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Nanoscale Advances Jun 2024Water has shown a myriad of highly interesting properties and behaviors, such as very low friction, phase transition under unexpected conditions, massive property...
Water has shown a myriad of highly interesting properties and behaviors, such as very low friction, phase transition under unexpected conditions, massive property alterations, inside strong nanoconfinements of few-nanometer to sub-nanometer diameters. Water-water hydrogen bonding is one of the most important factors dictating such water behavior and properties inside such strong nanoconfinements. In this paper, we employ Reactive Force Field (ReaxFF) molecular dynamics (MD) simulations for studying multiple facets of such water-water hydrogen bonds (HBs) inside boron-nitride nanotubes (BNNTs) having diameters ranging from a few nanometers to sub-nanometers. First, the strength of the water-water HB interactions, as a function of the HB configuration, is quantified by studying the corresponding PMF (potential of mean force). For water present in extreme confinements (BNNTs with sub-nanometric diameters), we see completely isolated HB basins. On the other hand, for bulk water the HB basin is connected ( a saddle point) to a nearby second PMF well. Therefore, our analysis successfully distinguishes the HB characteristics between the cases of water in extreme confinement and bulk water. Second, we study the kinetics of such water-water HBs: HBs formed by a given pair of water molecules in extreme confinements show a much larger probability of remaining intact once formed or re-forming after they have been broken. Both these results, which shed new light on water-water hydrogen bonding inside strong nanoconfinements, can be explained by the single-file structure formed by the water molecules in extreme BNNT confinements.
PubMed: 38933867
DOI: 10.1039/d3na00948c -
Nanoscale Advances Jun 2024The fluorescence response of a chromophore in the proximity of a plasmonic nanostructure can be enhanced by several orders of magnitude, yielding the so-called...
The fluorescence response of a chromophore in the proximity of a plasmonic nanostructure can be enhanced by several orders of magnitude, yielding the so-called surface-enhanced fluorescence (SEF). An in-depth understanding of SEF mechanisms benefits from fully atomistic theoretical models because SEF signals can be non-trivially affected by the atomistic profile of the nanostructure's surface. This work presents the first fully atomistic multiscale approach to SEF, capable of describing realistic structures. The method is based on coupling density functional theory (DFT) with state-of-the-art atomistic electromagnetic approaches, allowing for reliable physically-based modeling of molecule-nanostructure interactions. Computed results remarkably demonstrate the key role of the NP morphology and atomistic features in quenching/enhancing the fluorescence signal.
PubMed: 38933865
DOI: 10.1039/d4na00080c -
Nanoscale Advances Jun 2024Magnonics is an emerging field broadly recognized as a paradigm shift for information technologies based on the use of spin waves. However, the low flexibility and...
Magnonics is an emerging field broadly recognized as a paradigm shift for information technologies based on the use of spin waves. However, the low flexibility and variety of the existing systems still hamper their applications. Herein, we propose an unprecedented chemical approach to magnonics based on the creation of hybrid molecular/2D heterostructures. We analyse the modulation of the magnetic properties, magnon dispersion and spin dynamics of a single layer of CrSBr after the deposition of sublimable organic molecules first-principles calculations. Our results predict a modulation of magnetic exchange, a shift in the magnon frequencies and an enhancement of their group velocities up to ∼7%. Interestingly, we find a linear correlation between these effects and the donor character of the molecules. This will pave the way for the design of a new class of magnonic materials that can be selectively tailored by a chemical approach.
PubMed: 38933864
DOI: 10.1039/d4na00230j -
Nanoscale Advances Jun 2024Ultrasmall nanoparticles have a diameter between 1 and 3 nm at the border between nanoparticles and large molecules. Usually, their core consists of a metal, and the... (Review)
Review
Ultrasmall nanoparticles have a diameter between 1 and 3 nm at the border between nanoparticles and large molecules. Usually, their core consists of a metal, and the shell of a capping ligand with sulfur or phosphorus as binding atoms. While the core structure can be probed by electron microscopy, electron and powder diffraction, and single-crystal structure analysis for atom-sharp clusters, it is more difficult to analyze the ligand shell. In contrast to larger nanoparticles, ultrasmall nanoparticles cause only a moderate distortion of the NMR signal, making NMR spectroscopy a qualitative as well as a quantitative probe to assess the nature of the ligand shell. The application of isotope-labelled ligands and of two-dimensional NMR techniques can give deeper insight into ligand-nanoparticle interactions. Applications of one- and two-dimensional NMR spectroscopy to analyze ultrasmall nanoparticles are presented with suitable examples, including a critical discussion of the limitations of NMR spectroscopy on nanoparticles.
