The increasing emergence of infectious diseases associated with multidrug-resistant Gram-positive pathogens has raised the urgent need to develop novel antibiotics. GA (15:1) is a natural product derived from Ginkgo biloba and possesses a wide range of bioactivities, including antimicrobial activity.

Pedestrian dead reckoning (PDR) systems based on a microelectromechanical-inertial measurement unit (MEMS-IMU) providing advantages of full autonomy and strong anti-jamming performance are becoming a feasible choice for pedestrian indoor positioning. In order to realize the accurate positioning of pedestrians in a closed environment, an improved pedestrian dead reckoning algorithm, mainly including improved step estimation and heading estimation, is proposed in this paper. Firstly, the original signal is preprocessed using the wavelet denoising algorithm. Then, the multi-threshold method is proposed to ameliorate the step estimation algorithm. For heading estimation suffering from accumulated error and outliers, robust adaptive Kalman filter (RAKF) algorithm is proposed in this paper, and combined with complementary filter to improve positioning accuracy. Finally, an experimental platform with inertial sensors as the core is constructed. Experimental results show that positioning error is less than 2.5% of the total distance, which is ideal for accurate positioning of pedestrians in enclosed environment.

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A solid-state enzymatic time-temperature indicator (TTI) was developed in this paper.Glucoamylase microcapsules, emulsifier, and substrate solution were mixed uniformly, then the mixture was coated on a paper and could be activated by an agar cover. Both single factors and orthogonal experiments were conducted to obtain qualified formulations whose endpoints ranged from 5 to 6 days with storage temperature maintained at 4°C. The Arrhenius activation energy (E A ) of obtained TTIs was also calculated at 107, 97.5, 88.0, 107, 98.5, 87.7, and 89.7 kJ/mol. For the application of TTIs to chilled fresh pork monitoring, both the spoilage mechanism and kinetic properties of pork were studied and an E A value of 64.7 kJ/mol was obtained.After isothermal verification, a qualified TTI formulation was obtained, of which the mass of glucoamylase microcapsules was 0.02 g, the mass of amylose was 5 g, the concentration of iodine solution was 0.1M, and the thickness of agar cover was 2 mm. The time-temperature history of chilled fresh pork can be indicated by the colour response of the TTI.

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Biofilm formation and hemolytic activity are closely related to the pathogenesis of Staphylococcus aureus infections. Herein, we show that lapatinib (12.5 μM) significantly inhibits biofilm formation and hemolytic activity of both methicillinsensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) isolates. Using quantitative reverse transcription PCR, we found that the RNA levels of transcriptional regulatory genes (RNAIII, agrA, agrC, saeR, and saeS), biofilm-formation-related genes (atl, cidA, clfA, clf B, and icaA), and virulence-related genes (cap5A, hla, hld, hlg, lukDE, lukpvl-S, staphopain B, alpha-3 PSM, beta PSM, and delta PSM) of S. aureus decreased after 6 h treatment with lapatinib. Wild-type S. aureus isolates were continuously cultured in vitro in the presence of increasing concentrations of lapatinib for about 140 days. Subsequently, S. aureus isolates with reduced susceptibility to lapatinib (the inhibitory effect of lapatinib on the biofilm formation of these S. aureus isolates was significantly weakened) were selected. Mutations in the genomes of S. aureus isolates with reduced susceptibility to lapatinib were detected by whole-genome sequencing. We identified four genes with mutations: three genes with known functions (membrane protein, pyrrolidone-carboxylate peptidase, and sensor histidine kinase LytS, respectively) and one gene with unknown function (hypothetical protein). In conclusion, this study indicates that lapatinib significantly inhibits biofilm formation and the hemolytic activity of S. aureus.