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The construction of heterostructures was considered to be an excellent strategy to achieve efficient charge separation and enhanced photocatalytic activity. Herein, the two-dimensional spherical In2S3 anchored onto the porous carbon nitride surface by a facile self-assembly process benefiting from the special structural design, and the composite material is endowed with a large specific surface area and more active sites. And the novel S-type heterojunction structure can not only greatly improve the problem of carrier recombination but also maintain a high redox potential, thus further enhancing the performance of photocatalysts. Results showed that the best total photocatalytic degradation and remarkable photocatalytic activity effect of CBZ reaches 98.3% after 120 min could be obtained at the g-C3N4/In2S3 under near room temperature and pressure and without using any sacrificial agents or promoters. The composite catalyst still exhibited excellent stability after five cycles. This work will provide the deep understanding of constructing interface engineering modulation, providing enlightenment for the design of high-performance photocatalysts. [ABSTRACT FROM AUTHOR]

Additive friction stir deposition (AFSD) is a friction stir-based deposition additive manufacturing technology that has garnered significant research attention. This article reviews the research progress of AFSD, covering its process, parameters, characteristics, and applications. AFSD is a thermoplastic machining process that is driven by key process parameters such as tool rotating speed, feed rate, and layer height. The finite element simulation method utilized by AFSD is comparable to that of friction stir welding (FSW). The core process characteristics comprise solid-state deposition and the formation of fine, equiaxed microstructures. Components produced by AFSD exhibit mechanical properties that vary gradually along the build direction. The potential applications of AFSD in additive manufacturing, coating, composite manufacturing, and repair are then presented. Finally, the paper concludes by proposing future directions, including the control of quality, the expansion of applications, and the achievement of automation and intelligence. [ABSTRACT FROM AUTHOR]

Lysosomes are degradation and signalling centres crucial for homeostasis, development and ageing1. To meet diverse cellular demands, lysosomes remodel their morphology and function through constant fusion and fission2,3. Little is known about the molecular basis of fission. Here we identify HPO-27, a conserved HEAT repeat protein, as a lysosome scission factor in Caenorhabditis elegans. Loss of HPO-27 impairs lysosome fission and leads to an excessive tubular network that ultimately collapses. HPO-27 and its human homologue MROH1 are recruited to lysosomes by RAB-7 and enriched at scission sites. Super-resolution imaging, negative-staining electron microscopy and in vitro reconstitution assays reveal that HPO-27 and MROH1 self-assemble to mediate the constriction and scission of lysosomal tubules in worms and mammalian cells, respectively, and assemble to sever supported membrane tubes in vitro. Loss of HPO-27 affects lysosomal morphology, integrity and degradation activity, which impairs animal development and longevity. Thus, HPO-27 and MROH1 act as self-assembling scission factors to maintain lysosomal homeostasis and function.The conserved HEAT repeat protein HPO-27 is identified as a lysosome scission factor in Caenorhabditis elegans, and the human homologue MROH1 also serves the same function to maintain lysosomal homeostasis. [ABSTRACT FROM AUTHOR]

In this work, the addition of 5%SiO2 to 7.5%WO3-ZrO2 catalyst increased the content of tetragonal ZrO2 and BET, which could promote the formation of W–O–Zr(Si) bonds between WOx species and 5%SiO2-ZrO2 material, thus reducing the degree of aggregation of WOx species. The oligomerized WOx species on the 7.5%WO3-5%SiO2-ZrO2 catalyst could not only remain stable, but also provided stable Lewis acid for the activation of hydrogen peroxide and maleic anhydride for epoxidation. In addition, the Si–O–Zr bond on SiO2-modified 7.5%WO3-ZrO2 catalyst could provide an additional Brønsted acid site for activating the hydrolysis of epoxysuccinic acid to DL-tartaric acid. Therefore, the DL-tartaric acid yield of SiO2-modified 7.5%WO3-ZrO2 catalyst was higher than that of 7.5%WO3-ZrO2 catalyst, and also higher than that of Na2WO4 catalyst. The SiO2-modified 7.5%WO3-ZrO2 catalyst rich in stable Lewis and Brønsted acid not only had good cyclic stability but also had good catalytic activity under mild condition. [ABSTRACT FROM AUTHOR]

