Reduced Form Research Articles

The accumulation of cadmium and lead in wheat grains is primarily determined by the soil-reducible cadmium level during wheat tillering

The significant increase in cadmium (Cd) and lead (Pb) pollution in agricultural soil has greatly heightened environmental contamination issues and the risk of human diseases. However, the mechanisms underlying the transformation of Cd and Pb in soil as well as the influencing factors during their accumulation in crop grains remain unclear. Based on the analysis of the distribution trend of Cd and Pb in soil during the growth and development stages of wheat (tillering, filling, and maturity) in alkaline heavy metal-polluted farmland in northern China, this study investigated the response mechanism of soil heavy metal form transformation to soil physicochemical properties, and elucidated the main determining periods and influencing factors for Cd and Pb enrichment in wheat grains. The results showed that an increase in CEC and SOM levels, along with a decrease in pH level, contributed to enhancing the bioavailability of Cd in the soil. This effect was particularly evident during the tillering stage and grain filling stage of wheat. Nevertheless, the effects of soil physicochemical properties on bioavailable Pb was opposite to that on bioavailable Cd. The enrichment of Cd and Pb in grain was significantly influenced by soil pH (r = −0.786, p < 0.01), SOM (r = 0.807, p < 0.01), K (r = −0.730, p < 0.01), AK (r = 0.474, p = 0.019), and AP (r = −0.487, p = 0.016). The reducible form of Cd in soil during the wheat tillering stage was identified as the primary factor contributing to the accumulation of Cd and Pb in wheat grains, with a significant contribution rate of 84.5%. This study provides a greater scientific evidence for the management and risk control of heavy metal pollution in alkaline farmland.

Biophysical features of using a recombination sensor to detect lactate dehydrogenase: sensitivity mechanisms analysis

Background. Most pathologies of the human body (in particular, malignant neoplasms, myocardial hypoxia, liver diseases, etc.) are accompanied by a violation of the integrity of cells in target tissues and the release of intracellular macromolecules into the extracellular environment. Thus, an important diagnostic and prognostic indicator is the level of activity of certain enzymes in blood serum, which are normally intracellular. One of the most promising areas of modern medical electronics and biophysics is the development and optimization of enzyme screening methods in biological fluids. In this study, we aimed to investigate the biophysical characteristics of using a recombination sensor for determining LDH activity in biological fluids. Materials and Methods. Experiments were performed on preparations of standard human blood serum. The reference determination of lactate dehydrogenase activity was carried out photometrically based on the change (decrease) in the concentration of the reduced form of the NADH coenzyme. The passage of the lactate dehydrogenase reaction was experimentally recorded by measuring the photocurrent of a silicon structure with a buried barrier under light irradiation from the region of strong absorption (λ = 532 nm). Results. The biophysical features of the device were studied. The detection of lactate dehydrogenase becomes possible due to the transfer of a hydrogen ion from nicotinamide adenine dinucleotide (NADH) to pyruvate, as a result of which lactate and NAD+ are formed. The effect is explained by the local electrostatic influence on the parameters of the recombination centers in the near-surface bending zone near the silicon surface, which leads to a change in the surface recombination rate. Conclusions. Our approach can be considered as a promising way to develop a highly sensitive method for the detection of lactate dehydrogenase. It has been experi­mentally shown that effective detection is possible in two changes at the surface ben­ding of the deep barrier silicon substrate zone.

Major generation route of cytotoxic protein adducts derived from acetaldehyde, a metabolite of alcohol

