Acidic Products Research Articles

Interaction between marine and terrestrial biogenic volatile organic compounds: Non-linear effect on secondary organic aerosol formation

Biogenic volatile organic compounds (BVOCs) are the largest source of secondary organic aerosols (SOA) globally. However, the complex interactions between marine and terrestrial BVOCs remain unclear, inhibiting our in-depth understanding of the SOA formation in the coastal areas and its environmental impacts. Here, we performed smog chamber experiments with mixed α-pinene (a typical monoterpene) and dimethyl sulfide (DMS, a typical marine emission BVOC) to investigate their possible interactions and subsequent SOA formation. It is found that DMS has a non-linear effect on SOA generation: The mass concentration and yield of SOA show increasing and then decreasing trends with the increase of the initial concentration of DMS. The increasing trend can be attributed to OH regeneration from isomerization of the CH3SCH2OO radical together with acid-catalyzed heterogeneous reactions by the oxidation of DMS, while the decreasing trend is explained by the less contribution of isomerization reaction and the high OH reactivity that inhibits the formation of low volatility products. The results from infrared spectra and mass spectra together reveal the contribution of sulfur-containing molecules in the mixed system. Moreover, the mass spectra results indicate that acidic products generated by DMS photooxidation enhance the O:C ratio, while organosulfates are produced to contribute to the formation of mixed SOA. In addition, the trends in relative abundance of highly oxygenated organic molecules (HOMs) with C8 - C10 multiple functional groups in different mixed systems agree well with the turning point of the SOA yield. The findings of this study have significant implications for understanding binary or more complex systems in the atmosphere in the coastal areas.

Little-Cost Potentiometric and Spectrophotometric Procedures for Cephalothin Assessment in Pure and Biological Fluids.

Low-cost potentiometric and spectrophotometric procedures for cephalothin (CPI) determination in pure and biological fluids were investigated. The potentiometric technique is created through titration of CPI with an aqueous medium of 0.1 M NaOH at an ionic strength of μ = 0.3 M sodium chloride and room temperature by a combined glass pH electrode. Using the standard addition method, we found that the detection and quantitative limits were 0.042 mg/mL, with the standard deviation SD = 0.011, correlation coefficient R = 0.9880 (n = 5), and linear concentration ranges from 0.042 to 0.82 mg/mL. This technique was utilized to assess CPI in pure solutions, urine, and serum with suitable results. No interference was exposed in the presence of public components of the samples under study. Recovery of CPI for pure and biological fluids is in the range of 98.2-101%. Also, the spectrophotometric method has been performed through the formation of the Prussian Blue (PB) complex. The reaction between the acidic hydrolysis product of CPI (T = 60 °C) and the mixture of Fe3+ with hexacyanoferrate (III) ions (HCF(III)) was detected for the spectrophotometric determination of the drug. The maximum absorbance of the formed complex was measured at λ = 283 nm with 2.0 × 103 L mol-1 cm-1 molar absorptivity. Reaction states have been advanced to acquire the PB complex of great sensitivity and longer stability. In optimal states, the absorbent of the PB compound was attained to grow linearly with the increase in the concentration of CPI, which agrees with the correlation coefficient values. The detection and quantitative limits were 0.000036 and 0.0012 mg/mL, respectively, with the standard deviation, SD = 0.0005, correlation coefficient, R = 0.9955 (n = 5), and the linearity range of the calibration plot 0.0005-0.02 mg/mL CPI. The planned technique was positively utilized for the detection of CPI in both urine and serum models. The results fit well with the data found from the potentiometric method.

Exploring the Potential of Kishk-like Novel Product in Solving the Acidic Whey Conundrum in the Dairy Industry

Acidic whey, unlike sweet whey, poses significant environmental challenges in the dairy industry. The Lebanese population consumes large quantities of labneh (strained yogurt) and white cheese, resulting in substantial acidic whey production, which presents disposal issues and pollution risks. Kishk, a fermented-milk cereal mixture, has a characteristic acidic taste. This study developed a Kishk-Like product using concentrated acidic whey as a substitute for fermented milk, addressing the disposal problem while enhancing dairy industry profitability. This study was conducted from April to June 2023. As consumer acceptance is the first step in food product development, a triangle sensory test was performed three times with 30 panelists each time, who attempted to differentiate between an established fermented cow’s milk kishk (CMK) and the new Kishk-Like product (KLP) made with three-fold concentrated acidic whey. In the three runs, 11, 9 and 13 out of 30 panelists were able to differentiate between the CMK and KLP samples, yielding p-values of 0.415, 0.713 and 0.166, respectively. These findings, coupled with the fact that approximately 12 kg of acidic whey is required to produce 1 kg of KLP, highlight its potential as a straightforward, economically viable solution for the acidic whey disposal dilemma, warranting further research into its development, characterization and standardization.

