Microstructure and cutting performance of V-C based coatings deposited by HIPIMS/UBM

The poisoning of different target materials under Direct Current Magnetron Sputtering (DCMS) and DCMS/ High Power Impulse Magnetron Sputtering (HIPIMS) discharges, using two reactive gases, were analysed. For both discharges, in mixed Ar+CH4+N2 atmosphere, low flow processes were influenced by methane; conversely, at high flow they were dominated by nitrogen. In DC discharges, vanadium targets were poisoned at 55% of reactive gas flow. Poisoning resulted in a 2-fold increase in total pressure and a 50 % increase in discharge voltage/current ratio. TiAl targets poisoned at lower reactive gas flows exhibited narrower hysteresis than V targets. For DCMS/HIPIMS discharges, both targets poisoned earlier and the hysteresis was narrower than in DC discharge. It is confirmed by trends in the partial pressure, the voltage/current ratio and ion fluxes of metals and reactive gasses. These effects are due to higher reactivity of the plasma; this is evidenced by higher fluxes of N+ and N2+ and radicals containing H, C and N. The voltage/current ratio reduced by 50% as the target is poisoned; this is a contrast to operation in DC mode where it increased. This could be attributed to efficient ionization and drop in plasma impedance. The effect of target poisoning using two reactive gases was utilised to deposit a series of TiAlCN/VCN coatings. As the target was more poisoned, the coating thickness decreases. The microstructure of coatings changed from glassy amorphous to a NaCl-type cubic crystalline phase with columnar structure. The column density decreases with increased flow. Coatings showed an increase in nitrogen and carbon content. Coatings with a high nitrogen and carbon content, show low adhesion to the base layer, and therefore poor wear resistance. Introducing a gas flow ramping between a VN base layer and the TiAlCN/VCN multilayer coating, as well as introducing a metallic layer, improves wear resistance of the coatings. The wear resistance was confirmed during cutting test on the P20 metal bar

Puffed cereals with added chamomile – quantitative analysis of polyphenols and optimization of their extraction method

Introduction Functional food plays an important role in the prevention, management and treatment of chronic diseases. One of the most interesting techniques of functional food production is extrusion-cooking. Functional foods may include such items as puffed cereals, breads and beverages that are fortified with vitamins, some nutraceuticals and herbs. Due to its pharmacological activity, chamomile flowers are the most popular components added to functional food. Objective. Quantitative analysis of polyphenolic antioxidants, as well as comparison of various methods for the extraction of phenolic compounds from corn puffed cereals, puffed cereals with an addition of chamomile (3, 5, 10 and 20%) and from Chamomillae anthodium. Material and Methods Two modern extraction methods – ultrasound assisted extraction (UAE) at 40oC and 60oC, as well as accelerated solvent extraction (ASE) at 100oC and 120oC were used for the isolation of polyphenols from functional food. Analysis of flavonoids and phenolic acids was carried out using reversed-phase high-performance liquid chromatography and electrospray ionization mass spectrometry (LC-ESI-MS/MS). Results and Conclusions For most of the analyzed compounds, the highest yields were obtained by ultrasound assisted extraction. The highest temperature during the ultrasonification process (60oC) increased the efficiency of extraction, without degradation of polyphenols. UAE easily arrives at extraction equilibrium and therefore permits shorter periods of time, reducing the energy input. Furthermore, UAE meets the requirements of ‘Green Chemistry

Traxoprodil, a selective antagonist of the NR2B subunit of the NMDA receptor, potentiates the antidepressant-like effects of certain antidepressant drugs in the forced swim test in mice

One of the newest substances, whose antidepressant activity was shown is traxoprodil, which is a selective antagonist of the NR2B subunit of the NMDA receptor. The main goal of the present study was to evaluate the effect of traxoprodil on animals’ behavior using the forced swim test (FST), as well as the effect of traxoprodil (10 mg/kg) on the activity of antidepressants, such as imipramine (15 mg/kg), fluoxetine (5 mg/kg), escitalopram (2 mg/kg) and reboxetine (2.5 mg/kg). Serotonergic lesion and experiment using the selective agonists of serotonin receptors 5-HT(1A) and 5-HT(2) was conducted to evaluate the role of the serotonergic system in the antidepressant action of traxoprodil. Brain concentrations of tested agents were determined using HPLC. The results showed that traxoprodil at a dose of 20 and 40 mg/kg exhibited antidepressant activity in the FST and it was not related to changes in animals’ locomotor activity. Co-administration of traxoprodil with imipramine, fluoxetine or escitalopram, each in subtherapeutic doses, significantly affected the animals’ behavior in the FST and, what is important, these changes were not due to the severity of locomotor activity. The observed effect of traxoprodil is only partially associated with serotonergic system and is independent of the effect on the 5-HT(1A) and 5-HT(2) serotonin receptors. The results of an attempt to assess the nature of the interaction between traxoprodil and the tested drugs show that in the case of joint administration of traxoprodil and fluoxetine, imipramine or escitalopram, there were interactions in the pharmacokinetic phase

