May 2021 • Science Bulletin
Sharon Shwartz
High-photon-energy electromagnetic radiations in the forms of X-rays and c-rays and particles such as neutrons and electrons are routinely used for various imaging and diffraction modalities with applications ranging from materials science and chemistry to biomedical imaging and industrial imaging. They provide important unique information on the structure and the functionality of the investigated samples that other methods cannot provide. However, despite the extensive efforts, there are several critical challenges that hamper further improvements in the performances of the modalities and thus limit the accessible information. Interestingly, while very different in the way high-photon-energy radiation and particles interact with the sample, imaging modalities that utilize them share similar challenges. Among the major challenges are damage to the sample when it is exposed to the probe beam and the limited resolution of the images (for electrons the resolution can be high but only for small samples). The origin of the damage is the large quanta of energy that is absorbed during the interaction between the probe and the sample. The resolution is limited since magnification and point-to-point imaging are very challenging with high energy photons and particles due to the limited available optics. For some applications, the sensitivity and the slow time response are also obstructive. Traditionally, two approaches for imaging have been utilized. In the first approach, a wide beam irradiates the sample, and a pixelated detector is mounted after the sample to measure the intensity distribution of the transmitted or scattered beam. In the second approach, a …
Show moreMay 2021
Nigel G Laing
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.
Show moreMay 2021 • Microscopy Research and Technique
Ilya Olevsko, Kaitlin Szederkenyi, Jennifer Corridon, Aaron Au, Brigitte Delhomme, Thierry Bastien, Julien Fernandes, Christopher Yip, Martin Oheim, Adi Salomon
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 …
Show moreMay 2021 • Nanophotonics
Adi Salomon, Heiko Kollmann, Manfred Mascheck, Slawa Schmidt, Yehiam Prior, Christoph Lienau, Martin Silies
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 …
Show moreMay 2021 • OSA Continuum
Dana Gotthilf-Nezri, Yoram S Bonneh, Zeev Zalevsky
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 …
Show moreMay 2021 • CLEO: QELS_Fundamental Science, FF2I. 4, 2021
Alexey Gorlach, Aviv Karnieli, Raphael Dahan, Eliahu Cohen, Avi Pe’er, Ido Kaminer
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.
Show moreMay 2021 • Science Bulletin
Sharon Shwartz
High-photon-energy electromagnetic radiations in the forms of X-rays and c-rays and particles such as neutrons and electrons are routinely used for various imaging and diffraction modalities with applications ranging from materials science and chemistry to biomedical imaging and industrial imaging. They provide important unique information on the structure and the functionality of the investigated samples that other methods cannot provide. However, despite the extensive efforts, there are several critical challenges that hamper further improvements in the performances of the modalities and thus limit the accessible information. Interestingly, while very different in the way high-photon-energy radiation and particles interact with the sample, imaging modalities that utilize them share similar challenges. Among the major challenges are damage to the sample when it is exposed to the probe beam and the limited resolution of the images (for electrons the resolution can be high but only for small samples). The origin of the damage is the large quanta of energy that is absorbed during the interaction between the probe and the sample. The resolution is limited since magnification and point-to-point imaging are very challenging with high energy photons and particles due to the limited available optics. For some applications, the sensitivity and the slow time response are also obstructive. Traditionally, two approaches for imaging have been utilized. In the first approach, a wide beam irradiates the sample, and a pixelated detector is mounted after the sample to measure the intensity distribution of the transmitted or scattered beam. In the second approach, a …
Show moreMay 2021 • Journal of Solid State Electrochemistry
Tirupathi Rao Penki, Sapir Gilady, Prasant Kumar Nayak, Hadar Sclar, Yuval Elias, Judith Grinblat, Michael Talianker, Boris Markovsky, Christoph Erk, Shalom Luski, Doron Aurbach
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 …
Show moreMay 2021 • CLEO: Science and Innovations, STh4J. 4, 2021
Amirhassan Shams-Ansari, Guanhao Huang, Lingyan He, Mikhail Churaev, Prashanta Kharel, Zelin Tan, Jeffrey Holzgrafe, Rebecca Cheng, Di Zhu, Junqiu Liu, Boris Desiatov, Mian Zhang, Tobias J Kippenberg, Marko Lončar
We measured the absorption-limited loss at telecommunication wavelengths for thin-film lithium niobate micro-ring resonators using Kerr-calibrated linear response technique. We find the average absorption loss-rate κ abs/2π to be 3.65±0.70 MHz, corresponding to a Q-factor of 55 Million.