The photocatalytic application of graphic carbon nitrate (g-C3N4) was limited due to the defects of few exposed active sites and serious recombination rate of photogenerated carrier. In this paper, boric acid-assisted thermal etching strategy is designed from melamine as precursor to realize nanosheets of B-doped porous g-C3N4 as high-performance photocatalyst and first applied to the mineralization and degradation of 2, 4-dichlorophenoxyacetic acid (2, 4-D) wastewater. Porous morphologies with increased specific surface area accelerate photocatalytic activity. It is noted that boron atoms were simultaneously doped into g-C3N4 matrix, which broke the symmetry of pristine g-C3N4, resulting in more effective separation of electron/hole pairs. Under simulated sunlight irradiation, the removal efficiency of 2, 4-D over this catalyst increased up to 94.9%. The degradation rate was maintained at 78.4% after four reuse cycles, indicating that the catalyst has decent stability. Based on gas chromatography–mass spectrometry analysis, degradation pathways were designed. The proposed synthesis strategy provides meaningful guidance for the industrial-scale production of high-performance g-C3N4 and its practical application in the environmental field. [ABSTRACT FROM AUTHOR]

Understanding the damage evolution behavior of coal under stress wave can provide a theoretical basis for preventing rock burst. In this work, the impact experiments of coal samples were carried out by split Hopkinson pressure bar (SHPB); the stress wave propagation characteristics were recorded by dynamic strain acquisition instrument; the evolution behaviors of coal samples’ surface displacement were analyzed by digital image correlation (DIC); the correlation between stress wave and displacement were discussed based on the multi-fractal theory. The results proved the stress wave propagates in the non-linear attenuation mode of multiple incidences, reflection, and transmission. Among them, the attenuation velocity of the incident wave is the largest, followed by the reflected wave, and the transmitted wave is the smallest. The incident and reflected stress waves are mainly dominated by high amplitude signals, while the transmitted stress waves are mainly dominated by low amplitude signals. The horizontal displacement on the coal sample surface is changed in the form of variable velocity, acceleration, and direction during the process of the stress wave propagation. The impact velocity is favorably linked with the amplitudes and attenuation velocities of incident, reflected, and transmitted waves as well as the surface displacement, displacement velocity, and acceleration of coal samples. The multi-fractal characteristic parameters of stress wave and displacement show that the proportional relationship and difference between the large- and small-scale displacement are influenced by those between the high- and low-intensity signal of the stress wave, and the transmission wave can exert greater influence. [ABSTRACT FROM AUTHOR]

Fully understanding the dynamic tensile behavior of coal is of great significance to the prevention and control of rock burst in underground coal resource mining. In this study, the split Hopkinson pressure bar and the digital image correlation were used to conduct dynamic Brazilian splitting experiments on coal to explore its dynamic tensile behavior. The evolution behaviors of vertical displacement, displacement velocity, and displacement acceleration fields in the process of dynamic tensile fracture of coal were investigated; the damage process of coal was characterized quantitatively; and the relationship between damage and energy was analyzed. The results showed that absolute values of displacement, displacement velocity, and displacement acceleration gradually expand along the central axis to the upper and lower ends of coal. The displacement changed in the form of variable velocity and acceleration, proving that the damage of coal evolves in the form of variable velocity and acceleration. The damage acceleration reached the maximum soonest, followed by the damage velocity, and the degree of damage was last. Before the peak stress, the absorbed energy can only cause slight damage to the coal but it led to high damage velocity and acceleration. After the peak stress, a little added absorbed energy can lead to more severe damage to the coal, with high damage velocity and low damage acceleration. Although the strength, energy, displacement, displacement velocity, and displacement acceleration of coal at different impact velocities were different, their forms of evolution and damage modes were similar. [ABSTRACT FROM AUTHOR]

