Solid Core Research Articles

The computational complexity of the solid torus core recognition problem

The computational complexity of the solid torus core recognition problem

Pan-Draft: automated reconstruction of species-representative metabolic models from multiple genomes

The accurate reconstruction of genome-scale metabolic models (GEMs) for unculturable species poses challenges due to the incomplete and fragmented genetic information typical of metagenome-assembled genomes (MAGs). While existing tools leverage sequence homology from single genomes, this study introduces pan-Draft, a pan-reactome-based approach exploiting recurrent genetic evidence to determine the solid core structure of species-level GEMs. By comparing MAGs clustered at the species-level, pan-Draft addresses the issues due to the incompleteness and contamination of individual genomes, providing high-quality draft models and an accessory reactions catalog supporting the gapfilling step. This approach will improve our comprehension of metabolic functions of uncultured species.

Magnetic Field Evolution for Crystallization-driven Dynamos in C/O White Dwarfs

We investigate the evolution of magnetic fields generated by the crystallization-driven dynamo in carbon–oxygen white dwarfs (WDs) with masses ≲1.05 M ⊙. We use scalings for the dynamo to demonstrate that the initial magnetic field strength (B 0) has an upper limit that depends on the initial convection zone size (R out,0) and the WD mass. We solve the induction equation to follow the magnetic field evolution after the dynamo phase ends. We show that the predicted surface magnetic field strength (B surf) differs from B 0 by at least a factor of ∼0.3. This reduction depends on R out,0, where values smaller than half of the star radius give B surf ≲ 0.01 B 0. We implement electrical conductivities that account for the solid phase effect on the ohmic diffusion. We observe that the conductivity increases as the solid core grows, freezing in the magnetic field at a certain point of the evolution and slowing its outward transport. We study the effect of turbulent magnetic diffusivity induced by the convection and find that for a small R out,0, B surf is stronger than the nonturbulent diffusion cases because of the more rapid transport, but still orders of magnitude smaller than B 0. Given these limitations, the crystallization-driven dynamo theory could explain only magnetic C/O WDs with field strengths less than a few megagauss for the mass range 0.45–1.05 M ⊙. Our results also suggest that a buried fossil field must be at least 100 times stronger than observed surface fields if crystallization-driven convection is responsible for its transport to the surface.

Using Extensive Core‐Reflected Phases to Constrain Sharp Inner Core Boundary Beneath East Asia

AbstractThe physical properties of the Earth's inner core boundary (ICB) are crucial for understanding inner core growth and geodynamo generation. In this study, we analyze the differential travel time residuals (DTTRs) and waveform similarities of the core‐reflected phases (PKiKP and PcP) to investigate fine‐scale seismic structures of the ICB. To study the ICB beneath East Asia, we collect a total of 4,272 PKiKP and PcP phase pairs from 37 earthquakes occurring from January 2009 to December 2018 recorded by permanent stations in the Chinese Digital Seismic Network (CDSN). This extensive PKiKP dataset allows for a geographically continuous depiction of the ICB beneath East Asia, revealing a diverse scope on its topography and sharpness. There are three main findings in our study. First, we collect a comprehensive PKiKP and PcP dataset with extensive ray coverage across East Asia. Numerous weak precritical PKiKP signals are detected, enabling robust constraints on the ICB across wide regions. Second, the PKiKP‐PcP DTTRs exhibit an average offset of −0.25 s (ranging from −1.5 to 1.0 s) relative to the PREM model, suggesting the outer core is approximately 1.3 km thinner than predicted by the PREM model, although it remains largely consistent with it. Third, the bin‐stacked PKiKP and PcP waveforms show high similarity across most sampled areas, indicating that the ICB thickness is no more than 2 km mostly beneath East Asia, which aligns with the hypothesis of a rapid transition from the solid inner core to the liquid outer core in our study region.

