Stabilizing Schottky-to-Ohmic Switching in HfO-Based Ferroelectric Films via Electrode Design.

The discovery of ferroelectric phases in HfO-based films has reignited interest in ferroelectrics and their application in resistive switching (RS) devices. This study investigates the pivotal role of electrodes in facilitating the Schottky-to-Ohmic transition (SOT) observed in devices consisting of ultrathin epitaxial ferroelectric HfYO (YHO) films deposited on LaSrMnO-buffered Nb-doped SrTiO (NbSTO|LSMO) with Ti|Au top electrodes. These findings indicate combined filamentary RS and ferroelectric switching occurs in devices with designed electrodes, having an ON/OFF ratio of over 100 during about 10 cycles.

Interfacial vs confinement effects in the anisotropic frequency-dependent dielectric, THz and IR response of nanoconfined water.

We investigate the anisotropic frequency-dependent dielectric, THz and IR response of liquid water confined between two planar graphene sheets with force-field- and density-functional-theory-based molecular dynamics simulations. Using spatially resolved anisotropic spectra, we demonstrate the critical role of the volume over which the spectral response is integrated when reporting spatially averaged electric susceptibilities. To analyze the spectra, we introduce a unique decomposition into bulk, interfacial, and confinement contributions, which reveals that confinement effects on the spectra occur only for systems with graphene separation below 1.

Propensity of hydroxide and hydronium ions for the air-water and graphene-water interfaces from ab initio and force field simulations.

Understanding acids and bases at interfaces is relevant for a range of applications from environmental chemistry to energy storage. We present combined ab initio and force-field molecular dynamics simulations of hydrochloric acid and sodium hydroxide highly concentrated electrolytes at the interface with air and graphene. In agreement with surface tension measurements at the air-water interface, we find that HCl presents an ionic surface excess, while NaOH displays an ionic surface depletion, for both interfaces.

Depth-Resolved X-Ray Photoelectron Spectroscopy Evidence of Intrinsic Polar States in HfO-Based Ferroelectrics.

The discovery of ferroelectricity in nanoscale hafnia-based oxide films has spurred interest in understanding their emergent properties. Investigation focuses on the size-dependent polarization behavior, which is sensitive to content and movement of oxygen vacancies. Though polarization switching and electrochemical reactions is shown to co-occur, their relationship remains unclear.

Modeling Water Interactions with Graphene and Graphite via Force Fields Consistent with Experimental Contact Angles.

Accurate simulation models for water interactions with graphene and graphite are important for nanofluidic applications, but existing force fields produce widely varying contact angles. Our extensive review of the experimental literature reveals extreme variation among reported values of graphene-water contact angles and a clustering of graphite-water contact angles into groups of freshly exfoliated (60° ± 13°) and not-freshly exfoliated graphite surfaces. The carbon-oxygen dispersion energy for a classical force field is optimized with respect to this 60° graphite-water contact angle in the infinite-force-cutoff limit, which in turn yields a contact angle for unsupported graphene of 80°, in agreement with the mean of the experimental results.

Multiscale Modeling of Aqueous Electric Double Layers.

From the stability of colloidal suspensions to the charging of electrodes, electric double layers play a pivotal role in aqueous systems. The interactions between interfaces, water molecules, ions and other solutes making up the electrical double layer span length scales from Ångströms to micrometers and are notoriously complex. Therefore, explaining experimental observations in terms of the double layer's molecular structure has been a long-standing challenge in physical chemistry, yet recent advances in simulations techniques and computational power have led to tremendous progress.

Enhanced interfacial water dissociation on a hydrated iron porphyrin single-atom catalyst in graphene.

Single Atom Catalysis (SAC) is an expanding field of heterogeneous catalysis in which single metallic atoms embedded in different materials catalyze a chemical reaction, but these new catalytic materials still lack fundamental understanding when used in electrochemical environments. Recent characterizations of non-noble metals like Fe deposited on N-doped graphitic materials have evidenced two types of Fe-N fourfold coordination, either of pyridine type or of porphyrin type. Here, we study these defects embedded in a graphene sheet and immersed in an explicit aqueous medium at the quantum level.

