Fizeau drag in graphene plasmonics.

Dragging of light by moving media was predicted by Fresnel1 and verified by Fizeau's celebrated experiments2 with flowing water. This momentous discovery is among the experimental cornerstones of Einstein's special relativity theory and is well understood3,4 in the context of relativistic kinematics. By contrast, experiments on dragging photons by an electron flow in solids are riddled with inconsistencies and have so far eluded agreement with the theory5-7. Here we report on the electron flow dragging surface plasmon polaritons8,9 (SPPs): hybrid quasiparticles of infrared photons and electrons in graphene. The drag is visualized directly through infrared nano-imaging of propagating plasmonic waves in the presence of a high-density current. The polaritons in graphene shorten their wavelength when propagating against the drifting carriers. Unlike the Fizeau effect for light, the SPP drag by electrical currents defies explanation by simple kinematics and is linked to the nonlinear electrodynamics of Dirac electrons in graphene. The observed plasmonic Fizeau drag enables breaking of time-reversal symmetry and reciprocity10 at infrared frequencies without resorting to magnetic fields11,12 or chiral optical pumping13,14. The Fizeau drag also provides a tool with which to study interactions and nonequilibrium effects in electron liquids.

Fundamental limits to graphene plasmonics.

Plasmon polaritons are hybrid excitations of light and mobile electrons that can confine the energy of long-wavelength radiation at the nanoscale. Plasmon polaritons may enable many enigmatic quantum effects, including lasing 1 , topological protection2,3 and dipole-forbidden absorption 4 . A necessary condition for realizing such phenomena is a long plasmonic lifetime, which is notoriously difficult to achieve for highly confined modes 5 . Plasmon polaritons in graphene-hybrids of Dirac quasiparticles and infrared photons-provide a platform for exploring light-matter interaction at the nanoscale6,7. However, plasmonic dissipation in graphene is substantial 8 and its fundamental limits remain undetermined. Here we use nanometre-scale infrared imaging to investigate propagating plasmon polaritons in high-mobility encapsulated graphene at cryogenic temperatures. In this regime, the propagation of plasmon polaritons is primarily restricted by the dielectric losses of the encapsulated layers, with a minor contribution from electron-phonon interactions. At liquid-nitrogen temperatures, the intrinsic plasmonic propagation length can exceed 10 micrometres, or 50 plasmonic wavelengths, thus setting a record for highly confined and tunable polariton modes. Our nanoscale imaging results reveal the physics of plasmonic dissipation and will be instrumental in mitigating such losses in heterostructure engineering applications.

Liver function tests in primary care provide a key opportunity to diagnose and engage patients with hepatitis C.

Since the advent of direct-acting antiviral therapy, the elimination of hepatitis c virus (HCV) as a public health concern is now possible. However, identification of those who remain undiagnosed, and re-engagement of those who are diagnosed but remain untreated, will be essential to achieve this. We examined the extent of HCV infection among individuals undergoing liver function tests (LFT) in primary care. Residual biochemistry samples for 6007 patients, who had venous blood collected in primary care for LFT between July 2016 and January 2017, were tested for HCV antibody. Through data linkage to national and sentinel HCV surveillance databases, we also examined the extent of diagnosed infection, attendance at specialist service and HCV treatment for those found to be HCV positive. Overall HCV antibody prevalence was 4.0% and highest for males (5.0%), those aged 37-50 years (6.2%), and with an ALT result of 70 or greater (7.1%). Of those testing positive, 68.9% had been diagnosed with HCV in the past, 84.9% before the study period. Most (92.5%) of those diagnosed with chronic infection had attended specialist liver services and while 67.7% had ever been treated only 38% had successfully cleared infection. More than half of HCV-positive people required assessment, and potentially treatment, for their HCV infection but were not engaged with services during the study period. LFT in primary care are a key opportunity to diagnose, re-diagnose and re-engage patients with HCV infection and highlight the importance of GPs in efforts to eliminate HCV as a public health concern.

Multi-messenger nanoprobes of hidden magnetism in a strained manganite.

