Development of Methodology for the Synthesis of Cytotoxic NHC-Ag-Complexes

Recently disclosed silver N-heterocyclic carbene complexes holding 4-alkylated imidazoles have been proved to hold cytotoxic properties. In this work, derivatives of such alkylated imidazoles were synthesised to be complexed with silver(I). N,N-diphenyl-4-methylimidazolium teterafluoroborate was synthesised by means of a two step synthetic pathway. The synthesis involved a selective N1-arylation of 4-methyl-1H- imidazole using the palladium-catalysed Buchwald N-arylation method, followed by a direct quaternisation using phenylboronic acid. A 2^2 factorial design was initiated to investigate how the reaction temperature and reaction time influenced the conversion of the starting material. No clear correlation was found, and a full conversion of the starting material was not obtained. The formation of the product was confirmed by LC-MS, but a successful isolation was not achieved. A N,N-diphenyl-4-heptylimidazolium tetrafluoroborate synthesis was attempted by means of a seven/eight step synthetic pathway. The synthesis involved a selective iodination of an imidazole backbone, followed by an altering of the electronic properties by the introduction of an auxiliary group. A first attempt of implementing this step using flow chemistry was successfully performed. The backbone iodide was replaced in a Sonogashira coupling reaction, in which the installed alkyne moiety was reduced using gaseous hydrogen in the presence of Pearlman's catalyst. An attempt of reducing the alkyne moiety using indium as the reducing agent was carried out, without furnishing the desired product. The palladium-catalysed Buchwald method was used to perform an N1-arylation, before phenylboronic acid was utilised in an attempt to obtain the quaternised imidazole. Only traces of the desired product were observed. It is thought that the imidazole side chain constitutes a steric hindrance that reduces the conversion of the starting material.MAMN-KJEMKJEM399

Analysis and monitoring of drilling risers on DP vessels

The object of this master thesis is to investigate a drilling riser exposed to currents, waves and vessel motions at different water depths. The aim is to develop an advisory system for vessel position based on the riser response and also to better predict the transition from operation to a potential disconnect. The advisory system will make use of watch circles which define the limits for normal operation, halt in operation and a possible disconnect. As the most accessible oil reservoirs are exploited, there is a need for drilling operations at ever greater water depths and in harsher environments. The riser, and its interactions with the vessel and the blow-out preventer (BOP), is a crucial element in a drilling operation. In order to ensure a safe and productive operation, the riser top and bottom angles must be within acceptable limits. For excessive angles, a disconnect from the well is carried out. This will imply a major loss of income, and it is therefore highly undesirable to disconnect when not necessary. However, the consequences of not disconnecting when necessary are even more severe. The riser is exposed to currents, waves and vessel motions which cause it to deflect. The effect from these influences must be investigated in order to predict the riser angles in various conditions and thereby develop watch circles taking these angles into account. The riser has been modeled and analyzed in RIFLEX, a software program developed at MARINTEK for static and dynamic analysis of slender marine structures. In order to investigate the response in both shallow and deep waters, water depths of 300 and 2000 [m] have been applied. The riser is exposed to unidirectional current, regular waves and vessel motions. The top tension is kept constant for each water depth. At 300 [m] water depth, the riser was found to be highly affected by vessel offsets, and the control objective for this depth must be to avoid any offset. At 2000 [m] water depth, however, both lower and upper angle will stabilize at acceptable magnitudes for the maximum static vessel offset studied in this thesis. The upper angle will however be excessive during the movement. The lower angle will not immediately respond to a motion at the top end of the riser, and it increases slowly for an increasing vessel offset. Hence, for a drive-off, which is an uncontrolled excursion of the vessel due to a failure in the DP system, the DP operator will have some time before a disconnect has to be carried out. The current affects the riser considerably more in deep waters compared to shallow waters. Also, first-order waves affect the upper angle significantly more than the lower angle, both in shallow and deep water. The watch circles which have been developed prove that the limits for a halt in the operation and a possible disconnect are larger than the conventional guidance limits. By allowing the top angle to become excessive during a limited amount of time, one can uphold the operation for a longer period of time, and also avoid an unnecessary disconnect. The main contributions in this thesis are the simulation study of the drilling riser and the proposed guidance limits for operation and disconnect. &nbsp

Social epigenetics: a science of social science?

