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Attempt of developing bio-safety and functional layered double hydroxides (LDHs) modified plasma electrolytic oxidation (PEO) coatings, has become a hotspot in the protection of magnesium (Mg) based biomedical implants. In the present work, Mg-Fe LDH films with different Fe contents were fabricated on PEO coating via a novel two-step method: firstly, the FeOOH films were prepared by immersing PEO sample in Fe2+-containing solution, and then Mg-Fe LDH films were formed by transforming the FeOOH films via a hydrothermal treatment in water. The highly-oriented LDH nano-sheets could enhance the anti-corrosion performance of PEO coating, which was proved by the results of electrochemical test, hydrogen evolution and corroded morphology. PEO/Mg-Fe LDH coatings showed a low hemolysis rate (less 5%) than PEO coating. In addition, PEO/Mg-Fe LDH coatings were more favorable for cell adhesion and proliferation than PEO coating. Moreover, PEO/Mg-Fe LDH coatings showed good photothermal conversion property, which demonstrated the excellent rapid antibacterial effect under NIR light. In vitro culture of rat bone marrow stem cell (rBMSC) suggested that cells cultured in the extract of PEO/Mg-Fe LDH coatings had a better osteogenic activity. In vivo subcutaneous implantation test revealed that PEO/Mg-Fe LDH coatings exhibited good anti-corrosion and histocompatibility.

In this paper, a novel improvement in the catalytic Fenton reaction system named MHACF-NH2-MIL-101(Cr) was constructed based on H2 and Pd/NH2-MIL-101(Cr). The improved system would result in an accelerated reduction in FeIII, and provide a continuous and fast degradation efficiency of the 10 mg L-1 4-chlorophenol which was the model contaminant by using only trace level FeII. The activity of Pd/NH2-MIL-101(Cr) decreased from 100% to about 35% gradually during the six consecutive reaction cycles of 18 h. That could be attributed to the irreversible structural damage of NH2-MIL-101(Cr).

Morphological transitions in Candida species are key factors in facilitating invasion and adapting to environmental changes. N-acetylglucosamine (GlcNAc) is a monosaccharide signalling molecule that can regulate morphological transitions in Candida albicans and Candida tropicalis. Interestingly, although the uptake and metabolic pathways of GlcNAc and GlcNAc-mediated white-to-opaque cell switching are similar between the two Candida species, GlcNAc induces hyphal development in C. albicans, whereas it suppresses hyphal development in C. tropicalis. These findings indicate that the characteristics of C. albicans and C. tropicalis in response to GlcNAc are remarkably different. Here, we compare the conserved and divergent GlcNAc-mediated signalling pathways and catabolism between the two Candida species. Deletion of NGT1, a GlcNAc transportation gene, inhibited hyphal formation in C. albicans but promoted hyphal development in C. tropicalis. To further understand these opposite effects on filamentous growth in response to GlcNAc in the two Candida species, the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) signalling pathways in both C. albicans and C. tropicalis were compared. Interestingly, GlcNAc activated the cAMP/PKA signalling pathway of the two Candida species, suggesting that the hyphal development-regulated circuit is remarkably diverse between the two species. Indeed, the Ndt80-like gene REP1, which is critical for regulating GlcNAc catabolism, exhibits distinct roles in the hyphal development of C. albicans and C. tropicalis. These data suggest possible reasons for the divergent hyphal growth response in C. albicans and C. tropicalis upon GlcNAc induction.

Graphene and its derivatives attract extensive research interests in the biomedicine field due to their outstanding physiochemical properties. Lots of studies have reported that graphene materials exhibit antibacterial activities. However, antibacterial mechanisms of graphene materials still remain controversial and need further investigation. Herein, graphene oxide (GO) with and without nitrogen-doping were fabricated on the titanium surface by cathodic electrophoretic deposition and antibacterial activities were systematically investigated. Results showed that GO on the titanium surface presented antibacterial activity, while nitrogen-doped GO lost the antibacterial activity. The reason is that antibacterial mechanisms for the GO-metal system contain two steps. First, electron transfer occurs from bacterium’s cell membrane to GO surface which destroys the bacterial respiratory chain; subsequently, electrons on GO surface induce the production of reactive oxygen species (ROS) that damage the membrane structure and eventually lead to bacterial death. For nitrogen-doped GO, nitrogen atoms denote electrons into GO leading to n-type doping. Nitrogen-doped GO as an electron donor cuts off the electron transfer from the cell membrane to GO and subsequently inhibits the production of ROS. This is why nitrogen-doped GO exhibits no antibacterial activity. This work confirms the antibacterial mechanisms for the GO-metal system with a synergistic effect of non-oxidative electron transfer and ROS mediated oxidative stress.

Soft tissue sealing around implants acts as a barrier between the alveolar bone and oral environment, protecting implants from the invasion of bacteria or external stimuli. In this work, magnesium (Mg) and zinc (Zn) are introduced into titanium by plasma immersed ion implantation technology, and their effects on the behaviors of human gingival fibroblasts (HGFs) as well as the underlying mechanisms are investigated. Surface characterization confirms Mg and Zn exist on the surface in metallic and oxidized states. Contact angle test suggests that surface wettability of titanium changes after ion implantation and thus influences protein adsorption of surfaces. In vitro studies disclose that HGFs on Mg ion-implanted samples exhibit better adhesion and migration while cells on Zn ion-implanted samples have higher proliferation rate and amounts. The results of immunofluorescence staining and real-time reverse-transcriptase polymerase chain reaction (RT-PCR) suggest that Mg mainly regulates the motility and adhesion of HGFs through activating the MAPK signal pathway whereas Zn influences HGFs proliferation by triggering the TGF-β signal pathway. The synergistic effect of Mg and Zn ions ensure that HGFs cultured on co-implanted samples possessed both high proliferation rate and motility, which are critical to soft tissue sealing of implants., Graphical abstract Released Mg ions from the surface spur the expression of ITGB1 and influence HGFs adhesion and migration. Zn ions regulate HGFs proliferation through stimulating Zn transporters gene. Their impacts on HGFs probably involve MAPK and TGF-β signal pathways. Mg and Zn ions implantation improve cell migration and proliferation of HGFs, two important cell behaviors for soft tissue regeneration, respectively.Image 1, Highlights • Mg and Zn PIII promoted different behaviors of HGFs, respectively. • Mg PIII improved the adhesion and migration of HGFs through MAPK signal pathway. • Zn PIII regulated the proliferation of HGFs through TGF-β signal pathway.

