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In this work, the reaction mechanism of 2-ethylanthraquinone (eAQ) and Tetrahydro-2-ethyl anthraquinone (H4eAQ) hydrogenation over Pd and Pd-M bimetallic catalysts (M = Ni and Cu) was first investigated by density functional theory (DFT) using VASP software. The simulation results showed that the reaction mechanism of eAQ and H4eAQ over different catalysts is similar. The three benzene rings of eAQ or H4eAQ are on bridge sites over the surface of Pd(111) or PdM(111). Dihydrogen is preferentially adsorbed on the top site of a Pd atom in Pd-eAQ or Pd-H4eAQ model, and then the hydrogen atoms dissociated from dihydrogen are located at two neighboring threefold hollow fcc positions. The two carbonyl oxygen atoms of eAQ and H4eAQ successively react with the hydrogen atoms on the surface of Pd(111) or PdM to produce anthrahydroquinone (eAQ) and tetrahydroanthrahydroquinone (H4eAQ), respectively. Moreover, the simulation results showed that the reaction activation energy for the hydrogenation of H4eAQ and eAQ over Pd-Ni bimetallic catalyst is lower than those over other catalysts, which is attributed to the better synergy of Pd and Ni on the surface of Pd-Ni bimetallic catalyst. The reaction activation energy of the hydrogenation of H4eAQ is lower than that of the hydrogenation of eAQ.

The benzene and acetonitrile azeotropic mixture was proposed to be separated by extractive distillation using an ionic liquid (IL) as the entrainer. The suitable IL was selected by the COSMO-RS model, and 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) was considered as the suitable entrainer mainly due to its high selectivity, low viscosity, and low price. The experimental vapor pressure data of the IL-containing systems (benzene + [EMIM][BF4] and acetonitrile + [EMIM][BF4]) were measured in the full concentration range. The results show that acetonitrile has a stronger interaction with IL than benzene, and the low deviations between the experimental and UNIFAC predicted values show the reliability of the UNFIAC model. The UNIFAC predicted vapor-liquid equilibrium data of the benzene + acetonitrile + dimethyl sulfoxide (DMSO)/[EMIM][BF4] system show that the relative volatility of benzene to acetonitrile is higher when the entrainer is [EMIM][BF4]. The process simulation results show that [EMIM][BF4] can reduce the material and energy consumptions compared with DMSO.

Ionic liquids (ILs) as separating agents have been extensively studied in chemical separation processes. For IL-containing systems, the UNIFAC model for ILs (i.e., UNIFAC-Lei model) has become a po...

The SAFT-γ Mie model is a recent version of statistical associating fluid theory (SAFT), which uses a group contribution approach to obtain a high-quality equation of state. In this work, this model is, for the first time, extended to ionic liquids (ILs). The SAFT-γ Mie calculated values agree well with the experimental data for one-component, binary and ternary systems that contain ILs, thus indicating the versatility and accuracy of this extension.

In this work, the solubility data and liquid-phase mass transfer coefficients of hydrogen (H2), methane (CH4) and their mixtures in vacuum gas oil (VGO) at temperatures (353.15–453.15 K) and pressures (1–7 MPa) were measured, which are necessary for catalytic cracking process simulation and design. The solubility of H2 and CH4 in VGO increases with the increase of pressure, but decreases with the increase of temperature. Henry's constants of H2 and CH4 follow the relation of ln H = − 413.05/T + 5.27 and ln H = − 990.67/T + 5.87, respectively. The molar fractions of H2 and system pressures at different equilibrium time were measured to estimate the liquid-phase mass transfer coefficients. The results showed that with the increase of pressure, the liquid-phase mass transfer coefficients increase. Furthermore, the solubility of H2 and CH4 in VGO was predicted by the predictive COSMO-RS model, and the predicted values agree well with experimental data. In addition, the gas–liquid equilibrium (GLE) for H2 + CH4 + VGO system at different feeding gas ratios in volume fraction (i.e., H2 85% + CH4 15% and H2 90% + CH4 10%) was measured. The selectivity of H2 to CH4 predicted by the COSMO-RS model agrees well with experimental data. This work provides the basic thermodynamic and dynamic data for fuel oil catalytic cracking processes.

