Improving the Lithography Sensitivity of Atomically Precise Tin-Oxo Nanoclusters via Heterometal Strategy.

Tin-oxo clusters are increasingly recognized as promising materials for nanolithography technology due to their unique properties, yet their structural impacts on lithography performance remain underexplored. This work explores the structural impacts of heterometal strategies on the performance of tin-oxo clusters in nanolithography, focusing on various metal dopants and their coordination geometries. Specifically, SnOC-1(In), SnOC-1(Al), SnOC-1(Fe), and SnOC-2 were synthesized and characterized. These clusters demonstrate excellent solubility, dispersibility, and stability, facilitating the preparation of high-quality films via spin-coating for lithographic applications. Notably, this work innovatively employs nano-infrared (nano-IR), neutron reflectivity (NR), and X-ray reflectivity (XRR) measurements to confirm film homogeneity. Upon electron beam lithography (EBL), all four materials achieve 50 nm line patterns, with SnOC-1(In) demonstrating the highest lithography sensitivity. This enhanced sensitivity is attributed to indium dopants, which possess superior EUV absorption capabilities and unsaturated coordination environments. Further studies on exposure mechanisms indicated that Sn-C bond cleavage generates butyl free radicals, promoting network formations that induce solubility-switching behaviors for lithography. These findings underscore the efficacy of tailored structural design and modulation of cluster materials through heterometal strategies in enhancing lithography performance, offering valuable insights for future material design and applications.

Coordination-Delayed-Hydrolysis Method for the Synthesis and Structural Modulation of Titanium-Oxo Clusters.

ConspectusAtomically precise titanium-oxo clusters (TOCs) are the structure and reactivity model compounds of technically important TiO2 materials, which could help build structure-property relationships and achieve property modulation at the molecular level. However, the traditional formation of TOCs has relied on the poorly controllable hydrolysis of titanium alkoxide in the solvent for a long time, limiting the development of TOC structural chemistry to a great extent. In addition, easily hydrolyzable alkoxy groups would be still coordinated on the surface of the TOCs generated by this method, making the clusters sensitive and unstable to the moisture. To achieve controllable preparation of TOCs, we believe it is crucial to attenuate the hydrolysis of titanium ions in the formation process of a cluster. To this end, we have recently applied an effective coordination-delayed-hydrolysis (CDH) strategy for TOC synthesis, which provides powerful tools for tuning their structures.In this Account, at the beginning, a brief introduction to the coordination-delayed-hydrolysis strategy is supplied, and its predominant features for constructing novel TOCs are highlighted. In subsequent sections, we discuss how the applied chelating organic/inorganic ligands (named hydrolysis delayed ligands) influence the hydrolysis process of Ti4+ ions to form a large family of TOCs with various nuclearities and core structures. Various hydrolysis delayed ligands have been explored, ranging from common O-donor ligands (carboxylate, phenol, or sulfate) to rarely used N-donor ligands (pyrazole) or bifunctional O/N-donor ones (quinoline, oxime, or alkanolamine). Breakthroughs in the symmetry, configuration, and cluster nuclei of TOCs have been accordingly achieved. Then, we show that this CDH method can be used to tune the surface structure of TOCs by modifying functional organic ligands. As a result, the physicochemical properties of TOCs, especially optical band gaps, can be optimized, and their stability under ambient conditions is significantly improved. In addition, we illustrate that the reversible bonds between hydrolysis delayed ligands and Ti ions further allows us to introduce active heterometal ions or clusters upon or inside the Ti-O cores to prepare heterometallic TOCs with unprecedented structures and properties. In particular, noble metal (Ag ions or clusters) has been incorporated into Ti-O clusters for the first time. As a summary, the coordination-delayed-hydrolysis strategy has realized the controllable hydrolysis of Ti4+ ions to some extent, breaking through the limitations of traditional synthesis methods and producing fruitful results in the field of titanium-oxo clusters. It is believed that this CDH method would also be effective for synthesizing oxo clusters of other easily hydrolyzed metal ions (Al3+, Sn4+, In3+, etc.) to afford significant contribution for the cluster community.

Electron-Rich MoIV 3 -Polyoxomolybdates Resembling the Paratungstic Archetype.

