Parity-time (PT)-symmetric crystals are a class of non-Hermitian systems that allow, for example, the existence of modes with real propagation constants, for self-orthogonality of propagating modes, ...and for uni-directional invisibility at defects. Photonic PT-symmetric systems that also support topological states could be useful for shaping and routing light waves. However, it is currently debated whether topological interface states can exist at all in PT-symmetric systems. Here, we show theoretically and demonstrate experimentally the existence of such states: states that are localized at the interface between two topologically distinct PT-symmetric photonic lattices. We find analytical closed form solutions of topological PT-symmetric interface states, and observe them through fluorescence microscopy in a passive PT-symmetric dimerized photonic lattice. Our results are relevant towards approaches to localize light on the interface between non-Hermitian crystals.
The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 health-related quality of life questionnaire is one of the most widely used cancer-specific health-related quality of ...life questionnaires worldwide. General population norm data can facilitate the interpretation of QLQ-C30 data obtained from cancer patients. This study aimed at systematically collecting norm data from the general population to develop European QLQ-C30 norm scores and to generate comparable norm data for individual countries in Europe and North America.
We collected QLQ-C30 data from the general population across 11 European Union (EU) countries, Russia, Turkey, Canada and United States (n ≥ 1000/country). Representative samples were stratified by sex and age groups (18–39, 40–49, 50–59, 60–69 and ≥ 70 years). After applying weights based on the United Nations population distribution statistics, we calculated QLQ-C30 domain scores to generate a ‘European QLQ-C30 Norm’ based on the EU countries. Further, we calculated QLQ-C30 norm scores for all 15 individual countries.
A total of 15,386 respondents completed the online survey. For the EU sample, most QLQ-C30 domains showed differences by sex/age, with men scoring somewhat better health than women, while age effects varied across domains. Substantially larger differences were seen in inter-country comparisons, with Austrian and Dutch respondents reporting consistently better health compared with British and Polish respondents.
This study is the first to systematically collect EORTC QLQ-C30 general population norm data across Europe and North America applying a consistent data collection method across 15 countries. These new norm data facilitate valid intra-country as well as inter-country comparisons and QLQ-C30 score interpretation.
•Updated general population norm data for EORTC QLQ-C 30 based on 15,386 persons across 13 European countries, Canada, and USA.•Study strength: all individual country QLQ-C30 norm data collected based on a common sampling strategy and survey design.•New normative data facilitate valid intracountry and especially intercountry comparisons and QLQ-C30 score interpretation.
We analyze the transport of light in the bulk and at the edge of photonic Lieb lattices, whose unique feature is the existence of a flat band representing stationary states in the middle of the band ...structure that can form localized bulk states. We find that transport in bulk Lieb lattices is significantly affected by the particular excitation site within the unit cell, due to overlap with the flat band states. Additionally, we demonstrate the existence of new edge states in anisotropic Lieb lattices. These states arise due to a virtual defect at the lattice edges and are not described by the standard tight-binding model.
Over the past 2 decades there have been substantial improvements in the methods used to quantify viral nucleic acid in body fluids and in our understanding of how to use viral load measurements in ...the diagnosis and management of patients with a number of viral infections. These methods are now integrated into a wide range of diagnostic and treatment guidelines and commonly deployed in a variety of clinical settings.
Quantitative nucleic acid amplification methods that are used to measure viral load are described along with key issues and important variables that affect their performance. Particular emphasis is placed on those methods used in clinical laboratories as US Food and Drug Administration-cleared or laboratory-developed tests. We discuss the clinical applications of these methods in patients with HIV-1, hepatitis C virus, hepatitis B virus, cytomegalovirus, Epstein-Barr virus, and BK polyomavirus infections. Finally, the current challenges and future directions of viral load testing are examined.
Quantitative nucleic acid amplification tests provide important information that can be used to predict disease progression, distinguish symptomatic from asymptomatic infection, and assess the efficacy of antiviral therapy. Despite the advances in technology, large challenges remain for viral testing related to accuracy, precision, and standardization. Digital PCR, a direct method of quantification of nucleic acids that does not rely on rate-based measurements or calibration curves, may address many of the current challenges.
