A Tutorial on Instrumental Parameters in Pulsed Force Kelvin Probe Force Microscopy.

For the creation of smaller and smaller electrical devices and fundamental studies, Kelvin Probe Force Microscopy (KPFM) offers a technique that measures the surface potential with nanometer lateral resolution and allows for a more precise understanding of properties such as the work function, the localization of charges and the doping of materials. Despite its obvious potential, the complexity of its implementation is currently a bottleneck for its extensive application. Here, we introduce a step-by-step overview of the different experimental parameters that need to be controlled in PF-KPFM to ensure their useful effect on the measured contact potential difference.

Synthesis of furanotriterpenoids from betulin and evaluation of Tyrosyl-DNA phosphodiesterase 1 (Tdp1) inhibitory properties of new semi-synthetic triterpenoids.

For the first time, a synthetic route for preparing lupane and oleanane derivatives with a hydrogenated furan ring as a cycle A of triterpene scaffold is described. Most of the synthesized compounds, furanoterpenoids and their synthetic intermediates, were non-toxic against the tested cancer and non-cancerous cell lines, and evinced significant inhibitory activity with IC 1.0-9.

Synthesis and Anticancer Activity of A-Ring-Modified Derivatives of Dihydrobetulin.

Multidrug resistance (MDR) is a common phenomenon in clinical oncology, whereby cancer cells become resistant to chemotherapeutic drugs A common MDR mechanism is the overexpression of ATP-binding cassette efflux transporters in cancer cells, with P-glycoprotein (P-gp) being one of them. New 3,4-seco-lupane triterpenoids, and the products of their intramolecular cyclization with the removed 4,4-gem-dimethyl group, were synthesized by the selective transformations of the A-ring of dihydrobetulin. Among the semi-synthetic derivatives, the MT-assay-enabled methyl ketone (), exhibiting the highest cytotoxicity (0.

The Molecular Mechanisms of Oleanane Aldehyde-β-enone Cytotoxicity against Doxorubicin-Resistant Cancer Cells.

Oleanane aldehyde-β-enone (), being the semi-synthetic derivative of the triterpenoid betulin, effectively inhibits the proliferation of HBL-100 and K562 cancer cells (IC 0.47-0.53 µM), as well as the proliferation of their resistant subclones with high P-gp expression HBL-100/Dox, K562/i-S9 and K562/i-S9_Dox (IC 0.

Surface flow for colonial integration in reef-building corals.

Reef-building corals are endangered animals with a complex colonial organization. Physiological mechanisms connecting multiple polyps and integrating them into a coral colony are still enigmatic. Using live imaging, particle tracking, and mathematical modeling, we reveal how corals connect individual polyps and form integrated polyp groups via species-specific, complex, and stable networks of currents at their surface.

Broadband terahertz generation by optical rectification of ultrashort multiterawatt laser pulses near the beam breakup threshold.

We identify the physical factors that limit the terahertz (THz) yield of an optical rectification (OR) of ultrashort multiterawatt laser pulses in large-area quadratically nonlinear crystals. We show that the THz yield tends to slow its growth as a function of the laser driver energy, saturate, and eventually decrease as the laser beam picks up a spatiotemporal phase due to the intensity-dependent refraction of the OR crystal. We demonstrate that, with a careful management of the driver intensity aimed at keeping the nonlinear length larger than the coherence length, OR-based broadband THz generation in large-area lithium niobate (LN) crystals is energy-scalable, enabling an OR of multiterawatt laser pulses, yielding ∼10µ/ of THz output energy per unit crystal area.

Statistical detection of synergy: New methods and a comparative study.

Combination therapies are increasingly adopted as the standard of care for various diseases to improve treatment response, minimise the development of resistance and/or minimise adverse events. Therefore, synergistic combinations are screened early in the drug discovery process, in which their potential is evaluated by comparing the observed combination effect to that expected under a null model. Such methodology is implemented in the BIGL R-package which allows for a quick screening of drug combinations.

Hybrid x-ray laser-plasma/laser-synchrotron facility for pump-probe studies of the extreme state of matter at NRC "Kurchatov Institute".

We developed a hybrid optical pump-x-ray probe facility based on the "Kurchatov's synchrotron radiation source" and terawatt (TW) femtosecond laser. The bright x-ray photon source is based on either synchrotron radiation [up to 6 × 10 photons/(s mm mrad 0.1% bandwidth)] or laser-plasma generators (up to 10 photons/sr/pulse).

