Heterogeneously Integrated Laser on Silicon with Non-Volatile Wavelength Tuning

The von-Neumann bottleneck has constrained computing systems from efficiently operating on the increasingly large demand in data from networks and devices. Silicon (Si) photonics offers a powerful solution for this issue by providing a platform for high-bandwidth, energy-efficient interconnects. Furthermore, memristors have emerged as a fundamental building block for non-volatile data storage and novel computing architectures with powerful in-memory processing capabilities. In this paper, we integrate an Al2O3 memristor into a heterogeneous Si quantum dot microring laser to demonstrate the first laser with non-volatile optical memory. The memristor alters the effective optical modal index of the microring laser cavity by the plasma dispersion effect in the high resistance state (HRS) or Joule heating in the low resistance state (LRS), subsequently controlling the output wavelength of the laser in a non-volatile manner. This device enables a novel pathway for future optoelectronic neuromorphic computers and optical memory chips

Oriented Assembled TiO₂ Hierarchical Nanowire Arrays with Fast Electron Transport Properties

Developing high surface area nanostructured electrodes with rapid charge transport is essential for artificial photosynthesis, solar cells, photocatalysis, and energy storage devices. Substantial research efforts have been recently focused on building one-dimensional (1D) nanoblocks with fast charge transport into three-dimensional (3D) hierarchical architectures. However, except for the enlargement in surface area, there is little experimental evidence of fast electron transport in these 3D nanostructure-based solar cells. In this communication, we report single-crystal-like 3D TiO₂ branched nanowire arrays consisting of 1D branch epitaxially grown from the primary trunk. These 3D branched nanoarrays not only demonstrate 71% enlargement in large surface area (compared with 1D nanowire arrays) but also exhibit fast charge transport property (comparable to that in 1D single crystal nanoarrays), leading to 52% improvement in solar conversion efficiency. The orientated 3D assembly strategy reported here can be extended to assemble other metal oxides with one or multiple components and thus represents a critical avenue toward high-performance optoelectronics

[101̅0] Oriented Multichannel ZnO Nanowire Arrays with Enhanced Optoelectronic Device Performance

Crystallographic orientation and microstructure of metal oxide nanomaterials have great impact on their properties and applications. Here, we report [101̅0] oriented ZnO nanowire (NW) arrays with a multichannel mesostructure. The NW has a preferential growth of low energy (101̅0) crystal plane and exhibits 2–3 orders of magnitude faster electron transport rate than that in nanoparticle (NP) films. Furthermore, the surface area of the as-prepared NW arrays is about 5 times larger than that of conventional NW arrays with similar thickness. These lead to the highest power conversion efficiency of ZnO NW array-based sensitized solar cells. We anticipate that the unique crystallographic orientation and mesostructure will endow ZnO NW arrays new properties and expand their application fields

High-Performance Photoelectronic Sensor Using Mesostructured ZnO Nanowires

Semiconductor photoelectrodes that simultaneously possess rapid charge transport and high surface area are highly desirable for efficient charge generation and collection in photoelectrochemical devices. Herein, we report mesostructured ZnO nanowires (NWs) that not only demonstrate a surface area as high as 50.7 m²/g, comparable to that of conventional nanoparticles (NPs), but also exhibit a 100 times faster electron transport rate than that in NP films. Moreover, using the comparison between NWs and NPs as an exploratory platform, we show that the synergistic effect between rapid charge transport and high surface area leads to a high performance photoelectronic formaldehyde sensor that exhibits a detection limit of as low as 5 ppb and a response of 1223% (at 10 ppm), which are, respectively, over 100 times lower and 20 times higher than those of conventional NPs-based device. Our work establishes a foundational pathway toward a better photoelectronic system by materials design

Enhanced Photocatalytic Reaction at Air–Liquid–Solid Joint Interfaces

Semiconductor photocatalysis has long been considered as a promising approach for water pollution remediation. However, limited by the recombination of electrons and holes, low kinetics of photocatalysts and slow reaction rate impede large-scale applications. Herein, we addressed this limitation by developing a triphase photocatalytic system in which a photocatalytic reaction is carried out at air–liquid–solid joint interfaces. Such a triphase system allows the rapid delivery of oxygen, a natural electron scavenger, from air to the reaction interface. This enables the efficient removal of photogenerated electrons from the photocatalyst surface and minimization of electron–hole recombination even at high light intensities, thereby resulting in an approximate 10-fold enhancement in the photocatalytic reaction rate as compared to a conventional liquid/solid diphase system. The triphase system appears an enabling platform for understanding and maximizing photocatalyst kinetics, aiding in the application of semiconductor photocatalysis

Construction of Myc-PRL-3 fusion expression vector and expression in B16F1 murine melanoma cells.

