178 research outputs found
Rational Design of PheâBODIPY Amino Acids as Fluorogenic Building Blocks for Peptideâbased Detection of Urinary Tract Candida Infections
Fungal infections caused by Candida species are among the most prevalent in hospitalized patients. However, current methods for the detection of Candida fungal cells in clinical samples rely on timeâconsuming assays that hamper rapid and reliable diagnosis. Herein, we describe the rational development of new PheâBODIPY amino acids as small fluorogenic building blocks and their application to generate fluorescent antimicrobial peptides for rapid labelling of Candida cells in urine. We have used computational methods to analyse the fluorogenic behaviour of BODIPYâsubstituted aromatic amino acids and performed bioactivity and confocal microscopy experiments in different strains to confirm the utility and versatility of peptides incorporating PheâBODIPYs. Finally, we have designed a simple and sensitive fluorescenceâbased assay for the detection of Candida albicans in human urine samples
Home Language and Literacy Environments and Early Literacy Trajectories of Low-Socioeconomic Status Chilean Children
This study used Latent Class Analysis to identify groups of children exposed to similar Home Language and Literacy Environments (HLLE) and explored whether belonging to a given HLLE group was related to children's language and early literacy growth from prekindergarten to kindergarten. Participants were 1,425 Chilean mothers and their children (M-age = 52.52 months at baseline) from low-socioeconomic status households. Four HLLE groups were identified, which were associated with different trajectories of language and early literacy development. Children from groups whose mothers either read and talk about past events with them or teach them letters in addition to reading and talking about past events, showed higher relative vocabulary and letter knowledge. Implications for research and interventions are discussed
Frustrated magnetism and caloric effects in Mn-based antiperovskite Nitrides : Ab Initio theory
We model changes of magnetic ordering in Mn-antiperovskite nitrides driven by biaxial lattice strain at zero and at finite temperature. We employ a non-collinear spin-polarised density functional theory to compare the response of the geometrically frustrated exchange interactions to a tetragonal symmetry breaking (the so called piezomagnetic effect) across a range of Mn3AN (A = Rh, Pd, Ag, Co, Ni, Zn, Ga, In, Sn) at zero temperature. Building on the robustness of the effect we focus on Mn3GaN and extend our study to finite temperature using the disordered local moment (DLM) first-principles electronic structure theory to model the interplay between the ordering of Mn magnetic moments and itinerant electron states. We discover a rich temperature-strain magnetic phase diagram with two previously unreported phases stabilised by strains larger than 0.75\% and with transition temperatures strongly dependent on strain. We propose an elastocaloric cooling cycle crossing two of the available phase transitions to achieve simultaneously a large isothermal entropy change (due to the first order transition) and a large adiabatic temperature change (due to the second order transition)
EnzymeâActivatable Chemokine Conjugates for In Vivo Targeting of TumorâAssociated Macrophages
Increased levels of tumorâassociated macrophages (TAMs) are indicators of poor prognosis in most cancers. Although antibodies and small molecules blocking the recruitment of macrophages to tumors are under evaluation as anticancer therapies, these strategies are not specific for macrophage subpopulations. Herein we report the first enzymeâactivatable chemokine conjugates for effective targeting of defined macrophage subsets in live tumors. Our constructs exploit the high expression of chemokine receptors (e.g., CCR2) and the activity of cysteine cathepsins in TAMs to target these cells selectively over other macrophages and immune cells (e.g., neutrophils, T cells, B cells). Furthermore, we demonstrate that cathepsinâactivatable chemokines are compatible with both fluorescent and therapeutic cargos, opening new avenues in the design of targeted theranostic probes for immune cells in the tumor microenvironment
Nonequilibrium Fermi golden rule for electronic transitions through conical intersections
Imaging Proteins Sensitive to Direct Fusions Using Transient PeptideâPeptide Interactions
