BINA

An electrochemical ‘Lab-on-a-chip’for water toxicity detection is presented. This miniaturized device containing an array of nano liter electrochemical cells, which integrates bacteria and can emulate physiological reactions in response to different chemicals. Bacteria, which have been genetically engineered to respond to environmental stress, act as a sensor element and trigger a sequence of processes, which leads to generation of electrical current.

A sample‐type protein monolayer, that can be a stepping stone to practical devices, can behave as an electrically driven switch. This feat is achieved using a redox protein, cytochrome C (CytC), with its heme shielded from direct contact with the solid‐state electrodes. Ab initio DFT calculations, carried out on the CytC–Au structure, show that the coupling of the heme, the origin of the protein frontier orbitals, to the electrodes is sufficiently weak to prevent Fermi level pinning. Thus, external bias can bring these orbitals in and out of resonance with the electrode. Using a cytochrome C mutant for direct S−Au bonding, approximately 80 % of the Au–CytC–Au junctions show at greater than 0.5 V bias a clear conductance peak, consistent with resonant tunneling. The on–off change persists up to room temperature, demonstrating reversible, bias‐controlled switching of a protein ensemble, which, with its built‐in …

The parasite Trypanosoma brucei, the causative agent of sleeping sickness, cycles between an insect and a mammalian host. Here, we investigated the presence of pseudouridines (Ψs) on the spliceosomal small nuclear RNAs (snRNAs), which may enable growth at the very different temperatures characterizing the two hosts. To this end, we performed the first high-throughput mapping of spliceosomal snRNA Ψs by small RNA Ψ-seq. The analysis revealed 42 Ψs on T. brucei snRNAs, which is the highest number reported so far. We show that a trypanosome protein analogous to human protein WDR79, is essential for guiding Ψ on snRNAs but not on rRNAs. snoRNA species implicated in snRNA pseudouridylation were identified by a genome-wide approach based on ligation of RNAs following in vivo UV cross-linking. snRNA Ψs are guided by single hairpin snoRNAs, also implicated in rRNA modification …

Quick charging of Li-ion batteries is often accompanied by rapid expansion of composite battery electrodes, resulting in the appearance of transient stresses inside the electrodes’ bulk. Although predicted theoretically, they have never been tracked by direct in situ measurements. Herein, using multiharmonic electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D), acoustic images of strong transient deformations in LiFePO4 electrodes were obtained in the form of giant resonance frequency and resonance width shifts. The formation of cracks was verified by scanning electron microscopy. The effects of charging rate, stiffness of the polymeric binder, and solution concentration have been identified. The attractive feature of EQCM-D is its high sensitivity for selective probing of average mechanical characteristics of the operated electrodes, especially of the particle–binder interactions, directly …

Whenever a quantum system undergoes a cyclic evolution governed by a slow change of parameters, it acquires a phase factor: the geometric phase. Its most common formulations are known as the Aharonov–Bohm phase and the Pancharatnam and Berry phase, but both earlier and later manifestations exist. Although traditionally attributed to the foundations of quantum mechanics, the geometric phase has been generalized and become increasingly influential in many areas from condensed-matter physics and optics to high-energy and particle physics and from fluid mechanics to gravity and cosmology. Interestingly, the geometric phase also offers unique opportunities for quantum information and computation. In this Review, we first introduce the Aharonov–Bohm effect as an important realization of the geometric phase. Then, we discuss in detail the broader meaning, consequences and realizations of the …

Bacterial resistance to antibiotics is a major challenge in health research. A recent approach to combat this resistance is by interfering with vital bacterial functional systems. Calcium ions play an important role in bacterial functions such as bacterial cell stability, regulation of virulence genes, and in the function of various intracellular proteins. Bisphosphonate compounds have a high affinity for calcium ions and the antibacterial activity of bisphosphonates in combination with antibiotics has been recently studied. However, the antibacterial behavior of the bisphosphonate group itself has hardly been investigated. New cross-linked poly(styryl bisphosphonate) nanoparticles (poly(StBP) NPs) with a narrow size distribution and high yield were engineered using a dispersion copolymerization of styryl bisphosphonate monomer with the cross-linking monomer triethylene glycol diacrylate and the primary amino monomer N …

Diagnosis and treatment of breast cancer can be greatly enhanced and personalized based on the quantitative detection of mRNA markers. Here, we targeted the development of a fluorescent oligonucleotide probe to detect specifically the HER-2 mRNA breast cancer marker. We have selected the chromophore of the Green Fluorescent Protein (GFP), 4-hydroxybenzylidene imidazolinone (HBI), as a fluorophore covalently bound to an oligonucleotide probe and potentially capable of intercalating within a probe-mRNA duplex. We first synthesized the two-ring scaffold of the HBI chromophore 5 and coupled it to 2′-deoxyuridine at C5-position via a 7-atom-spacer, to give 4. Indeed, in the highly viscous glycerol used to mimic the reduced conformational flexibility of the intercalated HBI, chromophore 4 displayed a quantum yield of 0.29 and brightness of 20600 M−1cm−1, while no fluorescent signal was observed in …

