Terahertz Radiation of a Low-inductance Discharge in Vacuum with Laser-plasma Initiation

The results of the study of terahertz radiation, which is generated by the plasma of a low-inductance discharge with micropinchs, are presented in this paper. The discharge was initiated by focused radiation from a pulsed Nd:YAG laser (pulse duration is 10 ns, pulse energy is 0.8 J). The energy that was stored in the capacitor of the discharge system was ∼ 40 J. The principal role of micropinch for the generation of THz radiation was proposed. The oscillogram of the diode current was obtained to visualize the presence of micropinch plasma. The power of the THz source was calculated and an experimental study of the spectrum of this source was carried out

ПОВЫШЕНИЕ ТОЧНОСТИ ИЗМЕРЕНИЙ РАДИОИЗОТОПНОГО ПЛОТНОМЕРА

The experimental investigations of spatial energy distribution for beta particles in a measuring gap of a basis weight sensor are described. We propose the measurement procedure, which employs a local domain of the ionization chamber input window. The average scattering angles in polyethylenterephtalate films are determined. Suggested technical solutions allow more then three times to reduce the error of measuring of radioisotope densitometer.Проведены экспериментальные исследования пространственного распределения рассеянных бета-частиц в измерительном зазоре радиоизотопного плотномера. Предложена схема измерений, основанная на использовании локальной области входного окна ионизационной камеры. Определены средние углы рассеяния в пленках полиэтилентерефталата. Предложено техническое решение, позволяющее более чем в 3 раза снизить погрешность измерений радиоизотопного плотномера.

Polymorphism in Gag Gene Cleavage Sites of HIV-1 Non-B Subtype and Virological Outcome of a First-Line Lopinavir/Ritonavir Single Drug Regimen

Virological failure on a boosted-protease inhibitor (PI/r) first-line triple combination is usually not associated with the detection of resistance mutations in the protease gene. Thus, other resistance pathways are being investigated. First-line PI/r monotherapy is the best model to investigate in vivo if the presence of mutations in the cleavage sites (CS) of gag gene prior to any antiretroviral treatment might influence PI/r efficacy. 83 patients were assigned to initiate antiretroviral treatment with first-line lopinavir/r monotherapy in the randomised Monark trial. We compared baseline sequence of gag CS between patients harbouring B or non-B HIV-1 subtype, and between those who achieved viral suppression and those who experienced virological failure while on LPV/r monotherapy up to Week 96. Baseline sequence of gag CS was available for 82/83 isolates; 81/82 carried at least one substitution in gag CS compared to HXB2 sequence. At baseline, non-B subtype isolates were significantly more likely to harbour mutations in gag CS than B subtype isolates (p<0.0001). Twenty-three patients experienced virological failure while on lopinavir/r monotherapy. The presence of more than two substitutions in p2/NC site at baseline significantly predicted virological failure (p = 0.0479), non-B subtype isolates being more likely to harbour more than two substitutions in this specific site. In conclusion, gag cleavage site was highly polymorphic in antiretroviral-naive patients harbouring a non-B HIV-1 strain. We show that pre-therapy mutations in gag cleavage site sequence were significantly associated with the virological outcome of a first-line LPV/r single drug regimen in the Monark trial

Cancer Biomarker Discovery: The Entropic Hallmark

Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases

INCREASING OF ACCURACY FOR DENSITY MEASUREMENT MAKING BY A RADIOISOTOPIC BASIS WEIGHT SENSOR

The experimental investigations of spatial energy distribution for beta particles in a measuring gap of a basis weight sensor are described. We propose the measurement procedure, which employs a local domain of the ionization chamber input window. The average scattering angles in polyethylenterephtalate films are determined. Suggested technical solutions allow more then three times to reduce the error of measuring of radioisotope densitometer

THE INFLUENCE OF MODIFICATION OF THE SURFACE OF NANOPOROUS CARBON MATERIAL BY THE OXIDES OF METALS

Nitrogen containing carbon materials with metal of oxides (Fe, Ni, Co) prepared by the chemical precipitation method have been shown to be outstanding novel materials for electrochemical capacitors. The electrochemical properties of the electrodes have been studied by considering the effect of the mole ratio of metals. Cyclic voltammetric measurements indicate that nickel, cobalt and iron oxides increase specific capacity of electrochemical capacitors up to 260 F/g in 30% KOH electrolyte. Impedance studies show that the enhanced electrical properties and high frequency response are attributed to the presence of Fe oxides