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1.
Science ; 369(6500): 138-139, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32646984
2.
Chemosphere ; 257: 127123, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32505037

RESUMO

It is a central issue to improve the separation efficiency of photogenerated charge carriers and the utilization of visible light in the field of photocatalysis. Herein, taking MIL-125(Ti) as a host material, the Pt/MIL-125(Ti) was first prepared by solvothermal method to build the interface of Schottky junction. Ag was then introduced onto the surface of Pt/MIL-125(Ti) to form the interface with the surface plasmon resonance effect. These double interfaces in the composite play a synergistic role on the photodagradation. The morphology, crystallinity and photochemical properties of the material were tested. By comparison, Pt/MIL-125(Ti)/Ag (4 wt% Ag) exhibited the best performance in the photodegradation of ketoprofen (KP, 10 mg/L) and the degradation process conformed to the pseudo-first-order kinetics. The photodegradation rate is 0.0253 min-1, which was higher than MIL-125(Ti) (0.0009 min-1). The TOC removal efficiency of KP reached approximately 51.5%. The electron paramagnetic resonance (EPR) and free radical capture tests verified that h+ and ·OH played the prominent roles during the reaction system. The degradation process, possible pathways and reaction mechanism were proposed. The design of the double interfaces between semiconductor and noble metals is a novel strategy to enhance the photocatalytic performance.


Assuntos
Cetoprofeno/química , Modelos Químicos , Catálise , Luz , Dietilamida do Ácido Lisérgico/análogos & derivados , Fotólise , Semicondutores , Prata/química , Titânio/química
3.
PLoS One ; 15(5): e0232184, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32369508

RESUMO

The ternary chalcogenide Cu3VSe4 (CVSe) with sulvanite structure has been theoretically predicted to be a promising candidate for photovoltaic applications due to its suitable bandgap for solar absorption and the relatively earth-abundant elements in its composition. To realize the absorber layer via an inexpensive route, printed thin-films could be fabricated from dispersions of nano-sized Cu3VSe4 precursors. Herein, cubic Cu3VSe4 nanocrystals were successfully synthesized via a hot-injection method. Similar with reported Cu3VS4 nanocrystals, Cu3VSe4 nanocrystals with cubic structure exhibit three absorption bands in the UV-Visible range indicative of a potential intermediate bandgap existence. A thin film fabricated by depositing the nanoparticles Cu3VSe4 on FTO coated glass substrate, exhibited a p-type behavior and a photocurrent of ~ 4 µA/cm2 when measured in an electrochemical cell setting. This first demonstration of photocurrent exhibited by a CVSe nanocrystals thin film signifies a promising potential in photovoltaic applications.


Assuntos
Nanopartículas/química , Compostos de Selênio/química , Compostos de Selênio/síntese química , Técnicas Eletroquímicas , Nanopartículas/ultraestrutura , Tamanho da Partícula , Processos Fotoquímicos , Semicondutores
4.
Int J Nanomedicine ; 15: 1863-1870, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32231432

RESUMO

Background: Electronic devices which mimic the functionality of biological synapses are a large step to replicate the human brain for neuromorphic computing and for numerous medical research investigations. One of the representative synaptic behaviors is paired-pulse facilitation (PPF). It has been widely investigated because it is regarded to be related to biological memory. However, plasticity behavior is only part of the human brain memory behavior. Methods: Here, we present a phenomenon which is opposite to PPF, i.e., paired-pulse inhibition (PPI), in nano oxide devices for the first time. The research here suggests that rather than being enhanced, the phenomena of memory loss would also be possessed by such electronic devices. The device physics mechanism behind memory loss behavior was investigated. This mechanism is sustained by historical memory and degradation manufactured by device trauma to regulate characteristically stimulated origins of artificial transmission behaviors. Results: Under the trauma of a memory device, both the signal amplitude and signal time stimulated by a pulse are lower than the first signal stimulated by a previous pulse in the PPF, representing a new scenario in the struggle for memory. In this way, more typical human brain behaviors could be simulated, including the effect of age on latency and error generation, cerebellar infarct, trauma and memory loss pharmacological actions (such as those caused by hyoscines and nitrazepam). Conclusion: Thus, this study developed a new approach for implementing the manner in which the brain works in semiconductor devices for improving medical research.


