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When earth pressure balance tunnel boring machines (EPB-TBMs) tunnelling in abrasive sandy ground, soil additives are critical for promoting excavation surface stability, reducing residual soil permeability, decreasing screw conveyor torque, avoiding mud cake siltation and preventing excessive tool wear. However, the existing studies mainly focus on the first four aspects. The influence mechanism of soil additives on cutting tool wear is still unclear due to the lack of reliable test methods. In the present study, a newly developed WHU-SAT tester (Soil Abrasion Tester developed by Wuhan University) was used to evaluate the influence of conditioning additives (foam additives and bentonite slurry) on soil abrasivity. Scraper wear in additive-conditioned sand has been compared with that in water-conditioned sand to reveal the mechanism of foam additive and bentonite slurry. The soil additive parameters (solution concentration and injection ratio) were optimized to reduce scraper wear in abrasive sandy ground. The results indicate that the mitigation effect of the foam additive on scraper wear is related to the lubrication of the active agent and the cushioning of the air bubbles. The optimized foam solution concentration and foam injection ratio for the quartz sand samples are FSC = [5%, 10%] and FIR = [22.5%, 25.0%], respectively. The aggravation in scraper wear caused by bentonite slurry is related to the improvement of particle gradation and the increase of sand cohesion. The bentonite slurry parameters should be selected to keep the water content of the conditioned sand away from the peak water content to decrease scraper wear. [ABSTRACT FROM AUTHOR]

The shear behaviour of natural joints generally exhibits anisotropy due to variations in morphological characteristics. The anisotropic shear behaviour of natural joints mainly determines the rock mass stability. It is improbable to sample a large number of natural joints with same surface morphologies in the field. In this study, 3D laser scanning and 3D engraving techniques were adopted to reconstruct natural joints in the laboratory. In the reconstruction process, a series of trial and error engraving tests were conducted due to the lack of engraving resolution evaluation and engraving parameter selection methods. Both 2D and 3D characterization methods were used to quantitatively assess the engraving resolution. A method was proposed to determine the interval path based on the cone angle of the cutter. A series of engraving tests were conducted to study the effect of the path interval on the engraving resolution and to verify the proposed method. The results indicated that the engraving path interval should not be too large (> 0.20 mm) or too small (< 0.10 mm), which could result in a strip between adjacent engraving paths or overengraving, respectively. The natural joints in the sandstone specimen could be successfully reconstructed when the optimal cutter radius and path interval were 0.40 and 0.10 mm, respectively. The root mean square error (RMSE) of the profile height between the original and reconstructed joints was less than 0.10 mm. The difference in the 3D roughness θ max ∗ / C + 1 between the original and engraved joints was less than 0.5. The methods proposed in this study can be employed to accurately assess the engraving resolution and to quickly determine reasonable engraving parameters. In this way, natural joints can be reconstructed with high engraving resolution. The anisotropic shear behaviour of natural joints can be suitably investigated in the laboratory. [ABSTRACT FROM AUTHOR]

Rockbursts have become one of the main engineering disasters in deep-buried tunnel, seriously threatening the safety of worker and equipment. To monitor microseismic (MS) events and predict rockburst, in the present study, a MS monitoring system was established in a deep-buried tunnel excavated by tunnel boring machine (TBM). Characteristics of MS events were studied and a prediction method for intense rockburst was proposed by analyzing the temporal–spatial distribution, source parameters, and failure mechanism. The results indicated that most of MS events occurred during the tunneling process and within 15 min after a tunneling cycle completed. The MS events mainly distributed within 15 m before and after the tunneling face, and within approximate 2.0 times of the tunnel diameter. The energy of these MS events mainly ranged from 30 to 100 kJ. The prediction method based on cumulative energy index of per day and cumulative apparent volume cannot predict intense rockburst accurately in the present study, the forecast accuracy less than 60%. The proposed prediction index based on the energy index of per MS event and the apparent volume of per MS event can effectively sharpen the forecast accuracy (> 85%). The failure mechanism of MS events was predominated by tensile failure. While as the rockburst segment transited from mild to intense, the percentage of MS events of mixed failure and shear failure increased, especially shear failure events. Highlights: The temporal and the spatial distribution characteristics of rockburst segment in a deep-buried tunnel were revealed. Microseismic event count, energy, energy index, apparent volume, failure mechanism, and the development process of mild, moderate, and intense rockburst segments were studied. A prediction index based on energy index and apparent volume of per microseismic event was proposed to forecast intense rockburst. [ABSTRACT FROM AUTHOR]

Two main methods are commonly used in tunnel excavation, drilling and blasting (DB) and tunnel boring machine (TBM) tunnelling method. To better understand the differences and predict rockbursts, the characteristics of microseismic (MS) events in two parallel tunnels excavated by DB and TBM methods were compared, including temporal distribution, spatial distribution, and intensity distribution. The results indicated that the characteristics of MS events induced by two excavation methods had some differences. In the DB excavated tunnel, the number of MS events decreased exponentially as the time to a blasting cycle increased. The MS events predominantly occurred within 15 min to a blasting cycle. On the other hand, in the TBM excavated tunnel, the MS events primarily occurred while the TBM was working. Similarly, when a tunnelling cycle was completed, there was an exponential decrease in the number of MS events, which mainly occurred within 15 min. The distribution of MS events in relation to the tunnelling face exhibited similarities for both excavation methods, presenting a normal distribution. The range of the TBM excavation (approximately 2.3 times of tunnel diameter) was generally larger compared to the DB excavation (approximately a time of tunnel height). In terms of energy levels, both the DB and TBM excavations predominantly produced low-level energy MS events (less than 30 kJ). For moderate and high-level energy events, the percentage of TBM excavation induced events was higher than that of DB excavation induced. In the TBM excavation, surrounding rocks maintain good integrity and high bearing capacity, and a large tangential stress gradient is near the tunnelling face. It is more likely to induce a large rupture scale of seismic sources and lead to a more prolonged and widespread active period. On the other hand, the fracturing zone induced by the DB excavation reduces bearing capacity of surrounding rocks, and strain energy within surrounding rocks is released to a certain extent. The tangential stress gradient is relatively small, so it is associated with more localized and short-lived seismic activity in the DB excavated tunnel. [ABSTRACT FROM AUTHOR]