The ground-state properties of correlated electron systems can be extraordinarily sensitive to external stimuli, offering abundant platforms for functional materials. Using the multi-messenger combination of atomic force microscopy, cryogenic scanning near-field optical microscopy, magnetic force microscopy and ultrafast laser excitation, we demonstrate both 'writing' and 'erasing' of a metastable ferromagnetic metal phase in strained films of La2/3Ca1/3MnO3 (LCMO) with nanometre-resolved finesse. By tracking both optical conductivity and magnetism at the nanoscale, we reveal how strain-coupling underlies the dynamic growth, spontaneous nanotexture and first-order melting transition of this hidden photoinduced metal. Our first-principles calculations reveal that epitaxially engineered Jahn-Teller distortion can stabilize nearly degenerate antiferromagnetic insulator and ferromagnetic metal phases. We propose a Ginzburg-Landau description to rationalize the co-active interplay of strain, lattice distortions and magnetism nano-resolved here in strained LCMO, thus guiding future functional engineering of epitaxial oxides into the regime of phase-programmable materials.

Increased case-finding and uptake of direct-acting antiviral treatment essential for micro-elimination of hepatitis C among people living with HIV: a national record linkage study.

OBJECTIVES: Micro-elimination of hepatitis C virus (HCV) in people living with HIV (PLHIV) and co-infected with HCV has been proposed as a key contribution to the overall goal of HCV elimination. While other studies have examined micro-elimination in HIV-treated cohorts, few have considered HCV micro-elimination among those not treated for HIV or at a national level. METHODS: Through data linkage of national and sentinel surveillance data, we examined the extent of HCV testing, diagnosis and treatment among a cohort of PLHIV in Scotland identified through the national database of HIV-diagnosed individuals, up to the end of 2017. RESULTS: Of 5018 PLHIV, an estimated 797 (15%) had never been tested for HCV and 70 (9%) of these had undiagnosed chronic HCV. The odds of never having been tested for HCV were the highest in those not on HIV treatment [adjusted odds ratio (aOR) = 7.21, 95% confidence interval (CI): 5.15-10.10). Overall HCV antibody positivity was 11%, and it was at its highest among people who inject drugs (49%). Most of those with chronic HCV (91%) had attended an HCV treatment clinic but only half had been successfully treated (54% for those on HIV treatment, 12% for those not) by the end of 2017. The odds of never having been treated for HCV were the highest in those not on HIV treatment (aOR = 3.60, 95% CI: 1.59-8.15). CONCLUSIONS: Our data demonstrate that micro-elimination of HCV in PLHIV is achievable but progress will require increased effort to engage and treat those co-infected, including those not being treated for their HIV.

Phosphonate Treatment Effects on Phytophthora Root Rot Control, Phosphite Residues and Phytophthora cactorum Inoculum in Young Apple Orchards.

Phytophthora root rot, caused by Phytophthora cactorum, is an economically important disease on young apple trees. Limited information is available on the effect of different phosphonate application methods and dosages on disease control, fruit and root phosphite concentrations, and soil and root pathogen inoculum levels. Evaluation of phosphonate treatments in three apple orchard trials (two in the Grabouw and one in the Koue Bokkeveld region) showed that foliar sprays (ammonium or potassium phosphonate), trunk sprays and trunk paints, were equally effective at increasing trunk diameter in one trial and yield in a second trial over a 25-month period. Foliar ammonium and potassium phosphonate sprays (12 g of phosphorous acid/tree), and two different dosages of the ammonium phosphonate sprays (∼4.8 g or 12 g of phosphorous acid/tree) were all equally effective at improving tree growth. The addition of a bark penetrant (polyether-polymethylsiloxane-copolymer) to trunk sprays did not improve the activity of trunk sprays. The low dosage ammonium phosphonate foliar spray (∼4.8 g a.i./tree) was the only treatment that, in general, yielded significantly lower root phosphite concentrations than the other phosphonate treatments. Root phosphite concentrations were significantly positively correlated (P < 0.0001) with an increase in trunk diameter and negatively (P < 0.0001) with P. cactorum root DNA quantities. Phosphite fruit residues were <31 ppm for all treatments, with the trunk paint treatment (80 g of phosphorous acid/tree applied annually) yielding significantly lower residues than the higher dosage foliar sprays (∼12 g a.i./tree). Twenty-one months posttreatment, most of the phosphonate treatments in all of the trials similarly significantly reduced P. cactorum DNA quantities estimated directly from roots, but not from soil based on soil baiting DNA analysis. Pathogen quantities in fine feeder roots did not differ significantly from those in higher-order roots (<5 mm diameter). P. cactorum DNA quantities estimated using DNA quantification directly from roots were significantly correlated (P < 0.0001) with those obtained through root leaf baiting DNA analysis and, to a lesser extent, with soil leaf baiting DNA quantities (P = 0.025).