Show moreMay 2021 • Entropy
Felix Thiel, Itay Mualem, David Kessler, Eli Barkai
A classical random walker starting on a node of a finite graph will always reach any other node since the search is ergodic, namely it fully explores space, hence the arrival probability is unity. For quantum walks, destructive interference may induce effectively non-ergodic features in such search processes. Under repeated projective local measurements, made on a target state, the final detection of the system is not guaranteed since the Hilbert space is split into a bright subspace and an orthogonal dark one. Using this we find an uncertainty relation for the deviations of the detection probability from its classical counterpart, in terms of the energy fluctuations. View Full-Text
Show moreMay 2021 • ACS applied materials & interfaces
Yael N Slavin, Kristina Ivanova, Javier Hoyo, Ilana Perelshtein, Gethin Owen, Anne Haegert, Yen-Yi Lin, Stephane LeBihan, Aharon Gedanken, Urs O Häfeli, Tzanko Tzanov, Horacio Bach
The emergence of bacteria resistant to antibiotics and the resulting infections are increasingly becoming a public health issue. Multidrug-resistant (MDR) bacteria are responsible for infections leading to increased morbidity and mortality in hospitals, prolonged time of hospitalization, and additional burden to financial costs. Therefore, there is an urgent need for novel antibacterial agents that will both treat MDR infections and outsmart the bacterial evolutionary mechanisms, preventing further resistance development. In this study, a green synthesis employing nontoxic lignin as both reducing and capping agents was adopted to formulate stable and biocompatible silver–lignin nanoparticles (NPs) exhibiting antibacterial activity. The resulting silver–lignin NPs were approximately 20 nm in diameter and did not agglomerate after one year of storage at 4 °C. They were able to inhibit the growth of a panel of MDR clinical …
Show moreMay 2021 • Nature communications
Ido Amit, Ortal Iancu, Alona Levy-Jurgenson, Gavin Kurgan, Matthew S McNeill, Garrett R Rettig, Daniel Allen, Dor Breier, Nimrod Ben Haim, Yu Wang, Leon Anavy, Ayal Hendel, Zohar Yakhini
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 …
Show moreMay 2021 • Journal of chemical information and modeling
Shani Zev, Keren Raz, Renana Schwartz, Reem Tarabeh, Prashant Kumar Gupta, Dan T Major
The coronavirus SARS-CoV-2 main protease, Mpro, is conserved among coronaviruses with no human homolog and has therefore attracted significant attention as an enzyme drug target for COVID-19. The number of studies targeting Mpro for in silico screening has grown rapidly, and it would be of great interest to know in advance how well docking methods can reproduce the correct ligand binding modes and rank these correctly. Clearly, current attempts at designing drugs targeting Mpro with the aid of computational docking would benefit from a priori knowledge of the ability of docking programs to predict correct binding modes and score these correctly. In the current work, we tested the ability of several leading docking programs, namely, Glide, DOCK, AutoDock, AutoDock Vina, FRED, and EnzyDock, to correctly identify and score the binding mode of Mpro ligands in 193 crystal structures. None of the codes …
Show moreMay 2021 • Advanced Functional Materials
Merav Antman‐Passig, Jonathan Giron, Moshe Karni, Menachem Motiei, Hadas Schori, Orit Shefi
Nerve growth conduits are designed to support and promote axon regeneration following nerve injuries. Multifunctionalized conduits with combined physical and chemical cues, are a promising avenue aimed at overcoming current therapeutic barriers. However, the efficacious assembly of conduits that promote neuronal growth remains a challenge. Here, a biomimetic regenerative gel is developed, that integrates physical and chemical cues in a biocompatible “one pot reaction” strategy. The collagen gel is enriched with magnetic nanoparticles coated with nerve growth factor (NGF). Then, through a remote magnetic actuation, highly aligned fibrillar gel structure embedded with anisotropically distributed coated nanoparticles, combining multiple regenerating strategies, is obtained. The effects of the multifunctional gels are examined in vitro, and in vivo in a 10‐mm rat sciatic nerve injury model. The magneto‐based …
Show moreMay 2021
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
Show moreMay 2021 • Molecules
Elena Levi, Doron Aurbach, Carlo Gatti
Most of TM6-cluster compounds (TM = transition metal) are soluble in polar solvents, in which the cluster units commonly remain intact, preserving the same atomic arrangement as in solids. Consequently, the redox potential is often used to characterize structural and electronic features of respective solids. Although a high lability and variety of ligands allow for tuning of redox potential and of the related spectroscopic properties in wide ranges, the mechanism of this tuning is still unclear. Crystal chemistry approach was applied for the first time to clarify this mechanism. It was shown that there are two factors affecting redox potential of a given metal couple: Lever’s electrochemical parameters of the ligands and the effective ionic charge of TM, which in cluster compounds differs effectively from the formal value due to the bond strains around TM atoms. Calculations of the effective ionic charge of TMs were performed in the framework of bond valence model, which relates the valence of a bond to its length by simple Pauling relationship. It was also shown that due to the bond strains the charge depends mainly on the atomic size of the inner ligands.
