Publications by authors named "Weicheng Lai"

Diabetic liver injury is a serious complication due to the lack of effective treatments and the unclear pathogenesis. Ferroptosis, a form of cell death involving reactive oxygen species (ROS)-dependent lipid peroxidation (LPO), is closely linked to autophagy and diabetic complications. Therefore, this study is aimed at investigating the role of autophagy in regulating ferroptosis by modulating the degradation of acyl-CoA synthetase long-chain family member 4 (ACSL4) in diabetic hepatocytes and its potential impact on diabetic liver injury.

View Article and Find Full Text PDF

Tetrabromobisphenol A (TBBPA), a brominated flame retardant (BFR), has been implicated as the neurotoxic effects in mammalian. However, the exact mechanisms underlying TBBPA-induced neurotoxicity remain unclear. In the present study, Neuro-2a cells, a mouse neural crest-derived cell line, were used to examine the mechanism of TBBPA-induced neuronal cytotoxicity.

View Article and Find Full Text PDF

Paraquat (PQ), a toxic and nonselective bipyridyl herbicide, is one of the most extensively used pesticides in agricultural countries. In addition to pneumotoxicity, the liver is an important target organ for PQ poisoning in humans. However, the mechanism of PQ in hepatotoxicity remains unclear.

View Article and Find Full Text PDF

Objectives: To investigate the effect and mechanism of ulinastatin (UTI) on development of lungs in fetal rabbits with intrauterine growth retardation (IUGR).

Methods: Twenty pregnant rabbits were equally divided into normal, IUGR, UTI, and LY groups. The normal group was only injected with saline and marked with tattoo ink.

View Article and Find Full Text PDF

This paper reports design, fabrication, and experimental demonstration of a silicon nitride photonic integrated circuit (PIC). The PIC is capable of conducting one-dimensional interferometric imaging with twelve baselines near λ = 1100-1600 nm. The PIC consists of twelve waveguide pairs, each leading to a multi-mode interferometer (MMI) that forms broadband interference fringes or each corresponding pair of the waveguides.

View Article and Find Full Text PDF

Corrosion protection of complex surface is an active area of research due to its importance to commercial applications such as electrochemical fabrication. However, conventional coatings exhibit limited conductivity, thermal stability, and durability and are thus not suitable. Recent work has shown the potential of graphene, a two-dimensional carbon allotrope, for corrosion protection.

View Article and Find Full Text PDF

We designed and demonstrated a tri-layer SiN/SiO photonic integrated circuit capable of vertical interlayer coupling with arbitrary splitting ratios. Based on this multilayer photonic integrated circuit platform with each layer thicknesses of 150 nm, 50 nm, and 150 nm, we designed and simulated the vertical Y-junctions and 3D couplers with arbitrary power splitting ratios between 1:10 and 10:1 and with negligible(< -50 dB) reflection. Based on the design, we fabricated and demonstrated tri-layer vertical Y-junctions with the splitting ratios of 1:1 and 3:2 with excess optical losses of 0.

View Article and Find Full Text PDF

We demonstrate hybrid integration of modified uni-traveling carrier photodiodes on a multi-layer silicon nitride platform using total reflection mirrors etched by focused ion beam. The hybrid photodetectors show external responsivity of 0.15 A/W and bandwidth of 3.

View Article and Find Full Text PDF

This paper demonstrates rapidly reconfigurable, high-fidelity optical arbitrary waveform generation (OAWG) in a heterogeneous photonic integrated circuit (PIC). The heterogeneous PIC combines advantages of high-speed indium phosphide (InP) modulators and low-loss, high-contrast silicon nitride (SiN) arrayed waveguide gratings (AWGs) so that high-fidelity optical waveform syntheses with rapid waveform updates are possible. The generated optical waveforms spanned a 160 GHz spectral bandwidth starting from an optical frequency comb consisting of eight comb lines separated by 20 GHz channel spacing.

View Article and Find Full Text PDF

A total of 112 cases of Naja atra envenomation were examined at two referring hospitals: Taichung Veterans General Hospital in central Taiwan and Taipei Veterans General Hospital (VGH-TP) in northern Taiwan. Overall, 77% (86/112) of cases developed clinically suspected wound infections and 54% (61/112) required surgery secondary to tissue necrosis, finger or toe gangrene, and/or necrotizing fasciitis. Morganella morganii was the most abundant gram-negative bacterial strain isolated from bite wounds, followed by Proteus spp.

View Article and Find Full Text PDF

Flexible inorganic electronic devices promise numerous applications, especially in fields that could not be covered satisfactorily by conventional rigid devices. Benefits on a similar scale are also foreseeable for silicon photonic components. However, the difficulty in transferring intricate silicon photonic devices has deterred widespread development.

