Nano-Bioelectronics Zhang, Anqi; Lieber, Charles M
Chemical reviews,
01/2016, Letnik:
116, Številka:
1
Journal Article
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Nano-bioelectronics represents a rapidly expanding interdisciplinary field that combines nanomaterials with biology and electronics and, in so doing, offers the potential to overcome existing ...challenges in bioelectronics. In particular, shrinking electronic transducer dimensions to the nanoscale and making their properties appear more biological can yield significant improvements in the sensitivity and biocompatibility and thereby open up opportunities in fundamental biology and healthcare. This review emphasizes recent advances in nano-bioelectronics enabled with semiconductor nanostructures, including silicon nanowires, carbon nanotubes, and graphene. First, the synthesis and electrical properties of these nanomaterials are discussed in the context of bioelectronics. Second, affinity-based nano-bioelectronic sensors for highly sensitive analysis of biomolecules are reviewed. In these studies, semiconductor nanostructures as transistor-based biosensors are discussed from fundamental device behavior through sensing applications and future challenges. Third, the complex interface between nanoelectronics and living biological systems, from single cells to live animals, is reviewed. This discussion focuses on representative advances in electrophysiology enabled using semiconductor nanostructures and their nanoelectronic devices for cellular measurements through emerging work where arrays of nanoelectronic devices are incorporated within three-dimensional cell networks that define synthetic and natural tissues. Last, some challenges and exciting future opportunities are discussed.
Applying a “co-search” algorithm to Internet traffic at the SEC׳s EDGAR website, we develop a novel method for identifying economically related peer firms and for measuring their relative importance. ...Our results show that firms appearing in chronologically adjacent searches by the same individual (Search-Based Peers or SBPs) are fundamentally similar on multiple dimensions. In direct tests, SBPs dominate GICS6 industry peers in explaining cross-sectional variations in base firms׳ out-of-sample: (a) stock returns, (b) valuation multiples, (c) growth rates, (d) R&D expenditures, (e) leverage, and (f) profitability ratios. We show that SBPs are not constrained by standard industry classification, and are more dynamic, pliable, and concentrated. We also show that co-search intensity captures the degree of similarity between firms. Our results highlight the potential of the collective wisdom of investors — extracted from co-search patterns — in addressing long-standing benchmarking problems in finance.
Common causes of hearing loss in humans - exposure to loud noise or ototoxic drugs and aging - often damage sensory hair cells, reflected as elevated thresholds on the clinical audiogram. Recent ...studies in animal models suggest, however, that well before this overt hearing loss can be seen, a more insidious, but likely more common, process is taking place that permanently interrupts synaptic communication between sensory inner hair cells and subsets of cochlear nerve fibers. The silencing of affected neurons alters auditory information processing, whether accompanied by threshold elevations or not, and is a likely contributor to a variety of perceptual abnormalities, including speech-in-noise difficulties, tinnitus and hyperacusis. Work described here will review structural and functional manifestations of this cochlear synaptopathy and will consider possible mechanisms underlying its appearance and progression in ears with and without traditional ‘hearing loss’ arising from several common causes in humans.
•Noise can cause rapid synaptic loss and slow degeneration of cochlear nerve fibers, even if hair cells survive.•Diffuse cochlear synaptopathy does not raise audiometric or ABR thresholds, but does decrease ABR amplitudes.•Ears exposed to ‘synaptopathic’ noise show exaggerated synaptic and neural losses as they age after exposure.
Lineage plasticity, the ability of cells to transition from one committed developmental pathway to another, has been proposed as a source of intratumoural heterogeneity and of tumour adaptation to an ...adverse tumour microenvironment including exposure to targeted anticancer treatments. Tumour cell conversion into a different histological subtype has been associated with a loss of dependency on the original oncogenic driver, leading to therapeutic resistance. A well-known pathway of lineage plasticity in cancer - the histological transformation of adenocarcinomas to aggressive neuroendocrine derivatives - was initially described in lung cancers harbouring an EGFR mutation, and was subsequently reported in multiple other adenocarcinomas, including prostate cancer in the presence of antiandrogens. Squamous transformation is a subsequently identified and less well-characterized pathway of adenocarcinoma escape from suppressive anticancer therapy. The increased practice of tumour re-biopsy upon disease progression has increased the recognition of these mechanisms of resistance and has improved our understanding of the underlying biology. In this Review, we provide an overview of the impact of lineage plasticity on cancer progression and therapy resistance, with a focus on neuroendocrine transformation in lung and prostate tumours. We discuss the current understanding of the molecular drivers of this phenomenon, emerging management strategies and open questions in the field.
