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In this study, a new hollow nanotube material, 30% Co–CHNTs was prepared by the impregnation–chemical reduction–calcination method. This material can be used as a peroxymonosulfate (PMS) activator to catalyse the degradation of sulfamethoxazole (SMX). The best reaction conditions that correspond to the degradation rate of SMX, up to 97.5%, are as follows: the concentration of SMX is 10 mg L−1, the amount of catalyst is 0.20 g L−1, the dosage is 1.625 mM, and the solution pH is 6.00. X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical emission spectrometry (ICP-OES) show that the calcined composites mainly stimulate an increase in the content of bivalent cobalt in PMS and reduce the leaching of cobalt ions after the reaction. Additionally, the 30% Co–CHNTs + PMS reaction system exhibits a reasonable SMX degradation rate in a natural organic matter solution and excellent stability after three repeated experiments. Furthermore, the possible degradation mechanism in the 30% Co–CHNTs + PMS reaction system was analysed through electron paramagnetic resonance (EPR) and free-radical capture experiments, and it was observed that the non-radical degradation of 1O2 plays a leading role in SMX degradation. Finally, according to the nine degradation intermediates detected by liquid chromatography-mass spectrometry (LC–MS), four possible SMX degradation routes were proposed. This study proved that a 30% Co–CHNTs heterogeneous catalyst is easily prepared, inexpensive, and environmentally friendly and has potential application in antibiotic wastewater treatment.

Background Genome-wide functional genetic studies of food-borne pathogens could provide a comprehensive understanding of the mechanisms underline their survival and pathogenesis in the harsh environments during food processing and infections. Traditional methods such as physical mutagenesis, chemical mutagenesis, and labeled DNA fragment insertion mutation techniques are time-consuming, labor-intensive and low precision. Although RNA-Seq and other omics methods enable high-throughput research on a genome-wide scale, the obtained results of gene transcription or expression cannot establish direct causal connection between the genetic determinants and particular functions. Scope and approach Transposon sequencing (Tn-seq) is an emerging microbial functional genomic technology based on transposon mutagenesis and high-throughput sequencing technologies, which is able to quantitatively track millions of independent mutants in a single experiment, and therefore efficiently map the “genotype-phenotype” relationship and the genetic interaction networks of a bacterium. Key findings and conclusions This article summarizes the common types and hazards of food-borne pathogens, the development of Tn-seq technology, and its applications in studying the physiology, pathogenesis, and environmental survival of food-borne pathogens.

Morphology and dispersity are key factors for activating peroxymonosulfate (PMS). In this study, we designed a recyclable open-type NiCo2O4 hollow microsphere via a simple hydrothermal method with the assistance of an NH3 vesicle. The physical structure and chemical properties were characterized using techniques such as scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), N2 adsorption and X-ray photoelectron spectroscopy (XPS). The test results confirm that the inner and outer surfaces of open-type NiCo2O4 hollow-sphere can be efficiently utilized because of the hole on the surface of the catalyst, which can minimize the diffusion resistance of the reactants and products. Under optimized conditions, the total organic carbon (TOC) removal efficiency of rhodamine B (RhB) can reach up to 80% in 40 min, which is almost 50% shorter than the reported values. The reactive radicals were identified and the proposed reaction mechanism was well described. Moreover, the disturbances of HCO3−, NO3−, Cl− and H2PO4− were further investigated. As a result, HCO3− and NO3− suppressed the reaction while Cl− and H2PO4− had a double effect on reaction.

A phosphorus removal biochar adsorbent was prepared from Fenton sludge. The adsorption process was optimized, and its phosphorus adsorption mechanism was discussed. It was found that the phosphorus adsorption performance of biochar prepared from single Fenton sludge (FBC-400) was better than that of co-pyrolysis of Fenton sludge and bamboo powder. The optimum condition was that Fenton sludge pyrolyzed at 400°C (FBC-400). FBC-400 had a larger specific surface area than that prepared by co-pyrolysis with bamboo powder. And the high content of iron element could provide a higher surface charge of the biochar, thereby increasing the electrostatic adsorption of phosphorus onto FBC-400. The phosphorus adsorption was highly pH dependent by FBC-400, which can enhance electrostatic adsorption and increase adsorption capacity in acidic conditions. The effect of coexisting anion on adsorption performance was mainly affected by CO