Preparation, structure, reactivity, Lewis acidic and fluorescence properties of arylpyridine based boron C,N-chelates featuring weakly coordinating anions.

Herein, we present the preparation of a series of electronically and/or sterically distinct borenium-type species based on a simple 2-arylpyridine scaffold. Corresponding arylpyridine was firstly subjected to electrophilic borylation (BBr3 / i-Pr2NEt) and formed BBr2 chelate was reduced with LiAlH4 to yield arylpyridine boron dihydride. Elimination of one hydride led to Lewis acidic borenium-like products. Four methods of hydride elimination were evaluated and influence of counterions on reactivity, Lewis acidic and luminescent properties was assessed both experimentally and computationally. Arylpyridine chelates featuring weakly coordinating counterions exhibit fluorescent properties upon UV irradiation. Several general trends were inferred to modulate emission wavelength and fluorescence quantum yield. Based on our observations, we have devised and prepared borenium-type fluorophores with yellow-green fluorescence and quantum yields up to 93%.

Fe2O3, Al2O3, or sludge ash-catalyzed pyrolysis of typical 3D printing waste toward tackling plastic pollution

Catalytic pyrolysis offers a potential solution to tackling plastic pollution by transforming plastic waste into valuable chemicals. This study explored the catalytic pyrolysis of 3D printing waste (3DPW), specifically focusing on photosensitive resin waste (PRW) and polycaprolactone waste (PCLW), with Al2O3, Fe2O3, or sludge ash (SA) containing Fe/Al. The study revealed a synergistic effect between the catalyst and 3DPW, influencing the pyrolysis properties and kinetic models. The addition of Fe2O3 significantly accelerated the main degradation stages, promoting the releases of 2-Ethylacrolein (64.78 % from PRW) and 2-Oxepanone (16.45 % from PCLW), as well as decreasing the acidic products. The catalytic pyrolysis changed the valence state of Fe, with some Fe(III) shifting to Fe(II), accompanied by the release of CO2. The addition of Al2O3 or SA generated new gaseous products (e.g., 2.93 % 1,3-Pentadiene, 2-methyl-, (E)-) through volatile reforming. The joint optimization of the multi-response artificial neural network revealed PCLW/Fe2O3 between 325–399 °C (D = 0.669) as the optimal operation for achieving both minimal remaining mass and maximum decomposition rate. These findings offer actionable insights into the catalytic pyrolysis of 3DPW, promoting its efficient treatment and clean reutilization.

The impact of preparing food in aluminum cookware on human health – a literature review

Introduction. Aluminum is an element commonly found in the environment. It is used in various industrial sectors, for example as a manufacturing material for food-grade utensils. Aim. The aim of this scientific paper is to answer to the question of whether people expose their health to the harmful effects of aluminum by utilising these types of items for preparing and storing food. Description of the state of knowledge. Aluminum has a proven noxious impact on the human body. Due to its neurotoxic properties, it may induce clinical symptoms. Excessive exposure to this element is also associated with the occurrence of bladder and lung cancer, while the connection with breast tumours remains debatable. Additionally, aluminum can be harmful to our health, as a component of some medical preparations. Conclusions. It is crucial to emphasise the necessity of complying with the amounts of aluminum consumption recommended by international institutions. Short-term use of aluminum pots does not pose a threat to our well-being. Also, long-term usage in most cases does not lead to exceeding the aluminum consumption standards, although children may be at risk. However, it is good practice to avoid cooking acidic products in aluminum utensils. Furthermore, it is worth washing the dishes according to the manufacturers’ recommendations and replacing them with new ones every few years. In addition, some scientists suggest choosing pots made of different materials, e.g. titanium. Moreover, a noticeable decrease in the levels of vitamin B1 and C in food prepared in aluminum dishes may be one of the reasons for their lower nutritional value, however this issue should be examined further. Keywords: aluminum; cooking and eating utensils; food safety; neurotoxicity.