Previous underground test methods for coal seam permeability are usually based on radial flow theory, which ignores the impact of coal deformation and permeability dynamic evolution. Thus, these methods have some limitations in theoretical reliability, result stability and method applicability. Therefore, this paper derives a gas–solid coupling model considering pore sorption strain. Based on this model and a hybrid optimization algorithm, which combines particle swarm optimization (PSO) and Levenberg–Marquardt (LM) algorithm, a novel method for determining coal seam permeability, namely the GP method, is proposed. The feasibility and reliability of this method were verified by numerical experiments and field tests, respectively. The findings indicate that the proposed PSO + LM algorithm was superior to PSO algorithm and LM algorithm in terms of convergence and computational efficiency. In field application, the test value of the GP method was closer to the true value of coal seam permeability, and its theoretical model can better reflect the change of borehole gas flow, whether compared with the traditional radial flow method from the global perspective or compared with other classical permeability models from the local perspective. Therefore, the GP method has the potential to become an effective test method for coal seam permeability. This study has certain reference significance for the acquisition of mechanical parameters and gas parameters. [ABSTRACT FROM AUTHOR]

During deep underground coal mining, coal is typically fractured under high in situ and mining-related stresses, thus increasing the risk for dynamic disasters. However, knowledge regarding the mechanical and permeability characteristics of initially fractured coal remains limited. In this study, laboratory investigations were performed to examine the anisotropic strength, failure modes, and permeability of initially fractured coal subjected to true triaxial stresses. The results indicated that initially fractured coal can be classified into semi-brittle Class I failure modes. A new failure plane can be formed for initially fractured coal samples after failure, which was different from the intact coal samples' failure mode. The peak strength of initially fractured coal was typically observed when the maximum principal stress was subjected perpendicular to the bedding planes, while minimum values were obtained when the maximum principal stress was subjected parallel to the butt cleats. The brittleness of initially fractured coal was increased with intermediate stress. The permeability evolution curves for initially fractured coal exhibited an L-shaped trend. The pulverized coal grains in initially fractured coal can block the gas flow channel contributing to the continuous decrease in permeability. Intermediate stress exerts a more significant effect on permeability reduction when deviatoric stresses are applied parallel to cleats in coal. [ABSTRACT FROM AUTHOR]

The utilization of deep mineral resources is severely restricted by dynamic disasters, such as rock burst, caused by mining disturbances. This study is aimed at investigating the instability failure mechanism and precursory response of coal specimen, with the aid of acoustic emission (AE) monitoring, under triaxial loading and unloading disturbance. The AE time-varying characteristics were analyzed, the crack propagation mode was explored, and the statistical b value and βt value (damage parameters) of AE events were introduced to evaluate the damage state of the loaded coal under disturbance. The results show that: the dynamic disturbance loads will accelerate the deformation process of coal specimen under high static confining stress, resulting in a positive relation between the AE characteristic parameters (AE counts and energy) and the increasing disturbance amplitude. The proportion of low-frequency and high-amplitude AE signals increases with the disturbance amplitude, indicating the disturbance with large amplitude will promote the formation of large-magnitude cracking events. Those stress-induced cracks, judged from the RA-AF value of AE signals, are mainly tensile mode (i.e., mode-I) under the applied disturbance load, but shear cracks are the critical factor affecting the instability and failure of the loaded coal specimen. Both the b value and βt value can reflect the time-varying evolution process of internal damage for the loaded coal specimen. The sudden decreasing of the b value together with the exponential increasing of the βt value can be regarded as a short-impending precursor indicator for the coal instability and failure. The results of this study will provide some experiment basic and theoretical guidance for dynamic disaster monitoring and early-warning during the deep coal mining. Highlights: The instability failure mechanism and the precursory response of coal specimens under triaxial loading and unloading disturbance were investigated. By analyzing the AE characteristic parameters, the internal damage evolution processes, crack propagation mode and the mechanisms of disturbance were studied. The damage accumulation process and precursor warning information of coal instability failure are extracted by the b and βt values. [ABSTRACT FROM AUTHOR]