The Brazilian test is extensively used to indirectly measure the tensile strength of rock. However, the Brazilian tensile strength (BTS) does not always align with the direct tensile strength (DTS), resulting in a lack of consensus regarding the applicability of Brazilian test across diverse rock types. To evaluate the applicability of Brazilian test loading with various platens, the different numerical tensile tests based on the discrete element procedure PFC2D were conducted. The simulation results indicate that the discrepancy between the BTS and DTS of rock is heavily influenced by the rock's uniaxial compressive strength (UCS) to direct tensile strength (DTS) ratio. Specifically, the DTS/BTS ratio exhibits a strong negative correlation with the UCS/DTS. This negative correlation holds true across the usage of different loading platens in the Brazilian test. Moreover, the simulation results indicate that the process of crack initiation and propagation of specimens in Brazilian test is closely related to the relative relationship between the BTS and DTS. The UCS/DTS ratio of rock and the selection of the loading platen simultaneously affect the process of crack initiation and propagation. Specimens with a low UCS/DTS ratio tend to crack from the loading ends inward under concentrated end loading, such as flat platen and curved jaws. In this scenario, the BTS often underestimates the rock's tensile strength. If the UCS/DTS ratio of a specimen is sufficiently high, cracking does not originate from the end, but rather from discrete microcracks in the internal tensile stress zone. These microcracks then propagate towards the loading end, leading to failure. Under these conditions, the BTS typically overestimates the tensile strength. Utilizing platforms with a central angle of 20°can mitigate stress concentration at the loading end in Brazilian tests, prompting internal crack initiation. However, the resulting BTS is also more likely to overestimate the tensile strength. Therefore, selecting an appropriate loading platen based on the rock's UCS/DTS ratio is crucial to minimize the difference between the BTS and DTS. The proper range of UCS/DTS ratios of rock for the Brazilian test with flat platen, curved jaws and loading platforms are recommended as 10–15, 8–10 and 5–8, respectively. Highlights: The discrepancy between the direct tensile strength (DTS) and Brazilian tensile strength (BTS) of rock is closely related to its compression-tension ratio. The initiation and propagation of cracks during the Brazilian test are influenced by both the compression-tension ratio of rock and the chosen loading platen. The applicable range of compression-tension ratios for rock during Brazilian tests loading with different platens are proposed. [ABSTRACT FROM AUTHOR]

The macro-indentation test is widely used to evaluate rock mechanical properties. Due to the complex indentation process and the multi-peak force–penetration curve, many indentation indices are proposed to evaluate rock properties. It is critically important to assess these indices and select the proper index for certain usages (i.e., estimating rock strength, representing rock brittleness, and drillability). In the present study, indentation indices proposed in the previous studies were summarized first. To analyze statistical characteristic of the indentation indices (i.e., distribution characteristic and correlation), the indentation test was conducted on 47 granite specimens. 26 indentation indices were calculated from each force–penetration curve of the indentation test. The indentation indices are generally concentrated at the mean value, but these indices have different dispersion degree. The force indices and energy indices of the same large-scale fracture are highly correlated, while the force indices and modulus indices are little correlated. Most modulus indices are correlated with each other, while most dimensionless indices are independent of each other. For highly correlated indices, the index with small dispersion is the first choice for usage. Finally, proper indices are suggested for estimating rock strength and representing rock brittleness and drillability according to their distribution characteristics, correlations, and prediction accuracy. The minimal testing number to attain the required accuracy is also proposed for these selected indices. Highlights: The definition and application of the existing indentation indices are summarized. The indentation test is conducted on 47 granite specimens to evaluate the applicability of the indentation index. The distribution characteristics and correlations of the testing data of the indentation indices are studied. Proper indentation indices are suggested for estimating rock strength and representing rock brittleness and drillability. [ABSTRACT FROM AUTHOR]

During tunneling in urban areas, ground deformation may cause damage to surface and sub-surface structures and buildings, especially the shallow-buried twin-tunnel. In the present study, a 3D numerical simulation and field measurements are adopted to study the ground deformation and stress characteristics of the segment of Guangzhou Metro Line 18. Two measures are adopted to reduce the ground deformation, i.e., grouting from the middle shield and compressed air assistance. The results indicate that the ground surface does not have a settlement as the TBM passes, but an upheaval as the two measures are adopted properly. The maximum upheaval values of the advance tunnel and second tunnel are approximately 45 mm and 5 mm, respectively. As the buried depth of the tunnel increases, the ground upheaval decreases gradually. When the advance tunnel is excavated, soils adjacent to the tunnel have an outward horizontal displacements. The maximum horizontal displacement is approximately 40 mm at the turning of the tunnel. As the tunnel is excavated along straight line, the maximum horizontal displacement is approximately 20 mm. The second tunnel excavated has similar effect on the soils, rendering a slight squeezing effect on the advance tunnel. The maximum horizontal displacement of soils between the two tunnels is approximately 25 mm. While the squeezing effect has a slight effect on the deformation and force distribution of the segments of the advance tunnel. The grouting from middle shield and compressed air assistance can well control the ground deformation of the shallow-buried twin-tunnel with small spacing. [ABSTRACT FROM AUTHOR]

