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The conventional method of urban subway tunnel excavation using a double-shield tunnel boring machine (DS-TBM) typically involves a two-stage backfilling process behind the segment wall using pea gravel and grouting. However, this method has inherent drawbacks such as uneven backfilling of pea gravel and delayed grouting, which can lead to structural issues such as segment dislocation, damage, and groundwater leakage during tunnel excavation. To address these problems, this study proposes a technical theory of synchronous backfilling self-compacting concrete backfilling material (SCCBM), considering the limitations of the conventional DS-TBM backfill method. This theory uses a specially designed wear-resistant seal plate suitable for a DS-TBM shield tail. The optimal proportion of SCCBM for backfilling the segment wall was determined based on Okamura's empirical method using anti-dispersion powder, fine stones (1–5 mm particle size), and coarse stones (5–10 mm particle size) as the basic materials. The SCCBM was designed and evaluated using various test methods, including the mini-slump, standard slump flow, standard L-box, and improved L-box tests. The engineering characteristics of the backfill material, such as initial setting time, blocking ability ratio, stone rate, and axial compressive strength, were considered during the evaluation. The results demonstrate that all indicators meet the standards for backfilling behind subway tunnel segment walls. Furthermore, an on-site synchronous backfilling SCCBM experiment was conducted to validate the feasibility and advantages of the new synchronous backfilling technology. The experiment involved observing the complete backfill process and monitoring the vertical displacement of the segment. Through these observations, the practicality and benefits of the proposed synchronous backfilling technology were confirmed. • A novel synchronous backfilling technology using self-compacting concrete in double-shield TBM tunnel was proposed. • The optimal proportion of self-compacting concrete backfilling material (SCCBM) using empirical methods was determined. • The feasibility and advantages of the proposed synchronous backfilling technology was confirmed by field data. [ABSTRACT FROM AUTHOR]

Abstract: Rel\NF-κB signal transduction pathway is evolutionarily conserved and involved in numerous biological processes. We report here, for the first time that a homologue of Rel\NF-κB transcription factor, Ab-Rel, was identified and functionally characterized in a gastropod abalone, H. diversicolor supertexta. The full-length Ab-Rel cDNA consists of 1943bp with an ORF encoding a 584 amino acids protein. Amino acid sequence analysis revealed that Ab-Rel shares conserved signature motifs with other Rel proteins, including the Rel homology domain (RHD), nuclear localization signal (NLS) and phosphorylation site, RRPS. Northern hybridization and real-time PCR indicated that Ab-Rel was ubiquitously and constitutively expressed in abalone. The recombinant Ab-Rel RHD protein was confirmed to specifically bind the consensus NF-κB binding site. Furthermore, EMSA showed that NF-κB activity was induced in abalone hemocytes by stimulation with LPS. These results strongly suggest that Ab-Rel is a Rel homologue, which plays a conserved role in the immune response of the ancient invertebrate, abalone, allowing us to study the Rel\NF-κB signaling pathway in an evolutionary context. [Copyright &y& Elsevier]

The excavation by earth pressure balance (EPB) shield could cause stress fields varied, which is harmful to adjacent existing structures. Thus the effect of excavation clearance of the EPB shield on the settlement of existing structures should be taken into account. The transit tunnel from Meicun to Shangmeilin of Shenzhen Metro Line 9 constructed by the EPB shield with mid-shield-grouting was investigated. The deformation of existing tunnel is analysed by three-dimensional (3D) finite element methods (FEM). It is found that the settlement of overburden soil is obviously influenced by the structure of the existing tunnels through the plastic development of the soil. The rate of settlement is remarkable when the shield effect zone approaches the existing tunnels so that timely mid-shield grouting is an efficient method of controlling the settlement induced by the excavation clearance. However, the grout used in this method should be with the properties of short hardening time, large elastic modulus and low shear strength. Different standards of settlement control should be employed with respect to different underground tunnels, in which minimum elastic modulus of the filler that is usually determined by fitting function. This can be taken as a guide rule of the selection of material parameters in the project. The simulation results are in good agreement with the settlements measured for the existing tunnels and the ground surface. The parameter sensitivity analysis by means of the Spearman’s correlation coefficients shows that the elastic modulus of filling material significantly influences on the settlement of the existing tunnels and the ground surface. [ABSTRACT FROM AUTHOR]

