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A simple and efficient visible-light-induced photoredox-catalyzed diarylation of N-methacryloyl-2-arylbenzoimidazoles with aryl diazonium salts was developed. The reaction provides a convenient access to a variety of benzimidazoisoquinolinones through the construction of two C C bonds in one step under mild reaction conditions.

We demonstrate in this work online in situ characterization of potash fertilizer, a powder material, at its final production stage in factory on the production conveyer belt for quality assessment, with a specifically developed laser-induced breakdown spectroscopy (LIBS) instrument and dedicated data treatment software based on machine learning. Besides the usual difficulties encountered in online LIBS analysis, the specific challenge resides in moisture variation in the product, which results in a complex sample of powder of particle size ∼100 μm mixed with water (H2O). The influence on the LIBS spectrum was clearly observed, while no detailed physical model is available to describe such an influence. In addition, the emission line intensity from hydrogen (Hα line) observed in the spectrum did not show a clear relationship to the H2O concentration. The approach of analysis by correlation of the whole spectrum to the concentration was used to first determine the H2O concentration, which was further used as an additional parameter to concatenate with a LIBS spectrum in the formation of a generalized spectrum. The last was used as the input vector to train a potassium chloride (KCl) concentration calibration model. More specifically, LIBS spectra were first transformed into 2-D images with continuous wavelet transform (CWT). A convolutional neural network (CNN) then allowed mapping of the spectrum-images to the H2O concentrations of the corresponding samples, while a back-propagation neural network (BPNN) mapped generalized spectra to the KCl concentrations of the samples. The tests with online LIBS spectra and the corresponding offline analysis data of 119 samples taken during the period of LIBS measurements demonstrate advanced analytical performances of the trained models for H2O and KCl. Comparison between the model-predicted concentrations and the data from the offline analysis shows determination biases which fulfil the requirements of the concerned national standards (bias ≦0.20% for H2O and ≦0.598% for KCl) for the quasi totality of the tested samples.

This work was designed to observe and further correct the physical matrix effect in the analysis of solid materials with laser-induced breakdown spectroscopy (LIBS), an effect that arises when a calibration model established with a set of certified reference materials (CRMs) with a smooth surface is used for prediction with LIBS spectra acquired from materials with an irregular surface, such as scraps produced by an automobile shredder for example. CRMs of an aluminum alloy were prepared in such way that one half of the surface of each sample was mechanically destroyed to present an asperity similar to a scrap. LIBS measurements were then performed in the two halves of the sample surface in the same conditions. The spectra acquired from the smooth part of the sample surface served as a training data set to train calibration models, while those taken from the irregular part of the surface were used as a validation data set to assess the prediction performance of the calibration models. Four elements (magnesium, silicon, iron, and zinc), which are important for the recycling of aluminum alloy scraps, were analyzed. The study started with univariate models, where the influence of the surface asperity was clearly observed. A first correction with internal standard normalization showed limited effectiveness. Further improvements were attempted using a machine learning-based multivariate regression, where the calibration performance of the models was significantly improved thanks to an optimized correction of the chemical matrix effect, whereas the prediction performance was still unsatisfactory due to the surface asperity alternation of the validation samples. A transfer learning-based regression model, where a part of the irregular samples joined the training data set, was thus developed to effectively correct both chemical and physical matrix effects and allowed significantly improved the performances of both calibrations, with a relative error of calibration (REC) at 2.3%, and prediction for irregular samples, with a relative error of prediction (REP) at 16.3% on average for the 4 tested elements.

To explore a new approach for fabricating the load bearing implants with the combination of bioactivity, biocompatibility, and mechanical properties, mechanically mixed hydroxyapatite (HA) and titanium (Ti) powders containing 30, 50, and 70 wt% Ti were sprayed onto a 316L stainless steel substrate using a warm spray (WS) process. The microstructures, phase compositions, chemical structures, and mechanical properties of WS HATi composite coatings were comprehensively investigated and compared to those of WS HA coating. Experimental results indicate that the cross-sectional microstructures of WS HATi composite coatings present typical lamellar structures composed of curved stripes formed by well-deformed and oxidized Ti splats and limited deformed HA splats, and are significantly influenced by the Ti content in the original powders. Phase constitutions of the composite coatings mainly consist of HA, Ti, TiO2, and TiO. Chemical structures of HA in the composite coatings deposited using powders with Ti content less than 30% are similar to the structures in the original powder. The microhardness, elastic modulus, and bond strength of the coatings increased from 0.32 ± 0.15 GPa to 1.41 ± 0.31 GPa, from 1.37 ± 0.28 GPa to 23.28 ± 3.45 GPa, and from 17.3 ± 2.2 MPa to 34.8 ± 3.2 MPa, respectively. The abrasive wear weight loss of the coatings on Al2O3 abrasive paper decreased from 2.9 mg to 1 mg, as the addition of Ti particles in original powders increased from 0 to 70%.