The first polyoxometalates (POMs) composed of MoIV , MoV 2 , discrete d1 -MoV and MoVI , [MoIV 3 MoV 6 MoVI 4 O32 (µ2 -OH)(µ3 -OH)py9 ] (1), was prepared from the solvothermal partial oxidation of [MoIV 3 O2 (O2 CCH3 )6 (H2 O)3 ]ZnCl4 in a mixture of pyridine and water. The MoV =O adduct-free unit [H2 Mo12 O33 py9 ] presents the 11e-reduced Mo derivative of the paratungtic archetype. The use of methanol, ethanol, n-propyl alcohol and triglycol instead of water produced the isostructural [MoIV 3 MoV 6 MoVI 4 O32 (µ3 -OH)(µ2 -OR)py9 ](R=CH3 , 2; C2 H5 , 3; C3 H7 , 4; C2 H4 OH, 5), providing the first examples of MoIV 3 -POMs containing bridging alkoxyl groups. The addition of [CrIII Mo6 O24 ]9- led to the substitution of {MoV =O}3+ with {CrIII -py}3+ in the allomer [MoIV 3 MoV 5 MoVI 4 CrIII O32 (µ-OH)2 py10 ] (6). Using a mixture of Mo3 and MoW2 precursors afforded WVI -incorporated allomer [MoIV 3 MoV 6 MoVI WVI 3 O32 (µ-OH)2 py9 ] (7). The complete substitution of MoVI with WVI by using a mixture of the Mo2 W, MoW2 and W3 precursors produced the diamagnetic [MoIV 3 MoV 6 WVI 4 O33 (µ3 -OH)py9 ]- (syn-8) resulting from the anti→syn conversion between the top and bottom M3 triads concomitant with MoV -MoV bonding. Both anti-1-7 and syn-8 have been characterized by X-ray single crystal structural analyses. The spin distribution and magnetic interactions have been investigated by temperature-dependent magnetic susceptibility and DFT theoretical calculations. Heterogeneous hydrogen transfer catalysis has been examined by the Lewis catalysis field (LCF) theory.

Structural Regulation and Transformation of Oxalate-Bridged Polyoxo-Titanium Nanoclusters: Intercluster Docking Strategy and Polyiodides Induced Rearrangement.

Although significant progress has been made in the synthetic and structural chemistry of polyoxo-titanium clusters (PTCs), the rational regulation of their geometric and electronic configurations is rather difficult. Meanwhile, it is also challenging to induce their systematic structural transformation, thereby customizing their physicochemical properties. In this work, we illustrate the intercluster docking strategy, which utilizes oxalates as multidentate ligands to connect and regulate the modular assembly of polynuclear Ti-O subunits into nanoclusters Ti24(µ3-O)26(µ2-O)4(OiPr)34(Oxal) (PTC-361), Ti28(µ4-O)2(µ3-O)28(µ2-O)8(OtBu)22(PA)12(Oxal) (PTC-362), Ti10(µ3-O)6(OtBu)14(PA)6(Oxal)2(tBC)2 (PTC-363), and Ti24(µ3-O)20(µ2-O)12(PA)12(Oxal)2(Hoxal)8(PyA)8 (PTC-364) (H2Oxal = oxalic acid; HOiPr = isopropanol; HOtBu = t-butanol; H2tBC = 4-tert-butylcatechol; HPA = propionic acid; and HPyA = 2-picolinic acid). Furthermore, the stepwise addition of iodine gives rise to polyiodide I3- to assist the controllable structure transformation of PTC-361 to [Ti12(µ-O)15(OiPr)17]I3 (PTC-365) and even to [Ti24(µ2-O)2(µ3-O)30(OiPr)30](I3)2 (PTC-366) with increasing polyiodide content. Moreover, modification with 4-tert-butylcatecholate as light absorbent material on the surface layers of PTCs and polyiodide I3- incorporation in PTCs expand their light response to the visible region and reduce their highest occupied molecular orbital-lowest unoccupied molecular orbital gaps. This work successfully develops an intercluster docking strategy and gives precise modulation on the geometry of nanoclusters as well as the optimization of their desired properties.

