UK PubMed Central (United Kingdom)

BackgroundLifestyle, genetics and environmental factors are established determinants of bone density. We aimed to describe the bone characteristics of competitive top-ranked Nigerian...Full Text Available

UK PubMed Central (United Kingdom)

This paper presents a new approach to improve the in silico modeling of ultrasound transducer arrays. While current simulation tools accurately predict the theoretical element...Full Text Available

KoreaScience (Korea)

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Norwegian Open Research Archives (NORA)

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Energy Technology Data Exchange (ETDEWEB)

Use of a broadband Local Area Network (LAN) for transmission of classified and secure unclassified information requires monitoring capabilities which are sensitive to discrete segments of the network frequency spectrum. A viable monitoring system must be capable of detecting possible intrusion attempts or network malfunctions and alerting operating and security personnel. This report documents the results of an evaluation of the Magnavox CATV Systems Inc. Digital System Sentry software for network monitoring. Recommendations are made on its possible future role in broadband LAN security monitoring throughout the Nuclear Weapons Complex.

UK PubMed Central (United Kingdom)

We investigate a method for gene delivery to vascular smooth muscle cells using ultrasound triggered delivery of plasmid DNA from electrostatically coupled cationic microbubbles. Microbubbles...Full Text Available

UK PubMed Central (United Kingdom)

A bladder neck obstruction was suspected after ultrasound investigation at 16 weeks' gestation. Evaluation of protein content in the amniotic fluid, fetal ascites, and fluid from the overdistended bladder...Full Text Available

UK PubMed Central (United Kingdom)

Although previous intravascular ultrasound (IVUS) radiofrequency-based analysis data showed acceptable reproducibility for plaque composition, measurements are not easily obtained, particularly that...Full Text Available

DEFF Research Database (Denmark)

Interest in optics for hard X-ray broad-band application is growing. In this paper, we compare the hard X-ray (20-100 keV) reflectivity obtained with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity of the multilayer is found to agree extraordinarily well with theory (assuming an interface roughness of 4.5 Angstrom), while the agreement for the gold film is less, The overall performance of the supermirror is superior to that of gold, extending the band of reflection at least a factor of 2.8 beyond that of the gold, Various other design options are discussed, and we conclude that continued interest in the X-ray supermirror for broad-band hard X-ray applications is warranted.

Science.gov (United States)

An understanding of the mechanism of generation of Lg from underground nuclear explosions is essential for seismic monitoring and source discrimination. Near-source scattering of explosion-generated Rg into S appears to be responsible for the low-frequenc...

UK PubMed Central (United Kingdom)

A new method of random data analysis has been developed with special implications for membrane noise. The integral spectrometer uses overlapping broad-band filters of simple design, whose bandwidth...Full Text Available

Science.gov (United States)

... [5] GT Gullberg, RH Huesman, DNG Roy, J. Qi and BW Reutter, Esti- mation of the parameter covariance matrix for a one-compartment cardiac ...

UK PubMed Central (United Kingdom)

ObjectiveAngiography remains a critical component for diagnostic imaging and therapeutic intervention in peripheral arterial disease (PAD). The goal of this study...Full Text Available

International Nuclear Information System (INIS)

Ultrasound examinations for foetal brain abnormalities have been a part of the routine antenatal screening programme in the UK for many years. In utero brain magnetic resonance imaging (MRI) is now being used increasingly successfully to clarify abnormal ultrasound findings, often resulting in a change of diagnosis or treatment plan. Interpretation requires an understanding of foetal brain development, malformations and acquired diseases. In this paper we will outline the technique of foetal MRI, relevant aspects of brain development and provide illustrated examples of foetal brain pathology.

UK PubMed Central (United Kingdom)

BackgroundCardiovascular magnetic resonance (CMR) allows volumetric carotid plaque measurement that has advantage over 2-dimensional ultrasound (US) intima-media thickness (IMT)...Full Text Available

CERN Document Server

The spectral properties of Lyman break galaxies (LBGs) offer a means to isolate pure samples displaying either dominant Ly-alpha in absorption or Ly-alpha in emission using broadband information alone. We present criteria developed using a large z ~ 3 LBG spectroscopic sample from the literature that enables large numbers of each spectral type to be gathered in photometric data, providing good statistics for multiple applications. In addition, we find that the truncated faint, blue-end tail of z ~ 3 LBG population overlaps and leads directly into an expected Ly-alpha emitter (LAE) population. As a result, we present simple criteria to cleanly select large numbers of z ~ 3 LAEs in deep broadband surveys. We present the spectroscopic results of 32 r' <~ 25.5 LBGs and r' <~ 27.0 LAEs at z ~ 3 pre-selected in the Canada-France-Hawaii Telescope Legacy Survey that confirm these criteria.

British Library Electronic Table of Contents (United Kingdom)

The growth of silver chloride nanoparticles on ancient textile was achieved by sequential dipping steps in alternating bath of potassium chloride and silver nitrate under ultrasound irradiation. The effect of ultrasound irradiation and sequential dipping steps in growth of the AgCl nanoparticles has been studied. These systems depicted a decrease in the particles size accompanying a decrease in the sequential dipping steps. The samples were characterized with powder X-ray diffraction (XRD) and scanning electron microscopy. XRD analyses indicated that the prepared AgCl nanoparticles on fiber were crystalline. The textile samples containing AgCl nanoparticles were tested for their antibacterial efficacy against Escherichia coli and were found to possess significant antibacterial activity.

International Nuclear Information System (INIS)

A prospective comparative study with pathology was performed to assess the clinical value of Computed Tomography (CT) and endoscopic ultrasound (EUS) for nodal staging in lung cancer. A total of 329 nodal stations were dissected or sampled and 755 lymph nodes were examined at histology. On a pre-station basis, CT had greater sensitivity (74%) than EUS (56%), but EUS was more specific (83% versus 93%). The accuracy rates of the two techniques were similar. In conclusion, endoscopic ultrasound should be part of a routine preoperative diagnostic approach to non-small-cell lung cancer., because of its high specificity. Results can be improved when EUS and CT are combined., which suggests that these imaging modalities should be used together in selected patients for the noninvasive staging of non-small-cell lung cancer to identify local lymphatic spread.