STRENGTHENING SOCIETAL RESILIENCE DURING COVID-19 PANDEMIC.

Objective: The aim: To investigate factors that can negatively affect societal resilience in the context of the COVID-19 pandemic and identify communication aspects of strengthening resilience through information policy formation.

Patients And Methods: Materials and methods: In the research process, the authors employed the monographic and abstract-logical methods. The communication aspect analysis of strengthening social resilience in the context of the COVID-19 pandemic also grounded upon the results of the authors' sociological study "Motivation of compliance/non-compliance with quarantine restrictions by the population of Ukraine".

APPLICATION OF BEHAVIORAL ECONOMICS INSIGHTS TO INCREASE EFFECTIVENESS OF PUBLIC AWARENESS OF COVID-19.

Objective: The aim: To determine the level of public awareness of COVID-19 and information needs, as well as level of public confidence in both official information on COVID-19 and to develop recommendations for communication policy on longer-term awareness in pandemic settings COVID-19, using principles of behavioral economics.

Patients And Methods: Materials and methods: 4 focus group interviews were conducted in residents of Ukraine, with a total quantity of 48 people aged 16-70 years questioned and an anonymous questionnaire was conducted in 1,700 respondents, representing the adult population aged 18 years and older from all over Ukraine. The representative error of the study with probability of 0.

Malignant and benign thyroid nodule differentiation through the analysis of blood plasma with terahertz spectroscopy.

The liquid and lyophilized blood plasma of patients with benign or malignant thyroid nodules and healthy individuals were studied by terahertz (THz) time-domain spectroscopy and machine learning. The blood plasma samples from malignant nodule patients were shown to have higher absorption. The glucose concentration and miRNA-146b level were correlated with the sample's absorption at 1 THz.

Coherently enhanced microwave pulses from midinfrared-driven laser plasmas.

Ultrafast ionization of a gas medium driven by ultrashort midinfrared laser pulses provides a source of bright ultrabroadband radiation whose spectrum spans across the entire microwave band, reaching for the sub-gigahertz range. We combine multiple, mutually complementary detection techniques to provide an accurate polarization-resolved characterization of this broadband output as a function of the gas pressure. At low gas pressures, the lowest-frequency part of this output is found to exhibit a drastic enhancement as this field builds up its coherence, developing a well-resolved emission cone, dominated by a radial radiation energy flux.

Terahertz spectroscopy of diabetic and non-diabetic human blood plasma pellets.

Significance: The creation of fundamentally new approaches to storing various biomaterial and estimation parameters, without irreversible loss of any biomaterial, is a pressing challenge in clinical practice. We present a technology for studying samples of diabetic and non-diabetic human blood plasma in the terahertz (THz) frequency range.

Aim: The main idea of our study is to propose a method for diagnosis and storing the samples of diabetic and non-diabetic human blood plasma and to study these samples in the THz frequency range.

Direct nose to brain delivery of small molecules: critical analysis of data from a standardized screening model in rats.

The blood-brain barrier (BBB) is often a limiting factor for getting drugs in the brain. Bypassing the BBB by intranasal (IN), or also called nose to brain (NTB), route is an interesting and frequently investigated concept for brain drug delivery. However, despite the body of evidence for IN drug delivery in literature over the last decades, reproducibility and interpretation of animal data remain challenging.

Free-beam spectral self-compression at supercritical peak powers.

We demonstrate free-beam spectral self-compression of ~100-GW femtosecond laser pulses due to self-phase modulation (SPM) in a transparent dielectric. While all the earlier studies of SPM-induced spectral narrowing have been performed using optical fibers, experiments and simulations presented in this Letter show that this type of spectral transformation can be implemented as a part of a full three-dimensional field-waveform dynamics and can be extended to peak powers ∼10 times higher than the critical power of self-focusing. With a properly chosen initial chirp, spectral self-compression is accompanied by pulse compression, providing spectral-temporal mode self-compression as a whole.

BIGL: Biochemically Intuitive Generalized Loewe null model for prediction of the expected combined effect compatible with partial agonism and antagonism.

Clinical efficacy regularly requires the combination of drugs. For an early estimation of the clinical value of (potentially many) combinations of pharmacologic compounds during discovery, the observed combination effect is typically compared to that expected under a null model. Mechanistic accuracy of that null model is not aspired to; to the contrary, combinations that deviate favorably from the model (and thereby disprove its accuracy) are prioritized.

