[Study of the resistome of human microbial communities using a targeted panel of antibiotic resistance genes in COVID-19 patients]

AIM

To study overall drug resistance genes (resistome) in the human gut microbiome and the changes in these genes during COVID-19 in-hospital therapy.

MATERIALS AND METHODS

A single-center retrospective cohort study was conducted. Only cases with laboratory-confirmed SARS-CoV-2 RNA using polymerase chain reaction in oro-/nasopharyngeal swab samples were subject to analysis. The patients with a documented history of or current comorbidities of the hepatobiliary system, malignant neoplasms of any localization, systemic and autoimmune diseases, as well as pregnant women were excluded. Feces were collected from all study subjects for subsequent metagenomic sequencing. The final cohort was divided into two groups depending on the disease severity: mild (group 1) and severe (group 2). Within group 2, five subgroups were formed, depending on the use of antibacterial drugs (ABD): group 2A (receiving ABD), group 2AC (receiving ABD before hospitalization), group 2AD (receiving ABD during hospitalization), group 2AE (receiving ABD during and before hospitalization), group 2B (not receiving ABD).

RESULTS

The median number of antibiotic resistance (ABR) genes (cumulative at all time points) was significantly higher in the group of patients treated with ABD: 81.0 (95% CI 73.8-84.5) vs. 51.0 (95% CI 31.1-68.4). In the group of patients treated with ABD (2A), the average number of multidrug resistance genes (efflux systems) was significantly higher than in controls (group 2B): 47.0 (95% CI 46.0-51.2) vs. 21.5 (95% CI 7.0-43.9). Patients with severe coronavirus infection tended to have a higher median number of ABR genes but without statistical significance. Patients in the severe COVID-19 group who did not receive ABD before and during hospitalization also had more resistance genes than the patients in the comparison group.

CONCLUSION

This study demonstrated that fewer ABR genes were identified in the group with a milder disease than in the group with a more severe disease associated with more ABR genes, with the following five being the most common: SULI, MSRC, ACRE, EFMA, SAT.

Hot-electron preheat and mitigation in polar-direct-drive experiments at the National Ignition Facility

Target preheat by superthermal electrons from laser-plasma instabilities is a major obstacle to achieving thermonuclear ignition via direct-drive inertial confinement fusion at the National Ignition Facility (NIF). Polar-direct-drive surrogate plastic implosion experiments were performed on the NIF to quantify preheat levels at an ignition-relevant scale and develop mitigation strategies. The experiments were used to infer the hot-electron temperature, energy fraction, and divergence, and to directly measure the spatial hot-electron energy deposition profile inside the imploding shell. Silicon layers buried in the ablator are shown to mitigate the growth of laser-plasma instabilities and reduce preheat, providing a promising path forward for ignition designs at an on-target intensity of about 10^{15}W/cm^{2}.

Direct Measurements of DT Fuel Preheat from Hot Electrons in Direct-Drive Inertial Confinement Fusion

Hot electrons generated by laser-plasma instabilities degrade the performance of laser-fusion implosions by preheating the DT fuel and reducing core compression. The hot-electron energy deposition in the DT fuel has been directly measured for the first time by comparing the hard x-ray signals between DT-layered and mass-equivalent ablator-only implosions. The electron energy deposition profile in the fuel is inferred through dedicated experiments using Cu-doped payloads of varying thickness. The measured preheat energy accurately explains the areal-density degradation observed in many OMEGA implosions. This technique can be used to assess the viability of the direct-drive approach to laser fusion with respect to the scaling of hot-electron preheat with laser energy.

Direct-drive laser fusion: status, plans and future

Laser-direct drive (LDD), along with laser indirect (X-ray) drive (LID) and magnetic drive with pulsed power, is one of the three viable inertial confinement fusion approaches to achieving fusion ignition and gain in the laboratory. The LDD programme is primarily being executed at both the Omega Laser Facility at the Laboratory for Laser Energetics and at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. LDD research at Omega includes cryogenic implosions, fundamental physics including material properties, hydrodynamics and laser-plasma interaction physics. LDD research on the NIF is focused on energy coupling and laser-plasma interactions physics at ignition-scale plasmas. Limited implosions on the NIF in the 'polar-drive' configuration, where the irradiation geometry is configured for LID, are also a feature of LDD research. The ability to conduct research over a large range of energy, power and scale size using both Omega and the NIF is a major positive aspect of LDD research that reduces the risk in scaling from OMEGA to megajoule-class lasers. The paper will summarize the present status of LDD research and plans for the future with the goal of ultimately achieving a burning plasma in the laboratory. This article is part of a discussion meeting issue 'Prospects for high gain inertial fusion energy (part 2)'.