Studying the anisotropic seepage characteristics of coal is of great significance to the safe and efficient extraction of coalbed methane (CBM). The effective stress law (σe = σ – αp) is often used to solve the fluid–solid coupling problem of rocks. However, the Biot's coefficient α = 1 is often assumed in the current study, and the remaining researches on the α evolution of coal are mainly focused on the conventional triaxial stress state and the elastic range, which cannot reflect the anisotropic evolution of α of damaged coal under true triaxial stress state in actual formation. In the current study, an experimental study on the effect of induced damage on α and permeability of coal subjected to different true triaxial stress states was carried out, and the anisotropy of coal structure was also considered. The experimental results show that αij and permeability are closely related to the fracture evolution, and both increase with the increase in fracture density and opening. Influenced by the induced damage, αij exhibits a significant anisotropy. α1 achieves larger than α2 and α3, and α3 > α2 occurs in the horizontal direction, and the difference between α3 and α2 increases with the increase in the horizontal stress difference. Under different initial stress states, αij for high horizontal stress is lower than αij in the low due to the restraining effect of horizontal stress on fracture propagation. Under different flow directions, αij increases the most with the increase in axial strain under the gas flow perpendicular to bedding, indicating that the natural fractures distributed along the bedding face are more likely to propagate under the external stress drive compared with the face and butt cleats. At the initial plastic stage, αij exhibits αface cleat > αbutt cleat > αbedding, and the permeability also shows kface cleat > kbutt cleat > kbedding, indicating that the natural fractures distributed along the cleats are more than those near the bedding. In this study, a new coal permeability model considering the damage effect and anisotropy of Biot's coefficient is established, which shows good agreement with the experimental permeability of simulating mining stress disturbance, and considering anisotropic αij in the model is closer to the measured permeability than assuming αij = 1. Highlights: Biot's coefficient αij and permeability of damaged coal increase with fracture density and opening increase, and always show α1 > α3 > α2. Considering anisotropic coal structure, αface cleat > αbutt cleat > αbedding, and αij increases the most under gas flow perpendicular to bedding. New permeability model considering damage and αij is established, considering αij in the model is closer to the permeability than assuming αij = 1. [ABSTRACT FROM AUTHOR]

Cleat and permeability altered by CO2 injection are key issues for enhanced coalbed methane production and CO2 geo-sequestration into unminable coal seams. As the main channel for CO2 flowing through, pre-existing macro- and micro-cleats in coal directly determine permeability. Both permeability and cleats are pressure-dependent. However, few researches have been made to observe directly changes in micro-cleats as a function of injection pressure during CO2 flooding. In this study, using a novel in situ micro-CT core flooding apparatus, we observed the gradual closure of micro-cleats in small anthracite coal at CO2 injection pressures from 1 to 4 MPa. Quantitative micro- aperture size variations were analyzed further. An increasing-then-decreasing trend of the mean aperture size of the micro-cleat with increasing injection pressures was obtained, and the rebound in mean micro-cleat aperture size measured parallel to cleat directions was higher than that perpendicular to bedding plane direction. The permeability decreased drastically first and then slowly with increase in saturation time. Relatively weak coal permeability anisotropy (< 50%) was observed in this test and the permeability measured in the bedding plane direction was not necessarily smaller than that in the cleat directions for a small coal body. [ABSTRACT FROM AUTHOR]

The design and synthesis of novel energetic compounds with integrated properties of high density, high energy, good thermal stability and sensitivities is particularly challenging due to the inherent contradiction between energy and safety for energetic compounds. In this study, a novel structure of 4-amino-7,8-dinitropyrazolo-[5,1-d] [1,2,3,5]-tetrazine 2-oxide (BITE-101) is designed and synthesized in three steps. With the help of the complementary advantages of different explosophoric groups and diverse weak interactions, BITE-101 is superior to the benchmark explosive HMX in all respects, including higher density of 1.957 g·cm−3, highest decomposition temperature of 295 °C (onset) among CHON-based high explosives to date and superior detonation velocity and pressure (D: 9314 m·s−1, P: 39.3 GPa), impact and friction sensitivities (IS: 18 J, FS: 128 N), thereby showing great potential for practical application as replacement for HMX, the most powerful military explosive in current use. The design of high energy density materials (HEDM) with good detonation performance but which are also safe to handle is challenging. Here, the authors synthesize a PTX analogue and incorporate explosophoric groups to obtain an HEDM with improved detonation performance but low impact and friction sensitivity. [ABSTRACT FROM AUTHOR]

