Plasmapolymerisation und Partikelwachstum

In this thesis various experiments are presented, that have been exercised in the frame of the project B13 of the Sonderforschungsbereich TR24, titled Fundamentals of Complex Plasmas. All of the presented experiments have been realized at the research vessel ATILA at the Institute for experimental and applied physics in Kiel. They deal with the synthesis of nanoparticles in a radio frequency plasma at low pressure with acetylene as precursor gas. The focus of this work is the chemical and physical interaction between the electrically charging particles and the plasma. In order to understand the time-space phenomena, different techniques have been applied with emphasis on in-situ techniques. The nanoparticle growth cycle has been seperated into three phases and all diagnostics have been time correlated, so that they become comparable. In more detail the applied diagnostics are the electrical characterisation of the discharge by the self-bias voltage at the powered electrode, laser light scattering at the dense dust cloud, Langmuir probe measurements, RF-phase resolved camera measurements of the plasma sheath region above the driven electrode, energy resolved mass spectrometry and quartz micro balance measurements for deposition rate determination. As one of the main hypothesis it was brought out, that the nucleation and coagulation of the nanoparticles occurs simultaneously throughout the entire phase I of the growth cycle, and thus, its duration determines the width of the particle size distribution. In both of the following phases, however, the precursor concentration in the gas decreases strongly, so that no further nucleation can take place. Hence, in dust collection experiments often a mono disperse particle population is found. Strongly simplifed models have been used to interpret the Langmuir probe data and to calculate the particle charge and density approximately. Further more the ion current density and plasma sheath width in front of the powered electrode could be estimated by simple Child-Langmuir laws. The mass-spectrometric investigations allowed for the confirmation of already known reaction schemes in acetylene containing plasmas as well as for the recording of the time dependent ion energies. By the help of simple calculations the diffusion constants and loss rates for the radicals C and CH2 have been determined. Finally, the measurement of the deposition rate, shows interesting indications for the importance of the contribution to the film growth by hydrocarbon ions. This may be interesting work to investigate further in future.Diese Doktorarbeit stellt verschiedene Experimente vor, die innerhalb des Projektes B13 des Sonderforschungsbereiches TR24-Grundlagen komplexer Plasmen an der Anlage ATILA am Institut für Experimentelle und Angewandte Physik in Kiel durchgeführt wurden. Es handelt sich dabei um Versuche an einem Nanopartikel bildenden Hochfrequenzplasma im Niederdruck unter der Verwendung von Acetylen als Präkursor. Schwerpunkt der Arbeit ist die chemische und physikalische Wechselwirkung der sich elektrisch aufladenden Partikel mit dem Plasma. Um diese zeitlichen und räumlichen Phänomene zu Erfassen, wurden unterschiedliche Diagnostiken angewandt, wobei die Betonung auf in-situ Techniken liegt. Um die zahlreichen Ergebnisse miteinander vergleichen zu können, wurde der Wachstumszyklus der Nanopartikel in drei Phasen unterteilt und alle diagnostischen Methoden zeitlich zueinander korreliert. Es handelt sich bei den Diagnostiken im Wesentlichen um die elektrische Charakterisierung der Entladung anhand der sich einstellenden Gleichspannung auf der kapazitiv gekoppelten Elektrode, Laserlichtstreuung an den Nanopartikeln, Langmuirsondenmessungen, HF-phasenaufgelöste Kameramessungen der Randschicht über der getriebenen Elektrode, energieaufgelöste Massenspektrometrie und Quartz-Mikrowägung zur Bestimmung der Schichtabscheidungsrate. Als eine der Hauptthesen wurde dabei herausgearbeitet, dass die Nukleation und Koagulation des Nanostaubs zeitgleich und während der kompletten Phase I im Wachstumszyklus stattfindet, sodass folglich dessen Dauer die Breite der Partikelgrößenverteilung bestimmt. In den beiden darauf folgenden Phasen hingegen sinkt die Präkursorkonzentration in der Gasphase stark ab, sodass keine weitere Nukleation mehr stattfinden kann, weshalb in Sammelexperimenten meist eine monodisperse Partikelpopulation gefunden wird. Stark vereinfachte Modelle wurden verwendet, um die Langmuirsondendaten zu interpretieren und um die Partikelladung und -dichte annhähernd zu errechnen. Des Weiteren konnten mithilfe einfacher Child-Langmuir Gesetze die Ionenstromdichte und die Randschichtdicke vor der getriebenen Elektrode analysiert werden. Die massenspektrometrischen Untersuchungen erlaubten sowohl die Bestätigung bekannter Reaktionsschema in acetylenhaltigen Plasmen als auch Messung der zeitabhängigen Ionenenergie. Mithilfe einfachster Modellrechungen wurden die Diffusionskonstanten und Verlustraten für die Radikale C und CH2 bestimmt. Die Messung der Schichtabscheidungsrate lieferte schließlich interessante Hinweise auf den entscheidenden Beitrag der Kohlenwasserstoffionen zum Schichtwachstum. Dies mag ein Ansatz in Richtung zukünftiger Arbeiten sein

