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Water content is an important factor affecting the rock-breaking efficiency of tunnel boring machine (TBM) disc cutters. However, limited efforts have been made to study the fracturing mechanism of sandstone excavation by TBM disc cutters under varying water content conditions. To investigate the breakage behavior of water-soaked sandstone by TBM disc cutters, five sets of penetration tests on sandstone specimens with different water content levels were performed. The tests were conducted using a modified RYL-600 computer-controlled rock shear rheometer. An acoustic emission (AE) monitoring system was utilized throughout the entire process to track the AE activity of the specimens. The force–depth curves of the penetration process at various water content levels were investigated. The effects of water content on AE characteristics, rock fracture properties, and specific energy were analyzed. The results indicate that AE activity can be divided into three stages: quiet period, slow rise period, and active period. With increasing water content, peak penetration force, consumed energy, and specific energy decrease gradually, while chip volume increases. Water promotes mutual penetration of surface and internal cracks of the specimen, resulting in the formation of larger chip volumes. These findings provide theoretical guidance for designing and improving TBM cutter head parameters in water-rich soft rock formations. [ABSTRACT FROM AUTHOR]

The interval section of the Liuyang River flood control levee project of the Changsha Metro Line 6 is used as the engineering background of this study. A three-dimensional finite element numerical model of a tunnel shield containing complex interfaces is established by using the multifield coupling software COMSOL. The paper studied the deformation of flood control levees under shield tunnel excavation working conditions. The results show that when the left line shield machine is excavated below the Liuyang River flood control levee, the deformation of the flood control levee and the surrounding rock of the tunnel is biased towards the built right line tunnel. And it has an impact on the bridge pile near the tunnel. When the shield of the left line crosses the flood control levee, it can easily cause a large deformation and displacement of the levee above the area between the two shields. To ensure the controlled deformation of the levee, the construction should ensure the spacing between the two tunnel palm faces as far as possible and should be far away from other structures on the levee. When the shield crosses the levee, the deformation that occurs at the base of the levee is significantly higher than the deformations that occur at other locations of the levee. Displacement monitoring and secondary reinforcement at the base of the flood control levee appear to be necessary. The numerical simulation results validate the feasibility of using the multifield coupling software COMSOL to study the construction modeling of shield tunnels through rivers and its advantages. This method provides a practical framework for similar tunnel performance engineering or displacement monitoring in future projects. [ABSTRACT FROM AUTHOR]

Asthma is a chronic airway inflammatory disease caused by multiple genetic and environmental factors. This study mainly sought to provide potential therapeutic targets and biomarkers for neutrophilic asthma (NA). Three gene expression profiling datasets were obtained from the Genome Expression Omnibus (GEO) database. GSE45111 and GSE41863 were used to identify hub genes and potential biomarkers, and GSE137268 was used for data verification. We verified the repeatability of intragroup data and identified differentially expressed genes (DEGs). Then, we conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of the DEGs, and a protein–protein interaction (PPI) network was constructed to identify the hub genes. Finally, receiver operating characteristic (ROC) analysis was used to verify the ability of the hub genes to differentiate between NA and eosinophilic asthma (EA). In this study, we identified 411 DEGs by comprehensive analysis of NA/EA patients and NA/healthy controls (HCs). Ten hub genes (CXCR1, FCGR3B, CXCR2, SELL, S100A12, CSF3R, IL6R, JAK3, CD48, and GNG2) were identified from the PPI network. Finally, based on the ROC analysis, 7 genes showed good diagnostic value for discriminating NA from EA—CXCR1, FCGR3B, CXCR2, SELL, S100A12, CSF3R, and IL6R (AUC > 0.7). We identified 7 hub genes that can distinguish NA from EA. The IL-8-mediated signaling may be the primary pathway to determine the NA phenotype in asthma. CXCR1/2 and S100A12 may be the primary genes determining the NA phenotype. CXCR1/2 and S100A12 might be biomarkers and new therapeutic targets for NA. Supplemental data for this article is available online at at [ABSTRACT FROM AUTHOR]

Adenine modifications, including m6A, m1A, APA, and A‐to‐I modifications, are the most impactful RNA modifications. These modifications are primarily produced by enzymes called writers. The main purpose of this study was to explore the cross‐talk and potential roles of these writers in severe asthma. We found 13 RNA writers potentially related to severe asthma and three RNA modification patterns. Cluster 3 showed predominant neutrophil infiltration and C‐type lectin receptor signaling; cluster 1 showed predominant innate immune cell infiltration and ubiquitin–proteasome system activation; and cluster 2 did not show obvious immune infiltration characteristics. We found that RNA modification writers modified immune cell–related genes and led to both accumulation of different immune cells in the airways and activation of a series of biological processes, which ultimately leads to severe asthma. TRMT6, WTAP, and TRMT6A were included in a random forest model as predictors. Cromoglicic acid, thioperamide, and fluvastatin were potential drugs for clusters 1, 2, and 3, respectively. We found that cross‐talk of RNA modifications is significant in severe asthma, which provides insight into severe asthma pathogenesis and possible treatment avenues. [ABSTRACT FROM AUTHOR]

