, the research procedures, where the descriptive approach was relied on to analyze the sample taken from the research community, which is a set of works that have been viewed through books and scientific sources and the selection of a sample representing the subject in an intentional manner amounted to 3 drawing works with the use of the observation tool and what was stated in the indicators for analysis. Keywords: renewal, technical, art, realism, excessive.

Natural polyphenols are promising compounds for the pharmacological control of oxidative stress in various diseases. However, low bioavailability and rapid metabolism of polyphenols in a form of glycosides or aglycones have stimulated the search for the vehicles that would provide their efficient delivery to the systemic circulation. Conjugation of polyphenols with cationic amphiphilic peptides yields compounds with a strong antioxidant activity and ability to pass through biological barriers. Due to a broad range of biological activities characteristic of polyphenols and peptides, their conjugates can be used in the antioxidant therapy, including the treatment of viral, oncological, and neurodegenerative diseases. In this work, we synthesized linear and dendrimeric cationic amphiphilic peptides that were then conjugated with gallic acid (GA). GA is a non-toxic natural phenolic acid and an important functional element of many flavonoids with a high antioxidant activity. The obtained GA-peptide conjugates showed the antioxidant (antiradical) activity that exceeded 2-3 times the antioxidant activity of ascorbic acid. GA attachment had no effect on the toxicity and hemolytic activity of the peptides. GA-modified peptides stimulated the transmembrane transfer of the pGL3 plasmid encoding luciferase reporter gene, although GA attachment at the N-terminus of peptides reduced their transfection activity. Several synthesized conjugates demonstrated the antibacterial activity in the model of Escherichia coli Dh5α growth inhibition. [ABSTRACT FROM AUTHOR]

Članak istražuje pojam proegzistencije, poglavito kroz prizmu novozavjetnih svjedočanstava o Isusovu životu i djelovanju, te hyper (ὑπὲρ) formula. Proegzistenciju također promatra kao bitno obilježje Isusove osobe, koje se očituje kroz različita otajstva njegova povijesnog života, pri čemu je najistaknutiji aspekt služenja kao bitnog sadržaja proegzistencije. U radu se, nadalje, pokazuje na glavni izvor i smjer Isusove proegzistencije, a to je Bog Otac. Time je proegzistencija označena kao ontološko i teološko, a ne samo humanističko obilježje Isusa iz Nazareta, Krista. Konačno, članak ističe da je nasljedovanje Kristove proegzistencije konkretan poziv prema kojemu je čovjek pozvan živjeti i na njega odgovoriti.

Prion diseases are progressive neurodegenerative disorders affecting humans and various mammals. The prominent neuropathological change in prion-affected brains is neuroinflammation, histopathologically characterized by reactive gliosis surrounding prion deposition. The cause and effect of these cellular responses are still unclear. Here we investigate the impact of innate immune responses on prion replication using in vitro cell culture models. Hamster-adapted transmissible mink encephalopathy prions, hyper (HY) and drowsy (DY) strains, were assayed for accumulation of pathogenic prion protein (PrPSc) in primary glial cultures derived from 8-day-old hamster pups. The kinetics of PrPSc accumulation largely depended on prion strain and brain regions from where glial cells originated. Glial cells derived from the cerebellum were susceptible to HY, but resistant to DY strain as determined by western blot analysis, immunocytochemistry, and animal bioassay. Glial cells from the cerebral cortex were, however, refractory to both strains. PrPSc accumulation was affected by innate immune modulators. Priming glial cells with lipopolysaccharide decreased prion replication, whereas pre-treatment with dexamethasone, inhibiting innate immunity, increased susceptibility to DY infection. Our results suggest that neuroinflammation resulting from prion infection is a response to resolve and/or prevent prion propagation in the brain. It implies a therapeutic potential of innate immune modulation in the early stages of prion disease. [ABSTRACT FROM AUTHOR]

Copyright of Church in the World / Crkva u Svijetu is the property of University of Split, Catholic Faculty of Theology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cell metabolism heavily relies on the redox reactions that inevitably generate reactive oxygen species (ROS). It is now well established that ROS fluctuations near basal levels coordinate numerous physiological processes in living organisms, thus exhibiting regulatory functions. Hydrogen peroxide, the most long‐lived ROS, is a key contributor to ROS‐dependent signal transduction in the cell. H2O2 is known to impact various targets in the cell; therefore, the question of how H2O2 modulates physiological processes in a highly specific manner is central in redox biology. To resolve this question, novel genetic tools have recently been created for detecting H2O2 and emulating its generation in living organisms with unmatched spatiotemporal resolution. Here, we review H2O2‐sensitive genetically encoded fluorescent sensors and opto‐ and chemogenetic tools for controlled H2O2 generation. [ABSTRACT FROM AUTHOR]

