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A facile and practical protocol to construct 2 H -imidazoles by applying an oxime acetate block as the sole component via oxidative homo/cross-coupling catalyzed by Cu(I) was developed. This strategy provides a straightforward method to produce a series of substituted 2 H -imidazoles in moderate to excellent yields. The transformation process is straightforward to operate and is considered as a readily available catalytic system exhibiting good substrate compatibility, eliminating the necessity for pre-functionalization of azides or the use of additives.

Oxidative stress is one of the obstacles preventing wound regeneration, especially for chronic wounds. Herein, designing a wound dressing with an anti-oxidant function holds great appeal for enhancing wound regeneration. In this study, a biocompatible and degradable nanofiber with a core-shell structure was fabricated via coaxial electrospinning, in which polycaprolactone (PCL) was applied as the core structure, while the shell was composed of a mixture of silk fibroin (SF) and tocopherol acetate (TA). The electrospun PST nanofibers were proven to have a network structure with significantly enhanced mechanical properties. The PSTs exhibited a diameter distribution with an average of 321 ± 134 nm, and the water contact angle of their surface is 124 ± 2°. The PSTs also exhibited good tissue compatibility, which can promote the adhesion and proliferation of L929 cells. Besides, the dissolution of silk fibroin encourages the release of TA, which could play a synergistic effect and regulate the oxidative stress effect in the damaged area, for it promotes the adhesion and proliferation of skin fibroblasts (L929), reduces the cytotoxicity of hydrogen peroxide to cells, and lowers the level of reactive oxygen species. The animal experiment indicated that the PSTs would promote the reconstruction of skin. These nanofibers are expected to repair skin ulcers related to diabetes.

A novel and efficient metal-free cascade oxidative radical addition of styrenes is developed for the construction of 1,3-dichloro-1,5-diarylpentan-5-ones. This protocol presents a practical one-pot procedure that delivers highly functionalized 1,3-dichloro-1,5-diarylpentan-5-ones in moderate-to-good yields with a broad substrate scope under mild conditions.

With the rise of two-dimensional (2D) materials, unique properties that are completely distinct from bulk counterparts continue to emerge at low-dimensional scales, presenting numerous opportunities and challenges. It also provides a new perspective for the study of transition metal systems. Here, based on density functional theory (DFT), the physical properties of 2D monolayer LiV 2 S 4 have been studied. Remarkable changes have been observed, i.e. , vanadium dimerization, ferromagnetism, charge distribution and metal-insulator transition (MIT). It is argued that the electronic instability leads to the V dimerization, which further lifts the degeneracy of charge distribution and stabilizes the charge and spin ordering state.

Lipid-based delivery systems are commonly used to encapsulate hydrophobic bioactive compounds for enhancing their bioaccessibility and bioavailability, especially for triacylglycerol (TAG) oil-based delivery systems. However, studies on the development of 1,3-diacylglycerol (DAG) oil-based delivery systems are rather limited. Herein, the influence of 1,3-DAG oil as a carrier oil on the properties of nanoemulsions and the bioaccessibility of encapsulated hydrophobic nobiletin (NOB) were investigated. High-purity 1,3-DAG (over 93% pure) was prepared by a combination of enzymatic esterification and ethanol crystallization. 1,3-DAG oil as a carrier oil could be used to formulate nanoemulsions with smaller droplet size, narrower size distribution and similar stability compared to TAG oil. Importantly, 1,3-DAG oil could efficiently encapsulate high-loading NOB (1.45 mg g -1 ) in nanoemulsions and significantly improve the bioaccessibility of NOB (above 80%), which is attributable to its massive lipolysis and higher encapsulation capacity than TAG oil. Moreover, the addition of the 1,3-DAG component in TAG oil significantly improved the properties of nanoemulsions and the loading and bioaccessibility of NOB, especially as the 1,3-DAG content was not less than 50%. The structure of lipids (DAG versus TAG) influenced the nanoemulsion properties and the bioaccessibility of encapsulated NOB. Based on the good properties of 1,3-DAG oil coupled with its health benefits, 1,3-DAG oil-based nanoemulsion delivery systems have great prospects for improving and extending emulsion properties and bioactivity as well as bioaccessibility enhancement.

A green and efficient method for the synthesis of β-sulfonyl aliphatic sulfonyl fluorides was developed. This reaction works in aqueous media under mild and environmentally benign conditions without any ligand or additive. The efficiency of this method is demonstrated by isolating the desired products obtained through simple filtration.

The selective functionalization of alkanes has long been recognized as a prominent challenge and an arduous task in organic synthesis. Hydrogen atom transfer (HAT) processes enable the direct generation of reactive alkyl radicals from feedstock alkanes and have been successfully employed in industrial applications such as the methane chlorination process, etc. Nevertheless, challenges in the regulation of radical generation and reaction pathways have created substantial obstacles in the development of diversified alkane functionalizations. In recent years, the application of photoredox catalysis has provided exciting opportunities for alkane C-H functionalization under extremely mild conditions to trigger HAT processes and achieve radical-mediated functionalizations in a more selective manner. Considerable efforts have been devoted to building more efficient and cost-effective photocatalytic systems for sustainable transformations. In this perspective, we highlight the recent development of photocatalytic systems and provide our views on current challenges and future opportunities in this field., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Hematite is a potential photoelectrode for photoelectrochemical (PEC) water splitting. Nevertheless, its water oxidation efficiency is highly limited by its significant photogenerated carrier recombination, poor conductivity and slow water oxidation kinetics. Herein, under low-vacuum (LV) conditions, we fabricated a CoMoO 4 layer on oxygen-vacancy-modified hematite (CoMo-Fe 2 O 3 (LV)) for the first time for efficient solar water splitting. The existence of oxygen vacancies can significantly facilitate the electrical conductivity, while the large onset potential along with oxygen vacancies can be lowered by the CoMoO 4 with accelerated water oxidation kinetics. Therefore, a high photocurrent density of 3.53 mA cm -2 at 1.23 V RHE was obtained for the CoMo-Fe 2 O 3 (LV) photoanode. Moreover, it can be further coupled with the FeNiOOH co-catalyst to reach a benchmark photocurrent of 4.18 mA cm -2 at 1.23 V RHE , which is increased around 4-fold compared with bare hematite (0.90 mA cm -2 ). The combination of CoMoO 4 , FeNiOOH, and oxygen vacancies may be used as a reasonable strategy for developing high-efficiency hematite-based photoelectrodes for solar water oxidation.

