Maintaining carbon/nitrogen (C/N) metabolic balance is essential for cellular homeostasis, allowing microorganisms to adapt to fluctuating environmental conditions. In the autotrophic cyanobacteria, the C/N balance is achieved through a sophisticated network that coordinates the uptake of inorganic carbon and nitrogen, including the ATP-binding cassette (ABC) transporters CmpABCD and NRT that import bicarbonate and nitrate, respectively. Notably, both transporters possess an extra C-terminal regulatory domain (CRD) that is fused to one of the nucleotide-binding domains (NBDs). Via structure guided site-directed mutagenesis and bicarbonate transport activity assays, we found that CmpABCD is tightly regulated by the nitrate-binding CRD. At a low intracellular nitrate concentration, CmpBCD adopts an auto-inhibited conformation, in which the CRD locks the two NBDs of CmpC and CmpD. Upon binding to the nitrate, the CRD is released from NBDs and becomes highly flexible, thus restoring the transport activity of CmpABCD. We propose a distinct regulatory mechanism of ABC transporters, which may be broadly applicable to those fused with a regulatory domain. Moreover, these findings combined with previous reports establish a direct link between the inorganic carbon uptake and intracellular nitrate level through an ABC importer, providing a straightforward and economic strategy that coordinates the C/N homeostasis.

Pharmaceuticals and personal care products (PPCPs) are refractory emerging organic pollutants, and clofibric acid (CA) is a typical poorly biodegradable representative. Herein, a nitrogen-doped carbon nanotube (N-CNT) tubular ceramic membrane electrode was fabricated for electro-activated peroxymonosulfate (EA-PMS) degradation of CA, with systematic optimization of preparation and operational conditions. Nitrogen doping introduced pyrrolic/graphitic N active sites and increased structural defects, while the tubular configuration intensified mass transfer. The optimized electrode achieved > 90% CA removal within 30 min, maintained > 95% efficiency over 11 cycles, and exhibited broad-spectrum degradation for typical PPCPs, with low EE/O (0.0417 kWh m(-3)order(-1)) and high PMS utilization (84.3%). Singlet oxygen (O-1(2)) was the dominant reactive oxygen species, driving CA degradation via synergistic radical/non-radical oxidation. Three CA degradation pathways were elucidated by HPLC-MS, and ECOSAR simulations confirmed reduced aquatic toxicity of its intermediates. This work develops a high-performance EA-PMS electrocatalytic membrane system, providing a scalable platform for advanced treatment and risk control of trace PPCPs in water.

The rational design of high-performance adsorbents for lithium recovery from aqueous resources depends critically on understanding how metal doping modulates the structure and properties of metal-organic frameworks (MOFs). In this work, we systematically investigate the effects of Fe doping on the lithium adsorption and isotope separation performance of Al-MOFs through controlled synthesis of bimetallic Al/Fe-MOFs with varying metal ratios (1:4 to 4:1). The materials were characterized by XRD, XPS, TGA, and adsorption experiments, complemented by density functional theory calculations. Results show that optimal Fe incorporation (Al/Fe = 2:1) significantly improves Li+ adsorption capacity (24.07 mg g(-1)) and isotopic selectivity (alpha = 1.033) compared to the undoped MOFs (Q = 12.97 mg g(-1), alpha = 1.027). Structural analyses reveal Al/Fe-MOFs contraction (Delta d (002) = 0.36 angstrom) and surface charge modification (pH (ZPC) shift from 10.26 to 8.73), while electronic structure studies demonstrate Fe3+/Fe2+ redox activity promotes electron transfer. DFT calculations identify greatly increased adsorption energetics (-3.96 eV) through synergistic Al-O/Fe-O interactions, where the rigid Al-O framework ensures structural stability and flexible Fe-O sites support dynamic adsorption. The material exhibits excellent cycling stability (92 % capacity retention) due to dual stabilization mechanisms. These findings confirm that balanced bimetallic coordination in MOFs can enhance adsorption capacity and selectivity through geometric and electronic effects, providing valuable insights for designing advanced adsorbents for lithium recovery.

