Search

AbstractThis study was conducted to evaluate the effects of different additives on the fermentation quality and bacterial community of silage prepared from fresh-cut whole-plant quinoa (WPQ). Fresh-cut WPQ without wilting process was directly ensiled with one of the following additives: (i) untreated (control); (ii) fibrolytic enzyme (E); (iii) molasses (M); (iv) LAB inoculant (L); (v) a combination of fibrolytic enzyme and LAB inoculant (EL); and (vi) a combination of molasses and LAB inoculant (ML). The fermentation quality and bacterial community after 60 days of ensiling were analysed. The results showed that control silage was dominated by enterobacteria (>50%), with high pH value (5.25), acetic acid (77.9 g/kg DM) and NH3–N production (261 g/kg TN). Adding E, EL and ML shifted the fermentation pattern towards increased intensity of lactic acid production, as indicated by increased lactic acid content (>62.4 g/kg DM), lactic/acetic acid ratio (>1.12) and relative abundance of Lactobacillus(>62.0%), and decreased pH value (<4.73), contents of acetic acid (<60.7 g/kg DM) and NH3-N (<179 g/kg TN) and the relative abundance of enterobacteria. The results suggested that treatments of E, EL and ML could be the feasible solutions for improving the fermentation quality and protein preservation of silage prepared from fresh-cut WPQ. The results of this study could be beneficial for producing high-quality WPQ silage in aeras where wilting is hard to conduct before ensiling.HIGHLIGHTSWPQ silage was prone to acetic acid-type fermentation dominated by enterobacteria.Adding E, EL and ML improved the lactic acid fermentation and protein preservation of fresh-cut WPQ silage.This study provided feasible solutions for producing high-quality WPQ silage under adverse climate conditions.

Green hydrogen production from renewable biomass via bio-oil catalytic steam reforming was a prospective technology. In order to accelerate the development of high-performance and long-term catalyst, we selected acetic acid as a typical bio-oil model compound to carry out the studies of steam reforming. Excellent bimetallic Pt-Co/Al2O3catalysts were prepared using a sol-gel auto-combustion method. The effects of the molar ratio of ethylene glycol: citric acid: metal ions (EG/CA/M) on the catalyst structure and subsequent reforming performance were systematically investigated. It was found that the catalyst’s textural properties, reducibility, basic sites, and the dispersion of active metal could be carefully tuned by the EG/CA/M ratio. The catalyst prepared under EG/CA/M ratio of 6:3:1 performed the best reactivity in acetic acid steam reforming, showing a 97.6% acetic acid conversion and a 96.6% H2yield at the reaction conditions of 650 °C, steam to carbon molar ratio of 5, and space velocity of 6957 h–1. Furthermore, a bifunctional reaction mechanism of acetic acid catalytic steam reforming was proposed by in-situdiffuse reflective infrared Fourier transform spectroscopy analysis coupled with density functional theory calculations.

By using the shake-flask method, the acetoguanamine solubilities in water, acetonitrile, methanol, n-butanol, isopropanol, isobutanol, ethanol, n-propanol, N,N-dimethylformamide (DMF), 1,4-dioxane, ethyl acetate, and ethylene glycol (EG) were acquired over the temperatures from 283.15 to 323.15 K at ambient pressure (p= 101.2 kPa). The mole fraction of acetoguanamine in equilibrated liquor increased as the temperature increased and followed the order in different solvents: DMF > EG > ethyl acetate > 1,4-dioxane > n-butanol > isobutanol > n-propanol > isopropanol > ethanol > methanol > water > acetonitrile. The acquired solubility was correlated via the Apelblat equation. The largest root-mean-square deviation value and largest relative average deviation were, respectively, 28.12 × 10–6and 2.38 × 10–2.

