BINA

The changes occurring in mRNA organization during nucleo-cytoplasmic transport and export, are not well understood. Moreover, directionality of mRNA passage through the nuclear pore complex (NPC) has not been examined within individual NPCs. Here we find that an mRNP is compact during nucleoplasmic travels compared to a more open structure after transcription and at the nuclear periphery. Compaction levels of nuclear transcripts can be modulated by varying levels of SR proteins and by changing genome organization. Nuclear mRNPs are mostly rod-shaped with distant 5'/3'-ends, although for some, the ends are in proximity. The latter is more abundant in the cytoplasm and can be modified by translation inhibition. mRNAs and lncRNAs exiting the NPC exhibit predominant 5’-first export. In some cases, several adjacent NPCs are engaged in export of the same mRNA suggesting 'gene gating' …

Protein degradation mediated by the ubiquitin-proteasome pathway regulates signaling events in many physiological and pathological conditions. In vitro degradation assays have been instrumental in the understanding of how cell proliferation and other fundamental cellular processes are regulated. These assays are direct, time-specific and highly informative but also laborious, typically relying on low-throughput polyacrylamide gel-electrophoresis followed by autoradiography or immunoblotting. We present protein degradation on chip (pDOC), a MITOMI-based integrated microfluidic technology for discovery and analysis of proteins degradation in cell-free extracts. The platform accommodates hundreds of microchambers on which protein degradation is assayed quickly, simultaneously and using minute amounts of reagents in one or many physiochemical environments. Essentially, pDOC provides a sensitive …

Silicon-photonic integrated circuits are a pivotal technology for the continued growth of data communications. A main task of silicon photonics is the wavelength division multiplexing of communication channels to aggregate bandwidths that exceed the working rates available in electronics. In this work, we design and implement a 16-channel, wavelength division multiplexing device in silicon-on-insulator. The device operates at the O-band wavelengths, centered at 1310 nm, which are favored by many data center applications. The spacing between adjacent channels is 0.96 nm (167 GHz), close to those of dense wavelength division multiplexing standards in the 1550 nm wavelength range (C band). The layout consists of 15 Mach-Zehnder interferometers, cascaded in a four-stage tree topology. The differential phase delay within each interferometer is precisely trimmed post-fabrication, through local illumination of a photosensitive upper cladding layer of As 2 Se 3 chalcogenide glass. Trimming is performed subject to closed-loop feedback of transfer functions measurements. The devices can be useful in data center optical communications.

Plasmonic nano-objects have shown great potential in enhancing biological and chemical sensing, light harvesting and energy transfer, and optical and quantum computing to name a few. Therefore, an extensive effort has been vested in optimizing plasmonic systems and exploiting their field enhancement properties. Super-resolution imaging with quantum dots (QDs) is a promising method to probe plasmonic near-fields, but is hindered by the distortion of the emission intensity and radiation pattern. Here we investigate the interaction between QDs and 'L-shaped' gold nanoantennas, and demonstrate both theoretically and experimentally that this strong interaction can induce polarization-dependent modifications to the apparent QD emission intensity, polarization and localization. Based on FDTD simulations and polarization-modulated single-molecule microscopy, we show that the displacement of the emitter's localization is due to the interference between the emitter and the induced dipole and can be up to 100 nm. We also discovered that the emission polarization can rotate towards the symmetry axis or one arm of the L-shape because of the scattering. Our results could assist in paving a pathway for higher precision plasmonic near-field mapping and its underlying applications.

The velocity distribution of a classical gas of atoms in thermal equilibrium is the normal Maxwell distribution. It is well known that for sub-recoiled laser cooled atoms L\'evy statistics and deviations from usual ergodic behaviour come into play. Here we show how tools from infinite ergodic theory describe the cool gas. Specifically, we derive the scaling function and the infinite invariant density of a stochastic model for the momentum of laser cooled atoms using two approaches. The first is a direct analysis of the master equation and the second following the analysis of Bertin and Bardou using the lifetime dynamics. The two methods are shown to be identical, but yield different insights into the problem. In the main part of the paper we focus on the case where the laser trapping is strong, namely the rate of escape from the velocity trap is for and . We construct a machinery to investigate the time averages of physical observables and their relation to ensemble averages. The time averages are given in terms of functionals of the individual stochastic paths, and here we use a generalisation of L\'evy walks to investigate the ergodic properties of the system. Exploring the energy of the system, we show that when it exhibits a transition between phases where it is either an integrable or non integrable observable, with respect to the infinite invariant measure. This transition corresponds to very different properties of the mean energy, and to a discontinuous behaviour of the fluctuations. Since previous experimental work showed that both and are attainable we believe that both phases could be explored also experimentally.