Carboxysomes are self-assembled bacterial microcompartments (BMCs) that encapsulate the enzymes RuBisCO and carbonic anhydrase into a proteinaceous shell, enhancing the efficiency of photosynthetic carbon fixation. The chaperone CcmS was reported to participate in the assembly of β-carboxysomes; however, the underlying molecular mechanism remains elusive. We report the crystal structure of CcmS from Synechocystis sp. PCC 6803, revealing a monomer of α/β fold. Moreover, its complex structures with two types of BMC hexamers, CcmK1 homohexamer and CcmK1-CcmK2 heterohexamer, reveal a same pattern of CcmS binding to the featured C-terminal segment of CcmK1. Upon binding to CcmS, this C-terminal segment of CcmK1 is folded into an amphipathic α-helix protruding outward that might function as a hinge to crosslink adjacent BMC-H hexamers, thereby facilitating concerted and precise assembly of the β-carboxysome shell. Deletion of the ccmS gene or the 8-residue C-terminal coding region of ccmK1 resulted in the formation of aberrant and fewer carboxysomes, suppressed photosynthetic capacity in Synechocystis sp. PCC 6803. These findings enable us to propose a putative model for the chaperone-assisted assembly of β-carboxysome shell and provide clues for the design and engineering of efficient carbon fixation machinery.

Models of single-crystal and polycrystal M50NiL steel were established by the classical molecular dynamics simulation (MD) method. The uniaxial tensile deformation behavior and microstructure evolution of single-crystal and polycrystalline M50NiL steel models at 300 K and 0.02-Å/ps strain rate were studied in detail. The simulation results show that grain boundaries can reduce the compressive degree of the Fe matrix after relaxation and reduce the stress in the sample during the tensile process. The fracture time of polycrystalline M50NiL steel is earlier and the tensile strength of it is significantly lower than the single-crystal M50NiL steel, showing an inverse Hall–Petch law phenomenon. The main deformation mechanisms of both single-crystal and polycrystalline M50NiL steel samples are attributed to the glide of Shockley partial dislocations and the generation and expansion of stacking faults. Initially, the transformation of the FCC and HCP lattices occurs, during which defect atoms, stacking faults, and dislocation nucleation will be generated. As the number of FCC lattice atoms increases, dislocations begin to slip and leave stacking faults. Ultimately, due to dislocation reactions, micro-holes are formed and then evolve into cracks. As the number of dislocations decreases and the number of disordered atoms increases, cracks expand and fracture.

The 28 nm process has a high cost-performance ratio and has gradually become the standard for the field of radiation-hardened devices. However, owing to the minimum physical gate length of only 35 nm, the physical area of a standard 6T SRAM unit is approximately 0.16 m^2 , resulting in a significant enhancement of multi-cell charge-sharing effects. Multiple-cell upsets (MCUs) have become the primary physical mechanism behind single-event upsets (SEUs) in advanced nanometer node devices. The range of ionization track effects increases with higher ion energies, and spacecraft in orbit primarily experience SEUs caused by high-energy ions. However, ground accelerator experiments have mainly obtained low-energy ion irradiation data. Therefore, the impact of ion energy on the SEU cross section, charge collection mechanisms, and MCU patterns and quantities in advanced nanometer devices remains unclear. In this study, based on the experimental platform of the Heavy Ion Research Facility in Lanzhou, low- and high-energy heavy-ion beams were used to study the SEUs of 28 nm SRAM devices. The influence of ion energy on the charge collection processes of small-sensitive-volume devices, MCU patterns, and upset cross sections was obtained, and the applicable range of the inverse cosine law was clarified. The findings of this study are an important guide for the accurate evaluation of SEUs in advanced nanometer devices and for the development of radiation-hardening techniques.

In addressing challenges in Selective Catalytic Reduction (SCR) systems in vehicles, the development of novel SrCl2 composite materials with high ammonia adsorption and structural stability is crucial. In this context, we employed the porous magnesium oxychloride cement (PMOC) as a carrier material, successfully fabricating a mesoporous PMOC-SrCl2 material via solution impregnation technology. Simultaneously, we employed various characterization techniques such as XRD, full-pore analysis, TG, SEM, TEM, and EDS to examine the material. We conducted static adsorption assessments on numerous candidate materials at 0.1Mpa and 293.15 K. The synthesized C3 series material (Mass ratio of SrCl2 to PMOC = 10:3), solution impregnated for 1 h, exhibited exceptional ammonia adsorption capacity (up to 38.01 mmol center dot g(-1)). Through model fitting of experimental data, we discovered that the adsorption process of this material closely aligns with the pseudo-second-order kinetic model and the Langmuir model. Over an adsorption time span of 180 min, the adsorption rate of the composite material increased by 129 % compared to pure SrCl2. In the cycle performance testing phase, we observed that the material exhibited no significant degradation in performance after undergoing 10 cycles of adsorption/ desorption. This structurally stable, cost-effective, and readily accessible high-efficiency ammonia adsorption material undoubtedly possesses immense potential to solve the application challenges of ammonia adsorption materials within automotive selective catalytic reduction systems.