Cell metabolism heavily relies on the redox reactions that inevitably generate reactive oxygen species (ROS). It is now well established that ROS fluctuations near basal levels coordinate numerous physiological processes in living organisms, thus exhibiting regulatory functions. Hydrogen peroxide, the most long‐lived ROS, is a key contributor to ROS‐dependent signal transduction in the cell. H2O2 is known to impact various targets in the cell; therefore, the question of how H2O2 modulates physiological processes in a highly specific manner is central in redox biology. To resolve this question, novel genetic tools have recently been created for detecting H2O2 and emulating its generation in living organisms with unmatched spatiotemporal resolution. Here, we review H2O2‐sensitive genetically encoded fluorescent sensors and opto‐ and chemogenetic tools for controlled H2O2 generation. [ABSTRACT FROM AUTHOR]

Objectives: Although glutamate is an essential factor in the neuronal system, excess glutamate can produce excitotoxicity. We previously reported that Peroxiredoxin 5 (Prx5) protects neuronal cells from glutamate toxicity via its antioxidant effects. However, it is unclear whether cytosolic or mitochondrial Prx5 provides greater neuroprotection. Here, we investigated differences in the neuroprotective effects of cytosolic and mitochondrial Prx5. Methods: We analyzed patterns of cytosolic and mitochondrial H2O2 generation in glutamate toxicity using HyPer protein. And then, we confirmed the change of intracellular ROS level and apoptosis with respective methods. The mitochondrial dynamics was assessed with confocal microscope imaging and western blotting. Results: We found that the level of mitochondrial H2O2 greatly increased compared to cytosolic H2O2 and it affected cytosolic H2O2 generation after glutamate treatment. In addition, we confirmed that mitochondrial Prx5 provides more effective neuroprotection than cytosolic Prx5. Discussion: Overall, our study reveals the mechanisms of cytosolic and mitochondrial ROS in glutamate toxicity. Our findings suggest that mitochondrial ROS and Prx5 are attractive therapeutic targets and that controlling these factors be useful for the prevention of neurodegenerative diseases.

Application of genetically encoded biosensors of redox-active compounds promotes the elaboration of new methods for investigation of intracellular redox activities. Previously, we have developed a method to measure quantitatively the intracellular concentration of hydrogen peroxide (H2O2) in living cells using genetically encoded biosensor HyPer. In the present study, we refined the method and applied it for comparing the antioxidant system potency in human cells of different phenotypes by measuring the gradient between the extracellular and cytoplasmic H2O2 concentrations under conditions of H2O2-induced external oxidative stress. The measurements were performed using cancer cell lines (K-562 and HeLa), as well as normal human cells – all expressing HyPer in the cell cytoplasm. As normal cells, we used three isogenic lines of different phenotypes – mesenchymal stem/stromal cells (MSCs), induced pluripotent stem cells (iPSCs) derived from MSCs by reprogramming, and differentiated iPSC progenies with the phenotype resembling precursory MSCs. When exposing cells to exogenous H2O2, we showed that at low oxidative loads (50 μM of H2O2), which caused the exhaustion of thioredoxin activity in the cell cytoplasm, the gradient stabilized, pointing out that it is the functional status of the thioredoxin-depended enzymatic system that drives the dependence of the H2O2 gradient on the oxidative load in human cells. At high H2O2 concentrations, the cytoplasmic H2O2 level in cancer cells was found to be several hundred times lower than the extracellular one. At the same time, in normal cells, extracellular-to-intracellular gradient amounted to thousands of times. Upon reprogramming, the potency of cellular antioxidant defense increased. In contrast, differentiation of iPSCs did not result in the changes in antioxidant system activity in the cell cytoplasm, assuming that intensification of the H2O2-detoxification processes is inherent to a period of early human development.

Objectives: Although glutamate is an essential factor in the neuronal system, excess glutamate can produce excitotoxicity. We previously reported that Peroxiredoxin 5 (Prx5) protects neuronal cells from glutamate toxicity via its antioxidant effects. However, it is unclear whether cytosolic or mitochondrial Prx5 provides greater neuroprotection. Here, we investigated differences in the neuroprotective effects of cytosolic and mitochondrial Prx5. Methods: We analyzed patterns of cytosolic and mitochondrial H2O2 generation in glutamate toxicity using HyPer protein. And then, we confirmed the change of intracellular ROS level and apoptosis with respective methods. The mitochondrial dynamics was assessed with confocal microscope imaging and western blotting. Results: We found that the level of mitochondrial H2O2 greatly increased compared to cytosolic H2O2 and it affected cytosolic H2O2 generation after glutamate treatment. In addition, we confirmed that mitochondrial Prx5 provides more effective neuroprotection than cytosolic Prx5. Discussion: Overall, our study reveals the mechanisms of cytosolic and mitochondrial ROS in glutamate toxicity. Our findings suggest that mitochondrial ROS and Prx5 are attractive therapeutic targets and that controlling these factors be useful for the prevention of neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