The application of laser-induced breakdown spectroscopy (LIBS) for classification of rocks with the total alkali-silica (TAS) diagram is considered in this work. The attractive feature of LIBS compared to other spectrochemical techniques used for TAS classification in geological studies and especially for Mars exploration, such as X-ray fluorescence (XRF) and alpha particle X-ray spectrometry (APXS), consists in its ability for in situ stand-off analysis of samples in their natural state. The analysis accuracy of LIBS for geological samples, rocks, crusts, and soils, is however, seriously affected by the matrix effects due to the various chemical compositions and the different surface physical states of the samples. In this work with an originally designed experiment, a collection of 20 rocks were analyzed in the three different states: natural rock, with a polished surface and pressed pellets. This allowed the simulation of a real application scenario where a prediction model built with calibration standards prepared in a laboratory in the form of pressed pellets, is used to predict chemical compositions with the LIBS spectra acquired from geological samples in their natural state. In the framework of the TAS classification, the concentration of the major compounds in the rocks, SiO2, Na2O, and K2O, was thus determined first with univariate calibration models which were clearly affected by both the chemical and physical matrix effects. Multivariate calibration models were then developed based on machine learning to predict the concentrations of the above 3 compounds and perform the TAS classification. An efficient reduction of the chemical matrix effect has been demonstrated, and the influence of the physical matrix effect has been investigated in the cases of both univariate and multivariate calibration models.

Microbial degradation plays a major role in the dissipation of pendimethalin, and nitroreduction is an initial and detoxicating step. Previously, a pendimethalin nitroreductase, PNR, was identified...

Sodium ion batteries (SIBs) have achieved much attention and actively developed. Among possible anode materials of SIBs, nanosized metallic antimony is one of the most promising ones. However, the large volume changes of Sb and insufficient cyclability still remain a huge challenge for the large-scale applications. Herein, the effect of different Sb contents (named as C@Sb, C@Sb-L and C@Sb-H) on electrode performance, morphology, stability, and sodium storage mechanism has been systematically evaluated for the first time by a feasible electrospinning technique. As a result, the as-prepared C@Sb nanofibers exhibit excellent sodium storage performance with high-rate performance of 272.1 mAh g−1 at 20 A g−1, large reversible discharge capacity of 437.6 mAh g−1 after 300 cycles at 1 A g−1 and ultralong cycling life of 4000 cycles at 5 A g−1, such a cycling performance and high-rate capability for the C@Sb anode has rarely been reported. The significantly enhanced performance is ascribed to the synergetic effects between the well-dispersed ultrafine Sb nanoparticles and the N-rich 3D conductive carbon network structure. This homogeneously dispersed structure of ultrafine Sb nanoparticles encapsulated in the carbon network can dramatically improve the volume change and particle aggregation of Sb during ultralong charge/discharge process, thus solving the major problems of pulverization, loss of electrical contact and low utilization rate facing Sb anode. In addition, the full cell of Na3V2(PO4)3@C//C@Sb shows a high output potential of about 2.75 V and a discharge capacity of 264.3 mAh g−1 after 500 cycles at 1 A g−1. Those promising results should provide the basis for the potential large-scale application of Sb-based materials as high-performance anode for SIBs.

To investigate the wear behavior of bioceramic coating, two-body abrasive wear of air-plasma sprayed (APS) hydroxyapatite (HA) coating was studied in different conditions including: i) in simulated body fluid (SBF) and in dry conditions, and ii) sliding on Al2O3 abrasive paper, HA, polycarbonate (PC) and polyurethane (PU), as well as iii) on different applied loads. Cross-sectional microstructures and worn surface morphologies of the coating were examined by scanning electron microscopy (SEM). Phase constitutions were analyzed by X-Ray diffraction (XRD). Microhardness, elastic modulus, fracture toughness and bond strength of the coating were investigated. It was revealed that, under the load of 20 N and sling on different counterpart materials, the wear rates of the coating varied from 24.09 × 10−2to 0.25 × 10−2 mg/Nm in SBF and varied from 13.54 × 10−2 to 0.05 × 10−2 mg/Nm in dry condition, respectively. The accumulated weight loss of the coating sliding on HA in SBF increased from 3.1 to 7.9 mg as the applied load increased from 5 N to 20 N. As sliding on Al2O3 in dry condition and/or under high load, the abrasive wear of the coating dominantly occurred in the form of ploughing and peeling off of splats. As sliding on PC, PU and HA in SBF, the adhesive wear of the coating mainly occurred in the form of exfoliation.

An electrode for microbial electrocatalysis needs to interface biological-catalytic process with electrochemical-catalytic reaction, thereby both high loading of microbes (biocatalysts) and robust interfacial-catalytic activity are essential. Inspired by this insight, molybdenum carbide hybridized graphene nanocomposite is developed as an anode material for microbial fuel cell through a facile layer-by-layer electrostatic assembly followed by high-temperature carburization approach. Small-sized molybdenum carbide nanoparticles with good crystallinity are uniformly anchored on hierarchically porous-structured graphene, which greatly promotes the adhesion of Shewanella putrefaciens (an electricigen) cells to form compact electroactive biofilm with benefits from excellent biocompatibility and chemical flexibility of nanostructured molybdenum carbide. In return, the well-grown biofilm in-situ generates abundant electroactive biomolecules like flavins (endogenous electron shuttles) around the electrode interface, which can be used directly by molybdenum carbide nanocatalysts with outstanding electrocatalytic activity, thus leading to a dramatically enhanced extracellular electron transfer from bacterial cells to electrode. The developed hybrid anode delivers a maximum power density of 1697 mW m−2 with reliable stability, more than 2-fold and 13-fold over the undecorated graphene and carbon cloth, respectively. This work illustrates an efficient route to tailor microbial electrode with highly active nanocatalysts for synergistically boosting bioelectrocatalytic kinetics through integrating biological catalysis with electrochemical one.

