BINA

The processing of analog microwave-frequency signals using optical means becomes increasingly important as part of advanced cellular networks. Chip-level integration of microwave photonic filters, particularly in silicon, is considered necessary for their large-scale deployment. Discrete-time, delay-and-sum filters are widely used to select narrow spectral bands out of broad optical bandwidths. However, the long delays that are required to obtain narrowband filters are difficult to accommodate in integrated optic waveguide paths. In this work, we report discrete-time, integrated microwave photonic filters on standard silicon-on-insulator. Long delays are realized through the conversion of incoming radio-frequency modulation to the form of slow-moving surface acoustic waves. Conversion relies on thermo-elastic expansion of metallic gratings and does not involve piezoelectricity. Information is recovered in the …

Inter-polarization forward stimulated Brillouin scattering is studied in standard, polarization maintaining fibers. The process is driven by two orthogonally polarized pump tones. The stimulated acoustic waves induce non-reciprocal polarization switching of optical probe fields.

Fluorescence standards allow for quality control and for the comparison of data sets across instruments and laboratories in applications of quantitative fluorescence. For example, users of microscopy core facilities can expect a homogenous and time‐invariant illumination and an uniform detection sensitivity, which are prerequisites for imaging analysis, tracking or fluorimetric pH or Ca2+‐concentration measurements. Similarly, confirming the three‐dimensional (3‐D) resolution of optical sectioning microscopes calls for a regular calibration with a standardized point source. The test samples required for such measurements are typically different ones, they are often expensive and they depend much on the very microscope technique used. Similarly, the ever‐increasing choice among microscope techniques and geometries increases the demand for comparison across instruments. Here, we advocate and …

We demonstrate that free electrons can be used as ultrafast non-destructive photon detectors. Particularly, we show how one can measure photon statistics, temporal coherence, and implement full quantum state tomography using free electrons.

In this research we present a basis for a solution for Age Related Macular Degeneration (AMD) patients. The proposed solution is a binocular passive optical device composed of a contact lens and spectacles, both coated by light-reflecting material in order to generate a Fabry-Perot-like resonator. This bounces the light rays several times between the two surfaces, achieving optical simultaneous magnifications for near and far distances as needed for AMD patients in early stages of the disease. Our work has two parts: numerical simulation of the magnification achieved by the device and a clinical experiment, with non-AMD patients, in which we examined visual skills with simultaneous magnifications. The numerical simulations proved mathematically that the device can produce several different magnifications simultaneously, Zemax simulations confirmed this. In the clinical study, simultaneous vision was found to …

Integrated, discrete time microwave filters are realized in surface acoustic wave photonics over standard silicon on insulator. The magnitude and phase of each tap are adjusted independently. Twelve-tap filters with 5 MHz bandwidth are demonstrated.

A central issue in protein electronics is how far the structural stability of the protein is preserved under the very high electrical field that it will experience once a bias voltage is applied. This question is studied on the redox protein Azurin in the solid‐state Au/protein/Au junction by monitoring protein vibrations during current transport under applied bias, up to ≈1 GV m−1, by electrical detection of inelastic electron transport effects. Characteristic vibrational modes, such as CH stretching, amide (NH) bending, and AuS (of the bonds that connect the protein to an Au electrode), are not found to change noticeably up to 1.0 V. At >1.0 V, the NH bending and CH stretching inelastic features have disappeared, while the AuS features persist till ≈2 V, i.e., the proteins remain Au bound. Three possible causes for the disappearance of the NH and CH inelastic features at high bias, namely, i) resonance transport, ii …

Platinum group metal (PGM)-free catalysts for oxygen reduction reaction (ORR) have shown high oxygen reduction reaction activity in alkaline media. In order to reduce the overpotential losses in anion-exchange membrane fuel cells (AEMFCs), PGM-free catalysts need to have a high site density to compensate for their which will enable reaching high cell current and power densities. Herein, we will present our work on the synthesis, characterization, and utilization of heat-treated iron porphyrin aerogels as cathode catalysts in AEMFCs. The heat treatment effect was thoroughly studied using several techniques, and the best performing aerogel was showing an excellent performance in AEMFCs, reaching a peak power density of 580 mW cm-2 and a limiting current density of as high as 2.0 A cm-2, which can be considered as the state-of-the-art for PGM-free based AEMFCs.