Carboxysomes are large self-assembled microcompartments that serve as the central machinery of a CO2-concentrating mechanism (CCM). Biogenesis of carboxysome requires the fine organization of thousands of individual proteins; however, the packaging pattern of internal RuBisCOs remains largely unknown. Here we purified the intact β-carboxysomes from Synechococcus elongatus PCC 7942 and identified the protein components by mass spectrometry. Cryo-electron tomography combined with subtomogram averaging revealed the general organization pattern of internal RuBisCOs, in which the adjacent RuBisCOs are mainly arranged in three distinct manners: head-to-head, head-to-side, and side-by-side. The RuBisCOs in the outermost layer are regularly aligned along the shell, the majority of which directly interact with the shell. Moreover, statistical analysis enabled us to propose an ideal packaging model of RuBisCOs in the β-carboxysome. These results provide new insights into the biogenesis of β-carboxysomes and also advance our understanding of the efficient carbon fixation functionality of carboxysomes.

A new system for enrichment of 7Li by solvent extraction method. In the present work, a new system for the extraction and enrichment of 7Li was constructed, and provides a new idea for the separation of 7Li by extraction method.

High harmonic generation (HHG) of laser-ablated plasma plumes driven by an intense laser field is an effective method for generating coherent extreme ultraviolet radiation. We investigated the enhancement of high-order harmonics by the interaction of intense laser fields and laser-ablated low-density Ti plasma plumes. By analyzing the mechanism of HHG, the microscopic effect was proved to account for the enhancements of H27-H31. In addition, the density distribution of Ti plasma plumes was estimated and verified that the intensities of different order harmonics were influenced by different regions of Ti plasma plume density. Our results provide a pathway for optimizing the phase-matching conditions of resonant harmonics to improve the harmonic yield by means of controlling the density of laser-ablated plasma plumes (LPPs).

The versatile manipulation of cross-scale droplets is essential in many fields. Magnetic excitation is widely used for droplet manipulation due to its distinguishing merits. However, facile magnetic actuation strategies are still lacked to realize versatile multiscale droplet manipulation. Here, a type of magnetically actuated Janus origami robot is readily fabricated for versatile cross-scale droplet manipulation including three-dimensional transport, merging, splitting, dispensing and release of daughter droplets, stirring and remote heating. The robot allows untethered droplet manipulation from ~3.2 nL to ~51.14 μL. It enables splitting of droplet, precise dispensing (minimum of ~3.2 nL) and release (minimum of ~30.2 nL) of daughter droplets. The combination of magnetically controlled rotation and photothermal properties further endows the robot with the ability to stir and heat droplets remotely. Finally, the application of the robot in polymerase chain reaction (PCR) is explored. The extraction and purification of nucleic acids can be successfully achieved.

