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Herein, the effects of Gd2O3 on the laser cladding NiCoCrAlYTa coatings in terms of microstructure, phase structures, high temperature oxidation behaviors were investigated. The results showed that the addition of Gd2O3 changed the composition of coating phases, promoted homogeneous phase distribution, reduced porosity and improved coating density. During oxidation at 1100 °C for 150 h, the increase in the content of added Gd2O3 (at mass fractions of 0, 0.5, 1, 2, 5 and 10%) exhibited an initial inhibitory and then increased effect on the weight-gain rate of the coatings. Overall, 1% Gd2O3 addition resulted in the greatest improvement in the oxidation resistance of the coatings, with 49.58% decreases in oxidation kinetic constants, respectively, compared with those of unmodified coatings. However, at a Gd2O3 content of 10%, the thermally grown oxide on the coating surface exhibited large flaking areas. The high-temperature oxidation kinetic parameters of the coatings exhibited an inverted parabolic form with increasing Gd2O3 content. The higher Gd2O3 content led to the formation of excessive oxygen diffusion channels along grain boundaries, which is the reason for the decrease in the anti-oxidant performance of the coating. [ABSTRACT FROM AUTHOR]

In this work, rare-earth elements Eu and Y were added to La2Zr2O7 (LZ) as doping elements, and the ceramic coating of (La0.5Eu0.25Y0.25)2Zr2O7 (LEYZ) was prepared. The evolution of the sintering resistance, thermal shock resistance, and thermal insulation properties of the multi-element rare-earth co-doped modified coatings under long-term and high-temperature conditions was studied. The results showed that the sintering resistance of the doped coating was significantly improved, and the coating still does not fall off after 200 h at 1100 °C. The thermal shock life of the coating at 1000 °C is increased by 47% compared with that of the undoped modified LZ coating. The length of the vertical cracks in LEYZ ceramic layer is obviously shorter than that in LZ coating, which will be more beneficial to preventing the coating from peeling off. Compared with LZ coating, the insulation temperature of the LEYZ ceramic coating is increased by 24, 26 and 34% in the range of 900 ~ 1100 °C, respectively. The coating has the best thermal insulation effect, which is consistent with theoretical calculation results. The results demonstrate that the modified lanthanum zirconate coatings doped with Europium and Yttrium has great potential in high-temperature performance. [ABSTRACT FROM AUTHOR]

We study the vanishing shear viscosity limit and incompressible limit of two dimensional compressible dissipative elastodynamics systems near the equilibrium. The large value of the volume viscosity forces the limit system to be incompressible, and the vanishing shear viscosity indicates that the limit system is inviscid. Due to the weak dispersive estimate in dimensions two and the lack of the null structures in nonlinear terms, the generalised energy method (Klainerman and Sideris in Commun Pure Appl Math 49(3):615–666, 1996; Sideris in Ann Math 151(2):849–874, 2000; Sideris and Thomases in Commun Pure Appl Math 58(6):750–788, 2005), combined with the "ghost weight" method in (Alinhac in Invent Math 145(3):597–618, 2001), guarantees the global-in-time convergence from compressible dissipative elastodynamics to incompressible elastodynamics with the help of vector fields. [ABSTRACT FROM AUTHOR]

There is a growing interest in enhancing the bioactivity of TC4-based metallic biomaterials, which are known for their excellent biocompatibility. Bioactive glass (BG) has been recognized for its high potential in promoting bioactivity, particularly in osteo tissue engineering. This study focuses on investigating the influence of BG addition on the microstructure and electrochemical properties of TC4 coatings. The TC4/BG composite coatings were fabricated through laser cladding, and their microstructure was characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrochemical properties of the coatings were assessed through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests in three different solutions. The results revealed that the incorporation of BG had a significant impact on the microstructure of the TC4 coatings, leading to the formation of a well-defined interface between the TC4 matrix and the BG aggregates. The distribution of BG aggregates within the TC4 matrix coating was found to be random and unrelated to the specific regions of the coating. The metallographic microstructure variations were attributed to different heat dissipation conditions during the laser cladding process. Furthermore, the electrochemical corrosion behavior of TC4/BG composite coatings reveals that they exhibit stability similar to that of passive films and good resistance against media corrosion compared to TC4, while also showing enhanced corrosion resistance in 3.5 wt% NaCl and Dulbecco's modified Eagle medium (DMEM) solutions, indicating their potential for biomedical applications; however, the corrosion resistance decreases gradually in all solutions, potentially due to the elevated Cl− concentration. Further research can explore bioactivity enhancement of TC4/BG composite coatings and investigate the long-term stability and biological response of these coatings in diverse physiological environments. [ABSTRACT FROM AUTHOR]

Nanostructured carbon diffusion layers were produced on the 18Cr2Ni4WA low carbon steel using supersonic fine particles bombarding (SFPB) with activated carbon powders and low-temperature annealing at 500 °C. The microstructures and the formation mechanism of hard nanocrystalline carbon diffusion layers were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and molecular dynamics simulation. Additionally, the nano-hardness of the diffusion layer was measured by nanoindentation apparatus and the tribological properties were tested by wear tester. The results show that the thickness of the hard nano-carburized layer is about 20 μm. During SFPB treatment, high-speed Al2O3 particles carrying activated carbon powder impact on the surface of 18Cr2Ni4WA steel, resulting in the formation of high-density dislocations and nano-surface structure, and a large amount of carbide precipitates at grain boundaries and internal defects. The carbon content of the steel surface increased from 0.17 to 4.2% (wt.%). After annealing treatment, the nano-hardness of the carburized layer reaches 7.6 GPa and the friction coefficient decreases to 0.63. [ABSTRACT FROM AUTHOR]

