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Hot exciton dissociation in graphene nanoribbons
Abstract Exciton dissociation in semiconducting nanostructures is crucial for optoelectronic applications, especially when free-carrier generation is required. Despite considerable research, the question of whether and how such generation occurs in strongly excitonic systems remains elusive. Here, we use one-dimensional precision graphene nanoribbons (GNRs) as a model system to investigate exciton dissociation. We systematically explore the interplay between ribbon length ( l ), excitation energy, and band dispersion in various precision GNRs. Ultrafast Terahertz conductivity measurements reveal that hot exciton dissociation dominates carrier generation, with ribbon length significantly influencing free carrier lifetimes. We identify a critical Bjerrum length ( R B ) of approximately 20 nm that determines whether photoexcited hot carriers in GNRs can dissociate before forming tightly bound excitons. For shorter ribbons ( l < 2 R B ), rapid ~ps exciton formation prevails. Furthermore, the charge-carrier band dispersion in GNRs plays a critical role in determining dissociation efficiency. Long GNRs with strongly dispersed bands, and consequently low effective carrier masses, exhibit higher mobilities that promote efficient hot-exciton dissociation. These results advance fundamental understanding of dimensionality, energetics, and electronic structure in excitonic materials, providing design principles for optoelectronic devices based on excitonic materials.
HOA-OBL: hybrid opposition-based hippopotamus optimization framework for efficient UAV task allocation
Integrated theranostic nanoplatform empowers precision cancer care via radionuclide-labeled NIR-II aggregation-induced emission luminogens
Hybrid RSM–SF-AHP–fuzzy MARCOS approach for multi-response optimization of WAAM-fabricated Ni–SS bimetallics in face milling
Influence of protein aggregates, extracellular vesicles, and lipoprotein fusion on ionizable lipid nanoparticles protein corona analysis
Critical re-evaluation of experimental settings with fluorescent probes for bioorthogonal chemistry with palladium antimony inactivation-resistant catalyst
Ultra-rapid cryo-EM data acquisition method enabled by continuous recording based beam image shift
Abstract Cryo-electron microscopy (cryo-EM) data acquisition is time-intensive given that a large amount of data is required to obtain a high-resolution reconstruction. Here, we eliminate camera-induced delay time by continuously recording during beam-image shift acquisition using a method called Continuous Recording Beam-Image Shift (CR-BIS). The utilization of CR-BIS with K3 and Falcon 4 direct electron detectors and conventional data acquisition conditions enables the acquisition of ~34,000 micrographs and ~1,000 tilt series per 24 h in single-particle analysis mode and cryo-electron tomography mode, respectively. Three-dimensional reconstructions of single-particle and tomographic datasets show that CR-BIS accelerates data collection and maintains data quality. CR-BIS is broadly applicable for efficient high-resolution cryo-EM since it can be implemented into existing acquisition software through scripting and it does not require hardware modification.
Clinical and genomic surveillance of rotavirus causing acute gastroenteritis in the community of Madrid, Spain, 2021–2023: predominance of equine-like G3 strains
Higher visual areas act like domain-general filters with strong selectivity and functional specialization
Abstract Neuroscientific studies rely heavily on a-priori hypotheses, which can bias results toward existing theories. Here, we use a hypothesis-neutral approach to study category selectivity in higher visual cortex. Using only stimulus images and their associated fMRI activity, we constrain randomly initialized neural networks to predict voxel activity. Despite no category-level supervision, units in the trained networks act as detectors for semantic concepts like ‘faces’ or ‘words’, providing solid empirical support for categorical selectivity. Importantly, this selectivity is mostly maintained when training the networks without images that contain the preferred category, strongly suggesting that selectivity is not domain-specific machinery, but sensitivity to generic patterns that characterize preferred categories. The ability of the models’ representations to transfer to perceptual tasks further reveals the functional role of their selective responses. Finally, our models show selectivity only for a limited number of categories, all previously identified, suggesting that the essential categories are already known.
Defining functional puberty in female C57BL/6J mice using endocrine, cytological and morphological markers
Ribosomal allostery as a potential regulator of bacterial dormancy
Abstract Ribosomes are central to protein synthesis but also serve as dynamic hubs that integrate cellular stress responses. Here, we investigate how ribosomal protein L11 regulates ribosome conformational dynamics and long-distance coupling. Long-timescale molecular dynamics simulations of wild-type and L11-deleted (ΔL11) ribosomes reveal that L11 functions as a global allosteric regulator coordinating communication between the ribosomal stalk and the peptidyl transferase center. The absence of L11 disrupts long-distance couplings involving RelA and Obg and rigidifies the hibernation-promoting factor site, suggesting altered hibernation dynamics that could affect ribosome persistence under stress. To examine the physiological implications of these computational predictions, we construct a ΔL11 Bacillus subtilis strain and quantify its sporulation behavior. The ΔL11 variant exhibits delayed entry into and exit from dormancy, consistent with a breakdown in stress-adaptive ribosomal regulation. Overall, these results highlight the role of L11 in ribosomal allostery, suggesting how local perturbations propagate through the ribosome to influence global physiological outcomes and bacterial survival under environmental stress.