On thermally driven fluid flows arising in astrophysics

We investigate a potential model for an unbounded celestial bodies of finite mass composed of a solid core and a gaseous atmosphere. The system is governed by the Navier–Stokes–Fourier–Poisson equations, incorporating no-slip boundary conditions for velocity and a specified temperature distribution on the surface of the solid core. Additionally, a positive far-field condition is imposed on the temperature. This manuscript extends the mathematical theory of open fluid systems to unbounded exterior domains addressing these physically motivated yet highly challenging combination of boundary conditions. Notably, we establish the existence of global-in-time weak solutions and demonstrate the weak-strong uniqueness principle

Wavefront shaping and imaging through a multimode hollow-core fiber

Multimode fibers recently emerged as compact minimally-invasive probes for high-resolution deep-tissue imaging. However, the commonly used silica fibers have a relatively low numerical aperture (NA) limiting the spatial resolution of a probe. On top of that, light propagation within the solid core generates auto-fluorescence and Raman background, which interferes with imaging. Here we propose to use a hollow-core fiber to solve these problems. We experimentally demonstrate spatial wavefront shaping at the multimode hollow-core fiber output with tunable high-NA. We demonstrate raster-scan and speckle-based compressive imaging through a multimode hollow-core fiber.

Tailoring Core-Shell Metal Coordination for Smart Seed Coatings in Sustainable Agriculture.

The international agriculture and food security sector is grappling with challenges like low crop yields, soil health deficiencies, and inefficient agrochemical use. The application of smart nanotechnology in agriculture, particularly surface functionalization, holds promise but has limited implementation. Engineered nanomaterials used as seed treatments, known as nanopriming, offer a simple technology to improve crop yield and stress tolerance. In this study, a multicomponent platform called Phelm (Phenolic network with a lipid core and metal coordinated shell) is proposed for encapsulating a commercial plant growth regulator, indole-3 acetic acid (IAA). Phelm comprises a hydrophobic solid lipid core, loaded with IAA, and an outer metal coordinated phenolic shell of tannic acid (TA) and Fe3+. The platform aims to treat seeds with encapsulated IAA, which can be controllably released, as well as protect the germination process at high salt concentrations. Phelm showed a remarkable increase in growth parameters of wheat seeds up to 58.6%, despite being irrigated with high concentrations of saltwater (100 mM). These findings suggest that nanopriming of seeds can effectively increase their efficacy even under abiotic stress conditions, which can drastically improve crop yields. Moreover, we envisage that the Phelm core/shell assembly can encapsulate a wide range of agrochemicals and biostimulants to promote sustainable and smart agricultural practices.

Hyaluronic Acid in Nanopharmaceuticals: An Overview.

Hyaluronic acid (HA) is a naturally occurring, long, unbranched polysaccharide that plays a critical role in maintaining skin structure and hydration. Its unique properties make it a valuable component in the field of nanopharmaceuticals. The combination of HA into nanopharmaceuticals enhances its ability to interact with various therapeutic agents, improving the delivery and efficacy of drugs. HA-based nanoparticles, including solid lipid nanoparticles, and polymeric nanogels, offer controlled release, enhanced stability, and targeted delivery of therapeutic agents. These innovations significantly improve therapeutic outcomes and reduce side effects, making HA an essential tool in modern medicine. In general, HA-modified liposomes enhance drug encapsulation and targeting, while HA-modified solid lipid nanoparticles (SLNs) provide a solid lipid core for drug encapsulation, offering controlled release and stability. This article provides an overview of the potential applications and recent advancements of HA in nanopharmaceuticals, emphasizing its significant impact on the evolving field of targeted drug delivery and advanced therapeutic strategies. By delving into the unique properties of HA and its compatibility with various therapeutic agents, this review underscores the promising potential of HA in revolutionizing nanopharmaceuticals.

Coupled tidal tomography and thermal constraints for probing Mars viscosity profile