Our previous studies have showed that sulfatide-reactive type II NKT (i.e. variant NKT, vNKT) cells inhibit the immunogenic maturation during the development of mature lung dendritic cells (LDCs), leading todeclined allergic airway inflammation in asthma. Nonetheless, the specific immunoregulatory roles of vNKT cells in LDC-mediated Th2 cell responses remain incompletely understood. Herein, we found that administration of sulfatide facilitated the generation of CD4+FoxP3+ regulatory T (Treg) cells in the lungs of wild-type mice, but not in CD1d−/− and Jα18−/− mice, after ovalbumin or house dust mite exposure. This finding implies that the enhancement of lung Treg cells by sulfatide requires vNKT cells, which dependent on invariant NKT (iNKT) cells. Furthermore, the CD4+FoxP3+ Treg cells induced by sulfatide-reactive vNKT cells were found to be associated with PD-L1 molecules expressed on LDCs, and this association was dependent on iNKT cells. Collectively, our findings suggest that in asthma-mimicking murine models, sulfatide-reactive vNKT cells facilitate the generation of lung Treg cells through inducing tolerogenic properties in LDCs, and this process is dependent on the presence of lung iNKT cells. These results may provide a potential therapeutic approach to treat allergic asthma. [ABSTRACT FROM AUTHOR]

• Cellular senescence-related biological processes may be involved in the pathogenesis of severe asthma. • The expression of ETS2, ETS1 and AURKA were increased in the severe asthma. • Two distinct senescence subtypes were identified in severe asthma with distinct immune microenvironment and molecular biological characteristics. • The random forest predictive model based on PEBP1 and MDH1 has good accuracy in predicting senescence subtypes of severe asthma. • Bezafibrate, EBPC and felodipine may be the potential therapeutical drugs for Cluster 1, while FK-888, trimethobenzamide and PD-0325901 may be the potential therapeutical drugs for Cluster 2. Recent studies have shown that cellular senescence is involved in the pathogenesis of severe asthma (SA). The objective of this study was to investigate the role of cellular senescence-related genes (CSGs) in the pathogenesis of SA. Here, 54 differentially expressed CSGs were identified in SA patients compared to healthy control individuals. Among the 54 differentially expressed CSGs, 3 CSGs (ETS2, ETS1 and AURKA) were screened using the LASSO regression analysis and logistic regression analysis to establish the CSG-based prediction model to predict severe asthma. Moreover, we found that the protein expression levels of ETS2, ETS1 and AURKA were increased in the severe asthma mouse model. Then, two distinct senescence subtypes of SA with distinct immune microenvironments and molecular biological characteristics were identified. Cluster 1 was characterized by increased infiltration of immature dendritic cells, regulatory T cells, and other cells. Cluster 2 was characterized by increased infiltration levels of eosinophils, neutrophils, and other cells. The molecular biological characteristics of Cluster 1 included aerobic respiration and oxidative phosphorylation, whereas the molecular biological characteristics of Cluster 2 included activation of the immune response and immune receptor activity. Then, we established an Random Forest model to predict the senescence subtypes of SA to guide treatment. Finally, potential drugs were searched for each senescence subgroup of SA patients via the Connectivity Map database. A peroxisome proliferator-activated receptor agonist may be a potential therapeutic drug for patients in Cluster 1, whereas a tachykinin antagonist may be a potential therapeutic drug for patients in Cluster 2. In summary, CSGs are likely involved in the pathogenesis of SA, which may lead to new therapeutic options for SA patients. [ABSTRACT FROM AUTHOR]

• Anti-CD1d treatment suppress Th2 cell responses in asthma by suppresses immunogenic maturation of LDCs. • Anti-CD1d treatment lowers the abundance and activation of lung iNKT cells in asthma. • The influences of anti-CD1d treatment in LDCs of asthma were dependent on lung iNKT cells. • The influences of anti-CD1d treatment in LDCs of asthma were relevant to the downregulation of CD40L expression on lung iNKT cells. Our previous findings show that invariant natural killer T (iNKT) cells can promote immunogenic maturation of lung dendritic cells (LDCs) to enhance Th2 cell responses in asthma. It has been accepted that recognition of glycolipid antigens presented by CD1d molecules by the T cell receptors of iNKT cells leads to iNKT cell activation. Therefore, we examine the immunoregulatory influences of anti-CD1d treatment on Th2 cell response and immunogenic maturation of LDCs and subsequently explored whether these influences were dependent on lung iNKT cells in asthmatic mice. We discovered that in wild-type mice sensitized and challenged with house dust mite or ovalbumin (OVA), anti-CD1d treatment inhibited Th2 cell response and immunogenic maturation of LDCs. LDCs from asthmatic mice with anti-CD1d treatment had a markedly decreased influence on Th2 cell responses in vivo and in vitro. Furthermore, anti-CD1d treatment reduced the abundance and activation of lung iNKT cells in asthmatic mice. Moreover, in asthmatic iNKT cell-deficient Jα18-/- mice, anti-CD1d treatment did not influence Th2 cell responses and immunogenic maturation of LDCs. Meanwhile, the quantity of CD40L+ iNKT cells in asthmatic mice was significant decreased by anti-CD1d treatment. Finally, the inhibition of anti-CD1d treatment on LDC immunogenic maturation and Th2 cell responses in asthmatic mice was reversed by anti-CD40 treatment. Our data suggest that anti-CD1d treatment can suppress Th2 cell responses through inhibiting immunogenic maturation of LDCs dependent on lung iNKT cells, which could be partially related to the downregulation of CD40L expression on lung iNKT cells in asthmatic mice. [ABSTRACT FROM AUTHOR]

