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991.
Pham SV Dijkstra M van Wolferen HA Pollnau M Krijnen GJ Hoekstra HJ 《Optics letters》2011,36(15):3003-3005
We demonstrate a proof of concept of a novel and compact integrated mechano-optical sensor for H(2) detection based on a microcantilever suspended above a Si(3)N(4) grated waveguide. The fabricated devices are mechanically and optically modeled and characterized. Sensing operation of the sensor is demonstrated with 1% H(2) in N(2). The error in detection of the cantilever bending induced by absorption of H(2) is estimated to be approximately 10 nm. Significantly improved sensitivity (down to ~33 pm) is expected for reduced initial bending of the microcantilever. The simulation and experimental results are in good agreement and provide a good guideline for further optimization of the sensor. 相似文献
992.
M. Kerschhaggl G. AlderingP. Antilogus C. AragonS. Bailey C. BaltayS. Bongard C. ButonA. Canto M. Childress N. ChotardY. Copin H.K. Fakhouri E. GanglerE.Y. Hsiao M. KowalskiS. Loken P. Nugent K. PaechR. Pain E. PecontalR. Pereira S. Perlmutter D. RabinowitzK. Runge R. ScalzoG. Smadja C. Tao R.C. Thomas C. Wu 《Progress in Particle and Nuclear Physics》2011,66(2):335-339
The Nearby Supernova Factory (SNfactory) is currently finishing its first survey of low redshift (0.03<z<0.08) type Ia supernovae. These data add to the understanding of the expansion history of the universe. Observations are performed using the Supernova Integral Field Spectrograph (SNIFS), an integral field spectrograph delivering full spectro-photometric information of the target. The corresponding dataset aims at the inference of the Hubble diagram zero point with unprecedented accuracy. Moreover, the data offers a variety of related physical studies such as the understanding of progenitor systems, explosion scenarios and host galaxy characteristics. The SNfactory is also working on novel methods accessible with spectro-photometric measurements, reducing systematic uncertainties and improving the statistical power of the SN data. 相似文献
993.
Bronstein H Chen Z Ashraf RS Zhang W Du J Durrant JR Tuladhar PS Song K Watkins SE Geerts Y Wienk MM Janssen RA Anthopoulos T Sirringhaus H Heeney M McCulloch I 《Journal of the American Chemical Society》2011,133(10):3272-3275
We report the synthesis and polymerization of a novel thieno[3,2-b]thiophene-diketopyrrolopyrrole-based monomer. Copolymerization with thiophene afforded a polymer with a maximum hole mobility of 1.95 cm(2) V(-1) s(-1), which is the highest mobility from a polymer-based OFET reported to date. Bulk-heterojunction solar cells comprising this polymer and PC(71)BM gave a power conversion efficiency of 5.4%. 相似文献
994.
996.
Ana Carolina Sousa Pereira Daniela Nunes da Silva Laís Sales Porto Arnaldo Csar Pereira 《Electroanalysis》2020,32(9):1905-1913
This work describes the development of a biosensor for paracetamol (PAR) determination based on a glassy carbon electrode (GCE) modified with multiwalled carbon nanotubes (MWCNT) and laccase enzyme (LAC), which was immobilized by means of covalent crosslinking using glutaraldehyde. Voltammetric investigations were carried out by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV). The biosensor was characterized by Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FT‐IR). The results showed that the use of MWCNT/LAC composite increased the sensor sensitivity, compared to bare glassy carbon electrode. Factors affecting the voltammetric signals such as pH, ionic strength, scan rate and interferents were assessed. Linear range, limit of detection (LOD) and limit of quantitation (LOQ) obtained were 10–320 μmol L?1, 7 μmol L?1 and 10 μmol L? 1, respectively. The developed biosensor was successfully applied to PAR determination in urine and pharmaceutical formulations samples, with recovery varying from 99.96 to 106.20 % in urine samples and a relative standard deviation less than 1.04 % for PAR determination in pharmaceutical formulations. Therefore, the MWCNT‐LAC/GCE exhibits excellent sensitivity and can be used to PAR determination as a viable alternative in clinical analyzes and quality control of pharmaceutical formulations, through a simple, fast and inexpensive methodology. 相似文献
997.
