Spherical Indicatrices of a Bertrand Curve in Three Lie Groups

In this paper, new representations of a Bertrand curve pair in three dimensional Lie groups with bi-invariant metric are given. Besides, the spherical indicatrices of a Bertrand curve pair are obtain and the relations between the spherical indicatrices and new representations of Bertrand curve pair are shown.Comment: 12 page

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Production of a Cheese-Like Aroma via Fermentation of Plant Proteins and Coconut Oil with the Basidiomycetes Cyclocybe aegerita and Trametes versicolor

Cheese is one of the most common dairy products and is characterized by its complex aroma. However, in times of climate change and resource scarcity, the possibility to mimic the characteristic cheese-like aroma from plant-based sources is in demand to offer alternatives to cheese. Accordingly, the production of a natural cheese-like aroma via fermentation of four plant-based proteins and coconut oil with basidiomycetes has been addressed. Mixtures of soy and sunflower protein with coconut oil (15 g/L) have shown the formation of a cheese-like aroma after 72 and 56 h after fermentation with Cyclocybe aegerita and Trametes versicolor, respectively. Isovaleric acid, butanoic acid, ethyl butanoate, 1-octen-3-ol, and various ketones were identified as the key odorants. Similarities to typical cheeses were observed by the principal component analysis. Overall, the finding offered an approach to a sustainable production of a natural cheese-like aroma from a plant source, thus contributing to the development of cheese alternatives

Bioaccessibility of PAHs in Fuel Soot Assessed by an in Vitro Digestive Model with Absorptive Sink: Effect of Food Ingestion

We investigated the effects of changing physiological conditions in the digestive tract expected with food ingestion on the apparent bioaccessibility (<i>B</i>_app) of 11 polycyclic aromatic hydrocarbons (PAHs) in a fuel soot. A previously established in vitro digestive model was applied that included silicone sheet as a third-phase absorptive sink simulating passive transfer of PAHs to intestinal epithelium in the small intestine stage. The <i>B</i>_app is defined as the fraction found in the digestive fluid plus sheet after digestion. We determined that <i>B</i>_app was independent of gastric pH and addition of nonlipid milk representing dietary proteins and carbohydrates, whereas it increased with bile acids concentration (2.0–10 g/L), small intestinal pH (5.00–7.35), and addition of soybean oil representing dietary lipid (100% and 200% of the mean daily ingestion by 2–5 year olds in the U.S.). <i>B</i>_app of PAHs increases with small intestinal pH due to the combined effects of mass transfer promotion from nonlabile to labile sorbed states in the soot, weaker sorption of the labile state, and increasingly favorable partitioning from the digestive fluid to the silicone sink. Under fed conditions, <i>B</i>_app increases with inclusion of lipids due to the combined effects of mass transfer promotion from nonlabile to labile states, and increasingly favorable partitioning into bile acid micelles. Our results indicate significant variability in soot PAH bioaccessibility within the range of physiological conditions experienced by humans, and suggest that bioaccessibility will increase with coconsumption of food, especially food with high fat content

Sorption of Perfluoroalkyl Acids to Fresh and Aged Nanoscale Zerovalent Iron Particles

The sorption of perfluoroalkyl acids (PFAAs), particularly perfluorooctanesulfonic acid (PFOS), to freshly synthesized nanoscale zerovalent iron (nZVI) and aged (oxidized) and sulfidated nZVI, was investigated under anaerobic conditions. The sorption of PFAAs to nZVI was 2–4 orders of magnitude higher than what has been reported for sediments, soils, and iron oxides. The hydrophobicity of the perfluorocarbon chain dominated the sorption, although FTIR spectra indicated specific interactions between sulfonate and carboxylate head groups and nZVI. The contributions from electrostatic interactions depended on the surface charge and pH. Humic acids influenced sorption only at concentrations above 50 mg/L. nZVI aged in deoxygenated water up to 95 days showed similar sorption isotherms for PFOS to fresh nZVI, because Fe­(OH)₂ was the predominant phase on the nZVI surface independent of aging time. Sulfidation of nZVI reduced sorption of PFOS by 1 log unit owing to the FeS deposited, but the sorption affinity was restored after aging because of formation of Fe­(OH)₂. Oxidation of nZVI by water and dissolved oxygen also resulted in similar sorption of PFOS as fresh nZVI at environmentally relevant concentrations. The results suggest that injection of nZVI could reduce PFAA concentrations in groundwater despite changes to its surface chemistry with aging

