Pore Formation Research Articles

Damage analysis of solid propellants with default defects based on macro-microscopic approach

Solid Rocket Motors (SRMs) rely on solid propellants, directly impacting the energy capacity of launch vehicles. High energy density material (HEDM) propellant exhibits superior energy density owing to the incorporation of a substantial quantity of energetic particles. However, the elevated particle fill ratio makes the formation of pores more prevalent during the manufacturing process of propellants. These pores, representing default defects, are indispensable factors in the investigation of mechanical properties of propellants. This study investigated default defects effects on HEDM propellants, analyzing both microscopic and macroscopic perspectives. Utilizing micro-CT imaging, the microstructure and default defects were characterized. Subsequently, using the cohesive zone model (CZM), microscopic damage evolution was depicted with the representative volume element (RVE) model, allowing in-depth analysis. Furthermore, a damage constitutive model, based on microscopic damage, was developed, with its softening function calibrated using microscopic damage evolution characteristics. Implemented into ABAQUS via user-defined material subroutine (UMAT), this model enabled the prediction of the mechanical response of HEDM propellants with different defects. The results demonstrate that the developed model accurately predicts the mechanical responses of HEDM propellants with different defects, showcasing the potential of macro-microscopic approaches in analyzing propellants with default defects.

Effectiveness of Jute Cellulose Nanocrystal Reinforcement into Biodegradable Packaging “Sonali Bags®”

In an age marked by environmental consciousness, “Sonali Bags®” have emerged as promising substitutes for single-use plastic bags, invented in Bangladesh. It is a jute cellulose-based, totally biodegradable, compostable, recyclable, and environment-friendly biopolymer. However, certain physical limitations have hindered its widespread consumer appeal. To address these challenges, this study pioneers the integration of Jute Cellulose Nano-crystals (JCNC) into Sonali bags, with the objective of enhancing their physical properties. JCNC, obtained through a meticulous 64% concentrate sulfuric acid hydrolysis process, has been reinforced with Sonali Bags at varying loadings (0, 0.1, 0.2, 0.3, and 0.4 wt%). The SEM analysis showed spherical cellulose nanocrystals with high crystallinity and distinctive tear-like features on the nanoparticle's surface. Furthermore, the SEM micrographs depicted that JCNC loading up to 0.2% helped reduce the pore formation of bio-composite. Moreover, the thermal properties increased significantly, and tensile strength increased by approximately 37% MPa after reinforcing JCNC with Sonali Bag. The water-resistant capacity of 0.2% CNC reinforced film was about 30% better than other compositions. The JCNC-reinforced composite materials were found to moderate the degradation rate, contributing to the prolonged sustainability of these biodegradable solutions.

Effect of Scaffold Geometrical Structure on Macrophage Polarization during Bone Regeneration Using Honeycomb Tricalcium Phosphate.

The polarization balance of M1/M2 macrophages with different functions is important in osteogenesis and bone repair processes. In a previous study, we succeeded in developing honeycomb tricalcium phosphate (TCP), which is a cylindrical scaffold with a honeycomb arrangement of straight pores, and we demonstrated that TCP with 300 and 500 μm pore diameters (300TCP and 500TCP) induced bone formation within the pores. However, the details of the influence of macrophage polarization on bone formation using engineered biomaterials, especially with respect to the geometric structure of the artificial biomaterials, are unknown. In this study, we examined whether differences in bone tissue formation due to differences in TCP geometry were due to the polarity of the assembling macrophages. Immunohistochemistry for IBA-1, iNOS, and CD163 single staining was performed. The 300TCP showed a marked infiltration of iNOS-positive cells, which are thought to be M1 macrophages, during the osteogenesis process, while no involvement of CD163-positive cells, which are thought to be M2 macrophages, was observed in the TCP pores. In addition, 500TCP showed a clustering of iNOS-positive cells and CD163-positive cells at 2 weeks, suggesting the involvement of M2 macrophages in the formation of bone tissue in the TCP pores. In conclusion, we demonstrated for the first time that the geometrical structure of the artificial biomaterial, i.e., the pore size of honeycomb TCP, affects the polarization of M1/2 macrophages and bone tissue formation in TCP pores.

Eddy Current Sensor Probe Design for Subsurface Defect Detection in Additive Manufacturing.