Computing the tidal deformations of Mars, we explored various Mars spherically symmetric internal structures with different types of interface between the mantle and the liquid core. By assessing their compatibility with a diverse set of geophysical observations we show that despite the very short periods of excitation, tidal deformation is very efficient to constrain Mars interior. We calculated densities and thicknesses for Martian lithosphere, mantle, core–mantle boundary layers and core and found them consistent with preexisting results from other methods. We also estimated new viscosities for these layers. We demonstrated that the geodetic records associated with thermal constraints are very sensitive to the presence of a 2-layered interface on the top of the liquid core in deep Martian mantle. This interface is composed by 2 layers of similar densities but very different viscosity and rheology: the layer on the top of the core is liquid (Newtonian, NBL) and the one at the base of the mantle, overlaying the liquid one, is an Andrade layer (ABL) with a viscosity in average 10 orders of magnitude greater than the Newtonian layer. Our results also indicate that the existence of this 2-layered interface significantly impacts the viscosity profiles of the mantle and the lithosphere. More precisely, models including the 2-layered interface do not display significant viscosity contrast between the mantle and the lithosphere, preventing mechanical decoupling between a lithosphere and the mantle immediately below. Such models are in favor of a stagnant lid regime that can be supported by the current absence of an Earth-like plate tectonics on Mars. Finally, in our results, the presence of liquid Newtonian layer at the top of the liquid core is incompatible with the existence of a solid inner core.

Glucose-Responsive Microneedle Patch with High Insulin Loading Capacity for Prolonged Glycemic Control in Mice and Minipigs.

Transdermal microneedle-mediated glucose-responsive insulin delivery systems can modulate insulin release based on fluctuations in blood glucose levels, thus maintaining normoglycemia effectively in a continuous, convenient, and minimally invasive manner. However, conventional microneedles are limited by the low drug loading capacity, making it challenging to be applied on human skin at a reasonable size for a lasting glucose-controlling effect, thus hindering their clinical translation. Here, we design a microneedle patch with a solid insulin powder core to achieve a high loading capacity of insulin (>70 wt %) as well as a glucose-sensitive polymeric shell to realize glucose-responsive insulin release. Once exposed to hyperglycemia, the formation of negatively charged glucose-boronate complexes increases the charge density of the shell matrix, leading to swelling of the shell and accelerating insulin release from the core. We have demonstrated that this glucose-responsive microneedle patch could achieve long-term regulation of blood glucose levels in both type 1 diabetic mice and minipigs (up to 48 h with patches of ∼3.5 cm2 for minipigs >25 kg).

Spin orbit resonance cascade via core shell model: application to Mercury and Ganymede

We discuss a model describing the spin orbit resonance cascade. We assume that the body has a two-layer (core–shell) structure; it is composed of a thin external shell and an inner and heavier solid core that are interacting due to the presence of a viscous friction. We assume two sources of dissipation: a viscous one, depending on the relative angular velocity between core and shell and a tidal one, smaller than the first, due to the viscoelastic structure of the core. We show how these two sources of dissipation are needed for the capture in spin–orbit resonance. The shell and the core fall in resonance with different time scales if the viscous coupling between them is big enough. Finally, the tidal dissipation of the viscoelastic core, decreasing the eccentricity, brings the system out of the resonance in a third very long time scale. This mechanism of entry and exit from resonance ends in the 1 : 1 stable state.

New method for the investigation of mode coupling in graded-index polymer photonic crystal fibers using the Langevin stochastic differential equation

The mode coupling in a graded-index polymer photonic crystal fiber (GI PPCF) with a solid core has been investigated using the Langevin equation. Based on the computer-simulated Langevin force, the Langevin equation is numerically integrated. The numerical solutions of the Langevin equation align with those of the time-independent power flow equation (TI PFE). We showed that by solving the Langevin equation, which is a stochastic differential equation, one can successfully treat a mode coupling in GI PPCFs, which is an intrinsically stochastic process. We demonstrated that, in terms of effectiveness, the Langevin equation is preferable compared to the TI PFE. The GI PPCF achieves the equilibrium mode distribution (EMD) at a coupling length that is even shorter than the conventional GI plastic optical fiber (POF). The application of multimode GI PCFs in communications and optical fiber sensor systems will benefit from these findings.

BJS 2 - Tumour targeted oxygen-generating nanoparticles for enhanced radiotherapy in the treatment of pancreatic cancer

