Browse Articles

Unilateral biportal endoscopic decompression combined with percutaneous pedicle screw fixation offers new treatment option for thoracolumbar burst fractures with secondary spinal stenosis

Compact high-precision Jones matrix metasurfaces for producing high-order vector vortex waves at microwave frequencies

Compact, high-precision Jones matrix metasurfaces, employing quasi-two-dimensional metasurfaces composed of a single-layer quasi-H-type patch, are presented for producing high-order vector vortex waves at microwave frequencies. The relationship between the spatial polarization mode of the vector waves described in the higher-order Poincaré (HOP) sphere and the higher-precision Jones matrix metasurface is established based on a derivation of the Jones matrix. The numerical results show that vector waves with spatial polarization mode orders of ±1 and ±2 can be accurately realized using compact, high-precision Jones matrix metasurfaces with orders of ±1 and ±2. In principle, Jones matrix metasurfaces can realize vector vortex waves of arbitrary order described in the HOP sphere. Two prototypes, namely, high-precision Jones matrix metasurfaces with orders of +1 and +2, are fabricated and experimentally investigated with various polarization morphologies. Good agreement is achieved between the simulations and the experimental results. These results will benefit the development of polarization multiplexing and help expand the applications of vector beams in the microwave range.

Using electrical resistivity techniques (ERT and SP) for nondestructive detection of seepage channels at the Leitai heritage site, China

Optimization of fin-slanted angles for enhanced electrical performance in lateral <i>β</i>-Ga2O3 MOSFETs

In this work, the influence of fin-slanted angles (α) on the electrical performance of lateral β-Ga2O3 MOSFETs was investigated through a combination of experiments and Sentaurus TCAD simulations. The fin-slanted devices demonstrated enhancement-mode characteristics with an on/off ratio of around 107. The increment in α resulted in improved drain-to-source current (IDS) and extrinsic transconductance (Gm). The voltage-blocking performance also showed significant enhancement with increasing α due to the mitigation of edge crowding, achieving a 40% increase in the breakdown voltage (VBR) for devices with an α of 15° and gate-to-drain length (LGD) of 10 μm. A detailed simulation analysis of the electric field distribution within the fin at the gate electrode edge identified an optimal α of approximately 25°, which effectively mitigates electric field crowding and has the potential to enhance the DC performance of the MOSFETs. These findings highlight the critical role of fin-slanted angle optimization in advancing the performance of lateral β-Ga2O3 MOSFETs, positioning them as promising candidates for next-generation power electronics.

Antimicrobial properties of Graphene sheets embedded with Titanium Oxide and Calcium Oxide nanoparticles for industrial wastewater treatment

Enhanced red-light photorefractive response speed of LiNbO3 crystals for full color holographic display

As a promising candidate material for holographic displays, lithium niobate (LN) is limited by its slow photorefractive (PR) response. Recently, it was discovered that Bi3+, with its lone-pair electrons, can effectively enhance the PR speed of LN crystals. However, this enhancement is only effective in the short-wavelength range of visible light, and the response time remains inadequate for full-color dynamic displays. In this paper, a theoretical framework is established to guide the shallow energy-level PR doping of LN crystals. We simulate the energy band structure, electron mobility, and other properties of LN crystals doped with Tl, Pb, and Sb ions, which feature lone-pair electrons, using first-principles calculations. The theoretical results indicate that when Sb occupies the Nb site (SbNb0), the defect level position in the bandgap is shallow, and the electron mobility is 79.029 cm2 V–1 s–1 subsequently, we grew a series of LN:Sb and LN:Sb,Mg crystals and characterized their crystalline quality and PR properties. High-resolution x-ray rocking curve results demonstrate that all the as-grown crystals exhibit excellent crystalline quality, with FWHM values ranging from approximately 0.007° to 0.008°. Notably, the LN:Sb1.0,Mg6.0 crystal demonstrates a rapid PR response time of 1.67 s at 671 nm, nearly three times faster than that of the LN:Bi1.0,Mg6.0 crystal.