To better understand the mechanical behavior in a jointed rock mass, a series of uniaxial compression tests were conducted on non-persistently jointed rock specimens with double circular holes. Acoustic emission (AE) and digital image correlation (DIC) techniques were applied to capture micro-crack events and real-time strain field evolution in the specimens. The results indicate that the existence of non-persistent joints has a significant influence on the strength characteristics of the specimens. Specifically, peak strength decreases at first and reaches a minimum at 30° then increases with increase in the joint dip angle. DIC technology has successfully monitored the development of surface strain fields. The fracture evolution process is comprehensively understood. Every sudden change in a strain field is usually accompanied by apparent AE events and stress–strain curves take the form of oscillations. The crack coalescence modes among joints can be summarized as six types and the crack coalescence patterns around holes and joints can be divided into three categories. These results are helpful to understanding further the mechanical properties and fracture mechanism of openings in non-persistently jointed rock masses. [ABSTRACT FROM AUTHOR]

GH42 enzymes are potential candidates for bifunctional β-galactosidase/α-L-arabinopyranosidase. A novel GH42 enzyme (BaBgal42A) from Bacillus was identified, the recombinant BaBgal42A hydrolyzed not only β-D-galactopyranosidic bonds in p NP-β-D-galactopyranoside, o NP-β-D-galactopyranoside, lactose, galactan, and arabinan but also α-L-arabinopyranosidic linkages in p NP-α-L-arabinopyranoside, wheat arabinoxylan and galactan. The K m values of BaBgal42A for p NP-β-D-galactopyranoside and p NP-α-L-arabinopyranoside were 2.76 and 16.23 mM, respectively. Investigation of cooperative activities of BaBgal42A with cognate enzymes revealed that BaBgal42A showed obvious synergy with an endo-β-1,4-galactanase (BaGal53A) in the decomposition of galactan, supplementing BaBgal42A resulted in a 0.56-fold increase in the release of reducing sugars; BaBgal42A also exhibited a little synergy with its cognate endoxylanase (BaXynA)/α-L-arabinofuranosidase (BaAraA) in hydrolyzing wheat arabinoxylan/arabinan, addition of BaBgal42A released 12.7%/7.8% more reducing sugars than that produced by BaXynA/BaAraA alone. Moreover, BaBgal42A is a cold-adapted enzyme, exhibiting 28–46% of the maximal activity at the range of 5–20 °C and its activity was slightly stimulated by addition of Na+, K+, or Ca2+ at low concentrations. This study not only expands the diversity within GH42 family, but also provides new insights into the role of microbial GH42 enzymes, which would contribute to its potential application in polysaccharides degradation and milk lactose hydrolysis. [ABSTRACT FROM AUTHOR]

Background: B cells were believed to act as antigen-presenting cells (APCs) to promote T helper type 2 (Th2) cell responses. However, the role of lung B cells and its subpopulations in Th2 cell responses in asthma remains unclear. Objective: We leveraged an anti-CD20 monoclonal antibody (mAb) treatment that has been shown to selectively deplete B cells in mice and investigated whether this treatment modulates Th2 cell responses and this modulation is related to lung follicular mature (FM) B cells in a murine model of asthma. Methods and results: We used a house dust mite (HDM)-induced asthma mouse model and found that anti-CD20 mAb treatment attenuates Th2 cell responses. Meanwhile, anti-CD20 mAb treatment did dramatically reduce the number of B cells, especially FM B cells in the lungs, but did not impact the frequency of other immune cell types, including lung T cells, dendritic cells, natural killer cells, and regulatory T cells in wild-type mice. Moreover, we found that the suppressive effect of anti-CD20 mAb treatment on Th2 cell responses could be reversed upon adoptive transfer of lung FM B cells, but not lung CD19+ B cells without FM B cells in asthmatic mice. Conclusions: These findings reveal that anti-CD20 mAb treatment alleviates Th2 cell responses, possibly by depleting lung FM B cells in a Th2-driven asthma model. This implies a potential therapeutic approach for asthma treatment through the targeting of lung FM B cells. [ABSTRACT FROM AUTHOR]

Extensive and detailed investigations have been made to better understand the rock-breaking mechanism of the tunnel boring machine (TBM) disc cutter, but the crack propagation and failure modes induced by the disc cutter when the confining stresses and joint characteristics vary have not been comprehensively investigated. To address this area of research, a triaxial testing machine (TRW-3000) is modified to investigate the effect of different confining stresses (0, 2.5, 5, 7.5 and 10 MPa) on the rock breaking of different joint angles (0°, 30°, 60°, and 90°) induced by the disc cutter. In this series of tests, the crack propagation and failure modes of the intact and jointed rock with different confining stresses are analysed. During the experiments, four different types of failure modes have been observed. The failure mode is affected by the joint orientation at low confining stress. The existence of joints has no obvious effect on the failure mode when the confining stress increases to a certain extent. [ABSTRACT FROM AUTHOR]

In the conventional FDEM (Combined Finite and Discrete Element Method), each contact pair might have multiple contact points where friction forces are applied, leading to non-unique friction force assignments and potentially introducing computational errors. This study introduces a new contact friction algorithm for FDEM based on the resultant normal contact force. This method necessitates determining the friction force at a unique equivalent contact point, thereby significantly simplifying the computational flow and reducing memory usage. A series of numerical tests are performed to validate the effectiveness of the proposed contact model. Using collision and block sliding tests, the proposed contact friction model is verified to be able to accurately capture the frictional effect between discrete bodies and circumvent the problematic kinetic energy dissipation issue associated with the original contact friction algorithm. For the Brazilian splitting and uniaxial compression tests, the simulated results closely align with those generated using the original contact friction algorithm and match the experimental measurements well, demonstrating the applicability of the proposed algorithm in fracturing analysis. Furthermore, by using the proposed contact friction algorithm, a computational efficiency enhancement of 8% in contact force evaluation can be achieved. [ABSTRACT FROM AUTHOR]