1-Oleoyl-2-palmitoyl-3-linoleoylglycerol (OPL), a key structural lipid in the breast milk fat, plays a critical role in providing nutrients and energy for infants. OPL is more abundant in Chinese breast milk fat and might be better for Chinese infants' growth. However, few studies have investigated the effect of OPL on the growth and intestinal health of the organism in early life. OPL-rich oil with 45.77% OPL was prepared by immobilized lipase-catalyzed synthesis and purification. The effects of OPL on the nutritional properties and the regulation of intestinal microbiota in early life were further investigated in vivo ( Micropterus salmoides ). Dietary OPL-rich oil significantly increased the juvenile fish weight gain rate, protein content, and muscular polyunsaturated fatty acids, which in turn markedly altered the muscle texture in springiness and cohesiveness. Dietary OPL-rich oil could also protect intestinal tissues by significantly increasing fish intestinal fold height, mucosal thickness, and intestinal wall thickness. Furthermore, dietary OPL-rich oil regulated intestinal microbiota. Particularly, OPL significantly increased the probiotics ( Cetobacterium_sp014250685 , Streptomyces_mutabilis , Saccharopolyspora_spinosa , and Nocardiopsis_kunsanensis ) and reduced the potential pathogens ( Staphylococcus_nepalensis , Salmonella_enterica , the Candidatus_berkiella ). The structured OPL significantly promoted fish growth and improved nutritional composition due to its higher bioavailability relative to tripalmitate (PPP). Moreover, OPL significantly improved the growth, cholesterol metabolism, and intestinal health than the mixed oil (MO), which was attributed to the higher palmitic acid content in the sn-2 position. Overall, the structure of triacylglycerols and its distribution of fatty acids affected early growth and intestinal health, and OPL was more effective in the improvement of juvenile growth and intestinal health.

A multifunctional undecapeptide, YYDPLGLADYY, was designed and synthesized for the photowrapping of silica-coated gold nanorods. The obtained nanocapsules, bearing a well-defined core-shell structure, were able to encapsulate a therapeutic drug, respond to an MMP-upregulated tumor microenvironment, and achieve NIR-triggered anticancer chemo-photothermal therapy with favorable efficacy.

The growth kinetics mechanism of microarc oxidation (MAO) coatings on Ti6Al4V alloy was studied by designing a binary mixed electrolyte with various SiO 3 2- and B 4 O 7 2- ion ratios via scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and potentiodynamic polarization. When the ratio of B 4 O 7 2- in the electrolyte is 100%, B 4 O 7 2- dissolves molten TiO 2 at a high temperature, exposing nano-scale filamentary channels in the barrier layer of MAO coating, resulting in the repeated nucleation of microarc in the same area. When the ratio of SiO 3 2- in the binary mixed electrolyte reaches 10%, the amorphous SiO 2 formed by SiO 3 2- at high temperatures from discharge blocks discharge channels and induces microarc nucleation in other regions, thus inhabiting the discharge cascade phenomenon. When the ratio of SiO 3 2- in the binary mixed electrolyte increases from 15% to 50%, the amounts of molten oxides cover some of the pores formed by the primary microarc discharge, so part of the secondary discharge preferentially generates in the uncovered pores. Finally, the discharge cascade phenomenon occurs. Moreover, the thickness of the MAO coating obtained in the binary mixed electrolyte containing B 4 O 7 2- and SiO 3 2- shows a power function with time., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Nanozymes with wide applications have rapidly attracted tremendous attention from various fields in the last decade. However, research on the standardization of nanozymes is still lacking. Currently, the accurate evaluation and effective tracing of the enzyme-like activity of nanozymes have become a common concern. This work aims to develop a certified reference material (CRM) of Prussian blue nanozymes (PBNEs) for their peroxidase (POD)-like activity. The homogeneity and stability studies demonstrated that the property value of POD-like activity is consistent across different packing units, and remains unchanged during the one-year validity period of storage in the dark at 4 °C. The certified value of the POD-like activity of the PBNE CRM is assigned as 174 ± 13 U mg -1 ( k = 2) by interlaboratory comparison studies and traceable uncertain evaluation. Furthermore, the need for quality control of the POD-like activity of nanozymes was exemplified by comparing the influence of two additional PBNEs on the dry and wet chemical detection of glucose (Glu). As the first quality assurance tool of nanozymes, the PBNE CRM is expected to replace natural horse radish peroxidase (HRP) as an effective benchmark for assessing the analytical method and laboratory competence. In addition, this work also inspires the further standardization of nanozymes.

In the field of dental and orthopedic implantation, the core issue is achieving good and stable osseointegration rapidly as well as for long-term, which is associated with a series of biological activities involving osteogenesis. Various surface modification methods have been applied to ameliorate the performance of titanium-based implants, among which plasma electrolytic oxidation (PEO) is very promising and has gained popularity in recent years. PEO produces thick, microporous, ceramic oxide layers on Ti and Ti alloys, which are described as "crater-like" or "volcano-like" morphology, and the physicochemical properties of PEO coating highly depend on PEO parameters. Furthermore, by adjusting the composition of the electrolytes of PEO, this technology enables the formation of element-incorporated coatings, exhibiting great potential. Plenty of studies reported in the literature revealed that multiple elements positively influence osteogenesis, but the issue of dose-dependent efficiency and safety concentration still requires careful consideration. Since osteoimmunomodulatory properties are regarded as the new target of implants, the osteoimmunomodulatory function of PEO coatings in the aspect of macrophage polarization has been discussed as well. The aim of this review is to describe the current state of different element-incorporated PEO coatings and their effect on the physicochemical and osteogenic properties of implants, intending to offer solutions for the development of implants that efficiently promote osseointegration.

