Latest ArticlesSkeletonema costatum is a diatom widely distributed in red tide microalgae blooms and as one of the main algae causing harmful algal blooms, because of their rapid reproduction and production of toxic and harmful substances, often play a negative role in aquatic ecosystems, and human health and wellbeing. Bacillomycin D is a nonribosomal cyclic antifungal lipopeptide in the iturins family. In this study, Bacillomycin D was tested for its ability to inhibit the growth of S. costatum. The EC50 24h of Bacillomycin D on S. costatum was 24.70 μg/mL. The chlorophyll fluorescence parameters Fv/Fm, Fv/Fo, and yield of the diatoms decreased significantly with increasing concentrations of Bacillomycin D. Study of the mechanism showed that Bacillomycin D induced cell death by changing cell membrane permeability, promoting the release of cellular contents. In this study, transcriptomic analysis showed Bacillomycin D significantly inhibited the photosynthesis and metabolism of S. costatum. These findings investigated the inhibitory effect of Bacillomycin D on the growth of S. costatum and provided a theoretical foundation for the development of new environmentally friendly biological algicide.
Considering the significant importance in both ecological and environmental fields, converting nitrogen oxide (NOx, especially NO) into value-added NH3 or harmless N2 lies in the core of research over the past decades. Exploring catalyst for related gas molecular activation and highly efficient reaction systems operated under low temperature or even mild conditions are the key issues. Enormous efforts have been devoted to NO removal by utilizing various driving forces, such as thermal, electrical or solar energy, which shine light on the way to achieve satisfying conversion efficiency. Herein, we will review the state-of-the-art catalysts for NO removal driven by the above-mentioned energies, including a comprehensive introduction and discussion on the pathway and mechanism of each reaction, and the recent achievements of catalysts on each aspect. Particularly, the progress of NO removal by environmentally friendly photocatalysis and electrocatalysis methods will be highlighted. The challenges and opportunities in the future research on the current topic will be discussed as well.
Regulation of chemical composition and nanostructure, such as the introduction of dopant into two-dimensional nanomaterials, is a general and valid strategy for the efficient electrocatalyst design. In this work, Co4S3/Co9S8 nanosheets, with an ultrathin layer structure, were successfully synthesized via an efficient solvothermal process combined with ultrasonic exfoliation. Different metal ions (M = Fe3+, Cr3+, Mn2+ and Ni2+) were then doped by a simple cation exchange method and the effects of different dopants on the OER activities of Co4S3/Co9S8 NS were further investigated in alkaline media. The corresponding results implied that M-doped Co4S3/Co9S8 NS (M = Fe3+, Cr3+, Mn2+ and Ni2+) exhibited different electrocatalytic properties. Evidenced by XPS spectra, the different OER activities were mainly aroused by the redistribution of charge at the interface due to an electronic interaction between the doped metal ions and Co4S3/Co9S8 NS.
Highly dispersed silicotungstic acid-derived WO3 composited with ZrO2 supported on SBA-15 (WZ/SBA-15) as an ordered mesoporous solid acid catalyst was prepared via a facile incipient wetness impregnation (IWI) method that active ingredients, ZrO2 and WO3, were impregnated into the channels of SBA-15 simultaneously with a subsequent calcination process. The relationship between catalyst nature and performance was explored by high resolution transmission electron microscopy (HRTEM), high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), FT-IR, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), N2 adsorption-desorption, NH3 temperature-programmed desorption (NH3-TPD), and FT-IR of pyridine adsorption (Py-IR) characterization techniques. The catalytic performance of W12Z15/SBA-15 is not only greater than that of single component solid acid catalysts, WO3/SBA-15 and ZrO2/SBA-15, but also W12/Z15/SBA-15 prepared by impregnating active ingredients, ZrO2 and WO3, into SBA-15 in sequence. The outstanding performance of W12Z15/SBA-15 is derived from the strong interaction between ZrO2 and WO3, which results in more acid sites, and relatively high specific surface area, large pore volume, and ordered mesoporous structure of SBA-15. The characterization and reaction results clearly demonstrate that the synergy of ZrO2 and WO3 has a clear boost for the alkenylation. The optimized W12Z15/SBA-15-500 achieves a 99.4% conversion of phenylacetylene and a 92.3% selectivity of main product α-arylstyrene for the alkenylation of p-xylene with phenylacetylene, with very low level of oligomers producing at the same time. Moreover, W12Z15/SBA-15-500 shows excellent catalytic stability and regeneration. Therefore, W12Z15/SBA-15-500 is a promising solid acid catalyst for the alkenylation.