The accumulation of senescent cells within the organism positively correlates with age and is considered as one of the risk factors for an age-dependent increase in the incidence of neoplastic diseases. The tumor-promoting role of senescent cells is associated with the paracrine effect of the secretory phenotype of senescent cells in the microenvironment. However, according to recent studies, neoplastic transformation may also be due to genomic instability in senescent cells resulting from accumulated DNA damage. The present studyaimed to unravel the intracellular molecular mechanisms that can mediatethe occurrence and accumulation of DNA damage during cellsenescence. Here we applied replicative and stress-induced senescence of human endometrial stromal cells (ESCs) as models of cell senescence. We revealed that both types of ESC senescence are characterized by the formation of persistent DNA damage foci. Using a genetically encoded HyPer biosensor we detected a decreased efficiency of antioxidant protection in senescent ESCs. At the same time, the level of endogenous reactive oxygen species (ROSs) significantly increased in senescent cells, which may mediate the formation of the DNA damage foci. Further accumulation of DNA damage foci can be mediated by a decrease in the efficiency of the repair systems in senescent ESCs, as evidenced by both transcriptomic analysis and the results reflecting the dynamics of DNA damage repair caused by oxidative stress or ionizing radiation. Thus, the accumulation of DNA damage in senescent ESCs is, on the one hand, mediated by the ineffective antioxidant protection and increasing ROS levels, and on the other hand, by a low efficiency of damage repair. [ABSTRACT FROM AUTHOR]

Background: Studies suggest that blood lactate differs between survivors and non-survivors of out-of-hospital cardiac arrest who are transported to hospital. The prognostic role of lactate taken during out-of-hospital cardiac arrest remains unexplored. Aims: To measure the association between lactate taken during out-of-hospital cardiac arrest, survival to hospital and 30-day mortality. Methods: This is a feasibility, single-centre, prospective cohort study. Eligible for inclusion are patients aged ≥18 years suffering out- of-hospital cardiac arrest, receiving cardiopulmonary resuscitation, in the catchment of Newcastle or Gateshead hospitals, who are attended to by a study-trained specialist paramedic. Exclusions are known/apparent pregnancy, blunt or penetrating injury as primary cause of out-of-hospital cardiac arrest and an absence of intravenous access. Between February 2020 and March 2021, 100 participants will be enrolled. Primary outcome is survival to hospital; secondary outcomes are return of spontaneous circulation at any time and 30-day mortality. [ABSTRACT FROM AUTHOR]

The phenomenon of migration and the experience of migrants is impossible to summarize even when we go into specifics. Diverse sociological, religious, and political approaches have produced a large volume of literature and research. This article is a modest attempt at partial understanding and maintains a limited scope. Research on language is to some extent rendered impossible, as it posits an understanding of language as a complete experience of communication. Hence, the term language is limited here to the definition of television language formulated by Neil Postman. We leave aside the language of media as a generic term for all the actual means of communication, which goes beyond the language of television. The term ‘migrant’ also does not include sociological, religious, political and anthropological interpretation but is limited to the fields of news and entertainment. Even the terms of news and entertainment are understood in the sense defined by art theorist Boris Groys and philosopher Gilles Lipovetsky. Hence the scope and purpose of the present article is not a comprehensive attempt at some sort of final interpretation of the reality of the migrant experience through a hermenautical approach. Rather, the article is a synthesis of views by three authors in a narrow context limited by the terms ‘the language of television’, ‘news’ and ‘entertainment’, so that discussion of the migrant phenomenon can be continued and developed into new and different views and interpretations [ABSTRACT FROM AUTHOR]

Copyright of Al-Mustansiriyah Journal of Science is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reactive oxygen species such as hydrogen peroxide have been implicated in causing metabolic dysfunction such as insulin resistance. Heme groups, either by themselves or when incorporated into proteins, have been shown to scavenge peroxide and demonstrate protective effects in various cell types. Thus, we hypothesized that a metalloporphyrin similar in structure to heme, Fe(III)tetrakis(4-benzoic acid)porphyrin (FeTBAP), would be a peroxidase mimetic that could defend cells against oxidative stress. After demonstrating that FeTBAP has peroxidase activity with reduced nicotinamide adenine dinucleotide phosphate (NADPH) and NADH as reducing substrates, we determined that FeTBAP partially rescued C2C12 myotubes from peroxide-induced insulin resistance as measured by phosphorylation of AKT (S473) and insulin receptor substrate 1 (IRS-1, Y612). Furthermore, we found that FeTBAP stimulates insulin signaling in myotubes and mouse soleus skeletal muscle to about the same level as insulin for phosphorylation of AKT, IRS-1, and glycogen synthase kinase 3β (S9). We found that FeTBAP lowers intracellular peroxide levels and protects against carbonyl formation in myotubes exposed to peroxide. Additionally, we found that FeTBAP stimulates glucose transport in myotubes and skeletal muscle to about the same level as insulin. We conclude that a peroxidase mimetic can blunt peroxide-induced insulin resistance and also stimulate insulin signaling and glucose transport, suggesting a possible role of peroxidase activity in regulation of insulin signaling. [ABSTRACT FROM AUTHOR]