Renata leite Tavares Maria Helena Araújo de Vasconcelos Maria Letícia da Veiga Dutra Aline Barbosa DOliveira Marcos dos Santos Lima Mirian Graciela da Silva Stiebbe Salvadori Ramon de Alencar Pereira Adriano Francisco Alves Yuri Mangueira do Nascimento Josean Fechine Tavares Omar Guzman-Quevedo Jailane de Souza Aquino 《Molecules (Basel, Switzerland)》2020,25(23)
This study evaluated the effect of Mucuna pruriens (MP) administration on neuroinflammation and behavioral and murinometric parameters in obese rats. Proximate composition, oligosaccharide and phenolic compound profile of MP were determined. Wistar adult male rats were randomized into healthy (HG) and obese group (OG). The HG consumed a control chow diet while OG consumed a cafeteria diet for eight weeks. Then, they were subdivided into: Healthy (HG); Healthy with MP administration (HGMP); Obese (OG); Obese with MP administration (OGMP), with the consumption of the respective diets remaining for another eight weeks, in addition to gavage with MP extract to supplemented groups (750 mg/kg weight). MP presented a composition rich in proteins and phenolic compounds, especially catechin, in addition to 1-kestose and levodopa. Supplementation reduced food intake, body weight, and thoracic and abdominal circumferences in obese rats. MP showed anxiolytic and antidepressant effects and reduced morphological damage and expression of interleukin 6 in the hippocampus of obese rats. MP treatment showed satietogenic, slimming, anxiolytic and antidepressant effects, besides to minimizing hippocampal neuroinflammation in obese rats. Our results demonstrated the potential anti-obesity of MP which are probably related to the high content of bioactive compounds present in this plant extract. 相似文献
998.
Ana I. F. Lopes Mariana Monteiro Ana R. L. Araújo Ana Rita O. Rodrigues Elisabete M. S. Castanheira David M. Pereira Pedro Olim A. Gil Fortes M. Sameiro T. Gonalves 《Molecules (Basel, Switzerland)》2020,25(24)
The potential of plant extracts as bioinsecticides has been described as a promising field of agricultural development. In this work, the extracts of Punica granatum (pomegranate), Phytolacca americana (American pokeweed), Glandora prostrata (shrubby gromwell), Ulex europaeus (gorce), Tagetes patula (French marigold), Camellia japonica red (camellia), Ruta graveolens (rue or herb-of-grace) were obtained, purified, and their activity against Spodoptera frugiperda (Sf9) insect cells was investigated. From the pool of over twenty extracts obtained, comprising different polarities and vegetable materials, less polar samples were shown to be more toxic towards the insect cell line Sf9. Among these, a dichloromethane extract of R. graveolens was capable of causing a loss of viability of over 50%, exceeding the effect of the commercial insecticide chlorpyrifos. This extract elicited chromatin condensation and the fragmentation in treated cells. Nanoencapsulation assays of the cytotoxic plant extracts in soybean liposomes and chitosan nanostructures were carried out. The nanosystems exhibited sizes lower or around 200 nm, low polydispersity, and generally high encapsulation efficiencies. Release assays showed that chitosan nanoemulsions provide a fast and total extract release, while liposome-based systems are suitable for a more delayed release. These results represent a proof-of-concept for the future development of bioinsecticide nanoformulations based on the cytotoxic plant extracts. 相似文献
999.
Willem Jespers Grgory Verdon Jhonny Azuaje Maria Majellaro Henrik Kernen Xerardo García‐Mera Miles Congreve Francesca Deflorian Chris de Graaf Andrei Zhukov Andrew S. Dor Jonathan S. Mason Johan qvist Robert M. Cooke Eddy Sotelo Hugo Gutirrez‐de‐Tern 《Angewandte Chemie (International ed. in English)》2020,59(38):16536-16543
We present a robust protocol based on iterations of free energy perturbation (FEP) calculations, chemical synthesis, biophysical mapping and X‐ray crystallography to reveal the binding mode of an antagonist series to the A2A adenosine receptor (AR). Eight A2AAR binding site mutations from biophysical mapping experiments were initially analyzed with sidechain FEP simulations, performed on alternate binding modes. The results distinctively supported one binding mode, which was subsequently used to design new chromone derivatives. Their affinities for the A2AAR were experimentally determined and investigated through a cycle of ligand‐FEP calculations, validating the binding orientation of the different chemical substituents proposed. Subsequent X‐ray crystallography of the A2AAR with a low and a high affinity chromone derivative confirmed the predicted binding orientation. The new molecules and structures here reported were driven by free energy calculations, and provide new insights on antagonist binding to the A2AAR, an emerging target in immuno‐oncology. 相似文献
1000.
Bruno Pereira Motta Anderson Kiyoshi Kaga Juliana Oriel Oliveira Maiara Destro Inacio Cledson Ferreira da Silva Paulo Teixeira de Sousa Junior 《Natural product research》2020,34(16):2389-2393
Abstract Long-term hyperglycemia maintenance is responsible for increased protein glycation and formation of advanced glycation end products (AGEs), both are associated with the onset of diabetes mellitus complications. Efforts have been made to discover new agents having antiglycation potential. The aim of this study was to investigate the effects of the hydroethanolic extract and the ethyl acetate and methanolic fractions of Simaba trichilioides roots on the formation of AGEs. In an in vitro model system of protein glycation, incubations with hydroethanolic extract, ethyl acetate or methanolic fractions of S. trichilioides decreased the fluorescent AGEs, and markers of tyrosine and tryptophan oxidation. Protein crosslinking was reduced in the presence of the ethyl acetate fraction of S. trichilioides. Simaba trichilioides roots seem to be a promising source of compounds having ability to prevent glycoxidation changes, with potential applications in complementary therapies for management of diabetic complications. 相似文献