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A bentonite slurry mixed with seawater is prone to sedimentation, which will reduce the quality of the filter cake and lower the stability of the excavation surface in undersea tunnels. It is necessary to study the performance and influencing factors of the bentonite slurry mixed with seawater. This article simulates the process of undersea slurry shield tunnel construction, where the pressurized slurry penetrates into the sand layer and forms a filter cake when the shield stops pressurizing. We investigated the effects of bentonite, additives (CMC), fine sand, pressure, and formation permeability on the performance of the seawater slurry and filter cake. The sedimentation of mud caused by seawater interfered with the experiment, which manifested as the increase in bentonite, and delayed the formation of the filter cake. Fine sand with a particle size close to the average value of the formation can improve the speed and quality of filter cake formation. By conducting a sensitivity analysis on experimental data, the degree of influence of various factors on the formation rate, thickness, and porosity of the filter cake was determined. Fine sand and bentonite are the factors that have the greatest impact on the formation rate, thickness, and porosity of the filter cake. [ABSTRACT FROM AUTHOR]

As promising heterojunction photocatalysts, the binary CdS-based heterojunctions were investigated extensively. In most of the reported CdS-based heterojunctions, however, electrons come from the semiconductor with wide band gap (e.g., TiO2) would limit the visible-light absorption of CdS and hence lower the performance. In this work, we introduced 1T-MoS2 to form a novel ternary heterojunction, namely CdS/1T-MoS2/TiO2, in which 1T-MoS2 has more positive conduction band than CdS and TiO2. The hydrogen evolution rate of CdS/1T-MoS2/TiO2 reaches 3.15 mmol g−1 h−1, which is approximately 12 and 35 times higher than that of pure CdS and CdS/TiO2 binary heterojunction under the same conditions, respectively. This performance enhancement could be attributed to the presence of 1T-MoS2 and a plausible mechanism is proposed based on photoelectrochemical characterizations. Our results illustrate that the performance of CdS-based heterojunctions for solar hydrogen evolution can be greatly improved by appropriate materials selection. [ABSTRACT FROM AUTHOR]

Naturally synthesized secondary metabolites in plants are considered an important source of drugs, food additives, etc. Among them, research on natural plant medicinal components and their synthesis mechanisms has always been of high concern. We identified a novel medicinal floral crop, Plumbago auriculata L., that can be treated with methyl jasmonate (MeJA) for the rapid or sustainable production of natural bioactives from hairy roots. In the study, we globally analyzed the changes in the accumulation of plumbagin and others in the hairy roots of Plumbago auriculata L. hairy roots (PAHR) 15834 in P. auriculata L. based on 100 μmol/L of MeJA treatment by RNA-seq profiling, and we found that there was a significant increase in the accumulation of plumbagin and saponin before 24 h. To explain the principle of co-accumulation, it showed that MeJA induced JA signaling and the shikimic acid pathway, and the methylvaleric acid (MVA) pathway was activated downstream subsequently by the Mfuzz and weighted gene co-expression analysis. Under the shared metabolic pathway, the high expression of PAL3 and HMGR promoted the activity of the "gateway enzymes" phenylalanine ammonia lyase (PAL) and 3-hydroxy-3-methylglutaryl CoA reductase (HMGR), which respectively induced the high expression of key reaction enzyme genes, including chalcone synthase (CHS), isopentenyl diphosphate (IPP), and farnesyl pyrophosphate synthase (FPS), that led to the synthesis of plumbagin and saponin. We speculated that large amounts of ketones and/or aldehydes were formed under the action of these characteristic enzymes, ultimately achieving their co-accumulation through polyketone and high-level sugar and amino acid metabolism. The study results provided a theoretical basis for carrying out the factory refinement and biosynthesis of plumbagin and saponins and also provided new ideas for fully exploiting multifunctional agricultural crops and plants and developing new agricultural by-products., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Li, Zhao, Hu, Lei, Chen, Li, Yang, Hu and Gao.)

Under salt stress, recretohalophyte Plumbago auriculata tetraploids enhance salt tolerance by increasing selective secretion of Na + compared with that in diploids, although the mechanism is unclear. Using non-invasive micro-test technology, the effect of salt gland Ca 2+ content on Na + and K + secretion were investigated in diploid and tetraploid P. auriculata under salt stress. Salt gland Ca 2+ content and secretion rates of Na + and K + were higher in tetraploids than in diploids under salt stress. Addition of exogenous Ca 2+ increased the Ca 2+ content of the salt gland in diploids and is accompanied by an increase in the rate of Na + and K + secretion. With addition of a Ca 2+ channel inhibitor, diploid salt glands retained large amounts of Ca 2+ , leading to higher Ca 2+ content and Na + secretion rate than those of tetraploids. Inhibiting H 2 O 2 generation and H + -ATPase activity altered Na + and K + secretion rates in diploids and tetraploids under salt stress, indicating involvement in regulating Na + and K + secretion. Our results indicate that the increased Na + secretion rate of salt gland in tetraploids under salt stress was associated with elevated Ca 2+ content in salt gland., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Duan, Jiang, Lei, Ouyang, Liu, Zhao, Li, Yang, Li, Yi and Gao.)

In this work, ZIF-67 derivative Co 3 S 4 with diamond dodecahedron structure was firstly synthesized via a series of reactions, and ZnIn 2 S 4 @Co 3 S 4 heterostructures with adjustable band gaps were successfully obtained through a simple hydrothermal method. Consequently, ZnIn 2 S 4 @Co 3 S 4 heterostructures have significantly enhanced visible light absorption and improved photocatalytic efficiency, among which the ZC-5 composite exhibits the highest photocatalytic hydrogen production rate up to 4261 μmol g -1 h -1 under simulated sunlight, to be approximately 4.8 times higher than that of pure ZnIn 2 S 4 . The enhanced photocatalytic activity can be attributed to faster electron transfer and more efficient electron-hole pairs separation derived from the heterostructures which form at the interface between Co 3 S 4 and ZnIn 2 S 4 . Thus, this study provides a good strategy for photocatalytic hydrogen production without precious metals using heterostructures., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

As promising heterojunction photocatalysts, the binary CdS-based heterojunctions were investigated extensively. In most of the reported CdS-based heterojunctions, however, electrons come from the semiconductor with wide band gap (e.g., TiO 2 ) would limit the visible-light absorption of CdS and hence lower the performance. In this work, we introduced 1T-MoS 2 to form a novel ternary heterojunction, namely CdS/1T-MoS 2 /TiO 2 , in which 1T-MoS 2 has more positive conduction band than CdS and TiO 2 . The hydrogen evolution rate of CdS/1T-MoS 2 /TiO 2 reaches 3.15 mmol g -1 h -1 , which is approximately 12 and 35 times higher than that of pure CdS and CdS/TiO 2 binary heterojunction under the same conditions, respectively. This performance enhancement could be attributed to the presence of 1T-MoS 2 and a plausible mechanism is proposed based on photoelectrochemical characterizations. Our results illustrate that the performance of CdS-based heterojunctions for solar hydrogen evolution can be greatly improved by appropriate materials selection.