Dipeptidyl Peptidase IV Inhibitory Peptides Derived from Oat (<i>Avena sativa</i> L.), Buckwheat (<i>Fagopyrum esculentum</i>), and Highland Barley (<i>Hordeum vulgare trifurcatum</i> (L.) Trofim) Proteins

Peptides released from oat, buckwheat, and highland barley proteins were examined for their <i>in vitro</i> inhibitory effects on dipeptidyl peptidase IV (DPP4), an enzyme that deactivates incretin hormones involved in insulin secretion. All of the hydrolysates exhibited DPP4 inhibitory activities, with IC₅₀ values ranging from 0.13 mg/mL (oat glutelin alcalase digestion) to 8.15 mg/mL (highland barley albumin tryptic digestion). The lowest IC₅₀ values in gastrointestinal, alcalase, and tryptic digestions were 0.99 mg/mL (oat flour), 0.13 mg/mL (oat glutelin), and 1.83 mg/mL (highland barley glutelin). In all, 35 peptides of more than seven residues were identified in the tryptic hydrolysates of oat globulin using liquid chromatography–mass spectroscopy. Peptides LQA­F­E­PLR and EFL­L­A­G­NNK were synthesized and their DPP4 inhibitory activities determined. LQA­F­E­PLR showed high <i>in vitro</i> DPP4 inhibitory activity with an IC₅₀ value of 103.5 μM

Bioacessibility of PAHs in Fuel Soot Assessed by an <i>in Vitro</i> Digestive Model: Effect of Including an Absorptive Sink

Polycyclic aromatic hydrocarbons (PAHs) associated with soot or black carbon can enter the human digestive tract by unintentional ingestion of soil or other particles. This study investigated the bioaccessibility of 11 PAHs in a composite fuel soot sample using an <i>in vitro</i> digestive model that included silicone sheet as an absorptive sink during the small intestinal digestion stage. The sheet was meant to simulate the passive transfer of PAHs in lumen fluid across the small intestinal epithelium, which was postulated to promote desorption of labile PAHs from the soot by steepening the soot–fluid concentration gradient. We show that the presence of silicone sheet during a 4 h default digestion time significantly increased the apparent bioaccessible fraction (<i>B</i>_app, %), defined as the sum in the sheet and digestive fluid relative to the total PAH determined. The ability to increase <i>B</i>_app for most PAHs leveled off above a sheet-to-soot ratio of 2.0 g per 50 mg, indicating that the sheet is an effective absorptive sink and promotes desorption in the mentioned way. Enhancement of <i>B</i>_app by the sheet correlated positively with the octanol–water partition coefficient (<i>K</i>_ow), even though the partition coefficient of PAH between sheet and digestive fluid (which contains bile acid micelles) correlated negatively with <i>K</i>_ow. It was hypothesized that PAHs initially in the soot exist in labile and nonlabile states. The fraction of labile PAH still sorbed to the soot residue after digestion, and the maximum possible (limiting) bioaccessibility (<i>B</i>_lim) could be estimated by varying the sheet-to-soot ratio. We show conclusively that the increase in bioccessibility due to the presence of the sheet is accounted for by a corresponding decrease in fraction of labile PAH still sorbed to the soot. The <i>B</i>_lim ranged from 30.8 to 62.4%, independent of molecular size. The nonlabile fraction of individual PAHs (69.2–37.6% in this case) is therefore large and needs to be taken into account in risk assessment

