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To develop high-performance medical alloy coatings that can reduce the risk of postoperative infection, TiZrNbCux refractory medium-entropy alloy (RMEA) coatings are designed and prepared on the Ti6Al4V alloy. The effects of varying Cu additions on the microstructure, micro/nano-hardness, elastic modulus, wear resistance, corrosion resistance, and antibacterial properties are investigated. The microstructure reveals that the RMEA coatings comprise body-centered-cubic dendrites and an Mo2Si-type interdendritic (Ti, Zr)2Cu phase. Also, the contents and dimensions of (Ti, Zr)2Cu gradually increase with the increasing Cu contents. The increased amounts of Cu atoms are beneficial for the improvement of hardness and elastic modulus, but contribute little to wear resistance. Meanwhile, the electrochemical polarization curve reflects that Cu-containing RMEA coatings show superior corrosion resistance. The antibacterial test on the Cu0.1 RMEA coating demonstrates a 99.95% antibacterial rate against S. aureus after coculturing for 18 h, indicating its novel antibacterial property. Thus, TiZrNbCux RMEA coatings present huge potential in medical applications for implants. [ABSTRACT FROM AUTHOR]

To prolong the service life of the stirrer impeller made by SUS 904L austenitic super-stainless steel, a series of [(AlxTi1−x)-(FeCoNi)12](AlxTi1−x)0.5Cr2.5 high-entropy alloy (HEA) compositions were designed based on the cluster-plus-glue-atom model. The HEAs' coatings were successfully fabricated by laser cladding technology. The microstructure, microhardness, wear resistance and corrosion resistance were measured by a scanning electron microscope, transmission electron microscope, microhardness tester, wear machine and electrochemical workstation, respectively. The experimental results indicate that the phase structures of the [(AlxTi1−x)-(FeCoNi)12](AlxTi1−x)0.5Cr2.5 (x = 0, 0.5, 1) HEA coatings mainly consist of a single face-centered-cubic solid solution and the coatings produce BCC phase with the increase of Ti content. When x = 0, the coating has the highest hardness (402.3 HV0.2) which is 1.92 times that of 904L austenitic super-stainless steel (209.0 HV0.2), the lowest wear volume (0.866 mm3) and the best corrosion resistance. The addition of Ti refined the microstructure of the coatings and promoted the formation of BCC phase, which improved the hardness and wear resistance of the coatings. Considering the wide sources of Ti, Fe and Co elements and the convenience of laser cladding, the coating can provide a cheap protective layer for 904L stainless steel. [ABSTRACT FROM AUTHOR]

SnO2 compact layer (c‐SnO2) frequently suffers from degradation in high temperature processes (HTP) such as crack, worse interfacial contact, and electrical properties, that is, annealing effect. To solve this problem, a kind of bifunctional SnO2 colloid is developed by using small molecular oxalate whose organic components can be removed clearly at a low temperature process (LTP). The c‐SnO2 and SnO2 mesoporous layer (m‐SnO2) derived from the fresh and aged sols with the same colloid show no annealing effect, decreasing oxygen vacancy, and adsorbing water on increasing annealing temperature. The champion devices of LTP and HTP SnO2 planar perovskite solar cells (PSCs) achieve, respectively, stabilized photoelectric conversion efficiencies (PCEs) of 20.74% and 20.70%. In contrast, the performance of champion devices of their mesoporous counterparts is significantly improved, showing nearly hysteresis free character with stabilized PCEs of 22.40% and 22.37%, respectively. The inclusion of m‐SnO2 plays a role of an energy bridge, improving electrons collection efficiency, which is supported by photoluminescence and transient photoluminescence characterizations. HTP SnO2 mesoporous PSCs can preserve 97.6% and 80% of their initial PCEs after aging for 25 weeks and 8‐h irradiated/16‐h dark cycle within 104 h. The high stability of HTP SnO2 PSCs may ascribe to low oxygen vacancy and adsorbed water of HTP SnO2. [ABSTRACT FROM AUTHOR]