Macrophages in lung, including resident alveolar macrophages (AMs) and interstitial macrophages (IMs), and monocyte-derived macrophages, play important roles in pulmonary fibrosis (PF), but mechanisms underlying their differential regulation remain unclear. Recombination signal-binding protein Jκ (RBP-J)-mediated Notch signaling regulates macrophage development and phenotype. Here, using bleomycin-induced fibrosis model combined with myeloid-specific RBP-J disruption (RBP-JcKO ) mouse, we investigated the role of Notch signaling in macrophages during PF. Compared with the control, RBP-JcKO mice exhibited alleviated lung fibrosis as manifested by reduced collagen deposition and inflammation, and decreased TGF-β production. FACS analysis suggested that decreased Ly6clo MHCIIhi AMs might make the major contribution to attenuated fibrogenesis in RBP-JcKO mice, probably by reduced inflammatory factor release and enhanced matrix metalloproteinases expression. Using clodronate-mediated macrophage depletion in RBP-JckO mice, we demonstrated that embryonic-derived AMs play negligible role in lung fibrosis, which was further supported by adoptive transfer experiments. Moreover, on CCR2 knockout background, the effect of RBP-J deficiency on fibrogenesis was not elicited, suggesting that Notch regulated monocyte-derived AMs. Co-culture experiment showed that monocyte-derived AMs from RBP-JcKO mice exhibit reduced myofibroblast activation due to decreased TGF-β secretion. In conclusion, monocyte-derived Ly6clo MHCIIhi AMs, which are regulated by RBP-J-mediated Notch signaling, play an essential role in lung fibrosis.

Multifarious strategies have been proposed to enhance the antibacterial ability of implant surfaces for preventing bacterial infection, however, developing facile and universal modification methods still remains extremely elusive. Herein, inspired by the fact that the electron transfer respiratory chain of bacteria is embedded in the membrane, we proposed a novel strategy of local alkalinity disturbing bacterial respiration to endow implant materials with antibacterial ability. As a demonstration, MgO was deposited on biomedical titanium via magnetron sputtering to regulate surface alkalinity. With the thickness of MgO films increasing, they exhibited an excellent antibacterial rate against both Gram-negative and positive bacteria. The antibacterial mechanism confirmed that the alkaline surface can disturb the bacterial respiration action via weakening the transmembrane proton concentration gradient, resulting in the blockage of energy metabolism and the increase of oxidative stress of bacteria. Cell experiments indicated that MgO films not only have no obvious cytotoxicity to osteoblast cells, but can also selectively kill bacteria and promote cell proliferation in the presence of both bacteria and cells. More importantly, the by-product of MgO was only the biocompatible Mg2+, reducing any concerns about potential toxic effects. Furthermore, sputtering alkaline MgO films was confirmed to work well on polyetheretherketone polymer and zirconia ceramic implants, which indicates that this strategy has broad prospects of clinical application for preventing implant-associated bacterial infection.

In order to enhance the antibacterial ability of titanium components, an antibacterial coating was fabricated on Ti surface by micro-arc oxidation (MAO) and further nitrogen plasma immersion ion implantation (N-PIII). The XPS spectra demonstrated that nitrogen was incorporated into TiO2 coatings by N-PIII and the nitrogen content on the surface of TiO2 coatings increased as the N-PIII time increased. Nitrogen-incorporated samples exhibited remarkably increased absorbance in the visible region and the light absorption edge of nitrogen-incorporated samples showed a redshift compared to MAO samples. Escherichia coli and Staphylococcus aureus were seeded on the samples to assess their antibacterial ability. The bacterial experiment demonstrated that nitrogen-incorporated TiO2 could effectively reduce the bacterial viability in visible light. Thus, the antibacterial TiO2 coatings fabricated by MAO and further N-PIII might have large potential in the medical and marine fields.

A highly efficient arylation of para-quinone methides (p-QMs) with N,N-dimethylaniline under solvent free condition has been developed, which proceeded via a para-toluenesulfonic acid (TsOH)-promoted 1,6-conjugated addition pathway. This methodology provided a green and sustainable methodology to construct various novel unsymmetrical triarylmethanes (TAMs) with the advantages of good functional group tolerance, scalability, and regioselectivity.

Long-term function of dental implants relies on not only stable osseointegration but also strong soft tissue-sealing ability. Ideal soft tissue sealing around implants is an effective protective barrier between the external environment and alveolar bone, preventing the invasion of bacteria that is considered as a vital trigger of irreversible marginal bone loss. Carbon-based materials have been reported to be beneficial to soft tissue sealing, which can be regulated through the hybridization type of carbon atoms (sp2 or sp3), but its internal mechanism is still not clear. In this work, graphene oxide with both sp2- and sp3-hybridized carbons was electrophoretic deposited on titanium and reduced to regulate the hybridization type of carbon atoms to investigate its effect and possible mechanism on human gingival fibroblasts (HGFs). X-ray photoelectron spectroscopy and Raman mapping test show the increase of sp2 domain content and the decrease of their size after reduction. Through computer simulation, the possible mechanism of the decrease of sp2 domain size was proposed. In vitro studies disclose that the HGFs exhibit higher proliferation rate, better adhesion, and migration ability with the increase of sp2 domains and the decrease of their sizes. It may be due to the amount and size of sp2 domains that synergistically regulate the amount and properties of adsorbed proteins, thereby influencing the cellular behaviors of HGFs. Our results may offer a different perspective on material designing and academic research to enhance the soft tissue integration of implants.

