After our recent demonstration of a 3D-printed external light trap on a small solar cell, we now consider its potential for large solar panels. An external light trap consists of a parabolic ...concentrator and a spacer that redirects the photons that are reflected by the solar cell back towards the solar cell. These retro-reflections enable higher absorptance and improved power conversion efficiency. Scaling a single external light trap such that it covers a large solar panel has disadvantages in terms of height and cost of the external light trap. These disadvantages can be overcome by deploying an array of concentrators as the top part of the external light trap. We present an optimization study of concentrator arrays for external light trapping. We fabricated 3D-printed external light traps with a square, hexagonal and circular compound parabolic concentrator to test their suitability for concentrator arrays. The 3D-printed traps were placed on top of an organic solar cell which resulted in a significant enhancement of the external quantum efficiency. The required transmittance of these concentrator arrays is calculated as a function of the parameters of both the concentrator and the solar cell. We compare the theoretical and experimentally determined optical performance of the different concentrators. Finally, the prospects of external light trapping are analyzed and we give guidelines for improvements of the external light trap design.
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•We successfully 3D-printed a universally applicable external light trap.•We demonstrated an improvement of the EQE of an organic solar cell up to 62%rel.•The external light trap is made of a scalable array of concentrators.•Our model demonstrates potential for more enhancement by external light trapping.•A detailed technical pathway for further optimization is presented.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
To investigate the co-occurrence of migraine and depression and assess whether shared genetic factors may underlie both diseases.
Subjects were 2,652 participants of the Erasmus Rucphen Family ...genetic isolate study. Migraine was diagnosed using a validated 3-stage screening method that included a telephone interview. Symptoms of depression were assessed using the Center for Epidemiologic Studies Depression scale and the depression subscale of the Hospital Anxiety and Depression Scale (HADS-D). The contribution of shared genetic factors in migraine and depression was investigated by comparing heritability estimates for migraine with and without adjustment for symptoms of depression, and by comparing the heritability scores of depression between migraineurs and controls.
We identified 360 migraine cases: 209 had migraine without aura (MO) and 151 had migraine with aura (MA). Odds ratios for depression in patients with migraine were 1.29 (95% confidence interval CI 0.98-1.70) for MO and 1.70 (95% CI 1.28-2.24) for MA. Heritability estimates were significant for all migraine (0.56), MO (0.77), and MA (0.96), and decreased after adjustment for symptoms of depression or use of antidepressant medication, in particular for MA. Comparison of the heritability scores for depression between patients with migraine and controls showed a genetic correlation between HADS-D score and MA.
There is a bidirectional association between depression and migraine, in particular migraine with aura, which can be explained, at least partly, by shared genetic factors.
The World Health Organization has estimated that more than 1.7 billion persons are infected with
Mycobacterium tuberculosis
worldwide.
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A puzzling feature of mycobacterial infection is that ...clinically evident disease occurs in only a small proportion of those who are infected. However, the mechanisms that distinguish a successful immune response, which contains the infection, from an ineffective response, which enables progressive disease to occur, remain poorly understood. Familial clustering, racial differences in incidence, and twin studies suggest that genetic factors have a role in susceptibility.
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However, in contrast to the situation in mice, in which a number of single . . .
Congenital cytomegalovirus infection (cCMV) is the most common congenital infection worldwide and is a major cause of neurodevelopmental impairment in children. At this point there are insufficient ...data on neurodevelopmental outcome of children with cCMV, both symptomatic and asymptomatic.
This study aimed to describe the neurodevelopmental outcome in a large prospective cohort of children with cCMV.
All children with cCMV, included in the Flemish cCMV register, were eligible for this study. Data on neurodevelopmental outcome was available in 753 children. Data on neuromotor, cognitive, behavioral, audiological and ophthalmological outcome were analyzed.
Neurodevelopmental outcome was normal in 530/753 (70,4 %) at any age of last follow-up. Mild, moderate and severe neurodevelopmental impairment was found in 128/753 (16,9 %), 56/753 (7,4 %) and 39/753 (5,2 %), respectively. Adverse outcome is found both in the symptomatic and asymptomatic children (53,5 % versus 17,8 %). Autism spectrum disorder (ASD) was diagnosed more often than in the general population in Flanders (2,5 % versus 0,7 %). Speech and language impairment was found in 2 %, even in absence of hearing loss.
Both symptomatic and asymptomatic cCMV children are at risk of sequelae, with higher risk in case of first trimester infection. During follow-up of this population, special attention should be given to the audiological follow-up, the presence of hypotonia at young age, the possible higher risk of ASD and the risk of speech and language impairment even in absence of hearing loss. Our results emphasize the need for multidisciplinary neurodevelopmental follow-up of all cCMV infected children.