In this study, the impact of three unsaturated fatty acids (Oleic acid: OA, Eicosapentaenoic acid: EPA, Docosahexaenoic acid: DHA) on the oxidation and structure of rainbow trout myofibrillar protein (MP) was explored. The findings revealed a notable increase in carbonyl content (P < 0.05) and a significant decrease in total sulfhydryl content (P < 0.05) of MP with the concentration increase of the three unsaturated fatty acids. Endogenous fluorescence spectroscopy and surface hydrophobicity analyses showed that unsaturated fatty acids can cause unfolding and exposure of hydrophobic groups in MP. In addition, SDS-PAGE showed that disulfide bonds were associated with MP cross-linking and aggregate size induced by unsaturated fatty acids. Overall, three unsaturated fatty acid treatments facilitated the oxidation of myofibrillar proteins, and the extent of protein oxidation was closely associated with the concentration of unsaturated fatty acids. • The relationship between MP oxidation and fatty acids in rainbow trout was revealed. • Degree of protein oxidation is dependent on the concentration of unsaturated fatty acids. • Unsaturated fatty acids induced oxidation also causes structural changes in proteins. [ABSTRACT FROM AUTHOR]

In crustaceans, the steroid hormone 20-hydroxyecdysone (20E) initiates molting, and the molting process is also regulated by energy metabolism. AMPK is an energy sensor and plays a critical role in systemic energy balance. Here, the regulatory mechanism in the interaction between 20E and AMPK was investigated in Chinese mitten crab, Eriocheir sinensis. The results showed that the 20E concentration and the mRNA expression levels of 20E receptors in hepatopancreas were down-regulated post AMPK activator (AICAR) treatment, and were up-regulated after AMPK inhibitor (Compound C) injection in crabs. Besides, the molt-inhibiting hormone (MIH) gene expression in eyestalk showed the opposite patterns in response to the AICAR and Compound C treatment, respectively. Further investigation found that there was a significant reduction in 20E concentration post PI3K inhibitor (LY294002) treatment, and the phosphorylation level of PI3K was increased in hepatopancreas after AMPK inhibitor injection. On the other hand, the positive regulation of PI3K-mediated activation of AMPK was also observed, the phosphorylation levels of AMPKα, AMPKβ and PI3K in hepatopancreas were significantly increased post 20E injection. In addition, the phosphorylation levels of AMPKα and AMPKβ induced by 20E were decreased after the injection of PI3K inhibitor. Taken together, these results suggest that the regulatory cross-talk between 20E and AMPK is likely to act through PI3K pathway in E. sinensis , which appeared to be helpful for a better understanding in molting regulation. • AMPK could negatively regulate the concentration of 20E. • AMPK inhibited 20E concentration by decreasing the phosphorylation of PI3K. • The phosphorylation levels of AMPK and PI3K were increased after 20E injection. • The phosphorylation level of AMPK induced by 20E was decreased after inhibiting PI3K. [ABSTRACT FROM AUTHOR]

This study investigates the characteristics of vertical soil deformation induced by fully overlapping tunnels constructed using a tunnel boring machine (TBM). The Peck formula is improved to consider the variation in the tunnel axis depth and stratum loss ratio. Comparing the settlements both monitored and simulated on the fully overlapping tunnels of the Tianjin Metro, it is shown that our improved Peck formula is suitable to predict the surface settlement of fully overlapping tunnels. The present comprehensive research shows that during the construction of fully overlapping tunnels, the ultimate maximum settlement value is more affected by the construction of an upper-line tunnel than by the construction of a lower-line tunnel. The width of the ground settlement trough in fully overlapping tunnels construction is only affected by the lower-line tunnel, but the final settlement value is not simply the sum of the settlements of the two tunnels. The overlapping effect between the upper and lower lines reduces the stratum loss and the maximum settlement caused by excavation of the upper-line tunnel. [ABSTRACT FROM AUTHOR]