Solid acid catalysts are widely used in the production of various high-value added and industrially important chemicals. Although the use of organosilicon compounds to modify the vacancy site has been extensively studied, the covalent tethering — SO3H functionalized organosilicon modified polyoxometalates (POMs) has been rarely reported. In this work, two catalysts (TBA4[SiW11O39(O(SiC3H6SO3H)2)] (compound 2) and TBA4[SiW11O39 (O(SiC8H8SO3H)2)] (compound 3)) were synthesized successfully through covalently grafting different sulfonic acid (-SO3H) groups onto [SiW11O39]8− cluster, respectively. Compound 2 was achieved by surface grafting and in situ oxidation (3-mercaptopropyl)-trimethoxysilane, while compound 3 was achieved by surface grafting of 2-(4-chlorosulfonylphenyl) ethyltrimethoxysilane. Strong Brønsted acid strength of compounds 2 and 3 can be demonstrated by different methods including potentiometric titration, pyridine adsorption studies, and the 31P trimethylphosphine oxides (TMPO) nuclear magnetic resonance (NMR). The systematic investigation of the relationship among POM structures, acid strength, and electron density was carried out based on density functional theory (DFT) calculation and experimental results, which revealed that covalent modification of compounds 2 and 3 decreased the electron density of the O-H bond, and promoted the release of H+. When applied in hydroxyalkylation/alkylation (HAA) reaction of 2-methylfuran (2-MF) with cyclohexanone, compound 2 exhibited better catalytic performance with conversion of ∼93%, monocyclic fuel precursors (1a) yield of 79.9% and selectivity of 85.7% than compound 3, which can be attributed to strong Brønsted acid and the intramolecular hydrogen-bonding interactions between the neighboring -SO3H moieties in compound 2. Finally, compound 2 also showed excellent catalytic activity in the HAA reaction of 2-MF with several different aldehydes and ketones (e.g., furfuraldehyde, 5-methylfurfuraldehyde, acetone, butyraldehyde and 4-methoxybenzaldehyde). This result opens a new pathway for design and fabrication of novel solid acid catalysts. [ABSTRACT FROM AUTHOR]

Investigations of the impact of heavy metals on microbial community structure are crucial for bioremediation of the contaminated sites. To this end, high-throughput 16S rRNA sequencing was performed to assess the variations of bacterial communities in 6 heavy metal-contaminated soils sampled from Liujiaping (LJP) and Shanping (SP) lead–zinc tailings situated in northwestern China. Compared with those of the farmland soil (NT), the heavy metal levels and chemical properties of the tailing soils were significantly different. Consistently, the bacterial community structures have been changed, displaying as the bacterial richness and diversity in the tailing soils were either increased or decreased, i.e., trending as SP > NT > LJP. The relative abundances of certain bacterial phyla mainly including Actinobacteriota, Acidobacteriota, Cyanobacteria, Gemmatimonadota, and Bacteroidota were significantly increased in certain SP and/or LJP soils. Further, the relative abundances of Actinobacteriota and Bacteroidota were positively correlated with Cd, TP, TK, SOM, TN, and pH. The abundance of Cyanobacteria was significantly upregulated by Cu, Zn, and TP. Acidobacteriota was notably positively correlated with Cr, Pb, and NO3−_N. On the contrary, the relative abundance of Chloroflexi was negatively correlated with all the environmental parameters, especially with Cd, NO3−_N, TP, SOM, and TN. Together, our results implied that the heavy metals and chemical properties were both driving forces of the variations of the bacterial community structures in the tailing soils. Overall, we have successfully identified certain bacterial species such as s__unclassified_g__Sulfurifustis, s__unclassified_f__Rhodanobacteraceae, s__unclassified_g__Conexibacter, s__unclassified_g__norank_f__norank_o__Gaiellales, and s__unclassified_g__Blastococcus which were probably heavy metal-tolerant in these specific tailing soils, and this will provide a theoretical support for further bioremediations. [ABSTRACT FROM AUTHOR]