In the current work, electrodeposition method has been used to prepare Cu 2 O thin films on ITO substrates. The bath temperature was controlled from 40 to 80 °C and additive concentration varied from 2 to 10 mM. The structure, surface morphology and optical properties of the as-prepared films were investigated by X-ray diffractometer (XRD), field-emission scanning electron microscope (SEM), Raman spectrophotometer and UV–visible (vis) spectrophotometer. The morphology of the Cu 2 O films varies obviously at different bath temperature and additive concentration. Intensity of Raman peaks increase with the increase of KCl concentration. UV–vis absorption spectra measurements have shown the average absorbance for the film deposited at 80 °C is higher than those deposited at 40 and 60 °C. Meanwhile, average absorbance of the Cu 2 O thin film deposited at 10 mM KCl is larger than those deposited at 2 and 5 mM KCl, which should be associated with the morphology. [ABSTRACT FROM AUTHOR]

• Jointed rock mass containing a circular hole specimen under compression-shear loading were analysed by DIC and DEM modelling. • Analysed the effect of joint inclination on strength behaviour of the specimen under compression-shear loading. • The crack evolution process was investigated and four types of crack coalescence among joints were summarized. • Three kinds of crack coalescence between joints and hole were found. The tunnels excavated in a mountain body interact with the jointed rock mass under compression-shear and present a complex stress state. The joints often have a significant influence on the possible damage points of tunnels. However, the failure behaviour of jointed rock mass with a hole under the compression-shear condition is still unclear. The crack coalescence mechanism needs to be further explored. In this study, compression-shear tests were carried out on jointed rock-like specimens containing a circular hole. The corresponding numerical model was established by the discrete element method (DEM) modelling. The results show that with the increase in joint inclination, the peak load first increases and decreases. Four types of crack coalescence among joints and three kinds between joint and hole were found. The crack coalesces with the hole easily occur on both sides of the hole. When the joint inclination is small, the crack coalesces through the shear slip. However, the tensile crack coalesces with the joints and hole when the joint inclination is large. Finally, the failure behaviour of the specimen was further analysed based on the displacement field. The experimental results also verify the above analysis and agree well with simulation results. [ABSTRACT FROM AUTHOR]

Presents information on a study which discussed the Hemoroscopid larva fossils discovered from the Lower Cretaceous in Southwest Beijing, China. Description of the fossils; Systematic position; Stratigraphic significance of the Lushangfen Entomofauna.

The management of rock mass deformation in high-stress roadways is a pivotal aspect of deep geotechnical engineering. Given the fruitful outcomes of research in rock mechanics regarding traditional confining pressure control methods, scholars have increasingly turned their attention to exploring pressure-relieving techniques, including borehole pressure relief and blasting pressure relief. However, there is limited research on pressure relief methods for deep-buried hard rock tunnels. This article commences with an overview of pressure relief in the roadway and conducts a detailed study on the parameters and methods of pressure relief in the roadway. To address safety and mining efficiency challenges, such as severe deformation leading to support failures, this study conducted a parameter analysis using the Sanshandao Gold Mine as a case study. Based on existing support methods, a strategy for arranging pressure relief roadways at varying distances from the main roadway is proposed, significantly enhancing the stress environment there. Numerical simulation software was employed to model two scenarios: (1) excavating the pressure relief roadway, main roadway, and maintenance roadway simultaneously and (2) first excavating the pressure relief roadway, followed by the main roadway and the maintenance roadway simultaneously. Simulation results indicated that the first pressure relief approach outperforms the second. The optimal position for both pressure relief roadways is 15 m from the main roadway, resulting in maximum deformation of the main roadway within 100 mm. These findings align with on-site stress monitoring data and satisfy safety production criteria. The research offers a theoretical foundation for similar pressure relief techniques in deeply buried, high-stress roadways. [ABSTRACT FROM AUTHOR]

Layered rock masses with joints are widely found in nature. Their mechanical behavior plays a key role in rock engineering applications. However, previous studies have concentrated on the single lithologic layer, and few studies have reported the crack coalescence mechanism in layered rock masses with joints. In this study, uniaxial compression tests were performed on jointed rock-like specimens with two dissimilar layers. The acoustic emission (AE) and the digital image correlation (DIC) techniques are employed to investigate the crack coalescence process of specimens with two dissimilar layers. The influence of the joint angle and rock bridge angle on the mechanical behavior and failure processes in layered rock masses is investigated. The results show that the peak strength is associated with the joint angle and the rock bridge angle. Seven types of crack coalescence have been identified in the specimens, which are not only related to the joint angle and the rock bridge angle but also influenced by the rock layers. Cracks easily coalesce when the joint angle and the rock bridge angle are small. However, when the joint angle and the rock bridge angle are larger, it is difficult for cracks to initiate and propagate in the layer with higher strength. The failure mechanism of the specimens is primarily caused by crack propagation in the layer with lower strength. [ABSTRACT FROM AUTHOR]

• Yellow sandstone containing pre-existing surface crack was tested under uniaxial cycle fatigue tests. • The effect of crack angle on the mechanical fatigue properties under cyclic loading was investigated. • A damage constitutive model was developed considering the effect of macro–micro coupling damage on the fractured rock mass. In engineering practice, rock masses are often subjected to cyclic loading. Under cyclic loading, the mechanical properties of rocks are significantly different from those under conventional loading conditions. The mechanical behaviour and fatigue of intact rock has been extensively studied. However, the mechanical fatigue properties of rock masses with surface cracks and related damage evolution models are not well understood. In this study, a series of fatigue damage tests were carried out on yellow sandstone specimens; five different pre-existing surface crack angles (0°, 15°, 30°, 45° and 60°) and three different maximum cyclic stress levels (19.1 MPa, 25.6 MPa and 30.3 MPa) were considered. The results showed that with the increase in the number of cycles, Young's modulus gradually stabilized, while the secant modulus decreased non-linearly. The maximum strain and residual strain continuously accumulated. The influence of macro cracks on the damage of rocks was studied through the increase in strain energy. Based on the macro–micro coupling damage, a constitutive model was proposed for the fatigue test. The theoretical results were fitted with the experimental data, showing that the proposed model can effectively describe the fatigue damage characteristics of fractured rock masses. The research results have certain reference value for the long-term stability evaluation in fractured rock mass engineering. [ABSTRACT FROM AUTHOR]

