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A weak circumferential resolution of defects in the corner part of engineering components brings great challenges to quantitative non-destructive testing. Especially for the corner of carbon fiber reinforced plastics (CFRP), the complex wave propagation behaviors caused by the elastic anisotropy, laminate structure, and curved surface make the information of defects hard to be distinguished, which finally results in a poor imaging resolution. The surface adaptive ultrasonic (SAUL) method for CFRP corner is investigated, and an improved strategy, focusing in receiving (FiR) of SAUL signals is proposed here. With an isotropic plexiglass as a comparison, the effectiveness of FiR is verified by finite element simulations and experiments. The elastic properties of CFRP corner are accurately characterized and a finite element model is established. On this basis, the wave propagation behavior in the corner is studied, and the influence of the water distance h on the maximum amplitude (MAD) and signal-to-noise ratio (SNR) at the defect is analyzed. The results show that the structural noise can be eliminated, and the imaging quality and SNR can be improved by optimizing the h. After FiR, the maximum increase of defect amplitude is about 9.5 dB and 13.2 dB for plexiglass and CFRP, respectively. Meanwhile, the maximum relative error in length is reduced by 16.7% in plexiglass, and by 13.4% for the 3-mm delamination in CFRP. The strategy would be promising to improve the detection quality of the corner in curved components. [ABSTRACT FROM AUTHOR]

Zn3Mo2O9 with various morphologies were constructed using hydrothermal, solvothermal, and high-temperature solid-phase strategies and used as negative electrodes of lithium-ion batteries firstly. The Zn3Mo2O9 obtained by high-temperature solid-state method (ZMO-t) is constructed by lots of small nanosheets, which has relatively uniform size and small particles among three samples. The unique morphology is beneficial for electrolyte permeation and further promotes the migration rate of lithium ions. At various current densities, test results can illustrate that the ZMO-t exhibited the best electrochemical performance than those of Zn3Mo2O9 obtained by solvothermal method (ZMO-s) and hydrothermal way (ZMO-h) materials at the same rates. Based on these results, the Zn3Mo2O9 synthesized via high-temperature solid-state strategy has the potential to become a novel negative electrode for Li-ion batteries going forward. [ABSTRACT FROM AUTHOR]

The synergistic catalysis of heterojunction electrocatalysts for the multi-step process in hydrogen evolution reaction (HER) is a promising approach to enhance the kinetics of alkaline HER. Herein, we proposed a strategy to form nanoscale Ni/NiO heterojunction porous graphitic carbon composites (Ni/NiO-PGC) by reduction-pyrolysis of the preformed Ni-metal-organic framework (MOF) under H2/N2 atmosphere. Benefiting from low electron transfer resistance, increased number of active sites, and unique hierarchical micro-mesoporous structure, the optimized Ni/NiO-PGC10−1−400 exhibited excellent electrocatalytic performance and robust stability for alkaline HER (η10 = 30 mV, 65 h). Density functional theory (DFT) studies revealed that the redistribution of electrons at the Ni/NiO interface enables the NiO phase to easily initiate the dissociation of alkaline H2O, and shifts down the d-band center of Ni and optimizes the H* adsorption-desorption process of Ni, thereby leading to extremely high HER activity. This work contributes to a further understanding of the synergistic promotion of the multi-step HER processes by heterojunction electrocatalysts. [ABSTRACT FROM AUTHOR]