The habitual excessive consumption of alcohol has been implicated in the onset and/or progression of alcoholic-associated liver/brain diseases (ALD/ABD), lung disease, rheumatoid arthritis, and cardiac tissue injury. Alcohol (ethanol) is metabolized to acetaldehyde (AA), a two-carbon carbonyl compound that reacts with proteins to form covalent AA-protein adducts (AAPAs). We herein propose that AA reacts with liver and/or brain proteins to generate AAPAs, which contribute to alcohol-induced liver injury and neurotoxicity in vivo, respectively. The viability of hepatocytes was significantly lower in a culture treated with AAPAs than in a culture treated with Nε-(ethyl)lysine (NEL), the reduced form of Schiff bases, or a control culture. Furthermore, a correlation was observed between staining for AAPA and 4-hydroxy-2-nonenal in the liver and the severity of ALD in both rats and humans. The chronic consumption of alcohol produces AAPAs and reactive oxygen species, both of which have been implicated in the pathogenesis of ALD. Moreover, a dose-dependent increase in neuronal cell death was noted in cortical neurons incubated with AAPAs, the neurotoxicity of which was completely suppressed by an anti-AAPA antibody, but not an anti-NEL antibody. AAPA epitopes have been detected in the brains of individuals withalcohol-related brain damage. AAPAs have also been shown to contribute to the pathogenesis of ABD. The hypothesis proposed herein is that strongly cytotoxic AAPAs are iminobutane structures, which differ from the known structures of NEL. We suggest the importance of structural epitope AAPAs as toxic moieties for hepatocytes and neuronal cells in alcoholism.

Comparative Analysis of the Reduced form Model and the Structural Model in Credit Risk Modelling

Credit risk models are statistical tools to infer the future default probabilities and loss distribution of values of a portfolio of debts. Credit risk modelling is prevalent in today’s financial decision-making process. It turns out that both models of modelling credit risk contribute to explaining the default risk of listed firms, however, reduce-form model outperformances the structural model. Structural models are used to calculate the probability of default for a firm based on the value of assets and liabilities. The basic idea is that a company (with limited liability) defaults if the value of its assets is less than the debt of the company. The causal driver of defaults in structural model will choose to work with variables that help us explain what causes defaults. Default risk is endogenous in the structural model, this is so because the factors that causes defaults within a path are predictable. The structural model is an economic model with focus on options pricing, call option and put option. It provides clarity about the nature of defaults and how the various economic features that are chosen to relate with each other when defaults occur. The reduced form model is mostly concerned with prediction of when does defaults occurs? Default risk is exogenous to the reduced form model, can be caused by random events and most often comes as a surprise. Statistical models are used to observe the variables and help maximise the reduced form model. The empirical result suggests that reduce-form model can better predict the firm’s default risk.

Learning to predict: Second language perception of reduced multi-word sequences

The cognitive entrenchment of frequent sequences comes as ‘chunking’ (holistic storage) and as ‘procedure strengthening’ (predicting elements in a sequence). A growing body of research shows effects of entrenchment of multi-word sequences in the native language, which is learned and shaped continuously and intuitively. But how do they affect second language (L2) speakers, whose language acquisition is more analytic but who nonetheless also learn through usage? The present study tests advanced English learners’ receptive processing of multi-word sequences with a word-monitoring experiment. Recognition of to in the construction V to Vinf was tested for full and reduced forms ([tʊ] vs. [ɾə]), conditioned by the general frequency of the V- to sequence and the transitional probability (TP) of to given the verb (V &gt; to). The results are compared with those previously obtained from native speakers. Results show that recognition profits from surface frequency, but not from TP. Reduced forms delay recognition, but this is mitigated in high-frequency sequences. Unlike native speakers, advanced learners do not exhibit a chunking effect of high-frequency reduced forms, and no facilitating effect of TP. We attribute these findings to learners’ lesser experience with spontaneous speech and phonetic reduction. They recognize reduced forms less easily, show weaker entrenchment of holistic representations, and do not draw on the full range of probabilistic cues available to native speakers.

The Importance of Including Variable Exposure Concentrations When Assessing Toxicity of Sediment-Associated Pharmaceuticals to an Amphipod.

