Controlling crystal cleavage in focused ion beam shaped specimens for surface spectroscopy.

Our understanding of quantum materials is commonly based on precise determinations of their electronic spectrum by spectroscopic means, most notably angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy. Both require atomically clean and flat crystal surfaces, which are traditionally prepared by in situ mechanical cleaving in ultrahigh vacuum chambers. We present a new approach that addresses three main issues of the current state-of-the-art methods: (1) Cleaving is a highly stochastic and, thus, inefficient process; (2) fracture processes are governed by the bonds in a bulk crystal, and many materials and surfaces simply do not cleave; and (3) the location of the cleave is random, preventing data collection at specified regions of interest.

Switchable tribology of ferroelectrics.

Switchable tribological properties of ferroelectrics offer an alternative route to visualize and control ferroelectric domains. Here, we observe the switchable friction and wear behavior of ferroelectrics using a nanoscale scanning probe-down domains have lower friction coefficients and show slower wear rates than up domains and can be used as smart masks. This asymmetry is enabled by flexoelectrically coupled polarization in the up and down domains under a sufficiently high contact force.

The Effect of Chemical Environment and Temperature on the Domain Structure of Free-Standing BaTiO via In Situ STEM.

Ferroelectrics, due to their polar nature and reversible switching, can be used to dynamically control surface chemistry for catalysis, chemical switching, and other applications such as water splitting. However, this is a complex phenomenon where ferroelectric domain orientation and switching are intimately linked to surface charges. In this work, the temperature-induced domain behavior of ferroelectric-ferroelastic domains in free-standing BaTiO films under different gas environments, including vacuum and oxygen-rich, is studied by in situ scanning transmission electron microscopy (STEM).

Smooth velocity fields for tracking climate change.

Describing the spatial velocity of climate change is essential to assessing the challenge of natural and human systems to follow its pace by adapting or migrating sufficiently fast. We propose a fully-determined approach, "MATCH", to calculate a realistic and continuous velocity field of any climate parameter, without the need for ad hoc assumptions. We apply this approach to the displacement of isotherms predicted by global and regional climate models between 1950 and 2100 under the IPCC-AR5 RCP 8.

Correlative imaging of ferroelectric domain walls.

The wealth of properties in functional materials at the nanoscale has attracted tremendous interest over the last decades, spurring the development of ever more precise and ingenious characterization techniques. In ferroelectrics, for instance, scanning probe microscopy based techniques have been used in conjunction with advanced optical methods to probe the structure and properties of nanoscale domain walls, revealing complex behaviours such as chirality, electronic conduction or localised modulation of mechanical response. However, due to the different nature of the characterization methods, only limited and indirect correlation has been achieved between them, even when the same spatial areas were probed.

Roughness and dynamics of proliferating cell fronts as a probe of cell-cell interactions.

Juxtacellular interactions play an essential but still not fully understood role in both normal tissue development and tumour invasion. Using proliferating cell fronts as a model system, we explore the effects of cell-cell interactions on the geometry and dynamics of these one-dimensional biological interfaces. We observe two distinct scaling regimes of the steady state roughness of in-vitro propagating Rat1 fibroblast cell fronts, suggesting different hierarchies of interactions at sub-cell lengthscales and at a lengthscale of 2-10 cells.

Local Probe Comparison of Ferroelectric Switching Event Statistics in the Creep and Depinning Regimes in Pb(Zr_{0.2}Ti_{0.8})O_{3} Thin Films.

Ferroelectric materials provide a useful model system to explore the jerky, highly nonlinear dynamics of elastic interfaces in disordered media. The distribution of nanoscale switching event sizes is studied in two Pb(Zr_{0.2}Ti_{0.

Clinical and Epidemiological Aspects of Parkinson's Disease in the South of Western Siberia.

The article is devoted to one of the most common neurodegenerative diseases in the world-Parkinson's disease (PD), the prevalence of which in Russia reaches 140-150 people per 100,000 people. The clinical and anamnestic profile of a patient with PD is presented, the prevalence of motor and non-motor symptoms is reflected, and a comparative characteristic of the neurological deficit in the Siberian population of patients with other cohorts of patients with Parkinson's disease in different countries and ethnic groups is presented. We studied 140 patients with Parkinson's disease.

Better, Faster, and Less Biased Machine Learning: Electromechanical Switching in Ferroelectric Thin Films.

Machine-learning techniques are more and more often applied to the analysis of complex behaviors in materials research. Frequently used to identify fundamental behaviors within large and multidimensional datasets, these techniques are strictly based on mathematical models. Thus, without inherent physical or chemical meaning or constraints, they are prone to biased interpretation.

Biological evaluation and molecular dynamics simulation of water-soluble fullerene derivative C[C(COOH)].

One of the most studied fullerene members, C, has a potential of application in various fields of biomedicine including reactive oxygen species (ROS) scavenging activity, inhibiting of tumours development, inactivating of viruses and bacteria, as well as elaboration of diagnostic and targeted drug delivery tools. However, the hydrophobicity of this molecule impedes its practical use, therefore the actuality of the research devoted to functionalisation of fullerenes leading to amphiphilic derivatives remains important. In this work, the water-soluble carboxylated fullerene derivative C[C(COOH)] was studied.

Surface charged species and electrochemistry of ferroelectric thin films.