A metal-free inactive C(sp 3 )-H bond functionalization of thioethers with styrenes using TBHP as an initiator and DBU as a base has been developed. This transformation has broken through the low activity of thioethers and realized moderate yields. Herein extended experiments were conducted to confirm the radical relay process, reaction energy and intermediate transformations.

Recently, extensive experimental and theoretical studies on two-dimensional materials have attracted enormous interest in exploring the properties of these materials by decorating their surfaces. In the present work, we present a detailed investigation of the structures, and electronic and magnetic properties of pristine, hydrogenated, and fluorinated BeO monolayers using the ab initio density functional theory approach. Structurally, the most stable adsorption sites are directly above the host Be atom for half-hydrogenation, above the middle of the Be-O bond for half-fluorination, and directly above the host Be atom and below the host O atom for full-hydrogenation and full-fluorination. Moreover, the electronic and magnetic properties of the BeO monolayer exhibit high sensitivity to chemical functionalization: half-hydrogenation induces nonmagnetic-magnetic transition and the reduction of the band gap reaches about 75%. Full-hydrogenation results in metallization of the BeO monolayer. Half-fluorination makes the BeO monolayer a 100% spin polarized material regardless of the adsorption site. However, depending on different adsorption sites, full-fluorination can produce either magnetically half-metallic or nonmagnetic semiconductor structures. These results demonstrate that the tunability of the electronic and magnetic properties of the BeO monolayer can be realized by chemical functionalization for future nano-electronic and spintronic device applications.

In this study, a carbon membrane-mediated CdSe and TiO 2 ternary film (CdSe/C/TiO 2 ) was prepared to degrade methylene blue (MB). Carbon membrane and CdSe were introduced to the surface of a TiO 2 nanofiber film via an in situ hydrothermal deposition process successively. The investigation shows that the carbon membrane not only provides a charge transfer channel to promote the transfer of electron from the conduction band of CdSe to that of TiO 2 , but also improves the poor conduct between the TiO 2 film and electrolyte. The synergies between the carbon membrane and CdSe can make the ternary system harvest more visible light energy and facilitate the charge transfer property of TiO 2 . The current density of CdSe/C/TiO 2 was about 9 folds higher compared with that of pure TiO 2 under UV and visible light irradiations. This ternary hybrid exhibits a superior activity during the photoelectrochemical (PEC) degradation of MB, and 92.43% can be removed after 120 min irradiation, which is improved by 21.14% than that of TiO 2 ., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Applications in the harsh environment require hydrogels with ultra-stiffness, toughness, and stretchability. However, it remains a challenge to increase the elastic modulus without sacrificing the maximum elongation of hydrogels, because of the trade-off between stiffness and extensibility. Inspired by the crosslinking hierarchy of mussel byssus cuticle, here, we report a strategy to fabricate an ultra-stiff, tough and stretchable triple-crosslinked (TC) hydrogel. The polymer is crosslinked by chemical crosslinker at first, subsequently by introducing a polyphenolic compound, tannic acid (TA), and metal ions. The hydrogen-bond-based network between the polymer and TA works as an extensible and energy-dissipative network, mimicking the matrix of the cuticle, while the higher crosslinked domains formed by the coordinate bonds between TA and metal ions contribute to the stiffness. The triple-crosslinked hydrogel exhibits two orders of magnitude increase in stiffness (E = 58 MPa), but without sacrificing the maximum elongation (ε = 850%), compared with those of metal-free hydrogels (E = 0.18 MPa, and ε = 860%). The combination of ultra-stiffness, toughness, and stretchability in hydrogels is successfully achieved through leveraging the hierarchically cross-linked network based on hydrogen bonding and coordination bonding. Moreover, utilizing the wide distribution of bonding strength of coordination interaction, the mechanical properties of triple-crosslinked hydrogels can be manipulated by using different kinds of catechol-metal coordination.

The emergence of the plasmid-mediated colistin resistance mechanism (mcr-1) makes bacterial resistance to colistin increasingly serious. This mcr-1 mediated bacterial resistance to colicin is conferred primarily through modification of lipid A in lipopolysaccharides (LPS). In our previous research, antimicrobial peptide F1 was derived from Tibetan kefir and has been shown to effectively inhibit the growth of Gram-negative bacteria (E. coli), Gram-positive bacteria (Staphylococcus aureus), and other pathogenic bacteria. Based on this characteristic of antibacterial peptide F1, we speculated that it could inhibit the growth of the colicin-resistant E. coli SHP45 (mcr-1) and not easily produce drug resistance. Studies have shown that antimicrobial peptide F1 can destroy the liposome structure of the phospholipid bilayer by destroying the inner and outer membranes of bacteria, thereby significantly inhibiting the growth of E. coli SHP45 (mcr-1), but without depending on LPS. The results of this study confirmed our hypothesis, and we anticipate that antimicrobial peptide F1 will become a safe antibacterial agent that can assist in solving the problem of drug resistance caused by colistin.

The exploration of weak coordinated amine derivative enabled regioselective C-H functionalization remains challenging due to the elusive achievement of reactivity and selectivity simultaneously. Herein, regioselective C-H alkynylation of various readily transformable nitrogen functionalities was developed with great efficiency, with the assistance of the mono-N-protected amino acid (MPAA) ligand via Pd(ii) catalysis proceeding via 5, 6 and 7-membered palladacycle intermediates.

