6,779 research outputs found

    Development of Non-Petroleum-Based Binders for Use in Flexible Pavements – Phase II

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    Bio-binders can be utilized as asphalt modifiers, extenders, and replacements for conventional asphalt in bituminous binders. From the rheology results of Phase I of this project, it was found that the bio-binders tested had good performance, similar to conventional asphalt, except at low temperatures. Phase II of this project addresses this shortcoming and evaluates the Superpave performance of laboratory mixes produced with the enhanced bio-binders. The main objective of this research was to develop a bio-binder capable of replacing conventional asphalt in flexible pavements by incorporating ground tire rubber (GTR) into bio-oil derived from fast pyrolysis of agriculture and forestry residues. The chemical compatibility of the new bio-binder with GTR was assessed, and the low-temperature performance of the bio-binders was enhanced by the use of GTR. The newly developed binder, which consisted of 80 percent conventional binder and 20 percent rubber-modified bio-oil (85 percent bio-oil with 15 percent GTR), was used to produce mixes at two different air void contents, 4 and 7 percent. The laboratory performance test results showed that the performance of the newly developed bio-binder mixes is as good as or better than conventional asphalt mixes for fatigue cracking, rutting resistance, moisture sensitivity, and low-temperature cracking. These results need to be validated in field projects in order to demonstrate adequate performance for this innovative and sustainable technology for flexible pavements

    Fibre-based fluorescence-lifetime imaging microscopy:a real-time biopsy guidance tool for suspected lung cancer

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    Lung cancer is the most common cause of cancer-related deaths worldwide. Early detection improves outcomes, however, existing sampling techniques are associated with suboptimal diagnostic yield and procedure-related complications. Autofluorescence-based fluorescence-lifetime imaging microscopy (FLIM), a technique which measures endogenous fluorophore decay rates, may aid identification of optimal biopsy sites in suspected lung cancer. Our fibre-based fluorescence-lifetime imaging system, utilising 488 nm excitation, which is deliverable via existing diagnostic platforms, enables real-time visualisation and lifetime analysis of distal alveolar lung structure. We evaluated the diagnostic accuracy of the fibre-based fluorescence-lifetime imaging system to detect changes in fluorescence lifetime in freshly resected ex vivo lung cancer and adjacent healthy tissue as a first step towards future translation. The study compares paired non-small cell lung cancer (NSCLC) and non-cancerous tissues with gold standard diagnostic pathology to assess the performance of the technique. Paired NSCLC and non-cancerous lung tissues were obtained from thoracic resection patients (N=21). A clinically compatible 488 nm fluorescence-lifetime endomicroscopy platform was used to acquire simultaneous fluorescence intensity and lifetime images. Fluorescence lifetimes were calculated using a computationally-lightweight, rapid lifetime determination method. Fluorescence lifetime was significantly reduced in ex vivo lung cancer, compared with non-cancerous lung tissue [mean ± standard deviation (SD), 1.79±0.40 vs. 2.15±0.26 ns, P&lt;0.0001], and fluorescence intensity images demonstrated distortion of alveolar elastin autofluorescence structure. Fibre-based fluorescence-lifetime imaging demonstrated good performance characteristics for distinguishing lung cancer, from adjacent non-cancerous tissue, with 81.0% sensitivity and 71.4% specificity. Our novel fibre-based fluorescence-lifetime imaging system, which enables label-free imaging and quantitative lifetime analysis, discriminates ex vivo lung cancer from adjacent healthy tissue. This minimally invasive technique has potential to be translated as a real-time biopsy guidance tool, capable of optimising diagnostic accuracy in lung cancer. </p

    Mycobacterium avium subsp. paratuberculosis Infection in a Patient with HIV, Germany

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    Mycobacterium avium subsp. paratuberculosis (MAP), the causative agent of Johne disease in ruminants, has been incriminated as the cause of Crohn disease in humans. We report the first case of human infection with MAP in a patient with HIV; infection was confirmed by obtaining isolates from several different specimen types

    Neural correlates of executive function and working memory in the 'at risk mental state'

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    Background and Aims: People with ‘prodromal’ symptoms have a very high risk of developing psychosis. We used functional MRI to examine the neurocognitive basis of this vulnerability. Method: Cross-sectional comparison of subjects with an ARMS (n=17), first episode schizophreniform psychosis (n=10) and healthy volunteers (n=15). Subjects were studied using functional MRI while they performed an overt verbal fluency task, a random movement generation paradigm and an N-Back working memory task. Results: During an N-Back task the ARMS group engaged inferior frontal and posterior parietal cortex less than controls but more than the first episode group. During a motor generation task, the ARMS group showed less activation in the left inferior parietal cortex than controls, but greater activation than the first episode group. During verbal fluency using ‘Easy’ letters, the ARMS group demonstrated intermediate activation in the left inferior frontal cortex, with first episode groups showing least, and controls most, activation. When processing ‘Hard’ letters, differential activation was evident in two left inferior frontal regions. In its dorsolateral portion, the ARMS group showed less activation than controls but more than the first episode group, while in the opercular part of the left inferior frontal gyrus / anterior insula activation was greatest in the first episode group, weakest in controls and intermediate in the ARMS group. Conclusions: The ARMS is associated with abnormalities of regional brain function that are qualitatively similar to those in patients who have just developed psychosis but less severe

    Impact of boat anchoring on the Mediterranean endemic bivalve Pinna nobilis: An experimental approach

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    The impact of boat anchoring on the Mediterranean endemic bivalve Pinna nobilis Linnaeus (1758) was assessed experimentally in the field by installing non-biological mimic units of the bivalve in the islands of Mallorca and Malta. In each of these two Mediterranean localities, two study areas having different levels of boat anchoring activities: ‘control’ (no anchoring allowed) and ‘impacted’ (anchoring allowed), were used for the field experiment. A significant number of P. nobilis mimic bivalves were affected by boat anchoring in the impacted areas; the impact was 3 times higher in impacted areas compared to control areas. Boat anchoring also had an adverse impact on Posidonia oceanica meadows, since seagrass cover was lower in the impacted areas.peer-reviewe

    Surveillance for Prion Disease in Cervids, Germany

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    An active survey on transmissible spongiform encephalopathies was performed from 2002 to 2005 on 4,255 roe deer, 1,445 red deer, and 1,604 fallow deer in Germany. All cervids tested negative. This survey has been the largest in European wildlife and provides no evidence of prion diseases in free-living German cervids
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