Preparation and Visible-Light Response of Salicylate-Stabilized Heterobimetallic Pb-Ti-Oxo Clusters Initiated via Auxiliary Quaternary Ammonium Salts and a Solvent Effect.

In this study, with the assistance of quaternary ammonium salts we have successfully prepared a new family of salicylate-stabilized heterobimetallic Pb-Ti-oxo clusters, including H(TEA)[Pb2Ti6(µ2-O)2(µ3-O)2(OiPr)4(PA)2(Sal)6(NO3)2] (PTC-321; TEA = tetraethylammonium; HOiPr = isopropanol; H2PA = phenylphosphonic acid; H2Sal = salicylic acid), {PbTi3(µ2-O)(µ3-O)(OiPr)2(PA)(Sal)3(DMF)·CH3CN}n (PTC-322; DMF = dimethylformamide), {PbTi5(µ3-O)6(Sal)3(CH3COO)2(DMF)(OiPr)2}n (PTC-323), [Pb2Ti4(Sal)6(EtO)2(OiPr)6(HOiPr)2]·CH3NH2 (PTC-324; EtOH = CH3CH2OH), H[Pb4Ti9(µ2-O)2(µ3-O)(µ4-O)6(Sal)7(OiPr)13] (PTC-325), and Pb2Ti12(µ2-O)3(µ3-O)3(µ4-O)4(Sal)4(OEt)24 (PTC-326). Single-crystal X-ray diffraction studies demonstrate that the {Ti3Pb(Sal)3} unit acts as the building block to constitute the diverse assembly of PTC-321-PTC-323. Thereinto, the clusters in PTC-322 and PTC-323 are connected into infinite one-dimensional chains. Furthermore, the solvent effects have facilitated the heterobimetallic Pb-Ti-oxo clusters into various configurations in PTC-323-PTC-326. Solid-state ultraviolet-visible spectroscopy analysis indicates that the optical absorption bands of these compounds shift effectively toward the visible-light region, and they were also employed as electrode precursors to investigate their visible-light-driven photocurrent response.

Research on the Principle and Cooperative Processing Method of MRS Multisystem Joint Detection.

Magnetic resonance sounding (MRS) technology is the only geophysical means to directly and quantitatively detect groundwater and has achieved good results in hydrogeological prospecting applications. In recent years, researchers have conducted considerable research on the efficiency of a single instrument, yielding certain results. However, the overall work efficiency of this method has not been effectively determined in its application to a large-scale survey. Hence, we propose both a joint detection method for MRS that determines the minimum working distance when multiple systems operate simultaneously and a collaborative measurement method of dual systems operating simultaneously in a fixed range of work areas. The cooperative working mode of the instruments is tested in the detection area, and the working mode proposed in this paper is shown to effectively avoid measurement interference between systems. Compared with the working mode of a single set of instruments, the measurement efficiency is more than doubled. Through this research, the feasibility of multiple MRS instruments working together in the same work area is verified, which provides effective technical support for the rapid and high-efficiency utilization of MRS over a wide range of measurement areas.

Internalized Carbon Dots for Enhanced Extracellular Electron Transfer in the Dark and Light.

Cellular internalization of nanomaterials to endow cells with more functionalities is highly desirable. Herein, a straightforward strategy for internalizing red-emission carbon dots (CDs) into Shewanella xiamenensis is proposed. This suggests that the internalized CDs not only afford enhanced conductivity of bacteria but also trigger the cellular physiological response to secrete abundant electron shuttles to aid the boosting of extracellular electron transfer (EET) efficiency. Additionally, once illuminated, internalized CDs can also serve as light absorbers to allow for photogenerated electrons to be transferred into cellular metabolism to further facilitate light-enhanced EET processes. Specifically, the findings advance the fundamental understanding of the interaction between internalized carbon-based semiconductor and cells in the dark and light, and provide a facile and effective strategy for enhancing EET efficiency.

Supramolecular Co-assembly of the Ti8L12 Cube with [Ti(DMF)6] Species and Ti12-Oxo Cluster.