Insulin-secreting pancreatic β-cells play a critical role in blood glucose homeostasis and the development of type 2 diabetes (T2D) in the context of insulin resistance. Based on data obtained at the whole cell level using poorly specific chemical probes, reactive oxygen species (ROS) such as superoxide and hydrogen peroxide have been proposed to contribute to the stimulation of insulin secretion by nutrients (positive role) and to the alterations of cell survival and secretory function in T2D (negative role). This raised the controversial hypothesis that any attempt to decrease β-cell oxidative stress and apoptosis in T2D would further impair insulin secretion. Over the last decade, the development of genetically-encoded redox probes that can be targeted to cellular compartments of interest and are specific of redox couples allowed the evaluation of short- and long-term effects of nutrients on β-cell redox changes at the subcellular level. The data indicated that the nutrient regulation of β-cell redox signaling and ROS toxicity is far more complex than previously thought and that the subcellular compartmentation of these processes cannot be neglected when evaluating the mechanisms of ROS production or the efficacy of antioxidant enzymes and antioxidant drugs under glucolipotoxic conditions and in T2D. In this review, we present what is currently known about the compartmentation of redox homeostatic systems and tools to investigate it. We then review data about the effects of nutrients on β-cell subcellular redox state under normal conditions and in the context of T2D and discuss challenges and opportunities in the field. Image 1 • New genetically-encoded redox probes allow the study of changes in cellular redox state in a compartment-specific manner. • Nutrient-induced changes in pancreatic β-cell redox state are highly compartmentalized. • The impact of acute glucose stimulation on cytosolic and mitochondrial redox probe oxidation remains controversial. • The cytosol, mitochondria, ER and peroxisomes could play a role in β-cell oxidative stress under nutrient toxic conditions. • Intravital microscopy may improve the study of subcellular oxidative stress in insulin resistance and type 2 diabetes. We are aware, and agree, that the term "oxidants" may be more adequate than "reactive oxygen species" (ROS) to collectively refer to hydrogen peroxide (H 2 O 2), superoxide (O 2 −), and other oxidants when the specific molecule involved is not known [1]. However, to avoid disturbing the reader from the β-cell field, and as both terms are equally vague, we chose to use "ROS" rather than "oxidants" throughout this review. [ABSTRACT FROM AUTHOR]

A multitude of cellular metabolic and regulatory processes rely on controlled thiol reduction and oxidation mechanisms. Due to our aerobic environment, research preferentially focuses on oxidation processes, leading to limited tools tailored for investigating cellular reduction. Here, we advocate for repurposing HyPer1, initially designed as a fluorescent probe for H 2 O 2 levels, as a tool to measure the reductive power in various cellular compartments. The response of HyPer1 depends on kinetics between thiol oxidation and reduction in its OxyR sensing domain. Here, we focused on the reduction half-reaction of HyPer1. We showed that HyPer1 primarily relies on Trx/TrxR-mediated reduction in the cytosol and nucleus, characterized by a second order rate constant of 5.8 × 10 2  M -1 s -1 . On the other hand, within the mitochondria, HyPer1 is predominantly reduced by glutathione (GSH). The GSH-mediated reduction rate constant is 1.8 M -1 s -1 . Using human leukemia K-562 cells after a brief oxidative exposure, we quantified the compartmentalized Trx/TrxR and GSH-dependent reductive activity using HyPer1. Notably, the recovery period for mitochondrial HyPer1 was twice as long compared to cytosolic and nuclear HyPer1. After exploring various human cells, we revealed a potent cytosolic Trx/TrxR pathway, particularly pronounced in cancer cell lines such as K-562 and HeLa. In conclusion, our study demonstrates that HyPer1 can be harnessed as a robust tool for assessing compartmentalized reduction activity in cells following oxidative stress., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The pandemic produced by COVID-19 has surprised almost all health and socio-economic systems worldwide with its high degree of infectivity and mortality. In short time we have learned many aspects of the epidemiology, pathophysiology and clinical aspects of the virus responsible, SARS-Cov-2, and the disease it induces. COVID-19 is known to produce in some patients the development of an excessive immune response and hyperinflammation, damaging various organs and sometimes causing death. There is no effective treatment available at the moment, other than life support, and for this reason different revealing therapeutic options are being tested but pending confirmation of their effectiveness and safety in well-designed clinical trials. We describe the anti-inflammatory and immunomodulatory effects of Acupuncture, as well as its preclinical and clinical effectiveness in different conditions that have some similarities to the severe forms of COVID-19. The proven biological plausibility of acupuncture, together with its acceptable level of clinical effectiveness and safety, make this medical technical procedure an option to try in this health emergency situation. We propose an adjusted classification of the clinical presentation of COVID-19 and an appropriate adjuvant Acupuncture protocol for each phase of the disease. [ABSTRACT FROM AUTHOR]