The great challenge in preparing a biomimetic enzyme sensor is to have sensitivity and selectivity equal to or better than its corresponding biological sensor. Porous electrodes possess a large surface area and are often used to greatly improve the sensor sensitivity. However, how to tailor the pore structure, especially the pore size distribution to further improve the sensitivity and selectivity of a biomimetic sensor, has not been investigated yet. The superoxide anion (O2˙−) plays essential roles in various biological processes and is of importance in clinical diagnosis and life science research. It is generally detected by the superoxide dismutase enzyme. Herein, we delicately tailor the pore structure of carbon nanofibers (CNFs) by pyrolysis to obtain an optimal mesopore structure for strong adsorption of DNA, followed by guiding the growth of Mn3(PO4)2 as a biomimetic enzyme toward highly sensitive detection of O2˙−. The Mn3(PO4)2–DNA/CNF sensor achieves the best sensitivity among the reported O2˙− sensors while possessing good selectivity. The enhancement mechanism is also investigated, indicating that the mesopore ratio of CNFs plays an essential role in the high sensitivity and selectivity due to their strong adsorption of DNA for guiding the growth of a large amount of uniform sensing components, Mn3(PO4)2, toward high sensitivity and selectivity. The biomimetic sensor was further used to in situ monitor O2˙− released from human keratinocyte cells and human malignant melanoma cells under drug stimulation, showing high sensitivity to real-time quantitative detection of O2˙−. This work provides a highly sensitive in situ real-time biomimetic O2˙− sensor for applications in biological research and diagnosis, while shedding light on the enhancement mechanism of the pore structure, especially the pore size distribution of a porous electrode for high performance sensing processes.

The present paper investigates the deposition behavior of cold spraying agglomerated hydroxyapatite (HA) particles on stainless steel (SS) and HA substrates; for that purpose, the surface morphologies and cross-section microstructures of splats were investigated and compared to that of original HA particles. Full characterization of the coating was performed through the evaluation of (i) phase constitutions, crystallographic structure and composition, and coating/substrate interface as well as (ii) nanohardness of the powder, microhardness, tensile strength and the abrasive wear properties of the coating. HA splats on both substrates exhibited cap-like shape morphology with rough surface, and had some ring grooves on surface and some radial stripes on periphery composing of tiny HA granules. The cross-section of HA splats presented an asymmetric ellipsoid morphology with a flat bottom surface and convex up surface as well as compact area near bottom interface. Bonding of splats/substrate interface was related to the splats size and substrate materials. CS HA coating possessed a dense and homogeneous microstructure with reduced pores and crystal size, similar chemical structures, phase constitutions and chemical compositions to original powder. These microstructure evolutions were related to the deformation behavior of HA splats, i.e. radial spreading and compacting in impact direction by the un-continuous moving of agglomerates or granules in low temperature. Microhardness, tensile strength and the abrasive wear rate of the coating were 59.0 ± 5.6 kg/mm2, 10.9 ± 1.1 MPa and 1.3 ± 0.2 × 10−1 mg/(m·N), respectively.

A visible-light-induced Pd-catalyzed ortho-trifluoromethylation of acetanilides with CF3SO2Na was developed. The reaction proceeded smoothly at room temperature in air without any external photocatalyst or additive, providing the desired products in moderate to good yields with good functional group tolerance and regioselectivity.

Early-stage screening and diagnosis of ovarian cancer represent an urgent need in medicine. Usual ultrasound imaging and cancer antigen CA-125 test when prescribed to a suspicious population still require reconfirmations. Spectroscopic analyses of blood, at the molecular and atomic levels, provide useful supplementary tests when coupled with effective information extraction methods. Laser-induced breakdown spectroscopy (LIBS) was employed in this work to record the elemental fingerprint of human blood plasma. A machine learning data treatment process was developed combining feature selection and regression with a back-propagation neural network, resulting in classification models for cancer detection among 176 blood plasma samples collected from patients, including also ovarian cyst and normal cases. Cancer diagnosis sensitivity and specificity of respectively 71.4% and 86.5% were obtained for randomly selected validation samples.

As any spectrochemical analysis method, laser-induced breakdown spectroscopy (LIBS) usually relates characteristic spectral lines of the elements or molecules to be analyzed to their concentrations in a material. It is however not always possible for a given application scenario, to rely on such lines because of various practical limitations as well as physical perturbations in the spectrum excitation and recording process. This is actually the case for determination of carbon in steel with LIBS operated in the ambient gas, where the intense C I 193.090 nm VUV line is absorbed, while the C I 247.856 nm near UV one heavily interferes with iron lines. This work uses machine learning, especially a combination of least absolute shrinkage and selection operator (LASSO) for spectral feature selection and back-propagation neural networks (BPNN) for regression, to correlate a LIBS spectrum to the carbon concentration for its precise determination without explicitly including carbon-related emission lines in the selected spectral features.