Carnosic acid (CA) represents one of the most effective antioxidants that can be applied for the prevention of degenerative and chronic diseases. However, the intrinsic hydrophobic nature of CA results in low solubility and poor dissolution in the gastrointestinal (GI) tract, which limits its applications in a variety of functional food systems. In order to address these issues, we encapsulated CA in a lecithin-based nanoemulsion (CA-NE) to improve its bioaccessibility and bioavailability which are evaluated using in vitro and in vivo digestion models. The CA-NE demonstrated a loading capacity of 2.6-3.0%, an average particle size of 165 nm, a ζ-potential value of -57.2 mV, and good stability during 4-weeks of storage at 4, 25, and 37 °C. The in vitro static pH-stat lipolysis model and dynamic TNO gastrointestinal (TIM-1) model demonstrated a 12.6 and 5.6 fold increase in the total bioaccessibility of CA encapsulated in nanoemulsion, respectively, as opposed to CA in suspension form. Moreover, the in vivo pharmacokinetics study on a rat model (Male Sprague Dawley) confirmed that the bioavailability of CA in nanoemulsion showed a 2.2 fold increase, as compared to that of CA in suspension form. In conclusion, the bioaccessibility and bioavailability of CA were remarkably improved by encapsulation of CA in a lecithin-based nanoemulsion. Moreover, the combined in vitro and in vivo study could serve as a useful approach for the comprehensive evaluation of oral lipid-based delivery systems.

The ligand-free palladium-catalyzed C3-cyanation of indoles via direct C-H functionalization was achieved. This protocol, utilizing CH 3 CN as a green and readily available cyanide source, produced the desired products in moderate to good yields through transition-metal-catalyzed C-CN bond cleavage.

Citrus peel essential oil (CPEO) contains abundant volatile compounds and exhibits fragrance properties and beneficial pharmacological effects on humans. Herein, we aimed to investigate the effects of CPEO on the prevention of hypercholesterolemia and hepatic steatosis in high-fat diet-fed rats and identify its possible regulatory mechanisms in lipid metabolism by combining lipidomics with gene expression analysis. CPEO at effective supplementation levels of 0.5% and 0.75% significantly ameliorated hypercholesterolemia and hepatic steatosis, including decreased serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), hepatic TC and triglyceride (TG) levels, and hepatic lipid droplet accumulation. Lipidomics analysis revealed that the total levels of fatty acid (FFA), TG and cholesteryl ester (CE) classes in the liver tissue were remarkably decreased after 0.75% CPEO supplementation some of which (3 TGs and 4 CEs) might emerge as potential lipid biomarkers in response to the effects of CPEO. Furthermore, these lipidomics findings were associated with downregulation of lipogenesis-related genes SREBP-1c, ACC and FAS and upregulation of bile acid biosynthesis-related genes LXRα, CYP7A1 and CYP27A1 in the liver. This study indicated that CPEO could effectively prevent hypercholesterolemia and hepatic steatosis, possibly because of its mediation of lipid and cholesterol homeostasis by altering liver lipid metabolites and regulating lipid metabolism-related genes.

A Zr-Cu alloy, as a new type of filler metal, is proposed for brazing SiC ceramic under special working conditions. The wetting angle of Zr-Cu alloy/SiC ceramic at different temperatures and holding times was investigated by a high-temperature wetting tester. The composition of the wetting interface was tested by XRD, and the interfacial reaction layer was analyzed with SEM and EDS. The results show that the wetting angle decreases sharply with the change in temperature from 1100 °C to 1175 °C and remains unchanged when the temperature is higher than 1175 °C, about 34 ± 1°. The dynamic wetting angle of Zr-Cu/SiC at 1200 °C with the increase in holding time conforms to the law of exponential decay, and the equilibrium wetting angle is 5°. The transition layer with a certain thickness is formed during the spreading process of the Zr-Cu alloy at a high temperature, and the microstructure of the interfacial reaction layer mainly consists of ZrC and Zr 2 Si., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Icariin (1a), a 7-O-glycosylated flavonoid glycoside, is recognized as the major pharmacologically active ingredient of Epimedium plants, which have been used in traditional Chinese medicine for thousands of years. However, no glycosyltransferase (GT) responsible for the 7-O-glycosylation of flavonoids has been identified from Epimedium plants to date. Herein, a GT, Ep7GT, was identified from E. pseudowushanense B. L. Guo, which can regiospecifically transfer a glucose moiety to baohuoside (1) at 7-OH to form icariin (1a). Ep7GT showed a rare broad donor substrate spectrum, including UDP-glucose, UDP-xylose, UDP-N-acetylglucosamine, UDP-rhamnose, UDP-galactose, UDP-glucuronic acid and TDP-glucose. Moreover, two new derivatives of icariin (1a), 7-O-β-d-[2-(acetylamino)-2-deoxy-glucopyranosyl]-baohuoside (1b) and 7-O-β-d-xylosyl-baohuoside (1c), were biosynthesized by using Ep7GT in vitro. Engineered Escherichia coli harbouring Ep7GT was constructed, and 10.1 μg mL -1 icariin (1a) was yielded by whole-cell biotransformation with baohuoside (1) as the substrate. The present work not only characterizes the GT responsible for the 7-O-glycosylation in the biosynthesis of icariin in Epimedium plants, but also indicates the significant potential of an enzymatic approach for the production of glycosylated baohuoside derivatives with different sugar moieties. What's more, these findings also provide a promising alternative for producing natural/unnatural bioactive flavonoid glycosides by metabolic engineering.

Psidium guajava L. leaves have a long history of being consumed as herbal teas in many countries. The aim of this study was to identify compounds with anticancer potentials from Psidium guajava L. leaves. Utilizing various extraction and chromatographical techniques, we have isolated one new (2) and two known compounds (1, 3). Structural analyses by the spectroscopic methods of TOF-MS, 1H NMR, 13C NMR, HSQC, and HMBC identified these three compounds as guavinoside E (1), 3,5-dihydroxy-2,4-dimethyl-1-O-(6'-O-galloyl-β-d-glucopyranosyl)-benzophenone (2), and guavinoside B (3). Cell viability assays showed that compounds 2 and 3 inhibited the growth of HCT116 human colon cancer cells in a dose-dependent manner, where compound 2 was more potent than compound 3. Based on flow cytometry analysis, compound 2 showed stronger activity in inducing cellular apoptosis in cancer cells than compound 3. Furthermore, compounds 2 and 3 modulated expression levels of key proteins involved in cell proliferation and apoptotic signaling. Specifically, compound 2 increased the levels of p53, p-ERK1/2, p-JNK, and cleaved caspases 8 and 9, and compound 3 increased the levels of p53 and cleaved caspase 8. Overall, this study provided identities of three bioactive compounds from P. guajava L. leaves and their anti-cancer effects against human colon cancer cells, which could facilitate the utilization of these compounds and P. guajava L. leaves as potential chemoprevention agents against colon carcinogenesis.

