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According to our recent studies on hydrophobicity, this work is aimed at understanding the dependence of hydrophobic interactions on the shape of a solute's surface. It has been observed that dissolved solutes primarily affect the structure of interfacial water, which refers to the top layer of water at the interface between the solute and water. As solutes aggregate in a solution, hydrophobic interactions become closely related to the transition of water molecules from the interfacial region to the bulk water. It is inferred that hydrophobic interactions may depend on the shape of the solute surface. To enhance the strength of hydrophobic interactions, the solutes tend to aggregate, thereby minimizing their surface area-to-volume ratio. This also suggests that hydrophobic interactions may exhibit directional characteristics. Moreover, this phenomenon can be supported by calculated potential mean forces (PMFs) using molecular dynamics (MD) simulations, where different surfaces, such as convex, flat, or concave, are associated with a sphere. Furthermore, this concept can be extended to comprehend the molecular packing parameter, commonly utilized in studying the self-assembly behavior of amphiphilic molecules in aqueous solutions. [ABSTRACT FROM AUTHOR]

In this work, molecular dynamic (MD) simulations are applied to investigate the heterogeneous nucleation mechanism of KI on a graphene surface in water. As graphene is immersed in water, it mainly affects the structure of interfacial water (the topmost water layer at the interface between the substance and water). To maximize the hydrogen bonding of water, the dissolved solutes tend to accumulate to form the aggregate at the graphene surface, which undoubtedly affects the nucleation pathways of solutes in water. In comparison with homogeneous nucleation, a lower barrier may be expected during the heterogeneous nucleation of KI on a graphene surface in water. Therefore, as the graphene is immersed in water, this facilitates solute nucleation. From this work, it may be derived that heterogeneous nucleation may be closely related to the geometric characteristics of foreign surfaces, especially their geometric shape. [ABSTRACT FROM AUTHOR]

Ion channels exhibit strong selectivity for specific ions over others under electrochemical potentials, such as KcsA for K+ over Na+. Based on the thermodynamic analysis, this study is focused on exploring the mechanism of ion selectivity in nanopores. It is well known that ions must lose part of their hydration layer to enter the channel. Therefore, the ion selectivity of a channel is due to the rearrangement of water molecules when entering the nanopore, which may be related to the hydrophobic interactions between ions and channels. In our recent works on hydrophobic interactions, with reference to the critical radius of solute (Rc), it was divided into initial and hydrophobic solvation processes. Additionally, the different dissolved behaviors of solutes in water are expected in various processes, such as dispersed and accumulated distributions in water. Correspondingly, as the ion approaches the nanopore, there seems to exist the "repulsive" or "attractive" forces between them. In the initial process (

Monochoria korsakowii is an increasingly significant threat to rice production across China, particularly in Liaoning province. Few studies have reported herbicide resistance in M. korsakowii , and resistance status and mechanisms are poorly understood. Here, thirty field populations of M. korsakowii were collected from 11 rice-growing regions of Liaoning, and 97% of populations had evolved resistance to bensulfuron-methyl (BM), with majority (24 of 28) showing high resistance levels (RI > 10). The first in-depth analysis of molecular features of AHAS1 and AHAS2 in BM-resistant populations showed that four Pro197 mutations (Pro197 to His, Ala, Leu or Ser) in AHAS1 and one mutation (Pro197Ser) in AHAS2 were identified. Notably, novel double Pro197Ser mutations co-occurred in both AHAS1 and AHAS2 in the most resistant line LN-20. Furthermore, resistant mutants were used to investigate the effect of Pro197 mutations on AHAS functionality, binding modes, gene expression and cross-resistance in M. korsakowii. All the detected Pro197 mutations considerably reduced in vitro AHAS sensitivity to BM by weakening hydrogen bonds and hydrophobic interactions in the predicted BM-AHAS complexes, especially the double Pro197Ser mutations. This novel resistance mutation combination slightly impacted the extractable AHAS activity, and increased the affinity and catalytic rate of pyruvate. Also, the AHAS expression level was significantly up-regulated. Moreover, all mutations provided resistance only to other sulfonylureas herbicides but not triazolopyrimidine or pyrimidinyl-benzoates herbicides. In conclusion, bensulfuron-methyl resistance in M. korsakowii was grim in Liaoning, China, and amino acid mutations on AHAS isozymes were the primary resistance mechanism. Double Pro197Ser mutations in both AHAS1 and AHAS2 confer higher herbicide resistance than single mutations in AHAS1. Thus, this work deepens our understanding of resistance status and mechanisms of M. korsakowii. [Display omitted] • Target-site mutations on AHAS isozymes were the primary resistance mechanism of M. korsakowii in Liaoning, China. • Four Pro197 mutations (Pro197 to His, Ala, Leu or Ser) in AHAS1 and one mutation (Pro197Ser) in AHAS2 were identified in M. korsakowii. • Pro197 mutations show different functional impacts on AHAS functionality, binding modes, gene expression and cross resistance. • Double Pro197Ser mutations in both AHAS1 and AHAS2 confer higher herbicide resistance than single mutations in AHAS1. [ABSTRACT FROM AUTHOR]