Introduction: Systemic lupus erythematosus (SLE) can affect bone metabolism and homeostasis of serum electrolytes that are associated with abnormal levels of vitamin D. Mycophenolate mofetil (MMF) is a commonly used immunosuppressant with the active metabolite mycophenolic acid (MPA). The area under the plasma concentration–time curve (AUC) of MPA is often monitored during the treatment to assess the exposure levels. This study aims to explore the association between exposure levels of MPA and 25-hydroxyvitamin D [25(OH)D] levels in children with SLE. Methods: Repeated measured data of children with SLE who were treated with MMF and under therapeutic drug monitoring (TDM) were retrospectively collected from the electronic medical records. MPA exposure levels were reflected by the area under the concentration–time curve over 24 h (AUC0–24h). Univariate and multivariate linear regression models were employed to analyze factors associated with 25(OH)D levels. Hierarchical linear models were developed to analyze the intra- and inter-individual effects of AUC0–24h on the variance of 25(OH)D levels. Results: Data from 184 children with SLE (142 female and 42 male) with 518 follow-ups were collected. The median age was 14 years (range 3–18 years) at TDM. Children with normal 25(OH)D levels had significantly higher AUC0–24h than children with low 25(OH)D levels (98.71 vs. 84.05 mg·h/L, P = 0.004). Intra- and inter-individual effects of AUC0–24h on 25(OH)D levels were similar ( γ 10 = 0.034 vs. γ 01 = 0.037) but only the intra-individual effect was significant (P = 0.001) in hierarchical models. Other associated factors include age, sex, season at measurement, glucocorticoid daily dose, and external vitamin D3 supplements. Conclusion: 25(OH)D levels are associated with MPA exposure levels, and may serve as a potential indicator to optimize the exposure level of MPA during treatment. AUC0–24h of 98.71 mg·h/L or AUC0–12h of 49.36 mg·h/L could be the targeted exposure level for children with SLE. [ABSTRACT FROM AUTHOR]

In underground coal mining, coal failure generally occurs due to the relatively weak strength of the coal and the high applied mining-induced stresses. The outer complex geological conditions (i.e., tectonic structure and water intrusion) and internal structural anisotropy of the coal introduce uncertainty in predicting its mechanical properties and failure behavior. In this study, laboratory investigations of the mechanical properties and failure behavior of dry and water-saturated anisotropic coal samples subjected to different true-triaxial loading stresses were conducted. The effects of water weakening, intermediate stress, and structural anisotropy on the mechanical properties and failure behavior of the coal were systematically studied. The results indicate that the presence of water significantly reduced the strength, elastic modulus, and strength anisotropy of the coal. The maximum stress at failure first increased and then decreased with increasing intermediate stress. The residual strength-to-peak strength ratios and failure plane angles of the coal showed a linear increase with increasing intermediate stress. When the coal samples were loaded in the bedding plane direction, the brittleness of the coal was higher than when they were loaded in the other two cleat plane directions. In addition, when the coal samples were loaded in the butt cleat plane direction, the brittleness of the coal decreased with increasing intermediate stress. Two typical failure modes of the dry and water-saturated coal samples were observed: shear and mixed splitting and shear failures. The dominant failure mode of the coal also varied with the loading direction relative to the weakness planes, which could be well recognized and predicted by the acoustic emission (AE) characteristic curves. To further reveal the fracture mechanism, the microcrack patterns of the coal were further identified based on the AE parameters. [ABSTRACT FROM AUTHOR]

