707 research outputs found

    Favorable outcome of early treatment of new onset child and adolescent migraine-implications for disease modification.

    Get PDF
    There is evidence that the prevalence of migraine in children and adolescents may be increasing. Current theories of migraine pathophysiology in adults suggest activation of central cortical and brainstem pathways in conjunction with the peripheral trigeminovascular system, which ultimately results in release of neuropeptides, facilitation of central pain pathways, neurogenic inflammation surrounding peripheral vessels, and vasodilatation. Although several risk factors for frequent episodic, chronic, and refractory migraine have been identified, the causes of migraine progression are not known. Migraine pathophysiology has not been fully evaluated in children. In this review, we will first discuss the evidence that early therapeutic interventions in the child or adolescent new onset migraineur, may halt or limit progression and disability. We will then review the evidence suggesting that many adults with chronic or refractory migraine developed their migraine as children or adolescents and may not have been treated adequately with migraine-specific therapy. Finally, we will show that early, appropriate and optimal treatment of migraine during childhood and adolescence may result in disease modification and prevent progression of this disease

    Small Polarons in Transition Metal Oxides

    Full text link
    The formation of polarons is a pervasive phenomenon in transition metal oxide compounds, with a strong impact on the physical properties and functionalities of the hosting materials. In its original formulation the polaron problem considers a single charge carrier in a polar crystal interacting with its surrounding lattice. Depending on the spatial extension of the polaron quasiparticle, originating from the coupling between the excess charge and the phonon field, one speaks of small or large polarons. This chapter discusses the modeling of small polarons in real materials, with a particular focus on the archetypal polaron material TiO2. After an introductory part, surveying the fundamental theoretical and experimental aspects of the physics of polarons, the chapter examines how to model small polarons using first principles schemes in order to predict, understand and interpret a variety of polaron properties in bulk phases and surfaces. Following the spirit of this handbook, different types of computational procedures and prescriptions are presented with specific instructions on the setup required to model polaron effects.Comment: 36 pages, 12 figure

    Quantum dynamics in strong fluctuating fields

    Full text link
    A large number of multifaceted quantum transport processes in molecular systems and physical nanosystems can be treated in terms of quantum relaxation processes which couple to one or several fluctuating environments. A thermal equilibrium environment can conveniently be modelled by a thermal bath of harmonic oscillators. An archetype situation provides a two-state dissipative quantum dynamics, commonly known under the label of a spin-boson dynamics. An interesting and nontrivial physical situation emerges, however, when the quantum dynamics evolves far away from thermal equilibrium. This occurs, for example, when a charge transferring medium possesses nonequilibrium degrees of freedom, or when a strong time-dependent control field is applied externally. Accordingly, certain parameters of underlying quantum subsystem acquire stochastic character. Herein, we review the general theoretical framework which is based on the method of projector operators, yielding the quantum master equations for systems that are exposed to strong external fields. This allows one to investigate on a common basis the influence of nonequilibrium fluctuations and periodic electrical fields on quantum transport processes. Most importantly, such strong fluctuating fields induce a whole variety of nonlinear and nonequilibrium phenomena. A characteristic feature of such dynamics is the absence of thermal (quantum) detailed balance.Comment: review article, Advances in Physics (2005), in pres

    The use of nano/micro-layers, self-healing and slow release coatings to prevent corrosion and biofouling

    Get PDF
    The mitigation of corrosion and biofouling is a challenge. Through application of chemicals and special techniques can slow these undesired processes, an effective resolution requires a multidisciplinary approach involving scientists, engineers, and metallurgists. In order to understand the importance of the use of nano- and microlayers as well as self-healing coatings, the basic concepts of corrosion, corrosion mechanisms, corrosion inhibition and the microbiologically influenced corrosion will be summarised. The preparation, characterization and application of Langmuir-Blodgett and self assembled nanolayers in corrosive and microbial environment will be discussed. Preparation and characterization of microcapsules/ microspheres and their application in coatings will be demonstrated by a number of examples

    A rare IL33 loss-of-function mutation reduces blood eosinophil counts and protects from asthma.

    Get PDF
    Efst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinnIL-33 is a tissue-derived cytokine that induces and amplifies eosinophilic inflammation and has emerged as a promising new drug target for asthma and allergic disease. Common variants at IL33 and IL1RL1, encoding the IL-33 receptor ST2, associate with eosinophil counts and asthma. Through whole-genome sequencing and imputation into the Icelandic population, we found a rare variant in IL33 (NM_001199640:exon7:c.487-1G>C (rs146597587-C), allele frequency = 0.65%) that disrupts a canonical splice acceptor site before the last coding exon. It is also found at low frequency in European populations. rs146597587-C associates with lower eosinophil counts (β = -0.21 SD, P = 2.5×10-16, N = 103,104), and reduced risk of asthma in Europeans (OR = 0.47; 95%CI: 0.32, 0.70, P = 1.8×10-4, N cases = 6,465, N controls = 302,977). Heterozygotes have about 40% lower total IL33 mRNA expression than non-carriers and allele-specific analysis based on RNA sequencing and phased genotypes shows that only 20% of the total expression is from the mutated chromosome. In half of those transcripts the mutation causes retention of the last intron, predicted to result in a premature stop codon that leads to truncation of 66 amino acids. The truncated IL-33 has normal intracellular localization but neither binds IL-33R/ST2 nor activates ST2-expressing cells. Together these data demonstrate that rs146597587-C is a loss of function mutation and support the hypothesis that IL-33 haploinsufficiency protects against asthma.Netherlands Asthma Foundation University Medical Center Groningen Ministry of Health and Environmental Hygiene of Netherlands Netherlands Asthma Stichting Astma Bestrijding BBMRI European Respiratory Society private and public research funds AstraZeneca ALK-Abello, Denmar

