642 research outputs found
Impact of chromophores on colour appearance in a computational skin model
Early diagnosis of skin cancer offers the patient more favorable treatment options. Color fidelity of skin images is a major concern for dermatologists as adoption of digital dermatoscopes is increasing rapidly. Accurate color depiction of the lesion and surrounding skin are vital in diagnostic evaluation of a lesion.
We previously introduced VCT-Derma, a pipeline for dermatological Virtual Clinical Trials (VCTs) including detailed and flexible models of human skin and lesions, which represent the patient in the entire dermatoscopy-based diagnostic process. However, those initial models of skin and lesions did not properly account for tissue colors.
Our new skin model accounts for tissue color appearance by incorporating chromophores (e.g., melanin, blood) into the tissue model, and simulating the optical properties of the various skin layers. The physical properties of the skin and lesion were selected from clinically plausible values. The model and simulated dermatoscope images were created in open modelling software, assuming a linear camera model. We have assumed ambient white lighting, with a 6mm distance to the camera.
Our model of color appearance was characterised by comparing the brightness of the lesion to its depth. The brightness of the lesion is compared through the variability of the mean gray values of a cropped region around the lesion. We compare two skin models, one without extensive chromophore content and one with. Our preliminary evaluation of increasing chromophore content shows promise based on the results presented here. Further refinement and validation of the model is ongoing
Novel deletions causing pseudoxanthoma elasticum underscore the genomic instability of the ABCC6 region
Mutations in ABCC6 cause pseudoxanthoma elasticum (PXE), a heritable disease that affects elastic fibers. Thus far, >200 mutations have been characterized by various PCR-based techniques (primarily direct sequencing), identifying up to 90% of PXE-causing alleles. This study wanted to assess the importance of deletions and insertions in the ABCC6 genomic region, which is known to have a high recombinational potential. To detect ABCC6 deletions/insertions, which can be missed by direct sequencing, multiplex ligation-dependent probe amplification (MLPA) was applied in PXE patients with an incomplete genotype. MLPA was performed in 35 PXE patients with at least one unidentified mutant allele after exonic sequencing and exclusion of the recurrent exon 23-29 deletion. Six multi-exon deletions and four single-exon deletions were detected. Using MLPA in addition to sequencing, we expanded the ABCC6 mutation spectrum with 9 novel deletions and characterized 25% of unidentified disease alleles. Our results further illustrate the instability of the ABCC6 genomic region and stress the importance of screening for deletions in the molecular diagnosis of PXE. Journal of Human Genetics (2010) 55, 112-117; doi: 10.1038/jhg.2009.132; published online 15 January 201
Experimental investigation of solidification in metal foam enhanced phase change material
A major challenge for the use of phase change materials (PCMs) in thermal energy
storage (TES) is overcoming the low thermal conductivity of PCMâs. The low conductivity gives rise to limited power during charging and discharging TES. Impregnating metal foam with PCM, however, has been found to enhance the heat transfer. On the other hand, the effect of foam parameters such as porosity, pore size and material type has remained unclear. In this paper, the effect of these foam parameters on the solidification time is investigated. Different samples of PCM-impregnated metal foam were experimentally tested and compared to one without metal foam. The samples varied with respect to choice of material, porosity and pore size. They were placed in a rectangular cavity and cooled from one side using a coolant flowing through a cold plate. The other sides of the rectangular cavity were Polymethyl Methacrylate (PM) walls exposed to ambient. The temperature on the exterior walls of the cavity was monitored as well as the coolant flow rate and its temperature. The metal foam inserts reduced the solidification times by at least 25 %. However, the difference between the best performing and worst performing metal foam is about 28 %. This shows a large potential for future research.This study has received funding from European Unionâs Horizon 2020 research and innovation programme under grant agreement NÂș 657466 (INPATH-TES)
Semantics in the wild : a digital assistant for Flemish citizens
Public service fragmentation across more than 800 digital channels of government administrations in the region of Flanders (Belgium), causes administrative burden and frustrations, as citizens expect a coherent service. Given the autonomy of the various entities, the fragmentation of information and budget constraints, it is not feasible to rewire the entire e-gov ecosystem to a single portal. Therefore, the Flemish Government is building a smart digital assistant, which supports citizens on the governmental portals, by integrating status information of various transactions. This paper outlines our ongoing research on a method for raising semantic interoperability between different information systems and actors. In this approach, semantic agreements are maintained and implemented end-to-end using the design principles of Linked Data. The lessons learned can speed-up the process in other countries that face the complexity of integrating e-government portals
A new recurrent inversion, inv(7)(p15q34), leads to transcriptional activation of HOXA10 and HOXA11 in a subset of T-cell acute lymphoblastic leukemias
Performance evaluation of CHP with heat storage in buildings
Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.Combined heat and power (CHP) production gains more
and more attention. Offices and public buildings often have a
large thermal power demand in combination with a fairly large
electrical power demand. On the other hand they are seldom
occupied by night and in weekends, reducing the actual
operational time of the heating system. This in turn brings
down the financial benefits of investing in CHP. A second
problem is that electrical and thermal demands are often shifted
in time. The running time of the engine is again limited this
way, as it is often not allowed to deliver electricity to the power
grid. A possible solution is using heat storage. This way the
CHP-engine can run when the electricity demand is high. In the
paper a simulation model of CHP with gas engine and heat
storage by means of a hot water vessel is developed. The model
is validated through experiments on an engine and a vessel.