Show moreMay 2021 • Neuro-oncology
Farshad Nassiri, Justin Z Wang, Olivia Singh, Shirin Karimi, Tatyana Dalcourt, Nazanin Ijad, Neda Pirouzmand, Ho-Keung Ng, Andrea Saladino, Bianca Pollo, Francesco Dimeco, Stephen Yip, Andrew Gao, Kenneth Aldape, Gelareh Zadeh
Background There is a critical need for objective and reliable biomarkers of outcome in meningiomas beyond WHO classification. Loss of H3K27me3 has been reported as a prognostically unfavorable alteration in meningiomas. We sought to independently evaluate the reproducibility and prognostic value of H3K27me3 loss by immunohistochemistry (IHC) in a multicenter study. Methods IHC staining for H3K27me3 and analyses of whole slides from 181 meningiomas across three centers was performed. Staining was analyzed by dichotomization into loss and retained immunoreactivity, and using a 3-tiered scoring system in 151 cases with clear staining. Associations of grouping with outcome were performed using Kaplan-Meier survival estimates. Results A total of 21 of 151 tumors (13.9%) demonstrated complete loss of H3K27me3 staining in tumor with …
Show moreMay 2021 • Light: Science & Applications
Enrico Rebufello, Fabrizio Piacentini, Alessio Avella, Muriel A de Souza, Marco Gramegna, Jan Dziewior, Eliahu Cohen, Lev Vaidman, Ivo Pietro Degiovanni, Marco Genovese
Is it possible that a measurement of a spin component of a spin-1/2 particle yields the value 100? In 1988 Aharonov, Albert and Vaidman argued that upon pre-and postselection of particular spin states, weakening the coupling of a standard measurement procedure ensures this paradoxical result 1. This theoretical prediction, called weak value, was realised in numerous experiments 2, 3, 4, 5, 6, 7, 8, 9, but its meaning remains very controversial 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, since its “anomalous” nature, ie, the possibility to exceed the eigenvalue spectrum, as well as its “quantumness” are debated 20, 21, 22. We address these questions by presenting the first experiment measuring anomalous weak values with just a single click, without the need for statistical averaging. The measurement uncertainty is significantly smaller than the gap between the measured weak value and the nearest eigenvalue. Beyond …
Show moreMay 2021 • ACS Applied Materials & Interfaces
Milena Perovic, Sapir Shekef Aloni, Wuyong Zhang, Yitzhak Mastai, Markus Antonietti, Martin Oschatz
Chiral separation and asymmetric synthesis and catalysis are crucial processes for obtaining enantiopure compounds, which are especially important in the pharmaceutical industry. The efficiency of the separation processes is readily increased by using porous materials as the active material can interact with a larger surface area. Silica, metal–organic frameworks, or chiral polymers are versatile porous materials that are established in chiral applications, but their instability under certain conditions in some cases requires the use of more stable porous materials such as carbons. In addition to their stability, porous carbon materials can be tailored for their ability to adsorb and catalytically activate different chemical compounds from the liquid and the gas phase. The difficulties imposed by the functionalization of carbons with chiral species were tackled in the past by carbonizing chiral ionic liquids (CILs) together with a …
Show moreMay 2021 • Nanophotonics
Adi Salomon, Heiko Kollmann, Manfred Mascheck, Slawa Schmidt, Yehiam Prior, Christoph Lienau, Martin Silies
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 …
Show moreMay 2021 • Journal of The Electrochemical Society
David Malka, Shaul Bublil, Ran Attias, Michal Weitman, Reut Cohen, Yuval Elias, Yosef Gofer, Thierry Brousse, Doron Aurbach
The specific capacity of activated carbon electrodes for supercapacitors may be enhanced with additional faradaic redox reactions by grafting of electroactive aromatic molecules with heteroatoms that act as redox centers. Such enrichment was demonstrated recently with anthraquinone and catechol using diazonium chemistry. Here, trihydroxybenzene, which has obvious advantages, was successfully grafted, yielding a mass enrichment of 25%. Electrochemical characterization in acidic aqueous solution after in situ methoxy deprotection demonstrated an initial specific capacity of 65 mAh g− 1, which faded only slightly to 55 mAh g− 1 after about 2000 cycles and remained stable for over 4500 cycles.
Show more