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Lithium metal batteries (LMBs) based on metallic Li exhibit high energy density to be competent for advanced energy storage applications. However, the unstable solid electrolyte interphase (SEI) layer due to continuous decomposition of electrolytes, and the attendant problem of Li dendrite growth frustrate their commercialization process. Herein, a hybrid SEI comprising abundant LiF, lithiophilic Li-Ge alloy, and Ge nanoparticles is constructed via a simple brush coating method. This fluorinated interface layer with embedded Ge-containing components isolates the Li anode from the corrosive electrolyte and facilitates homogenous Li nucleation as well as uniform growth. Consequently, the modified Li anode exhibits remarkable stability without notorious Li dendrites, delivering stable cycling lives of more than 1000 h for symmetric Li∥Li cells and over 600 cycles for Li∥Cu cells at 1 mA·cm−2. Moreover, the reinforced Li anodes endow multiple full-cell architectures with dramatically improved cyclability under different test conditions. This work provides rational guidance to design an artificial hybrid SEI layer and would stimulate more ideas to solve the dendrite issue and promote the further development of advanced LMBs. [ABSTRACT FROM AUTHOR]

Bacterial biofilms formation is one of the major reasons for treatment failure in chronic wound infections. Therefore, diagnostic biomarkers remain the best option for prevention and treatment of chronic wound infections by biofilms. Herein, Pseudomonas aeruginosa PAO1 was used to mimic biofilm development in porcine skin explants wells as ex vivo wound model. The microscopic imaging showed that PAO1 in porcine skin explants wells formed micro-colonies at 24 h, developed mushroom-like structure at 48 h, and at 72 h mushroom-like structure disappeared, remaining a thin bacterial lawn. RNA-seq data analysis revealed that the expression levels of genes involved in the type II hxc secretion system were significantly higher in biofilms than in planktonic cells, especially the expression of lapA encoding alkaline phosphatase. However, the expression levels of genes associated with denitrification pathway were markedly decreased in biofilms, especially the transcription of nirS encoding nitrite reductase to produce nitric oxide (NO). Therefore, their expressions and products were further detected using RT-qPCR and biochemical assays, respectively. The results found that the expression of lapA and alkaline phosphatase activity were induced, but the expression of nirS and intracellular NO were reduced at the whole biofilms cycle. The study indicates that LapA and NO would play an important role for P. aeruginosa biofilm formation in chronic wound infections. LapA would serve as potential target to monitor chronic wound infections by P. aeruginosa biofilms. Inducing NO would be used to treat chronic wound infections due to P. aeruginosa biofilms. [ABSTRACT FROM AUTHOR]

Bacterial biofilm infection is perplexing people's life. Systemic administration of antibiotics usually causes adverse effects and bacterial resistance. How to make antibacterial agents quickly penetrate and eradicate the biofilm without adverse effects is an urgent problem. Here, polyamine-functionalized carbon quantum dots (CQDs), abbreviated as CQD600, CQD1w and CQD2.5w, are synthesized by a simple hydrothermal treatment of citric acid and branched polyethyleneimine (bPEI) with different molecular weight (MW). It is found that the antibacterial activity is promoted with high MW of bPEI, which is due to the protonated amines on the surface of the CQDs. Moreover, in terms of eradicating mature Staphylococcus aureus biofilm, CQD2.5w possesses significantly higher activity than CQD600 and CQD1w because of stronger electrostatic interactions and longer surface coronas. Additionally, the cytotoxicity test exhibits the L929 cells can keep at high survival rates even treated with 500 µg mL−1 CQDs for 3 days. In this study, the surface chemistry related to antibacterial activity and low cytotoxicity give the chance in designing and developing better CQDs for biofilm infection. [ABSTRACT FROM AUTHOR]

Photochromic spiropyran with a long chain alkyl substitute can form axial complexes with α-, β-, and γ-cyclodextrin, respeetively. The complexes show normal photochromism. The novel property of the colored forms of the inclusion complexes is that they can assemble into dimers at relatively low concentration or J-aggregates at relatively high concentration. For α-, β-, and γ-cyclodextrin, λmax of the J-aggregates appear at 700 650, and 630 nm, respectively. The sizes of the cavities of cyclodextrins have very little effect on the spectra and decoloration kinetics of the dimers, but have great effects on the spectra of the J-aggregates. Unlike the charge transfer complex of Krongauz, the decoloration process of the dimers or J-aggregates cannot be described by an exponential or a two-exponential kinetics, but obey half-order kinetics very well. Another result that can be deduced from the kinetic analysis is that unlike the dimers formed in apolar solvents or in polymers, which consist of a colored molecule (B’) and a colorless molecule (Á) with a composition of A’B’, in the present system, the dimer of the inclusion complex consists of two colored molecules (B). All these results can be interpreted by the proposed structure model and decoloration mechanism. [ABSTRACT FROM AUTHOR]

Genetic engineering in livestock was greatly enhanced by the emergence of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9), which can be programmed with a single-guide RNA (sgRNA) to generate site-specific DNA breaks. However, the uncertainties caused by wide variations in sgRNA activity impede the utility of this system in generating genetically modified pigs. Here, we described a single blastocyst genotyping system to provide a simple and rapid solution to evaluate and compare the sgRNA efficiency at inducing indel mutations for a given gene locus. Assessment of sgRNA mutagenesis efficiencies can be achieved within 10 days from the design of the sgRNA. The most effective sgRNA selected by this system was successfully used to induce site-specific insertion through homology-directed repair at a frequency exceeding 13%. Additionally, the highly efficient gene deletion via the selected sgRNA was confirmed in pig fibroblast cells, which could serve as donor cells for somatic cell nuclear transfer. We further showed that direct cytoplasmic injection of Cas9 mRNA and the favorable sgRNA into zygotes could generate biallelic knockout piglets with an efficiency of up to 100%. Thus, our method considerably reduces the uncertainties and expands the practical possibilities of CRISPR/Cas9-mediated genome engineering in pigs. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO), produced through the denitrification pathway, regulates biofilm dynamics through the quorum sensing system in Pseudomonas aeruginosa. NO stimulates P. aeruginosa biofilm dispersal by enhancing phosphodiesterase activity to decrease cyclic di-GMP levels. In a chronic skin wound model containing a mature biofilm, the gene expression of nirS, encoding nitrite reductase to produce NO, was low, leading to reduced intracellular NO levels. Although low-dose NO induces biofilm dispersion, it is unknown whether it influences the formation of P. aeruginosa biofilms in chronic skin wounds. In this study, a P. aeruginosa PAO1 strain with overexpressed nirS was established to investigate NO effects on P. aeruginosa biofilm formation in an ex vivo chronic skin wound model and unravel the underlying molecular mechanisms. Elevated intracellular NO levels altered the biofilm structure in the wound model by inhibiting the expression of quorum sensing-related genes, which was different from an in vitro model. In Caenorhabditis elegans as a slow-killing infection model, elevated intracellular NO levels increased worms' lifespan by 18%. Worms that fed on the nirS-overexpressed PAO1 strain for 4 h had complete tissue, whereas worms that fed on empty plasmid-containing PAO1 had biofilms on their body, causing severe damage to the head and tail. Thus, elevated intracellular NO levels can inhibit P. aeruginosa biofilm growth in chronic skin wounds and reduce pathogenicity to the host. Targeting NO is a potential approach to control biofilm growth in chronic skin wounds wherein P. aeruginosa biofilms are a persistent problem., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)