BINA

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 …

In the last few decades, point-of-care (POC) sensors have become increasingly important in the detection of various targets for the early diagnostics and treatment of diseases. Diverse nanomaterials are used as building blocks for the development of smart biosensors and magnetite nanoparticles (MNPs) are among them. The intrinsic properties of MNPs, such as their large surface area, chemical stability, ease of functionalization, high saturation magnetization, and more, mean they have great potential for use in biosensors. Moreover, the unique characteristics of MNPs, such as their response to external magnetic fields, allow them to be easily manipulated (concentrated and redispersed) in fluidic media. As they are functionalized with biomolecules, MNPs bear high sensitivity and selectivity towards the detection of target biomolecules, which means they are advantageous in biosensor development and lead to a more sensitive, rapid, and accurate identification and quantification of target analytes. Due to the abovementioned properties of functionalized MNPs and their unique magnetic characteristics, they could be employed in the creation of new POC devices, molecular logic gates, and new biomolecular-based biocomputing interfaces, which would build on new ideas and principles. The current review outlines the synthesis, surface coverage, and functionalization of MNPs, as well as recent advancements in magnetite-based biosensors for POC diagnostics and some perspectives in molecular logic, and it also contains some of our own results regarding the topic, which include synthetic MNPs, their application for sample preparation, and the …

The advent of functional devices based on two-dimensional (2D) materials has further intensified the interest in the latter. However, the fabrication of structures using layered materials remains a key challenge. Recently, we proposed the so-called “Laser-Induced Transfer” method (LIT), as a digital and solvent-free approach for the high-resolution and intact transfer of 2D materials’ pixels. Here, we will further highlight the versatility of LIT by reporting results on the high-quality digital transfer of graphene and MoS2. These materials have emerged in the field of nanoelectronics, sensors and photonics due to their unique optoelectronic properties, but their high-quality transfer remains a hurdle. The quality of the transferred films has been confirmed with systematic characterization based on Scanning Electron Microscopy and Raman spectroscopy, as well as mobility’s extraction. Then we will present how the laser …

All‐solid‐state lithium batteries (ASSLBs) are considered as an alternative solution to lithium‐ion batteries, because of their safety and high theoretical energy density. Argyrodite‐based solid‐electrolytes (SEs), Li6PS5X (X = Cl, Cl0.5Br0.5 or Br), are promising candidates for ASSLBs. Most of the previous reports have used Li6PS5Cl as the default SE composition. Here, the electrochemical behavior of three different argyrodites with Cl− or Br−, or both, as the halogen is systematically studied. Using LiNi0.6Co0.2Mn0.2O2 as a model cathode, the behavior of these SEs in ASSLB cells is also studied. SEs containing Br show higher near‐room‐temperature ionic conductivity (>2 mS cm−1) and the critical current density (≥1 mA cm−2) during Li plating/stripping, and are stable up to 5 V versus Li/Li+. Li6PS5Br gives the best electrochemical performance in terms of C‐rate and long‐term cycling among the three …

Corrosion resistance, porous structure and high surface area are becoming more and more significant as electrode properties in long-term operation of polymer electrolyte membrane fuel cell. In this work, high surface area, porous titanium-based ceramic compound was synthesized via the facile modified urea glass method (mUGM) and utilized as electrocatalyst support for oxygen resection reaction (ORR) in fuel cells cathodes. The as-prepared compound was found to have surface area and crystallite sizes of the scale of carbon black (CB) with strong dependency on the Ti precursor to urea molar ratio. N–C bonds were found to be involved, as suggested from the X-ray photoelectron spectra, and little to-no residual bulk carbon was found in the samples (X-ray diffraction and Raman spectroscopy). After deposition of Pt metal catalyst, the ceramic-based system demonstrated superior ORR activity and fuel cell …

