Post-compression of powerful femtosecond pulses after second harmonic generation.

A proof-of-principle experiment of highly efficient (38%) second harmonic generation was implemented at a ∼1T W/c m 2 intensity of a 45 fs pulse in a composite nonlinear sample-a 1 mm KDP crystal glued onto a 1 mm fused silica substrate. The attenuated replica of the second harmonic pulse (455 nm) was compressed down to 28.6 fs by means of dispersive mirrors, with a significant reduction in both the wings and the far temporal contrast. The peak power of the second harmonic was ∼74% of the power of the fundamental harmonic, which ensured a three-fold increase in the focal intensity.

Upgrading the front end of the petawatt-class PEARL laser facility.

A new front-end laser system with optical synchronization of chirped femtosecond and pump pulses for the petawatt laser complex PEtawatt pARametric Laser (PEARL) has been developed. The new front-end system provides a broader femtosecond pulse spectrum, temporal shaping of the pump pulse, and a significant increase in the stability of the parametric amplification stages of the PEARL.

Experimental evidence for short-pulse laser heating of solid-density target to high bulk temperatures.

Heating efficiently solid-density, or even compressed, matter has been a long-sought goal in order to allow investigation of the properties of such state of matter of interest for various domains, e.g. astrophysics. High-power lasers, pinches, and more recently Free-Electron-Lasers (FELs) have been used in this respect. Here we show that by using the high-power, high-contrast "PEARL" laser (Institute of Applied Physics-Russian Academy of Science, Nizhny Novgorod, Russia) delivering 7.5 J in a 60 fs laser pulse, such coupling can be efficiently obtained, resulting in heating of a slab of solid-density Al of 0.8 µm thickness at a temperature of 300 eV, and with minimal density gradients. The characterization of the target heating is achieved combining X-ray spectrometry and measurement of the protons accelerated from the Al slab. The measured heating conditions are consistent with a three-temperatures model that simulates resistive and collisional heating of the bulk induced by the hot electrons. Such effective laser energy deposition is achieved owing to the intrinsic high contrast of the laser which results from the Optical Parametric Chirped Pulse Amplification technology it is based on, allowing to attain high target temperatures in a very compact manner, e.g. in comparison with large-scale FEL facilities.

Use of ViaBahn open revascularisation technique for above-knee femoro-popliteal anastomosis: a technical note.

We describe a ViaBahn Open Revascularization TEChnique (VORTEC) application in peripheral femoro-popliteal polytetrafluoroethylene (PTFE) graft bypass in 13 patients.

A new minimally invasive hybrid technique for femoro - above knee popliteal bypass.

Femoro above knee popliteal bypass using synthetic graft is a well recognized revascularization procedure in patients with severe lower limb ischemia with either critical limb ischemia (CLI), limiting claudication (IC) or with acute limb ischemia (ALI).Occasionally the patient's general condition would mandate a short and minimally invasive procedure. When endovascular revascularization is not possible or fails then the peripheral VORTEC technique is used. A telescopic sutureless anastomosis is created between an ePTFE graft to the above knee popliteal artery with a bridging piece of VIABHAN. The technique was described in detail and has been published in the August 2011 issue of the EJVES. Between April 2010 and October 2011 seventeen procedures were accomplished successfully in 16 patients. The median follow up was 13 months (range 3-17). Two patients died during follow up from unrelated caused, both from acute cardiac events and both with patent bypasses, one and 5 months after the index operation. There were 2 occasions of limb loss but only one graft loss related amputation. There were 4 thrombectomies for graft occlusions. All four did not have a distal anastomotic stenosis that could predict graft failure on pre occlusion follow up duplex scans. Primary patency for the whole cohort was 65%, the primary assisted patency was 70% and the secondary patency was 85%. In conclusion we believe that this technique could be advantageous in morbid patients and we therefore recommend using it in high risk patients if no endovascular option or saphenous vein are available.

200 TW 45 fs laser based on optical parametric chirped pulse amplification.

200 TW peak power has been achieved experimentally using a Cr:forsterite master oscillator at 1250 nm, a stretcher, three optical parametrical amplifiers based on KD*P (DKDP) crystals providing 14.5 J energy in the chirped pulse at 910 nm central wavelength, and a vacuum compressor. The final parametrical amplifier and the compressor are described in detail. Scaling of such architecture to multipetawatt power is discussed.