Abstract Aim To determine if novel oxygen-generating nanoparticles, encased in a pH-sensitive polymethacrylate polymer (SOG-01), can enhance radiotherapy-based treatment in a preclinical pancreatic cancer model. SOG-01 nanoparticles are stable in circulation and, at the lower pH in hypoxic tumours, the polymer coating dissolves to expose a solid peroxide core, capable of generating oxygen in the tumour microenvironment. Since hypoxia reduces the efficacy of radiotherapy, this particle could potentially be employed to enhance radiotherapy-based approaches for the treatment of pancreatic cancer. Methods A human xenograft pancreatic cancer model (BxPC-3) in mice was employed as a target. SOG-01 was administered systemically and animals (n=6 per experimental group) were subsequently treated with radiation (a single dose of 6 Gy) using a Gulmay (160kV) AGO HS-MP1 X-Ray generator. Control animals were either untreated, treated with SOG-01 alone, or radiation alone. Tumour size and survival were employed as a measure of therapeutic efficacy. Results When the mean tumour size of groups treated with SOG-01 or radiation alone was compared with that of the untreated group at day 23 no statistically significant decrease was observed. However, a dramatic 89% and statistically significant decrease (p = 0.001; α = 0.05) was observed for tumours treated with combination of SOG-01 and radiation. Additionally, Kaplan Meier analysis demonstrated enhanced survival to 65 days when compared with 38 day survival for the group treated with radiation alone. Conclusions The data suggest that SOG-01 may play a role in enhancing radiotherapy-based approaches for the treatment of pancreatic cancer.

Protocols for transitioning to adult mental health services for adolescents with ADHD

BackgroundFor Attention Deficit/Hyperactivity Disorder (ADHD) youth transitioning from child to adult services, protocols that guide the transition process are essential. While some guidelines are available, they do not always consider the effective workload and scarce resources. In Italy, very few guidelines are currently available, and they do not adhere to common standards, possibly leading to non-uniform use.MethodsThe present study analyzes 6 protocols collected from the 21 Italian services for ADHD patients that took part in the TransiDEA (Transitioning in Diabetes, Epilepsy, and ADHD patients) Project. The protocols’ content is described, and a comparison with the National Institute for Clinical Health and Excellence (NICE) guidelines is carried out to determine whether the eight NICE fundamental dimensions were present.ResultsIn line with the NICE guidelines, the dimensions addresses in the 6 analyzed documents are: early transition planning (although with variability in age criteria) (6/6), individualized planning (5/6), and the evaluation of transfer needs (5/6). All protocols also foresee joint meetings between child and adult services. The need to include the families is considered by 4 out of 6 protocols, while monitoring (2/6), and training programs (1/6) are less encompassed. In general, a highly heterogeneous picture emerges in terms of quality and quantity of regulations provided.ConclusionsWhile some solid points and core elements are in common with international guidelines, the content’s variability highlights the need to standardize practices. Finally, future protocols should adhere more to the patients’ needs and the resources available to clinicians.

Splitting of double-core solid-in-water-in-oil droplet in a microfluidic Y-junction

Solid particle-encapsulated droplets have significant applications in biochemistry, advanced materials, and inertial confinement fusion (ICF) experiments. However, there is a problem of encapsulating two solid cores in a single droplet during the preparation of single-core droplets, which reduces the utilization efficiency. In this study, an effective microfluidic approach for continuous splitting of solid-in-water-in-oil droplets encapsulating double solid cores is developed. Visualization experiments are conducted to analyze the movements of solid cores and evolution of liquid–liquid interface during the splitting. The results show that the squeezing stage during the splitting process is shortened due to the presence of solid cores. The splitting mechanisms were also revealed by analyzing the interaction forces between the solid cores and aqueous phase. The force analysis of the aqueous phase showed that sum of squeezing and shear force could overcome the interfacial tension, ensuring the successful splitting of the double-core droplets. The force analysis of the solid cores revealed that the motion of the core could be divided into three typical stages: deceleration, hitting and separation. The combined effect of the aqueous phase, channel wall, and interfacial forces ensured the stable separation of the two solid cores. The length distribution of the daughter droplets exhibited excellent monodispersity. The microfluidic method proposed in this work would effectively improve the controlled preparation efficiency of solid-in-water-in-oil droplets.