Background: Drug-resistance and immunological escape of Staphylococcus aureus and its “superbug”, methicillin-resistant S. aureus (MRSA), have become one of main causes of bacterial infection in both human and animals. In dairy cattle, elimination of bovine mastitis induced by S. aureus is of importance because S. aureus-infected cows normally are culled passively. Methods: Here, we investigated the beneficial effects of bovine trafficking protein particle complex 9 (TRAPPC9) gene and folic acid supplementation in the control of mastitis induced by S. aureus or MRSA by a series of in vivo and in vitro experiments. Results: The data showed that the genetic mutations and DNA methylation of TRAPPC9 were highly linked with the mastitis resistance of dairy cows. Additionally, knockdown of bovine TRAPPC9 was significantly involved in the mRNA expression levels of interleukin’s genes (increased IL-1β and IL-6), and down-regulated the protein level of NF-κB-P65 in the mastitis cell model induced by MRSA. Meanwhile, dose-dependent folic acid addition can inhibit the invasion of MRSA into Mac-T cells and improve TRAPPC9 expression in dairy cows. Conclusions: Altogether, our data suggest that an appropriate dose of folic acid can significantly reduce the inflammation caused by MRSA partially through TRAPPC9 mediated NF-κB pathway. These findings provide new insights to control the drug-resistant pathogens and to restrict the overuse of antibiotics through combined effects of the intrinsic host gene and extrinsic nutrient.

A combinatorial screening approach combining quantum chemical (QC) calculation and molecular dynamics (MD) simulation was presented for the selection of ionic liquid (IL) extractant to remove methanol from methylal. The thermodynamic properties of the distributional coefficient and selectivity were calculated by COSMO-RS based on QC calculation to qualitatively narrow down the IL candidates. The separation performance of these IL candidates was further evaluated through MD to determine the best IL extractant. Then, the methanol removal performance of the best IL was further evaluated by the liquid – liquid equilibrium experiments and the process simulation. Finally, the separation mechanism of the IL was investigated through QC calculations, wavefunction and MD analysis. The consistency between simulations and experiments indicates that this approach is a very useful tool to screen ILs for specific separation tasks.

A united chemical thermodynamic model, that is, the COSMO-UNIFAC model, was first proposed to predict the phase equilibrium of multicomponent systems in which the UNIFAC model parameters are missing. This model combines the advantages of the UNIFAC model (accurate prediction) and the COSMO-based models (a priori prediction). The predicted vapor–liquid equilibrium results by the COSMO-UNIFAC model were compared with experimental data from the literature and this work, confirming that it can provide a moderate quantitative prediction even if the UNIFAC model parameters are missing.

Vapor pressure data for the binary systems (water/methanol/ethanol + 1-ethyl-3-methylimidazolium acetate ([EMIM]+[Ac]−)) and the ternary systems (methanol + water + [EMIM]+[Ac]−, ethanol + water + [EMIM]+[Ac]−, and methanol + ethanol + [EMIM]+[Ac]−) were measured by a modified equilibrium still. For the above systems, the maximum average relative deviation between experimental data and the UNIFAC-Lei model predicted values was 7%, confirming the prediction accuracy of the UNIFAC-Lei model. Thus, this model was further used to predict the isobaric vapor–liquid equilibrium (VLE) data at 101.3 kPa for the methanol + water + [EMIM]+[Ac]−, ethanol + water + [EMIM]+[Ac]−, and methanol + ethanol + [EMIM]+[Ac]− systems at a fixed mole fraction of ionic liquid (IL) (xIL = 0.2). It was demonstrated that the ionic liquid [EMIM]+[Ac]− was an appropriate entrainer to separate the methanol–ethanol–water mixture. On this basis, the extractive distillation process was simulated using the rigorous equilibrium (EQ) stage m...

Methylal is used as an important synthetic fuel blended with diesel oil to reduce the particulate emissions of toxic gas pollutants without affecting the energy density. The mixed entrainers (dimethylformamide (DMF) + ionic liquid (IL)) are proposed to replace conventional DMF for the separation of methylal and methanol by extractive distillation. [EMIM]+[Ac]− might be the most promising entrainer screened by COSMO-RS model considering relative volatility and solvent capacity together. Vapor–liquid equilibrium (VLE) experiments demonstrated that the relative volatility of methylal to methanol is obviously improved after the addition of [EMIM]+[Ac]− into DMF. Moreover, the UNIFAC-Lei model was extended to the methylal-methanol-DMF-IL system, and the corresponding interaction parameters were obtained and input into the equilibrium (EQ) stage model established in this work. Based on the thermodynamic study, process simulation was developed. It was found that the overall heat duty of reboilers decreased 9.25% using the proposed mixed entrainers when compared to pure DMF. In addition, the COSMO-RS model and DFT calculation provide some theoretical insights into the separation mechanism.