Quality of life in female myocardial infarction survivors: a comparative study with a randomly selected general female population cohort

Background: A substantial burden associated with MI has been reported. Thus, how survivors experience their quality of life (QOL) is now being given increasing attention. However, few studies have involved women and a comparison with the general population. The aims of this study were to determine the QOL of female MI survivors, to investigate whether their QOL differed from that of the general population, and to evaluate the clinical significance of the findings. Methods: Two cross-sectional surveys were performed; on female MI survivors and the general Norwegian population. The MI survey included women aged 62–80 years, three months to five years after their MI. One hundred and forty-five women responded, yielding a response rate of 60%. A subset of women in the same age range (n = 156) was drawn from a study of 1893 randomly selected Norwegian citizens. QOL was measured in both groups with the World Health Organization Quality of Life Instrument Abbreviated (WHOQOL-BREF). Results: The majority (54%) of the female MI survivors presented with ST-elevation in their ECG, 31% received thrombolysis, and 38% had reduced left ventricular ejection fraction. Female MI survivors reported significantly lower satisfaction with general health (p = 0.020) and overall QOL (p = 0.017) than women from the general population. This was also the case for the physical and environmental QOL domains (p < 0.001), but not for the psychological and social relationship domains. Estimated effect sizes between the two groups of participants ranged from 0.1 to -0.6. Conclusion: The burden of MI significantly affects the physical health of elderly women. Still, female MI survivors fare as well as the general female population on psychosocial QOL domains. Action should be taken not only to support women's physical needs but also to reinforce their strengths in order to maintain optimal QOL

Perspectives Among Canadian Physicians on Factors Influencing Implementation of Mifepristone Medical Abortion: A National Qualitative Study.

PURPOSE: Access to family planning health services in Canada has been historically inadequate and inequitable. A potential solution appeared when Health Canada approved mifepristone, the gold standard for medical abortion, in July 2015. We sought to investigate the factors that influence successful initiation and ongoing provision of medical abortion services among Canadian health professionals and how these factors relate to abortion policies, systems, and service access throughout Canada. METHODS: We conducted 1-on-1 semistructured interviews with a national sample of abortion-providing and nonproviding physicians and health system stakeholders in Canadian health care settings. Our data collection, thematic analysis, and interpretation were guided by Diffusion of Innovation theory. RESULTS: We conducted interviews with 90 participants including rural practitioners and those with no previous abortion experience. In the course of our study, Health Canada removed mifepristone restrictions. Our results suggest that Health Canada's initial restrictions discouraged physicians from providing mifepristone and were inconsistent with provincial licensing standards, thereby limiting patient access. Once deregulated, remaining factors were primarily related to local and regional implementation processes. Participants held strong perceptions that mifepristone was the new standard of care for medical abortion in Canada and within the scope of primary care practice. CONCLUSION: Health Canada's removal of mifepristone restrictions facilitated the implementation of abortion care in the primary care setting. Our results are unique because Canada is the first country to facilitate provision of medical abortion in primary care via evidence-based deregulation of mifepristone

In-Vivo Biodistribution and Safety of 99mTc-LLP2A-HYNIC in Canine Non-Hodgkin Lymphoma

Theranostic agents are critical for improving the diagnosis and treatment of non-Hodgkin Lymphoma (NHL). The peptidomimetic LLP2A is a novel peptide receptor radiotherapy candidate for treating NHL that expresses the activated α4β1 integrin. Tumor-bearing dogs are an excellent model of human NHL with similar clinical characteristics, behavior, and compressed clinical course. Canine in vivo imaging studies will provide valuable biodistribution and affinity information that reflects a diverse clinical population of lymphoma. This may also help to determine potential dose-limiting radiotoxicity to organs in human clinical trials. To validate this construct in a naturally occurring model of NHL, we performed in-vivo molecular targeted imaging and biodistribution in 3 normal dogs and 5 NHL bearing dogs. 99mTc-LLP2A-HYNIC-PEG and 99mTc-LLP2A-HYNIC were successfully synthesized and had very good labeling efficiency and radiochemical purity. 99mTc-LLP2A-HYNIC and 99mTc-LLP2A-HYNIC-PEG had biodistribution in keeping with their molecular size, with 99mTc-LLP2A-HYNIC-PEG remaining longer in the circulation, having higher tissue uptake, and having more activity in the liver compared to 99mTc-LLP2A-HYNIC. 99mTc-LLP2A-HYNIC was mainly eliminated through the kidneys with some residual activity. Radioactivity was reduced to near-background levels at 6 hours after injection. In NHL dogs, tumor showed moderately increased activity over background, with tumor activity in B-cell lymphoma dogs decreasing after chemotherapy. This compound is promising in the development of targeted drug-delivery radiopharmaceuticals and may contribute to translational work in people affected by non-Hodgkin lymphoma

