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A new GelMA/κ-carrageenan (GelMA/KC) double network (DN) hydrogel with excellent physical properties and biocompatibility is developed through a double cross-linking strategy.

Biochar reinforced advanced nanocomposites are of interest to a wide circle of researchers. Herein, we describe a novel MOF-derived reinforced cow dung biochar composite, which was prepared by a one-step hydrothermal method to form the MOF MIL-125(Ti) onto a nitrogen and sulfur co-doped bio-carbon (NSCDBC). The UV-vis diffuse reflectance spectrum of NSCDBC/MIL-125(Ti) exhibits an extension of light absorption in the visible region (360-800 nm), indicating its higher visible light capture capacity relative to pure MIL-125(Ti). The photocatalytic activity results show that all the NSCDBC/MIL-125(Ti) composite samples, namely NSCM-5, NSCM-10, NSCM-20 and NSCM-30 display good performance in the removal of tetracycline hydrochloride compared to pure MIL-125(Ti). Among them, NSCM-20 exhibits the highest catalytic activity with a removal rate of 94.62%, which is attributed to the excellent adsorption ability of NSCDBC and the ability to inhibit the complexation of photogenerated electron-hole pairs. Photoluminescence verifies that the loading of biochar successfully enhances the separation of photogenerated electron-hole pairs. Subsequently, the active species in the photocatalytic process are identified by using electron spin resonance spin-trap techniques and free radical trapping experiments. Finally, the possible reaction mechanism for the photocatalytic process is revealed. These results confirm that NSCDBC/MIL-125(Ti) is a potentially low-cost, green photocatalyst for water quality improvement.

Graphene grown on metal substrates has been reported to provide efficient and robust hydrophobicity during water vapor condensation on metal surfaces. However, due to the intrinsic negative coefficient of thermal expansion (CTE) of graphene, the potential thermal stress in real application environments can cause CTE mismatch and then damage the protective graphene coatings, leading to loss of surface hydrophobicity and anticorrosion properties. In this study, the effect of thermal treatments on anticorrosion properties and subsequent hydrophobicity of the graphene surface has been investigated. The as-grown graphene on nickel (Ni–Gr) is explored in terms of survival under severe thermal cycling (up to 14.62 °C s−1) and effectively maintains its surface properties. As a comparison, the as-grown graphene on copper (Cu–Gr) easily peeled off from the metal surface due to the thermal stress and intercalation of oxides. The thermal treatment at 200 °C under ambient atmosphere can elevate the corrosion rate 2.2 times and 29 times on the Ni–Gr and Cu–Gr surfaces compared to situations without thermal treatments, respectively. This study shows that the Ni–Gr surface is significantly more robust than the Cu–Gr surface as a sustainable hydrophobic surface in a complicated thermal environment.

In this study, dendritic polyamine chitosan beads with and without 2-aminomethyl pyridine were facilely prepared and characterized. Compared to CN (without the pyridine function), more adsorption active sites, larger pores, higher nitrogen content, higher specific surface area, and higher strength could be obtained for CNP (with the pyridine function). CNP microspheres afforded a larger adsorption capacity than those obtained by CN for different pH values; further, the uptake amounts of Cu(II) were 0.84 and 1.12 mmol g−1 for CN and CNP beads, respectively, at pH 5. The CNP microspheres could scavenge Cu(II) from highly acidic and salty solutions: the maximum simulated uptake amount of 1.93 mmol g−1 at pH 5 could be achieved. Due to the strong bonding ability and weakly basic property of pyridine groups, the adsorption capacity of Cu(II) at pH 1 was 0.75 mmol g−1 in highly salty solutions, which was comparative to those obtained from the commercial pyridine chelating resin M4195 (QCu(II) = 0.78 mmol g−1 at pH 1). In addition, a distinct salt-promotion effect could be observed for CNP beads at both pH 5 and 1. Therefore, the prepared adsorbent CNP beads can have promising potential applications in the selective capturing of heavy metals in complex solutions with higher concentrations of H+ and inorganic salts, such as wastewaters from electroplating liquid and battery industries.

