Background: Thyroid hormone levels are associated with the distribution of body components in humans.
Objective: This study aimed to investigate the associations between thyroid hormone (TH) levels, central sensitivity to THs, and body composition in overweight and obese patients with euthyroid type 2 diabetes mellitus (T2DM).
Methods: This cross-sectional study included 1215 euthyroid T2DM patients (721 men and 494 women) aged 20-80 years.
Background: Denys-Drash syndrome (DDS) is a rare disease characterized with pseudohermaphroditism, nephroblastoma (also known as Wilms tumor), and diffuse mesangial sclerosis. The therapy for DDS is largely supportive, i.e.
View Article and Find Full Text PDFWe report the observation of magneto-optical nonreciprocity in Faraday geometry in a hybrid metamaterial consisting of an Archimedean spiral metasurface and semiconductor InSb that serves as the magneto-optical medium. None of the metamaterial constituents possesses chirality, which is usually a necessary ingredient for optical nonreciprocity in natural materials when the light travels along the magnetic field direction. We also find that our metamaterial can serve as an optical element for polarization control via magnetic field.
View Article and Find Full Text PDFEthnopharmacological Relevance: Smilax glabra Roxb., the dry rhizome of Sarsaparilla, which is also known as Tu fuling (TFL) in China, is a well-known traditional CHINESE medicine that is widely used for detoxication, relieving dampness and as a diuretic. We have previously shown that the extracted TFL flavonoids (designated TFLF) possess anti-cardiac hypertrophy effects in vitro.
View Article and Find Full Text PDFThe Faraday effect due to the cyclotron resonance of conduction electrons in semiconductor InSb allows for nonreciprocity of transmitted light in our Faraday THz isolator operating in the presence of a small magnetic field. We select InSb as an efficient medium for our isolator due to its high electron mobility, low electron effective mass, and narrow band gap. Experimental measurements of the isolator performance indicate a maximum achieved isolation power of 18.
View Article and Find Full Text PDFMetamaterials with their customized properties enable us to efficiently manipulate the polarization states of electromagnetic waves with flexible approaches, which is of great significance in various realms. However, most current metamaterial-based polarization controllers can only realize single function, which has extremely hindered the expansion of their applications. Here, we experimentally demonstrate highly efficient and multifunctional polarization conversion effects using metagrating by integrating single-structure metallic meta-atoms into the dielectric gratings.
View Article and Find Full Text PDFWe present experimental and theoretical investigations on the polarization properties of a single- and a double-layer gold (Au) grating, serving as a wire grid polarizer. Two layers of Au gratings form a cavity that effectively modulates the transmission and reflection of linearly polarized light. Theoretical calculations based on a transfer matrix method reveals that the double-layer Au grating structure creates an optical cavity exhibiting Fabry-Perot (FP) resonance modes.
View Article and Find Full Text PDFBecause of the strong inherent resonances, the giant optical activity obtained via chiral metamaterials generally suffers from high dispersion, which has been a big stumbling block to broadband applications. In this paper, we propose a type of planar chiral metamaterial consisting of interconnected metal helix slat structures with four-fold symmetry, which exhibits nonresonant Drude-like response and can therefore avoid the highly dispersive optical activity resulting from resonances. It shows that the well-designed chiral metamaterial can achieve nondispersive and pure optical activity with high transmittance in a broadband frequency range.
View Article and Find Full Text PDFWe demonstrate that the metamaterial perfect absorber behaves as a meta-cavity bounded between a resonant metasurface and a metallic thin-film reflector. The perfect absorption is achieved by the Fabry-Perot cavity resonance via multiple reflections between the "quasi-open" boundary of resonator and the "close" boundary of reflector. The characteristic features including angle independence, ultra-thin thickness and strong field localization can be well explained by this meta-cavity model.
View Article and Find Full Text PDFWe use computational approaches to explore the role of a high-refractive-index dielectric TiO grating with deep subwavelength thickness on InSb as a tunable coupler for THz surface plasmons. We find a series of resonances as the grating couples a normally-incident THz wave to standing surface plasmon waves on both thin and thick InSb layers. In a marked contrast with previously-explored metallic gratings, we observe the emergence of a much stronger additional resonance.
View Article and Find Full Text PDFOver the years, there has been increasing interest in the integration of metal hole array (MHA) with optoelectronic devices, as a result of enhanced coupling of incident light into the active layer of devices via surface plasmon polariton (SPP) resonances. However, not all incident light contributes to the SPP resonances due to significant reflection loss at the interface between incident medium and MHA. Conventional thin-film antireflection (AR) coating typically does not work well due to non-existing material satisfying the AR condition with strong dispersion of MHA's effective impedances.
View Article and Find Full Text PDFWe present a computational study of terahertz optical properties of a grating-coupled plasmonic structure based on micrometer-thin InSb layers. We find two strong absorption resonances that we interpret as standing surface plasmon modes and investigate their dispersion relations, dependence on InSb thickness, and the spatial distribution of the electric field. The observed surface plasmon modes are well described by a simple theory of the air/InSb/air tri-layer.
View Article and Find Full Text PDFObjectives: To evaluate clinical usefulness of computed tomography perfusion imaging (CTPI) in gastric cancer.