Possible glendonite mineral pseudomorphs in the aftermath of the end-Permian extinction

AbstractGlendonites (from the precursor of ikaite, CaCO3.6H2O) preferentially precipitate within sediments in cold waters (− 2 to 7°C) via either organotrophic or methanogenic sulphate reduction. Here, we report the first occurrence of possible glendonites associated with the end Permian mass extinction in the earliest Triassic (ca. 252 Million years ago, Ma) subtropical marine carbonates on the Arabian Plateau, Oman. The authigenic carbonate crystals are small (&lt; 2 mm) and precipitated either on bedding planes or reworked within micro cross-laminations, erosional scours, or lags at the base of calcisiltite turbidites, supporting a syn-depositional origin. The observed shape and macrostructure bear resemblance to that of glendonites. SEM and cathodoluminescent imaging reveals unzoned internal structures with three mineral phases: irregular, pseudo-hexagonal and spherical low-Mg calcite crystals (Type 1), low-Mg calcite cement (Type 2), and a later void-filling silica cement (Type 3). The pseudomorphs show δ13C values from − 0.14‰ to − 0.85‰ (mean − 0.43‰; n = 5) that are more positive than the associated micritic matrix, where values range from − 0.92‰ to − 2.39‰ (mean − 1.64‰; n = 7), indicating that oceanic dissolved inorganic carbon (DIC) was the primary carbon source rather than either methane or organic matter. These δ13C values significantly differ from typical δ13C signatures of authentic glendonites, except for Ordovician examples. If these are glendonites, we infer that they could have precipitated due to the unusually elevated alkalinity and pH (&gt; 9) oceanic conditions present in the aftermath of the end-Permian extinction associated with highly disrupted carbon cycle dynamics, possibly accompanied with the upwelling of cold, anoxic oceanic water.

Large piezoelectric response in paraelectric region of PMN-32PT near morphotropic phase boundary

We report an effective piezoelectric coefficient of deff = 40 ± 6 pm/V in the paraelectric phase of (1-x)Pb(Mg1/3Nb2/3)O3−(x)PbTiO3 single crystals with x = 0.32 (PMN-32PT), which is near the morphotropic phase boundary (x = 0.30). This value for deff in the paraelectric phase is significantly larger than that for other ferroelectrics measured so far. Our detailed investigation of symmetry-disallowed piezoelectricity indicates bias effects due to alternating current (AC) electric fields (100–800 kHz) and AC field cooling. The application of moderate AC fields (100–350 V/cm) gives rise to a nonlinear response of the piezoelectric effect, leading to an irreversible increase in the piezoelectric coefficient in the paraelectric phase. Along with changes in the elastic properties, the observed poling due to AC electric fields is reminiscent of irreversible ferroelectric–ferroelastic domain wall motion in ferroelectric phases. Such behavior is absent in cubic SrTiO3 where precursor effects are commonly observed at much lower temperatures.

Examining isotonic and isometric exercises for post-activation performance enhancement in kickboxers upper limb strength and power

Tunable interfacial Rashba spin–orbit coupling in asymmetric AlxIn1−xSb/InSb/CdTe quantum well heterostructures

We report the manipulation of the Rashba-type spin–orbit coupling (SOC) in molecular beam epitaxy-grown AlxIn1−xSb/InSb/CdTe quantum well heterostructures. The effective band bending warrants a robust two-dimensional quantum confinement effect, and the unidirectional built-in electric field arisen from the asymmetric hetero-interfaces leads to a pronounced Rashba SOC strength. By tuning the Al concentration in the top AlxIn1−xSb barrier layer, the optimal structure of x = 0.15 exhibits the largest Rashba coefficient of 0.23 eV Å as well as the highest low-temperature electron mobility of 4400 cm2 · V−1 · s−1. Moreover, quantitative investigations of the weak anti-localization effect further justify the prevailing D'yakonov–Perel spin relaxation mechanism during the charge-to-spin conversion process. Our results underscore the importance of quantum well engineering in shaping the magneto-resistance responses, and the narrow bandgap semiconductor-based heterostructures may serve as a reliable framework for designing energy-efficient spintronic applications.