The contribution of iron deficiency to the risk of peripartum transfusion: a retrospective case control study.

BACKGROUND: Iron deficiency in pregnancy is associated with inferior maternal and fetal outcomes. Postpartum depression, prematurity, intrauterine growth restriction, impaired childhood cognition and transfusion are all sequelae of maternal iron deficiency anemia. Transfusion to women of childbearing age has important consequences including increasing the risk of hemolytic disease of the fetus and newborn with future pregnancies. The relative contribution of iron deficiency to transfusion rates in the peripartum period is unknown. This study aimed to identify the prevalence of iron deficiency and anemia in pregnant women that received peripartum transfusions relative to age-matched non-transfused controls. METHODS: We performed a retrospective case-control study of all women that were transfused in the peripartum period from January, 2014 to July, 2018. Cases were compared to the next age matched control to deliver at our institution. The primary objective was to determine the proportion of patients with iron deficiency in pregnancy or anemia in pregnancy in cases and controls. Charts were reviewed for predisposing risk factors for iron deficiency, laboratory measures of iron deficiency and anemia, iron supplementation history and maternal and fetal outcomes. Factors associated with peripartum transfusion were analyzed using a multivariate logistic regression. RESULTS: 169 of 18, 294 (0.9%) women were transfused in the peripartum period and 64 (44%) of those transfused received 1 unit. Iron deficiency or anemia were present in 103 (71%) transfused women and 74 (51%) control women in pregnancy (OR 2.34, 95% CI: 3.7-18.0). Multivariate analysis identified social work involvement (adjusted OR 4.1, 95% CI: 1.8-10.1), intravenous iron supplementation in pregnancy (adjusted OR 3.8, 95% CI: 1.2-17.4) and delivery by unscheduled cesarean section (adjusted OR 2.8, 95% CI: 1.3-6.2) as significant predictors of peripartum transfusion. CONCLUSIONS: Pregnant women being followed by a social worker, receiving intravenous iron supplementation in pregnancy or who deliver by unscheduled cesarean section are more likely to receive a red blood cell transfusion. Women with iron deficiency or anemia in pregnancy are at increased risk of peripartum blood transfusions and warrant early and rigorous iron supplementation.

Correction to: The contribution of iron deficiency to the risk of peripartum transfusion: a retrospective case control study.

Following publication of the original article [1], we have been notified that there is a missing conflict of interest.

Determining Mancozeb Deposition Benchmark Values on Apple Leaves for the Management of Venturia inaequalis.

Apple scab, caused by Venturia inaequalis, is the most common fruit and foliar disease in commercial apple production worldwide. Early in the production season, preventative contact fungicide sprays are essential for protecting highly susceptible continuously unfolding and expanding young leaves. In South Africa, mancozeb is a key contact fungicide used for controlling apple scab early in the season. The current study developed deposition benchmarks indicative of the biological efficacy of mancozeb against apple scab, using a laboratory-based apple seedling model system. The model system employed a yellow fluorescent pigment that is known to be an effective tracer of mancozeb deposition. A concentration range of mancozeb (0.15 to 1 times the registered dosage) and fluorescent pigment concentrations was sprayed onto seedling leaves, which yielded various fluorescent particle coverage (FPC%) levels. Modeling of the FPC% values versus percent disease control yielded different benchmark values when disease quantification was conducted using two different methods. Thermal infrared imaging (TIRI) disease quantification resulted in a benchmark model where 0.40%, 0.79%, and 1.35 FPC% yielded 50, 75, and 90% apple scab control, respectively. These FPC% values were higher than the benchmarks (0.10, 0.20, and 0.34 FPC%, respectively) obtained with quantitative real-time PCR (qPCR) disease quantification. The qPCR benchmark model is recommended as a guideline for evaluating the efficacy of mancozeb sprays on leaves in apple orchards since the TIRI benchmark model underestimated disease control. The TIRI benchmark model yielded 68% disease control at the lowest mancozeb dosage, yet no visible lesion developed at this dosage. Both benchmark models showed that mancozeb yielded high levels of disease control at very low concentrations; for the qPCR benchmark model the FPC% value of the FPC90 (90% control) corresponded to 0.15 times that of the registered mancozeb concentration in South Africa, i.e., 85% lower than the registered dosage.