Pharmaceuticals have been classified as an environmental concern due to their increasing consumption globally and potential environmental impact. We examined the toxicity of sediment-associated diclofenac and citalopram administered as both single compounds and in a mixture to the sediment-living amphipod Corophium volutator. This laboratory-based study addressed the following research questions: (1) What is the toxicity of sediment-associated diclofenac and citalopram to C. volutator? (2) Can the mixture effect be described with either of the two mixture models: concentration addition (CA) or independent action (IA)? (3) What is the importance of the choice of (i) exposure measure (start concentration, time-weighted average [TWA], full exposure profile) and (ii) effect model (concentration-response vs. the toxicokinetic-toxicodynamic model general unified threshold model for survival in its reduced form [GUTS-RED]) for the derived effect concentration values? Diclofenac was more toxic than citalopram to C. volutator as a single compound (10-day exposure). Diclofenac exposure to C. volutator provided median lethal concentrations (LC50s) within the same range (11 µg g-1 dry wt sediment) using concentration-response based on TWA and both GUTS-RED models. However, concentration-response based on measured start concentrations provided an approximately 90% higher LC50 (21.6 ± 2.0 µg g-1 dry wt sediment). For citalopram, concentration-response parameters were similar regardless of model or concentration used (LC50 85-97 µg g-1 dry wt sediment), however, GUTS-RED with the assumption of individual tolerance resulted in a lower LC50 (64.9 [55.3-74.8] µg g-1 dry wt sediment). The mixture of diclofenac and citalopram followed the CA quite closely, whereas the result was synergistic when using the IA prediction. In summary, concentration-response based on TWA and GUTS-RED provided similar and reasonably good fits compared to the data set. The implications are that GUTS-RED will provide a more flexible model, which, in principle, can extend beyond the experimental period and make predictions based on variable exposure profiles (toxicity at different time frames and at different variable exposure scenarios) compared to concentration-response, which provides contaminant toxicity at one point in time. Environ Toxicol Chem 2024;43:1767-1777. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Synergistic Effect of Co and Ni Co-Existence on Catalytic Decomposition of Ammonia to Hydrogen—Effect of Catalytic Support and Mg-Al Oxide Matrix

Hydrotalcite-derived mixed metal oxides containing Co and Ni and containing these metals supported on MgO and Al2O3 were prepared and tested as catalysts for the decomposition of ammonia to hydrogen and nitrogen. The obtained samples were characterised in terms of chemical composition (ICP-OES), structure (XRD), textural parameters (low-temperature N2 adsorption–desorption, SEM), form and aggregation of transition-metal species (UV-Vis DRS), reducibility (H2-TPR) and surface acidity (NH3-TPD). The catalytic efficiency of the tested systems strongly depends on the support used. Generally, the alumina-based catalyst operated at lower temperatures compared to transition metals deposited on MgO. For both series of catalysts, a synergistic effect of the co-existence of cobalt and nickel on the catalytic efficiency was observed. The best catalytic results were obtained for hydrotalcite-derived catalysts; however, in the case of these catalysts, an increase in the Al/Mg ratio resulted in a further increase in catalytic activity in the decomposition of ammonia.

Metal-free adsorption and photodegradation methods for methylene blue dye removal using different reduction grades of graphene oxide

The release of organic pollutants and dyes into the environment by industries has had profound and harmful effects on both humans and ecosystems. Graphene oxide (GO) and its reduced form have been investigated for their effectiveness in removing pollutant dyes. GO nano-powder was synthesized using an improved version of Hummer's method and subsequently thermally reduced at various temperatures, including 125, 150, 175, and 200 °C, under vacuum conditions. In the X-ray diffraction spectra, an intense (001) diffraction peak was initially observed at 9.136° (2θ) for pristine GO. This peak gradually shifted towards higher angles as the reduction process took place and eventually disappeared when the GO was reduced at 200 °C. The intensity ratio of the D and G bands (ID/IG ratio) for GO nano-powder in the Raman spectra decreased from 0.94 to 0.76 due to the reduction process. The FTIR spectra of GO and reduced graphene oxide (rGO) also illustrated the reduction process. The bandgap of pristine GO significantly decreased from 2.31 to 0.73 eV, as determined by ultraviolet–visible (UV–Vis) diffuse reflectance spectrophotometry during the reduction process. The surface area and pore volume of both pristine GO and rGO-150 were determined using the BET (Brunauer-Emmett-Teller) and BJH (Barrett-Joyner-Halenda) methods. The results indicated an increase in the BET surface area from 6.61 to 7.86 m2/g and a corresponding enhancement in pore volume from 0.118 to 0.128 cc/g after reduction. The adsorption and photocatalytic degradation behavior of pristine GO and reduced graphene oxides (rGOs) were examined using methylene blue dye. The pristine GO demonstrated impressive adsorption capability, effectively removing the dye by 85.78 % within just 15 min and achieving nearly 97 % removal after 4 h. In contrast, the highest photocatalytic degradation of methylene blue, about 47.58 %, was attained for the rGO sample reduced at 150 °C under the illumination of visible light.

