86 research outputs found
Grzyby drożdżopodobne izolowane od studentów
No full textThe occurrence of yeast-like fungi in the most important infection portals of the respiratory
system in 200 randomly chosen students of biology and veterinary medicine was examined.
The students come into direct contact with plants and animals that may be colonised by fungi
belonging to various systematic groups.
nine species of yeast-like fungi, including 7 species determined in the biologists, were
recorded in the subjects. Candida tropicalisand C.albicanswere the most frequently isolated
fungi. The greatest number of fungi was isolated from the oral cavity (124 isolates), fewer
from the throat (79 isolates), and the smallest number from the nose (8 isolates). Fungi
occurred more frequently in autumn and slightly less frequently in spring, and were isolated
more frequently from women than from men.W pracy przeanalizowano występowanie grzybów drożdżopodobnych w głównych wrotach
zakażenia układu oddechowego, dwustu losowo wybranych studentów biologii i medycyny
weterynaryjnej, mających w trakcie studiów bezpośredni kontakt z roślinami i zwierzętami,
które mogą być zasiedlane przez grzyby z różnych grup systematycznych.
W przeprowadzonych badaniach u wszystkich studentów stwierdzono 9 gatunków grzybów drożdżopodobnych, z czego 7 u biologów. Najczęściej izolowano: Candida tropicalis(83
izolaty) i Candida albicans (77 izolatów). Najwięcej grzybów wyizolowano z jamy ustnej (124
izolaty), mniej z gardła (79), najmniej z nosa (8). Grzyby częściej występowały jesienią, nieco rzadziej wiosną, u kobiet niż u mężczyzn. Ogółem najwyższy odsetek wyników dodatnich
odnotowano u osób zgłaszających nadużywanie kawy (30%), palących papierosy (63,6%) i
nadużywających alkoholu (51,7%).
Izolowanie grzybów potencjalnie chorobotwórczych od zdrowych studentów wskazuje na
obniżony stan ich odporności i skłania do położenia większego nacisku na analizy i badania
mikologiczne w celu zwiększenia profilaktyki przeciwgrzybicznej w grupach osób zdrowych
Molecular Modelling of Interface Occurrence of Ti (C,N,O) - Fe Composite
No full textHigh demands that are posed to modern materials exposed to the action of thermal, mechanical or chemical loads oblige one to seek new solutions and technologies. Compliance with these expectations requires designing the composite materials without structural notches, and the application of gradient materials. Transient zone, determining the interphase compound, is an essential element of each composite. Interaction forces creating transient structural zones determine the value of the adhesion forces. Among all forces determining the adhesion the strongest are the forces of a chemical bond. Therefore, the molecular modeling should be a valuable method to investigate and design the composites. In the presented research the conditions of coat adhesion of the Ti (C,N,O)-type to steel substrate are taken into consideration. Using a standard quantum-chemistry program, the energies of the following systems (clusters) - Fe-α- N-Ti, Fe-α-C-Ti, and Fe-α-O-Ti - are calculated. The aim of the analysis was to determine the conditions for preparation of initial substrate, which are advantageous for the process of coat formation. This analysis confirmed benefits arising from nitriding as an initial treatment of the steel
Electrochemical Behavior of Titanium Implants in Artificial Saliva After Laser Surface Treatment
No full textPeri-implantitis is a pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri-implant connective tissue and progressive loss of supporting bone. In the treatment of peri-implantitis, a laser surgical technique is used. Lasers are a safe and gentle alternative to traditional dental tools. They allow oral surgeons and dentists to accomplish more complex tasks, reduce blood loss, decrease post-operative discomfort, reduce the chance of wound infection, achieve better wound healing and perform some procedures in close methods without access flap. The aim of the work was to determine the impact of laser surface treatment of titanium dental implants on its electrochemical behavior in artificial saliva at 37°C. The study used an Er, Cr: YSGG laser and diode lasers 810 nm and 980 nm for debridement of titanium implant surface. In the research, the thread on the surface of implant was scanned with the diode laser beam of energy 1, 1.25, 1.5 and 2 W, cw and Er, Cr YSGG: 1,5 and 2 W, pulse 30 Hz
Influence of cerium concentration on the structure and properties of silica-methacrylate sol-gel coatings
No full textThe aim of this work was to study the effect of the incorporation of cerium nitrate in a silica-methacrylate sol–gel hybrid matrix reinforced with silica nanoparticles. Sols, coatings and powders have been studied, focusing specially in the determination of the redox ratio Ce3+/Ce4+ and films structure. Sols have been characterised using viscosity measurements and FT-IR spectroscopy, and powders and coatings obtained with different Ce contents through UV–Vis and FT-IR spectroscopy, TGA, TEM, AFM and FE-SEM. The goal was to reach the best compromise between maximum cerium concentration and coating stability to better understand the mechanisms acting in active anti-corrosive processes.Fil: Rosero Navarro, Nathaly C.. Instituto de Ceramica y Vidrio de Madrid; EspañaFil: Figiel, Pawel. West Pomeranian University of Technology; PoloniaFil: Jedrzejewski, Roman. West Pomeranian University of Technology; PoloniaFil: Biedunkiewicz, Anna. West Pomeranian University of Technology; PoloniaFil: Castro, Yolanda. Instituto de Ceramica y Vidrio de Madrid; EspañaFil: Aparicio, Mario. Instituto de Ceramica y Vidrio de Madrid; EspañaFil: Pellice, Sergio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación en Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Durán, Alicia. Instituto de Ceramica y Vidrio de Madrid; Españ
