Role of surface microgeometries on electron escape probability and secondary electron yield of metal surfaces.

The influence of microgeometries on the Secondary Electron Yield (SEY) of surfaces is investigated. Laser written structures of different aspect ratio (height to width) on a copper surface tuned the SEY of the surface and reduced its value to less than unity. The aspect ratio of microstructures was methodically controlled by varying the laser parameters. The results obtained corroborate a recent theoretical model of SEY reduction as a function of the aspect ratio of microstructures. Nanostructures - which are formed inside the microstructures during the interaction with the laser beam - provided further reduction in SEY comparable to that obtained in the simulation of structures which were coated with an absorptive layer suppressing secondary electron emission.

Real life results of direct acting antiviral therapy for HCV infection in HIV-HCV-coinfected patients: Epi-Ter2 study.

The aim of this study was to evaluate the baseline demographics and real-life efficacy of direct acting antivirals (DAAs) in HIV-HCV-positive patients as compared to patients with HCV monoinfection. The analysis included 5690 subjects who were treated with DAAs: 5533 were HCV-positive and 157 were HIV-HCV-positive. Patients with HCV-monoinfection were older (p < .0001) and in HIV-HCV group there were more men (p < .0001). Prevalence of genotype 1a (p = .002), as well as of genotypes 3 and 4 (p < .0001) was higher in HIV-HCV-coinfected patients. Genotype 1b was more frequent (p < .0001) in the HCV-mono-infection group. Patients with HCV-monoinfection had a higher proportion of fibrosis F4 (p = .0004) and lower proportion of fibrosis F2 (p < .0001). HIV-HCV-coinfected individuals were more often treatment-naïve (p < .0001). Rates of sustained viral response after 12 weeks did not differ significantly between both groups (95.9% versus 97.3% in coinfection and monoinfection group, respectively; p > .05). They were, however, influenced by HCV genotype (p < .0001), stage of hepatic fibrosis (p < .0001), male sex (p < .0001), BMI (p = .0001) and treatment regimen modifications (p < .0001). Although factors associated with worse response to therapy (male sex, genotype 3) occurred more often in the HIV coinfection group, real-life results of DAAs did not differ significantly between both populations.

Treatment of HCV infection in Poland at the beginning of the interferon-free era-the EpiTer-2 study.

The aim of the EpiTer-2 study was to analyse patient characteristics and their medication for HCV infection in Poland at the beginning of the interferon-free era. Analysis of data of HCV infected patients treated during the initial period of availability of interferon-free regimens in Poland, who started therapy after 1 July 2015 and had available an efficacy evaluation report before 30 June 2017 was undertaken. A total of 2879 patients with chronic hepatitis C were entered, including 46% with liver cirrhosis. The most common was genotype 1b (86.8%). The study population was gender balanced, the majority of patients were overweight or obese and 69% presented comorbidities, with the highest prevalence that for hypertension. More than half of patients were retreated due to failure of previous therapy with pegylated interferon and ribavirin. Almost two-third of patients received current therapy with ombitasvir/paritaprevir/ritonavir±dasabuvir (OPrD) ±ribavirin. Other patients received mostly sofosbuvir-based regimens including combination with ledipasvir and pegylated interferon and ribavirin for genotype 3-infected patients. Efficacy of treatment in the whole study population measured as intent-to-treat analysis was 95%. The most frequent regimen, administered for patients infected with genotype 1b, was 12 weeks of OPrD, resulting in an SVR rate of 98%. At least one adverse event was reported in 38% of patients, and the death rate was 0.8%. In conclusion, data from the EpiTer-2 study confirmed the excellent efficacy and safety profile of the real-world experience with recently introduced therapeutic options for genotype 1 HCV infection, but demonstrated weakness of the current therapeutic programme regarding genotype 3 infections.

Constraints on nebular dynamics and chemistry based on observations of annealed magnesium silicate grains in comets and in disks surrounding Herbig Ae/Be stars.

Understanding dynamic conditions in the Solar Nebula is the key to prediction of the material to be found in comets. We suggest that a dynamic, large-scale circulation pattern brings processed dust and gas from the inner nebula back out into the region of cometesimal formation-extending possibly hundreds of astronomical units (AU) from the sun-and that the composition of comets is determined by a chemical reaction network closely coupled to the dynamic transport of dust and gas in the system. This scenario is supported by laboratory studies of Mg silicates and the astronomical data for comets and for protoplanetary disks associated with young stars, which demonstrate that annealing of nebular silicates must occur in conjunction with a large-scale circulation. Mass recycling of dust should have a significant effect on the chemical kinetics of the outer nebula by introducing reduced, gas-phase species produced in the higher temperature and pressure environment of the inner nebula, along with freshly processed grains with "clean" catalytic surfaces to the region of cometesimal formation. Because comets probably form throughout the lifetime of the Solar Nebula and processed (crystalline) grains are not immediately available for incorporation into the first generation of comets, an increasing fraction of dust incorporated into a growing comet should be crystalline olivine and this fraction can serve as a crude chronometer of the relative ages of comets. The formation and evolution of key organic and biogenic molecules in comets are potentially of great consequence to astrobiology.

[Chromosome analysis of ducklings with a defective phenotype]. / Chromozomálna analýza kácat s defektným fenotypom.

In two equal periods, using the conventional method of processing bone-marrow cells after Konstantinov and Dobriyanov (1974), we studied the connection between the occurrence of chromosomal aberrations and deviations of phenotype. In the first part of the observation we found 8.5% numerical aberrations in 20 ducklings with retarded motility, torticollis and contractures of the fingers, compared with 1.27% in the control group with normal phenotype. In the second part of the observation the occurrence of aberrations in ducklings with defective phenotype of the same breeding dropped considerably to 1.7% and in the control group to 0.54%. The statistical evaluation of the results showed statistically significant differences (chi (4)2 = 56.78; p less than 0.05, and/or chi (4)2 = 27.74; p less than 0.05).