BINA

SwissSPAD3 is the latest of a family of widefield time-gated SPAD imagers developed for fluorescence lifetime imaging (FLI) applications. Its distinctive features are (i) the ability to define shorter gates than its predecessors (width W < 1 ns), (ii) support for laser repetition rates up to at least 80 MHz and (iii) a dual-gate architecture providing an effective duty cycle of 100%. We present widefield macroscopic FLI measurements of short lifetime NIR dyes, analyzed using the phasor approach. The results are compared with those previously obtained with SwissSPAD2 and to theoretical predictions.

Cisplatin (CP) is the first-line standard of care for bladder cancer. However, a significant percentage of advanced bladder cancer patients are ineligible to receive standard CP treatment, due to the drug’s toxicity, and in particular its nephrotoxicity. These patients currently face suboptimal therapeutic options with lower efficacy. To overcome this limitation, here we designed CP-conjugated gold nanoparticles (GNPs) with specific properties that prevent renal toxicity, and concurrently preserve the therapeutic efficacy of CP. Safety and efficacy of the particles were studied in bladder tumor-bearing mice, using clinically-relevant fractionated or non-fractionated dosing regimens. A non-fractionated high dose of CP-GNP showed long-term intratumoral accumulation, blocked tumor growth, and nullified the lethal effect of CP. Treatment with fractionated lower doses of CP-GNP was also superior to an equivalent treatment with free CP, demonstrating both anti-tumor efficacy and prolonged mouse survival. Moreover, as opposed to free drug, CP-conjugated GNPs did not cause fibrosis or necrosis in kidney. These results indicate that conjugating CP to GNPs can serve as an effective, combined anti-cancer and renoprotective approach, and thus has potential to widen the range of patients eligible for CP-based therapy.

We demonstrate that the direction of current rectification via one of nature’s most efficient light-harvesting systems, the photosystem 1 complex (PS1), can be controlled by its orientation on Au substrates. Molecular self-assembly of the PS1 complex using four different linkers with distinct functional head groups that interact by electrostatic and hydrogen bonds with different surface parts of the entire protein PS1 complex was used to tailor the PS1 orientation. We observe an orientation-dependent rectification in the current–voltage characteristics for linker/PS1 molecule junctions. Results of an earlier study using a surface two-site PS1 mutant complex having its orientation set by covalent binding to the Au substrate supports our conclusion. Current–voltage–temperature measurements on the linker/PS1 complex indicate off-resonant tunneling as the main electron transport mechanism. Our ultraviolet photoemission …

Memristive devices based on correlated Mott materials have great potential for memory applications, and specifically neuromorphic computations, due to their simple structure, miniaturization capabilities, power efficiency, and operation speeds. For these reasons, many efforts are made to design improved synaptic devices based on Mott materials. This work demonstrates a nonvolatile memristive three-terminal transistor based on the correlated oxide , which has a (Mott) metal-insulator transition near room temperature. An ultrathin layer is incorporated in a metal-oxide-semiconductor field-effect geometry using alumina as the gate dielectric. A field effect is demonstrated to modify the channel’s resistance in a nonvolatile and reversible fashion. However, only when the gate voltage is applied at the metallic state of the does the resistance of the insulating state change. Thus, the metallic and insulating states …

The coherent dynamics in networks of coupled oscillators is of great interest in wave-physics since the coupling produces various dynamical effects, such as coherent energy exchange (beats) between the oscillators. However, it is common wisdom that these coherent dynamics are transients that quickly decay in active oscillators (e.g. lasers) since pump saturation causes mode competition that results, for homogeneous gain, in the prevalence of the single winning mode. We observe that pump saturation in coupled parametric oscillators counter-intuitively encourages the multi-mode dynamics of beating and indefinitely preserves it, despite the existence of mode competition. We explore in detail the coherent dynamics of a pair of coupled parametric oscillators with a shared pump and arbitrary coupling in a radio frequency (RF) experiment, as well as in simulation. Specifically, we realize two parametric oscillators as …