Corrosion Characteristics of Composites of (Mo, Ti)C Ti and TiC/Ti Type Manufactured with SLM technique
No full textThe addition of hard ceramic particles of nc-(Ti, Mo)C in carbon network into Ti matrix has been proved to be an efficient way to enhance their properties. The purpose of this work was to analyze the corrosion, tribological, mechanical and morphological effects of combining nc-(Ti, Mo)C/C with titanium metal, to create a unique composite via selective laser melting technique (SLM). Composites with different weight percentage (5, 10 and 20 wt%) of ceramic phase were produced. The samples of pure Ti and Ti-6Al-4V alloy were also tested, as a reference. These composites were examined for corrosion resistance in body fluid (artificial saliva solution). Moreover, the properties of titanium composites reinforced with nc-TiC powders were compared. It was stated that mechanical properties were significantly improved with increasing amount of nc-(Ti, Mo)C/C in Ti matrix. In terms of corrosion resistance, the composites showed worse properties compared to pure titanium and Ti-6Al-4V alloy, but better than TiC-reinforced composites
Grzyby chorobotworcze o wzrastajacej ekspansywnosci
No full textThis paper compared occurrence and intenseness of growth C. glabrata, S. capsularis and T. beigelii isolated from sputum, material's bronchoscopic, oral cavity, skin and catheters during 10 years observation ( 1991-2000). All investigated fungi from 1997 years have been characteristic very distinct rise expansiveness appeared in mare intenseness of growth and growing rate of replace new ontocenoses. Most likely is this consequence successive of decrease immunity of man organism about infections yeast-like fungi
PATHOGENIC FUNGI ABOUT RISES EXPANSIVENESS
No full textThis paper compared occurrence and intenseness of growth C. glabrata, S. capsularis and T. beigelii isolated from sputum, material's bronchoscopic, oral cavity, skin and catheters during 10 years observation ( 1991-2000). All investigated fungi from 1997 years have been characteristic very distinct rise expansiveness appeared in mare intenseness of growth and growing rate of replace new ontocenoses. Most likely is this consequence successive of decrease immunity of man organism about infections yeast-like fungi
Candida dubliniensis Sullivan et al., a new species in the human respiratory system
No full textLong-term observations of broadly defined mycological features of various human ontocoenoses show that the ontocoenosis of the resoiratory system is characterised by rapid changes of the dynamics and biodiversity of the fungi. The continuity of studies on the subject and a great biological diversification of the clinical material, collected mostly from individuals suffering from chronic diseases of the respiratory system and from oncological patients, contribute to the detection of many interesting and important species. In the last few years, the studies have been extended to include healthy individuals. Special attention is paid to the age and the place of residence of the subjects. The group analysed in this project comprised randomly chosen students from whom biological material was collected from primary infection routes. The material collected was treated in keeping with generally accepted recommendations for diagnostic mycological laboralories. Candida dubliniensis a species not recorded in Poland previously was found among the 7 fungi identified in the reconnaissance studies. The fungus is an opportunistic pathogen, strictly related to Candida albicans, however, different from it epidemiologically. Candida dubliniensis was isolated from the oral cavity and the throat. Its growth was poor or medium on Sabouraud agar; the colonies were creamy-coloured, soft and smooth. On Nickerson medium, it produced pseudomycelium with characteristic thick and inflated pseudohyphae on which grape-like blastoconidia, and big, darkly pigmented terminal chlamydosporcs, appearing characteristically between 1 and 3, formed. Chlamydospore formation under the inflated terminal cell is also characteristic of this species. The isolation of Candida dubliniensis from the respiratory system strictly corresponds to the studies by Dynowska (1993) on the blurring of physiological and ecological boundaries between trophic groups of potentially pathogenic fungi and corroborates her hypotheses on the continuous occurrence of new species in organ ontocoenoses
Application of artificial neural nerworks in oxidation kinetic analysis of nanocomposites
No full textThis study concerns the application of artificial neural networks in oxidation kinetic analysis of ceramic nanocomposites. The oxidation of the Ti-Si-C ceramic nanocomposite in dry air was studied. The size of the nanoparticles was determined by scanning electron microscopy (SEM). The gaseous oxidation products were analysed by mass spectroscopy (MS) while the solid oxidation products by X-ray diffraction (XRD). The kinetic analysis of the oxidation was based on the Coats-Redfern equation. The kinetic models were identified for the consecutive stages and then the A and E parameters of the Arrhenius equations were evaluated. Artificial neural networks were used at each step of the kinetic calculations
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