Epigenetics has considerable potential to transform social science by embedding mutually regulative reciprocal connections between biological and social processes within the human activities it studies. This paper highlights common epigenetic methods and outlines practical considerations in the design of ‘social epigenetics’ research addressing the identification of biomolecular pathways, statistical inference of causality, conceptualization of the environment as a biochemical event, heritability of epigenetic alterations and intergenerational accountability, and concept of time implied by attempts to capture complex, non‐linear gene‐environment interactions. Finally, we reflect on the social epigenome as a conceptual space and try to identify barriers to translation, and practical and ethical issues raised by epigenetics research. In order for social epigenetics and social science to contribute to the emergence of this putative ‘science of social science’ and to capture meaningful human experience they will both need to change significantly

An epidemiological study of cancer in adult twins born in Norway 1905–1945

We have identified 23 334 individuals (40%) of twins born in Norway 1905–45 where both twins were alive in 1960 without malignant disease. These were linked to the Cancer Registry of Norway. A reduced risk of malignant disease was demonstrated among twins for all tumour sites combined; standardized incidence rate (SIR): 0.90 (95% CI 0.85–0.94) in females and 0.95 (95% Cl 0.90–0.99) in males. In both sexes, we observed a significant reduced incidence of malignant melanomas of the skin. The incidence of colorectal cancer tended to be reduced for both sexes. In females, the incidence of tumours of the central nervous system and lungs were reduced. We consider our findings are real, but cannot explain them. © 2001 Cancer Research Campaign http://www.bjcancer.co

God ernæringspleie til eldre ortopediske pasientar

Bachelor i sjukepleie SK 159Bakgrunn: Underernæring medfører auka risiko for slitasje- og brotskader hos eldre. Det er sjukepleiaren sitt ansvar å kartlegge ernæringsmessig risiko, og gi pasienten individuelt tilpassa behandling. Det vil dermed vere hensiktsmessig å få innsikt i kva for sjukepleieintervensjonar som kan bidra til betre kartlegging og utreiing av underernæring, samt konkrete tiltak for å auke næringsinntaket til pasienten, og optimalisere næringssamansetjinga i maten. Problemstilling: Korleis kan sjukepleiaren bidra til god ernæringsstatus for eldre pasientar på sjukehus? Metode: Oppgåva er ein litteraturstudie basert på søk i medisinske databasar, samt gjennomgang av pensumlitteratur og nasjonale retningslinjer. Konklusjon: God ernæringspleie bidrar til raskare mobilisering, færre postoperative komplikasjonar og dermed betre prognose for eldre ortopediske pasientar. Det er sjukepleiaren sitt ansvar å kartlegge ernæringsstatus, samt opprette ein individuell ernæringsplan for risikopasientar. Ein må ta omsyn til særskilte preferansar og behov hos den enkelte pasienten, og sørgje for aktiv involvering av pasienten i ernæringsbehandlinga. Det er behov for meir kunnskap om ernæring blant sjukepleiarar, som vil kunne føre til større engasjement for emnet, og betre formidling av kunnskap til pasienten. Ein ser også nytten av meir tverrfagleg samarbeid for å oppnå betre langtidsverknader. Oppgåva talar for at det bør leggjast meir vekt på ernæringsbehandling på ortopediske avdelingar

The relationship between default on loans and operating costs in microfinance institutions

Master's thesis Business Administration BE501 - University of Agder 2016One of the challenges in microfinance is to solve asymmetric information and cost concerns related to serving poor customers with little or no collateral, in order to offer poor people and small businesses access to financial services. In resent times the industry has been critiqued for maintaining harsh collection practices and charging too high interest rates to their clients. The microfinance mission of serving the poor has been questioned from several holds. There are sufficient previous studies that show that the interest rate to a great extent is driven by the operating costs in the institutions. Identifying the drivers of the operating costs thus becomes necessary in order to lower interest rates offered to the customers. The critique on collection practices is not uncalled for. Frequent collection of repayment is in the microfinance industry generally viewed as an essential component in reducing the risk of default, which historically has been a prominent goal of microfinance institutions due to the lack of collateral offered by their clients. The lack of credit history further adds to the need to manage risk, but with little background information allocation of resources becomes problematic. Transaction costs are therefore high in the industry. It is a paradox that the world’s poorest are charged with the highest cost of capital, and the industry faces a need for lower interest rates in order to help more people. This study investigates the relationship between default rates and operating costs in the microfinance sector, and looks into whether the microfinance sector over time has been too concerned with lowering default rates. Has the focus on default rates left the microfinance institutions with too high operating costs due to extensive transaction costs connected to monitoring, control and collection practices? Would they be better off by allowing for higher levels of default and lower transaction costs

Mobilization of asbestos fibers by weathering of a corrugated asbestos cement roof