Pore and crack formation in parts produced by additive manufacturing (AM) processes, such as laser powder bed fusion, is one of the issues associated with AM technology. Surface and subsurface cracks and pores are induced during the printing process, undermining the printed part durability. In-situ detection of defects will enable the real-time or intermittent control of the process, resulting in higher product quality. In this paper, a new eddy current-based probe design is proposed to detect these defects in parts with various defects that mimic pores and cracks in additively manufactured parts. Electromagnetic finite element analyses were carried out to optimize the probe geometry, followed by fabricating a prototype. Artificial defects were seeded in stainless steel plates to assess the feasibility of detecting various flaws with different widths and lengths. The smallest defect detected had a 0.17 mm radius for blind holes and a 0.43 mm notch with a 5 mm length. All the defects were 0.5 mm from the surface, and the probe was placed on the back surface of the defects. The surface roughness of the tested samples was less than 2 µm. The results show promise for detecting defects, indicating a potential application in AM.

Superhydrophobic cement with hierarchically tunable pore structure by additive manufacturing towards super sound absorption

Noise pollution as a form of environmental problem can have significant negative impacts on human health and the economy. To address this issue, a variety of noise-reduction construction materials have been developed. However, most present noise reduction materials suffer from a narrow absorbing band due to the simple pore structure which restricts their ability to absorb sound energy across a wide frequency range. Here, we demonstrate a hydrogel templating method and create hierarchically structured cement-based materials with tunable pore sizes by means of additive manufacturing. The introduction of this hierarchically tunable structure with micro-nano pores generated by cement hydration contributes to the formation of multi-scale pores (micro-, meso- and macropores), which achieves a sound absorption coefficient of 0.89 at 1000 Hz and ensures broadband acoustic absorption performance (noise reduction coefficient of 0.54, around 50 % improvement compared to traditional construction sound absorption materials). Meantime, this lightweight material has good compressive strength (1.31 MPa) and superhydrophobicity (water contact angle of 152.5°), together with thermal conductivity (0.088 W m−1 K−1) and excellent fire resistance. This study provides a new approach for designing cement-based materials with super sound absorption.

Impact of diatomit on the transport behavior of unmodified and carboxyl-modified nanoplastics in saturated porous media

Due to the extensive use of plastic products and unreasonable disposal, nanoplastics contamination has become one of the important environmental problems that mankind must face. The composition and structure of porous media can determine the complexity and diversity of the transport behavior of nanoplastics. In this study, the influence of diatomite (DIA) on the nanoplastics transport in porous media is investigated by column experiments combined with XDLVO interaction energy and transport model. Results suggest that the recovery rates of unmodified polystyrene nanoparticles (PSNPs) and carboxyl-modified polystyrene nanoparticles (PSNPs-COOH) in the porous media containing DIA decreases compared with that in the pure quartz sand (QS), and the BTCs showed a “blocking” pattern. The presence of DIA inhibits the transport of both PSNPs and PSNPs-COOH, but the inhibition is not significant. This may be because the presence of DIA provides more favorable deposition sites for PSNPs and PSNPs-COOH to some extent. However, since DIA itself carries a certain negative charge, this can only play a role in compressing the double electric layer for PSNPs and PSNPs-COOH with the same negative charge, and cannot destabilize them. The migration capacity of PSNPs and PSNPs-COOH is strongest in the DIA-QS porous media at pH = 7, and is weak at pH = 9 and pH = 5. The inhibition of migration at pH = 9 can be attributed to the dissolution of the DIA surface under alkaline conditions and the formation of pore and defect structures, which provide more deposition sites for PSNPs and PSNPs-COOH. The presence of humic acid (HA) leads to an increase in the mobility of PSNPs and PSNPs-COOH, and the mobility is enhanced with HA concentration. The mobility of PSNPs and PSNPs-COOH in DIA-QS decreases with ionic valence and ionic strength, and PSNPs-COOH is more significantly inhibited compared to PSNPs.

Multifunctional Chitosan Nanofiber-Based Sponge Materials Using Freeze-Thaw and Post-Cross-Linking Method.