Non-typical fluorescence effects and biological activity in selected 1,3,4-thiadiazole derivatives : spectroscopic and theoretical studies on substituent, molecular aggregation, and pH effects

The below article presents the results of spectroscopic research, theoretical (time-dependent density functional theory (TD-DFT)), microbiological, and antioxidative calculations for three compounds from the group of 1,3,4-thiadiazoles: 2-amino-5-phenyl-1,3,4-thiadiazole (TB), 2-amino-5-(2-hydroxyphenyl)-1,3,4-thiadiazole (TS), 2-amino-5-(2-hydroxy-5-sulfobenzoyl)-1,3,4-thiadiazole (TSF). In the fluorescence emission spectra (TS) of solutions with varying concentrations of hydrogen ions, a particularly interesting effect of dual fluorescence was observed. The aforementioned effect was observed even more clearly in the environment of butan-1-ol, relative to the compound’s concentration. Depending on the modification of the resorcylic substituent (TS and TSF), we observed the emergence of two separate, partially overlapping, fluorescence emission spectra or a single emission spectrum. Interpretation of the obtained spectra using stationary and time-resolved spectroscopy allowed the correlation of the effect’s emergence with the phenomenon of molecular aggregation (of a particular type) as well as, above all, the structure of the substituent system. The overlap of said effects most likely induces the processes related to the phenomenon of charge transfer (in TS) and is responsible for the observed fluorescence effects. Also, the position of the –OH group (in the resorcylic ring) is significant and can facilitate the charge transfer (CT). The determinations of the changes in the dipole moment and TD-DFT calculations further corroborate the above assumption. The following paper presents the analysis (the first for this particular group of analogues) of the fluorescence effects relative to the changes in the structure of the resorcylic group combined with pH effects. The results of biological studies also indicate the highest pharmacological potential of the analogue in the case where the effects of dual fluorescence emission are observed, which predisposes this particular group of fluorophores as effective fluorescence probes or potential pharmaceuticals with antimycotic properties

Antioxidant activity of lemongrass essential oil and its constituents

Plants and their ingredients (essential oil, flavonoids, etc.) are considered to be functional food if specific health benefits are attained by their consumption. These benefits include mostly preventive and protective but sometimes curative properties against one or more diseases, usually the so-called civilization diseases (different types of cancer, cardiovascular and neurodegenerative diseases) [1]. The essential oil (EO) obtained from Cymbopogon citratus (DC.) Stapf. (Poaceae) is a perfect functional food ingredient. Its characteristic, pleasant and refreshing odor goes hand in hand with its antiinflammatory, diuretic and sedative activities, due to which the plant was used in folk medicine for the treatment of nervous and gastrointestinal illnesses [2].                The aim of this work was an assessment of the antioxidant activity of lemongrass essential oil and its constituents. EO was hydrodistilled from the leaves and also the stems of C. citratus grown in Poland, while its chemical composition was analyzed by GC-MS. Both essential oils had a very similar chemical composition, with the exception of the presence of a sesquiterpene alcohol, elemol, in the stems oil, as well as a different antioxidant activity, which was higher for the EO obtained from the stems. The next stage of our research work was the isolation of the major components by the use of high-performance counter-current chromatography (HPCCC). The isolated compounds, neral, geranial, and elemol, as well as citronellol and citronellal, were subjected to antioxidant activity testing by TLC-bioautography using DPPH as the detection reagent, as well as by the CUPRAC method. However, the performed studies did not confirm the antioxidant activity of the major components alone present in the lemongrass essential oil. In total, neral, geranial, and elemol constituted 84.2% of all components present in the EO from C. citratus stems but they were not responsible for the observed antioxidant effect. It can be concluded that the antioxidant activity of lemongrass oil is the result of a synergistic effect of all ingredients present in this EO

ESIPT-related origin of dual fluorescence in the selected model 1,3,4-thiadiazole derivatives

In our previous work, we discussed the emergence of the dual fluorescence phenomenon in selected compounds from the group of 1,3,4-thiadiazoles. The results obtained in a number of experimental studies, supported by [TD]DFT calculations, clearly indicated that the phenomenon of dual fluorescence stemmed from an overlap of several factors, including the correct conformation of the analyzed molecule and, very significantly in this context, aggregation effects. Where those two conditions were met, we could observe the phenomenon of intermolecular charge transfer (CT) and the emergence of electronic states responsible for long wave emissions. However, in light of the new studies presented in this paper, we were able, for the first time, to provide a specific theory for the effect of dual fluorescence observed in the analyzed group of 1,3,4-thiadiazoles. We present the results of spectroscopic measurements conducted for two selected analogues from the 1,3,4-thiadiazole group, both in polar and non-polar solvents, which clearly evidence (as we have already suspected in the past, albeit have not shown in publications to date) the possibility of processes related to emission from the tautomer formed in the process of excited state intramolecular proton transfer, which is responsible for the long-wavelength emissions observed in the selected analogues. The presented results obtained with the use of UV-Vis, fluorescence (stationary and time-resolved), FTIR, and Raman spectroscopy, as well as from calculations of dipole moment changes between the ground and excited state with the use of two derivatives with different structures of the resorcylic system, corroborated our standing hypothesis. At the same time, they excluded the presence of ground state keto forms of the analyzed analogues unless necessitated by the structure of the molecule itself. In this case, aggregation factors enhance the observed effects related to the dual fluorescence of the analyzed compounds (by way of AIE—aggregated induced emissions)

