BINA

In the past couple of decades great advancements have been made in the development of PGM-free catalysts based on earth-abundant elements, nitrogen, carbon and transition metals (usually Fe or Co), inspired by biological systems such as porphyrins and phthalocyanines.1-6 In order to overcome the poor stability and low catalytic activity of transition-metal complexes, a new class of high temperature-treated (HT-treated) catalysts, composed of the same elements, i.e., a transition metal, carbon and nitrogen, was developed. Although HT-treated PGM-free catalysts exhibit improved activity and stability, their performance remains inferior to PGM catalysts, calling for further improvements to make them a viable alternative to the state-of-the-art materials. In this work, we designed, synthesized and characterized ORR catalysts based on iron, carbon and nitrogen in a well-defined, high surface-area …

Page 8995. Dr. Bosmat Levi-Hevroni designed, synthesized, and supplied the major compound investigated in our joint paper. Her name was originally on the author list but then was omitted by mistake. Unfortunately, we did not notice this mistake until after the article was published. Her name has been readded to the list with the approval of all of the authors.

One of the many challenges in the study of chiral nanosurfaces and nanofilms is the design of accurate and controlled nanoscale films with enantioselective activity. Controlled design of chiral nanofilms creates the opportunity to develop chiral materials with nanostructured architecture. Molecular layer deposition (MLD) is an advanced surface-engineering strategy for the preparation of hybrid inorganic–organic thin films, with a desired embedded property; in our study this is chirality. Previous attempts to grow enantioselective thin films were mostly focused on self-assembled monolayers or template-assisted synthesis, followed by removal of the chiral template. Here, we report a method to prepare chiral hybrid inorganic–organic nanoscale thin films with controlled thickness and impressive enantioselective properties. We present the use of an MLD reactor for sequenced vapor deposition to produce enantioselective …

Terpene cyclases are responsible for the initial cyclization cascade in the multistep synthesis of a large number of terpenes. CotB2 is a diterpene cyclase from Streptomyces melanosporofaciens, which synthesizes the formation of cyclooctat-9-en-7-ol, a precursor to the next-generation anti-inflammatory drug, cyclooctatin. In this work, we present evidence for a significant role of the active site residues in CotB2 on the reaction energetics using quantum mechanics calculations in an active site cluster model. The results using the active site model reveal the significant effect of the active site residues on the relative electronic energy of the intermediates and transition state (TS) structures with respect to gas phase data. A detailed understanding of the role of the enzyme environment on the CotB2 reaction cascade can provide important

Conclusion:An in vivo platform and a standardised methodology to perform stem cell tracking on a muscle regeneration model, through non-invasive SPECT/CT imaging, were established and are being presented. The first results, showing the fate of the GNPs and of labelled cells is being presented.

ObjectiveTo explore the use of fluorescence lifetime imaging microscopy in thyroid tissues, and to investigate how different thyroid lesions affect fluorescence lifetime.MethodFluorescence lifetime measurements were taken of fresh frozen thyroid surgical specimens stained with fluorescein isothiocyanate tagged anti-thyroglobulin monoclonal antibodies.ResultsThe mean fluorescence lifetime measurements in 12 patients – 3 with multinodular goitre, 4 with follicular adenoma, 4 with papillary thyroid carcinoma and 1 with follicular carcinoma – were 3.16 ns (range, 2.66–3.52 ns), 3.75 ns (range, 2.99–4.57 ns), 2.97 ns (range, 2.57–3.21 ns) and 3.61 ns, respectively. The fluorescence lifetime of follicular adenoma patients was higher than that of papillary thyroid carcinoma patients by 26 per cent (p = 0.058). The fluorescence lifetime in the follicular carcinoma patient was similar to the follicular adenoma group, but …

An electrically driven switch can be formed by a cytochrome C monolayer, sandwiched between a gold layer and a gold nanowire, as reported by D. Cahen et al. in their Communication on page 11852 ff. The charge-transport mechanism of cytochrome C can be switched between on-and off-resonant tunneling by varying the applied voltage bias, even at room temperature. This is an important step towards protein-based electronics.

We study the crossover between fermions and bosons in a system of two coupled one-dimensional chains subjected to a gauge flux (two-leg flux ladder), with both attractive and repulsive interaction. In the presence of strong attractive nearest-neighbour interaction and repulsive next-to-nearest-neighbour interaction, the system crosses into a regime in which fermions form tightly-bound pairs, which behave as bosonic entities. By means of numerical simulations based on the density-matrix-renormalization-group (DMRG) method, we analyze such crossover in specific limits. We show in particular that in the strongly-paired regime, the gauge flux induces a quantum phase transition of the Ising type from vortex density wave (VDW) to a charge density wave (CDW), characteristic of bosonic systems.