Mobilization of asbestos fibers from a 60-year-old corrugated asbestos cement roof was studied in material samples collected from a domestic house in Southern-Norway. Samples included pieces of the roof itself, rainfall simulated run off-water and moss growing on the roof surface. Weathered roof debris below the rain water system was investigated for asbestos fibers leached from the roof, and air samples were collected for asbestos concentrations in ambient air. Micrographs obtained by scanning electron microscopy show that weathering exposed asbestos fibers on the deteriorated roof surface. A high number of fibers found in the run off-water as well as in the weathered roof debris sample illustrates that exposed fibers are prone to mobilization. Investigation of weathering-induced magnesium depletion by scanning electron microscopy energy dispersive X-ray spectroscopy of asbestos fibers collected from the moss, roof underside and surface revealed that fibers had MgO weight % comparable to reference material. The major element chemistry of the fibers is therefore unaltered. Our findings demonstrate that care must be taken when working on and handling old corrugated asbestos cement roof as asbestos fibers might be released. In order to limit exposure to mobile fibers, moss covering asbestos cement roof should not be removed.Mobilization of asbestos fibers by weathering of a corrugated asbestos cement roofpublishedVersio

Measurements of airborne asbestos fibres during refurbishing

Although the use of asbestos fibres in building materials has been prohibited in Norway since 1985, asbestos-containing materials (ACMs) are still found in many buildings. Lack of knowledge and awareness of these materials may lead to exposure during refurbishing. The aim of this study was to investigate the airborne fibre concentration and classify fibres found during the abatement of various ACMs. The release of fibres during short-term work tasks, such as drilling and sawing, was also investigated. Parallel air samples were collected during asbestos abetment of different building materials and analysed with scanning electron microscope (SEM) and phase-contrast microscope (PCM), respectively. Material samples were analysed with SEM. A real-time fibre monitor was used to measure asbestos during short-term work. The highest fibre concentrations were measured for samples collected during the removal of asbestos insulating boards (1.5–4.5 fibres/cm3 [f/cm3]), and the numbers were relatively similar for SEM and PCM. A large difference in asbestos concentrations was found between SEM and PCM when analysing floor materials, which were probably caused by a high number of gypsum fibres that the PCM operator counted. Thin fibres (<0.2 µm in width) were included in the SEM count and constituted up to 50% of the total fibre concentration for the asbestos cement materials. The presence of other inorganic and organic fibres on these samples probably led to similar results between SEM and PCM. Short-term work led to peak concentrations above 30 f/cm3.Measurements of airborne asbestos fibres during refurbishingpublishedVersio

Characterization of dust and crystalline silica exposure during indoor demolition

Exposure to dust and respirable crystalline silica (RCS) is a continuing concern in the construction industry when working with silica-containing materials, such as concrete, brick, or stone. Increased knowledge of the dust characteristics can be used to improve measures to reduce potential exposure. This study aimed to characterize dust collected from indoor demolition in terms of particle size distribution and mineral content, including quartz. Airborne dust was collected with Sioutas cascade impactors at five different construction sites involved in indoor demolition and renovation. Four of the locations had workers demolishing concrete, while at the fifth location brick structures were demolished. An aerodynamic particle sizer (APS) was used to continually monitor the particle number concentrations in the size range 0.54 µm to 17 µm. Material samples of demolished material were collected from each location to determine mineral content. The filters from the Sioutas cascade impactors were weighted to determine dust concentrations in five size fractions ranging from 10 µm down to less than 0.25 µm. Quartz concentrations were quantified with X-ray diffraction using the NIOSH 7500 method and Rietveld refinement was further used to determine other mineral content in the Sioutas impactor samples and material samples. Respirable dust and quartz concentrations were calculated from the Sioutas data. The mass- and number-based particle size distributions measured by the APS were similar for the four locations involved in concrete demolition, whereas the location working with brick had a different distribution. The concentration levels varied widely, and the highest levels were observed at an enclosed location with no natural ventilation where concrete demolition took place. Limited natural or mechanical ventilation led to an accumulation of smaller particles around 1 µm and a lower mass median aerodynamic diameter for RCS, down to 1.2 µm, compared to locations with ventilation. The quartz percentages of the dust collected by Sioutas impactors were found to increase with increasing particle size. The dust contained less quartz than the source material, and an up-concentration of softer minerals like calcite was observed. The knowledge of particle size distributions and concentration levels occurring in the field during indoor demolition is important to ensure effective measures to reduce worker exposure. The results highlight the importance of effective ventilation to reduce the accumulation of airborne particles.publishedVersio