88 research outputs found
Electronic structure and time-dependent description of rotational predissociation of LiH
Adiabatic potential energy curves of the and states of
the LiH molecule have been calculated. They correlate asymptotically to atomic
states, like 2s+1s, 2p+1s, 3s+1s, 3p+1s, 3d+1s, 4s+1s, 4p+1s and 4d+1s. Very
good agreement is found between our calculated spectroscopic parameters and
experimental ones. The dynamics of the rotational predissociation process of
the state has been studied by solving the time-dependent
Schr\"{o}dinger equation. The classical experiment of Velasco [Can. J. Phys.
{35}, 1204 (1957)] on dissociation in the state is explained in
detail
Electronic structure and rovibrational predissociation of the 2sPi state in KLi
Adiabatic potential energy curves of the 3sSigma+, 3tSigma+, 2sPi and 2tPi
states correlating for large internuclear distance with the K(4s) + Li(2p)
atomic asymptote were calculated. Very good agreement between the calculated
and the experimental curve of the 2sPi state allowed for a reliable description
of the dissociation process through a small (20 cm-1 for J = 0) potential
energy barrier. The barrier supports several rovibrational quasi-bound states
and explicit time evolution of these states via the time-dependent nuclear
Schroedinger equation, showed that the state populations decay exponentially in
time. We were able to precisely describe the time-dependent dissociation
process of several rovibrational levels and found that our calculated spectrum
match very well with the assigned experimental spectrum. Moreover, our approach
is able to predict the positions of previously unassigned lines despite their
low intensit
Nonspecific bacterial flora isolated from the body surface and inside Ixodes ricinus ticks
Ixodes ricinus and other representatives of the order Ixodida are vectors of typical pathogens: Borrelia burgdorferi sensu lato, Anaplasma
phagocytophilium, Babesia spp., a tick-borne encephalitis virus, and other microorganisms which are important from a medical and veterinary
point of view. "e presented study focuses on the verification of nonspecific bacterial &ora of I. ricinus. We analyzed ticks collected in
a$forest region in Silesia, an industrial district in Poland. Methods of classical microbiology and biochemical assays (API 20 NE test, API
Staph test and MICRONAUT System) were used for isolation and identification of microorganisms living on the body surface of I. ricinus
and inside ticks. "e results show the presence of various bacteria on the surface and inside ticks’ bodies. During the study, we isolated
Acinetobacter lwoffi, Pseudomonas "uorescens, Aeromonas hydrophila, Achromobacter denitrificans, Alcaligenes faecalis, Stenotrophomonas
maltophilia, Pseudomonas oryzihabitans, Micrococcus spp., Kocuria varians, Staphylococcus lentus, Kocuria kristinae, Streptococcus pneumo-
niae, Rhizobium radiobacter, Staphylococcus xylosus. Majority of the isolated species are non-pathogenic environmental microorganisms,
but some of the isolated bacterial strains could cause severe infections
Application of a Real-Time PCR method for Salmonella spp., Escherichia coli, Staphylococcus and Clostridium perfringens detection in water samples
The diagnostic assessment of water sanitary state is based mainly on the cultivation of bacteria retained on membrane filters. However classical microbiology methods have a lot of disadvantages. More and more frequently, rapid detection and identification of pathogens present in water is based on molecular biology techniques. The aim of this study was to determine the effectiveness and usefulness of a real-time PCR method, when compared to the recommended bacteria culture method, in diagnostics of pathogens in water samples. The research concerned the detection and identification of main sanitary indicators of water such as: Salmonella spp., Escherichia coli, Staphylococcus aureus and Clostridium perfringens. The analyses were conducted in water samples contaminated with the reference materiał (the aforementioned bacteria) and real environmental samples, which were examined for the presence of nucleic acid of: Salmonella spp., E. coli, S. aureus and C. perfringens using a real-time PCR method
Optimization of broadband semiconductor chirped mirrors with genetic algorithm
Genetic algorithm was applied for optimization
of dispersion properties in semiconductor Bragg reflectors
for applications in femtosecond lasers. Broadband,
large negative group-delay dispersion was achieved in the
optimized design: The group-delay dispersion (GDD) as
large as −3500 fs2
was theoretically obtained over a 10-nm
bandwidth. The designed structure was manufactured and
tested, providing GDD −3320 fs2
over a 7-nm bandwidth.
