Phase-sensitive imaging of diffracted light by single nanoslits: measurements from near to far field

We perform phase-sensitive imaging of optical wavefront emanating from a single nanoslit and propagating into free space by using scattering type near-field scanning optical microscope combined with an optical interferometer. By analyzing polarization resolved optical amplitudes and phases, the propagation directions of surface waves are determined and the phase difference between two orthogonal polarization components of the surface wave are discussed for increasing distance from the slit.

Acute exacerbation of idiopathic pulmonary fibrosis: incidence, risk factors and outcome

Although acute exacerbation of idiopathic pulmonary fibrosis (IPF) has become well recognised, the reported incidence and outcomes are highly variable, and risk factors are unknown. The aim of this study was to estimate the incidence, risk factors and impact of acute exacerbations, and other known causes of rapid deterioration. This was a retrospective review of 461 patients with IPF (269 cases were biopsy-proven). The median follow-up period was 22.9 months. Rapid deterioration requiring hospitalisation occurred in 163 (35.4%) patients, with multiple episodes in 42 patients. Acute exacerbation was the most frequent cause (55.2%), followed by infection. The 1- and 3-yr incidences of acute exacerbation were 14.2 and 20.7%, respectively. Never having smoked and low forced vital capacity (FVC) were significant risk factors. The in-hospital mortality rate was 50.0%, and the 1- and 5-yr survival rates from the initial diagnosis were 56.2 and 18.4%, respectively. Acute exacerbation was a significant predictor of poor survival after the initial diagnosis, along with increased age, low FVC and diffusing capacity of the lung for carbon monoxide, and steroid use with or without cytotoxic therapy. 1- and 3-yr incidences of acute exacerbation were 14.2 and 20.7%, respectively. Never having smoked and low FVC were risk factors. Acute exacerbation had a serious impact on the overall survival of the patients with IPF.

Results of primary ossiculoplasty in ears with an intact stapes superstructure and malleus handle: inflammation in the middle ear at the time of surgery does not affect hearing outcomes

OBJECTIVE

To determine whether any factors are predictive of success or failure in primary ossiculoplasty employing autologous bone in Austin-Kartush Group A (stapes and malleus handle present) ears.

STUDY DESIGN

Retrospective review of a single-surgeon case series.

SETTING

Two District General Hospitals in the United Kingdom.

PATIENTS

Of 135 patients undergoing primary repair, 116 had sufficient data for analysis (mean follow-up 33 months).

MAIN OUTCOMES MEASURED

Postoperative air-bone gaps (pABG) in patients with differing qualities of middle-ear mucosa (active versus inactive), differing pathologies (mucosal versus squamous) and differing surgical procedures [canal-wall up (CWU) versus canal-wall down (CWD)].

SECONDARY OUTCOME MEASURE

'Belfast Rule of Thumb' (operated ear hearing brought to 30 dB or better or to within 15 dB of contralateral ear).

RESULTS

Postoperative ABGs were closed within 10 dB in 37%, 20 dB in 74% at latest follow-up. The only significant factors predicting hearing outcomes were the status of the canal wall (CWU = 14.1 dB, CWD = 24.7 dB: significant, P = 0.00) and whether surgery was primary or revision. Mean ABG was 14.7 for inactive middle ear mucosa, 17.2 for active middle ear mucosa (not significant, P = 0.25). Excluding CWD procedures from the analysis improved outcomes to 80% (within 20 dB) and 41% (within 10 dB) overall, and the mean for active and inactive ears to 14.2 and 14.0 dB respectively. Postoperatively, 82% of patients fulfilled the 'Belfast Rule of Thumb'.

CONCLUSION

The most significant prognostic factor affecting hearing outcomes - status of the canal wall - is independent of staging. The factor most associated with staging - the status of the middle ear mucosa - is only weakly associated with a successful functional outcome.

Substrate effect on aperture resonances in a thin metal film

We present a simple theoretical model to study the effect of a substrate on the resonance of an aperture in a thin metal film. The transmitted energy through an aperture is shown to be governed by the coupling of aperture waveguide mode to the incoming and the outgoing electromagnetic waves into the substrate region. Aperture resonance in the energy transmission thus depends critically on the refractive index of a substrate. We explain the substrate effect on aperture resonance in terms of destructive interference among evanescent modes or impedance mismatch. Our model shows an excellent agreement with a rigorous FDTD calculation and is consistent with previous experimental observations.

