Molecular Mechanisms of the Anti-obesity Properties of Agardhiella subulata in Mice Fed a High-Fat Diet.

The overweight and obese population has skyrocketed, resulting in a high incidence of metabolic disorders. Agardhiella subulata (AS) contains a variety of beneficial components, such as sulfur-containing polysaccharides (dietary fiber) and astaxanthin, which is considered to have anti-obesity potential. In this study, we investigated the effects and possible mechanisms of dietary AS on high-fat diet (HFD)-induced obesity in mice. AS supplementation significantly reduced HFD-induced weight gain (19%) and the visceral adiposity index (4.1%). In addition, the level of total cholesterol, triglyceride, and low-density lipoprotein was significantly decreased; adiponectin was significantly increased in serum and fecal triglyceride excretion was significantly higher in mice fed AS compared with mice on an HFD. Preadipocyte factor 1 and Sry-box transcription factor 9 that were significantly higher than the levels found for the HFD group lead to reduced adipogenesis. Moreover, accompanying the lipolysis and fatty acid ß-oxidation that occur in the AS group, the concentration of non-esterified fatty acids was lowered to 0.4 ± 0.1 mEq/L. In addition, peroxisome proliferator-activated receptor γ and phosphorylation acetyl-CoA carboxylase increased 1.5- and 1-fold, thus increasing the expression of adiponectin and the activation of AMPK and ultimately resulting in lower blood glucose levels. The results of this study suggest that AS supplementation increases lipid excretion and improves energy metabolism to prevent obesity in mice fed a HFD.

Co-dosing Ozone and Deionized Water as Oxidant Precursors of ZnO Thin Film Growth by Atomic Layer Deposition.

Characteristics of atomic layer deposition (ALD)-grown ZnO thin films on sapphire substrates with and without three-pulsed ozone (O3) as oxidant precursor and post-deposition thermal annealing (TA) are investigated. Deposition temperature and thickness of ZnO epilayers are 180 °C and 85 nm, respectively. Post-deposition thermal annealing is conducted at 300 °C in the ambience of oxygen (O2) for 1 h. With strong oxidizing agent O3 and post-deposition TA in growing ZnO, intrinsic strain and stress are reduced to 0.49% and 2.22 GPa, respectively, with extremely low background electron concentration (9.4 × 1015 cm-3). This is originated from a lower density of thermally activated defects in the analyses of thermal quenching of the integrated intensity of photoluminescence (PL) spectra. TA further facilitates recrystallization forming more defect-free grains and then reduces strain and stress state causing a remarkable decrease of electron concentration and melioration of surface roughness.

Optimal Silicon Doping Layers of Quantum Barriers in the Growth Sequence Forming Soft Confinement Potential of Eight-Period In0.2Ga0.8N/GaN Quantum Wells of Blue LEDs.

The features of eight-period In0.2Ga0.8N/GaN quantum wells (QWs) with silicon (Si) doping in the first two to five quantum barriers (QBs) in the growth sequence of blue light-emitting diodes (LEDs) are explored. Epilayers of QWs' structures are grown on 20 pairs of In0.02Ga0.98N/GaN superlattice acting as strain relief layers (SRLs) on patterned sapphire substrates (PSSs) by a low-pressure metal-organic chemical vapor deposition (LP-MOCVD) system. Temperature-dependent photoluminescence (PL) spectra, current versus voltage (I-V) curves, light output power versus injection current (L-I) curves, and images of high-resolution transmission electron microscopy (HRTEM) of epilayers are measured. The consequences show that QWs with four Si-doped QBs have larger carrier localization energy (41 meV), lower turn-on (3.27 V) and breakdown (- 6.77 V) voltages, and higher output power of light of blue LEDs at higher injection current than other samples. Low barrier height of QBs in a four-Si-doped QB sample results in soft confinement potential of QWs and lower turn-on and breakdown voltages of the diode. HRTEM images give the evidence that this sample has relatively diffusive interfaces of QWs. Uniform spread of carriers among eight QWs and superior localization of carriers in each well are responsible for the enhancement of light output power, in particular, for high injection current in the four-Si-doped QB sample. The results demonstrate that four QBs of eight In0.2Ga0.8N/GaN QWs with Si doping not only reduce the quantum-confined Stark effect (QCSE) but also improve the distribution and localization of carriers in QWs for better optical performance of blue LEDs.

8.13 µm in length and CMOS compatible polarization beam splitter based on an asymmetrical directional coupler.

A compact silicon polarization beam splitter (PBS) is proposed based on an asymmetrical directional coupler consisting of a wide waveguide and a dielectric loaded narrow waveguide. Given that TE and TM polarizations are the dominant mode in the wide and narrow waveguides, respectively, a perfect phase-matching condition in the TM mode but a huge phase mismatching in the TE mode can be achieved. Therefore, the TE mode is almost uncoupled regardless of device length but the TM mode can only completely couple to the cross port at an appropriate coupling length. An ultrashort (∼8.13 µm long) PBS is designed based on a silicon-on-insulator nanowire with a loading refractive index of 2.0 and a gap width of 200 nm. Numerical simulations show that the proposed PBS has a broad bandwidth (∼100 nm) with large extinction ratio (>10 dB) and low insertion loss (<0.61 dB). The fabrication-error tolerance of the PBS is also discussed.

Ultracompact polarization rotator in an asymmetric single dielectric loaded rib waveguide.

A compact polarization rotator (PR) with an asymmetric single dielectric loaded rib waveguide is proposed. The core of the waveguide is designed to have a specific rectangular configuration. The waveguide requires only a single asymmetrical dielectric loading on the core to complete the polarization conversion. The optical field is confined to the vicinity of the core center, which matches the optical field of the input/output waveguides. The transition loss of the PR is as low as 0.03-0.21 dB/facet without the taper or offset schemes. Such results can facilitate the fabrication of a PR with an operating length of 10 µm. In a comprehensively designed PR with a length of 7.92 µm, a -1 dB bandwidth for polarization conversion efficiency (PCE) is greater than 100 nm at the communicating wavelength of 1550 nm. The loading width and thickness with ±20 nm tolerance exhibit -0.87 and -0.49 dB changes in PCE, respectively.

Pyridyl Pyrrolide Boron Complexes: The Facile Generation of Thermally Activated Delayed Fluorescence and Preparation of Organic Light-Emitting Diodes.

The electron positive boron atom usually does not contribute to the frontier orbitals for several lower-lying electronic transitions, and thus is ideal to serve as a hub for the spiro linker of light-emitting molecules, such that the electron donor (HOMO) and acceptor (LUMO) moieties can be spatially separated with orthogonal orientation. On this basis, we prepared a series of novel boron complexes bearing electron deficient pyridyl pyrrolide and electron donating phenylcarbazolyl fragments or triphenylamine. The new boron complexes show strong solvent-polarity dependent charge-transfer emission accompanied by a small, non-negligible normal emission. The slim orbital overlap between HOMO and LUMO and hence the lack of electron correlation lead to a significant reduction of the energy gap between the lowest lying singlet and triplet excited states (ΔET-S ) and thereby the generation of thermally activated delay fluorescence (TADF).