Aims: Biological soil crusts (BSCs) are widely considered critical for soil fertility in arid ecosystems. However, how microbial communities regulate the C and N cycles during BSC succession is not well understood. Methods: We utilized GeoChip 5.0 to analyze the functional potential of bacteria and fungi involved in the C and N cycles of BSCs along a 61-year revegetation chronosequence. Results: The normalized average signal intensities of different functional genes involved in C and N metabolism in 61-year-old BSCs were significantly different from those in younger BSCs and most functional gene subcategories and the corresponding dominant functional populations were derived from bacterial rather than fungal communities. Most C degradation genes (dominated by the starch-degrading gene amyA) were derived from Actinobacteria (mainly Streptomyces) in bacteria, but Ascomycota (mainly Aspergillus) was the key population for lignin degradation (dominated by the phenol oxidase gene) during BSC succession. N cycle genes involved in denitrification (such as narG, nirK/S, and nosZ) and N fixation (nifH) were mainly derived from Unclassified Bacteria, whereas genes involved in ammonification (ureC) were mainly derived from Streptomyces. Moreover, redundancy analysis showed that soil biogeochemical properties were closely related to bacterial and fungal functional gene structures during BSC succession. Conclusions: These findings indicate that bacteria play a crucial role in the regulation of C and N cycles during BSC succession in arid ecosystems, while fungi perform supplementary degradation of lignin, and these communities can successfully stimulate an increase in C and N metabolism in soil during the later successional stages of BSCs. [ABSTRACT FROM AUTHOR]

The geological sequestration of CO2, underground coal mining, and coalbed methane production in deep coal reservoirs is executed under high levels of 3-D geo-stress, and it is accompanied by significant variations in both vertical and horizontal stresses. In addition, coal is a highly fractured porous medium characterized by complex natural fracture systems. This exterior and interior anisotropy complicates the replication of in situ conditions in the laboratory. In this study, we divided pre-existing fracture systems of cubic coal into three flow planes: a bedding plane, face cleat plane, and butt cleat plane. Gas flowed through cubic coal samples along each flow plane under differently designed true triaxial stress paths. We then further analyzed anisotropic mechanical and flow property responses of cubic coal after failure by model fitting, CT scan reconstruction, and fractal representation. The experimental results indicate that pre-existing flow planes play significant roles in the strength levels, failure modes, and permeability levels. Low strength levels, typical shear failure patterns, and low initial permeability levels were observed in the butt cleat plane direction. Anisotropic strength data can be effectively fit by applying a linear relationship between octahedral shear stress and mean effective normal stress. After coal failure, the peak permeability observed in the face and butt cleat plane directions also presents a strong linear relationship with the fractal dimension. An anisotropic conceptual failure process model was established for the description of internal fracture development during stress loading. Horizontal stress unloading decreased the strength and formed a more complex fracture system in cubic coal regardless of the different flow planes involved, producing the increments of associated peak permeability. [ABSTRACT FROM AUTHOR]

Assisted hatching (AH) is initially developed to provide an artificial manipulation of the zona pellucida (ZP) to help embryos hatch and improve the capacity of the embryos to implant. However, these effects remain unclear and controversial because of variation in patient characteristics, and it is critical to ascertain the indications for AH and to identify those patients who might benefit from AH. Here, this study aimed to assess the effect of laser-assisted zona thinning hatching technology (LAH) during the frozen-thawed D3 embryos on pregnancy outcomes in patients with previous repeated failures in vitro fertilization-embryo transfer (IVF-ET). To the best of our knowledge, these relationships have not been previously investigated. A retrospective cohort analysis was carried out. Infertility patients with previous repeated failure who underwent assisted reproductive therapy at our in vitro fertilization (IVF) center from May 2014 to May 2016 were enrolled. A total of 415 cleavage FET cycles (225 in the LAH group and 190 in the control group) were analyzed. Clinical outcomes including clinical pregnancy, implantation, live birth, miscarriage, and multiple gestation rates after transfer were compared between the LAH and control groups. The clinical pregnancy (49.3% versus 38.9%) and implantation rates (31.2% versus 24.6%) were significantly higher for the LAH group than the control group (P < 0.05). The live birth (44.8% versus 35.8%), multiple pregnancy (32.4% versus 31.0%), preterm birth (22.8% versus 17.1%), miscarriage (7.2% versus 5.4%), and ectopic rates (1.9% versus 0%) did not differ significantly between the two groups (P > 0.05). This study showed that LAH via zona pellucida (ZP) thinning significantly improves clinical outcomes, particularly clinical pregnancy and implantation rates, associated with FET cycles among patients with previous repeated failure. [ABSTRACT FROM AUTHOR]

