Browse Articles

Personalized metronomic radiopharmaceutical therapy through injection profile optimization via physiologically based pharmacokinetic (PBPK) modeling

Enhancing counterfeit RFID tag classification through distance based cognitive risk control

AI-driven video summarization for optimizing content retrieval and management through deep learning techniques

Extended T2 times of shallow implanted NV in chemically mechanically polished diamond

Mechanical polishing of diamond is known to be detrimental to the spin coherence time and strain environment of near-surface defects via intrinsic introduction of subsurface damage: this damage is typically removed by inductively coupled plasma reactive ion etching (ICP-RIE). By utilizing a chemical mechanical polishing (CMP) process to prepare ⟨001⟩ diamond surfaces, we demonstrate that we can achieve 13C-limited spin lifetimes of shallow implanted (≤34 nm) nitrogen vacancy (NV) centers in an industrially scalable process. We compare spin lifetimes (T2) of three diamonds processed with CMP with one processed by ICP-RIE and observe an increased median T2 of 340 μs in the CMP-processed samples for 15NV centers implanted and annealed under identical conditions.

The impact of action descriptions on attribution of moral responsibility towards robots

Landau levels induced by synthetic strain in plasmonic metasurface

The quantum Hall effect arises when electrons in a two-dimensional plane are subjected to a magnetic field, causing them to undergo cyclotron motion and form discrete energy levels, known as Landau levels. These levels play a critical role in condensed matter physics. However, practical limitations of applying a magnetic field have led to the introduction of pseudomagnetic fields, which can similarly induce Landau levels. Such pseudomagnetic fields are typically generated through synthetic strain, achieved by deforming geometric patterns, and have been applied to systems like graphene, photons, and phonon crystals. Building on previous research in electronics and optics, we present a plasmonic metasurface that induces Landau levels via synthetic strain in the microwave frequency range. This strain is realized by printing metal structures of specific shapes on a dielectric substrate using printed circuit board technology. The fundamental unit of the plasmonic metasurface is a C6 symmetric structure composed of six localized surface plasmon patches. By applying a displacement function along the transmission direction, we discretize the dispersion curve, leading to band degeneration and the emergence of edge states. The distribution of these edge states is influenced by the strength of the pseudomagnetic field, which is controlled by the magnitude of the displacement function. We validate our design through fabricated models and demonstrate the existence of edge states using near-field scanning experiments. Our work, which combines synthetic magnetic fields and plasmonic metasurface, provides valuable insights for the development and application of integrated photonic devices.

Ecological overview of hard ticks (Ixodida: Ixodidae) in Nagasaki prefecture of western Japan during winter 2021–2022

High resolution multicolor holograms encoded into color print images with hybrid dielectric/plasmonic metasurfaces

Multicolor holograms encoded into color print images are structures that generate holographic images when illuminated with lasers, while showing completely different images when viewed with the eye or with microscopes under white light incoherent illumination. Despite their promising applications in optical document security, they have been the subject of only a handful of research efforts, underscoring the need for further exploration in this area. Here, we propose a hybrid metasurface that achieves this functionality and thoroughly characterize its performance using simulations. In our device, nanohole arrays in an aluminum film function as plasmonic color filters for blue, green, and red channels with low crosstalk. Amorphous titanium dioxide (aTiO2) nanopillars comprise the hologram metasurface, which modulates the outgoing light's phase to produce a holographic image. Due to the subwavelength dimensions of the unit cell of the color filter (e.g., 415 nm for red, 315 nm for green, and 255 nm for blue wavelengths) and metasurface hologram (e.g., 430 nm for red, 360 nm for green, and 305 nm for blue wavelengths), the color print and holographic images can have very high resolution. Simulations reveal that the metasurface can be perceived as a tricolor image under incoherent white light, whereas under illumination from red, green, and blue lasers, three distinct holographic images can be observed.