A pretrained biomedical large language model for Persian biomedical text mining
Direct Asymmetric α-C Conjugate Addition of Aminomethylphosphonate Enabled by Carbonyl/Iminium Double Organoactivation
Fast surface reconstruction of human brain MRI: benchmarking deep-learning based morphometry tools
Abstract Time efficient and reliable pipelines for quantitative evaluation of structural brain MRI are essential to utilize the potential of morphometry tools for large scale research projects as well as to pave the path towards future clinical applications. In our work, we have explored this idea by evaluating three deep learning models for brain segmentation and cortex parcellation (DeepSCAN, FastSurferCNN and QuickNAT) as input for an 11-min surface reconstruction pipeline adapted from the well studied open source software package FreeSurfer. Performance was assessed using both, large publicly available human MRI datasets and a synthetic dataset with known metrics and reference surfaces. Evaluation criteria included closeness to the surface reconstruction by FreeSurfer’s full pipeline, reproducibility within same-session rescans, performance stability across a wide age range, sensitivity to variations of the grey-white contrast in the MRI and accuracy regarding metrics of synthetic surfaces. Metrics derived from the DeepSCAN-based pipeline demonstrated the highest agreement with FreeSurfer in the human data and the greatest fidelity to the expected metrics in the synthetic dataset. Our findings identify the DeepSCAN-based surface reconstruction pipeline as a rapid, yet reliable alternative to established research-grade structural MRI processing. Time expenditure and reliability suggest it is suitable for research applications with high-throughput requirements. This is an essential first step towards necessary subsequent studies aimed at evaluating robustness, pathological variability, and utility in the context of clinical diagnostics.
Energy-translation coupling limits anaerobic yeast growth
Development and characterization of mineral oil–neem oil ester mixed insulation for transformer applications
pH-dependent activation of the Na+/H+ antiporter NhaA and conformational dynamics of its N-terminus
Abstract Na⁺/H⁺ antiporters are vital for regulating intracellular pH and sodium ion levels across all domains of life. In Escherichia coli , NhaA is the principal Na⁺/H⁺ antiporter, exhibiting strong pH sensitivity and rapid turnover, yet the structural transitions underlying its activation and substrate recognition have remained obscure. Here, we use single-particle cryo-electron microscopy to determine the conformational ensemble of NhaA across a physiological pH range and in the presence of Na⁺, complemented by constant-pH molecular dynamics simulations. High-resolution structures of apo and Na⁺-bound NhaA reconstituted in lipid nanodiscs reveal progressive opening of the cytoplasmic funnel with increasing pH. We also visualize the previously unresolved N-terminal tail, which forms a dynamic plug at the cytoplasmic entrance under low-pH conditions and disengages at alkaline pH, coinciding with activation. The Na⁺-bound structure captures Na⁺ coordination at the ion-binding site, and simulations suggest potential roles for the conserved charged residues. Together, these findings illuminate how pH sensing, N-terminal gating, and substrate binding are structurally coordinated in NhaA, providing a framework for understanding Na⁺/H⁺ antiporter activation and regulation, and the basis for targeting clinical important antiporters.
Hybrid cooperative complex treatment is associated with reduced facial pore size in a pilot study
Abstract Enlarged facial pores are a common aesthetic concern associated with aging and reduced dermal support. Hybrid Cooperative Complex (HCC), a stabilized hyaluronic acid formulation, has been proposed to improve skin quality through bioremodeling. This prospective observational pilot study evaluated changes in facial pore size after treatment with Hybrid Cooperative Complex (HCC) using standardized photography, clinical assessment, and validated rating scales. Ten healthy adult participants received two treatment sessions according to the Bio Aesthetic Points protocol, and outcomes were assessed at baseline and on Days 30, 60, 120, and 180. Visible improvement in facial pore size and skin texture was observed after treatment. Peak pore refinement was noted at Day 120 in most participants, while partial regression was observed in many cases by Day 180, although skin quality remained improved compared with baseline. HCC may be associated with visible improvement in facial pore size and skin quality in this pilot cohort. Changes in pore morphology may represent a practical clinical marker for estimating maintenance treatment timing, although larger controlled studies are needed.
Efficacy of Pam3CSK4 as a cross-species adjuvant for polysaccharide vaccines in humanized mouse and non-human primate models
Abstract Polysaccharide-based vaccines are essential for preventing bacterial infections, but their effectiveness is limited by weak antibody responses and lack of suitable adjuvants. TLR4 agonists enhance polysaccharide-specific antibody responses through B cell–intrinsic TLR4-MyD88 signaling in mice, but this mechanism is not conserved in primates, prompting the search for alternative MyD88-activating agonists. In vitro, the TLR1/2 agonist Pam3CSK4 synergizes with strong BCR crosslinking to enhance activation and antibody secretion by mouse and human B cells. In vivo, Pam3CSK4 in squalene emulsion increases protective pneumococcal polysaccharide–specific antibody responses in both immunocompetent and humanized mice. Although a dual TLR2/7 agonist shows strong in vitro activity, it fails to enhance polysaccharide-specific IgG responses in vivo, consistent with antagonism observed when Pam3CSK4 and TLR7 agonists are combined. In contrast, incorporating Pam3CSK4 into an adjuvant containing a TLR4 agonist, synthetic cord factor, and squalene emulsion further enhances memory B cell generation and protective antibody responses in mice and restores adjuvant activity in non-human primates, supporting Pam3CSK4-based formulations as promising adjuvants for polysaccharide vaccines.