The mirror performance was verified in semiconductor
structures grown with molecular beam epitaxy. The mirror
was tested in a passively mode-locked Yb:KYW laser
Hepatic tissue changes in rats due to chronic invasion of Babesia microti
The etiological agents of babesiosis are intraerythrocytic parasites of the genus Babesia, which are transmitted by ticks. The course of disease is characterized by variable severity. The risk of a complicated course of babesiosis occurs in premature infants, the elderly, splenectomized patients and other immunocompromised patients. Severe cases of this disease can lead to multiple organ dysfunction. The study focuses on the impact assessment of chronic Babesia microti invasion on the morphology and ultrastructure of rat liver. The
analyzed material was comprised of liver samples collected from Wistar rats infected with a reference strain of B. microti (ATCC 30221). None of the livers collected from rats with babesiosis was enlarged. The histopathological analyses showed signs of intensive inflammatory processes, especially in the perivascular areas. The hepatic mononuclear phagocyte system was characterized by increased activity. The ultrastructral analyses confirmed disintegration of hepatocytes with vacuolization in the perivascular areas. In addition, the perisinusoidal space (space of Disse) had irregular structure. In some areas, the space of Disse was enlarged or compressed. The morphological and ultrastructural analyses of rat liver with chronic babesiosis caused by B. microti showed significant pathological changes in perivascular areas which may be the cause of hepatic dysfunction
Rat spleen in the course of Babesia microti invasion: histological and submicroscopic studies
The course of babesiosis in humans is characterized by various intensity levels − from a subclinical level to the severe one − associated
with multiple organ failure, which leads to death. The aim of this study was to evaluate the effect of 21-day and 6-month invasion
of B. microti on Wistar rats spleen. Histological changes in the rats’ spleen were characterized by swelling of splenic tissue, especially the
tissue adjacent to the capsule. In the structure of the white pulp in some rats, high concentrations of lymphocytes occurred. The boundary
between the white pulp and red pulp was blurred. In the red pulp structure of rats, a lot of macrophages and extracellular deposits of
bilirubin were present. The submicroscopic studies showed that the nuclear matrix was slightly shrunken. In the red pulp fragments of the
damaged cells were located in the intercellular spaces. Near these areas, many thrombocytes were visible. The ultrastructural observation
also revealed thickened endoplasmic reticulum membranes, local cellular swelling filled with amorphous substance, and digested erythrocytes.
B. microti invasion affects the splenic morphology and ultrastructure in rats. The immunological hyperactivity and signs of inflammation
indicate an important role of spleen in a fight against parasites
Ovaries of Tubificinae (Clitellata, Naididae) resemble ovary cords found in Hirudinea (Clitellata)
The ultrastructure of the ovaries and oogenesis was studied in three species of three genera of Tubificinae. The paired ovaries are small, conically shaped structures, connected to the intersegmental septum between segments X and XI by their narrow end. The ovaries are composed of syncytial cysts of germ cells interconnected by stable cytoplasmic bridges (ring canals) and surrounded by follicular cells. The architecture of the germ-line cysts is exactly the same as in all clitellate annelids studied to date, i.e. each cell in a cyst has only one ring canal connecting it to the central, anuclear cytoplasmic mass, the cytophore. The ovaries found in all of the species studied seem to be meroistic, i.e. the ultimate fate of germ cells within a cyst is different, and the majority of cells withdraw from meiosis and become nurse cells; the rest continue meiosis, gather macromolecules, cell organelles and storage material, and become oocytes. The ovaries are polarized; their narrow end contains mitotically dividing oogonia and germ cells entering the meiosis prophase; whereas within the middle and basal parts, nurse cells, a prominent cytophore and growing oocytes occur. During late previtellogenesis/early vitellogenesis, the oocytes detach from the cytophore and float in the coelom; they are usually enveloped by the peritoneal epithelium and associated with blood vessels. Generally, the organization of ovaries in all of the Tubificinae species studied resembles the polarized ovary cords found within the ovisacs of some Euhirudinea. The organization of ovaries and the course of oogenesis between the genera studied and other clitellate annelids are compared. Finally, it is suggested that germ-line cysts formation and the meroistic mode of oogenesis may be a primary character for all Clitellata
Validation of a Spanish translation of the Gratitude Questionnaire (GQ-6) with a Chilean sample of adults and high schoolers
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