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The viable but nonculturable (VBNC) state refers to a state in which bacteria lose their ability to grow and reproduce in conventional media under adverse environmental stress conditions. Bacteria in the VBNC state are usually still metabolically active and remain pathogenic and virulent. Bacteria in the VBNC state can recover and return to a state where they can be cultured normally under certain suitable conditions, posing potential risks to food safety. In this review, the morphological, physiological, biochemical and biomacromolecular characteristics of bacteria, especially foodborne pathogens, in the VBNC state are comprehensively described. Meanwhile, various factors that induce bacteria to enter the VBNC state, including temperature and pH unsuitable for bacteria survival, are summarized. The laboratory conditions for bacterial recovery from the VBNC state are outlined with special reference to adequate nutrition as an indispensable factor for recovery from the VBNC state. Finally, the major methods for the detection of bacteria in the VBNC state are discussed, including molecular biological methods, flow cytometry, and optical microscopy. Molecular biological methods have been widely used in the detection of bacteria in the VBNC state due to their advantages of accuracy, rapidity and high sensitivity. This review provides more ideas for further research on the induction, resuscitation and detection of foodborne pathogens in the VBNC state.

Benzalkonium chloride is a quaternary ammonium compound with bactericidal activity, which is widely used in domestic and healthcare settings as well as in food processing environments. It plays an important role in the prevention and control of foodborne pathogens. However, the presence of biofilms or improper use of benzalkonium chloride may enable foodborne pathogens to adapt to bactericides, affecting the tolerance to homologous or heterologous biocidal agents. The review summarizes the relationship between the adaptation of foodborne pathogens to benzalkonium chloride and their tolerance to this biocide. The reasons for the increased tolerance to benzalkonium chloride are explained from the perspectives of the expression of efflux pump genes, cell membrane modification, and the formation of the viable but non-cultivable (VBNC) state. Furthermore, the influence of benzalkonium chloride adaptation on the antibiotic resistance of foodborne pathogens is discussed, and the reasons for the increased antibiotic resistance are summarized from the perspectives of biofilm formation, spontaneous mutations, horizontal gene transfer, and the role of efflux pumps in antibiotic resistance. This review could help understand the mechanism of the adaption of foodborne pathogens to benzalkonium chloride and provide a reference for the rational use of biocides and the prevention and control of foodborne pathogens.

Coumestan represents a biologically relevant structural motif distributed in a number of natural products, and the rapid construction of related derivatives as well as the characterization of targets would accelerate lead compound discovery in medicinal chemistry. In this work, a general and scalable approach to 8,9‐dihydroxycoumestans via two‐electrode constant current electrolysis was developed. The application of a two‐phase (aqueous/organic) system plays a crucial role for success, protecting the sensitive o‐benzoquinone intermediates from over‐oxidation. Based on the structurally diverse products, a primary SAR study on coumestan scaffold was completed, and compound 3 r exhibited potent antiproliferative activities and a robust topoisomerase I (Top1) inhibitory activity. Further mechanism studies demonstrates that compound 3 r was a novel Top1 poison, which might open an avenue for the development of Top1‐targeted antitumor agent. [ABSTRACT FROM AUTHOR]

The types of obstacles encountered in the road environment are complex and diverse, and accurate and reliable detection of obstacles is the key to improving traffic safety. Traditional obstacle detection methods are limited by the type of samples and therefore cannot detect others comprehensively. Therefore, this paper proposes an obstacle detection method based on longitudinal active vision. The obstacles are recognized according to the height difference characteristics between the obstacle imaging points and the ground points in the image, and the obstacle detection in the target area is realized without accurately distinguishing the obstacle categories, which reduces the spatial and temporal complexity of the road environment perception. The method of this paper is compared and analyzed with the obstacle detection methods based on VIDAR (vision-IMU based detection and range method), VIDAR + MSER, and YOLOv8s. The experimental results show that the method in this paper has high detection accuracy and verifies the feasibility of obstacle detection in road environments where unknown obstacles exist. [ABSTRACT FROM AUTHOR]