The Efficacy of Semiselective Chemicals and Chloropicrin/1,3-Dichloropropene-Containing Fumigants in Managing Apple Replant Disease in South Africa.

Apple replant disease (ARD) is a biological phenomenon that is encountered when old apple orchards are replanted, resulting in tree growth and yield reductions in young trees. Three ARD orchard trials were conducted, which showed that semiselective chemicals (fenamiphos, metalaxyl, imidacloprid, and phosphonates) used independently, two fumigant formulations (33.3% chloropicrin and 60.8% 1,3-dichloropropene [Pic33-1,3D] and 57.% chloropicrin and 38% 1,3 dichloropropene [Pic57-1,3D]), and semiselective chemicals combined with Pic33-1,3D or Pic57-1,3D all contributed to significant increases in tree growth (trunk diameter and shoot length) relative to the untreated control 3 to 4 years postplanting. The treatments did not differ significantly from each other in improving tree growth. Yield was more indicative of treatment efficacy, but this varied between the three orchards. The Pic33-1,3D fumigant in combination with semiselective chemistries was the most consistent in significantly increasing cumulative yields. The Pic57-1,3D treatment was superior in increasing yields relative to the Pic33-1,3D treatment, because (i) it significantly increased cumulative yields in comparison with the Pic33-1,3D treatment in one orchard and (ii) in another orchard, a significant increase in yield was obtained with Pic57-1,3D relative to the control treatment but not with the Pic33-1,3D treatment. The quantification of ARD causative agents 20 months postplant showed that Phytophthora cactorum contributed to disease development in all three orchards; significant negative correlations existed between the quantity of P. cactorum DNA detected in tree roots and tree growth and less often, yield. In two orchards, only some of the treatments that significantly reduced the quantity of P. cactorum DNA in tree roots relative to the control also resulted in a significant increase in tree growth. Some of the aforementioned trends were also evident for Pratylenchus spp. root densities in two of the orchards. There was a significant positive correlation between P. cactorum root DNA quantities and Pratylenchus spp. root densities. Pythium spp. and "Cylindrocarpon"-like DNA quantities detected in tree roots typically were not indicative of treatment efficacy. However, a significant positive correlation existed between these two pathogen groups, suggesting complex interactions not associated with pathogen quantities per se.

Free-breathing Pulmonary MR Imaging to Quantify Regional Ventilation.