Reaumuria soongorica (Pall.) Maxim., a perennial semi-shrub, is widely found in semi-arid areas in northwestern China and can survive severe desiccation of its vegetative organs. In order to study the protective mechanism of desiccation tolerance in R. soongorica, diurnal patterns of net photosynthetic rate (Pn), water use efficiency (WUE) and chlorophyll fluorescence parameters of Photosystem II (PSII), and sugar content in the source leaf and stem were investigated in 6-year-old plants during progressive soil drought imposed by the cessation of watering. The results showed that R. soongorica was characterized by very low leaf water potential, high WUE, photosynthesis and high accumulation of sucrose in the stem and leaf abscission under desiccation. The maximum Pn increased at first and then declined during drought, but intrinsic WUE increased remarkably in the morning with increasing drought stress. The maximal photochemical efficiency of PSII (Fv/Fm) and the quantum efficiency of noncyclic electric transport of PSII(ΦPSII) decreased significantly under water stress and exhibited an obvious phenomenon of photoinhibition at noon. Drought stressed plants maintained a higher capacity of dissipation of the excitation energy (measured as NPQ) with the increasing intensity of stress. Conditions of progressive drought promoted sucrose and starch accumulation in the stems but not in the leaves. However, when leaf water potential was less than −21.3 MPa, the plant leaves died and then abscised. But the stem photosynthesis remained and, afterward the plants entered the dormant state. Upon rewatering, the shoots reactivated and the plants developed new leaves. Therefore, R. soongorica has the ability to reduce water loss through leaf abscission and maintain the vigor of the stem cells to survive desiccation. [ABSTRACT FROM AUTHOR]

The physiological effects of lanthanum (III) ions on the ferritin-regulated antioxidant process were studied in wheat ( Triticum aestivum L.) seedlings under polyethylene glycol (PEG) stress. Treatment with 0.1 m M La3+ resulted in increased levels of chlorophyll, carotenoid, proline, ascorbate, and reduced glutathione. The activities of superoxide dismutase, catalase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, glutathione reductase, and peroxidase were also increased after La3+ treatment. Treatment with La3+ seems to enhance the capacity of the reactive oxygen species scavenging system, affect the Fe2+ and Fe3+ electron-transfer process in ferritin, and restrain the formation of hydroxyl radical (OH), alleviating the oxidative damage induced by PEG stress. [ABSTRACT FROM AUTHOR]

The damage accumulation and strength deterioration within rock masses due to frequent disturbance loads is a significant concern in the fields of rock mass engineering and deep mining. This study employed the ultrasonic detection system and the Hopkinson pressure bar test device to conduct cyclic impact tests on sandstone, aiming to unveil the energy evolution patterns and strain rate effect in sandstone under cyclic impact. The investigation focused on studying the characteristics of the stress wave spectrum during cyclic impact, as well as revealing anomalies in the stress wave spectrum resulting from progressive load cyclic impact. Additionally, a cumulative damage constitutive model of cyclic impact based on ultrasonic wave velocity was established. The results indicate the PWR initially shows two forms: a slight increase followed by a subsequent monotonic decrease, and a monotonic decrease throughout. The ed shows two trends: a slight increase in the initial stage followed by a decrease oscillation, and a slight rise in the early stage followed by a subsequent monotonic or direct decrease. The spectrum of reflected wave and transmission wave exhibit an initial increase followed by a decrease, with the peak frequency typically ranging from 1000 to 3000 Hz. Under constant load cyclic impact, the number of impacts enhances the spectrum peak of the reflected wave while weakening that of the transmission wave. Under progressive load cyclic impact, both the reflected wave and transmission wave show a gradual upward trend for their respective spectrum peaks, but with different rates of increase. [ABSTRACT FROM AUTHOR]