Dechlorination Helps Defluorination: Insights into the Defluorination Mechanism of Florfenicol by S‑nZVI and DFT Calculations on the Reaction Pathways

Defluorination is essential to eliminate the antibiotic resistance and detrimental effects of florfenicol (C12H14Cl2FNO4S, FF), which is achievable by sulfidated nanoscale zerovalent iron (S-nZVI), yet a comprehensive understanding of the mechanism is lacking. Herein, we used experimental data and density functional theory calculations to demonstrate four dechlorination-promoted defluorination pathways of FF, depending on S-nZVI or not. FF was defluorinated in a rapid and then slow but continuous manner, accompanying a consecutive dechlorination to deschloro (dFF) and dideschloro FF (ddFF). Unexpectedly, the predominant defluorination occurs by spontaneous hydrolysis of ddFF to form the hydrolyzed byproduct (HO-ddFF), i.e., independent of S-nZVI, which is initiated by intramolecular attack from carbonyl O to alkyl F and is thus limited for FF and dFF owing to the diminished nucleophilicity by electron-withdrawing Cl. The removal of Cl also makes the reductive defluorination of ddFF by S-nZVI amenable. The other two minor but more rapid defluorination pathways occur in synergy with the dechlorination of FF and dFF, which are mediated by the reactive carbanion intermediates and generate HO-dFF and HO-ddFF, respectively. The reliability of these dechlorination-facilitated defluorination pathways was verified by the consistency of theoretical calculations with experimental data, providing valuable insights into the degradation of fluorinated contaminants

Dechlorination Helps Defluorination: Insights into the Defluorination Mechanism of Florfenicol by S‑nZVI and DFT Calculations on the Reaction Pathways

Defluorination is essential to eliminate the antibiotic resistance and detrimental effects of florfenicol (C12H14Cl2FNO4S, FF), which is achievable by sulfidated nanoscale zerovalent iron (S-nZVI), yet a comprehensive understanding of the mechanism is lacking. Herein, we used experimental data and density functional theory calculations to demonstrate four dechlorination-promoted defluorination pathways of FF, depending on S-nZVI or not. FF was defluorinated in a rapid and then slow but continuous manner, accompanying a consecutive dechlorination to deschloro (dFF) and dideschloro FF (ddFF). Unexpectedly, the predominant defluorination occurs by spontaneous hydrolysis of ddFF to form the hydrolyzed byproduct (HO-ddFF), i.e., independent of S-nZVI, which is initiated by intramolecular attack from carbonyl O to alkyl F and is thus limited for FF and dFF owing to the diminished nucleophilicity by electron-withdrawing Cl. The removal of Cl also makes the reductive defluorination of ddFF by S-nZVI amenable. The other two minor but more rapid defluorination pathways occur in synergy with the dechlorination of FF and dFF, which are mediated by the reactive carbanion intermediates and generate HO-dFF and HO-ddFF, respectively. The reliability of these dechlorination-facilitated defluorination pathways was verified by the consistency of theoretical calculations with experimental data, providing valuable insights into the degradation of fluorinated contaminants

A reinforcement learning based Lagrangian relaxation algorithm for multi-energy allocation problem in steel enterprise

The integrated iron and steel enterprises are typically characterized by the presence of multiple energy media that are highly coupled, frequent start-stop cycles of energy conversion equipment, and fluctuations in energy supply and demand. In this paper, we address the problem of byproduct gas-steam-electricity scheduling in iron and steel enterprises to achieve optimal energy distribution and conversion and reduce the energy cost. This optimization problem for the multi-period full energy chain is formulated as a mathematical programming model that considers equipment start-stop cycles, with the objective of minimizing energy system operating cost. A Lagrangian relaxation framework is employed to decouple the energy management model into several independent single schedules. To further improve the algorithm performance, a novel reinforcement learning-based Lagrangian relaxation algorithm (RL-LR) is proposed, which can dynamically set step size coefficients during the iteration process. Numerical results are presented demonstrating that the RL-LR algorithm can achieve higher optimization efficiency.</p