Background. NUDT15 gene polymorphisms have been identified to predispose Asian patients with an inflammatory bowel disease (IBD) to thiopurine-induced leukopenia. This study predicted the influence of NUDT15 haplotypes and diplotypes on azathioprine (AZA)-induced leukopenia as well as the long-term influence of AZA on hematologic parameters in IBD. Methods. 194 IBD patients were tested for NUDT15 genotypes. We collected clinical data of 80 patients with AZA treatment including adverse events, dosage, white blood cell (WBC) count, platelet (PLT) count, and mean corpuscular volume (MCV) after AZA initiation. Patients without adverse events and drug withdrawal were followed up for at least one year. The relationship between NUDT15 haplotypes and diplotypes and leukopenia was analyzed. Results. The haplotypes NUDT15 c.415C > T and c.36_37insGGAGTC as well as the diplotypes NUDT15 ∗ 1/ ∗ 2, ∗ 3/ ∗ 3, and ∗ 3/ ∗ 5 were significantly associated with AZA-induced leukopenia. Only one patient with NUDT15 c.52G > A experienced leukopenia. NUDT15 ∗ 1/ ∗ 3 was not associated with leukopenia. After AZA initiation, the WBC count showed a downward trend in both wild types and mutants. The mean of WBC count in the mutant group at 1st month after AZA initiation was lower than that in the wild-type group (P = 0.006). The MCV increased gradually in mutant cases (P = 0.039), and the differences were obvious at 6th and 12th months compared with the baseline (P = 0.014 a n d P = 0.042 , respectively). The PLT count showed a decreasing trend in the mutant group, but there was no difference until 11 months after initiating treatment (P = 0.023). The final dose of AZA in the NUDT15 mutant group was significantly lower than that in the wild-type group (P = 0.006). Conclusion. NUDT15 polymorphisms may be an appropriate predictor of AZA abnormal hematologic indices in IBD patients. It is necessary for IBD patients to monitor hematological indices and optimize AZA therapy. [ABSTRACT FROM AUTHOR]

The effects of supersonic particle bombardment (SFPB) on the microstructure, microhardness and wear property of Ti6Al4V alloy prepared by laser metal deposition (LMD) were investigated in this paper. The electrochemical corrosion behaviors of the LMDed Ti6Al4V alloy samples before and after SFPB treatment in 3.5% NaCl solution were measured. The results showed that a gradient severe deformation layer of ~ 350 μm thickness was formed with refined equiaxed grains oriented in various directions on the surface of LMDed Ti6Al4V alloy after SFPB treatment. The microhardness of the deformation layer was significantly increased due to the plastic deformation, grain refinement, dislocations and deformation twins increment. After SFPB treatment, the LMDed Ti6Al4V exhibited higher wear resistance which is about 55.6% decrease in wear loss than that of the untreated sample. Moreover, the corrosion resistance and corrosion rate of the SFPB-treated samples in 3.5% NaCl solution improved due to the finer hexagonal grains and high density of grain boundary in the severe deformation layer. [ABSTRACT FROM AUTHOR]

We establish interior and boundary $ \varepsilon $-regularity criteria at one scale for suitable weak solutions to the five dimensional stationary incompressible Navier-Stokes equations which improve previous results in [19] and [32]. Our proof is based on an iteration argument, Campanato's method, and interpolation techniques. [ABSTRACT FROM AUTHOR]

The bottleneck challenge of laser‐cladded coating preparation of magnesium alloys is the low melting point of alloys. This greatly restricts the selection of coating material. In this article, the composition of Ni–Ti–Cu coating is designed by cluster line criterion, and the thermal properties of the coating are simulated by JMatPro software. Through the analysis of simulation results, the Ni51.6Ti34.4Cu14 coating is selected and successfully prepared on AZ91D magnesium alloy via laser cladding technology. Then the microstructure, wear resistance, and corrosion resistance of the coating are studied in detail. The results of X‐Ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), and transmission electron microscope (TEM) demonstrated that there is a good metallurgical bond between the coating and the substrate, and the coating is mainly composed of Ni3Ti, TiNi0.8Cu0.2, and (Cu, Ni) solid solution phases. Also, there are no obvious pores and crack defects in the coating. Remarkably, AZ91D alloy showed significant improvement in corrosion resistance and wear resistance. Among them, the wear volume of the coating is decreased by 71.9% than that of AZ91D alloy. In particular, the corrosion current density of the coating is three orders of magnitude lower than that of AZ91D alloy. [ABSTRACT FROM AUTHOR]