The mechanical properties of rock, especially the uniaxial compressive strength (UCS), the elastic modulus (E), and the Brazilian tensile strength (BTS) are critically important for rock engineering. Since standard laboratory tests have some limitations, various indirect methods have been developed for estimating these mechanical properties, e.g., the indentation test. In the indentation test, an indenter is forced into the rock to obtain the load-displacement curve. Most estimation models of rock mechanical properties by indentation test are appropriate for fine-grained rock or soft rock, and there is little estimation model for coarse-grained rock and hard rock. Therefore, it is important to establish an estimation model appropriate for rock with large grain sizes and high strength. Since the specimen size may affect the test result, specimens with different sizes were tested first to study the specimen size effect. The result showed that both the specimen diameter and height affect the specimen failure pattern, the load-displacement curve, and the indentation indices. The proper specimen size is suggested using in the indentation test with a 7-mm diameter indenter. Then, 8 types of rock were prepared for indentation tests, uniaxial compression tests, and Brazilian tests. The UCS, BTS, and E all increase with indentation indices, e.g., the energy per unit (W) and the indentation modulus of the first peak (IM1). There are linear correlations between the UCS, E, BTS, and indentation indices (W and IM1) with high determination coefficients. [ABSTRACT FROM AUTHOR]

In this paper, we carry out a comprehensive study for the unconstrained L 1 over L 2 sparsity promoting model, widely used in the regime of coherent dictionaries for recovering nonnegative sparse signals. First, we prove the existence of global solutions. Second, we analyze the sparse property of any local minimizer of the L 1 / L 2 model. This property serves as a certificate to rule out the nonlocal minimizers. Third, we focus on algorithmic development on the unconstrained model with nonnegative constraint. We derive an analytical solution for the proximal operator of the L 1 / L 2 with nonnegative constraint. Then, we apply the alternating direction method of multipliers in a particular splitting way, referred to as ADMM p + . We establish its global convergence to a d-stationary solution (sharpest stationary) by verifying the Lyapunov function with the Kurdyka-Łojasiewicz property instead of imposing. Extensive numerical simulations confirm the superiority of ADMM p + over the existing state-of-the-art methods in nonnegative sparse recovery. [ABSTRACT FROM AUTHOR]

With the rapid development of urbanization and industrialization, electric power consumption continues to increase on a worldwide basis. Traditional overhead transmission lines cannot satisfy the requirements for modernization of power distribution systems. Cable tunnels with ultra-high-voltage and complex network have become the trend of urban power transmission lines for their advantages in flexibility, expandability, and convenient maintenance. Although cable tunnels have good adaptability in power transmission, their application is severely restricted by construction and inspection technologies. Especially for long-distance cross-river tunnels installed with 1000 kV equipment, there is still a lack of reliable solutions to deal with complex challenges encountered during the construction and inspection of ultra-high-voltage cable tunnels. In the present study, complexity features of the first underwater gas-insulated transmission line for 1000 kV power in the world, Sutong GIL Yangtze River Crossing Cable Tunnel, have been analyzed. Engineering challenges encountered during the construction and inspection of long-distance cable tunnel have been discussed. Key technologies including embankment deformation control, gas explosion prevention, synchronous transportation organization, dust-free equipment installation, and robot intelligent inspection have been developed. The application of these technologies has enabled the safe and efficient construction and inspection of a high-quality cross-river cable tunnel. [ABSTRACT FROM AUTHOR]

The novel strain TF-2, isolated from a contaminated site and identified as Burkholderia stabilis, is able to degrade chlorobenzene via assimilation (51%-89%) and co-metabolism (98%-100%) for 60–200 mg/L chlorobenzene. Whole-genome sequencing experiments of strain TF-2 were carried out to reveal its global metabolism. Notably, 19 aromatic hydrocarbon dioxygenase genes and a gene cluster related to chlorobenzene metabolism were discovered in this strain. Moreover, the complete genome of strain TF-2 is composed of three circular chromosomes and two plasmids. The total length is 8.83 Mb, containing 8,807 protein coding genes, 18 rRNA genes and 69 tRNAs genes. Additionally, it contains 209 carbohydrate-active-enzyme-encoding genes, of which mainly 33.0% distributed in glycosyl transferases, 24.8% in carbohydrate esterases and 21.1% in auxiliary activities. Finally, the degradation pathway of chlorobenzene in TF-2 was proposed. The annotated complete genome sequence of TF-2 will provide genetic insights into the degradation of chlorobenzenes. [ABSTRACT FROM AUTHOR]

The full-face shield tunnel boring machine (TBM) has been widely used to build tunnels in urban area. Ground deformations usually occur during tunnelling processes, which is closely related to engineering geological property. A large ground deformation may lead to large-scale surface settlement or ground collapse, especially for shallow buried tunnels. In general, synchronous grouting is adopted to reduce the ground deformation. The temporal and spatial distribution of the grout pressure and consolidation processes of grouting have a significant influence on the deformation. For a better understanding the relationship between the grout material type and the ground deformation, the present study models a complex numerical model in FLAC3D based on the Guangzhou Metro line 18. A numerical method is proposed to reproduce the tunnelling process and the consolidation process of grout material. The effect of grouting material on ground deformation is discussed, i.e., immediately solidified type, quick hardening type, and good mobility type. The ground deformation of the numerical simulation are compared to those monitored in the field. The results indicate that the immediately solidified type grout can reduce the ground settlement effectively and is mainly applicable to secondary grouting. The quick hardening type can make the ground upheaval, which is smaller than that induced by immediately solidified type. The good mobility type can reduce the ground settlement and well control the ground deformation. The good mobility type recommends using in the numerical study for simulating the synchronous grouting. [ABSTRACT FROM AUTHOR]