Preserving the left arm vein in cases of hemodialysis access generating left internal mammary artery steal syndrome.

In patients undergoing chronic hemodialysis (HD) through an arm arteriovenous fistula (AVF), coronary insufficiency can occur if the patient undergoes a coronary artery bypass graft (CABG) using the ipsilateral internal mammary artery (1-4). Therefore, the creation of a new AVF after CABG should avoid using the arm ipsilateral to the side where the internal thoracic artery was used. In cases where coronary syndrome appears when this advice is not followed, treatment should be offered aimed at overcoming the hemodynamic interference between the diminished coronary supply through the left or right internal mammary artery by closure of the existing fistula, with or without temporary central venous line insertion until the maturation of a new fistula. We suggest a different approach by moving only the arterial inflow site of the AVF to the controlateral subclavian artery, but in addition, leaving the well functioning venous outflow tract intact. In cases of left internal mammary steal it is achieved by creating a conduit running from the right subclavian artery to the left cephalic vein; therefore, creating a new arterial inflow source, connected to the existing functioning old venous outflow tract to maintain an immediately functioning new fistula without a coronary steal.

Predicting the mesophases of copolymer-nanoparticle composites.

The interactions between mesophase-forming copolymers and nanoscopic particles can lead to highly organized hybrid materials. The morphology of such composites depends not only on the characteristics of the copolymers, but also on the features of the nanoparticles. To explore this vast parameter space and predict the mesophases of the hybrids, we have developed a mean field theory for mixtures of soft, flexible chains and hard spheres. Applied to diblock-nanoparticle mixtures, the theory predicts ordered phases where particles and diblocks self-assemble into spatially periodic structures. The method can be applied to other copolymer-particle mixtures and can be used to design novel composite architectures.

Simple "kink" model of melt intercalation in polymer-clay nanocomposites.

We propose a simple semiphenomenological model to describe the dynamics of polymer melt intercalation in the gallery between the adjacent clay sheets in polymer-clay nanocomposites. Within this model, the intercalation process is driven by the motion of localized excitations ("kinks") which open up the tip between the clay sheets. These kinks belong to a novel type of solitonlike excitations that appear due to the interplay between the double-well potential of the clay-clay long-range interaction, bending elasticity of the sheets, and external shear force. We find that the kink solutions can exist only if applied shear is sufficiently strong, in a qualitative agreement with experimental data.

[Surgery in patients over 100 years of age--5-year experience (1995-2000)].

The age distribution of a given national population is of utmost importance when dealing with public health and analyzing the use of various national health facilities. This is based on the totally different use of health sources by different age groups. Despite continuous prolongation of life expectancy and the related aging of the western hospitalized population the sub-group of patients over 100 year old of age is unusual demographically and accounts for only a very small portion of the total number of patients hospitalized in surgical wards. During the 5 year experience between 1995 and 2000 seventeen such patients were admitted to our surgical departments. Eight of those underwent 11 operations with zero peri-operative mortality and no significant complications. These 11 operations in this elderly population are the basis of our report.

Kinetic model of phase separation in binary mixtures with hard mobile impurities.

We develop a mean-field rate-equation model for the kinetics of phase separation in binary mixtures with hard mobile impurities. For impurities preferentially wet by one of the components, the phase separation is arrested in the late stage. The "steady-state" domain size depends strongly on both the particle diffusion constant and the particle concentration. We compare theoretical results with the simulation data and find good qualitative agreement.

Beware of absent femoral pulse (or how to prevent major complications after minor procedures).

The following is presented to illustrate the importance of examining all peripheral pulses, especially the femoral pulse, before performing minor surgical procedures on the lower extremity, even limited toe amputation. This simple examination is a must in identifying patients at risk for severe peripheral arterial insufficiency, which can lead to major complications if underestimated or undiagnosed. We offer three examples to illustrate this point. All patients underwent successful revascularization and major lower limb amputation was avoided.

[The mechanisms of the antiviral action of the bora-adamantane derivative preparation BG-12]. / Izuchenie mekhanizmov protivovirusnogo deistviia proizvodnogo boraadamantana preparata BG-12.