ПРЕДПОЛАГАЕМЫЙ МЕХАНИЗМ ВЛИЯНИЯ КРАТКОВРЕМЕННОЙ ГИПОКСИИ НА ОБОНЯТЕЛЬНУЮ ЧУВСТВИТЕЛЬНОСТЬ

The article is focused on the effect of short-term hypoxia on the olfactory sensitivity. The effect of short-term hypoxia on the olfactory sensitivity in human and rats were studied by determination thresholds for n-butanol. We have shown that reduced oxygen partial pressure leads to reduction of olfactory sensitivity. As known, odorant detection thresholds characterize the functional state of receptor cells. It can be assumed that the weakening of their sensitivity may be caused by a lack of energy supply to the olfactory perception process in hypoxia. To test this hypothesis, we stimulated rat olfactory sensory neurons with n-butanol in rotenone model. The reaction of cellular respiration of olfactory sensory neurons was evaluated by changing the intensity of intrinsic fluorescence of reduced pyridine nucleotides (NADH) according to the B. Chance method. Analysis of the results showed that under normoxia, stimulation of olfactory neurons by odorant caused an increase in the intensity of NADH fluorescence, which indicates the accumulation of the reduced form of pyridine nucleotides in mitochondria, and, consequently, the activation of cellular respiration due to exposure to odorant. In hypoxia caused by rotenone, an increase in the induced change of fluorescence of NADH was either not registered or the amplitude of the reaction was halved. This means that the recovery of NADH due to the odorant either did not occur at all, or this reaction to the smell was significantly lower than with normoxia, which indicates a weakening of cellular respiration during hypoxia. This is the reason for the decrease in ATP synthesis, which affects the efficiency of the olfactory transduction process and the sensitivity of olfactory sensory neurons. Therefore, based on our results, it can be concluded that the weakening of olfactory sensitivity in rats and humans with hypoxia may be due to a weakening of cellular respiration in olfactory sensory neurons.

Theoretical exploration of copper based electrolytes for third generation dye sensitized solar cells

Dye-sensitized solar cells (DSSCs) present a promising avenue for addressing the escalating need for clean energy solutions. These innovative cells offer a sustainable approach to meet the rising demands for environmentally friendly power sources. An assessment was conducted on a copper complex containing a hexadentate ligand, serving as a redox shuttle, alongside triphenylamine-based organic dyes in the construction of DSSC. This study thoroughly investigates the electronic structures, FMO, MEP surfaces, and photophysical properties of copper redox shuttle and triphenylamine dyes employing DFT and TDDFT calculations. The copper system, [Cu(bpyPY4)]2+/+, analyzed in this study, is anchored by the hexadentate polypyridyl ligand bpyPY4 (6,6′-bis(1,1-di(pyridine-2-yl)ethyl)-2,2′-bipyridine), scrutinized as a redox shuttle (RS). The assessed redox potential for [Cu(bpyPY4)]2+/+ is −4.67 eV. This indicates that the dye can effectively undergo regeneration by transferring electrons from the reduced form of the redox shuttle to the oxidized form of the dye. The photovoltaic efficiency has been analyzed with regard to various factors, including the energy gap between the HOMO and LUMO, the excited-state oxidation potential (Edye*), electron injection ability (∆Ginj), electron regeneration (∆Greg), light harvesting efficiency, short-circuit current density (JSC) and the open-circuit voltage (Voc). This study sheds light on present-day developments and forthcoming prospects in utilizing 3d transition metal-based redox shuttles, presenting them as compelling candidates for integration with organic dyes in Dye-Sensitized Solar Cells (DSSCs). This integration holds promise for more efficient solar spectrum absorption and enhanced performance of solar devices.