Eine Monoschicht aus Cytochrom C die an eine Goldschicht gebunden und mit einem Goldnanodraht überzogen ist, kann sich wie ein elektrisch betriebener Schalter verhalten, wie D. Cahen et al. in ihrem Forschungsartikel auf S. 11978 berichten. Der Ladungstransportmechanismus von Cytochrom C kann, selbst bei Raumtemperatur, durch Ändern der angelegten Vorspannung zwischen An-und Aus-Resonanztunneln geschaltet werden. Dies ist ein wichtiger Schritt in Richtung einer proteinbasierten Elektronik.

We show that sub-attosecond delays and sub-Angstrom optical path differences can be measured by using Hong-Ou-Mandel interference measurements with x-rays. We propose to use a system comprising a source based on spontaneous parametric down-conversion for the generation of broadband x-ray photon pairs and a multilayer-based interferometer. The correlation time of the photon pairs and the Hong-Ou-Mandel dip are shorter than 1 attosecond, hence the precision of the measurements is expected to be better than 0.1 attosecond. We anticipate that the scheme we describe in this work will lead to the development of various techniques of quantum measurements with ultra-high precision at x-ray wavelengths.

Fundamental challenge of imaging through a scattering media has been resolved by various approaches in the past two decades. Optical wavefront shaping technique is one such method in which one shapes the wavefront of light entering a scattering media using a wavefront shaper such that it cancels the scattering effect. It has been the most effective technique in focusing light inside a scattering media. Unfortunately, most of these techniques require direct access to the scattering medium or need to know the scattering properties of the medium beforehand. Through the novel scheme presented on this paper, both the illumination module and the detection are on the same side of the inspected object and the imaging process is a real time fast converging operation. We model the scattering medium being a biological tissue as a matrix having mathematical properties matched to the physical and biological aspects …

The dissemination of resistant pathogenic microbes has become one of the most challenging problems that modern medicine has faced. Developing novel drugs based on new molecular targets that previously were not targeted, is therefore the highest priority in antibiotics research. One approach that has been recently suggested is to inhibit copper transporters in prokaryotic systems. Copper is required for many biological pathways, but sometimes it can harm the cell. Pathogenic systems have a highly sophisticated copper-regulation network; therefore, a better understanding of how this network operates at the molecular level should assist in developing the next generation of antibiotics. The CusB protein is part of the CusCBA periplasmic Cu(I) efflux system in Gram-negative bacteria, and was recently reported to play a key role in the functioning of the whole CusCBA system, in which conformational changes as well as the assembly/disassembly process control the opening of the transporter. More knowledge of the underlying mechanism is needed to attain a full understanding of CusB functioning, which is associated with targeting specific and crucial residues in CusB. Here, we combine in-vitro structural measurements, which use EPR spectroscopy and UV-Vis measurements, with cell experiments to explore the role of the various methionine residues in CusB. We targeted two methionine residues (M227 and M241) that are essential for the proper functioning of CusB.

Expression of the key anti-inflammatory cytokine IL-10 in lipopolysaccharide (LPS)-stimulated macrophages is mediated by a delayed autocrine / paracrine loop of type I interferons (IFN) to ensure timely attenuation of inflammation. We have previously shown that cAMP synergizes with early IL-10 expression by LPS, but is unable to amplify the late type I IFN-dependent activity. We now examined the mechanism of this synergistic transcription in mouse macrophages at the promoter level, and explored the crosstalk between type I IFN signaling and cAMP, using the

Over the past decade graphene devices have inspired the progress of future electronic and optoelectronic technologies. The unique combination of fast carrier dynamics and intrinsic quantum capacitance of graphene is a fertile ground for implementing novel device architectures. Here, we report on a novel device architecture comprising graphene Schottky diode varactors and assess the potential applications of this type of new device in optoelectronics. We show that graphene varactor diodes exhibit significant advantages compared with existing graphene photodetectors including elimination of high dark currents and enhancement of the external quantum efficiency (EQE). Our devices demonstrate a large photoconductive gain and EQE of up to 37%, fast photoresponse, and low leakage currents at room temperature.

We study the crossover between fermions and bosons in a system of two coupled one-dimensional chains subjected to a gauge flux (two-leg flux ladder), with both attractive and repulsive interaction. In the presence of strong attractive nearest-neighbour interaction and repulsive next-to-nearest-neighbour interaction, the system crosses into a regime in which fermions form tightly-bound pairs, which behave as bosonic entities. By means of numerical simulations based on the density-matrix-renormalization-group (DMRG) method, we analyze such crossover in specific limits. We show in particular that in the strongly-paired regime, the gauge flux induces a quantum phase transition of the Ising type from vortex density wave (VDW) to a charge density wave (CDW), characteristic of bosonic systems.