Synergistic antimicrobial action of chlorogenic acid and ultraviolet-A (365 nm) irradiation; mechanisms and effects on DNA integrity

Chlorogenic acid (CGA) is abundant in various plants and notably in coffee beans. This study investigated the bactericidal activity of CGA combined with ultraviolet-A light (UVA, 365 nm) (CGA + UVA) against Escherichia coli DH5α, with the aim of developing novel strategies for food preservation and healthcare. CGA + UVA treatment was superiorin reducing bacterial survival than either treatment alone. At 20 J/cm2 and pH 7, CGA (0.3%) + UVA treatment resulted in only about a 3-log reduction in bacterial survival, whereas at 15 J/cm2 and pH 3, no surviving bacteria could be detected, demostrating that the treatment was more effective at acidic pH. CGA + UVA treatment was also bactericidal in green plum juice, confirming that its low pH-dependent property could be effective in acidic food products. To elucidate the bactericidal mechanism of CGA + UVA treatment, its effects on reactive oxygen species (ROS) generation, membrane integrity, and enzyme activity were measured. ROS generated via the type-1 reaction, such as hydrogen peroxide (H2O2) and hydroxyl radicals (·OH), were mainly detected. CGA + UVA disrupted the bacterial cell membrane, causing the leakage of cellular components, particularly proteins. CGA + UVA treatment also led to deoxyribonucleic acid (DNA) degradation and reduced succinate-coenzyme Q reductase activity by approximately 72 %. Furthermore, CGA + UVA treatment decreased β-lactamase activity and plasmid transforming efficacy with maximal reductions of 68 % and 98 %, respectively, highlighting its potential for increasing antibiotic susceptibility and preventing the spread of antimicrobial resistance. The results demonstrate that CGA + UVA treatment could be used to effectively combat antibiotic-resistant bacteria and prevent the spoilage of preserved foods or food poisoning.

Degradation of the AMP/PZ-based solvent CESAR1 and effects of solvent management in two longtime pilot plant tests

Two 24/7 longtime testing campaigns at the CO2 capture pilot plant at Niederaussem with an accumulated testing time of more than 40,000 h with the CESAR1 solvent, an aqueous solution of 26.7 wt% 2-amino-2-methylpropan-1-ol (AMP) and 12.9 wt% piperazine (PZ), provide a unique data base for the development of solvent management technologies and the evaluation of hypotheses on amine degradation. In the first campaign with a testing time of 34,000 h without replacement of the solvent inventory, three solvent management strategies with different effect mechanisms were investigated: adsorptive removal of trace elements from the solvent by two kinds of active carbon, removal of ionic contaminants by ion exchange using cation and anion exchange resins, and removal of NO2 from the flue gas by treatment with a thiosulfate/sulfite solution. After replacement of the solvent inventory the second campaign was conducted, in which none of the solvent management technologies mentioned have been applied for 10,000 h. The results of the two campaigns allow a direct comparison of the solvent degradation behavior. It is shown that active carbon does not significantly affect the accumulation rate of degradation products in CESAR1, and that an inappropriate kind of active carbon can cause foaming. Anionic degradation products, metal complexes, trace components and cationic contaminants can be effectively removed from the aged solvent by ion exchange. However, after their removal, accelerated formation of oxidative degradation products by a factor of up to 3 higher than before the anion exchange was observed. Removal of NO2 from the flue gas did not affect the NH3 emissions from the CO2 absorber, but it led to the highest observed increase rate of the accumulation of acidic degradation products for aged CESAR1. The results show that exaggerated efforts for solvent management are contra-productive and that a reassessment of the effect mechanisms of solvent management technologies is necessary.

A growth-based screening strategy for engineering the catalytic activity of an oxygen-sensitive formate dehydrogenase.

