Experimental and computational-theoretical studies of the electron energy distribution function (EEDF) at the afterglow stage of a glow discharge in a mixture of helium (content of 98.5% He) and ...xenon (content of 1.5% Xe) for pressures of 1, 2, and 3 Torr and a discharge current of 10 mA are carried out. The discharge is ignited in a tube with a radius of 1.25 cm. According to the measurements, the electron energy distribution function (EEDF) has a form close to the Maxwellian function in the low-energy region. A characteristic feature of the measured distribution functions is also a plateau in the energy range of 1–4 eV. The formation of this plateau is associated with fast electrons (4.5 eV) formed during chemionization with the participation of metastable xenon atoms. The calculations are performed within the nonstationary Boltzmann equation in the local approximation for the EEDF, taking into account the source of fast electrons. Experimental and calculated results are compared.
Supramolecular structure of ultrathin films of hemicyanine dye bearing a crown ether group (CrHCR) was tuned by lateral pressure and investigated by means of compression isotherms, UV–vis and ...fluorescence spectroscopies, and X-ray reflectivity. Two different types of aggregation were revealed, depending on the absence or the presence of metal cations in the water subphase. While CrHCR forms at high surface pressures head-to-tail stacking aggregates on pure water, changing the subphase to a metal-cation-containing one leads to the appearance of well-defined excimers with head-to-head orientation. The structure of monolayers transferred onto solid supports by the Langmuir–Blodgett (LB) technique was examined by use of X-ray reflectivity measurements and molecular modeling. A model of cation-induced excimer formation in hemicyanine Langmuir monolayers is proposed. Finally, fluorescence emission properties of LB films of CrHCR can be managed by appropriate changes in the subphase composition, this last one determining the type of chromophore aggregation.
Experimental and theoretical studies of plasma parameters of the positive column of a direct current glow discharge in xenon were carried out. In the experiments, a discharge tube with a radius of 2 ...cm and a distance between the electrodes of 56 cm was used. The experiments were carried out for the gas pressure of 0.1 and 1 Torr, and the discharge current was varied in the range of 10–50 mA. The electric field strength in the positive column of the discharge and the population of the lower metastable 1
s
5
state of the xenon atom (the population is measured only for the pressure of 0.1 Torr) on the axis of the discharge tube are measured. A self-consistent 0-dimensional kinetic model of the discharge in xenon was developed and verified by comparing the calculation results with the data published in literature. Calculations performed for the above experimental conditions showed that the theoretical values of electric field strength differ markedly from the measured ones. Possible reasons for this difference are discussed. It is shown, in particular, that at the reduced electric field, which is implemented in the discharge plasma at a pressure of 1 Torr, the electron–electron collisions significantly affect the shape of the electron energy distribution function and, accordingly, the rate of the processes of production and loss of electrons. Concerning the population of the lower metastable level of the Xe atom, the calculated values agree well with the results of measurements. Within the developed discharge model, the emission spectrum of the discharge plasma in the range of 119–3400 nm is also calculated. It is shown that most of the energy is emitted in the UV region at a wavelength of 147 nm.
The effect of the drug Stimforte on infection by the Hepatitis C virus (HCV) has been studied. Stimforte partially inhibits HCV infection at a dose of 100 μg/mouse and almost completely at a dose of ...300 μg/mouse within 24 h after administration of the drug. The mice sera resulting after 24 h in the presence of 100 and 300 µg/mouse of Stimforte effectively inhibit the production of HCV. Doses of 150, 200, and 250 µg/mouse are not effective. Stimulation of interferon-β (IFN-β) production is only observed at doses of 100 and 300 µg/mouse, which explains well the neutralizing capacity of the sera. The amount of IFN-γ also correlates well with the antiviral activity and neutralizing activity of mice sera. The drug practically does not stimulate production of IFN-λ. Thus, the neutralizing activity of sera and the antiviral activity are largely determined by the 1st and 2nd IFN groups.
Stimforte, an immune response-stimulating preparation, is active with respect to hepatitis C virus (HCV) and herpes simplex virus type I (HSV-1). The effects of Stimforte in animals infected with ...either HCV or HSV-1 are fundamentally different. In mice with acute herpes virus infection, Stimforte administration leads to a higher activity of natural killer cells and cytotoxic lymphocytes, and the amount of interferon (IFN) λ grows. In mice infected with HCV, Stimforte administration results in a significant increase in IFN-β but not IFN-λ in blood and affected organs. Stimforte has been found to affect directly HCV reproduction that causes the infected cell death, but it does not affect HSV-1 reproduction in the Vero cells (V).
Transplantation of human bone marrow mesenchymal stem cells is considered as a promising therapeutic approach to the therapy of many diseases. However, the problem of possible alterations of the ...properties of mesenchymal stem cells during their expansion in in vitro cultures before transplantation is not solved. In our study, one of two hundred examined cultures of mesenchymal stem cell cultures derived from donors without bone marrow pathologies and developed under standard culturing conditions demonstrated spontaneous disturbances in morphology, proliferation, and karyotype at early passages. The cells of this abnormal culture retained immunophenotype characteristic of normal mesenchymal stem cells, but some of them (15-25%) had numerous numerical and structural chromosome aberrations.
Transplantation of human bone marrow mesenchymal stem cells is considered as a promising therapeutic approach to the therapy of many diseases. However, the problem of possible alterations of the ...properties of mesenchymal stem cells during their expansion in in vitro cultures before transplantation is not solved. In our study, one of two hundred examined cultures of mesenchymal stem cell cultures derived from donors without bone marrow pathologies and developed under standard culturing conditions demonstrated spontaneous disturbances in morphology, proliferation, and karyotype at early passages. The cells of this abnormal culture retained immunophenotype characteristic of normal mesenchymal stem cells, but some of them (15-25%) had numerous numerical and structural chromosome aberrations.
Aims To investigate whether changes in clinical characteristics and treatment strategies between 1991 and 2001 have had an impact on the survival of patients hospitalized with congestive heart ...failure (CHF) and whether those with normal left ventricular ejection fraction (LVEF≥50%) differ in this respect from those with depressed LVEF. Methods and results We studied 1482 patients who had been admitted to the Cardiology Service of a tertiary Spanish hospital in the last 10 years with CHF. Among the 1110 for whom LVEF was evaluated, the prevalence of normal LVEF rose from 37% in the period 1991–96 (Period 1) to 47% in the period 2000–2001 (Period 3). The intensity of both diagnostic and therapeutic measures also increased during this 10-year period. The 1-year survival rate remained virtually unchanged in the whole group of patients, being 82, 84, and 82% in Periods 1, 2 (1997–99), and 3, respectively, even though the prognosis of patients with depressed LVEF (<50%) improved significantly, with 1-year survival rates of 76, 77, and 84% in Periods 1, 2, and 3, respectively; the normal LVEF group had decreasing 1-year survival rates of 88, 86, and 81% in Periods 1, 2, and 3, respectively, although the increased risk of death was not statistically significant. Conclusion Although in our centre the death rate among hospitalized CHF patients with depressed LVEF during the first year after discharge has tended to fall over the past 10 years, application of current clinical guidelines has led to no such decrease for patients with normal LVEF. This situation points to a need to reconsider the diagnostic and therapeutic strategy to be employed with this latter group of patients.
PDF
