Latest ArticlesDendrite growth of zinc (Zn) anode at high current density severely affects the fast-charging performance of aqueous zinc metal batteries (AZMBs). While interfacial modification strategies can optimize Zn performance, challenges such as complicated preparation processes, excessive layer thicknesses, and high voltage hysteresis should be addressed. Herein, we utilize a cost-effective liquid fluorosiloxane, (3,3,3-trifluoropropyl)trimethoxysilane, for scalable modification of Zn foil via drop-casting at room temperature, resulting in an ultra-thin interphase layer of only 20 nm. The Si-O-Zn bonds formed between fluorosiloxane and Zn ensure interfacial stability, and the Si-O-Si bonds between fluorosiloxane molecules help to homogenize the electric field distribution. Additionally, the abundant highly electronegative fluorine atoms on the anode surface act as zincophilic sites, promoting the uniform deposition of Zn2+. Thus, the modified Zn foil (SiFO-Zn) exhibits excellent dendrite suppression, reduced voltage hysteresis, and prolonged cycle life at ultra-high current density (40 mA/cm2), achieving a cumulative areal capacity of 12.9 Ah/cm2. Further, the full cell assembled with 10 µm-thick SiFO-Zn anode and MnO2 cathode achieves 2600 cycles at 5 A/g with minimal capacity degradation, and a large-size (22.5 cm−2) pouch cell powers the light-emitting diode even after reverse bending, demonstrating the potential of AZMBs for fast-charging flexible devices.
Surface chemistry focuses on the investigation of the adsorption, migration, assembly, activation, reaction, and desorption of atoms and molecules at surfaces. Surface chemistry plays the pivotal roles in both fundamental science and applied technology. This review will summarize the recent progresses on surface assembly, synthesis and catalysis investigated mainly by scanning tunneling microscopy and atomic force microscopy. Surface assemblies of water and small biomolecules, construction of Sierpiński triangles and surface chirality are summarized. On-surface synthesis of conjugated carbo- and heterocycles and other kinds of carbon nanostructures are surveyed. Surface model catalysis, including single-atom catalysis and electrochemical catalysis, are discussed at the single-atom level.
Regulation of cell fate requires the establishment and erasure of 5-methylcytosine (5mC) in genomic DNA. The formation of 5mC is achieved by DNA cytosine methyltransferases (DNMTs), whereas the removal of 5mC can be accomplished by various pathways. Aside from ten-eleven translocation (TET)-mediated oxidation of 5mC followed by thymine DNA glycosylase (TDG)-initiated base excision repair (BER), the direct deformylation of 5-formylcytosine (5fC) and decarboxylation of 5-carboxylcytosine (5caC) have also been discovered as the novel DNA demethylation pathways. Although these novel demethylation pathways have been identified in stem cells and somatic cells, their precise roles in regulating cell fate remain unclear. Here, we differentiate mouse embryonic stem cells (mESCs) into mouse embryoid bodies (mEBs), followed by further differentiation into mouse neural stem cells (mNSCs) and finally into mouse neurons (mNeurons). During this sequential differentiation process, we employ probe molecules, namely 2′-fluorinated 5-formylcytidine (F-5fC) and 2′-fluorinated 5-carboxyldeoxycytidine (F-5caC), for metabolic labeling. The results of mass spectrometry (MS) analysis demonstrate the deformylation and decarboxylation activities are progressively decreased and increased respectively during differentiation process, and this opposite demethylation tendency is not associated with DNMTs and TETs.
The new reactions between o-hydroxyphenyl enaminones and Langlois reagent (CF3SO2Na) for the tunable synthesis of 3-(trifluoromethylthio) chromones and 3-trifluoromethylsulfinyl chromones are reported herein. Both type of reactions proceed under transition metal-free conditions. In addition, the conditions for the synthesis of 3-trifluoromethylsulfinyl chromones have also been found to be applicable for the synthesis of 3-alkyl/arylsulfinyl chromones.