Enzyme engineering is a powerful tool for improving or altering the properties of biocatalysts for industrial, research, and therapeutic applications. Fast and accurate screening of variant libraries is often the bottleneck of enzyme engineering and may be overcome by growth-based screening strategies with simple processes to enable high throughput. The currently available growth-based screening strategies have been widely employed for enzymes but not yet for catalytically potent and oxygen-sensitive metalloenzymes. Here, we present a screening system that couples the activity of an oxygen-sensitive formate dehydrogenase to the growth of Escherichia coli. This system relies on the complementation of the E. coli formate hydrogenlyase (FHL) complex by Mo-dependent formate dehydrogenase H (EcFDH-H). Using an EcFDH-H-deficient strain, we demonstrate that growth inhibition by acidic glucose fermentation products can be alleviated by FHL complementation. This allows the identification of catalytically active EcFDH-H variants at a readily measurable cell density readout, reduced handling efforts, and a low risk of oxygen contamination. Furthermore, a good correlation between cell density and formate oxidation activity was established using EcFDH-H variants with variable catalytic activities. As proof of concept, the growth assay was employed to screen a library of 1,032 EcFDH-H variants and reduced the library size to 96 clones. During the subsequent colorimetric screening of these clones, the variant A12G exhibiting an 82.4% enhanced formate oxidation rate was identified. Since many metal-dependent formate dehydrogenases and hydrogenases form functional complexes resembling E. coli FHL, the demonstrated growth-based screening strategy may be adapted to components of such electron-transferring complexes.IMPORTANCEOxygen-sensitive metalloenzymes are highly potent catalysts that allow the reduction of chemically inert substrates such as CO2 and N2 at ambient pressure and temperature and have, therefore, been considered for the sustainable production of biofuels and commodity chemicals such as ammonia, formic acid, and glycine. A proven method to optimize natural enzymes for such applications is enzyme engineering using high-throughput variant library screening. However, most screening methods are incompatible with the oxygen sensitivity of these metalloenzymes and thereby limit their relevance for the development of biosynthetic production processes. A microtiter plate-based assay was developed for the screening of metal-dependent formate dehydrogenase that links the activity of the tested enzyme variant to the growth of the anaerobically grown host cell. The presented work extends the application range of growth-based screening to metalloenzymes and is thereby expected to advance their adoption to biosynthesis applications.

Sorption decontamination of aqueous and organic media from TBP and acidic products of its decomposition

The processes of sorption decontaminationof aqueous solutions from TBP on the polymeric sorbent Polysorb-1,as well as of a 70% solution of TBP indodecane from butylphosphoric acids using layered double oxides and Mg-Alhydroxides were studied. It has been established that the useof the polymeric sorbent Polysorb-1 makes it possible to decontaminateaqueous solutions from TBP in static and dynamic modes, andthe use of the LDH-Mg-Al-CD-OH sorbent allows the decontamination ofTBP solutions in dodecane from acid products of decomposition andhydrolysis of TBP.

Structural characterization and immune activity evaluation of a polysaccharide from Lyophyllum Decastes

An innovative acidic hydrolysate fingerprinting workflow was proposed for the characterization of Lyophyllum Decastes polysaccharide (LDP) by ultra performance liquid chromatography-mass spectrometry (UPLC-MS). The crude polysaccharides were firstly separated and purified by using DE-52 column and the BRT GPC purification system, respectively. The molecular weight and monosaccharide content of homogeneous polysaccharides were ascertained by utilizing HPGPC and ion chromatography separately. Secondly, the linkage of LDP was identified by methylation analysis and 1D/2D NMR spectra. The UPLC-MS/MS was used to scan and identify the acidic hydrolysate products of LDP using the PGC column. The oligosaccharides were collected by chromatography and identified by mass spectrometry. Thirdly, the expression of IL-1β, IL-6, iNOS, TNF-α and IFNAR-I was measured in order to assess the immunological activity of LDP. Besides, the targeted receptors identification of polysaccharides was performed by screening the expression of TLRs family protein. The results showed that oligosaccharide fragments with different molecular weights can be obtained by partial hydrolysis, which further verified that the structures of LDP polysaccharides was a 1–6-linked β-glucan. Moreover, the LDP polysaccharide can up-regulate the content of IL-1β, IL-6, iNOS, TNF-α and IFNAR-I and plays an important immunoregulation role through TLRs family.