A grain fine surface plastic deformation layer with a thickness of about 108.6 ± 1.5 μm was fabricated on 20Cr2Ni4A steel by supersonic fine particle bombardment (SFPB). The microstructure, wettability, and tribological properties of original and SFPB-treated (including Co-SFPB samples: activated carbon was added to the bombarded powder (Al2O3) followed by SFPB; Precoat + SFPB samples: the activated carbon is precoated on the surface of the original material followed by SFPB) low carbon steel were characterized by optical microscope (OM), scanning electron microscope (SEM), static water contact angle, friction, and wear test. The results show that SFPB can refine the surface microstructure and the grain size is about 21 nm. The surface hardness is as high as 428.1 HV0.2, which is 89.3% higher than the original samples. Compared with the residual stress of the original samples (− 116.7 MPa), the residual stress on the surface of Precoat + SFPB samples (− 333.8 MPa) is significantly increased. The measurement results of static water contact angle illustrate that Precoat + SFPB samples have the best hydrophobicity (133.4°). After the treatment of SFPB, 20Cr2Ni4A steel is worn for a certain time, combined with the comprehensive analysis results of friction coefficient, mass loss, and wear morphology, Precoat + SFPB samples have the best wear resistance, which is due to its high surface hardness, large residual compressive stress, and the alloying layer formed by pre-coating activated carbon under the SFPB. [ABSTRACT FROM AUTHOR]

This work concerns the incompressible limit of compressible viscoelastic systems when the shear viscosity converges to zero. The incompressible limit is characterised by the large value of the volume viscosity. In the limit, the dispersive effect of pressure waves disappears and the global convergence to the limit system around an equilibrium is justified with the help of vector fields. [ABSTRACT FROM AUTHOR]

Background: Intestinal immune dysfunction is involved in the onset of Crohn's disease (CD). Dendritic cells (DCs), antigen-presenting cells, play a key role in the maintenance of intestinal immune homeostasis. The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor widely expressed in various immune cells, including DCs. Although AhR plays an important role in immune tolerance, its role in the DCs is unclear. The purpose of this study was to investigate whether the activation of AhR can induce tolerogenic DCs (tolDCs) and the differentiation of regulatory T (Treg) cells, as well as ameliorate experimental colitis. Results: AhR activation in the DCs resulted in a lower expression of surface markers such as CD80, CD83, CD86, and pro-inflammatory cytokine production, and higher anti-inflammatory production (IL-1β, IL-23, and IL-12) compared to the control DCs. The surface dendrites in DCs were significantly reduced following AhR activation by 6-formylindolo [3,2-b]carbazole (FICZ). Such DCs with FICZ-mediated activation of AhR, namely tolDCs, promoted Treg cell differentiation. Adoptive transfer of tolDCs to a TNBS-induced colitis mouse model significantly alleviated the severity of inflammation by improving the colon length and decreasing the disease activity index (DAI) and histopathological score. Moreover, the transferred tolDCs decreased the frequency of Th17 cells and increased the frequency of Treg cells in the spleen and mesenteric lymph nodes (MLNs) in murine colitis models. Conclusions: Activation of AhR in the DCs could induce tolDCs, and the transplantation of tolDCs may help in relieving intestinal inflammation and maintaining the Th17/Treg differentiation balance. Thus, our data suggest that AhR may be a potential therapeutic target for CD. [ABSTRACT FROM AUTHOR]

The welding solidification crack is a common welding defect occurring in the narrow gap laser welded high-strength steel joint, which poses a detrimental effect in reducing the weld quality. However, the relationship between the weld geometric characteristics and the metallurgical characteristics with the solidification crack of the narrow gap laser weld is still unclear. In this study, a 20-mm-thick 10Ni5CrMoV high-strength steel with a root gap of 3 mm and groove angle of 1º was used to analyze the single-pass welding process of narrow gap laser welding using high-frequency beam oscillation. The correlation between the weld form factor and the welding solidification crack was discussed, alongside with the clarification on the influence of the welding process parameter on the welding solidification crack, the aim of which was to analyze the causes for the formation of welding solidification crack and explore the effective ways to suppress it. The results showed that the influence of welding process parameters on welding solidification crack could be attributed to change in the form factor of the weld and weld metal solidification crystallization characteristics. The smaller the weld form factor, the larger the area of the opposite crystal growth in the upper part of the weld cross section, and the higher the tendency toward solidification crack formation. Furthermore, the higher welding speed was also likely to have columnar grains with a larger angle of crystallization direction with the centerline. This resulted in a higher tendency of solidification crack formation. Under the test conditions used in this study, a weld form factor φ = 0.8 was considered effective for controlling welding solidification crack. [ABSTRACT FROM AUTHOR]

Background: The intestinal microbiota is thought to be involved in the occurrence of inflammatory bowel disease in remission with irritable bowel syndrome (IBS)-type symptoms, but the specific distinct profile of these bacteria remains unclear. This cross-sectional study aims to investigate the fecal microbiota profiling in patients with these diseases.Methods: Fecal samples from 97 subjects, including Crohn's disease patients in remission with IBS-type symptoms (CDR-IBS+) or without IBS-type symptoms (CDR-IBS-), ulcerative colitis patients in remission with IBS-type symptoms (UCR-IBS+) or without IBS-type symptoms (UCR-IBS-), IBS patients and healthy controls, were collected and applied 16S ribosomal DNA (rDNA) gene sequencing. The V4 hypervariable regions of 16S rDNA gene were amplified and sequenced by the Illumina MiSeq platform. The differences in the sample diversity index in groups were analyzed with R software.Results: The richness of the intestinal microbiota in the CDR-IBS group was markedly lower than those in the control and IBS groups based on the analysis of observed species and the Chao index (P < 0.05). The observed species index in the CDR-IBS+ group was higher than that in the CDR-IBS- group (median index: 254.8 vs 203, P = 0.036). No difference was found in alpha diversity between UCR patients with IBS-type symptoms and those without related symptoms. At the genus level, the number of Faecalibacterium in CDR patients with IBS-type symptoms increased significantly, while Fusobacterium decreased versus those without such symptoms (mean relative abundance of Faecalibacterium: 20.35% vs 5.18%, P < 0.05; Fusobacterium: 1.51% vs 5.2%, P < 0.05). However, compared with the UCR-IBS- group, the number of Faecalibacterium in the UCR-IBS+ group decreased, while the number of Streptococcus increased, but there was no significant difference in the genus structure. The abundance and composition of the microbiota of IBS patients were not distinct from those of healthy controls.Conclusions: The IBS-type symptoms in CD patients in remission may be related to an increase in Faecalibacterium and a decrease in Fusobacterium. The IBS-type symptoms in UC patients in remission cannot be explained by changes in the abundance and structure of the intestinal microbiota. [ABSTRACT FROM AUTHOR]

