An influence of electron beam on thin oxide films

Bakalárska práca sa zaoberá skúmaním vplyvu elektrónového lúča rastrovacieho elektrónového mikroskopu na povrch vzorky SiO2/Si(100). V práci je stručne popísaná elektrónová mikroskopia a mikroskopia atomárnych síl. Hlavným riešeným problémom je pozorovaná zmena odtieňu pri pozorovaní vzorky SiO2/Si(100) rastrovacím elektrónovým mikroskopom. V práci je zistené, že na povrchu vzorky sa vytvárajú objekty o výške niekoľko nm. Zvyšok práce je potom venovaný meraniu závislosti výšky objektu na rôznych premenných. Merania sú väčšinou založené na selektívnom ožarovaní povrchu vzorky rastrovacím elektrónovým mikroskopom, meraní ožiarených častí pomocou mikroskopu atomárnych síl a vyhodnocovaní v aplikácie Gwyddion.This bachelor work deals with a study of the influence of electron beam of scanning electron microscope on the surface of the SiO2/Si (100) – sample. In the work the electron and atomic force microscopy briefly described. The main objective of experimental part is to describe variation in the brightness of sample SiO2/Si (100) in Scanning electron microscope images. In this study is found that on the sample surface are created objects few nm high. The rest of the work is then devoted to measuring the dependence of the object’s high on different variables. Experiments are generally based on the selective irradiation of the sample surface by scanning electron microscope, measurement of irradiated parts using atomic force microscope and evaluation in the application Gwyddion.

Cellular localization of a Hsp90 homologue in Porphyromonas gingivalis

We previously reported an association between elevated serum antibody titers to the 90-kDa human heat shock protein (Hsp90), periodontal health and colonization by Porphyromonas gingivalis . In this study, we examined the cellular localization of the Hsp90 homologue of P. gingivalis . Cultures of P. gingivalis were heat-stressed (45°C) and examined for localization of the Hsp90 homologue. Heat stress induced a 4–5-fold increase in anti-Hsp90 antibody reactivity over that of the unstressed controls. Western blot analysis revealed two bands (44 and 68 kDa) that reacted with anti-Hsp90 antibodies. The 68-kDa band was heat-inducible, while the 44-kDa band was not. Immunogold staining revealed that the Hsp90 homologue localized principally to the membrane and extracellular vesicles. Subcellular fractionation confirmed that the Hsp90 homologue was primarily membrane-associated.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72856/1/j.1574-6968.1999.tb08820.x.pd

Exosomes Released from Mycoplasma Infected Tumor Cells Activate Inhibitory B Cells

Mycoplasmas cause numerous human diseases and are common opportunistic pathogens in cancer patients and immunocompromised individuals. Mycoplasma infection elicits various host immune responses. Here we demonstrate that mycoplasma-infected tumor cells release exosomes (myco+ exosomes) that specifically activate splenic B cells and induce splenocytes cytokine production. Induction of cytokines, including the proinflammatory IFN-γ and the anti-inflammatory IL-10, was largely dependent on the presence of B cells. B cells were the major IL-10 producers. In splenocytes from B cell deficient μMT mice, induction of IFN-γ+ T cells by myco+ exosomes was greatly increased compared with wild type splenocytes. In addition, anti-CD3-stimulated T cell proliferation was greatly inhibited in the presence of myco+ exosome-treated B cells. Also, anti-CD3-stimulated T cell signaling was impaired by myco+ exosome treatment. Proteomic analysis identified mycoplasma proteins in exosomes that potentially contribute to the effects. Our results demonstrate that mycoplasma-infected tumor cells release exosomes carrying mycoplasma components that preferentially activate B cells, which in turn, are able to inhibit T cell activity. These results suggest that mycoplasmas infecting tumor cells can exploit the exosome pathway to disseminate their own components and modulate the activity of immune cells, in particular, activate B cells with inhibitory activity

Assessment of intracranial vessels in association with carotid atherosclerosis and brain vascular lesions in rheumatoid arthritis

BACKGROUND: Stroke has been associated with rheumatoid arthritis (RA). We assessed patients with RA and healthy control subjects by transcranial Doppler (TCD), carotid ultrasonography and brain magnetic resonance imaging (MRI). METHODS: Altogether, 41 female patients with RA undergoing methotrexate (MTX) or biologic treatment and 60 age-matched control subjects underwent TCD assessment of the middle cerebral artery (MCA) and basilar artery. Pulsatility index (PI), resistivity (resistance) index (RI) and circulatory reserve capacity (CRC) were determined at rest (r) and after apnoea (a) and hyperventilation (h). The presence of carotid plaques and carotid intima-media thickness (cIMT) were also determined. Intracerebral vascular lesions were investigated by brain MRI. RESULTS: MCA PI and RI values at rest and after apnoea were significantly increased in the total and MTX-treated RA populations vs control subjects. MCA CRC was also impaired, and basilar artery PI was higher in RA. More patients with RA had carotid plaques and increased cIMT. Linear regression analysis revealed that left PI(r) and RI(r) correlated with disease duration and that left PI(r), RI(r), PI(a), PI(h) and basilar PI correlated with disease activity. Right CRC inversely correlated with 28-joint Disease Activity Score. Disease activity was an independent determinant of left PI(a) and right CRC. Compared with long-term MTX treatment alone, the use of biologics in combination with MTX was associated with less impaired cerebral circulation. Impaired cerebral circulation was also associated with measures of carotid atherosclerosis. CONCLUSIONS: To our knowledge, this is the first study to show increased distal MCA and basilar artery occlusion in RA as determined by TCD. Patients with RA also had CRC defects. We also confirmed increased carotid plaque formation and increased cIMT. Biologics may beneficially influence some parameters in the intracranial vessels

