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The rational optimization of the electromagnetic field enhancement and charge transfer in a Raman substrate is vital for achieving efficient surface-enhanced Raman scattering (SERS). Herein, a ternary plasmonic substrate, whose structure-adjustable Au nanotriangle/Cu2O hybrids are combined with two-dimensional Ti3C2Tx MXene ultrathin nanosheets, is prepared and used for efficient SERS detection of molecules. By controlling the growth of Cu2O on Au nanotriangles, Au/Cu2O hybrids with three tips exposed are prepared, which show much better SERS performance than bare Au and core–shell Au@Cu2O in detecting methylene blue (MB) under excitation at 785 nm due to the optimized electromagnetic field enhancement and charge transfer. Furthermore, the Au/Cu2O hybrids are transferred to the plasmonic Ti3C2Tx nanosheet, generating a further enhanced electromagnetic field around their interfaces. As a result, the MXene/Au/Cu2O hybrids present further improved SERS activity, and their analytical enhancement factor reaches 2.4 × 109 and the detection limit is as low as 10−12 M. The enhancement mechanism can be ascribed to the improved electric field enhancement around the Au tips and the interface between MXene and Au/Cu2O. Meanwhile, the multiple charge-transfer processes between Au, Cu2O, MXene, and MB also play an important role in improving the SERS signal. [ABSTRACT FROM AUTHOR]

Background The clinical value of programmed death-ligand 1 (PD-L1) expression in colorectal liver oligometastases (CLOs) remains undefined. This study aimed to detect PD-L1 in the microenvironment of CLOs and determine its association with patient prognosis. Methods We collected 126 liver-resection specimens from CLO patients who underwent curative liver resection between June 1999 and December 2016. Immunohistochemistry (IHC) was performed to assess PD-L1 expression in paraffin-embedded specimens. Overall survival (OS) and recurrence-free survival (RFS) were analysed using the Kaplan–Meier method and log-rank test. Results PD-L1 was mainly expressed in the stroma of liver oligometastases. Patients with high PD-L1 expression had a higher proportion of clinical-risk scores (CRSs) of 2–4 (67.7% vs 40.4%; P  =   0.004). With a median 58-month follow-up, patients with high PD-L1 expression had a significantly lower 3-year OS rate (65.5% vs 92.7%; P  =   0.001) and 3-year RFS rate (34.7% vs 83.8%; P  <   0.001) than patients with low PD-L1 expression. Multivariate Cox analysis demonstrated that high PD-L1 expression (hazard ratio [HR] = 3.581; 95% confidence interval [CI] 2.301–9.972; P  =   0.015), CRS 2–4 (HR = 6.960; 95% CI 1.135–42.689; P  =   0.036) and increased preoperative CA19-9 (HR = 2.843; 95% CI 1.229–6.576; P  =   0.015) were independent risk factors for OS. High PD-L1 expression (HR = 4.815; 95% CI 2.139–10.837; P  <   0.001) and lymph-node metastasis (HR = 2.115; 95% CI 1.041–4.297; P  =   0.038) were independent risk factors for RFS. Conclusion This study found that PD-L1 was commonly expressed in the tumour stroma of CLOs and high PD-L1 expression was associated with poor prognosis. [ABSTRACT FROM AUTHOR]

Constructing isotype g‐C3N4/g‐C3N4 heterojunction is an approach to improve the efficiency of g‐C3N4 towards solar‐assisted oxidation of water. Such functional configuration can effectively overcome the intrinsic drawback of rapid charge recombination of g‐C3N4. Here, a modified g‐C3N4, with homogeneous phosphorus doping, is prepared in this work through a phosphide‐involved gas phase reaction. The resulting P‐g‐C3N4 displays altered electronic structure, including upshifted band edge potential, narrowed band gap and improved electronic conductivity. These features allow P‐g‐C3N4 as an outstanding candidate to form isotype junction with pristine g‐C3N4. As expected, the accelerated charge separation and migration in target junction is validated by various measurements. The optimized isotype g‐C3N4/P‐g‐C3N4 heterojunction achieves a photocurrent as high as 0.3 mA cm−2 at 1.23 V vs RHE (AM 1.5G, 100 mW cm−2), representing 8‐fold's enhancement compared with pristine g‐C3N4. The present strategy for constructing g‐C3N4‐based isotype heterojunction networks is found effective for large‐scale manufacturing. Isotype photoanode: A phosphorus‐doped g‐C3N4 with suitable electronic structure was explored to construct metal‐free isotype photojunction in large‐scale manufacturing. The percolated networks exhibit largely increased photocurrent than its single component as a result of efficient charge transfer being qualitatively identified. [ABSTRACT FROM AUTHOR]

Coal is well developed with beddings, and the beddings play an important role in the stability of tunnel stability of coal mine. This study focused on jointed rock mass with two sets of joint and proposed an extended ubiquitous model and associated numerical implementation accounting for joint spacing to represent geometric features of coal. The failure criteria of two sets of joint proposed in this paper not only accounted for joint spacing, but also contained the ubiquitous joint model. This extended theory was validated against the discontinuous deformation analysis method, the plane of weakness theory and experimental results for jointed coal with different joint fabric. The model is also used to analyze tunnel stability of roadways in coal mine with different joint spacing. The ubiquitous joint model could simulate jointed coal with small joint spacing, but for that with larger joint spacing, the ubiquitous joint model is not applicable and the joint model containing joint spacing proposed by this paper should be used. A series of comparisons demonstrated that the proposed model was capable of considering the influence of joint spacing on jointed coal tunnel with two sets of joint. [ABSTRACT FROM AUTHOR]