Magnesium biometals exhibit great potentials for orthopeadic applications owing to their biodegradability, bioactive effects and satisfactory mechanical properties. However, rapid corrosion of Mg implants in vivo combined with large amount of hydrogen gas evolution is harmful to bone healing process which seriously confines their clinical applications. Enlightened by the superior biocompatibility and corrosion resistance of passive titanium oxide layer automatically formed on titanium alloy, we employ the Ti and O dual plasma ion immersion implantation (PIII) technique to construct a multifunctional TiO2 based nano-layer on ZK60 magnesium substrates for enhanced corrosion resistance, osteoconductivity and antimicrobial activity. The constructed nano-layer (TiO2/MgO) can effectively suppress degradation rate of ZK60 substrates in vitro and still maintain 94% implant volume after post-surgery eight weeks. In animal study, a large amount of bony tissue with increased bone mineral density and trabecular thickness is formed around the PIII treated group in post-operation eight weeks. Moreover, the newly formed bone in the PIII treated group is well mineralized and its mechanical property almost restores to the level of that of surrounding mature bone. Surprisingly, a remarkable killing ratio of 99.31% against S. aureus can be found on the PIII treated sample under ultra-violet (UV) irradiation which mainly attributes to the oxidative stress induced by the reactive oxygen species (ROS). We believe that this multifunctional TiO2 based nano-layer not only controls the degradation of magnesium implant, but also regulates its implant-to-bone integration effectively. Statement of significance Rapid corrosion of magnesium implants is the major issue for orthopaedic applications. Inspired by the biocompatibility and corrosion resistance of passive titanium oxide layer automatically formed on titanium alloy, we construct a multifunctional TiO2/MgO nanolayer on magnesium substrates to simultaneously achieve superior corrosion resistance, satisfactory osteoconductivity in rat intramedullary bone defect model and excellent antimicrobial activity against S. aureus under UV irradiation. The current findings suggest that the specific TiO2/MgO nano-layer on magnesium surface can achieve the three objectives aforementioned and we believe this study can demonstrate the potential of biodegradable metals for future clinical applications.

Titanium implants fabricated by micro-arc oxidation (MAO) are widely used in orthopedic therapies. However, TiO2 is a bio-inert material and lacks antibacterial properties. Therefore, it is crucial to enhance the biological activity and antibacterial properties of MAO implants. In this work, TiO2 coatings were fabricated by MAO and further hydrogen plasma immersion ion implantation (H-PIII). The formation of Ti-OH bonds promoted cell proliferation and osteogenic differentiation. The presence of Ti3+ and oxygen vacancies narrowed the forbidden band of TiO2 and showed bacteriostatic effect to E. coli and S. aureus.

Local tissue microenvironment is able to regulate cell-to-cell interaction that leads to effective tissue repair. This study aims to demonstrate a tunable magnesium ionic (Mg2+) microenvironment in bony tissue that can significantly induce bone defect repair. The concept can be realized by using a newly fabricated nanocomposite comprising of custom-made copolymer polycaprolactone-co-poly(ethylene glycol)-co-polycaprolactone (PCL-PEG-PCL) and surface-modified magnesium oxide (MgO) nanoparticles. In this study, additive manufacturing (AM) technology had been adopted to help design the porous three-dimensional (3D) scaffolds with tunable Mg2+ microenvironment. We found that the wettability and printability of new copolymer had been improved as compared with that of PCL polymer. Additionally, when MgO nanoparticles incorporated into the newly synthesized hydrophilic copolymer matrix, it could lead to increased compressive moduli significantly. In the in vitro studies, the fabricated nanocomposite scaffold with low concentration of Mg2+ microenvironment not only demonstrated better cytocompatibility, but also remarkably enhanced osteogenic differentiation in vitro as compared with the pure PCL and PCL-PEG-PCL co-polymer controls. In the animal studies, we also found that superior and early bone formation and tissue mineralization could be observed in the same 3D printed scaffold. However, the nanocomposite scaffold with high concentration of Mg2+ jeopardized the in situ bony tissue regeneration capability due to excessive magnesium ions in bone tissue microenvironment. Lastly, this study demonstrates that the nanocomposite 3D scaffold with controlled magnesium concentration in bone tissue microenvironment can effectively promote bone defect repair.

A novel catalytic Fenton system based on H2 and the solid catalyst Pd/MIL-101(Cr) (MHACF-MIL-101(Cr)) was developed at normal temperature and pressure. In this system, the reduction process of FeIII back to FeII was accelerated significantly. Using only trace levels of FeII at the beginning of the reaction, MHACF-MIL-101(Cr) provided continuous production of hydroxyl radicals and rapid degradation of the model contaminant 4-chlorophenol (10 mg L−1) under the initial conditions of pH 3, 25 μM FeII, 25 mM H2O2, 85 mL min−1 H2 and 2 g L−1 Pd/MIL-101(Cr). The activity of the solid catalyst gradually decreased from 100% to about 70% after 6 consecutive degradation reaction cycles of 18 h. This may mainly be attributed to the structural damage and the surface area reduction of this catalyst.

Epilepsy (SE) is a common and serious neurological disease. NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome participates in the pathogenesis of SE, while its underlying mechanism is still unclear. Here, we attempted to explore the mechanism of action of NLRP3 inflammasome in SE. SE mouse model was constructed by administration of kainic acid (KA). Astrocytes were treated with KA to mimic SE cell model. MCC950 (NLRP3 inhibitor) and Z-YVAD-FMK (Caspase-1 inhibitor) were used to treat astrocytes to inhibit the activity of NLRP3 and Caspase-1. Nissl staining was performed to examine the morphology of neuron. Western blot, enzyme-linked immunosorbent assay and immunofluorescence staining were performed to assess protein expression. SE mouse model exhibited an increase of neuronal loss, and an up-regulation of Cleaved-Caspase-1, IL-1β and IL-18 in hippocampus. The levels of GFAP+ADK+ cells were significantly increased in SE mice. MCC950 or Z-YVAD-FMK abolished these impacts conferred by KA in SE mice. Moreover, KA treatment enhanced the expression of NLRP3, Cleaved-Caspase-1, IL-1β and IL-18 in astrocytes, which was rescued by knockdown of NLRP3 or Caspase-1. Additionally, CREB, p-CREB, REST were up-regulated, and SP1 was down-regulated in the KA-treated SE mice and KA-treated astrocytes. Inhibition of NLRP3 or Caspase-1 rescued these proteins expression in KA-treated astrocytes. CREB or REST silencing reduced adenosine kinase (ADK) expression, while SP1 knockdown enhanced ADK expression in KA-treated astrocytes. In conclusion, NLRP3 inflammasome activation enhances ADK expression to accelerate SE in mice through regulating CREB/REST/SP1 signaling pathway. Thus, inhibition of NLRP3 inflammasome may be a treatment for SE.