Immune disorders play an important role in the pathogenesis of Crohn's disease (CD). Notably, the increased immune response of Th1 cells and related cytokines is associated with the onset of CD. IL-27 is a newly discovered IL-12-related cytokine, but its expression and clinical significance in CD patients are still controversial. This study is aimed at evaluating the serum levels of IL-27 in CD patients and analyzing their clinical significance. The results indicated that serum levels of IL-27 in CD patients were significantly higher than those in control subjects (median (interquartile range (IQR)): 110.0 (95.0, 145.0) vs. 85.0 (80.0, 95.0) pg/ml, P < 0.001). Furthermore, the IL-27 levels significantly increased in CD patients at the active stage compared with CD patients in remission (CDR) (127.5 (100.0, 150.0) vs. 90 (80.0, 110.0) pg/ml, P < 0.001). However, there was no difference in IL-27 levels between CDR and control subjects. The levels of IL-27 were positively correlated with Crohn's disease activity index (CDAI), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), fecal calprotectin (FC), and Simple Endoscopic Score for Crohn's Disease (SES-CD) and negatively correlated with hemoglobin (Hb) and serum albumin (ALB). IL-27 combined with CRP favored the prediction of CD activity (area under the curve (AUC): 0.88). Additionally, the proportions of Th17 and Th1 cells in peripheral blood were higher in CD patients than in control subjects. Active CD patients exhibited significantly higher proportions of Th17 and Th1 cells than those in remission. Moreover, correlation analysis indicated that the serum levels of IL-27 were positively associated with the frequency of Th17 cells in CD patients (r = 0.519 , P = 0.013) but not associated with the frequency of Th1 cells in CD patients. IL-27 is positively associated with multiple inflammation indicators and may exert a proinflammatory profile by regulating Th17 cell differentiation in the development of Crohn's disease. In the future, IL-27 combined with CRP is expected to become an important biological marker of CD activity. [ABSTRACT FROM AUTHOR]

The directional array TiN-reinforced AlCoCrFeNiTi high-entropy alloy (HEA) coatings were successfully synthesized by magnetic field-assisted laser cladding on Ti-6Al-4V (TC4) alloy. The effect of magnetic induction intensity of AlCoCrFeNiTi HEA coatings was investigated methodically on thermodynamic calculation, microstructure characterization and corrosion resistance. The results show HEA coatings are mainly composed of body-centered cubic (BCC) solid solution phase, (Ni, Co)Ti2 intermetallic compound and TiN ceramic phase. With 1 T magnetic induction intensity assisted laser cladding, the microstructures of in situ TiN display a "cross" shape of the directional array. In 3.5 wt.% NaCl solution, the 1 T HEA coating could significantly decrease the corrosion rate compared with TC4 alloy. [ABSTRACT FROM AUTHOR]

The directional array TiN-reinforced AlCoCrCuNiTi high-entropy alloy (HEA) coating was designed and the correlative coating was successfully synthesized by magnetic-field-assisted laser cladding on Ti-6Al-4V (TC4) alloy. The effect of the directional array TiN on the phase structure, microstructure, microhardness and wear resistance of HEA coating were investigated methodically. As a result, the HEA coatings are mainly composed of body-centered-cubic solid solution phase, (Ni, Co)Ti2 inter metallic compound and TiN ceramic phase. With 1 T magnetic induction intensity assisted laser cladding, the microstructure of in-situ TiN displays a "cross" shape of the directional array. And the coating shows excellent wear resistance with an average microhardness of 760 HV. The worn surface morphologies of HEA coatings show that the wear mechanism is adhesive wear regardless of whether a magnetic field is added. This work can provide a novel and effective method to synthesize directional array microstructures to improve the performance of HEA coating, which will promote the further application of directional array microstructures in advanced manufacturing fields. [ABSTRACT FROM AUTHOR]