Control of the deposition location and morphology of metals on semiconductors is of considerable importance for the fabrication of metal–semiconductor hybrid structures. For this purpose, selective nanoscale deposition of gold on silicon was successfully achieved by a two-step method in this paper. The first preparation step comprises the fabrication of ripples with a femtosecond laser. The second preparation step is to immerse the samples in a mixed aqueous solution of hydrofluoric acid (HF) and chloroauric acid (HAuCl4). The periodically ablated ripple structures on silicon surfaces fabricated by the femtosecond laser changed the physical and chemical properties of silicon and then controlled the nucleation positions of gold nanoparticles. Gold particles tend to grow in raised positions of the ripples and no substantial growth was observed in the recesses of the ablated ripple structures. Similar phenomena were observed on the modified ripple structures; this led to the formation of periodically distributed gold sub-micron wires. Above all, this paper proposes a new mask-free method of selective metal electroless deposition that can be realized without complicated experimental equipment and tedious experimental operations.

A one-pot synthesis, initiated by a copper salt with inorganic (NH4)2CO3 as the nitrogen source, forms divergent aryl imidazole derivatives from ketones via α-amination and oxidative C–C bond cleavage reactions. The approach provides a simple and rapid synthesis of imidazole derivatives and has certain versatility.

A new cyanate ester resin-based composite with higher toughness and thermal conductivity was developed. First, a poly(n-butyl acrylate)/poly(methyl methacrylate-co-acrylamide) (PBMAM) core–shell structured latex was prepared by seeded emulsion polymerization. Second, hexagonal boron nitride (h-BN) particles were modified by a surface coupling agent, 3-(2-amino ethyl amino)propyl trioxysilane, to improve the dispersion in cyanate ester resin (BADCy). Third, PBMAM and the modified boron nitride were mixed with BADCy resin to increase mechanical properties and thermal conductivity. The monomer conversion in the emulsion polymerization process of the PBMAM was monitored by determining the solid content. Its particle size was characterized by dynamic laser scattering, and the morphology of the particles was characterized using scanning and transmission electron microscopes. The modified boron nitride (ABN) was verified by FTIR and TGA measurements. The mechanical properties and thermal conductivity of the BADCy/PBMAM/ABN composites were determined at various BN contents. Results showed that the unnotched impact strength of the composite increased by 151% and the thermal conductivity increased by 85% at a PBMAM content of 5 wt% and ABN content of 6 wt%. With the enhanced properties and ease of fabrication, the developed composites have good potential for application in high-end industries such as microelectronic packaging.

Semiconductor photocatalysis is an advanced oxidation process driven by solar energy which has widespread applications in the treatment of organic pollutants in liquid and gas phases. In this work, titanium dioxide nanoparticles modified with yttrium ions (Y3+) were prepared by a ball milling method. The effects of Y3+ mole fraction, ball-to-powder weight ratio, milling time and milling rate on the photocatalytic activities were evaluated by the degradation of methylene blue (MB) under UV light. Then Y3+/TiO2 photocatalysts prepared at the optimized ball milling conditions were applied to treat shrimp wastewater under UV and visible light. Chemical oxygen demand (CODCr), 3D fluorescence spectroscopy and total organic carbon (TOC) were used to detect the water samples taken from the photocatalytic experiments. Experimental results showed that when the mole fraction was 2%, the ball-to-powder weight ratio was 4 : 1, milling time was 4 h and milling rate was 500 rpm, the reaction rate constant of MB degradation can reach up to 0.1112 min−1 which was 4.2 times as fast as pure TiO2. All Y3+/TiO2 samples showed a red shift of absorption compared to pure TiO2 and it led to a visible light absorption response. The content of surface oxygen vacancies has significantly increased and the BET specific area increased to 104 m2 g−1. The CODCr removal rates of shrimp wastewater were 43.8% and 37.5% for 2% Y3+/TiO2 under UV and visible light, respectively. Besides, the TOC removal rates were 67.5% and 38.8%, respectively. Humic-like substances and fulvic-like substances in shrimp wastewater can be mineralized after 90 minutes irradiation.

