Browse Articles

Contributions of countries without a carbon neutrality target to limit global warming

Elastic properties associated with liquid–liquid phase transition in molten cerium

Cerium is regarded as one of the few metals that exhibit a first-order liquid–liquid phase transition (LLPT). However, despite the theoretical attribution of the LLPT to the localized-itinerant transition of f-electrons, there is still a lack of compelling experimental evidence to support this important scientific inquiry. In this study, we investigate the evolution of sound velocity in molten cerium along the isothermal and isobaric paths under static compression. Drawing parallels with the extensively studied γ–α isostructural phase transition, the V-shaped trend of temperature-dependent sound velocity in liquid suggests the existence of LLPT and identifies an associated mechanism predominating liquids' compressibility.

Analysis of the influence of different types of anti-slide piles on lining structures under landslide loading

Speciation and historical invasions of the Asian black-spined toad (Duttaphrynus melanostictus)

Residual strain optimization in 3D MOSFET structures for enhanced mobility via nanoscale heat transfer

This study addresses the optimization of strain in continuous MOSFET downscaling, particularly at the nanoscale, where traditional Fourier models fail due to non-diffusive phonon transport effects. We introduce a multi-physics simulation approach that combines Finite Element Method (FEM) and Density Functional Theory (DFT) calculations to design strain-optimized 3D MOSFET structures. By implementing the kinetic collective model within FEM simulations, we accurately predict thermal-induced strains in the Si channel layer. Our DFT calculations further elucidate the impact of these strains on the electronic properties, particularly the electron effective mass, thereby offering insights into mobility enhancement strategies. The study not only advances the implications of nanoscale heat transfer for device performance but also provides a robust framework for optimizing next-generation semiconductor devices through strain engineering and sophisticated multi-physics simulations.

Taxonomy of high pressure vibration spectra of zincblende semiconductor alloys based on the percolation model

High frequency CCR5 editing in human hematopoietic stem progenitor cells protects xenograft mice from HIV infection

An innovative and rapid method for permanent hydrophilic modification of polydimethylsiloxane (PDMS) chip surfaces

Polydimethylsiloxane (PDMS), a fundamental material in the fabrication of microfluidic devices, suffers from nonspecific adsorption of biological samples due to its hydrophobic nature. Herein, by employing a radiation-induced grafting strategy to introduce hydrophilic functional groups onto the PDMS surface, a significant improvement in hydrophilicity is achieved, leading to a notable reduction in the contact angle by up to ∼90° and improvement of antifouling performance against biological samples. Effects between monomer concentration, grafting efficiency, and mechanical integrity are balanced to optimize the grafting process, achieving promised hydrophilicity enhancement while the mechanical properties are not degraded. The content of carboxyl groups exposed on the surface of grafted PDMS was computationally analyzed using MD simulations, which revealed the key role of carboxyl groups in the wettability of the PDMS surface. Our study extensively showcases the effective grafting of acrylic acid onto PDMS, which is characterized by diverse grafting rates. Remarkably, the hydrophilic modification is stable over time compared to conventional plasma treatment, offering a more reliable and enduring strategy, and making it a valuable enhancement for PDMS chips with extensive applications.

Platelet indicators do not influence the impact of ABO blood groups on lung adenocarcinoma susceptibility

Catalytic asymmetric C–N cross-coupling towards boron-stereogenic 3-amino-BODIPYs

All-optical vector magnetometry based on fine and hyperfine interactions in spin-32 centers in silicon carbide

The possibility of using axial spin centers with S=3/2 in silicon carbide for all-optical measurement of the projection Bz of the external magnetic field onto the c-axis of the SiC crystal, as well as the polar and azimuthal angles of the magnetic field relative to the direction of the c-axis, at room and significantly higher temperatures is shown. Spin centers in SiC, where optically induced spin alignment occurs, have a unique system of spin levels in a magnetic field, caused by the interaction of the fine structure and hyperfine interaction with the 29Si nuclei. There is a wide range of level anticrossings (LACs) resulting in an extremely strong change in the photoluminescence intensity at LAC. The dependence of the LAC spectrum on the orientation of the external magnetic field is also observed. The proposed magnetometer is based on the compensation of the external magnetic field at the position of the optical excitation spot of the confocal microscope. The sensitivity to a constant magnetic field for the z-component of the magnetic field (Bz) is better than 0.1μT/Hz in the confocal volume at room temperature. The sensitivity of polar and azimuthal angle determination depends on the sensitivity of the perpendicular component of the magnetic field, which is better than ∼0.01mT/Hz in the range from −0.4 to 0.4 mT.