Background T cell immunoglobulin and mucin domain-containing-3 (Tim-3) is a negative regulator expressed on T cells, and is also expressed on natural killer (NK) cells. The function of Tim-3 chiefly restricts IFNγ-production in T cells, however, the impact of Tim-3 on NK cell function has not been clearly elucidated. Results In this study, we demonstrated down-regulation of Tim-3 expression on NK cells while Tim-3 is upregulated on CD4+ T cells during HIV infection. Functional assays indicated that Tim-3 mediates suppression of CD107a degranulation in NK cells and CD4+ T cells, while it fails to inhibit the production of IFN-γ by NK cells. Analyses of downstream pathways using an antibody to block Tim-3 function demonstrated that Tim-3 can inhibit ERK and NFκB p65 signaling; however, it failed to suppress the NFAT pathway. Further, we found that the NFAT activity in NK cells was much higher than that in CD4+ T cells, indicating that NFAT pathway is important for promotion of IFN-γ production by NK cells. Conclusions Thus, our data show that the expression of Tim-3 on NK cells is insufficient to inhibit IFN-γ production. Collectively, our findings demonstrate a potential mechanism of Tim-3 regulation of NK cells and a target for HIV infection immunotherapy.

Total organic carbon (TOC) can reflect the total amount of organic matter in water. This paper introduces the common methods of measuring organic carbon, including high temperature combustion method, potassium persulfate oxidation method, spectrometry, ozone oxidation chemiluminescence method, supercritical water oxidation method and so on. At present, high temperature combustion method is the most widely used method for TOC measurement in seawater, because of its high oxidation efficiency. TOC sensor needs to be developed to realize in-situ and long-term monitoring.

BackgroundPropofol is the most commonly used general anesthesia for patients with gastric cancer undergoing radical surgery. Studies have suggested that propofol exerts beneficial effects on the immune function of patients with cancer. However, the potential mechanism underlying propofol-mediated immune regulation remains to be elucidated. The present study investigated the regulatory effects of propofol on immune function in patients with gastric cancer undergoing radical surgery. MethodsELISA, reverse transcription-quantitative polymerase chain reaction, western blotting, gene transfection and immunohistochemistry were used to analyze the effects of propofol on gastric cancer cells.ResultsResults demonstrated that propofol general anesthesia resulted in an increased percentage of cluster of differentiation (CD)4+ and CD8+ cells, increased serum concentrations of interleukin (IL)-2 and tumor necrosis factor (TNF)-α, decreased serum concentrations of IL-1β and IL-8 following propofol general anesthesia in gastric cancer patients undergoing radical surgery compared with midazolam. In addition, propofol general anesthesia induced an imbalance in T helper (Th)1/Th2 cells, increased the number of natural killer cells and B cells, decreased the expression of prognostic factors, and improved tumor metastasis, recurrence and survival in patients with gastric cancer compared with midazolam. Furthermore, immunohistochemistry demonstrated that propofol downregulated nuclear factor (NF)-κBp65, and upregulated Janus kinase 1 (JAK1) and signal transducer and activator of transcription 3 (STAT3) expression level in gastric cancer tissues, downregulated the protein expression levels of NF-κBp65, JAK1, STAT3, TNF-α, IL-1β and IL-8 protein expression in gastric cancer cells isolated from gastric cancer tissues. NF-κBp65 overexpression inhibited propofol-mediated upregulation of JAK1, STAT3, TNF-α, IL-1β and IL-8 expression in gastric cancer cells. ConclusionsThese data indicate that that propofol may increase the number of T cells, stimulate T-cell proliferation, upregulate IL-2 and TNF-α expression, and enhance immune function via the NF-κB-mediated JAK1-STAT3 signaling pathway in patients with gastric cancer undergoing radical surgery.

Layered double hydroxides (LDHs) are widely studied to enhance corrosion resistance and biocompatibility of Mg alloys, which are promising bone implants. However, the influence of LDH coating on the osteointegration of Mg implants lacks of a systematic study. In this work, Mg-Al LDH coating was prepared on pure Mg via hydrothermal treatment. The as-prepared Mg-Al LDH coated Mg exhibited better in vitro and in vivo corrosion resistance than bare Mg and Mg(OH)2 coated Mg. In vitro culture of mouse osteoblast cell line (MC3T3-E1) suggested that Mg-Al LDH coated Mg was more favorable for its osteogenic differentiation. In vitro culture of HUVECs revealed that cells cultured in the extract of Mg-Al LDH coated Mg showed superior angiogenic behaviors. More importantly, the immune response of Mg-Al LDH coated Mg was studied by in vitro culturing murine-derived macrophage cell line (RAW264.7). The results verified that Mg-Al LDH coated Mg could induce macrophage polarize to M2 phenotype (anti-inflammatory). Furthermore, the secreted factor in the macrophage-conditioned culture medium of Mg-Al LDH group was more suitable for the bone differentiation of rat bone marrow stem cells (rBMSCs) and the angiogenic behavior of human umbilical vein endothelial cells (HUVECs). Finally, the result of femoral implantation suggested that Mg-Al LDH coated Mg exhibited better osteointegration than bare Mg and Mg(OH)2 coated Mg. With favorable in vitro and in vivo performances, Mg-Al LDH is promising as protective coating on Mg for orthopedic applications., Graphical abstract Image 1, Highlights • Mg-Al LDH film was prepared on pure Mg via hydrothermal treatment. • Mg-Al LDH film was favorable for bone differentiation and angiogenic behavior. • Mg-Al LDH film could induce M2 polarization of RAW264.7 • Mg-Al LDH film showed improved in vivo osteointegration.

Implant-associated infections is one of the most challenging post-operative complications in bone-related implantations. To tackle this clinical issue, we developed a low-cost and durable surface coating for medical grade titanium implants that uses positively charged silane molecules. The in vitro antimicrobial tests revealed that the titanium surface coated with (3-aminopropyl) triethoxysilane, which has the appropriate length of hydrophobic alkyl chain and positive charged amino group, suppressed more than 90% of the initial bacterial adhesion of S. aureus, P. aeruginosa, and E. coli after 30 minutes of incubation. In terms of growth inhibitory rate, the treated surface was able to reduce 75.7% ± 11.9% of bacterial growth after a 24-hour culturing, thereby exhibiting superior anti-biofilm formation in the late stage. When implanted into the rat model infected by S. aureus, the treated surface eliminated the implant-associated infection through the mechanism of inhibition of bacterial adhesion on the implant surface. Additionally, the treated surface was highly compatible with mammalian cells. In general, our design demonstrated its potential for human clinical trials as a low-cost and effective antibacterial strategy to minimize post-operative implant-related bacterial infection.