Assuntos
Semicondutores , Sinapses/fisiologia , Biomimética , Encéfalo/fisiologia , Desenho de Equipamento , Nanoestruturas , Plasticidade Neuronal , Óxidos/metabolismo
5.
PLoS One ; 15(3): e0229382, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32142551

RESUMO

Conversion of vacuum fluctuations into real particles was first predicted by L. Parker considering an expanding universe, followed in S. Hawking's work on black hole radiation. Since their experimental observation is challenging, analogue systems have gained attention in the verification of this concept. Here we propose an experimental set-up consisting of two adjacent piezoelectric semiconducting layers, one of them carrying dynamic quantum dots (DQDs), and the other being p-doped with an attached gate on top, which introduces a space-dependent layer conductivity. The propagation of surface acoustic waves (SAWs) on the latter layer is governed by a wave equation with an effective metric. In the frame of the DQDs, this space- and time-dependent metric possesses a sonic horizon for SAWs and resembles that of a two dimensional non-rotating and uncharged black hole to some extent. The non-thermal steady state of the DQD spin indicates particle creation in form of piezophonons.


Assuntos
Sistemas Microeletromecânicos/métodos , Modelos Teóricos , Pontos Quânticos , Semicondutores , Simulação por Computador , Elétrons , Tamanho da Partícula , Física , Espalhamento de Radiação
6.
Nat Commun ; 11(1): 1135, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32111825

RESUMO

Cancer stem cells (CSC) can be identified by modifications in their genomic DNA. Here, we report a concept of precisely shrinking an organic semiconductor surface-enhanced Raman scattering (SERS) probe to quantum size, for investigating the epigenetic profile of CSC. The probe is used for tag-free genomic DNA detection, an approach towards the advancement of single-molecule DNA detection. The sensor detected structural, molecular and gene expression aberrations of genomic DNA in femtomolar concentration simultaneously in a single test. In addition to pointing out the divergences in genomic DNA of cancerous and non-cancerous cells, the quantum scale organic semiconductor was able to trace the expression of two genes which are frequently used as CSC markers. The quantum scale organic semiconductor holds the potential to be a new tool for label-free, ultra-sensitive multiplexed genomic analysis.


Assuntos
Materiais Biocompatíveis/química , DNA/química , Genoma Humano , Semicondutores , Animais , Composição de Bases , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Técnicas Biossensoriais/instrumentação , Linhagem Celular , Metilação de DNA , Epigênese Genética , Expressão Gênica , Humanos , Camundongos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Pontos Quânticos/química , Reprodutibilidade dos Testes , Análise Espectral Raman
7.
PLoS One ; 15(3): e0227368, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32130215

RESUMO

The idea that households produce and consume their own energy, that is, energy self-sufficiency at a very local level, captures the popular imagination and commands political support across parts of Europe. This paper investigates the technical and economic feasibility of household energy self-sufficiency in Switzerland, which can be seen as representative for other regions with a temperate climate, by 2050. We compare sixteen cases that vary across four dimensions: household type, building type, electricity demand reduction, and passenger vehicle use patterns. We assume that photovoltaic (PV) electricity supplies all energy, which implies a complete shift away from fossil fuel based heating and internal combustion engine vehicles. Two energy storage technologies are considered: short-term storage in lithium-ion batteries and long-term storage with hydrogen, requiring an electrolyzer, storage tank, and a fuel cell for electricity conversion. We examine technological feasibility and total system costs for self-sufficient households compared to base cases that rely on fossil fuels and the existing power grid. PV efficiency and available rooftop/facade area are most critical with respect to the overall energy balance. Single-family dwellings with profound electricity demand reduction and urban mobility patterns achieve self-sufficiency most easily. Multi-family buildings with conventional electricity demand and rural mobility patterns can only be self-sufficient if PV efficiency increases, and all of the roof plus most of the facade can be covered with PV. All self-sufficient cases are technically feasible but more expensive than fully electrified grid-connected cases. Self-sufficiency may even become cost-competitive in some cases depending on storage and fossil fuel prices. Thus, if political measures improve their financial attractiveness or individuals decide to shoulder the necessary investments, self-sufficient buildings may start to become increasingly prevalent.