In recent years, MoS2 catalyzed/cocatalyzed Fenton/Fenton-like systems have attracted wide attention in the field of pollution control, but there are few studies on the effect of H2O2 feeding way on the whole Fenton process. Here, we report a new type of composite catalyst (MoS2-Fex) prepared in a simple way with highly dispersed iron to provide more active sites. MoS2-Fex was proved to possess selectivity for singlet oxygen (1O2) in effectively degrading sulfadiazine with a wide pH adaptability (4.0~10.0). Importantly, the mechanism of the interaction between H2O2 and MoS2 on the Fenton reaction activity was revealed through the combination of experiment and density functional theory (DFT) calculations. Compared to the traditional "a large amount for one time" feeding way of H2O2, the "small amount for multiple times" of H2O2 feeding way can increase the degradation rate of sulfadiazine from 36.9% to 91.1% in the MoS2-Fex heterogeneous Fenton system. It is demonstrated that the "small amount for multiple times" of H2O2 feeding way can reduce the side reaction of decomposition of H2O2 by MoS2 and effectively improve the utilization rate of H2O2 and the stability of MoS2-Fex. Compared with Fe2O3-based Fenton system, MoS2-Fex can significantly save the amount of H2O2. Compared with nano-iron powder, the formation of iron sludge in MoS2-Fex system was significantly reduced. Furthermore, long-term degradation test showed that the MoS2-Fe75/H2O2 system could maintain the effectiveness of degrading organic pollutants for 10 days (or even longer). This study has a guiding significance for the large-scale treatment of industrial wastewater by improved Fenton technology in the future.
Accurate single-cell capture is a crucial step for single cell biological and chemical analysis. Conventional single-cell capturing often confront operational complexity, limited efficiency, cell damage, large scale but low accuracy, incompetence in the acquirement of nano-upgraded single-cell liquid. Flow cytometry has been widely used in large-scale single-cell detection, while precise single-cell isolation relies on both a precision operating platform and a microscope, which is not only extremely inefficient, but also not conducive to couple with modern analytical instruments. Herein, we develop a modular single-cell pipette (mSCP) microfluidic chip with high efficiency and strong applicability for accurate direct capture of single viable cell from cell suspensions into nanoliter droplets (30-1000 nL). The mSCP is used as a sampling platform for the detection of CdTe quantum dots in single cells with electrothermal atomic absorption spectrometry (ETAAS) for the first time. It also ensures precise single-cell sampling and detection by inductively coupled plasma mass spectrometry (ICP-MS).
Here, we report a finding on light-mediated CO2-responsiveness. It is found on the microgels that are made of side-chain type metallopolymers containing metalla-aromatics. Turbidity and laser light scattering studies on dilute aqueous dispersion of these microgels in dark indicate high CO2-responsivity, but poor reversibility upon N2 purge, which can be improved by exposing to light. This light-mediated CO2-responsiveness can be elucidated by the loss of aromaticity from initial photoexcitation and concurrent formation of a less reactive, antiaromatic excited state of relatively low CO2 binding affinity, and by subsequent relief of antiaromaticity that can enhance the CO2 removal. The finding is also checked by CO2 uptake-release experiments on the microgels, which enables both CO2 capture of high capacity and CO2 removal of good reversibility under a mild condition, allowing effective and reversible response to dilute CO2.
Magnetic particles (MPs) are the most widely used commercialized engineering particles, which gained great success in various biological applications. Inspired by their intrinsic Fe isotope composition, we discovered a commercialized MPs-internal standard's novel function to realize the accurate quantification of biomolecules. The bioassay of carcinoembryonic antigen (CEA) was chosen as a modal system. The Fe isotope in MPs and Au isotope in report probes were simultaneously and sensitively detected by the elemental mass spectrometry. 197Au/57Fe isotopic ratios and CEA concentrations showed good linearity in the range of 0.6–300 ng/mL, with a detection limit of 0.09 ng/mL (3σ). The accuracy and precision of the proposed MPs-based immunoassay were greatly improved, by eliminating potential MPs loss during magnetic separation and absolute intensity fluctuations. Considering the exceptional availability and universality of commercialized MPs, the proposed method might open a new avenue for MPs' biological applications.
H2S selective catalytic oxidation technology is a prospective way for the treatment of low concentration acid gas with simple process operation and low investment. However, undesirable results such as large formation of SO2 and catalyst deactivation inevitably occur, due to the temperature rise of fixed reaction bed caused by the exothermic reaction. Catalyst with high activity in wide operating temperature window, especially in high temperature range, is urgently needed. In this paper, a series of copper-substituted hexaaluminate catalysts (LaCux, x = 0, 0.5, 1, 1.5, 2, 2.5) were prepared and investigated for the H2S selective oxidation reaction at high temperature conditions (300-550℃). The LaCu1 catalyst exhibited excellent catalytic performance and great stability, which was attributed to the best reductive properties and proper pore structure. Besides, two facile deep processing paths were proposed to eliminate the remaining H2S and SO2 in the tail gas.
Spin-crossover (SCO) complexes with multiple spin states are promising candidates for high-order magnetic storage and multiple switches. Here, by employing the N, Nʹ-4-dipyridyloxalamide (dpo) ligand, we synthesize two Hofmann-type metal-organic frameworks (MOFs) [Fe(dpo){Ag(CN)2}2]·3DMF (1) and [Fe(dpo){Ag(CN)2}2]·0.5MeCN·2DEF (2), which exhibit guest dependent four-step SCO behaviors with the sequences of LS → ~LS2/3HS1/3 → LS1/2HS1/2 → ~LS3/10HS7/10 → HS and LS → ~LS2/3HS1/3 → LS1/2HS1/2 → ~LS1/4HS3/4 → HS, respectively. Therefore, the incorporation of hydrogen-donating/hydrogen-accepting groups into the Hofmann-type MOFs may effectively explore the multi-step SCO materials by tuning hydrogen-bonding interactions.