Sharp Loss Research Articles

The evaluation of combined CT pulmonary and bronchial arteriography for the diagnosis of hemoptysis

To establish the method of multi-slice spiral CT pulmonary angiography (CTPA)combined with bronchial angiography (CTBA) and to evaluate its value for diagnosis and treatment in hemoptysis. After contrast material was administered intravenously, a 16-detector row helical CT scanner (Light Speed Ultra 16; GE Medical Systems) was used to complete CTPA first with a scan delay time of 12 - 16 s. Then CTBA was carried out, with a scan delay time of 26 - 28 s. The images were reformatted to evaluate the pulmonary artery and bronchial artery (BA). In 36 cases of hemoptysis, CTPA showed 7 pulmonary arterial abnormalities (3 cases with pulmonary embolism, 4 cases with one of pulmonary artery abnormity, primary pulmonary artery leiomyosarcoma, loss of sharpness of pulmonary artery or occlusion of right-inferior lung artery). In the 36 cases, CTBA showed 37 right BAs (11 tortuosity and thickening), 40 left right BAs (10 tortuosity and thickening) and 3 non-bronchial systemic arteries (1 from abdominal aorta tortuosity and thickening). Abnormal vessels had a close relation with pulmonary diseases. With this method CTPA and CTBA can be completed in a single procedure and abnormal pulmonary arteries and bronchial arteries can be shown clearly. This procedure maybe of important value for the diagnosis and treatment of hemoptysis.

Acoustic Surface Plasmon Dispersion on Nanostructured Cu(111)

In the present paper, the acoustic surface plasmon (ASP) dispersion is investigated on nanostructured Cu(111) by angle-resolved high-resolution electron energy loss spectroscopy (HREELS). The surface is prepared by ion bombardment at different crystal temperatures and ion fluences, following the recipes given by J. Naumann et al. (Surf Sci 388:212–219, 1997). We demonstrate that, at room temperature, the ASP survives to the disordering introduced by sputtering. The slope of the dispersion curve is thereby slightly reduced with respect to the one measured on pristine Cu(111), in accord with the disorder induced up-shift of the Shockley surface state. When ion bombardment is performed at 393 K and the surface restructures at the nanoscale forming hexagonal holes, an additional sharp loss is observed at 0.87 eV for wave vectors around 0.15 A−1, while the ASP loss gradually faints off with sputtering dose. Eventually, HREELS shows evidence only for the interband transition from the bottom of the Shockley surface state to the Fermi level.

Pyrolytic characteristics of biomass acid hydrolysis residue rich in lignin

Pyrolytic characteristics of acid hydrolysis residue (AHR) of corncob and pinewood (CAHR, WAHR) were investigated using a thermo-gravimetric analyzer (TGA) and a self-designed pyrolysis apparatus. Gasification reactivity of CAHR char was then examined using TGA and X-ray diffractometer. Result of TGA showed that thermal degradation curves of AHR descended smoothly along with temperature increasing from 150°C to 850°C, while a “sharp mass loss stage” for original biomass feedstock (OBF) was observed. Char yield from AHR (42.64–30.35wt.%) was found to be much greater than that from OBF (26.4–19.15wt.%). In addition, gasification reactivity of CAHR char was lower than that of corncob char, and there was big difference in micro-crystallite structure. It was also found that CAHR char reactivity decreased with pyrolysis temperature, but increased with pyrolysis heating rate and gasification temperature at 850–950°C. Furthermore, CAHR char reactivity performed better under steam atmosphere than under CO2 atmosphere.

PAR-3 Oligomerization May Provide an Actin-Independent Mechanism to Maintain Distinct Par Protein Domains in the Early Caenorhabditis elegans Embryo

Par proteins establish discrete intracellular spatial domains to polarize many different cell types. In the single-cell embryo of the nematode worm Caenorhabditis elegans, the segregation of Par proteins is crucial for proper division and cell fate specification. Actomyosin-based cortical flows drive the initial formation of anterior and posterior Par domains, but cortical actin is not required for the maintenance of these domains. Here we develop a model of interactions between the Par proteins that includes both mutual inhibition and PAR-3 oligomerization. We show that this model gives rise to a bistable switch mechanism, allowing the Par proteins to occupy distinct anterior and posterior domains seen in the early C. elegans embryo, independent of dynamics or asymmetries in the actin cortex. The model predicts a sharp loss of cortical Par protein asymmetries during gradual depletion of the Par protein PAR-6, and we confirm this prediction experimentally. Together, these results suggest both mutual inhibition and PAR-3 oligomerization are sufficient to maintain distinct Par protein domains in the early C. elegans embryo.