We aimed to evaluate the types and concentrations of trace elements in tears of individuals living in urban and rural environments using particle induced X-ray emission (PIXE) and the possible association with exposure to air pollution and suggest a novel method for tear-based biomonitoring studies. This cross-sectional pilot study comprised 42 healthy subjects, 28 living in a rural area and 14 in an industrial city. Tears were collected with Schirmer paper and characterized by PIXE. Trace element concentrations from both eyes were averaged together with environmental pollution data. Main outcome measures were between-group differences in types and concentrations of trace elements in tears and comparison to environmental data. The rural group included 12/28 men, mean age 45.2 ± 14.8 years. The urban group consisted of 11/14 men of mean age 27 ± 5.9 years. Six rural and all urban were active smokers. Air pollution data showed more toxic elements in the rural environment. On PIXE analysis, chlorine, sodium, and potassium were found in similar concentrations in all samples. Normalizing to chlorine yielded higher values of aluminum, iron, copper, and titanium in the rural group; aluminum was found only in the rural group. The higher levels of certain trace elements in the rural group may, in part, be a consequence of exposure to specific environmental conditions. No direct association was found with air pollution data. PIXE is useful to analyze trace elements in tears, which might serve as a marker for individual exposure to environmental pollutants in biomonitoring studies.

Among extensively studied Li‐ion cathode materials, LiCoO2 (LCO) remains dominant for portable electronic applications. Although its theoretical capacity (274 mAh g−1) cannot be achieved in Li cells, high capacity (≤240 mAh g−1) can be obtained by raising the charging voltage up to 4.6 V. Unfortunately, charging Li‐LCO cells to high potentials induces surface and structural instabilities that result in rapid degradation of cells containing LCO cathodes. Yet, significant stabilization is achieved by surface coatings that promote formation of robust passivation films and prevent parasitic interactions between the electrolyte solutions and the cathodes particles. In the search for effective coatings, the authors propose RbAlF4 modified LCO particles. The coated LCO cathodes demonstrate enhanced capacity (>220 mAh g−1) and impressive retention of >80/77% after 500/300 cycles at 30/45 °C. A plausible mechanism …

The optimal performance of organic electrodes for aqueous batteries requires their full compatibility with selected electrolyte solutions. Electrode materials having 1–3-dimensional structures of variable rigidity possess a confined space in their structure filled with water and electrolyte solutions. Depending on the rigidity and confined space geometry, insertion and extraction of ions into electrode structures are often coupled with incorporation/withdrawal of water molecules. Aside from the scientific interest in understanding the charging mechanism of such systems, co-insertion of solvent molecules affects strongly the charge storage capability of the electrodes for energy storage devices. We present herein in situ electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) investigations of polyaniline (PANI) electrodes operating in various aqueous Na+-containing electrolytes, namely, Na2SO4 …

Lithium-ion batteries are commonly charged following the constant current-constant voltage (CC-CV) protocol. Current flow during charging implies an equivalent ionic flow through the battery materials. Intercalation and de-intercalation of Li+ are accompanied by concentration gradients that are reflected by the rise in the cells' potentials that is required to maintain the constant current during the CC regime. In this work, two new pulsed charging protocols were tested. First, a square current pulse is applied to the cell until the cut-off voltage is reached, followed by a pulsed square voltage protocol (PV). The second methodology keeps the same current pulse; however, after the limiting voltage was reached, the pulsing regime consisted in alternating between a maximum voltage value and a minimum, non-zero, constant current value. Different voltage pulse widths and frequencies were tested, in order to study the …

In nanophotonics, small mode volume and high-quality factor (Q-factor) resonances fundamentally scales with high refractive index values. Topological insulators (TI) are a new class of materials possessing narrow bulk bandgap and gapless Dirac surface states, and exhibit ultra high permittivity values. In this work, I will discuss our latest results on Bi2Te3 and Bi2Se3 TI meta-optics. Using polarized far-field and near field Nanospectroscopy we reveal that Bi2Se3 nanobeams exhibit mid-infrared resonant modes with 2pi phase shifts across the resonance. We further demonstrate that Bi2Te3 metasurfaces exhibit deep subwavelength resonant modes utilizing their record high index value peaking at n~11.