Efficient activation of molecular oxygen (O2) is considered a promising technique for the removal of antibiotics. However, how to effectively regulate electrons distribution to promote O2 activation remains a challenge at present. In this study, phosphorus and sodium co-doped carbon nitride (PNaCN) were designed to rearrange the electrons distribution to activate O2 for the degradation of tetracycline. The generation of •O2−was innovatively observed via in-situ O2 fitting Fourier transform infrared (FTIR) spectroscopy, demonstrating the outstanding O2 activation ability of PNa5. Density functional theory (DFT) further confirmed that the rational co-doping led to the rearrangement of local electrons, resulting in electron-rich Na sites and electron-deficient P sites. These sites exhibited greater susceptibility to O2 adsorption and charge transfer. Besides, the degradation rate of tetracycline was increased by 2.44 times using co-doped CN. This study provides a new inspiration for enhancing O2 activation by inducing electrons rearrangement.
Parkinson’s disease (PD) is an aging-associated neurodegenerative movement disorder with increasing morbidity and mortality rates. The current gold standard for diagnosing PD is clinical evaluation, which is often challenging and inaccurate. Metabolomics and lipidomics approaches have been extensively applied because of their potential in discovering valuable biomarkers for medical diagnostics. Here, we used comprehensive untargeted metabolomics and lipidomics methodologies based on liquid chromatography-mass spectrometry to evaluate metabolic abnormalities linked with PD. Two well-characterized cohorts of 288 plasma samples (143 PD patients and 145 control subjects in total) were used to examine metabolic alterations and identify diagnostic biomarkers. Unbiased multivariate and univariate studies were combined to identify the promising metabolic signatures, based on which the discriminant models for PD were established by integrating multiple machine learning algorithms. A 6-biomarker predictive model was constructed based on the omics profile in the discovery cohort, and the discriminant performance of the biomarker panel was evaluated with an accuracy over 81.6% both in the discovery cohort and validation cohort. The results indicated that PC (40:7), eicosatrienoic acid were negatively correlated with severity of PD, and pentalenic acid, PC (40:6p) and aspartic acid were positively correlated with severity of PD. In summary, we developed a multi-metabolite predictive model which can diagnose PD with over 81.6% accuracy based on this unique metabolic signature. Future clinical diagnosis of PD may benefit from the biomarker panel reported in this study.
Water-soluble inorganic ions (WSIIs) play a pivotal role in atmospheric chemical reactions, particularly influencing the formation of secondary particulate matter. A comprehensive grasp of the vertical distribution of atmospheric pollutants holds immense significance in understanding the diffusion and transportation of these pollutants. This study investigates the WSIIs of PM2.5 and size-segregated particles at the top (~2060 m a.s.l.) and foot of Mt. Hua during the winter of 2020. All the measured ions present significant higher concentrations (1.9~6.9 times) at the foot than the top. Cl− and K+ at the foot are more than 4 times of those at the top, whereas Ca2+ and Mg2+ are only 1.3–1.9 times higher. The particle size distribution of NO3−, SO42−, K+ and Cl− demonstrate a single peak distribution (0.7–1.1 µm) at the foot, but with a bimodal distribution (0.7–1.1 µm and 4.7–5.8 µm) at the top. These differences suggest that the aerosol at the alpine region is mainly transported via long-distance from Northwest/North China, but limited influenced by vertical transport through valley breeze. The changes of concentration and size distribution of WSIIs in dust event and non-dust period indicate that the effects of dust event on aerosols at ground surface were weaker than that of the free troposphere of Guanzhong Plain. Notably, our study underscores the dominant influence of NO3− in shaping the gas-particle distribution of ammonia within the winter free troposphere. Our results highlight the significant role of long-range transport on aerosols in the free troposphere in Guanzhong Plain, Northwest China.