Fluorescence microscopy enables specific visualization of proteins in living cells and has played an important role in our understanding of the protein subcellular location and function. Some proteins, however, show altered localization or function when labeled using direct fusions to fluorescent proteins, making themdifficult to study in live cells. Additionally, the resolution of fluorescence microscopy is limited to âŒ200 nm, which is 2 orders of magnitude larger than the size of most proteins. To circumvent these challenges, we previously developed LIVE-PAINT, a live-cell superresolution approach that takes advantage of short interacting peptides to transiently bind a fluorescent protein to the protein-ofinterest. Here, we successfully use LIVE-PAINT to image yeastmembrane proteins that do not tolerate the direct fusion of a fluorescent protein by using peptide tags as short as 5-residues. We also demonstrate that it is possible to resolve multiple proteins at the nanoscale concurrently using orthogonal peptide interaction pairs.KEYWORDS: membrane protein, proteinâprotein interaction, super-resolution microscopy, live-cell imaging, LIVE-PAINT, yeas
Coupled electron-nuclear dynamics: Charge migration and charge transfer initiated near a conical intersection
Inserting âOFF-to-ONâ BODIPY Tags into Cytokines: A Fluorogenic Interleukin IL-33 for Real-Time Imaging of Immune Cells
The essential functions that cytokine/immune cell interactions play in tissue homeostasis and during disease have prompted the molecular design of targeted fluorophores to monitor their activity in real time. Whereas activatable probes for imaging immune-related enzymes are common, many immunological functions are mediated by binding events between cytokines and their cognate receptors that are hard to monitor by live-cell imaging. A prime example is interleukin-33 (IL-33), a key cytokine in innate and adaptive immunity, whose interaction with the ST2 cell-surface receptor results in downstream signaling and activation of NF-ÎșB and AP-1 pathways. In the present work, we have designed a chemical platform to site-specifically introduce OFF-to-ON BODIPY fluorophores into full cytokine proteins and generate the first native-like fluorescent analogues of IL-33. Among different incorporation strategies, chemical aminoacylation followed by bioorthogonal derivatization led to the best labeling results.Importantly, the BODIPY-labeled IL-33 derivatives -unlike IL-33-GFP constructs- exhibited ST2-specific binding and downstream bioactivity profiles comparable to those of the wild-type interleukin. Real-time fluorescence microscopy assays under no wash conditions confirmed the internalization of IL-33 through ST2 receptors and its intracellular trafficking through the endosomal pathway. We envision that the modularity and versatility of our BODIPY labeling platform will facilitate the synthesis of minimally tagged fluorogenic cytokines as the next generation of imaging reagents for real-time visualization of signaling events in live immune cells
Systematic review: probiotics in the management of lower gastrointestinal symptoms in clinical practice â an evidence-based international guide
Background Evidence suggests that the gut microbiota play an important role in gastrointestinal problems. Aim To give clinicians a practical reference guide on the role of specified probiotics in managing particular lower gastrointestinal symptoms/problems by means of a systematic review-based consensus. Methods Systematic literature searching identified randomised, placebo-controlled trials in adults; evidence for each symptom/problem was graded and statements developed (consensus process; 10-member panel). As results cannot be generalised between different probiotics, individual probiotics were identified for each statement. Results Thirty seven studies were included; mostly on irritable bowel syndrome [IBS; 19 studies; treatment responder rates: 18â80% (specific probiotics), 5â50% (placebo)] or antibiotic-associated diarrhoea (AAD; 10 studies). Statements with 100% agreement and âhighâ evidence levels indicated that: (i) specific probiotics help reduce overall symptom burden and abdominal pain in some IBS patients; (ii) in patients receiving antibiotics/Helicobacter pylori eradication therapy, specified probiotics are helpful as adjuvants to prevent/reduce the duration/intensity of AAD; (iii) probiotics have favourable safety in patients in primary care. Items with 70â100% agreement and âmoderateâ evidence were: (i) specific probiotics help relieve overall symptom burden in some patients with diarrhoea-predominant IBS, and reduce bloating/distension and improve bowel movement frequency/consistency in some IBS patients and (ii) with some probiotics, improved symptoms have led to improvement in quality of life. Conclusions Specified probiotics can provide benefit in IBS and antibiotic-associated diarrhoea; relatively few studies in other indications suggested benefits warranting further research. This study provides practical guidance on which probiotic to select for a specific problem
Electron dynamics upon ionization: Control of the timescale through chemical substitution and effect of nuclear motion
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