Sucker rod straightness measurement method based on probability statistics of edge point detection

Dielectric reliability and interface trap characterization in MOCVD grown <i>in situ</i> Al2O3 on β-Ga2O3

In this article, we investigate the in situ growth of Al2O3 on β-Ga2O3 using metal-organic chemical vapor deposition at a high temperature of 800 °C. The Al2O3 is grown within the same reactor as the β-Ga2O3, employing trimethylaluminum and O2 as precursors without breaking the vacuum. We characterize the shallow and deep-level traps through stressed capacitance–voltage (C–V) and photo-assisted C–V methods. The high-temperature deposited dielectric demonstrates an impressive catastrophic breakdown field of approximately 10 MV/cm. Furthermore, we evaluate the reliability and lifetime of the dielectrics using time-dependent dielectric breakdown measurements. By modifying the dielectric deposition process to include a high-temperature (800 °C) thin interfacial layer and a low-temperature (600 °C) bulk layer, we report a 10-year lifetime under a stress field of 3.5 MV/cm along a catastrophic breakdown field of 7.8 MV/cm.

Use of inpatient palliative care in metastatic testicular cancer patients undergoing critical care therapy: insights from the national inpatient sample

AbstractTo test for rates of inpatient palliative care (IPC) in metastatic testicular cancer patients receiving critical care therapy (CCT). Within the Nationwide Inpatient Sample (NIS) database (2008–2019), we tabulated IPC rates in metastatic testicular cancer patients receiving CCT, namely invasive mechanical ventilation (IMV), percutaneous endoscopic gastrostomy tube (PEG), dialysis for acute kidney failure (AKF), total parenteral nutrition (TPN) or tracheostomy. Univariable and multivariable logistic regression models addressing IPC were fitted. Of 420 metastatic testicular cancer patients undergoing CCT, 70 (17%) received IPC. Between 2008 and 2019, the rates of IPC among metastatic testicular cancer patients undergoing CCT increased from 5 to 19%, with the highest rate of 30% in 2018 (EAPC: + 9.5%; 95% CI + 4.7 to + 15.2%; p = 0.005). IPC patients were older (35 vs. 31 years, p = 0.01), more frequently had do not resuscitate (DNR) status (34 vs. 4%, p &lt; 0.001), more frequently exhibited brain metastases (29 vs. 17%, p = 0.03), were more frequently treated with IMV (76 vs. 53%, p &lt; 0.001) and exhibited higher rate of inpatient mortality (74 vs. 29%, p &lt; 0.001). In multivariable analyses, DNR status (OR 10.23, p &lt; 0.001) and African American race/ethnicity (OR 4.69, p = 0.003) were identified as independent predictors of higher IPC use. We observed a significant increase in rates of IPC use in metastatic testicular cancer patients receiving CCT, rising from 5 to 19% between 2008 and 2019. However, this rates remain lower compared to metastatic lung cancer patients, indicating the need for further awareness among clinicians treating metastatic testicular cancer. The increase in IPC rates for metastatic testicular cancer patients receiving CCT indicates a need for ongoing education and awareness among healthcare providers. This could enhance the integration of IPC in the treatment of advanced cancer, potentially improving quality of life and care outcomes for survivors.

Flexible 3ω sensors on submicron-thick parylene substrates for thermal conductivity measurements of liquids and soft materials

Measurement of thermal conductivity in liquids and soft materials is pivotal across various sectors, from designing cooling systems for electronic devices to monitoring biological parameters via medical devices and studying the thermal properties of tissues. Accurate thermal conductivity measurements require high sensitivity, and a flexible measurement device is advantageous to adapt to the shape of the sample. The 3ω method stands out as an ideal technique that meets these criteria, offering a simple and sensitive approach to assess the thermal properties of materials. In this study, we introduce a 3ω sensor fabricated on submicron-thick parylene substrates. The parylene substrate not only provides the necessary flexibility but also acts as an insulating layer, essential for the measurement of conductive materials. The sensor's sensitivity was enhanced by reducing the thickness of the parylene substrate. A thermal peeling film was utilized as a supporting substrate during the fabrication of the 3ω sensor with a thin parylene substrate, which has a thickness of 0.77 μm. The performance of the sensor was evaluated by measuring the thermal conductivities of water, isopropyl alcohol, and their mixtures, achieving results within 15% of previously reported values.

