No abstract

Molecular analysis of exhaled breath aerosol (EBA) with simple procedures represents a key step in clinical and point-of-care applications. Due to the crucial health role, a face mask now is a safety device that helps protect the wearer from breathing in hazardous particles such as bacteria and viruses in the air; thus exhaled breath is also blocked to congregate in the small space inside of the face mask. Therefore, direct sampling and analysis of trace constituents in EBA using a face mask can rapidly provide useful insights into human physiologic and pathological information. Herein, we introduce a simple approach to collect and analyze human EBA by combining a face mask with solid-phase microextraction (SPME) fiber. SPME fiber was inserted into a face mask to form SPME-in-mask that covered nose and mouth for in vivo sampling of EBA, and SPME fiber was then coupled with direct analysis in real-time mass spectrometry (DART-MS) to directly analyze the molecular compositions of EBA under ambient conditions. The applicability of SPME-in-mask was demonstrated by direct analysis of drugs and metabolites in oral and nasal EBA. The unique features of SPME-in-mask were also discussed. Our results showed that this method is enabled to analyze volatile and nonvolatile analytes in EBA and is expected to have a significant impact on human EBA analysis in clinical applications. We also hope this method will inspire biomarker screening of some respiratory diseases that usually required wearing of a face mask in daily life.

Transient transformation is simpler, more efficient and economical in analyzing protein subcellular localization than stable transformation. Fluorescent fusion proteins were often used in transient transformation to follow the in vivo behavior of proteins. Onion epidermis, which has large, living and transparent cells in a monolayer, is suitable to visualize fluorescent fusion proteins. The often used transient transformation methods included particle bombardment, protoplast transfection and Agrobacterium-mediated transformation. Particle bombardment in onion epidermis was successfully established, however, it was expensive, biolistic equipment dependent and with low transformation efficiency. We developed a highly efficient in planta transient transformation method in onion epidermis by using a special agroinfiltration method, which could be fulfilled within 5 days from the pretreatment of onion bulb to the best time-point for analyzing gene expression. The transformation conditions were optimized to achieve 43.87% transformation efficiency in living onion epidermis. The developed method has advantages in cost, time-consuming, equipment dependency and transformation efficiency in contrast with those methods of particle bombardment in onion epidermal cells, protoplast transfection and Agrobacterium-mediated transient transformation in leaf epidermal cells of other plants. It will facilitate the analysis of protein subcellular localization on a large scale.

With the booming microwave and terahertz technology for communication, detection, and healthcare, the consequently increasingly complicated electromagnetic environment is in urgent need of high-performance microwave and terahertz absorption materials. However, it is still a huge challenge to achieve consecutively strong absorption in both microwave and terahertz regimes. Herein, an ultra-broadband and highly efficient absorber for both microwave and terahertz bands based on the monolithic three-dimensional cross-linked Fe3O4/graphene material (3DFG) is first reported. The 3DFG shows an incredible wide qualified absorption bandwidth (with reflection loss less than −10 dB) from 3.4 GHz to 2.5 THz, which is the best result in this area by far. Furthermore, the remarkable absorption performance can be maintained under oblique incidence, different compressive strains, and even after 200 compression/release cycles. The designed highly porous structure for minimizing surface reflection combined with the micro–macro integrated high lossy framework results in the excellent absorptivity, as verified by the terahertz time-domain spectroscopy technique. With these, the 3DFG achieves an unprecedentedly average absorption intensity of 38.0 dB, which is the maximum value among the broadband absorbers. In addition, its specific average microwave and terahertz absorption value is over 2 orders of magnitude higher than other kinds of reported materials. The results provide new insights for developing novel ultra-broadband absorbers with stronger reflection loss and wider absorption bandwidth.

Herein, we have developed a composite antibacterial hydrogel with photodynamic therapy (PDT) and photothermal therapy (PTT) antibacterial capabilities, triggered by white light and NIR light irradiation. A water-insoluble conjugated polymer (PDPP) with photothermal ability was prepared into nanoparticles by the nanoprecipitation method, and the cell-penetrating peptide TAT was grafted on the surface of the nanoparticles. Based on our previous work that developed a hybrid hydrogel with an enhanced PDT effect from polyisocyanide (PIC) hydrogel and cationic conjugated polythiophene (PMNT), PDPP nanoparticles (CPNs-TAT) with photothermal ability are introduced to realize the synergistic antibacterial effect of PDT and PTT. Using the PIC hydrogel to combine PIC and CPNs-TAT has the following advantages. First, the PIC hydrogel can regulate the aggregation state of PMNT, making it better dispersed and improving its capacity of reactive oxygen species (ROS) production. Second, CPNs-TAT can be uniformly dispersed in the PIC hybrid, thereby avoiding the toxicity caused by too high local concentration, achieving a uniform increase in system temperature, and enhancing the therapeutic effect of PTT. Third, the PIC hybrid has the synergistic treatment effect of PDT and PTT. The PIC hybrid intelligently regulates its antibacterial ability through white light and NIR light, which can be used in the white light and NIR light areas. When irradiated with white light and NIR light sequentially, synergistic PDT and PTT exhibit stronger antibacterial ability than PDT or PTT alone. The combination of two antibacterial methods realizes the dual-control antibacterial hydrogel of PDT and PTT and provides an antibacterial mode based on PIC hybrids. Therefore, the PIC hybrids are promising as an antibacterial excipient for clinical wounds.