For high-temperature catalytic reaction, it is of significant importance and challenge to construct stable active sites in catalysts. Herein, we report the construction of sufficient and stable ...copper clusters in the copper‒ceria catalyst with high Cu loading (15 wt.%) for the high-temperature reverse water gas shift (RWGS) reaction. Under very harsh working conditions, the ceria nanorods suffered a partial sintering, on which the 2D and 3D copper clusters were formed. This partially sintered catalyst exhibits unmatched activity and excellent durability at high temperature. The interaction between the copper and ceria ensures the copper clusters stably anchored on the surface of ceria. Abundant in situ generated and consumed surface oxygen vacancies form synergistic effect with adjacent copper clusters to promote the reaction process. This work investigates the structure-function relation of the catalyst with sintered and inhomogeneous structure and explores the potential application of the sintered catalyst in C1 chemistry.
The recycled fine-powder (RFP), produced during the recycling process, will induce a serious impact on the environment with improper disposition. A potential green way to reuse RFP is to add it as ...supplementary cementitious material in concrete. The effects of RFP on the hydration, microstructure, shrinkage and mechanical properties of ultra-high performance engineered cementitious composites (UHP-ECC) with different replacement ratios up to 50% were investigated. The hydration kinetics were compared among the different replacement ratios using the isothermal calorimetry, which demonstrated an accelerating effect of RFP to the hydration of UHP-ECC matrix. The phase development was quantified by the thermal gravimetric analysis and proved the pozzolanic effect of RFP. The compressive and tensile properties of UHP-ECCs were obtained at 3, 7 and 28 days, respectively, to trace their development along the curing ages. The addition of RFP significantly reduced the autogenous shrinkage of UHP-ECC. Besides, the single fiber pullout test was investigated to quantify the influence of RFP at the fiber level. The environmental scanned electron microscope analysis was conducted to study the morphology of PE fiber at the fracture surface.
•Up to 50% of cement was replaced by recycled fine powder (RFP) without significant loss in mechanical properties•Effects of RFP on the hydration, microstructure, shrinkage and mechanical properties of UHP-ECC were investigated•A linkage of micro-mechanical scale at the fiber level and to macro-mechanical scale at the composite level was established.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The propensity of the activated neutrophils to form extracellular traps (NETs) is demonstrated in multiple inflammatory conditions. In this study, we investigated the roles of NETs in metastasis of ...hepatocellular carcinoma (HCC) and further explored the underlying mechanism of how NETs affect metastasis as well as the therapeutic value.
The neutrophils were isolated from the blood of human HCC patients and used to evaluate the formation of NETs. The expression of NET markers was detected in tumor specimens. A LPS-induced NET model was used to investigate the role of NETs on HCC metastasis. RNA-seq was performed to identify the key molecular event triggered by NETs, and their underlying mechanism and therapeutic significance were explored using both in vitro and in vivo assays.
NET formation was enhanced in neutrophils derived from HCC patients, especially those with metastatic HCCs. NETs trapped HCC cells and subsequently induced cell-death resistance and enhanced invasiveness to trigger their metastatic potential, which was mediated by internalization of NETs into trapped HCC cells and activation of Toll-like receptors TLR4/9-COX2 signaling. Inhibition of TLR4/9-COX2 signaling abrogated the NET-aroused metastatic potential. A combination of DNase 1 directly wrecking NETs with anti-inflammation drugs aspirin/hydroxychloroquine effectively reduced HCC metastasis in mice model.
NETs trigger tumorous inflammatory response and fuel HCC metastasis. Targeting NETs rather than neutrophils themselves can be a practice strategy against HCC metastasis.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Tumor metastasis is a hallmark of cancer. The communication between cancer-derived exosomes and stroma plays an irreplaceable role in facilitating pre-metastatic niche formation and cancer ...metastasis. However, the mechanisms underlying exosome-mediated pre-metastatic niche formation during colorectal cancer (CRC) liver metastasis remain incompletely understood. Here we identified HSPC111 was the leading upregulated gene in hepatic stellate cells (HSCs) incubated with CRC cell-derived exosomes. In xenograft mouse model, CRC cell-derived exosomal HSPC111 facilitated pre-metastatic niche formation and CRC liver metastases (CRLM). Consistently, CRC patients with liver metastasis had higher level of HSPC111 in serum exosomes, primary tumors and cancer-associated fibroblasts (CAFs) in liver metastasis than those without. Mechanistically, HSPC111 altered lipid metabolism of CAFs by phosphorylating ATP-citrate lyase (ACLY), which upregulated the level of acetyl-CoA. The accumulation of acetyl-CoA further promoted CXCL5 expression and secretion by increasing H3K27 acetylation in CAFs. Moreover, CXCL5-CXCR2 axis reinforced exosomal HSPC111 excretion from CRC cells and promoted liver metastasis. These results uncovered that CRC cell-derived exosomal HSPC111 promotes pre-metastatic niche formation and CRLM via reprogramming lipid metabolism in CAFs, and implicate HSPC111 may be a potential therapeutic target for preventing CRLM.
