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Locally resonant metamaterials (LRMs) have recently emerged in the search for lightweight noise and vibration solutions. These materials have the ability to create stop bands, which arise from the sub-wavelength addition of identical resonators to a host structure and result in strong vibration attenuation. However, their manufacturing inevitably introduces variability such that the system as-manufactured often deviates significantly from the original as-designed. This can reduce attenuation performance, but may also broaden the attenuation band. This work focuses on the impact of variability within tolerance ranges in resonator properties on the vibration attenuation in metamaterial beams. Following a qualitative pre-study, two non-intrusive uncertainty propagation approaches are applied to find the upper and lower bounds of three performance metrics, by evaluating deterministic metamaterial models with uncertain parameters defined as interval variables. A global search approach is used and compared with a machine learning (ML)-based uncertainty propagation approach which significantly reduces the required number of simulations. Variability in resonator stiffnesses and masses is found to have the highest impact. Variability in the resonator positions only has a comparable impact for less deep sub-wavelength designs. The broadening potential of varying resonator properties is exploited in broadband optimization and the robustness of the optimized metamaterial is assessed.This article is part of the theme issue 'Current developments in elastic and acoustic metamaterials science (Part 2)'.

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INTRODUCTION: The Standardized Uptake Value (SUV) in single lesions on 18F-FDG PET/CT scans and serum S-100B concentrations are inversely associated with disease-free survival in stage IV melanoma. The aim of this study was to assess the association between biomarkers (S-100B, LDH) and the PET-derived metrics SUVmean/max, metabolic active tumor volume (MATV), and total lesion glycolysis (TLG) in stage IV melanoma in order to understand what these biomarkers reflect and their possible utility for follow-up. METHODS: In 52 stage IV patients the association between PET-derived metrics and the biomarkers S-100B and LDH was assessed and the impact on survival analyzed. RESULTS: S-100B was elevated (>0.15 µg/l) in 37 patients (71%), LDH in 11 (21%). There was a correlation between S-100B and LDH (R2 = 0.19). S-100B was correlated to both MATV (R2 = 0.375) and TLG (R2 = 0.352), but LDH was not. Higher MATV and TLG levels were found in patients with elevated S-100B (p < 0.001) and also in patients with elevated LDH (>250 U/l) (p < 0.001). There was no association between the biomarkers and SUVmean/max. Survival analysis indicated that LDH was the only predictor of melanoma-specific survival. CONCLUSION: In newly diagnosed stage IV melanoma patients S-100B correlates with 18F-FDG PET/CT derived MATV and TLG in contrast to LDH, is more often elevated than LDH (71% vs. 21%) and seems to be a better predictor of disease load and disease progression. However, elevated LDH is the only predictor for survival. The biomarkers, S-100B and LDH appear to describe different aspects of the extent of metastatic disease and of tumornecrosis.

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Different compound feeds have to be manufactured in the same production line. As a consequence, traces of the first produced feed may remain in the production and get mixed with the next feed batches. This "carry-over" is unavoidable, and so non-medicated feed can be contaminated with veterinary drugs like antibiotics added to the previous batch of medicated feed. To monitor the carry-over of antibiotics in the Netherlands, 21 feed mills were visited and 140 samples of flushing feeds were collected and analysed for containing residues of antibiotics. Results show that 87% of all samples contain concentrations of antibiotics in the range of 0.1-154 mg/kg. It is expected that these levels - which are in the same range as previously found for the nowadays banned antimicrobial growth promoters (AMGPs) - have an effect on the occurrence of microbial resistance. Analysis of a second set of samples collected at four different feed mills directly after the production of oxytetracycline-medicated feed demonstrated that the first part of a flushing feed has much higher contamination than the last part of the batch. Furthermore, it was demonstrated that the carry-over percentage shows no correlation with the carry-over determined by one of the standard GMP+ procedures. These observations, unavoidable carry-over, inhomogeneous batches of feed with antibiotics and difficulties to predict the carry-over levels, together with the awareness of the increasing problem of microbial resistance, motivated the NEVEDI, association of Dutch Feed Producers, to announce that they will voluntarily stop the production of medicated feed in 2011. The alternatives for medicated feed are for example water or milk medication or the use of top-dressings at the farm. The consequences and possible new risks of carry-over at the farm are not completely clear yet.

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PURPOSE: Description of a very rare case of internal abdominal hernia, namely herniation of the proximal jejunum in the Landzert fossa, through a hole in the mesocolon transversum. MATERIAL AND METHODS: Based on preoperative history, clinical state and radiological findings, the diagnosis of internal hernia was strongly suspected. RESULTS: Suspected diagnosis was confirmed during laparotomy. After reduction of the jejunum and closure of the hernia orifice, the patient recovered promptly. CONCLUSION: The diagnosis of internal herniation should always be considered in every patient who presents with an acute abdomen, signs of (sub)obstruction and non-typical history. The most important diagnostic tool is computer tomography, that is accurate in 77%.

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The ICF syndrome: New case and update: We report the clinical progress in a 5-year-old boy with the <> (ICF) syndrome. Early diagnosis and intervention has led to a good outcome. DNMT3B mutation analysis was negative, supporting genetic heterogeneity in this condition.

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BACKGROUND: Angular placentation may be a cause of retained placenta and may require hysterotomy. CASE: A 33-year-old woman with a prior cesarean section underwent an uncomplicated vaginal delivery, had a retained placenta with postpartum hemorrhage and required hysterotomy because the placenta was inaccessible due to its angular location. CONCLUSION: Antepartum ultrasound diagnosis may be possible in some cases of angular placentation.

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