Analysis of the He-, Ar- and Kr-broadening coefficients of water vapor transitions in a wide spectral region

An analysis of the measured He-, Ar- and Kr- broadening coefficients γ for 1575 water vapor transitions of 27 vibrational bands belonging to the 0.6-11,200 cm^-1 spectral region is performed using an empirical function that contains adjustable parameters. A universal function is detected during the analysis. This function depends on the parameters that are common for all perturbers A = (He, Ar or Kr). A universal function multiplied by one additional parameter x₂₀(A) determines the broadening coefficients γ(A) for each perturber A = (He, Ar or Kr).Two fitting procedures are used. The first considers the fit of measured γ(exp) for individual rotational branches while the other considers the global fit of all 1575 measured γ(exp). In the second procedure, ratios of γ(Kr)/γ(He) = 2.543 ± 0.040 and γ(Kr)/γ(Ar) = 1.252 ± 0.036 are found. The coefficients derived from the fitted parameters are compared statistically to measured coefficients.

Geometrical-optics computer model of metal-knitted mesh for calculations of solar pressure on space deployable antenna reflectors

A novel computer 3D model is presented for calculations of optical parameters (transmittance, reflectance, and absorbance) of a metal-knitted mesh textile as a structural element of deployable antenna reflectors for space satellites. The model is based on geometrical-optics ray tracing upon diffuse scattering of a broadband light source (Sun) at a complex knitted mesh structure with different inclinations to the radiative source. The proposed computer model is built for the special type of metal-wire textile (two-bar large void tricot) possessing extremely high transmittance and is verified by comparison with the experimental measurements of light scattering parameters of real antenna mesh samples of data-relaying satellites (Russian series "Loutch"). The model is used for calculations of solar radiation pressure exerted on a knitted mesh antenna reflector and gives the maximal pressure value of about 0.28  μN/m².

Study of the H2O dipole moment and polarisability vibrational dependence by the analysis of rovibrational line shifts

The study of the H₂O dipole moment μ and polarisability α vibrational dependence is based on the comparison of experimental and calculated line shifts induced by argon, nitrogen, and air pressure in different H₂O vibrational bands. Obtained dependence α on the stretching vibrations is in good agreement with the existing ab initio calculations in the literature, but the dependence α on the bending vibration is quite different. To clarify the dependence of μ and α on the bending vibration, the shifts of selected H₂O lines of the 4ν₂, 5ν₂, and 6ν₂ bands induced by argon, hydrogen and helium pressure are measured with the help of a Bruker IFS HR 125 spectrometer at room temperature with a spectral resolution of 0.01 cm^-1. The comparison of experimental and calculated results with different values of μ and α line shifts is given.

Theory and measurements of convective Raman side scatter in inertial confinement fusion experiments

Raman side scatter, whereby scattered light is resonant while propagating perpendicularly to a density gradient in a plasma, was identified experimentally in planar-target experiments at the National Ignition Facility at intensities orders of magnitudes below the threshold for absolute instability. We have derived a new theoretical description of convective Raman side scatter below the absolute threshold, validated by numerical simulations. We show that inertial confinement fusion experiments at full ignition scale, i.e., with mm-scale spot sizes and density scale lengths, are prone to increased coupling losses from Raman side scatter as the instability can extend from the absolute regime near the quarter-critical density to the convective regime at lower electron densities.

Tripled yield in direct-drive laser fusion through statistical modelling

Focusing laser light onto a very small target can produce the conditions for laboratory-scale nuclear fusion of hydrogen isotopes. The lack of accurate predictive models, which are essential for the design of high-performance laser-fusion experiments, is a major obstacle to achieving thermonuclear ignition. Here we report a statistical approach that was used to design and quantitatively predict the results of implosions of solid deuterium-tritium targets carried out with the 30-kilojoule OMEGA laser system, leading to tripling of the fusion yield to its highest value so far for direct-drive laser fusion. When scaled to the laser energies of the National Ignition Facility (1.9 megajoules), these targets are predicted to produce a fusion energy output of about 500 kilojoules-several times larger than the fusion yields currently achieved at that facility. This approach could guide the exploration of the vast parameter space of thermonuclear ignition conditions and enhance our understanding of laser-fusion physics.