Collective modes and quantum effects in two-dimensional nanofluidic channels.

Nanoscale fluid transport is typically pictured in terms of atomic-scale dynamics, as is natural in the real-space framework of molecular simulations. An alternative Fourier-space picture, that involves the collective charge fluctuation modes of both the liquid and the confining wall, has recently been successful at predicting new nanofluidic phenomena such as quantum friction and near-field heat transfer, that rely on the coupling of those fluctuations. Here, we study the charge fluctuation modes of a two-dimensional (planar) nanofluidic channel.

MicroRNAs in Tumor Endothelial Cells: Regulation, Function and Therapeutic Applications.

Tumor endothelial cells (TECs) are key stromal components of the tumor microenvironment, and are essential for tumor angiogenesis, growth and metastasis. Accumulating evidence has shown that small single-stranded non-coding microRNAs (miRNAs) act as powerful endogenous regulators of TEC function and blood vessel formation. This systematic review provides an up-to-date overview of these endothelial miRNAs.

SIRT1 regulates DNA damage signaling through the PP4 phosphatase complex.

The Sirtuin family of NAD+-dependent enzymes plays an important role in maintaining genome stability upon stress. Several mammalian Sirtuins have been linked directly or indirectly to the regulation of DNA damage during replication through Homologous recombination (HR). The role of one of them, SIRT1, is intriguing as it seems to have a general regulatory role in the DNA damage response (DDR) that has not yet been addressed.

Effects of above ground pathogen infection and fungicide application on the root-associated microbiota of apple saplings.

Background: The root-associated microbiome has been of keen research interest especially in the last decade due to the large potential for increasing overall plant performance in agricultural systems. Knowledge about the impact of above ground plant disturbances on the root-associated microbiome remains limited. We addressed this by focusing on two potential impacts, foliar pathogen infection alone and in combination with the application of a plant health protecting product.

Electrokinetic, electrochemical, and electrostatic surface potentials of the pristine water liquid-vapor interface.

Although conceptually simple, the air-water interface displays rich behavior and is subject to intense experimental and theoretical investigations. Different definitions of the electrostatic surface potential as well as different calculation methods, each relevant for distinct experimental scenarios, lead to widely varying potential magnitudes and sometimes even different signs. Based on quantum-chemical density-functional-theory molecular dynamics (DFT-MD) simulations, different surface potentials are evaluated and compared to force-field (FF) MD simulations.

Spatio-temporal variation in the root-associated microbiota of orchard-grown apple trees.

Background: The root-associated microbiome has been of keen research interest especially in the last decade due to the large potential for increasing overall plant performance in agricultural systems. Studies about spatio-temporal variation of the root-associated microbiome focused so far primarily on community-compositional changes of annual plants, while little is known about their perennial counterparts. The aim of this work was to get deep insight into the spatial patterns and temporal dynamics of the root associated microbiota of apple trees.

Hydrophobicity of Self-Assembled Monolayers of Alkanes: Fluorination, Density, Roughness, and Lennard-Jones Cutoffs.

The interplay of fluorination and structure of alkane self-assembled monolayers and how these affect hydrophobicity are explored via molecular dynamics simulations, contact angle goniometry, and surface-enhanced infrared absorption spectroscopy. Wetting coefficients are found to grow linearly in the monolayer density for both alkane and perfluoroalkane monolayers. The larger contact angles of monolayers of perfluorinated alkanes are shown to be primarily caused by their larger molecular volume, which leads to a larger nearest-neighbor grafting distance and smaller tilt angle.

The Hydrotropic Effect of Ionic Liquids in Water-in-Salt Electrolytes*.

Water-in-salt electrolytes have successfully expanded the electrochemical stability window of aqueous electrolytes beyond 2 V. Further improvements in stability can be achieved by partially substituting water with either classical organic solvents or ionic liquids. Here, we study ternary electrolytes composed of LiTFSI, water, and imidazolium ionic liquids.

The Impact of Halogenated Phenylalanine Derivatives on NFGAIL Amyloid Formation.