Graph: Figure 3 Effects of ITGB4 overexpression on HCC cell proliferation, colony formation, invasion and EMT. Author Correction: Integrin 4 promotes cell invasion and epithelial-mesenchymal transition through the modulation of Slug expression in hepatocellular carcinoma (A) ITGB4 was ectopically expressed in the Bel-7402 and SMMC-7721 cell lines, and cell viability was assessed using the MTT assay, and showed significantly higher rates of cell proliferation compared with negative control. [Extracted from the article]

The inherent intermittency of solar power due to diurnal and seasonal cycles has usually resulted in the need for alternative generation sources thereby increasing system operation costs. However, when solar power is spread over a large geographical area with significant time differences, the intermittency can be significantly reduced and also the electricity market balancing cost. The aim of this article is to address the fundamental scientific question on how the intermittency of solar power generation is affected by aggregation, which is of great interest in the wider power and energy community and would have profound impacts on the solar energy integration into the energy supply and Net-Zero Implementation. This article goes beyond the typical regional analysis by investigating solar power intermittency at 5 aggregation levels from a global perspective based on global 7 year hourly meteorological re-analysis data with a fine spatial resolution of 0.25 ∘ × 0.25 ∘ (∼ 28 km × 28 km) . In the proposed assessment framework, a coefficient of variation (CV) is used to quantify solar power intermittency and hence characterize the potential benefits of wide area solar power aggregation. A duration curve is used to characterize the intermittency in terms of power availability and a probability density function is further employed to investigate the dispersion and scaling behavior of CV at different aggregation levels. The findings indicate that the CV of solar power generation of 'Inner Mongolia' in China drops from 129.65 to 105.65% in the level of 'Asia' (by 24% decrease), to 56.11% in 'Asia-North_America' (by 73.54% decrease) and to the smallest 43.50% in 'Global' (by 86.15% decrease), nearly 3.5 times of that in 'Asia'; (b) the availability of solar power generation increases from 52.17% in Germany, to 73.30% in 'Europe_EU_plus', to 77.82% in 'Europe', to 98.59% in 'Europe-North_America' (80.60% in 'Europe-Africa', 96.90% in 'Europe-Asia'), to 100% in 'Global'. Finally, conclusions and recommendations are provided to support a Net-Zero strategy. [ABSTRACT FROM AUTHOR]

A novel mycelium-forming actinomycete strain, designated YIM S01255T were isolated from a salt lake. Optimal growth occurred in the presence of 0–5.0% (w/v) NaCl, at pH 7.0–8.0, and at 37 °C. Strain YIM S01255T contained meso-diaminopimelic acid as the diagnostic diamino acid, and glucose, galactose and arabinose as the whole-cell sugars. The major fatty acid (> 5.0%) were iso-C16:0, iso-C16:1H and iso-C15:0. The major menaquinone were MK-9(H4) and MK-8(H4). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylinositolmannoside and phosphatidylinositol. The DNA G + C content was 70.7 mol%. The 16S rRNA gene sequence of the strain showed high similarity to members of genera in the family Pseudonocardiaceae with values less than 95.8%, and most closely related to the genus Amycolatopsis. Both of phylogenetic analysis based on 16S rRNA gene sequences and the up-to-date bacterial genome sequences analysis revealed that strains YIM S01255T and Prauserella shujinwangii XJ46T formed a distinct monophyletic clade and was separated from the other members within the family Pseudonocardiaceae. The average nucleotide identity (ANI) values and digital DNA-DNA hybridization (dDDH) between the two strains were 81.0% and 40.6%, respectively. The distinctive polyphasic evidences differentiated YIM S01255T from members of the family Pseudonocardiaceae, so strain YIM S01255T is considered to represent a novel species of a novel genus of the family Pseudonocardiaceae, for which the name Qaidamihabitans albus gen. nov., sp. nov. is proposed. The type strain of genus Qaidamihabitans is YIM S01255T (= KCTC 49476T = CGMCC 4.7684T). Moreover, Prauserella shujinwangii is also proposed to being transferred into the genus Qaidamihabitans as Qaidamihabitans shujinwangii comb. nov. (type strain XJ46T = CGMCC 4.7125T = JCM 19736T). [ABSTRACT FROM AUTHOR]

There are various types of distributed generators (DGs) with different grid integration strategies. The transient characteristics of the fault currents provided by the DGs are different to those of conventional synchronous generators. In this paper, a distribution network with multi-type DGs is investigated, including consideration of DG low-voltage ride through (LVRT). The fault current characteristics of two typical DGs, i.e. an inverter-interfaced distributed generator (IIDG) and a doubly-fed induction generator (DFIG), are analyzed, considering the specific operation modes. Based on analysis of the fault characteristics, an equivalent model of the multi-type DGs under symmetrical/asymmetrical fault conditions is established. A fast-iterative fault calculation method for enhancing the calculation efficiency while avoiding local convergence is then proposed using an improved particle swarm optimization (PSO) algorithm. A simulation system of the distribution network with multi-type DGs is established in PSCAD/EMTDC. The simulation results validate the high accuracy and calculation efficiency of the proposed calculation method of the fault components. This can assist in the settings of the protection threshold. [ABSTRACT FROM AUTHOR]