Cellular antioxidant systems control the levels of hydrogen peroxide (H2O2) within cells. Multiple theoretical models exist that predict the diffusion properties of H2O2 depending on the rate of H2O2 generation and amount and reaction rates of antioxidant machinery components. Despite these theoretical predictions, it has remained unknown how antioxidant systems shape intracellular H2O2 gradients. The relative role of thioredoxin (Trx) and glutathione systems in H2O2 pattern formation and maintenance is another disputed question. Here, we visualized cellular antioxidant activity and H2O2 gradients formation by exploiting chemogenetic approaches to generate compartmentalized intracellular H2O2 and using the H2O2 biosensor HyPer to analyze the resulting H2O2 distribution in specific subcellular compartments. Using human HeLa cells as a model system, we propose that the Trx system, but not the glutathione system, regulates intracellular H2O2 gradients. Antioxid. Redox Signal. 31, 664–670. [ABSTRACT FROM AUTHOR]

Abstract HyPer is a genetically encoded fluorogenic sensor for hydrogen peroxide which is generally used for the ratiometric imaging of H 2 O 2 fluxes in living cells. Here, we demonstrate the advantages of HyPer-based ratiometric flow cytometry assay for H 2 O 2 , by using K562 and human mesenchymal stem cell lines expressing HyPer. We show that flow cytometry analysis is suitable to detect HyPer response to submicromolar concentrations of extracellularly added H 2 O 2 that is much lower than concentrations addressed previously in the other HyPer-based assays (such as cell imaging or fluorimetry). Suggested technique is also much more sensitive to hydrogen peroxide than the widespread flow cytometry assay exploiting H 2 O 2 -reactive dye H 2 DCFDA and, contrary to the H 2 DCFDA-based assay, can be employed for the kinetic studies of H 2 O 2 utilization by cells, including measurements of the rate constants of H 2 O 2 removal. In addition, flow cytometry multi-parameter ratiometric measurements enable rapid and high-throughput detection of endogenously generated H 2 O 2 in different subpopulations of HyPer-expressing cells. To sum up, HyPer can be used in multi-parameter flow cytometry studies as a highly sensitive indicator of intracellular H 2 O 2. Graphical abstract fx1 Highlights • Ratiometric flow cytometry (FC) analysis is applicable for HyPer-based studies. • FC is suitable to detect submicromolar concentrations of extracellularly added H 2 O 2. • FC can be employed for the measurements of the rate constants of H 2 O 2 removal. • FC is suitable to detect changes in the level of endogenously generated H 2 O 2. • Multi-parameter FC analysis enables detection of H 2 O 2 in different cell populations. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Information Technology is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hydrogen peroxide (H2O2) plays an important role in various biological processes in numerous organisms. Depending on the concentration and the distribution within the cell, it can act as stressor or redox signalling molecule. To analyse the effects of H2O2 and its diffusion within the cell we developed the new genetically encoded photosensitizer KillerRed-SOD1 which enables a light-induced spatially and temporally controlled generation of H2O2 in living cells. The KillerRed-SOD1 is a fusion protein of the photosensitizer KillerRed (KR) and the cytosolic superoxide dismutase isoform 1 (SOD1) connected by a helix-forming peptide linker. Light irradiation at a wavelength of 560 nm induced superoxide radical formation at the KR domain which was transformed to H2O2 at the SOD1 domain. H2O2 was specifically detected under live cell conditions using the fluorescent sensor protein HyPer. Genetically encoded photosensitizers have the advantage that appropriate tag sequences can determine the localisation of the protein within the cell. Herein, it was exemplarily shown that the peroxisomal targeting sequence 1 directed the photosensitizer KR-SOD1 to the peroxisomes and enabled H2O2 formation specifically in these organelles. In summary, with the photosensitizer KR-SOD1 a new valuable tool was established which allows a controlled intracellular H2O2 generation for the analysis of H2O2 effects on a subcellular level. [ABSTRACT FROM AUTHOR]

