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Two-dimensional liquid foam systems comprised of an odd number N of bubbles arranged in a staircase configuration are studied as they are packed within a confined straight channel. Energy minimization is employed to characterize the permitted topology and geometry of the system at equilibrium. It is known that in an infinite staircase, bubble films are flat. The configuration for a finite number of bubbles, however, deviates from that of an infinite staircase at the edges. It is known that films near the edges are not flat and structures with a few bubbles (up to N=3) are well characterized. To study what happens as more bubbles are added, and how the behaviour approaches that of an infinite staircase, structures comprised of N=[5,7,...] bubbles are studied here. For these N values, minimum and maximum bubble areas are found that can pack in a staircase configuration within a straight channel. However, for an infinite staircase and also for N=3 , there are maximum areas, but no minima. Staircases with very short films, which make the structure susceptible to break in various ways, are also identified. [ABSTRACT FROM AUTHOR] more...

We present a novel deoxygenation method for heterocyclic Noxides utilizing iodide as a catalyst. Iodide acts as a reducing catalyst that is regenerated by formic acid, which also serves as a Brønsted activator and solvent. The method demonstrates high efficiency and excellent selectivity in the reduction of a variety of heterocyclic N-oxides and tertiary amines. Our computational DFT investigation revealed that the reduction mechanism entails a direct interaction between iodide and the oxygen of the N-oxide within a Mg2+/formic acid framework, resulting in the formation of the N-heterocycle and the release of a hypoiodite unit. Additionally, a molecular mechanism for the regeneration of iodide from hypoiodite, facilitated by formic acid, is suggested. This method provides an environmentally friendly approach for the deoxygenation of N-oxides and related species. [ABSTRACT FROM AUTHOR] more...

We present a convenient and efficient deoxygenation method for synthesizing disulfides and thioethers. The reaction involves an iodide-catalyzed reduction of methyl sulfinates or sulfoxides, respectively, employing formic acid as a stoichiometric reductant. The methodology demonstrates excellent yields and remarkable orthogonality towards other reducible functional groups. In silico explorations revealed the synergistic action of formic acid and in situ generated hydroiodic acid as Brønsted donors within a formic acid framework. This molecular arrangement activates the sulfinyl group and promotes subsequent deoxygenation. Notably, this approach enables the deoxygenation of sulfur-based functional groups using formic acid as the stoichiometric reductant without needing transition metals or strong acidic media such as hydroiodic acid. Overall, this methodology contributes to the advancement of the reduction of diverse oxygenated sulfur-containing compounds in a sustainable approach. [ABSTRACT FROM AUTHOR] more...

Ethyl cyanoformate and methyl cyanoformate (Mander's reagent) are both routinely used to perform C-selective ketone alkoxycarbonylations. Interestingly, both reagents were found to yield oxoalkenenitriles through an unprecedented deoxycyanation of 1,3-dicarbonyl compounds (e.g., 2-methylcyclohexane-1,3-dione). Although this method is not general, this is the first time that both Mander's reagent and ethyl cyanoformate have been used for the deoxycyanation of 1,3-dicarbonyl compounds for the preparation of synthetically useful oxoalkenenitriles. Limitations on the substrate scope of the present method are discussed. [ABSTRACT FROM AUTHOR] more...

Background and Objective : A previous study investigated the in vitro release of methylene blue (MB), a widely used cationic dye in biomedical applications, from nanocellulose/nanoporous silicon (NC/nPSi) composites under conditions simulating body fluids. The results showed that MB release rates varied significantly with the nPSi concentration in the composite, highlighting its potential for controlled drug delivery. To further analyze the relationship between diffusion dynamics and the MB concentration, this study developed a finite element (FE) method to solve Fick's equations governing the drug delivery system. Methods : Release profiles of MB from NC/nPSi composites with varying nPSi concentrations (0%, 0.1%, 0.5%, and 1.0%) were experimentally measured in triplicate using phosphate-buffered saline (PBS) at 37 °C, pH 7.4, and 100 rpm. Mathematical models incorporating linear and quadratic dependencies of the diffusion coefficient on the MB concentration were developed and tested using the FE method. Model parameters were refined by minimizing the error between simulated and experimental MB release profiles. Results : The proposed FE method closely matched experimental data, validating its accuracy and robustness in simulating the diffusion and release processes. Conclusions : This study emphasizes the significant impact of the nPSi concentration on enhancing release control and highlights the importance of material composition in designing drug delivery systems. The findings suggest that the FE method can be effectively applied to model other complex systems, paving the way for advancements in precision drug delivery and broader biomedical applications. more...