High prevalence of vitamin D deficiency has been found among Crohn's disease (CD) patients. Vitamin D probably participates in the pathogenesis of CD, but this idea remains controversial. This study was to investigate the levels of vitamin D in CD patients and analyze the relationship between vitamin D and intestinal inflammation. Vitamin D levels were measured by chemiluminescence immunoassay in 198 CD patients (96 in active, 102 in remission) and 100 healthy controls. The correlation between vitamin D levels and clinical parameters was analysed. The expression of intestinal tight junction (TJ) proteins in CD patients was measured by immunofluorescence staining. Treg and Th17 percentages in the peripheral blood were determined by flow cytometry. CD patients exhibited significantly lower 25(OH)D levels than healthy controls, especially in active CD patients. Serum 25(OH)D levels in CD patients were negatively correlated with the CD activity index (CDAI), the simple endoscopic score for CD (SES-CD), and inflammatory markers, including erythrocyte sedimentation rate (ESR), platelet (PLT) count and faecal calprotectin (FC) levels. Moreover, in patients with vitamin D deficiency, the expression of TJ proteins (Occludin, claudin-1, ZO-1 and JAM-1) in the intestinal mucosa was reduced, and Treg cells in the peripheral blood were decreased, while Th17 cells were increased compared to those with vitamin D sufficiency and controls. Vitamin D deficiency in CD patients is common. Vitamin D is associated with disease activity and intestinal inflammation, which may affect the Treg/Th17 balance and the expression of gut TJ proteins. [ABSTRACT FROM AUTHOR]

Intestinal microbiota dysbiosis has been described in inflammatory bowel disease (IBD), but data from China are limited. In this study, we performed molecular analysis of the fecal microbial community from 20 healthy Chinese subjects and 25 patients with Crohn's disease (CD), and evaluated associations with bacterial and fungal compositions. Decreased richness and diversity of bacterial composition was observed in the CD group compared with healthy (H) subjects. Significant structural differences in bacterial (but not fungal) composition among healthy controls and CD patients were found. A reduction in Firmicutes and Actinobacteria abundance, and overrepresentation of Proteobacteria were observed in the CD patients compared with the H group. The Escherichia-Shigella genus was overrepresented in the CD group, whereas Faecalibacterium, Gemmiger, Bifidobacterium, Romboutsia, Ruminococcus, Roseburia, and Fusicatenibacter abundance were decreased in the CD group compared with H subjects. Differences in fungal microbiota between the H and CD groups were observed at the genus rather than at the phylum level. The Candida genus was overrepresented in the CD (active disease) group compared with the H group, whereas no difference between CD (remission) and H groups was observed. Aspergillus, unclassified_Sordariomycetes, and Penicillium genera had greater representation in the H subjects compared with the CD group. Bacterial and fungal intra- and inter-kingdom correlations were observed between the H and CD groups. Therefore, fecal bacterial and fungal microbiome communities differed considerably between H and CD patients, and between Chinese and Western populations. The role of gut microbiota in homeostasis and in gastrointestinal disorders should be investigated further. [ABSTRACT FROM AUTHOR]

Growing evidence suggested that microRNAs (miRNAs) contributed to the progression of Crohn's disease (CD), but the exact physiological functions of many miRNAs in CD patients still remain illusive. In this study, we explore the potent pathogenicity of miRNAs in CD. Expressions of miRNAs and aryl hydrocarbon receptor (AHR) protein were determined in the colitic colon of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis mice and CD patients. Colitis was induced in wild-type (WT), miR-124a overexpression (miR-124a-Nju), and AHR knockout (AHR−/−) mice. Intestinal barrier function was evaluated in colitis mice and Caco2 monolayers. There was a negative relationship between miR-124a and AHR protein in inflamed colons from CD patients. MiR-124a-Nju and AHR−/− mice treated with TNBS had more severe intestinal inflammation than WT mice. Both miR-124a-Nju mice and AHR−/− mice underwent evident intestinal barrier destruction, and anti-miR-124a administration could reverse this dysfunction in miR-124a-Nju mice but not in AHR−/− mice. In vitro studies revealed that miR-124a mimics downregulated the expression of AHR and tight junction proteins and induced hyperpermeability by increasing miR-124a expression, which was abrogated by miR-124a inhibitor and AHR antagonist FICZ. This study suggests that miR-124a can induce intestinal inflammation and cause intestinal barrier dysfunction by supressing AHR. [ABSTRACT FROM AUTHOR]

The blood–brain barrier (BBB) restricts access to the brain of more than 98 % of therapeutic agents and is largely responsible for treatment failure of glioblastoma multiforme (GBM). Therefore, it is of great importance to develop a safe and efficient strategy for more effective drug delivery across the BBB into the brain. Inspired by the extraordinary capability of rabies virus (RABV) to enter the central nervous system, we report the development and evaluation of the metal–organic framework‐based nanocarrier MILB@LR, which closely mimicked both the bullet‐shape structure and surface functions of natural RABV. MILB@LR benefited from a more comprehensive RABV‐mimic strategy than mimicking individual features of RABV and exhibited significantly enhanced BBB penetration and brain tumor targeting. MILB@LR also displayed superior inhibition of tumor growth when loaded with oxaliplatin. The results demonstrated that MILB@LR may be valuable for GBM targeting and treatment. [ABSTRACT FROM AUTHOR]

The blood–brain barrier (BBB) restricts access to the brain of more than 98 % of therapeutic agents and is largely responsible for treatment failure of glioblastoma multiforme (GBM). Therefore, it is of great importance to develop a safe and efficient strategy for more effective drug delivery across the BBB into the brain. Inspired by the extraordinary capability of rabies virus (RABV) to enter the central nervous system, we report the development and evaluation of the metal–organic framework‐based nanocarrier MILB@LR, which closely mimicked both the bullet‐shape structure and surface functions of natural RABV. MILB@LR benefited from a more comprehensive RABV‐mimic strategy than mimicking individual features of RABV and exhibited significantly enhanced BBB penetration and brain tumor targeting. MILB@LR also displayed superior inhibition of tumor growth when loaded with oxaliplatin. The results demonstrated that MILB@LR may be valuable for GBM targeting and treatment. [ABSTRACT FROM AUTHOR]