Titanium-based coordination cages are fascinating in the field of supramolecular and photophysical chemistry. Herein, we address the unprecedented supramolecular co-assembly arrangement of a cubic Ti8L12 cage with [Ti(DMF)6] species and Ti12-oxo cluster, contributing to the cocrystals of {Ti8L12 + Ti(DMF)6} (PTC-116) and {Ti8L12 + Ti12-oxo} (PTC-117). The ESI-MS and 1H NMR measurements reveal their stability in solution. The photophysical properties of these supramolecular complexes in solution, including light absorption and photoluminescent behaviors, were further investigated.

Uniaxial Dynamical Decoupling for an Open Quantum System.

Dynamical decoupling (DD) is an active and effective method for suppressing decoherence of a quantum system from its environment. In contrast to the nominal biaxial DD, this work presents a uniaxial decoupling protocol that requires a significantly reduced number of pulses and a much lower bias field satisfying the "magic" condition. We show this uniaxial DD protocol works effectively in a number of model systems of practical interest, e.g., a spinor atomic Bose-Einstein condensate in stray magnetic fields (classical noise), or an electron spin coupled to nuclear spins (quantum noise) in a semiconductor quantum dot. It requires only half the number of control pulses and a 10-100 times lower bias field for decoupling as normally employed in the above mentioned illustrative examples, and the overall efficacy is robust against rotation errors of the control pulses. The uniaxial DD protocol we propose shines new light on coherent controls in quantum computing and quantum information processing, quantum metrology, and low field nuclear magnetic resonance.

Sequential Isomerization of a Macrocyclic Polyoxometalate Archetype.

Controlled isomerization of individual {α-P2W12O48} polyoxotungstate building blocks under the constricted conditions of the macrocyclic [P8W48O184]40- archetype ({P8W48}) is linked to site-specific CuII coordination. The derivatives [αγαγ-P8W48O184{Cu(H2O)}2]36- (1), [γγγγ-P8W48O184{Cu(H2O)0.5}4]32- (2), and [αγγγ-P8W48O184{Cu(H2O)}3]34- (3) feature the {αγαγ-P8W48} and the hitherto unknown {γγγγ-P8W48} and {αγγγ-P8W48} isomers based on {α-P2W12} and/or CuII-stabilized {γ-P2W12} units and form from the reactions of the classical {P8W48} (={αααα-P8W48}) and CuCl2 in sodium acetate medium (pH 5.2). All products were thoroughly characterized in both the solid state and aqueous solutions, including electrocatalysis assessments.

Cataluminescence sensing of carbon disulfide based on CeO2 hierarchical hollow microspheres.

Material morphology-dependent cataluminescence (CTL) sensing characteristic and application are presented in this work. Hierarchical hollow microspheres CeO2 were synthesized via the hydrothermal reaction of glucose and N, N-dimethyl-formamide (Glu-DMF). SEM, XRD, TEM, HRTEM and BET were used to characterize the prepared CeO2 materials. Compared with CeO2 cubics (CeO2 Cubs), CeO2 hierarchical hollow microspheres (CeO2 HMs) show an enhanced CTL response to carbon disulfide. The response and recovery times of CeO2 HMs-based CTL sensor towards carbon disulfide are about 8 s and 20 s, respectively. CeO2 HMs exhibits a linear CTL response to carbon disulfide in the concentration range of 0.50~10 µg•mL-1 with an excellent sensitivity and selectivity. These results suggest that CeO2 HMs will be a highly promising CTL sensing material for the detection and monitoring carbon disulfide. Graphical abstract CeO2 hierarchical hollow microspheres (CeO2 HMs) were synthesized via the hydrothermal reaction of glucose and N, N-dimethyl-formamide (Glu-DMF). Meanwhile, the prepared CeO2 HMs shows commendable CTL response towards carbon disulfide. Due to the excellent analytical performance of designed CeO2 HMs-based sensor for carbon disulfide, it has potential application value in various locations.

Encapsulating Fe3O4 into calcium alginate coated chitosan hydrochloride hydrogel beads for removal of Cu (II) and U (VI) from aqueous solutions.