In order to tackle the issue of terramycin mycelial dreg (TMD) diagnosis and removal of terramycin and antibiotic resistance genes (ARGs), this study adopted aerobic composting (AC) technology and added homemade compound microbial inoculum (HCMI) to promote the AC of TMD and enhance the removal of terramycin and ARGs. The findings demonstrated that terramycin residue could be basically harmless after AC. Moreover, HCMI not only reduced QacB and tetH but also increased the degradation rates of VanRA, VanT, and dfrA24 by 40.81%, 5.65%, and 54.18%, respectively. The HCMI improved the removal rate of ARG subtypes to a certain extent. According to redundancy analysis, during AC, the succession of the microbial community had a stronger influence on the variance of ARG subtype than the environmental conditions. Differences in the abundance of various bacteria due to changes in temperature may be an intrinsic mechanism for the variation of ARG subtypes.

In the present work, a microwave-assisted and secondary roasting preparation process was used to synthesize nanocomposite materials. These materials were modified with amorphous cobalt nanoparticles (Co NPs) on the surface of biochar doped with different nitrogen sources (melamine (Me), 1,10-phenanthroline (Ph), and urea (Ur)). The nanocomposite (Co-N-C(Ur)) with urea as the nitrogen source promoted the generation of mesopores on the surface of carbon materials due to its evaporation during the preparation process thus enhancing the attachment sites of cobalt nanoparticles. The Co-N-C(Ur) had a more significant degradation effect on the primary carcinogen sulfamethazine (SMT) by activating peroxymonosulfate (PMS). The degradation rate of SMT pollutants was 96.6 % within 30 min. The optimal reaction conditions were as follows: catalyst dosage of 0.4 g L−1, PMS dosage of 0.812 mM, SMT concentration of 10 mg L−1, and pH of 5.67. Additionally, the Co-N-C(Ur) catalysts possess excellent specific surface area due to the evaporation effect of the calcination process of urea itself compared to other nitrogen source doping. Electrochemical tests revealed that the composites prepared with urea as the nitrogen source had higher PMS-induced current density and lowered material impedance values, which effectively promoted the catalytic performance of SMT degradation. Concurrently, the Co-N-C (Ur) + PMS reaction system exhibited excellent catalytic performance against other antibiotic organic pollutants. Subsequently, through the capture experiments and electron paramagnetic resonance technical analyses, it was determined that the singlet 1O2 played a leading role in the reaction system. Finally, a thorough liquid chromatography-mass spectrometry analysis suggested the possible SMT degradation pathways, thereby providing a new strategy for the subsequent heterogeneous catalysts to degrade persistent organic pollutants.

To address the problem of antibiotic mycelial dreg (AMD) treatment and removal of antibiotic resistance genes (ARGs), this study adopted anaerobic digestion (AD) technology, and added biochar (BC) and biochar loaded with nanosized zero-valent iron (nZVI-BC) to promote the AD of AMD and enhance the removal of ARGs. Results showed that nZVI-BC was better than BC in promoting AD due to the hydrogen evolution corrosion and the synergistic effect of nZVI and BC. In addition, BC and nZVI-BC can enhance the oxidative stress response and reduce ammonia stress phenomenon, which significantly reduces the abundance of aadA, ant(2″)-Ⅰ, qacEdelta1 and sul1. In conclusion, the enhance effect of nZVI-BC is greater than BC. The removal efficiency rates of nZVI-BC on the above-mentioned four ARGs were improved by 33%, 9%, 24% and 11%.

To efficiently treat low-concentration chromium wastewater at low cost, adsorbent iron-modified ceramsite (FCM) was successfully prepared. The adsorbent was characterized by SEM, XRD, FT-IR, XPS, ζ potential and VSM. From the experimental results, the optimum adsorption pH, adsorbent dosage and adsorption time were 4, 1 g/L and 120 min, respectively. The percentage removal of Cr(VI) was 93% and the reduction efficiency of Cr(VI) was 74.3% when the concentration was 2 mg/L. After 5 cycles, using 0.1 mol/L NaOH as the regeneration agent, the removal rate of Cr(VI) did not decrease significantly. Furthermore, the mechanism of deep reduction and adsorption, the process of regeneration, the kinetics and adsorption isotherms were also explored. This paper can provide theoretical and technical support for reducing the toxicity and the advanced treatment of hexavalent chromium.