The rise in interest in fuel cells’ technologies increased the number of researchers and publications in the field. The ultimate test of new materials in a lab setup would be in a membrane electrode assembly (MEA), operating under realistic operating conditions (temperature, backpressure, humidity, etc.). The fabrication of the MEA for polymer electrolyte fuel cells (PEFC) is known to greatly affect their performance. Although several good studies were conducted on different parameters in the MEA fabrication, mostly one at a time, there is no comprehensive work on all of the critical parameters required to optimize the fabrication procedure for high performance in one study. Since one parameter may affect another, it is important to optimize all of them together. In addition, the availability of commercial membranes, gas diffusion layers, ionomers and catalysts is constantly changing, and calling for revision of fabrication …

The gene, and its protein product, in a serious inherited muscle disease was first identified in the case of Duchenne muscular dystrophy some twenty years ago. Dystrophin turned out to be a sarcolemmal protein. This was somewhat of a surprise because many had harboured the view up until then that most muscle diseases, if not all, might be due to defects in the sarcomere itself. After all this was the site of muscle contraction. However many other muscular dystrophies have subsequently been shown to be due to defects in various other sarcolemma-associated proteins. 1The structure of the sarcomere itself has been studied and known for many years. 2 But only in more recent times has the role of its structural and contractile proteins been detailed in specific muscle diseases. The cytoskeleton is held together by filamentous proteins, such as a-actinin and desmin, and the microtubular protein tubulin. Other proteins are nebulin and telethonin and the elastic element titin. Finally there are the contractile proteins troponin, tropomyosin, actin and myosin. Here experts in the field describe a variety of diseases associated with defects in these sarcomeric proteins often first suspected because of a pronounced accumulation of the relevant protein in the muscle tissue.

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) 2017-05-16

Localized surface plasmon resonances of individual sub-wavelength cavities milled in metallic films can couple to each other to form a collective behavior. This coupling leads to a delocalization of the plasmon field at the film surface and drastically alters both the linear and nonlinear optical properties of the sample. In periodic arrays of nanocavities, the coupling results in the formation of propagating surface plasmon polaritons (SPP), eigenmodes extending across the array. When artificially introducing dislocations, defects and imperfections, multiple scattering of these SPP modes can lead to hot-spot formation, intense and spatially confined fluctuations of the local plasmonic field within the array. Here, we study the underlying coupling effects by probing plasmonic modes in well-defined individual triangular dimer cavities and in arrays of triangular cavities with and without artificial defects. Nonlinear confocal …

Controlling off-target editing activity is one of the central challenges in making CRISPR technology accurate and applicable in medical practice. Current algorithms for analyzing off-target activity do not provide statistical quantification, are not sufficiently sensitive in separating signal from noise in experiments with low editing rates, and do not address the detection of translocations. Here we present CRISPECTOR, a software tool that supports the detection and quantification of on-and off-target genome-editing activity from NGS data using paired treatment/control CRISPR experiments. In particular, CRISPECTOR facilitates the statistical analysis of NGS data from multiplex-PCR comparative experiments to detect and quantify adverse translocation events. We validate the observed results and show independent evidence of the occurrence of translocations in human cell lines, after genome editing. Our methodology is …