The aim of this work was to study the removal of Cu (II) and U (VI) ions from aqueous solutions by encapsulating magnetic Fe3O4 nanoparticles into calcium alginate coated chitosan hydrochloride (CCM) hydrogel beads. ATR-FTIR and XRD analysis data indicated that the CCM composites were successfully prepared. SEM images and EDX spectra showed that Cu2+ and UO22+ ions were adhered onto sorbents. Adsorption properties for removal of both copper and uranium ions under various experimental conditions were investigated. Kinetic data and sorption equilibrium isotherms were also conducted in batch process. The sorption kinetic analysis revealed that sorption of Cu (II) and U (VI) followed the pseudo-second-order model well and exhibited 3-stage intraparticle diffusion model during the whole sorption process. Equilibrium data were best described by Langmuir model, and the CCM composite hydrogel beads showed the estimated maximum adsorption capacity 143.276mg/g and 392.692mg/g for Cu (II) and U (VI), respectively. The CCM adsorbent exhibited excellent reusability for five cycles use without significant changes in the adsorption capacity and structural stability. The results demonstrated that CCM can be an effective and promising sorbent for Cu (II) and U (VI) ions in wastewater.

Graphene oxide encapsulated polyvinyl alcohol/sodium alginate hydrogel microspheres for Cu (II) and U (VI) removal.

In this work, a novel sodium alginate (SA)/polyvinyl alcohol (PVA)/graphene oxide (GO) hydrogel microspheres were prepared by a simple method. Sodium alginate was physically crosslinked by Ca2+; GO was encapsulated into the composite to strengthen the hydrogels; PVA played a significant role in well dispersing of GO in SA. The SA/PVA/GO (SPG) hydrogels were employed as an efficient adsorbent for removal of Cu (II) and U (VI) from aqueous solution. Batch experiments with the subject of the pH, initial metal ion concentration, competing ions and contact time were investigated. Structure characterization was successfully conducted by FTIR, SEM, EDX, BET and XPS. Furthermore, the sorption kinetics of Cu2+ and UO22+ followed pseudo-second order model and exhibited 3-stage intraparticle diffusion model. Equilibrium data were best described by Langmuir model and the obtained maximum adsorption capacities of SPG hydrogel microspheres for Cu2+ and UO22+ were 247.16 and 403.78 mg/g, respectively. The difference in adsorption capacity can be confirmed by the percentage of elements in EDX spectra and the intension of peak of elements in XPS spectra. The SPG sorbent exhibited excellent reusability after 5 adsorption-desorption cycles. All results suggested that the prepared adsorbents could be considered as effective and promising materials for removal of Cu (II) and U (VI) in wastewater.

Design of Meter-Scale Antenna and Signal Detection System for Underground Magnetic Resonance Sounding in Mines.

Magnetic resonance sounding (MRS) is a novel geophysical method to detect groundwater directly. By applying this method to underground projects in mines and tunnels, warning information can be provided on water bodies that are hidden in front prior to excavation and thus reduce the risk of casualties and accidents. However, unlike its application to ground surfaces, the application of MRS to underground environments is constrained by the narrow space, quite weak MRS signal, and complex electromagnetic interferences with high intensities in mines. Focusing on the special requirements of underground MRS (UMRS) detection, this study proposes the use of an antenna with different turn numbers, which employs a separated transmitter and receiver. We designed a stationary coil with stable performance parameters and with a side length of 2 m, a matching circuit based on a Q-switch and a multi-stage broad/narrowband mixed filter that can cancel out most electromagnetic noise. In addition, noises in the pass-band are further eliminated by adopting statistical criteria and harmonic modeling and stacking, all of which together allow weak UMRS signals to be reliably detected. Finally, we conducted a field case study of the UMRS measurement in the Wujiagou Mine in Shanxi Province, China, with known water bodies. Our results show that the method proposed in this study can be used to obtain UMRS signals in narrow mine environments, and the inverted hydrological information generally agrees with the actual situation. Thus, we conclude that the UMRS method proposed in this study can be used for predicting hazardous water bodies at a distance of 7-9 m in front of the wall for underground mining projects.

Probing Frontier Orbital Energies of {Co9(P2W15)3} Polyoxometalate Clusters at Molecule-Metal and Molecule-Water Interfaces.