Medical implants are designed to replace missing parts or improve body functions and must be capable of providing structural support or therapeutic intervention for a medical condition. Advances in materials science have enabled the development of devices made from metals, polymers, bioceramics, and composites, each with its specific advantages and limitations. This review analyzes the incorporation of biopolymers, proteins, and other biomacromolecules into implants, focusing on their role in biological integration and therapeutic functions. It synthesizes advancements in surface modification, discusses biomacromolecules as carriers for controlled drug release, and explores the application of nanoceramics and composites to improve osseointegration and tissue regeneration. Biomacromolecule systems are capable of interacting with device components and therapeutic agents - such as growth factors (GFs), antibiotics, and nanoceramics - allowing control over substance release. Incorporating therapeutic agents into these systems enables localized treatments for tissue regeneration, osseointegration, post-surgery infection control, and disease and pre-existing conditions. The review highlights these materials' therapeutic advantages and customization opportunities, by covering mechanical and biological perspectives. Developing composites and hybrid drug delivery systems align with recent efforts in interdisciplinary personalized medicine and implant innovations. For instance, a trend was observed for integrating inorganic (especially nanoceramics, e.g., hydroxyapatite) and organic phases in composites for better implant interaction with biological tissues and faster recovery. This article supports understanding how integrating these materials can create more personalized, functional, durable, and biocompatible implant devices., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2025 Calais, Garcia, de Moura Júnior, Soares, Lona, Beppu, Hernandez-Montelongo and Rocha Neto.) more...

Single-cell RNA sequencing has transformed the study of biological tissues by enabling transcriptomic characterizations of their constituent cell states. Computational methods for gene expression deconvolution use this information to infer the cell composition of related tissues profiled at the bulk level. However, current deconvolution methods are restricted to discrete cell types and have limited power to make inferences about continuous cellular processes such as cell differentiation or immune cell activation. We present ConDecon, a clustering-independent method for inferring the likelihood for each cell in a single-cell dataset to be present in a bulk tissue. ConDecon represents an improvement in phenotypic resolution and functionality with respect to regression-based methods. Using ConDecon, we discover the implication of neurodegenerative microglia inflammatory pathways in the mesenchymal transformation of pediatric ependymoma and characterize their spatial trajectories of activation. The generality of this approach enables the deconvolution of other data modalities, such as bulk ATAC-seq data., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.) more...

Nanocellulose (NC) is a promising material for drug delivery due to its high surface area-to-volume ratio, biocompatibility, biodegradability, and versatility in various formats (nanoparticles, hydrogels, microspheres, membranes, and films). In this study, nanocellulose films were derived from "Bolaina blanca" ( Guazuma crinita ) and combined with nanoporous silicon microparticles (nPSi) in concentrations ranging from 0.1% to 1.0% ( w / v ), using polyvinyl alcohol (PVA) as a binding agent to create NC/nPSi composite films for drug delivery systems. The physicochemical properties of the samples were characterized using UV-Vis spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The mechanical properties and drug release capabilities were also evaluated using methylene blue (MB) as an antibacterial drug model. Antibacterial assays were conducted against S. aureus and E. coli bacteria. The results show that NC/nPSi composites with 1% nPSi increased the T 50% by 10 °C and enhanced mechanical properties, such as a 70% increase in the elastic modulus and a 372% increase in elongation, compared to NC films. Additionally, MB released from NC/nPSi composites effectively inhibited the growth of both bacteria. It was also observed that the diffusion coefficients were inversely proportional to the % nPSi. These findings suggest that this novel NC/nPSi-based material can serve as an effective controlled drug release system. more...