Terahertz near-field vectorial imaging of subwavelength apertures and aperture arrays

We present measurements of the complete terahertz (THz) electric near-field distribution, E(x), E(y) and E(z), in both the time- and frequency-domains, for subwavelength apertures and subsections of subwavelength aperture arrays. Measuring the individual components of the THz near-field with subwavelength spatial resolution, as they emerge from these structures, illustrates how the field interacts with the apertures. We observe the small but measurable y- and z-components of the electric field for both single apertures and arrays. Resonant contributions, attributed to Bloch modes, are detected and we observe the presence of a longitudinal field component, E(z), within the different array apertures, which can be attributed to a diffractive effect. These measurements illustrate in detail the individual THz field components emerging from subwavelength apertures and provide a direct measure of two important mechanisms that contribute to the net transmission of light through arrays.

Terahertz near-field enhancement in narrow rectangular apertures on metal film

We report huge field accumulations in rectangular aperture arrays on thin metal film by using shape resonance in THz frequency region. A huge far-field transmission enhancement is observed in samples of various widths ranging from 10 mum to 1.8 mum which correspond to only an order of lambda/100. Theoretical calculations based on vector diffraction theory indicates 230 times near-field enhancement in case of the 1.8 mum wide rectangular aperture. Transmission measurement through the single rectangular aperture shows that the shape resonance, not the periodicity, is mainly responsible for the transmission enhancement and the corresponding field enhancement.

Circulating interleukin 17 is increased in the acute stage of Kawasaki disease

OBJECTIVES

During the acute phase, patients with Kawasaki disease (KD), an acute systemic vasculitis, demonstrate a drastic increase in serum interleukin-6 (IL-6), which parallels the duration of the fever. Recently, IL-17 has been reported to induce IL-6 production. The aim of this study was to elucidate the involvement of IL-17 in the pathogenesis of KD.

METHODS

Serum samples were obtained from patients with KD (n=30) and normal controls (n=20), and the concentrations of IL-17 and IL-6 measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Compared with the normal controls (2.08 +/- 2.14 pg/mL), serum IL-17 was markedly elevated in patients with acute KD (25.47 +/- 5.05 pg/mL): levels gradually decreased in the subacute phase (5.94 +/- 2.83 pg/mL). In the acute phase, levels of IL-6 were 83.52 +/- 19.12 pg/L, which correlated well with the serum levels of IL-17.

CONCLUSION

These results suggest that IL-17 may be involved in the development of, or the effects of inflammation in KD.

Epibulbar complex choristoma and hemimegalencephaly in linear sebaceous naevus syndrome

Epidermal naevus syndrome is a group of congenital syndromes comprising epidermal naevi associated with a variety of developmental abnormalities of the ocular, nervous, skeletal, cardiovascular and urogenital systems. We describe a case of an 8-month-old boy with a brown alopecic plaque on his face and scalp and a vascularized epibulbar mass involving the entire cornea, which had been present since birth. Histopathological examination identified sebaceous naevus in combination with complex choristoma. Magnetic resonance imaging of the brain showed hemimegalencephaly.

Bragg reflection of terahertz waves in plasmonic crystals

We present experimental and theoretical studies on terahertz surface plasmon (TSP) propagation on slit and rectangular aperture arrays in an aluminum sheet. Terahertz waves are coupled onto the plasmonic structures via a parallel plate waveguide. Long-lasting oscillations are observed in the temporal pulse shape after propagating through the periodic structure, whose Fourier transformation into the frequency domain results in Bragg-resonance spectral features. We show that the interference between the incident wave and the radiation reflected from both the aperture array and the waveguide block is responsible for this Bragg-resonance behavior. The reflection coefficient for a single slit is deduced to be 0.017 +/- 0.002.

Combined use of QuantiFERON-TB Gold assay and chest computed tomography in a tuberculosis outbreak

OBJECTIVE

To evaluate the value of the QuantiFERON-TB Gold (QFT-G) assay and chest computed tomography (CT), in addition to the conventional use of the tuberculin skin test (TST) and chest radiography (CXR), in a contact investigation of a tuberculosis (TB) outbreak.