Efficient recovery of lithium from mother liquor of Li2CO3 is considered as an effective way to mitigate the rapidly growing demand of lithium but poses a daunting challenge. Herein, a series of synergistic hydrophobic deep eutectic solvents (HDESs) coupling beta-diketones and neutral extractants were developed as novel extraction media for recovery of Li+ from aqueous solution. The newly developed HDES exhibited very low viscosity and high hydrophobicity, enabling their direct use in liquid-liquid extraction. The extraction performance of the systems could be easily manipulated by simply altering the composition of HDESs, with the thenoyltrifluoroacetone-tributyl phosphate (HTTA-TBP) and thenoyltrifluoroacetone-trioctylphosphine (HTTA-TOPO) HDES displaying excellent extraction capacity and selectivity towards Li+. The selective extraction mechanism was exemplified by HTTA-TBP HDES and revealed by molecular dynamics simulation for the first time, whereby Li+ was driven into HDES phase mainly through its strong electrostatic interaction with deprotonated HTTA, while TBP interacted with Li+ via the coordination effect. The stoichiometry of extracted complex was 1:1:1, with the form of Li+center dot TTA(-)center dot TBP. The cooperation of HTTA and TBP in HDES prohibited the participation of water molecule in the formation of extracted complex, thus preventing the emulsification during extraction. Interaction energy analysis demonstrated that Li+ interacted with both TTA(-) and TBP much more strongly than Na+ and K+, explicitly elucidating the high selectivity of HDES towards Li+ over Na+ and K+. Finally, both of the HTTA-TBP and HTTA-TOPO HDES were utilized to recover Li+ from the mother liquor of Li2CO3, with recovery rates of Li+ over 80 % through single-stage extraction, scrubbing and stripping. Moreover, the stripped HDESs could be directly used in subsequent extraction cycles without regeneration, and their extraction performances remained virtually unchanged, suggesting that the developed HEDSs are highly promising and feasible.

The evolution of the nuclear industry is inextricably linked to lithium isotopes. With its distinct benefits, the solvent extraction approach is projected to achieve industrial separation of lithium isotopes. However, the lack of studies on the extraction process conditions and mechanisms has limited the devel-opment of multi-stage processes. In this paper, based on the 4-NO2-B15C5/[BMIm][NTf2] system, the pro-cess conditions and extraction mechanism of the system were investigated by thermodynamic and kinetic studies. The results indicate that lithium isotope separation is a spontaneous exothermic process controlled by diffusion. In addition, DFT calculations show that the binding sites of crown ether and Li+ are located in the coronary heart of crown ether, and electrostatic and van der Waals forces mainly exist between them. On this basis, a 10-stage cross-flow extraction experiment was carried out using crown ether as the extractant. The aqueous phase feed solution is fully utilized, and the 7Li abundance is increased to 93.29 %. In summary, this research provides a foundation for the development of synergistic multi-stage extraction techniques in the future. (C) 2022 Elsevier B.V. All rights reserved.

At the first step of phage infection, the receptor-binding proteins (RBPs) such as tail fibers are responsible for recognizing specific host surface receptors. The proper folding and assembly of tail fibers usually requires a chaperone encoded by the phage genome. Despite extensive studies on phage structures, the molecular mechanism of phage tail fiber assembly remains largely unknown. Here, using a minimal myocyanophage, termed Pam3, isolated from Lake Chaohu, we demonstrate that the chaperone gp25 forms a stable complex with the tail fiber gp24 at a stoichiometry of 3:3. The 3.1-Å cryo-electron microscopy structure of this complex revealed an elongated structure with the gp25 trimer embracing the distal moieties of gp24 trimer at the center. Each gp24 subunit consists of three domains: the N-terminal α-helical domain required for docking to the baseplate, the tumor necrosis factor (TNF)-like and glycine-rich domains responsible for recognizing the host receptor. Each gp25 subunit consists of two domains: a non-conserved N-terminal β-sandwich domain that binds to the TNF-like and glycine-rich domains of the fiber, and a C-terminal α-helical domain that mediates trimerization/assembly of the fiber. Structural analysis enabled us to propose the assembly mechanism of phage tail fibers, in which the chaperone first protects the intertwined and repetitive distal moiety of each fiber subunit, further ensures the proper folding of these highly plastic structural elements, and eventually enables the formation of the trimeric fiber. These findings provide the structural basis for the design and engineering of phage fibers for biotechnological applications.

The demand for lithium-ion batteries (LIBs) has risen dramatically over the years. However, many of the essential component elements in cathodes, such as cobalt and lithium, are both costly with limited resources. Therefore, the recycling of spent LIB cathodes is of great significance to conserving resources and the environment. In this work, we reported a novel metal-based strategy to selectively leach lithium from different types of cathodes (NCM, LCO, and LMO) by Co2+ or Mn2+, which can realize over 95% lithium leaching rates without other metal ions, such as Ni2+, Co2+, and Mn2+, left in the leachate, and the residual transition metal oxides can be used as cathode precursors. Taking the spent LiCoO2 as an example, the regenerated LiCoO2 particles show decent electrochemical performance, i.e., a reversible discharge capacity of 137.9-162.5 mAh/g upon being charged to 4.2-4.4 V with excellent rate performance and cycling stability at 4.2 V. It is a facile, closed-loop, and scalable process for recycling spent LIB cathodes based on the preferentially selective extraction of lithium, which offers a novel strategy for recycling compositional Li-ion cathode materials.

