Search for: All records

Abstract This study examines burst laser-induced pitting (BLIP), an understudied surface modification phenomenon driven by ultrafast laser bursts with sub-picosecond to picosecond inter-pulse delays. Through SEM and AFM analysis, we characterize BLIP as sub-micron pits with polarizationdependent oval shapes, alongside high-fluence melting zones and localized ripple-like structures. Unlike conventional LIPSS, BLIP demonstrates exceptional energy coupling efficiency, evidenced by 10× greater damage areas and a steeper fluence-scaling expansion rate than LIPSS, attributed to transient carrier-mediated processes. Pit density decays exponentially with delay (τ ≈ 6.6-8.9 ps), matching the timescale of self-trapped exciton (STE) relaxation, while spatial statistics reveal a delay-driven transition from field-guided ordering (1-5 ps) to randomized distributions (>10 ps). The resonant-like angular distributions and delay-dependent ellipticity reduction indicate competing mechanisms: optical field enhancement dominates at short delays, while energy dissipation and structure disordering prevail at longer delays. Simulation of nanoplasma excitation reveals near-field optical field enhancements responsible for the ellipticity and ripple-like structures. Beyond their fundamental significance, these BLIP nanostructures offer practical functionalities, including use as anti-reflection coatings and hydrophobic surfaces. These findings establish BLIP as a new paradigm in ultrafast laser-material interactions, where burst parameters selectively activate defect-mediated or field-driven modification pathways in dielectrics. 

PurposeFreezing extends the shelf life of food. Home freezing of fresh foods and the purchase of frozen foods have been advocated as approaches to reduce food waste in US households. This paper discusses how commonly US households apply these practices, quantifies frozen food waste and relates these practices to food waste. Design/methodology/approachWe add questions to the summer 2022 wave of the US Household Food Waste Tracking Survey. The novel survey data provide important baseline information and household behaviours, such as food waste, home freezing of fresh food and the purchase of frozen foods. We analyse the association among these behaviours from more than 1,000 US households. FindingsWe find that US household wastes about 26 g per person per week of food that was once frozen, which is about 6% of all household food waste. The finding indicates that a small portion of food waste in US households comes from frozen food. Vegetables and meats are the most commonly discarded frozen foods. Among the frozen items reported as discarded, about 30% were purchased as frozen rather than purchased fresh and then frozen at home by the consumer and about 30% more were reported as discarded from the refrigerator rather than directly from the freezer. The findings are important for informing strategies to reduce household food waste. Research limitations/implicationsWhile the data provide important baseline information and correlate the use of freezing with lower waste levels, more work is needed to understand if interventions encouraging frozen food purchase or home freezing would reduce household food waste. Originality/valueWe provide unique, detailed information about the quantity of frozen food waste in US households and the relationships between consumer food waste and the practices of frozen food purchasing and home freezing. 

Lipoxygenase (LOX) is associated with responses to plant hormones, environmental stresses, and signaling substances. Methyl jasmonate (MeJA) treatment triggers the production of LOX, polyphenol oxidase, and protease inhibitors in various plants, producing resistance to herbivory. To examine the response of MtLOX24 to MeJA, the phenotypic and physiological changes in Medicago truncatula MtLOX24 overexpression and lox mutant plants were investigated. Additionally, wild-type R108, the MtLOX24-overexpressing line L4, and the mutant lox-1 were utilized as experimental materials to characterize the differentially expressed genes (DEGs) and metabolic pathways in response to MeJA. The results indicate that after treatment with 200 µM of MeJA, the damage in the mutants lox-1 and lox-2 was more serious than in the overexpressing lines L4 and L6, with more significant leaf wilting, yellowing, and oxidative damage in lox-1 and lox-2. Exogenous application of MeJA induced H2O2 production and POD activity but reduced CAT activity in the lox mutants. Transcriptome analysis revealed 10,238 DEGs in six libraries of normal-growing groups (cR108, cL4, and clox1) and MeJA-treated groups (R108, L4, and lox1). GO and KEGG functional enrichment analysis demonstrated that under normal growth conditions, the DEGs between the cL4 vs. cR108 and the clox-1 vs. cR108 groups were primarily enriched in signaling pathways such as plant–pathogen interactions, flavonoid biosynthesis, plant hormone signal transduction, the MAPK signaling pathway, and glutathione metabolism. The DEGs of the R108 vs. cR108 and L4 vs. cL4 groups after MeJA treatment were mainly enriched in glutathione metabolism, phenylpropanoid biosynthesis, the MAPK signaling pathway, circadian rhythm, and α-linolenic acid metabolism. Among them, under normal growth conditions, genes like PTI5, PR1, HSPs, PALs, CAD, CCoAOMT, and CYPs showed significant differences between L4 and the wild type, suggesting that the expression of these genes is impacted by MtLOX24 overexpression. CDPKs, CaMCMLs, IFS, JAZ, and other genes were also significantly different between L4 and the wild type upon MeJA treatment, suggesting that they might be important genes involved in JA signaling. This study provides a reference for the study of the response mechanism of MtLOX24 under MeJA signaling.