DESIGN

In a contact investigation of a TB outbreak in a high school, TST and CXR were performed on all 1044 employees and students. QFT-G was performed on TST-positive subjects, and CT on QFT-G-positive subjects and students with TST > or =20 mm.

RESULTS

TST was positive in 388 subjects (37.2%), while QFT-G was positive in 7.6% (30/394). CXR showed abnormal findings suggestive of TB in 10 (1.0%) subjects, all of whom were TST-positive and six of whom were QFT-G-positive. Findings suggestive of active TB were noted in 17 (32.7%) of 52 subjects by CT. Collectively, among 21 (1.1%) TB patients, all were TST-positive, 12 (57.1%) were QFT-G-positive and active TB was diagnosed by CT, and not by CXR, in 11 subjects.

CONCLUSION

Compared to the conventional approach, the additional use of QFT-G in TST-positive subjects and chest CT in subgroups with a high probability of infection was found to be more effective in the differentiation between active TB, latent TB and non-infected subjects in a contact investigation.

Dramatic effect of single-base mutation on the conformational dynamics of human telomeric G-quadruplex

Guanine-rich DNA sequences can form G-quadruplexes. These four-stranded structures are known to form in several genomic regions and to influence certain biological activities. Sometimes, the instability of G-quadruplexes causes the abnormal biological processes. Mutation is a culprit for the destabilization of G-quadruplexes, but the details of mutated G-quadruplexes are poorly understood. In this article, we investigated the conformational dynamics of single-base mutated human telomeric G-quadruplexes in the presence of K(+) with single-molecule FRET spectroscopy. We observed that the replacement of single guanine by thymine in a G-track induces various folded structures, i.e. structural polymorphism. Moreover, direct observation of their dynamics revealed that a single-base mutation causes fast unfolding of folded states under physiological conditions. Furthermore, we found that the degree of destabilization varies according to mutation positions. When the central guanine of a G-track is replaced, the G-quadruplexes unfold quickly at any K(+) concentrations and temperature. Meanwhile, outer-quartet mutated G-quadruplexes have heterogeneous dynamics at intermediate K(+) concentrations and longstanding folded states at high K(+) concentrations. Several factors such as base-stacking interaction and K(+) coordination are responsible for the different dynamics according to the mutation position.

Local capacitor model for plasmonic electric field enhancement

We present a local capacitor model that enables a simple yet quantitatively accurate description of lightning rod effect in nanoplasmonics. A notion of lambda-zone capacitance is proposed and applied to predict the strongly induced electric field by a light source near nanoscale metal edges such as metal tip or metal gap. The enhancement factor, calculated from the local capacitor model, shows excellent agreement with more rigorous results. The lambda-zone capacitor allows a blockwise treatment of nano-optical devices and constitutes a basic element of optical nanocircuits.

3-dimensional local field polarization vector mapping of a focused radially polarized beam using gold nanoparticle functionalized tips

We have measured local electric field polarization vectors in 3-dimensional space on the nanoscale. A radial polarized light is generated by using a radial polarization converter and focused by an objective lens. Gold nanoparticle functionalized tips are used to scatter the focused field into the far-field region. Two different methods, rotational analyzer ellipsometry and Stokes parameters, are used in determining the polarization state of the scattered light. Two methods give consistent results with each other. Three dimensional local polarization vectors could be reconstructed by applying back transformation of the fully characterized polarizability tensor of the tip.

Establishing a surveillance network for severe lower respiratory tract infections in Korean infants and young children