Li-rich Mn-based layered oxide cathodes with a high discharge capacity hold great promise for high energy density lithium-ion batteries. However, application is hampered by voltage and capacity decay and gas evolution during cycling due to interfacial side reactions. Here, we report coating by oxygen-deficient perovskite La0.9Sr0.1CoO3 using the Pechini process. X-ray photoelectron spectroscopy and scanning transmission electron microscopy both exhibit a uniform coating layer with a high oxygen vacancy concentration. The coating effectively mitigates the first cycle irreversible capacity loss and voltage decay while increasing cyclability. Optimized coating improves capacity retention from 55.6% to 84.8% after 400 cycles at 2 C. Operando differential electrochemical mass spectroscopy shows that such a coating can significantly mitigate the release of oxygen and carbon dioxide. Electrochemical impedance …

The fabrication and characterisation of ultra-thin, transparent lms is paramount for protective layers on semiconductors, solar cells, as well as for nano-composite materials and optical coatings. Similarly, the probe volume of nano-sensors, as well the calibration of axial distances in super-resolution microscopies, all require the metrology of axial uorophore distances. However, the reliable production and precise characterisation of such nanometric thin layers are di cult and labor-intense and they require specialized equipment and trained personnel. In our present work, we describe a simple, non-invasive, all-optical technique for simultaneously measuring the refractive index, thickness, and homogeneity of such thin lms. We assemble transparent layers from My-133-MC, a biomimetic transparent polymer with a refractive index of 1.33, amenable for applications in the life sciences. All parameters characterising the lms are obtained in a single measurement from the analysis of supercritical angle uorescence radiation patterns acquired on a minimally modi ed inverted microscope. Results compare favorably to those obtained through a combination of atomic force and electron microscopy, surface-plasmon resonance spectroscopy and ellipsometry. To illustrate the utility of our technique, we present two applications, one in metrology and one in bio-imaging;(i), the calibration of axial uorophore distance in a total internal re ection uorescence geometry; and,(ii), live-cell super-resolution imaging of organelle dynamics in cortical astrocytes, an important type of brain cell. Our approach is cheap, versatile and it has obvious applications in pro lometry …

Superhydrophobic coatings on polymeric films are in high demand due to their various real-world applications in a number of different fields. However, reported coatings lack durability or have complicated processes rendering them impractical. Here, tetraethylorthosilicate is polymerized via a modified Stöber method in the presence of a corona treated PP film (in-situ) which results in a thin silica-structured layer, covalently bonded to the PP film. Fluorocarbon silanes are then further reacted with the silica layer. The high surface roughness of the silica structures and low surface energy of the fluorocarbon silanes produce superhydrophobic surfaces. PP films coated with flake-like silica structures resulted in higher surface roughness and superhydrophobicity than the particle-like coating. Additionally, the flake-like silica coating exhibited good self-cleaning properties and durability to sandpaper abrasion tests. This …

Metal–semiconductor interfaces are ubiquitous in modern electronics. These quantum-confined interfaces allow for the formation of atomically thin polarizable metals and feature rich optical and optoelectronic phenomena, including plasmon-induced hot-electron transfer from metal to semiconductors. Here, we report on the metal–semiconductor interface formed during the intercalation of zero-valent atomic layers of tin (Sn) between layers of MoS2, a van der Waals layered material. We demonstrate that Sn interaction leads to the emergence of gap states within the MoS2 band gap and to corresponding plasmonic features between 1 and 2 eV (0.6–1.2 μm). The observed stimulation of the photoconductivity, as well as the extension of the spectral response from the visible regime toward the mid-infrared suggests that hot-carrier generation and internal photoemission take place.

The seven-transmembrane superfamily member 3 protein (TM7SF3) is a p53-regulated homeostatic factor that attenuates cellular stress and the unfolded protein response. Here we show that TM7SF3 localizes to nuclear speckles; eukaryotic nuclear bodies enriched in splicing factors. This unexpected location for a trans-membranal protein enables formation of stable complexes between TM7SF3 and pre-mRNA splicing factors including DHX15, LARP7, HNRNPU, RBM14, and HNRNPK. Indeed, TM7SF3 regulates alternative splicing of >330 genes, mainly at the 3’end of introns by directly modulating the activity of splicing factors such as HNRNPK. These effects are observed both in cell lines and primary human pancreatic islets. Accordingly, silencing of TM7SF3 results in differential expression of 1465 genes (about 7% of the human genome); with 844 and 621 genes being up- or down-regulated, respectively …