The fabrication of porous sponge materials with stable structures via cross-linking diverse polymers presents significant challenges due to the simultaneous requirements for phase separation as a pore-forming step and cross-linking reactions during the fabrication process. To address these challenges, we developed a sponge material solely from natural-based polymers, specifically chitosan nanofibers (CSNFs) and dialdehyde carboxymethyl cellulose (DACMC), employing a straightforward, eco-friendly technique. This technique integrates a facile freeze-thaw method with subsequent cross-linking between CSNFs and DACMC. This method effectively addresses the difficulties associated with pore formation in materials, which typically arise from the rapid formation and precipitation of polyionic complexes during the mixing of anionic and cationic polymers, using ice crystals as a rigid template. The resultant sponge materials exhibit remarkable shape recoverability in their wet state and maintain light, stable porosity in the dry state. Furthermore, in comparison to commonly used commercial foams, this composite porous material demonstrates superior fire retardancy and thermal insulation properties in its dry state. Additionally, it shows effective adsorption capacities for both cationic and anionic dyes and metal ions. This method of using biobased polymers to produce porous composites offers a promising avenue for creating multifunctional materials, with potential applications across various industries.

Biological and physicochemical characterization of carbonated hydroxyapatite-honeycomb-polyethylene oxide bone scaffold fabricated using the freeze-drying method

In this work, a carbonated hydroxyapatite/honeycomb/polyethylene oxide (CHA/HCB/PEO) scaffold was fabricated using the freeze-drying method. The CHA bioceramic component was synthesized from oyster shells using the precipitation method. HCB and PEO act as reinforcing materials that influence the physicochemical properties of the scaffold and as antibacterial agents on the scaffold. The CHA produced was B-type, confirmed by Fourier transform infrared (FTIR) and x-ray diffractometer (XRD) spectra of the CHA. FTIR analysis of the scaffold demonstrated the presence of functional group vibrations originating from PEO and HCB, affirming the successful application of the freeze-drying method, which preserved the polymer content within the scaffold during the evaporation process, thus facilitating pore formation. The XRD results show that a lower CHA concentration is associated with a smaller size of the scaffold crystallites, potentially inducing dislocations favorable for cellular proliferation. The porosity of the formed scaffold is in the ideal range of >60% with CHA concentration of 5 and 10 wt%. The size of the pores that formed on the scaffold was 3–69 μm, classifying them within the micropore category. The in vitro test results in the form of an antibacterial test revealed that the scaffold could inhibit S. aureus and E. coli bacteria. Notably, a scaffold consisting of 10 wt% of CHA had a larger zone of inhibition diameter, 10.083 ± 0.104 for S. aureus and 10.517 ± 0.247 mm for E. coli. The MTT assay and cell morphology MC3T3E1 results in the scaffold show that the CHA/HCB/PEO scaffold is non-cytotoxic and can facilitate cells to attach and proliferate. The cell viability of the scaffold was 96.23% at the concentration of 31.25 μg ml−1, and the IC50 value was at 16144 μg ml−1. Therefore, CHA/HCB/PEO composites can be an alternative material in scaffold fabrication for bone tissue engineering.

Transient liquid phase sintering in spark plasma sintered tungsten heavy alloys with Nb and Mo additives

In the present investigation spark plasma sintered tungsten heavy alloys of composition 90W-7Ni-3Fe, 84W-7Ni-3Fe-6Mo, and 84W-7Ni-3Fe-6Nb were analyzed to determine the effect of Mo and Nb addition on microstructure and phase formation. The alloys were sintered at temperatures ranging from 1150 °C to 1275 °C and at a fixed sintering pressure of 30 MPa. Nb added alloy exhibited a maximum relative density of 99% at sintering temperature of 1200 °C. Whereas the base alloy and Mo added alloy, exhibited a maximum relative density of 97.9% and 95.9% at 1150 °C respectively. Transient liquid phase sintering was found to play a crucial role in the base alloy and Mo added alloy whereas the Nb added alloy was found to undergo persistent liquid phase sintering. Microstructure characterisation by SEM revealed formation of finer tungsten grains with average grain size ranging from 1 μm to 4.3 μm. Mo addition restricted the tungsten grain growth while Nb addition promoted the tungsten grain growth compared to the base alloy. Phase analysis by XRD revealed the formation of Ni4W intermetallic (at lower temperatures) for the base alloy, NbO2 and NbW intermetallics for Nb added alloy and MoNi rich phase for Mo added alloys. Hardness measured by Vickers hardness method revealed a declining trend in hardness with increase in sintering temperature, owing to tungsten grain growth in all the alloys and along with Kirkendall pore formation and growth for the base alloy and Mo added alloy. Nb addition resulted in maximum hardness of 678 HV1 which is highest ever reported for SPSd WHA with 90 wt% concentration of W.