Sclerostin as a biomarker of physical exercise in osteoporosis: A narrative review

Osteoporosis, a disease of low bone mass, is characterized by reduced bone mineral density (BMD) through abnormalities in the microarchitecture of bone tissue. It affects both the social and economic areas, therefore it has been considered a lifestyle disease for many years. Bone tissue is a dynamic structure exhibiting sensitivity to various stimuli, including mechanical ones, which are a regulator of tissue sclerostin levels. Sclerostin is a protein involved in bone remodeling, showing an anti-anabolic effect on bone density. Moderate to vigorous physical activity inhibits secretion of this protein and promotes increased bone mineral density. Appropriate exercise has been shown to have an osteogenic effect. The effectiveness of osteogenic training depends on the type, intensity, regularity and frequency of exercise and the number of body parts involved. The greatest osteogenic activity is demonstrated by exercises affecting bone with high ground reaction forces (GRF) and high forces exerted by contracting muscles (JFR). The purpose of this study was to review the literature for the effects of various forms of exercise on sclerostin secretion

Role of Gut Microbiota, Probiotics and Prebiotics in the Cardiovascular Diseases

In recent years, there has been a growing interest in identifying and applying new, naturally occurring molecules that promote health. Probiotics are defined as “live microorganisms which, when administered in adequate amounts, confer health benefits on the host”. Quite a few fermented products serve as the source of probiotic strains, with many factors influencing the effectiveness of probiotics, including interactions of probiotic bacteria with the host’s microbiome. Prebiotics contain no microorganisms, only substances which stimulate their growth. Prebiotics can be obtained from various sources, including breast milk, soybeans, and raw oats, however, the most popular prebiotics are the oligosaccharides contained in plants. Recent research increasingly claims that probiotics and prebiotics alleviate many disorders related to the immune system, cancer metastasis, type 2 diabetes, and obesity. However, little is known about the role of these supplements as important dietary components in preventing or treating cardiovascular disease. Still, some reports and clinical studies were conducted, offering new ways of treatment. Therefore, the aim of this review is to discuss the roles of gut microbiota, probiotics, and prebiotics interventions in the prevention and treatment of cardiovascular disease

Extraction Methods for the Isolation of Isoflavonoids from Plant Material

The purpose of this review is to describe and compare selected traditional and modern extraction methods employed in the isolation of isoflavonoids from plants. Conventional methods such as maceration, percolation, or Soxhlet extraction are still frequently used in phytochemical analysis. Despite their flexibility, traditional extraction techniques have significant drawbacks, including the need for a significant investment of time, energy, and starting material, and a requirement for large amounts of potentially toxic solvents. Moreover, these techniques are difficult to automate, produce considerable amount of waste and pose a risk of degradation of thermolabile compounds. Modern extraction methods, such as: ultrasound-assisted extraction, microwave-assisted extraction, accelerated solvent extraction, supercritical fluid extraction, and negative pressure cavitation extraction, can be regarded as remedies for the aforementioned problems. This manuscript discusses the use of the most relevant extraction techniques in the process of isolation of isoflavonoids, secondary metabolites that have been found to have a plethora of biological and pharmacological activities

The Impact of Processing Parameters on the Content of Phenolic Compounds in New Gluten-Free Precooked Buckwheat Pasta

Buckwheat is a generous source of phenolic compounds, vitamins and essential amino acids. This paper discusses the procedure of obtaining innovative gluten-free, precooked pastas from roasted buckwheat grains flour, a fertile source of natural antioxidants, among them, phenolic acids. The authors also determined the effect of the extruder screw speed and the level of moisture content in the raw material on the quantity of free phenolic acids. The qualitative and quantitative analysis of phenolic acids in pasta was carried out using high-performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The chromatographic method was validated. For extracts with the highest total content of free phenolic acids and unprocessed flour from roasted buckwheat grain, the TLC-DPPH test was also performed to determine the antioxidant properties of the tested pasta. The level of moisture in the raw material had an impact on the content of phenolic acids. All pastas made from buckwheat flour moistened up to 32% exhibited a higher total content of free phenolic acids than other mixes moistened to 30 and 34% of water