Assuntos
Poluição do Ar/prevenção & controle , Clima , Indústria da Construção/métodos , Fontes de Energia Elétrica/economia , Semicondutores/economia , Automóveis/economia , Mudança Climática , Indústria da Construção/economia , Indústria da Construção/tendências , Fontes de Energia Elétrica/tendências , Eletrólise/economia , Estudos de Viabilidade , Combustíveis Fósseis/efeitos adversos , Humanos , Hidrogênio/química , Hidrogênio/economia , Lítio/química , Lítio/economia , Densidade Demográfica , Suíça
8.
Biochemistry (Mosc) ; 85(Suppl 1): S196-S212, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32087060

RESUMO

Rhodopsins are light-sensitive membrane proteins enabling transmembrane charge separation (proton pump) on absorption of a light quantum. Bacteriorhodopsin (BR) is a transmembrane protein from halophilic bacteria that belongs to the rhodopsin family. Potential applications of BR are considered so promising that the number of studies devoted to the use of BR itself, its mutant variants, as well as hybrid materials containing BR in various areas grows steadily. Formation of hybrid structures combining BR with nanoparticles is an essential step in promotion of BR-based devices. However, rapid progress, continuous emergence of new data, as well as challenges of analyzing the entire data require regular reviews of the achievements in this area. This review is devoted to the issues of formation of materials based on hybrids of BR with fluorescent semiconductor nanocrystals (quantum dots) and with noble metal (silver, gold) plasmonic nanoparticles. Recent data on formation of thin (mono-) and thick (multi-) layers from materials containing BR and BR/nanoparticle hybrids are presented.


Assuntos
Bacteriorodopsinas/química , Bacteriorodopsinas/fisiologia , Nanopartículas Metálicas/química , Pontos Quânticos/química , Campos Eletromagnéticos , Ouro/química , Ouro/metabolismo , Halobacterium salinarum/citologia , Membrana Purpúrea/metabolismo , Células Fotorreceptoras Retinianas Bastonetes/metabolismo , Rodopsina/química , Semicondutores , Prata/química , Prata/metabolismo , Análise Espectral Raman
9.
Nat Commun ; 11(1): 879, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-32054851

RESUMO

Bio-hybrid light-emitting diodes (Bio-HLEDs) based on color down-converting filters with fluorescent proteins (FPs) have achieved moderate efficiencies (50 lm/W) and stabilities (300 h) due to both thermal- and photo-degradation. Here, we present a significant enhancement in efficiency (~130 lm/W) and stability (>150 days) using a zero-thermal-quenching bio-phosphor design. This is achieved shielding the FP surface with a hydrophilic polymer allowing their homogenous integration into the network of a light-guiding and hydrophobic host polymer. We rationalize how the control of the mechanical and optical features of this bio-phosphor is paramount towards highly stable and efficient Bio-HLEDs, regardless of the operation conditions. This is validated by the relationships between the stiffness of the FP-polymer phosphor and the maximum temperature reached under device operation as well as the transmittance of the filters and device efficiency.


Assuntos
Proteínas de Fluorescência Verde/genética , Luz , Organofosfatos/química , Polimetil Metacrilato/química , Semicondutores , Bioengenharia/métodos , Dicroísmo Circular , Cor , Desenho de Equipamento , Proteínas de Fluorescência Verde/química , Proteínas de Fluorescência Verde/isolamento & purificação , Mutação , Estrutura Secundária de Proteína/genética , Estrutura Terciária de Proteína/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Temperatura
10.
Occup Environ Med ; 77(4): 238-248, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32019845

RESUMO

OBJECTIVE: This study evaluated the relationship between brain and other central nervous system cancer ('CNS cancer') and exposures at two semiconductor and electronic module manufacturing facilities and at a storage device manufacturing facility. METHODS: The case-control study, nested in a cohort of 126 836 employees, compared 120 CNS cancer cases and 1028 matched controls with respect to employment in 10 process groups and estimated cumulative exposure to 31 known or possible carcinogens. RESULTS: CNS cancer was associated with module manufacturing operations at two facilities. Module manufacturing is a process that begins with production of ceramic substrates followed by attachment of completed semiconductor chips and metal-containing circuitry resulting in a high performing electronic device. Positive associations with the highest tertile of estimated cumulative exposure were found for several chemicals, including 2-butoxyethanol, cyclohexanone, ortho-dichlorobenzene, cadmium, molybdenum, trichloroethylene and vinyl chloride. CONCLUSIONS: Results suggested positive associations between CNS cancer and specific operations and chemicals experienced in the semiconductor and electronic module manufacturing industry. However, lack of external support for these findings precludes a causal interpretation, and the observed associations may have been due to chance.