Aspergillus flavus (A. flavus) is a kind of ubiquitous pathgenic fungi, of which an early and accurate detection and inhibition mehtod is essential to reduce its resulted damage of Afatoxions. Here real-time monitoring superoxide anions (O2•−) released from cinnamaldehyde-treated A. flavus was performed for the first time by an electrochemical enzyme-free biomimetic O2•− sensor to offer not only a facile and reliable approach to monitor the effect of inhibiting methods against A. flavus growth, but also a highly sensitive analytical tool to detect A. flavus, thus holding great promise for the sensor to continuously real-time monitor A. flavus released from infection or/and contamination of food in A. flavus-related biological researches and clinic diagnosis of some fatal diseases.

Nanostructured hydroxyapatite (nHA) coatings on implant surface are highly desirable owing to their excellent osteoconductive properties in association with intrinsic small crystals. Low processing temperature of cold spray makes it an ideal technique to prepare nHA coatings with nanostructured feedstock. This work demonstrated that dense and thick nHA coatings were achievable by cold spraying nanostructured feedstock onto TC4 alloy surface. Coating formation mechanisms were explored by investigating the deposition of individual particles. Microstructures, mechanical profiles and biological properties of the coatings were comprehensively investigated. A porous Ti buffer layer significantly enhanced the bonding between nHA coatings and the substrate. As-deposited nHA coatings exhibited a high wear resistance when slid against polyurethane or polycarbonate and a strong apatite-forming ability when being immersed in simulated body fluid (SBF). Findings of this work will contribute to a comprehensive understanding of building mechanisms, structures and properties of cold sprayed nHA coatings.

Microbial electrochemical systems are able to harvest electricity or synthesize valuable chemicals from organic matters while simultaneously cleaning environmentally hazardous wastes. The sluggish extracellular electron transfer (EET) between “non- or poor-conductive” microbes and electrode involves both bio- and electrocatalytic processes but is one of the main impediments to fast microbial electrode kinetics. To boost EET, researches have been focused on engineering electrochemically active microbes, constructing a unique nanostructured electrode endowed with a large amount loading of microbes and enhancing biotic–abiotic interactions for rapid electrode kinetics. After surveys of fundamentals of microbial electrocatalysis, particularly the diverse EET mechanisms with discussions on scientific insights, this review summarizes and discusses the recent advances in bioengineering highly active biocatalytic microbes and nanoengineering unique electrode nanostructures for significantly improved microbial EET processes. In particular, this review associated with our researches analyzes in more detail the EET pathways, which contain direct and mediated electron transfer. The confusion between the energy efficiency and electron transfer rate is clarified and the approaches to elevate the EET rate are further discussed. These discussions shed both theoretical and practical lights on further research and development of more high-performance microbial catalysts by using synthetic biology coupled with nanoengineering approach for high energy conversion efficiency while achieving high power density for practical applications. The challenges and perspectives are presented. It is believed that a next wave of research of microbial electrochemical systems will produce a new generation of sustainable green energy technologies and demonstrate great promise in their broad applications and industrializations.

In order to improve the mechanical and electrochemical properties of hydroxyapatite (HA) coating, nanostructured HA/Ti (nHA/Ti) composite coatings with different Ti contents of 30, 50 and 70 wt% were deposited on 316L stainless steel (SS) substrates by high-velocity suspension flame spray (HVSFS) and compared to HVSFS-deposited nanostructured HA (nHA) coatings. Microstructures and phase compositions of as-sprayed coatings were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The deposition mechanism of nanostructured HA/Ti composite coatings was also examined. Microhardness and Young's modulus were measured. Electrochemical corrosion behaviors of all coatings were tested in Hanks’ simulated body fluid using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Results showed that the nHA/Ti composite coatings contained HA and Ti in addition to some Ti-O compounds. Compared to nHA coatings, nHA/Ti composite coatings presented dense and typical lamella structures formed mostly by flattened splats. Microhardness and Young's modulus of nHA/Ti composite coatings increased with increasing Ti content. Potentiodynamic polarization and EIS measurements illustrated that nHA/Ti composite coatings had excellent corrosion resistance compared to nHA coatings and bare SS substrate.

Carbonated hydroxyapatite (CHA) coatings were deposited onto 316L stainless steel substrates using an in-house developed warm spraying system. Microstructures of the coatings were comprehensively investigated. Microhardness, tensile strength and wear resistance of the CHA coatings were examined. In addition, bioactivities of the coatings were studied after immersing in simulated body fluid (SBF). Results show that the as-sprayed coatings exhibited typical lamellar architectures consisting of partially melted and flattened splats, i.e., with molten shells and un-molten cores of original powders. The CHA coatings had nearly identical Ca/P ratios, crystalline structures and phase constitutions to those of the feedstock powders, indicating that undesired decompositions caused by overheating can be avoided by employing the warm spraying process. Microhardness and tensile strength of as-sprayed coatings were around 690 and 11.4-20.6 MPa, respectively. Moreover, the warm-sprayed CHA coating exhibited a high resistance against abrasion wear when sliding took place with polymers. After being immersed in Hank’s SBF for 28 and 60 days, new apatite was formed on the coating surface corroborating the good biocompatibility of the coating.

