Doppler backscattering diagnostic with dual homodyne detection on the Globus-M compact spherical tokamak.

This article considers a four-frequency microwave Doppler backscattering (DBS) system in the compact spherical tokamak Globus-M. The hardware was adequate for the purposes of studying the peripheral plasma in the tokamak. The multichannel DBS system is based on duplication of a dual homodyne detection circuit for four incident Ka-band frequencies. The ray tracing results for a spherical torus are described, and specific requirements for the antenna tilt adjustment are defined. Some new experimental results are given for using DBS diagnostics on the Globus-M tokamak in order to illustrate its efficiency.

[Contribution of chromosomal microarray analysis by a multidisciplinary prenatal diagnosis center]. / Apport de l'analyse chromosomique par puce à ADN dans un centre de diagnostic prénatal pluridisciplinaire.

OBJECTIVE: Chromosomal analysis by array CGH is a cytogenetic technique that has opened its application to prenatal diagnosis in recent years. The main objective of the study was to analyze the contribution for couples using chromosomal analysis by array CGH in a CPDPN. METHODS: A retrospective cohort study was conducted in 2015 in a CPDPN. All the patients with array CGH analysis were included in the study. The analysis indications were CN≥3.5mm, ultrasound signs, intra-uterine growth retardation and fetal deaths. Data were collected in the prenatal diagnosis and genetic records. RESULTS: In total, 155 patients underwent analysis by array CGH, which corresponds to 36% of patients with invasive sampling indication. Fifteen CGH analysis were positive which represents 9.6% of indications. None of those diagnoses was possible with standard karyotype. These positive results have changed the outcome of pregnancy and what to do for a future pregnancy in 54% of cases. CONCLUSION: Array CGH enables a diagnostic gain despite a delicate interpretation and changes taking care of patients in future pregnancies. These results should be confirmed in a prospective multicenter study.

[Modern approaches to the study of sanitary and irretrievable losses of surgical nrofile in military].

The article presents a comparative characteristics of domestic and foreign approaches to the static analysis of losses of surgical profile in military conflicts. The ways of improvements of statistical materials on military losses for improvement of surgical aid delivery are mapped out. The authors proved the need to establish the register of combat trauma.

Laser-induced transformation of supramolecular complexes: approach to controlled formation of hybrid multi-yolk-shell Au-Ag@a-C:H nanostructures.

In the present work an efficient approach of the controlled formation of hybrid Au-Ag-C nanostructures based on laser-induced transformation of organometallic supramolecular cluster compound is suggested. Herein the one-step process of the laser-induced synthesis of hybrid multi-yolk-shell Au-Ag@a-C:H nanoparticles which are bimetallic gold-silver subnanoclusters dispersed in nanospheres of amorphous hydrogenated a-C:H carbon is reported in details. It has been demonstrated that variation of the experimental parameters such as type of the organometallic precursor, solvent, deposition geometry and duration of laser irradiation allows directed control of nanoparticles' dimension and morphology. The mechanism of Au-Ag@a-C:H nanoparticles formation is suggested: the photo-excitation of the precursor molecule through metal-to-ligand charge transfer followed by rupture of metallophilic bonds, transformation of the cluster core including red-ox intramolecular reaction and aggregation of heterometallic species that results in the hybrid metal/carbon nanoparticles with multi-yolk-shell architecture formation. It has been found that the nanoparticles obtained can be efficiently used for the Surface-Enhanced Raman Spectroscopy label-free detection of human serum albumin in low concentration solution.

Direct laser writing of µ-chips based on hybrid C-Au-Ag nanoparticles for express analysis of hazardous and biological substances.

Micro-chips based on organic-inorganic hybrid nanoparticles (NPs) composed of nanoalloys of gold (Au) and silver (Ag) embedded in an amorphous carbonaceous matrix (C-Au-Ag NPs) were prepared directly on a substrate by the laser-induced deposition (for short: LID) method. The C-Au-Ag NPs show a unique plasmon resonance which enhances Raman scattering of analytes, making the µ-chips suitable to detect ultra-low-volumes (10(-12) liter) and concentrations (10(-9) M) of bio-agents and a hazardous compound. These micro-chips constitute a novel, flexible solid-state device that can be used for applications in point-of-care diagnostics, consumer electronics, homeland security and environmental monitoring.