[The use of extra-intracranial microanastomosis in the treatment of cerebral ischemia in patients with nontraumatic subarachnoid hemorrhage]

OBJECTIVE

to evaluate the use of extra-intracranial microanastomosis (EICMA) in the treatment of brain ischemia in patients with nontraumatic subarachnoid hemorrhage (SAH).

MATERIAL AND METHODS

In the period from 01.01.14 to 01.07.15, there were 229 surgeries for ruptured intracranial aneurysms performed in the urgent surgery unit. Nine patients with marked and widespread angiospasm, subcompensated and decompensated cerebral ischemia underwent the simultaneous clipping of ruptured intracranial aneurysms and EICMA. The age of patients varied from 32 to 52 years (mean 36 years). The severity of patient's state was assessed as III-IV grades on the Hunt and Hess scale before operation. The surgery was performed 1-2 days after admission to the hospital, 1-8 days after the development of SAH.

RESULTS AND CONCLUSION

Excellent and good outcome was recorded in 4 patients, severe disability in 3 patients, fatal outcome in 2 patients. The fatal outcome was due to decompensated cerebral ischemia and progressive angiospasm with the high linear blood flow rate and the following reduction in perfusion in the affected hemisphere. The simultaneous clipping of ruptured intracranial aneurysms and EICMA in the acute stage of SAH of patients with subcompensated cerebral ischemia allow to improve treatment

RESULTS

This technique is most applicable for patients with proximal angiospasm of M1- and M2-segments of the middle cerebral artery in the first 24 h of the development of a focal neurological deficit supported by the reduction in perfusion in the corresponding vascular area.

Readout models for BaFBr0.85I0.15:Eu image plates

The linearity of the photostimulated luminescence process makes repeated image-plate scanning a viable technique to extract a more dynamic range. In order to obtain a response estimate, two semi-empirical models for the readout fading of an image plate are introduced; they relate the depth distribution of activated photostimulated luminescence centers within an image plate to the recorded signal. Model parameters are estimated from image-plate scan series with BAS-MS image plates and the Typhoon FLA 7000 scanner for the hard x-ray image-plate diagnostic over a collection of experiments providing x-ray energy spectra whose approximate shape is a double exponential.

Origins and Scaling of Hot-Electron Preheat in Ignition-Scale Direct-Drive Inertial Confinement Fusion Experiments

Planar laser-plasma interaction (LPI) experiments at the National Ignition Facility (NIF) have allowed access for the first time to regimes of electron density scale length (∼500 to 700  μm), electron temperature (∼3 to 5 keV), and laser intensity (6 to 16×10^{14}  W/cm^{2}) that are relevant to direct-drive inertial confinement fusion ignition. Unlike in shorter-scale-length plasmas on OMEGA, scattered-light data on the NIF show that the near-quarter-critical LPI physics is dominated by stimulated Raman scattering (SRS) rather than by two-plasmon decay (TPD). This difference in regime is explained based on absolute SRS and TPD threshold considerations. SRS sidescatter tangential to density contours and other SRS mechanisms are observed. The fraction of laser energy converted to hot electrons is ∼0.7% to 2.9%, consistent with observed levels of SRS. The intensity threshold for hot-electron production is assessed, and the use of a Si ablator slightly increases this threshold from ∼4×10^{14} to ∼6×10^{14}  W/cm^{2}. These results have significant implications for mitigation of LPI hot-electron preheat in direct-drive ignition designs.

An algorithm for filtering detector instabilities in search of novel non-exponential decay and in conventional half-life determinations

Recent reports of Solar modulation of beta-decay have reignited interest in whether or not radioactive half-lives are constants. A numerical approach for filtering instrumental effects on residuals is developed, using correlations with atmospheric conditions recorded while counting ²⁰⁴Tl emissions with a Geiger-Müller counter. Half-life oscillations and detection efficiency oscillations can be separated provided their periods are substantially different. A partial uncertainty budget for the ²⁰⁴Tl half-life shows significant decreases to medium-frequency instabilities correlated with pressure and temperature, which suggests that further development may aid general improvements in half-life determinations.

