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The construction environment of deep rock tunnels is complex, and effectively enhancing tunnel boring machine (TBM) tunneling efficiency is paramount. Increasing rock-breaking efficiency and minimizing cutter consumption are essential strategies for improving TBM tunneling efficiency. Selecting suitable tunneling parameters is crucial for enhancing rock-breaking efficiency and reducing cutter consumption. Existing research on the optimization of the ratio of maximum cutter spacing to penetration (Smax/P) based on field-measured data is limited, and few studies compare and analyze the relationship between SE, CI, and the Smax/P ratio separately. Consequently, this study determined optimal tunneling parameters for various types of surrounding rock and construction environments, aiming to more accurately optimize TBM tunneling performance during construction processes based on on-site construction data. This study conducted a comparative analysis of specific energy (SE) and the coarseness index (CI). Under both working conditions, the quadratic fitting coefficients of the CI are 4.2% and 10.6% higher than those of the SE, respectively, with the CI selected to represent the particle size distribution of rock chips. Finally, taking into account both the correlations between the CI and the ratio of maximum cutter spacing to penetration (Smax/P), as well as cutter consumption and the Smax/P ratio, an optimization method for the TBM tunneling parameter was established under both dry and saturated conditions. The research findings indicate that cutter consumption exhibits an exponential increase with a higher rock Cerchar Abrasivity Index (CAI); it initially decreases as the Smax/P ratio increases and subsequently increases in both dry and saturated conditions. Instead, the CI demonstrates an initial increase and subsequent decrease as the Smax/P ratio increases. Maximizing rock-breaking efficiency and minimizing cutter consumption are crucial for improving tunneling performance. In saturated conditions, the corresponding optimal Smax/P ratio ranges are 7.055–8.319 for soft rock, 8.606–8.931 for medium–hard rock, and 13.50–14.00 for hard rock, and these optimal ranges under dry conditions are 8.495–9.457, 10.972–12.169, and 16.5–17.5 for the same rock types. This study provides optimal Smax/P ratio ranges for TBM tunneling, thereby significantly enhancing tunneling efficiency. [ABSTRACT FROM AUTHOR]

Millions of craniofacial surgeries are performed annually worldwide, and materials for craniofacial bone repair are widely needed. However, traditionally applied materials, such as titanium and polymethylmethacrylate, have some shortcomings (limited malleability, material-based toxicity, non-biodegradability, lack of bioactivity, etc.). Zinc based biodegradable metals possess superior mechanical properties, biodegradability, and bioactivity, which make them promising candidate materials. Here, we successfully fabricated Zn-0.6Cu thin sheets (thickness ≤0.5 mm, suitable for craniofacial surgery) through combined extrusion and rolling. The in vitro and in vivo performances were generally evaluated and compared to those of a commercially applied pure titanium mesh. The mechanical properties of Zn-0.6Cu sheets were superior to those of clinically used polymethyl methacrylate. They were easy to shape and would not fracture during deformation. The Zn-0.6Cu sheet exhibited a gentle degradation mode, and proper implant-derived Zn improved osteogenic differentiation of rat bone marrow mesenchymal stem cells by up-regulating expression of osteogenesis related genes (alkaline phosphatase, bone morphogenetic protein-2). Thus, it further promoted extracellular matrix mineralization by improving calcium deposition for bone formation. It also improved the expression of angiogenesis-related genes (vascular endothelial growth factor, hypoxia-inducible factor alpha). The Zn-0.6Cu sheet exhibited high osteogenic activity in a cranial defect animal model compared to a non-biodegradable pure titanium mesh. Significant surface degradation occurred after two months in vivo, and degradation products were compatible with surrounding tissues. In general, the Zn-0.6Cu thin sheet seems to be a bioactive material selection for craniofacial bone repair, which might possibly accelerate defect repair and prevent adverse complications. [ABSTRACT FROM AUTHOR]