Na-ion batteries have been considered promising candidates for stationary energy storage. However, their wide application is hindered by issues such as high cost and insufficient electrochemical performance, particularly for cathode materials. Here, we report a solvent-free mechanochemical protocol for the in-situ fabrication of sodium vanadium fluorophosphates. Benefiting from the nano-crystallization features and extra Na-storage sites achieved in the synthesis process, the as-prepared carbon-coated Na 3 (VOPO 4 ) 2 F nanocomposite exhibits capacity of 142 mAh g −1 at 0.1C, higher than its theoretical capacity (130 mAh g −1 ). Moreover, a scaled synthesis with 2 kg of product was conducted and 26650-prototype cells were demonstrated to proof the electrochemical performance. We expect our findings to mark an important step in the industrial application of sodium vanadium fluorophosphates for Na-ion batteries.

To recycle the sharply growing spent lithium-ion batteries and alleviate concerns over shortages of resources, particularly Li, is still an urgent issue. In this work, an organic acids based leaching approach at room temperature is proposed to recover Li and FePO4 from spent LiFePO4 cathode powder. The coexistent metal ions, Cu and Al, have also been investigated. Citrus fruit juices, rich in organic acids, such as citric acid and malic acid, have been used as leaching agents in this work. Among lemon, orange and apple, lemon juice shows the best leaching effect based on its suitable pH of the reaction system. Under the optimized conditions, the leaching rates of Li, Cu and Al can reach up to 94.83%, 96.92% and 47.24%, while Fe and P remain as low as 4.05% and 0.84%, respectively. Li2CO3 and FePO4 can be recovered from the leachate and the leaching residue, respectively. The recovered FePO4 was used to prepare new cathode material LiFePO4. The crystalline carbon, present in the spent LiFePO4 cathode scraps, has a significant effect on the electrochemical performances of the regenerated LiFePO4. The regenerated LiFePO4 cathode material delivered a comparable discharge capacity of 155.3 mAh g(-1) at 0.1C and rate capacity to the fresh LiFePO4. For the cycling stability, it displays capacity retention of 98.30% over 100 cycles at 1 C with a fading rate of 0.017% per cycle. The proposed organic acids-based recycling strategy is much benign for recycling the spent LiFePO4 cathode materials. (C) 2020 Elsevier Ltd. All rights reserved.

Since the oxygen evolution reaction (OER) is a fundamental step in the overall water splitting process, it is necessary for an ideal catalyst to require a small amount of energy to overcome the energy barrier at the electrode-electrolyte interface. Therefore, developing highly active and integrated catalysts is of great significance. Herein, we present a facile and viable method to fabricate flower-like NiFe oxide nanosheets electrocatalysts that are directly grown on nickel foam substrates through a hydrothermal reaction. By tuning the Ni:Fe ratio, the as-synthesized NiFe oxide exhibits excellent catalytic activity that surpasses the activity of the RuO2 benchmark catalyst, when tested as an electrocatalyst for the overall water splitting reaction. More importantly, the optimized NiFe oxide electrode possesses excellent OER activity in 1 M KOH with small overpotentials of 255 and 280 mV at 10 and 50 mA cm(-2), respectively. When employed as a stable bifunctional catalyst to split water, this electrode achieved a current density of 10 mA cm(-2) at a cell voltage of 1.59 V. This work presents a highly promising candidate for use as an electrode material and represents promising progress in its practical utilization and comprehensive industrialization.

With large-scale molecular dynamics simulations, we investigate systematically displacement cascades in nanotwinned Cu with different twin spacings. Coherent twin boundaries (CTBs) are proven to be effective defect sinks, and they exhibit preferential absorption of interstitials. The existence of twin boundary affected zone is confirmed, and its width depends on the energy of primary knock-on atom. When stacking fault tetrahedra nucleate near CTBs, their growth are suppressed, resulting in truncation. CTB migration is observed, which is induced by transient internal stress arising from collision cascades.