With the excessive consumption of nonrenewable resources, the exploration of effective and durable materials is highly sought after in the field of sustainable energy conversion and storage system. In this aspect, metal‐organic frameworks (MOFs) are a new class of crystalline porous organic‐inorganic hybrid materials. MOFs have recently been gaining traction in energy‐related fields. Owing to the coordination flexibility and multiple accessible oxidation states of vanadium ions or clusters, vanadium‐MOFs (V‐MOFs) possess unique structural characteristics and satisfactory electrochemical properties. Furthermore, V‐MOFs‐derived materials also exhibit superior electrical conductivity and stability when used as electrocatalysts and electrode materials. This review summarizes the research progress of V‐MOFs (inclusive of pristine V‐MOFs, V/M‐MOFs, and POV‐based MOFs) and their derivatives (vanadium oxides, carbon‐coated vanadium oxide, vanadium phosphate, vanadate, and other vanadium doped nanomaterials) in electrochemical energy conversion (water splitting, oxygen reduction reaction) and energy storage (supercapacitor, rechargeable battery). Future possibilities and challenges for V‐MOFs and their derivatives in terms of design and synthesis are discussed. Lastly, their applications in energy‐related fields are also highlighted. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks possessing relatively large pores, high surface areas, and unsaturated metal sites are attractive materials for use as electrocatalysts in the reduction of N2 to NH3. In this work, a MIL-101(Fe)/MoS3 hybrid catalyst, prepared by using a precursor-transformation strategy, is shown to be an effective electrocatalyst for the N2 reduction reaction (NRR). Under solvothermal conditions, micro-sized octahedral MIL-101(Fe) precursors are converted into ultra-small nanodots, while amorphous MoS3 derived from (NH4)2MoS4 provides a surface suitable for anchoring the MIL-101(Fe) nanodots. The as-prepared composite exhibits excellent electrocatalytic activity and durability for the NRR with a Faraday efficiency of 36.71% and an NH3 yield of 25.7 µg h−1 mgcat−1 at −0.1 V vs. RHE in 0.1 M HCl. The results show that the dispersion and adherence of MIL-101(Fe) nanodots on amorphous MoS3 improves the exposure of active centers and aids mass transfer, resulting in greatly enhanced catalytic activity and stability. [ABSTRACT FROM AUTHOR]

Therapeutic enzymes play important roles in modern medicine due to their high affinity and specificity. However, it is very expensive to use them in clinical medicine because of their low stability and bioavailability. To improve the stability and effectiveness of therapeutic enzymes, immobilization techniques have been employed to enhance the applications of therapeutic enzymes in the past few years. Reported immobilization techniques include entrapment, adsorption, and covalent attachment. In addition, protein engineering is often used to improve enzyme properties; however, all methods present certain advantages and limitations. For carrier-bound immobilization, the delivery and release of the immobilized enzyme depend on the properties of the carrier and enzyme. In this review, we summarize the advantages and challenges of the current strategies developed to deliver therapeutic enzymes and provide a future perspective on the immobilization technologies used for therapeutic enzyme delivery. [ABSTRACT FROM AUTHOR]

Sodium‐ion batteries (SIBs) have aroused great attention because of the low cost and environmental benignity of sodium resources. However, practical applications of SIBs are plagued by the sluggish kinetics of sodium ions with large size in the host structure, which results in poor rate performance and rapid capacity decline. Herein, a self‐templated approach was developed to synthesize MoS2/Cu2Se nanosheets with improved interfacial electron‐ and ion‐transfer kinetics. The MoS2/Cu2Se nanosheets provided superior sodium storage performance, delivering 139 mAh g−1 at a high current density of 100 A g−1 and 222 mAh g−1 after 14000 cycles (at 20 A g−1). The outstanding electrochemical performance was attributed to the synergetic engineering of interface and structure, which could enhance the electrochemical kinetics and gave excellent mechanical properties to deal with the volume expansion phenomenon. Combined with a high‐voltage cathode, the full battery demonstrated a high energy density of 152 Wh kg−1 at a power density of 420 W kg−1, which opens a new avenue for the development of high‐performance SIBs. [ABSTRACT FROM AUTHOR]

Okara (soybean curd residue) has a wide range of sources, but its high content of anti-nutritional factors and crude fiber. Microbial fermentation can improve the nutritional properties of okara and increase the content of active substances. Fermented okara has physiological functions such as improving intestinal health, promoting the digestion and absorption of nutrients, improving the body's antioxidant capacity and regulating fat metabolism. The article reviews the research progress on nutritional properties of fermented okara, the mechanism of active substances and its application in aquatic products, in order to provide a reference for the rational application of fermented okara in aquatic products. [ABSTRACT FROM AUTHOR]

The development of bifunctional non-noble metal electrocatalysts demonstrating high activity and stability for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of great significance for renewable and clean energy. In this work, we report hierarchically structured integrated Fe–MoS2/Ni3S2/NF (NF = nickel foam) materials prepared by a facile in situ solvothermal method, and among them, the Fe-doped MoS2 was assembled into spine-like nanorods. The optimized electrocatalyst (denoted as Fe–MoS2/Ni3S2/NF-2) demonstrated excellent activity and durability for performing the HER and OER in an alkaline electrolyte (pH = 14) with low overpotentials of 130.6 mV and 256 mV (vs. RHE) at a current density of 10 mA cm−2, as well as no significant loss in catalytic performance even after 2000 cyclic voltammetry (CV) cycles. An outstanding durability of 180 h could be achieved for OER. The overall water splitting made up of the two-electrode system with Fe–MoS2/Ni3S2/NF-2 as both the anode and the cathode required a voltage of only 1.61 V to drive a current density of 10 mA cm−2 along with an outstanding long-term stability of 20 h, displaying its great potential for application in water splitting. The effective construction of multi-component synergistic structures shows a good pathway for high-performance electrocatalysis and energy storage. [ABSTRACT FROM AUTHOR]