Materials And Methods: Twenty subjects without gastric diseases (control group) and fifty patients with gastric cancer were studied prospectively using CTPI examinations. Four perfusion parameter values, i.
An efficient and catalyst-free synthesis of trisubstituted allylic sulfones through an allylic sulfonylation reaction of Morita-Baylis-Hillman (MBH) carbonates with sodium sulfinates has been developed. Under the optimized reaction conditions, a series of trisubstituted allylic sulfones were rapidly prepared in good to excellent yields (71%-99%) with good to high selectivity (Z/E from 79:21 to >99:1). Compared with known synthetic methods, the current protocol features mild reaction temperature, high efficiency and easily available reagents.
View Article and Find Full Text PDFWe present experiments and analysis on enhanced transmission due to dielectric layer deposited on a metal film perforated with two-dimensional periodic array of subwavelength holes. The Si3N4 overlayer is applied on the perforated gold film (PGF) fabricated on GaAs substrate in order to boost the transmission of light at the surface plasmon polariton (SPP) resonance wavelengths in the mid- and long-wave IR regions, which is used as the antireflection (AR) coating layer between two dissimilar media (air and PGF/GaAs). It is experimentally shown that the transmission through the perforated gold film with 1.
View Article and Find Full Text PDFThis paper is focused on analyzing the impact of a two-dimensional metal hole array structure integrated to the back-illuminated quantum dots-in-a-well (DWELL) infrared photodetectors. The metal hole array consisting of subwavelength-circular holes penetrating gold layer (2D-Au-CHA) provides the enhanced responsivity of DWELL infrared photodetector at certain wavelengths. The performance of 2D-Au-CHA is investigated by calculating the absorption of active layer in the DWELL structure using a finite integration technique.
View Article and Find Full Text PDFSwitching the handedness, or the chirality, of a molecule is of great importance in chemistry and biology, as molecules of different handedness exhibit dramatically different physiological properties and pharmacological effects. Here we experimentally demonstrate handedness switching in metamaterials, a new class of custom-designed composites with deep subwavelength building blocks, in response to external optical stimuli. The metamolecule monolayer flips the ellipticity and rotates the polarization angle of light in excess of 10° under optical excitation, a much stronger electromagnetic effect than that of naturally available molecules.
View Article and Find Full Text PDFWe experimentally and numerically study the nature of coupling between laterally paired terahertz metamaterial split-ring resonators. Coupling is shown to modify the inductive-capacitive (LC) resonances resulting in either red or blue-shifting. Results indicate that tuning of the electric and magnetic coupling parameters may be accomplished not by changing the orientation or density of SRRs, but by a design modification at the unit cell level.
View Article and Find Full Text PDFWe introduce a new class of plasmonic crystals possessing graphene-like internal symmetries and Dirac-type spectrum in k-space. We study dynamics of surface plasmon polaritons supported in the plasmonic crystals by employing the formalism of Dirac dynamics for relativistic quantum particles. Through an analogy with graphene, we introduce a concept of pseudo-spin and chirality to indicate built-in symmetry of the plasmonic crystals near Dirac point.
View Article and Find Full Text PDFWe present a novel approach of antireflection coating using metamaterials. It dramatically reduces the reflection and greatly enhances the transmission near a specifically designed frequency over a wide range of incidence angles for both transverse magnetic and transverse electric polarizations. A classical interference mechanism is identified through analytical derivations and numerical simulations.
View Article and Find Full Text PDFA pair of mutually twisted metallic cross-wires can produce giant optical activity. When this single chiral layer is stacked layer by layer in order to build a thick chiral metamaterial, strong coupling effects are found between the two adjacent chiral layers. We studied these coupling effects numerically and experimentally.
View Article and Find Full Text PDFThe properties of periodic pairs of mutually twisted metallic (silver) crosses separated by dielectric layer have been investigated by numerical simulation. The results show that the exceptionally strong polarization rotation and circular dichroism, negative permeability and negative refractive index are found at the infrared communication wavelength (1.55 microm).
View Article and Find Full Text PDFIn this letter, the properties of split-ring resonators (SRRs) loaded with high-Q capacitors and nonlinear varactors are theoretically analyzed and experimentally measured. We demonstrate that the resonance frequency f(m) of the nonlinear SRRs can be tuned by increasing the incident power. f(m) moves to lower and higher frequencies for the SRR loaded with one varactor and two back-to-back varactors, respectively.
View Article and Find Full Text PDFWe propose a simple and effective way to reduce the losses in left-handed metamaterials by manipulating the values of the effective parameters R, L, and C. We investigate the role of losses of the short-wire pairs and the fishnet structures. Increasing the effective inductance to capacitance ratio, L/C, reduces the losses and the figure of merit can increase substantially, especially at THz frequencies and in the optical regime.
View Article and Find Full Text PDFCarcinoma cell metastasis is mediated by increased mobility and invasiveness via epithelial-mesenchymal transition (EMT). Snail, a zinc-finger transcription factor, triggers EMT by directly repressing E-cadherin expression. In this study, the correlation between E-cadherin and Snail expression was investigated.
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