The Brucella spp encounter stressful environment inside their host cells. The Lon protein is an important protease related to cellular protein degradation and resistance to stress in Brucella. However, the molecular mechanism between Lon protein and stress response was still unknown. In this study, it was found that the lon mutant exhibited obvious growth defect in TSB medium, compared with its parent strain. In addition, our results indicated that Lon protein was involved in resistance to various stress conditions and all the β-lactam antibiotics tested. Although deletion of this protease did not affect Brucella virulence in macrophage, the mutant strain was significantly attenuated in mice infection model at 1 week post infection, and the expression level of several cytokine genes was significantly changed in vivo. To gain insight into the genetic basis for the distinctive phenotypic properties exhibited by the lon mutant strain, RNA-seq was performed, and the result showed that various genes involved in stress response, quorum sensing and transcriptional regulation were significantly altered in Δlon strain. Overall, these studies have preliminary uncovered the molecular mechanism between Lon protease, stress response and bacterial virulence.

Considering the complexity of traditional cobalt phosphide (Co

Considering the complexity of traditional cobalt phosphide (Co2P) loaded biochar synthesis research on a simple and efficient synthesis method has practical significance. In this study, after phosphoric acid activation, Neosinocalamus affinis biochar (NAB) and nanoplate Co3O4 quickly formed a Co2P-NAB composite material with high Co2P crystallinity and was uniformly dispersed on the surface of NAB in a microwave reactor. Co2P-NAB has an excellent catalytic degradation effect in the activation of peroxymonosulfate (PMS) to degrade tetracycline (TC). The optimal TC degradation efficiency was achieved with the addition of 50 mg L−1 TC concentration, 0.2 g L−1 catalysts, 0.406 mM PMS and pH = 6.02. In addition, according to the pseudo-first-order reaction rate constant calculation, the composite of Co2P-NAB and PMS the synergy efficiency is 81.55 %. Compared with Co2P-NAB (10.83 %) and PMS (7.62 %) alone, the Co2P-NAB/PMS system has a significant promotion effect on the degradation of TC molecules. Additionally, the Co2P-NAB/PMS system had a TC mineralization rate of 68 % in 30 min. Furthermore, after a series of characterization, detection and analysis, and influencing factor experiments, we proposed a potential mechanism for the Co2P–NAB/PMS reaction system to degrade TC and found that singlet oxygen (1O2) plays an essential role in the non-radical degradation process. Finally, according to the liquid chromatography-mass spectrometry (LC-MS) detection of TC degradation intermediates, a possible degradation route was proposed. Therefore, this work uses microwave technology to present a novel and simple synthesis method for transition metal phosphides, which provides potential application value for the treatment of actual wastewater with heterogeneous catalysts.

To achieve efficient degradation of toluene, a series of Cu1-yMn2CeyOx/sepiolite catalysts (y = 0.1, 0.2, and 0.3) with different Cu1-yMn2CeyOx loadings (10%, 20%, and 30%) were prepared via the co-precipitation method. The structure-activity and surficial elemental species of Cu1-yMn2CeyOx/sepiolite were characterized by XRD, TEM, SEM, BET, ICP-MS and XPS. The catalytic activity of the catalysts was tested in the oxidation reaction of toluene, results showed that 20%Cu0.8Mn2Ce0.2Ox/sepiolite remains able to remove toluene completely with high efficiency at a temperature of 289 °C. Two kinetic models have been selected and tested to describe the oxidation of toluene, the Mars-van krevele (MVK) model provided a good fit (R2 ≥ 0.99). And the optimal relation of the surface oxidation activation energy (26.074 kJ mol−1) and surface reduction activation energy (23.591 kJ mol−1) were calculated.