Serotonin-selective reuptake transporter (SERT) regulates extracellular availability of serotonin (5-hydroxytryptamine; 5-HT) and participates in the pathogenesis of functional disorders. Colonic SERT expression is decreased in colonic sensitized rats, and the glucagon-like peptide-1 analogue, exendin-4, reduces visceral hypersensitivity by decreasing 5-HT levels and increasing SERT expression. The present in vitro study aimed to further investigate the effects of exendin-4 on SERT expression, and to examine the role of GLP-1 and its receptor in the regulation of 5-HT. SERT mRNA and protein expression levels were detected by reverse transcription-quantitative PCR and western blotting. A [3H]−5-HT reuptake experiment was performed in IEC-6 rat intestinal epithelial cells treated with exendin-4. Effects on the adenosine cyclophosphate (AC)/PKA pathway were examined by variously treating cells with the AC activator forskolin, the protein kinase A (PKA) inhibitor H89 and the AC inhibitor SQ22536. Exendin-4 treatment upregulated SERT expression and enhanced 5-HT reuptake in IEC-6 cells. Also, PKA activity in IEC-6 cells was increased by both exendin-4 and forskolin, whereas these effects were abolished by the pre-treatment of exendin-9, which is a GLP-1R inhibitor, SQ22536 and H89. In conclusion, exendin-4 may be associated with the upregulation of SERT expression via the AC/PKA signaling pathway. [ABSTRACT FROM AUTHOR]

The aim of this work is to study the effect of solution treatment time on the Ti2Ni second phase morphology, phase transformations, mechanical properties and superelastic behavior of plasma arc deposited (PAD) nitinols. The results demonstrate that the Ti2Ni second phases are significantly affected by the solution treatment time. The Ti2Ni second phase is dissolved into the TiNi matrix phase gradually, and its size and volume fraction also gradually decreases with increasing solution treatment time. Additionally, the solution treatment time exhibits a visible influence on the phase transformation, mechanical properties and superelasticity of the PAD nitinol, but the degree of influence depends on the size, volume fraction and distribution of the Ti2Ni second phase. With increasing solution treatment time, the phase transformation temperatures gradually increase, and the phase transformation peaks decrease in width and become sharp with a single transformation. Besides, the compressive strength first increases and then decreases, while the plasticity increases with solution treatment time increases from 0 to 8 h. Moreover, the superelastic stability of the PAD nitinol is improves as the solution treatment time increases from 0 to 6 h and then decreases. This phenomenon is closely related to the critical stress for dislocation slip, which depends on the change in the Ti2Ni second phase. [ABSTRACT FROM AUTHOR]

Intestinal microbiota dysbiosis has been described in inflammatory bowel disease (IBD), but data from China are limited. In this study, we performed molecular analysis of the fecal microbial community from 20 healthy Chinese subjects and 25 patients with Crohn's disease (CD), and evaluated associations with bacterial and fungal compositions. Decreased richness and diversity of bacterial composition was observed in the CD group compared with healthy (H) subjects. Significant structural differences in bacterial (but not fungal) composition among healthy controls and CD patients were found. A reduction in Firmicutes and Actinobacteria abundance, and overrepresentation of Proteobacteria were observed in the CD patients compared with the H group. The Escherichia-Shigella genus was overrepresented in the CD group, whereas Faecalibacterium, Gemmiger, Bifidobacterium, Romboutsia, Ruminococcus, Roseburia, and Fusicatenibacter abundance were decreased in the CD group compared with H subjects. Differences in fungal microbiota between the H and CD groups were observed at the genus rather than at the phylum level. The Candida genus was overrepresented in the CD (active disease) group compared with the H group, whereas no difference between CD (remission) and H groups was observed. Aspergillus, unclassified_Sordariomycetes, and Penicillium genera had greater representation in the H subjects compared with the CD group. Bacterial and fungal intra- and inter-kingdom correlations were observed between the H and CD groups. Therefore, fecal bacterial and fungal microbiome communities differed considerably between H and CD patients, and between Chinese and Western populations. The role of gut microbiota in homeostasis and in gastrointestinal disorders should be investigated further. [ABSTRACT FROM AUTHOR]

With the expansion of the application range of titanium alloys, the wear protection problem has become increasing prominent due to their poor wear resistance, especially in high-temperature environments. To solve this problem, in this work, Ni60+h-BN coatings on Ti-6Al-4V (TC4) alloys were prepared using a laser cladding technique. The results indicated that the Ni60+h-BN coatings mainly contain the phases of NiTi2, TiN, TiB, (Si, Al)2Cr, and solid solution Fe0.2Ni4.8Ti5, possessing much higher microhardness (1,055.36 ± 16.33 HV0.22) than TC4 substrates (309 ± 10 HV0.2), and the Ni60+h-BN coatings show excellent wear resistance and antifriction properties at 600 °C with the dominant wear mechanism of slight adhesive wear and oxidative wear. As observed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses, most of the initial h-BN particles in the mixed powders were decomposed and the reinforcements of TiB and TiN were in situ synthesized after high-power laser irradiation, which plays a role in wear resistance, and the metal oxides (TiO2, Al2O3, NiO, and Fe2O3) produced under high-temperature friction condition play a role in lubrication and antifriction at 600 °C. As a consequence, the synergy effect of coupling the reinforcements and the metal oxides contributes to the excellent tribological performance of Ni60+h-BN coatings at 600 °C. [ABSTRACT FROM AUTHOR]

