14 research outputs found
The local adsorption geometry of benzenethiolate on Cu(1 0 0)
The local adsorption geometry of benzenethiolate in the ordered c(2 × 6) phase on Cu(1 0 0) has been investigated by a combination of S K-edge near-edge X-ray absorption fine structure (NEXAFS), normal incidence X-ray standing waves (NIXSW) and S 1s scanned-energy mode photoelectron diffraction (PhD). NEXAFS and PhD show that the molecular plane is tilted from the surface normal by 20 ± 15°, while NIXSW clearly identifies the S head-group as occupying the four-fold coordinated hollow sites. PhD shows the S atoms lies 1.34 ± 0.04 Å above the outermost Cu atomic layer, leading to a Cu–S bondlength of 2.25 ± 0.02 Å. The combination of the PhD and NIXSW results shows the Cu surface layer has an outward relaxation of 0.15 ± 0.06 Å. Possible origins for this large adsorbate-induced relaxation are discussed
Bringing online adaptive radiotherapy to a standard C-arm linac
Current online adaptive radiotherapy (oART) workflows require dedicated equipment. Our aim was to develop and implement an oART workflow for a C-arm linac which can be performed using standard clinically available tools. A workflow was successfully developed and implemented. Three patients receiving palliative radiotherapy for bladder cancer were treated, with 33 of 35 total fractions being delivered with the cone-beam computed tomography (CBCT)-guided oART workflow. Average oART fraction duration was 24 min from start of CBCT acquisition to end of beam on. This work shows how oART could be performed without dedicated equipment, broadening oART availability for application at existing treatment machines
Fatigue and health-related quality of life in inflammatory bowel disease: Results from a population-based study in the Netherlands: The IBD-South Limburg cohort.
BACKGROUND:: The importance of fatigue in chronic disease has been increasingly recognized; however, little is known about fatigue in inflammatory bowel disease (IBD). The aim of the present study was to investigate the prevalence and severity of fatigue and the impact on health-related quality of life (HRQoL) in patients included in a population-based IBD cohort in the Netherlands. METHODS:: IBD patients, diagnosed between January 1st, 1991, and January 1st, 2003, were followed up for a median of 7.1 years. They completed a questionnaire, which included a disease activity score, the Multidimensional Fatigue Inventory (MFI-20), the Inflammatory Bowel Disease Questionnaire (IBDQ), and the Short Form health survey (SF-36). Hemoglobin levels were recorded. RESULTS:: Data were available in 304 Crohn's disease (CD), 368 ulcerative colitis (UC), and 35 indeterminate colitis (IC) patients. During quiescent disease, the prevalence of fatigue was nearly 40%. MFI-20 and HRQoL scores were significantly worse in IBD patients having active disease. In a multivariate analysis, disease activity was positively related with the level of fatigue in both CD and UC. In UC, anemia influenced the general fatigue score independently of disease activity. Disease activity as well as fatigue were independently associated with an impaired IBDQ. CONCLUSIONS:: In IBD, even in remission, fatigue is an important feature. Both in CD and in UC, fatigue determined HRQoL independently of disease activity or anemia. This implies that in IBD patients physicians need to be aware of fatigue in order to better understand its impact and to improve the HRQoL. (Inflamm Bowel Dis 2010)
Testing the reliability of standard and complementary DNA barcodes for the monocot subfamily Alooideae from South Africa
Although a standard DNA barcode has been identified for plants, it does not always provide species-level specimen identifications for investigating important ecological questions. In this study, we assessed the species-level discriminatory power of standard (rbcLa + matK) and complementary barcodes (ITS1 and trnH-psbA) within the subfamily Alooideae (Asphodelaceae), a large and recent plant radiation, whose species are important in horticulture yet are threatened. Alooideae has its centre of endemism in southern Africa, with some outlier species occurring elsewhere in Africa and Madagascar. We sampled 360 specimens representing 235 species within all 11 genera of the subfamily. With three distance-based methods, all markers performed poorly for our combined data set, with the highest proportion of correct species-level specimen identifications (30%) found for ITS1. However, when performance was assessed across genera, the discriminatory power varied from 0% for all single markers and combinations in Gasteria to 63% in Haworthiopsis, again for ITS1, suggesting that DNA barcoding success may be related to the evolutionary history of the lineage considered. Although ITS1 could be a good barcode for Haworthiopsis, the generally poor performance of all markers suggests that Alooideae remains a challenge. As species boundaries within Alooideae remain controversial, we call for continued search for suitable markers or the use of genomics approaches to further explore species discrimination in the group.The University of Johannesburg, the Royal Society of London, and the National Research Foundation of South Africa. Part of this project was also funded by the Government of Canada through Genome Canada and the Ontario Genomics Institute (2008-OGI-ICI-03).http://www.nrcresearchpress.com/journal/genPlant Scienc
Bringing online adaptive radiotherapy to a standard C-arm linac
Current online adaptive radiotherapy (oART) workflows require dedicated equipment. Our aim was to develop and implement an oART workflow for a C-arm linac which can be performed using standard clinically available tools. A workflow was successfully developed and implemented. Three patients receiving palliative radiotherapy for bladder cancer were treated, with 33 of 35 total fractions being delivered with the cone-beam computed tomography (CBCT)-guided oART workflow. Average oART fraction duration was 24Â min from start of CBCT acquisition to end of beam on. This work shows how oART could be performed without dedicated equipment, broadening oART availability for application at existing treatment machines