•This is one of the largest cohorts of children with congenital CMV in which neurodevelopmental outcome is described•Both symptomatic as asymptomatic children can develop long-term sequelae, be it more frequently in the symptomatic group•Special attention should be given to audiological follow-up, to the detection of hypotonia which might impact motor development, to the possible higher risk of ASD and to the risk of speech impairment even in absence of hearing loss.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Fragile X syndrome (FXS) is one of the most common known causes of inherited mental retardation. The gene mutated in FXS is named FMR1, and is well conserved from human to Drosophila. In order to ...generate a genetic tool to study FMR1 function during vertebrate development, we generated two mutant alleles of the fmr1 gene in zebrafish. Both alleles produce no detectable Fmr protein, and produce viable and fertile progeny with lack of obvious phenotypic features. This is in sharp contrast to published results based on morpholino mediated knock-down of fmr1, reporting defects in craniofacial development and neuronal branching in embryos. These phenotypes we specifically addressed in our knock-out animals, revealing no significant deviations from wild-type animals, suggesting that the published morpholino based fmr1 phenotypes are potential experimental artifacts. Therefore, their relation to fmr1 biology is questionable and morpholino induced fmr1 phenotypes should be avoided in screens for potential drugs suitable for the treatment of FXS. Importantly, a true genetic zebrafish model is now available which can be used to study FXS and to derive potential drugs for FXS treatment.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The effect of hypochlorite treatment on the layer thickness and conductivity of a state-of-the-art high conducting poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is investigated ...as a function of exposure time and hypochlorite concentration. Because of overoxidation by the hypochlorite the PEDOT:PSS conductivity is decreased by 10 orders of magnitude. Comparison of thickness and conductivity as a function of time shows that a residual insulating layer remains on the substrate upon treatment. Going from a low (<0.01%) to a high (>0.1%) hypochlorite concentration the interaction between PEDOT:PSS and hypochlorite changes from reaction- to diffusion limited. The decrease in conductivity can be interpreted in terms of the interruption of percolating conductive pathways by the reaction between PEDOT and hypochlorite.
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IJS, KILJ, NUK, PNG, UL, UM
Humans sleep approximately a third of their lifetime. The observation that individuals with either long or short sleep duration show associations with metabolic syndrome and psychiatric disorders ...suggests that the length of sleep is adaptive. Although sleep duration can be influenced by photoperiod (season) and phase of entrainment (chronotype), human familial sleep disorders indicate that there is a strong genetic modulation of sleep. Therefore, we conducted high-density genome-wide association studies for sleep duration in seven European populations (N=4251). We identified an intronic variant (rs11046205; P=3.99 × 10(-8)) in the ABCC9 gene that explains asymptotically =5% of the variation in sleep duration. An influence of season and chronotype on sleep duration was solely observed in the replication sample (N=5949). Meta-analysis of the associations found in a subgroup of the replication sample, chosen for season of entry and chronotype, together with the discovery results showed genome-wide significance. RNA interference knockdown experiments of the conserved ABCC9 homologue in Drosophila neurons renders flies sleepless during the first 3h of the night. ABCC9 encodes an ATP-sensitive potassium channel subunit (SUR2), serving as a sensor of intracellular energy metabolism.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Autosomal recessive juvenile parkinsonism (AR-JP, PARK2; OMIM 602544), one of the monogenic forms of Parkinson's disease (PD), was initially described in Japan. It is characterized by early onset ...(before age 40), marked response to levodopa treatment and levodopa-induced dyskinesias. The gene responsible for AR-JP was recently identified and designated parkin. We have analysed the 12 coding exons of the parkin gene in 35 mostly European families with early onset autosomal recessive parkinsonism. In one family, a homozygous deletion of exon 4 could be demonstrated. By direct sequencing of the exons in the index patients of the remaining 34 families, eight previously undescribed point mutations (homozygous or heterozygous) were detected in eight families that included 20 patients. The mutations segregated with the disease in the families and were not detected on 110–166 control chromosomes. Four mutations caused truncation of the parkin protein. Three were frameshifts (202–203delAG, 255delA and 321–322insGT) and one a nonsense mutation (Trp453Stop). The other four were missense mutations (Lys161Asn, Arg256Cys, Arg275Trp and Thr415Asn) that probably affect amino acids that are important for the function of the parkin protein, since they result in the same phenotype as truncating mutations or homozygous exon deletions. Mean age at onset was 38 ± 12 years, but onset up to age 58 was observed. Mutations in the parkin gene are therefore not invariably associated with early onset parkinsonism. In many patients, the phenotype is indistinguishable from that of idiopathic PD. This study has shown that a wide variety of different mutations in the parkin gene are a common cause of autosomal recessive parkinsonism in Europe and that different types of point mutations seem to be more frequently responsible for the disease phenotype than are deletions.
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