Conservation Opportunities in Spanish JuniperJuniperus thuriferaWoodlands: The Case of Migratory ThrushesTurdusspp.

Conservation opportunities in Spanish juniper Juniperus thurifera woodlands: the case of migratory thrushes Turdus spp.Spanish juniper Juniperus thurifera woodlands are the core habitat of several sites included in the Nature 2000 Network and the wintering ground of many European thrushes Turdus spp. These birds have a major ecological role as seed dispersers and are increasingly taken into account in the design of strategies aimed to conserve or restore plant communities. Socio-economic changes in rural Spain have reduced traditional sheep grazing in juniper woodlands, which are now increasingly used for wood production. This has brought the opportunity to improve their carrying capacity for migratory thrushes. Here we explore the spatio-temporal patterning of fleshy cone production and the way birds track this resource. We also investigate whether fleshy cone availability constrains bird numbers. The results show sharp losses of cones during the ripening period, inter-site and inter-winter changes in cone production and the tracking of ripe cones by birds. Mean availability of ripe cones in poorly productive patches was insufficient to maintain thrushes in mid January and highly productive patches offered resources to maintain birds for around 12 days. This suggests an insufficiency of food in the woodlands to permit thrushes to complete the winter and to begin their return northward migration in March. These results are used to suggest some guidelines for improving the carrying capacity of these woodlands for migratory thrushes.

Loss of fine structure and edge sharpness in fast‐spin‐echo carotid wall imaging: Measurements and comparison with multiple‐spin‐echo in normal and atherosclerotic subjects

To test whether the k-space acquisition strategy used by fast-spin-echo (FSE) is a major source of blurring in carotid wall and plaque imaging, and investigate an alternative acquisition approach. The effect of echo train length (ETL) and T(2) on the amount of blurring was studied in FSE simulations of vessel images. Edge sharpness was measured in black-blood T(1) W and proton density-weighted (PDW) carotid images acquired from 5 normal volunteers and 19 asymptomatic patients using both FSE and multiple-spin-echo (Multi-SE) sequences at 3 Tesla (T). Plaque images were classified and divided in group α (tissues' average T(2) ∼ 40-70 ms) and group β (plaque components with shorter T(2) ). Simulations predicted 26.9% reduction of vessel edge sharpness from Multi-SE to FSE images (ETL = 9, T(2) = 60 ms). This agreed with in vivo measurements in normal volunteers (27.4%) and in patient group α (26.2%), while in group β the loss was higher (31.6%). FSE significantly reduced vessel edge sharpness along the phase-encoding direction in T(1) W and PDW images. Blurring was stronger in the presence of plaque components with short T(2) times. This study shows a limitation of FSE and the potential of Multi-SE to improve the quality of carotid imaging.

Head and neck radiology: role of multidetector computed tomography in the evaluation of the tympanic canaliculus

This study was undertaken to evaluate the potential of multidetector computed tomography (MDCT) for multiplanar visualisation of the tympanic canaliculus both in healthy individuals and in patients affected by chronic inflammatory disease of the middle ear. A preliminary study was performed on three dried skulls by placing a metal landmark inside the tympanic canal lumen with a view to optimising depiction by multiplanar CT. Subsequently, 50 patients were enrolled in a prospective study. Three of the 100 petrous pyramids studied were excluded owing to the presence of jugulotympanic glomus tumour with severe bone changes. The entire course of the tympanic canaliculus was identified in 80/97 petrous pyramids (82.4%), 57 of which were normal (75.4% detection rate) and 40 pathological (90% detection rate). To assess the tympanic canaliculus in the pathological petrous pyramids and evaluate its possible role in the disease process, some qualitative criteria were introduced: canal enlargement, loss of margin sharpness, focal erosion of canal margins and presence of pathological tissue. MDCT represents the only technique allowing evaluation of the tympanic canal in vivo and with multiplanar images in a large number of cases (82.4%).