A high-resolving-power x-ray spectrometer for the OMEGA EP Laser (invited)

A high-resolving-power x-ray spectrometer has been developed for the OMEGA EP Laser System based on a spherically bent Si [220] crystal with a radius of curvature of 330 mm and a Spectral Instruments (SI) 800 Series charge-coupled device. The instrument measures time-integrated x-ray emission spectra in the 7.97- to 8.11-keV range, centered on the Cu K_α1 line. To demonstrate the performance of the spectrometer under high-power conditions, K_α1,2 emission spectra were measured from Cu foils irradiated by the OMEGA EP laser with 100-J, 1-ps pulses at focused intensities above 10¹⁸ W/cm². The ultimate goal is to couple the spectrometer to a picosecond x-ray streak camera and measure temperature-equilibration dynamics inside rapidly heated materials. The plan for these ultrafast streaked x-ray spectroscopy studies is discussed.

[Guidelines for the management of severe traumatic brain injury. Part 3. Surgical management of severe traumatic brain injury (Options)]

Traumatic brain injury (TBI) is one of the main causes of mortality and severe disability in young and middle age patients. Patients with severe TBI, who are in coma, are of particular concern. Adequate diagnosis of primary brain injuries and timely prevention and treatment of secondary injury mechanisms markedly affect the possibility of reducing mortality and severe disability. The present guidelines are based on the authors' experience in developing international and national recommendations for the diagnosis and treatment of mild TBI, penetrating gunshot wounds of the skull and brain, severe TBI, and severe consequences of brain injury, including a vegetative state. In addition, we used the materials of international and national guidelines for the diagnosis, intensive care, and surgical treatment of severe TBI, which were published in recent years. The proposed recommendations for surgical treatment of severe TBI in adults are addressed primarily to neurosurgeons, neurologists, neuroradiologists, anesthesiologists, and intensivists who are routinely involved in treating these patients.

Demonstration of Fuel Hot-Spot Pressure in Excess of 50 Gbar for Direct-Drive, Layered Deuterium-Tritium Implosions on OMEGA

A record fuel hot-spot pressure P_{hs}=56±7  Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium-tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility, these implosions achieved a Lawson parameter ∼60% of the value required for ignition [A. Bose et al., Phys. Rev. E 93, 011201(R) (2016)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is approximately 40% lower. Three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.

[Guidelines for the diagnosis and treatment of severe traumatic brain injury. Part 2. Intensive care and neuromonitoring]

Traumatic brain injury (TBI) is one of the major causes of death and disability in young and middle-aged people. The most problematic group is comprised of patients with severe TBI who are in a coma. The adequate diagnosis of primary brain injuries and timely prevention and treatment of the secondary injury mechanisms largely define the possibility of reducing mortality and severe disabling consequences. When developing these guidelines, we used our experience in the development of international and national recommendations for the diagnosis and treatment of mild traumatic brain injury, penetrating gunshot wounds to the skull and brain, severe traumatic brain injury, and severe consequences of brain injuries, including a vegetative state. In addition, we used international and national guidelines for the diagnosis, intensive care, and surgical treatment of severe traumatic brain injury, which had been published in recent years. The proposed guidelines concern intensive care of severe TBI in adults and are particularly intended for neurosurgeons, neurologists, neuroradiologists, anesthesiologists, and intensivists who are routinely involved in the treatment of these patients.

Two-Plasmon Decay Mitigation in Direct-Drive Inertial-Confinement-Fusion Experiments Using Multilayer Targets

Multilayer direct-drive inertial-confinement-fusion targets are shown to significantly reduce two-plasmon decay (TPD) driven hot-electron production while maintaining high hydrodynamic efficiency. Implosion experiments on the OMEGA laser used targets with silicon layered between an inner beryllium and outer silicon-doped plastic ablator. A factor-of-5 reduction in hot-electron generation (>50  keV) was observed in the multilayer targets relative to pure CH targets. Three-dimensional simulations of the TPD-driven hot-electron production using a laser-plasma interaction code (lpse) that includes nonlinear and kinetic effects show good agreement with the measurements. The simulations suggest that the reduction in hot-electron production observed in the multilayer targets is primarily caused by increased electron-ion collisional damping.