UK PubMed Central (United Kingdom)

The goal of ultrasonic molecular imaging is the detection of targeted contrast agents bound to receptors on endothelial cells. We propose imaging methods that can distinguish adherent microbubbles...Full Text Available

UK PubMed Central (United Kingdom)

Advances in neuroscience have resulted in the development of new diagnostic and therapeutic agents for potential use in the central nervous system (CNS). However, the ability to deliver the...Full Text Available

UK PubMed Central (United Kingdom)

OBJECTIVES: To define a method for measurement of the cross sectional area and volume of the quadriceps femoris muscle using magnetic resonance imaging (MRI) in conjunction with stereology, and to compare...Full Text Available

UK PubMed Central (United Kingdom)

Percutaneous coronary intervention can be associated with distal embolization of thrombotic material causing myocardial necrosis and infarction.We discuss the role of intravascular imaging to...Full Text Available

UK PubMed Central (United Kingdom)

Background:During transurethral resection surgery (TUR), accidental stimulation of the obturator nerve can cause violent adductor contraction, leading to serious intraoperative...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The audible noise produced by corona on high-voltage transmission lines has several characteristics that differentiate it from other community noises. Transmission line noise is quite broadband and has a significant high frequency content. Special instrumentation designed to measure this type of noise pollution is described. All measuring systems have the same three basic elements: a transducer, a processing device, and an output device. Recorders, microphone devices, frequency analyzers, and meteorological instrumentation are discussed.

DEFF Research Database (Denmark)

OBJECTIVE: To evaluate the interobserver agreement of ultrasonographic assessment of finger and toe joints in patients with rheumatoid arthritis (RA) by 2 investigators with different medical backgrounds. METHODS: Ultrasonography and clinical examination were performed on 150 small joints of 30 patients with active RA. A General Electric LOGIQ 500 ultrasound unit with a 7-13-MHz linear array transducer was used. In each patient, 5 preselected small joints (second and third metacarpophalangeal, second proximal interphalangeal, first and second metatarsophalangeal) were examined independently on the same day by 2 ultrasound investigators (an experienced musculoskeletal radiologist and a rheumatologist with limited ultrasound training). Joint effusion, synovial thickening, bone erosions, and power Doppler signal were evaluated in accordance with an introduced 4-grade semiquantitative scoring system, on which the investigators ...

Science.gov (United States)

The current status of a computational aeroacoustics (CAA) approach to simulate broadband noise is reviewed. The method rests on the use of steady Reynolds averaged Navier-Stokes (RANS) simulation to describe the time-averaged motion of turbulent flow. By means of synthetic turbulence the steady one-point statistics (e.g. turbulence kinetic energy) and turbulent length- and time-scales of RANS are translated into fluctuations having statistics that very accurately reproduce the initial RANS target-setting. The synthetic fluctuations are used to prescribe sound sources which drive linear perturbation equations. The whole approach represents a methodology to solve statistical noise theory with state-of-the-art CAA tools in the time-domain. A brief overview of the synthetic turbulence model and its numerical discretization in terms of the random particle-mesh (RPM) and fast random particle-mesh (FRPM) method is given. Results are presented for trailing-edge noise, slat ...

Energy Technology Data Exchange (ETDEWEB)

In principle four different methods (ultrasound, microwaves, {gamma}-radiation and x-rays) are available for the non-destructive testing of refractories. Three of these methods, i.e. ultrasound, microwaves and {gamma}-radiation, are in use by different producers of AZS materials to carry out the quality control of their products. This paper will compare the three methods on the basis of the physical properties, present the existing devices, and show the advantages as well as the limits of the different methods. {gamma}-radiography, the oldest method in use, has one main disadvantage, which is the requirement of protection against radioactive radiation. Furthermore, while cracks and cavities can be detected with this method, structural changes can not be monitored. Therefore, the ultrasonic method was developed that allows to detect variations of porosity and grain size as well as cracks and voids when the ultrasonic parameters are tuned as well ...

Energy Technology Data Exchange (ETDEWEB)

I summarize the extant direct and indirect data on the sky background SNAP will see at the North Ecliptic Pole over the wavelength range 0.4 < {lambda} < 1.7 {micro}m. At the spatial resolution of SNAP the sky background due to stars and galaxies is resolved, so the only source considered is zodiacal light. Several models are explored to provide interpolation in wavelength between the broadband data from HST and COBE observations. I believe the input data are now established well enough that the accuracy of the sky background presented here is sufficient for SNAP simulations, and that it will stand up to scrutiny by reviewers.

British Library Electronic Table of Contents (United Kingdom)

In this work, the antibacterial effect of fluoroquinolones (FQs) upon Escherichia coli (E.coli) was measured with and without application of 40kHz ultrasound (US) stimulation. The research results demonstrated that simultaneous application of 40kHz US apparently enhanced the antibacterial effectiveness of FQs. That is, the synergistic effect was observed and the bacterial viability was reduced when FQs and US were combined. In addition, various influencing factors, such as FQs drug concentration, US irradiation time and solution temperature, on the inhibition of E.coli were also investigated. The antibacterial activity was enhanced apparently with increasing of FQs drug concentration, US irradiation time and solution temperature. Furthermore, we discussed preliminarily the mechanism of US ...