The pathomechanism of bone marrow edema in the femoral head necrosis with pericollapse stage

Siah2 antagonism of Pard3/JamC modulates Ntn1-Dcc signaling to regulate cerebellar granule neuron germinal zone exit

A radial micro-vibration system for reducing friction of passive interventional guidewire

Endovascular guidewire interventional surgery is an effective treatment for vascular diseases. However, due to factors, such as blood viscosity and complex vascular morphology, the guidewire is interfered by strong varying resistance when moving in the lesion’s vasculature. This greatly affects the efficiency and safety of the clinical operation. Here, we develop a novel system that applies ultrasonic micro-amplitude vibration to the conventional passive guidewire for studying a drag reduction effect under multiple factors. The system is mainly composed of a sandwich-type ultrasonic transducer and a step-type horn for concentrating the unidirectional energy for micro-vibration. Subsequently, comparative experiments are designed to verify the effectiveness of this system for drag reduction. Through the multifactorial interactions, we study the friction reduction law of the microvibration-assisted method on the guidewire and the optimal drag reduction parameter combinations. The results show that the drag reduction effect varies with the amplitude–frequency response curve. An ultrasound vibration amplitude and a simulated vessel bending angle were the most significant factors. Only vibration frequency and amplitude interacted with a simulated vessel shape. Finally, using the resonance frequency and the maximum vibration amplitude to drive the guidewire vibration, the maximum friction reduction rate can be obtained, up to 85.2%. This system is expected to have important applications in clinical vascular interventional procedures.

Subject-specific biomechanics influences tendon strains in patients with Achilles tendinopathy

Safety and immunogenicity of an optimized self-replicating RNA platform for low dose or single dose vaccine applications: a randomized, open label Phase I study in healthy volunteers

Electrical properties of ScN thin films controlled by defect engineering using oxygen ion implantation

Defects tend to modify significantly the properties of semiconductors, such as transport properties, by increasing the scattering of electrons and phonons, or optical properties, by modifying the band structure and the Fermi level. The high interest of ScN thin films for thermoelectric applications results from the incorporation of oxygen, which is well known to be the source for their degenerate n-type state and their significant power factor. Indeed, oxygen acts as a donor defect when substituted to nitrogen. In this study, oxygen ion implantation was performed at a high damage level as a way to modify electrical properties through defect engineering. Hence, we measured the changes in electrical properties induced by oxygen implantation at room temperature. Two types of defects have been identified as being responsible for the change in resistivity, carrier concentration, mobility, and Seebeck coefficient. At first, the point-like defects, recombining from 440 K and onward, introduce localized states near the Fermi level, inducing a change in the conduction mode from a metallic-like to a hopping mechanism. The relationship between Mott's temperature and defect concentration has been clearly demonstrated through in situ resistivity measurements in the 80–750 K temperature range. Furthermore, these measurements highlight that oxygen induced defects result not only from ballistic effects, but also from chemical effects that are involved. Second, the complex-like defects introduce deep acceptor levels into the bandgap and act as scattering centers that modify the Debye temperature as well as the electron–phonon interactions. These complexes, likely between scandium vacancies and oxygen atoms (VSc-yO, y ≤ 4), are primarily responsible for the increase of the Seebeck coefficient and the reduced mobility. The concentration of such defects can qualitatively be assessed as their formation introduces an additional term, independent of temperature, in the variation of resistivity, mobility, and also the Seebeck coefficient. The recovery of the complex-like defects takes place at a minimum temperature of 750 K. Results show that the effectiveness of oxygen in creating defects exceeds that of noble gases in terms of concentration, demonstrating the promise of this approach to control the electrical properties of ScN.

The effect of NLRP3 inflammasome on cardiovascular prognosis in patients with acute coronary syndrome

Author Correction: Back flux during anaerobic oxidation of butane support archaea-mediated alkanogenesis

Photoluminescence dynamics and ligand exchange in PbS/CdS core/shell nanocrystal films

Photoluminescence studies in PbS/CdS core/shell nanocrystal thin films reveal that the length of organic ligands at the nanocrystal surface controls the photoluminescence rise time and the short-lived decay component. The long-lived photoluminescence does not depend on the ligand length but strongly depends on the detection wavelength and temperature. We conclude that the observed complex photoluminescence dynamics are governed by a combination of energy transfer and exciton recombination and propose a method to separate these processes.