Purpose To measure regional specific ventilation with free-breathing hydrogen 1 (1H) magnetic resonance (MR) imaging without exogenous contrast material and to investigate correlations with hyperpolarized helium 3 (3He) MR imaging and pulmonary function test measurements in healthy volunteers and patients with asthma. Materials and Methods Subjects underwent free-breathing 1H and static breath-hold hyperpolarized 3He MR imaging as well as spirometry and plethysmography; participants were consecutively recruited between January and June 2017. Free-breathing 1H MR imaging was performed with an optimized balanced steady-state free-precession sequence; images were retrospectively grouped into tidal inspiration or tidal expiration volumes with exponentially weighted phase interpolation. MR imaging volumes were coregistered by using optical flow deformable registration to generate 1H MR imaging-derived specific ventilation maps. Hyperpolarized 3He MR imaging- and 1H MR imaging-derived specific ventilation maps were coregistered to quantify regional specific ventilation within hyperpolarized 3He MR imaging ventilation masks. Differences between groups were determined with the Mann-Whitney test and relationships were determined with Spearman (ρ) correlation coefficients. Statistical analyses were performed with software. Results Thirty subjects (median age: 50 years; interquartile range [IQR]: 30 years), including 23 with asthma and seven healthy volunteers, were evaluated. Both 1H MR imaging-derived specific ventilation and hyperpolarized 3He MR imaging-derived ventilation percentage were significantly greater in healthy volunteers than in patients with asthma (specific ventilation: 0.14 [IQR: 0.05] vs 0.08 [IQR: 0.06], respectively, P < .0001; ventilation percentage: 99% [IQR: 1%] vs 94% [IQR: 5%], P < .0001). For all subjects, 1H MR imaging-derived specific ventilation correlated with plethysmography-derived specific ventilation (ρ = 0.54, P = .002) and hyperpolarized 3He MR imaging-derived ventilation percentage (ρ = 0.67, P < .0001) as well as with forced expiratory volume in 1 second (FEV1) (ρ = 0.65, P = .0001), ratio of FEV1 to forced vital capacity (ρ = 0.75, P < .0001), ratio of residual volume to total lung capacity (ρ = -0.68, P < .0001), and airway resistance (ρ = -0.51, P = .004). 1H MR imaging-derived specific ventilation was significantly greater in the gravitational-dependent versus nondependent lung in healthy subjects (P = .02) but not in patients with asthma (P = .1). In patients with asthma, coregistered 1H MR imaging specific ventilation and hyperpolarized 3He MR imaging maps showed that specific ventilation was diminished in corresponding 3He MR imaging ventilation defects (0.05 ± 0.04) compared with well-ventilated regions (0.09 ± 0.05) (P < .0001). Conclusion 1H MR imaging-derived specific ventilation correlated with plethysmography-derived specific ventilation and ventilation defects seen by using hyperpolarized 3He MR imaging. © RSNA, 2018 Online supplemental material is available for this article.

Gate-tuning of graphene plasmons revealed by infrared nano-imaging.

Surface plasmons are collective oscillations of electrons in metals or semiconductors that enable confinement and control of electromagnetic energy at subwavelength scales. Rapid progress in plasmonics has largely relied on advances in device nano-fabrication, whereas less attention has been paid to the tunable properties of plasmonic media. One such medium--graphene--is amenable to convenient tuning of its electronic and optical properties by varying the applied voltage. Here, using infrared nano-imaging, we show that common graphene/SiO(2)/Si back-gated structures support propagating surface plasmons. The wavelength of graphene plasmons is of the order of 200 nanometres at technologically relevant infrared frequencies, and they can propagate several times this distance. We have succeeded in altering both the amplitude and the wavelength of these plasmons by varying the gate voltage. Using plasmon interferometry, we investigated losses in graphene by exploring real-space profiles of plasmon standing waves formed between the tip of our nano-probe and the edges of the samples. Plasmon dissipation quantified through this analysis is linked to the exotic electrodynamics of graphene. Standard plasmonic figures of merit of our tunable graphene devices surpass those of common metal-based structures.

Limited impact of awareness-raising campaigns on hepatitis C testing practices among general practitioners.

The global hepatitis strategy calls for increased effort to diagnose those infected, with a target of 90% diagnosed by 2030. Scotland's Action Plan on Hepatitis C included awareness-raising campaigns, undertaken during 2008-2011, to promote testing by general practitioners. We examined hepatitis C virus (HCV) testing practice among general practitioners before and following these campaigns. Scottish general practitioners were surveyed, using Dillman's method, in 2007 and 2013; response rates were 69% and 60%, respectively. Most respondents offer testing when presented with a risk history (86% in 2007, 88% in 2013) but only one-fifth actively sought out risk factors (19% in 2007, 21% in 2013). Testing was reportedly always/almost always/usually offered to people who inject drugs (84% in 2007, 87% in 2013). Significant improvements in the offer of testing were reported in patients with abnormal LFTs (41% in 2007, 65% in 2013, P<.001) and who had received medical/dental treatment in high prevalence countries (14% in 2007, 24% in 2013, P=.001). In 2013, 25% of respondents had undertaken HCV-related continued professional development. This group was significantly more likely to actively seek out risk factors (P=.009) but only significantly more likely to offer a test to patients who had received medical/dental treatment in high prevalence countries (P=.001). Our findings suggest that government-led awareness raising campaigns have limited impact on general practitioners' testing practices. If the majority of the HCV-infected population are to be diagnosed, practitioner-based or physician-centred interventions should be considered alongside educational initiatives targeted at professionals.