To reduce morbidity and mortality through integrated case management, a pilot study to detect respiratory viruses in patients with acute lower respiratory infections (ALRIs) was designed as part of a nationwide surveillance for this disease in Korea. The study population consisted of hospitalized patients under the age of 5 years with bronchiolitis, pneumonia, croup, or acute respiratory distress syndrome. A prospective 6-month study was performed. Two hundred and ninety-seven nasopharyngeal secretions were collected and multiplex reverse transcriptase polymerase chain reactions (RT-PCR)/polymerase chain reactions (PCR) were performed to detect respiratory viruses. If there were any positive RT-PCR/PCR results, viral cultures were proceeded for confirmation. Respiratory viruses were identified in 49.6% of 296 patients. The detection rates were as follows: respiratory syncytial virus (RSV) was the most commonly detected in 52.7% (87/165), human metapneumovirus (hMPV) in 15.8%, human corona virus (hCoV) in 5.5%, adenovirus in 9.7%, human bocavirus (hBoV) in 5.5%, parainfluenza virus (PIV) in 3.6%, rhinovirus (RV) in 4.2%, and the influenza virus in 3% of the patients with ALRIs. The consistent rate of positive results between RT-PCR and viral culture was 92% (105/114). Using our methods to detect viral causes seemed to be acceptable for the national surveillance of severe acute respiratory infections in infants and children.

Near field imaging of terahertz focusing onto rectangular apertures

We performed terahertz near-field experiments on single rectangular holes with various lengths grown on an electro-optic crystal substrate with lambda/100 resolution. We find that the near-field amplitude becomes proportionally larger as the rectangle becomes narrower, strongly suggesting that a constant energy passes through even for a very narrow slit. The occurrence of a large field enhancement at the fundamental localized resonance is discussed confirming the funneling of energy at the near-field.

Clinical course and lung function change of idiopathic nonspecific interstitial pneumonia

Most studies of idiopathic nonspecific interstitial pneumonia (NSIP) have primarily studied mortality. In order to clarify the detailed outcome and prognostic markers in idiopathic NSIP, the clinical course with initial radiological and clinical features was analysed. The clinical course of 83 patients who were classified with idiopathic NSIP (72 fibrotic, 11 cellular; 27 males and 56 females; mean+/-sd age 54.4+/-10.1 yrs) was retrospectively analysed. In fibrotic NSIP, 16 (22%) patients died of NSIP-related causes with a median (range) follow-up of 53 (0.3-181) months. Despite the favourable survival (5-yr 74%), patients with fibrotic NSIP were frequently hospitalised with recurrence rate of 36%. Reduced forced vital capacity at 12 months was a predictor of mortality. On follow-up, lung function was improved or stable in approximately 80% of the patients. The extent of consolidation and ground-glass opacity on initial high-resolution computed tomography correlated significantly with serial changes of lung function, and the presence of honeycombing was a predictor of poor prognosis. During follow-up, eight (10%) patients developed collagen vascular disease. In conclusion, the overall prognosis of fibrotic nonspecific interstitial pneumonia was good; however, there were significant recurrences despite initial improvement and a subset of the patients did not respond to therapy. Some patients developed collagen vascular diseases at a later date.

Role of human cytochrome P450 3A4 in the metabolism of DA–8159, a new erectogenic

The purpose of this paper was to characterize cytochrome P450 (CYP) enzymes involved in N-dealkylation of a new oral erectogenic, DA-8159 to DA-8164, a major circulating active metabolite, in human liver microsomes and to investigate the inhibitory potential of DA-8159 on CYP enzymes. CYP3A4 was identified as the major enzyme responsible for DA-8159 N-dealkylation to DA-8164 based on correlation analysis and specific CYP inhibitor and antibody-mediated inhibition study in human liver microsomes, and DA-8159 metabolism in cDNA expressed CYP enzymes. There is the possibility of drug-drug interactions when prescribing DA-8159 concomitantly with known inhibitors or inducers of CYP3A4. DA-8159 was found to be only a very weak inhibitor of eight major CYPs (1A2, 2A6, 2C8, 2C9, 2C19, 2D6, 2E1 and 3A4), the largest inhibition occurring against CYP2D6 (IC5o 67.7 microM) in human liver microsomes. Drug-drug interactions would not be predicted on the basis of DA-8159 inhibiting the metabolism of coadministered drugs.

Coherent exciton-surface-plasmon-polariton interaction in hybrid metal-semiconductor nanostructures

We report measurements of a coherent coupling between surface plasmon polaritons (SPP) and quantum well excitons in a hybrid metal-semiconductor nanostructure. The hybrid structure is designed to optimize the radiative exciton-SPP interaction which is probed by low-temperature, angle-resolved, far-field reflectivity spectroscopy. As a result of the coupling, a significant shift of approximately 7 meV and an increase in broadening by approximately 4 meV of the quantum well exciton resonance are observed. The experiments are corroborated by a phenomenological coupled-oscillator model predicting coupling strengths as large as 50 meV in structures with optimized detunings between the coupled exciton and SPP resonances. Such a strong interaction can, e.g., be used to enhance the luminescence yield of semiconductor quantum structures or to amplify SPP waves.