Summary: Staphylococcus aureus is a prominent foodborne pathogen causing Staphylococcal food poisoning (SFP) in dairy products. This study estimated S. aureus growth and thermal inactivation kinetic parameters and variability in various dairy products by conducting a meta‐analysis. Cheese exhibited a lower theoretical minimum temperature (Tmin), indicating favourable conditions for S. aureus growth even at lower temperatures. Tmin values for other matrices ranged from 5.0 to 7.2 °C, providing insights for production parameter formulation. Meanwhile, significant variations in the maximum population density (Ymax) are among dairy products at the same temperature. Keeping temperatures below 0 °C in pasteurised milk, raw milk and cheese limited Ymax to approximately 102–4 CFU mL−1, below the international toxicity threshold. Factors influencing D values were smaller than strain variability, and NaCl concentration emerged as a significant factor affecting S. aureus growth. These parameters can serve as references for quality control, safety and production optimisation in dairy product processes. [ABSTRACT FROM AUTHOR]

[Objective] Respiratory monitoring is essential for determining the vital characteristics of the human body and diagnosis of sleep-disordered breathing, critical diseases, and neonates. Moreover, micro/nanosensors play an important role in healthcare. In particular, they can detect changes in humidity around the nose and mouth for analysis of respiratory behavior. Herein, a high-performance flexible wearable humidity sensor was developed using a chitosan/conductive carbon black (CS/CB) hybrid film as the sensitive layer for respiratory detection. [Methods] The humidity sensor was fabricated by screen-printing a CS/CB film on a flexible poly (ethylene terephthalate) substrate with interdigitated electrodes. Scanning electron microscopy (SEM) was conducted to demonstrate the successful synthesis and combination of the CS/CB hybrid film. The SEM results showed that the CB particles are uniformly embedded in the CS/CB film with porous and rough nanostructures, which can help water molecules diffuse into the sensitive film. The humidity performance of the humidity sensor was tested by switching the device between different RH levels established by several saturated salt solutions (11%-97% RH) at room temperature. The resistance of the CS/CB sensor was measured with a high-precision data logger. The CS/CB humidity sensor had good electrical conductivity, and its resistance was increased with the increase in RH with good linearity. The sensor was experimentally evaluated for its performance parameters, such as sensitivity, response recovery characteristics, and repeatability. The humidity switching test demonstrated that the sensor has a fast response rate and good discrimination to different humidity environments. The sensor under the humidity rise reduction test showed good symmetry and coincidence, indicating that the hysteresis effect can be ignored. The CS/CB humidity sensor demonstrated good repeatability, rapid response/recovery time, and negligible hysteresis. A flexible wearable film-type breath detection platform was developed using a single-chip microcomputer and LabvIEW technologies, which achieved real-time data reading and processing of humidity, communication between the microcontroller and computer terminal, and display of breath waveforms. The detection platform has low production costs and is easy to operate, providing new insights into the practical application of high-performance humidity sensor detection technology. The sensor is placed in the mask for respiratory behavior monitoring, including normal breathing, slow breathing, rapid breathing, stop breathing, Biot's breathing, wave breathing, tidal breathing, febrile patient breathing, etc. The breathing frequency and intensity can be observed clearly. [Results] The flexible wearable humidity sensor could monitor and analyze human respiratory conditions with high accuracy and reliability. It demonstrated good application in realtime human breath monitoring. The humidity-sensitive mechanism of the sensor was ascribed to the good hydrophilicity and many active sites (hydrophilic groups and vacancies) on the CS/CB nanomaterials to absorb water molecules. In addition, the CS/CB nanomaterial with high surface area had numerous surface-active sites to adsorb water molecules. [Conclusions] The developed CS/CB humidity sensor has great practical potential in wearable applications, especially in humidity sensing detection. It also promotes students' in-depth understanding of the experiments and applications of flexible wearable sensors, effectively enhancing their motivation and effectiveness of teaching. [ABSTRACT FROM AUTHOR]