A novel technology for the precise fabrication of quartz resonators for MEMS applications is introduced. This approach is based on the laser-induced chemical etching of quartz. The main processing steps include femtosecond UV laser treatment of a Cr-Au-coated Z-cut alpha quartz wafer, followed by wet etching. The laser-patterned Cr-Au coating serves as an etch mask and is used to form electrodes for piezoelectric actuation. This fabrication approach does not alter the quartz’s crystalline structure or its piezo-electric properties. The formation of defects, which is common in laser micromachined quartz, is prevented by optimized process parameters and by controlling the temporal behavior of the laser-matter interactions. The process does not involve any lithography and allows for high geometric design flexibility. Several configurations of piezoelectrically actuated beam-type resonators were fabricated using …

Superhydrophobic surfaces are receiving increasing attention due to their real-world applications. However, these surfaces suffer from a lack of durability and complicated synthetic processes. This research uses a combination of a simple in-situ coating process between oxygen-activated polypropylene films and unreacted silane monomers. The in-situ process uses a modified Stöber method with the addition of the surfactant cetyltrimethylammonium bromide (CTAB) which aggregates silica (SiO 2) particles in a basic aqueous solution. This resulted in a layer of covalently bonded hierarchical coating of individual and aggregated SiO 2 “flakes” and particles. These coatings were found to have at least double the surface roughness than samples prepared without CTAB with superhydrophilic properties due to their high surface roughness and hydrophilic surface chemical groups. A second layer of fluorocarbon silane …

Due to their atomic-scale thickness, handling and processing of two-dimensional (2D) materials often require multistep techniques whose complexity hampers their large-scale integration in modern device applications. Here we demonstrate that the laser-induced forward transfer (LIFT) method can achieve the one-step, nondestructive printing of the prototypical 2D material MoS2. By selecting the optimal LIFT experimental conditions, we were able to transfer arrays of MoS2 pixels from a metal donor substrate to a dielectric receiver substrate. A combination of various characterization techniques has confirmed that the transfer of intact MoS2 monolayers is not only feasible, but it can also happen without incurring significant defect damage during the process. The successful transfer of MoS2 shows the broad potential the LIFT technique has in the emerging field of printed electronics, including printed devices based …

Cold atoms hold much promise for the realization of quantum technologies, but still encounter many challenges. In this work we show how the fundamental Casimir-Polder force, by which atoms are attracted to a surface, may be temporarily suppressed by utilizing a specially designed quantum potential, which is familiar from the hydrodynamic or Bohmian reformulations of quantum mechanics. We show that when harnessing the quantum potential via suitable atomic wave-packet engineering, the absorption by the surface can be dramatically reduced. As a result, the probing time of the atoms as sensors can increase. This is proven both analytically and numerically. Furthermore, an experimental scheme is proposed for achieving the required shape for the atomic wave packet. All these may assist existing applications of cold atoms in metrology and sensing and may also enable prospective ones. Finally, these …

Coupling electromagnetic radiation with matter, e.g., by resonant light fields in external optical cavities, is highly promising for tailoring the optoelectronic properties of functional materials on the nanoscale. Here, we demonstrate that even internal fields induced by coherent lattice motions can be used to control the transient excitonic optical response in CsPbBr3 halide perovskite crystals. Upon resonant photoexcitation, two-dimensional electronic spectroscopy reveals an excitonic peak structure oscillating persistently with a 100-fs period for up to ~2 ps which does not match the frequency of any phonon modes of the crystals. Only at later times, beyond 2 ps, two low-frequency phonons of the lead-bromide lattice dominate the dynamics. We rationalize these findings by an unusual exciton-phonon coupling inducing off-resonant 100-fs Rabi oscillations between 1s and 2p excitons driven by the low-frequency …

Cold atoms hold much promise for the realization of quantum technologies, but still encounter many challenges. In this work we show how the fundamental Casimir-Polder force, by which atoms are attracted to a surface, may be temporarily suppressed by utilizing a specially designed quantum potential, which is familiar from the hydrodynamic or Bohmian reformulations of quantum mechanics. We show that when harnessing the quantum potential via suitable atomic wave-packet engineering, the absorption by the surface can be dramatically reduced. As a result, the probing time of the atoms as sensors can increase. This is proven both analytically and numerically. Furthermore, an experimental scheme is proposed for achieving the required shape for the atomic wave packet. All these may assist existing applications of cold atoms in metrology and sensing and may also enable prospective ones. Finally, these …