A three dimensional (3D) porous nickel oxide (NiO)/graphene composite is developed through one-pot hydrothermal synthesis with a biopolymer-pectin for tailoring the porous structure. The introduction of pectin makes the NiO grow into nanoflakes-assembled micro spheres that insert in the graphene layers rather than just deposit on the surface of graphene nanosheets as nanoparticles. As the increase of pectin ratio, the size and the amount of NiO micro spheres are both increased, which resulting a 3D hierarchical porous structure. With the optimized pectin concentration, the obtained NiO/graphene nanocomposite anode possesses good electrocatalytic capability and delivers maximum power density of 3.632 Wm−2 in Shewanella putrefaciens CN32 microbial fuel cells (MFCs). This work provides a new way to develop low cost, high performance anode materials for MFCs.

Hollow microflower-shaped CoSe2 particles were successfully constructed and further evaluated as an anode material for sodium-ion batteries. It yielded a large discharge capacity of 220 mA h g−1 and ultralong cycle life of 1690 cycles at 1 A g−1. This ultralong cycle life can be attributed to a surface-controlled pseudocapacitive behavior and resulting rapid electron/sodium ion transport.

An efficient microbial electrocatalysis in microbial fuel cells (MFCs) needs both high loading of microbes (biocatalysts) and robust interfacial electron transfer from microbes to electrode. Herein a nanoporous molybdenum carbide (Mo2C) functionalized carbon felt electrode with rich 3D hierarchical porous architecture is applied as MFC anode to achieve superior electrocatalytic performance. The nanoporous Mo2C functionalized anode exhibits strikingly improved microbial electrocatalysis in MFCs with 5-fold higher power density and long-term stability of electricity production. The great enhancement is attributed to the introduction of rough Mo2C nanostructural interface into macroporous carbon architecture for promoting microbial growth with great excretion of endogenous electron shuttles (flavins) and rich available nanopores for enlarging electrochemically active surface area. Importantly, the nanoporous Mo2C functionalized anode is revealed for the first time to have unique electrocatalytic activity towards redox reaction of flavins with more negative redox potential, indicating a more favourable thermodynamic driving force for anodic electron transfer. This work not only provides a promising electrode for high performance MFCs but also brings up a new insight into the effect of nanostructured materials on interfacial bioelectrocatalysis.

The development of low-cost, scalable and realistic electrodes with robust catalytic activity and stability remains a great challenge for large-scale hydrogen production from electrochemical water splitting. Herein, we firstly reported a 3D self-supported porous hydrogen evolution cathode constructed by in-situ growth of nano-porous molybdenum carbide (Mo2C) nanoflakes on a commercial graphite felt (GF) through a facile electrostatic self-assembly followed by high-temperature carburization approach. Owing to a synergistic effect from high activity of nano-porous Mo2C and rich macroporous architecture of GF for fast diffusion of electrolyte and generated hydrogen bubbles, the 3D Mo2C@GF hybrid electrode only needs a low overpotential of 124 and 129 mV to deliver a cathodic current density of 10 mA cm−2 in 0.5 M H2SO4 and 1 M KOH solution, respectively. Particularly, the strong incorporation of nano-Mo2C onto graphite fibers promotes interfacial electron transfer and enables superior stability and durability in both acidic and basic electrolyte. This work provides a proof of concept and design rules for developing truly workable electrodes with promising potential in practical hydrogen evolution.

Both physical structure and chemical property of an electrode play critical roles in extracellular electron transfer from microbes to electrodes in microbial fuel cells (MFCs). Herein a novel polyaniline hybridized large mesoporous carbon (PANI-LMC) anode is fabricated from natural biomass by nanostructured CaCO3 template-assisted carbonization followed by in situ chemical polymerizing PANI to enable fast extracellular electron transfer, in which the LMC with rich disorder-interconnected large mesopores (∼20−50 nm) and large surface area facilitates a fast mediated electron transfer through electron mediators, while the decorated PANI on LMC surface enables the direct electron transfer via bacterial outer-membrane redox centers. Owing to the unique synergistic effect from both excellent electron transfer paths, the PANI-LMC hybrid anode harvests high power electricity with a maximum output power density of 1280 mW m−2 in Shewanella putrefaciens CN32 MFCs, 10-fold higher than that of conventional carbon cloth. The findings from this work suggest a new insight on design of high-efficient anode according to the multiple and flexible electrochemical process for practical MFC applications.