Femtosecond phase control of spatial localization of the optical near-field in a metal nanoslit array

We demonstrate spatial control of optical near-fields by femtosecond phase shaping in one-dimensional plasmonic structures. The near-field images display striking temporal-phase dependence, switching between double- and single-peak images within one lattice constant. The change of the near-field distribution is studied in the time and spectral domain. The spectral composition change observed by varying the time delay between two phase-locked femtosecond pulses explains the spatial control of the near-field images. Modal expansion calculations of linear light transmission using the surface impedance boundary condition are in excellent agreement with experiments.

Enhanced surface-excitonic emission in ZnO/Al(2)O(3) core-shell nanowires

We report the influence of an Al(2)O(3) shell on the photoluminescence emission of ZnO nanowires. At room temperature, the spectrum of the core-shell nanowires shows a strong reduction of the relative intensity of the green defect emission with respect to the near-band-edge emission. At 5 K an increase of the relative intensity of the surface exciton band with respect to the donor-bound exciton emission is observed. Annealing the core-shell nanowires at 500 °C does not increase the green defect luminescence at 5 K. We propose a model explaining the spectral changes.

Pulmonary tuberculosis with acute respiratory failure

The aim of the present study was to evaluate the clinical characteristics, prognoses and predictors of mortality of patients with pulmonary tuberculosis (TB) with acute respiratory failure (ARF), and to investigate the adjunctive use of corticosteroids in such cases. TB patients with ARF requiring mechanical ventilation (n = 90) were enrolled retrospectively during 1989-2006. The patients were divided into two groups: tuberculous pneumonia (TBP; n = 66), and miliary TB (MTB; n = 24). The TBP patients were older than the MTB patients (mean age 68.0 versus 54.5 yrs), and the mean+/-SD interval from hospital admission to start of anti-TB treatment was longer for the TBP than for the MTB group (5.0+/-7.0 versus 2.8+/-2.5 days). However, there was no difference in in-hospital mortality rate between the two groups (68.2 versus 58.3%). In the TBP patients, multivariate analysis showed that advanced age and shock unrelated to sepsis were associated with poor outcomes. Even though corticosteroid use was a predictor of survival in TBP patients, it was difficult to conclusively determine the efficacy of corticosteroids in TBP with ARF because of the retrospective study design. The present study reveals the need for randomised controlled trials to clarify the role of corticosteroids as adjunctive therapy in the management of tuberculous pneumonia with acute respiratory failure.

Surface plasmon polariton detection discriminating the polarization reversal image dipole effects

Image dipole effects are highly dependent on the polarization direction, constructive (destructive) interference between real and image dipoles for the vertically (horizontally) aligned one in the vicinity of metal surfaces, respectively. This polarization-reversal of the image dipole effects is quantitatively investigated by using a gold nanoparticle functionalized tip as a local dipolar scatterer and a propagating surface plasmon polariton as an excitation source of dipoles. The polarization-resolved detection technique is applied to separate the radiations of the vertical and the horizontal dipoles from each other. In our study, the image dipole effects on the far-field detected signals are fully explained by the Fabry-Perot like interference between the radiations from the real and the image dipoles, and by considering the finite size effects of the gold nanoparticle.

Advanced terahertz electric near-field measurements at sub-wavelength diameter metallic apertures

Using terahertz-light excitation, we have measured with sub-wavelength spatial, and sub-cycle temporal resolution the time- and frequency-dependent electric-field and surface-charge density in the vicinity of small metallic holes. In addition to a singularity like concentration of the electric field near the hole edges, we observe, that holes can act as differential operators whose near-field output is the time-derivative of the incident electric field. Our results confirm the well-known predictions made by Bouwkamp, Philips Res. Rep. 5, 321-332 (1950), and reveal, with unprecedented detail, what physically happens when light passes through a small hole.