New horizons in comprehensive geriatric assessment.

In this article, we discuss the emergence of new models for delivery of comprehensive geriatric assessment (CGA) in the acute hospital setting. CGA is the core technology of Geriatric Medicine and for hospital inpatients it improves key outcomes such as survival, time spent at home and institutionalisation. Traditionally It is delivered by specialised multidisciplinary teams, often in dedicated wards, but in recent years has begun to be taken up and developed quite early in the admission process (at the 'front door'), across traditional ward boundaries and in specialty settings such as surgical and pre-operative care, and oncology. We have scanned recent literature, including observational studies of service evaluations, and service descriptions presented as abstracts of conference presentations to provide an overview of an emerging landscape of innovation and development in CGA services for hospital inpatients.

A Global Perspective on the Population Structure and Reproductive System of Phyllosticta citricarpa.

The citrus pathogen Phyllosticta citricarpa was first described 117 years ago in Australia; subsequently, from the summer rainfall citrus-growing regions in China, Africa, and South America; and, recently, the United States. Limited information is available on the pathogen's population structure, mode of reproduction, and introduction pathways, which were investigated by genotyping 383 isolates representing 12 populations from South Africa, the United States, Australia, China, and Brazil. Populations were genotyped using seven published and eight newly developed polymorphic simple-sequence repeat markers. The Chinese and Australian populations had the highest genetic diversities, whereas populations from Brazil, the United States, and South Africa exhibited characteristics of founder populations. The U.S. population was clonal. Based on principal coordinate and minimum spanning network analyses, the Chinese populations were distinct from the other populations. Population differentiation and clustering analyses revealed high connectivity and possibly linked introduction pathways between South Africa, Australia, and Brazil. With the exception of the clonal U.S. populations that only contained one mating type, all the other populations contained both mating types in a ratio that did not deviate significantly from 1:1. Although most populations exhibited sexual reproduction, linkage disequilibrium analyses indicated that asexual reproduction is important in the pathogen's life cycle.

IR near-field spectroscopy and imaging of single Li(x)FePO4 microcrystals.

This study demonstrates the unique capability of infrared near-field nanoscopy combined with Fourier transform infrared spectroscopy to map phase distributions in microcrystals of Li(x)FePO4, a positive electrode material for Li-ion batteries. Ex situ nanoscale IR imaging provides direct evidence for the coexistence of LiFePO4 and FePO4 phases in partially delithiated single-crystal microparticles. A quantitative three-dimensional tomographic reconstruction of the phase distribution within a single microcrystal provides new insights into the phase transformation and/or relaxation mechanism, revealing a FePO4 shell surrounding a diamond-shaped LiFePO4 inner core, gradually shrinking in size and vanishing upon delithiation of the crystal. The observed phase propagation pattern supports recent functional models of LiFePO4 operation relating electrochemical performance to material design. This work demonstrates the remarkable potential of near-field optical techniques for the characterization of electrochemical materials and interfaces.

Edge and Surface Plasmons in Graphene Nanoribbons.

We report on nano-infrared (IR) imaging studies of confined plasmon modes inside patterned graphene nanoribbons (GNRs) fabricated with high-quality chemical-vapor-deposited (CVD) graphene on Al2O3 substrates. The confined geometry of these ribbons leads to distinct mode patterns and strong field enhancement, both of which evolve systematically with the ribbon width. In addition, spectroscopic nanoimaging in the mid-infrared range 850-1450 cm(-1) allowed us to evaluate the effect of the substrate phonons on the plasmon damping. Furthermore, we observed edge plasmons: peculiar one-dimensional modes propagating strictly along the edges of our patterned graphene nanostructures.