Ultrathin metal–organic framework (MOF) nanosheets (NSs) offer potential for many applications, but the synthetic strategies are largely limited to top‐down, low‐yield exfoliation methods. Herein, Ni–M–MOF (M=Fe, Al, Co, Mn, Zn, and Cd) NSs are reported with a thickness of only several atomic layers, prepared by a large‐scale, bottom‐up solvothermal method. The solvent mixture of N,N‐dimethylacetamide and water plays key role in controlling the formation of these two‐dimensional MOF NSs. The MOF NSs can be directly used as efficient electrocatalysts for the oxygen evolution reaction, in which the Ni–Fe–MOF NSs deliver a current density of 10 mA cm−2 at a low overpotential of 221 mV with a small Tafel slope of 56.0 mV dec−1, and exhibit excellent stability for at least 20 h without obvious activity decay. Density functional theory calculations on the energy barriers for OER occurring at different metal sites confirm that Fe is the active site for OER at Ni–Fe–MOF NSs. [ABSTRACT FROM AUTHOR]

Ultrathin metal–organic framework (MOF) nanosheets (NSs) offer potential for many applications, but the synthetic strategies are largely limited to top‐down, low‐yield exfoliation methods. Herein, Ni–M–MOF (M=Fe, Al, Co, Mn, Zn, and Cd) NSs are reported with a thickness of only several atomic layers, prepared by a large‐scale, bottom‐up solvothermal method. The solvent mixture of N,N‐dimethylacetamide and water plays key role in controlling the formation of these two‐dimensional MOF NSs. The MOF NSs can be directly used as efficient electrocatalysts for the oxygen evolution reaction, in which the Ni–Fe–MOF NSs deliver a current density of 10 mA cm−2 at a low overpotential of 221 mV with a small Tafel slope of 56.0 mV dec−1, and exhibit excellent stability for at least 20 h without obvious activity decay. Density functional theory calculations on the energy barriers for OER occurring at different metal sites confirm that Fe is the active site for OER at Ni–Fe–MOF NSs. [ABSTRACT FROM AUTHOR]

Abstract: Metal–organic frameworks (MOFs) are a class of promising materials for diverse heterogeneous catalysis, but they are usually not directly employed for oxygen evolution electrocatalysis. Most reports focus on using MOFs as templates to in situ create efficient electrocatalysts through annealing. Herein, we prepared a series of Fe/Ni‐based trimetallic MOFs (Fe/Ni/Co(Mn)‐MIL‐53 accordingly to the Material of Institute Lavoisier) by solvothermal synthesis, which can be directly adopted as highly efficient electrocatalysts. The Fe/Ni/Co(Mn)‐MIL‐53 shows a volcano‐type oxygen evolution reaction (OER) activity as a function of compositions. The optimized Fe/Ni2.4/Co0.4‐MIL‐53 can reach a current density of 20 mA cm−2 at low overpotential of 236 mV with a small Tafel slope of 52.2 mV dec−1. In addition, the OER performance of these MOFs can be further enhanced by directly being grown on nickel foam (NF). [ABSTRACT FROM AUTHOR]

Abstract: Metal–organic frameworks (MOFs) are a class of promising materials for diverse heterogeneous catalysis, but they are usually not directly employed for oxygen evolution electrocatalysis. Most reports focus on using MOFs as templates to in situ create efficient electrocatalysts through annealing. Herein, we prepared a series of Fe/Ni‐based trimetallic MOFs (Fe/Ni/Co(Mn)‐MIL‐53 accordingly to the Material of Institute Lavoisier) by solvothermal synthesis, which can be directly adopted as highly efficient electrocatalysts. The Fe/Ni/Co(Mn)‐MIL‐53 shows a volcano‐type oxygen evolution reaction (OER) activity as a function of compositions. The optimized Fe/Ni2.4/Co0.4‐MIL‐53 can reach a current density of 20 mA cm−2 at low overpotential of 236 mV with a small Tafel slope of 52.2 mV dec−1. In addition, the OER performance of these MOFs can be further enhanced by directly being grown on nickel foam (NF). [ABSTRACT FROM AUTHOR]