Credit default swap pricing with counterparty risk in a reduced form model with Hawkes process

Credit default swap pricing with counterparty risk in a reduced form model with Hawkes process

Effect of the mitochondrial membrane potential on the absorbance of the reduced form of cytochrome c oxidase

The effect of mitochondrial membrane potential (ΔΨm) on the absorbance of the reduced cytochrome c oxidase (COX) was evaluated in isolated rabbit heart mitochondria using integrating sphere optical spectroscopy. Maximal reduction of the mitochondrial cytochromes was achieved by either blowing nitrogen to remove oxygen, or by adding cyanide. Gradual depolarization of ΔΨm by adding increasing concentrations of uncoupler resulted in an increase of up to 50 % in the absorbance of cytochrome aa3 under nitrogen saturation, and of 25 % with cyanide. Cytochrome aa3 absorbance increases were also observed in the presence of cyanide with apyrase (20 %) or oligomycin (12 %). The bL heme absorbance also decreased as expected from ΔΨm depolarization. A ~ 1 nm red shift in the peak wavelength of cytochrome aa3 was observed under anoxic conditions as ΔΨm was depolarized. Importantly, cytochrome c and c1 absorbances remained constant at levels corresponding to full reduction under all experimental manipulations of ΔΨm, especially with cyanide. These data suggest that ΔΨm-dependent changes in the absorbance of reduced COX were due to a variable extinction coefficient of heme a and/or a3 as a function of ΔΨm. A similar increase in the reduced cytochrome aa3 absorbance without changes in cytochrome c and c1 was observed in the perfused rabbit heart when decreasing ΔΨm with uncoupler. Our results imply that COX absorbance in its fully reduced state does not simply reflect the oxygen tension but also the ΔΨm. This may prove useful in monitoring ΔΨm under anoxic or ischemic conditions in intact tissue.

Inhibition of QDPR synergistically modulates intracellular tetrahydrobiopterin profiles in cooperation with methotrexate

Tetrahydrobiopterin (BH4) is an essential cofactor for dopamine and serotonin synthesis in monoaminergic neurons, phenylalanine metabolism in hepatocytes, and nitric oxide synthesis in endothelial and immune cells. BH4 is consumed as a cofactor or is readily oxidized by autooxidation. Quinonoid dihydropteridine reductase (QDPR) is an enzyme that reduces quinonoid dihydrobiopterin (qBH2) back to BH4, and we have previously demonstrated the significance of QDPR in maintaining BH4 in vivo using Qdpr-KO mice. In addition to the levels of BH4 in the cells, the ratios of oxidized to reduced forms of BH4 are supposed to be important for regulating nitric oxide synthase (NOS) via the so-called uncoupling of NOS. However, previous studies were limited due to the absence of specific and high-affinity inhibitors against QDPR. Here, we performed a high-throughput screening for a QDPR inhibitor and identified Compound 9b with an IC50 of 0.72 μM. To understand the inhibition mechanism, we performed kinetic analyses and molecular dynamics simulations. Treatment with 9b combined with methotrexate (MTX), an inhibitor of another BH4-reducing enzyme, dihydrofolate reductase (DHFR), significantly oxidized intracellular redox states in HepG2, Jurkat, SH-SY5Y, and PC12D cells. Collectively, these findings suggest that 9b may enhance the anticancer and anti-autoimmune effects of MTX.

INTERACTION OF 7,7´-DIOXO-7H, 7´ H-3, 3´ -BENZIMIDAZO[2,1-a]BENZO[de]ISOQUINOLINE-4, 4´ -DICARBOXYLIC ACID WITH SODIUM DITHIONITE IN WATER-ALKALINE SOLUTION