Significance: Hydrogen peroxide (H2O2) is a key signaling molecule involved in the regulation of both physiological and pathological cellular processes. Genetically encoded HyPer probes are currently among the most effective approaches for monitoring H2O2 dynamics in various biological systems because they can be easily targeted to specific cells and organelles. Since its development in 2006, HyPer has proved to be a robust and powerful tool in redox biology research. Recent Advances: HyPer probes were used in a variety of models to study the role of H2O2 in various redox processes. HyPer has been increasingly used in the past few years for in vivo studies, which has already led to many important discoveries, for example, that H2O2 plays a key role in the regulation of signaling cascades involved in development and aging, inflammation, regeneration, photosynthetic signaling, and other biological processes. Critical Issues: In this review, we focus on the main achievements in the field of redox biology that have been obtained from in vivo experiments using HyPer probes. Future Directions: Further in vivo studies of the role of H2O2 largely depend on the development of more suitable versions of HyPer for in vivo models: those having brighter fluorescence and a more stable signal in response to physiological changes in pH. Antioxid. Redox Signal. 29, 569–584. [ABSTRACT FROM AUTHOR]

In recent years, genetically encoded fluorescent probes have allowed a dramatic advancement in time-lapse imaging, enabling this imaging modality to be used to investigate intracellular events in several apicomplexan parasite species. In this study, we constructed a plasmid vector to stably express a genetically encoded H 2 O 2 sensor probe called HyPer in Babesia bovis . The HyPer-transfected parasite population was successfully developed and subjected to a time-lapse imaging analysis under in vitro culture conditions. HyPer was capable of sensing an increasing H 2 O 2 concentration in the parasite cells which was induced by the administration of paraquat as a superoxide donor. HyPer fluorescence co-staining with MitoTracker Red indicated the mitochondria as the major source of reactive oxygen species (ROS) in parasite cells. The fluctuating ROS dynamics in the parasite gliding toward, attaching to, and invading the target red blood cell was visualized and monitored in real time with the HyPer expressing parasite population. This is the first report to describe the application of the HyPer probe in an imaging analysis involving Babesia parasites. Hyper-expressing parasites can be widely utilized in studies to investigate the mechanisms of emergence and the reduction of oxidative stress, as well as the signal transduction in the parasite cells during host invasion and intercellular development. [ABSTRACT FROM AUTHOR]

Emerging evidence indicates that some reactive oxygen species (ROS), such as the superoxide anion radical and hydrogen peroxide (H2O2), are central regulators of plant responses to biotic and abiotic stresses. Thus, the cellular levels of ROS are thought to be tightly regulated by an efficient and elaborate pro- and antioxidant system that modulates the production and scavenging of ROS. Until recently, studies of ROS in plant cells have been limited to biochemical assays and the use of fluorescent probes; however, the irreversible oxidation of these fluorescent probes makes it impossible to visualize dynamic changes in ROS levels. In this work, we describe the use of Hyper, a recently developed live cell probe for H2O2 measurements in living cells, to monitor oxidative stress in Arabidopsis roots subjected to aluminum treatment. Hyper consists of a circularly permuted YFP (cpYFP) inserted into the regulatory domain of the Escherichia coli hydrogen peroxide-binding protein (OxyR), and is a H2O2-specific ratiometric, and therefore quantitative, probe that can be expressed in plant and animal cells. Now we demonstrate that H2O2 levels drop sharply in the elongation zone of roots treated with aluminum. This response could contribute to root growth arrest and provides evidence that H2O2 is involved in early Al sensing.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with a very fast progression, no diagnostic tool for the presymptomatic phase, and still no effective treatment of the disease. Although ALS affects motor neurons, the overall pathophysiological condition points out to the non-cell autonomous mechanisms, where astrocytes and microglia play crucial roles in the disease progression. We have already shown that IgG from sera of ALS patients (ALS IgG) induce calcium transients and an increase in the mobility of acidic vesicles in cultured rat astrocytes. Having in mind the role of microglia in neurodegeneration, and a well-documented fact that oxidative stress is one of the many components contributing to the disease, we decided to examine the effect of ALS IgG on activation, oxidative stress and antioxidative system of BV-2 microglia, and to evaluate their acute effect on cytosolic peroxide, pH, and on reactive oxygen species (ROS) generation. All tested ALS IgGs (compared to control IgG) induced oxidative stress (rise in nitric oxide and the index of lipid peroxidation) followed by release of TNF-α and higher antioxidative defense (elevation of Mn- and CuZn-superoxide dismutase, catalase, and glutathione reductase with a decrease of glutathione peroxidase and glutathione) after 24 h treatment. Both ALS IgG and control IgG showed same localization on the membrane of BV-2 cells following 24 h treatment. Cytosolic peroxide and pH alteration were evaluated with fluorescent probes HyPer and SypHer, respectively, having in mind that HyPer also reacts to pH changes. Out of 11 tested IgGs from ALS patients, 4 induced slow exponential rise of HyPer signal, with maximal normalized fluorescence in the range 0.2–0.5, also inducing similar increase of SypHer intensity, but of a lower amplitude. None of the control IgGs induced changes with neither of the indicators. Acute ROS generation was detected in one out of three tested ALS samples with carboxy-H2DCFDA. The observed phenomena demonstrate the potential role of inflammatory humoral factors, IgGs, as potential triggers of the activation in microglia, known to occur in later stages of ALS. Therefore, revealing the ALS IgG signaling cascade in microglial cells could offer a valuable molecular biomarker and/or a potential therapeutic target.