Copper's essentiality and toxicity require a meticulous mechanism for its acquisition, cellular distribution and excretion, which remains hitherto elusive. Herein, we jointly employed electron paramagnetic resonance spectroscopy and all-atom simulations to resolve the copper trafficking mechanism in humans considering the route travelled by Cu(i) from the metallochaperone Atox1 to the metal binding domains 3 and 4 of ATP7B. Our study shows that Cu(i) in the final part of its extraction pathway is most likely mediated by binding of Atox1 monomer to MBD4 of ATP7B. This interaction takes place through weak metal-stabilized protein–protein interactions.

The performance of cells with high‐voltage LiNi0.5Mn1.5O4 positive electrodes and graphite negative electrodes is affected most adversely by the decomposition of LiPF6‐based electrolyte solutions components and the dissolution of transition metal (TM) ions. Novel approaches to overcome the severe degradation of performance are crucial for the successful design and commercialization of LNMO‐based cells, which are very advantageous due to their high voltage (4.7 V). Acid‐scavenging separators based on poly(divinylbenzene‐4‐vinylpyridine) were tested as a mean for enhancing the stability of LNMO/graphite cells with an additives‐free standard 1 M LiPF6/EC : EMC (3 : 7 v/v) electrolyte solution. Improved cycling performance was demonstrated over reference cells containing commercial polypropylene separators during prolonged cycling at both 30 and 45 °C. Electrochemical impedance …

Bell's theorem renders quantum correlations distinct from those of any local-realistic model. Although being stronger than classical correlations, quantum correlations are limited by the Tsirelson bound. This bound, however, applies for Hermitian, commutative operators corresponding to non-signaling observables in Alice's and Bob's spacelike-separated labs. As an attempt to explore theories beyond quantum mechanics and analyze the uniqueness of the latter, we examine in this work the extent of non-local correlations when relaxing these fundamental assumptions, which allows for theories with non-local signaling. We prove that, somewhat surprisingly, the Tsirelson bound in the Bell–Clauser–Horne–Shimony–Holt scenario, and similarly other related bounds on non-local correlations, remain effective as long as we maintain the Hilbert space structure of the theory. Furthermore, in the case of Hermitian …

J-aggregates are molecular nanoscale self-assemblies with distinct excitonic properties, such as highly delocalized excitons, making them main candidates for designing excitonic energy transfer systems. Here, we show a technique to form J-aggregates of the cyanine dye 1,1′-dioctyl-3,3′-di(4sulfobutyl)-5,5′,6,6′-tetrachloro-benzimidazolocarbocyanine (C8S4) in organic solutions of chloroform and acetone. These J-aggregates have a spectrum with three red-shifted absorption peaks and two sharp emission peaks. Spin-coated thin films of C8S4 aggregates have similar spectra. Investigation of the thin films via electron microscopy shows two morphologies of aggregates, which partially explains the complicated spectra. We have shown two ways for isolating the type of aggregate with the lowest transition energy. Atomic force microscopy and high-resolution transmission electron microscopy images of the …

Mild fluorination of high‐energy nickel‐cobalt‐manganese (HE‐NCM) materials with low pressures of elementary fluorine gas (F2) at room temperature was systematically studied. The fluorinated HE‐NCM samples were analysed by ion chromatography, inductively coupled plasma mass spectrometry, FT‐IR spectroscopy, powder X‐ray diffraction, magic angle spinning NMR spectroscopy, scanning electron microscopy, thermo‐gravimetric analysis, differential thermal analysis, electrochemical testing, and X‐ray photoelectron spectroscopy. The treatment of the cathode materials with low pressures (a few hundred mbar) of elementary fluorine gas at room temperature led to the elimination of the basic surface film (LiOH, Li2CO3, Li2O, etc.), and the resulting thin amorphous LiF film led to increased capacity and long‐term stability of the battery. Impedance built‐up was greatly reduced for these systems throughout …

Lung cancer is a highly metastatic disease. Although commonly considered to be a late event in disease pathogenesis, micrometastasis may also occur as an early phenomenon. Induction of epithelial-mesenchymal transition (EMT) is associated with changes in mechanical properties, predominantly due to increased cell contractility and actin stress fiber formation. The molecular mechanisms regulating actin dynamics during EMT in premalignant cells have not yet been defined. Using a novel constricted migration selection strategy and physomic techniques, including deformability cytometry and atomic force microscopy, we identified a highly motile (HM) subpopulation of HBECs, with enhanced heritable migratory capacity both in vitro and in vivo. The HBECs used for selection were modified with genetic changes that can be found in premalignancy (p53null, activated Kras-G12D). Thus, this sub-population of HM …