Cuboidal [Ni4O4] clusters supported by a pyridine alkoxide ligand have been developed. One of these clusters was selected as a precursor for carbon-hosted Ni nanoparticles (NiNPs/C) which were efficient catalysts for the conversion of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) at room temperature. [ABSTRACT FROM AUTHOR]

In this work, we fabricate new yolk–shell Pd@ZIF-8 (ZIF = zeolitic imidazolate framework) nanoparticles (NPs) through reactions of the preformed core–shell Pd@ZnO NPs with 2-methylimidazole under mild conditions. In this method, ZnO is used as the self-template and the Zn2+ source for the formation of the ZIF-8 shell. The morphology, composition and structure of the as-prepared yolk–shell nanomaterial are characterized by scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, powder X-ray diffraction, energy dispersive X-ray spectroscopy, and inductively coupled plasma atomic emission spectroscopy. The formation of this well-defined yolk–shell nanostructure is highly dependent on the solvent system and reaction time. This nanomaterial can be employed as an excellent heterogeneous catalyst for the liquid-phase hydrogenation of olefins with high size-selectivity at room temperature, which is mainly due to the inherent porous structure of the outer ZIF-8 shell along with the enclosed Pd NPs. The nanocatalyst system can be recycled at least three times without any evident loss of the catalytic efficiency. [ABSTRACT FROM AUTHOR]

We report the synthesis of unique Au–Pd bimetallic alloy nanoparticles (NPs) supported on a hollow Cu2O–CuO core–shell heterostructure via the galvanic replacement method, which represents the first example of Au–Pd alloy nanoparticles immobilized on hollow Cu2O@CuO nanocubes. The morphological evolution can be controlled by the reaction time. The morphology, composition, and structure of the as-prepared Cu2O@CuO/(Au–Pd) material are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), elemental analysis (EDS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The size of the Au–Pd bimetallic NPs deposited onto the Cu2O@CuO nanocubes is ca. 15 nm. These bimetallic NPs showed a high catalytic activity towards the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in water at room temperature. Significantly, the strong synergistic effect between Au and Pd, and the high specific surface area of Cu2O@CuO enhance the catalytic efficiency. The catalytic system can be reused for several cycles without any obvious decay of the catalytic efficiency. [ABSTRACT FROM AUTHOR]

An efficient method for synthesis of 1,3-diynes through the CuI/1,10-phenanthroline-catalyzed oxidative decarboxylative homocoupling of aryl pioprolic acids in aqueous DMF has been developed. The catalytic system was suitable for a variety of arylpropiolic acids, and the corresponding 1,3-diynes could be prepared in high yields. The catalytic system was recovered from the organic products by filtration and its aqueous DMF filtrate retained good activity even after at least four cycles of use. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the curative efficacy of osteonecrosis of the femoral head (ONFH) in a hip-preserving operative approach, by grafting a vascularized greater trochanter flap combined with a free iliac flap, in an attempt to seek an innovative approach for patients who suffered middle to late stage ONFH without total hip arthroplasty (THA) surgery. Method: Our research included a total of 60 patients (66 hips) who accepted hip-preserving surgery by grafting a vascularized greater trochanter flap combined with a free iliac flap which was tightly filled by hammering because of ONFH (most were Association Research Circulation Osseous (ARCO) stage III patients) from January, 2006 to December, 2010. A Harris Hip Score was obtained during follow-ups, evaluating the clinical efficacy, X-rays were taken regularly for image assessing, and the SF-36 scale was used for estimating quality of life. Terminal observation time was considered when patients had symptom-dependant indications for performing another hip-preserving surgery or THA surgery. Results: Fifty-eight patients (64 hips) were eventually contacted by telephone for an out-patient clinic return visit, with a mean follow-up time of 35.8 months (varied from 12 months to 60 months), but two patients lost contact for various reasons. The demographic data were as follows: there were 16 ARCO IIIA cases, 22 ARCO IIIB cases, and 26 ARCO IIIC cases, respectively. Postoperative X-rays revealed a well-repaired necrotic area of the femoral head and improvement of femoral-acetabulum coverage. The last follow-up mean Harris Hip Score was 86.56 ± 7.38 (excellent results reached 87.50 %), which were greatly improved compared to 50.95 ± 6.86 pre-operatively. Also the postoperative mean scores of all dimensions of the SF-36 scale were improved to some extent. Additionally the physical component summary (PSC) scores were enhanced from 42 ± 13 pre-operatively to 78 ± 11, while the postoperative mental component summary (MCS) scores (76 ± 11) largely increased in contrast to pre-operative scores (51 ± 10), with both target indices having statistical significance ( p = 0.005, p = 0.01), signifying hugely improvement of the quality of life of the patients. A correlation was found between Harris Hip Score and all dimensions of SF-36 scale ( r = 0.32-0.72), especially closely correlated with physical functioning (PF), role-physical (RP) and bodily pain (BP) in PCS aspect ( r = 0.72, p < 0.01; r = 0.58, p < 0.01; r = 0.65, p < 0.01, respectively). Conclusion: There is definite curative efficacy for the treatment of ONFH with an hip-preserving operative approach by grafting a vascularized greater trochanter flap combined with a free iliac flap which was tightly filled by hammering. This kind of operative approach reconstructs the biological stability of femoral head, which promotes repair of necrotic areas and indirectly preserves the femoral head of patients and a majority of hip function. It possesses vast clinical as well as practical significance, because the long-term efficacy can satisfy fundamental life requirements, especially for those young and middle-aged patients who suffer ONFH to avoid or put off the time of total hip arthroplasty(THA) surgery. [ABSTRACT FROM AUTHOR]