Using the spectrophotometric method, the interaction of 7,7´-dioxo-7H, 7´ H-3, 3´ -benzimidazo[2,1-a]benzo[de]isoquinoline-4, 4´ -dicarboxylic acid with sodium dithionite in an aqueous-alkaline solution in aerobic and anaerobic conditions has been studied. It is found, that in the initial stage of process very rapidly formation of a tetraanion is observed due to the addition of two electrons. In the future, depending on the conditions of the reaction (aerobic, anaerobic atmosphere, small or large concentrations of the reducing agent), the tetraanion transition to the initial compound is observed due to its oxidation with air oxygen or sulfite anion formed from dithionite anions, as well as at sufficiently high concentrations of the reducing agent. A subsequent chemical stage of cyclization is possible with the cleavage of two carboxyl groups from the reduced form of the initial compound. It has also been established that the cyclization product is N,N'-di(benzimidazole)diimides of perilen-tetracarboxylic acid, which is isolated from a solution in a solid state. Its elemental composition is analyzed, IR- and electronic absorption spectra were obtained. The reversible nature of the initial stage of the interaction of 7, 7´-dioxo-7H, 7' H-3, 3´-benzimidazo[2,1-a]benzo[de]isoquinoline-4,4´-dicarboxylic acid with sodium dithionite is indicated by the fact that under aerobic conditions the concentration of the intermediate product present in the form of tetraanion decreases faster than the anaerobic atmosphere. The transition of the reduced form of the initial compound to the original, non-restored one is also observed during bubbling of air through the reaction mixture. It has been established by cyclic voltammetry that reversible reduction of the initial compound is also possible due to an electrochemical reaction occurring on a carbon-metal electrode in an aqueous-alkaline solution. The analysis of the voltage dependences showed that two electrons participate in the electrode reaction. For citation: Polenov Yu.V., Egorova E.V. Interaction of 7,7´-dioxo-7H, 7´ H-3, 3´ -benzimidazo[2,1-a]benzo[de]isoquinoline-4, 4´ -dicarboxylic acid with sodium dithionite in water-alkaline solution. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 6. P. 80-87. DOI: 10.6060/ivkkt.20246706.7056.

Supply Chain Inventory Optimization With Multiple Types of Customers and Equal Priorities: A Study Using Heuristic and Simulation Methods

In this study, the optimal inventory policies for a supply chain with multiple types of customers is investigated to minimize the total inventory cost. Each customer type has specific demand patterns in terms of ordering frequency and order quantity; moreover, there is no difference in priority among the customers. Due to the computational complexity of this optimization problem, we develop a reduced form of the original problem and propose a heuristic that is easily implementable by practitioners. In addition, a simulation model is developed on the same problem setting as a benchmark. To illustrate the implementation and the effectiveness of the proposed heuristic, a numerical example is studied, followed by a sensitivity analysis of the key parameters. The numerical results show that our heuristic provides a comparable performance as simulation-based optimization (a 2.6% difference), and the sensitivity analysis shows a reliable robustness of the model (less than 5.2% difference).

Synthesis of lignin-based carbon/graphene oxide foam and its application as sensors for ammonia gas detection

The present study highlights the integration of lignin with graphene oxide (GO) and its reduced form (rGO) as a significant advancement within the bio-based products industry. Lignin-phenol-formaldehyde (LPF) resin is used as a carbon source in polyurethane foams, with the addition of 1 %, 2 %, and 4 % of GO and rGO to produce carbon structures thus producing carbon foams (CFs). Two conversion routes are assessed: (i) direct addition with rGO solution, and (ii) GO reduction by heat treatment. Carbon foams are characterized by thermal, structural, and morphological analysis, alongside an assessment of their electrochemical behavior. The thermal decomposition of samples with GO is like those having rGO, indicating the effective removal of oxygen groups in GO by carbonization. The addition of GO and rGO significantly improved the electrochemical properties of CF, with the GO2% sensors displaying 39 % and 62 % larger electroactive area than control and rGO2% sensors, respectively. Furthermore, there is a significant electron transfer improvement in GO sensors, demonstrating a promising potential for ammonia detection. Detailed structural and performance analysis highlights the significant enhancement in electrochemical properties, paving the way for the development of advanced sensors for gas detection, particularly ammonia, with the prospective market demands for durable, simple, cost-effective, and efficient devices.