The solubilities of d-tryptophan in neat n-propanol, ethyl acetate, ethylene glycol (EG), n-butanol, acetonitrile, 1-octanol, and dimethyl sulfoxide and of l-tyrosine in ethyl acetate, EG, isopropanol, acetonitrile, n-butanol, and N,N-dimethylformamide (DMF) were determined via a shake-flask method at temperatures from 283.15 to 328.15 K under about 101.2 kPa. At the fixed temperature, the mole fraction solubility of d-tryptophan was the largest in EG and the lowest in 1-octanol. However, for l-tyrosine, the maximum solubility was observed in the ethyl acetate and minimum in n-butanol. X-ray powder diffraction analysis was carried out to analyze the solids equilibrated with the corresponding liquor, indicating that no polymorphic transformation or solvate formation took place in the studied systems. The solubility correlation was performed via the Apelblat equation. The obtained maximum root-mean-square deviation and relative average deviation values were 13.65 × 10–5and 4.32%, respectively. In addition, the solvent–solvent and solute–solvent interactions were investigated on the basis of the approach of linear solvation energy relationship.

The o-nitrophenylacetonitrile solubilities in some pure solvents such as n-propanol, methanol, toluene, ethanol, isopropanol, acetonitrile, acetone, cyclohexane, ethyl acetate, n-butanol, 2-butanone, isobutanol, acetic acid, water, 1,4-dioxane, and ethylbenzene were determined via a shake-flask method at temperatures from 278.15 to 333.15 K under about 101.2 kPa. Good dissolution ability was found for o-nitrophenylacetonitrile in the organic solvents. The order of solubility magnitude from high to low, except for the solvents of ethyl acetate and 1,4-dioxane, was as follows: acetone > 2-butanone > acetonitrile > toluene > (acetic acid, ethylbenzene) > methanol > ethanol > n-propanol > isopropanol > n-butanol > isobutanol > cyclohexane > water. X-ray powder diffraction analysis was carried out to analyze the solids equilibrated with the corresponding liquor, indicating that no polymorphic transformation or solvate formation took place in the 16 solvents. The correlation of the determined solubility was performed via the Wilson model, Apelblat equation, nonrandom two-liquid model, and λhequation. Maximum root-mean-square deviation and relative average deviation were 49.66 × 10–4and 4.97%, respectively. The Apelblat equation presented the best correlating results among these models. In addition, the solvent–solvent and solute–solvent interactions were investigated on the basis of the approach of the linear solvation energy relationship.

The determination of 2-amino-6-chloropurine solubility in water and 11 organic solvents including dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), 2-butanone, ethylene glycol (EG), n-butanol, n-propanol, isobutanol, isopropanol, 1,4-dioxane, ethanol, and methanol was performed by using the shake flask technique. The experiments were conducted covering the temperatures from 278.15 to 333.15 K at ambient pressure p= 101.2 kPa. The values of solubility for 2-amino-6-chloropurine in selected solvents increased as the temperature rised. The maximum solubility value of 2-amino-6-chloropurine was recorded in DMSO, and the minimum, in water. They ranked as DMSO > DMF > 2-butanone > EG > n-butanol > n-propanol > isobutanol > isopropanol >1,4-dioxane > ethanol > methanol > water. The solubility data obtained were mathematically described through the Apelblat equation. The largest percentage of average relative deviation was 1.75 × 10–2, and the maximum value of root-mean-square deviation, 1.14 × 10–4. Moreover, using the Kamlet and Taft linear solvation energy relationship analysis of the solvent effect, the type and degree of solvent, solute, and solvent–solvent interactions were recognized.

The saturated thermodynamic solubilities of micoflavin in four mixtures of dimethyl sulfoxide (DMSO, 1) + water (2), isopropanol (1) + water (2), propylene glycol (PG, 1) + water (2), and ethanol (1) + water (2) are reported in this contribution. All experiments were carried out via the saturation shake-flask technique at temperatures from 278.15/293.15 to 318.15 K. The solubility data were maximum in neat DMSO (isopropanol, PG, or ethanol) for the four mixtures studied. The micoflavin solubility was mathematically well described through the Jouyban–Acree model, attaining root-mean-square deviation values lower than 3.68 × 10–4and relative average deviation values lower than 6.27%. The local mole fractions of DMSO (isopropanol, ethanol, PG and water) around micoflavin were quantitatively studied via the method of inverse Kirkwood–Buff integrals on the basis of the solubility data determined. The solvation of micoflavin was preferential by water for these mixtures in the water-rich compositions, whereas in the cosolvent-rich and intermediate compositions, the solvation of micoflavin was preferential by DMSO (isopropanol, PG, or ethanol) in the DMSO (isopropanol, PG, or ethanol) + water mixtures. In addition, the cosolvency effect was reorganized by considering the Kamlet and Taft linear solvation energy relationships, and the relative importance of the solvent–solvent and solvent–solute interactions was distinguished. Results indicated that the micoflavin solubility variation was governed by the cavity term in the DMSO + water solution and the cavity and α terms in the aqueous solutions of PG, isopropanol, and ethanol.