ОБЕРТАЛЬНИЙ МОМЕНТ БЕЗПАЗОВОГО МОМЕНТНОГО ДВИГУНА З ПОСТІЙНИМИ МАГНІТАМИ ТА МАСИВНИМ МАГНІТОПРОВОДОМ СТАТОРА

The properties of the solid magnetic core of the stator of a slotless torque motor with permanent magnets are considered. It is noted that the solid stator under the conditions of low rotation speed has some advantages over the traditional laminated magnetic circuit. These advantages consist in the cost reduction of the design, its compactness and the low time of production preparation. The mathematical model's assumptions and the input data's limitations are formulated. A model of a static magnetic field with a moving electrically conductive medium is chosen. The two-dimensional model is implemented in the "Magnetic fields" interface of the "COMSOL Multiphysics" software. The maximum torque values were obtained and the optimal number of pole pairs was found. The method of calculating the torque based on eddy current losses in the magnetic medium is used. The decrease in torque with increasing rotor speed is calculated. The correction coefficients of the maximum moment were obtained to correct the results of two-dimensional modelling using a three-dimensional model. References 5, figures 6, tables 1.

Aquasomes: A Promising Delivery Systems for Poorly Soluble Bioactives

Aquasomes are considered an excellent and efficient carrier system for the transport of drugs or biochemically active long chain macromolecules such as proteins and peptides, various hormones, antigens, enzymes, and genes in the recently burgeoning field of nanobiotechnology research. These are three-layer self-collecting structures composed of an oligomeric film covering a strong stage nanocrystalline centre to which biochemically dynamic particles adhere to, independent of changes in the environment and which self-assembles through non-covalent or ionic connections. Aquasomes are circular particles, 60–300 nm in size, that are used to deliver antigens and medications. The structural stability is provided by the solid core, while the active drug molecules are stabilized and protected from dehydration by the polyhydroxy oligomer covering. The most common way to distribute aquasome formulations is parenterally, however recent research indicates that there may be additional, oral, ways as well. A combination of targeted molecular shielding and prolonged release mechanism is used by aquasome to deliver their bioactive chemicals. The present paper offers an overview of the aquasome as a potentially useful medication delivery technique. It covers every facet of aquasome, such as their structure, the processes for preparing them, ways to characterize them, and medical uses as a drug delivery system.

Experimental and numerical investigation of damage in multilayer sandwich panels with square and trapezoidal corrugated cores under quasi-static three-point bending

Multilayer composite sandwich panels with corrugated cores have the potential for structural applications requiring high stiffness and strength-to-weight ratios. This study aims to experimentally and numerically investigate the bending response of sandwich panels with novel square and trapezoidal corrugated core configurations fabricated from E-glass fiber-reinforced epoxy composites, both with and without polyurethane foam filling. Quasi-static three-point bending tests were conducted to evaluate and compare the flexural stiffness and maximum load capacity of the panel designs. The cores were manufactured using vacuum-assisted resin transfer molding. Key results showed that changing the core geometry from square to trapezoidal improved the bending stiffness by up to 26 %. Incorporating polyurethane foam further increased the bending stiffness by up to 41 % and maximum load by up to 47 % compared to solid cores. Failure initiation and progression were governed by matrix cracking in the face sheets and cores, followed by core cell wall buckling and delamination. Finite element modeling using ABAQUS captured the progressive damage behavior, exhibiting good agreement with experimental force-displacement responses. Failure modes included matrix cracks, fiber fractures, core buckling and delamination. This study provides valuable insights into the mechanical performance of innovative corrugated core sandwich panel designs under quasi-static bending loads. The validated FE approach also enables virtual testing and optimization of composite sandwich structures.

Spherical nucleic acids for biomedical applications

Spherical nucleic acids (SNAs) are a 3D spherical nanostructure composed of highly oriented, dense layers of oligonucleotides conjugated to a hollow or solid core. This structure allows SNAs to show resistance to nuclease degradation, enter into nearly all cells without transfection agents and enable precise interactions with target molecules. Based on superior biological properties, SNAs can be tailored for diverse biological applications, rendering them a flexible and biosafe tool for biological applications as well as an enabling platform for therapy. In this review, we mainly discuss the structure and conjugation mode of SNAs and focus on recent advances in their applications, such as biomedical detection, imaging, and drug delivery. Finally, the remaining challenges and future directions of SNAs are also discussed and proposed.

Effect of Speed of Rotation and Catheter Shape on Rotation Response of Solid Core Conduction System Pacing Lead

Effect of Speed of Rotation and Catheter Shape on Rotation Response of Solid Core Conduction System Pacing Lead