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1.
Bioresour Bioprocess ; 10(1): 5, 2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-38647792

RESUMO

In order to meet the contemporary concept of sustainable development, the reuse of biological waste has also been emphasized. Lots of papers nowadays study the extraction of primary residues. The disposal of secondary residues is often neglected. The chemical composition and biological activity of secondary residues of Turkish Gall (SRTG) were researched in this paper. We selected five methods to extract the SRTG, and the extraction conditions were water, hydrochloric acid buffer (pH = 2), artificial gastric juice (pH = 2), phosphate buffer (pH = 6.8), and artificial intestinal solution (pH = 6.8). The changes of phenolic components were determined by spectrophotometry and high-performance liquid chromatography. The acid-base environment did not affect total polyphenols contents and gallic acid ethyl ester contents in SRTG. But it affected the gallic acid contents in SRTG. The contents of gallic acid in the hydrochloric acid buffer extraction groups were 1.63 times that of the water extraction group. The SRTG were extracted by hydrochloric acid buffer also had better inhibition on Escherichia coli and Staphylococcus aureus. In addition, SRTG showed positive effects on 1,1-Diphenyl-2-picrylhydrazyl Free, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), ·OH radicals, and Ferric ion reducing antioxidant power. Some active components of SRTG can be effectively released through the digestion of simulated gastric juices in vitro. The change of active ingredients affects the antibacterial and antioxidant capacity. The results provide data support for the conversion of secondary residues into products, such as feed additives. The SRTG has certain contributes to the value of the circular economy.

2.
J Phys Chem Lett ; 13(3): 884-893, 2022 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-35049317

RESUMO

Dielectric SiO2 has possible uses as an active layer for emerging memory due to its high on/off ratio and low operation voltage. However, SiO2-based memory that relies on the conducting filament still has limited endurance and stability. Here, we have constructed a passivated layer of SiO2 using Ag-doped SrTiO3, which serves as a Ag ion reservoir for the control of filament formation. It is demonstrated that the modified memristor presents an excellent endurance switching and could stably be operated in an ambient environment for 20 days without visible degradation. Based on the reliable switching, the synaptic functions such as excitatory postsynaptic current, paired-pulse facilitation, transition from short-term memory to long-term memory, and potentiation/depression have also been implemented. Furthermore, a 7 × 7 pixel array made from memristors has successfully mimicked simple learning and forgetting behavior. The experimental results offer an alternative approach for SiO2-based memristors and a possibility to be applied in neuromorphic computing.

3.
Nanoscale Res Lett ; 15(1): 30, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32006131

RESUMO

In this study, by inserting a buffer layer of TiOx between the SiOx:Ag layer and the bottom electrode, we have developed a memristor device with a simple structure of Ag/SiOx:Ag/TiOx/p++-Si by a physical vapor deposition process, in which the filament growth and rupture can be efficiently controlled during analog switching. The synaptic characteristics of the memristor device with a wide range of resistance change for weight modulation by implementing positive or negative pulse trains have been investigated extensively. Several learning and memory functions have been achieved simultaneously, including potentiation/depression, paired-pulse-facilitation (PPF), short-term plasticity (STP), and STP-to-LTP (long-term plasticity) transition controlled by repeating pulses more than a rehearsal operation, and spike-time-dependent-plasticity (STDP) as well. Based on the analysis of logarithmic I-V characteristics, it has been found that the controlled evolution/dissolution of conductive Ag-filaments across the dielectric layers can improve the performance of the testing memristor device.

4.
Materials (Basel) ; 12(24)2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31817654

RESUMO

Near-infrared brain imaging technology has great potential as a non-invasive, real-time inspection technique. Silicon-tin (SiSn) alloy films could be a promising material for near-infrared brain detectors. This study mainly reports on the structure of amorphous silicon tin alloy thin films by Raman spectroscopy to investigate the influence of doped-Sn on an a-Si network. The variations in TO peak caused by the increase in Sn concentration indicate a decrease in the short-range order of the a-Si network. A model has been proposed to successfully explain the non-linear variation in Raman parameters of ITA/ITO and ILA+LO/ITO. The variations of Raman parameters of the films with a higher deposition temperature indicate the presence of SiSn nanocrystals, though the SiSn nanocrystals present no Raman peaks in Raman spectra. XRD and TEM analysis further illustrate the existence of nanocrystals. The ratio of photo/dark conductivity and optical bandgap results demonstrate that the films can be selected as a sensitive layer material for NIR-II region sensors.

5.
IET Nanobiotechnol ; 13(6): 565-570, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31432787

RESUMO

Carbon aerogels have attracted considerable attention in basic research and for their potential applications in many fields. Here, the fabrication of a magnetic cellulose nanofibre (CNF)/poly(vinyl alcohol) (PVA)/multiwalled carbon nanotubes (MWCNT) carbon aerogel (m-CPMCA) is reported using a simple freeze-drying followed by a carbonisation process, and direct immobilisation of Fe3O4 nanoparticle on the surface of aerogels. The obtained target aerogel has the characteristics of low density (0.098 g/cm3), high porosity (>90%) and 3D interpenetrating porous structures. Furthermore, m-CPMCA has a surprising compressive strength (about 0.35 MPa) which is obviously higher than many other cellulose-based carbon aerogels. After Carbonization, m-CPMCA exhibits superhydrophobicity, selective absorption for organic solvents and fire-resistance. The m-CPMCA also exhibited a magnetic response and can absorb oil on the water surface and can be actuated by a small magnet. More importantly, the m-CPMCA could be recycled many times by combustion, which showed economic significance. To sum up, the authors believe that m-CPMCA will become a very potential adsorbent for dealing with the increasingly serious problem of organic pollution.