Lactic acid (LA) is an effective sanitizer for disinfection of fresh produce. Tap water is generally used to wash disinfected fresh produce because sanitizer residues negatively affect the quality and organoleptic properties of the produce. However, tap water is ineffective for secondary disinfection compared with sanitizers. Thus, we propose a disinfection method using LA plus aqueous ozone (AO), an oxidizing sanitizer that does not lead to secondary residue. We compared the proposed method of 1% LA (90 s) plus 1 mg L−1 AO (30 s) or 2 mg L−1 AO (30 s) with the traditional method of 100 ppm chlorine (120 s) or 1% LA (120 s) plus tap water (30 s) and 2 mg L−1 AO (150 s). Microbial analysis showed that LA plus AO led to the greatest reductions in microbes (Escherichia coli O157:H7, aerobic mesophilic counts, aerobic psychrophilic counts, moulds, and yeasts) during storage (0–5 days at 5 °C). Quality analysis (colour, sensory qualities, electrolyte leakage, polyphenolic content, and weight loss) showed that LA + AO did not cause additional quality loss compared with tap water treatment. These results indicate that the hurdle technology proposed (LA plus AO) has a good potential for use in fresh produce disinfection.

In this study, we demonstrate an Ir(iii)-catalyzed thioether directed alkenylation of arene C-H bonds under mild reaction conditions. The selectivity for mono- or di-alkenylation is controlled by the concentration of alkene and oxidant loading. Various functional groups are tolerated, and moderate to good yields of alkenylated products are achieved.

A catalytic asymmetric method for the synthesis of polysubstituted chromans via an oxa-Michael-nitro-Michael reaction has been developed. The squaramide-catalyzed domino reaction of 2-hydroxynitrostyrenes with trans-β-nitroolefins produced chiral chromans with excellent enantioselectivities (up to 99% ee), diastereoselectivities (up to >20 : 1 dr), and moderate to good yields (up to 82%).

Functional active wound dressings are expected to provide a moist wound environment, offer protection from secondary infections, remove wound exudate and accelerate tissue regeneration, as well as to improve the efficiency of wound healing. Chitosan-based hydrogels are considered as ideal materials for enhancing wound healing owing to their biodegradable, biocompatible, non-toxic, antimicrobial, biologically adhesive, biological activity and hemostatic effects. Chitosan-based hydrogels have been demonstrated to promote wound healing at different wound healing stages, and also can alleviate the factors against wound healing (such as excessive inflammatory and chronic wound infection). The unique biological properties of a chitosan-based hydrogel enable it to serve as both a wound dressing and as a drug delivery system (DDS) to deliver antibacterial agents, growth factors, stem cells and so on, which could further accelerate wound healing. For various kinds of wounds, chitosan-based hydrogels are able to promote the effectiveness of wound healing by modifying or combining with other polymers, and carrying different types of active substances. In this review, we will take a close look at the application of chitosan-based hydrogels in wound dressings and DDS to enhance wound healing.

An ultrasensitive and label-free DNA biosensor for the detection of deoxyribonuclease I (DNase I) activity was comprehensively studied based on electrochemical methods by cyclic voltammetry (CV) and square wave voltammetry (SWV). For the preparation of the DNA biosensor, the arbitrary 76-bp single-stranded DNA reporter probes and electrochemical indicator methylene blue (MB) were modified on the Au electrode. Initially, the sensor generated a strong signal because of the redox indicator MB. In the presence of DNase I, the enzyme cleaved single-stranded DNA at their phosphate backbone, and then the MB was removed from the electrode, resulting in the reduction of current signals. The differential current signals were directly proportional to the logarithm of the concentration of DNase I in the range of 10−5 units per mL to 0.5 units per mL with a detection limit of 10−6 units per mL (S/N = 3). The sensor exhibits a wide linear range and superior sensitivity and can be applied in more bioanalytical systems.

We present the second example of mixed Nb/W addendum based trimer, Cs12[(SiW9Nb3O38)3WO3(OH)3]·33H2O by utilizing in situ formed Keggin-type {SiW9(NbO2)3} unit as the secondary building block. The polyanion [(SiW9Nb3O38)3WO3(OH)3]12− incorporates three saturated niobium-substituted tungstosilicate {SiW9Nb3} clusters that are linked together by three Nb–O–Nb bridges and a tungsten joint. The compound has been thoroughly characterized by single crystal X-ray diffraction, UV-Vis spectroscopy, TG analysis, PXRD and FTIR spectra. In addition, the photocatalytic activities of the title compound and the two precursors A-α-Na10[SiW9O34]·23H2O and K7HNb6O19·13H2O for H2 evolution were also evaluated.

