33 research outputs found
Multi-environmental evaluation of wheat tetraploid genotypes for agronomic traits under rainfed conditions in Syria
This study was conducted at Homs, Al-Swaida and Tartous, General Commission for Scientific Agricultural Research, Syria during 2016/2017 season. Seven wheat genotypes were planted under rainfed conditions in randomized complete block design with three replications. Studied traits were days to maturity, plant height, number of grain per spike, grain weight per spike, 1000 kernal weight and grain yield per plant to evaluate variance between genotypes and locations. Results showed existence of high variance between studied genotypes in all traits especially plant height. It resulted that genotype W45193 was significantly superior in grain yield per plant with an increasing rate of 69.62% comparing to control Sham 5. Also, it was significantly superior in spike numbers with an increasing rate of 53.53%, 57.24% compared to both controls Sham 3 and Sham 5, respectively. Genotype W45064 was significantly superior in grain weight per spike and 1000 kernal weight compare to both controls Sham 3 and Sham 5. W 45194 was significantly superior in 1000 kernal weight comparing to control Sham 5 (36.34, 31.16 g), respectively. Furthermore, all studied traits (except spike number per plant) were more significant in Tartous compare to both Homs and Al-Swaida
Dielectric nanohole array metasurface for high-resolution near-field sensing and imaging
Dielectric metasurfaces support resonances that are widely explored both for far-field wavefront shaping and for near-field sensing and imaging. Their design explores the interplay between localised and extended resonances, with a typical trade-off between Q-factor and light localisation; high Q-factors are desirable for refractive index sensing while localisation is desirable for imaging resolution. Here, we show that a dielectric metasurface consisting of a nanohole array in amorphous silicon provides a favourable trade-off between these requirements. We have designed and realised the metasurface to support two optical modes both with sharp Fano resonances that exhibit relatively high Q-factors and strong spatial confinement, thereby concurrently optimizing the device for both imaging and biochemical sensing. For the sensing application, we demonstrate a limit of detection (LOD) as low as 1 pg/ml for Immunoglobulin G (IgG); for resonant imaging, we demonstrate a spatial resolution below 1 µm and clearly resolve individual E. coli bacteria. The combined low LOD and high spatial resolution opens new opportunities for extending cellular studies into the realm of microbiology, e.g. for studying antimicrobial susceptibility
Femtomolar detection of Cu2+ ions in solution using super-Nernstian FET-sensor with a lipid monolayer as top-gate dielectric
International audienceThe development of ions sensors with low limit of detection and high sensitivity and selectivity is required in many fields of application and still remains a challenge. We report on the first dual-gated field effect transistor sensor with an engineered lipid monolayer as top gate dielectric. The sensor was designed and fabricated for the specific detection of Cu 2+ using the Di-2-picolylamine as recognition unit. The lipid monolayer was reticulated to achieve high mechanical and dielectric stability over device operation. The resulting sensor exhibits exceptional performances with a limit of detection at 10 femtomolar, with a linear dependency over 10 decades and a super-Nernstian sensitivity of ~100 mV/decade. We also show that the lipid layer forms a good barrier to ions trapping, hence providing a high stability of the sensor over measurements
On miniaturization of efficient ultrawideband printed quazi-Yagi antenna array for indoor applications
International audienceThis paper describes the design and analysis of a compact and efficient ultrawideband unidirectional printed antenna array for indoor applications.A12.2×6.3×1 cm antenna array is capable of covering an ultra-wide frequency band starting from LTE up to Wi-MAX with an average gain approaching 5 dBi over the entire bandwidth. In comparison with the already existing antenna systems in the wireless market for similar purposes, the proposed antenna has considerably better performance and supplementary compactness, which makes it competitive among other antenna models. Simulation results have also shown low cross polarization levels, where the sidelobe level was also minimized by introducing a special reflecting element in the designed model. Adopting the proposed antenna in indoor communication systems would surely enhance the quality of signal within the covered area as well as minimize the number of access points needed for a given network. © 2017, Allerton Press, Inc
Diversity analysis and structural modeling for some traits in wheat genotypes
This investigation was carried out during 2018/2019 season in three locations Homs, Al-Swaida and Tartous belongs to the General Commission for Scientific Agricultural Research in Syria, using 17 Italian, Syrian and Ethiopian wheat genotypes to estimate the potential diversity by principle component and cluster analysis, and to study the structural modeling between grain yield and other traits to define best traits as predictors and selection indexes of grain yield, and to determine the superior genotypes in grain yield. Results indicated a remarkable variation of 74% due only to the first four principle components with Eigen value > 1. PC Biplot showed that Tartous was the best location, and the genotype SD09 was superior in grain yield per plant followed by SH5 and IP39. Structural modeling results revealed that the total and fertile tillers number per plant were the best predictors for grain yield per plant, while fertile tillers per plant with grain weight per spike could be used as selection indexes of wheat grain yield because they had positive strong direct effect on grain yield per plant. Cluster analysis results confirmed the need to assess more various genotypes from different origins
Subpicomolar Iron Sensing Platform Based on Functional Lipid Monolayer Microarrays
International audienceWe report herein the fabrication of novel micro-arrays based on air-stable functional lipid monolayers over silicon using a combination of e-beam lithography and lift-off. We demonstrate these microarrays can be use as ultrasensitive platform for Kelvin probe force microscopy in sensing experiments. Specificity of the detection is given by the functional group grafted at the lipid headgroup. The arrays developed for the detection of ferric ions, Fe3+, using a gamma-pyrone derivative chelator, demonstrate subpicomolar limit of detection with high specificity. In addition, the technique takes advantage of the structure of the array with the silicon areas playing the role of reference for the measurement, and we determine critical pattern dimensions below which the probe size/shape impacts the measured results
A 10-Omega High-Voltage Nanosecond Pulse Generator
Devices used for biological experiments on cell cultures can present a low impedance. In this paper, a numerical and experimental characterization of a high-voltage, nanosecond-pulse, 10-Omega generator is proposed. The generator makes use of a combination of microstrip-line technology and laser-triggered photoconductive semiconductor switches that operate in the linear regime. A standard electroporation cuvette is used to load the generator. SPICE and finite-difference time-domain (FDTD) models of the whole setup (i.e., the generator and the cuvette) are developed. Numerical characterization is performed comparing SPICE analysis and FDTD simulations. Experimental characterization on a built prototype is carried out by means of a wideband frequency voltage sensor. A good level of consistency is obtained between the numerical and the experimental voltage intensities measured across the cuvette electrodes
Characterization of a 50-Ω Exposure Setup for High-Voltage Nanosecond Pulsed Electric Field Bioexperiments
International audienceAn exposure system for a nanosecond pulsed electric field is presented and completely characterized in this paper. It is composed of a high-voltage generator and an applicator: the biological cuvette. The applied pulses have high intensities (up to 5 kV), short durations (3 and 10 ns), and different shapes (square, bipolar). A frequency characterization of the cuvette is carried out based on both an analytical model and experimental measurements (S11) in order to determine its matching bandwidth. High voltage measurements in the time domain are performed. Results show that the cuvette is well adapted to 10-ns pulses and limited to those of 3 ns. The rise/fall times of the pulses should not be less than 1.5 ns. In addition, numerical calculation providing voltage distribution within the cuvette is performed using an in-house finite-difference time-domain code. A good level of voltage homogeneity across the cuvette electrodes is obtained, as well as consistency with experimental data for all the applied pulses