Molecular architecture of coronavirus double-membrane vesicle pore complex

Coronaviruses remodel the intracellular host membranes during replication, forming double-membrane vesicles (DMVs) to accommodate viral RNA synthesis and modifications1,2. SARS-CoV-2 non-structural protein 3 (nsp3) and nsp4 are the minimal viral components required to induce DMV formation and to form a double-membrane-spanning pore, essential for the transport of newly synthesized viral RNAs3–5. The mechanism of DMV pore complex formation remains unknown. Here we describe the molecular architecture of the SARS-CoV-2 nsp3–nsp4 pore complex, as resolved by cryogenic electron tomography and subtomogram averaging in isolated DMVs. The structures uncover an unexpected stoichiometry and topology of the nsp3–nsp4 pore complex comprising 12 copies each of nsp3 and nsp4, organized in 4 concentric stacking hexamer rings, mimicking a miniature nuclear pore complex. The transmembrane domains are interdigitated to create a high local curvature at the double-membrane junction, coupling double-membrane reorganization with pore formation. The ectodomains form extensive contacts in a pseudo-12-fold symmetry, belting the pore complex from the intermembrane space. A central positively charged ring of arginine residues coordinates the putative RNA translocation, essential for virus replication. Our work establishes a framework for understanding DMV pore formation and RNA translocation, providing a structural basis for the development of new antiviral strategies to combat coronavirus infection.

Satellite cell-derived TRIM28 is pivotal for mechanical load- and injury-induced myogenesis

Satellite cells are skeletal muscle stem cells that contribute to postnatal muscle growth, and they endow skeletal muscle with the ability to regenerate after a severe injury. Here we discover that this myogenic potential of satellite cells requires a protein called tripartite motif-containing 28 (TRIM28). Interestingly, different from the role reported in a previous study based on C2C12 myoblasts, multiple lines of both in vitro and in vivo evidence reveal that the myogenic function of TRIM28 is not dependent on changes in the phosphorylation of its serine 473 residue. Moreover, the functions of TRIM28 are not mediated through the regulation of satellite cell proliferation or differentiation. Instead, our findings indicate that TRIM28 regulates the ability of satellite cells to progress through the process of fusion. Specifically, we discover that TRIM28 controls the expression of a fusogenic protein called myomixer and concomitant fusion pore formation. Collectively, the outcomes of this study expose the framework of a novel regulatory pathway that is essential for myogenesis.

Modeling stable cavitation of coated microbubbles: A framework integrating smoothed dissipative particle dynamics and the Rayleigh-Plesset equation.

Coated microbubbles are widely used in medical applications, particularly in enhanced drug and gene delivery. One of the mechanisms underlying these applications involves the shear stress exerted on the cell membrane by acoustic microstreaming generated through cavitation bubbles. In this study, we develop a novel simulation approach that combines the smooth dissipative particle dynamics (SDPD) simulation method with numerical modeling of the Rayleigh-Plesset-like equation in an ad hoc manner to simulate stable cavitation of microbubbles at microsecond and micrometer scales. Specifically, the SDPD method is utilized to model fluid dynamics, while the Rayleigh-Plesset-like equation is employed to describe bubble dynamics. Adopting a 1.5 μm coated microbubble driven by ultrasound with a frequency of 2MHz and a pressure of 500kPa as a representative example, we observe a high-velocity microstreaming pattern emerging around the bubble on a very small scale of a few micrometers after only a few microseconds. These spatiotemporal scales may pose challenges for experimental observation. The formation of this microstreaming arises from the opposing motion of the fluid layer next to the bubble and the fluid layers further away. Furthermore, our simulations reveal high shear stress levels of thousands of Pascals exerted on a wall located a few micrometers from the bubble. This contrasts with the shear stress values of a few Pascals calculated from theoretical models in the literature, which do not incorporate radial streaming into their theories. The implications of our results for bubble cavitation-induced pore formation on the cell membrane are discussed in some details.