Highly birefringent photonic bandgap Bragg fiber loop mirror for simultaneous measurement of strain and temperature

A highly birefringent photonic bandgap Bragg fiber loop mirror configuration for simultaneous measurement of strain and temperature is proposed. The group birefringence and the sharp loss peaks are observable in the spectral response. Because the sensing head presents different sensitivities for strain and temperature measurands, these physical parameters can be discriminated by using the matrix method. It should be noted that this Bragg fiber presents high sensitivity to temperature, of ∼5.75 nm/°C, due to the group birefringence variation. The rms deviations obtained are ±19.32 με and ±0.5 °C, for strain and temperature measurements, respectively.

Evaporation and decomposition of acrylic acid grafted luminescent silicon quantum dots in ultrahigh vacuum

A thin film of silicon quantum dots (Si-QDs) is a potential thermoelectric material with a high figure of merit. Evaporation and deposition in ultrahigh vacuum is a novel method to produce such a thin film of high quality. Acrylic acid grafted luminescent Si-QDs have been synthesized by a simplified method. Their surface electronic core levels were investigated by X-ray photoelectron spectroscopy (XPS) at various temperatures. At room temperature, three components at 100.4, 102, and 104.4 eV were identified, corresponding to Si core, Si-C, and silicon oxide on surface, respectively. The appearance of Si-C component showed that acrylic acid has been successfully grafted onto Si-QDs surface. At 200° C, intact evaporation took place and the ratios of silicon to carbon in core levels remained constant as the annealing time increased. Decomposition occured at 340°C, where the ratios of Si2p to C1s began to change. The XPS results are in agreement with thermogravimetric analysis (TGA) measurements which showed a sharp weight loss of 80% at 200° C, which is the intact evaporation temperature. Another slow weight loss of 14% took place between 300°C and 500°C, which is a footprint of surface Si-C decomposition.

Tunable electromagnetic band gap-embedded multimode resonators for ultra-wideband dual band, lower-ultra-wideband and upper-ultra-wideband applications

Three ultra-wideband (UWB) microstrip band-pass filters (BPFs) are proposed using tunable electromagnetic band gap (EBG)-embedded multiple-mode resonator (MMR) and fork resonator. In the first case, a compact dual-band BPF is implemented using a cascade of a multimodal fork resonator with tunable EBG. The fork resonator forms the basic structure yielding multiple band-pass realisations and the EBG selects the desired bands. This yields a compact dual-band BPF with sharp cut-off characteristics, wide bandwidth and low insertion loss. In the second case, a lower UWB filter is proposed by tuning an EBG-embedded MMR with parallel coupled microstrip line. Open circuited coupling stubs are introduced within the EBG structure to suppress higher order pass bands. In the third case, an upper UWB BPF is proposed in a similar manner as the lower UWB filter. However, the EBG-embedded MMR structure and the coupling technique are different. It is shown that the measured results are well matched to the predicted ones in terms of insertion/return losses over the plotted frequency range of 0.1–20.0 GHz. All simulations were performed with advanced design system (ADS) momentum (2.5D method of moments).

Confinement effects on liquid–liquid transitions: pore size dependence of sulfur's living polymerization

Modifications in the living polymerization or λ-transition of liquid sulfur, caused by confinement in nanonoporous sol–gel-derived glasses, are investigated by Raman scattering. Raman spectra are analyzed to provide the extent of polymerization, through which the temperature-dependence of the respective heat capacity is calculated. The data reveal that the sharp, second-order-type transition which takes place in bulk sulfur experiences severe rounding (loss of sharpness of the λ-transition) and systematic shift (increase) of the characteristic transition temperature upon restricting the liquid to smaller pore sizes. The observed confinement-induced changes in the transition temperature are discussed in the framework of theoretical predictions of finite-size scaling phenomena revealing a dependence on the inverse first power of the mean pore size in accordance with theoretical and experimental data.