Evaluation of an aquatic liverwort and terrestrial moss as biomonitors of heavy metals associated with particulate matter

Color astrophotography with a 100 mm-diameter f/2 polymer flat lens

We demonstrate a 100 mm-diameter, 2.4 μm-thick multilevel diffractive lens (MDL) with a 200 mm focal length, optimized for the 400 to 800 nm wavelength range—specifications that are difficult to achieve even with complex multi-element refractive systems. Created using an inverse-design approach and grayscale lithography, the MDL achieves achromatic focusing, confirmed through hyperspectral point-spread function (PSF) characterization. Imaging experiments resolved spatial frequencies up to 181 lp/mm and demonstrated the MDL's capability in capturing high-quality, full-color images of the moon, sun, and distant terrestrial scenes. Color-enhanced lunar images revealed key geological features, while solar imaging identified visible sunspots. Additionally, the MDL was integrated with a refractive achromatic lens to form a hybrid telescope, significantly reducing weight for airborne and space-based imaging applications. Simulations and experimental results reported here underscore the potential of large-area achromatic flat lenses as lightweight alternatives to conventional refractive systems for astrophotography and other long-range imaging tasks.

Environmental and health risk assessment of polycyclic aromatic hydrocarbons and toxic elements in the red sea using Monte Carlo simulation

Abstract This research evaluates the environmental and health risks linked to potentially toxic elements (PTEs) and PAHs along the western coast of the Gulf of Suez, Egypt. This study investigated the concentration of 16 PAH compounds in the Suez Gulf, revealing significantly higher levels than the EU (0.20 µg/L) and US (0.030 µg/L) standards. The average total PAH concentration across eight locations was significantly higher, with the Suez area having the highest concentration at 479 µg/L. Pyrene (Pyr) was the dominant PAH with a concentration of 443 µg/L in Suez, while acenaphthylene (Ace) had the lowest concentration at 0.120 µg/L in Northern Zaafarana. Carcinogenic PAHs (CAR) ranged from 8.67 µg/L at Ras Gharib to 29.62 µg/L at Suez, highlighting the urgent need for regulatory measures. Confirmatory ratios pointed to industrial and shipping influences as petrogenic sources. Elevated total organic carbon (TOC) levels in Suez Bay indicated aggravated organic pollution, exacerbated by oil rigs and refineries. The ecological risk assessment highlighted substantial risks, particularly in Suez, necessitating immediate interventions to combat PAH contamination and preserve the environmental balance of the Red Sea. The dominant metals in water samples were arranged in descending order as follows: Pb > Fe > Cr > Cu > Zn > Mn > Cd > Ni. The study evaluated environmental and human health risks using a multifaceted approach, including cluster analysis, principal component analysis, and various indices (HPI, RI, MI, HQ, HI, and CR). Most water samples exhibited high pollution risks, surpassing permissible limits for HPI (> 100) and MI (> 6). Notably, HI oral values indicated significant non-carcinogenic risks for adults and children. While HI values for adults suggested low-risk dermal contact, those for children showed a substantial proportion in the high-risk category. Most water samples displayed CR values exceeding 1 × 10–4 for Cd, Cr, and Pb, indicating vulnerability to carcinogenic effects in both age groups. Monte Carlo simulations reinforced these findings, revealing a significant carcinogenic impact on children and adults. The identified clusters, reflective of industrial, petroleum-related, and urban runoff contamination sources, were consistently validated and clarified through PCA, enhancing the reliability of the findings. In light of these results, urgent and comprehensive water treatment measures are imperative to mitigate carcinogenic and non-carcinogenic health risks. These insights provide a foundation for implementing targeted management strategies to effectively address the challenges of heavy metal contamination in the Red Sea.

Laser-induced thermal size effects in micro-Raman thermal conductivity measurements

Thermal conductivity measurements of submicrometer structures are at the core of the efficient power design of semiconductor devices. Micro-Raman spectroscopy measures thermal conductivity in a fast, nondestructive, and non-contact manner. However, the focused laser heating in micro-Raman experiments may cause drastic thermal size effects. To date, the role of such effects in the accuracy and limitations of the measurement has not been addressed. Here, we present an advanced thermal model to capture the role of material properties, laser power, and film thickness in the thermal size effects, based on the three-dimensional (3D) gray phonon Boltzmann transport equation. Recalling that laser-induced thermal size effects can lead to unexpectedly high local temperatures, even damaging the measured materials, our advanced 3D model gains particular importance for the accurate measurements of directional thermal conductivities in submicrometer structures using future high-resolution optical pump–probe techniques.