Nickel oxide (NiOx) is desirable hole selective material (HSMs) for perovskite photovoltaics because of the characteristic in stability and low cost. However, they deliver limited open‐circuit voltage (VOC) compared to some organic HSMs. As it is known, the performance of perovskite solar cells is predominantly limited by trap‐assisted non‐radiative recombination at the perovskite/hole‐selective layer interfaces. A typical lithium‐doping strategy leads to the valence‐band maximum shift and the electronic levels of NiOx can be tuned robustly to match perovskite active layer in perovskite solar cells. More critically, carrier dynamics studies demonstrate another critical PN4N interlayer strategy reduced interfacial density of defect sites and trap‐assisted recombination. These merits contribute coordinately to lower energy loss across the perovskite/NiOx interface and facilitate charge transport process through the relevant interface, yielding VOC values increase to 1.14 V and power conversion efficiencies over 20%. [ABSTRACT FROM AUTHOR]

Abstract Background Previous studies have demonstrated that claudin-6 functions as a cancer suppressor in human MCF-7 breast cancer cells. The growth inhibitory effect could be attributed to inhibition of cell proliferation and induction of apoptosis. The purpose of the current study was to examine the involvement of apoptosis signal-regulating kinase 1 (ASK1) in the anticancer effect of claudin-6. Methods Immunohistochemical analysis was performed to evaluate the ASK1 protein expression and the correlation between ASK1, claudin-6 and clinicopathological features in 85 samples of breast invasive ductal carcinomas (IDC). Western blotting and RT-PCR was carried out to examine the expression of ASK1 and claudin-6 in MCF-7 cell clones transfected with claudin-6. Results Immunohistochemical analysis showed that ASK1 expression was significantly related with that of claudin-6 in breast invasive ductal carcinomas (P < 0.05). In addition, a positive correlation between ASK1 and C-erb B 2 protein expression was identified (P < 0.05). Western blotting and RT-PCR consistently revealed that the level of ASK1 protein and mRNA was upregulated in MCF-7 cell clones transfected with claudin-6. Conclusions Our data suggests, for the first time, that the ASK1 signal may play a positive role in the inhibitory effect of claudin-6 in breast cancer. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1200314318763661

Abstract Background Claudin-6 is a candidate tumor suppressor gene in breast cancer, and has been shown to be regulated by DNA methylation and histone modification in breast cancer lines. However, the expression of claudin-6 in breast invasive ductal carcinomas and correlation with clinical behavior or expression of other markers is unclear. We considered that the expression pattern of claudin-6 might be related to the expression of DNA methylation associated proteins (methyl-CpG binding protein 2 (MeCP2) and DNA methyltransferase 1 (DNMT1)) and histone modification associated proteins (histone deacetylase 1 (HDAC1), acetyl-histone H3 (H3Ac) and acetyl- histone H4 (H4Ac)). Methods We have investigated the expression of claudin-6, MeCP2, HDAC1, H3Ac and H4Ac in 100 breast invasive ductal carcinoma tissues and 22 mammary gland fibroadenoma tissues using immunohistochemistry. Results Claudin-6 protein expression was reduced in breast invasive ductal carcinomas (P < 0.001). In contrast, expression of MeCP2 (P < 0.001), DNMT1 (P = 0.001), HDAC1 (P < 0.001) and H3Ac (P = 0.004) expressions was increased. Claudin-6 expression was inversely correlated with lymph node metastasis (P = 0.021). Increased expression of HDAC1 was correlated with histological grade (P < 0.001), age (P = 0.004), clinical stage (P = 0.007) and lymph node metastasis (P = 0.001). H3Ac expression was associated with tumor size (P = 0.044) and clinical stage of cancers (P = 0.034). MeCP2, DNMT1 and H4Ac expression levels did not correlate with any of the tested clinicopathological parameters (P > 0.05). We identified a positive correlation between MeCP2 protein expression and H3Ac and H4Ac protein expression. Conclusions Our results show that claudin-6 protein is significantly down-regulated in breast invasive ductal carcinomas and is an important correlate with lymphatic metastasis, but claudin-6 down-regulation was not correlated with upregulation of the methylation associated proteins (MeCP2, DNMT1) or histone modification associated proteins (HDAC1, H3Ac, H4Ac). Interestingly, the expression of MeCP2 was positively correlated with the expression of H3Ac and H3Ac protein expression was positively correlated with the expression of H4Ac in breast invasive ductal carcinoma Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4549669866581452