In this work, we prepared an iron-based frictional material from vanadium-bearing titanomagnetite concentrates by in situ carbothermic reaction with improved tribological properties. Effects of different amounts of rare-earth oxides on the microstructure and properties of the Fe-based friction materials were investigated. The microstructure of the Fe-based friction material consisted of an Fe matrix, hard particles (mainly TiC) and a lubricating phase (graphite). The moderate addition of rare-earth oxides improved the microstructure and properties of the Fe-based friction material significantly. Particularly, the friction coefficient decreased from 0.61 to 0.48-0.56 and the wear rate reduced from 7.8 × 10 -7 cm 3 J -1 to 2.6 × 10 -7 ∼4.9 × 10 -7 cm 3 J -1 . Addition of La 2 O 3 (≤0.2 wt%) or CeO 2 (≤0.4 wt%) contributed to sintering densification and improved the relative density, hardness and wear resistance. The dominant wear mechanism changes from severe abrasive wear and oxidative wear to mild oxidative wear. However, when rare-earth oxide addition was increased further, the microstructure, relative density, hardness, and wear performance of the Fe-based friction materials deteriorated. Consequently, the optimal additions of La 2 O 3 and CeO 2 were 0.2 wt% and 0.4 wt%, respectively., Competing Interests: The authors declare that they have no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Liquid-liquid phase separation has been proven to be a valuable method for producing structured materials and creating chemical systems. Although several strategies have been developed to date, osmotically driven oil/water phase separation has never been achieved owing to the limited solubility of inorganic salts in conventional organic solvents and thus the insufficient osmotic driving force to counterbalance the Laplace pressure associated with the interfacial tension. Herein, we report the discovery that a mixture of 1-alkyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide and LiTf 2 N can generate sufficient and widely tunable osmotic pressure in oil to realize water transport from the surrounding aqueous phase into the oil phase, triggering spontaneous phase separation. This osmotically driven phase separation could be modulated with unprecedented flexibility, offering unlimited possibilities to facilely access diverse thermodynamically metastable structures using one system. Importantly, this oil system can serve as a general phase separation carrier platform for realizing phase separation of various substances., (This journal is © The Royal Society of Chemistry 2019.)

Ammonia borane (AB) is an ideal hydrogen-storage material for fuel cells but its application has been strongly limited by using rare noble-metal-based catalysts. Here we have prepared a hybrid material of Ni 0.5 Co 0.5 O nanoparticles on nitric-acid treated carbon nitride (NCN) for the hydrolysis of AB. The Ni 0.5 Co 0.5 O-NCN catalyst achieves a high total turnover frequency (TOF) value of 76.1 (H 2 ) mol per (Cat-metal) mol min in pure water at room temperature, with a good stability by keeping 83.2% activity after 6 runs. The TOF is comparable to the best values ever reported for noble-metal-free catalysts without extra conditions such as light illumination or a strong alkaline environment. Synchrotron radiation based X-ray absorption spectroscopy reveals that the carbon nitride substrate has two reaction centers to form stable interfacial interaction with the NPs, in which carbon can act as the electron acceptor while nitrogen acts as the electron donor. Thus the NP-NCN system has a hybridized electronic structure which is favorable for the catalytic reaction to produce hydrogen. In-depth understanding of the interfacial interaction between NCN and NPs may also shed light on the mechanism study of various energy-related applications based on carbon nitride., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Although multi-drug synergetic therapy is increasingly important in clinical application, sophisticated delivery systems with the ability to deliver multiple drugs and realize sequential release with independently tunable kinetics at different stages are highly desirable. In this study, a dual-generation mesoporous silica nanoparticle (DAMSN) with three-dimensional dendrimer-like structure as an adaptable dual drug delivery system is developed. The DAMSN was synthesized via a heterogeneous interfacial reaction and was of uniformly spherical morphology (150-170 nm) with dendritic structures and hierarchical pores (inner pore, 3.5 nm; outer pore, 8.3 nm). And the inner generation of DAMSN was modified with 3-aminopropyltriethoxysilane (APTMS). The IBU and BSA as model drugs were loaded into the inner generation via covalent conjugation and the outer generation by electrostatic adsorption, respectively. Intriguingly, DAMSN underwent a rapid bio-degradation for about 4 days, partly due to its center-radial dendritic channel structure. The release results showed that IBU was of a typical two-phase release profile with almost zero release in the first 12 h and more sustained release for the following 88 h, while BSA was sustained over a long period of 100 h. Notably, the release behaviors of both drugs can be independently tailored by changing the intrinsic properties of the DAMSN. In addition, DAMSN exhibited good bio-compatibility. These results indicated that the dual-generation, dendrimer-like MSN structure could spatiotemporally present different drugs to realize sequential drug release, and has potential use in the field of tissue engineering and regenerative medicine., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Matrix metalloproteinase-13 (MMP-13) is an attractive drug target for the treatment of osteoarthritis (OA). In this study, a series of quinazolinone derivatives as MMP-13 inhibitors were firstly systematically studied using QSAR, molecular docking and molecular dynamics (MD) simulation. The reliable CoMFA ( q 2 = 0.646, r 2 = 0.992, R pred 2 = 0.829) and CoMSIA ( q 2 = 0.704, r 2 = 0.992, R pred 2 = 0.839) models were constructed and verified by the Topomer CoMFA model. Results of contour maps indicated that the electrostatic, hydrophobic and H-bond acceptor fields primarily influenced the activity of MMP-13 inhibitors in the models. Several key residues (Ala238, Thr245, Thr247, Met253, Asn215 and Lys140) were identified as important factors to improve the activity and stability of the inhibitor through hydrogen bonding and electrostatic interaction. Based on these results, eight novel quinazolinones ( D1-D8 ) were further designed. Additionally, all designed compounds showed good pharmacokinetic properties by ADMET predictions. Compounds D3 and D8 exhibited excellent predictive activity, and the 10 ns MD simulations analysis revealed that the hydrogen bonding interaction with residues (Ser250 and Gly248) was enhanced, and the small group in R2 and U-shaped conformation was of pivotal importance. These results provided strong guidance for the discovery and design of novel potential MMP-13 inhibitors.