A Ni-Cr-Co-Ti-V-Al high-entropy alloy (HEA) coating with a BCC phase and (Ni, Co)Ti compounds was synthesized successfully by laser surface alloying on a Ti-6Al-4V substrate. The microstructure of as-synthesized coatings is typical, namely, the microstructure from the coating to the substrate changes from equiaxed grains to columnar grains. After remaining at 900 °C for 8 h, the constituent phases remain unchanged. However, owing to the unceasing dissolution of the Ti element, the lattice parameter of the BCC HEA phase changes from 3.06 Å to 3.16 Å. The thermoanalysis results show that the oxidation film on the Ni-Cr-Co-Ti-V-Al HEA coating is mainly composed of TiO, VO, and NiO. The oxidation resistance of this HEA coating may be due to the existence of NiO and the alloying elements Al, Cr, and Co; the oxidation phenomenon should be responsible for the mass increase in the thermogravimetry process. The differential scanning calorimetry and the dynamic differential scanning calorimetry curves show that the synthesized HEA coating is stable below 1005 °C. [ABSTRACT FROM AUTHOR]

The long-term durability is a considerable challenge for the use of thermal barrier coatings (TBCs). In order to solve this problem, introduction of yttria-stabilized zirconia (YSZ) short fibers in functionally graded system is employed to strengthen the durability of TBCs. Four coatings are deposited on In738LC substrate by atmospheric plasma spray (APS). Thermal cycling behaviors and fiber toughening mechanisms of coatings are systematically studied. Result shows that the thermal cycling lifetime of graded TBCs with the addition of fibers can reach 406 ± 21 at 850 °C, which increases by 60% compared to that of typical APS YSZ TBCs. Moreover, the improvement of lifetime mainly attributes to the fiber breakage, the fiber-matrix interface debonding, and the crack deflection. [ABSTRACT FROM AUTHOR]

Brush plating provides an effective method for creating a coating on substrates of various shapes. A corroded zirconium-based conversion coating was removed from the surface of a magnesium alloy and then replaced with new coatings prepared via brush plating. The structure and composition of the remanufactured coating were determined via x-ray photoelectron spectroscopy, x-ray diffraction, and Fourier transform infrared spectroscopy. The results revealed that the coatings consist of oxide, fluoride, and tannin-related organics. The composition of the coatings varied with the voltage. Furthermore, as revealed via potentiodynamic polarization spectroscopy, these coatings yielded a significant increase in the corrosion resistance of the magnesium alloy. The friction coefficient remained constant for almost 300s during wear resistance measurements performed under a 1-N load and dry sliding conditions, indicating that the remanufactured coatings provide effective inhibition to corrosion. [ABSTRACT FROM AUTHOR]

The Ni-based WC coatings enhanced by WC particle were fabricated on FV520B by plasma cladding device. The influence of magnetic force on the microstructure and performance of the coating was investigated. If the magnetic field does not exist, the microstructure of coating is a cluster of block-shaped structures; it is observably different from the dendritic and crumbling snowflake-like structures formed under transverse and longitudinal magnetic fields. The WC particles were distributed at the grain boundary. With the effect of longitudinal magnetic field, wear resistance and erosion resistance of coatings improved markedly. When axial magnetic field intensity came to 38 mT, the microhardness of coatings reached a maximum value, 720 HV0.2. Electron probe microanalyzer (EPMA) indicates the metallurgical combination at the interface and element interdiffusion happened between the coating and substrate. [ABSTRACT FROM AUTHOR]

A Ni/Ti composite coating enhanced by an in situ synthesized TiN phase was fabricated on FV520B steel by plasma cladding technology. The in situ formation of the TiN phase was confirmed by XRD, SEM, and TEM. The cladding layer consisted of three regions on going from the top to the bottom, namely, columnar grain regions, columnar dendritic regions, and fine grain regions. The cladding layer was composed of NiTi, TiN, (Fe, Ni), and Ti phases. The dendritic and columnar regions were mainly composed of the NiTi and (Fe, Ni) phases. The Ti phase was observed at the branches of dendrite crystals and columnar grains. The volume fraction of the TiN phase in the cladding layer was about 3.2%. The maximum micro-hardness value of the in situ formed coating (760 HV) was higher than that of the pure coating (537 HV). The cladding layer had a small amount of scratch and wear debris when a load of 20 N was used. As the test load increased, the wear debris in the cladding layer also increased and the massive furrows were not observed. [ABSTRACT FROM AUTHOR]