International Nuclear Information System (INIS)

17 patients with chronic aortic dissection were examined by MRI. In 12 patients, comparison between gradient echo sequences and SE sequences was possible. Gradient echo sequences, unlike SE sequences, permitted evaluation of flow in the true and false lumen, reliable differentiation between thrombus and flowing blood and clear delination of the intimal flap. An additional comparison between transoesophageal ultrasound and MRT in 15 patients showed significant advantages in favour of MRI. In three patients MRI was able to detect more proximal origins of the dissection. Moreover, MRI allowed evaluation of the major aortic branches and their relation to the dissection; this was not possible with ultrasound. MRI plays an important role in the follow-up of chronic aortic dissections. (orig.).

British Library Electronic Table of Contents (United Kingdom)

Calcaneus quantitative ultrasound (QUS) assessment is a safe and reliable method for evaluating skeletal status. Until now, considerable data have been accumulated on the distribution of QUS in Caucasian populations, whereas such data are still insufficient in Asian populations, especially in Chinese mainland. The present study aimed to obtain the distribution characteristic of calcaneus QUS in healthy Chinese women, and to further investigate the distribution of low bone mass by QUS stiffness index (SI). This study included 2,498 healthy Chinese females aged 10-87 yr. The QUS exhibited a characteristic mild rise and then fall pattern with increasing age. Age, body height, and weight were significant influencing factors on SI, especially age and weight. The prevalence of osteoporosis detec...

Science.gov (United States)

PMID:20864132

UK PubMed Central (United Kingdom)

This case report presents the prenatal diagnosis of conjoined twins at 7 weeks and 6 days’ gestation according to the last menstrual period and 6 weeks and 4 days’ gestation according...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Traffic characterization is an important means for Internet Service Providers (ISPs) to adapt and to optimize their networks to the requirements of the customers. Most network measurements are performed in the backbone of these ISPs, showing both, residential and business Internet traffic. However, the traffic characteristics of business and home users differ significantly. Therefore, we have performed measurements of home users at a broadband wireless access service provider in order to reflect only home user traffic characteristics. In this paper, we present the results of these measurements, showing daily traffic fluctuations, flow statistics as well as application distributions. The results show a difference to backbone traffic characteristics. Furthermore, we observed a shift from web...

CERN Document Server

Acoustic metamaterials with negative effective mass below a cut-off frequency are studied. An equivalent mass-spring structure is firstly proposed for such metamaterials, the effective mass is found to follow the Drude model: being negative below a specific frequency. The peculiar behavior is then verified by transmission experiments operating in the low-frequency regime. Inspired by the mass-spring model, we investigate the two-dimensional elastic waveguide with clamped boundaries and attribute the bandgap occurring below a critical frequency to negative effective mass density. The finding helps us to design a new acoustic Drude metamaterial, which enables shearing and bending deformations, in contrast to the membrane-type ones. Both simulation and experimental results show that the proposed metamaterial exhibits negative effective mass below 1200 Hz, thus opening broadband applications in vibration and noise controls.

British Library Electronic Table of Contents (United Kingdom)

The launch of the first spaceborne hyperspectral instrument, Hyperion, in 2000 has provoked further research into its capabilities with regard to mineral exploration. Our study in the remote, mountainous region of Pulang, China employed a two-step progressive approach, first to locate target areas characterized by hydrothermal mineral alteration, using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and secondly, to attempt detailed mineral mapping using Hyperion. The preliminary target detection involved principal components and broad-band spectral analysis and led to the detection of two target areas characterized by argillic alteration, iron-oxide- and sulphate-bearing minerals. A focused hyperspectral study followed using Spectral Angle Mapper (SAM) and Mixt...

International Nuclear Information System (INIS)

Orbit correction is now routinely performed at the few-micron level in the Advanced Photon Source (APS) storage ring. Three diagnostics are presently in use to measure and control both AC and DC orbit motions: broad-band turn-by-turn rf beam position monitors (BPMs), narrow-band switched heterodyne receivers, and photoemission-style x-ray beam position monitors. Each type of diagnostic has its own set of systematic error effects that place limits on the ultimate pointing stability of x-ray beams supplied to users at the APS. Limiting sources of beam motion at present are magnet power supply noise, girder vibration, and thermal timescale vacuum chamber and girder motion. This paper will investigate the present limitations on orbit correction, and will delve into the upgrades necessary to achieve true sub-micron beam stability.

International Nuclear Information System (INIS)

For the evaluation of diseases of salivary origin, ultrasound and/or sialography is recommended instead of MRI. In cases of salivary tumor, ultrasound may be helpful in delineating superficial tumors. For small tumors no further imaging is needed. When dealing with a large tumor or a tumor in the deep lobe of the parotid gland, MRI is the preferred imaging method. Not only does MRI provide a large variety of soft tissue signal differences, but also the multiplanar facilities are helpful in delineating the extent of the tumor, whether located in the submandibular, sublingual, or parotid gland. Skull base invasion is often well seen by MRI. Subtle changes may be missed and in those cases CT is recommended to exclude or prove destruction of the skull base. For the evaluation of patients presenting with a recurrent pleomorphic adenoma, MRI is recommended in all patients. MRI delineates the extent and number of recurrent tumors better than palpation ...

International Nuclear Information System (INIS)

For good image quality using ultrasound inverse scattering, one alternately solves the well-posed forward scattering equation for an estimated total field and the ill-posed inverse scattering equation for the desired object property function. In estimating the total field, error or noise contaminates the coefficients of both matrix and data of the inverse scattering equation. Previous work on ill-posed inverse ultrasonic scattering commonly used Tikhonov regularization, which considers error only in the data. The solution so obtained is not precise enough to reconstruct the quantitative internal structure of a large or high-contrast object. This paper adopts the truncated total least squares method, simultaneously considering error and noise on both sides of the inverse scattering equation, and compares it with the classical Tikhonov regularization. We show that it can substantially improve reconstruction fit and image quality when the inverse scattering equation ...