This is the first work to investigate the hydrodynamics and gas-liquid mass transfer of carbon dioxide (CO2) absorbed into the amino-functionalized ionic liquid (IL) [NH2e-mim][BF4] and monoethanol-amine (MEA) mixture through a vertical circular monolith channel by means of computational fluid dynamics (CFD). It is shown that there are five flow patterns (i.e., bubbly flow, Taylor flow, slug-bubbly flow, slug-annular flow, and annular flow), and Taylor flow is the main flow pattern. The intrinsic kinetics of CO2 absorbed into the [NH2e-mim][BF4]-MEA mixture was obtained, the reaction orders relative to CO2, [NH2e-mim][BF4], and MEA being 1, and the activation energy Ea (19,313 and 28,991 J•mol−1) and pre-exponential factor k0 (3.34×105 and 7.04×106 mol-1•L•min−1) for CO2 absorbed in [NH2e-mim][BF4] and MEA were derived. After the kinetic parameters were imported into the mass transfer model, it was found that the liquid phase volumetric mass transfer coefficient (kLa) in the presence of a chemical reaction can be improved by three to eight times, indicating that mass transfer can be enhanced remarkably by chemical reaction. Moreover, a correlation formula is developed to predict kLa, which agrees well with the simulation results. This work provides a new way to capture CO2 with the combination of IL and MEA in a monolith reactor.

The catalytic performance of Pd-N/Silicon Dioxide/Cordierite (Pd-N/SD/C) (N = Ga and Ag) bimetallic monolithic catalysts for 2-ethylanthraquinone (eAQ) hydrogenation was investigated. Catalyst characterization by HRTEM, XPS, and TPR reveal that Pd-Ga/SD/C can form an alloy structure to produce significant synergetic effects. Moreover, the use of different Pd/Ga mass ratio in catalysts reveals that when the mass ratio of Pd and Ga/Ag = 2:1, Pd-Ga/SD/C obtains the highest yield of H2O2 and selectivity toward active quinones, which can reach 7.4 g L−1 and 90%. Moreover, to have a deep understanding of the eAQ-PdN(1 1 1) or eAQ-Pd(1 1 1) interaction mechanism, the calculation of eAQ adsorption on Pd-N/SD/C catalysts surface was performed by density functional theory (DFT). It is shown that the higher catalytic activity over Pd-Ga/SD/C is due to the stronger carbonyl group of eAQ adsorption on Pd3Ga1 (1 1 1).

In this work, two possible alkylation mechanisms (i.e., consecutive and associative mechanisms) of benzene and propylene to produce cumene were investigated by the density functional theory (DFT) using the B3LYP functional of the Gaussian 09 package with the 8 T model of HZSM-5 zeolite. The results showed that the main alkylation mechanism of benzene and propylene on HZSM-5 zeolite is the associative mechanism, which has a lower energy barrier than the consecutive mechanism. Moreover, two kinds of zeolites (i.e., HZSM-5 and H-Beta) for benzene alkylation with propylene to produce cumene are compared. For the associative mechanism, the activation energy (99 kJ/mol) on HZSM-5 is lower than that on H-Beta (106 kJ/mol). For the consecutive mechanism, in the protonation step, the activation energy of H-Beta is 66 kJ/mol, while the activation energy of HZSM-5 is 59 kJ/mol, which is due to HZSM-5 having stronger acidity to readily furnish Ha acidic protons. In the alkylation step, HZSM-5 has a lower energy barrier (229 kJ/mol) than H-Beta (294 kJ/mol). Thus, benzene alkylation with propylene is easier to carry out on HZSM-5 zeolite than on H-Beta zeolite.

Mammary gland is an important organ for milk synthesis and secretion. It undergoes dramatic physiological changes to adapt the shift from peak to late lactation stage. Protein plays a final very vital role in many life functions, and the protein changes during different lactation stages potentially reflect the biology of lactation and the functions of mammary gland in cows. In current study, we adopted tandem mass tags label-based quantitative analysis technique and to investigate proteome changes occurring in bovine mammary gland from peak to late lactation stages. A total of 3753 proteins from mammary tissues taken at two lactation points from four individual cows by biopsy were quantified, out of which 179 proteins were expressed differentially between two stages. We observed five new DEPs (AACS, DHCR7, GSTM3, SFRP1 and SFRP4) and nine functional well-studies known proteins (PLIN2, LPIN1, PLIN3, GSN, CD74, MMP2, SOD1, SOD3 and GPX3) related to milk performance and mammary morphology. Bioinformatics analyses of the DEPs showed a majority of the up-regulated proteins during late lactation stage were related to apoptosis and immune process, while the downregulated proteins were mainly involved in localization, lipid metabolic and transport process. This suggests that the mammary gland can adapt to different molecular functions according to the biological need of the animal. From the integrated analysis of the differentially expressed proteins with known quantitative trait loci and genome-wide association study data, we identified 95 proteins may potentially affect milking performance. We expect findings in this study could be a valuable resource for future studies investigating the bovine proteome and functional studies.

