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We present experimental data and a complete theoretical description of the magneto-optical contributions to the complex refractive index in the extreme ultraviolet (XUV) range covering the 3p resonances of Fe, Co, and Ni. The direct comparison of the two allows us to conclude that many-body corrections to the ground state and local field effects are crucial for an accurate description of M-edge spectra. Our results are relevant for investigation of static magnetization, via XUV spectroscopy of multielement systems, as well as the dynamics of magnetization, as needed in the study of femtomagnetism and spintronics.
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We present an optically induced remanent photostriction in BiFeO_{3}, resulting from the photovoltaic effect, which is used to modify the ferromagnetism of Ni film in a hybrid BiFeO_{3}/Ni structure. The 75% change in coercivity in the Ni film is achieved via optical and nonvolatile control. This photoferromagnetic effect can be reversed by static or ac electric depolarization of BiFeO_{3}. Hence, the strain dependent changes in magnetic properties are written optically, and erased electrically. Light-mediated straintronics is therefore a possible approach for low-power multistate control of magnetic elements relevant for memory and spintronic applications.
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We monitor how destructive interference of undesired phonon frequency components shapes a quasi-monochromatic hypersound wavepacket spectrum during its local real-time preparation by a nanometric transducer and follow the subsequent decay by nonlinear coupling. We prove each frequency component of an optical supercontinuum probe to be sensitive to one particular phonon wavevector in bulk material and cross-check this by ultrafast x-ray diffraction experiments with direct access to the lattice dynamics. Establishing reliable experimental techniques with direct access to the transient spectrum of the excitation is crucial for the interpretation in strongly nonlinear regimes, such as soliton formation.
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We investigate coherent phonon propagation in a thin film of ferroelectric PbZr(0.2)Ti(0.8)O(3) (PZT) by ultrafast x-ray diffraction experiments, which are analyzed as time-resolved reciprocal space mapping in order to observe the in- and out-of-plane structural dynamics, simultaneously. The mosaic structure of the PZT leads to a coupling of the excited out-of-plane expansion to in-plane lattice dynamics on a picosecond time scale, which is not observed for out-of-plane compression.
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Current computed tomography (CT) shielding practices are largely based on calculations of scattered radiation emitted from an acrylic head or body phantom, such as the Computed Tomography Dose Index (CTDI) phantom, or anthropomorphic phantoms of these two anatomical categories. This report considers the difference in scattered air kerma or dose from phantom models, to actual patient scatter under a variety of clinical scan conditions. Empirical patient scatter measurements recorded at different positions around the gantry, for 3 different CT scanners, resulted in average patient scatter fractions per unit Dose Length Product (DLP: mGy cm) at 1 m from the isocentre of 0.09 ± 0.03 and 0.17 ± 0.04 µGy (mGy cm)-1 for head and body scans respectively. For the purposes of shielding design and scattered dose estimates to staff it is recommended that a single standard deviation be applied to these averages in the continued interest of conservatism. These values are reasonably comparative to the widely published scatter fractions by the National Council of Radiological Protection using the CTDI phantom, and the British Institute of Radiology using head and body anthropomorphic phantoms.
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Protección Radiológica , Humanos , Fantasmas de Imagen , Dosis de Radiación , Protección Radiológica/métodos , Tomógrafos Computarizados por Rayos X , Tomografía Computarizada por Rayos XRESUMEN
In this study we report on the investigation of epitaxially grown Sb2Te3 by employing Fourier-Transform transmission Spectroscopy (FTS) with laser-induced Coherent Synchrotron Radiation (CSR) in the Terahertz (THz) spectral range. Static spectra in the range between 20 and 120 cm-1 highlight a peculiar softening of an in-plane IR-active phonon mode upon temperature decrease, as opposed to all Raman active modes which instead show a hardening upon temperature decrease in the same energy range. The phonon mode softening is found to be accompanied by an increase of free carrier concentration. A strong coupling of the two systems (free carriers and phonons) is observed and further evidenced by exciting the same phonon mode at 62 cm-1 within an ultrafast pump-probe scheme employing a femtosecond laser as pump and a CSR single cycle THz pulse as probe. Separation of the free carrier contribution and the phonon resonance in the investigated THz range reveals that, both damping of the phonon mode and relaxation of hot carriers in the time domain happen on the same time scale of 5 ps. This relaxation is about a factor of 10 slower than expected from the Lorentz time-bandwidth limit. The results are discussed in the framework of phonon scattering at thermal and laser induced transient free carriers.