International Nuclear Information System (INIS)

Objective: To compare the enhancement pattern of hilar cholangiocarcinoma on contrast-enhanced ultrasound (CEUS) with that on contrast-enhanced computed tomography (CECT). Methods: Thirty-two consecutive patients with pathologically proven hilar cholangiocarcinomas were evaluated by both low mechanical index CEUS and CECT. The enhancement feature of the tumor, portal vein infiltration, and lesion conspicuity on them was investigated. Results: In the arterial phase, the numbers of the lesions showing hyperenhancement, isoenhancement, and hypoenhancement, were 14 (43.8%), 14 (43.8%), and 4 (12.6%), on CEUS, and 12 (37.5%), 9 (28.1%), and 11 (34.4%), on CECT (P = 0.162). In portal phase, the numbers of the lesions showing hypoenhancement, isoenhancement, and hyperenhancement were 30 (93.8%), 1 (3.1%), and 1 (3.1%), on CEUS, and 23 (71.9%), 8 (25.0%), and 1 (3.1%), on CECT (P = 0.046). The detection rates for portal vein infiltration were 84.2% (16/19) for baseline ...

CERN Document Server

The nature of the hard X-ray source XSSJ12270-4859 is still unclear though it was claimed to be a magnetic Cataclysmic Variable. We here present a broad-band X-ray and gamma ray study based on a recent XMM-Newton observation and archival INTEGRAL and RXTE data. From the Fermi/LAT 1-year point source catalogue, we tentatively associate XSSJ12270-4859 with 1FGLJ1227.9-4852, a source of high energy gamma rays with emission up to 10GeV. We complement the study with UV photometry from XMM-Newton and ground-based optical and near-IR photometry. The X-ray emission is highly variable showing flares and intensity dips. The X-ray flares consist of flare-dip pairs. Flares are also detected in the UV range but not the dips. Aperiodic dipping behaviour is also observed during X-ray quiescence but not in the UV. The 0.2-100keV spectrum is featureless and described by a power law model with Gamma=1.7. The 100MeV-10GeV spectrum is instead represented by a power law index of 2.45. ...

CERN Document Server

We examine the star clusters in the irregular galaxy NGC 4449. We use a near-infrared spectrum and broad-band images taken with the HST to place a limit of 8--15 Myrs on the age of the bright central ojbect in NGC 4449. Its luminosity and size suggest that it is comparable to young super star clusters. However, there is a peculiar nucleated-bar structure at the center of this star cluster, and we suggest that this structure is debris from the interaction that has produced the counter-rotating gas systems and extended gas streamers in the galaxy. From the images we identify 60 other candidate compact star clusters in NGC 4449. Fourteen of these could be background elliptical galaxies or old globular star clusters. Of the star clusters, three, in addition to the central object, are potentially super star clusters, and many others are comparable to the populous clusters found in the LMC. The star clusters span a large range in ages with no obvious peak in cluster ...

CERN Document Server

The near infrared (NIR) upgrade to the Robert Stobie Spectrograph (RSS) on the Southern African Large Telescope (SALT), RSS/NIR, extends the spectral coverage of all modes of the visible arm. The RSS/NIR is a low to medium resolution spectrograph with broadband imaging, spectropolarimetric, and Fabry-Perot imaging capabilities. The visible and NIR arms can be used simultaneously to extend spectral coverage from approximately 3200 A to 1.6 um. Both arms utilize high efficiency volume phase holographic gratings via articulating gratings and cameras. The NIR camera is designed around a 2048x2048 HAWAII-2RG detector housed in a cryogenic dewar. The Epps optical design of the camera consists of 6 spherical elements, providing sub-pixel rms image sizes of 7.5 +/- 1.0 um over all wavelengths and field angles. The exact long wavelength cutoff is yet to be determined in a detailed thermal analysis and will depend on the semi-warm instrument cooling scheme. Initial estimates ...

CERN Document Server

NGC 2770 has been the host of three supernovae of Type Ib during the last 10 years, SN 1999eh, SN 2007uy and SN 2008D. SN 2008D attracted special attention due to the serendipitous discovery of an associated X-ray transient. In this paper, we study the properties of NGC 2770 and specifically the three SN sites to investigate whether this galaxy is in any way peculiar to cause a high frequency of SNe Ib. We model the global SED of the galaxy from broadband data and derive a star-formation and SN rate comparable to the values of the Milky Way. We further study the galaxy using longslit spectroscopy covering the major axis and the three SN sites. From the spectroscopic study we find subsolar metallicities for the SN sites, a high extinction and a moderate star-formation rate. In a high resolution spectrum, we also detect diffuse interstellar bands in the line-of-sight towards SN 2008. A comparison of NGC 2770 to the global properties of a galaxy sample with high SN ...

International Nuclear Information System (INIS)

We have studied photoluminescence and thermoluminescence (PL and TL) in CaGa2Se4:Eu crystals in the temperature range 77-400 K. We have established that broadband photoluminescence with maximum at 571 nm is due to intracenter transitions 4f6 5d-4f7 (8S7/2) of the Eu2+ ions. From the temperature dependence of the intensity (log I-103/T), we determined the activation energy (Ea = 0.04 eV) for thermal quenching of photoluminescence. From the thermoluminescence spectra, we determined the trap depths: 0.31, 0.44, 0.53, 0.59 eV. The lifetime of the excited state 4f6 5d of the Eu2+ ions in the CaGa2Se4 crystal found from the luminescence decay kinetics is 3.8 ?sec. (authors)

CERN Document Server

Low noise, high resolution and high dose efficiency are the common requirements for most X-ray imaging applications. Especially in medical applications the dose efficiency is a necessity for detector systems. We present the imaging performance of the Medipix2 readout chip bump bonded to a 300 mu m thick Si detector as a function of the detection threshold, a free parameter not available in conventional integrating imaging systems. Spatial resolution has been measured using the modulation transfer function (MTF) and it varies between 8.2 Ip/mm and 11.0 Ip/mm at 70%. An associated measurement of noise power spectrum (NPS) permits us to derive the detective quantum efficiency (DQE) which can be as a high as 25.5 % for a broadband incoming spectrum. The influence of charge diffusion in the sensor together with threshold variation in the readout chip is discussed. Although the Medipix2 system is used in photon counting mode with a single threshold in energy, the system ...