The goal of this study was to investigate Cannabidiol (CBD) hepatotoxicity in 8-week-old male B6C3F
mice. Animals were gavaged with either 0, 246, 738, or 2460 mg/kg of CBD (acute toxicity, 24 h) or ...with daily doses of 0, 61.5, 184.5, or 615 mg/kg for 10 days (sub-acute toxicity). These doses were the allometrically scaled mouse equivalent doses (MED) of the maximum recommended human maintenance dose of CBD in EPIDIOLEX
(20 mg/kg). In the acute study, significant increases in liver-to-body weight (LBW) ratios, plasma ALT, AST, and total bilirubin were observed for the 2460 mg/kg dose. In the sub-acute study, 75% of mice gavaged with 615 mg/kg developed a moribund condition between days three and four. As in the acute phase, 615 mg/kg CBD increased LBW ratios, ALT, AST, and total bilirubin. Hepatotoxicity gene expression arrays revealed that CBD differentially regulated more than 50 genes, many of which were linked to oxidative stress responses, lipid metabolism pathways and drug metabolizing enzymes. In conclusion, CBD exhibited clear signs of hepatotoxicity, possibly of a cholestatic nature. The involvement of numerous pathways associated with lipid and xenobiotic metabolism raises serious concerns about potential drug interactions as well as the safety of CBD.
5-(Hydroxymethyl)furfural (HMF) and furfural (FF) have been identified as valuable biomass-derived fuel precursors suitable for catalytic hydrodeoxygenation (HDO) to produce high octane fuel ...additives such dimethyl furan (DMF) and methyl furan (MF), respectively. In order to realize economically viable production of DMF and MF from biomass, catalytic processes with high yields, low catalyst costs, and process simplicity are needed. Here, we demonstrate simultaneous coprocessing of HMF and FF over Cu–Ni/TiO2 catalysts, achieving 87.5% yield of DMF from HMF and 88.5% yield of MF from FF in a one pot reaction. The Cu–Ni/TiO2 catalyst exhibited improved stability and regeneration compared to Cu/TiO2 and Cu/Al2O3 catalysts for FF HDO, with a ∼7% loss in FF conversion over four sequential recycles, compared to a ∼50% loss in FF conversion for Cu/Al2O3 and a ∼30% loss in conversion for Cu/TiO2. Characterization of the Cu–Ni/TiO2 catalyst by X-ray photoelectron spectroscopy, scanning transmission electron microscopy, and H2–temperature-programmed reduction and comparison to monometallic Cu and Ni on Al2O3 and TiO2 and bimetallic Cu–Ni/Al2O3 catalysts suggest that the unique reactivity and stability of Cu–Ni/TiO2 derives from support-induced metal segregation in which Cu is selectively enriched at the catalyst surface, while Ni is enriched at the TiO2 interface. These results demonstrate that Cu–Ni/TiO2 catalysts promise to be a system capable of integrating directly with a combined HMF and FF product stream from biomass processing to realize lower cost production of liquid fuels from biomass.
Technological links and predictable returns Lee, Charles M.C.; Sun, Stephen Teng; Wang, Rongfei ...
Journal of financial economics,
06/2019, Letnik:
132, Številka:
3
Journal Article
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Employing a classic measure of technological closeness between firms, we show that the returns of technology-linked firms have strong predictive power for focal firm returns. A long-short strategy ...based on this effect yields monthly alpha of 117 basis points. This effect is distinct from industry momentum and is not easily attributable to risk-based explanations. It is more pronounced for focal firms that: (a) have a more intense and specific technology focus, (b) receive lower investor attention, and (c) are more difficult to arbitrage. Our results are broadly consistent with sluggish price adjustment to more nuanced technological news.
This study investigates a particularly brazen form of corporate abuse, in which controlling shareholders use intercorporate loans to siphon billions of RMB from hundreds of Chinese listed companies ...during the 1996–2006 period. We document the nature and extent of these transactions, evaluate their economic consequences, examine factors that affect their cross-sectional severity, and report on the mitigating roles of auditors, institutional investors, and regulators. Collectively, our findings shed light on the severity of the minority shareholder expropriation problem in China, as well as the relative efficacy of various legal and extra-legal governance mechanisms in that country.
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