[POSITIVE END-EXPIRATORY PRESSURE (PEEP) INFLUENCES ON INTRACRANIAL PRESSURE, SYSTEMIC HEMODYNAMICS AND PULMONARY GAS EXCHANGE IN PATIENTS WITH INTRACRANIAl HEMORRHAGE IN CRITICAL STATE]

Positive end-expiratory pressure is one of the main parameters of respiratory support influencing the gas exchange. However, despite the number ofpositive effects, PEEP can compromise venous outflow from the cranial cavity, increased intracranial pressure, decreased venous return and cardiac output and, consequently, reduced blood pressure and cerebral perfusion. The article presents the results of a survey of 39 patients with intracranial hemorrhage in critical state, undergoing respiratory support with different levels of positive end-expiratory pressure. Increasing of PEEP to 15 cm H2O had no adverse effect on mean arterial pressure, heart rate and cerebral perfusion pressure and led only to an clinical insignificant increase (maximum on 2.4 +/- 5.1 mmHg) in intracranial pressure. The greatest hemodynamic changes were observed with increasing PEEP up to 20 cm H2O in patients with preserved compliance ofthe respiratory system. The instability of cerebral perfusion and intracranial pressure associated with a decrease in cardiac output and preload and the exhaustion of compensatory mechanism of peripheral vascular resistance. High levels of PEEP despite the trend towards Cstat reduction will not lead to an increase in the content of extravascular lung water Thus a gradual increase of PEEP to 15 cm H2O can be safe and effective method of improving pulmonary gas exchange in patients with intracranial hemorrhage in critical state.

Gigabar spherical shock generation on the OMEGA laser

This Letter presents the first experimental demonstration of the capability to launch shocks of several-hundred Mbar in spherical targets--a milestone for shock ignition [R. Betti et al., Phys. Rev. Lett. 98, 155001 (2007)]. Using the temporal delay between the launching of the strong shock at the outer surface of the spherical target and the time when the shock converges at the center, the shock-launching pressure can be inferred using radiation-hydrodynamic simulations. Peak ablation pressures exceeding 300 Mbar are inferred at absorbed laser intensities of ∼3×10(15)  W/cm2. The shock strength is shown to be significantly enhanced by the coupling of suprathermal electrons with a total converted energy of up to 8% of the incident laser energy. At the end of the laser pulse, the shock pressure is estimated to exceed ∼1  Gbar because of convergence effects.

Guidelines for the management of severe head injury. Part 1. Neurotrauma system and neuroimaging

Traumatic brain injury is one of the main causes of mortality and disability in young and middle-aged individuals. The patients with severe traumatic brain injury who are in coma are the most difficult to deal with. Appropriate diagnosis of the primary brain injuries and early prevention and treatment of secondary damage mechanisms largely determine the possibility of reducing mortality and severe disabling consequences. The authors compiled these guidelines based on their experience in development of international and Russian recommendations on the diagnosis and treatment of mild traumatic brain injury, penetrating gunshot injury of the skull and brain, severe traumatic brain injury, and severe consequences of brain injuries, including a vegetative state. In addition, we used the materials of international and Russian recommendations on the diagnosis, intensive care, and surgical treatment of severe traumatic brain injury published in recent years. The proposed recommendations are related to organization of medical care and diagnosis of severe traumatic brain injury in adults and are primarily addressed to neurosurgeons, neurologists, neuroradiologists, anesthesiologists, and emergency room doctors, who are routinely involved in management of these patients.

[Effect of normobaric hyperoxia on cerebral oxygenation, metabolism and oxidative stress in patients with subarachnoid hemorrhage caused by intracranial aneurysm rupture]

The development of cerebral vasospasm in subarachnoid hemorrhage (SAH) due to cerebral aneurysms rupture results in cerebral circulation disturbances. Application of normobaric hyperoxia can be an effective way for improving of oxygen delivery to injured brain tissues. The purpose of this study was to assess of normobaric hyperoxia influence on intracranial pressure (ICP), cerebral oxygenation and metabolism, oxidative stress and endogenous factors of vascular regulation in II critically ill patients with nontraumatic SAH due to cerebral aneurysms rupture. Increase of FiO2 from 0.3 to 0.5 and 1.0 was accompanied with brain oxygen tension (PbrO2) increase and cerebral extraction ratio for oxygen (O2ER) decrease. Application of normobaric hyperoxia had no effect on ICP, cerebral perfusion pressure, arterial blood pressure and cerebral metabolism. The results obtained from patients with nontraumatic SAH showed an evident increase of oxidative stress which had a significant effect on vascular endothelial function, causing an imbalance in the endogenous regulation of vascular tone. Application of normobaric hyperoxia was not accompanied by an increase of free-radical processes in critically ill patients with nontraumatic SAH due to cerebral aneurysms rupture.