Engines are systems and devices that convert one form of energy into another, typically into a more useful form that can perform work. In the classical setup, physical, chemical, and biological engines largely involve the conversion of heat into work. This energy conversion is at the core of thermodynamic laws and principles and is codified in textbook material. In the quantum regime, however, the principles of energy conversion become ambiguous, since quantum phenomena come into play. As with classical thermodynamics, fundamental principles can be explored through engines and refrigerators, but, in the quantum case, these devices are miniaturized and their operations involve uniquely quantum effects. Our work provides a broad overview of this active field of quantum engines and refrigerators, reviewing the latest theoretical proposals and experimental realizations. We cover myriad aspects of these devices, starting with the basic concepts of quantum analogs to the classical thermodynamic cycle and continuing with different quantum features of energy conversion that span many branches of quantum mechanics. These features include quantum fluctuations that become dominant in the microscale, non-thermal resources that fuel the engines, and the possibility of scaling up the working medium's size, to account for collective phenomena in many-body heat engines. Furthermore, we review studies of quantum engines operating in the strong system-bath coupling regime and those that include non-Markovian phenomena. Recent advances in thermoelectric devices and quantum information perspectives, including quantum measurement …

Classical first-passage times under restart are used in a wide variety of models, yet the quantum version of the problem still misses key concepts. We study the quantum hitting time with restart using a monitored quantum walk. The restart strategy eliminates the problem of dark states, ie, cases where the particle evades detection, while maintaining the ballistic propagation which is important for a fast search. We find profound effects of quantum oscillations on the restart problem, namely, a type of instability of the mean detection time, and optimal restart times that form staircases, with sudden drops as the rate of sampling is modified. In the absence of restart and in the Zeno limit, the detection of the walker is not possible, and we examine how restart overcomes this well-known problem, showing that the optimal restart time becomes insensitive to the sampling period.

Metal–sulfur batteries, especially lithium/sodium–sulfur (Li/Na-S) batteries, have attracted widespread attention for large-scale energy application due to their superior theoretical energy density, low cost of sulfur compared to conventional lithium-ion battery (LIBs) cathodes and environmental sustainability. Despite these advantages, metal–sulfur batteries face many fundamental challenges which have put them on the back foot. The use of ether-based liquid electrolyte has brought metal–sulfur batteries to a critical stage by causing intermediate polysulfide dissolution which results in poor cycling life and safety concerns. Replacement of the ether-based liquid electrolyte by a solid electrolyte (SEs) has overcome these challenges to a large extent. This review describes the recent development and progress of solid electrolytes for all-solid-state Li/Na-S batteries. This article begins with a basic introduction to metal–sulfur batteries and explains their challenges. We will discuss the drawbacks of the using liquid organic electrolytes and the advantages of replacing liquid electrolytes with solid electrolytes. This article will also explain the fundamental requirements of solid electrolytes in meeting the practical applications of all solid-state metal–sulfur batteries, as well as the electrode–electrolyte interfaces of all solid-state Li/Na-S batteries.

We study the motion of an overdamped particle connected to a thermal heat bath in the presence of an external periodic potential in one dimension. When we coarse-grain, ie, bin the particle positions using bin sizes that are larger than the periodicity of the potential, the packet of spreading particles, all starting from a common origin, converges to a normal distribution centered at the origin with a mean-squared displacement that grows as 2 D* t, with an effective diffusion constant that is smaller than that of a freely diffusing particle. We examine the interplay between this coarse-grained description and the fine structure of the density, which is given by the Boltzmann-Gibbs (BG) factor e− V (x)/k B T, the latter being nonnormalizable. We explain this result and construct a theory of observables using the Fokker-Planck equation. These observables are classified as those that are related to the BG fine structure, like the …