Optoacoustic monitoring of cerebral venous blood oxygenation though intact scalp in large animals.

Monitoring (currently invasive) of cerebral venous blood oxygenation is a key to avoiding hypoxia-induced brain injury resulting in death or severe disability. Noninvasive, optoacoustic monitoring of cerebral venous blood oxygenation can potentially replace existing invasive methods. To the best of our knowledge, we report for the first time noninvasive monitoring of cerebral venous blood oxygenation through intact scalp that was validated with invasive, "gold standard" measurements. We performed an in vivo study in the sheep superior sagittal sinus (SSS), a large midline cerebral vein, using our novel, multi-wavelength optoacoustic system. The study results demonstrated that: 1) the optoacoustic signal from the sheep SSS is detectable through the thick, intact scalp and skull; 2) the SSS signal amplitude correlated well with wavelength and actual SSS blood oxygenation measured invasively using SSS catheterization, blood sampling, and measurement with "gold standard" CO-Oximeter; 3) the optoacoustically predicted oxygenation strongly correlated with that measured with the CO-Oximeter. Our results indicate that monitoring of cerebral venous blood oxygenation may be performed in humans noninvasively and accurately through the intact scalp using optoacoustic systems because the sheep scalp and skull thickness is comparable to that of humans whereas the sheep SSS is much smaller than that of humans.

Optoacoustic monitoring of cerebral venous blood oxygenation through extracerebral blood.

There is strong clinical evidence that controlling cerebral venous oxygenation (oxyhemoglobin saturation) is critically important for patients with severe traumatic brain injury as well as for patients undergoing cardiac surgery. However, the only available method for cerebral venous blood oxygenation monitoring is invasive and requires catheterization of the internal jugular vein. We designed and built a novel optoacoustic monitor of cerebral venous oxygenation as measured in the superior sagittal sinus (SSS), the large midline cerebral vein. To the best of our knowledge, optical monitoring of cerebral venous blood oxygenation through overlying extracerebral blood is reported for the first time in this paper. The system was capable of detecting SSS signals in vivo at 700, 800, and 1064 nm through the thick (5-6 mm) sheep skull containing the circulating blood. The high (submillimeter) in-depth resolution of the system provided identification of the SSS peaks in the optoacoustic signals. The SSS peak amplitude closely followed the actual SSS blood oxygenation measured invasively using catheterization, blood sampling, and "gold standard" CO-Oximetry. Our data indicate the system may provide accurate measurement of the SSS blood oxygenation in patients with extracerebral blood over the SSS.

Release and elementary mechanisms of nitric oxide in hair cells.

The enzyme nitric oxide (NO) synthase, that produces the signaling molecule NO, has been identified in several cell types in the inner ear. However, it is unclear whether a measurable quantity of NO is released in the inner ear to confer specific functions. Indeed, the functional significance of NO and the elementary cellular mechanism thereof are most uncertain. Here, we demonstrate that the sensory epithelia of the frog saccule release NO and explore its release mechanisms by using self-referencing NO-selective electrodes. Additionally, we investigated the functional effects of NO on electrical properties of hair cells and determined their underlying cellular mechanism. We show detectable amounts of NO are released by hair cells (>50 nM). Furthermore, a hair-cell efferent modulator acetylcholine produces at least a threefold increase in NO release. NO not only attenuated the baseline membrane oscillations but it also increased the magnitude of current required to generate the characteristic membrane potential oscillations. This resulted in a rightward shift in the frequency-current relationship and altered the excitability of hair cells. Our data suggest that these effects ensue because NO reduces whole cell Ca(2+) current and drastically decreases the open probability of single-channel events of the L-type and non L-type Ca(2+) channels in hair cells, an effect that is mediated through direct nitrosylation of the channel and activation of protein kinase G. Finally, NO increases the magnitude of Ca(2+)-activated K(+) currents via direct NO nitrosylation. We conclude that NO-mediated inhibition serves as a component of efferent nerve modulation of hair cells.

Suppression of n=1 tilt instability by magnetic shaping coils in Rotamak plasmas.

Measurements from the array of Mirnov magnetic coils provide the first evidence for n=1 tilt and radial shift instabilities in a 40 ms field-reversed configuration (FRC) driven by rotating magnetic field. External plasma-shaping magnetic coils are utilized to suppress the n=1 instability modes. It is demonstrated that by energizing the middle shaping coil with 250-500 A current, the tilt mode is completely suppressed when a doublet FRC with an internal figure-of-eight separatrix is formed.