Tumor‐associated macrophages (TAMs) are crucial components of the tumor microenvironment. They play vital roles in hepatocellular carcinoma (HCC) progression. However, the interactions between TAMs ...and HCC cells have not been fully characterized. In this study, TAMs were induced using human monocytic cell line THP‐1 cells in vitro to investigate their functions in HCC progression. S100 calcium‐binding protein A9 (S100A9), an inflammatory microenvironment‐related secreted protein, was identified to be significantly upregulated in TAMs. S100A9 expression in tumor tissues was associated with poor survival of HCC patients. It could enhance the stem cell‐like properties of HepG2 and MHCC‐97H cells by activating nuclear factor‐kappa B signaling pathway through advanced glycosylation end product‐specific receptor in a Ca2+‐dependent manner. Furthermore, we found that, after treatment with S100A9, HepG2 and MHCC‐97H cells recruited more macrophages via chemokine (CC motif) ligand 2, which suggests a positive feedback between TAMs and HCC cells. Taken together, our findings reveal that TAMs could upregulate secreted protein S100A9 and enhance the stem cell‐like properties of HCC cells and provide a potential therapeutic target for combating HCC.
What's new?
Prognosis of hepatocellular carcinoma (HCC) is influenced by tumor‐associated macrophages (TAMs) in the tumor microenvironment. Little is known, however, about how TAMs fuel HCC progression. This comparative analysis of RNA‐sequencing and whole‐genome expression profiling between TAMs and nonactivated M0 macrophages identified three common upregulated genes with potential impact on HCC prognosis. Among them, S100 calcium binding protein A9 (S100A9) was found to enhance stem cell‐like properties in HCC cells, via Ca2+‐dependent signaling along the AGER/NF‐κB axis. Moreover, S100A9 increased TAM infiltration by facilitating CCL2 secretion. The findings warrant further investigation of S100A9 secretion and enhanced HCC cell stemness by TAMs.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Notch receptors (Notch1-4) play critical roles in tumorigenesis and metastasis of malignant tumors, including breast cancer. Although abnormal Notch activation is related to various tumors, the ...importance of single receptors and their mechanism of activation in distinct breast cancer subtypes are still unclear. Previous studies by our group demonstrated that Notch3 may inhibit the emergence and progression of breast cancer. PTEN is a potent tumor suppressor, and its loss of function is sufficient to promote the occurrence and progression of tumors. Intriguingly, numerous studies have revealed that Notch1 is involved in the regulation of PTEN through its binding to CBF-1, a Notch transcription factor, and the PTEN promoter. In this study, we found that Notch3 and PTEN levels correlated with the luminal phenotype in breast cancer cell lines. Furthermore, we demonstrated that Notch3 transactivated PTEN by binding CSL-binding elements in the PTEN promoter and, at least in part, inhibiting the PTEN downstream AKT-mTOR pathway. Notably, Notch3 knockdown downregulated PTEN and promoted cell proliferation and tumorigenesis. In contrast, overexpression of the Notch3 intracellular domain upregulated PTEN and inhibited cell proliferation and tumorigenesis in vitro and in vivo. Moreover, inhibition or overexpression of PTEN partially reversed the promotion or inhibition of cell proliferation induced by Notch3 alterations. In general, Notch3 expression positively correlated with elevated expression of PTEN, ER, lower Ki-67 index, and incidence of involved node status and predicted better recurrence-free survival in breast cancer patients. Therefore, our findings demonstrate that Notch3 inhibits breast cancer proliferation and suppresses tumorigenesis by transactivating PTEN expression.
Mixed‐dimensional (0D, 1D, and 3D) heterostructures based on 2D layered materials have been proven as a promising candidate for future nanoelectronics and optoelectronics applications. In this work, ...it is demonstrated that 1D atomic chain based Se nanoplates (NPs) can be epitaxially grown on monolayer ReS2 by a chemical transport reaction, thereby creating an interesting mixed‐dimensional Se/ReS2 heterostructure. A unique epitaxial relationship is observed with the (110) planes of the Se NPs parallel to the corresponding ReS2 (010) planes. Experimental and theoretical studies reveal that the Se NPs could conjugate with underlying monolayer ReS2 via strong chemical hybridization at heterointerface, which is expected to originate from the intrinsic defects of ReS2. Remarkably, photodetectors based on Se/ReS2 heterostructures exhibit ultrahigh detectivity of up to 8 × 1012 Jones, and also show a fast response time of less than 10 ms. These results illustrate the great advantage of directly integrated 1D Se based nanostructure on planar semiconducting ReS2 films for optoelectronic applications. It opens up a feasible way to obtain mixed‐dimensional heterostructures with atomic interfacial contact by epitaxial growth.