[Influence of cerebral perfusion pressure and cardiac output on brain oxygenation and metabolism]

The article contains results of examination of correlation between systemic hemodynamic and brain oxygenation and metabolism in patients with intracranial hemorrhage. Cardiac index (CI) and cerebral perfusion pressure (CPP) levels were compared to brain oxygenation and metabolism in 8 patients with intracranial hemorrhage (137 measurements). CI alterations didn't influence on PbrO2, glucose level or lactate/pyruvate ratio in the brain interstitial fluid in patients with traumatic brain injury. CPP elevation led to cerebral metabolism improvement. Optimal metabolic state was mentioned in CPP > 80 mm Hg. CPP elevation led to PbrO2 increasing in patients with subarachnoid hemorrhage due to aneurism rupture. This phenomenon can be explained by damage mechanisms of cerebral blood flow autoregulation. In these cases CI elevation was accompanied by worsening of aerobic metabolism in theoretically intact regions and improving it in injured brain regions.

Experimental validation of the two-plasmon-decay common-wave process

The energy in hot electrons produced by the two plasmon decay instability, in planar targets, is measured to be the same when driven by one or two laser beams and significantly reduced with four for a constant overlapped intensity on the OMEGA EP. This is caused by multiple beams sharing the same common electron-plasma wave. A model, consistent with the experimental results, predicts that multiple laser beams can only drive a resonant common two plasmon decay electron-plasma wave in the region of wave numbers bisecting the beams. In this region, the gain is proportional to the overlapped laser beam intensity.

Time-resolved measurements of hot-electron equilibration dynamics in high-intensity laser interactions with thin-foil solid targets

Time-resolved K(α) spectroscopy has been used to infer the hot-electron equilibration dynamics in high-intensity laser interactions with picosecond pulses and thin-foil solid targets. The measured K(α)-emission pulse width increases from ~3 to 6 ps for laser intensities from ~10(18) to 10(19) W/cm(2). Collisional energy-transfer model calculations suggest that hot electrons with mean energies from ~0.8 to 2 MeV are contained inside the target. The inferred mean hot-electron energies are broadly consistent with ponderomotive scaling over the relevant intensity range.

[Sepsis in patients with intracranial hemorrhage: incidence and influence on outcome]

The aim of the study is to analyze sepsis and septic shock incidence and their influence on the outcome in critically ill patients with intracranial hemorrhage. Sepsis incidence (33,7%) and septic shock incidence (18,6%) in the patients studied did not depend on intracranial hemorrhage etiology. Septic complications led to higher mortality which was 22,8% in patients with sepsis and 74,4% in patients with septic shock. Sepsis and septic shock risk factors are defined. The problem of sepsis and septic shock diagnosis in critically ill patients with intracranial hemorrhage are highlighted.

IR spectroscopy of water vapor confined in nanoporous silica aerogel

The absorption spectrum of the water vapor, confined in the nanoporous silica aerogel, was measured within 5000-5600 cm(-1) with the IFS 125 HR Fourier spectrometer. It has been shown, that tight confinement of the molecules by the nanoporous size leads to the strong lines broadening and shift. For water vapor lines, the HWHM of confined molecules are on the average 23 times larger than those for free molecules. The shift values are in the range from -0.03 cm(-1) to 0.09 cm(-1). Some spectral lines have negative shift. The data on the half-widths and center shifts for some strongest H(2)O lines have been presented.

Scaling hot-electron generation to high-power, kilojoule-class laser-solid interactions

Thin-foil targets were irradiated with high-power (1 ≤ P(L) ≤ 210 TW), 10-ps pulses focused to intensities of I>10(18) W/cm(2) and studied with K-photon spectroscopy. Comparing the energy emitted in K photons to target-heating calculations shows a laser-energy-coupling efficiency to hot electrons of η(L-e) = 20 ± 10%. Time-resolved x-ray emission measurements suggest that laser energy is coupled to hot electrons over the entire duration of the incident laser drive. Comparison of the K-photon emission data to previous data at similar laser intensities shows that η(L-e) is independent of laser-pulse duration from 1 ≤ τ(p) ≤ 10 ps.

