Epstein Barr Virus-positive large T-cell lymphoma presenting as acute appendicitis 17 years after cadaveric renal transplant: a case report

<p>Abstract</p> <p>Introduction</p> <p>The majority of post-transplant lymphoproliferative disorders in renal transplant patients are of the B-cell phenotype, while the T-cell phenotype is rare. We report a case of Epstein Barr Virus-positive, T-cell lymphoma in a renal transplant patient, presenting unusually as acute appendicitis.</p> <p>Case presentation</p> <p>A 45-year-old Hispanic male renal transplant patient presented with right-side abdominal pain 17 years after transplant. The laboratory studies were unremarkable. Laparoscopic exploration showed an inflamed appendix so a laparoscopic appendectomy was performed. Pathology of the appendix showed large cells positive for CD3, CD56 and Epstein Barr Virus-encoded RNA staining, and negative for CD20 and CD30. The tissue tested positive for T-cell receptor gene rearrangement by polymerase chain reaction analysis. Treatment management involved reduction of immunosuppression and initiation of chemotherapy with cisplatin, etoposide, gemcitabine, and solumedrol followed by cyclophosphamide, hydroxydaunorubicin, vincristine and prednisone). He recovered and the allo-grafted kidney is fully functional.</p> <p>Conclusion</p> <p>We report a rare case of post-renal transplant large T-cell lymphoma, with an unusual presentation of acute appendicitis and Epstein Barr Virus-positivity, which responded well to chemotherapy.</p

Propagation of guided waves in a hollow circular cylinder application to non destructive testing

In this paper, we study the propagation of guided waves in a tube and their interaction with surface defects. Axisymmetric (longitudinal and torsional) modes and nonaxisymmetric (flexural) modes are found and represented in phase and group velocity dispersion diagrams. The mode chosen to be generated is the second longitudinal mode L (0, 2), for the frequency-thickness product equal to 1 MHz.mm, at this product, the radial component of displacement is very small with regard to the axial component so, the attenuation is less important. According to our experimental results the L (0, 2) mode is sensitive to the depth variation and to the defect circumference. A relation of proportionality between the amplitude of the signal reflected by the defect and its depth was established. The results of the modal decomposition method, concerning the amplitude of the modes diffracted by circumferential defects according to the circumference of the defect, were presented and compared with the experimental measures results

Continuous waves probing in dynamic acoustoelastic testing

Consolidated granular media display a peculiar nonlinear elastic behavior, which is normally analysed with dynamic ultrasonic testing exploiting the dependence on amplitude of different measurable quantities, such as the resonance frequency shift, the amount of harmonics generation, or the break of the superposition principle. However, dynamic testing allows measuring effects which are averaged over one (or more) cycles of the exciting perturbation. Dynamic acoustoelastic testing has been proposed to overcome this limitation and allow the determination of the real amplitude dependence of the modulus of the material. Here, we propose an implementation of the approach, in which the pulse probing waves are substituted by continuous waves. As a result, instead of measuring a time-of-flight as a function of the pump strain, we study the dependence of the resonance frequency on the strain amplitude, allowing to derive the same conclusions but with an easier to implement procedure

Experimental Study of Lamb Waves Propagation inside an Impact Damage in the Size of the Used Wavelength

The present work is an experimental study of Lamb waves propagation in an aluminum plate with an impact damage in the size of the S0 mode wavelength. The aim of this study is to visualize the wavefield near the defect in the case of extreme diffusion, as well as the interference of the modes inside of it and their transformation. The results were obtained by applying the continuous wavelet transform (CWT) on the wavefield data recorded by two ultrasonic scanning techniques: the air coupled ultrasonic (ACU) and the Laser doppler vibrometry (LDV), to obtain a C-scan and a B-scan of the plate respectively. Space-wavenumber representations showed the behavior of Lamb waves in the plate as well as the reduction in thickness of the impacted area. The width of the latter could be estimated and the modes present at each position of the plate could be identified

Investigation of the validity of Dynamic AcoustoElastic Testing for measuring nonlinear elasticity

International audienceMeasurement of the dependence of the elastic moduli on the strain, i.e., the characterization of nonlinear elastic properties of solid media, poses intrinsic experimental difficulties. The Dynamic AcoustoElastic Technique has been recently developed as an efficient tool for the determination of the modulus in both compression and tension. The goal of the present paper is to discuss the limitations of the experimental implementation and the interpretation of the measured quantities in terms of nonlinear parameters. For this purpose, simulation results will be presented for both classical and nonclassical nonlinear elastic media

Effect of Vacancies on Electronic and Magnetic Properties of Hydrogen Passivated Graphene Nanoribbons

Using first-principles calculations we have demonstrated that electronic and magnetic properties of armchair graphene nanoribbons are modified by introducing vacancies defects. The equilibrium geometries, electronic, charge spin density distributions, electronic band structures, and magnetic moments were examined in the presence of vacancies. We have found that introducing vacancies into armchair graphene nanoribbons changes the spatial distribution of neighbor atoms, particularly those located around the vacancies. Our calculations showed that the vacancies have significant effect on the magnetization of armchair graphene nanoribbons. Magnetic moment values and electronic behavior in different configurations depend on the number of vacancies. These results suggest that vacancy defects can be used to modify the electronic and the magnetic properties of armchair graphene nanoribbons