Highlights • Sodium dodecyl sulphate (SDS) is found to be an efficient Mg corrosion inhibitor. • Inhibitors are adsorbed on AlMn intermetallics to suppress micro-galvanic corrosion. • Large amounts of inhibitors are physically adsorbed on corroded α-Mg region. • A passive hydrophobic corrosion layer is formed to kinetically inhibit corrosion. • Adsorption of SDS on Mg surface follows Langmuir adsorption isotherm. Abstract The inhibition mechanism of a high-efficiency corrosion inhibitor (sodium dodecyl sulfate, SDS) is unveiled and the strategy to design effective inhibitors for Mg alloys is suggested. It was found that SDS is chemically absorbed on the cathodic intermetallics to inhibit micro-galvanic corrosion. Anodic Mg dissolution is also kinetically suppressed by physisorption of SDS since the long hydrophobic tail of the surfactant contributes to building up a protective corrosion layer. Utilization and synthesis of such green inhibitors can pave the way for a wider range of applications for Mg alloy and provide active corrosion protection for coated Mg surfaces. [ABSTRACT FROM AUTHOR]

• The poly(N-isopropyl acrylamide) (PNIPAM)/graphene oxide (GO) mixed system gives temperature-responsive phase separation. • The phase separation produces a gel phase and a water phase. • Metal ions can be adsorbed on GO surface and then transferred into the gel phase. • The phase separation can achieve efficient removal of metal ions from polluted water in an extraction-like process. A temperature-responsive phase separation system based on poly(N-isopropyl acrylamide) (PNIPAM) and graphene oxide (GO) has been developed for efficient removal of metal ions from polluted water. PNIPAM undergoes a coil-to-globule conformational transition upon temperature increase to above its lower critical solution temperature (LCST), which can induce phase separation of the system into a condensed gel phase and a water phase. In this process all GO sheets can be transferred to the gel phase by having strong interactions with PNIPAM molecules via hydrophobic interaction, electrostatic interaction, and hydrogen bonding. Moreover, by having abundant carboxyl, hydroxyl, and epoxy groups to chelate with heavy metal ions, GO sheets can adsorb metal ions efficiently and enrich them into the gel phase. The gel phase can then be separated from the water phase in an extraction-like process, achieving easy removal of the pollutant metal ions from water. This method takes advantages of PNIPAM's temperature responsive phase transition and GO's high adsorption capacity, enabling high versatility, easy treatment and separation, and good reusability in treatment of metal ion pollutions, being highly potential for practical industry applications. [ABSTRACT FROM AUTHOR]

The demand for pharmaceutical-grade plasmid DNA in vaccine applications and gene therapy has been increasing in recent years. In the present study, a process consisting of alkaline lysis, tangential flow filtration, purification by anion exchange chromatography, hydrophobic interaction chromatography and size exclusion chromatography was developed. The final product met the requirements for pharmaceutical-grade plasmid DNA. The chromosomal DNA content was <1 μg/mg plasmid DNA, and RNA was not detectable by agarose gel electrophoresis. Moreover, the protein content was <2 μg/mg plasmid DNA, and the endotoxin content was <10 EU/mg plasmid DNA. The process was scaled up to yield 800 mg of pharmaceutical-grade plasmid DNA from approximately 2 kg of bacterial cell paste. The overall yield of the final plasmid DNA reached 48%. Therefore, we have established a rapid and efficient production process for pharmaceutical-grade plasmid DNA. [Copyright &y& Elsevier]