Antibacterial Mechanism of Garviecin LG34 Against S. Aureus and L. Monocytogenes and its Application in Milk Preservation

The objective of this study was to reveal the antibacterial mode of action of garviecin LG34 against S. aureus CICC 21600 and L. monocytogenes CICC 21633 and measure the inhibitions on these two foodborne pathogenic bacteria in milk. Antibacterial mechanism of garviecin LG34 was ascertained by its effect on the efflux of Potassium (K+) ions, extracellular electrical conductivity, UV-absorbing substances, potential across the membrane (ΔΨ), and cell permeability. The inhibition of garviecin LG34 against S. aureus CICC 21600 and L. monocytogenes CICC 21600 in milk was studied by viable counting method. Supplementation with 160 AU/ml of garviecin LG34 had a bactericidal effect on S. aureus CICC 21600 and L. monocytogenes CICC 21633. A total of 80, 160, and 320 AU/ml of garviecin LG34 resulted in the effusion of potassium ion and UV-absorbing substances, the leakage of cellular electrolytes, and the dissipation of electrical potential across the membrane of these two food-borne bacteria and showed a dose-dependent. Moreover, the increase in cell permeability of both strains was observed by flow cytometer after cells treated with 160 AU/ml of garviecin LG34. Garviecin LG34 significantly inhibited the growth of these two food-borne bacteria in milk, especially in skimmed milk. Garviecin LG34 could cause pore formation, intracellular materials release, and permeability increase of S. aureus CICC 21600 and L. monocytogenes CICC 21633, and could be applied to milk as bio-preservative.

Soft and diffusion-controlled Sr-MOF for efficient separation of H2O/D2O

Heavy water (D2O) electrolysis is the primary technology for D2 production, playing an irreplaceable role in fields such as nuclear fusion research and isotope tracing. However, the inherent similarity in chemical properties between H2O and D2O (with only a 1.4 °C difference in boiling points) poses significant challenges to their separation. Furthermore, the extremely low natural abundance of D2O (0.015 %) increases the difficulty and cost of separation, while traditional electrolysis and distillation techniques are highly energy intensive. Therefore, there is an urgent need to develop novel adsorbents for efficient and environmentally sustainable H2O/D2O separation. Herein, we used polydentate ligand 2, 5-dihydroxyterephthalic acid (DOBDC) and its derivatives 4,4́-(anthracene-9,10-diyl) bis (2-hydroxybenzoic acid (ABHB) as raw materials to prepare two novel high coordination Sr-MOFs namely IPE-1 and IPE-2, respectively. These MOFs were applied for efficient separation of H2O and D2O at room temperature. X-ray diffraction results reveal that one Sr atom in IPE-1 is coordinated with 9 oxygen atoms. This high coordination number results in the formation of ultra-small rectangular pores of approximately 2.5 Å. Adsorption isotherms of N2, CO2, H2O, and D2O indicate that the ultramicroporous structure of IPE-1 precludes efficient diffusion of CO2 and H2O molecules into the MOF channels. In contrast, the activated IPE-2 exhibits good CO2, H2O, and D2O uptake capacities of 3 mmol/g, 8.38 mmol/g, and 6.51 mmol/g at 298 K, respectively. The Qst values and Ksap values of H2O and D2O indicate that the adsorption rates of H2O were much higher than D2O under 0.2 < P/P0 < 0.7, with a calculated ratio of approximately 1.26. This study not only provides appealing MOFs materials for efficient H2O/D2O separation at room temperature but also provides a new avenue for preparing adsorbents with high stability and high separation performance.

Activity of Membrane-Permeabilizing Lpt Peptides.