International Nuclear Information System (INIS)

We describe a panoramic stigmatic spectrograph comprising a grazing-incidence toroidal mirror and a large-aperture free-standing transmission diffraction grating (5000 lines mm-1 ). Two spectrograph versions were constructed, with grazing angles of 7.6 and 40 and the short-wavelength spectral limits near 4 and 1.5 nm. The spectrograph aberrations were studied by numerical ray tracing. The spectrograph was used to record line and quasi-continuous spectra (1.5 - 30 nm) of multiply charged ions in a plasma generated by the second-harmonic pulses of an yttrium aluminate laser (Q = 0.15 J, ? = 5 ns, ? = 0.54 ?m, repetition rate = 0.5 Hz). In combination with a laser-produced plasma radiation source, the arrangement was used to characterise soft x-ray optical components and to generate collimated beams of polarised radiation in the 14 - 20 nm range. (laser applications and other topics in quantum electronics)

DEFF Research Database (Denmark)

This thesis - Resource Management in Broadband Communication Networks - deals with different ways of optimizing the available resources of data- or telecommunication networks. Especially topics like optimal routing, load balancing and fast recovery of routes in case of link failures are covered. The first part gives a brief description of some of the existing protocols for routing and controlling resources, such as RSVP, OSPF, BGP, PNNI, etc. The remaining part concerns the following two fundamentally different approaches to resource management etc.: - Software agents - Simulated ants In the beginning of the part concerning software agents a description of what exactly constitutes software agents, according to the scientists and according to the organization, FIPA is given. After this, the main results from the IMPACT project are presented. The IMPACT project is an EU-project that aimed at developing a demonstration platform, where software agents handled virtually ...

Energy Technology Data Exchange (ETDEWEB)

AIM: The purpose of the study was to evaluate the percutaneous use of the new nitinol SMARTeR stents in patients with biliary obstruction. MATERIALS AND METHODS: Four stents were placed in three patients percutaneously under ultrasound and fluoroscopic guidance. RESULTS: The deployment of the stents was successful in all three patients. All stents maintained their patency and position after short-term follow-up. CONCLUSION: The nitinol SMARTeR stent is useful in the management of patients with biliary obstruction although accurate placement across the ampulla was found to be technically more difficult than with the Wallstent. Larger, long-term follow-up studies are required to evaluate the long-term patency of these new devices.

British Library Electronic Table of Contents (United Kingdom)

Abstract Suspension of solids in stirred reactor is widely used for catalytic reactions, dissolution, etc. Quality of solid suspension is an important parameter required for the reliable design, optimum performance, and scale up of the system. Quality of suspension depends on local characteristics of solid velocity and hold up profiles. The present work was focused on investigating quality of solid suspension using ultrasound velocity profiler (UVP) measurements and CFD simulations. The slip velocity measurements carried out with UVP were used to evaluate different drag correlations used in CFD simulations. Results discussed in this work would be useful for extending the applications of CFD models for simulating large stirred slurry reactors.

British Library Electronic Table of Contents (United Kingdom)

Opinion statement Because a minority of patients with D-transposition of the great arteries are diagnosed in utero by ultrasound, most present after delivery with cyanosis. In the absence of apparent lung disease, cyanotic neonates suspected of having a cardiac lesion should be immediately transferred to an intensive care unit at a pediatric tertiary care center for monitoring, resuscitation, and to define the cardiac anatomy and physiology. A prostaglandin E-1 infusion is usually initiated to maintain ductal patency and promote intra-cardiac mixing. In the past, balloon atrial septostomy (BAS) was routinely performed to enlarge the atrial septal defect and improve intra-cardiac mixing while the infants awaited surgery. Recent literature has reported an increase risk of stroke in neonates ...

British Library Electronic Table of Contents (United Kingdom)

Objective To report the clinical response to image-guided percutaneous cryotherapy (IPC) for the palliative management of localized metastases in patients with gynecologic malignancies. Methods Institutional review board approval and patient consent were obtained. Gynecologic oncology patients were identified from our institution's cryotherapy database from August 2003 to August 2007. Cryotherapy was performed with 2.4?mm diameter probes (Endocare, Irvine, CA) with ultrasound or computerized tomography (CT) guidance under conscious sedation and local anesthesia. Follow-up was conducted by imaging studies and clinical encounters, using Response Evaluation Criteria in Solid Tumors (RECIST criteria). Results Twenty-eight ablation sessions were performed for 41 metastatic foci in 15 patients w...

International Nuclear Information System (INIS)

Fetal MRI examines non-invasively the unborn fetus. Ultrafast MRI sequences effectively suppress fetal motion. Multiple case reports and studies have shown that fetal MRI is particularly helpful in the evaluation of the central nervous system. The high contrast-to-noise ratio, the high spatial resolution, the multiplanar capabilities, the large field of view and the simultaneous visualisation of fetal and maternal structures have proven to be advantageous. Fetal MRI is particularly helpful in the evaluation of the normal and pathological development of the brain. Despite the fact that no side effects have been reported or are to be expected, the use of MRI during pregnancy is still limited to the second and third trimester of pregnancy. Magnetic resonance imaging contrast media are not to be used as it passes the placenta. Ultrasound remains the primary screening modality for fetal pathology; fetal MRI can serve as an adjunct or second-line imaging modality. ...