The hexapeptide hIAPP (NFGAIL) is known as a crucial amyloid core sequence of the human islet amyloid polypeptide (hIAPP) whose aggregates can be used to better understand the wild-type hIAPP's toxicity to β-cell death. In amyloid research, the role of hydrophobic and aromatic-aromatic interactions as potential driving forces during the aggregation process is controversially discussed not only in case of NFGAIL, but also for amyloidogenic peptides in general. We have used halogenation of the aromatic residue as a strategy to modulate hydrophobic and aromatic-aromatic interactions and prepared a library of NFGAIL variants containing fluorinated and iodinated phenylalanine analogues.

Fractal Geometry of Higher Derivative Gravity.

We determine the scaling properties of geometric operators such as lengths, areas, and volumes in models of higher derivative quantum gravity by renormalizing appropriate composite operators. We use these results to deduce the fractal dimensions of such hypersurfaces embedded in a quantum spacetime at very small distances.

Water-in-salt electrolytes for aqueous lithium-ion batteries with liquidus temperatures below -10 °C.

Crystallization near room temperature is a common challenge for water-in-salt electrolytes. We demonstrate that water-in-salt electrolytes based on lithium (pentafluoroethanesulfonyl)(trifluoromethanesulfonyl)imide remain thermodynamically in the liquid state down to at least -10 °C. Combined with their excellent chemical and electrochemical stability as well as high lithium-ion conductivity, these electrolytes represent a key enabler for the next generation of high-voltage aqueous lithium-ion batteries.

Unraveling the Formation Mechanism of Solid-Liquid Electrolyte Interphases on LiPON Thin Films.

Most commercial lithium-ion batteries and other types of batteries rely on liquid electrolytes, which are preferred because of their high ionic conductivity, and facilitate fast charge-transfer kinetics at the electrodes. On the other hand, hybrid battery concepts that combine solid and liquid electrolytes might be needed to suppress unwanted shuttle effects in liquid electrolyte-only systems, in particular if mobile redox systems are involved in the cell chemistry. However, at the then newly introduced interface between liquid and solid electrolytes, a solid-liquid electrolyte interphase forms.

A rapid identification technique for drug-resistant isolates using mismatch specific cleavage enzyme.

The emergence of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) strains is a major health problem for high Tuberculosis (TB) incidence countries. Therefore, it is of interest to identify antibiotic resistant bacteria by mismatch detection using DNA hybridization. We generated PCR products for five genes (rpoB, inhA, katG, gyrA and rrs) associated with drug resistance TB from MDR and XDR Mycobacterium tuberculosis (MTB) DNA samples.

Local control of globally competing patterns in coupled Swift-Hohenberg equations.

We present analytical and numerical investigations of two anti-symmetrically coupled 1D Swift-Hohenberg equations (SHEs) with cubic nonlinearities. The SHE provides a generic formulation for pattern formation at a characteristic length scale. A linear stability analysis of the homogeneous state reveals a wave instability in addition to the usual Turing instability of uncoupled SHEs.

The t(12;21)(p13;q22) in Pediatric B-Acute Lymphoblastic Leukemia: An Update.

Erratum: Figure 1 on the last edition The Journal of the Association of Genetic Technologists. 2017;43(3): 113-127 does not contain the derivative 21. We are replacing this figure with the present one.

A Molecular and Cytogenetic Update on Non-Small Cell Lung Carcinoma.

Lung cancer is one of the leading causes of cancer-related death worldwide. Among patients with lung cancer, approximately 85% have non-small cell lung carcinoma (NSCLC). The discovery of oncogenic driver mutations in NSCLC opened new personalized treatment options.

The t(12;21)(p13;q22) in Pediatric B-Acute Lymphoblastic Leukemia: An Update.

Pediatric B-cell acute lymphoblastic leukemia (B-ALL) is the most common hematological malignancy in children, and the t(12;21)(p13;q22) occurs in approximately 25% of these cases, making it is the most prevalent chromosomal abnormality. The t(12;21) which disrupts hematopoietic differentiation and proliferation, and can be present as a sole abnormality or within the context of a complex karyotype characterized by three or more chromosomal abnormalities. The prognosis of t(12;21) within a complex karyotype is extensively debated.