Functionalization of polyoxotungstates with organoarsonate coligands enabling surface decoration was explored for the triangular cluster architectures of the composition [CoII9(H2O)6(OH)3(p-RC6H4AsVO3)2(α-PV2WVI15O56)3]25- ({Co9(P2W15)3}, R = H or NH2), isolated as Na25[Co9(OH)3(H2O)6(C6H5AsO3)2(P2W15O56)3]·86H2O (Na-1; triclinic, P1̅, a = 25.8088(3) Å, b = 25.8336(3) Å, c = 27.1598(3) Å, α = 78.1282(11)°, ß = 61.7276(14)°, γ = 60.6220(14)°, V = 13888.9(3) Å3, Z = 2) and Na25[Co9(OH)3(H2O)6(H2NC6H4AsO3)2(P2W15O56)3]·86H2O (Na-2; triclinic, P1̅, a = 14.2262(2) Å, b = 24.8597(4) Å, c = 37.9388(4) Å, α = 81.9672(10)°, ß = 87.8161(10)°, γ = 76.5409(12)°, V = 12920.6(3) Å3, Z = 2). The axially oriented para-aminophenyl groups in 2 facilitate the formation of self-assembled monolayers on gold surfaces and thus provide a viable molecular platform for charge transport studies of magnetically functionalized polyoxometalates. The title systems were isolated and characterized in the solid state, in aqueous solutions, and on metal surfaces. Using conducting tip atomic force microscopy, the energies of {Co9(P2W15)3} frontier molecular orbitals in the surface-bound state were found to directly correlate with cyclic voltammetry data in aqueous solution.

Organoarsonate Functionalization of Heteropolyoxotungstates.

Functionalization of the {P8W48} polyoxotungstate (POT) archetype with aromatic organoarsonates results in the first homometallic {P8W48} derivatives, with the general formula [(RAsVO)4PV8WVI48O184]32- [R = C6H5 (1) or p-(H2N)C6H4 (2)]. Short As-O bonds here induce unusual bending of the otherwise rigid {P8W48} macrocycle, breaking its D4h symmetry. The obtained species also represent the first lacunary POTs functionalized with organoarsonates and can potentially act as polyoxometalate precursors themselves. We elaborate solution stability in different aqueous media using 1H and 31P NMR spectroscopy and possible pathways for subsequent transformations in aqueous solutions of the functionalized polyanions. Recrystallization of the K+/Li+/dimethylammonium salt of 2 from 4 M LiCl solution yielded a further functionalized POT, [(H3NC6H4AsO)3P8W48O184Hx{WO2(H2O)2}0.4](30.2-x)- (3), revealing dissociation of the organoarsonate fragments in slightly acidic aqueous solutions followed by their rearrangement within the inner POT cavity.

Development of a Rigid One-Meter-Side and Cooled Coil Sensor at 77 K for Magnetic Resonance Sounding to Detect Subsurface Water Sources.

Magnetic resonance sounding (MRS) using the Earth's magnetic field is a noninvasive and on-site geophysical technique providing quantitative characteristics of aquifers in the subsurface. When the MRS technology is applied in a mine or tunnel for advance detecting the source of water that may cause disastrous accident, spatial constraints limit the size of coil sensor and thus lower the detection capability. In this paper, a coil sensor for detecting the weak MRS signal is designed and the signal to noise (SNR) for the coil sensor is analyzed and optimized. The coil sensor has a rigid structure and square size of 1 m for deploying in a narrow underground space and is cooled at a low temperature of 77 K for improving the SNR. A theoretical calculation and an experimental test in an electromagnetically shielded room (EMSR) show that the optimal design of coil sensor consists of an 80-turn coil and a low-current-noise preamplifier AD745. It has a field sensitivity of 0.17 fT / Hz in the EMSR at 77 K, which is superior to the low temperature Superconducting Quantum Interference Device (LT SQUID) that is the latest application in MRS and the cooled coil with a diameter of 9 cm when detecting the laboratory NMR signal in kHz range. In the field experiment above the Taipingchi Reservoir near Changchun in China, the cooled coil sensor (CCS) developed in this paper has successfully obtained a valid weak MRS signal in high noise environment. The field results showed that the quality of measured MRS signal at 77 K is significantly superior to that at 298 K and the SNR is improved up to three times. This property of CCS makes the MRS instrument more convenient and reliable in a constricted space underground engineering environment (e.g., a mine or a tunnel).