PubMed: 38933863
DOI: 10.1039/d4na00139g -
Nanoscale Advances Jun 2024Mesoporous silica nanoparticles hosting guest molecules are a versatile tool with applications in various fields such as life and environmental sciences. Current...
Mesoporous silica nanoparticles hosting guest molecules are a versatile tool with applications in various fields such as life and environmental sciences. Current commonly applied pore blocking strategies are not universally applicable and are often not robust enough to withstand harsh ambient conditions ( geothermal). In this work, a titania layer is utilized as a robust pore blocker, with a test-case where it is used for the encapsulation of fluorescent dyes. The layer is formed by a hydrolysis process of a titania precursor in an adapted microemulsion system and demonstrates effective protection of both the dye payload and the silica core from disintegration under otherwise damaging external conditions. The produced dye-MSN@TiO particles are characterized by means of electron microscopy, elemental mapping, ζ-potential, X-ray diffraction (XRD), nitrogen adsorption, Thermogravimetric analysis (TGA), fluorescence and absorbance spectroscopy and Fourier Transform Infrared Spectroscopy - Total Attenuated Reflectance (FT-IR ATR). Finally, the performance of the titania-encapsulated MSNs is demonstrated in long-term aqueous stability and in flow-through experiments, where owing to improved dispersion encapsulated dye results in improved flow properties compared to free dye properties. This behavior exemplifies the potential advantage of carrier-borne marker molecules over free dye molecules in applications where accessibility or targeting are a factor, thus this encapsulation method increases the variety of fields of application.
PubMed: 38933859
DOI: 10.1039/d4na00242c -
Frontiers in Endocrinology 2024Exosomes, as pivotal entities within the tumor microenvironment, orchestrate intercellular communication through the transfer of diverse molecules, among which... (Review)
Review
Exosomes, as pivotal entities within the tumor microenvironment, orchestrate intercellular communication through the transfer of diverse molecules, among which non-coding RNAs (ncRNAs) such as miRNAs, lncRNAs, and circRNAs play a crucial role. These ncRNAs, endowed with regulatory functions, are selectively incorporated into exosomes. Emerging evidence underscores the significance of exosomal ncRNAs in modulating key oncogenic processes in thyroid cancer (TC), including proliferation, metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, and immunoediting. The unique composition of exosomes shields their cargo from enzymatic and chemical degradation, ensuring their integrity and facilitating their specific expression in plasma. This positions exosomal ncRNAs as promising candidates for novel diagnostic and prognostic biomarkers in TC. Moreover, the potential of exosomes in the therapeutic landscape of TC is increasingly recognized. This review aims to elucidate the intricate relationship between exosomal ncRNAs and TC, fostering a deeper comprehension of their mechanistic involvement. By doing so, it endeavors to propel forward the exploration of exosomal ncRNAs in TC, ultimately paving the way for innovative diagnostic and therapeutic strategies predicated on exosomes and their ncRNA content.
Topics: Humans; Exosomes; Thyroid Neoplasms; RNA, Untranslated; Disease Progression; Tumor Microenvironment; Biomarkers, Tumor; Animals; Epithelial-Mesenchymal Transition; Gene Expression Regulation, Neoplastic
PubMed: 38933820
DOI: 10.3389/fendo.2024.1337226 -
Saudi Pharmaceutical Journal : SPJ :... Jul 2024Natural products (NPs) play an irreplaceable role in the intervention of various diseases and have been considered a critical source of drug development. Many new... (Review)
Review
Natural products (NPs) play an irreplaceable role in the intervention of various diseases and have been considered a critical source of drug development. Many new pharmacodynamic compounds with potential clinical applications have recently been derived from NPs. These compounds range from small molecules to polysaccharides, polypeptides, proteins, self-assembled nanoparticles, and extracellular vesicles. This review summarizes various active substances found in NPs. The investigation of active substances in NPs can potentiate new drug development and promote the in-depth comprehension of the mechanism of action of NPs that can be beneficial in the prevention and treatment of human diseases.
