284 research outputs found
Thermal relaxation of magnetic clusters in amorphous Hf_{57}Fe_{43} alloy
The magnetization processes in binary magnetic/nonmagnetic amorphous alloy
Hf_{57}Fe_{43} are investigated by the detailed measurements of magnetic
hysteresis loops, temperature dependence of magnetization, relaxation of
magnetization and magnetic ac susceptibility, including a nonlinear term.
Blocking of magnetic moments at lower temperatures is accompanied with the slow
relaxation of magnetization and magnetic hysteresis loops. All of the observed
properties are explained with the superparamagnetic behaviour of the single
domain magnetic clusters inside the nonmagnetic host, their blocking by the
anisotropy barriers and thermal fluctuation over the barriers accompanied by
relaxation of magnetization. From magnetic viscosity analysis based on thermal
relaxation over the anisotropy barriers it is found out that magnetic clusters
occupy the characteristic volume from 25 up to 200 nm3 . The validity of the
superparamagnetic model of Hf_{57}Fe_{43} is based on the concentration of iron
in the Hf_{100-x}Fe_{43} system that is just below the threshold for the long
range magnetic ordering. This work throws more light on magnetic behaviour of
other amorphous alloys, too
Acute promyelocytic leukemia after whole brain irradiation of primary brain lymphomainan HIV-infected patient
The occurrence of acute promyelocytic leukemia (APL) in HIV-infected patients has been reported in only five cases. Due to a very small number of reported HIV/APL patients who have been treated with different therapies with the variable outcome, the prognosis of APL in the setting of the HIV-infection is unclear. Here, we report a case of an HIV-patient who developed APL and upon treatment entered a complete remission. A 25-years old male patient was diagnosed with HIV-infection in 1996, but remained untreated. In 2004, the patient was diagnosed with primary central nervous system lymphoma. We treated the patient with antiretroviral therapy and whole-brain irradiation, resulting in complete remission of the lymphoma. In 2006, prompted by a sudden neutropenia, we carried out a set of diagnostic procedures, revealing APL. Induction therapy consisted of standard treatment with all-trans-retinoic-acid (ATRA) and idarubicin. Subsequent cytological and molecular analysis of bone marrow demonstrated complete hematological and molecular remission. Due to the poor general condition, consolidation treatment with ATRA was given in March and April 2007. The last follow-up 14 months later, showed sustained molecular APL remission. In conclusion, we demonstrated that a complete molecular APL remission in an HIV-patient was achieved by using reduced-intensity treatment
Coulomb-nuclear interference in the breakup of Be
Within a theory of breakup reactions formulated in the framework of the post
form distorted wave Born approximation, we calculate contributions of the pure
Coulomb and the pure nuclear breakup as well as those of their interference
terms to a variety of cross sections in breakup reactions of the one-neutron
halo nucleus Be on a number of target nuclei. In contrast to the
assumption often made, the Coulomb-nuclear interference terms are found to be
non-negligible in case of exclusive cross sections of the fragments emitted in
this reaction on medium mass and heavy target nuclei. The consideration of the
nuclear breakup leads to a better description of such data.Comment: 9 pages, latex, 2 figures, to be published in Phys. Rev. C (Rapid
Communication
Investigation of cluster states in 13b using the 9li-α resonant elastic scattering
The excitation function of the resonant reaction 4He(9Li,α) was measured with the aim of investigating the compound nucleus 13B. These measurements were performed in inverse kinematics at center-of-mass scattering angles close to 180° by using a thick 4He gas target and a 9Li beam. The 13B excitation energy region explored was 14-20 MeV where 9Li-αurations of 13B are predicted by Antysimmetrised Molecular Dynamics calculations. The measured excitation function at θcm= 180°s different clear structures in a 13B excitation energy region which was experimentally unknown
Bootstrap method for constructing covariance matrices of optical-model parameters in the study of the threshold anomaly
The parameters of optical-model potentials are usually obtained by adjusting theoretical calculations to the corresponding experimental elastic-scattering data. It has been observed that the use of conventional covariance matrices for the evaluation of the uncertainties of the parameters obtained in this way, leads in general to unrealistically small values. This underestimate may be caused by either, an incorrect use of the statistical recipes, or by the lack of a systematic study of the robustness of the uncertainty values against the inclusion or exclusion of experimental data points within a given data set. In the present contribution we explore both factors. Regarding the first aspect we use a re-normalization for χ2, similar to the one proposed by R.T. Birge. In the second case we use the Bootstrap method to create synthetic sets based on all the available experimental data in order to derive an effective covariance matrix. These procedures were applied to the re-analysis of elastic-scattering data for several heavy-ion systems at energies close to the Coulomb barrie
Development of a patient decision aid for children and adolescents following anterior cruciate ligament rupture: an international mixed-methods study
AIM: To develop and user test an evidence-based patient decision aid for children and adolescents who are considering anterior cruciate ligament (ACL) reconstruction.DESIGN: Mixed-methods study describing the development of a patient decision aid.SETTING: A draft decision aid was developed by a multidisciplinary steering group (including various types of health professionals and researchers, and consumers) informed by the best available evidence and existing patient decision aids.PARTICIPANTS: People who ruptured their ACL when they were under 18 years old (ie, adolescents), their parents, and health professionals who manage these patients. Participants were recruited through social media and the network outreach of the steering group.PRIMARY AND SECONDARY OUTCOMES: Semistructured interviews and questionnaires were used to gather feedback on the decision aid. The feedback was used to refine the decision aid and assess acceptability. An iterative cycle of interviews, refining the aid according to feedback and further interviews, was used. Interviews were analysed using reflexive thematic analysis.RESULTS: We conducted 32 interviews; 16 health professionals (12 physiotherapists, 4 orthopaedic surgeons) and 16 people who ruptured their ACL when they were under 18 years old (7 were adolescents and 9 were adults at the time of the interview). Parents participated in 8 interviews. Most health professionals, patients and parents rated the aid's acceptability as good-to-excellent. Health professionals and patients agreed on most aspects of the decision aid, but some health professionals had differing views on non-surgical management, risk of harms, treatment protocols and evidence on benefits and harms.CONCLUSION: Our patient decision aid is an acceptable tool to help children and adolescents choose an appropriate management option following ACL rupture with their parents and health professionals. A clinical trial evaluating the potential benefit of this tool for children and adolescents considering ACL reconstruction is warranted.</p
Study of interstrip gap effects and efficiency for full energy detection of Double Sided Silicon Strip Detectors
In this work is reported a study on the response of double sided silicon strip detectors. In order to investigate the effect of the electrode segmentation on the detector response, two experiments were performed aimed to measure the efficiency for full energy detection. Results show that the efficiency for full energy detection, that is directly related to effective width of the inter-strip region, varies with both detected ion energy and bias voltage. The experimental results are qualitatively reproduced by a simplified model based on the Shockley-Ramo-Gunn framework
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