Insect-based products commercialized online: a snapshot of lipid oxidation and mineral content

This research aims to monitor the conservation status of the lipid and mineral contents of four shelf-stable insect-based products (yellow mealworm, house cricket, mole cricket, and silkworm) marketed online. A total of 32 single-species packs were purchased from various online commercial suppliers. Moisture, lipids, fatty acids, titratable acidity, mineral elements, and primary and secondary lipid oxidation products were determined. Statistical multivariate approaches were applied to investigate the contribution of each chemical variable to the characterization of edible insects. Titratable acidity (up to 37.3 g oleic acid per 100 g of crickets), as well as primary and secondary lipid oxidation products, showed great variability within and between species. The study revealed a significant occurrence of rancidity (45.5% of the samples exceeded the peroxide limit of 10 mEqO2/kg; 100% of the samples exceeded the indication of 1 mg/kg malondialdehyde), whereas the heavy metal content indicated a relatively safe condition, suggesting the absence of potential risks to human health. Both the chemical and the elemental properties could be regarded as potential characteristics suitable for authenticating this food matrix. This study contributes to the description of several chemical features in commercialized processed insect-based products, aiming to highlight possible safety concerns and identify those unfit for human consumption.

Metabolomic and biochemical disorders reveal the toxicity of environmental microplastics and benzo[a]pyrene in the marine polychaete Hediste diversicolor

Recently, the abundance of environmental microplastics (MPs) has become a global paramount concern. Besides the danger of MPs for biota due to their tiny size, these minute particles may act as vectors of other pollutants. This study focused on evaluating the toxicity of environmentally relevant concentrations of MPs (10 and 50 mg/kg sediment) and benzo[a]pyrene (B[a]P, 1 µg/kg sediment), alone and in mixture, for 3 and 7 days in marine polychaete Hediste diversicolor, selected as a benthic bioindicator model. The exposure period was sufficient to confirm the bioaccumulation of both contaminants in seaworms, as well as the potential capacity of plastic particles to adsorb and vehiculate the B[a]P. Interestingly, increase of acidic mucus production was observed in seaworm tissues, indicative of a defense response. The activation of oxidative system pathways was demonstrated as a strategy to prevent lipid peroxidation. Furthermore, the comprehensive Nuclear Magnetic Resonance (NMR)-based metabolomics revealed significant disorders in amino acids metabolism, osmoregulatory process, energetic components, and oxidative stress related elements. Overall, these findings proved the possible synergic harmful effect of MPs and B[a]P even in small concentrations, which increases the concern about their long-term presence in marine ecosystems, and consequently their transfer and repercussions on marine fauna.

Modulation of the intestinal mucosal and cell-mediated response against natural helminth infection in the African catfish Clarias gariepinus

Fish gut is a versatile organ serving as the primary pathway for invasion by pathogens, particularly parasites, playing a crucial role in modulating the intestinal adaptive immune response. This study aimed to investigate the cellular-mediated reaction, mucosal acidity, and the expression of proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and CD68 in the intestines of catfish, Clarias gariepinus, naturally infected with helminths. Forty catfish were collected from the Nile River and examined for intestinal parasites. The intestinal tissues of the control and infected fish were fixed for histochemical and immunohistochemical studies. Two groups of helminths were found: cestodes Tetracampos ciliotheca and Polyonchobothrium clarias, and nematodes Paracamallanus cyathopharynx, with a prevalence rate of 63.63%, 18.0%, and 18.0%, respectively. Our results showed that the infected fish had a statistically significant rise in the activity of immune cells, including mast cells, eosinophil granular cells, and dendritic cells. This correlated with upregulation in the expressions of PCNA, VEGF, and CD68. Histochemical analyses demonstrated a marked increase in acidic mucus production, Sudan black B, and bromophenol mercury blue. This study enriches our understanding of the evolution of vertebrate immunity in combating intestinal parasitic infections and the host’s adaptive responses.

Sustainable Development of an Innovative Spreadable Plant-Based Product of High Added Value through the Valorization of an Agro-Food By-Product