Hypoxia is commonly encountered in the tumor microenvironment and drives proliferation, angiogenesis, and resistance to therapy. Imaging of hypoxia is important in many disease states in oncology, cardiology, and neurology. Finding clinically approved imaging biomarkers for hypoxia has proved challenging. Candidate biomarkers have shown low uptake into tumors and low signal to background ratios that adversely affect imaging quality. Copper complexes have been identified as potential biomarkers for hypoxia owing to their redox ability. Active uptake of copper complexes into cells could ensure selectivity and high sensitivity. We explored the reactivity and selectivity of the ATSM-Cu(II) biomarker to proteins that are involved in the copper cycle using electron paramagnetic resonance (EPR) spectroscopy and UV–vis measurements. We show that the affinity of the ATSM-Cu(II) complex to proteins in the …

Purpose: Photoreceptor precursor cells (PRPs) differentiated from embryonic stem cells (ESC) can serve as a source for cell replacement therapy aimed at vision restoration in patients suffering from degenerative diseases of the outer retina, such as retinitis pigmentosa and age related macular degeneration. This work presents the thorough electrophysiological activity characterization of PRPs, and the investigation of their expression pattern of different voltage-gated ion channels.Methods: Human embryonic stem cells were differentiated into PRPs and whole-cell recordings at four time points along the differentiation process were performed for electrophysiological characterization. In addition, qPCR analysis was performed at these 4 time-points to characterize the expression pattern of various ion channels which shape the electrophysiological response. Finally, to characterize the electrically induced calcium …

Purpose: Prosthetic restoration of central vision in age-related macular degeneration (AMD) involves a combination of prosthetic vision in the central macula along with natural vision in the periphery. Here we study cortical interaction of visible and prosthetic stimuli, which is of great clinical and scientific importance.Methods: Subretinal implantation of 1mm-diameter photovoltaic arrays in wild-type rats induced a localized degeneration of the photoreceptors above the implant, whereas the surrounding retina was left intact, similar to the localized retinal degeneration caused by AMD. Using a customized projection system, we induced prosthetic and natural visual responses with NIR (910nm) and visible light (532nm), respectively. Each presentation was comprised of a central 1mm prosthetic or visible stimulus encircled with a 3mm visible surround. We recorded visual evoked potentials (VEP) in response to either non …

Presentation Description: Current retinal prostheses offer a promising solution to people with degenerative diseases of the outer retina. Notwithstanding, the obtained visual acuity is still severely limited and offers very basic vision restoration. In this lecture I will describe the main limitations of current retinal prosthetic approaches and will describe the concept of" active sensing", where super-resolved vision is achieved by actively scanning the visual scene. To simulate prosthetic vision reading, we displayed pixelated word images at different phosphene densities and contrasts. We measured word recognition rate and reading speed for various phosphene densities and contrasts with and without active sensing or zoom. Our results show that active scanning can significantly increase reading performance in simulated prosthetic vision and yield super-resolving capabilities. These results highlight the importance of a …

Purpose: Delivering cells to replace degenerate cells in degenerative disease of the outer retina in the effort to restore vision carries great hope. Many approaches for optimizing the 3D scaffold for improving the spatial orientation, function, viability and potentially the synaptic formation of transplanted cells have been pursued, and are the focus of many studies. Here we investigated, in vitro, the morphological characterization and viability of single human photoreceptors precursors cells (hPRP) cells in microwells array.Methods:–hPRP were differentiated form human embryonic stem cells following a protocol optimized by our group. GFP labeled PRP cells were seeded on an SU8 scaffold array fabricated by lithography containing 17,424 wells 20µm in diameter and 17 µm in height suitable for a single cell dimension. SU8 surfaces were treated with serum, plasma, matrigel, collagen and PEI to enhance cell …

Summary from only given. We report on the fabrication of few-atomic-layer-thick wafer-scale crystalline silver films, along with the observation of plasmons in the near-to-mid infrared spectral regions upon lithographic structuring. Our measured optical spectra reveal narrow plasmons (quality factor ~ 4), further supported by a low sheet resistance comparable to bulk metal in few-atomic-layer silver films down to 7 Ag(111) monolayers. Good crystal quality and plasmon narrowness are obtained despite the addition of a thin passivating dielectric, which renders our samples resilient to ambient conditions.

Measurement of very small refractive index changes is very important from a material's characterization point of view. This paper demosntrates a compact, simple and accurate technique for measuring refractive indices of transparent liquids, based on Snell's law and laser speckle correlation. Furthermore, considering the cutting-edge technology of 3D printing and its ability to enhance a technique's functionality by providing a sturdy framework, a 3D printed hand-held device for measurement of refractive indices is also demonstrated. The device measures very small change in refractive index by measuring the change in the objective speckle pattern arising due to the change in laser light passing the liquid solution, which is caused by the apparent shift of a point source. Change in the speckle pattern is presented in terms of correlation coefficient which is computed by comparing a speckle pattern corresponding to …