[Systemic hemodynamic disorders in critically ill patients with intracranial hemorrhages]

The paper analyzes systemic hemodynamic disorders in 45 victims of severe brain injury and patients with nontraumatic intracranial hemorrhages. The incidence of hypovolemia in patients with nontraumatic intracranial hemorrhages and victims of severe brain injury is 65.4% and 73.7%, respectively. Infusion therapy based on the estimation of routine hemodynamic parameters (blood pressure, heart rate, central venous pressure, daily fluid balance) could not prevent hypovolemia in the examinees and caused a high rate of sympathomimetic use in uncorrected volemic states.

[Effect of hemotransfusion on brain oxygenation and metabolism in patients with intracranial hemorrhages]

The paper analyzes the impact of anemia correction on the time course of changes in oxygen tension in the brain and on the biochemical composition of brain interstitial fluid (tissue microdialysis) in the affected and conditionally intact hemisphere in 8 patients with intracranial hemorrhages and a reduced awakening level up to 4-8 scores by the Glasgow coma scale. Anemia correction in patients with intracranial hemorrhage was shown to fail to change oxygen tension in the brain and to be followed by a reduction in lactate/pyruvate ratio in the involved cerebral hemisphere. Only in significant anemia (Hb < 7 g/dl), hemotransfusion elevated cerebral perfusion pressure, by increasing mean blood pressure.

[Effect of volemic status on brain oxygenation and metabolism in patients with intracranial hemorrhages]

The paper analyzes the impact of the volemic status and its correction on systemic hemodynamic parameters (transpulmonary thermodilution PiCCO plus technique), the value of intracranial pressure and the biochemical composition of brain interstitial fluid (tissue microdialysis) in the affected and conditionally intact hemisphere in 8 patients with intracranial hemorrhages and a reduced awakening level up to 4-8 scores by the Glasgow coma scale. It has been shown that in patients with significant metabolic disturbance in the involved hemisphere, hypovolemia correction using hydroxyethyl starch 130/0.4 is accompanied by activated oxidative phosphorylation and a lower lactate/pyruvate ratio, without changing the of blood pressure and increasing pulmonary extravascular water.

[Correction of intracranial hypertension syndrome using hyperosmolar solutions in patients with severe brain damage (multicenter randomized clinical study)]

The paper presents the results of a muticenter study of the effect of 3 hyperosmolar solutions (15% mannitol solution, 10% sodium chloride solution, and the combined solution HyperHAES containing 7.2% sodium chloride and hydroxyethyl starch 200/0.5) on the value of intracranial pressure (ICP) (invasive ICP monitoring) and systemic hemodynamic parameters (PiCCOplus) in 94 clinical cases of intracranial hypertension (ICP more than 20 mm Hg) in 25 patients with acute cerebral pathology (severe brain injury, aneurysmatic subarachnoid hemorrhage). Intravenous infusion of the solutions was found to induce a reduction in ICP; however, this was most pronounced (by 30-40%) and longer (up to 4 hours) when HyperHAES solution was used. This solution produced not only an osmotic, but also hemodynamic effect.

High-current, relativistic electron-beam transport in metals and the role of magnetic collimation

High-resolution coherent transition radiation (CTR) imaging diagnoses electrons accelerated in laser-solid interactions with intensities of approximately 10;{19} W/cm;{2}. The CTR images indicate electron-beam filamentation and annular propagation. The beam temperature and half-angle divergence are inferred to be approximately 1.4 MeV and approximately 16 degrees , respectively. Three-dimensional hybrid-particle-in-cell code simulations reproduce the details of the CTR images assuming an initial half-angle divergence of approximately 56 degrees . Self-generated resistive magnetic fields are responsible for the difference between the initial and measured divergence.

[Role of multicomponent neuromonitoring in the determination of intensive care tactics in a female patient with subarachnoidal hemorrhage due to cerebral arterial aneurysmal rupture]

The paper describes a case of aneurysmal subarachnoidal hemorrhage in a female patient during intensive care involving the whole set of the latest neuromonitoring parameters: intracranial and cerebral perfusion pressure, brain tissue oxygen tension and temperature, as well as a set of biochemical parameters studied by the tissue microdialysis technique. The high diagnostic value of the parameters that cannot be changed by any other neuromonitoring modalities is shown.