Herein, we investigated the toxicity and membrane-permeabilizing capabilities of Lpt and Lpt-like peptides, belonging to type I toxin-antitoxin systems carried by plasmid DNA of Lacticaseibacillus strains. These 29 amino acid peptides are predicted to form α-helical structures with a conserved central hydrophobic sequence and differently charged hydrophilic termini. Like Lpt, the expression of Lpt-like in E. coli induced growth arrest, nucleoid condensation, and cell membrane damage, suggesting membrane interaction as the mode of action. The membrane permeabilization activity of both peptides was evaluated by using liposome leakage assays, dynamic light scattering, and CD spectroscopy. Lpt and Lpt-like showed liposome leakage activity, which did not lead to liposome disruption but depended on peptide concentration. Lpt was generally more effective than Lpt-like, probably due to different physical chemical properties. Leakage was significantly reduced in larger liposomes and increased with negatively charged PCPS liposomes, indicating that electrostatic interactions and membrane curvature influence peptide activity. Contrary to most membrane-active peptides, Lpt an Lpt-like progressively lost their α-helical structure upon interaction with liposomes. Our data are inconsistent with the formation of membrane-spanning peptide pores but support a mechanism relying on the transient failure of the membrane permeability barrier possibly through the formation of "lipid pores".

Obtaining Melanin-Synthesizing Strains of Bacillus thuringiensis and their Use for Biological Preparations.

A pivotal objective in crop production and plant protection lies in developing environmentally friendly insecticidal preparations and biostimulants. We employed Bacillus thuringiensis strains with varied insecticidal spectra and engineered melanogenic mutants. We demonstrated a significant increase in insecticidal activity in the isolated mutants. Meanwhile, there was no observable impact of the enhanced synthesis of water-soluble melanin on the nature and abundance of spore and crystal formation. This heightened efficacy can be attributed to the photoprotective qualities of the synthesized pigment, shielding spores and crystals against the detrimental effects of UV radiation and insolation. We demonstrated the high biological activity of water-soluble bacterial melanin through in vivo experiments involving multiple plant species. Our findings indicate that bacterial melanin is a potent phytostimulant. This preparation accelerates and amplifies plant growth and development processes, leading to a substantial increase in crop yield by 20-40%. The simultaneous synthesis of two biologically active substance, melanin and insecticidal toxins, ensures an elevated level of effectiveness in utilizing melaninogenic strains.

Introducing surface adsorption lithium storage mechanism to enhance safety of graphite

The thermal stability of lithiated graphite plays an important role in the thermal safety of lithium-ion batteries (LIBs). However, a safer graphite anode usually leads to a lower energy density. This article starts from multiple hazardous factors of lithiated graphite when thermal runaway occurs, considering the impact of defects on the electrochemical performance and thermal safety of graphite electrodes. In this study, turbostratic graphite was prepared as the anode for LIBs. The stacking of graphite was altered to form narrow pores and spherical aggregates, and introducing defects. By varying the ball-milling time, the structural changes of different ball-milled graphites were analyzed. The impact mechanism of defect structure on electrode electrochemical performance and safety performance was investigated. The results show that the spherical structure and large specific surface area are beneficial to increase the active sites and delay the self-heating of the battery. The formation of defects and pores increases the adsorption sites, which makes the surface adsorption of Li+ dominant and improves the ion diffusion. In addition, the dominance of surface adsorption and desorption effectively suppresses the problem of graphite flake peeling and intensified thermal runaway caused by graphite phase transition and lithium evolution heat release at high temperature. The thermal safety test was carried out by accelerated calorimeter (ARC), and its thermodynamics and reaction kinetics were quantitatively analyzed. It was proved that the introduction of surface adsorption lithium storage method successfully delayed the thermal runaway of the battery, realizing the balance between high electrochemical performance and high safety.

Antifungal characterizations of a novel endo-β-1,6-glucanase from Flavobacterium sp. NAU1659

β-1,6-Glucan plays a crucial role in fungal cell walls by linking the outer layer of mannoproteins and the inner layer of β-1,3-glucan, contributing significantly to the maintenance of cell wall rigidity. Therefore, the hydrolysis of β-1,6-glucan by β-1,6-glucanase directly leads to the disintegration of the fungal cell wall. Here, a novel β-1,6-glucanase FlGlu30 was identified from the endophytic Flavobacterium sp. NAU1659 and heterologously expressed in Escherichia coli BL21 (DE3). The optimal reaction conditions of purified FlGlu30 were 50℃ and pH 6.0, resulting in a specific activity of 173.1 U/mg using pustulan as the substrate. The hydrolyzed products of FlGlu30 to pustulan were mainly gentianose within 1 h of reaction. With the extension of reaction time, gentianose was gradually hydrolyzed to glucose, indicating that FlGlu30 is an endo-β-1,6-glucanase. The germination of Magnaporthe oryzae Guy11 spores could not be inhibited by FlGlu30, but the appressorium formation of spores was completely inhibited under the concentration of 250.0 U/mL FlGlu30. The disruptions of cell wall and accumulation of intracellular reactive oxide species (ROS) were observed in FlGlu30-treated M. oryzae Guy11 cells, suggesting the significant importance of β-1,6-glucan as a potential antifungal target and the potential application of FlGlu30.Key points• β-1,6-Glucan is a key component maintaining the rigid structure of fungal cell wall.• β-1,6-Glucanase is an antifungal protein with significant potential applications.• FlGlu30 is the first reported β-1, 6-glucanase derived from Flavobacterium.