View Article and Find Full Text PDF

We demonstrate subwavelength bidirectional grating (SWG) coupled slot waveguide fabricated in silicon-on-sapphire for transverse electric polarized wave operation at 3.4 μm wavelength. Coupling efficiency of 29% for SWG coupler is experimentally achieved.

View Article and Find Full Text PDF

We experimentally demonstrate simultaneous selective detection of xylene and trichloroethylene (TCE) using multiplexed photonic crystal waveguides (PCWs) by near-infrared optical absorption spectroscopy on a chip. Based on the slow light effect of photonic crystal structure, the sensitivity of our device is enhanced to 1 ppb (v/v) for xylene and 10 ppb (v/v) for TCE in water. Multiplexing is enabled by multimode interference power splitters and Y-combiners that integrate multiple PCWs on a silicon chip in a silicon-on-insulator platform.

View Article and Find Full Text PDF

We demonstrate experimentally that in photonic crystal sensors with a side-coupled cavity-waveguide configuration, group velocity of the propagating mode in the coupled waveguide at the frequency of the resonant mode plays an important role in enhancing the sensitivity. In linear L13 photonic crystal microcavities, with nearly same resonance mode quality factors ∼7000 in silicon-on-insulator devices, sensitivity increased from 57 nm/RIU to 66 nm/RIU as group index in the coupled waveguide increased from 10.2 to 13.

View Article and Find Full Text PDF

We experimentally demonstrate label-free photonic crystal (PC) microcavity biosensors in silicon-on-insulator (SOI) to detect the epithelial-mesenchymal transition (EMT) transcription factor, ZEB1, in minute volumes of sample. Multiplexed specific detection of ZEB1 in lysates from NCI-H358 lung cancer cells down to an estimated concentration of 2 cells per micro-liter is demonstrated. L13 photonic crystal microcavities, coupled to W1 photonic crystal waveguides, are employed in which resonances show high Q in the bio-ambient phosphate buffered saline (PBS).

View Article and Find Full Text PDF

We experimentally demonstrate highly efficient coupling into a slow light slotted photonic crystal waveguide. With optical mode converters and group index tapers that provide good optical mode matching and impedance matching, a nearly flat transmission over the entire guided mode spectrum of 68.8 nm range with 2.

View Article and Find Full Text PDF

Current trends in photonic crystal microcavity biosensors in silicon-on-insulator (SOI), that focus on small and smaller sensors have faced a bottleneck trying to balance two contradictory requirements of resonance quality factor and sensitivity. By simultaneous control of the radiation loss and optical mode volumes, we show that both requirements can be satisfied simultaneously. Microcavity sensors are designed in which resonances show highest Q ≈ 9300 in the bio-ambient phosphate buffered saline (PBS) as well as highest sensitivity among photonic crystal biosensors.

View Article and Find Full Text PDF

We experimentally demonstrate a method to create large-scale chip-integrated photonic crystal sensor microarrays by combining the optical power splitting characteristics of multi-mode interference (MMI) power splitters and transmission drop resonance characteristics of multiple photonic crystal microcavities arrayed along the length of the same photonic crystal waveguide. L13 photonic crystal microcavities are employed which show high Q values (~9300) in the bio-ambient phosphate buffered saline (PBS) as well as high sensitivity, experimentally demonstrated to ~98 atto-grams. Two different probe antibodies were specifically detected simultaneously with a control sample, in the same experiment.

View Article and Find Full Text PDF

We experimentally demonstrated photonic crystal microcavity based resonant sensors coupled to photonic crystal waveguides in silicon nano-membrane on insulator for chemical and bio-sensing. Linear L-type microcavities are considered. In contrast to cavities with small mode volumes, but low quality factors for bio-sensing, we showed increasing the length of the microcavity enhances the quality factor of the resonance by an order of magnitude and increases the resonance wavelength shift while retaining compact device characteristics.

View Article and Find Full Text PDF

A solution approach based on Au(CN)(2)(-) chemistry is reported for the formation of nanoparticles. The covalent character of the Au(CN)(2)(-) precursor was exploited in the formation of sub-10 nm nanospheres (≈2.4 nm) and highly monodisperse icosahedral Au nanoparticles (≈8 nm) at room temperature in a one-pot aqueous synthesis.

View Article and Find Full Text PDF

We demonstrate a 300 μm long silicon photonic crystal (PC) slot waveguide device for on-chip near-infrared absorption spectroscopy, based on the Beer-Lambert law for the detection of methane gas. The device combines slow light in a PC waveguide with high electric field intensity in a low-index 90 nm wide slot, which effectively increases the optical absorption path length. A methane concentration of 100 ppm (parts per million) in nitrogen was measured.

View Article and Find Full Text PDF