For hard tissue replacement, an implant with a multifunctional surface, which combines long term anticorrosion potential, osteogenesis and antibacterial properties is one of the most ideal products people strive for. In this work, stable Mn-containing titania coatings on titanium were obtained by introducing a strong electrolyte and strong oxidant, potassium permanganate (KMnO4), into a conventional micro-arc oxidation (MAO) electrolyte solution. The MAO-synthesized Mn-containing titania coating showed a compacted surface, which results in excellent anticorrosion capacity and provides a stable Mn delivery platform that can sustainedly release Mn ions at a desirably slow rate for more than 6 weeks. The subsequent releasing of Mn ions improves the osteogenic activity and antibacterial ability of the titania coating. Thus, we have combined osteogenesis and antibacterial properties in an Mn-containing titania coating, which provides insight into the design of better biomedical implant surfaces in the future.

PEEK-based biomaterials have great potential applications as hard tissue substitutes in bone tissue engineering. However, inherent bio-inert properties limited their clinical use. In order to improve the bioactivity, in this work, zirconium ions were implanted into the carbon fiber-reinforced PEEK (CFR-PEEK) using plasma immersion ion implantation (PIII) technology. Surface morphologies and chemical compositions of Zr-PIII treated samples were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), respectively. The results indicated that nanostructures and ZrO2 nanoparticles were formed on the surface of CFR-PEEK after Zr-PIII. Mechanical tests revealed that nanohardness, elastic modulus, and elastic resistance increased after implantation, especially for the elastic modulus with a maximum value of about 14 GPa, which is much close to that of human natural bone. In vitro cellular experiments showed that Zr-PIII treated samples enhanced the initial adhesion of rBMSCs, spreading and proliferation significantly. Moreover, the heightened ALP activity, collagen secretion, and extracellular matrix mineralization suggested that Zr-PIII treatment could greatly lead to an up-regulated osteogenic differentiation of rBMSCs on CFR-PEEK. In addition, antibacterial properties were also investigated and the results showed that Zr-PIII treated CFR-PEEK with nanostructures exhibited obvious antibacterial activity against S. aureus but no effect on E. coli.

In this study, titania nanotubes (TNTs) incorporating silicon (Si) were formed on Ti disks using anodization and electron beam evaporation (EBE) technology to improve the osteogenic activity. The amount of Si was exquisitely adjusted by controlling the duration of EBE to optimize the biofunctionality. As the Si was incorporated, the samples exhibited hydrophilic surfaces. Long lasting and controllable Si release was observed from the EBE-modified samples without cytotoxicity. Moreover, initial cell adhesion, spreading, proliferation and osteogenic differentiation of MC3T3-E1 cells were evaluated. The results showed a notable enhancement of spreading, osteogenesis and differentiation of cells on silicon-coated TNTs (Si-TNTs). In particular, samples with highest amount of silicon (∼5.93% Si) displayed greatest augmentation of ALP activity, osteogenic-related gene expression and mineralization compared to the others in the present study. It was indicated that the modification with TNTs and appropriated Si content resulted in enhanced osteoblastic spreading, proliferation and differentiation, and therefore has the potential for future applications in the field of orthopedics.

Acetonitrile inorganic salt aqueous two-phase extraction method was established for the determination of triazine herbicides (simeton, cyanazine, desmetryn, terbumeton, terbuthylazine and dimethametryn) in environmental water samples by high-performance liquid chromatography (HPLC). The extraction solvents types and volume of acetonitrile, the inorganic salt types and amount of (NH4)2SO4, extraction time and pH of sample solution were optimized by single-factor experiment and central composite design. Under the optimum extraction conditions, all linear ranges were obtained with coefficients of determination (r) ≥ 0.9993. The limits of detection for this proposed method were in the range of 0.16–0.28 μg/L for six triazine herbicides. The developed method has been successfully applied to the analysis of target triazine herbicides from lake, canal and moat in real-world water samples. The recoveries of target analytes were in the range from 87.0 to 110.9% and the relative standard deviation was lower than 7.3%.

Adipocyte fatty acid‐binding protein (FABP4) is abundant in macrophage and adipocyte. It is known to be involved in lipid metabolism. The role of FABP4 has been reported in various cancers, such as non‐small cell lung cancer, breast cancer, ovarian cancer, and prostatic cancer. However, its role remains unclear in hepatocellular carcinoma (HCC). In our study, we investigated the expression of FABP4 at both mRNA and protein levels, and by examining 175 cases of patients with cancer of the liver tissue microarray, the significance between the expression of FABP4 and clinical characteristics had been discussed. We found that FABP4 was lowly expressed in HCC tissues compared to the corresponding tissue adjacent, and the expression of FABP4 was significantly associated with the tumor size, PVTT, recurrence‐free survival and overall survival. Moreover, multivariate Cox regression analysis indicated that the expression of FABP4, Alb, AFP, HBsAg, and PVTT were independent risk factors for overall survival, and the expression of FABP4, AFP, GGT, tumor size, and encapsulation were independent risk factors for HCC recurrence. In addition, we revealed that FABP4 suppressed HCC cell proliferation and invasion in vitro. Moreover, overexpression of FABP4 led to inhibit tumor growth and decreased tumor volume in vivo. These phenotypes were associated with altered expression of Snail and p‐STAT3. Our studies thus suggest that FABP4 could be a potential target for HCC chemotherapy.