•.The model of jointed rock mass with double holes was developed using DEM modelling. • The peak strength and elastic modulus exhibited a U-shaped change with the joint angle. • Four typical failure modes were summarized. • Five types of crack coalescence among the holes and adjacent joints were found. Underground projects are typically performed in nonpersistent jointed rock masses. Excavation of tunnels or chambers causes crack initiation, propagation and coalescence, resulting in the instability and destruction of surrounding rocks. The failure behaviour of rocks is complicated owing to the interaction between holes and joints. Therefore, understanding the failure characteristics of holes in jointed rock masses is essential. In this paper, the mechanical characteristics of a jointed rock mass with double circular holes under uniaxial loading was investigated using the discrete element method. The effects of different joint parameters on the strength and failure behaviour of the jointed rock mass with double circular holes were studied. The results show that the existence of joints degrades the mechanical behaviour of the rock mass. Specifically, the peak strength and elastic modulus of the specimens show a "U" shape change with the joint dip angle and reach the minimum value when the angle is 30°. With an increase in joint spacing, the peak strength and elastic modulus increase gradually. An investigation of the crack coalescence process and displacement field of the specimens reveal the crack propagation mechanism based on the interaction between holes and joints under uniaxial loading. Five types of crack coalescence among the holes and adjacent joints were summarized. Four typical failure modes were observed: tensile failure across joints, block rotation failure around holes, shear failure through joint planes and tensile–shear mixed failure through holes. [ABSTRACT FROM AUTHOR]

• A 2D cylindrical model of thermally-induced hydrate dissociation was built. • The temperature distributions and dissociation fronts under different hot water injection speeds and temperatures were simulated. • The rules of gas production rate and cumulative gas production under different conditions were revealed. Natural Gas Hydrate (NGH) is characterized by large reserves and cleanliness, which has attracted wide attention around the world. Thermal stimulation is considered to be one of the possible methods to facilitate hydrate dissociation. In this paper, the hydrate is dissociated through injecting hot water. In order to reveal the influence of the speed and the temperature of injected hot water on the temperature distribution, hydrate dissociation front, gas production rate, and cumulative gas production, a 2D cylindrical mathematical model of thermally-induced hydrate dissociation was established. The results show that the dissociation process can be regarded as a moving boundary ablation process. The dissociation front divides the whole reservoir into three sections: complete dissociation section, ongoing dissociation section, and undissociated section, and the range of ongoing dissociation section is a very narrow area characterized by a relatively intensive temperature contour, which indicates that the temperature drops rapidly during the hydrate dissociation. The temperature at the dissociation front is almost constant under different hot water injection speeds or temperatures. The injection speed and the temperature of hot water seem to have similar effects on hydrate dissociation. The enhanced hot water injection speed or hot water injection temperature will result in a faster gas production rate, a quicker movement of the dissociation front, and a shorter duration time of gas production, however, hot water injection speed and temperature have little impact on the final gas production. The results may provide a guidance for safely and efficiently exploiting NGH. [ABSTRACT FROM AUTHOR]

5-Fluorouracil (5-FU) is an analog of pyrimidine and has been shown to display antitumor and immunomodulatory effects. However, the impacts of 5-FU in regulating asthma, an inflammatory disease associated with T helper cell 2 (Th2) responses, remain unclear. Here, we determine the modulatory effects of low-dose 5-FU on Th2 cell responses in asthma and delineate the underlying mechanisms using adoptive cell transfer and in vitro culture experiments. Our data show that low-dose 5-FU treatment not only inhibits the induction of asthma in allergen-sensitized mice but also abrogates the major features of asthma in mice with established disease. We find that this protection of 5-FU treatment against asthma is accompanied by a decrease in the number of lung monocyte-derived dendritic cells (moDCs) in the asthmatic murine. Furthermore, we show that adoptive transfer of moDCs reverses the inhibitory effects of 5-FU treatment on Th2 cell responses in asthmatic mice. Surprisingly, 5-FU treatment does not suppress surface maturation markers and immunogenicity of moDCs in the lungs of asthmatic mice. Instead, it induces apoptotic cell death of mouse moDCs both in vitro and in vivo. In addition to its impact on mouse moDCs, we observe that low-dose 5-FU treatment can induce apoptotic cell death of human moDCs derived from peripheral blood mononuclear cells in vitro. Together, our findings reveal that low-dose 5-FU ameliorates Th2 cell responses, which may be at least partially related to the induction of apoptotic cell death of moDCs in asthma. [Display omitted] • Allergic asthma is driven by Th2 cell responses. • 5-Fluorouracil ameliorates Th2 cell responses in allergic asthma. • Monocyte-derived dendritic cells are critical in driving Th2 cell responses. • 5-Fluorouracil induces apoptotic cell death of monocyte-derived dendritic cells. [ABSTRACT FROM AUTHOR]