Microbial electrochemical system (MES) has attracted ever-growing interest as a promising platform for renewable energy conversion and bioelectrochemical remediation. Shewanella species, the dissimilatory metal reduction model bacteria with versatile extracellular electron transfer (EET) strategies, are the well-received microorganisms in diverse MES devices for various practical applications as well as microbial EET mechanism investigation. Meanwhile, the available genomic information and the unceasing established gene-editing toolbox offer an unprecedented opportunity to boost the applications of Shewanella species in MES. This review thoroughly summarizes the status quo of the applications of Shewanella species in microbial fuel cells for bioelectricity generation, microbial electrosynthesis for biotransformation of valuable chemicals and bioremediation of environment-hazardous pollutants with synoptical discussion on their EET mechanism. Recent advances in rational design and genetic engineering of Shewanella strains for either promoting the MES performance or broadening their applications are surveyed. Moreover, some emerging applications beyond electricity generation, such as biosensing and biocomputing, are also documented. The challenges and perspectives for Shewanella-based MES are also discussed elaborately for the sake of not only discovering new scientific lights on microbial extracellular respiratory but also propelling practical applications.

An effective protocol of photoredox catalyzed C2-alkylation of benzothiazoles with aliphatic carboxylic acids was disclosed. In the presence of an acridinium salt as a photocatalyst and air as an oxidant, a wide range of secondary or tertiary aliphatic carboxylic acids were employed as alkylation reagents, providing the desired products in good to excellent yields under mild reaction conditions with a broad substrate scope.

To overcoming their respective shortcomings of graphene and carbon nanotube, a hierarchically porous multi-walled carbon nanotube@reduced graphene oxide (MWCNT@rGO) hybrid is fabricated through a versatile and scalable solvent method, in which the architecture is tailored by inserting MWCNTs as scaffolds into the rGO skeleton. An appropriate amount of inserted 1-D MWCNTs not only effectively prevent the aggregation of rGO sheets but also act as bridges to increase multidirectional connections between 2-D rGO sheets, resulting in a 3-D hierarchically porous structure with large surface area and excellent biocompatibility for rich bacterial biofilm and high electron transfer rate. The MWCNT@rGO 1:2 /biofilm anode delivers a maximum power density of 789 mW m −2 in Shewanella putrefaciens CN32 microbial fuel cells, which is much higher than that of individual MWCNT and rGO, in particular, 6-folder higher than that of conventional carbon cloth. The great enhancement is ascribed to a synergistic effect of the integrated biofilm and hierarchically porous structure of MWCNT@rGO 1:2 /biofilm anode, in which the biofilm provides a large amount of bacterial cells to raise the concentration of local electron shuttles for accelerating the direct electrochemistry on the 3-D hierarchically porous structured anodes.

Advanced glycation endproducts (AGEs) have been recognized as hazards in processed foods that can induce chronic diseases such as cardiovascular disease, diabetes, and diabetic nephropathy. In this study, we investigated the AGEs contents of 35 types of industrial seafood products that are consumed frequently in eastern China. Total fluorescent AGEs level and Ne-carboxymethyl-lysine (CML) content were evaluated by fluorescence spectrophotometry and gas chromatography-mass spectrometry (GC-MS), respectively. The level of total fluorescent AGEs in seafood samples ranged from 39.37 to 1178.3 AU, and was higher in canned and packaged instant aquatic products that were processed at high temperatures. The CML content in seafood samples ranged from 44.8 to 439.1 mg per kg dried sample, and was higher in roasted seafood samples. The total fluorescent AGEs and CML content increased when seafood underwent high-temperature processing, but did not show an obvious correlation. The present study suggested that commonly consumed seafood contains different levels of AGEs, and the seafood processed at high temperatures always displays a high level of either AGEs or CML.

An amine-terminated ionic liquid (IL-NH 2 ) is applied to functionalize carbon nanotubes (CNTs) for improving the interfacial electron transfer of Shewanella putrefaciens (S. putrefaciens) anode in Microbial fuel cells (MFCs). The introduction of thin layer of ILs does not change the morphology of CNTs a lot but increases surface positive charges as well as nitrogen functional groups of the CNTs based anode. The CNT-IL composite not only improves the adhesion of S. putrefaciens cells but also promotes both of the flavin-mediated and the direct electron transfer between the S. putrefaciens cells and the anode. It is interesting that the CNT-IL is more favorable for the mediated electron transfer than for the direct electron transfer. The CNT-IL/carbon cloth anode delivers 3-fold higher power density than that of CNT anode and shows great long-term stability in the batch-mode S. putrefaciens MFCs. This CNT-IL could be a promising anode material for high performance MFCs.

Effects of oligonucleotide length and probe number on the assembly of gold nanoparticles (AuNPs) with DNA origami templates were investigated for the first time. The optimal length and probe number are proposed to efficiently anchor AuNPs for the construction of plasmonic chiral nanostructures.