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Lead attenuation characteristic curves are often consulted in premises radiation shielding assessments employing the non-destructive testing (NDT) method. This study developed lead attenuation characteristics mathematical models for the radionuclide Co-57. These models take into account the statistical variation of the attenuation characteristics. The results are a set of equations that a NDT assessor can use to predict the range of transmission factors for the NDT measurement or, using the inverse functions, to gauge the lead equivalence (with the associated uncertainty) of a radiation barrier. This study showed that the combined effect of types of statistical variations can form an uncertainty region on the transmission characteristics such that the relative uncertainty decreases for values of lead mass per unit area up to approximately 20 kg/m2 and 15 kg/m2 for the Ludlum 18 and Ludlum 2241-2 survey meters respectively but thereafter increases.
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Plomo/química , Modelos Químicos , Protección Radiológica/métodos , Simulación por Computador , Relación Dosis-Respuesta en la Radiación , Dosis de Radiación , Dispersión de RadiaciónRESUMEN
BACKGROUND: Although there have been reports of injury rates in men's World Cup rugby, there has been no research into injury rates in women's international rugby. OBJECTIVE: To determine the rate of injury at the 2006 Women's Rugby World Cup (WRWC). METHODS: All participating teams in the 2006 WRWC were enrolled prospectively in this study. Healthcare workers for each team collected data on training and game exposure and information on injuries. RESULTS: 55 players (16%) sustained at least one injury (10.0/1000 player hours); 4 players (1%) sustained two injuries. 45 injuries occurred during games (37.5/1000 player hours) and 14 injuries occurred during practice (12.5/1000 player hours), a statistically significant difference (RR = 12.5, 95% CI 6.9 to 22.8). The injury rate was 39.3/1000 player hours for the forwards and 42.2/1000 player hours for the backs (RR = 1.3, 95% CI 0.7 to 2.3). The front row had the highest injury rate (62.5/1000 player hours). 63.6% of injuries occurred during the tackle. Most injuries occurred to the neck, knee and head/face. The majority of injuries were sprains, muscle injuries and contusions. There were five fractures during the event and four reported concussions. CONCLUSION: Female players sustained a considerable rate of injury during the 2006 WRWC. Backs had a slightly higher rate of injury than forwards, but the players most often injured were in the front row. The neck/cervical spine and knee were the most commonly injured regions, followed by the head and face. This is the first study to examine injury rates in female rugby players at a World Cup and reports valuable data in this population.
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Fútbol Americano/lesiones , Adulto , Traumatismos en Atletas/epidemiología , Conducta Competitiva/fisiología , Femenino , Humanos , Puntaje de Gravedad del Traumatismo , Estudios ProspectivosRESUMEN
This position paper was produced by a working party set up by the Radiology Special Interest Group of the ACPSEM in 2001. It is designed to give the consensus view of College members in Australia and New Zealand on the nature and frequency of tests which should be performed on diagnostic x-ray equipment to maintain adequate quality control of imaging performance and radiation safety. Tests on mammographic equipment have been excluded having been covered in a previous ACPSEM position paper (Australas Phys Eng Sci Med, 24(3):107-131, 2001). Detailed descriptions of test procedures are not given but it is intended that a series of workbooks should be produced giving College recommended test methods for each imaging modality. The recommendations are produced here in an easy-to-read, tabular form giving the nature and purpose of each test and the implications of non-compliance with regard to image quality and radiation safety.