Retraction Note: Fabrication of a magnetic alginate-silk fibroin hydrogel, containing halloysite nanotubes as a novel nanocomposite for biological and hyperthermia applications

Structural and electrical properties of fiber textured and epitaxial molybdenum thin films prepared by magnetron sputter epitaxy

Molybdenum (Mo) due to its optimal structural, physical, and acoustic properties finds application as electrode material in aluminum scandium nitride and aluminum nitride (AlN) based bulk acoustic wave (BAW) resonators. Epitaxial Mo thin films exhibiting low resistivity can improve the performance of the BAW resonator by enhancing both the electro-mechanical coupling coefficient (keff2) and quality factor Q. In this study, we systematically vary the growth temperature of Mo grown on fiber-textured and epitaxial wurtzite-aluminum nitride (AlN) to study the changes in structural and electrical properties of the Mo films. Results show that Mo grown at 700 °C on epitaxial AlN exhibits low surface roughness (Rq = 0.8 nm), large average grain diameter (dgrain = 330 nm), low resistivity (ρ=6.6 ± 0.06  μΩ cm), and high crystal quality (XRD Mo 110 ω-FWHM = 0.63°). XRD pole figure and ϕ-scan analysis reveal that irrespective of the growth temperature, Mo is fiber textured on fiber-textured AlN and has three rotational domains on epitaxial AlN. This study shows that the resistivity of Mo reduces with increasing growth temperature, which we relate to increasing average grain diameter. Additionally, we show that fiber-textured Mo has more high angle grain boundaries resulting in consistently higher resistivity than its epitaxial equivalent.

Prognostic implications of system inflammation response index in atrial fibrillation patients with type 2 diabetes mellitus

Coupling of photoluminescence and flexoelectricity in all-inorganic flexible transparent heterojunctions induced by mechanical strain

Flexible and transparent optoelectronic technology has shown great application prospects in various fields. Introducing rare earth luminescent centers into inorganic ferroelectric systems can benefit the electrical properties by utilizing the polar nanodomains brought about by rare earth doping and also facilitate the investigation of coupling effect between luminescence modulation and flexoelectric effect. This article studies Pr3+-doped barium titanate all-inorganic flexible transparent heterojunctions and explores the direct modulation of the fluorescence and flexoelectric response through mechanical strain stimulation. We aim to investigate the essential correlation and physical mechanism of strain-flexoelectricity-photoluminescence (force-electric-photon) coupling, providing an important basis for the dynamic balance regulation between radiative and non-radiative transitions. Therefore, this work will significantly promote the development of highly integrated flexible sensing and intelligent optoelectronic devices.

An analysis of extraskeletal osteosarcoma based on the literature

Reliability of NiO/β-Ga2O3 bipolar heterojunction

Ultra-wide bandgap (UWBG) NiO/β-Ga2O3 p–n junction has recently emerged as a key building block for emerging electronic and optoelectronic devices. However, the long-term reliability of this bipolar junction remains elusive. Here, the temporal evolution of the transient parametric shift is characterized in this junction under the prolonged forward- and reverse-bias stresses as well as in the post-stress recoveries. The temperature-dependent evolutions reveal the energy level and time constant of the dominant trap. The forward-bias stress is found to induce a negative turn-on voltage (VON) shift, the magnitude of which correlates with the stressed current density, while the reverse-bias stress leads to the opposite effect. Such VON shift is induced by an electron trap with an activation energy of 0.46 eV, which may originate from native point defects in β-Ga2O3 near the junction interface. Under a high forward current stress of 1000 A/cm2, device failure is found to be located at the edge region with the thinnest NiO, which is likely to be caused by the injection of hot electrons that diffuse across the entire NiO layer. Overall, the magnitude of parametric shift is approaching or comparable to those reported in the native SiC and GaN p–n junctions, suggesting that the NiO/β-Ga2O3-based UWBG devices have good potential to achieve a reliability comparable to their WBG counterparts.