Highlights from the article: Specific Immobilization of Escherichia coli Expressing Recombinant Glycerol Dehydrogenase on Mannose-Functionalized Magnetic Nanoparticles. Escherichiacoli Expressing Recombinant Glycerol Of Escherichia coli expressing recombinant glycerol dehydrogenase on mannose-functionalized magnetic.

The development of highly active, stable, low‐cost, and earth‐abundant electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) remains a great challenge. Herein, the cobalt (Co)‐modified MoS2 hybrid catalysts grown on nickel foam (NF) are successfully synthesized by a facile solvothermal method. The optimized catalyst (denoted as Co‐Mo‐S‐2/NF) shows excellent HER activity with low overpotentials of 77 and 96 mV at a current density of 10 mA cm−2, as well as excellent stability with negligible loss of the cathodic current after 3000 cycles in 1.0 M KOH and 1.0 M phosphate‐buffered saline (pH = 7), respectively. Significantly, when used as OER catalyst, the Co‐Mo‐S‐2/NF hybrid also displays outstanding OER activity with a low overpotential of 294 mV at a current density of 10 mA cm−2 and good long‐term stability for 120 h at 10 mA cm−2 without observable fading under alkaline condition. The excellent electrocatalytic activity of the generated catalyst is mainly due to abundant active site, large active area, improved conductivity, and synergistic effect within MoS2, Co9S8, and CoMoS3.13. This work provides a unique strategy to design the high‐performance and stable electrocatalysts for HER and OER. [ABSTRACT FROM AUTHOR]

Mannose-functionalized magnetic nanoparticles were prepared for the immobilization of Escherichia coli cells harboring the recombinant glycerol dehydrogenase gene. Immobilization of whole E. coli cells on the carrier was carried out through specific binding between mannose on the nanoparticles and the FimH lectin on the E. coli cell surface via hydrogen bonds and hydrophobic interactions. The effects of various factors including cell concentration, pH, temperature, and buffer concentration were investigated. High degrees of immobilization (84%) and recovery of activity (82%) were obtained under the following conditions: cell/support 1.3 mg/mL, immobilization time 2 h, pH 8.0, temperature 4°C, and buffer concentration 50 mM. Compared with the free cells, the thermostability of the immobilized cells was improved 2.56-fold at 37 °C. More than 50% of the initial activity of the immobilized cells remained after 10 cycles. The immobilized cells were evaluated functionally by monitoring the catalytic conversion of glycerol to 1,3-dihydroxyacetone (DHA). After a 12 h reaction, the DHA produced by the immobilized cells was two-fold higher than that produced by the free cells. These results indicate that mannose-functionalized magnetic nanoparticles can be used for the specific recognition of gram-negative bacteria, which gives them great potential in applications such as the preparation of biocatalysts and biosensors and clinical diagnosis. [ABSTRACT FROM AUTHOR]