The combination of scanning probe microscopy and ambient pressure X-ray photoelectron spectroscopy opens up new perspectives for the study of combined surface chemical, electrochemical and electromechanical properties at the nanoscale, providing both nanoscale resolution of physical information and the chemical sensitivity required to identify surface species and bulk ionic composition. In this work, we determine the nature and evolution over time of surface chemical species obtained after water-mediated redox reactions on Pb(Zr0.2,Ti0.

[The experience of using cellex in treatment of patients with acute ischemic stroke].

Aim: To evaluate the efficacy and safety of the combination of cellex with basic therapy in patients with ischemic stroke in the acute stage.

Material And Methods: An analytical prospective, randomized, simple, blind study included 52 patients with ischemic stroke. The main group of patients (n=26) was treated with basic therapy, which included hypotensive drugs, antiaggregants or anticoagulants depending on the concomitant pathology as well as vascular medications.

Non-Ising and chiral ferroelectric domain walls revealed by nonlinear optical microscopy.

The properties of ferroelectric domain walls can significantly differ from those of their parent material. Elucidating their internal structure is essential for the design of advanced devices exploiting nanoscale ferroicity and such localized functional properties. Here, we probe the internal structure of 180° ferroelectric domain walls in lead zirconate titanate (PZT) thin films and lithium tantalate bulk crystals by means of second-harmonic generation microscopy.

Computer vision distortion correction of scanning probe microscopy images.

Since its inception, scanning probe microscopy (SPM) has established itself as the tool of choice for probing surfaces and functionalities at the nanoscale. Although recent developments in the instrumentation have greatly improved the metrological aspects of SPM, it is still plagued by the drifts and nonlinearities of the piezoelectric actuators underlying the precise nanoscale motion. In this work, we present an innovative computer-vision-based distortion correction algorithm for offline processing of functional SPM measurements, allowing two images to be directly overlaid with minimal error - thus correlating position with time evolution and local functionality.

Data systems for the Linac coherent light source.

The data systems for X-ray free-electron laser (FEL) experiments at the Linac coherent light source (LCLS) are described. These systems are designed to acquire and to reliably transport shot-by-shot data at a peak throughput of 5 GB/s to the offline data storage where experimental data and the relevant metadata are archived and made available for user analysis. The analysis and monitoring implementation (AMI) and Photon Science ANAlysis (psana) software packages are described.

Low-noise humidity controller for imaging water mediated processes in atomic force microscopy.

We demonstrate the construction of a novel low-noise continuous flow humidity controller and its integration with a commercial variable-temperature atomic force microscope fluid cell, allowing precise control of humidity and temperature at the sample during nanoscale measurements. Based on wet and dry gas mixing, the design allows a high mechanical stability to be achieved by means of an ultrasonic atomiser for the generation of water-saturated gas, improving upon previous bubbler-based architectures. Water content in the flow is measured both at the inflow and outflow of the fluid cell, enabling the monitoring of water condensation and icing, and allowing controlled variation of the sample temperature independently of the humidity.

Identification of a strong contamination source for graphene in vacuum systems.

To minimize parasitic doping effects caused by uncontrolled material adsorption, graphene is often investigated under vacuum. Here we report an entirely unexpected phenomenon occurring in vacuum systems, namely strong n-doping of graphene due to chemical species generated by common ion high-vacuum gauges. The effect-reversible upon exposing graphene to air-is significant, as doping rates can largely exceed 10(12) cm(-2) h(-1), depending on pressure and the relative position of the gauge and the graphene device.

Optimal ferromagnetically-coated carbon nanotube tips for ultra-high resolution magnetic force microscopy.

Using single-walled carbon nanotubes homogeneously coated with ferromagnetic metal as ultra-high resolution magnetic force microscopy probes, we investigate the key image formation parameters and their dependence on coating thickness. The crucial step of introducing molecular beam epitaxy for deposition of the magnetic coating allows highly controlled fabrication of tips with small magnetic volume, while retaining high magnetic anisotropy and prolonged lifetime characteristics. Calculating the interaction between the tips and a magnetic sample, including hitherto neglected thermal noise effects, we show that optimal imaging is achieved for a finite, intermediate-thickness magnetic coating, in excellent agreement with experimental observations.

Intrinsic terahertz plasmons and magnetoplasmons in large scale monolayer graphene.

We show that in graphene epitaxially grown on SiC the Drude absorption is transformed into a strong terahertz plasmonic peak due to natural nanoscale inhomogeneities, such as substrate terraces and wrinkles. The excitation of the plasmon modifies dramatically the magneto-optical response and in particular the Faraday rotation. This makes graphene a unique playground for plasmon-controlled magneto-optical phenomena thanks to a cyclotron mass 2 orders of magnitude smaller than in conventional plasmonic materials such as noble metals.

Direct measurement of the phi(1020) leptonic branching ratio.

The process e(+)e(-)-->mu(+)mu(-) has been studied by the SND detector at the VEPP-2M e(+)e(-) collider in the phi(1020)-resonance energy region. The measured effective phi meson leptonic branching ratio B(phi-->l(+)l(-)) identical with square root of B(phi-->e(+)e(-))B(phi-->mu(+)mu(-))] = (2.89 +/- 0.

Measurement of CP-violating asymmetries in B0 decays to CP eigenstates.

We present measurements of time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurement uses a data sample of 23x10(6) Upsilon(4S)-->BbarB decays collected by the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we find events in which one neutral B meson is fully reconstructed in a CP eigenstate containing charmonium and the flavor of the other neutral B meson is determined from its decay products.