Spinel oxides, e.g., NiCo

The CeO2@ZSM-5 was prepared by the dipping method. We used ZSM-5 and CeO2 as the carrier and load components, respectively. The aim was to reduce the low concentration of Cr(VI) in simulated wastewater (the concentration of Cr(VI) ranged from 0.2 to 1 mg/L). The characteristics of ZSM-5 and CeO2@ZSM-5 samples were determined by X-ray powder diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET). Characterization results showed that the particle size, BET surface area and pore volume for CeO2@ZSM-5 was around 0.783 nm, 421.307 m2/g and 0.313 m3/g, respectively. In addition, the optimum conditions were obtained by the orthogonal test, and the details were as follows: optimal pH, adsorbent dose, initial concentration of Cr(VI) and equilibrium time were 3, 5 g/L, 0.6 mg/L and 70 min respectively. The removal of Cr(VI) was 99.56% in these conditions. The pseudo-second-order model best described the adsorption kinetics of Cr(VI) onto CeO2@ZSM-5. Isotherm data were treated according to Langmuir, Freundlich and Temkin isotherm models. The results showed that the Freundlich adsorption isotherm model fitted best in the temperature range studied. Adsorption capacity increased with temperature, showing the endothermic nature of Cr(VI) adsorption. The desorption results showed the best recovery of Cr(VI) using 0.1 M HCl.

The mineralization of organic pollutants under visible light is challenging, limiting the practical application of photocatalytic technology in wastewater treatment. To achieve the efficient mineralization of Acid red 3R (AR3R), a series of honeycombed catalysts (TiO

To efficiently treat low-concentration chromium wastewater at low cost, adsorbent iron-modified ceramsite (FCM) was successfully prepared. The adsorbent was characterized by SEM, XRD, FT-IR, XPS, ζ potential and VSM. From the experimental results, the optimum adsorption pH, adsorbent dosage and adsorption time were 4, 1g/L and 120min, respectively. The percentage removal of Cr(VI) was 93% and the reduction efficiency of Cr(VI) was 74.3% when the concentration was 2mg/L. After 5cycles, using 0.1mol/L NaOH as the regeneration agent, the removal rate of Cr(VI) did not decrease significantly. Furthermore, the mechanism of deep reduction and adsorption, the process of regeneration, the kinetics and adsorption isotherms were also explored. This paper can provide theoretical and technical support for reducing the toxicity and the advanced treatment of hexavalent chromium.

Stratification occurs after a reaction between SO2 and tetraalkylammonium halide aqueous solution. To explore the interactions between SO2 and tetraalkylammonium halide, the effects of temperature, concentration, length of alkyl chain, and halide anion on the solubility of SO2 in tetraalkylammonium halide aqueous solutions were investigated. To determine the mechanism of absorption of SO2 by aqueous tetrabutylammonium bromide solution, the composition and concentrations of each component in the upper and lower liquid phase were measured from 283.15 K to 303.15 K. The solubility of SO2 in aqueous tetraalkylammonium halide solutions increased with a corresponding increase in the alkyl chain length and a decrease in temperature. When SO2 was added into the solution by bubbling, SO2 molecules diffused into the clathrate compound of tetrabutylammonium bromide⋯nH2O (TBAB⋯nH2O) hydrate and formed a more stable clathrate inclusion complex.

Spinel oxides, e.g., NiCo2O4, is a promising catalyst for the catalytic oxidation of toluene. Understanding and designing versatile NiCo2O4 spinel is important for low-temperature toluene oxidation. Here, we investigated the surface-characteristic-dependent degradation activity of NiCo2O4 crystals through experiment and characterization. NiCo2O4 nanosheet using ethanol as solvent (named E--NiCo2O4) exposing {110} crystal planes exhibited the lowest temperature toluene oxidation. The T99 of toluene conversion was 256 °C, which is much lower than that of NiCo2O4 nanosheet using ethylene glycol as solvent (named EG--NiCo2O4), NiCo2O4 octahedron (named O--NiCo2O4) and NiCo2O4 truncated octahedron (named TO--NiCo2O4). Characterization using various techniques such as XRD, TEM, BET, XPS, H2-TPR and CO2-TPD showed that Co3+ and surface adsorbed oxygen (Osur) enriched surface, excellent redox properties and effective diffusion of the reaction product reasonably explain the enhancement in catalytic activity over the E--NiCo2O4. The research reveals that the effect of specific crystal planes and solvent was the key factor to govern the activity of low-temperature toluene oxidation.