British Library Electronic Table of Contents (United Kingdom)

Background: Superficial inferior epigastric artery (SIEA) flap has a great advantage over other flaps of the area, that is, readily non-existent donor-site problems. The main reason why the SIEA flap has never been extensively used in breast reconstruction is the small diameter and variable anatomy of its donor artery. This study presents a possibility of enlarging the SIEA diameter using the delay-phenomenon mechanism. Methods: A prospective clinical study of 26 patients was undertaken. Prior to surgery, ultrasound examinations were performed, measuring the diameter of SIEA and the velocity of blood flow in SIEA. The ipsilateral deep inferior epigastric artery (DIEA) was then ligated in all patients who had a measurable SIEA preoperatively. Two weeks later, measurements were repeated. The...

Energy Technology Data Exchange (ETDEWEB)

The techniques in order to measure the depth of defect in weldment and structure accurately have been developed. Many researches have made efforts to develop the methods for the accurate depth sizing of defect. TOFD is known as the most accurate method of various methods for measuring depth sizing. However, there is a possibility to miss defects because of the limitation of beam coverage for the ultrasound incident angle. In this study, the results for detectability and depth sizing using phased array ultrasonic technique for thick body were compared with those of conventional TOFD technique. It was experimentally confirmed that the phased array ultrasonic TOFD technique gives good detectability and accurate depth measurement for the various types of defects. The phased array ultrasonic TOFD technique developed in this study will contribute to increase the inspection reliability in thick component such as the pressure vessel of power generation industry

International Nuclear Information System (INIS)

Purpose: For planning the therapeutic strategies and estimating the prognosis in esophageal cancer, N-staging is very important. To date, MRI still is of minor importance as imaging modality of the mediastinum despite promising developments in the past, like ECG-gating or 'averaging' sequences, e.g. LOTA (Long-term averaging), which facilitate mediastinal and thoracic MR-imaging. In a prospective approach, the value of MRI based N-staging was examined with respect to LOTA-sequences. Material and Methods: Within from weeks prior to esophagectomy, standardized MRI of the esophagus was performed in 15 patients (10 squamous-cell-carcinomas and 5 adenocarcinomas) using a 1.5 T whole body scanner. Imaging quality was classified based on depiction of aortic wall or tracheal wall layers. Criteria for malignant infiltration were a diameter of more than 15 mm or a round appearance of a lymph node together with GD-DTPA enhancement. All data were blinded and separately read by two radiologists. ...

DEFF Research Database (Denmark)

Purpose To investigate the sensitivity and accuracy of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for restaging the mediastinum after induction chemotherapy in patients with non-small-cell lung cancer (NSCLC). Patients and Methods One hundred twenty-four consecutive patients with tissue-proven stage IIIA-N2 disease who were treated with induction chemotherapy and who had undergone mediastinal restaging by EBUS-TBNA were reviewed. On the basis of computed tomography, 58 patients were classified as having stable disease and 66 were judged to have had a partial response. All patients subsequently underwent thoracotomy with attempted curative resection and a lymph node dissection regardless of EBUS-TBNA findings. Results Persistent nodal metastases were detected by using EBUS-TBNA in 89 patients (72%). Of the 35 patients in whom no metastases were assessed by EBUS-TBNA, 28 were found to have residual stage IIIA-N2 disease at ...

Science.gov (United States)

Of 1850 patients with cholelithiasis diagnosed in the past 17 years, 1116 female and 734 male, 598 patients (32.3%) presented with one or more of three major symptoms, i.e., abdominal pain, fever and jaundice, whereas the remainder (67.7%) had none of these symptoms. The proportion of the asymptomatic patients was similar in all age groups, being around 70%. Only 20 per cent of 680 asymptomatic patients, followed for 10 to 17 years (median 13.3 years), developed biliary symptoms. Older patients over 70 years of age had a higher rate of change to the symptomatic group, as compared with younger patients under 70, 29.5% vs. 19.3%, respectively. During this period, carcinoma of the gallbladder developed in one of the asymptomatic patients (0.1%). Oral dissolution therapy was successful in only 4.2 per cent of attempted cases and associated with a recurrence rate of as high as 20%. We conclude that asymptomatic gallstone patients should only be followed up by ultrasound ...

International Nuclear Information System (INIS)

The solid-pseudopapillary tumor (SPT) of the pancreas is a rare type of exocrine pancreatic neoplasm. SPT predominantly affects young women and female children, and is usually discovered incidentally. This tumor is generally benign with a low incidence of malignancy. A 13-year-old girl was admitted to the hospital with a few weeks' history of mild abdominal pain and jaundice. On physical examination, there was no palpable mass. The laboratory tests showed increased SR, CRP, high bilirubin, amylase and lipase serum levels. Ultrasound imaging revealed a solid lesion in the region of the pancreatic head. On MRI, precise tumor localization in the head of the pancreas with pancreatic duct dilatation and compression of the common bile duct were visualized. Pancreaticoduodenectomy and cholecystectomy was performed with good clinical outcome. Microscopic and immunohistochemical studies indicated that tumor cells were typical of SPT without any signs of malignancy. After ...

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Fiber delivered laser pulses emulsify thrombus by mechanical stresses that include a combination of pressure, tension and shear stress. Laser radiation is delivered to the locality of a thrombus and the radiation is absorbed by blood, blood dot, or other present materials. The combination of a leading pressure wave and subsequent vapor bubble cause efficient, emulsification of thrombus. Operating the laser in a low average power mode alleviates potential thermal complications. The laser is operated in a high repetition rate mode to take advantage of ultrasound frequency effects of thrombus dissolution as well as to decrease the total procedure time. Specific parameter ranges for operation are described. The device includes optical fibers surrounding a lumen intended for flow of a cooling agent. The fibers may be arranged concentrically around the lumen to deliver radiation and heat over as large an area as possible. An alternative design approach incorporates the ...