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Análisis de Falla de Equipo/métodos , Análisis de Falla de Equipo/normas , Guías como Asunto , Garantía de la Calidad de Atención de Salud/métodos , Garantía de la Calidad de Atención de Salud/normas , Radiografía/instrumentación , Radiografía/métodos , Australasia , Adhesión a DirectrizRESUMEN
To further elucidate the role of tumor necrosis factor alpha (TNF alpha) in cell adhesion, we investigated the effect of TNF alpha on the expression of surface adhesive protein. After treatment with TNF alpha for 1 h, the increased expression of surface adhesive proteins (beta subunit) was observed on granulocytes but not on monocytes or lymphocytes. The expression of Mac-1 (3,4-fold increase) was consistently enhanced more than p 150,95 (1.4-fold increase) and LFA-1 expression was unchanged. Dose-response and time course studies indicated a parallel relationship between TNF alpha-increased expression of surface adhesive proteins and TNF alpha-induced granulocyte adhesion. The anti-inflammatory drug Dexamethasone suppressed both TNF alpha-induced granulocyte adhesion and TNF alpha-induced expression of surface adhesive proteins. The inhibition of granulocyte adhesion correlated with the reduction of surface adhesive protein expression. The data suggest that one contributing factor in the mechanism by which Dexamethasone inhibited TNF alpha-induced granulocyte adhesion may be diminished expression of surface adhesive proteins.
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Antígenos de Superficie/biosíntesis , Adhesión Celular/efectos de los fármacos , Leucocitos/efectos de los fármacos , Factor de Necrosis Tumoral alfa/farmacología , Dexametasona/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Leucocitos/análisis , Leucocitos/citología , Antígeno-1 Asociado a Función de Linfocito , Antígeno de Macrófago-1 , Neutrófilos/citología , Neutrófilos/efectos de los fármacos , Proteínas Recombinantes/farmacología , Estimulación QuímicaRESUMEN
The effects of tumor necrosis factor alpha (TNF-alpha) on human polymorphonuclear (PMN) cells were investigated. We found that 125I-TNF-alpha bound specifically to high-affinity receptors on PMN cells. At 4 degrees C, the binding occurred rapidly and reached steady state after 20 min. The Scatchard plot showed a single class of high-affinity receptors with approximately 2200 receptors/cell and a dissociation constant of 2 x 10(-10) M. There was a linear relationship between TNF-alpha binding and TNF-alpha-induced PMN cell adherence. The concentration of TNF-alpha required to achieve approximately 50% of maximum binding was also approximately the concentration required to reach 50% cell adherence. Auranofin was shown to inhibit TNF-alpha-induced PMN cell adherence at a dose of 5-10 micrograms/ml. This inhibitory effect was not due to the inhibition of TNF-alpha binding to PMN cells by the drug. These observations may have clinical implications.
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Neutrófilos/metabolismo , Receptores de Superficie Celular/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Auranofina/farmacología , Adhesión Celular/efectos de los fármacos , Humanos , Neutrófilos/fisiología , Receptores del Factor de Necrosis TumoralRESUMEN
The activities of trovafloxacin and ciprofloxacin against 38 strains of non-beta-lactamase-producing enterococci, resistant to ampicillin, 34 strains susceptible to ampicillin, and 3 vancomycin-resistant enterococci were studied. Trovafloxacin was more active than ciprofloxacin against all the enterococci studied. The ampicillin-resistant strains were more susceptible than the ampicillin-susceptible strains to both agents. The effect of combining trovafloxacin with gentamicin, ampicillin-sulbactam, novobiocin, rifampin, teicoplanin, and vancomycin was determined for 17 strains by the checkerboard method. An additive effect by inhibition was seen with all antibiotics studied. The results by killing varied with the different agents studied. Gentamicin, ampicillin-sulbactam, and novobiocin produced an additive killing effect with trovafloxacin. Reduced killing was seen when rifampin, vancomycin, or teicoplanin were added to trovafloxacin.