In this work, we prepared an iron-based frictional material from vanadium-bearing titanomagnetite concentrates by in situ carbothermic reaction with improved tribological properties. Effects of Mn content (1-4 wt%) on the microstructure and properties of iron-based friction material were investigated. The microstructure and properties of iron-based friction material with Mn are significantly improved. In particular, the friction coefficient decreases from 0.54 to 0.40-0.49 and the wear rate reduces from 1.899 × 10 -7 cm 3 J -1 to 0.229 × 10 -7 cm 3 J -1 - 1.309 × 10 -7 cm 3 J -1 . Appropriate Mn addition (1-3 wt%) contributes efficiently to the sintering densification and increasing laminated pearlites. Comparatively, the density, hardness and wear resistance are improved. The dominant wear mechanism changes from severe abrasive wear to mild abrasive wear and oxidative wear is also enhanced. However, when Mn content increases to 4 wt%, the microstructure, relative density, hardness and wear performance of iron-based friction material are deteriorated. Consequently, the optimal addition of Mn is 3 wt% in the iron-based friction material., Competing Interests: The authors declare that they have no conflict of interest., (This journal is © The Royal Society of Chemistry.)

The soaring concerns globally on antibiotic overuse have made calls for the development of rapid and sensitive detection methods urgent. Here we report that the hybrid CuCoO-GO matrix allows for sensitive detection of various antibiotics in combination with MALDI TOF MS. The new matrix is composed of few-layered GO nanosheets decorated with CuCoO nanoparticles with an average size of 10 nm, and exhibits excellent aqueous suspensibility. Accurate quantitation of the sulfonamide antibiotics in milk samples have been demonstrated using a CuCoO-GO matrix and a stable isotope (C 13 )-labeled analyte as the internal standard. Our experiments have achieved lower limits of detection (LOD) by several hundred fold for the detection of a panel of representative antibiotics, in comparison with the literature reports. Both intrabacterial and extrabacterial residual antibiotics can be sensitively detected with our method. We have further investigated the molecular mechanism of the enhanced desorption/ionization efficiency by the CuCoO-GO matrix with synchrotron radiation techniques for the first time. This work provides a sensitive matrix enabling MALDI-TOF MS to be applied in small molecular analysis, but also presents a distinct perspective on the mechanism behind the material functions.

In this study, a facile one-step route was used to synthesize a novel magnetic mesoporous greigite (Fe 3 S 4 )-CTAB composite, which was utilized to remove hexavalent chromium (Cr(vi)). The optimized Fe 3 S 4 -CTAB 0.75 composite with a CTAB dosage of 0.75 g possessed the maximum specific surface, showing the highest Cr(vi) adsorption capacity of 330.03 mg g -1 . The mechanism analysis revealed that Fe(ii) and S(-ii) were critical for the reduction of Cr(vi). CTAB can promote the removal of Cr(vi) by Fe 3 S 4 -CTAB composites, possibly due to increased S(-ii) concentration, better dispersion of nanoparticles, and greater zeta potential. Besides, there is mild effect of Fe 0 on Cr(vi) removal, which is confirmed by the disappearance of the Fe 0 peak from the XPS analysis. The pseudo-second-order kinetic model could explain the Cr(vi) removal processes well. The adsorption of Cr(vi) at different initial concentrations was more consistent with a Langmuir isotherm. The existence of H + was beneficial for Cr(vi) removal by Fe 3 S 4 -CTAB 0.75 . Our work confirmed that the obtained Fe 3 S 4 -CTAB 0.75 composites exhibit considerable potential for Cr(vi) removal from aqueous solution., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this study, a novel magnetic nanocomposite was prepared using waste toner (WT) through high temperature decomposition, and calcination was conducted in different atmospheres (air, ammonia, and vacuum). WT calcined in ammonia (WT(NH 3 )), and it was then utilized as an efficient absorbent for the reduction of Cr(vi) in aqueous solutions; a batch experiment with different conditions was performed to investigate its Cr(vi) removal ability. The effects of two pH-regulating acid (HCl and H 2 SO 4 ) treatments were also studied. It was found that WT(NH 3 ) could remove about 99% Cr(vi) at pH 2 under H 2 SO 4 treatment. The XRD and TEM results coupled with VSM results confirmed that WT(NH 3 ) is an Fe 3 O 4 /Fe 2 N nanohybrid, which possesses excellent water-dispersibility and remarkable magnetic properties. XPS analysis showed the presence of Cr(vi) and Cr(iii) on the surface of WT(NH 3 ), which indicated that Cr(vi) was reduced to Cr(iii). Furthermore, H 2 SO 4 regulation also promoted the reduction of Cr(vi) by WT(NH 3 ), and this reduction was higher than that obtained by HCl regulation., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The Zr-Cu filler metal is mainly used for the joining of SiC ceramic as a nuclear fuel cladding material. The physical and chemical properties of the alloy, the interfacial reaction between the Zr-Cu filler metal and SiC ceramic, the residual stress of the SiC joint and the thermal neutron absorption cross section of the filler metal are considered during the design of the Zr-Cu filler metal. 80Zr-20Cu (wt%) is used as the filler metal in these experiments, showing good wettability and brazing properties with SiC ceramic., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The low specific capacity of graphite limits the further increase of the energy density of lithium-ion batteries and their widespread applications. Exploring new anode materials is the key issue. Herein, a new mullite-type compound Bi2Mn4O10 is designed and synthesized. The Bi2Mn4O10/C composite delivers a high reversible specific capacity of 846 mA h g-1 (more than twice that of graphite), and exhibits a high capacity retention of 100% after 300 cycles at 600 mA g-1, which is reported for the first time. The high specific capacity originates from the combination of the conversion reaction and alloying-dealloying reaction, which has been confirmed by the ex situ XRD, IR, SEM and TEM studies. In addition, the unique nanocomposite generated during the charge-discharge process provides excellent cycling stability. This work proves that Bi2Mn4O10/C is a potential anode material for advanced lithium-ion batteries.

