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We demonstrate a multilevel optical memristive switch based on a silicon Fabry–Perot resonator. The resonator is constructed by a pair of waveguide Bragg gratings at the ends of a multimode interferometer (MMI) covered with sub-micrometer-size Ge2Sb2Te5 (GST) thin film on top. The interaction between the optical field and GST is greatly enhanced due to the resonant effect. The GST phase transition is triggered by applying electrical pulses to the doped-silicon microheater. Light is transmitted when GST is amorphous while it is highly absorbed by the crystalline GST at the resonance wavelength, leading to a higher on-off extinction ratio (ER) compared to the non-resonant device. The resonant device achieves a maximum transmission contrast of 10.29 dB and a total of 38 distinct nonvolatile switching levels. Our work provides an effective solution to improving the multilevel switching performance of phase-change devices and paves the way for future nonvolatile silicon photonics devices.

The present study was designed to measure the mean values of body mass index (BMI), random blood sugar/ fast ing blood sugar (RBS/FBS) tests, and Hb A1c and to investigate the role of a genetic variant rs1544410 in the VDR gene in a Pakistani cohort. For this purpose, a total of 917 samples including 469 diabetes mellitus type 2 (T2DM), 145 DM type 1 (T1DM), and 303 healthy control were collected. Out of the total sample set, 500 individuals (250 T2DM cases and 250 controls) were genotyped for rs1544410. It was found that 65 (26.0%) cases and 32 (12.8%) controls had homozygous AA, while 69 (27.6%) cases and 139 (55.6%) controls had heterozygous AG, and 116 (46.4%) cases and 79 (31.6%) controls had homozygous GG (χ2 = 41.81, p = 0.0001). In addition, a similar distribution of allele frequency was determined in cases and controls [p value = 0.866; odds ratio (OR) = 0.967; relative risk (RR) = 1.034]. A significant difference was observed in homozygous dominant [OR = 2.394 (1.501-3.816); RR = 1.46 (1.225-1.740); p = 0.003] and homozygous recessive models [OR = 2.970 (2.086-4.227); RR = 1.798 (1.501-2.154); p =

Surface plasmons, continuous and cumulative electron vibrations confined to metal-dielectric interfaces, play a pivotal role in aggregating optical fields and energies on nanostructures. This confinement exploits the intrinsic subwavelength nature of their spatial profile, significantly enhancing light–matter interactions. Metals, semiconductors, and 2D materials exhibit plasmonic resonances at diverse wavelengths, spanning from ultraviolet (UV) to far infrared, dictated by their unique properties and structures. Surface plasmons offer a platform for various light–matter interaction mechanisms, capitalizing on the orders-of-magnitude enhancement of the electromagnetic field within plasmonic structures. This enhancement has been substantiated through theoretical, computational, and experimental studies. In this comprehensive review, we delve into the plasmon-enhanced processes on metallic and metamaterial-based sensors, considering factors such as geometrical influences, resonating wavelengths, chemical properties, and computational methods. Our exploration extends to practical applications, encompassing localized surface plasmon resonance (LSPR)-based planar waveguides, polymer-based biochip sensors, and LSPR-based fiber sensors. Ultimately, we aim to provide insights and guidelines for the development of next-generation, high-performance plasmonic technological devices. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells have therapeutic properties that are related to their potentials for trans-differentiation, immunomodulation, anti-inflammatory, inhibitory effect on tumor proliferation, and induction of apoptosis. This study was performed to analyze the role of mesenchymal stem cells as an alternative for cellular signaling growth factors involved in the pathogenesis of leukemogenesis in rats. Treatment of rats with 7,12-dimethyl benz [a] anthracene induced leukemogenesis appeared as a significant decrease in hematological parameters with concomitant significant increase in bone marrow oxidative and inflammatory indices (transforming growth factor beta and interleukin-6) in comparison with normal groups. On the contrary, Western immunoblotting showed a significant increase in the signaling growth factors: PI3K, AKT, mTOR proteins and a significant decrease in PTEN in 7,12-dimethyl benz [a] anthracene–treated group. In addition, a significant increase in the transcript levels of B cell lymphoma-2 protein gene in the 7,12-dimethyl benz [a] anthracene group, while that of C-X-C motif chemokine receptor-4 and B cell lymphoma-2 protein associated x-protein were significantly downregulated compared to controls. Meanwhile, therapeutic mesenchymal stem cells treatment predict a significant improvement versus 7,12-dimethyl benz [a] anthracene group through the modulation of growth factors that confront bone marrow dysplasia. In the same direction treatment of 7,12-dimethyl benz [a] anthracene group with mesenchymal stem cells, it induced apoptosis and increased the homing efficacy to bone marrow. In conclusion, mesenchymal stem cells improve hematopoiesis and alleviate inflammation, and modulated PI3K/AKT signaling pathway contributed to experimental leukemogenesis.

We numerically investigate a promising mid-infrared supercontinuum (SC) source through the design of an on-chip complementary metal oxide semiconductor compatible 3-mm-long inverse tapered waveguide made using stoichiometric silicon nitride (Si 3 N 4 ) as the core and silica (SiO 2 ) glass as both the upper and lower claddings. The proposed waveguide is designed for pumping only in the anomalous dispersion regime. To explore SC generation in terms of spectral flatness and mid-infrared expansion, three different types of inverse tapered geometry are analyzed. These are inverse linear tapering, hyperbolic tapering, and parabolic tapering approaches. The proposed structures are optimized by varying their width based on the tapering variation coefficient along the pulse propagation direction. Keeping the waveguide thickness (height) constant at 2 μ m, each geometry is engineered by varying widths between 1.2 and 0.75 μ m in the mode of inverse tapering approach. Using a pump at 1.55 μ m with a peak power of 8 kW, SC generation is explored in all tapering geometries with an ultrashort pulse of 50 fs. The largest SC spectra covering a region from 0.76 μ m to beyond 6.67 μ m have been realized with a good spectral flatness by the parabolic-type taper among the three tapering geometries considered here. To the best of the authors' knowledge, this is the first time report of broadband SC coverage through numerical study in the region of mid-infrared by Si 3 N 4 planar design through a tapering approach. After spectral broadening up to 3.5 μ m with a conventional uniform design, a dip has been observed at the middle of the spectra which gradually becomes large with further dimensional variations of a typical uniform waveguide. However, such spectral dip problems can largely be eliminated through selective spectral enhancement by applying an inverse tapering approach. The coherence calculation of the predicted SC coverages also shows a high coherence at the proposed tapers output. The proposed inverse tapered planar designs show a significant improvement not only in mid-infrared spectral expansion but also in spectral flatness compared to the axially unvarying waveguide design. [ABSTRACT FROM AUTHOR]