The mineralization of organic pollutants under visible light is challenging, limiting the practical application of photocatalytic technology in wastewater treatment. To achieve the efficient mineralization of Acid red 3R (AR3R), a series of honeycombed catalysts (TiO2, C-TiO2-X, Au@TiO2 and Au@C-TiO2-X) were prepared via a facile in situ synthetic method and characterized by XRD, TEM, BET, XPS and DRS, respectively. The introduction of C and Au species promote the simultaneous generation of •O2− and •OH over Au@C-TiO2-X under visible light radiation. The Au@C-TiO2-X catalyst showed superior performance for the deep mineralization of AR3R, affording a TOC removal rate larger than 90 % within 240 min under visible light (> 420 nm). The photocatalytic degradation mechanism of AR3R is proposed according to UV–vis and in situ DRIFTS analysis. The superior photocatalytic activity of Au@C-TiO2-X is attributed to the synergistic effect of •O2− and •OH owing to C doping and Au deposition.

The CeO

To achieve efficient degradation of toluene, a series of Cu

Solvent-dispersible magnetite nanoparticles (Fe3O4) end-functionalized with amino groups were successfully prepared by a facile one-pot template-free method to immobilize PdII and Pd0 using a metal adsorption and reduction procedure. They were characterized by TEM, XRD, XPS, FT-IR and VSM. Interestingly, the PdII catalyst exhibited better catalytic activity for carbonylative cross-coupling reactions than the Pd0 catalyst. According to the catalytic activities of a variety of arylboronic acids and aryl iodides catalyzed by two kinds of Pd catalysts, the proposed reaction mechanism of Suzuki carbonylative cross-coupling reactions using the Pd catalyst was also inferred. More importantly, agglomeration of Pd0 nanoparticles was obviously observed in the TEM images of the catalysts after reactions. Therefore, agglomeration of Pd0 nanoparticles should be considered as a significant reason for different catalytic activities of the reactions catalyzed by immobilized PdII and Pd0 catalysts. Furthermore, the PdII catalyst revealed high efficiency and stability during recycling stages.

In the present work, nickel (Ni) and palladium (Pd) core–shell structure nanospheres with various thicknesses have been facilely obtained via a one-pot synthesis process. These hybrid structures allow us to correlate the Pd thickness with their performance in the hydrogen evolution reaction (HER). The HER activity increases with a decrease of the Pd thickness, and it can be ascribed to the enhancement of electron donation of Pd (111) caused by the electron flow from Ni (111) to Pd (111) based on first-principles calculations. In this hybrid system, the difference in work functions of Pd and Ni results in surface polarization on the Pd surface, tuning its charge state for hydrogen reduction. Meanwhile, with the assistance of a polyethyleneimine–reduced graphene oxide (PEI–rGO) support, the examined Ni@Pd4:1/PEI–rGO50:1 (10 wt%) electrocatalyst presents outstanding HER activity comparable with that of platinum (Pt). This work opens up possibilities for reducing Pd usage while achieving high HER performance.

A high-performance palladium catalyst was developed by the covalent binding of a Schiff base ligand, N,N′-bis(3-salicylidenaminopropyl)amine (salpr), on the surface of hollow magnetic mesoporous spheres (HMMS) followed by immobilization with Pd(0). The catalyst was characterized by TEM, EDX, FT-IR, XRD, VSM, TGA and N2 adsorption–desorption. The novel catalyst exhibited high activity in hydrogenation and Suzuki coupling reaction. Furthermore, it could be recovered from the reaction mixture in a facile manner and recycled six times without any loss of activity.

Fe3O4@PPy composite microspheres have been synthesized using Fe3O4 microspheres as a chemical template in an ultrasonic treatment process. Pt nanoparticles (NPs) were immobilized on Fe3O4@PPy by using ethylene glycol (EG) and NaBH4 as reducing agents. The information on the morphologies, sizes, and dispersion of Pt NPs of the as-prepared catalysts was verified by TEM, XRD, FTIR and XPS. As expected, the chemical reduction methods remarkably affected the size of Pt NPs (∼2.5 nm and ∼5.5 nm) and the prepared catalysts exhibited high catalytic activities as well as awesome stabilities for aerobic oxidation of benzylic alcohols and hydrogenation reduction of nitroaromatics. It was highlighted that size effects for the catalytic properties of the two reactions were found to be quite different. Fe3O4@PPy–Pt (2.5 nm) afforded a higher conversion for benzylic alcohol aerobic oxidation, while the selectivities toward benzaldehyde over these two catalysts were similar. However, they showed almost the same catalytic performance for hydrogenation reduction of a majority of nitroaromatics. What is more, Fe3O4@PPy–Pt (5.5 nm) gave better activities than several nitroaromatics, which were relatively difficult to be hydrotreated under the same conditions. In addition, the EG reduced Fe3O4@PPy–Pt catalyst exhibited slightly poorer stability than the NaBH4 reduced Fe3O4@PPy–Pt catalyst in the recycle tests, which might be due to the agglomeration of small Pt NPs.