There is an increased demand for healthy foods by the consumer nowadays, while at the same time, circular bio-economy and sustainability in food production represent top priority issues for the food industry. In this context, purslane, a highly nutritious annual plant that grows abundant during the hottest months of the year but is considered a by-product of the agricultural process, was utilized for the development of an innovative, ready-to-eat food product suitable for a vegetarian diet in the form of a bread spread. Following an initial small-scale experimentation for the stabilization of apparent quality attributes, the product’s recipe was finalized on an industrial scale, and the hazard analysis and critical control point (HACCP) for the manufacturing process, the physicochemical (pH, water activity) and sensorial analysis of the end product, together with its nutritional value, shelf-life, and antioxidant capacity, were determined. The results suggested that the acidic (pH 4.3) product had a shelf-life of a minimum of six months to one year and, according to EU legislation, it comprised a source of (dietary) fibers and protein, while being high in poly-unsaturated (e.g., omega-3, omega-6), and mono-unsaturated (e.g., oleic acid) fatty acids. Total phenolic content (TPC) with the Folin–Ciocalteau assay and total antioxidant capacity (TAC) using the Ferric-Reducing Antioxidant Power assay of the product, presented concentrations of 0.95 mg of gallic acid equivalent/g and 0.016 mmol of Fe2+/g of dry weight of sample, respectively. However, the predicted bioavailability for TPC and TAC was 28% and 31%, respectively. The product was evaluated positively by a panel of potential consumers without significant differences compared to conventional familiar products. The potential of using agro-food chain by-products, such as purslane, for the development of novel foods representing a healthy and tasty food choice at any time of the day is a promising opportunity for the food industry to meet growing consumer demands for more sustainable, nutritious, and healthy food products with a reduced environmental footprint compared to the traditional plant-originated products of intensive agriculture.

Influence of carbonate-inducing bacteria on desulfurization effect of medium and high sulfur coal gangue under spraying and preparation of desulfurized coal gangue mortar

Medium and high sulfur coal gangue (MHSCG) presents challenges for safe application on civil engineering building materials due to the high content of unstable pyrite, of which the acidic oxidation products are against alkali cementitious materials. For better utilization of MHSCG, in this research, the carbonate-inducing bacterium Sporosarcina Pasteurii with its nutrient (urea) and mineralization source (calcium) was firstly explored in MHSCG desulfurization leaching tests, revealing the mechanism of desulfurization. On this basis, the desulfurizing modification on MHSCG sand by the bacteria under different factors of OD600, urea and calcium was conducted. Moreover, the gangue sand was used to prepare the desulfurized coal gangue mortar (DCGM) and the relevant mechanical properties and influence mechanisms were discussed. The results of total sulfur and XRD analysis show that Sporosarcina Pasteurii can accelerate the desulfurization in the 7-days-spraying modification. When the optimum dosages of OD600 (0.84) and urea solution concentration (1.41 mol/L) are adopted, the total sulfur can be reduced by 33.66∼36.32 %. The total sulfur has been further reduced by 7.69 % compared with group without calcium as calcium concentration is 1.56 mol/L. The introduction of calcium can enhance the mechanical properties of MHSCG and DCGM although the desulfurization treatment has a negative impact on them. The crushing index of MHSCG sand at most decreases 10.44 % from it without calcium. When OD600 is about 0.90, urea concentration is about 1.50 mol/L and calcium concentration is about 1.49 mol/L, the 28-d compressive strength of DCGM increases to 32.01 MPa, 76.85 % higher than group without calcium, and 23.54 % higher than raw-material preparing mortar.

Elaboration and Characterization of Novel Kombucha Drinks Based on Truffles (Tuber melanosporum and Tuber aestivum) with Interesting Aromatic and Compositional Profiles.

The organoleptic and bioactive properties of truffles place these fungi as interesting materials for use in the of design functional foods based on fruiting bodies outside commercial standards. Moreover, kombucha beverages have become more popular in the Western world, leading to novel drinks using alternative substrates instead of tea leaves. In this work, two truffle species (Tuber melanosporum, TMEL; Tuber aestivum, TAES) and three different symbiotic consortia of bacteria and yeasts (SCOBYs: SC1, SC2, and SC3) were tested. Fermentation (21 days) was monitored in terms of physicochemical (pH, viscosity), biochemical (total carbohydrates, alcohol, soluble proteins, phenolic compounds), and sensory attributes (volatile organic compounds, VOCs). The obtained pH ranges were adequate, alcohol levels were undetectable or very low, and sugar content was lower than in traditional kombuchas or other beverages. In most cases, the usual bottling time could be applied (7-10 days), although longer fermentations are recommended (14 days) to reach higher protein and phenolic compounds contents. Truffle kombuchas produced up to 51 volatile organic compounds (alcohols, acids, esters, ketones, and aldehydes, among others), with TMEL showing a more complex profile than TAES. During the first week, acidic compound production was observed, especially acetic acid. Similar behavior in the VOC profile was reported with different SCOBYs.