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The diagnostic imaging findings in hepatic amoebiasis and the capabilities of percutaneous drainage have already been described but some debate is open on both diagnosis and treatment. It is reported the experience with the ultrasound (US) and Computed Tomography (CT) studies of the hepatic amoebic abscess and its management. [Italian] I reperti con diagnostica per immagini nell'amebiasi epatica e le possibilita' del drenaggio percutaneo sono stati gia' illustrati; esistono tuttavia controversie sul piano sia diagnostico che terapeutico. Obiettivo di questo lavoro e' quello di riportare l'esperienza personale nella diagnostica con ecografia e tomografia computerizzata (TC) e nel trattamento degli ascessi amebici del fegato.

Science.gov (United States)

The R&D in satellite communications in Korea has been driven mainly by KCC (Korea Communications Commission) but in a small scale compared to Korea space development program organized by MEST (Ministry of Education, Science and Technology). Public and civilian satcom sector R&D has been led mainly by ETRI with small/medium companies contrary to rare investment in private sector while military sector R&D has been orchestrated by ADD with defense industry. By the COMS (Communication, Ocean and Meteorological Satellite) experimental Ka-band payload, Korea pursues a space qualification of own technology for national infrastructure evolution as well as industrialization of space R&D results. Once COMS launched and space qualified in 2009, subsequent application experiments and new technology R&D like UHDTV will entail service and industry promotion. The payload technology is expected for the next Korean commercial satellites or for new OBP satellites. The COMS ground ...

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In Chapter 2 the evaluation methods of input ground motions for seismic design are summarized and especially the empirical and/or stochastic Green's function method is introduced in order to calculate the broadband strong motions based on the physically reliable fault model. Then the evaluation procedure is applied to the Ulsan fault system near which Wolsung nuclear power plant is located. In chapter3, the PSHA case studies for Wolsung NPP site are performed, in which multi attenuation equations of earthquake motions are adopted. Moreover, the results of seismic hazard evaluation for eight sites in Korea are shown. In addition, the contents of two literatures on seismic hazard evaluation are introduced. In chapter 4, isolation devices for emergency diesel generator have been studied. The models for friction-pendulum system, high damping rubber bearing and natural rubber bearing are developed and implemented in the TDAP-III. Then, the rubber bearings as ...

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During the previous 9 months the major part of the Fusion-FEM has been constructed. The 2 MV Insulated Core Transformer, the electron gun, the accelerator, the focusing lenses and the undulator have been tested on-site. In the present - temporary - set-up, the electron beam line consists of a 12 A, 80 keV thermionic electron gun, a 2 MeV dc accelerator, beam transport optics, the undulator and a collector. The gun is mounted in the high voltage terminal, which is now at -2 MV, and the undulator and mm-wave system am at ground potential outside the SF{sub 6}-filled pressure tank. This so-called inverse set-up allows easy access to the larger part of the beam line, the undulator and the mm-wave system, which is important in the conditioning phase. The decelerator and depressed collector am not yet installed. The design of the electron beam line has been optimised using the GPS particle-tracking code and the TOSCA code. The TOSCA code is used for accurate field calculations of the ...

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To assess the feasibility of transluminal radiofrequency thermal ablation using a stent-type electrode and to determine, by means of in-vivo and in-vivo animal studies, the appropriate parameters. In-vivo: the radiofrequency electrode used was a self-expandable nitinol stent with 1cm insulated ends. A stent was placed in the portal vein of bovine liver, and ablations at target temperatures of 70, 80, 90, and 100 .deg. C were performed. Ablated sizes were measured longitudinally. In vivo: four mongrel dogs were anesthetized, and a stent was inserted in the common bile duct under fluoroscopic guidance through an ultrasound-guided gall bladder puncture site. The ablation temperature was set at 80 .deg. C, and each dog underwent proximal and distal esophageal ablations lasting 12 minutes. They were sacrificed immediately. In-vivo: ablated sizes showed significant correlation with target temperatures (r>0.04; p<0.05). Although most lesions were fusiform, ...

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In a prospective study 102 patients with malignant tumors of the tongue, oropharynx, hypopharynx, and larynx were staged by means of MRI. Special attention was directed at those tumour extensions that could influence the treatment strategy. The MR findings were correlated with the results of palpation, endoscopy, ultrasound, computerised tomography and histopathological findings. MRI showed a good delineation of pT{sub 2} to pT{sub 4} tumours. However, visualisation of small tumours in the soft palate, the tonsils, the pyriform sinuses and vocal cords was difficult. In conclusion our results suggest that in addition to endoscopy MRI is a valuable tool for the examination of tumours of tongue, oropharynx, hypopharynx and larynx. (orig.) [Deutsch] In einer prospektiven Studie wurden 102 Patienten mit malignen Tumoren der Mundhoehle, des Oro- und Hypopharynx sowie des Larynx mit der Mgnetresonanztomographie (MRT) untersucht, wobei besonders Wert auf die Bestimmung ...

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The present investigation was aimed to assess the usefulness of biliary agents scintigraphy in the diagnosis of hepatocellular carcinoma (HCC) and to ascertain the relationship between the uptake of these agents and the degree of HCC differentiation. Forty-four patients with this hepatic cancer were included in the study. Liver scans were performed 20 min and 3 hr after the administration of 99mTc diisopropyliminodiacetic acid (DISIDA). DISIDA scintigraphy could not be assessed in six cases. In 16 (42%) out of the remaining 38 patients, the tumor exhibited equal or greater radioactivity uptake than the surrounding liver. In six out of these 16 patients, tumor uptake was apparent in the early and delayed hepatic scans, while in the other ten subjects radioactivity uptake by the HCC could only be detected in the 3-hr delayed scans. In the remaining 22 patients, HCC appeared as a cold area. Tumor location by this technique did not differ from that observed by 99mTc-sulfur colloid scan or ...

