Let It Alone

https://digitalcommons.library.umaine.edu/mmb-vp/3245/thumbnail.jp

The frequent exacerbator phenotype of Chronic Obstructive Pulmonary Disease in pulmonary rehabilitation – assessment of clinical outcomes and inflammation

Chronic obstructive pulmonary disease (COPD) patients who suffer recurrent exacerbations are a recognised clinical phenotype. Pulmonary rehabilitation is considered a cornerstone treatment in the management of COPD. The aim of this thesis was to investigate how frequent exacerbators respond to pulmonary rehabilitation in terms of clinical outcomes and inflammation. Study 1 suggested that frequent exacerbators were less likely to complete pulmonary rehabilitation (44% vs 69%; p=0.025), but those who completed experienced clinically important improvements in outcomes. Study 2 demonstrated that fibrinogen concentrations were significantly reduced in both frequent and infrequent exacerbators (p=0.033), and total leukocyte (p=0.018) and neutrophil (p=0.018) counts reduced in frequent exacerbators only upon completion of pulmonary rehabilitation. Study 3 suggested a tendency towards an increase in MKP-1 anti-inflammatory gene expression in response to corticosteroid treatment (2hr, p=0.060) in both frequent and infrequent exacerbators upon completion of pulmonary rehabilitation. Study 4 showed that an acute bout of exercise at the beginning of pulmonary rehabilitation induced increases in leukocyte counts (p=0.002) and immature neutrophils (p=0.002) in both groups. No differences in inflammatory responses to acute exercise were observed with an acute bout of exercise at the end of pulmonary rehabilitation in both groups. Study 5 suggested that frequent exacerbators recorded fewer daily steps (d=0.3) and spent less time in light (d=0.8) and moderate-to-vigorous activities (d=0.3). There were no definitive differences in inflammation between frequent and infrequent exacerbators. Overall, this thesis shows that pulmonary rehabilitation should be encouraged in frequent exacerbators as they stand to have significant improvements in clinical outcomes and resolution of inflammation

Detecting Alpha-induced Radioluminescence in the UVC Wavelength Range Using a UVTron Flame Sensor, and the Effect of a Gas Flow on Detection Rates as Compared to an Air Atmosphere

Alpha-induced radioluminescence provides a potential avenue for the detection of alpha-emitting materials from a distance far greater than the travel of alpha-particles themselves. This work details experiments carried out into the detection of this radioluminescence in the ultraviolet C wavelength range (180-280 nm) using an off-the-shelf flame sensor, the UVTron (Hamamatsu, Japan). There is less interference from natural and artificial background lighting in the ultraviolet C wavelength range than at other ultraviolet wavelengths. A UVTron flame sensor (R9533, Hamamatsu, Japan), which is sensitive only in the ultraviolet C wavelength range, was used to detect the presence of a 6.95 MBq 210 Po source at a distance of approximately 20 mm. The signal (0.3280 counts per second) was over 147 times that of the background, which was very low (2.224 × 10 -3 counts per second) under the general laboratory/commercial lighting conditions. The limit of detection, where the signal can be distinguished from background, can be calculated to be approximately 240 mm under these conditions, assuming a standard 1/r 2 , which is much greater than the alpha particle travel. Gas was flowed over the alpha sample to determine if this would enhance the radioluminescence and hence the detection by the UVTron. Gases of Ar, Xe, Ne, N2, Kr and P10 were tested, all of which increased the signal detected by the UVTron sensor. The greatest increase was found to be in a flow of Xe, which greater than doubled the counts per second of the detector in one instance. The ability of the UVTron to detect the radioluminescence from alpha-emitting materials and the enhancement which may be possible using a flow of gas, indicate the potential of the UVTron sensor for inclusion in an alpha-emitting materials detection system which could be operated at a distance in the field, for example for nuclear decommissioning characterisation purposes or nuclear security applications

The importance of attractive three-point interaction in enantioselective surface chemistry: stereospecific adsorption of serine on the intrinsically chiral Cu{531} surface

Both enantiomers of serine adsorb on the intrinsically chiral Cu{531} surface in two different adsorption geometries, depending on the coverage. At saturation, substrate bonds are formed through the two oxygen atoms of the carboxylate group and the amino group (μ3 coordination), whereas at lower coverage, an additional bond is formed through the deprotonated β−OH group (μ4 coordination). The latter adsorption geometry involves substrate bonds through three side groups of the chiral center, respectively, which leads to significantly larger enantiomeric differences in adsorption geometries and energies compared to the μ3 coordination, which involves only two side groups. This relatively simple model system demonstrates, in direct comparison, that attractive interactions of three side groups with the substrate are much more effective in inducing strong enantiomeric differences in heterogeneous chiral catalyst systems than hydrogen bonds or repulsive interactions