The estimation of soil abrasivity and cutting tool wear during soft ground tunneling is complicated and arduous work due to the lack of a generally accepted testing system. To date, geotechnical baseline reports (GBRs) and geotechnical data reports (GDRs) still cannot provide reliable soil abrasion indices for tool life prediction. This is considered a deficiency in the geotechnical investigation of shield-driven tunnel projects. In this study, the Multifunctional Shield Test System (MSTS) developed by the Key Laboratory of Safety for Geotechnical and Structural Engineering of Hubei Province at Wuhan University is presented. The MSTS was motivated by the need for a test platform with the ability to simulate undisturbed soil conditions and actual tool working environments to explore the mechanism of cutting tool wear, bentonite slurry penetration, and filter cake formation in various geomaterials with grain sizes including clay, silt, sand, and gravel (< 15 mm). Experimental studies on the effect of alloy hardness on cutting tool wear are conducted. The soil samples used in the tests are dense fine silty sand from the Sutong GIL Yangtze River Crossing Cable Tunnel. When the wear extent is plotted against the alloy hardness, an inverted S-shaped band bounded by the highest and lowest alloy hardnesses is formed. The sensitive hardness interval is HRC = [47, 52]. If the alloy hardness is higher than 52 HRC, the wear extent is relatively small. Since alloy hardness is negatively correlated with bending strength, using a cutting tool material with a hardness slightly higher than the upper limit of the sensitive hardness interval is optimal. Thus, an alloy with a hardness interval of HRC = [52, 63] is recommended for the dense fine silty sand ground at the Sutong GIL Yangtze River Crossing Cable Tunnel. [ABSTRACT FROM AUTHOR]

Zinc ion (Zn2+) is a necessary transition metal ion in the human body and plays a vital role in biological systems. Therefore, it is meaningful for rapid, sensitive, and specific detection of Zn2+. Herein, a "switch-on" fluorescence sensing platform for the detection of Zn2+ was successfully established. In this work, we report an optical nanoprobe with amino functional groups based on porphyrin metal-organic frameworks (PCN-NH2) through a simple treatment method. The modification of the salicylaldehyde (SA) through the C=N acts as a quencher of PCN-NH2 and the ligand of Zn2+ can effectively inhibit the fluorescence emission of PCN-NH2. The complex of porphyrin-based metal-organic framework and salicylaldehyde (PCN/SA) acts as the fluorescence sensing probe. The presence of Zn2+ results in the new emission peak at 448 nm due to the formation of a complex between Zn2+ and SA. The corresponding fluorescence signal changes were used to accurately detect the concentration of Zn2+. The fluorescence sensing platform shows advantages, including rapid response, high sensitivity, and excellent specificity with a linear detection range of Zn2+ between 0.1 and 250 μM, and a low detection limit (LOD) of 0.07 μM. And the feasibility of the method was verified for the quantification of Zn2+ in cell lysate, environmental water, and plasma. [ABSTRACT FROM AUTHOR]

However, the value of crack closure stress ( I i SB cc sb ) and crack initiation stress ( I i SB ci sb ) will be clearly changed by small fluctuations of Poisson's ratio. If the stress level is higher than the crack damage stress ( I i SB cd sb ) but lower than peak strength ( I i SB f sb ), cracks will propagate continuously and coalescence to reach macroscopic failure. 6 Curves of lateral strain difference for a siliceous siltstone and b limestone Moving Point Regression Method (MPR) Eberhardt et al. ([4]) proposed a new method to obtain the crack closure stress ( I i SB cc sb ) and the crack initiation stress ( I i SB ci sb ). If the stress level is higher than crack initiation stress ( I i SB ci sb ) but lower than crack damage stress ( I i SB cd sb ), cracks randomly initiated but they will cease at a certain length without coalescence. [Extracted from the article]

LiVPO4F has attracted increasing research interest in the field of Li-ion batteries due to its high working voltage platform and high theoretical energy density. However, the construction of stable LiVPO4F cathode material with excellent electrochemical properties is still a major challenge. Herein, we successfully synthesized spherically shaped LiVPO4F/C via a spray drying–roasting method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) results indicate that the well crystallized LiVPO4F/C with triclinic structure shows spherical morphology with an average diameter of 1–3 μm. The spherically shaped LiVPO4F/C delivers a discharge capacity of 137.9 mAh·g−1 at 0.1C rate in the range of 3.0–4.5 V and remains 91.4% capacity retention of its initial discharge capacity after 50 cycles. These results reveal that spray drying–roasting method is a promising approach to synthesize spherically shaped LiVPO4F/C cathode material with stable crystal structure and excellent performance. [ABSTRACT FROM AUTHOR]

Numerous rockbursts controlled by small-scale structural planes have occurred frequently during tunnel boring machine (TBM) excavation in a headrace tunnel. To understand the evolutionary process of structure-type rockbursts, a real-time microseismic (MS) monitoring system was deployed during the advancement of TBM. By combination with the true reflection tomography technique, a new method is proposed to estimate the P-wave velocity for in situ hypocentral locations. A typical structure-type rockburst is investigated to study the relationship between the rockburst characteristics and microseismicity. By further analyzing the temporal–spatial distribution of microseismicity and the quantitative interpretation of the MS source parameters, the potential failure zone and the precursor features are recognized during the development of this structure-type rockburst. Based on the MS monitoring results, some proactive treatment measures are put forward for the mitigation of rockburst hazards. The results of the current research can contribute to the understanding of structure-type rockbursts and provide valuable references for rockburst forewarning and construction management in similar tunneling projects. [ABSTRACT FROM AUTHOR]