Aqueous salt batteries with high concentrations of salt or water in salt aqueous systems have received considerable attention with focus on improving working voltage range and energy density. Here, the effect of NaClO4 salt concentration on the electrochemical performance and stability of tunnel-type Na0. 44MnO2 (NMO) cathodes and organic polyimide (PI) derivative anodes was studied. High capacity retention and 100% coulombic efficiency were shown for NMO/PI full cell in saturated NaClO4 electrolyte. A high, stable capacity of 115 mAh/g was achieved for the PI anode material, and the full cell showed a stable capacity of 41 mAh/g at 2C rate for 430 cycles (calculated for the weight of NMO cathode). Even at a fast 5C rate, a discharge capacity of 33 mAh/g was maintained for 2,400 prolonged cycles with nearly 100% efficiency. The full cell device can achieve an average voltage of 1 V with energy density of 24 Wh/kg. This study highlights concentrated sodium perchlorate as a promising electrolyte solution for stabilization enhancement of electrochemical performance in aqueous media. of electrodes and

Among the cathode materials for advanced Li-ion batteries, nickel-rich Ni-Co-Mn (NCM) LiNi x Co y Mn y O 2 (x> 0.5, x+ 2y= 1) attracts great interest as promising materials owing to their high capacity, low cost, good cycling stability, safety and the fact that their stable capacity can be extracted by charging up to 4.3 V vs. Li. In this work, the effect of the synthesis route—freeze-drying, self-combustion, solid state and co-precipitation on the performance of NCM622 (LiNi x Co y Mn y O 2, x= 0.6, y= 0.2) cathodes—in Li cells was thoroughly studied. The material prepared by freeze-drying exhibited superior electrochemical properties. The effect of in situ and ex situ Zr 4+ cations doping on the electrodes’ capacity, stability and average voltage was also studied. Doping via a top–down, ex situ mode improved the performance in terms of capacity stabilization, whereas electrodes comprising materials that were doped via a …

The characteristics of RNA editing, including the lower risk compared with genome editing, may loosen the ethical barriers that are currently imposed on genetic engineering, thus opening new possibilities for research, therapy, and human enhancement. We should start considering the future ethical and social implications of this new and promising technology.

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) 2015-04-06

Employing organic redox mediators (ORMs) as mobile catalyst into the electrolyte system has been selected as an important strategy to lower the charging overpotentials in lithium-oxygen (Li-O2) batteries. Careful choice of molecular designs of ORMs can also tailor their redox potential and rate of electron-transfer to improve the catalytic efficiency. However, the stability of ORMs in Li–O2 cells was scarcely studied. In here, catalytic efficiency and stability of several important ORMs are assessed through in situ gas analysis and reactivity tests with singlet oxygen. Some well-known ORMs are detrimentally decomposed during the first cycle in Li–O2 cells, whereas nitroxyl-radical-based ORMs bear the most stable and efficient response. Analogous nitroxyl-radical derivatives further increase round-trip energy efficiency and electron-transfer kinetics. This study also emphasizes the evaluation of chemical stability of …

Among the cathode materials for advanced Li-ion batteries, nickel-rich Ni-Co-Mn (NCM) LiNi x Co y Mn y O 2 (x> 0.5, x+ 2y= 1) attracts great interest as promising materials owing to their high capacity, low cost, good cycling stability, safety and the fact that their stable capacity can be extracted by charging up to 4.3 V vs. Li. In this work, the effect of the synthesis route—freeze-drying, self-combustion, solid state and co-precipitation on the performance of NCM622 (LiNi x Co y Mn y O 2, x= 0.6, y= 0.2) cathodes—in Li cells was thoroughly studied. The material prepared by freeze-drying exhibited superior electrochemical properties. The effect of in situ and ex situ Zr 4+ cations doping on the electrodes’ capacity, stability and average voltage was also studied. Doping via a top–down, ex situ mode improved the performance in terms of capacity stabilization, whereas electrodes comprising materials that were doped via a …

We report a proof of principle experiment demonstrating the use of structured illumination and coincidence for x-ray fluorescence imaging at very high spatial resolution and short measurement time with a conventional x-ray tube.

We demonstrate efficient interaction of hard x-ray single photons with a beam splitter for the first time and use it to show the nonclassical behavior of x-ray heralded photons.