• The interaction between the interface and crack in the double-layer composite rock-like specimens was considered. • The crack evolution of specimens was investigated by combining AE technology and DIC method. • Five typical failure modes were summarized: Single-layer X-conjugate failure, interface friction failure, tensile failure of the airfoil at interface, overall slip shear failure along the interface and local interface splitting tensile failure. Composite rock with interfaces is widely distributed in nature. Its mechanical properties are significantly different from those of a single layer rock, which has become one of the highlighted issues in engineering design and operation. In this study, uniaxial compression tests are performed on rock-like specimens with two dissimilar layers. The evolution process of the apparent strain field of the specimen is analysed by digital image correlation (DIC). Acoustic emission (AE) technology is used to analyse the damage evolution process of specimens based on energy dissipation theory and the damage evolution model. The research results show that with the increase in the interface angle, the peak compressive strength of the specimen decreases slowly first and then decreases rapidly, increasing when reduced to the minimum. When the inclination angle of the specimen interface is 60°, its strength is the lowest. The higher the overall strength of the specimen is, the more obvious the above phenomenon. DIC technology captures the apparent strain field characteristics of each stage of specimen failure, which provides a basis for the analysis of the specimen failure mode. The failure modes of the specimens can be divided into five categories. When the inclination angles of the interface are 0°, 60°, 75° and 90°, the failure modes of the specimens are mainly affected by the inclination angle. When the inclination angles are 15°, 30° and 45°, the failure modes are affected by the inclination angle and the rock matrix strength. The damage evolution process of most specimens is divided into four stages. Some specimens only show three stages, such as those specimens with an interface inclination angle of 60°. [ABSTRACT FROM AUTHOR]

The tunnel engineering has become increasingly common with the needs of urban development. However, excavation sequence has a significant effect on the stability of the tunnel perimeter rock, which can lead to more unpredictable perimeter rock hazards and more difficulty in maintaining perimeter rock stability. In this study, to investigate the effect of different excavation sequences on tunnel deformation and creep, biaxial compression experiments were conducted on muddy siltstone specimens by using the acoustic emission (AE) and digital image correlation (DIC) techniques. The results indicated that, as the distance from the tunnel portal increases, the amount of stress and strain change decreases, with the largest values of stress changes occurring in the tunnel vault and middle area of twin tunnels. The specimen undergoes two stages in the creep process: deceleration creep and steady-state creep. The steady-state creep rate of the measurement points depends on the degree of excavation disturbance impact it experiences. The AE events during excavation can be divided into two phases: the quiet period when the specimen is not excavated and the active period when the specimen is excavated, and the cumulative counting curve shows a "stepwise" increase with the number of excavations. There is a sudden drop in the b-value during excavation and a decrease in the b-value during the deceleration creep phase. The results of this study can reflect the creep patterns of the surrounding rock under different excavation sequences, which can help to choose a more suitable excavation plan in terms of rock creep stability. [ABSTRACT FROM AUTHOR]

• Mechanical properties and failure behaviour of anchored granite containing two filled edge-notched fissures were analysed. • Effects of rockbolt on jointed hard rock with different confining pressures and fissure angleswere studied,. • Adverse effects of rockbolt borehole were discussed subjected to high confining pressure. High in-situ stress commonly exists in deep rock engineering and causes great difficulties in underground mining support systems. To elucidate the relationship between the anchoring effect of bolts and confining pressures, triaxial compression tests were performed to study the deformation characteristics, mechanical properties, and failure behaviour of anchored granite with two pre-existing fissures. The results demonstrated that the deformation characteristics or mechanical properties of anchored granite, including triaxial compressive strength, elastic modulus, and stored or dissipated energy, increased with increasing confining pressure under low confining pressures. Rockbolt boreholes significantly weaken the mechanical properties and failure behaviour under high confining pressures and have a negative impact on the peak axial strength and stored or dissipated energy of the anchored granite. The fissure angle and confining pressure have a direct impact on the failure mode of anchored granite. With increasing confining pressures or fissure angles, shear cracks and anti-wing cracks instead of tensile wing cracks are more likely to cause ultimate failure. In addition, four modes of crack coalescence were identified: no coalescence, two types of direct crack coalescence, and indirect crack coalescence. [ABSTRACT FROM AUTHOR]

• Three types of failure mode of the specimens were summarized. • The effect of filling material on the crack types was revealed. • The crack evolution process was investigated by using the PFC2D. • Displacement field in the PFC2D was used to study the crack pattern. In rock engineering, the failure mechanism of a fractured rock mass under compression-shear stress has been focused on, but the effect of filler in fracture-filled rock masses has not received widespread attention. In this research, compression-shear tests are performed on rock-like specimens with three fissures under four filling conditions, unfilled, gypsum filled, cement filled and resin filled, to obtain the effect of three fillers on the mechanical characteristics and failure mode of fractured specimens. The discrete element method (DEM) is used to analyse the crack propagation and coalescence of the specimens. The results show that the peak load and displacement of specimens primarily depend on the strength of the fillers and inclination angle of the central fissure. For gypsum and cement filled specimens, when the fissure inclination angle is small, the influence of fillers on the peak load and displacement is obvious, but the effect can be neglected when the fissure inclination angle is large. The resin has a remarkable influence on the peak load and displacement of all specimens. Three failure modes were found in this study. Failure mode I primarily occurs when the fissure inclination angle is 0°. Failure mode II appears in specimens with a fissure inclination angle equal to 30° or 45°. The failure mode of specimens with a fissure inclination angle equal to 60°, 75° or 90° is defined as mode III. For the failure mode, the action mechanism of filler is to weaken stress borne by rock-like material. The larger the weakening degree of the shear stress is, the easier tensile failure occurs in filled specimens. However, when the stress is substantially weakened, the failure mode of filled specimens is similar to that of specimens containing no fissures. [ABSTRACT FROM AUTHOR]