Assuntos
Neoplasias do Sistema Nervoso Central/induzido quimicamente , Neoplasias do Sistema Nervoso Central/mortalidade , Doenças Profissionais/induzido quimicamente , Doenças Profissionais/mortalidade , Exposição Ocupacional/efeitos adversos , Semicondutores/efeitos adversos , Neoplasias Encefálicas , Estudos de Casos e Controles , Monitoramento Ambiental , Humanos , Indústria Manufatureira , Instalações Industriais e de Manufatura , Compostos Orgânicos/efeitos adversos , Sistema de Registros , Estados Unidos/epidemiologia
11.
Chem Commun (Camb) ; 56(20): 3035-3038, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32048636

RESUMO

It remains challenging to develop new materials exhibiting enzyme-like activities and understand the structure-property correlations and catalytic mechanisms. In this study, the characteristics, mechanisms, and applications of a light-activated mimic oxidase based on semiconducting polymer dots (Pdots) prepared from an organic conjugated polymer are demonstrated.


Assuntos
Luz , Polímeros/química , Pontos Quânticos/química , Materiais Biomiméticos/química , Materiais Biomiméticos/metabolismo , Catálise , Estrutura Molecular , Oxirredutases/química , Oxirredutases/metabolismo , Semicondutores
12.
J Environ Manage ; 258: 110050, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31929077

RESUMO

Photocatalytic degradation is among the promising technology for removal of various dyes and organic contaminants from environment owing to its excellent catalytic activity, low energy utilization, and low cost. As one of potential photocatalysts, Fe2O3 has emerged as an important material for degradation of numerous dyes and organic contaminants caused by its tolerable band gap, wide harvesting of visible light, good stability and recyclability. The present review thoroughly summarized the classification, synthesis route of Fe2O3 with different morphologies, and several modifications of Fe2O3 for improved photocatalytic performance. These include the incorporation with supporting materials, formation of heterojunction with other semiconductor photocatalysts, as well as the fabrication of Z-scheme. Explicitly, the other photocatalytic applications of Fe2O3, including for removal of heavy metals, reduction of CO2, evolution of H2, and N2 fixation are also deliberately discussed to further highlight the huge potential of this catalyst. Moreover, the prospects and future challenges are also comprised to expose the unscrutinized criteria of Fe2O3 photocatalyst. This review aims to contribute a knowledge transfer for providing more information on the potential of Fe2O3 photocatalyst. In the meantime, it might give an idea for utilization of this photocatalyst in other environmental remediation application.


Assuntos
Corantes , Luz , Catálise , Semicondutores
13.
Nature ; 577(7789): 171-172, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31915392
14.
Nat Commun ; 11(1): 94, 2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31901080

RESUMO

The rapid development of scientific CMOS (sCMOS) technology has greatly advanced optical microscopy for biomedical research with superior sensitivity, resolution, field-of-view, and frame rates. However, for sCMOS sensors, the parallel charge-voltage conversion and different responsivity at each pixel induces extra readout and pattern noise compared to charge-coupled devices (CCD) and electron-multiplying CCD (EM-CCD) sensors. This can produce artifacts, deteriorate imaging capability, and hinder quantification of fluorescent signals, thereby compromising strategies to reduce photo-damage to live samples. Here, we propose a content-adaptive algorithm for the automatic correction of sCMOS-related noise (ACsN) for fluorescence microscopy. ACsN combines camera physics and layered sparse filtering to significantly reduce the most relevant noise sources in a sCMOS sensor while preserving the fine details of the signal. The method improves the camera performance, enabling fast, low-light and quantitative optical microscopy with video-rate denoising for a broad range of imaging conditions and modalities.