Macrophages play critical roles in renal fibrosis. However, macrophages exhibit ontogenic and functional heterogeneities, and which population of macrophages contributes to renal fibrosis and the underlying mechanisms remain unclear. In this study, we genetically targeted Notch signaling by disrupting the transcription factor recombination signal binding protein-Jκ (RBP-J), to reveal its role in regulation of macrophages during the unilateral ureteral obstruction (UUO)-induced murine renal fibrosis. Myeloid-specific disruption of RBP-J attenuated renal fibrosis with reduced extracellular matrix deposition and myofibroblast activation, as well as attenuated epithelial-mesenchymal transition, likely owing to the reduced expression of TGF-β. Meanwhile, RBP-J deletion significantly hampered macrophage infiltration and activation in fibrotic kidney, although their proliferation appeared unaltered. By using macrophage clearance experiment, we found that kidney resident macrophages made negligible contribution, but bone marrow (BM)-derived macrophages played a major role in renal fibrogenesis. Further mechanistic analyses showed that Notch blockade reduced monocyte emigration from BM by down-regulating CCR2 expression. Finally, we found that myeloid-specific Notch activation aggravated renal fibrosis, which was mediated by CCR2+ macrophages infiltration. In summary, our data have unveiled that myeloid-specific targeting of Notch could ameliorate renal fibrosis by regulating BM-derived macrophages recruitment and activation, providing a novel strategy for intervention of this disease. Electronic supplementary material The online version of this article (10.1007/s13238-018-0527-6) contains supplementary material, which is available to authorized users.

Single‐chain variable fragment (scFv) antibodies are the smallest immunoglobulins with high antigen‐binding affinity. We have previously reported that fibroblast growth factor 1 played pivotal roles in cancer development and generated a mouse scFv (mscFv1C9) could effectively prohibit cancer cell proliferation in vitro and in vivo. Here, we further humanized this scFv (hscFv1C9) using a structure‐guided complementarity determining region grafting strategy. The purified hscFv1C9 maintained similar antigen‐binding affinity and specificity as mscFv1C9, and it was capable of inhibiting growth of different tumours in vitro and in vivo. These data strongly suggested that hscFv1C9 has antitumour potentials.

A series of zirconolite ceramics with stoichiometry Ca1-xCexZrTi2-2xAl2xO7 (x = 0 – 0.35), considered as a host phase for the immobilisation of separated plutonium, were prepared from a mixture of oxide precursors by sintering in air at 1450°C. Ce was utilised as a structural surrogate for Pu, with Al added to provide charge compensation. XRD and electron diffraction analyses indicated crystallisation of the zirconolite-2M polytype for all compositions, accompanied by various secondary phases contingent on the doping level, consistent with microstructure observation. The relative yield of zirconolite phases remained above 94 wt.% for 0.05

Herein, a novel smart chemical strategy for regulating the corrosion reaction to reinforce the plasma electrolytic oxidation (PEO) coating on magnesium by amorphous MnOOH is proposed. The MnOOH film could provide PEO coating with both physical shielding and chemical active healing abilities. During corrosion process, MnOOH spontaneously reacts with the corrosion-produced Mg2+ and OH– to form layered double hydroxides, resulting in high improvement of the long-term anti-corrosion of PEO coating. Moreover, the PEO/MnOOH coating presented a certain self-healing ability for scratches, and could be used for repairing corrosion defects on further coated films.

A novel CHACF-JUC-505 system through the introduction of H2 and Pd/JUC-505 into the classic Fenton system under normal temperature and pressure was developed in this work. Through the experiment of quenching hydroxyl radical (·OH) by methanol, the analysis of degradation intermediates and total organic carbon, it was confirmed from the reverse that the target pollutant sulfamethazine (SMT) could be quickly adsorbed by JUC-505. The activated hydrogen generated from the adsorbed and activated H2 by Pd/JUC-505 accelerated the reduction of FeIII. It was confirmed that the continuous production of ·OH required only a trace amount of iron by the detection of para-hydroxybenzoic acid. The removal of SMT was further enhanced by the degradation of ·OH. The cleavage of S N bond was considered to be the major degradation pathway of SMT. The concentration of FeII in the CHACF-JUC-505 system could be at least 14.72 μM. And the removal efficiency of SMT was about 96.77 %. That was 3 and 4.6 times that of the Fenton system in the same reaction condition, respectively. The effects of the dosage of ferrous ion, H2O2 and Pd/JUC-505, initial concentration of SMT and pH, and the flow of H2 were investigated. The robustness and morphological changes in Pd/JUC-505 were also systematically analyzed.

Graphene oxide has attracted widespread attention in the biomedical fields due to its excellent biocompatibility. Herein we investigated the layer-number dependent antibacterial and osteogenic behaviors of graphene oxide in biointerfaces. Graphene oxide with different layer numbers was deposited on the titanium surfaces by cathodal electrophoretic deposition with varied deposition voltages. The initial cell adhesion and spreading, cell proliferation, and osteogenic differentiation were observed from all the samples using rat bone mesenchymal stem cells. Both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were used to investigate the antibacterial effect of the modified titanium surfaces. Cocultures of human gingival fibroblasts (HGF) cells with Escherichia coli and Staphylococcus aureus were conducted to simulate the conditions of the clinical practice. The results show that the titanium surfaces with graphene oxide exhibited excellent antibacterial and osteogenic effects. Increasing the layer-number of graphene oxide resulted in the augment of reactive oxygen species levels and the wrinkling, which led to the antibacterial and osteogenic effects, respectively. Compared to pure titanium surface in the cells-bacteria coculture process, the modified titanium surfaces with graphene oxide exhibited higher surface coverage percentage of cells.

Silver nanoparticles (Ag NPs) were widely explored for antimicrobial applications, whereas the translation into drugs and implantable antibacterial devices provoked serious concerns about their potential cytotoxicity. Herein, Ag NPs with diameters ranging from 4 to 19 nm were in situ fabricated and immobilized on titanium by using a plasma immersion ion implantation process. The particles have a population-dependent capability in activating the integrin α5 orchestrated MAPK/ERK signal cascade of osteoblast differentiation in rat bone marrow stem cells (BMSCs), and promoting osteointegration of titanium. It was demonstrated that the titanium-supported Ag NPs played an important role in motivating integrin α5 through triggering the galvanic hydrogen evolution reactions, which was found in positive correlation with the distribution density of the immobilized Ag NPs. Since cellular uptake is a key factor determining the cytotoxic performance of Ag NPs, the extracellular effects of immobilized Ag NPs on promoting osteogenesis provided new insights into the safe application of nanomaterials, and into designing and developing renewed antibacterial devices with selective toxicity.