Noninvasive monitoring of cerebral blood oxygenation in ovine superior sagittal sinus with novel multi-wavelength optoacoustic system.

Noninvasive monitoring of cerebral blood oxygenation with an optoacoustic technique offers advantages over current invasive and noninvasive methods. We report the results of in vivo studies in the sheep superior sagittal sinus (SSS), a large central cerebral vein. We changed blood oxygenation by increasing and decreasing the inspired fraction of oxygen (FiO(2)). Optoacoustic measurements from the SSS were performed at wavelengths of 700, 800, and 1064 nm using an optical parametric oscillator as a source of pulsed near-infrared light. Actual oxygenation of SSS blood was measured with a CO-Oximeter in blood samples drawn from the SSS through a small craniotomy. The amplitude of the optoacoustic signal induced in the SSS blood at lambda = 1064 nm closely followed the changes in blood oxygenation, at lambda = 800 nm was almost constant, and at lambda = 700 nm was changing in the opposite direction, all in accordance with the absorption spectra of oxy- and deoxyhemoglobin. The optoacoustically predicted oxygenation correlated well with actual blood oxygenation in sheep SSS (R(2) = 0.965 to 0.990). The accuracy was excellent, with a mean difference of 4.8% to 9.3% and a standard deviation of 2.8% to 4.2%. To the best of our knowledge, this paper reports for the first time accurate measurements of cerebral venous blood oxygenation validated against the "gold standard" CO-Oximetry method.

In vivo monitoring of blood oxygenation in large veins with a triple-wavelength optoacoustic system.

A noninvasive optoacoustic technique could be a clinically useful alternative to existing, invasive methods for cerebral oxygenation monitoring. Recently we proposed to use an optoacoustic technique for monitoring cerebral blood oxygenation by probing large cerebral and neck veins including the superior sagittal sinus and the internal jugular vein. In these studies we used a multi-wavelength optoacoustic system with a nanosecond optical parametric oscillator as a light source and a custom-made optoacoustic probe for the measurement of the optoacoustic signals in vivo from the area of the sheep neck overlying the external jugular vein, which is similar in diameter and depth to the human internal jugular vein. Optoacoustic signals induced in venous blood were measured with high resolution despite the presence of a thick layer of tissues (up to 10 mm) between the external jugular vein and the optoacoustic probe. Three wavelengths were chosen to provide accurate and stable measurements of blood oxygenation: signals at 700 nm and 1064 nm demonstrated high correlation with actual oxygenation measured invasively with CO-Oximeter ("gold standard"), while the signal at 800 nm (isosbestic point) was independent of blood oxygenation and was used for calibration.

Accurate, noninvasive measurement of total hemoglobin concentration with optoacoustic technique.

The measurement of total hemoglobin concentration is currently invasive and time consuming. The optoacoustic technique may provide accurate and noninvasive measurements of total hemoglobin concentration by probing blood vessels. We studied the influence of blood vessel diameter and lateral displacement of the optoacoustic probe on accuracy of total hemoglobin concentration measurements with this technique.

In vivo noninvasive monitoring of cerebral blood with optoacoustic technique.

We present the results of blood oxygenation (oxyhemoglobin saturation) measurements using an optoacoustic system in vivo in the superior sagittal sinus of sheep. The system included a nanosecond Nd:YAG laser as a source of radiation and a specially designed optoacoustic probe for signal detection. The optoacoustic signal induced in the superior sagittal sinus by the nanosecond laser pulses correlated well with actual oxyhemoglobin saturation measured with CO-oximeter. We propose to use a two- or multi- wavelength optoacoustic system for noninvasive continuous monitoring of cerebral venous blood oxygenation. The spectra of effective attenuation coefficient were measured in the range 680-1300 nm for oxy- and deoxygenated whole blood and can be employed for calibration of the system.

Optoacoustic technique for continuous, noninvasive measurement of total hemoglobin concentration: an in vivo study.

We used an optoacoustic technique to measure continuously and noninvasively total hemoglobin concentration in human blood in vivo. An optoacoustic probe, which combined illuminating fibers and a piezoelectric sensitive element, was placed in contact with the skin over the radial artery. Measurements in healthy volunteers agreed well with actual hemoglobin concentration.