Purpose – The aim of the present paper is to investigate the mechanical performance of multi-layer films. With the wide application of optic and electronic thin-films, membrane materials and membrane technology have become one of the most active fields of research in contemporary materials science (Dumont et al., 1997). Multi-layer films have evolved as candidates for these applications because of their unique properties. TiN and Ti/TiN multi-layer films were fabricated using the DC magnetron sputtering method. A nano-indentation tester and electronic film distribution tester were utilized to evaluate the mechanical properties and residual stress of the films. The existence of interface effects on the mechanical properties and corrosion resistance of the films were analyzed. Design/methodology/approach – In this study, the Ti/TiN multi-layer films were fabricated using the DC magnetron sputtering method. The films were deposited on polished 45# steels. Ti was used as the sputtering target. Ar and N2 were applied as working and reactive gases, respectively. Surface morphology was measured using transmission electron microscopy. The composition was analyzed using D8 X-ray diffraction. Nano-indentation tests were performed using Nanoindenter G200 with a Berkovich indenter. A BGS 6341 electronic film stress distribution tester was used to measure the distribution of stress in the films. Findings – The film surface was very smooth and the structure was very dense. The elastic modulus and micro-hardness of Ti/TiN multi-layer films were smaller, compared to those of the TiN film. Furthermore, both of these parameters initially decreased and later increased, with a decrease in the modulation period. The residual stress in the film was compressive. The corrosion resistance properties of TiN films were the best in NaCl solution, less so in alkaline solution and worst in acid solution. For the Ti/TiN multi-layer films tested in an acid medium, the corrosion resistance performance was better when the modulation period was decreased to micron grade under exposure conditions at ambient temperature. Originality/value – In the present paper, the Ti/TiN multi-layer films were fabricated using PVD with different variations, and the influence on the performance of Ti/TiN multi-layer films due to each single layer period of TiN was studied. The findings should provide useful guidelines for the preparation of high quality Ti/TiN multi-layer thin films. [ABSTRACT FROM AUTHOR]

The new carboxylic acid-neodymium anhydrous conversion films were successfully prepared and applied on the AZ91D magnesium alloy surface by taking absolute ethyl alcohol as solvent and four kinds of soluble carboxylic acid as activators. The corrosion resistance of the coating was measured by potentiodynamic polarization test in 3.5 wt.% NaCl solution in pH 7.0. The morphology, structure, and constituents of the coating were observed by scanning electron microscope, energy dispersivespectrum, x-ray photoelectron spectrum, and Fourier infrared spectrometer. Results show that corrosion resistance properties of samples coated with four different anhydrous conversion films were improved obviously. The corrosion potential increased, corrosion current density decreased, and polarization resistance increased. Among these four kinds of conversion films the one added with phytic exhibits the best corrosion resistant property. The mechanism of anhydrous-neodymium conversion film formation is also analyzed in this paper. It reveals that the gadolinium conversion coating is mainly composed of stable NdO, MgO, Mg(OH), and carboxylate of Nd. And that the sample surface is rich in organic functional groups. [ABSTRACT FROM AUTHOR]

The service condition determines the Rolling Contact Fatigue(RCF) failure mechanism and lifetime under ascertain material structure integrity parameter of thermal spray coating. The available literature on the RCF testing of thermal spray coatings under various condition services is considerable; it is generally difficult to synthesize all of the result to obtain a comprehensive understanding of the parameters which has a great effect on a thermal spray coating's resistance of RCF. The effects of service conditions(lubrication states, contact stresses, revolve speed, and slip ratio) on the changing of thermal spray coatings' contact fatigue lifetime is introduced systematically. The effects of different service condition on RCF failure mechanism of thermal spray coating from the change of material structure integrity are also summarized. Moreover, In order to enhance the RCF performance, the parameter optimal design formula of service condition and material structure integrity is proposed based on the effect of service condition on thermal spray coatings' contact fatigue lifetime and RCF failure mechanism. The shortage of available literature and the forecast focus in future researches are discussed based on available research. The explicit result of RCF lifetime law and parameter optimal design formula in term of lubrication states, contact stresses, revolve speed, and slip ratio, is significant to improve the RCF performance on the engineering application. [ABSTRACT FROM AUTHOR]

Co-based coating was prepared by plasma cladding on FV520B substrates. Microstructure of the coatings was observed by scanning electron microscope. Finite element simulation as a predictive method to research the stress distributed after thermal cycling. Thermal fatigue resistance of the coating-substrate was evaluated at temperature of 600 °C, 700 °C, 800 °C, and 900 °C. Results indicate that the surface/interface structure has excellent thermal fatigue resistance at 600 °C, and the thermal fatigue crack initiated near the interface and extended along the grain boundary. The difference of expansion coefficient of the coating and substrate is small near 600 °C, and the difference increased when the temperature climbed above 600 °C. The diffuse elements could be found near the interface after the thermal cycle, and the dislocations and precipitated phase were observed. [ABSTRACT FROM AUTHOR]

In our work, an equiatomic Ni‐Cr‐Co‐Ti‐V multi‐principal element alloy is prepared by vacuum hot‐pressing sintering. The phase structure is investigated by Transmission electron microscopy (TEM) and properties of hardness, wear and corrosion resistance are studied. Furthermore, some reported high‐entropy alloys (HEAs) and conventional alloys are used as contrast for more intuitive evaluation of properties of Ni‐Cr‐Co‐Ti‐V HEA. The average micro‐hardness of this alloy reaches 1130 ± 15 HV. By nano‐indentation testing, the value of average Young's modulus and nano‐hardness are 318.6 ± 9 GPa and 17.21 ± 0.77 GPa, respectively. Compared with the room temperature, this alloy still keeps a good wear resistance at 600 °C and adhesive wear is the main wear mechanism. In the 3.5 wt% NaCl electrolyte, the passivating capacity of this alloy is significantly higher than that of 304 stainless steel and the corrosion rate of this alloy is relatively low, ≈0.035 mm/year. Thus, this alloy is expected to be applied in the severe interaction work environment of high temperature, wear, and corrosion. [ABSTRACT FROM AUTHOR]