The hierarchical porous Fe3O4/PPy-Pd-II catalyst has been synthesized using Fe3O4 microspheres both as chemical template and oxidant source under sonication. The catalyst characterized by TEM, XRD, FT-IR, XPS and vibrating sample magnetometry (VSM). The catalyst showed high reactivity for the carbonylative cross-coupling reaction of aryl iodides with arylboronic acids. This newly developed catalyst could be easily recovered and revealed high efficiency and high stability under the reaction conditions and during recycling stages. (C) 2014 Elsevier B.V. All rights reserved.

A palladium-based catalyst supported on amine-functionalized hollow magnetite nanoparticles was successfully prepared by a facile template-free method. The catalyst was characterized by TEM, XRD, FT-IR, VSM and XPS. The catalyst afforded fast conversions for various aromatic nitro compounds under a H2 atmosphere in ethanol even at room temperature. Furthermore, it was found that the catalyst showed a high activity for the Suzuki reaction. Interestingly, the novel catalyst could be recovered in a facile manner from the reaction mixture and recycled five times without any significant loss in activity.

We report on the synthesis, characterization and catalytic performance of a palladium-based superparamagnetic catalyst of Fe3O4@polyaniline core/shell microspheres (Fe3O4@PANI–PdII). The material was characterized by TEM, FT-IR, vibrating sample magnetometry (VSM), XRD, and XPS. The catalyst showed high activity for the carbonylative cross-coupling reaction of aryl iodide with arylboronic acid. Moreover it could selectively reduce the formation of a direct-coupling product. The newly developed catalyst could be recovered from the liquid phase easily by magnetic separation and recycled 5 times without any significant loss of activity.

A cobalt-based magnetic nanocatalyst was prepared by linking cobalt acetylacetonate with (3-aminopropyl)triethoxysilane functionalized magnetic mesoporous silica nanospheres. The material was characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), a vibrating sample magnetometer (VSM), X-ray diffraction (XRD), and N2 adsorption–desorption. The results showed that the sample had a mesoporous structure with a relatively high surface area and that cobalt acetylacetonate was covalently anchored on the magnetic mesoporous silica nanospheres. The catalyst was found to be highly efficient for the oxidation of cyclohexane with oxygen as the oxidant.

An acid–base bifunctionalized magnetic nanoparticles catalyst Fe3O4@SiO2-A/B was successfully synthesized by immobilization of both organic base and acid groups together over silica-coated magnetite nanoparticles. The catalyst has been characterized by transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectra (XPS) measurements. The bifunctionalized magnetic nanoparticles act as an easily recovered, highly efficient catalyst for the Henry reaction of 4-nitrobenzaldehyde with nitromethane at mild reaction conditions, even exceeding any monofunctionalized catalyst or physical mixture of two monofunctionalized nanoparticles in the catalytic behavior. In addition, a probable mechanism has been proposed to explain the cooperative interactions from the presence of the immobilized base and acid groups in close proximity. Importantly, the catalyst can be simply recoverable from the reaction mixture by magnetic decantation and recycled without significant degradation in reactivity.

A simple and novel method to fill carbon nanotubes (CNTs) with Ni–Fe alloys by methylbenzene-oriented constant current electrodeposition is demonstrated. The method is based on the difference in the surface conductivity of CNTs inside and outside in electrodeposition process owing to the covering of methylbenzene. The Ni–Fe alloys filled multiwalled carbon nanotubes (MWCNTs) were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and atomic absorption spectroscopy (AAS), respectively. Then the Ni–Fe alloys filled MWCNTs were used as hydrazine oxidation electrocatalysts in direct hydrazine (N2H4)-air fuel cells. Cyclic voltammograms (CVs) indicated that Ni85Fe15-filled MWCNTs had superior electrocatalytic activity for hydrazine electrocatalysis than catalysts with other compositions.

