Distance-dependent plasmon-enhanced fluorescence of upconversion nanoparticles using polyelectrolyte multilayers as tunable spacers

Lanthanide-doped upconversion nanoparticles (UCNPs) have attracted widespread interests in bioapplications due to their unique optical properties by converting near infrared excitation to visible emission. However, relatively low quantum yield prompts a need for developing methods for fluorescence enhancement. Plasmon nanostructures are known to efficiently enhance fluorescence of the surrounding fluorophores by acting as nanoantennae to focus electric field into nano-volume. Here, we reported a novel plasmon-enhanced fluorescence system in which the distance between UCNPs and nanoantennae (gold nanorods, AuNRs) was precisely tuned by using layer-by-layer assembled polyelectrolyte multilayers as spacers. By modulating the aspect ratio of AuNRs, localized surface plasmon resonance (LSPR) wavelength at 980 nm was obtained, matching the native excitation of UCNPs resulting in maximum enhancement of 22.6-fold with 8 nm spacer thickness. These findings provide a unique platform for exploring hybrid nanostructures composed of UCNPs and plasmonic nanostructures in bioimaging applications

The Exergy Loss Distribution and the Heat Transfer Capability in Subcritical Organic Rankine Cycle

Taking net power output as the optimization objective, the exergy loss distribution of the subcritical Organic Rankine Cycle (ORC) system by using R245fa as the working fluid was calculated under the optimal conditions. The influences of heat source temperature, the evaporator pinch point temperature difference, the expander isentropic efficiency and the cooling water temperature rise on the exergy loss distribution of subcritical ORC system are comprehensively discussed. It is found that there exists a critical value of expander isentropic efficiency and cooling water temperature rise, respectively, under certain conditions. The magnitude of critical value will affect the relative distribution of exergy loss in the expander, the evaporator and the condenser. The research results will help to better understand the characteristics of the exergy loss distribution in an ORC system

Electrospun polysulfone/poly(lactic acid) nanoporous fibrous mats for oil removal from water

The study of oil sorbents with high oil sorption capacity is of great significance for oil–water separation, especially for oil spillage on seawater. In this work, we report polysulfone, poly(lactic acid), and polysulfone/poly(lactic acid) nanoporous fibrous mats prepared by one-step electrospinning process used as oil sorbents for oil–water separation. The morphology, porous structure, oleophilicity and hydrophobicity, oil sorption capacity, and oil retention of these nanoporous fibrous mats are investigated in detail. It is noticeable that the motor oil and linseed oil sorption capacity of polysulfone and polysulfone/poly(lactic acid) fibrous mats have little difference, but the motor oil sorption capacity (147.8 g g −1 ) of polysulfone is approximately 2.95 times as much as that (50.1 g g −1 ) of poly(lactic acid). The linseed oil sorption capacity (131.3 g g −1 ) is approximately 3.74 times than that (34.6 g g −1 ) of poly(lactic acid). Besides, they all exhibit quick oil sorption speed and high buoyancy. It is suggested that polysulfone and polysulfone/poly(lactic acid) nanoporous fibrous mats have a better oil sorption capacity than poly(lactic acid) nanoporous fibrous mat, which is contributed to volume expansion, highly micrometer porous structure among fibers, and specific surface area of fiber

Growing interface structure of pearlite in an aged 100Mn13 steel

Growing interface structure of pearlite in 100Mn13 high carbon high manganese steel was studied after 1323 K solution treatment and subsequently 823 K aging treatment by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The results show that longer pearlite lamellae consisting of ferrite lamella and cementite lamella are formed in initial growth stage of pearlite colony, in which there are protrusions and branches in M3C/γ interface. The cementite lamella is divided along (01¯0) M3C into two parts which differ in some respects, such as edge dislocations, (01¯0) M3C lattice arrangement. Besides, edge interface of ferrite lamella is wavy morphology including two peaks presenting small curvature radius, which accommodate more C atoms under the premise of meeting composition condition for transformation to accelerate the transformation. The growth physical model of cementite lamella with protrusions and branches, ferrite lamella with two peaks and three troughs are respectively proposed

A Comprehensive Overview of the Antibiotics Approved in the Last Two Decades: Retrospects and Prospects

Due to the overuse of antibiotics, bacterial resistance has markedly increased to become a global problem and a major threat to human health. Fortunately, in recent years, various new antibiotics have been developed through both improvements to traditional antibiotics and the discovery of antibiotics with novel mechanisms with the aim of addressing the decrease in the efficacy of traditional antibiotics. This manuscript reviews the antibiotics that have been approved for marketing in the last 20 years with an emphasis on the antibacterial properties, mechanisms, structure–activity relationships (SARs), and clinical safety of these antibiotics. Furthermore, the current deficiencies, opportunities for improvement, and prospects of antibiotics are thoroughly discussed to provide new insights for the design and development of safer and more potent antibiotics

Reply to Zrelovs et al. PVJ1 Is Not the First Tailed Temperate Phage Infecting Bacteria from Genus Psychrobacillus. Comment on “Liu et al. Isolation and Characterization of the First Temperate Virus Infecting Psychrobacillus from Marine Sediments. Viruses 2022, 14, 108”

We thank Zrelovs et al. [...