In the exploration of circularly polarized luminescence (CPL) materials, doping cholesteric liquid crystals (CLCs) with achiral dyes is a common strategy. Conjugated polymers are favored as achiral dyes for their superior luminescent properties. In this study, a series of oligomers (M1-M3) and the conjugated polymer F8BT were synthesized to systematically assess the impact of the length of the conjugated backbone on CPL signals of CLCs doped with conjugated polymers. As the length rose from M1 to M3, CPL intensity concurrently increased (glum increased from 0.35 to 0.84), attributable to enhanced dichroism (order parameter, SF increased from 0.20 to 0.56). In contrast, F8BT polymer resulted in diminished CPL intensity (|glum| = 0.64) due to the reduced compatibility. Achieving a balance between dichroism and compatibility is crucial for optimizing CPL in conjugated polymer-doped CLCs. The guiding principle established here may have broad applicability in other CPL assemblies, offering a strategic avenue to engineer high-performance CPL materials with conjugated polymer.
Four novel compounds based on hexanuclear thorium cluster were synthesized and characterized. Compound 1 [Th6(HPyC)8(HCOO)4] is formed by replacing formate ligands of preassembled thorium cluster [Th6O4(OH)4(H2O)6(HCOO)12] with eight H2PyC (4-pyrazolecarboxylic acid) under solvothermal conditions. Each of the HPyC− ligands is coordinated with one Cu2+ to form the (4,8)-connected -net structure of compound 2 [(CuCl2)2Th6(HPyC)8(HCOO)4]. In compound 3 [(CuCl2)2Th6(HPyC)10(HCOO)4], ten of the formate ligands of preassembled Th6 cluster are replaced by HPyC− ligands. Compared with compound 2, the two extra HPyC− ligands in the equatorial plane of the Th6 cluster in compound 3 are not further connected to copper ions. Therefore, the topology structure of compound 3 is same with that of compound 2. Compound 4 [(Cu3Cl2)(CuCl2)Th6(PyC)3(HPyC)4(HCOO)5] contains three kinds of metal nodes, Th6 cluster, Cu3 cluster and mononuclear Cu2+, and exhibits a novel (5,7)-connected net structure, which was first discovered in actinide MOFs. Furthermore, considering the satisfactory stability of compound 4 and its unsaturated metal nodes and Lewis acid sites, the catalysis of cycloaddition of CO2 was further studied. We found that this thorium-copper heterometallic cluster organic framework can be used as a potential actinide functional material for catalyzing the efficient CO2 conversion to value-added products.
As a key biomarker for noninvasive diagnosis of diabetes, the selective detection of trace acetone in exhaled gas using a portable and low-cost device remains a great challenge. Semiconductor metal oxide (SMO) based gas sensors have drawn signification attention due to their potential in miniaturization, user-friendliness, high cost-effectiveness and selective real-time detection for noninvasive clinical diagnosis. Herein, we propose a one-pot solvent evaporation induced tricomponent co-assembly strategy to design a novel ordered mesoporous SMO of silica-implanted WO3 (SiO2/WO3) as sensing materials for trace acetone detection. The controlled co-assembly of silicon and tungsten precursors and amphiphilic diblock copolymer poly(ethylene oxide)-block-polystyrene (PEO-b-PS), and the subsequent thermal treatment enable the local lattice disorder of WO3 induced by the amorphous silica and the formation of ordered mesoporous SiO2/WO3 hybrid walls with a unique metastable ε-phase WO3 framework. The obtained mesoporous SiO2/WO3 composites possess highly crystalline framework with large uniform pore size (12.0–13.3 nm), high surface area (99–113 m2/g) and pore volume (0.17–0.23 cm3/g). Typically, the as-fabricated gas sensor based on mesoporous 2.5%SiO2/WO3 exhibits rapid response/recovery rate (5/17 s), superior sensitivity (Rair/Rgas = 105 for 50 ppm acetone), as well as high selectivity towards acetone. The limit of detection is as low as 0.25 ppm, which is considerably lower than the thresh value of acetone concentration (>1.1 ppm) in the exhaled breath of diabetic patients, demonstrating its great prospect in real-time monitoring in diabetes diagnosis. Moreover, the mesoporous 2.5%SiO2/WO3 sensor is integrated into a wireless sensing module connected to a smart phone, providing a convenient real-time detection of acetone.