Skeletal muscle is the most economically valuable tissue in meat-producing animals and enhancing muscle growth in these species may enhance the efficiency of meat production. Skeletal muscle mass is negatively regulated by myostatin (MSTN), and non-functional mutations of the MSTN gene in various animal species have led to dramatic hypermuscularity. This study was designed to assess the characteristics of male MSTN-knockout (KO) pigs. A transcription activator-like effector nuclease (TALEN) pair targeting exon 1 of the swine MSTN gene was constructed and used to transfect porcine fetal fibroblasts (PFFs). We obtained a cell line consisting of a 2-bp deletion in one allele and a 4-bp deletion in the other allele, and this was used as a donor to generate cloned pigs via SCNT, and delivered 18 live piglets. They developed and grew normally to sexual maturity. These MSTN-KO boars grew normally to adulthood and showed visually-clear hypermuscular characteristics, increased carcass dressing percentage and loin eye size, and decreased backfat thickness. These pigs may show greater meat production, as well as being used in animal models of human diseases.

Microcapsules are widely applied in coatings; however, there are very few reports on the dispersion of microcapsules in the coating material or the effects of dispersion on their performance. Herein, the efficiency of three types of dispersants bearing distinctive functional groups for the dispersion of concentrated thermochromic microcapsules in a solvent and coating resin is studied. The dispersion properties of 35 wt% thermochromic microcapsules in toluene and in coating resin are investigated by measuring their sedimentation and rheological behavior. Interactions between the dispersant and microcapsules are characterized by Fourier transform infrared spectroscopy in order to identify the dominant dispersion mechanism. The physical quality and thermochromic performance of the coating films are characterized by electron microscopy observations and temperature variation tests. The most effective dispersant for thermochromic microcapsules is determined. Compared to the coating film containing non-dispersed microcapsules, the film with well-dispersed microcapsules shows improved surface flatness, with few or no pores in the microstructure. In addition, the color of the film with well-dispersed thermochromic microcapsules shows faster response to temperature variation, resulting in complete and uniform color transformation.

Lactic acid (LA) is an effective sanitizer for disinfection of fresh produce. Tap water is generally used to wash disinfected fresh produce because sanitizer residues negatively affect the quality and organoleptic properties of the produce. However, tap water is ineffective for secondary disinfection compared with sanitizers. Thus, we propose a disinfection method using LA plus aqueous ozone (AO), an oxidizing sanitizer that does not lead to secondary residue. We compared the proposed method of 1% LA (90 s) plus 1 mg L

Semiconductor photocatalysis is an advanced oxidation process driven by solar energy which has widespread applications in the treatment of organic pollutants in liquid and gas phases. In this work, titanium dioxide nanoparticles modified with yttrium ions (Y

Resonance Raman spectra (rRS) of the CO-Ns H-NOX (heme nitric oxide and oxygen binding) complex, a bacterial model for the mammalian CO–sGC (soluble Guanylyl Cyclase) complex, are reported. The CO-Ns H-NOX complex exhibited two Fe–CO stretching modes (νFe–CO) with an intense band at 470 cm−1 and a weaker band at 494 cm−1, which are very similar to those observed for a CO-ligated full-length bovine lung sGC. However, the rRS of truncated sGC β1(1–194) H-NOX exhibited comparable bands, but with a reversed intensity ratio, the νFe–CO at 492 cm−1 was dominant. This difference is similar to that observed for six-coordinate CO–sGC's in the absence and presence of YC-1, an effector. Molecular dynamic (MD) simulations of truncated sGC β1(1–194) H-NOX demonstrate that water may enter the distal heme pocket to form a hydrogen bond with ligated CO; whereas it hardly happens to Ns H-NOX. By employing density functional theory (DFT) analysis, we calculated the C–O and Fe–CO stretching frequencies of the isolated imidazole (ImH)- and porphyrin (P) containing complex, (ImH)FeP(CO), in the presence or absence of water molecules. The calculated rRS exhibited bands at a higher νFe–CO frequency in the presence of water, in agreement with observations for truncated sGC, further supporting the hypothesis that water access to the distal heme pocket influences the ligation of CO, although the proximal effects remain to be elucidated.

A facile and green approach was developed to prepare biobased graphene oxide (GO)/furan resin nanocomposites by directly transferring GO from water dispersion into furan resin. The structure of nanocomposites was characterized by Fourier infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). A good dispersion of GO within furan resin was observed. Performance investigation revealed there was a significant improvement in thermal, mechanical and chemical resistance properties of biobased GO/furan resin nanocomposites when a low content of GO was introduced into neat furan resin. The nanocomposite with a low content of 0.05 wt% GO showed better improvement in tensile strength and Young's modulus of 72% and 282%, respectively. Thermal analysis of the nanocomposites also illustrated an enhancement in thermal stability. The obtained biobased GO/furan resin showed good chemical resistance.

