@phdthesis{Mueller2012,
  author    = {M{\"u}ller, Andreas},
  title     = {Towards functional oxide heterostructures},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72478},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {Oxide heterostructures attract a lot of attention as they display a vast range of physical phenomena like conductivity, magnetism, or even superconductivity. In most cases, these effects are caused by electron correlations and are therefore interesting for studying fundamental physics, but also in view of future applications. This thesis deals with the growth and characterization of several prototypical oxide heterostructures. Fe3O4 is highly ranked as a possible spin electrode in the field of spintronics. A suitable semiconductor for spin injection in combination with Fe3O4 is ZnO due to its oxide character and a sufficiently long spin coherence length. Fe3O4 has been grown successfully on ZnO using pulsed laser deposition and molecular beam epitaxy by choosing the oxygen partial pressure adequately. Here, a pressure variation during growth reduces an FeO-like interface layer. Fe3O4 films grow in an island-like growth mode and are structurally nearly fully relaxed, exhibiting the same lattice constants as the bulk materials. Despite the presence of a slight oxygen off-stoichiometry, indications of the Verwey transition hint at high-quality film properties. The overall magnetization of the films is reduced compared to bulk Fe3O4 and a slow magnetization behavior is observed, most probably due to defects like anti-phase boundaries originating from the initial island growth. LaAlO3/SrTiO3 heterostructures exhibit a conducting interface above a critical film thickness, which is most likely explained by an electronic reconstruction. In the corresponding model, the potential built-up owing to the polar LaAlO3 overlayer is compensated by a charge transfer from the film surface to the interface. The properties of these heterostructures strongly depend on the growth parameters. It is shown for the first time, that it is mainly the total pressure which determines the macroscopic sample properties, while it is the oxygen partial pressure which controls the amount of charge carriers near the interface. Oxygen-vacancy-mediated conductivity is found for too low oxygen pressures. A too high total pressure, however, destroys interface conductivity, most probably due to a change of the growth kinetics. Post-oxidation leads to a metastable state removing the arbitrariness in controlling the electronic interface properties by the oxygen pressure during growth. LaVO3/SrTiO3 heterostructures exhibit similar behavior compared to LaAlO3/SrTiO3 when it comes to a thickness-dependent metal-insulator transition. But in contrast to LaAlO3, LaVO3 is a Mott insulator exhibiting strong electron correlations. Films have been grown by pulsed laser deposition. Layer-by-layer growth and a phase-pure pervoskite lattice structure is observed, indicating good structural quality of the film and the interface. An electron-rich layer is found near the interface on the LaVO3 side for conducting LaVO3/SrTiO3. This could be explained by an electronic reconstruction within the film. The electrostatic doping results in a band-filling-controlled metal-insulator transition without suffering from chemical impurities, which is unavoidable in conventional doping experiments.},
  subject      = {Oxide},
  language  = {en}
}
@article{KasangKalluvyaMajingeetal.2016,
  author    = {Kasang, Christa and Kalluvya, Samuel and Majinge, Charles and Kongola, Gilbert and Mlewa, Mathias and Massawe, Irene and Kabyemera, Rogatus and Magambo, Kinanga and Ulmer, Albrecht and Klinker, Hartwig and Gschmack, Eva and Horn, Anne and Koutsilieri, Eleni and Preiser, Wolfgang and Hofmann, Daniela and Hain, Johannes and M{\"u}ller, Andreas and D{\"o}lken, Lars and Weissbrich, Benedikt and Rethwilm, Axel and Stich, August and Scheller, Carsten},
  title     = {Effects of Prednisolone on Disease Progression in Antiretroviral-Untreated HIV Infection: A 2-Year Randomized, Double-Blind Placebo-Controlled Clinical Trial},
  series = {PLoS One},
  volume    = {11},
  journal   = {PLoS One},
  number    = {1},
  doi       = {10.1371/journal.pone.0146678},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146479},
  pages     = {e0146678},
  year      = {2016},
  abstract  = {Background HIV-disease progression correlates with immune activation. Here we investigated whether corticosteroid treatment can attenuate HIV disease progression in antiretroviral-untreated patients. Methods Double-blind, placebo-controlled randomized clinical trial including 326 HIV-patients in a resource-limited setting in Tanzania (clinicaltrials.gov NCT01299948). Inclusion criteria were a CD4 count above 300 cells/μl, the absence of AIDS-defining symptoms and an ART-na{\"i}ve therapy status. Study participants received 5 mg prednisolone per day or placebo for 2 years. Primary endpoint was time to progression to an AIDS-defining condition or to a CD4-count below 200 cells/μl. Results No significant change in progression towards the primary endpoint was observed in the intent-to-treat (ITT) analysis (19 cases with prednisolone versus 28 cases with placebo, p = 0.1407). In a per-protocol (PP)-analysis, 13 versus 24 study participants progressed to the primary study endpoint (p = 0.0741). Secondary endpoints: Prednisolone-treatment decreased immune activation (sCD14, suPAR, CD38/HLA-DR/CD8+) and increased CD4-counts (+77.42 ± 5.70 cells/μl compared to -37.42 ± 10.77 cells/μl under placebo, p < 0.0001). Treatment with prednisolone was associated with a 3.2-fold increase in HIV viral load (p < 0.0001). In a post-hoc analysis stratifying for sex, females treated with prednisolone progressed significantly slower to the primary study endpoint than females treated with placebo (ITT-analysis: 11 versus 21 cases, p = 0.0567; PP-analysis: 5 versus 18 cases, p = 0.0051): No changes in disease progression were observed in men. Conclusions This study could not detect any significant effects of prednisolone on disease progression in antiretroviral-untreated HIV infection within the intent-to-treat population. However, significant effects were observed on CD4 counts, immune activation and HIV viral load. This study contributes to a better understanding of the role of immune activation in the pathogenesis of HIV infection.},
  language  = {en}
}
@article{HelassGreinacherGoetzetal.2022,
  author    = {Helaß, Madeleine and Greinacher, Anja and G{\"o}tz, Sebastian and M{\"u}ller, Andreas and G{\"u}ndel, Harald and Junne, Florian and Nikendei, Christoph and Maatouk, Imad},
  title     = {Age stereotypes towards younger and older colleagues in registered nurses and supervisors in a university hospital: A generic qualitative study},
  series = {Journal of Advanced Nursing},
  volume    = {78},
  journal   = {Journal of Advanced Nursing},
  number    = {2},
  doi       = {10.1111/jan.15021},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262751},
  pages     = {471 -- 485},
  year      = {2022},
  abstract  = {Aim This study aimed to identify and compare age stereotypes of registered nurses and supervisors in clinical inpatient settings. Design Generic qualitative study using half-standardized interviews. Method Nineteen face-to-face interviews and five focus groups (N = 50) were conducted with nurses of varying levels at a hospital of maximum medical care in Germany between August and November 2018 and were subjected to structured qualitative content analysis. Results Reflecting the ageing process and cooperation in mixed-age teams, nursing staff and supervisors defined similar age stereotypes towards older and younger nurses reminiscent of common generational labels 'Baby Boomers' and Generations X. Their evaluation created an inconsistent and contradictory pattern differing to the respective work context and goals. Age stereotypes were described as both potentially beneficial and detrimental for the individual and the cooperation in the team. If a successfully implemented diversity management focuses age stereotypes, negative assumptions can be reduced and cooperation in mixed-age teams can be considered beneficial. Conclusion Diversity management as measures against age stereotypes and for mutual acceptance and understanding should include staff from various hierarchical levels of the inpatient setting.},
  language  = {en}
}