The later stages of cooling of molecules and clusters in the interstellar medium are dominated by emission of vibrational infrared radiation. With the development of cryogenic storage it has become possible to experimentally study these processes. Recent storage ring results demonstrate that intramolecular vibrational redistribution takes place within the cooling process, and an harmonic cascade model has been used to interpret the data. Here we analyze this model and show that the energy distributions and the photon emission rates develop into near-universal functions that can be characterized with only a few parameters, irrespective of the precise vibrational spectra and oscillator strengths of the systems. We show that the photon emission rate and emitted power vary linearly with total excitation energy with a small offset. The time developments of ensemble internal energy distributions are calculated with …

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 Aharonov-Bohm effect is a fundamental topological phenomenon with a wide range of applications. It consists of a charge encircling a region with a magnetic flux in a superposition of wave packets having their relative phase affected by the flux. In this work we analyze this effect using an entropic measure known as realism, originally introduced as a quantifier of a system's degree of reality and mathematically related to notions of global and local quantum coherence. More precisely, we look for observables that lead to gauge-invariant realism associated with the charge before it completes its loop. We find that the realism of these operators has a sudden change when the line connecting the center of both wave packets crosses the solenoid. Moreover, we consider the case of a quantized magnetic-field source, pointing out similarities and differences between the two cases. Finally, we discuss some …

Severe combined immunodeficiency (SCID) is a group of disorders caused by mutations in genes involved in the process of lymphocyte maturation and function. CRISPR-Cas9 gene editing of the patient’s own hematopoietic stem and progenitor cells (HSPCs) ex vivo could provide a therapeutic alternative to allogeneic hematopoietic stem cell transplantation, the current gold standard for treatment of SCID. To eliminate the need for scarce patient samples, we engineered genotypes in healthy donor (HD)-derived CD34+ HSPCs using CRISPR-Cas9/rAAV6 gene-editing, to model both SCID and the therapeutic outcomes of gene-editing therapies for SCID via multiplexed homology-directed repair (HDR). First, we developed a SCID disease model via biallelic knockout of genes critical to the development of lymphocytes; and second, we established a knockin/knockout strategy to develop a proof-of-concept single …

The unique fluorescent nanomaterials known as carbon dots (CDs) are highly resistant to photobleaching, have low toxicity, and are well soluble in water. Polyethyleneimine (PEI) coated CDs are a novel fluorophore with good biocompatibility and pH sensing ability. Here, p-phenylenediamine (p-PD) is used as a carbon source and hyperbranched PEI is used as a surface passivation agent in a simple, one-step hydrothermal synthesis process. The CDs optical characteristics are pH-responsive due to the presence of different amine groups on PEI, which is functional polycationic polymer. The limits of techniques based on fluorescence intensity can be overcome by fluorescent lifetime imaging microscopy (FLIM), a very sensitive method for detecting a microenvironment. In this study, FLIM was used to measure pH with pH-sensitive CDs. These molecules are nontoxic to the cells, and the positively charged CDs have …

Time-lenses can image ultrafast signals in time. Placing them in a 2-f configuration leads to Fourier transform of the input signal and ultrafast spectroscopy. We utilized two time-lenses in a 4-f configuration and formed an interferometer in the time domain. Our time lenses are based on four-wave mixing process, generating an idler beam which serves as the output. The output from the first time-lens is the input to the second time-lens. At the output of the second time-lens, we get an interference between the signal beams of both time-lenses and the idler beams of both time-lenses. This interference is sensitive to ultrafast phase shifts in time and can lead to interfere signals in different times. This interferometer is good for quantum imaging, and studying the temporal structure of entangled photons. In this talk we will demonstrate the interferometer, how we exploit time-lenses for interferometry, the application of the …

X-ray optical wave mixing is a nonlinear diffraction method that gives direct information about the Ångstrom and femtosecond-scale structure of the local optically-induced charge density in bulk solids, information unavailable to purely optical methods. The first measurements of wave mixing between x rays and optical photons were reported for single crystal diamond [Glover et al., Nature 488, 603 (2012)]. Here we report x-ray optical wave mixing experiments using the Swiss-FEL and LCLS hard x-ray free-electron lasers. To measure the wave-mixing signal we use silicon crystal optics to monochromate the free-electron laser output and analyze the energy-angle dependent wave-mixing signal while rejecting the elastic background. The results include the first measurements from silicon and the first measurement of the higher-order wave-mixing process generating the sum frequency of two optical and one x-ray …