The mutual solubilities for ternary systems of p-nitroacetophenone (1) + m-nitroacetophenone (2) + methanol (3), p-nitroacetophenone (1) + m-nitroacetophenone (2) + toluene (3), and p-nitroacetophenone (1) + m-nitroacetophenone (2) + ethyl acetate (3) were investigated through a steady method at 283.15, 298.15, and 313.15 K, respectively, under a local ambient pressure of 101.2 kPa. The isothermal phase diagrams of the three systems were constructed in terms of the obtained mutual solubilities. At a fixed temperature, there were two neat solids formed, namely neat p-nitroacetophenone and neat m-nitroacetophenone, which were recognized through Schreinemakers’ wet residue method. The crystallization regions of neat p-nitroacetophenone and neat m-nitroacetophenone increased with decreasing temperature. The mutual solubility was correlated through the Wilson and NRTL equations. The relative average deviations for p-nitroacetophenone + m-nitroacetophenone + methanol/toluene/ethyl acetate systems were, respectively, 4.44 × 10–2, 3.86 × 10–2, and 3.35 × 10–2for the NRTL equation and 4.33 × 10–2, 2.51 × 10–2, and 2.29 × 10–2for the Wilson equation. The acquired solubility data and the ternary phase diagrams for the three systems were very significant for designing and optimizing the purification process of p-nitroacetophenone and m-nitroacetophenone mixtures.

The stable solid–liquid phase equilibrium for ternary systems of terephthaldialdehyde + 4-hydroxybenzaldehyde + ethyl acetate and terephthaldialdehyde + 4-hydroxybenzaldehyde + acetone was determined using the isothermal saturation method at 293.15, 303.15, and 313.15 K under ambient pressure of 101.2 kPa. In terms of the obtained mutual solubility data, the isothermal phase diagrams of the two systems were constructed. At a given temperature, there were two pure solids formed, pure 4-hydroxybenzaldehyde and pure terephthaldialdehyde, which were identified by Schreinemakers’ wet residue method and X-ray powder diffraction analysis. The crystallization zones of pure 4-hydroxybenzaldehyde and pure terephthaldialdehyde increased with rising temperature. The crystalline zone of terephthaldialdehyde was larger than that of 4-hydroxybenzaldehyde at the same temperature. The mutual solubility data of solid–liquid phase equilibrium were correlated with nonrandom two-liquid (NRTL) and Wilson models. The calculated solubility data with NRTL model agreed well with the determined values. The mutual solubility data and ternary phase diagrams for the two systems were of great significance for optimizing the purification procedure of 4-hydroxybenzaldehyde and terephthaldialdehyde.

The solubility of trimetazidine hydrochloride in 12 neat solvents namely ethanol, methanol, isopropyl alcohol, n-propanol, acetone, toluene, 2-butanone, ethyl acetate, n-butanol, acetonitrile, N,N-dimethylformamide (DMF), and 1,4-dioxane and binary liquid mixtures methanol + (ethanol, DMF, or ethyl acetate) was measured using the isothermal method over the temperature range from 278.15 to 323.15 K under local atmospheric pressure of 101.2 kPa. The observed mole fraction solubility was the largest in methanol and smallest in toluene. The experimental data in monosolvents was correlated through the Apelblat equation; while in mixed solvents, by the van’t Hoff–Jouyban–Acree model, Jouyban–Acree model and Apelblat–Jouyban–Acree model. Consequently, for the selected monosolvents, the largest relative average and root-mean-square deviations were 0.79% and 0.227 × 10–4, respectively; and for the binary solvent mixtures, 3.00% and 2.22 × 10–4. Solvent–solvent and solute–solvent interactions were analyzed in the 12 net solvents with linear solvation energy relationship analysis. The solubility in monosolvents depends significantly upon the Hildebrand parameter and nonspecific dipolarity/polarizability interactions. The values of log x12deviated from the mean values of log x12in the monosolvents. Results were interpreted based on different modes of the solvation interactions.