The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

Investigation of an Escherichia coli O145 outbreak in a child day-care centre - extensive sampling and characterization of eae- and stx1-positive E. coli yields epidemiological and socioeconomic insight

<p>Abstract</p> <p>Background</p> <p>On October 29^th2009 the health authorities in the city of Trondheim, Norway were alerted about a case of Shiga toxin-positive <it>E. coli </it>(STEC) O145 in a child with bloody diarrhoea attending a day-care centre. Symptomatic children in this day-care centre were sampled, thereby identifying three more cases. This initiated an outbreak investigation.</p> <p>Methods</p> <p>A case was defined as a child attending the day-care centre, in whom <it>eae- </it>and <it>stx</it>₁- but not <it>stx</it>₂-positive <it>E. coli </it>O145:H28 was diagnosed from a faecal sample, with multilocus variable number of tandem repeat analysis (MLVA) profile identical to the index isolate. All 61 children, a staff of 14 in the day-care centre, and 74 close contacts submitted faecal samples. Staff and parents were interviewed about cases' exposure to foods and animals. Faecal samples from 31 ewes from a sheep herd to which the children were exposed were analyzed for <it>E. coli </it>O145.</p> <p>Results</p> <p>Sixteen cases were identified, from which nine presented diarrhoea but not haemolytic uremic syndrome (HUS). The attack rate was 0.26, and varied between age groups (0.13-0.40) and between the three day-care centre departments (0.20-0.50), and was significantly higher amongst the youngest children. Median duration of shedding was 20 days (0-71 days). Children were excluded from the day-care centre during shedding, requiring parents to take compassionate leave, estimated to be a minimum total of 406 days for all cases. Atypical enteropathogenic <it>E. coli </it>(aEPEC) were detected among 14 children other than cases. These isolates were genotypically different from the outbreak strain. Children in the day-care centre were exposed to faecal pollution from a sheep herd, but <it>E. coli </it>O145 was not detected in the sheep.</p> <p>Conclusions</p> <p>We report an outbreak of <it>stx</it>₁- and <it>eae-</it>positive STEC O145:H28 infection with mild symptoms among children in a day-care centre. Extensive sampling showed occurrence of the outbreak strain as well as other STEC and aEPEC strains in the outbreak population. MLVA-typing of the STEC-isolates strongly indicates a common source of infection. The study describes epidemiological aspects and socioeconomic consequences of a non-O157 STEC outbreak, which are less commonly reported than O157 outbreaks.</p

The predictive value of post-traumatic stress disorder symptoms for quality of life: a longitudinal study of physically injured victims of non-domestic violence

<p>Abstract</p> <p>Background</p> <p>Little is known about longitudinal associations between post-traumatic stress disorder (PTSD) and quality of life (QoL) after exposure to violence. The aims of the current study were to examine quality of life (QoL) and the predictive value of post-traumatic stress disorder (PTSD) for QoL in victims of non-domestic violence over a period of 12 months.</p> <p>Methods</p> <p>A single-group (n = 70) longitudinal design with three repeated measures over a period of 12 months were used. Posttraumatic psychological symptoms were assessed by using the Impact of Event Scale, a 15-item self-rating questionnaire comprising two subscales (intrusion and avoidance) as a screening instrument for PTSD. The questionnaire WHOQOL-Bref was used to assess QoL. The WHOQOL-BREF instrument comprises 26 items, which measure the following broad domains: physical health, psychological health, social relationships, and environment. Results of the analysis were summarized by fitting Structural Equation Modelling (SEM).</p> <p>Results</p> <p>For each category of PTSD (probable cases, risk level cases and no cases), the mean levels of the WHOQOL-Bref subscales (the four domains and the two single items) were stable across time of assessment. Individuals who scored as probable PTSD or as risk level cases had significantly lower scores on the QoL domains such as physical health, psychological health, social relationships and environmental than those without PTSD symptoms. In addition, the two items examining perception of overall quality of life and perception of overall health in WHOQOL showed the same results according to PTSD symptoms such as QoL domains. PTSD symptoms predicted lower QoL at all three assessments. Similarly PTSD symptoms at T1 predicted lower QoL at T2 and PTSD symptoms at T2 predicted lower QoL at T3.</p> <p>Conclusion</p> <p>The presence of PTSD symptoms predicted lower QoL, both from an acute and prolonged perspective, in victims of non-domestic violence. Focusing on the individual's perception of his/her QoL in addition to the illness may increase the treatment priorities and efforts.</p