The effect of one of the derivatives of boraadamantane, preparation BG-12, on reproduction of influenza type A and B viruses was studied. This preparation was shown to inhibit multiplication of a wide range of influenza type A and B virus strains. It is important that BG-12 inhibits in cell culture the replication of a mutant of fowl plague virus A/FPV/Weibridge resistant to remantadine. BG-12 was found to exert a marked viricidal effect, to inhibit the hemolytic activity of both influenza A and influenza B viruses, but not the neuraminidase activity of these viruses. The synthesis of some virus-specific proteins was found to be disturbed in influenza B/Ann Arbor/86-infected cells in the presence of BG-12. A FPVBAR mutant of influenza A/FPV/Weibridge (H7N7) virus resistant to BG-12 was obtained. All the BG-12-resistant reassortants inherited genes 4 and 7 coding for hemagglutinin (HA) and membrane proteins (M) from FPVBAR mutant, respectively, and the remaining genes from BG-12-sensitive A/Krasnodar/101/59 (H2N2) virus. The sequencing of a region of the M gene encoding for the transmembrane protein M2 revealed the substitution of Ala30-Thre in this protein. Multiple attempts at generating a mutant of influenza type B virus resistant to BG-12 failed.

[Circadian rhythm of pituitary-adrenal and pituitary-gonadal systems in patients with pulmonary tuberculosis]. / Sutochnye ritmy gipofizarno-nadpochechnikovoi i gipofizarno-gonadnoi sistem u bol'nykh tuberkulezom legkikh.

Circadian rhythms were investigated in the levels of ACTH, FSH, LH, hydrocortisone, testosterone, progesterone and estradiol in 12 healthy subjects against 32 patients suffering from infiltrative lung tuberculosis. It was found out that healthy subjects have fluctuations in the above hormones which come to an acrophase in morning hours (at 7-8 a.m.), have high mean values, stable time and amplitude structure. In contrast, tuberculosis patients exhibited impaired circadian cycle of the hormones with acrophase in day and evening hours (16-20 p.m.), reduced mean levels and amplitude in fluctuation, non-coincidence in time. The derangement in the rhythm was more distinct in disseminated tuberculosis with intoxication symptoms.

[Factors that cause a change in the antigenic structure of of the influenza virus hemagglutinin]. / Faktory, vyzyvaiushchie izmenenie antigennoi struktury gemaggliutinina viursa grippa.

Crossing of norakin-resistant mutant NR1 of A/Waybridge (H7N7) strain of fowl plague virus (FPV) with human influenza virus strains produced recombinants inheriting the hemagglutinin (HA) gene of the NR1 mutant and neuraminidase (NA) genes of human influenza virus strains. The R120 recombinant produced by crossing of NR1 with A/Taiwan/1/86 (H1N1) strain, unlike other recombinants and NR1 mutant, lost the capacity of reacting in H1 test with two monoclonal antibodies (MCA) to HA7: 71/4 and 46/6. The ts mutant A/FPV/Rostok which has ts-mutation in HA-gene also had changes in the antigenic specificity of HA. The RA and RB recombinants produced by crossing R120 with the A/Krasnodar/101/59 strain and inheriting HA-gene from R120 and NA-gene from A/Krasnodar/101/59 strain recovered the initial HA antigenic structure. No changes in the antigenic properties of HA were observed in the recombinants produced by crossing the original A/FPV/Waybridge strain with A/Taiwan/1/86 strain and inheriting HA-gene from the original A/FPV/Waybridge strain and NA-gene from A/Taiwan/1/86 strain. It is concluded that ts mutations in influenza virus HA-gene may be accompanied by changes in the antigenic specificity of this virus HA. The possibilities of manifestation of phenotypic suppression at the level of influenza virus virion membrane proteins and the causes of changes in the HA antigenic structure in this virus recombinants are discussed.

[Functional system of secretion in renal tuberculosis]. / Funktsional'naia sistema vydeleniia pri nefrotuberkuleze.

Data are given on the study of functional correlations of the pairs of organs (kidneys-liver and kidneys-lungs) that participate in provision of the functional system of secretion. The correlation of these pairs of organs contribution to the total secretion of metabolites as renal insufficiency grows is characterized by the S-shaped dependence, i.e. by a compensatory increase of the conjoined functions at the early stages and its depression at the graver stages of renal insufficiency. This approach makes it possible to determine the character, terms and significance of the participation of various organs in provision of metabolic homeostasis maintenance long before its failure and to reveal the main links in the pathogenesis of functional disorders of secretion.