Vacuum-free femtosecond fiber laser microplasma X-ray source for radiography.

Radiographic imaging using X-rays is a tool for basic research and applications in industry, materials science, and medical diagnostics. In this article, we present a novel approach for the generation of X-rays using a vacuum-free microplasma by femtosecond fiber laser. By tightly focusing a laser pulse onto a micrometer-sized solid density near-surface plasma from a rotating copper target, we demonstrate the generation of Cu K-photons (8-9 keV) with high yield ∼ 1.

Response of photosynthesis and electrical reactions of wheat plants upon the action of magnetic fields in the Schumann resonance frequency band.

Alternating magnetic fields (MF) with Schumann resonance frequencies accompanied the development of living organisms throughout evolution, but today it remains unclear whether they can have a special biological effect in comparison with surrounding non-resonant frequencies. This work shows some stimulating effect of extremely low-frequency MFs on morphometric parameters and the activity of physiological processes in wheat ( L.).

The Effect of an Extremely Low-Frequency Electromagnetic Field on the Drought Sensitivity of Wheat Plants.

Extremely low-frequency magnetic fields are thought to be capable of modulating the resistance of plants to adverse factors, particularly drought. Magnetic fields in this frequency range occur in nature in connection with so-called Schumann resonances, excited by lightning discharges in the Earth-ionosphere cavity. The aim of this work was to identify the influence of a magnetic field with a frequency of 14.

Single-shot femtosecond bulk micromachining of silicon with mid-IR tightly focused beams.

Being the second most abundant element on earth after oxygen, silicon remains the working horse for key technologies for the years. Novel photonics platform for high-speed data transfer and optical memory demands higher flexibility of the silicon modification, including on-chip and in-bulk inscription regimes. These are deepness, three-dimensionality, controllability of sizes and morphology of created modifications.

Dynamics of ultrafast phase transitions in MgF triggered by laser-induced THz coherent phonons.

The advent of free-electron lasers opens new routes for experimental high-pressure physics, which allows studying dynamics of condensed matter with femtosecond resolution. A rapid compression, that can be caused by laser-induced shock impact, leads to the cascade of high-pressure phase transitions. Despite many decades of study, a complete understanding of the lattice response to such a compression remains elusive.

Dynamics of Ultrafast Phase Transitions in (001) Si on the Shock-Wave Front.

We demonstrate an ultrafast (<0.1 ps) reversible phase transition in silicon (Si) under ultrafast pressure loading using molecular dynamics. Si changes its structure from cubic diamond to β-Sn on the shock-wave front.

Effect of extremely low-frequency magnetic fields on light-induced electric reactions in wheat.

Magnetic field oscillations resulting from atmospheric events could have an effect on growth and development of plants and on the responsive reactions of plants to other environmental factors. In the current work, extremely low-frequency magnetic field (14.3 Hz) was shown to modulate light-induced electric reactions of wheat ( L.

Time-resolved optical probing of the non-equilibrium supercritical state in molecular media under ns laser-plasma impact.

We proposed a complex method based on a combination of shadow photography and time-resolved Raman spectroscopy to observe the non-stationary laser-induced supercritical state in molecular media. Shadow photography is applied for retrieving pressure values, while Raman spectroscopy with molecular dynamics for temperature estimation. Time resolution of 0.

Change in H Transport across Thylakoid Membrane as Potential Mechanism of 14.3 Hz Magnetic Field Impact on Photosynthetic Light Reactions in Seedlings of Wheat ( L.).

Natural and artificial extremely low-frequency magnetic fields (ELFMFs) are important factors influencing physiological processes in living organisms including terrestrial plants. Earlier, it was experimentally shown that short-term and long-term treatments by ELFMFs with Schumann resonance frequencies (7.8, 14.

The Anomalous Behavior of Thermodynamic Parameters in the Three Widom Deltas of Carbon Dioxide-Ethanol Mixture.

Using molecular dynamics, we demonstrated that in the mixture of carbon dioxide and ethanol (25% molar fraction) there are three pronounced regions on the p-T diagram characterized by not only high-density fluctuations but also anomalous behavior of thermodynamic parameters. The regions are interpreted as Widom deltas. The regions were identified as a result of analyzing the dependences of density, density fluctuations, isobaric thermal conductivity, and clustering of a mixture of carbon dioxide and ethanol in a wide range of pressures and temperatures.