The solubility of terephthaldialdehyde in N-methyl-2-pyrrolidone (NMP) at temperatures ranging from T= 293.15 to 318.15 K and the mutual solubility for ternary systems of terephthalic acid + terephthaldialdehyde + N,N-dimethylformamide (DMF) and terephthalic acid + terephthaldialdehyde + NMP at T= 298.15, 308.15, and 318.15 K were measured with the technique of isothermal saturation under 101.2 kPa. Six phase diagrams were built on the basis of the determined solubility. There were two solids formed in each ternary system, which were terephthalic acid and terephthaldialdehyde. Each diagram consisted of one cosaturated point, three crystalline areas, and two cosaturated curves. Furthermore, the nonrandom two-liquid mode and Wilson model were used in correlating and calculating the solubility of terephthaldialdehyde in NMP and the mutual solubility data for terephthalic acid + terephthaldialdehyde + DMF/NMP systems. The maximum root-mean-square deviation was 3.58 × 10–3, and maximum value of relative average deviation was 1.74%. The liquid–solid phase diagram and the thermodynamic analysis could provide the basis for obtaining terephthalic acid with high purity.

The thiamphenicol solubility in aqueous cosolvent solutions of ethanol (1), methanol (1), 1,4-dioxane (1), and N,N-dimethylformamide (DMF, 1) was measured via the isothermal dissolution equilibrium method at temperatures ranging from 278.15 to 318.15 K under local pressure (101.1 kPa). At fixed composition of ethanol (methanol, 1,4-dioxane, or DMF) and temperature, the solubility of thiamphenicol was larger in DMF + water mixtures than in the ethanol/methanol/1,4-dioxane mixtures. The local solvent proportions were acquired with the method of inverse Kirkwood–Buff integrals. The absolute value of these preferential solvation parameters were all lower than 1.0 × 10–2for ethanol (1) + water (2) and 1,4-dioxane (1) + water (2) solutions in water-rich compositions and for methanol (1) + water (2) solutions in whole compositions. In the former two cosolvent mixtures in intermediate compositions and cosolvent-rich regions, thiamphenicol was preferentially solvated by cosolvent. However, for the DMF (1) + water (2) solutions, water solvated preferentially thiamphenicol in water-rich compositions and by DMF in intermediate and DMF-rich compositions. This case by cosolvent might be illustrated based on higher basic behavior of water, which interacted with Lewis acidic groups of thiamphenicol. In addition, the solubility of thiamphenicol was described with the van’t Hoff–Jouyban–Acree, Jouyban–Acree, and Apelblat–Jouyban–Acree models. The obtained average relative deviations were no greater than 1.85%. Furthermore, the solvent effect treatment through the KAT-LSER model indicated that the solubility variation was significantly affected by the cavity term.

Density functional theory calculations and microkinetic modeling were used to study the decomposition mechanisms of the bio-oil model compound formic acid over a cobalt-stepped surface. Zero-point-energy-corrected activation barriers and reaction energies and the rate and equilibrium constants of various elementary reactions were obtained. Formic acid dissociation likely starts from dehydrogenation and dehydroxylation, with activation barriers of less than 0.5 eV. The generation of an HCOO intermediate is thermodynamically favored, but such a compound is energetically difficult to convert. COOH formation is fast and dominant at low temperatures, and it is converted rapidly after 450 K. The most favorable formic acid decomposition pathway is HCOOH → COOH → CO. Its rate-determining step is CO–OH scission, with an activation barrier of 0.66 eV and strong exothermicity of −1.19 eV.