A Space-Variant Luminance Map based Color Image Enhancement

Improvement of image quality has been highly demanding for users in digital imaging systems. A variety of image enhancement algorithms has been developed to control image enhancement factors. This paper presents a color image enhancement method that makes use of a space-variant luminance map (SVLM) for the local brightness characterization. Two-dimensional gamma correction combined with the SVLM is developed to increase the intensity at the dark region and vice versa at the bright region in the luminance domain. The enhanced luminance information is applied to the adaptive contrast enhancing process and the linear color restoration. The proposed algorithm reveals details of the input image as well as minimizes loss of the edge sharpness in the non-uniform and low illumination conditions. The developed enhancement process resulted in the lowest absolute mean brightness error (AMBE) in a low-complexity fashion. A series of experimental results are discussed in terms of visual quality, the enhancement performance, and the complexity.

A Process for Production of a Niobium-containing TiAl Based Alloy

A new generation of turbine engines based on titanium aluminides may be commercially manufactured if these materials could be produced more cheaply and more easily. In the present work, challenges faced during the production of a γ-TiAl-based alloy (Ti-48Al-2Cr-2Nb-1B (at%) including the evaporation of aluminum and the formation of niobium-rich inclusions were studied and a set of recommendations has been proposed to overcome them. It was found that TiAl and Nb3Al are appropriate master alloys to produce an alloy with a controllable chemical composition and a microstructure free from inclusions without a need for any extra melting processes. A two stage mechanism was found to be responsible for chemical composition variation during the production of the alloy using elemental raw materials: a sharp aluminum loss in the first melting and a moderate one in the second and third melting processes. The first stage can be avoided by using master alloys.It was demonstrated that mechanical properties of an alloy produced after an appropriate heat treatment is comparable to alloys produced by other methods. Prevention of extra melting times has a strong impact on economics and commercialization of these materials.

Study on the pyrolytic behaviour of xylan-based hemicellulose using TG–FTIR and Py–GC–FTIR

Two sets of experiments, categorized as TG–FTIR and Py–GC–FTIR, are employed to investigate the mechanism of the hemicellulose pyrolysis and the formation of main gaseous and bio-oil products. The “sharp mass loss stage” and the corresponding evolution of the volatile products are examined by the TG–FTIR graphs at the heating rate of 3–80 K/min. A pyrolysis unit, composed of fluidized bed reactor, carbon filter, vapour condensing system and gas storage, is employed to investigate the products of the hemicellulose pyrolysis under different temperatures (400–690 °C) at the feeding flow rate of 600 l/h. The effects of temperature on the condensable products are examined thoroughly. The possible routes for the formation of the products are systematically proposed from the primary decomposition of the three types of unit (xylan, O-acetylxylan and 4-O-methylglucuronic acid) and the secondary reactions of the fragments. It is found that the formation of CO is enhanced with elevated temperature, while slight change is observed for the yield of CO 2 which is the predominant products in the gaseous mixture.

Boundedness of Fourier integral operators on Fourier Lebesgue spaces and affine fibrations

We study Fourier integral operators of Hörmander's type acting on the spaces $\mathcal F L^p(\mathbb R^d)_{\rm comp} $, $1\leq p\leq\infty$, of compactly supported distributions whose Fourier transform is in $L^p$. We show that the sharp loss of derivati

Calibrating 2-m Temperature of Limited-Area Ensemble Forecasts Using High-Resolution Analysis