Evidence suggests that fasting exerts extensive antitumor effects in various cancers, including colorectal cancer (CRC). However, the mechanism behind this response is unclear. We investigate the effect of fasting on glucose metabolism and malignancy in CRC. We find that fasting upregulates the expression of a cholesterogenic gene, Farnesyl-Diphosphate Farnesyltransferase 1 (FDFT1), during the inhibition of CRC cell aerobic glycolysis and proliferation. In addition, the downregulation of FDFT1 is correlated with malignant progression and poor prognosis in CRC. Moreover, FDFT1 acts as a critical tumor suppressor in CRC. Mechanistically, FDFT1 performs its tumor-inhibitory function by negatively regulating AKT/mTOR/HIF1α signaling. Furthermore, mTOR inhibitor can synergize with fasting in inhibiting the proliferation of CRC. These results indicate that FDFT1 is a key downstream target of the fasting response and may be involved in CRC cell glucose metabolism. Our results suggest therapeutic implications in CRC and potential crosstalk between a cholesterogenic gene and glycolysis. The molecular mechanisms underpinning how fasting inhibits tumourigenesis are not completely elucidated. Here, the authors show that fasting upregulates the cholesterogenic gene FDFT1 which leads to decreased AKT/mTOR/HIF1a signalling and glycolysis reduction in colorectal cancer. [ABSTRACT FROM AUTHOR]

Amplicon sequencing of functional genes is a powerful technique to explore the diversity and abundance of microbes involved in biogeochemical processes. One such key process, denitrification, is of particular importance because it can transform nitrate (NO3-) to N2 gas that is released to the atmosphere. In nitrogen limited alpine wetlands, assessing bacterial denitrification under the stress of wetland desertification is fundamental to understand nutrients, especially nitrogen cycling in alpine wetlands, and thus imperative for the maintenance of healthy alpine wetland ecosystems. We applied amplicon sequencing of the nirS gene to analyze the response of denitrifying bacterial community to alpine wetland desertification in Zoige, China. Raw reads were processed for quality, translated with frameshift correction, and a total of 95,316 nirS gene sequences were used for rarefaction analysis, and 1011 OTUs were detected and used in downstream analysis. Compared to the pristine swamp soil, edaphic parameters including water content, organic carbon, total nitrogen, total phosphorous, available nitrogen, available phosphorous and potential denitrification rate were significantly decreased in the moderately degraded meadow soil and in severely degraded sandy soil. Diversity of the soil nirS-type denitrifying bacteria communities increased along the Zoige wetland desertification, and Proteobacteria and Chloroflexi were the dominant denitrifying bacterial species. Genus Cupriavidus (formerly Wautersia), Azoarcus, Azospira, Thiothrix, and Rhizobiales were significantly (P <0.05) depleted along the wetland desertification succession. Soil available phosphorous was the key determinant of the composition of the nirS gene containing denitrifying bacterial communities. The proportion of depleted taxa increased along the desertification of the Zoige wetland, suggesting that wetland desertification created specific physicochemical conditions that decreased the microhabitats for bacterial denitrifiers and the denitrification related genetic diversity. [ABSTRACT FROM AUTHOR]

Rock strength is one of the most important parameters in geotechnical engineering. During excavation using a tunnel boring machine (TBM), a rapid and effective method to estimate rock strength is needed. The TBM muck produced during excavation contains blocky fragments which are suitable for a point load test (PLT). To use the PLT on blocky fragments to estimate rock strength, it is necessary to find the relation between the point load strength (PLS) of blocky fragments and uniaxial compressive strength (UCS) of surrounding rocks. In the present study, PLT was performed on both blocky fragments and core samples of limestone for the Yinsong Water Conveyance Project, China. The UCS of limestone was acquired. The PLS of blocky fragments and core samples was compared. The results show that the blocky fragments' PLS is lower than that of core samples; the declining ratio depends on the fractured degree of sampling sites; blocky fragments with width and thickness in a certain range are suitable for estimating rock strength; and when the size of the blocky fragment exceeds a certain range, it means the blocky fragment was not generated from the tunnel face. The limestone core samples simultaneously drilled from side wall have an average conversion factor from PLS to UCS of 24.61. The mean conversion factor from PLS of blocky fragments to UCS of limestone in the present study is 40.38. [ABSTRACT FROM AUTHOR]

To understand the effects of Lactobacillus rhamnosus GG (ATCC 53103) on intestinal barrier function in pre-weaning piglets under normal conditions, twenty-four newborn littermate piglets were randomly divided into two groups. Piglets in the control group were orally administered with 2 mL 0.1 g/mL sterilized skim milk while the treatment group was administered the same volume of sterilized skim milk with the addition of viable L. rhamnosus at the 1st, 3rd, and 5th days after birth. The feeding trial was conducted for 25 d. Results showed that piglets in the L. rhamnosus group exhibited increased weaning weight and average daily weight gain, whereas diarrhea incidence was decreased. The bacterial abundance and composition of cecal contents, especially Firmicutes, Bacteroidetes, and Fusobacteria, were altered by probiotic treatment. In addition, L. rhamnosus increased the jejunal permeability and promoted the immunologic barrier through regulating antimicrobial peptides, cytokines, and chemokines via Toll-like receptors. Our findings indicate that oral administration of L. rhamnosus GG to newborn piglets is beneficial for intestinal health of pre-weaning piglets by improving the biological, physical, and immunologic barriers of intestinal mucosa. [ABSTRACT FROM AUTHOR]