Assuntos
Microscopia de Fluorescência/instrumentação , Algoritmos , Animais , Bovinos , Linhagem Celular , Células HeLa , Humanos , Microscopia de Fluorescência/métodos , Microtúbulos/química , Mitocôndrias/química , Semicondutores , Razão Sinal-Ruído
15.
Artigo em Inglês | MEDLINE | ID: mdl-31607225

RESUMO

III-V semiconductor materials such as gallium arsenide (GaAs) and indium arsenide (InAs) are increasingly used in the fabrication of electronic devices. There is a growing concern about the potential release of these materials into the environment leading to effects on public and environmental health. The waste effluents from the chemical mechanical planarization process could impact microorganisms in biological wastewater treatment systems. Currently, there is only limited information about the inhibition of gallium- and indium-based nanoparticles (NPs) on microorganisms. This study evaluated the acute toxicity of GaAs, InAs, gallium oxide (Ga2O3), and indium oxide (In2O3) particulates using two microbial inhibition assays targeting methanogenic archaea and the marine bacterium, Aliivibrio fischeri. GaAs and InAs NPs were acutely toxic towards these microorganisms; Ga2O3 and In2O3 NPs were not. The toxic effect was mainly due to the release of soluble arsenic species and it increased with decreasing particle size and with increasing time due to the progressive corrosion of the NPs in the aqueous bioassay medium. Collectively, the results indicate that the toxicity exerted by the arsenide NPs under environmental conditions will vary depending on intrinsic properties of the material such as particle size as well as on the dissolution time and aqueous chemistry.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Gálio/toxicidade , Índio/toxicidade , Nanopartículas/toxicidade , Poluentes Químicos da Água/toxicidade , Aliivibrio fischeri/metabolismo , Arsenicais/química , Gálio/química , Índio/química , Metano/biossíntese , Nanopartículas/química , Tamanho da Partícula , Semicondutores , Esgotos/microbiologia , Propriedades de Superfície , Poluentes Químicos da Água/química , Purificação da Água/métodos
16.
Artigo em Inglês | MEDLINE | ID: mdl-31846386

RESUMO

This study evaluates application of three different nanopowder mixtures for decomposition of diclofenac (DCF), one of frequently detected pharmaceutical in wastewater. Analyzed three photocatalytic mixtures ZnO/SnO2, ZnO/TiO2 and ZnO/In2O3 are for the first time used for diclofenac degradation. A set of experiments were performed in order to investigate influence of catalyst concentration (0.10-0.60 mg mL-1), initial concentration of diclofenac (0.002-0.010 mg mL-1) and pH value (5-9). The increase in the catalyst concentration leads to a decrease in the degradation rate constant, which is the most pronounced in the ZnO/TiO2 and ranges from 0.47 (6) min-1 to 0.25 (3) min-1. The influence of pH on efficacy shows completely different effects: ZnO/In2O3 is most effective in alkaline environments, ZnO/TiO2 in neutral environments, while ZnO/SnO2 efficiency is good in both alkaline and acidic environments. Initial concentrations of diclofenac showed a complex effect on the degradation rate. The four dominant intermediates were detected by LC MS/MS technique. In case of all three nanomaterials, intensive degradation was achieved in first 30 minutes. The economical analysis of photocatalytic treatment was provided where the preparation of nanomaterials does not demand high costs and with the highest diclofenac concentration, total operation costs are the lowest (77.14 US$/kWh).


Assuntos
Diclofenaco/análise , Nanopartículas/química , Preparações Farmacêuticas/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Catálise , Cromatografia Líquida , Análise Custo-Benefício , Fotoquímica , Fotólise , Pós , Semicondutores , Propriedades de Superfície , Espectrometria de Massas em Tandem , Águas Residuárias/química , Purificação da Água/economia
17.
J Hum Genet ; 65(1): 69-77, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31420594

RESUMO

Nanopore DNA sequencing offers a new paradigm owing to its extensive potential for long-read, high-throughput detection of nucleotide modification and direct RNA sequencing. Given the remarkable advances in protein nanopore sequencing technology, there is still a strong enthusiasm in exploring alternative nanopore-sequencing techniques, particularly those based on a solid-state nanopore using a semiconductor material. Since solid-state nanopores provide superior material robustness and large-scale integrability with on-chip electronics, they have the potential to surpass the limitations of their biological counterparts. However, there are key technical challenges to be addressed: the creation of an ultrasmall nanopore, fabrication of an ultrathin membrane, control of the ultrafast DNA speed and detection of four nucleotides. Extensive research efforts have been devoted to resolving these issues over the past two decades. In this review, we briefly introduce recent updates regarding solid-state nanopore technologies towards DNA sequencing. It can be envisioned that emerging technologies will offer a brand new future in DNA-sequencing technology.