Publisher Correction: Role of total polyphenol content in seed germination characteristics of spring barley varieties amidst climate change

Raman signal enhancement via a micro-ring resonator

This study presents the use of micro-ring resonator (MRR) devices to extract and enhance nonlinear signals. MRRs “trap” incoming light and, therefore, have been shown to achieve extremely high local intensities of light. Thus, they can be used to facilitate highly nonlinear optical signals that are usually weak in intensity and require high excitation power. By embedding materials that host nonlinear optical processes inside the MRR, we expect to observe an enhancement in the strength of the nonlinear optical signals. This concept is demonstrated here by extracting the Raman signature of graphene that is placed inside a MRR device. A highly doped silica MRR featuring an optical bus waveguide coupled to a ring tuned to near-infrared wavelengths is used. Raman signal with an excitation wavelength of 522 nm via third-harmonic generation inside the MRR is observed. The higher-order Raman signal of the embedded graphene is also observed at the 1597.6 nm excitation wavelength. This work demonstrates the feasibility of the MRR as a nonlinear signal enhancer using high-Q MRR device setups.

Iron(III) edta-accelerated growth of gold/silver core/shell nanoparticles for wide-range colorimetric detection of hydrogen peroxide

Accurate and real-time acoustic holography using super-resolution and physics combined deep learning

Acoustic holography is a promising technique for contactless manipulation, remote sensing, and energy harvesting. It involves retrieving holograms used to modulate acoustic sources for reconstructing target acoustic fields. The performance of reconstruction is primarily determined by two key criteria, including the spatial bandwidth product, which measures the pixel number representing information capacity, and the resolution, which quantifies the pixel size supporting detail gain. However, existing techniques face limitations in reconstructing high-fidelity, dynamic, and real-time acoustic fields with enhanced spatial bandwidth product and resolution across the entire aperture size. These challenges stem from the reliance on physically constrained holograms with static nature or relatively low spatial bandwidth product and resolution. Here, we introduce super-resolution acoustic holography, wherein the spatial bandwidth and resolution of the reconstructed target acoustic fields surpass those of the retrieved source holograms, especially within the same aperture size. We further develop a deep learning strategy that combines a classical neural network architecture with a linear accumulation based physical model, allowing for the customization of reconstructed acoustic planes with higher resolution while maintaining the same lateral coverages. Extensive algorithmic validations, numerical simulations, and practical experiments demonstrate the capability of our method to achieve high-fidelity, dynamic, real-time super-resolution acoustic holography, rendering its potential to advance practical applications in holographic acoustics.

Long-term trends and patterns in ultra-processed food consumption among Korean adults from 1998 to 2022

Homogeneous linewidth behavior of narrow optical emitters at sub-kelvin temperatures

We explore the properties of ultranarrow spectral holes in ensembles of solid-state emitters in crystals over a range of sub-kelvin temperatures, as a new step toward leveraging their exceptional coherence properties more effectively. As an example, we consider the potential gain observed in their application in frequency stabilization schemes. We investigate how the parameters used to burn the spectral hole impact its shape, and how these factors determine the minimum achievable linewidth. In addition to the stability of the hole's center frequency, the linewidth and contrast play a crucial role in frequency locking. At sub-kelvin temperatures, the temperature-dependent T7 broadening from two-phonon Raman scattering is expected to be negligible, and the spectral hole's linewidth should therefore remain constant in this interval. We observe however a linear broadening with increasing temperature, highlighting the need for further investigation into the mechanisms governing the linewidth at ultra-low temperatures.

Differences in health related quality of life among older migrants and nonmigrants in India

Stearic acid/CNT-wrapped superhydrophobic/oleophilic sponge with Joule-heating effect for efficient removal of crude oil

Crude oil spill accidents cause extreme environmental damage, with huge economic costs that include the loss of oil resources. Despite the advances in conventional oil spill cleanup technology, such as dispersants, absorbents, and skimmers, there is still a need for more efficient solutions. In this study, we introduce a Joule-heated stearic acid/carbon nanotube-wrapped polyurethane sponge (SCPU) for rapid and all-weather recovery of leaked crude oil. SCPU is both hydrophobic and oleophilic and is electrically conductive. When 6 V were applied across the SCPU, the surface temperature increased to 146 °C within 70 s, which reduced the viscosity of crude oil and shortened the recovery time by over 99%. In addition, the Joule-heated SCPU can continuously recover crude oil floating on the water surface when connected to a peristaltic pump. This Joule-heated SCPU has a high crude oil adsorption capacity, a scalable preparation method, and is mechanically stable, and thus is expected to provide an efficient and practical solution for responding to crude oil spill accidents.