In this paper, the solubility of 5,5′-bis(2,4,6-trinitrophenyl)-2,2′-bis(1,3,4-oxadiazole) (TKX-55) was first determined by a dynamic laser monitoring at T = (293.15, 298.15, 303.15, 308.15, 313.15, 318.15, 323.15, 328.15 and 333.15) K in fourteen pure solvents, including nitrobenzene (NB), methylethylketone (MEK), dimethyl carbonate (DMC), N,N-dimethylformamide (DMF), methoxybenzene (MOB), ethenyl acetate (VAC), 1,2-propanediol (PDO), cyclohexanone (CYC), epichlorohydrin (ECH), 1-butanol (NBA), n-butyl acrylate (BA), dimethyl sulfoxide (DMSO), tributyl phosphate (TBP) and 2-butanol (IBA), under atmospheric pressure (P = 0.1 MPa). Besides, supersolubility as well as the metastable zone width of TKX-55 in PDO, BA, DMSO and IBA was determined by the dynamic laser monitoring method. The experimental results showed that the solubility of TKX-55 in fourteen pure solvents increases with increasing temperature and the metastable zone width decreases with increasing temperature. The metastable zone width is approximately 2.49 K–43.26 K. In addition, in order to improve the applicability of the solubility, the modified Apelblat equation, λh equation, the polynomial empirical equation, van't Hoff equation and NRTL equation were used to correlate the solubility data of TKX-55, and the results showed that all models can give a satisfactory correlation. The average root-mean-square deviation (102RMSD) values were 1.71, 8.91, 2.33, 6.12 and 3.30, respectively. Moreover, Hansen solubility parameter was used for explaining the solubility order of TKX-55 in selected solvents, the consequences showed that solubility order of TKX-55 resulted from the comprehensive function of several solubility parameters. The solubility parameter of Δδt between TKX-55 and solvents reached from 1.27 MPa0.5 to 15.28 MPa0.5. Furthermore, three kinds of thermodynamic properties of the mixing enthalpy (ΔmixH), the mixing entropy (ΔmixS) and the mixing Gibbs energy (ΔmixG) of TKX-55 in selected solvents were calculated by NRTL equation and the results turned out that the dissolution process was spontaneous. Besides, thermal properties of TKX-55 were measured by differential scanning calorimetry (DSC). The results showed that the melting temperature and the fusion enthalpy were 640.65 K and 19.60 kJ·mol−1, respectively. Finally, solubility values and thermodynamic relations of TKX-55 in fourteen pure solvents would be invoked as fundamental data and models regarding the purification process.

A rapid and sensitive immunochromatographic strip (ICS) based on a single-chain variable fragment (scFv) was developed for detecting fumonisin B1 (FB1). The ICS was based on a competitive reaction for colloidal gold-labeled scFv between FB1 and FB1-BSA, which was used along with sheep anti-mouse IgG as capture reagents immobilized at test and control lines, respectively, on a nitrocellulose membrane of the strip. The limit of detection of the ICS was 2.5 ng/mL (25 μg/kg) FB1 in buffer, and the sensitivity was eight times higher than that of monoclonal antibodies for the preparation of the scFv. The cross-reactivity of the scFv with common mycotoxins was determined by ICS, the results showed that the scFv were not against other mycotoxins. Eight naturally contaminated maize samples were analyzed with the scFv-based ICS and by LC-MS/MS. The results of analysis obtained with the strip assay showed good agreement with those obtained by LC-MS/MS.

This work demonstrates the efficiency of machine learning in the correction of spectral intensity variations in laser-induced breakdown spectroscopy (LIBS) due to changes of the laser pulse energy, such changes can occur over a wide range, from 7.9 to 71.1 mJ in our experiment. The developed multivariate correction model led to a precise determination of the concentration of a minor element (magnesium for instance) in the samples (aluminum alloys in this work) with a precision of 6.3% (relative standard deviation, RSD) using the LIBS spectra affected by the laser pulse energy change. A comparison to the classical univariate corrections with laser pulse energy, total spectral intensity, ablation crater volume and plasma temperature, further highlights the significance of the developed method.

In this study, two new antibacterial complexes based on the quinolone antibacterial drugs Norfloxacin (NF) and Ciprofloxacin (CF) and the polyoxometalates (POMs) were synthesized, that is, [CoII(C16H18FN3O3)2]2H4[SiW12O40]·6H2O (1) and [Co II (C17H18FN3O3)2]2H4[SiW12O40]·2H2O (2). Then the complexes were comprehensively characterized by elemental analysis, infrared (IR) spectroscopy, and X-ray single-crystal diffraction. Single-crystal structural analysis revealed that complexes 1 and 2 were made up of SiW12 clusters, binuclear cobalt clusters, and water molecules. Moreover, it was observed that the SiW12 clusters in complexes 1 and 2 formed inorganic chains through covalent bonds and three-dimensional (3D) supramolecular structures through noncovalent N⋯O interactions. In this work, we also assessed the antibacterial activities of complexes 1 and 2 using Escherichia coli, Staphylococcus aureus, and Bacillus subtilis strains. In general, it was found that the antibacterial activities of complexes 1 and 2 were slightly higher than those of free NF and CF at the same mass concentrations. Furthermore, we evaluated the capacity of complexes 1 and 2 to bind to calf thymus DNA (CT-DNA) using spectroscopic titrations in the UV range. These studies showed that complexes 1 and 2 bound to CT-DNA with binding constants (Kb) of 4.1 × 104 and 1.6 × 104 M L−1, respectively, which were somewhat lower than those of pure NF and CF (8.2 × 104 and 4.9 × 104 M L−1), respectively. These results indicated that the introduction of different drug molecules into the POM system can affect their antibacterial activities.