<p>(A) Schematic drawing of pTARGET-Myc-PRL-3 expression vector. (B) Schematic representation of Myc-PRL-3 mutations. Mutations were constructed from pTARGET-Myc-PRL-3-WT by PCR. (C) Photographs of transfection efficiency of B16F1 cells. B16F1 cells were transfected with pEGFP for 24 hours and then observed with fluorescent microscopy (right); same view as the right but with a light microscopy (left). (D) Level of Myc-PRL-3 was detected by Western blot. Results shown are representative of three independent trials.</p

Effect of PRL-3-WT/mutations on B16F1 melanoma cells metastasis <i>in vivo</i>.

<p>B16F1 melanoma cells transfected with mock vector, wild type or mutated Myc-PRL-3 expression vectors were injected intravenously into C57BL/6J mice via tail vein. After 20 days, the mice were dissected and analyzed for metastasis. (A) Representative examples of lungs from the mice. The top and middle panels show the stereo micrographs of lungs. The lower panels show the histological photomicrographs of lung section stained with hemotoxylin and eosin (100×). NL, normal lung tissue; T, metastatic tumor lesions. (B) Quantitative evaluation of macroscopically detectable lung metastases. After fixation in Bouin's solution, the number of macroscopically visible metastases on the lung surface was quantified. (C) Representative example of mesentery lymph node metastatic site. Data are mean±SEM of six mice. **, P<0.01, vs. mock vector.</p

Effects of PRL-3-WT/mutations and prenylation inhibitor FTI-277 on B16F1 melanoma cells adhesion and migration ability.

<p>(A) B16F1 cells transfected with wild type or mutated Myc-PRL-3 expression vectors and (B) PRL-3-WT transfected cells pretreated with 1 µM or 2 µM FTI-277 for 18 hours were seeded into the wells of 96-well plates coated with fibronectin (10 µg/ml). After incubation for 30 minutes at 37°C, non-adherent cells were gently washed away. The amount of the adherent cells was determined at 592 nm after crystal violet staining. Data are mean±SEM of three independent experiments and each experiment includes triplicate sets. (C) A single-cell suspension (100 µl, 1×10⁶ cells/ml) of cells was plated into the upper wells of Transwell inserts containing 8 µm pore polycarbonate membranes pre-coated with fibronectin on the under surface. Cells were allowed to migrate for 24 hours at 37°C, and then fixed, stained with crystal violet and counted. Quantitative analysis of the number of the cells migrated to the lower side of the membrane is shown. (D) Treatment with FTI-277 inhibits the migration of B16F1 melanoma cells. B16F1 cells were transfected with PRL-3-WT and incubated with FTI-277 1 µM or 2 µM for 18 hours before plated into the upper wells of Transwell inserts, which still contain different concentrations of FTI-277. All Data are mean±SEM of three independent experiments. *, P<0.05; **, P<0.01, vs. mock vector for (A) and (C) and vs. PRL-3-WT expression vector for (B) and (D).</p

Intracellular localization of PRL-3.

<p>B16F1 melanoma cells were transiently transfected with wild type and mutated Myc-PRL-3 expression vectors. Twenty-four hours after transfection, cells were fixed with 4% paraformaldehyde and stained with anti-Myc primary antibody and FITC labeled secondary antibody. Myc-PRL-3 wild type and mutations were detected under fluorescence microscopy (400×). Nuclei were counterstained with 4, 6-diamidino-2-phemylindole (blue). Pictures shown are representative of three independent trials.</p

Demographic and clinical characteristics of the matched pairs in the CAD-positive and CAD-negative groups.

*<p>data expressed as mean (SD).</p