Genesis and reservoir preservation mechanism of 10 000‐m ultradeep dolomite in Chinese craton basin

AbstractThe 10 000‐m ultradeep dolomite reservoir holds significant potential as a successor field for future oil and gas exploration in China's marine craton basin. However, major challenges such as the genesis of dolomite, the formation time of high‐quality reservoirs, and the preservation mechanism of reservoirs have always limited exploration decision‐making. This research systematically elaborates on the genesis and reservoir‐forming mechanisms of Sinian–Cambrian dolomite, discussing the ancient marine environment where microorganisms and dolomite develop, which controls the formation of large‐scale Precambrian–Cambrian dolomite. The periodic changes in Mg isotopes and sedimentary cycles show that the thick‐layered dolomite is the result of different dolomitization processes superimposed on a spatiotemporal scale. Lattice defects and dolomite embryos can promote dolomitization. By simulating the dissolution of typical calcite and dolomite crystal faces in different solution systems and calculating their molecular weights, the essence of heterogeneous dissolution and pore formation on typical calcite and dolomite crystal faces was revealed, and the mechanism of dolomitization was also demonstrated. The properties of calcite and dolomite (104)/(110) grain boundaries and their dissolution mechanism in carbonate solution were revealed, showing the limiting factors of the dolomitization process and the preservation mechanism of deep buried dolomite reservoirs. The in situ laser U‐Pb isotope dating technique has demonstrated the timing of dolomitization and pore formation in ancient carbonate rocks. This research also proposed that dolomitization occurred during the quasi‐contemporaneous or shallow‐burial periods within 50 Ma after deposition and pores formed during the quasi‐contemporaneous to the early diagenetic periods. And it was clear that the quasi‐contemporaneous dolomitization was the key period for reservoir formation. The systematic characterization of the spatial distribution of the deepest dolomite reservoirs in multiple sets of the Sinian and the Cambrian in the Chinese craton basins provides an important basis for the distribution prediction of large‐scale dolomite reservoirs. It clarifies the targets for oil and gas exploration at depths over 10 000 m. The research on dolomite in this study will greatly promote China's ultradeep oil and gas exploration and lead the Chinese petroleum industry into a new era of 10 000‐m deep oil exploration.

Thin-shelled hollow mesoporous TiO2 spheres with less tortuosity as fast-charging anode

TiO2 is a stable and abundantly available material that is a promising alternative to graphite anodes. However, compact stacking of TiO6 octahedra induces repulsion between the inserted Li ions, reducing rate performance and achievable capacity. Herein, we propose mesoporous hollow TiO2 spheres composed of nanosized anatase to mitigate these issues. The hollow structure allows for ion transport both inward and outward. The empty-core material is obtained by depositing sub-20 nm TiO2 particles synthesized through the sol–gel process onto a carbon nanosphere support, followed by scaffold elimination. Thin TiO2 shells facilitate ion migration via a reduced tortuosity with minimizing isolated pore formation, allowing DLi+ of 3.22 × 10−11 cm2 s−1 to be attained, which is 40 times higher than that of bulk-type TiO2. The facile Li-ion transport enables the insertion of 0.66 mol Li ions per mol of TiO2 at 0.5C and 67 % rate performance (10C vs. 0.5C). The designed hollow TiO2 exhibits stable capacity retention of 85.9 % for 1000 cycles at a fast charging rate of 20C. A full cell with a LiFePO4 cathode exhibits 60 % rate capability (2000 vs. 50 mA g−1). Thin mesoporous hollow TiO2 facilitates the Li-ion transport and enable fast charging, confirming the potential of this anode for fast-charging applications.