A fluorescent and colorimetric pH probe based on a rhodamine 6G derivative, RP1, was designed and synthesized. The probe was based on the pH induced change in the structure between the spirocyclic (non-fluorescent, colorless) and quinoid (fluorescent, pink) forms of rhodamine 6G. The effect of the acid concentration on the fluorescence “off-on” behaviors of RP1 was investigated. RP1 was fluorescent in the pH range of 1.1–3.1 and has a pKa value of 2.08 (±0.07). Thus RP1 should be useful for studies in strongly acidic environments. Possible interferences from fourteen common metal ions were tested and excluded showing the excellent selectivity of the probe. Finally, the probe exhibits an intense color change at pH values lower than 3.1 which makes it useful for naked-eye pH detection.

The crystal structure of GdFeMn alloy has been investigated by using X-ray powder diffraction (XRD) followed by Rietveld refinement technique, differential thermal analysis (DTA) and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) techniques. XRD results showed that annealed GdFeMn alloy was a single phase of Gd6(Fe0.5Mn0.5)23 compound, with Th6Mn23-structure. SEM/EDS results and Rietveld refinement revealed that GdFeMn alloy was not really a new ternary compound as reported, but a solid solution Gd6(Fe0.5Mn0.5)23 which was only a point between Gd6Fe23 and Gd6Mn23. It was also found from DTA measurement that a reaction, Gd (Fe0.5Mn0.5)2 → liquid (rich Gd) + Gd6(Fe0.5Mn0.5)23, had taken place above 650.81 oC, and the educed Gd existed in educed part of GdFeMn sample. The results demonstrated the real structure of the GdFeMn compound as reported was Gd6(Fe0.5Mn0.5)23 compound.

The monocyte/macrophage system plays an essential role in the host response and the fate of endosseous implanted materials. Macrophage behavior was thought to be regulated by nanostructured titanium which has been considered as a very promising candidate for dental implants. However, there is little known for subsequent effects of these activated macrophages on osteogenesis and angiogenesis which were essential for bone integration. Here we presented two different dimensions of titanium nanotubes generated by anodic oxidation at 10 V (NT 10) and 20 V (NT 20), respectively. The behavior of macrophages on the surfaces was evaluated, and their conditioned medium (CM) was collected to stimulate MC3T3 and HUVECs, with commercially pure titanium (cp Ti) as control. We found that NT 20 induced macrophage activation similar to the anti-inflammatory M2 macrophage state with the enhanced expression of IL-10 and ARG, while NT 10 was associated with M1 macrophage phenotype characterized by high levels of IL-1β, iNOS and TNF-α. Furthermore, the osteogenic capacity of MC3T3 in CM from NT 20 was enhanced (NT 20 > NT 10 ≈ cp Ti) and the tube formation capacity of HUVECs was promoted in CM from nanotubular surfaces with increasing tube dimensions (NT 20 > NT 10 > cp Ti). Our data suggest that dental implants with the large nanotube dimension surface could result in a favorable osteoimmunomodulatory microenvironment for the establishment of osseointegration.

To understand the interface effects between human gingival fibroblasts (HGFs) and the titanium substrate for soft tissue sealing, zinc (Zn) was incorporated into titanium by plasma immersion ion implantation (PIII) in the work, and the durations of 30, 60 and 90 min were adopted for serials of Zn content on titanium to identify the possible dose-effect relationship. Results showed that the implanted Zn formed metallic Zn and zinc oxide on the surface, and the Zn content increased with the extension of implantation time. The release of Zn ions occurred in the saline solution, but the amounts of released ions were inconsistent with the Zn content of implanted samples and their corrosion behaviors, indicating the different reaction activities among the sample surfaces. Moreover, in vitro studies disclosed that the incorporated samples were beneficial to the adhesion, proliferation, and migration of HGFs with appropriate dose of released Zn ions as well as the surface activities, as the fact it was not a directly proportional dose-effect relationship between released Zn ions and the behaviors of cells. It was suggested that Zn-PIII provided an approach to improve the soft tissue sealing of titanium through interfacial activities of implanted samples to regulate the behaviors of HGFs and the usage of Zn ions followed a synergistic manner.

Carbon fiber reinforced polyetheretherketone (CFRPEEK) possesses a similar elastic modulus to that of human cortical bone and is considered as a promising candidate to replace metallic surgical implants. However, the bioinertness and deficiency of antibacterial activities impedes the application of CFRPEEK as orthopedic and especially oral implants. In this work, dual zinc and oxygen plasma immersion ion implantation (Zn/O-PIII) is applied to modify CFRPEEK, achieving both zinc incorporation and introduction of unique micro-/nano-structures on the surface. Scanning electron microscopy (SEM) observation reveals the formation of micro-pits with the size of around 800 nm on the CFRPEEK surface. X-ray photoelectron spectroscopy (XPS) test results confirm the existence of ZnO on the near surface. In vitro cell adhesion, viability assay, and real-time PCR analyses disclose enhanced adhesion, proliferation, and osteo-differentiation of mouse osteoblasts (MC3T3-E1) and rat bone mesenchymal stem cells (bMSCs) on the structured surface. Furthermore, the multilevel structures on CFRPEEK exhibit great antibacterial activity to biofilm-positive Staphylococcus aureus (ATCC 25923), MRSA (ATCC 43300) and Staphylococcus epidermidis (ATCC 35984) while show no obvious inhibition to Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and biofilm-negative Staphylococcus epidermidis (ATCC 12228). The obtained results indicate that the CFRPEEK surface with specific biological properties can be enhanced by zinc incorporation and multilevel structure introduction, through which the application of CFRPEEK to orthopedic and dental implants can be further broadened.

An efficient iron(ii)-catalyzed sulfur directed C(sp3)-H bond amination/C-S cross coupling reaction has been developed. The reaction had high tolerance of functional groups under moderate conditions. The results of a deuterium labeling study and in situ ESI-MS experiments indicated that the reaction mechanism probably corresponds to a Fe(ii)/Fe(iii) catalytic cycle.

In this paper, we established a sequential injection method to monitoring the concentration of total dissolved nitrogen (TDN) in seawater, which combined with an UV-thermal digestion. The sequential injection method consumes less reagents and less time, mixes more evenly than the flow injection method. TDN detection process mainly includes three parts: the digestion process of conversion organic nitrogen to nitrate, the reduction process of nitrate to nitrite, and the process of reaction between nitrite and chromogenic agent. The UV-thermal digestion that transforms dissolved organic nitrogen (DON) into nitrate has the highest digestion efficiency. The nitrate reduction process with a UV lamp is considered a greener choice which avoids the toxic substance and complicated operation of cadmium column reduction. We analyzed the optimal concentrations of all the reagents used in the experiment with the univariate experimental design. The reaction conditions were optimized by using three kinds of DON, which were C2H5NO2, CH4N2S and C10H14N2Na2O8. Under the optimal reaction conditions, we tested the seawater in the Qingdao Sculpture Garden and the recovery rate of adding standard. In May, the TDN concentration of seawater in Qingdao Sculpture Garden was 122.94μg/L, the relative standard deviation was 0.34%. The recovery rate was as high as 99.94% to 100.39%. The outcomes indicate that the proposed method can apply to the potential in-situ monitor.