International Nuclear Information System (INIS)

The purpose of this study was to evaluate the safety and efficacy of percutaneous ultrasound (US)-guided radiofrequency ablation (RFA) in patients with intrahepatic cholangiocarcinoma (ICCA) in a small, nonrandomized series. From February 2004 to July 2008, six patients (four men and two women; mean age 69.8 years [range 48 to 83]) with ICCA underwent percutaneous US-guided RFA. Preintervetional transarterial embolization was performed in two cases to decrease heat dispersion during RFA in order to increase the area of ablation. The efficacy of RFA was evaluated using contrast-enhanced dynamic computed tomography (CT) 1 month after treatment and then every 3 months thereafter. Nine RFA sessions were performed for six solid hepatic tumors in six patients. The duration of follow-up ranged from 13 to 21 months (mean 17.5). Posttreatment CT showed total necrosis in four of six tumors after one or two RFA sessions. Residual tumor was observed in two patients with larger ...

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Purpose: The purpose of this research was to identify the extent and scope of changes to radiography practice. Method: Questionnaires were sent to radiology managers at acute National Health Service (NHS) hospitals in 2000 as a follow-up to an initial survey conducted in 1998. Information was sought on region, teaching/non-teaching status, the nature of extended role tasks undertaken and the year in which these tasks were first undertaken. Results: Some 172 questionnaires were returned from a total of 253 dispatched (68%). In 161 hospitals radiographers administered intravenous injections and performed barium enemas in 119 hospitals, while a red-dot system was in operation in 141 hospitals. Reporting by radiographers had increased since 1998. Replies indicated that, at 124 hospitals, radiographers were reporting in ultrasound. Skeletal reporting was the second most-frequently-reported activity, with 63 hospitals indicating that radiographers reported in this ...

International Nuclear Information System (INIS)

Background: Pleural biopsy and cytology are standard procedures for the investigation of pleural disease. Recent medical literature has suggested that image-guided pleural biopsy shows improved sensitivity for the diagnosis of pleural malignancy, when compared with the more commonly performed reverse bevel needle biopsy such as Abrams' needle. In our centre there has been an increasing trend towards performing image-guided pleural biopsies, and to our knowledge there is no large published series documenting the complication rate and diagnostic yield. Methods: The radiology and pathology databases were searched for all image-guided [computed tomography (CT) and ultrasound (US)] pleural biopsies from January 2001 to December 2004. All imaging and histology were reviewed, and final diagnostic information about patients was obtained from the respiratory multidisciplinary team database and patient notes. A record was made of complications following biopsy, presence of ...

International Nuclear Information System (INIS)

Objective was to assess the accuracy of a single versus combined use of ultrasound (US) or computed tomography (CT) in the localization of diseased parathyroid glands. Forty-one patients with hyper-parathyroidism treated surgically between January 2000 to December 2005 at Jordan University Hospital, Amman, Jordan were included in this study. Preoperative ultrasonographic and CT findings were reviewed and compared to the intraoperative and pathologic diagnosis of diseased parathyroid glands. The mean age of patients was 46 years (range 16-70; 15 males and 26 females). Parathyroid adenoma was confirmed in 33 patients and hyperplasia of the parathyroid glands in 8 patients. Preoperative evaluation was carried out in 32 patients (CT scan) and in 23 patients (US). In 18 cases, the diagnosis of parathyroid disease was based on CT findings alone and in 9 patients the diagnosis was based on a single US finding. Combined CT and US evaluation was carried out in 14 cases and ...

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Purpose: For planning the therapeutic strategies and estimating the prognosis in esophageal cancer, N-staging is very important. To date, MRI still is of minor importance as imaging modality of the mediastinum despite promising developments in the past, like ECG-gating or 'averaging' sequences, e.g. LOTA (Long-term averaging), which facilitate mediastinal and thoracic MR-imaging. In a prospective approach, the value of MRI based N-staging was examined with respect to LOTA-sequences. Material and Methods: Within from weeks prior to esophagectomy, standardized MRI of the esophagus was performed in 15 patients (10 squamous-cell-carcinomas and 5 adenocarcinomas) using a 1.5 T whole body scanner. Imaging quality was classified based on depiction of aortic wall or tracheal wall layers. Criteria for malignant infiltration were a diameter of more than 15 mm or a round appearance of a lymph node together with GD-DTPA enhancement. All data were blinded and separately read by ...

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Minimally invasive thermotherapies for focal tissue destruction on the basis of laser-, microwave-, focused ultrasound-, or cryogeninduced changes of tissue temperature represent an alternative to surgical tissue ablation, particularly in the treatment of tumors. The thermotherapy modalities listed necessitate indirect guidance and monitoring, since they often do not lend themselves to immediate visual control. In the brain, in head and neck tumors, in the liver, and in the prostate, MRI reliably and accurately delineates both the positions of interstitial thermotherapy applicators and - in contrast-enhanced, T1-weighted images - the perfusion defects in tissue necrosis induced by thermotherapy. The transfer of results of in-vitro and in-vivo model studies to assess interstitial temperature and lesion development during thermotherapy to the actual treatment of patients, however, is still in an initial phase. Further development of both rapid MRI sequences and MRI ...

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Computed Tomography (CT) and, more recently, ultrasound (US), have proved excellent tools for quantifying adipose tissue distribution. Body fat distribution is an important factor in the treatment of obesity and its complications. In this work it is investigated the correlation between CT and US measurements in pediatric obesity. Forty obese children and adolescents aged 4.1-14.8 years were submitted to CT and US. Intra-abdominal, subcutaneous and total body fat were calculated (in cm{sup 2}), with the CT image analysis software. The rectus muscle-spine and rectus muscle-aorta distances, as indicative of visceral fat thickness, were measured on US images with(out) compression. The distance between skin fat and fat-rectus muscle interfaces was measured as subcutaneous fat thickness. US-CT findings have been compared with other morphometric variables-i.e., patient's (ideal) body weight and skin fold measures. A statistically significant correlation was found ...