A high precision FE model is the key basis for cause analysis and overcoming of inner polygon defect of hot rolled seamless steel tubes. In this paper, the viscoelastic-plastic FEM is adopted in order to develop a high precision FE model for predicting the defect of inner polygon. Mechanical properties of tube material under rolling environment is obtained through five sets of high temperature compression tests, thus the viscoelastic-plastic constitutive equation of tube material is regressed and agrees with the tests results. Heat transfer boundary conditions, roll constant speed and contact friction boundary conditions are applied simultaneously on the FE model and thermo-mechanical coupled explicit algorithm is adopted for solution. The precision of the FE model is verified through industry experiments. Results shows the simulated inner wall shape is in good accordance with the experiment results, and the friction force, stress, strain and temperature distribution in the deformation zone are also discussed. It can be concluded that the viscoelastic-plastic FE model is of high precision and can be applied for better analysis of the hot rolling results. [ABSTRACT FROM AUTHOR]

The theoretical specific energy of lithium-air battery is as high as 3436 Wh·kg−1, and the possible achieved value may reach 600-700 Wh·kg−1, which enables this energy storage system as an important propulsion power sources for electric vehicles with the driving range of 500-800 km. Currently, Li-air batteries are facing main challenges at stability, efficiency, applicability and safety. In particular, from a practical view of point, the Li-air batteries should be operated directly in ambient air. Solid-state battery system is the best avenue to eventually solve these main issues. At the heart of the solid state, Li-air technology is the solid-state Li+-conducting ceramic material. Developing solid-state lithium-air batteries (SSLAB) can solve the problem of applicability fundamentally and circumvent the safety issues completely, and it is also an important avenue to improve the stability of the battery system. In this paper, we provide a systematical review of the progress in the cell construction, the regulation of the electrode/electrolyte interface, the cell assembly, the electrochemical performance and the mechanism for the SSLAB. In every section, the contributions of the recent research progress in the main challenges and the remained questions will be commented. Based on these reviews, we attempt to propose some alternative approaches for the next stage and suggest a development prospective for the SSLAB. [ABSTRACT FROM AUTHOR]

A novel Gram-negative rod, endophytic bacterium, designated strain TMCC 8258, was isolated from the root of Camellia sinensis collected from Puer, south-west China. Comparative 16S rRNA gene sequence analysis showed that the strain belongs to the family Sphingobacteriaceae and a neighbour-joining phylogenetic tree suggested that strain TMCC 8258 formed a cluster with the type strain of Olivibacter ginsengisoli (showed the highest 16S rRNA gene sequence similarity of 95.8%). Chemotaxonomic data [major fatty acid iso-C, summed feature 3 (C ω7 c and/or C ω6 c), iso-C 3-OH and major respiratory quinone MK-7] confirmed the affiliation of strain TMCC 8258 to the genus Olivibacter. The G + C content was 39.1 mol %. The results of the phylogenetic analysis, together with the physiological, morphological and biochemical tests, suggested that strain TMCC 8258 should be classified as representing a novel species of the genus Olivibacter, for which the name Olivibacter flavus is proposed. The type strain is TMCC 8258 (=CGMCC 1.16141 = KCTC 42683). [ABSTRACT FROM AUTHOR]

A novel Gram-positive, aerobe, moderately halophilic bacterium was isolated from saline soil of Aiding lake in Xinjiang, north-west of China, designated strain YIM 98001. Cells were rod-shaped, motile and grew at 5-20% (w/v) NaCl (optimum 10%), pH 6-10 (optimum pH 7.0) and 4-45 °C (optimum 37 °C). The major cellular fatty acids were anteiso C, anteiso C, iso C. The predominant respiratory quinone was MK-7. Diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid were the major polar lipids. Meso-diaminopimelic acid was the diagnostic diamino acid of the cell-wall peptidoglycan. The G+C content was 36.46 mol%. 16S rRNA gene sequence analysis showed that the strain belongs to the family Bacillaceae, with the highest sequence similarity to the type strain Gracilibacillus thailandensis TP2-8 (96.84%), followed by Gracilibacillus saliphilus YIM 91119 (96.78%) and Gracilibacillus ureilyticus MF38 (96.57%), thus confirming the affiliation of strain YIM 98001 to the genus Gracilibacillus. The polyphasic approach indicates that strain YIM 98001 represents a novel species of the genus Gracilibacillus, for which the name Gracilibacillus aidingensis is proposed. The type strain is YIM 98001 (=KCTC 42683 = DSMZ 104330). [ABSTRACT FROM AUTHOR]

Dear Editor, We read with interest the recent systematic review and meta-analysis by Dr Lian et al., "Relationship of Circulating Copper Level with Gestational Diabetes Mellitus: a Meta-Analysis and Systemic Review", which appeared in the January 2021 issue of the I Biol Trace Elem Res i [[1]]. References 1 Lian S, Zhang T, Yu Y, Zhang B. Relationship of circulating copper level with gestational diabetes mellitus: a meta-analysis and systemic review. [Extracted from the article]

Wideband sparse spectral estimation is generally formulated as a multi-dictionary/multi-measurement (MD/MM) problem which can be solved by using group sparsity techniques. In this paper, the MD/MM problem is reformulated as a single sparse indicative vector (SIV) recovery problem at the cost of introducing an additional system error. Thus, the number of unknowns is reduced greatly. We show that the system error can be neglected under certain conditions. We then present a new subband information fusion (SIF) method to estimate the SIV by jointly utilizing all the frequency bins. With orthogonal matching pursuit (OMP) leveraging the binary property of SIV's components, we develop a SIF-OMP algorithm to reconstruct the SIV. The numerical simulations demonstrate the performance of the proposed method. [ABSTRACT FROM AUTHOR]