1D atomic chain based Se nanoplates (NPs) are epitaxially grown on monolayer ReS2 to form an interesting mixed‐dimensional Se/ReS2 heterostructure. Experimental and theoretical studies reveal that the Se NPs are chemically hybridized with underlying monolayer ReS2 through intrinsic defects in ReS2. Photodetectors based on Se/ReS2 heterostructures exhibit ultrahigh detectivity and fast response time.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Background
High incidence of asymptomatic venous thromboembolism (VTE) has been observed in severe COVID‐19 patients, but the characteristics of symptomatic VTE in general COVID‐19 patients have not ...been described.
Objectives
To comprehensively explore the prevalence and reliable risk prediction for VTE in COVID‐19 patients.
Methods/Results
This retrospective study enrolled all COVID‐19 patients with a subsequent VTE in 16 centers in China from January 1 to March 31, 2020. A total of 2779 patients were confirmed with COVID‐19. In comparison to 23,434 non‐COVID‐19 medical inpatients, the odds ratios (ORs) for developing symptomatic VTE in severe and non‐severe hospitalized COVID‐19 patients were 5.94 (95% confidence interval CI 3.91–10.09) and 2.79 (95% CI 1.43–5.60), respectively. When 104 VTE cases and 208 non‐VTE cases were compared, pulmonary embolism cases had a higher rate for in‐hospital death (OR 6.74, 95% CI 2.18–20.81). VTE developed at a median of 21 days (interquartile range 13.25–31) since onset. Independent factors for VTE were advancing age, cancer, longer interval from symptom onset to admission, lower fibrinogen and higher D‐dimer on admission, and D‐dimer increment (DI) ≥1.5‐fold; of these, DI ≥1.5‐fold had the most significant association (OR 14.18, 95% CI 6.25–32.18, p = 2.23 × 10−10). A novel model consisting of three simple coagulation variables (fibrinogen and D‐dimer levels on admission, and DI ≥1.5‐fold) showed good prediction for symptomatic VTE (area under the curve 0.865, 95% CI 0.822–0.907, sensitivity 0.930, specificity 0.710).
Conclusions
There is an excess risk of VTE in hospitalized COVID‐19 patients. This novel model can aid early identification of patients who are at high risk for VTE.
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FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The construction of stable active site in nanocatalysts is of great importance but is a challenge in heterogeneous catalysis. Unexpectedly, coordination-unsaturated and atomically dispersed copper ...species were constructed and stabilized in a sintered copper–ceria catalyst through air-calcination at 800 °C. This sintered copper–ceria catalyst showed a very high activity for CO oxidation with a CO consumption rate of 6100 μmolCO·gCu –1·s–1 at 120 °C, which was at least 20 times that of other reported copper catalysts. Additionally, the excellent long-term stability was unbroken under the harsh cycled reaction conditions. Based on a comprehensive structural characterization and mechanistic study, the copper atoms with unsaturated coordination in the form of Cu1O3 were identified to be the sole active site, at which both CO and O2 molecules were activated, thus inducing remarkable CO oxidation activity with a very low copper loading (1 wt %).
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IJS, KILJ, NUK, PNG, UL, UM
The release of nanomaterials into the environment, due to their massive production and application today, has caused ecological and health safety concerns. Semiconductor photocatalysts like TiO2 ...exhibit cytotoxicity to bacterial cells when exposed to UV irradiation. However, information about their impacts on individual or group bacterial behaviors is limited. In this work, the biofilm formation of Escherichia coli K12 in the presence of TiO2 with and without UV irradiation was investigated and biofilm formation was found not to be affected under the sole application of TiO2 or UV irradiation. However, biofilm development was substantially delayed by TiO2 under UV irradiation, although no obvious cytotoxicity to cell growth was observed. The reactive oxygen species photogenerated by TiO2 were found to quench the autoinducer 2 (AI-2) signals secreted by E. coli K12. As a result, the initiation of quorum sensing for biofilm formation activated by AI-2 was restrained. The expressions of two biofilm-formation-related genes, motA and rcsB, were also suppressed. A dose of an AI-2 precursor, 4,5-dihydroxy-2,3-pentanedione, effectively restored the biofilm development. These results show that the photoexcited TiO2 could suppress biofilm formation through quenching AI-2 signals. This work may facilitate a better understanding about the ecological effects of increasingly released nanomaterials and provide implications for development of antifouling membranes.
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IJS, KILJ, NUK, PNG, UL, UM
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