891 research outputs found

    Temporal characterization of individual harmonics of an attosecond pulse train by THz streaking

    Full text link
    We report on the global temporal pulse characteristics of individual harmonics in an attosecond pulse train by means of photo-electron streaking in a strong low-frequency transient. The scheme allows direct retrieval of pulse durations and first order chirp of individual harmonics without the need of temporal scanning. The measurements were performed using an intense THz field generated by tilted phase front technique in LiNbO_3 . Pulse properties for harmonics of order 23, 25 and 27 show that the individual pulse durations and linear chirp are decreasing by the harmonic order

    Primary care in Malta : the patients’s expectations in 2009

    Get PDF
    Given the strong literature base to support the positioning of Primary Care at the core of a sustainable National Health Service, this study examines what the Maltese general public prefer, and expect, from their family doctor, and explores their preferred systems of care changes.peer-reviewe

    ‘I am worthless and kind’: the specificity of positive and negative self-evaluation in adolescent depression

    Get PDF
    Objectives: Adolescence represents a critical phase when the concept of self is developed and consolidated. Depressed adolescents globally endorse more negative and fewer positive self-descriptive words compared with non-depressed adolescents. Yet the methods used have not allowed for more detailed exploration of the specific content of these self-endorsements. Methods: Adolescents, aged 12-18 years, were recruited from the community (n = 204) and from a child and adolescent mental health service in the UK (n = 87). Participants completed measures of depression and a self-description questionnaire which included 12 positive and 12 negative self-descriptive adjectives. Results: As expected, we replicated previous findings that depressive symptoms are associated with global positive and negative self-endorsements. The difference between mean scores was examined for each adjective. Depressed adolescents endorsed all negative adjectives more highly relative to community adolescents; ratings of ‘worthless’ and ‘useless’ had the biggest difference between community and depressed adolescents. Surprisingly, a group of positive prosocial self-descriptors were endorsed equally by depressed and community adolescents and were not associated with severity of depressive symptoms. Conclusions: Although depressed adolescents endorsed more negative descriptions of themselves than community adolescents, positive self-endorsements related to their relationships with other people were not impaired

    Reverse Foam Sclerotherapy of the Great Saphenous Vein with Sapheno-Femoral Ligation Compared to Standard and Invagination Stripping: a Prospective Clinical Series

    Get PDF
    AbstractObjectivesComparison of Reverse Foam Sclerotherapy of the great saphenous vein (GSV) combed with sapheno-femoral junction (SFJ) ligation to standard (Babcock) stripping and invagination (Pin) stripping in a prospective clinical series.DesignProspective clinical series.Materials and methods90 consecutive limbs of 82 patients with incompetence of the GSV resulting in varicose veins were prospectively randomised into 3 groups of 30, treated by SFJ ligation and either reverse foam sclerotherapy, standard stripping or invagination stripping of the GSV. Outcomes were assessed post-operatively and at 2-weeks follow-up. Peri-operative blood loss (24 hrs), analgesic requirement, bruising and residual varicosities were assessed. Bruising was assessed by both patients and independent assessors using questionnaires.ResultsSFJ ligation plus reverse foam sclerotherapy of the GSV was associated with significantly less blood loss, bruising and post-op discomfort than either of the stripping techniques. (p<0.001, Mann-Whitney)ConclusionStandard stripping of the GSV and invagination stripping are not associated with major discomfort and problems in the early post-operative period. SFJ ligation and GSV reverse foam sclerotherapy yielded greater patient satisfaction with less post-op bruising and discomfort and reduced analgesic requirements

    Ex vivo determination of bone tissue strains for an in vivo mouse tibial loading model