Mycoplasma Contamination Revisited: Mesenchymal Stromal Cells Harboring Mycoplasma hyorhinis Potently Inhibit Lymphocyte Proliferation In Vitro

Mesenchymal stromal cells (MSC) have important immunomodulatory effects that can be exploited in the clinical setting, e.g. in patients suffering from graft-versus-host disease after allogeneic stem cell transplantation. In an experimental animal model, cultures of rat T lymphocytes were stimulated in vitro either with the mitogen Concanavalin A or with irradiated allogeneic cells in mixed lymphocyte reactions, the latter to simulate allo-immunogenic activation of transplanted T cells in vivo. This study investigated the inhibitory effects of rat bone marrow-derived MSC subsequently found to be infected with a common mycoplasma species (Mycoplasma hyorhinis) on T cell activation in vitro and experimental graft-versus-host disease in vivo.We found that M. hyorhinis infection increased the anti-proliferative effect of MSC dramatically, as measured by both radiometric and fluorimetric methods. Inhibition could not be explained solely by the well-known ability of mycoplasmas to degrade tritiated thymidine, but likely was the result of rapid dissemination of M. hyorhinis in the lymphocyte culture.This study demonstrates the potent inhibitory effect exerted by M. hyorhinis in standard lymphocyte proliferation assays in vitro. MSC are efficient vectors of mycoplasma infection, emphasizing the importance of monitoring cell cultures for contamination

In-situ Wear Process Monitoring by Optical Methods

The thesis describes the development of methodology for in-situ observation of a wear process. The main goal is to correlate the friction coefficient development with the video record. It is approached by designing the external device that counts the cycles and determines the period based on infrared reflectance sensor. Another problem solved is the evaluation of the possibility of using the external probe for the in-situ Raman spectra measurement. The proposed interpretation technique is used for the deviation measurement at different rotational velocities. The techniques are demonstrated on the steel samples and DLC samples.Validerat; 20120706 (anonymous

Cradle & crucible : History and faith in the middle east

Washington, DCxv. 175 p.: index.; 23 c

"Det behövs först någon som kan hjälpa till, sen någon att prata och gråta med" : En kvalitativ intervjustudie om erfarenheter och behovet av anhörigstöd för anhöriga till närstående med psykisk funktionsnedsättning

Syftet med studien är att öka förståelsen om behovet av anhörigstöd för anhöriga till närstående med psykisk funktionsnedsättning, samt relatera dessa behov till befintligt kommunalt anhörigstöd. Empirin bygger på kvalitativa intervjuer med vuxna anhöriga till vuxna närstående med psykiska funktionsnedsättningar. Resultatet visar att anhörigas behov inte matchas av befintligt kommunalt anhörigstöd. Det främsta behovet för deltagarna i studien är att vård och insatser till deras närstående fungerar och att det finns en samverkan mellan och inom vården och myndigheter. Behov av individuellt och psykologiskt stöd i form av samtal och anhöriggrupper kommer i andra hand. Ett systemteoretiskt perspektiv har använts för att åskådliggöra nödvändigheten av en helhetssyn och för att illustrera komplexiteten när det gäller anhörigas behov och tillgång till stöd. Perspektivet skapar en förståelse för hur anhörigas behov av stöd och befintligt stöd hänger ihop och påverkas i ett större sammanhang. Vidare analyseras empirin utifrån Frasers teori Kampen om behoven. Analysen förklarar hur olika samhälleliga diskurser påverkar hur anhörigas behov tolkas och hur stöd utformas. Studiens resultat är intressant eftersom det belyser och problematiserar ”glappet” mellan vuxna anhörigas, till vuxna närstående med psykiska funktionsnedsättningar, behov av och tillgång till befintligt kommunalt anhörigstöd. Studien är betydelsefull för socialt arbete då resultatet pekar på att bristen på helhetssyn och samverkan inom och mellan vård och myndigheter har negativa konsekvenser både för den närstående och den anhöriga. The aim of the study is to increase knowledge about the situation for relatives of people with mental health disabilities and to consider their needs in relation to municipal support. The study is based on qualitative interviews with adult relatives of adult people with mental health disabilities. The study shows that the needs of relatives are not compatible with existing municipal support. The primary need for relatives is adequate healthcare and support for their relatives with mental health disabilities and joint action between healthcare and municipal agencies. Individual and psychological needs are secondary. The result is analysed by system theory and the Struggle over needs theory (Fraser 2003). The analysis shows how different societal discourses influence the interpretation of the needs of relatives. The study is important because it highlights and problematizes the discrepancy between the needs of relatives and their access to municipal support. The result is important and relevant for social work since it identifies the absence both of a holistic approach and of joint action between healthcare and municipal agencies, which results in negative consequences for relatives as well as for persons with mental health disabilities.