Traditional microbiological methods for detection of respiratory tract pathogens can be slow, are often not sensitive, may not distinguish infection from colonization, and are influenced by previous ...antibiotic therapy. Molecular diagnostic tests for common and atypical causative pathogens of community-acquired pneumonia have the potential to dramatically increase the diagnostic yield and decrease the time required to render results. Unfortunately, these tests often lack standardization and are not widely available. Consideration should be given to the development and evaluation of companion molecular diagnostic tests for detection of respiratory pathogens in future clinical trials of antimicrobials intended to treat community-acquired pneumonia.
Within all physical disciplines, it is accepted that wave transport is predetermined by the existence of disorder. In this vein, it is known that ballistic transport is possible only when a structure ...is ordered, and that disorder is crucial for diffusion or (Anderson-)localization to occur. As this commonly accepted picture is based on the very foundations of quantum mechanics where Hermiticity of the Hamiltonian is naturally assumed, the question arises whether these concepts of transport hold true within the more general context of non-Hermitian systems. Here we demonstrate theoretically and experimentally that in ordered time-independent -symmetric systems, which are symmetric under space-time reflection, wave transport can undergo a sudden change from ballistic to diffusive after a specific point in time. This transition as well as the diffusive transport in general is impossible in Hermitian systems in the absence of disorder. In contrast, we find that this transition depends only on the degree of dissipation.
We have demonstrated for the first time the permanent local modification of the bulk of silicon by repeated illumination with infrared (1.55 μm) picosecond pulses. Furthermore, we evaluated the ...characteristics of inscribing permanent modifications in the bulk material for different pulse durations from 0.8 to 10 ps in terms of their reproducibility and controllability of their morphology. Our results are based on a simple experimental setup that demonstrates the possibility of using picosecond pulses for the local modification of bulk silicon as a potential alternative to more complex irradiation strategies required for femtosecond pulse processing.
We present an experimental study on the drilling of metal targets with ultrashort laser pulses at high repetition rates (from 50 kHz up to 975 kHz) and high average powers (up to 68 Watts), using an ...ytterbium-doped fiber CPA system. The number of pulses to drill through steel and copper sheets with thicknesses up to 1 mm have been measured as a function of the repetition rate and the pulse energy. Two distinctive effects, influencing the drilling efficiency at high repetition rates, have been experimentally found and studied: particle shielding and heat accumulation. While the shielding of subsequent pulses due to the ejected particles leads to a reduced ablation efficiency, this effect is counteracted by heat accumulation. The experimental data are in good qualitative agreement with simulations of the heat accumulation effect and previous studies on the particle emission. However, for materials with a high thermal conductivity as copper, both effects are negligible for the investigated processing parameters. Therefore, the full power of the fiber CPA system can be exploited, which allows to trepan high-quality holes in 0.5mm-thick copper samples with breakthrough times as low as 75 ms.
BackgroundThe goal of the present study was to assess risk factors for perinatal hepatitis C virus (HCV) transmission and the natural history of infection among HCV-infected infants MethodsIn a ...cohort study, 244 infants born to HCV-positive mothers were followed from birth until age ⩾12 months. Maternal serum was collected at enrollment and delivery; infant serum was collected at birth and at 8 well-child visits. Testing included detection of antibody to HCV, detection of HCV RNA (qualitative and quantitative), and genotyping. HCV-infected infants were followed annually until age 5 years ResultsOverall, 9 of 190 (4.7% 95% confidence interval {CI}, 2.3%–9.1%) infants born to mothers who were HCV RNA positive at delivery became infected, compared with 0 of 54 infants born to HCV RNA–negative mothers (P=.10). Among HCV RNA–positive mothers, the rate of transmission was 3.8% (95% CI, 1.7%–8.1%) from the 182 who were human immunodeficiency virus (HIV) negative, compared with 25.0% (95% CI, 4.5%–64.4%) from the 8 who were HIV positive (P<.05). Three infected infants resolved their infection (i.e., became HCV RNA negative). In multivariate analysis restricted to HCV RNA–positive mothers, membrane rupture ⩾6 h (odds ratio OR, 9.3 95% CI, 1.5–179.7) and internal fetal monitoring (OR, 6.7 95% CI, 1.1–35.9) were associated with transmission of HCV to infants ConclusionIf duration of membrane rupture and internal fetal monitoring are confirmed to be associated with transmission, interventions may be possible to decrease the risk of transmission
PDF
