Probing paper ageing by label-free fluorescence lifetime microscopy

Paper ageing is a complex and irreversible process that critically affects materials ranging from packaging to cultural heritage artefacts. While both invasive and non-invasive analytical techniques exist to assess the deterioration of paper, many approaches still present limitations in terms of sensitivity, spatial resolution, or applicability to historical artefacts. Here, we present a fully optical, non-invasive method to monitor oxidation in paper using label-free Fluorescence Lifetime Imaging Microscopy (FLIM). We show that the intrinsic fluorescence lifetime of paper changes with oxidation and that these shifts correlate strongly with FTIR indicators of ageing. Validation was performed on both modern and historical samples subjected to controlled oxidation. This approach represents the first step toward a new diagnostic methodology for monitoring the degradation of paper-based materials in sensitive contexts such as heritage science

Genome Sequencing of <i>Pantoea agglomerans</i> C1 Provides Insights into Molecular and Genetic Mechanisms of Plant Growth-Promotion and Tolerance to Heavy Metals

Distinctive strains of Pantoea are used as soil inoculants for their ability to promote plant growth. Pantoea agglomerans strain C1, previously isolated from the phyllosphere of lettuce, can produce indole-3-acetic acid (IAA), solubilize phosphate, and inhibit plant pathogens, such as Erwinia amylovora. In this paper, the complete genome sequence of strain C1 is reported. In addition, experimental evidence is provided on how the strain tolerates arsenate As (V) up to 100 mM, and on how secreted metabolites like IAA and siderophores act as biostimulants in tomato cuttings. The strain has a circular chromosome and two prophages for a total genome of 4,846,925-bp, with a DNA G+C content of 55.2%. Genes related to plant growth promotion and biocontrol activity, such as those associated with IAA and spermidine synthesis, solubilization of inorganic phosphate, acquisition of ferrous iron, and production of volatile organic compounds, siderophores and GABA, were found in the genome of strain C1. Genome analysis also provided better understanding of the mechanisms underlying strain resistance to multiple toxic heavy metals and transmission of these genes by horizontal gene transfer. Findings suggested that strain C1 exhibits high biotechnological potential as plant growth-promoting bacterium in heavy metal polluted soils.6s

Engineering-geology model of the seismically-induced Cerda landslide

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Phyto-Beneficial Traits of Rhizosphere Bacteria: In Vitro Exploration of Plant Growth Promoting and Phytopathogen Biocontrol Ability of Selected Strains Isolated from Harsh Environments

Beneficial interactions between plants and some bacterial species have been long recognized, as they proved to exert various growth-promoting and health-protective activities on economically relevant crops. In this study, the growth promoting and antifungal activity of six bacterial strains, Paenarthrobacter ureafaciens, Beijerinckia fluminensis, Pseudomonas protegens, Arthrobacter sp., Arthrobacter defluii, and Arthrobacter nicotinovorans, were investigated. The tested strains resulted positive for some plant growth promoting (PGP) traits, such as indole-3-acetic acid (IAA), 1-aminocyclopropane-1- carboxylate-deaminase (ACC-deaminase), siderophore production, and solubilization of phosphates. The effect of the selected bacteria on Arabidopsis thaliana seedlings growth was assessed using different morphological parameters. Bacterial activity against the phytopathogenic fungal species Aspergillus flavus, Fusarium proliferatum, and Fusarium verticillioides was also assessed, since these cause major yield losses in cereal crops and are well-known mycotoxin producers. Strains Pvr_9 (B. fluminensis) and PHA_1 (P. protegens) showed an important growth-promoting effect on A. thaliana coupled with a high antifungal activity on all the three fungal species. The analysis of bacterial broths through ultra performance liquid chromatography–mass spectrometry (UPLC–MS) and liquid chromatography–electrospray ionization–mass spectrometry (LC–ESI–MS/MS) confirmed the presence of potential PGP-compounds, among these are desferrioxamine B, aminochelin, asperchrome B, quinolobactin siderophores, and salicylic acid

Do plant biostimulants affect the survival of Escherichia coli in lettuce?