Tumor hypoxia is one of the hostile tumor microenvironment characteristics occurring in solid tumors. This feature is closely related to tumor progression and can negatively impair the effectiveness of cancer therapeutics. Recently, various strategies have been developed that enable efficient tumor oxygenation, not only enhancing treatment outcome of oxygen-consuming cancer therapeutics such as radiotherapy and photodynamic therapy, but also reversing the immunosuppressive tumor microenvironment to promote cancer immunotherapy. This review focuses on the latest progress in design and fabrication of innovative tumor-targeted oxygen nanoshuttles that attenuate tumor hypoxia and enhance cancer therapy. Future perspectives for clinical translation of tumor-targeted oxygen nanoshuttles will be further discussed.

The profound mutualistic symbiosis between corals and their endosymbiotic counterparts, Symbiodiniaceae algae, has been threatened by the increase in seawater temperatures, leading to breakdown of the symbiotic relationship—coral bleaching. To characterize the heat-stress response of the holobiont, we generated vital apo-symbiotic Euphyllia paradivisa corals that lacked the endosymbiotic algae. Using RNA sequencing, we analyzed the gene expression of these apo-symbionts vs. symbiotic ones, to test the effect of the algal presence on the tolerance of the coral. We utilized literature-derived lists of “symbiosis differentially expressed genes” and “coral heat-stress genes” in order to compare between the treatments. The symbiotic and apo-symbiotic samples were segregated into two separate groups with several different enriched gene ontologies. Our findings suggest that the presence of endosymbionts has a greater negative impact on the host than the environmental temperature conditions experienced by the holobiont. The peak of the stress reaction was identified as 28 C, with the highest number of differentially expressed genes. We suggest that the algal symbionts increase coral holobiont susceptibility to elevated temperatures. Currently, we can only speculate whether coral species, such as E. paradivisa, with the plasticity to also flourish as apo-symbionts, may have a greater chance to withstand the upcoming global climate change challenge. View Full-Text

In this manuscript we examine an accelerated charged particle moving through an optical medium, and explore the emission of accelerated-Cherenkov radiation. The particle's reaction to acceleration creates a low-frequency spectral cutoff in the Cherenkov emission that has a sharp resonance at the superluminal threshold. Moreover, the effect of recoil on the radiation is incorporated kinematically through the use of an Unruh-DeWitt detector by setting an energy gap, ie the change in electron energy, to the recoil energy of the emitted photon. The simultaneous presence of recoil and acceleration conspire to produce a localized resonance peak in the emission. These theoretical considerations could be used to construct high precision tests of radiation reaction using Cherenkov emission under acceleration.

Disordered carbons are promising anode materials for sodium ion batteries. However, a major drawback of these materials is their low coulombic efficiency in the first cycles, which indicates parasitic reactions. Such reactions can be suppressed by alumina coating on the surface of the anodic materials; more ions are then available for electrochemical activity, and less electrolyte solution is lost. On the other hand, some pores and surface edge sites are passivated by the coating and are no longer available for reversible reaction with sodium ions; hence, their contribution is eliminated, leading to reduction in specific capacity. We show herein that electrochemical insertion of sodium ions into carbon anodes prior to alumina coating has a double positive effect on anode perfomances, meaning preventing passivation and maintaining high specific capacity. We show that the artificial layer still prevented parasitic …

Conditional probabilities in quantum systems which have both initial and final boundary conditions are commonly evaluated using the Aharonov–Bergmann–Lebowitz rule. In this short note, we present a seemingly disturbing paradox that appears when applying the rule to systems with slightly broken degeneracies. In these cases, we encounter a singular limit—the probability “jumps” when going from perfect degeneracy to negligibly broken one. We trace the origin of the paradox and solve it from both traditional and modern perspectives in order to highlight the physics behind it: the necessity to take into account the finite resolution of the measuring device. As a practical example, we study the application of the rule to the Zeeman effect. The analysis presented here may stress the general need to first consider the governing physical principles before heading to the mathematical formalism, in particular, when …

Recent developments in optical filters have enabled the facile use of Raman spectroscopy for detection of low frequency (LF) vibrational modes. LF-Raman spectroscopy offers fast and sensitive characterization of LF vibrations, and enables the measurement of single microcrystals and detection of defects. It is useful for probing intermolecular interactions in crystals, which are lower in energy, such as hydrogen bonds, shear modes, and breathing modes. Crystal excitation from multiple faces allows learning the orientation of intermolecular interactions, as polarization dependence varies with the polarizability of the interactions along the planes. Elucidating the orientations of the intermolecular interactions in organic crystals is essential for guiding the reactions or adsorption to a specific crystal face. In this study, we investigated the dependence of the LF-Raman signal intensity on the orientation of an organic single microcrystal of L-alanine. Three incident beam directions provided the orientations of the intermolecular interactions by analyzing the corresponding LF-Raman spectra. The signal intensity correlated well with the proximity between the incident beam’s direction and the orientations of the intermolecular interactions. Excellent compatibility was found between the spectra and simulated orientations based on structural information. View Full-Text