[Intracranial pressure, cerebral perfusion and metabolism in acute period of intracranial hemorrhage]

Estimation of the volume of cerebral lesion, reversibility of ischemia and prognosis of the disease determinate management tactics in patients with severe head injuries and non-traumatic intracranial hemorrhages. Data of multimodal neuromonitoring in patients with intracranial hemorrhage in the earlier stages of comatose period were analyzed in this paper. They included incracranial pressure, cerebral perfusion pressure, bulb oxymetry, brain oxygen tension, tissue microdialysis. Typical parameters for different types of neurological outcomes were defined.

[Tactics of infusion therapy in the acute period of intracranial hemorrhages]

The paper deals with the determination of infusion therapy tactics in critically ill patients with intracranial hemorrhages on the basis of invasive measurements of systemic hemodynamics. The routine hemodynamic parameters (blood and central venous pressures, heart rate) are noted to fail to assess the volemic status of the patients in full. Unlike the use of colloidal solutions, infusion therapy with physiological sodium chloride is not shown to correct systemic hemodynamics. It has been ascertained that in acute intracranial hemorrhages, infusion therapy with crystalloidal solutions leads to impaired pulmonary gas exchange and increased pulmonary extravascular fluid and the use of a combination of crystalloidal solutions and a colloidal agent in a 1:1 ratio can correct the volemic status of the patients and is not followed by lung dysfunctions.

[The first experience with simultaneous bilateral monitoring of brain oxygenation and metabolism in patients with intracranial hemorrhages]

The paper analyzes the first unique experience with simultaneous bilateral monitoring of oxygenation of the brain and the key parameters of its metabolism by microdialysis in 5 patients with acute neurosurgical abnormality. Monitoring of cerebral metabolism is shown to rapidly diagnose and correct intensive therapy tactics in the most seriously ill neurosurgically patients.

Shock ignition of thermonuclear fuel with high areal density

A novel method by C. Zhou and R. Betti [Bull. Am. Phys. Soc. 50, 140 (2005)] to assemble and ignite thermonuclear fuel is presented. Massive cryogenic shells are first imploded by direct laser light with a low implosion velocity and on a low adiabat leading to fuel assemblies with large areal densities. The assembled fuel is ignited from a central hot spot heated by the collision of a spherically convergent ignitor shock and the return shock. The resulting fuel assembly features a hot-spot pressure greater than the surrounding dense fuel pressure. Such a nonisobaric assembly requires a lower energy threshold for ignition than the conventional isobaric one. The ignitor shock can be launched by a spike in the laser power or by particle beams. The thermonuclear gain can be significantly larger than in conventional isobaric ignition for equal driver energy.

Pump side scattering in ultrapowerful backward Raman amplifiers

Extremely large laser power might be obtained by compressing laser pulses through backward Raman amplification (BRA) in plasmas. Premature Raman backscattering of a laser pump by plasma noise might be suppressed by an appropriate detuning of the Raman resonance, even as the desired amplification of the seed persists with a high efficiency. In this paper we analyze side scattering of laser pumps by plasma noise in backward Raman amplifiers. Though its growth rate is smaller than that of backscattering, the side scattering can nevertheless be dangerous, because of a longer path of side-scattered pulses in plasmas and because of an angular dependence of the Raman resonance detuning. We show that side scattering of laser pumps by plasma noise in BRA might be suppressed to a tolerable level at all angles by an appropriate combination of two detuning mechanisms associated with plasma density gradient and pump chirp.

Plasma ions dynamics in the wake of a short laser pulse

A new physical effect of a plasma channel formation by the ponderomotive force of a wakefield generated by a laser pulse with a length of the order of the electron plasma wavelength is discussed. For a narrow pulse, wherein the width is less than c/omega(pe) ( omega(pe) and c are the plasma frequency and light velocity, respectively), the channel has an annular form with on-axis density maximum. The depth of the channel increases with the distance from the pulse until the phase mixing arises and the wake starts to break. The linear fluid theory is used to obtain the scaling for wave-breaking conditions. The results of numerical simulations for high intensity laser pulses are in good agreement with theoretical predictions.