RESUMO
Stretchable conjugated polymers with conjugation break spacers (CBSs) synthesized via random terpolymerization have gained considerable attention because of their efficacy in modulating mobility and stretchability. This study incorporates a series of dianhydrohexitol diastereomers of isosorbide (ISB) and isomannide (IMN) units into the diketopyrrolopyrrole-based backbone as CBSs. It is found that the distorted CBS (IMN) improves the mobility-stretchability properties of the polymer with a highly coplanar backbone, whereas the extended CBS (ISB) enhances those of the polymer with a noncoplanar backbone. Additionally, the different configurations of ISB and IMN sufficiently affect the solid-state packing, aggregation capabilities, crystallographic parameters, and mobility-stretchability properties of the polymer. The IMN-based polymers exhibit the highest mobility of 1.69 cm2 V-1 s-1 and crystallinity retentions of (85.7, 78.6)% under 20% and 60% strains, outperforming their ISB-based or unmodified counterparts. The improvement is correlated with a robust aggregation capability. Furthermore, the CBS content affects aggregation behavior, notably affecting mobility. This result indicates that incorporating CBSs into the polymer can enhance backbone flexibility via movement and rotation of the CBS without affecting the crystalline regions.
Assuntos
Polímeros , Pirróis , Polímeros/química , Polímeros/síntese química , Pirróis/química , Estereoisomerismo , Estrutura Molecular , Polimerização , Cetonas/químicaRESUMO
Seaweed-origin electrophilic compounds are proposed as a class of neuroprotective compounds that provide neuroprotection through activation of the Nrf2/ARE pathway. Electrophilic hydroquinones are of particular interest due to their ability to become electrophilic quinones upon auto-oxidation. Although many marine plants produce a variety of electrophilic compounds, the detailed mechanism of action of these compounds remain unknown. Here, we focused on the neuroprotective effects of zonarol (ZO), a para-hydroquinone-type pro-electrophilic compound from the brown algae Dictyopteris undulata. We show that ZO activates the Nrf2/ARE pathway, induces phase-2 enzymes, and protects neuronal cells from oxidative stress. ZO is the first example of a neuroprotective pro-electrophilic compound obtained from brown algae.
Assuntos
Fator 2 Relacionado a NF-E2/metabolismo , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Phaeophyceae/química , Sesquiterpenos/farmacologia , Animais , Linhagem Celular , Células Cultivadas , Camundongos , Neurônios/metabolismo , Fármacos Neuroprotetores/química , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Sesquiterpenos/química , Transdução de Sinais/efeitos dos fármacosRESUMO
The vision-inspired artificial neural network based on optical synapses has drawn a tremendous amount of attention for emulating biological senses. Although photoexcitation-induced synaptic functionalities have been widely studied, optical habituation via the photoinhibitory pathway is yet to be demonstrated for sophisticated biomimetic visual adaptive systems. Here, the first optical neuromorphic block copolymer (BCP) phototransistor is demonstrated as an all-optical operation responding to various wavelengths, fulfilling photoassisted dynamic learning/forgetting cycles via optical potentiation without gate bias. The polyfluorene BCPs were precisely designed to enable wavelength-adaptive responses, benefiting from interfacial semiconductor/electret morphology and the crystallinity/electron affinity of the BCPs. Notably, this is the first work to simultaneously exhibit fully light-controlled short- and long-term memory based on organic material systems. The device presents a high current contrast above 100-fold and long-term retention over 104 s. As a proof-of-concept for neural networks, a 6 × 6 array of photosynapses performed outstanding visual pattern learning/forgetting with high accuracy. This study exploits the design strategy of a conjugated BCP electret to unleash the full potential of wavelength-adaptive visual neuroplasticity transitions. It provides an effective architecture for designing high-performance and high-storage capacity required applications in next-generation neuromorphic systems.
