Katholieke Universiteit Leuven

About: Katholieke Universiteit Leuven is a education organization based out in Leuven, Belgium. It is known for research contribution in the topics: Population & Transplantation. The organization has 61109 authors who have published 176584 publications receiving 6210872 citations.

Magnetic relaxation pathways in lanthanide single-molecule magnets

Abstract: Dysprosium alkoxides and dysprosium-doped yttrium alkoxides show very large energy barriers, greater than 800 K, to magnetic relaxation. These barriers arise from the presence of a strongly axial pseudo-octahedral crystal field, which switches off relaxation through the first excited state that typically occurs in single-molecule magnets, and favours a competitive pathway through higher-energy states.

A C9orf72 promoter repeat expansion in a Flanders-Belgian cohort with disorders of the frontotemporal lobar degeneration-amyotrophic lateral sclerosis spectrum: a gene identification study.

Abstract: Summary Background Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are extremes of a clinically, pathologically, and genetically overlapping disease spectrum. A locus on chromosome 9p21 has been associated with both disorders, and we aimed to identify the causal gene within this region. Methods We studied 305 patients with FTLD, 137 with ALS, and 23 with concomitant FTLD and ALS (FTLD-ALS) and 856 controls from Flanders (Belgium); patients were identified from a hospital-based cohort and were negative for mutations in known FTLD and ALS genes. We also examined the family of one patient with FTLD-ALS previously linked to 9p21 (family DR14). We analysed 130 kbp at 9p21 in association and segregation studies, genomic sequencing, repeat genotyping, and expression studies to identify the causal mutation. We compared genotype-phenotype correlations between mutation carriers and non-carriers. Findings In the patient-control cohort, the single-nucleotide polymorphism rs28140707 within the 130 kbp region of 9p21 was associated with disease (odds ratio [OR] 2·6, 95% CI 1·5–4·7; p=0·001). A GGGGCC repeat expansion in C9orf72 completely co-segregated with disease in family DR14. The association of rs28140707 with disease in the patient-control cohort was abolished when we excluded GGGGCC repeat expansion carriers. In patients with familial disease, six (86%) of seven with FTLD-ALS, seven (47%) of 15 with ALS, and 12 (16%) of 75 with FTLD had the repeat expansion. In patients without known familial disease, one (6%) of 16 with FTLD-ALS, six (5%) of 122 with ALS, and nine (4%) of 230 with FTLD had the repeat expansion. Mutation carriers primarily presented with classic ALS (10 of 11 individuals) or behavioural variant FTLD (14 of 15 individuals). Mean age at onset of FTLD was 55·3 years (SD 8·4) in 21 mutation carriers and 63·2 years (9·6) in 284 non-carriers (p=0·001); mean age at onset of ALS was 54·5 years (9·9) in 13 carriers and 60·4 years (11·4) in 124 non-carriers. Postmortem neuropathological analysis of the brains of three mutation carriers with FTLD showed a notably low TDP-43 load. In brain at postmortem, C9orf72 expression was reduced by nearly 50% in two carriers compared with nine controls (p=0·034). In familial patients, 14% of FTLD-ALS, 50% of ALS, and 62% of FTLD was not accounted for by known disease genes. Interpretation We identified a pathogenic GGGGCC repeat expansion in C9orf72 on chromosome 9p21, as recently also reported in two other studies. The GGGGCC repeat expansion is highly penetrant, explaining all of the contribution of chromosome 9p21 to FTLD and ALS in the Flanders-Belgian cohort. Decreased expression of C9orf72 in brain suggests haploinsufficiency as an underlying disease mechanism. Unidentified genes probably also contribute to the FTLD-ALS disease spectrum. Funding Full funding sources listed at end of paper (see Acknowledgments).

An integrated friction model structure with improved presliding behavior for accurate friction compensation

Abstract: Presents a dynamical friction model structure which allows accurate modeling both in the sliding and the presliding regimes. Transition between these two regimes is accomplished without a switching function. The model incorporates a hysteresis function with nonlocal memory and arbitrary transition curves. These last aspects prove essential for modeling presliding friction that is encountered in real physical situations. The model as a whole can also handle the Stribeck effect and stick-slip behavior as has been demonstrated by validation on a KUKA IR 361 robot. In this sense, this model can be considered as more complete in comparison with others found in the literature. The general friction model allows modeling of individual friction systems through the identification of a set of parameters that determine the complete behavior of the system. In this way, the model structure has been used to identify the friction behavior of a linear slide as well as that of the above mentioned KUKA robot. The results of the latter identification have been consequently used for feedforward friction compensation to obtain the most accurate tracking.

Effect of Subcutaneous Dupilumab on Nasal Polyp Burden in Patients With Chronic Sinusitis and Nasal Polyposis: A Randomized Clinical Trial

Abstract: Importance Dupilumab has demonstrated efficacy in patients with asthma and atopic dermatitis, which are both type 2 helper T-cell–mediated diseases. Objective To assess inhibition of interleukins 4 and 13 with dupilumab in patients with chronic sinusitis and nasal polyposis. Design, Setting, and Participants A randomized, double-blind, placebo-controlled parallel-group study conducted at 13 sites in the United States and Europe between August 2013 and August 2014 in 60 adults with chronic sinusitis and nasal polyposis refractory to intranasal corticosteroids with 16 weeks of follow-up. Interventions Subcutaneous dupilumab (a 600 mg loading dose followed by 300 mg weekly; n = 30) or placebo (n = 30) plus mometasone furoate nasal spray for 16 weeks. Main Outcomes and Measures Change in endoscopic nasal polyp score (range, 0-8; higher scores indicate worse status) at 16 weeks (primary end point). Secondary end points included Lund-Mackay computed tomography (CT) score (range, 0-24; higher scores indicate worse status), 22-item SinoNasal Outcome Test score (range, 0-110; higher scores indicating worse quality of life; minimal clinically important difference ≥8.90), sense of smell assessed using the University of Pennsylvania Smell Identification Test (UPSIT) score (range, 0-40; higher scores indicate better status), symptoms, and safety. Results Among the 60 patients who were randomized (mean [SD] age, 48.4 years [9.4 years]; 34 men [56.7%]; 35 with comorbid asthma), 51 completed the study. The least squares (LS) mean change in nasal polyp score was −0.3 (95% CI, −1.0 to 0.4) with placebo and −1.9 (95% CI, −2.5 to −1.2) with dupilumab (LS mean difference, −1.6 [95% CI, −2.4 to −0.7]; P P P P Conclusions and Relevance Among adults with symptomatic chronic sinusitis and nasal polyposis refractory to intranasal corticosteroids, the addition of subcutaneous dupilumab to mometasone furoate nasal spray compared with mometasone alone reduced endoscopic nasal polyp burden after 16 weeks. Further studies are needed to assess longer treatment duration, larger samples, and direct comparison with other medications. Trial Registration clinicaltrials.gov Identifier:NCT01920893

Biofilm formation and the food industry, a focus on the bacterial outer surface

Abstract: The ability of many bacteria to adhere to surfaces and to form biofilms has major implications in a variety of industries including the food industry, where biofilms create a persistent source of contamination. The formation of a biofilm is determined not only by the nature of the attachment surface, but also by the characteristics of the bacterial cell and by environmental factors. This review focuses on the features of the bacterial cell surface such as flagella, surface appendages and polysaccharides that play a role in this process, in particular for bacteria linked to food-processing environments. In addition, some aspects of the attachment surface, biofilm control and eradication will be highlighted.