Most of the biological impacts of Vitamin E, including the redox effects, have been raised from studies with α-tocopherol only, despite the fact that tocopherol-containing foods carry mixed tocopherol isomers. Here, we investigated the cellular mechanisms involved in the immediate antioxidant responses evoked by α-, γ- and δ-tocopherol in Caco-2 cells. In order to track the cytosolic redox impact, we performed imaging on cells expressing HyPer, a fluorescent redox biosensor, while cytosolic calcium fluctuations were monitored by means of Fura-2 dye and imaging. With this approach, we could observe fast cellular responses evoked by the addition of α-, γ- and δ-tocopherol at concentrations as low as 2.5 μM. Each isomer induced rapid and consistent increases in cytosolic calcium with fast kinetics, which were affected by chelation of extracellular Ca2+, suggesting that tocopherols promoted a calcium entry upon the contact with the plasma membrane. In terms of redox effects, δ-tocopherol was the only isomer that evoked a significant change in the HyPer signal at 5 μM. By mimicking Ca2+ entry with ionomycin and monensin, a decline in the HyPer signal was induced as well. Finally, by silencing calcium with 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA), an intracellular Ca2+ chelator, none of the isomers were able to induce redox changes. Altogether, our data indicate that an elevation in cytoplasmic Ca2+ is necessary for the development of a tocopherol-induced antioxidant impact on the cytoplasm of Caco-2 cells reported by HyPer biosensor.

Molecular level, mechanistic understanding of the roles of reactive oxygen species (ROS) in a variety of pathological conditions is hindered by the difficulties associated with determining the concentration of various ROS species. Here, we present an approach that converts fold-change in the signal from an intracellular sensor of hydrogen peroxide into changes in absolute concentration. The method uses extracellular additions of peroxide and an improved biochemical measurement of the gradient between extracellular and intracellular peroxide concentrations to calibrate the intracellular sensor. By measuring peroxiredoxin activity, we found that this gradient is 650-fold rather than the 7–10-fold that is widely cited. The resulting calibration is important for understanding the mass-action kinetics of complex networks of redox reactions, and it enables meaningful characterization and comparison of outputs from endogenous peroxide generating tools and therapeutics across studies.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with a very fast progression, no diagnostic tool for the presymptomatic phase, and still no effective treatment of the disease. Although ALS affects motor neurons, the overall pathophysiological condition points out to the non-cell autonomous mechanisms, where astrocytes and microglia play crucial roles in the disease progression. We have already shown that IgG from sera of ALS patients (ALS IgG) induce calcium transients and an increase in the mobility of acidic vesicles in cultured rat astrocytes. Having in mind the role of microglia in neurodegeneration, and a well-documented fact that oxidative stress is one of the many components contributing to the disease, we decided to examine the effect of ALS IgG on activation, oxidative stress and antioxidative system of BV-2 microglia, and to evaluate their acute effect on cytosolic peroxide, pH, and on reactive oxygen species (ROS) generation. All tested ALS IgGs (compared to control IgG) induced oxidative stress (rise in nitric oxide and the index of lipid peroxidation) followed by release of TNF-α and higher antioxidative defense (elevation of Mn- and CuZn-superoxide dismutase, catalase, and glutathione reductase with a decrease of glutathione peroxidase and glutathione) after 24 h treatment. Both ALS IgG and control IgG showed same localization on the membrane of BV-2 cells following 24 h treatment. Cytosolic peroxide and pH alteration were evaluated with fluorescent probes HyPer and SypHer, respectively, having in mind that HyPer also reacts to pH changes. Out of 11 tested IgGs from ALS patients, 4 induced slow exponential rise of HyPer signal, with maximal normalized fluorescence in the range 0.2-0.5, also inducing similar increase of SypHer intensity, but of a lower amplitude. None of the control IgGs induced changes with neither of the indicators. Acute ROS generation was detected in one out of three tested ALS samples with carboxy-H2DCFDA. The observed phenomena demonstrate the potential role of inflammatory humoral factors, IgGs, as potential triggers of the activation in microglia, known to occur in later stages of ALS. Therefore, revealing the ALS IgG signaling cascade in microglial cells could offer a valuable molecular biomarker and/or a potential therapeutic target. [ABSTRACT FROM AUTHOR]