For a long time, the research of the C3H6-SCR reaction relied only on experimental techniques, which limited the recognition of the mechanism for this process. Herein, we systematically calculated the adsorption characteristics, electronic structure, oxidation pathways, and reaction pathways of the C3H6-SCR procedure by density functional theory (DFT) based on a representative doping model. DFT calculations show that the C3H6oxidation with NO to CH3NO2/CH3CN is more favorable to achieve energetically than CH3NO/CH3NCO, while the NO2is a better oxidant than O2and NO for the C3H6oxidation at low temperatures. The excellent correlation between temperature programmed experiment and the C3H6-SCR reaction path barrier can reasonably conclude that the first step oxidation of C3H6and the formation of amino intermediates(−NH2) are the keys to the low-temperature activity of C3H6-SCR. Besides, the stronger charge non-localization on the surface with lanthanum doping demonstrated by XPS could be responsible for the enhanced oxidation of the active sites, hence promoting NO to NO2. The study shed more light on the C3H6-SCR reaction mechanism at the molecular level and expects to contribute to the development of low-temperature C3H6-SCR.

Two-dimensional (2D) MoS2is commonly used as an anode catalyst for electrochemical water splitting. However, the limited active edge sites of 2D MoS2have hindered its electrochemical performance in electrochemical water splitting. Here, experimental outcomes and density functional theory (DFT) calculations demonstrate that the catalytic performance of inert 2D MoS2surfaces can be triggered by doping transition-metal atoms and introducing S-vacancies. In this work, the catalytic activity of different metal-doped (Cu, Mn, and Nb) 2D MoS2with S-vacancies shows a great difference among tested MoS2-based samples. Characterizations verify the existence of dopant ions and S-vacancies. In particular, the Cu-doped electrocatalyst exhibits a low overpotential of 197 mV at 10 mA cm–2in an acidic solution and superior stability of less than 10 mV increase in overpotential after 12 h of continuous hydrogen production process, proving that Cu doping and introduced S-vacancies can benefit the electrochemical performance. Moreover, DFT calculations reveal that S-vacancies and the further introduction of different metal ions can alter the adsorption behavior of H atoms by changing the d-band center of the in-plane Mo site neighboring the doped heteroatom atoms and S-vacancy sites, which explains well the superior performance of Cu-doped 2D MoS2.

Sehen um zu glauben: Die optische chirale Erkennung von (R)‐ und (S)‐Binap gelang mithilfe des enantioselektiven Kollabierens von Metallogelen, die mit neuartigen Gelatoren aus Platin und Pinzettenliganden mit aromatischem, Linker‐ und Steroidteil hergestellt wurden. Van‐der‐Waals‐Wechselwirkungen, π‐Stapelung und Metall‐Metall‐Bindung führen zur Aggregation und chiralen Erkennung.

Seeing is believing: The visual chiral recognition of (R)‐ and (S)‐binap has been realized through an enantioselective breakdown of metallogels prepared from novel aromatic–linker–steroidal‐type pincer platinum gelators. Van der Waals interactions, π stacking, and metal–metal bonding are responsible for the aggregation and chiral recognition.

Letfbe a lower semi-continuous and bounded below function from a Banach spaceXinto (−∞,+∞] whereXis assumed to admit a Lipschitz smooth “bump-function.” Generalizing results of Chaney, we study optimality conditions for[formula]to be a local minimum point off. These conditions are described in terms of generalized Chaney's subdifferentials and second-order derivatives.

Objective To determine the levels of carcinoembryonic antigen (CEA), proliferating nuclear antigen Ki67 and p53 in pseudomyxoma peritonei (PMP) of appendiceal origin and to correlate the levels with clinicopathological characteristics and overall survival.Methods This retrospective study collected data on clinicopathological features and immunohistochemical staining of CEA, Ki67 and p53 in patients with PMP of appendiceal origin. Overall survival was evaluated using Kaplan–Meier plots. Median survival time was estimated by Log-rank tests. Potential prognostic factors were evaluated by Cox proportional hazards regression models.Results A total of 141 patients with PMP of appendiceal origin were enrolled in the study with a median age of 54 years. Of these, 93 (66.0%) were diagnosed with low-grade mucinous carcinoma, 43 (30.5%) with high-grade mucinous carcinoma and five (3.5%) with high-grade with signet ring cells. CEA exhibited ubiquitous immunopositivity in most cases and was not associated with overall survival. Ki67 labelling index (LI) and p53 status were related to histological grade and overall survival. The main pathological indicators affecting survival included histological grade, lymph node involvement, angiolymphatic invasion, Ki67 LI and p53.Conclusion Combined analysis of high Ki67 LI and aberrant p53 may provide the basis for evaluating the biological behaviour of PMP and predicting clinical outcome.