A new antibacterial complex based on the quinolone antibacterial drug ciprofloxacin (CF) and the polyoxometalates (POMs), [Co II (C17H18FN3O3)2]2H2[SiW12O40]·2H2O (1), has been synthesized and comprehensively characterized by elemental analyses, IR, and single crystal X-ray diffraction approaches. Single-crystal structural analysis revealed that complex 1 is composed of Keggin clusters grafted by binuclear cobalt clusters and water molecules. Moreover, we observed that complex 1 formed inorganic-organic hybrid chains via covalent bonds, and could also form a 2D supramolecular layer structure by N··O stacking. In this work, we assessed the antibacterial activities of complex 1 using Escherichia coli, Staphylococcus aureus, and Bacillus subtilis strains. In general, we observed that the antibacterial activities of complex 1 were slightly higher than that of free CF at the same mass concentrations. Overall, the results suggest that introduction of POMs to modify the CF not only affects the final structure of CF but also affects its antibacterial activities.

The normal state of cuprate superconductors exhibits many exotic behaviors qualitatively different from the Fermi liquid, the foundation of condensed-matter physics. Here we demonstrate that non-Fermi-liquid behaviors emerge naturally from scattering against an emergent Bose liquid. Particularly, we find a finite zero-energy scattering rate at the low-temperature limit that grows linearly with respect to temperature, against clean fermions' generic nondissipative characteristics. Surprisingly, three other seemingly unrelated experimental observations are also produced, including the well-studied ``kink'' in the quasiparticle dispersion, as well as the puzzling correspondences between the normal and superconducting states. Our findings provide a general route for fermionic systems to generate non-Fermi-liquid behavior and suggest that by room temperature large number of the doped holes in the cuprates have already formed an emergent Bose liquid of tightly bound pairs, whose low-temperature condensation gives unconventional superconductivity.

A new method-multifractal temporally weighted detrended cross-correlation analysis (MF-TWXDFA)-is proposed to investigate multifractal cross-correlations in this paper. This new method is based on multifractal temporally weighted detrended fluctuation analysis and multifractal cross-correlation analysis (MFCCA). An innovation of the method is applying geographically weighted regression to estimate local trends in the nonstationary time series. We also take into consideration the sign of the fluctuations in computing the corresponding detrended cross-covariance function. To test the performance of the MF-TWXDFA algorithm, we apply it and the MFCCA method on simulated and actual series. Numerical tests on artificially simulated series demonstrate that our method can accurately detect long-range cross-correlations for two simultaneously recorded series. To further show the utility of MF-TWXDFA, we apply it on time series from stock markets and find that power-law cross-correlation between stock returns is significantly multifractal. A new coefficient, MF-TWXDFA cross-correlation coefficient, is also defined to quantify the levels of cross-correlation between two time series.

Bacteria biofilm plays a key role in current generation of microbial fuel cells (MFCs), especially for the start-up stage. However, the detailed mechanism of the biofilm promoting the power generation is not very clear so far, especially for those exoelectrogens who rely on the self-excreted electron mediators for extracellular electron transfer. In this work, a biofilm formation inhibitor-sodium houttuyfonate (SH) is used to build a "non-biofilm" anode of Pseudomonas aeruginosa (P. aeruginosa) without affecting the bacteria growth during the MFC operation. According to the comparison results of the "non-biofilm" anode and biofilm-covered anode on current generation, phenazines concentration variation and anodic electrocatalysis, the biofilm on the anode not only provides plenty of bacterial cells for catalysis but also promotes the interfacial phenazine redox reaction through accumulating the self-generated mediators on anode for fast interfacial electron transfer. This work proves that the biofilm assisted electron mediator accumulation will benefit such kind of exoelectrogens to sustain sufficient electron mediators for extracellular electron transfer.

C38H42MnN4O14, monoclinic, C2/c (no. 15), a = 19.165(12) Å, b = 10.116(6) Å, c = 20.734(13) Å, β = 99.021(11)°, V = 3970(4) Å3, Z = 4, R gt(F) = 0.0486, wR ref(F 2) = 0.1442, T = 293(2) K.

The detection of aflatoxin B1 (AFB1) using immunoassays, especially electrochemical immunoassays, is fast, sensitive and efficient. In this study, 2-aminoethanethiol was used to enhance the speed and sensitivity of conventional electrochemical immunoassays for AFB1 detection by assembly on the surface of a Au electrode, forming self-assembled monolayers (SAMs). Then, non-competitive immunoassays occurred on the modified electrode surface forming an electrochemical immunoassay sensor. X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy were used to examine the state of the SAMs, and an electrochemical workstation was used to monitor the current change of the electrochemical reaction, so as to characterize the designed immunosensor. Our experimental results shows that, the 2-aminoethanethiol reagent was successfully assembled on the Au surface through Au-S bonding and the –NH2 terminal group faced outward. Herein, the minimum concentration of AFB1 which caused a significant current change was 0.01 ng mL−1. The prepared immunosensor also exhibited excellent stability and sensitivity after storage for 7 days or upon regeneration.