Descriptive statistics of phenotypic values for each trait in Holstein and Sanhe cattle. (DOCX 12 kb)

Staphylococcus aureus (S. aureus) is problematic for lactating mammals and public health. Understanding of mechanisms by which the hosts respond to severe invasion of S. aureus remains elusive. In this study, the genome-wide expression of mRNAs and miRNAs in bovine mammary gland cells were interrogated at 24 h after intra-mammary infection (IMI) with high or low concentrations of S. aureus. Compared to the negative control quarters, 194 highly-confident responsive genes were identified in the quarters with high concentration (109 cfu/mL) of S. aureus, which were predominantly implicated in pathways and biological processes pertaining to innate immune system, such as cytokine-cytokine receptor interaction and inflammatory response. In contrast, only 21 highly-confident genes were significantly differentially expressed in face of low concentration (106 cfu/mL) of S. aureus, which slightly perturbed the cell signaling and invoked corresponding responses like vasoconstriction, indicating limited perturbations and immunological evading. Additionally, the significant up-regulations of bta-mir-223 and bta-mir-21-3p were observed in the quarters infected by high concentration of S. aureus. Network analysis suggested that the two miRNAs' pivotal roles in defending hosts against bacterial infection probably through inhibiting CXCL14 and KIT. The significant down-regulation of CXCL14 was also observed in bovine mammary epithelial cells at 24 h post-infection of S. aureus (108 cfu/mL) in vitro. Integrated analysis with QTL database further suggested 28 genes (e.g., CXCL14, KIT, and SLC4A11) as candidates of bovine mastitis. This study first systematically revealed transcriptional and post-transcriptional responses of bovine mammary gland cells to invading S. aureus in a dosage-dependent pattern, and highlighted a complicated responsive mechanism in a network of miRNA-gene-pathway interplay.

Background Bovine mastitis is the most common and costly disease of lactating cattle worldwide. Apart from milk somatic cell count (SCC) and somatic cell score (SCS), serum cytokines such as interleukin-17 (IL-17) and interleukin-4 (IL-4) may also be potential indicators for bovine mastitis. The present study was designed to investigate the effects of single nucleotide polymorphisms (SNPs) in bovine IL-17F and IL-17A genes on SCC, SCS and serum cytokines in Chinese Holstein and Inner-Mongolia Sanhe cattle, and to compare the mRNA expression variations of the cows with different genotypes. Results A total of 464 lactating cows (337 Holstein and 127 Inner-Mongolia Sanhe cattle) were screened for SNPs identification and the data were analyzed using fixed effects of herd, parity, season and year of calving by general linear model procedure. The results revealed that SNP g.24392436C > T in IL-17F and SNP g.24345410A > G in IL-17A showed significant effects on SCC and IL-4 in Holstein (n = 337) and on IL-17 and IL-4 in Sanhe cattle (n = 127). The homozygous GG genotype of SNP g.24345410A > G had significantly higher mRNA expression compared with the heterozygous AG genotype. Conclusions The results indicate that IL-17F and IL-17A could be powerful candidate genes of mastitis resistance and the significant SNPs might be useful genetic markers against mastitis in both dairy and dual purpose cattle. Electronic supplementary material The online version of this article (doi:10.1186/s40104-016-0137-1) contains supplementary material, which is available to authorized users.

A sensitive and reliable method was developed and validated for the analysis of ractopamine in swine tissues. The sample preparation procedure was based on hydrolysis overnight, extraction with ethyl acetate, and solid-phase extraction cleanup. The target compound was determined by ultra-performance liquid chromatography coupled with tandem mass spectrometry. The average recoveries ranged between 93.3% and 106.5%, with relative standard deviations of 7.2–12.8%. The detection and quantification limits were 0.2 and 0.5 μg/kg, respectively. The depletion profile of ractopamine was studied in healthy pigs after oral administration of feed containing 20 mg/kg ractopamine for 30 consecutive days. Ractopamine residues were still detected 11 days post-medication in all tissues examined with the exception of muscle. The highest ractopamine level was found in lung tissue. The developed method has been successfully applied to the depletion study of ractopamine in swine tissues.

A method based on ultra-high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UHPLC-MS/MS) for the simultaneous determination of benzimidazole residues in bovine milk has been optimized and validated. Rapid chromatographic separation of 13 analytes in 8 min was obtained by means of UHPLC. The samples were subject to Oasis MCX solid-phase extraction cartridges for extraction and clean-up. Matrix-matched calibration curves were performed to compensate for the matrix effect and loss in sample preparation. Mean recoveries ranged from 80% to 101% and inter-day precision was lower than 14%. Limit of detection and limit of quantification of the method ranged from 0.01 to 0.5 μg L⁻¹ and from 0.1 to 1.0 μg L⁻¹, respectively.