Inter- and intrasubject variability of the inflammatory response to segmental endotoxin challenge in healthy volunteers.

Segmental endotoxin challenge with lipopolysaccharide (LPS) can be used as a pharmacodynamic model to safely induce a transient airway inflammation in the peripheral lung of healthy subjects and to test the anti-inflammatory efficacy of investigational new drugs. In contrast to whole lung LPS challenge only a fraction of the dose is required that can be precisely administered to a specific lung region and a vehicle challenged segment as an intra-subject control can be included. The aim of this study was to assess the intra- and inter-individual variability of the response to segmental LPS challenge for the appropriate design and power calculation of future clinical trials. Two cohorts with 10 subjects each underwent two segmental LPS challenges within five weeks. The inflammatory response was evaluated in bronchoalveolar lavage (BAL) fluid at 6 (cohort 1) and 24 h (cohort 2) both in the LPS and in a vehicle challenged segment, as well as in plasma for up to 26 h post LPS challenge. While the cytokine response was more pronounced at 6 h, the influx of neutrophils and monocytes dominated at 24 h; e.g. neutrophils increased from a median (inter-quartile range, IQR) of 0.14 (0.16) and 0.09 (0.08)x10(4) cells/mL BAL fluid at baseline to 10.2 (17.1) and 19.3 (15.9)x10(4) cells/mL 24 h after the two separate challenges. The within-subject variability was higher than the between-subject variability for most of the markers. However, sample size estimations based on the variability of outcome variables found lower or equal numbers with cross-over designs compared to parallel group designs for cellular markers at 24 h and cytokine variables at 6 h. The segmental LPS challenge model was safe. Future study designs have to balance between burden to the study subjects (4 versus 2 bronchoscopies), variability (within-versus between-subject), and the desired outcome variable (cells versus chemo/cytokine).

Secular trends in ischemic stroke subtypes and stroke risk factors.

BACKGROUND AND PURPOSE: Early diagnosis and treatment of a stroke improves patient outcomes, and knowledge of the cause of the initial event is crucial to identification of the appropriate therapy to maximally reduce risk of recurrence. Assumptions based on historical frequency of ischemic subtypes may need revision if stroke subtypes are changing as a result of recent changes in therapy, such as increased use of statins. METHODS: We analyzed secular trends in stroke risk factors and ischemic stroke subtypes among patients with transient ischemic attack or minor or moderate stroke referred to an urgent transient ischemic attack clinic from 2002 to 2012. RESULTS: There was a significant decline in low-density lipoprotein cholesterol and blood pressure, associated with a significant decline in large artery stroke and small vessel stroke. The proportion of cardioembolic stroke increased from 26% in 2002 to 56% in 2012 (P<0.05 for trend). Trends remained significant after adjusting for population change. CONCLUSIONS: With more intensive medical management in the community, a significant decrease in atherosclerotic risk factors was observed, with a significant decline in stroke/transient ischemic attack caused by large artery atherosclerosis and small vessel disease. As a result, cardioembolic stroke/transient ischemic attack has increased significantly. Our findings suggest that more intensive investigation for cardiac sources of embolism and greater use of anticoagulation may be warranted.

Optical coupling of gold nanoparticles on vertical graphenes to maximize SERS response.

Gold particle interaction with few-layer graphenes is of interest for the development of numerous optical nanodevices. The results of numerical studies of the coupling of gold nanoparticles with few-layer vertical graphene sheets are presented. The field strengths are computed and the optimum nanoparticle configurations for the formation of surface enhanced Raman spectroscopy (SERS) hotspots are obtained. The nanoparticles are modeled as 8 nm diameter spheres atop 1.5 nm (five layers) graphene sheet. The vertical orientation is of particular interest as it is possible to use both sides of the graphene structure and potentially double the number of particles in the system. Our results show that with the addition of an opposing particle a much stronger signal can be obtained, as well as the particle the number of atomic carbon layers can control separation. These results provide further insights and contribute to the development of next-generation plasmonic devices based on nanostructures with hybrid dimensionality.