The safety and effectiveness of a novel Chinese one-shot dilation technique based on stimulated diuresis for percutaneous nephrolithotomy (PCNL) were investigated. After the feasibility of the Chinese one-shot dilation based on stimulated diuresis was verified by an animal study, this technique was applied in the clinical practice. A total of 67 patients in our department underwent the modified PCNL from July 2014 to June 2015. After the renal infundibulum was distended by stimulated diuresis, the kidney was punctured under the ultrasonographic guidance via the fornix of the target calyx. The working channel was dilated using a special designed pencil-shaped fascial dilator. The successful access rate, nephrostomy tract creation time, pre- and postoperative hemoglobin values and serum creatinine concentrations, stone-free rate and complications were recorded and analyzed. The renal infundibulum was successfully distended in all of the patients by the diuresis treatment. Under the ultrasonographic guidance, the successful access rate was 100% and the mean tract creation time was 2.0 min (range: 1.5-5.0 min). The stone-free rate right after surgery was 91.0%. Although the postoperative hemoglobin was significantly reduced ( P<0.01), transfusion was not clinically necessary. There was no significant difference in serum creatinine concentrations before and after operation ( P>0.05). No severe complication occurred during or after the PCNL. It was suggested that this Chinese one-shot dilation technique based on stimulated diuresis is an efficient and safe innovation for PCNL, and is even helpful for those patients with non-dilated pelvicaliceal systems. [ABSTRACT FROM AUTHOR]

The article discusses a study which analyzed the strength anisotropy of quartz mica schist along the exploration adit of the DanBa hydroelectric power in Sichuan Province, China using the point load test. It provides information on the quartz mica schist used in the study, including its mineral composition and texture. It also mentions two types of failure modes observed during the point load test.

Protein phosphatase, Mg/Mn dependent, 1D (PPM1D) is emerging as an oncogene by virtue of its negative control on several tumor suppressor pathways. However, the clinical significance of PPM1D in pancreatic cancer (PC) has not been defined. In this study, we determined PPM1D expression in human PC tissues and cell lines and their irrespective noncancerous controls. We subsequently investigated the functional role of PPM1D in the migration, invasion, and apoptosis of MIA PaCa-2 and PANC-1 PC cells in vitro and explored the signaling pathways involved. Furthermore, we examined the role of PPM1D in PC tumorigenesis in vivo. Our results showed that PPM1D is overexpressed in human PC tissues and cell lines and significantly correlated with tumor growth and metastasis. PPM1D promotes PC cell migration and invasion via potentiation of the Wnt/β-catenin pathway through downregulation of apoptosis-stimulating of p53 protein 2 (ASPP2). In contrast to PPM1D, our results showed that ASPP2 is downregulated in PC tissues. Additionally, PPM1D suppresses PC cell apoptosis via inhibition of the p38 MAPK/p53 pathway through both dephosphorylation of p38 MAPK and downregulation of ASPP2. Furthermore, PPM1D promotes PC tumor growth in vivo. Our results demonstrated that PPM1D is an oncogene in PC. [ABSTRACT FROM AUTHOR]

Purpose: To identify key genes related to the effect of estrogen on ovarian cancer.Methods: Microarray data (GSE22600) were downloaded from Gene Expression Omnibus. Eight estrogen and seven placebo treatment samples were obtained using a 2 × 2 factorial designs, which contained 2 cell lines (PEO4 and 2008) and 2 treatments (estrogen and placebo). Differentially expressed genes were identified by Bayesian methods, and the genes with P < 0.05 and |log2FC (fold change)| ≥0.5 were chosen as cut-off criterion. Differentially co-expressed genes (DCGs) and differentially regulated genes (DRGs) were, respectively, identified by DCe function and DRsort function in DCGL package. Topological structure analysis was performed on the important transcriptional factors (TFs) and genes in transcriptional regulatory network using tYNA. Functional enrichment analysis was, respectively, performed for DEGs and the important genes using Gene Ontology and KEGG databases.Results: In total, 465 DEGs were identified. Functional enrichment analysis of DEGs indicated that ACVR2B, LTBP1, BMP7 and MYC involved in TGF-beta signaling pathway. The 2285 DCG pairs and 357 DRGs were identified. Topological structure analysis showed that 52 important TFs and 65 important genes were identified. Functional enrichment analysis of the important genes showed that TP53 and MLH1 participated in DNA damage response and the genes (ACVR2B, LTBP1, BMP7 and MYC) involved in TGF-beta signaling pathway.Conclusion: TP53, MLH1, ACVR2B, LTBP1 and BMP7 might participate in the pathogenesis of ovarian cancer. [ABSTRACT FROM AUTHOR]

The new transcription factor Sge1 has garnered much attention in filamentous fungi recently, which highlights its role in pathogenicity, conidiation, and the production of secondary metabolites. In this study, we demonstrated that FgSge1 is localized in the nucleus in Fusarium graminearum using fluorescent protein GFP. Mutants containing a T67A mutation within the potential protein kinase A (Pka) phosphorylation site of FgSge1 exhibited a significant decrease in conidiation and dramatically impaired virulence on both wheat head and non-host tomato. These results indicated that the Pka phosphorylation site is required for the function of FgSge1 in F. graminearum. In addition, we characterized the FgSGE1 deletion mutants and found that the mutants showed increased sensitivity to osmotic stress mediated by NaCl or KCl, and to cell wall damaging agent congo red (CR). Real-time PCR assays revealed increased transcription levels of FgSGE1 with the treatment of NaCl or CR, and decreased FgSGE1 transcription in the FgOS- 2 deletion mutant ΔFgOs-2. Based on the transcription levels, it can be concluded that FgSge1 is a downstream target of the mitogen-activated protein kinase FgOs-2. [ABSTRACT FROM AUTHOR]