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Antibacterianos/farmacología , Antiinfecciosos/farmacología , Ciprofloxacina/farmacología , Enterococcus faecalis/efectos de los fármacos , Enterococcus/efectos de los fármacos , Fluoroquinolonas , Naftiridinas/farmacología , Ampicilina/farmacología , Resistencia a la Ampicilina , Antibióticos Antituberculosos/farmacología , Relación Dosis-Respuesta a Droga , Farmacorresistencia Microbiana , Sinergismo Farmacológico , Quimioterapia Combinada/farmacología , Gentamicinas/farmacología , Humanos , Pruebas de Sensibilidad Microbiana , Novobiocina/farmacología , Rifampin/farmacología , Sulbactam/farmacología , Teicoplanina/farmacología , Vancomicina/farmacologíaRESUMEN
Klebsiella pneumoniae colonization of 53 patients with spinal cord injury was studied. Cultures of multiple body sites from patients, the environment, food, and hospital personnel were obtained. K. pneumonaie was cultured from one or more body sites in 46% of male patients. Significant bacteriuria was found in 10% of male patients. Positive cultures of the urethra and perineum for K. pneumoniae were significantly associated with the use of the external condom catheter (p less than 0.05, Fisher's exact test). K. pneumoniae colonization increased with length of stay in the hospital. Serotype 64, the predominant serotype found, was isolated only from patients who had been in the hospital for at least 4 wk and primarily in those patients using the external condom catheter. Urinary drainage bags were frequently colonized with K. pneumoniae at a time when the patients did not have significant bacteriuria. Colonized male patients were found to be the primary reservoir of K. pneumoniae and may serve as the major source for cross-contamination.
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Klebsiella pneumoniae/aislamiento & purificación , Traumatismos de la Médula Espinal/microbiología , Femenino , Humanos , Masculino , Pene/microbiología , Perineo/microbiología , Serotipificación , Caracteres Sexuales , Uretra/microbiología , Cateterismo UrinarioRESUMEN
OBJECTIVES: The objective of this study was to establish the identity of a protein found in high concentrations in squamous metaplasia of the bladder. DESIGN AND METHODS: The protein was isolated and subjected to a series of physical, chemical, and catalytic studies. RESULTS: In the normal urothelium the protein was confined to a juxtanuclear pattern on the luminal side of the umbrella cells; in squamous metaplasia and squamous cell carcinoma the protein was increased and exhibited a more diffuse intracellular distribution. The protein was found to be identical to triosephosphate isomerase (EC 5.3.1.1; TPI) with respect to its immunological properties, native and subunit molecular weights, electrophoretic mobility, catalytic activity, and amino acid sequence. CONCLUSIONS: While the basis for the altered distribution of TPI remains to be established, the increased amounts of the protein in urine or bladder tissue may be indicative of squamous metaplasia, squamous cell carcinoma, or other bladder injuries.
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Carcinoma de Células Escamosas/enzimología , Triosa-Fosfato Isomerasa/aislamiento & purificación , Enfermedades de la Vejiga Urinaria/enzimología , Neoplasias de la Vejiga Urinaria/enzimología , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/orina , Catálisis , Línea Celular , Femenino , Humanos , Masculino , Triosa-Fosfato Isomerasa/orina , Enfermedades de la Vejiga Urinaria/patología , Enfermedades de la Vejiga Urinaria/orina , Neoplasias de la Vejiga Urinaria/patología , Neoplasias de la Vejiga Urinaria/orinaRESUMEN
The relationship of pH and moisture to Pseudomonas aeruginosa and Klebsiella pneumoniae colonization of the perineal skin was studied in male patients with spinal cord injury. The increased pH of the perineal skin was significantly associated with the presence of P. aeruginosa but not other bacterial species. No correlation between colonization and moisture or pH and moisture was found. An antiperspirant produced a significant reduction in the number of total aerobic bacteria, total gram-negative bacilli, P. aeruginosa and K. pneumoniae over a 24-h period. Long-term use of the antiperspirant for 10 days did not alter the persistence of P. aeruginosa of the same serotypes on the perineum.