Bacillus cereus sensu lato (Bcsl) strains are widely explored due to their capacity to antagonize a broad range of plant pathogens. These include B. cereus sp. UW85, whose antagonistic capacity is attributed to the secondary metabolite Zwittermicin A (ZwA). We recently isolated four soil and root-associated Bcsl strains (MO2, S−10, S-25, LSTW-24) that displayed different growth profiles and in-vitro antagonistic effects against three soilborne plant pathogens models: Pythium aphanidermatum (oomycete) Rhizoctonia solani (basidiomycete), and Fusarium oxysporum (ascomycete). To identify genetic mechanisms potentially responsible for the differences in growth and antagonistic phenotypes of these Bcsl strains, we sequenced and compared their genomes, and that of strain UW85 using a hybrid sequencing pipeline. Despite similarities, specific Bcsl strains had unique secondary metabolite and chitinase-encoding genes that could potentially explain observed differences in in-vitro chitinolytic potential and anti-fungal activity. Strains UW85, S-10 and S-25 contained a (~500 Kbp) mega-plasmid that harbored the ZwA biosynthetic gene cluster. The UW85 mega-plasmid contained more ABC transporters than the other two strains, whereas the S-25 mega-plasmid carried a unique cluster containing cellulose and chitin degrading genes. Collectively, comparative genomics revealed several mechanisms that can potentially explain differences in in-vitro antagonism of Bcsl strains toward fungal plant pathogens.

Naive males court both virgin and mated females but learn through experience to discriminate between them, thus minimizing futile investments in nonreceptive female flies. In the laboratory, we can exploit the innate courtship enthusiasm of males and manipulate their behavior by placing them with a nonreceptive female (immature virgin females, decapitated mature virgin females, or mature mated females), termed as the courtship suppression/conditioning assay. Early studies showed that male flies that experience failure to mate upon interaction with nonreceptive previously mated females show decreased motivation to court (courtship suppression). Courtship suppression is an important experimental paradigm for studying genes and neuronal circuits that mediate short-and long-term memory. The anti-aphrodisiac male-specific pheromone 11-cis-vaccenyl-acetate plays a key role in this conditioned response, as …

As part of the performance characterization of a combined and enhanced new AFM-NSOM tip-photo-detector, diffraction limitations were studied on two complementary samples: a nano-barrier embedded between two nano-apertures and one nano-aperture embedded between two nano-barriers. These consecutive multiple-obstacle scanning paths are part of this challenging specifications study of a new conical-shaped and drilled tip-photodetector, sharing a subwavelength aperture. A super-resolution algorithm feature was added in order to overcome possible obstacles, while scanning the same object with several small angles. The new multi-mode system includes scanning topography, optical imaging and an obstacle-overcoming algorithm. The present article study emphasizes the complexity of nano-scanning multiple-apertures/barriers. Both complementary analytical (Python) and numerical (Comsol …

Courtship in Drosophila melanogaster involves a series of innate, complex behaviors that allow male and female flies to exchange sensory information and assess the quality of a potential mate. Although highly robust and stereotypical, courtship behaviors can be modulated by internal state and experience. This protocol describes methods for designing and carrying out experiments that measure courtship performance in single-pair assays, in which a male is paired with a female, or in competitive assays, in which a male is presented with a female and with a male competitor. It also includes approaches for measuring female sexual receptivity during courtship.

Coplanar microwave resonators made of NbN and YBa 2 Cu 3 O 7-δ show similar behavior under the influence of magnetic field. In particular, the two resonators exhibit marked difference between zero-field-cooled (ZFC) and field-cooled (FC) measurements, which is attributed to the presence of screening currents in ZFC but not in FC measurements.

The advancement of quantum computation is eager on generating fault tolerant qubits, and topological superconductivity is a very promising concept for reaching this goal. Early experimental achievements study hybrid systems as well as doped intrinsic topological or superconducting materials presenting the phenomena at very low temperatures. However, higher critical temperatures are indispensable for technological exploitation. Promising very recent angle-resolved photoemission spectroscopy results reveal that superconductivity of the type-I Weyl semimetal trigonal PtBi (t-PtBi) is located at the Fermi arcs surface states which renders t-PtBi a candidate for intrinsic topological superconductivity. Here we show, using scanning tunnelling microscopy and spectroscopy (STM/STS) that t-PtBi presents surface superconductivity at elevated temperatures (5 K). The gap magnitude is elusive: it is spatially inhomogeneous and spans from 0 to 20 meV. In particular, the large gap value and the shape of the quasiparticle excitation spectrum resemble the phenomenology of high-Tc superconductors. To our knowledge, this is the largest superconducting gap so far measured in a topological material. Moreover, we show that the superconducting state at 5 K persists up to 12 T magnetic field. Thus, we show that t-PtBi2 is a prime candidate for intrinsic topological superconductivity at technologically relevant temperatures, fields and gap magnitudes.