An eco-friendly first and second derivative synchronous spectrofluorimetry for quantification of florfenicol in presence of its different degradation products. Application to kinetic stability study.

Two rapid, simple, sensitive and selective derivative spectrofluorimetric methods (first and second derivative synchronous spectrofluorimetric (FDSFS and SDSFS) procedures) have been developed for the analysis of florfenicol in the presence of its various degradation products. FDSFS was applied to assay the drug in the presence of its alkaline, oxidative and photolytic degradation products while SDSFS was used to quantify it in the presence of its acidic degradation product. These methods permitted quantification of florfenicol at corresponding λ Em of 288, 287, 279 and 284 nm without interferences from any of its degradation products. Full validation procedures were applied to the suggested method according to International Conference of Harmonization guidelines. Moreover, different degradation kinetic parameters were calculated such as half-life (t 1/2), degradation rate constant (K) and activation energy (E a). Using the analytical eco-scale, green analytical procedure index and analytical greenness metric approach AGREE as greenness assessment tools, the proposed method was found to be environmentally friendly.

The effect of di-iso-amyl phosphate on the uranium extraction behavior and mechanisms of tri-iso-amyl phosphate: A new insight via experimental and theoretical approaches

Exploring the extraction behavior and mechanism of extractants in the presence of the radiolysis products was helpful to the design and subsequent utilization of those potential spent fuel extractants. In this work, Di-iso-amyl phosphate (HDiAP), a major acidic radiolysis product of Tri-iso-amyl phosphate (TiAP), was employed to study its effects on uranium (U(VI)) extraction behavior and mechanisms of 36 % TiAP/n-Dodecane (36 % TiAP/nDD) system by using extraction experiments, density functional theory calculations (DFT) and molecular dynamic simulations (MD). The results demonstrated that the presence of HDiAP improved U(VI) extraction but inhibited U(VI) stripping. The extracted U(VI) species analysis identified the UO2(NO3)2(L)2 and UO2(DiAP)2(L)2 (L = TiAP/HDiAP) as the primary extracted U(VI) complexes. The DFT calculations revealed a higher tendency and a more exothermic process for the formation of U(VI)–HDiAP complexes than U(VI)–TiAP complexes. The MD simulations showed that HDiAP will be closer to the interface than TiAP, which is beneficial to its interaction with U(VI). The electrostatic force dominated the interaction between U(VI) and ligands, and its strength follows the order of U–DiAP− > U–TiAP > U–HDiAP. The presence of DiAP− was the main reason that impeded the U(VI) stripping. This work reveals the U(VI) extraction behavior and mechanism of the 36 % TiAP/nDD system in the presence of HDiAP, providing new insights into the effects of radiolysis products on the U(VI) extraction by potential fuel reprocessing extractants.

EFFECT OF STATIC PHYSICAL ACTIVITY ON CENTRAL HEMODYNAMICS AND ARTERIAL DISTENSIBILITY IN ADOLESCENT ATHLETES INVOLVED IN SWIMMING AND CROSS-COUNTRY SKIING

The purpose of the paper is to compare arterial distensibility in endurance sports atheletes (track and field athletes and swimmers), in whom adaptation to muscle activity is formed in interaction with various environmental factors. Materials and methods. Qualified athletes (adolescents aged 13–17) performed a 5-minute isometric handgrip exercise, corresponding to 20 % of the maximum compression force. The authors assessed athletes’ hemodynamics, arterial elasticity and cardiac parameters using the SphygmoCor technology. Results. At rest, swimmers demonstrated increased systolic blood pressure, lower values of heart rate, augmentation index and relative systole duration. Immediately after load, swimmers showed an increase in blood pressure, augmentation pressure, and left ventricular contractility as a consequence of sympathoadrenal system activation during exercise. In skiers the answers were reduced. After 20-minute recovery, diastolic pressure and augmentation index in swimmers dropped below the baseline. It was probably due to the vasodilatory effect of acidic metabolic products washed out after exercise from isometrically contracted ischemic forearm muscles. Conclusion. The characteristic aspects of aquatic training influence background hemodynamic parameters, arterial distensibility and responsiveness to local isometric load.