    Get PDF
    AbstractPrevious studies introduced the digital image correlation (DIC) as a viable technique for measuring bone strain during loading. In this study, we investigated the sensitivity of a DIC system in determining surface strains in a mouse tibia while loaded in compression through the knee joint. Specifically, we examined the effect of speckle distribution, facet size and overlap, initial vertical alignment of the bone into the loading cups, rotation with respect to cameras, and ex vivo loading configurations on the strain contour maps measured with a DIC system.We loaded tibiae of C57BL/6 mice (12 and 18 weeks old male) up to 12N at 8N/min. Images of speckles on the bone surface were recorded at 1N intervals and DIC was used to compute strains. Results showed that speckles must have the correct size and density with respect to the facet size of choice for the strain distribution to be computed and reproducible. Initial alignment of the bone within the loading cups does not influence the strain distribution measured during peak loading, but bones must be placed in front of the camera with the same orientation in order for strains to be comparable. Finally, the ex vivo loading configurations with the tibia attached to the entire mouse, or to the femur and foot, or only to the foot, showed different strain contour maps.This work provides a better understanding of parameters affecting full field strain measurements from DIC in ex vivo murine tibial loading tests

    Tratamiento de fracturas toracolumbares: nuestra experiencia en el periodo 2000-2003. Protocolo de actuación

    Get PDF
    Presentamos una revisión de los resultados obtenidos en pacientes intervenidos de fracturas tóraco-lumbares durante los años 2000 a 2003, en ambos inclusive, por el servicio de Traumatología y Cirugía Ortopédica del Hospital Universitario Virgen de las Nieves de Granada; así como el protocolo seguido en el manejo diagnóstico-terapéutico de este tipo de pacientes. Las fracturas más frecuentes fueron en L1 y del tipo A3 de la clasificación AO. La vía de abordaje más utilizada fue la posterior (138 casos). En 132 casos se instrumentó la vértebra fracturada y en 39 casos fue necesaria la descompresión. El índice sagital medio preoperatorio fue de 17,5º y el postoperatorio de 3,5º. La pérdida de altura vertebral preoperatoria fue del 52% y del 14% al final del tratamiento. En 39 pacientes con déficit neurológico se realizó descompresión. En el 79% de los casos los resultados fueron excelentes y en el resto regulares o malos.We present the results of surgical treatment in patients with thoraco-lumbar fractures operated on between the years 2000 and 2003 at the Orthopedic and Traumatology Department of the hospital Virgen de las Nieves Hospital of Granada, Spain. The diagnosis and therapeutic protocol of this type of patients is also evaluated. A3 type from AO classification fracture of L1, was the most frequent injury. Posterior surgical approach of the spine was mainly used (138 cases), in 132 cases the fracture was stabilized by means of internal fixation and 39 cases required decompression of the lumbar canal. The average sagital index was 17,5º preoperative and 3,5º after surgery. The average loss of height was 52% preoperative and 14% at the end of treatment. In 39 surgical decompression was indicated for neurological impairment. Excellent results were obtained in 79% of the cases, the rest were fair and poor

    Search for the Hypothetical pi -> mu x Decay

    Full text link
    The KARMEN collaboration has reported the possible observation of a hitherto unknown neutral and weakly interacting particle x, which is produced in the decay pi -> mu + x with a mass m(x) = 33.9 MeV. We have searched for this hypothetical decay branch by studying muons from pion decay in flight with the LEPS spectrometer at the piE3 channel at PSI and find branching ratios BR(pi- to mu- anti-x) < 4e-7 and BR(pi+ to mu+ x) < 7e-8 (95\% C.L.). Together with the limit BR > 2e-8 derived in a recent theoretical paper our result would leave only a narrow region for the existence of x if it is a heavy neutrino.Comment: 10 pages, TeX (uses epsf), 3 Postscript figures uu-encode

    Evidence for a two component magnetic response in UPt3

    Get PDF
    The magnetic response of the heavy fermion superconductor UPt_3 has been investigated on a microscopic scale by muon Knight shift studies. Two distinct and isotropic Knight shifts have been found for the field in the basal plane. While the volume fractions associated with the two Knight shifts are approximately equal at low and high temperatures, they show a dramatic and opposite temperature dependence around T_N. Our results are independent on the precise muon localization site. We conclude that UPt_3 is characterized by a two component magnetic response.Comment: 5 pages, 4 figure
    • …
    corecore