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).

Optical Diagnostics of Supercritical CO and CO-Ethanol Mixture in the Widom Delta.

The supercritical CO (scCO) is widely used as solvent and transport media in different technologies. The technological aspects of scCO fluid applications strongly depend on spatial-temporal fluctuations of its thermodynamic parameters. The region of these parameters' maximal fluctuations on the p-T (pressure-temperature) diagram is called Widom delta.

Extensive layer clouds in the global electric circuit: their effects on vertical charge distribution and storage.

A fair-weather electric field has been observed near the Earth's surface for over two centuries. The field is sustained by charge generation in distant disturbed weather regions, through current flow in the global electric circuit. Conventionally, the fair-weather part of the global circuit has disregarded clouds, but extensive layer clouds, important to climate, are widespread globally.

Role of wavelength in photocarrier absorption and plasma formation threshold under excitation of dielectrics by high-intensity laser field tunable from visible to mid-IR.

The development of high power mid-IR laser applications requires a study on laser induced damage threshold (LIDT) in the mid-IR. In this paper we have measured the wavelength dependence of the plasma formation threshold (PFT) that is a LIDT precursor. In order to interpret the observed trends numerically, a model describing the laser induced electron dynamics, based on multiple rate equations, has been developed.

The representation of ionospheric potential in the global chemistry-climate model SOCOL.

In this paper, we present the first results of the ionospheric potential (IP) calculations with the chemistry-climate model (CCM) SOCOL (Solar Climate Ozone Links). For the study, we exploit a parameterization of the difference in electric potential between Earth's surface and lower boundary of the ionosphere as a function of thunderstorm and electrified cloud properties. The model shows a good enough agreement with the IP obtained by balloon soundings.

Anomalous behavior of nonlinear refractive indexes of CO and Xe in supercritical states.

Direct measurement of pressure dependent nonlinear refractive index of CO and Xe in subcritical and supercritical states are reported. In the vicinity of the ridge (or the Widom line), corresponding to the maximum density fluctuations, the nonlinear refractive index reaches a maximum value (up to 4.8*10m/W in CO and 3.

Generation of an adjustable multi-octave supercontinuum under near-IR filamentation in gaseous, supercritical, and liquid carbon dioxide.

A new supercontinuum (SC) source from high-pressure gas, liquid, and supercritical fluid CO aggregate states that covers more than two octaves (from 400 nm up to 2 μm) is successively reported by using a 200 fs pulsed pump at 1.24 μm under femtosecond filamentation. The key features of the proposed source are the highly adjustable nonlinear properties (comparable with condensed matter) of the medium.

[Experience with using laser surgery in the treatment of benign diseases of the cervix uteri when it is deformed].

Contact AYG laser was used in surgery on the deformed cervix uteri for cervicosis. The suggested method of using a contact laser scalpel at the main stages of the operation for partial stratification and miniconization provides a reliable hemostasis, minimal injury to the tissues, sterility of the operation site, and in stratification of the cervix uteri--a sufficiently easy dissection of the desired layer. The authors emphasize the usefulness of a differentiated approach to the choice of the method of surgical intervention (conization, plasty by partial or complete stratification), permitting the surgeon to combine the radical character of a surgical intervention with sparing of the anatomical shape of the cervical canal, and thus providing functionally stable results.

[The surgical treatment of miscarriage in isthmus-cervix incompetence].

Long-term outcomes of stratifying cervicoplasty for organic isthmic-cervical incompetence have been evaluated in 38 women. Pregnancy was achieved in 32 women and continued to term in 22 women; there were 16 cesarean deliveries, and 6 women were delivered vaginally despite recommended operative delivery. Spontaneous abortions occurred in 5 surgically treated women and abortion was induced in 5.

[Effectiveness of various methods of the surgical treatment in cervix rupture during labor].

Long-term results of wound healing in patients with cervical ruptures were presented. The use of two-rowed and one-rowed catgut sutures in 384 and 98 parturients, respectively, was discussed. Employment of two-rowed sutures resulted in 95.