Copper is an essential element in nature but in excess it is toxic to the living cell. The human metallochaperone Atox1 participates in copper homeostasis and is responsible for copper transmission. In a previous multiscale simulation study, we noticed a change in the coordination state of the Cu(I) ion, from 4 bound cysteine residues to 3, in agreement with earlier studies. Here we perform and analyse classical molecular dynamic simulations of various coordination states: 2, 3, and 4. The main observation is an increase in protein flexibility as a result of a decrease in coordination state. Additionally, we identified several populated conformations that correlate well with double electron‐electron resonance distance distributions or an X‐ray structure of Cu(I)‐bound Atox1. We suggest that the increased flexibility might benefit the process of ion transmission between interacting proteins. Further experiments can …

Humidity is often reported to compromise the stability of lead halide perovskites or of devices based on them. Here we measure the humidity dependence of the elastic modulus and hardness for two series of lead halide perovskite single crystals, varying either by cation or by anion type. The results reveal a dependence on bond length between, hydrogen bonding with, and polarizability/polarization of these ions. The results show an intriguing inverse relation between modulus and hardness, in contrast to their positive correlation for most other materials. This anomaly persists and is strengthened by the effect of humidity. This, and our overall findings are ascribed to the materials’ unique atomic-scale structure and properties, viz nano-polar domains and strong dynamic disorder, yet high-quality average order. Our conclusions are based on comparing results obtained from several different nano-indentation …

It has been recently shown that SmI2 is more azaphilic than oxophilic. Density functional theory calculations reveal that coordination of 1–3 molecules of ethylenediamine is more exothermic by up to 10 kcal/mol than coordination of the corresponding number of ethylene glycol molecules. Taking into account also hydrogen bonds between ligands and tetrahydrofuran doubles this preference. The intrinsic affinity parallels the order of basicity. The cooperativity with the hydrogen bonding makes SmI2 more azaphilic than oxophilic.

Background: The cost of heart failure hospitalizations in the US alone is over USD 10 billion per year. Over 4 million Americans are hospitalized every year due to heart failure (HF), with a median length of stay of 4 days and an in-hospital mortality rate that exceeds 5%. Hospitalizations of patients with HF can be prevented by early detection of lung congestion. Our study assessed a new contact-free optical medical device used for the early detection of lung congestion. Methods: The Gili system is an FDA-cleared device used for measuring chest motion vibration data. Lung congestion in the study was assessed clinically and verified via two cardiologists. An algorithm was developed using machine learning techniques, and cross-validation of the findings was performed to estimate the accuracy of the algorithm. Results: A total of 227 patients were recruited (101 cases vs. 126 controls). The sensitivity and specificity for the device in our study were 0.91 (95% CI: 0.86–0.93) and 0.91 (95% CI: 0.87–0.94), respectively. In all instances, the observed estimates of PPVs and NPVs were at least 0.82 and 0.90, respectively. The accuracy of the algorithm was not affected by different covariates (including respiratory or valvular conditions). Conclusions: This study demonstrates the efficacy of a contact-free optical device for detecting lung congestion. Further validation of the study results across a larger and precise scale is warranted.

This chapter provides the analysis of acoustic modes that are guided by the structure of standard single-mode optical fibers. The elastic wave equation is solved in cylindrical coordinates, and solutions are categorized according to their azimuthal symmetry. The boundary conditions of a bare fiber in air are formulated in terms of a matrice of coefficients, whose elements depend on the order of azimuthal symmetry. Discrete solutions of the boundary condition equations signify the cutoff frequencies of guided acoustic modes. Expressions are provided for the normalized transverse profiles of material displacement in modal solutions. Emphasis is given to radially symmetric modes and to torsional-radial modes with twofold azimuthal symmetry. The transverse profiles of these specific mode categories can match those of electrostrictive force terms that may be induced by guided light in the fiber.

Fast charging is regarded as one of the most coveted technologies for commercial Li-ion batteries (LIBs), but the lack of suitable electrolytes with sufficient ionic conductivity and effective passivation properties hinders its development. Herein, we designed a mixed-solvent electrolyte (1 M LiPF6 in fluoroethylene carbonate/acetonitrile, FEC/AN, 7/3 by vol.) to overcome these two limitations by achieving an FEC-dominated solvation structure and an AN-rich environment. The specific AN-assisted Li+ hopping transport behavior shortens the Li+ diffusion time, doubling the ionic conductivity to 12 mS cm–1, thus endowing the graphite anode with >300 mAh g–1 at 20C and reversible (de)intercalation over a wide temperature range (from −20 to +60 °C). Furthermore, the designed electrolyte triples the capacity of the 1 Ah graphite||LiNi0.8Mn0.1Co0.1O2 (NMC811) pouch cells at 8C in comparison with the commercial …