[Clinical and morphologic efficacy of a complex antioxidant and energy correction therapy of different duration in brain infarction: results of a multicenter randomized trial].

Aim: To compare clinical and morphological results of treatment of ischemic stroke in three groups of patients which differed by the forms and duration of an antioxidant therapy.

Material And Methods: A randomized clinical trial was performed in 8 vascular centers of the Russian Federation in 2010-2014. It included 373 patients with ischemic stroke in the carotid territory.

[Performance evaluation of integrated cytoprotective therapy of different duration in patients with cerebral infarction].

The paper reviews the preliminary results of a multicenter randomized clinical research. The aim of the study was to determine the optimal duration of different types of energy-correction therapy. 99 case report forms of patients with cerebral infarction were reviewed with their prior envelope randomization into three groups.

[Efficacy of antioxidant energocorreсtion in brain infarction (results of a multicenter randomized trial)].

Objective: To determine the optimal duration of energy corrective treatment of ischemic stroke (II) with cytoflavin or ascorbic acid.

Material And Methods: A multicenter randomized clinical trial included 185 patients, aged 40-75 years. Patients were randomized into 3 groups: the control group (n=64) received ascorbic acid; cytoflavin group 1 (n=72) was treated for 10 days and cytoflavin group 2 (n=49) for 20 days.

[Modern methods of energy homeostasis correction in elderly patients].

In the multicenter randomized clinical-instrumental prospective study 185 patients aged 55-75 years (mean age 68 years) with 94 men and 91 women with cerebral infarction were included. All the patients were hospitalized in the period from 6 to 24 hours from the time of the debut of clinical symptoms, 42,2% of patients scored 14 and above on NIH scale on admission. Patients were randomized into 3 groups: 1st group consisted of 64 patients treated as an antioxidant by 5% solution of ascorbic acid 2 times a day the recommended dose (20 ml/day) for 20 days; 2nd group consisted of 72 patients who received energy monitor Cytoflavin in a daily dose of 20 ml (10.

Polarization selection rules and optical transitions in terbium activated yttrium tantalate phosphor under x-ray, vacuum-ultraviolet, and ultraviolet excitations.

The terbium-activated yttrium tantalite (YTaO(4):Tb(3+)) phosphor is of great interest due to the interesting spectroscopic properties of rare earth ions in crystals and also practical use in x-ray imaging. Using the group-theoretical approach, we analyze the selection rules for the transition between Stark components of Tb(3+) in symmetry of the actual crystal field and the polarization for the allowed transitions. The luminescence upon UV, vacuum-ultraviolet (VUV), and x-ray excitation is presented and discussed.

Design rules for phase-matched terahertz surface electromagnetic wave generation by optical rectification in a nonlinear planar waveguide.

The theory of guided waves in metal-dielectric planar multilayer structures is applied to reduce the loss and maximize optical nonlinearity for efficient terahertz-field generation in a surface electromagnetic wave by femtosecond laser pulses confined in a (chi)((2)) nonlinear planar waveguide. For typical parameters of thin-film polymer waveguides and metal-dielectric interfaces, the optimal size of the (chi)((2)) waveguide core providing the maximum efficiency of terahertz plasmon-field generation is shown to be less than the wavelength of the optical pump field.

Fibonacci-like photonic structure for femtosecond pulse compression.

The compression of femtosecond laser pulses by linear quasiperiodic and periodic photonic multilayer structures is studied both experimentally and theoretically. We compare the compression performance of a Fibonacci and a periodic structure with similar total thickness and the same number of layers, and find the performance to be higher in the Fibonacci case, as predicted by numerical simulation. This compression enhancement takes place due to the larger group velocity dispersion at a defect resonance of the transmission spectrum of the Fibonacci structure.

Space weathering on airless planetary bodies: clues from the lunar mineral hapkeite.

Physical and chemical reactions occurring as a result of the high-velocity impacts of meteorites and micrometeorites and of cosmic rays and solar-wind particles are major causes of space weathering on airless planetary bodies, such as the Moon, Mercury, and asteroids. These weathering processes are responsible for the formation of their regolith and soil. We report here the natural occurrence of the mineral hapkeite, a Fe2Si phase, and other associated Fe-Si phases (iron-silicides) in a regolith breccia clast of a lunar highland meteorite.