    A retrospective review of paediatric head injuries in Asia - a Pan Asian Trauma Outcomes Study (PATOS) collaboration

    Get PDF
    Objective: We aim to examine the mechanisms of head-injured children presenting to participating centres in the Pan Asian Trauma Outcomes Study (PATOS) and to evaluate the association between mechanism of injury and severe outcomes.Design and Setting: We performed a retrospective review of medical records among emergency departments (EDs) of eight PATOS centres, from September 2014 - August 2015.Participants: We included children \u3c16 years old who presented within 24 hours of head injury and were admitted for observation or required a computed tomography (CT) of the brain from the ED. We excluded children with known coagulopathies, neurological co-morbidities or prior neurosurgery. We reviewed the mechanism, intent, location and object involved in each injury, and the patients\u27 physical findings on presentation.Outcomes: Primary outcomes were death, endotracheal intubation or neurosurgical intervention. Secondary outcomes included hospital and ED length of stay. Results: 1438 children were analysed. 953 children (66.3%) were male and the median age was 5.0 years (IQR 1.0-10.0). Falls predominated especially among children younger than 2 years (82.9%), while road traffic injuries were more likely to occur among children 2 years and above compared with younger children (25.8% vs 11.1%). Centres from upper and lower middle-income countries were more likely to receive head injured children from road traffic collisions compared with those from high-income countries (51.4% and 40.9%, vs 10.9%, p\u3c0.0001) and attended to a greater proportion of children with severe outcomes (58.2% and 28.4%, vs 3.6%, p\u3c0.0001). After adjusting for age, gender, intent of injury and gross national income, traffic injuries (adjusted OR 2.183, 95% CI 1.448 to 3.293) were associated with severe outcomes, as compared with falls.Conclusions: Among children with head injuries, traffic injuries are independently associated with death, endotracheal intubation and neurosurgery. This collaboration among Asian centres holds potential for future prospective childhood injury surveillance

    Adolescents with Obstructive Sleep Apnea Adhere Poorly to Positive Airway Pressure (PAP), but PAP Users Show Improved Attention and School Performance

    Get PDF
    Background: Obstructive Sleep Apnea (OSA) is associated with medical and neurobehavioral morbidity across the lifespan. Positive airway pressure (PAP) treatment has demonstrated efficacy in treating OSA and has been shown to improve daytime functioning in adults, but treatment adherence can be problematic. There are nearly no published studies examining functional outcomes such as academic functioning in adolescents treated with PAP. This study was conducted as an initial step towards determining whether PAP treatment improves daytime functioning among adolescents with OSA. Methods: Self-reported academic grades, self- and parent-reported academic quality of life, and objectively-measured attention were assessed before and after PAP was clinically initiated in a sample of 13 obese adolescents with OSA, as well as 15 untreated obese Controls without OSA. Based on adherence data, the treated group was divided into PAP Users (n = 6) and Non-Adherent participants (n = 7). Results: Though demographically similar, the three groups significantly differed in how their academic performance and attention scores changed from baseline to follow-up. Non-Adherent participants showed worsening functioning over time, while PAP Users showed stable or improved functioning, similar to controls. Conclusion: Although many adolescents prescribed PAP for OSA are non-adherent to the treatment, those who adhere t

    Ubiquitination of the bacterial inositol phosphatase, SopB, regulates its biological activity at the plasma membrane

    Get PDF
    The Salmonella type III effector, SopB, is an inositol polyphosphate phosphatase that modulates host cell phospholipids at the plasma membrane and the nascent Salmonella-containing vacuole (SCV). Translocated SopB persists for many hours after infection and is ubiquitinated but the significance of this covalent modification has not been investigated. Here we identify by mass spectrometry six lysine residues of SopB that are mono-ubiquitinated. Substitution of these six lysine residues with arginine, SopB-K6R, almost completely eliminated SopB ubiquitination. We found that ubiquitination does not affect SopB stability or membrane association, or SopB-dependent events in SCV biogenesis. However, two spatially and temporally distinct events are dependent on ubiquitination, downregulation of SopB activity at the plasma membrane and prolonged retention of SopB on the SCV. Activation of the mammalian pro-survival kinase Akt/PKB, a downstream target of SopB, was intensified and prolonged after infection with the SopB-K6R mutant. At later times, fewer SCV were decorated with SopB-K6R compared with SopB. Instead SopB-K6R was present as discrete vesicles spread diffusely throughout the cell. Altogether, our data show that ubiquitination of SopB is not related to its intracellular stability but rather regulates its enzymatic activity at the plasma membrane and intracellular localization

    Differences in the experience of fatigue in patients and healthy controls: patients' descriptions

    Get PDF
    Contains fulltext : 51764.pdf ( ) (Open Access)BACKGROUND: The primary objective was to develop an adjective checklist, the Fatigue Quality List (FQL), aimed at assessing different perceptions of fatigue. METHODS: 961 participants filled out the FQL (28 adjectives). A component and confirmatory factor analyses were performed and psychometric properties were evaluated. Differences on factor scores between different patients' groups were investigated and pre- and post treatment scores were compared in demonstrating change of perceptions after treatment of fatigue. RESULTS: Four independent factors were found with adequate psychometric properties. Different perceptions were found between the patients' groups. Patients who were recovered after treatment for fatigue showed similar scores on the factors as healthy controls. CONCLUSION: The FQL appears to be a promising tool in measuring different perceptions of fatigue, which can be especially interesting for clinical practice
    corecore