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., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Cinnamaldehyde (Cin) and citral (Cit) have been studied as antimicrobial agents and natural preservatives, but their action modes are controversial, and the knowledge of their antifungal mechanism against P. expansum is still incomplete. The present study was conducted to evaluate the antifungal mechanism of the combination of Cin and Cit (Cin/Cit) against P. expansum by observing the cellular ultrastructure, fourier transform infrared spectroscopy (FT-IR) fingerprints, plasma membrane, oxidative stress and volatile profile. Cin/Cit caused membrane invaginations, organelles and cytoplasm destruction, as shown by transmission electron microscopy (TEM) observations. The FT-IR spectra and followed principle component analysis (PCA) presented the significant differences in chemical compounds, particularly phospholipid, protein and fatty acids of cells exposed to Cin/Cit. Compared to controls, Cin/Cit induced a decrease of ergosterol by 39.40%, an increase of unsaturated fatty acid, and protein release level (3.5 times). Besides, membrane damage was further verified through the reduction of the membrane integrity by using a flow cytometer. Moreover, the increase of malondialdehyde (MDA) (40.09%) and reactive oxygen species (ROS) accumulation indicated an induction of oxidative stress in cells by Cin/Cit. To resist the unfavorable stress caused by Cin/Cit, P. expansum metabolized Cin or Cit to the predominant detoxification compounds, cinnamic alcohol, nerol, and geraniol. The alterations in volatile profile demonstrated the influences on specific metabolisms in P. expansum caused by Cin/Cit., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

Epimedium is used in traditional Chinese medicine and contains flavonol glycosides that exhibit multiple biological activities. These bioactive flavonol glycosides usually have a rhamnose moiety at the 3-OH position of prenylflavonols, such as icariin (9), baohuoside I (1a) and baohuoside II (2a). However, to date, no rhamnosyltransferase has been reported to catalyze the 3-O-rhamnosylation of prenylflavonols. In this article, a flavonol rhamnosyltransferase, EpPF3RT, was identified from E. pseudowushanense B. L. Guo. The recombinant enzyme regiospecifically transfers a rhamnose moiety to 8-prenylkaempferol (1) and anhydroicaritin (2) at the 3-OH position to form baohuoside II (1a) and baohuoside I (2a) in vitro. In addition, a UDP-rhamnose synthase gene, EpRhS, from E. pseudowushanense was functionally characterized and used to produce the UDP-rhamnose sugar donor. Furthermore, an engineered Escherichia coli strain containing EpPF3RT and EpRhS was established to produce baohuoside II (1a) from whole cells. These studies indicate the significant potential of an enzymatic approach for the rhamnosylation of bioactive flavonoids in Epimedium plants and will provide a promising alternative for producing bioactive rhamnosylated flavonoids combined with other genes/enzymes by synthetic biology.

Ex situ characterizations based on TGA and XRD techniques revealed that MeOH vapor had little influence on the Nafion microstructures. To reveal the underlying mechanism, in this study, we designed new FTIR-based equipment to track in situ the microstructural changes of a bulk Nafion membrane in MeOH-saturated air. First, an interesting MeOH-breathing phenomenon was found in the ionic domains of Nafion. It demonstrated that there existed a dynamic equilibrium between the sorption and desorption processes of MeOH vapor in Nafion. Second, the FTIR results also detected the high stability of the hydrophobic regions of Nafion in MeOH vapor. The super-acid -CF2-SO3H always retained a small quantity of bonded H2O (H(+)(H2O)n) inside the Nafion membrane. MeOH vapor was absorbed first into the hydrophilic regions, however, the interactions between -CF2-SO3H and MeOH vapor were much weaker than those between -CF2-SO3H and H(+)(H2O)n. Therefore, a protective layer composed of residual water formed in the lumen of the hydrophilic ionic domains of Nafion, which protected its hydrophobic regions from the MeOH attack. Hereby, the self-protection ability of Nafion in MeOH vapor was detected for the first time. This work gave a new insight into the complex interplay between Nafion and MeOH vapor.

An amphiphilic polymeric micelle is utilized as a microreactor to load a hydrophobic [FeFe]-hydrogenase mimic in water. The local concentration enhancement and strong interaction between the mimic and the photosensitizer as well as the water-mediated fast proton migration caused by the microreactor improve photocatalytic hydrogen production remarkably in water.

There is a growing interest in using paper as a biomaterial scaffold for cell-based applications. In this study, we made the first attempt to fabricate a paper-based array for the culture, proliferation, and direct differentiation of human induced pluripotent stem cells (hiPSCs) into functional beating cardiac tissues and create "a beating heart on paper." This array was simply constructed by binding a cured multi-well polydimethylsiloxane (PDMS) mold with common, commercially available paper substrates. Three types of paper material (print paper, chromatography paper and nitrocellulose membrane) were tested for adhesion, proliferation and differentiation of human-derived iPSCs. We found that hiPSCs grew well on these paper substrates, presenting a three-dimensional (3D)-like morphology with a pluripotent property. The direct differentiation of human iPSCs into functional cardiac tissues on paper was also achieved using our modified differentiation approach. The cardiac tissue retained its functional activities on the coated print paper and chromatography paper with a beating frequency of 40-70 beats per min for up to three months. Interestingly, human iPSCs could be differentiated into retinal pigment epithelium on nitrocellulose membrane under the conditions of cardiac-specific induction, indicating the potential roles of material properties and mechanical cues that are involved in regulating stem cell differentiation. Taken together, these results suggest that different grades of paper could offer great opportunities as bioactive, low-cost, and 3D in vitro platforms for stem cell-based high-throughput drug testing at the tissue/organ level and for tissue engineering applications.