PubMed: 38933713
DOI: 10.1016/j.jsps.2024.102124 -
Frontiers in Veterinary Science 2024Hydrogen sulfide (HS) is a gaseous signaling molecule produced in the body by three enzymes: cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and... (Review)
Review
Hydrogen sulfide (HS) is a gaseous signaling molecule produced in the body by three enzymes: cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST). HS is crucial in various physiological processes associated with female mammalian reproduction. These include estrus cycle, oocyte maturation, oocyte aging, ovulation, embryo transport and early embryo development, the development of the placenta and fetal membranes, pregnancy, and the initiation of labor. Despite the confirmed presence of HS-producing enzymes in all female reproductive tissues, as described in this review, the exact mechanisms of HS action in these tissues remain in most cases unclear. Therefore, this review aims to summarize the knowledge about the presence and effects of HS in these tissues and outline possible signaling pathways that mediate these effects. Understanding these pathways may lead to the development of new therapeutic strategies in the field of women's health and perinatal medicine.
PubMed: 38933705
DOI: 10.3389/fvets.2024.1378435 -
Fundamental Research Sep 2023RNA molecules serve a wide range of functions that are closely linked to their structures. The basic structural units of RNA consist of single- and double-stranded... (Review)
Review
RNA molecules serve a wide range of functions that are closely linked to their structures. The basic structural units of RNA consist of single- and double-stranded regions. In order to carry out advanced functions such as catalysis and ligand binding, certain types of RNAs can adopt higher-order structures. The analysis of RNA structures has progressed alongside advancements in structural biology techniques, but it comes with its own set of challenges and corresponding solutions. In this review, we will discuss recent advances in RNA structure analysis techniques, including structural probing methods, X-ray crystallography, nuclear magnetic resonance, cryo-electron microscopy, and small-angle X-ray scattering. Often, a combination of multiple techniques is employed for the integrated analysis of RNA structures. We also survey important RNA structures that have been recently determined using various techniques.
PubMed: 38933295
DOI: 10.1016/j.fmre.2023.06.001 -
Frontiers in Immunology 2024Succinate, traditionally viewed as a mere intermediate of the tricarboxylic acid (TCA) cycle, has emerged as a critical mediator in inflammation. Disruptions within the... (Review)
Review
Succinate, traditionally viewed as a mere intermediate of the tricarboxylic acid (TCA) cycle, has emerged as a critical mediator in inflammation. Disruptions within the TCA cycle lead to an accumulation of succinate in the mitochondrial matrix. This excess succinate subsequently diffuses into the cytosol and is released into the extracellular space. Elevated cytosolic succinate levels stabilize hypoxia-inducible factor-1α by inhibiting prolyl hydroxylases, which enhances inflammatory responses. Notably, succinate also acts extracellularly as a signaling molecule by engaging succinate receptor 1 on immune cells, thus modulating their pro-inflammatory or anti-inflammatory activities. Alterations in succinate levels have been associated with various inflammatory disorders, including rheumatoid arthritis, inflammatory bowel disease, obesity, and atherosclerosis. These associations are primarily due to exaggerated immune cell responses. Given its central role in inflammation, targeting succinate pathways offers promising therapeutic avenues for these diseases. This paper provides an extensive review of succinate's involvement in inflammatory processes and highlights potential targets for future research and therapeutic possibilities development.
Topics: Humans; Succinic Acid; Inflammation; Signal Transduction; Animals; Citric Acid Cycle; Receptors, G-Protein-Coupled
PubMed: 38933270
DOI: 10.3389/fimmu.2024.1404441