Assuntos
Celulose/química , Géis/síntese química , Nanopartículas de Magnetita/química , Microtecnologia/métodos , Nanotubos de Carbono/química , Força Compressiva , Géis/química , Interações Hidrofóbicas e Hidrofílicas , Fenômenos Magnéticos , Fenômenos Mecânicos , Nanofibras/química , Porosidade , Solventes , Estresse Mecânico , Água
6.
IET Nanobiotechnol ; 12(4): 500-504, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29768237

RESUMO

In recent years, carbon aerogels have attracted much attention in basic research and as potential applications in many fields. Herein, the authors report a novel approach using bamboo powder as raw material to fabricate cellulose nanofibers (CNFs)/multi-walled carbon nanotubes (MWCNTs) carbon aerogels by a simple dipping and carbonisation process. The developed material exhibits many exciting properties including low density (0.056 g cm-3), high porosity (95%), efficient capability for separation of oily droplets from water, and high adsorption capacity for a variety of oils and organic solvents by up to 110 times its own weight. Furthermore, the CNF/MWCNT carbon aerogels (CMCA) can be recycled many times by distillation and combustion, satisfying the requirements of practical oil-water separation. Taken together with its economical, environmentally benign manufacturing process, sustainability of the precursor and versatility of material, the CMCA developed in this study will be a promising candidate for addressing the problems arising from the spills of oily compounds.


Assuntos
Celulose/química , Nanofibras/química , Nanotubos de Carbono/química , Adsorção , Recuperação e Remediação Ambiental , Gasolina , Géis/química , Sasa/química , Molhabilidade
7.
Beilstein J Nanotechnol ; 9: 508-519, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29527428

RESUMO

With the worsening of the oil-product pollution problem, oil-water separation has attracted increased attention in recent years. In this study, a porous three-dimensional (3D) carbon aerogel based on cellulose nanofibers (CNFs), poly(vinyl alcohol) (PVA) and graphene oxide (GO) was synthesized by a facile and green approach. The resulting CNF/PVA/GO aerogels were synthesized through an environmentally friendly freeze-drying process and then carbonized to yield CNF/PVA/GO carbon aerogels with low density (18.41 mg cm-3), high porosity (98.98%), a water contact angle of 156° (super-hydrophobic) and high oil absorption capacity (97 times its own weight). The carbonization treatment of the CNF/PVA/GO aerogel not only improved the hydrophobic properties but also enhanced the adsorption capacity and specific surface area. Given the many good performance characteristics and the facile preparation process of carbon aerogels, these materials are viable candidates for use in oil-water separation and environmental protection.

8.
IET Nanobiotechnol ; 11(8): 929-934, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29155391

RESUMO

A hydrophobic and oleophilic trimethyl chlorosilane/reduced graphene oxide-coated cellulose nanofibres (TMCS/rGO/CNFs) aerogel with a three-dimensional structure was fabricated through a facile dip-coating process. The prepared aerogel exhibited several advantageous properties for absorption and expulsion of oils from water surfaces, such as a high specific surface area, low density (6.78 mg/cm3) and good porosity (99.12%). In addition, the TMCS/rGO/CNFs aerogel demonstrated good absorption capacities up to 39 times its own weight over a short time (1.5 min) for a broad range of oils. This research suggests that practical application of TMCS/rGO/CNFs aerogel in the cleanup of an oil spill is feasible.


Assuntos
Celulose/química , Géis/química , Grafite/química , Nanofibras/química , Óleos/química , Compostos de Trimetilsilil/química , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Propriedades de Superfície , Difração de Raios X
9.
Eur J Med Chem ; 108: 495-504, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-26717201

RESUMO

Vascular endothelial growth factor receptor (VEGFR) is a very important receptor tyrosine kinase (RTK) that can induce angiogenesis, increase cell growth and metastasis, reduce apoptosis, alter cytoskeletal function, and affect other biologic changes. Moreover, it is identified to be deregulated in varieties of human cancers. Therefore, VEGFR turn out to be a remarkable target of significant types of anticancer drugs in clinical trials. On the other side, c-Met is the receptor of hepatocyte growth factor (HGF) and a receptor tyrosine kinase. Previous studies have shown that c-Met elicits many different signaling pathways mediating cell proliferation, migration, differentiation, and survival. Furthermore, the correlation between aberrant signaling of the HGF/c-Met pathway and aggressive tumor growth, poor prognosis in cancer patients has been established. Recent reports had shown that c-Met/HGF and VEGFR/VEGF (vascular endothelial growth factor) can act synergistically in the progression of many diseases. They were also found to be over expressed in many human cancers. Thus, in a variety of malignancies, VEGFR and c-Met receptor tyrosine kinases have acted as therapeutic targets. With the development of molecular biology techniques, further understanding of the human tumor disease pathogenesis and interrelated signaling pathways known to tumor cells, using a single target inhibitors have been difficult to achieve the desired therapeutic effect. At this point, with respect to the combination of two inhibitors, a single compound which is able to inhibit both VEGFR and c-Met may put forward the advantage of raising anticancer activity. With the strong interest in these compounds, this review represents a renewal of previous works on the development of dual VEGFR and c-Met small molecule inhibitors as novel anti-cancer agents. Newly collection derivatives have been mainly describing in their biological profiles and chemical structures.


Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Humanos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas c-met/metabolismo , Piridinas/síntese química , Piridinas/química , Piridinas/farmacologia , Quinazolinas/síntese química , Quinazolinas/química , Quinazolinas/farmacologia , Quinolonas/síntese química , Quinolonas/química , Quinolonas/farmacologia , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química
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