Abstract Although the quality of numerical ensemble prediction systems (EPS) has greatly improved during the last few years, these systems still show systematic deficiencies. Specifically, they are underdispersive and lack both reliability and sharpness. A variety of statistical postprocessing methods allows for improving direct model output. Since 2007, Aire Limitée Adaptation Dynamique Développement International Limited Area Ensemble Forecasting (ALADIN-LAEF) has been in operation at the Central Institute for Meteorology and Geodynamics (ZAMG), and its 2-m temperature model output subject to calibration. This work follows the approach of nonhomogeneous Gaussian regression (NGR) that addresses a statistical correction of the first and second moment (mean bias and dispersion) for Gaussian-distributed continuous variables. It is based on the multiple linear regression technique and provides a predictive probability density function (PDF) in terms of a normal distribution. Fitting the regression coefficients, a minimum continuous ranked probability score (CRPS) estimation has been chosen instead of the more traditional maximum likelihood technique. The use of high-resolution analysis data on a 1 km × 1 km grid as training data improves the forecast skill in terms of CRPS by about 35%, especially on the local scale. The percentage of outliers decreases significantly without loss of sharpness. Sensitivity studies confirm that about half of the total improvement can be attributed to the effect of a bias correction. The training length plays a minor role, at least for the chosen verification period. A rescaling of the predictive PDF is important in order to obtain sharp forecasts, especially in the short range. Applying the same method to the global ensemble from the European Centre for Medium-Range Weather Forecasts (ECMWF) gives improvements of similar magnitude. However, the calibrated 2-m temperature of ALADIN-LAEF still remains slightly better than the 2-m temperature from calibrated ECMWF-EPS, which leads to the conclusion that statistical downscaling of EPS cannot replace dynamical downscaling. Finally, an advanced version of NGR, the so-called NGR-TD, which uses time-weighted averaging within minimum CRPS estimation, is able to yield a further improvement of about 5% in terms of the CRPS.

A novel synthesis of Fe2P–LiFePO4 composites for Li-ion batteries

Fe2P–LiFePO4 composites were synthesized by a novel method consisting of co-precipitation modified with in situ polyacrylamide (PAM) formation. Simultaneous thermogravimetric-differential scanning calorimetric analysis indicated that the in situ PAM precursor exhibited a moderate continuous weight loss rather than a sharp mass loss process. The best Fe2P–LiFePO4 composite was obtained from 14 wt% in situ PAM precursor under a sintering temperature of 750 °C for 20 h, which delivered a discharge capacity of 131 mAh g−1 at a rate of C/5 and 110 mAh g−1 at 1 C and sustained 30 cycles with almost no capacity fading. The relatively good electrochemical performance originates mainly from the well-mixed gelation precursor and conductive Fe2P phase with better electronic conductivity. This novel method verified that the electrochemical performance was improved compared to the conventional LiFePO4 without in situ PAM. It can be anticipated that the same process should be readily extendable to other olivines, such as LiMnPO4 and LiCoPO4, and also to other phosphates.

The benefits of darkness

The clever exploitation of dark modes in plasmonic nanostructures leads to devices with sharp resonances and low losses that promise applications in biochemical sensing and optical communications.

Financial Deregulation and Household Debt: The Australian Experience

Financial Deregulation and Household Debt: The Australian Experience

Stable, precise, and reproducible patterning of bicoid and hunchback molecules in the early Drosophila embryo.

Precise patterning of morphogen molecules and their accurate reading out are of key importance in embryonic development. Recent experiments have visualized distributions of proteins in developing embryos and shown that the gradient of concentration of Bicoid morphogen in Drosophila embryos is established rapidly after fertilization and remains stable through syncytial mitoses. This stable Bicoid gradient is read out in a precise way to distribute Hunchback with small fluctuations in each embryo and in a reproducible way, with small embryo-to-embryo fluctuation. The mechanisms of such stable, precise, and reproducible patterning through noisy cellular processes, however, still remain mysterious. To address these issues, here we develop the one- and three-dimensional stochastic models of the early Drosophila embryo. The simulated results show that the fluctuation in expression of the hunchback gene is dominated by the random arrival of Bicoid at the hunchback enhancer. Slow diffusion of Hunchback protein, however, averages out this intense fluctuation, leading to the precise patterning of distribution of Hunchback without loss of sharpness of the boundary of its distribution. The coordinated rates of diffusion and transport of input Bicoid and output Hunchback play decisive roles in suppressing fluctuations arising from the dynamical structure change in embryos and those arising from the random diffusion of molecules, and give rise to the stable, precise, and reproducible patterning of Bicoid and Hunchback distributions.