Oxidative removal of phenol by HRP-immobilized beads and its environmental toxicology assessment.

Horseradish peroxidase shows potential biological and environmental applications on the removal of phenolic compounds. In the present study, the HRP-immobilized beads were synthesized to detect the efficiency of the removal of phenol at optimum pH and H2O2 concentration. Comparative in vitro cytotoxicity of phenol/treated solutions were evaluated in HeLa, HepG2 and mcf-7 cells by using MTT method along with flow cytometry study for cell viability and cell cycle distributions. The results showed that the toxicity of phenol solutions were greatly reduced after treated by HRP-immobilized beads, and phenol could lead to deactivate of cells in the S phase and preventing them from going into the G2/M checkpoint. In addition, molecular docking study showed that phenol was a valid inhibitor for the cyclin E in the cell cycle and cell metabolism. Thereby, we established a suitable strategy with promising application for efficient harmless removal of phenol, which significantly decreased the cytotoxic impacts of phenol.

Continuous fixation of dissolved arsenite from flooded soil by cooperating ferrihydrite with Geobacter sulfurreducens.

The fixed arsenic in soil is easy to be released into the aquatic environment in the form of arsenite (As(III)) with high toxicity and mobility due to the eutrophication of environment under anaerobic conditions. However, As(III) is difficult to be fixed in situ continuously by traditional methods, especially for the most efficient fixation method by iron ores. Based on that Fe(II) could promote the fixation of As(III), this study investigated the possibility that Geobacter sulfurreducens (G. sulfurreducens) cooperates with ferrihydrite to fix released As(III) from flooded soil in a glass column continuously under anaerobic conditions. During 42 days of operation of reactors that simulated the actual flooded soil environment, the concentration of released As(III) in the reactor with adding G. sulfurreducens and ferrihydrite is always lower than that in reactors with adding ferrihydrite or no treatment. Compared with reactors without treatment, the accumulated content of released As(III) (2455.0 ± 313.1 µg) decreased by 39.4% in the reactor with adding G. sulfurreducens and ferrihydrite on the last day, while that in reactors with adding ferrihydrite only decreased by 11.6%, respectively. These were caused by the cooperation of G. sulfurreducens and ferrihydrite, which increased the relative abundance of iron-reducing microorganisms to inhibit metabolisms of As-reducing microorganisms, inhibited the quick release of As(III) from solid soil, and promoted the release of iron to accelerate the formation of stable secondary ores with As. This study could provide an environmentally friendly method to fix dissolved As(III) pollutants from soil continuously.

Interactions between arsenic migration and CH4 emission in a soil bioelectrochemical system under the effect of zero-valent iron.

Dissimilatory soil arsenic (As) reduction and release are driven by microbial extracellular electron transfer (EET), while reverse EET mediates soil methane (CH4) emission. Nevertheless, the detailed biogeochemical mechanisms underlying the tight links between soil As migration and methanogenesis are unclear. This study used a bioelectrochemical-based system (BES) to explore the potential effects of zero-valent iron (ZVI) addition on "As migration-CH4 emission" interactions from chemical and microbiological perspectives. Voltage and ZVI amendment experiments showed that dissolved As was efficiently immobilized with increased CH4 production in the soil BES, As release and CH4 production exhibited a high negative exponential correlation, and reductive As dissolution could be entirely inhibited in the methanogenic stage. Gene quantification and bacterial community analysis showed that in contrast to applied voltage, ZVI changed the spatial heterogeneity of the distribution of electroactive microorganisms in the BES, significantly decreasing the relative abundance of arrA and dissimilatory As/Fe-reducing bacteria (e.g., Geobacter) while increasing the abundance of aceticlastic methanogens (Methanosaeta), which then dominated CH4 production and As immobilization after ZVI incorporation. In addition to biogeochemical activities, coprecipitation with ferric (iron) contributed 77-93% dissolved As removal under ZVI addition. This study will enhance our knowledge of the processes and microorganisms controlling soil As migration and CH4 emission.