Many economically important species in demand in the market and with depleted populations have been artificial bred and their seed intensively released into the wild. As one of the most important fishery species in China, the swimming crab Portunus trituberculatus has been stocked in Panjin at a large scale since 2012. Nevertheless, no genetic profile considering genetic effects of these practices has been constructed. The present study traced the crab population enhancement in Panjin. In 2015, a total of 1671 crabs were captured in Panjin and among them 120 individuals were identified as being hatchery-raised, indicating that hatchery-raised seed contributed to the local resource. To address possible genetic effects from the hatchery stock, we compared the genetic characteristic among female broodstock, recaptured hatchery-raised, recaptured non-hatchery-raised and a wild control population based on six microsatellite markers. Results showed obvious reductions in gene diversity and effective population size (Ne) and increased relatedness in recaptured hatchery-raised crabs. Moreover, recaptured non-hatchery-raised – the local population in Panjin – also exhibited similar patterns of dramatic loss of Ne and increased degree of relatedness. The genetic homogeneity involving low Wright's fixation index (Fst), large percentage genetic variance among individuals and strong gene flow appeared in all sample locations distributed in the Bohai Sea and the Yellow Sea. Our data suggest that large-scale stock enhancement of P. trituberculatus presents strong potential genetic risks to the Panjin local population and even the whole waters surrounding the Liaodong Peninsula. Several approaches were proposed to gain better insight into P. trituberculatus enhancement practices in the future. [ABSTRACT FROM AUTHOR]

Hypoxia triggers diverse cell physiological processes, and the hypoxia inducible factors (HIFs) are a family of heterodimeric transcription factors that function as master regulators to respond to hypoxia in different cells. However, the knowledge about the hypoxic responses especially cell alteration mediated by HIFs under hypoxia stress is still limited in crustaceans. In the present study, a hypoxia-inducible factor-1α (HIF-1α) gene was identified (designed as Es HIF-1α). The relative mRNA expression level of Es HIF-1α was highest in hyalinocytes and lowest in granulocytes among three types of haemocytes in crabs. Hypoxia could significantly increase the Es HIF-1α protein expression level in haemocytes. Meanwhile, the proportion of hyalinocytes began to increase from 3 h post hypoxia treatment, and reached the highest level at 24 h. However, the opposite variation in proportion of granulocytes was observed under hypoxia stress. Further investigation showed that the inhibition of Es HIF-1α induced by KC7F2 (HIF-1α inhibitor) could lead to the significant decrease in the proportion of hyalinocytes under hypoxia stress, and also resulted in an increase of granulocytes proportion. While, after Es HIF-1α was activated by IOX4 (HIF-1α activator), the proportion of hyalinocytes was significantly up-regulated and the proportion of granulocytes was significantly down-regulated under post hypoxia treatment. These results collectively suggested that Es HIF-1α was involved in the regulation of proportion of three types of haemocytes induced by hypoxia stress, which provided vital insight into the understanding of the crosstalk between hypoxia and cell development in invertebrates. • The Es HIF-1α mRNA expression was highest in hyalinocytes and lowest in granulocytes. • Es HIF-1α protein expression in haemocytes is up-regulated post hypoxia treatment. • The proportion of hyalinocytes and granulocytes was differential respond to hypoxia. • Inhibition of Es HIF-1α decreases the proportion of hyalinocytes under hypoxia stress. • Activation of Es HIF-1α leads to increased hyalinocytes proportion under hypoxia stress. [ABSTRACT FROM AUTHOR]

The cutting forces of a disc cutter are of great significance for advancements toward the design of rock-cutting tools. Studies often model rock-breaking through the 2D analysis of the cutterhead pressure or a linear cutting test of single- or double-disc cutters. However, neither approaches accurately reflect the actual cutting pattern. In this study, two models were constructed for the numerical simulation of continuous multi-cutter rotary rock cutting: one for the modelling of sandstone with soft-to-medium hardness, and the other for the numerical calculation of rotary cutting based on the actual cutting motion of the disc cutter. The results were compared with those of similarity tests conducted in a laboratory. The normal force required by the disc cutter for breaking intact rock surfaces was observed to be greater than that for breaking the broken rock surfaces. Unlike in linear cutting, in multi disc rotary rock-breaking, the cutter applies lateral compression to the rock on both sides, thereby promoting crack extension and penetration. As the mounting radius of the disc cutter increases, the normal and rolling forces, as well as the cutting coefficient of the rolling force, increase; the side force decreases. Moreover, a low thrust and high torque are maintained by the cutterhead. [ABSTRACT FROM AUTHOR]