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Currently available deformability cytometry, combining microfluidics with the bright‐field high‐speed imaging system, has allowed label‐free mechanical characterizations of cells at a rate of hundreds of cells per second. However, the poor contrast between the signal and background under bright‐field imaging, especially for abnormal cells or cells treated with drugs, may produce artifacts during the recognition of cellular contours and subsequently bias the analysis of cellular deformability. In this study, a quantitative phase deformability cytometry (QPDC), constructed from a quantitative phase imaging system, is demonstrated with an improved signal‐to‐noise ratio of the acquired images and mitigated image artifacts, allowing a truthful illustration of cellular contours, especially for cells subjected to actin depolymerization. We have also demonstrated that the phase value extracted from captured images may provide an additional biophysical characteristic of cells. The presented QPDC platform is therefore expected to complement the existing deformability cytometry and expand the capacity of label‐free characterization of cells for biological and clinical applications. [ABSTRACT FROM AUTHOR]

The abuse of sulfameter (SME) in animal husbandry can cause drug resistance and toxic or allergic reactions in humans. Therefore, it is very important to establish a simple, inexpensive, and efficient method for detecting SME in food. In this work, we propose a single fluorescent aptamer/graphene oxide (GO)‐based biosensor to detect SME residues in milk. Aptamers that specifically bind to SME were screened using capture‐SELEX and a ssDNA library immobilized on magnetic beads. The 68 active candidate aptamers were chemically synthesized for specificity and affinity characterization. Among the aptamers, the aptamer sulf‐1 revealed the highest affinity (Kd = 77 ± 15 nM) to SME and was selected to construct a GO‐based fluorescent biosensor for real milk sample detection. Under optimal conditions, the single fluorescent aptasensor had a wide linear range (R2 was 0.997) from 7 to 336 ng/ml and a low detection limit of 3.35 ng/ml that was calculated with a 3SD/slope. The single fluorescent method was also validated using SME‐fortified milk samples, showing average recoveries ranging from 99.01% to 104.60% with a relative standard deviation of less than 3.88%. These results demonstrate that this novel aptamer sensor provides an opportunity for sensitive, convenient, and accurate detection of SME residues in milk. [ABSTRACT FROM AUTHOR]

Dental caries is a major disease associated with the proliferation of acidogenic bacterial species such as Streptococcus mutans that are part of the commensal microbiota of the mouth. Silver nanoparticles (AgNPs) are attractive antibacterial agents as they target multiple sites in bacteria which reduces antimicrobial resistance. In this study, we synthesised stable, highly positively charged AgNPs capped with branched PEI (BPEI‐AgNPs) and characterized them using UV–vis absorption, transmission electron microscopy (TEM), the size of which were approximately 7.5 nm. The antibacterial activity and anti‐biofilm capacity of BPEI‐AgNPs was investigated against cariogenic bacteria. Our results demonstrated that BPEI‐AgNPs are potent clinical oral antiseptics. The cytotoxicity of the BPEI‐AgNPs was also studied against two mammalian cell lines. The results indicated that BPEI‐AgNPs were non‐cytotoxic and were safer than commercially used dental antiseptics. We conclude that the BPEI‐AgNPs are safe for oral clinical application and are an effective oral antimicrobial agent. [ABSTRACT FROM AUTHOR]