Rainfall represents one of the most significant cause of landslide hazards. With runoff in the saturated zone of shallow soil considered, an improved Green–Ampt model was proposed to depict the rainfall infiltration process. Furthermore, a formula for calculating the depth of wetting front was derived, and the slope stability was evaluated accordingly. Finally, a formula for calculating the safety factor of multilayer slopes above different surfaces was obtained via the limit equilibrium method. An illustration is a multilayer colluvial slope in Guangdong Province of China, the results indicated that the downward speed of wetting front decreases gradually within the same layer with continuous rainfall but increases significantly when it extends to the interfaces between the soil layers. Safety factor of the slope decreases sharply at the initial stage of rainfall but then more slowly. Slope failure is more likely to occur along the first interface between the soil layers than along the surface of wetting front. The result from the proposed model is closer to the result of the physical model test than from the existed Green–Ampt model. The improved Green–Ampt model for multilayer slopes can accurately evaluate the infiltration process and related stability of multilayer slopes under rainfall. [ABSTRACT FROM AUTHOR]

Creep properties of soft interlayers are key factors associated with the long-term stability of geological bodies. An experimental and theoretical study on the ring shear creep properties of soft interlayers collected from Esheng, Sichuan province, China are performed in this study. Ring shear creep tests of soft interlayers, which are remolded into over-consolidated samples having various water contents and the same initial dry density, are performed in laboratory, to analyze the creep deformation characteristics of samples in detail. The calculated long-term shear strength of samples is close to residual strength. By substituting the dashpot with a new unsteady fractal dashpot, a novel unsteady fractal derivative creep (UFDC) model, which can be defined in series with an improved Maxwell model and an improved viscoplastic model, is proposed based on theory of fractal derivative. The new model can efficiently explain the soft interlayers creep deformation. The results indicate that most model parameters are sensitive to the shear stress. However, at the accelerated creep stage, the fractional order of the second dashpot in the UFDC model has little effect on the fitting of experimental data. [ABSTRACT FROM AUTHOR]

Background: At present, the predictive ability of the prognostic indicator of hepatocellular carcinoma (HCC) is still limited. This study aims to analyze the relationship between the preoperative high-sensitivity C-reactive protein to lymphocyte ratio (HCLR) and the clinicopathologic characteristics of HCC. Patients and methods: A total of 229 HCC patients undergoing surgical resection were retrospectively analyzed. The majority of the patients (132/229) had tumors larger than 5 cm, and 45 out of 229 had more than one tumor focus. Receiver operating characteristic curve analysis was used to decide the cutoff value of HCLR. The overall survival (OS) and progression-free survival (PFS) rates were evaluated by adopting the Kaplan–Meier method. Results: The cutoff value of HCLR for the best discrimination of HCC prognosis was 1.3 with a sensitivity of 75.5% and a specificity of 71.8%. The area under the receiver operating characteristic curve was 0.791 (95% CI, 0.731–0.840). Preoperative HCLR at a high level (>1.3) was positively correlated with large tumor size, TNM stage, microvascular invasion, and recurrence. The mean OS and PFS in patients with HCLR >1.3 were significantly shorter than in those with HCLR ≤1.3. Univariate and multivariate analyses revealed the HCLR was an independent predictor of OS and PFS. Conclusion: HCLR was an important independent predictor of dismal prognosis in HCC patients and can be used as a sensitive indicator for the dynamic monitoring of postoperative patients. [ABSTRACT FROM AUTHOR]

As one of China′s most precious cultural relics, the excavation and protection of the Terracotta Warriors pose significant challenges to archaeologists. A fairly common situation in the excavation is that the Terracotta Warriors are mostly found in the form of fragments, and manual reassembly among numerous fragments is laborious and time-consuming. This work presents a fracture-surface-based reassembling method, which is composed of SiamesePointNet, principal component analysis (PCA), and deep closest point (DCP), and is named SPPD. Firstly, SiamesePointNet is proposed to determine whether a pair of point clouds of 3D Terracotta Warrior fragments can be reassembled. Then, a coarse-to-fine registration method based on PCA and DCP is proposed to register the two fragments into a reassembled one. The above two steps iterate until the termination condition is met. A series of experiments on real-world examples are conducted, and the results demonstrate that the proposed method performs better than the conventional reassembling methods. We hope this work can provide a valuable tool for the virtual restoration of three-dimension cultural heritage artifacts. [ABSTRACT FROM AUTHOR]