Nearly half of the tailings dams in China are in a state of high-security risks and overservice, and the safety of these tailings dams has always been a concern for relevant scholars. The seepage characteristics of tailings are one of the essential factors affecting the safety of tailings dam. Now, due to the improvement of mineral processing technology, there are many fine tailings dam; the study of the seepage characteristics of the tailings dam is no longer applicable. Fine-grained tailings form uneven deposition in these tailings dams, resulting in the permeability of tailings not conforming to the previous law. Therefore, it is of great significance to study the permeability of fine-grained tailings with uneven deposition. In this paper, the physical model of the simulated tailings dam is established to study the influence of the dry beach slope on the distribution and deposition law of fine tailings during discharge. The test results show that the average particle size of tailings decreases along the length of dry beach, showing the phenomenon of coarsening upstream and thinning downstream. Then, based on the data of fine tailings deposition, the variation characteristics of the permeability coefficient of layered tailings under stable and unstable seepage conditions are studied. The test results show that the variation process of tailings permeability coefficient can be divided into four stages: rapid compaction stage, slow compaction stage, failure stage, and stable stage. Under stable and unstable seepage conditions, the permeability coefficients of unstratified tailing sand are about 10% and 15% higher, respectively, than those in the initial state. The permeability coefficient of layered tailings formed by uneven settlement changes more obviously, which is about 12% and 20% higher than the initial state. [ABSTRACT FROM AUTHOR]

• A parameter R was defined to characterize the mechanical behavior of the specimen. • The DIC method was applied to analyze the crack evolution process. • The ultimate failure modes were subdivided into six types. • The interface of the rock layer plays a role in crack propagation. A large number of two-layer rock-like specimens composed of different combinations of materials and containing two fissures with 30°, 45° or 60° fissure angles were manufactured and carried out a series of uniaxial compression tests. A special parameter R related to the upper rock layer strength and lower rock layer strength was defined, and it was regarded to characterize the behavior of the different double-layer composite rock-like specimens. The axial strength of the double-layer composite rock-like specimens containing two parallel fissures was greatly weakened by the presence of the fissures and the degree of weakening was related to the fissure angle and R, while the elastic and deformation modulus (E s and E 50) were mainly affected by R. The axial strain ε 1c fluctuates between 9‰ and 12‰ and gradually stabilizes and was not directly related to the fissure angle or R. The digital image correlation method was used to analyze crack evolution behavior and it showed that the rock failure characteristics of the double-layer composite rock-like specimens were obviously different from those of ordinary single-layer rock specimens. The ultimate failure modes could be divided into two major categories of coalescence mode and no-coalescence mode, and each mode could be subdivided into three types, which were mainly influenced by R and secondly influenced by the fissure angle. The results also indicate that the interface between the upper rock layer and the lower rock layer can play a role in linking cracks. [ABSTRACT FROM AUTHOR]

• Compressive-shear tests were conducted on double-notched sandstone rock specimens with different freeze–thaw cycles. • The influence of F-T treatment on the mode II fracture toughness are analyzed. • The 3D surface topography and fractal dimension value of fracture surface was obtained. • The 3D JRC value for 3D fracture surfaces was calculated. For jointed rock masses in cold regions, freeze–thaw cycles cause damage to the rock matrix and degradation of the strength parameters. To further understand the deterioration mechanism of freeze–thaw cycles, substantial efforts have been devoted to the investigation of the failure mechanism of rock after freeze–thaw treatments. Until now, little attention has been given to the degradation of fracture toughness and the change in the fracture surface morphology of rocks after cyclic freeze–thaw treatments, especially for planar shear fracture characteristics. In this research, experiments on double-notched sandstone specimens after different freeze–thaw cycles subjected to compression-shear tests were conducted to further investigate the effect of the freeze–thaw treatment on the mode II fracture toughness and fracture surface morphological characteristics. The results show that freeze–thaw cycles have an important role in the mode II fracture toughness and that the fracture toughness shows an obvious decreasing trend with an increase in freeze–thaw cycles (N). Moreover, the 3D surface topography was reconstructed by using 3D laser scanner scanning. Parameters such as fractal dimension, asperity height and slope angle show that the fracture surface becomes rougher with increasing N. In addition, based on the 2D contour lines extracted from fracture planes, the 3D joint roughness coefficient (JRC) values of 3D fracture surfaces were calculated. The results indicate that more freeze–thaw cycles will produce rougher fracture surfaces. [ABSTRACT FROM AUTHOR]

The species of the Strashilidae (strashilids) have been the most perplexing of fossil insects from the Jurassic period of Russia and China. They have been widely considered to be ectoparasites of pterosaurs or feathered dinosaurs, based on the putative presence of piercing and sucking mouthparts and hind tibio-basitarsal pincers purportedly used to fix onto the host's hairs or feathers. Both the supposed host and parasite occur in the Daohugou beds from the Middle Jurassic epoch of China (approximately 165 million years ago). Here we analyse the morphology of strashilids from the Daohugou beds, and reach markedly different conclusions; namely that strashilids are highly specialized flies (Diptera) bearing large membranous wings, with substantial sexual dimorphism of the hind legs and abdominal extensions. The idea that they belong to an extinct order is unsupported, and the lineage can be placed within the true flies. In terms of major morphological and inferred behavioural features, strashilids resemble the recent (extant) and relict members of the aquatic fly family Nymphomyiidae. Their ontogeny are distinguished by the persistence in adult males of larval abdominal respiratory gills, representing a unique case of paedomorphism among endopterygote insects. Adult strashilids were probably aquatic or amphibious, shedding their wings after emergence and mating in the water. [ABSTRACT FROM AUTHOR]