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Astringentes/farmacología , Klebsiella pneumoniae/efectos de los fármacos , Perineo/microbiología , Pseudomonas aeruginosa/efectos de los fármacos , Piel/microbiología , Traumatismos de la Médula Espinal/microbiología , Adolescente , Adulto , Femenino , Humanos , Humedad , Concentración de Iones de Hidrógeno , Klebsiella pneumoniae/crecimiento & desarrollo , Masculino , Persona de Mediana Edad , Pseudomonas aeruginosa/crecimiento & desarrollo , Factores de TiempoRESUMEN
Computed dental radiography is a filmless system of dental x-ray imaging. It features multiple sensors with receptive areas and image quality that approach the size and resolution of film. The system is able to match the utility of film on levels such as multiple-sized images and printing output. It approaches film in quality of image and diagnostic capacity. In features such as speed of image acquisition, reduction in radiation dose, retrieval of data, and organization and storage of images, the computed dental radiography system surpasses traditional x-ray film.
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Interpretación de Imagen Radiográfica Asistida por Computador/instrumentación , Radiografía Dental/instrumentación , Procesamiento de Señales Asistido por Computador/instrumentación , Estudios de Evaluación como Asunto , Humanos , Radiografía Dental/métodos , Reproducibilidad de los Resultados , SemiconductoresRESUMEN
We present an experimental setup of a laser-driven x-ray plasma source for femtosecond x-ray diffraction. Different normalization schemes accounting for x-ray source intensity fluctuations are discussed in detail. We apply these schemes to measure the temporal evolution of Bragg peak intensities of perovskite superlattices after ultrafast laser excitation.
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Rayos Láser , Gases em Plasma/química , Difracción de Rayos X/instrumentación , Compuestos de Calcio/química , Fenómenos Ópticos , Óxidos/química , Factores de Tiempo , Titanio/químicaAsunto(s)
Proteínas Portadoras/metabolismo , Proteínas del Ojo/aislamiento & purificación , Retina/metabolismo , Retinitis Pigmentosa/genética , ADN Complementario , Proteínas del Ojo/metabolismo , Plásmidos , Empalme del ARN , Saccharomyces cerevisiae/genética , Técnicas del Sistema de Dos Híbridos , beta-Galactosidasa/genéticaRESUMEN
A 67-year-old male patient with a pancreatic carcinoma and hepatic metastases was admitted with progressive dyspnea and anuria. Previously he had received five cycles of a palliative chemotherapy with gemcitabine and responded well with a reduction of the tumor mass. The laboratory results showed a distinct anemia, thrombocytopenia, an increase in creatinine and lactate dehydrogenase levels. With an additional finding of 21 per mille fragmentocytes in the periphery blood smear, we diagnosed a thrombotic microangiopathy (TMA). Until now the literature lacks well-defined therapy standards for this known but rare condition of gemcitabine. In a few case reports addressing the related microangiopathy of thrombotic thrombocytopenic purpura (TTP), which is characterised by a significant reduction of the von Willebrand factor (vWF) cleaving serum protease ADAMTS-13, encouraging results have been achieved by an immediate plasma exchange. Though ADAMTS-13 activity was not relevantly reduced in our patient, we still observed a rapid improvement of the clinical features as well as of LDH, thrombocytes and fragmentocytes under plasma exchange. The patient was discharged after one month in good clinical condition. Interestingly, during follow-up for further 21 months we found a continued stable status of the pancreatic carcinoma without any cytostatic therapy. In summary, this case provides evidence that the use of plasma exchange therapy in gemcitabine-associated TMA is justified.