Liquid–liquid phase separation (LLPS) forms biomolecular condensates or coacervates in cells. Metabolic enzymes can form phase‐separated subcellular compartments that enrich enzymes, cofactors, and substrates. Herein, we report the construction of synthetic multienzyme condensates that catalyze the biosynthesis of a terpene, α‐farnesene, in the prokaryote E. coli. RGGRGG derived from LAF‐1 was used as the scaffold protein to form the condensates by LLPS. Multienzyme condensates were then formed by assembling two enzymes Idi and IspA through an RIAD/RIDD interaction. Multienzyme condensates constructed inside E. coli cells compartmentalized the cytosolic space into regions of high and low enzyme density and led to a significant enhancement of α‐farnesene production. This work demonstrates LLPS‐driven compartmentalization of the cytosolic space of prokaryotic cells, condensation of a biosynthetic pathway, and enhancement of the biosynthesis of α‐farnesene. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur (Li−S) batteries have been considered one of the most promising energy storage systems, owing to the theoretical specific capacity (1675 mAh g−1) and energy density (2600 Wh g−1). However, it is challenging to solve the shuttling and low reduction kinetics of lithium polysulfides. Hence, the combination of electrospun and hydrothermal treatments acts as an effective strategy to synthesize copper ferrite nanoparticles decorated on nitrogen doped carbon nanofibers (CF/NC). The resultant material is employed as a positive current collector containing Li2S6 catholyte for Li−S batteries. The addition of CF nanoparticles plays a vital role in capturing polysulfides in both physical and chemical adsorption. Besides, promoted sulfur conversion kinetics are obtained due to the excellent catalytic effect, which enabled significantly improved sulfur utilization, high‐rate capability, and cycling stability. Under a 5.75 mg sulfur loading, the cell with CF/NC delivers an excellent cycling stability with 609 mAh g−1 after 300 cycles at 0.2 C. Even at 12.15 mg high sulfur loading, the high initial capacity of the cell is 9.4 mAh at 0.1 C. [ABSTRACT FROM AUTHOR]

In this study, we carried out an amplified luminescent proximity homogeneous assay (AlphaLISA) to detect sulfonamides (SAs) antibiotic residues in plasma, milk, pork, chicken, and fish. The SAs AlphaLISA method can detect 13 SAs with half‐inhibitory concentration (IC50) 2.11–29.77 ng/ml. The detection level of those SAs was 0.3–41.12 ng/ml in matrices, which satisfied the maximum residue limit (MRL) of the European Union, United States, and China. Our recoveries are in the range of 88% to 116.8% with a coefficient of variation less than 9.3% for different spiked food samples. We observed a good correlation between the AlphaLISA and liquid chromatography–tandem mass spectrometry (LC‐MS/MS) with blood samples from injected rabbits. The established AlphaLISA method provided a no‐washing, rapid, high‐throughput screening tool for SAs in food quality control, which is suitable for small‐volume samples. [ABSTRACT FROM AUTHOR]

The microstructural evolution and phase transformation mechanism in 18Cr2Ni4WA carburized steel during high‐temperature tempering is investigated using a thermodynamic model. The experimental results demonstrate that the retained austenite in the matrix decreases from the surface to the core, and martensite transform from acicular to lath‐type. Furthermore, the hardness distribution of the carburized layer increase initially, and then decrease. Based on thermodynamic calculations, the driving forces for the decomposition of martensite decomposition and nucleation of cementite in martensite are larger than those for the decomposition of austenite during tempering. Furthermore, cementite preferentially precipitate in martensite. The driving force for the overall phase transformation of the decomposition of the retained austenite is negative, and the driving force for the nucleation of cementite in the low‐carbon retained austenite is positive, indicating that cementite can nucleate only in high‐carbon retained austenite. The low‐carbon retained austenite transform into secondary martensite on cooling after the tempering process while the driving force gradually increase. The decomposition of the initial quenched martensite during the tempering process leads to a decrease in the overall hardness of the carburized layer. The secondary martensite obtained from the retained austenite contribute to the increase in the surface hardness. [ABSTRACT FROM AUTHOR]

In this work, a novel hexagonal Li2MgSi anode is successfully prepared through a hydrogen-driven chemical reaction technique. Electrochemical tests indicate significantly improved cycling stability for the as-synthesized Li2MgSi compared with that of Mg2Si. Ball-milling treatment induces a polymorphic transformation of Li2MgSi from a hexagonal structure to a cubic structure, suggesting that the cubic Li2MgSi is a metastable phase. The post-24-h-milled Li2MgSi delivers a maximum capacity of 807.8 mAh g−1, which is much higher than that of pristine Li2MgSi. In particular, the post-24-h-milled Li2MgSi retains 50% of its capacity after 100 cycles, which is superior to cycling stability of Mg2Si. XRD analyses correlated with CV measurements do not demonstrate the dissociation of metallic Mg and/or Li-Mg alloy involved in the lithiation of Mg2Si for the Li2MgSi anode, which contributes to the improved lithium storage performance of the Li2MgSi anode. The findings presented in this work are very useful for the design and synthesis of novel intermetallic compounds for lithium storage as anode materials of Li-ion batteries. [ABSTRACT FROM AUTHOR]