This model is used to analyze the design, control and
performance of cogeneration plants. It is shown that storage is
marginal beneficial and the design has to be done with great
care.cs201
The effects of an intronic polymorphism in TOMM40 and APOE genotypes in sporadic inclusion body myositis.
A previous study showed that, in carriers of the apolipoprotein E (APOE) genotype Δ3/Δ3 or Δ3/Δ4, the presence of a very long (VL) polyT repeat allele in "translocase of outer mitochondrial membrane 40" (TOMM40) was less frequent in patients with sporadic inclusion body myositis (sIBM) compared with controls and associated with a later age of sIBM symptom onset, suggesting a protective effect of this haplotype. To further investigate the influence of these genetic factors in sIBM, we analyzed a large sIBM cohort of 158 cases as part of an International sIBM Genetics Study. No significant association was found between APOE or TOMM40 genotypes and the risk of developing sIBM. We found that the presence of at least 1 VL polyT repeat allele in TOMM40 was significantly associated with about 4 years later onset of sIBM symptoms. The age of onset was delayed by 5 years when the patients were also carriers of the APOE genotype Δ3/Δ3. In addition, males were likely to have a later age of onset than females. Therefore, the TOMM40 VL polyT repeat, although not influencing disease susceptibility, has a disease-modifying effect on sIBM, which can be enhanced by the APOE genotype Δ3/Δ3
Hospital and community pharmacists' perceptions of which competences are important for their practice
The objective of the PHAR-QA (Quality assurance in European pharmacy education and training) project was to investigate how competence-based learning could be applied to a healthcare, sectoral profession such as pharmacy. This is the first study on evaluation of competences from the pharmacistsâ perspective using an improved Delphi method with a large number of respondents from all over Europe. This paper looks at the way in which hospital pharmacists rank the fundamental competences for pharmacy practice. European hospital pharmacists (n = 152) ranked 68 competences for pharmacy practice of two types (personal and patient care), arranged into 13 clusters. Results were compared to those obtained from community pharmacists (n = 258). Generally, hospital and community pharmacists rank competences in a similar way. Nevertheless, differences can be detected. The higher focus of hospital pharmacists on knowledge of the different areas of science as well as on laboratory tests reflects the idea of a hospital pharmacy specialisation. The difference is also visible in the field of drug production. This is a necessary competence in hospitals with requests for drugs for rare diseases, as well as paediatric and oncologic drugs. Hospital pharmacists give entrepreneurship a lower score, but cost-effectiveness a higher one than community pharmacists. This reflects the reality of pharmacy practice where community pharmacists have to act as entrepreneurs, and hospital pharmacists are managers staying within drug budgets. The results are discussed in the light of a âhospital pharmacyâ specialisation
Mutation analysis of P73 and TP53 in Merkel cell carcinoma
The p73 gene has been mapped to 1p36.33, a region which is frequently deleted in a wide variety of neoplasms including tumours of neuroectodermal origin. The p73 protein shows structural and functional homology to p53. For these reasons, p73 was considered as a positional and functional candidate tumour suppressor gene. Thus far, mutation analysis has provided no evidence for involvement of p73 in oligodendrogliomas, lung carcinoma, oesophageal carcinoma, prostatic carcinoma and hepatocellular carcinoma. In neuroblastoma, two mutations have been observed in a series of 140 tumours. In view of the occurrence of 1p deletions in Merkel cell carcinoma (MCC) and the location of p73 we decided to search for mutations in the p73 gene in five MCC cell lines and ten MCC tumours to test potential tumour suppressor function for this gene in MCC. In view of the possible complementary functions of p73 and TP53 we also examined the status of the TP53 gene. Sequence analysis of the entire coding region of the p73 gene revealed previously reported polymorphisms in four MCCs. In one MCC tumour, a mis-sense mutation located in the NH2-terminal transactivation region of the p73 gene was found. These results show that p73, analogous to neuroblastoma, is infrequently mutated in MCC. This is also the first report in which the role of TP53 in MCC has been investigated by sequencing the entire coding region of TP53. TP53 mis-sense mutations and one non-sense mutation were detected in three of 15 examined MCCs, suggesting that TP53 mutations may play a role in the pathogenesis or progression of a subset of MCCs. Moreover, typical UVB induced C to T mutations were found in one MCC cell line thus providing further evidence for sun-exposure in the aetiology of this rare skin cancer. © 2000 Cancer Research Campaig
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