Cisplatin (CP) is the rst-line standard of care for bladder cancer. However, a signi cant 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 e cacy. To overcome this limitation, here we designed CP-conjugated gold nanoparticles (GNPs) with speci c properties that prevent renal toxicity, and concurrently preserve the therapeutic e cacy of CP. Safety and e cacy 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 CPGNP showed long-term intratumoral accumulation, blocked tumor growth, and nulli ed 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 e cacy and prolonged mouse survival. Moreover, as opposed to free drug, CP-conjugated GNPs did not cause brosis 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.

The synchronization of human networks, and the possibility of obtaining an agreement in a group, are essential for our survival. The dynamics of human networks are affecting every aspect of our lives in politics, economics, science, and engineering, and are essential for our mental and physical health. We study the unique properties of human networks and their dynamics by resorting to coupled violin players. We found that the human ability to ignore inputs or to focus on an input change dramatically the dynamics of the network compared to other coupled networks. We show how human networks react to frustrating situations, how they change the network connectivity or the network coupling strength, and how they escape local minima. In addition, the formation of leaders has a significant impact on the dynamics of human groups and networks and can completely shift the trajectory of a society. We study how …

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 …

This review article summarizes the comprehensive work that was done in our laboratory in recent years, as-well-as other reports, on the various aspects of sonochemistry of molten gallium. The low mp (29.8 °C) of gallium enables its melting in warm water, aqueous solutions and organic liquids. This opened a new research direction that focused on the chemical and physical properties of gallium particles that were formed in such media. It includes their interactions with water and with organic and inorganic solutes in aqueous solutions and with carbon nanoparticles. Formation of nanoparticles of liquid gallium alloys was also reported.

Topological superconductors are predicted to exhibit outstanding phenomena, including non-Abelian anyon excitations, heat-carrying edge states, and topological nodes in the Bogoliubov spectra. Nonetheless, and despite major experimental efforts, we are still lacking unambiguous signatures of such exotic phenomena. In this context, the recent discovery of coexisting superconductivity and ferroelectricity in lightly doped and ultraclean SrTiO 3 opens new opportunities. Indeed, a promising route to engineer topological superconductivity is the combination of strong spin-orbit coupling and inversion-symmetry breaking. Here we study a three-dimensional parabolic band minimum with Rashba spin-orbit coupling, whose axis is aligned by the direction of a ferroelectric moment. We show that all of the aforementioned phenomena naturally emerge in this model when a magnetic field is applied. Above a critical Zeeman …

BackgroundHepatocellular carcinoma (HCC) is a model of diverse spectrum of cancers, since it is induced by well-known etiologies, mainly Hepatitis C virus (HCV) and Hepatitis B virus (HBV). Here we aimed to identify HCV-specific mutational signature and explored the link between the HCV-related regional variation in mutations rates and HCV-induced alterations in genome-wide chromatin organization.MethodsTo identify an HCV-specific mutational signature in HCC, we performed high-resolution targeted sequencing to detect passenger mutations on 64 HCC samples from three etiology groups – HBV, HCV, or other. To explore the link between genomic signature and genome-wide chromatin organization we performed ChIP-seq for the transcriptionally permissive H3K4me3, H3K9ac and suppressive H3K9me3 modifications following HCV infection.ResultsRegional variation in mutations rates analysis …

We present novel photonic neuromorphic computing scheme working with incoherent light while capable implementing negative weighting for the neural network and obtaining reliable/accurate computing of the linear multiply-accumulate function necessary for neural networks applications.

In fluorescence-based biosensing applications, to increase optical detection sensitivity, time-resolved measurements are extensively used. Magnetic modulation biosensing (MMB) is a novel, fast, and sensitive detection technology for various applications. While this technology provides high sensitivity detection of biomarkers, to date, only the time resolved signal was analyzed. Here, we use for the first time both time-resolved and spatial-resolved measurements and show that this combination drastically improves the sensitivity of an MMB-based assay.