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We reported a colorimetric paper-based device by integrating the modified acid RNA-cleaving DNAzymes (MaRCD-EC1) for highly sensitive (detection limit = 102 CFU mL−1), and rapid (within 30 min) detection of E. coli without amplification. This device exhibited a clinical sensitivity of 100% and a specificity of 100% in identifying E. coli-associated urinary tract infections (UTIs) using the clinical urine samples. [ABSTRACT FROM AUTHOR]

NiCoO2 (NCO) with a desirable redox activity, high lithium storage capacity and distinct rock-salt structure has gained increasing attention toward application in next-generation lithium ion batteries (LIBs) in comparison with other transition metal oxides (TMOs). However, the volumetric change and pulverization of the NCO electrode during the charge/discharge processes hugely limit its utilization in LIBs. In this study, we present a novel assembling protocol via integrating different structural configurations to address the general limitations of TMO anodes, which effectively improves the rate and cycling performance of the NCO anode. In addition, we provide an insightful understanding of the electrochemical behaviors of NCO through various ex situ characterization techniques and first-principles DFT calculations for the first time. This study reveals that the inherent rock-salt phase character of NCO could not only preserve 3D channels toward efficient ionic/electrical interdiffusion, but also retain high electrochemical reversibility during the long cycling process in comparison to the spinel NiCo2O4. Potential application of the NCO anode for LIBs has also been evaluated through assembling full cells. This study demonstrates the synergistic influences of the innate structure of NCO and elaborate composite architecture on the performance, paving the way for future design and manufacture of TMO anodes for practical applications. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) heterostructures combine the advantageous features of different 2D materials and represent advanced electrode architectures for the development of efficient energy storage devices. However, common 2D heterostructures made by stacking different 2D sheets in van der Waals (vdW) contact impose obvious limitations in light of the energy storage performance. Here, we shed light on how heterointerface conditions exert a great influence on the electrochemical properties of the heterostructured electrode and provide an example to modulate the interface contact mode via sandwiching unique g-C3N4 mesh (m-g-C3N4). We find that such m-g-C3N4 bonded heterointerfaces can greatly increase the electrochemical activity, redox conversion kinetics and structural integrity of the constituent component (NiS2), manifesting excellent electrochemical performance with respect to vdW heterostructures. Experimental characterization along with theoretical simulations demonstrates that the synergistic effects of the mesh-bonded interfacial contact and plenty of in-between porous channels contribute to superior electrochemical performance. This study directs attention to elaborate interface engineering toward high-performance energy storage and paves the way for designing and manufacturing of advanced heterostructured electrodes for supercapacitors, batteries and other hybrid devices. [ABSTRACT FROM AUTHOR]

In this paper, we propose a facile and mild route to prepare size-tunable silver nanoparticles (Ag NPs) and their finishing application on fabrication of antibacterial cotton fabrics. The as-prepared Ag NPs, with an average particles size of 2.3 nm, show the minimal inhibitory concentration of 7.8 µg/mL and the minimum bactericidal concentration of 15.6 µg/mL, respectively. In this study, sodium citrate served as a stabilizing agent to prevent Ag NP agglomeration in the synthesis process, and citric acid acted as a binder to fix Ag NPs on the cotton fabrics through chemical bonds in the finishing process. The results of Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy demonstrate that Ag NPs have been fixed and well dispersed on the cotton fabric surface. Ag contents in the hybrid fabrics were measured by the techniques of inductively coupled plasma atomic emission spectroscopy and UV-vis, and the antibacterial properties of hybrid fabrics were tested by the shake flask and agar diffusion plate method. It is found that the Ag NP coated cotton fabrics exhibit excellent antimicrobial activities against both the Gram-negative bacterium of Escherichia coli (E. coli) and the Gram-positive bacterium of Staphylococcus aureus (S. aureus). The percentages of reduction bacteria remain at 91.8% and 98.7% for S. aureus and E. coli, respectively, even after 50 cycles of consecutive laundering, which indicates that the antibiotic performance of the as-fabricated hybrid fabrics is also durable. [ABSTRACT FROM AUTHOR]

Zinc is the second trace element of living organisms after iron. Given its crucial importance, mammalian hosts restrict the bioavailability of Zinc ions (Zn2+) to bacterial pathogens. As a countermeasure, pathogens utilize high affinity Zn2+ transporters, such as ZnuACB to compete with the host for zinc. It is essential for bacteria to maintain zinc homeostasis and thus maintain their physiology and pathogenesis. In an attempt to uncover the zinc transporter in F4+ enterotoxigenic E. coli (ETEC) C83902, we analyzed two RNA-seq data sets of bacteria samples when different zinc treatments (restriction or abundance) were applied. Considering data revealing that the high affinity zinc uptake system ZnuACB acts as the main transporter in ETEC C83902 to resist zinc deficiency, we deleted znuACB genes to study the role of them in ETEC C83902. The deletion of znuACB genes results in growth perturbation and a sharp decrease in the ability of biofilm formation and adhesion of bacteria in vitro. Taking the data together, this study demonstrates that the ZnuACB system is required for ETEC C83902 to acquire zinc, which highly contributes to ETEC pathogenicity as well. [ABSTRACT FROM AUTHOR]