As an important indicator of water eutrophication and water ecological health, the monitoring methods of Chlorophyll-a are being increasingly valued by environmental supervision departments and relevant scientific research institutions. This paper reviews several commonly used monitoring methods, and systematically analyzes the advantages and disadvantages of each method. It is found that each monitoring method has certain restrictions. Therefore, when the environmental protection department conducts routine monitoring or scientific research institutions conduct long-term tracking monitoring, they should choose the appropriate method according to the different monitoring objects, or even combining different monitoring methods to determine chlorophyll-a, so as to provide reliable data support for water environmental management and scientific research work.

The Notch pathway plays critical roles in the development and functional modulation of myeloid cells. Previous studies have demonstrated that Notch activation promotes M1 polarization and phagocytosis of macrophages; however, the downstream molecular mechanisms mediating Notch signal remain elusive. In an attempt to identify Notch downstream targets in bone marrow-derived macrophages (BMDMs) using mass spectrometry, the signal regulatory protein α (SIRPα) appeared to respond to knockout of recombination signal-binding protein Jk (RBP-J), the critical transcription factor of Notch pathway, in macrophages. In this study, we validated that Notch activation could repress SIRPα expression likely via the Hes family co-repressors. SIRPα promoted macrophage M2 polarization, which was dependent on the interaction with CD47 and mediated by intracellular signaling through SHP-1. We provided evidence that Notch signal regulated macrophage polarization at least partially through SIRPα. Interestingly, Notch signal regulated macrophage phagocytosis of tumor cells through SIRPα but in a SHP-1-independent way. To access the translational value of our findings, we expressed the extracellular domains of the mouse SIRPα (mSIRPαext) to block the interaction between CD47 and SIRPα. We demonstrated that the soluble mSIRPαext polypeptides could promote M1 polarization and increase phagocytosis of tumor cells by macrophages. Taken together, our results provided new insights into the molecular mechanisms of notch-mediated macrophage polarization and further validated SIRPα as a target for tumor therapy through modulating macrophage polarization and phagocytosis.

Si-incorporated TiO2 nanopores films were prepared by anodization and silicon plasma immersion ion implantation. The microstructure and phase composition of the films were investigated by scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The hydrophilicity of the films was evaluated using water contact angle measurement and MG63 cells were cultured on the films to investigate the cytocompatibility. The results showed that the concentration and depth of silicon on the Si-incorporated TiO2 nanopores films increased with the duration time of implantation. Both the as-annealed and Si-incorporated nanopores films exhibited good hydrophilicity and cytocompatibility, while the TiO2 nanopores films implanted silicon for 1.0h showed higher proliferation rate and vitality of MG63 cells than others, indicating a great potential application for titanium implants.

In this work, we demonstrate the stable operation of 4H-silicon carbide (SiC) p-n diodes at temperature up to 600 °C. In-depth study methods of simulation, fabrication and characterization of the 4H-SiC p-n diode are developed. The simulation results indicate that the turn-on voltage of the 4H-SiC p-n diode changes from 2.7 V to 1.45 V as the temperature increases from 17 °C to 600 °C. The turn-on voltages of the fabricated 4H-SiC p-n diode decreases from 2.6 V to 1.3 V when temperature changes from 17 °C to 600 °C. The experimental I-V curves of the 4H-SiC p-n diode from 17 °C to 600 °C agree with the simulation ones. The demonstration of the stable operation of the 4H-SiC p-n diodes at high temperature up to 600 °C brings great potentials for 4H-SiC devices and circuits working in harsh environment electronic and sensing applications.

Molybdenum (Mo) film is deposited by Ion Beam Assisted Deposition (IBAD) on the 316L steel substrate surface in this experiment. The micro structure and nanohardness of the film are tested by Scanning Electronic Microscope (SEM) and nanoindentation tester. The tribological behaviors of Mo film under ZDDP and MoDTC lubrication are evaluated by SRV test machine. The tribo-film formed on the worn surfaces is investigated by X-ray photoelectron spectroscopy (XPS) to find out the tribological mechanisms between the Mo film and the two additional additives. The result shows that Mo film not only has friction reduction property but also has wear assistant property under ZDDP and MoDTC lubrication. As element Mo has advantage on promoting the deposition of these two lubricating additives.

Preparation of a nanometer zinc oxide/rectorite (ZnO/REC) composites photocatalyst based on natural rectorite was conducted using a hydrothermal intercalation method. The structure, thermal property, and surface morphology of ZnO/REC were characterized by X-ray diffractor (XRD), thermogravimetric analysis (TGA), high-resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM) techniques. The photocatalytic activity of ZnO/REC was evaluated by photocatalytic decolorization of methylene blue (MB) in aqueous solution as a model pollutant under simulated sunlight irradiation. The HRTEM results revealed that well-dispersed and uniform ZnO/REC nanocomposites with diameters of 10 nm were embedded in rectorite. The ZnO/REC nanocomposite exhibited high photocatalytic activity under simulated solar irradiation. After 2 h of irradiation by simulated solar light, over 99% of methylene blue solution (15 mg/L) was decolorized with 0.9 g/L of the photocatalyst. The ZnO/REC was reusable, which meant that the adsorption photocatalytic decolorization process could be operated at a relatively low cost. Since this process does not require the addition of hydrogen peroxide but uses sunlight, it can be developed as an economically feasible and environmentally friendly method to decolorize or treat dye wastewater using solar.

The electrochemical behavior of Fe-Cr-Mo codeposition was investigated by using linear scanning. The deposition potential of Fe2+ shifted negatively after adding glycine and additive W, while the deposition potential of Cr3+ had no obvious change, then the purpose of codeposition was achieved. Induced codeposition occurred after adding molybdate into the solution, at last alloy coating of good appearance was obtained.