In this work; the reinforcement of polyester resin material is conducted with two types, fiber reinforcement and powder reinforcement to produce an isotropic hyper composite materials composed of polyester resin, carbon powder and carbon or glass fibers with different volume fractions. Several tests were achieved to evaluate the mechanical and thermal properties of the manufactured specimens. The effect of adding powder on these properties and the influence of temperature on the modulus of elasticity are studied. The results showed that the modulus of elasticity, thermal conductivity and thermal effusively are increased with increasing volume fraction of carbon powder. It was observed that the hybridization improves the properties of composite materials at a specific volume fraction of carbon powder. The best mechanical and thermal properties for the materials reinforced with glass fibers was occurred in the specimen composed of 50% polyester, 30% glass fibers and 20% carbon powder, while for the material reinforced with carbon fibers it was occurred in the specimen composed of 60% polyester, 30% carbon fibers and 10% carbon powder. [ABSTRACT FROM AUTHOR]

Redox reactions play a key role in maintaining essential biological processes. Deviations in redox pathways result in the development of various pathologies at cellular and organismal levels. Until recently, studies on transformations in the intracellular redox state have been significantly hampered in living systems. The genetically encoded indicators, based on fluorescent proteins, have provided new opportunities in biomedical research. The existing indicators already enable monitoring of cellular redox parameters in different processes including embryogenesis, aging, inflammation, tissue regeneration, and pathogenesis of various diseases. In this review, we summarize information about all genetically encoded redox indicators developed to date. We provide the description of each indicator and discuss its advantages and limitations, as well as points that need to be considered when choosing an indicator for a particular experiment. One chapter is devoted to the important discoveries that have been made by using genetically encoded redox indicators. [ABSTRACT FROM AUTHOR]

Dysregulation of the production of pro-inflammatory mediators in microglia exacerbates the pathologic process of neurodegenerative disease. ROS actively affect microglia activation by regulating transcription factors that control the expression of pro-inflammatory genes. However, accurate information regarding the function of ROS in different subcellular organelles has not yet been established. Here, we analyzed the pattern of cytosolic and mitochondrial H 2 O 2 formation in LPS-activated BV-2 microglia using the H 2 O 2- sensitive protein HyPer targeted to specific subcellular compartments. Our results show that from an early time, cytosolic H 2 O 2 started increasing constantly, whereas mitochondrial H 2 O 2 rapidly increased later. In addition, we found that MAPK affected cytosolic H 2 O 2 , but not mitochondrial H 2 O 2 . Consequently, our study provides the basic information about subcellular H 2 O 2 generation in activated microglia, and a useful tool for investigating molecular targets that can modulate neuroinflammatory responses. [ABSTRACT FROM AUTHOR]

At low levels, reactive oxygen species (ROS) can act as signaling molecules within cells. When ROS production greatly exceeds the capacity of endogenous antioxidant systems, or antioxidant levels are reduced, ROS levels increase further. The latter is associated with induction of oxidative stress and associated signal transduction and characterized by ROS-induced changes in cellular redox homeostasis and/or damaging effects on biomolecules ( e . g . DNA, proteins and lipids). Given the complex mechanisms involved in ROS production and removal, in combination with the lack of reporter molecules that are truly specific for a particular type of ROS, quantification of (sub)cellular ROS levels is a challenging task. In this chapter we describe two strategies to measure ROS: one approach to assess general oxidant levels using the chemical reporter CM-H 2 DCFDA (5-(and-6)-chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate), and a second approach allowing more specific analysis of cytosolic hydrogen peroxide (H 2 O 2 ) levels using protein-based sensors (HyPer and SypHer). [ABSTRACT FROM AUTHOR]

Recent advances in genetically encoded fluorescent probes have dramatically increased the toolkit available for imaging the intracellular environment. Perhaps the biggest improvements have been made in sensing specific reactive oxygen species (ROS) and redox changes under physiological conditions. The new generation of probes may be targeted to a wide range of subcellular environments. By targeting such probes to compartments and organelle surfaces they may be exposed to environments, which support local signal transduction and regulation. The close apposition of the endoplasmic reticulum (ER) with mitochondria and other organelles forms such a local environment where Ca 2+ dynamics are greatly enhanced compared to the bulk cytosol. We describe here how newly developed genetically encoded redox indicators (GERIs) might be used to monitor ROS and probe their interaction with Ca 2+ at both global and local level. [ABSTRACT FROM AUTHOR]