The C2H2-type (also called TFIIIA-type) zinc finger protein family is a major family of eukaryotic transcription factors. C2H2-type zinc finger proteins in plants play important roles in regulating various developmental processes or responses to abiotic stresses. We isolated a complementary deoxyribonucleic acid (cDNA) clone, designated S olanum l ycopersicum cold zinc finger protein 1 ( SlCZFP1), from tomato by analyzing the previous microarray data of the low-temperature transcriptome of tomato. SlCZFP1 encodes a novel TFIIIA-type zinc finger protein, which contains two typical zinc finger motifs, CX CXFXQALGGHXH, and a potential nuclear localization signal (NLS). The SlCZFP1-GFP fusion protein was localized to the nucleus in a transient expression assay. Expression of SlCZFP1 was strongly induced by cold stress, dehydration, and salt treatment, but not by abscisic acid (ABA). Overexpression of SlCZFP1 in transgenic Arabidopsis and rice induced constitutive expression of cold-regulated (COR) or cold-responsive genes and conferred enhanced tolerance to freezing or cold treatments for non-acclimate transgenic plants, compared with wild-type plants. However, there was no obvious enhancement observed in drought and salt tolerance. Our data suggest that SlCZFP1 plays an important role in plant responses to cold stress by regulating cold-responsive gene expression and that SlCZEP1 might be a useful gene for improving cold tolerance in crop plants. [ABSTRACT FROM AUTHOR]

It is generally known that discontinuities have a remarkable influence on the mechanical behaviour of rock masses. To further understand the fracture mechanisms of jointed rock masses, substantial effort has been focused on the strength anisotropy and failure characteristics of rocks/rock-like specimens containing persistent joints with different geometric parameters. However, only a few laboratory tests have considered the failure mechanism of a rock mass with 3D joints, especially for non-persistent joints with different persistence levels. In the present work, experiments on cubic rock-like specimens containing non-persistent joints (in areal extent) subjected to uniaxial compression were conducted to further investigate the influence of the joint inclination (θ) and persistence (N) on the rock mechanical properties and failure characteristics. The strength of a 3D non-persistent jointed specimen is characterized by three stages as the joint inclination angle (θ) increases from 0° to 90°. The strength of jointed specimens decreases with increasing N for all θ values, with the highest strength obtained for N = 0.42 and the lowest strength recorded for N = 0.92. Based on CT scan results, four typical fracture modes were identified: splitting, splitting + sliding, sliding, and intact failure. Overall, as the joint inclination increases, the failure mode of the specimen transforms from splitting to sliding and then to the intact failure mode. However, with decreasing joint persistence, the failure modes of some specimens will change from sliding to mixed failure (splitting + sliding). • 3D printing technology was used to prepare cuboid rock-like specimens containing 3D non-persistent joints • The strength of the jointed specimen is characterized by three stages as the joint inclination angle (θ) increases. • The strength of the jointed specimen with the highest strength obtained for N = 0.42 and the lowest strength for N = 0.92. • Four typical fracture modes were identified: splitting, splitting + sliding, sliding, and intact failure. [ABSTRACT FROM AUTHOR]

Background: Cellulose and hemicellulose are the two largest components in lignocellulosic biomass. Enzymes with activities towards cellulose and xylan have attracted great interest in the bioconversion of lignocellulosic biomass, since they have potential in improving the hydrolytic performance and reducing the enzyme costs. Exploring glycoside hydrolases (GHs) with good thermostability and activities on xylan and cellulose would be beneficial to the industrial production of biofuels and bio-based chemicals. Results: A novel GH10 enzyme (XynA) identified from a xylanolytic strain Bacillus sp. KW1 was cloned and expressed. Its optimal pH and temperature were determined to be pH 6.0 and 65 °C. Stability analyses revealed that XynA was stable over a broad pH range (pH 6.0–11.0) after being incubated at 25 °C for 24 h. Moreover, XynA retained over 95% activity after heat treatment at 60 °C for 60 h, and its half-lives at 65 °C and 70 °C were about 12 h and 1.5 h, respectively. More importantly, in terms of substrate specificity, XynA exhibits hydrolytic activities towards xylans, microcrystalline cellulose (filter paper and Avicel), carboxymethyl cellulose (CMC), cellobiose, p-nitrophenyl-β-d-cellobioside (pNPC), and p-nitrophenyl-β-d-glucopyranoside (pNPG). Furthermore, the addition of XynA into commercial cellulase in the hydrolysis of pretreated corn stover resulted in remarkable increases (the relative increases may up to 90%) in the release of reducing sugars. Finally, it is worth mentioning that XynA only shows high amino acid sequence identity (88%) with rXynAHJ14, a GH10 xylanase with no activity on CMC. The similarities with other characterized GH10 enzymes, including xylanases and bifunctional xylanase/cellulase enzymes, are no more than 30%. Conclusions: XynA is a novel thermostable GH10 xylanase with a wide substrate spectrum. It displays good stability in a broad range of pH and high temperatures, and exhibits activities towards xylans and a wide variety of cellulosic substrates, which are not found in other GH10 enzymes. The enzyme also has high capacity in saccharification of pretreated corn stover. These characteristics make XynA a good candidate not only for assisting cellulase in lignocellulosic biomass hydrolysis, but also for the research on structure–function relationship of bifunctional xylanase/cellulase. [ABSTRACT FROM AUTHOR]