To explore the effects of the genetic background on the characteristics of wboA gene deletion rough mutants generated from different parent Brucella sp. strains, we constructed the rough-mutant strains Brucella melitensis 16 M-MB6, B. abortus 2308-SB6, B. abortus S19-RB6, and B. melitensis NI-NB6 and evaluated their survival, pathogenicity, and induced protective immunity in mice and sheep. In mice, the survival times of the four mutants were very different in the virulence assay, from less than 6 weeks for B. abortus S19-RB6 to 11 weeks for B. abortus 2308-SB6 and B. melitensis NI-NB6. However, B. abortus S19-RB6 and B. melitensis 16 M-MB6, with a shorter survival time in mice, offered better protection against challenges with B. abortus 2308 in protection tests than B. abortus 2308-SB6 and B. melitensis NI-NB6. It seems that the induced protective immunity of each mutant might not be associated with its survival time in vivo . In the cross-protection assay, both B. melitensis 16 M-MB6 and B. abortus S19-RB6 induced greater protection against homologous challenges than heterologous challenges. When pregnant sheep were inoculated with B. abortus S19-RB6 and B. melitensis 16 M-MB6, B. abortus S19-RB6 did not induce abortion, whereas B. melitensis 16 M-MB6 did. These results demonstrated the differences in virulence, pathogenicity, and protective immunity in vivo in the wboA deletion mutants from genetically different parent Brucella spp. and also indicated that future rough vaccine strain development could be promising if suitable parent Brucella strains and/or genes were selected.

We report on the synthesis, characterization and catalytic performance of new, supported Pd-II and Pd-0 catalysts. The catalysts are characterized by TEM, XRD, FTIR, X-ray photoelectron spectroscopy, and vibrating sample magnetometry. The catalysts are found to be active in both forms, Pd-II and Pd-0, for the carbonylative cross-coupling reaction of aryl iodides with arylboronic acids, and for the hydrogenation of aromatic nitroand unsaturated compounds. The newly developed catalysts are prepared by a synthetic strategy that is similar to the one used for other supported catalysts but are easier to recover- they can be recycled by magnetic separation from liquid phase reactions-and can be used for at least 5 consecutive trials without any decrease in activity.

A palladium-based catalyst supported on thiol-modified superparamagnetic nanoparticles was successfully prepared by co-precipitation method. These magnetic nanomaterials were characterized by elemental analysis (EA), inductively coupled plasma (ICP), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), fourier transform-infrared (FT-IR), thermogravimetric analysis (TGA) and vibrating sample magnetometry (VSM). The conversions of various aromatic nitro and unsaturated compounds can receive a really high yield with the existence of magnetic nanomaterials. The turn-over frequency (TOF) can be 66.46 h−1 in ethanol under a H2 atmosphere at room temperature. In this paper, the conversions of aromatic nitro bearing a variety of substituents were 93.56–100%, moreover, the catalyst afforded over 90% yield in the reducing unsaturated compounds. Another advantage is that the magnetite nanoparticles modified by thiol group can be separated just through the external magnetic force and can be reused atleast ten times without any significant loss in activity.

Highlights: Black-Right-Pointing-Pointer Palladium-based heterogeneous catalyst was prepared facilely via the co-precipitation method. Black-Right-Pointing-Pointer The particles are nearly spherical in shape with an average size of 20 {+-} 1.0 nm. Black-Right-Pointing-Pointer The developed magnetic catalyst showed high activity for Heck reaction. Black-Right-Pointing-Pointer The catalyst was easily recovered from the reaction mixture with external magnetic field. Black-Right-Pointing-Pointer The catalytic efficiency for Heck reaction remains unaltered even after 6 repeated cycles. -- Abstract: A novel and high-performance palladium-based catalyst for Heck reaction was prepared easily by the co-precipitation method. The catalyst was characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS) and atomic absorption spectrophotometry (AAS). The catalyst afforded a fast conversion of the 4-bromonitrobenzene to 4-nitrostilbene at a catalyst loading of 5 mol%, and the efficiency of the catalyst remains unaltered even after 6 repeated cycles. The excellent catalytic performance of the Pd/Fe{sub 3}O{sub 4} catalyst might be attributed to the enhanced synergistic effect between Pd nanoparticles and magnetite.