Macro-financial imbalances and cyclical systemic risk dynamics: understanding the factors driving the financial cycle in the presence of non-linearities

Abstract This paper develops a multivariate filter based on an unobserved component model to estimate the financial cycle. Our model features: (1) a dynamic relationship between the financial cycle and key variables; (2) time-varying shock volatility for trend and cycle components. We demonstrate that our approach not only exhibits superior early warning properties for banking crises but also outperforms commonly used indicators in terms of data fit for decomposition exercises, as evidenced by the higher marginal likelihood. We document three important properties of the financial cycle. First, the sensitivity of the financial cycle to changes in real estate valuations increased during the post-90s period. Second, the sensitivity of the cycle to changes in financial conditions displays volatility and country specificities. Finally, our reduced form estimates suggest that the banking crisis of 1988 was preceded by positive contributions from the risk appetite shock, while the primary source of vulnerabilities emanated from the housing market in the run-up to the Global Financial Crisis.

Perception of reduced forms in English by non-native users of English.

The article reports the results of a study on the perception of reduced forms by non-native users of English. It tests three hypotheses: (i) reduced forms with context are recognized more accurately and faster than reduced forms without context; (ii) gradient reduction is perceived less robustly than the categorical one; and (iii) subjects with musical background perceive reduced forms better than those without. An E-Prime study on 102 Polish learners of English was implemented, comparing participants' accuracy and reaction times with a control group of 14 native speakers. The study was corpus-based and used 287 reduced forms from a corpus of Lancashire. The results indicate that (i) lexical context and phone density significantly affect perception, (ii) the category of reduction process (gradient or categorical) is irrelevant, and (iii) musical background only partially impacts non-native perception.

Alpha-lipoic Acid: An Antioxidant with Anti-Aging Properties for Disease Therapy.

The anti-aging effects of alpha-lipoic acid (αLA), a natural antioxidant synthesized in human tissues, have attracted a growing interest in recent years. αLA is a short- -chain sulfur-containing fatty acid occurring in the mitochondria of all kinds of eukaryotic cells. Both the oxidized disulfide of αLA and its reduced form (dihydrolipoic acid, DHLA) exhibit prominent antioxidant function. The amount of αLA inside the human body gradually decreases with age resulting in various health disorders. Its lack can be compensated by supplying from external sources such as dietary supplements or medicinal dosage forms. The primary objectives of this study were the analysis of updated information on the latest two-decade research regarding the use of αLA from an anti-aging perspective. The information was collected from PubMed, Wiley Online Library, Scopus, ScienceDirect, SpringerLink, Google Scholar, and clinicaltrials.gov. Numerous in silico, in vitro, in vivo, and clinical studies revealed that αLA shows a protective role in biological systems by direct or indirect reactive oxygen/nitrogen species quenching. αLA demonstrated beneficial properties in the prevention and treatment of many age-related disorders such as neurodegeneration, metabolic disorders, different cancers, nephropathy, infertility, and skin senescence. Its preventive effects in case of Alzheimer's and Parkinson's diseases are of particular interest. Further mechanistic and clinical studies are highly recommended to evaluate the wide spectrum of αLA therapeutic potential that could optimize its dietary intake for prevention and alleviation disorders related to aging.

Rapid HPLC method reveals dynamic shifts in coenzyme Q redox state

Ubiquinol or coenzyme Q (CoQ) is a lipid-soluble electron carrier in the respiratory chain and an electron acceptor for various enzymes in metabolic pathways that intersect at this cofactor hub in the mitochondrial inner membrane. The reduced form of CoQ is an antioxidant, which protects against lipid peroxidation. In this study, we have optimized a UV-detected HPLC method for CoQ analysis from biological materials, which involves a rapid single-step extraction into n-propanol followed by direct sample injection onto a column. Using this method, we have measured the oxidized, reduced and total CoQ pools, and monitored shifts in the CoQ redox status in response to cell culture conditions and bioenergetic perturbations. We find that hypoxia or sulfide exposure induces a reductive shift in the intracellular CoQ pool. The effect of hypoxia is however, rapidly reversed by exposure to ambient air. Interventions at different loci in the electron transport chain can induce sizeable redox shifts in the oxidative or reductive direction, depending on whether they are up- or downstream of complex III. We have also used this method to confirm that CoQ levels are higher and more reduced in murine heart versus brain. In summary, the availability of a convenient HPLC-based method described herein, will facilitate studies on CoQ redox dynamics in response to environmental, nutritional and endogenous alterations.