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1.
Opt Lett ; 41(21): 4867-4870, 2016 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-27805637

RESUMO

We present, to the best of our knowledge, the first experimental investigation of a two-dimensional disk resonator on a dielectric multilayer platform sustaining Bloch surface waves. The disk resonator has been patterned into a few tens of nanometer thin (∼λ/25) titanium dioxide layer deposited on the top of the platform. We characterize the disk resonator by multi-heterodyne scanning near-field optical microscopy. The low loss characteristics of Bloch surface waves allowed us to reach a measured quality factor of 2×103 for a disk radius of 100 µm.

2.
Opt Express ; 18(7): 6530-6, 2010 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-20389676

RESUMO

We propose and theoretically study a metallo-dielectric photonic crystal (MDPhC) based on metallic annular aperture arrays (AAA) associated to a nonlinear material (LiNbO(3)) for the second harmonic generation (SHG). An optimal structure design can be found thanks to the relations that link the geometrical parameters to the operating point namely the wavelength of the fundamental and SHG signals. A slow light phenomenon, which occurs at the cut-off frequency of the guided mode through the annular cavities, is at the origin of the SHG signal enhancement. The benefit of the AAA is demonstrated through a comparison with cylindrical aperture arrays.

3.
Nat Prod Commun ; 11(4): 535-8, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27396212

RESUMO

The aim of this work was to determine the composition of the hydro-distilled essential oil of Salvia judaica Boiss. and S. multicaulis Vahl. (Lamiaceae) from Jordan by GC and GC-MS and to report the actual composition of their fresh leaves and flowers using SPME (Solid Phase Micro-Extraction).Their dual alpha-amylase/alpha glucosidase and pancreatic lipase inhibitory activities as well as their anti-proliferative potential were screened. The aroma profile of the leaves, flowers, and flowers at pre-flowering stages of S. judaica, obtained through SPME was composed of sesquiterpene hydrocarbons (87.7 %, 71.8 %, and 86.2 %, respectively) while the hydro-distilled oil of the dry leaves was rich in oxygenated sesquiterpenes (50.8%). Fresh leaves of S. multicaulis were rich in oxygenated monoterpenes (58.1%), while monoterpene hydrocarbons dominated the blooming flowers (57.2%) and the flowers at the pre-flowering stage (64.7%). The hydro-distilled oil of the dry leaves was rich in oxygenated monoterpenes (77.6%). With doxorubicin as a positive control, no anti-proliferative activity was observed against colorectal cancer cell lines HT29, HCT116, and SW620 using SRB assay for either Salvia spp. In vitro enzymatic starch digestion was evaluated with Acarbose (IC50: 0.2 ± 0.0 µg /mL) as the reference drug. The respective IC50 (mg/mL) values of S. judaica and S. multicaulis aqueous extracts were 4.9 ± 0.4 and 10.3 ± 0.9. Modulation of pancreatic lipase activity (PL) was determined by colorimetry and compared with Orlistat (IC50 : 0.11 ± 0.0 µg/mL). PL-IC50 values (µg/mL) obtained for S. judaica and S. multicaulis were 108.5±6.4 and 31.8 ± 0.8, respectively.


Assuntos
Óleos Voláteis/química , Salvia/química , Ensaios de Seleção de Medicamentos Antitumorais , Células HCT116 , Células HT29 , Humanos , Jordânia , Lipase/antagonistas & inibidores
4.
Nat Prod Res ; 29(10): 893-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25190268

RESUMO

Inula graveolens is a poisonous annual plant of Mediterranean origin. The invasive nature of the plant suggests that it may possess phytotoxic activity. The aim of this study was to assess the ability of I. graveolens to inhibit the growth of different plants in Petri dish and to identify the main bioactive compounds. Bio-guided fractionation of the plant extracts led to the isolation of 2,3,11ß,13-tetrahydroaromaticin (THA) and ilicic acid. Both compounds showed selective and significant phytotoxic activity at 25 ppm. Root length of barley, oat, millet, tuberous canary grass and lentils were significantly reduced by 25 ppm of THA, while the root of cauliflower, cress and radish were similarly reduced by ilicic acid at 25 ppm. The structure of each compound was elucidated by using NMR and HR-MS. X-ray crystallography of THA is reported for the first time to confirm the relative stereochemistry of the compound.


Assuntos
Herbicidas/química , Inula/química , Raízes de Plantas/efeitos dos fármacos , Sesquiterpenos/química , Cristalografia por Raios X , Herbicidas/isolamento & purificação , Espectroscopia de Ressonância Magnética , Extratos Vegetais/química , Sesquiterpenos/isolamento & purificação
5.
Nat Prod Res ; 29(2): 102-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25226348

RESUMO

Three new seco-ursadiene triterpenoids 1-3 together with 11 known compounds were isolated from Salvia syriaca of Jordanian origin. The compounds were identified by using NMR spectroscopy including extensive 2D NMR experiments and mass spectrometry. The structure of compound 3 was confirmed by X-ray crystallography, and the information thus obtained was used to confirm the stereochemistry of compounds 1 and 2. This is the second report of 17,22-seco-17(28),12-ursadien-22-oic acids.


Assuntos
Salvia/química , Triterpenos/química , Cristalografia por Raios X , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Triterpenos/isolamento & purificação
6.
J Ethnopharmacol ; 89(2-3): 193-7, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-14611882

RESUMO

To assess the current situation of sales and uses of herbal medicines in Jordan, more than 100 herbalists throughout the country were interviewed. The collected data included the types of herbs present in the market, the recommendations made by the herbalists in the treatment of ailments, the level of education and training of the herbalists, and miscellaneous observations. One hundred and fifty medicinal plant species were present in the local market. Based on their availability in the market and on the herbalists' recommendations, 9 plant species were considered very common and 17 were considered as common. The survey indicated that most of the herbalists were not educated or trained in the field of herbal medicine except for their expertise gained from their predecessor, none were licensed for this particular purpose; several odd or unprecedented recommendations were passed to the customers. This survey emphasizes the necessity of proper handling of herbal medicines that requires proper regulations and licensing.


Assuntos
Fitoterapia , Plantas Medicinais , Coleta de Dados , Jordânia , Medicina Tradicional , Preparações de Plantas/uso terapêutico , Estruturas Vegetais/química
7.
Micron ; 41(7): 742-5, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20630768

RESUMO

This paper presents a theoretical study showing the mechanism of light transmission through opaque metallic films perforated with nanocoaxial apertures thanks to the excitation of their cutoff-free TEM (Transverse ElectroMagnetic) guided mode. Full three-dimensional Finite Difference Time Domain (3D-FDTD) together with a Body-Of-Revolution FDTD simulation results are presented and discussed in order to optimize this extraordinary transmission. Very promising findings are pointed out opening the path to the design of new devices for both nano-optic and photovoltaic applications.

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