Krvácivé horečky vyvolané viry jsou závažná onemocnění přenášená na člověka živočichy (členovci, hlodavci, letouni), provázejí lidstvo po celou dobu jeho existence. Jde o multisystémový syndrom, při kterém je zasažena řada orgánů, zejména oběhový systém. Článek podává přehled onemocnění způsobovaných jednotlivými čeleděmi virů – flaviviry, filoviry, togaviry, bunyaviry, arenaviry. and Haemorrhagic fevers comprise a group of serious illnesses that are transferred to man from animal or insect hosts by various RNA viruses. Viral haemorrhagic fevers accompany mankind since its very beginning. They represent a multi-systemic syndrome, in that many organs in the body are affected. This article presents a survey of haemorrhagic diseases caused by different families of viruses – Flaviviridae, Filoviridae, Togaviridae, Bunyaviridae and Arenaviridae.
The paper describes design and realization of a flexible vortex microscope allowing three-dimensional localization and tracking of fluorescence excited and weakly scattering nanoparticles. Information about localized objects is obtained from the interference of light vortices created by optical components, which modulate both amplitude and phase of light and were prepared by electronbeam lithography. Design of the vortex microscope is based on the inverted microscope Nikon Eclipse E600 operating with additional illumination and imaging modules that enable recording and reconstruction of the sample in fluorescence, episcopic and diascopic imaging modes. The variability of the vortex microscope allows a dynamic spatial localization of nanoparticles in the axial range exceeding 23 times the depth of field of the microscope objective used, achieving an isotropic accuracy of 10-50 nm. The tracking of nanoparticles under Brownian motion was demonstrated in a volume of 14×10×16 mm3 . The practical usability of the system was tested by fluorescence imaging of LW13K2 cells and localization of cellular proteins. and V článku je popsán návrh a realizace flexibilního vírového mikroskopu, který umožňuje trojrozměrnou lokalizaci a sledování fluorescenčně excitovaných a slabě rozptylujících částic nanometrových rozměrů. Informace o lokalizovaných objektech je získána z interference světelných vírů vytvořených optickými komponentami, které současně modulují amplitudu i fázi světla a byly připraveny technikou elektronové litografie. Základem experimentálního systému je mikroskop Nikon Eclipse E600 rozšířený o zobrazovací a osvětlovací moduly, které umožňují záznam a rekonstrukci vzorku ve fluorescenčním, episkopickém a diaskopickém zobrazovacím režimu. Variabilita konstrukce vírového mikroskopu umožňuje dynamickou prostorovou lokalizaci nanometrových objektů v axiálním rozsahu převyšujícím až 23krát hloubku ostrosti použitého objektivu při izotropní přesností 10-50 nm. Sledování nanočástic při Brownově pohybu bylo demonstrováno v objemu 14×10×16 mm3 . Praktická použitelnost systému byla testována při fluorescenčním zobrazení krysích buněk LW13K2 a lokalizaci buněčných proteinů.
Development of combustion engines can be characterized by continuous increase in the number of computational simulations being applied in all areas. There is a clear trend to use chain or belt drives for the design of timing drives. Computational simulation of these drives has not been developing too long due to high demands on the computational technology. The paper focuses on simulation of dynamics of the timing chain drive with the use of a multi-body system. A mass-produced four cylinder in-line engine with two camshafts and two valves per cylinder has been used as a computational model. and Obsahuje seznam literatury
The Leishmania metalloproteinase GP63 has been reported to play important roles mainly in resistance of promastigotes to complement-mediated lysis and in interaction with macrophage receptors. On the other hand, its function in insect vectors is still unclear. We compared the structure and dosage of gp63 genes and the activity of GP63 in Leishmania major Yakimoff et Schokhor strains and lines differing in virulence for mice and ability to develop in sand flies. The results demonstrate considerable variability in amount and proteolytical activity of GP63 among L. major strains although genomic changes in the gp63 locus were not found. Attenuated LV561/AV line showed low amount and low enzymatic activity of GP63. Serial passages of attenuated parasites through either Phlebotomus duboscqi Neveu-Lemaire or through mice led to a recovery of GP63 proteolytical activity to the level present in virulent LV561/V line. Overexpression of GP63 was found in two L. major strains (L119, Neal) with defective lipophosphoglycan (LPG); both these strains were capable to cause mice infection but unable to survive and multiply in sand flies. Differences were found also in karyotypes and in amount of minichromosomes amplified in some lines of the LV561 strain. The results suggest that parasite virulence is not simply correlated with the activity of GP63; however, this enzyme plays a significant role in association with other surface molecules, especially LPG. Overexpression of GP63 can compensate LPG defect in the vertebrate host but in sand flies both molecules fulfil quite different functions and the defect in LPG is lethal for the parasite. On the other hand, linear minichromosomes of about 200 kb found in some lines of the LV561 strain are associated with development in vitro and in the vector but they are not essential for the infection of the vertebrate host.
Tomato samples were collected from the field of Absheron peninsula in Azerbaijan in order to evaluate the incidence of main Tobamoviruses. According to results of serological and molecular tests, Tomato mosaic virus (ToMV), Tobacco mosaic virus (TMV), and Pepper mild mottle virus (PMMoV) were detected as single and mixed infections (TMV + PMMoV; ToMV + PMMoV) in various tomato samples. It was found that Tobamovirus infection caused an increase in the content of malondialdehyde, alterations in the activities of peroxidase enzymes and quantitative and qualitative changes in their molecular isoforms. A comparison of thylakoid membrane polypeptides from virus-infected leaves indicated a decrease in the content of the thylakoid membrane polypeptides with molecular masses of 123, 55, 47, 33, 28-24, 17, and 15 kD. PSII efficiency and the content of chlorophylls (a and b) were significantly lower in the virus-infected leaves., I. M. Huseynova, S. M. Mirzayeva, N. F. Sultanova, D. R. Aliyeva, N. Sh. Mustafayev, J. A. Aliyev., and Obsahuje bibliografii