RESUMO
Neuromorphic computation possesses the advantages of self-learning, highly parallel computation, and low energy consumption, and is of great promise to overcome the bottleneck of von Neumann computation. In this work, a series of poly(3-hexylthiophene) (P3HT)-based block copolymers (BCPs) with different coil segments, including polystyrene, poly(2-vinylpyridine) (P2VP), poly(2-vinylnaphthalene), and poly(butyl acrylate), are utilized in photosynaptic transistor to emulate paired-pulse facilitation, spike time/rate-dependent plasticity, short/long-term neuroplasticity, and learning-forgetting-relearning processes. P3HT serves as a carrier transport channel and a photogate, while the insulating coils with electrophilic groups are for charge trapping and preservation. Three main factors are unveiled to govern the properties of these P3HT-based BCPs: i) rigidity of the insulating coil, ii) energy levels between the constituent polymers, and iii) electrophilicity of the insulating coil. Accordingly, P3HT-b-P2VP-based photosynaptic transistor with a sought-after BCP combination demonstrates long-term memory behavior with current contrast up to 105 , short-term memory behavior with high paired-pulse facilitation ratio of 1.38, and an ultralow energy consumption of 0.56 fJ at an operating voltage of -0.0003 V. As far as it is known, this is the first work to utilize conjugated BCPs in an electret-free photosynaptic transistor showing great potential to the artificial intelligence technology.
RESUMO
BACKGROUND AND AIM: We previously identified an anti-inflammatory compound, zonarol, a hydroquinone isolated from the brown algae Dictyopteris undulata as a marine natural product. To ascertain the in vivo functions of zonarol, we examined the pharmacological effects of zonarol administration on dextran sulfate sodium (DSS)-induced inflammation in a mouse model of ulcerative colitis (UC). Our goal is to establish a safe and effective cure for inflammatory bowel disease (IBD) using zonarol. METHODS AND RESULTS: We subjected Slc:ICR mice to the administration of 2% DSS in drinking water for 14 days. At the same time, 5-aminosalicylic acid (5-ASA) at a dose of 50 mg/kg (positive control) and zonarol at doses of 10 and 20 mg/kg, were given orally once a day. DSS-treated animals developed symptoms similar to those of human UC, such as severe bloody diarrhea, which were evaluated by the disease activity index (DAI). Treatment with 20 mg/kg of zonarol, as well as 5-ASA, significantly suppressed the DAI score, and also led to a reduced colonic ulcer length and/or mucosal inflammatory infiltration by various immune cells, especially macrophages. Zonarol treatment significantly reduced the expression of pro-inflammatory signaling molecules, and prevented the apoptosis of intestinal epithelial cells. Finally, zonarol protected against in vitro lipopolysaccharide (LPS)-induced activation in the RAW264.7 mouse macrophage cell line. CONCLUSIONS: This is the first report that a marine bioproduct protects against experimental UC via the inhibition of both inflammation and apoptosis, very similar to the standard-of-care sulfasalazine, a well-known prodrug that releases 5-ASA. We believe that the oral administration of zonarol might offer a better treatment for human IBDs than 5-ASA, or may be useful as an alternative/additive therapeutic strategy against UC, without any evidence of side effects.
Assuntos
Anti-Inflamatórios/farmacologia , Apoptose/efeitos dos fármacos , Hidroquinonas/farmacologia , Sesquiterpenos/farmacologia , Administração Oral , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/uso terapêutico , Linhagem Celular , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/patologia , Colo/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Hidroquinonas/química , Hidroquinonas/uso terapêutico , Inflamação/prevenção & controle , Interleucina-6/análise , Interleucina-6/genética , Lipopolissacarídeos/toxicidade , Masculino , Mesalamina/uso terapêutico , Camundongos , Camundongos Endogâmicos ICR , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/metabolismo , Phaeophyceae/química , Phaeophyceae/metabolismo , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/uso terapêutico , Fator de Necrose Tumoral alfa/análise , Fator de Necrose Tumoral alfa/genéticaRESUMO
A 29-year-old woman who presented with persistent ventricular premature beat during her delivery was referred to us. Her cardiac echocardiography showed a giant tumor located in the posterior wall of the left ventricle. She had no symptoms of heart failure. Partial resection of the mass was safely conducted using cardiopulmonary bypass. The histopathologic finding was fibroma. She has been doing well 6 years after operation. Periodic echocardiography has showed no growth in this tumor.