The salts contained in water can gradually accumulate in pore networks of rocks under wetting-drying cycles, which could cause rock deterioration. The salt-induced damage under this cyclic process can result in dynamically evolving mechanical and hydraulic properties of the rock, which is relevant to many rock-related engineering activities and geological hazards. In this study, the structure damage and permeability evolution of Three Gorges Reservoir (TGR) sandstone subjected to wetting-drying cycles with salt solution were investigated by a series of multiscale experiments. The results showed that the salt solution has a significant impact on the physical properties of TGR sandstone during the wetting-drying process. With increasing wetting-drying cycles, two typical macroscopic damage modes in form of surface peeling and internal cracking were observed. Various physical parameters indicated that the internal structure of the TGR sandstone experienced two stages: 1) Salt accumulation and new crack formation stage and 2) Crack propagation stage. This variation also profoundly affected the permeability of the TGR sandstone. Specifically, the permeability of TGR sandstone decreased slightly at first due to blocked seepage channels by crystals before cycle 5, followed by a slow growth until the 15th cycle and a rapid increase after the 15th cycle. Cubic and exponential functions showed good performances to describe the evolution features of permeability with porosity and wetting-drying cycles, respectively. The deterioration mechanism was further elucidated by an evaporation test. This test indicated that the salt solution was more likely to crystallize in narrow pores and expectedly exert pressure enough to crack the pores, contributing to the structure damage feature and the permeability enhancement. These findings and results in this study deepen our understanding of salt-induced rock deterioration mechanism under the wetting-drying cycles and would be meaningful for rock engineering safety and geological disaster forecast in complex groundwater environments. • Structure damage of TGR sandstone by salt solution under wetting-drying cycles is systematically revealed. • Permeability enhancement of TGR sandstone is functionalized by porosity and wetting-drying cycle. • Salt-induced deterioration mechanism is elucidated by its crystallization features of location and pressure. [ABSTRACT FROM AUTHOR]

Background: Preoperative peripheral blood neutrophil-to-lymphocyte ratio (NLR) has been proposed to predict prognosis of hepatocellular carcinoma (HCC). However, the cutoff value of NLR in several studies is not consistent. This study aims to investigate the correlation of preoperative NLR with clinicopathologic features and the prognosis in patients who have undergone resection for HCC., Methods: Clinical data of 256 patients with HCC who underwent radical hepatectomy were retrospectively analyzed. The patients were divided into the low-NLR group (NLR ≤ 2.31) and the high-NLR group (NLR > 2.31). A univariate analysis was performed to assess clinicopathologic characteristics that influenced disease-free survival (DFS) and overall survival (OS) in patients. The significant variables were further analyzed by a multivariate analysis using Cox regression. The Kaplan-Meier method was used to assess the DFS and OS rate., Results: The value of NLR was associated with tumor size, clinical tumor-node-metastasis (TNM) stage, portal vein tumor thrombus (PVTT), distant metastasis, and aspartate aminotransferase (AST) in HCC. NLR > 2.31, size of tumor > 5 cm, number of multiple tumors, III-IV of TNM stage, PVTT, distant metastasis, and AST > 40 U/l were predictors of poorer DFS and OS. NLR > 2.31, size of tumor >5 cm, III-IV of TNM stage, and AST > 40 U/l were independent predictors of DFS and OS., Conclusion: Preoperative NLR > 2.31 was an adverse predictor of DFS and OS in HCC after hepatectomy. This study suggested that NLR might be a novel prognostic biomarker in HCC after curative resection., (Copyright © 2014 Neoplasia Press, Inc. Published by Elsevier Inc. All rights reserved.)