Bi-doped compounds Li3V2-xBix(PO4)3/C (x = 0, 0.01, 0.03, 0.05, 0.07) are prepared by a sol-gel method. The effects of Bi doping on the physical and electrochemical properties of Li3V2(PO4)3 are investigated. X-ray diffraction (XRD) analysis indicates that Bi doping does not change the monoclinic structure of Li3V2(PO4)3. A detailed analysis of the XRD patterns suggests that Bi(3+) ions partly enter into the crystal structure of Li3V2(PO4)3 and enlarge the lattice volume of Li3V2(PO4)3. According to the results of cycle and rate performance measurements, moderate Bi(3+) doping is beneficial in improving the electrochemical properties of Li3V2(PO4)3. Among all the samples, Li3V1.97Bi0.03(PO4)3/C shows the best cycle and rate performance. At 3.0-4.3 V, the initial discharge capacity of Li3V1.97Bi0.03(PO4)3/C is as high as 130 mA h g(-1), close to the theoretical specific capacity of 133 mA h g(-1). The capacity retention of Li3V1.97Bi0.03(PO4)3/C is almost 100% after 100 cycles at 3.0-4.3 V. In addition, Li3V1.97Bi0.03(PO4)3/C exhibits excellent low-temperature and high-rate performance. Impedance spectroscopy (EIS) and cyclic voltammetry (CV) curves indicate lower charge transfer resistance and a larger Li ion diffusion rate of Li3V1.97Bi0.03(PO4)3/C than the primary Li3V2(PO4)3/C. The excellent electrochemical performance of Li3V1.97Bi0.03(PO4)3/C can be attributed to its larger Li ion diffusion channels, higher electronic conductivity, higher structural stability and smaller particle size.

To improve the photocatalytic efficiency and make full use of solar energy, ZnWO(4):Yb(3+),Tm(3+) (ZYT) was introduced as the upconversion luminescence agent on TiO(2) with a cotton template, and novel upconversion photocatalysts of TiO(2)/ZnWO(4):Yb(3+),Tm(3+) (TZYT-C) were synthesized and optimized with 5%-30% of ZYT. The heterostructure between ZYT and TiO(2) was formed in the TZYT-C composites with the presence of tube-like morphologies due to the addition of the cotton template. UV (364 nm) and blue (484 nm) light was emitted from ZYT upon 980 nm NIR irradiation. The BET specific surface areas of all the TZYT-C composites increased from 37 m(2) g(-1) (TiO(2)-C) to the maximum value of 75 m(2) g(-1) on 5%TZYT-C. The photocatalytic activities of the TZYT-C composites were tested using the degradation process of methyl orange (MO). 5%TZYT-C showed the highest degradation efficiency, with a value of 55.6% under sun-like irradiation for 210 min. The same performance was observed on 5%TZYT-C under NIR (λ ≥ 780 nm) irradiation, with a maximum removal rate of 9.02%, since 5%TZYT-C showed the most efficient electron-hole (e(-)/h(+)) pair separation, compared to ZYT and other TZYT-C composites.

Investigating the dehydration process of a Nafion membrane helps to understand the mechanism of the decrease in its proton conductivity under high-temperature and low-humidity conditions. Herein, the influence of thermal treatment on a H2O-saturated Nafion membrane was in situ studied by FTIR spectroscopy. With the aid of generalized two-dimensional correlation spectroscopy (2Dcos), the microstructural changes during the thermal treatment were discussed in detail. In short, side-chain regions first lost H2O, followed by the H2O loss in ionic cluster domains. It resulted in shrunken ionic channels in the Nafion membrane, which exhibited a negative influence on its proton conduction. The immediate aftermath was the crystallization of amorphous backbone regions. All these results were confirmed by TGA and XRD techniques, and the 2Dcos method was first applied in TGA and XRD results in this field.

Alkylthiothieyl substituted benzothiophene (BDT) and alkoxycarbonyl cyanovinyl modified thienothiophene (TT) were copolymerized to obtain a new two dimensional low band gap polymer PBDTTT-S-CN, which exhibited a promising efficiency of 7.0% in organic solar cells.

Through a modular ROMP (ring-opening metathesis polymerization) strategy, a random copolymer with anti-thrombotic activity and imaging capability has been constructed from RGD, rhodamine B and PEG modified norbornene monomers. As we expected, these tri-component polynorbornenes exhibit significant enhancement in anti-thrombotic efficacy and bioavailability in vivo.

A simple one-pot multi-component ROMP of hydrophilic, spiropyran (SP) and tert-butyloxycarbonyl-protected (Boc-protected) amino-functionalized norbornenes was developed, and a series of water-soluble copolymeric materials were provided. The photochromic SP moiety endows the copolymers the properties of switchable fluorescence imaging with alternating near-IR (NIR) two-photon and visible single-photon excitations; thereby the copolymers can serve as a promising NIR two-photon fluorescent probe for living cancer cells. The cationic ammonium group enhances the cell transporting capability of the copolymers as well. The present strategy of one-pot ROMP also makes polynorbornene a modular and flexible scaffold in designing and synthesizing specifically biocompatible polymers with applications in imaging, diagnosis and therapy.

Six β-diketonate ligands were used to prepare the corresponding antenna europium(III) ternary complexes using 1,10-phenanthroline as an ancillary ligand. All the complexes exhibited high decomposition temperatures. Photophysical properties such as FT-IR spectra, UV-Vis absorption spectra, excitation and emission spectra, relative luminescent intensity ratios, luminescence decay curves and quantum yields based on the complexes were systematically studied and compared with each other. The energy-transfer mechanism was proposed as a ligand-sensitized luminescence process. Bright red light-emitting diodes (LEDs) were then fabricated by coating the complexes onto 395 nm-emitting InGaN chips. The light emission from the InGaN chips could be completely absorbed in the spectra of LEDs. The Commission International de I'Eclairage (CIE) chromaticity coordinates are close to the National Television Standard Committee (NTSC) standard value for the red color. All these findings indicate that these Eu(III) complexes are promising red phosphors for fabrication of near UV-based white LEDs.