Tungsten trioxide (WO3) spheres decorated with nitrogen-doped graphene (NRGO–WO3) were synthesized by applying the spray-drying procedure and characterized for their ability to serve as an electro-catalyst support for formic acid electro-oxidation. A possible mechanism for the formation of NRGO–WO3 was proposed based on the results of tunneling electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Pd nanoparticles with dimensions of 4.8 nm were loaded onto the surface of NRGO–WO3 using a conventional sodium borohydride reduction method. The electrocatalytic performances of Pd/NRGO–WO3 for formic acid oxidation were investigated by using cyclic voltammetry and chronoamperometry. Due to the decrease in the resistance to electron transfer resulting from the modification of N-doped graphene, which produced an excellent electrical conductor, as well as due to the hydrogen spill-over effect, which accelerated the dehydrogenation of formic acid on Pd active sites, a great enhancement of the electrochemical performances was achieved.

An environmentally friendly wet chemistry approach is used to synthesize silver nanotrees with a single step. The silver nanotrees with single crystalline (111) faces were synthesized without any external reducing or stabilizing agents in water media, involving a galvanic-cell mechanism between the silver nanostructure and biomass-derived monolithic activated carbon (MAC). By varying the concentration of [Ag(NH3)2]NO3, silver nanoflowers, nanowires and nanorods can also be selectively obtained. The silver morphology can also be tuned by some anions such as PO43−, Cl− and OH− in MAC, which afford a more flexible morphological control in this galvanic-cell mechanism than those reported previously. Importantly, the obtained silver dendrites are found to yield excellent catalytic activity for the reduction of 4-nitroaniline by borohydride.

In this study, the influence mechanisms of graphene oxide (GO) on the membrane substrate/active layer for improving the water flux and anti-biofouling ability of thin-film composite (TFC) membranes in forward osmosis (FO) were systematically investigated. We fabricated a pristine TFC membrane, a TFC membrane in which the substrate or polyamide active layer was modified by GO (TFN-S membrane or TFN-A membrane), and a TFC membrane in which both the substrate and active layer were functionalized by GO (TFN-S + A membrane). Our results showed that the TFN-S membrane possesses a higher water flux (∼27.2%) than the TFN-A because the substrate that contained GO could improve the porous structure and porosity, while the TFN-A membrane exhibited a lower reverse salt flux and higher salt rejection than the TFN-S membrane, indicating that the surface properties played a more important role than the substrate for the salt rejection. Regarding the biofouling experiment, the TFN-A and TFN-S + A membranes facilitated a higher antifouling performance than the TFN-S and TFC membranes after 72 h of operation because of the greater hydrophilicity, lower roughness and facilitated higher bactericidal activity on the GO-modified surface. In addition, the biovolume and biofilm thickness of the TFN-A and TFN-S + A membranes were found to follow the same trend as flux decline performance. In conclusion, the substrate modified by GO could greatly improve the water flux, whereas the GO-functionalized active layer is favorable for salt rejection and biofouling mitigation. The advantage of TFN-A in biofouling mitigation suggests that the antibacterial effect of GO has a stronger influence on biofouling control than the changes of hydrophilicity and roughness.

A novel electrospun colon-specific delivery system for salmon calcitonin (SCT) was developed to improve its stability and bioavailability. Firstly, the pectin-coated SCT liposomes were prepared by film dispersion method and then a liposomes/sodium alginate/polyvinyl alcohol fiber mat was fabricated by electrospining. Scanning electron microscopy analysis indicated that the obtained nanofibers were uniform and smooth with an average diameter of about 350 nm. The release of SCT in different simulated digestive fluids was studied and corresponding release kinetics models were built. It was found that the fiber mat containing pectin-coated SCT liposomes had better stability and colon-specific properties compared with that containing uncoated SCT liposomes and the release of SCT in the colon followed the case II transport mechanism. In addition, there is no significant change in the bioactivity of released SCT measured by ELISA. This study shows that the electrospun colon-specific fiber mat is a potential delivery system for bioactive peptides.