Ga2O3 Bipolar Heterojunction-Based Optoelectronic Synapse Array with Visual Attention.

The human brain efficiently processes only a fraction of visual information, a phenomenon termed attentional control, resulting in energy savings and heightened adaptability. Translating this mechanism into artificial visual neurons holds promise for constructing energy-efficient, bioinspired visual systems. Here, we propose a self-rectifying artificial visual neuron (SEVN) based on a NiO/Ga2O3 bipolar heterojunction with attentional control on patterns with a target color. The device exhibits short-term potentiation (STP) with quantum point contact (QPC) traits at low bias and transitions to long-term potentiation (LTP) at high bias, particularly facilitated by electron capture in deep defects upon ultraviolet (UV) exposure. With the utilization of two wavelengths of light upon the target and interference part of CAPTCHA to simulate top-down attentional control, the recognition accuracy is enhanced from 74 to 84%. These findings have the potential to augment the visual capability of neuromorphic systems with implications for diverse applications, including cybersecurity, healthcare, and machine vision.

Vertically integrated spiking cone photoreceptor arrays for color perception.

The cone photoreceptors in our eyes selectively transduce the natural light into spiking representations, which endows the brain with high energy-efficiency color vision. However, the cone-like device with color-selectivity and spike-encoding capability remains challenging. Here, we propose a metal oxide-based vertically integrated spiking cone photoreceptor array, which can directly transduce persistent lights into spike trains at a certain rate according to the input wavelengths. Such spiking cone photoreceptors have an ultralow power consumption of less than 400 picowatts per spike in visible light, which is very close to biological cones. In this work, lights with three wavelengths were exploited as pseudo-three-primary colors to form 'colorful' images for recognition tasks, and the device with the ability to discriminate mixed colors shows better accuracy. Our results would enable hardware spiking neural networks with biologically plausible visual perception and provide great potential for the development of dynamic vision sensors.

Estrogen receptor-beta regulates psoriasin (S100A7) in human breast cancer.

We have previously observed a paradoxical relationship of the psoriasin/S100A7 gene with estrogen response in-vitro in ERalpha positive cells but its association with ERalpha negative status in-vivo raising the possibility that S100A7 might be regulated by ERbeta in breast cancer. Using doxycycline-inducible ERbeta and ERalpha expressing MCF-7 cells the hypothesis that psoriasin/S100A7 is ERbeta regulated was investigated To explore the relationship between psoriasin/S100A7 and ERbeta expression in-vivo, we also assessed a cohort of 233 ERalpha negative breast tumors using tissue microarrays and immunohistochemistry. Psoriasin/S100A7 was increased by 17beta-estradiol (E2) following ERbeta induction, in several clones of ERbeta over-expressing but not in the original MCF-7 cells, nor clones over-expressing ERalpha. The effect of E2 on psoriasin/S100A7 was inhibited by 4-hydroxytamoxifen and ICI 182780 but not with a selective ERalpha antagonist. An ERbeta selective-agonist but not an ERalpha selective-agonist, induced psoriasin/S100A7. This induction still occurred after stable down-regulation of ERalpha using siRNA in ERbeta inducible cells. E2 increased psoriasin/S100A7 mRNA but cycloheximide treatment inhibited this effect. A relationship between ERbeta and psoriasin/S100A7 was observed in the p53 immunohistochemically negative subset of invasive breast tumors in-vivo (r = 0.225, p = 0.046, n = 79). In conclusion we demonstrate that E2 induction of psoriasin/S100A7 can be specifically regulated through ERbeta in-vitro and associated with ERbeta in-vivo. These data support the hypothesis that psoriasin/S100A7 is specifically regulated by ERbeta activity and could be useful to guide future therapies targeting ERbeta in certain phenotypic subsets of breast cancers in-vivo.

Assessment of multiple different estrogen receptor-beta antibodies for their ability to immunoprecipitate under chromatin immunoprecipitation conditions.

Several different antibodies to total estrogen receptor (ER)beta, ERbeta1 and ERbeta2/cx have been tested and compared for their ability to immunoprecipitate ERbeta specific isoforms under chromatin immunoprecipitation conditions (ChIP). The rabbit polyclonal antibodies AP-ERbeta1 and AP-ERbeta2/cx, specific for ERbeta1 and ERbeta2/cx isoforms, respectively, were the most efficient for ChIP. The monoclonal antibody MCA1974/PPG5/10 was also able to ChIP ERbeta1, but less efficiently than AP-ERbeta1. All other antibodies tested were not suitable for ChIP analyses although most antibodies tested immunoprecipitated the appropriate ERbeta isoforms under standard conditions. To identify antibodies that can also be used to verify in-vivo expression profiles, a comparison of the antibodies to detect ERbeta isoforms by western blotting and immunohistochemistry was also undertaken. Under the tissue processing and autostaining conditions used at the Manitoba Breast Tumor Bank 385P/GC17, MCA1974/PPG5/10, Ab288/14C8 and MCA2279S/57/3 were found to be the best for IHC of ERbeta isoforms in human breast tissue biopsy sections, while Ab14021, AP-ERbeta1 and AP-ERbeta2/cx were best for western blot detection of ERbeta isoforms.