IntroductionConsidering that plant biostimulants can be sprayed multiple times on leafy crops even just before harvest, it is relevant to know the impact of biostimulant applications on Escherichia coli population dynamics of lettuce leaves to ensure food safety. Two trials were carried out to investigate whether the applications of a seaweed extract and a vegetal-derived protein hydrolysate (PH) could affect the E. coli growth in shake flasks (Exp. 1) and plant growth and survival of artificially inoculated E. coli on the leaf surface of lettuce grown in a floating system (Exp. 2).MethodsThe non-pathogenic E. coli strain K12 was used in both trials. In Exp. 1, biostimulants’ inhibitory/stimulatory effect on E. coli growth was evaluated in liquid culture after 24 hours of incubation at 37°C. The 31-day agronomic trial (Exp. 2) was conducted in a polyethylene greenhouse on lettuce grown in a floating system.ResultsIn Exp. 1, E. coli growth was not affected by LB medium amended with biostimulants, whereas both biostimulants stimulated total aerobic bacteria and inhibited E. coli population on lettuce leaves with a more pronounced inhibitory effect of PH applications on E. coli (Exp. 2). Total plant biomass and its partitioning (on fresh and dry weight basis), and N concentrations (as total N and nitrates) of leaves were not influenced by both biostimulant treatments.ConclusionThe use of plant biostimulants could be a valuable and sustainable strategy to improve the microbiological quality of leafy greens to produce ready-to-eat foods

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

Precondensed Plasmid DNA Enhances CAR-T Cell Generation via Lipid Nanoparticles

The advent of chimeric antigen receptor (CAR) T-cell therapy has introduced a novel and personalized approach to cancer treatment. Despite its promise, the challenge of developing a system that bypasses the need for viral vectors remains significant, particularly in terms of achieving a clinical efficacy and sustained durability. To address these challenges, lipid nanoparticles (LNPs) produced through advanced microfluidic technology have been recently utilized to encapsulate plasmid DNA (pDNA) encoding CAR receptors. However, the intrinsic challenges associated with pDNA encapsulation, along with the critical requirement for efficient expression, remain substantial obstacles. Here, we show that incorporating DNA-condensing agents into the microfluidic manufacturing of LNPs effectively overcomes these limitations. Briefly, we conducted a preliminary investigation to characterize LNPs with and without the commercial condensing agent P3000-Reagent (PR), focusing on their physicochemical properties and scrutinizing the biological outcomes primarily in the HEK-293 cell line. Our results demonstrated that precondensation of the pDNA with PR differentially increased the transfection efficiency of the tested formulations, whereas confocal microscopy indicated reduced lysosomal colocalization and major nuclear localization. Finally, PR was found to enhance LNP efficiency upon multiple administrations to the immortalized T-lymphocyte Jurkat cell line, enabling the delivery of both a luciferase reporter gene and a functional CAR-encoding plasmid. Overall, these findings underscore the great potential of introducing DNA-condensing agents into the LNP preparation process, especially for systems designed for challenging delivery applications, such as multiadministration transfection protocols

Opsonin-deficient nucleoproteic corona endows unPEGylated liposomes with stealth properties in vivo

For several decades, surface grafted polyethylene glycol (PEG) has been a go-to strategy for preserving the synthetic identity of liposomes in physiological milieu and preventing clearance by immune cells. However, the limited clinical translation of PEGylated liposomes is mainly due to the protein corona formation and the subsequent modification of liposomes’ synthetic identity, which affects their interactions with immune cells and blood residency. Here we exploit the electric charge of DNA to generate unPEGylated liposome/DNA complexes that, upon exposure to human plasma, gets covered with an opsonin-deficient protein corona. The final product of the synthetic process is a biomimetic nanoparticle type covered by a proteonucleotidic corona, or “proteoDNAsome”, which maintains its synthetic identity in vivo and is able to slip past the immune system more efficiently than PEGylated liposomes. Accumulation of proteoDNAsomes in the spleen and the liver was lower than that of PEGylated systems. Our work highlights the importance of generating stable biomolecular coronas in the development of stealth unPEGylated particles, thus providing a connection between the biological behavior of particles in vivo and their synthetic identity

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Immunotherapy for colorectal cancer: where are we heading?

Introduction: In the last few years, significant advances in molecular biology have provided new therapeutic options for colorectal cancer (CRC). The development of new drugs that target the immune response to cancer cells seems very promising and has already been established for other tumor types. In particular, the use of immune checkpoint inhibitors seems to be an encouraging immunotherapeutic strategy. Areas covered: In this review, the authors provide an update of the current evidence related to this topic, though most immunotherapies are still in early-phase clinical trials for CRC. To understand the key role of immunotherapy in CRC, the authors discuss the delicate balance between immune-stimulating and immune-suppressive networks that occur in the tumor microenvironment. Expert opinion: Modulation of the immune system through checkpoint inhibition is an emerging approach in CRC therapy. Nevertheless, selection criteria that could enable the identification of patients who may benefit from these agents are necessary. Furthermore, potential prognostic and predictive immune biomarkers based on immune and molecular classifications have been proposed. As expected, additional studies are required to develop biomarkers, effective therapeutic strategies and novel combinations to overcome immune escape resistance and enhance effector response