Assuntos
Sequenciamento por Nanoporos/métodos , Nanotecnologia/métodos , Análise de Sequência de DNA/métodos , Sequência de Bases , DNA de Cadeia Simples/química , Nanoporos , Nucleotídeos/química , Semicondutores
18.
Mater Sci Eng C Mater Biol Appl ; 106: 110104, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753374

RESUMO

Multifunctional nanoparticles have emerged as an outstanding candidate for a new generation of biomedical applications, mainly due to their remarkable properties and biocompatibility. Individual reports on multi-metal, semiconducting and superparamagnetic nanoparticles (SPIONs), elucidating on each's unique intrinsic properties, have demonstrated that the biological application of such materials is highly dependent of their size, shape, surface nature and core nature. However, reviews combining nanoparticles with multiple properties, as fluorescence and paramagnetism, as well as, biocompatibility, toxicology and biodegradability are yet seldom. This review highlights the highest output advances, of the last decade, on synthetic procedures for the design of multifunctional magneto-luminescent hybrid nanosystems based on quantum dots, SPIONs and mesoporous silica nanoparticles, as well as, surface modifications and their role for biological applications.


Assuntos
Nanopartículas/química , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Química Verde , Humanos , Nanopartículas de Magnetita/química , Microscopia Confocal , Nanopartículas/metabolismo , Neoplasias/diagnóstico , Neoplasias/diagnóstico por imagem , Pontos Quânticos/química , Semicondutores
19.
Chemosphere ; 239: 124686, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31494321

RESUMO

Oxidative degradation of aniline in aqueous solution was performed by the sono-activated peroxydisulfate coupled with PbO process, wherein a dramatic synergistic effect was found. Experiments were carried out in the batch-wise mode to investigate the influence of various operation parameters on the sonocatalytic behavior, such as ultrasonic power intensity, peroxydisulfate anion concentrations and PbO dosages. According to the scavenging effect of ethanol, methanol and tert-butyl alcohol, the principal oxidizing agents were presumed to be sulfate radicals descended from peroxydisulfate anions, activated via ultrasound or sonocatalysis of PbO. Based on the results attained from gas chromatograph-mass spectrometer, it was hypothesized that aniline was initially oxidized into iminobenzene radicals, followed with formation of nitrosobenzene, p-benzoquinonimine and nitrobenzene respectively. Condensation of nitrosobenzene with aniline generated azobenzene. Phenol was detected as one of degradation intermediates, which was sequentially converted into hydroquinone and p-benzoquinone.


Assuntos
Compostos de Anilina/química , Chumbo/química , Óxidos/química , Fenol/química , Sulfatos/química , Compostos Azo/síntese química , Benzoquinonas/síntese química , Etanol/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hidroquinonas/síntese química , Metanol/metabolismo , Nitrobenzenos/síntese química , Compostos Nitrosos/síntese química , Oxidantes , Oxirredução , Semicondutores , Ondas Ultrassônicas , terc-Butil Álcool/metabolismo
20.
IEEE Trans Biomed Circuits Syst ; 13(6): 1655-1663, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31825873

RESUMO

This report presents characterizations of in vivo neural recordings performed with a CMOS multichannel neural recording chip that uses rapid multiplexing directly at the electrodes, without any pre-amplification or buffering. Neural recordings were taken from a 16-channel microwire array implanted in rodent cortex, with comparison to a gold-standard commercial bench-top recording system. We were able to record well-isolated threshold crossings from 10 multiplexed electrodes and typical local field potential waveforms from 16, with strong agreement with the standard system (average SNR = 2.59 and 3.07 respectively). For 10 electrodes, the circuit achieves an effective area per channel of 0.0077 mm2, which is >5x smaller than typical multichannel chips. Extensive characterizations of noise and signal quality are presented and compared to fundamental theory, as well as results from in vivo and in vitro experiments. By demonstrating the validation of rapid multiplexing directly at the electrodes, this report confirms it as a promising approach for reducing circuit area in massively-multichannel neural recording systems, which is crucial for scaling recording site density and achieving large-scale sensing of brain activity with high spatiotemporal resolution.


Assuntos
Potenciais de Ação , Córtex Cerebelar/fisiologia , Eletroencefalografia/instrumentação , Amplificadores Eletrônicos , Animais , Eletrodos Implantados , Eletroencefalografia/métodos , Masculino , Ratos , Ratos Sprague-Dawley , Semicondutores , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído
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