380 research outputs found

    Structural characterization of a first-generation articulated-truss joint for space crane application

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    A first-generation space crane articulated-truss joint was statically and dynamically characterized in a configuration that approximated an operational environment. The articulated-truss joint was integrated into a test-bed for structural characterization. Static characterization was performed by applying known loads and measuring the corresponding deflections to obtain load-deflection curves. Dynamic characterization was performed using modal testing to experimentally determine the first six mode shapes, frequencies, and modal damping values. Static and dynamic characteristics were also determined for a reference truss that served as a characterization baseline. Load-deflection curves and experimental frequency response functions are presented for the reference truss and the articulated-truss joint mounted in the test-bed. The static and dynamic experimental results are compared with analytical predictions obtained from finite element analyses. Load-deflection response is also presented for one of the linear actuators used in the articulated-truss joint. Finally, an assessment is presented for the predictability of the truss hardware used in the reference truss and articulated-truss joint based upon hardware stiffness properties that were previously obtained during the Precision Segmented Reflector (PSR) Technology Development Program

    Donor Lymphocyte Infusion for Relapsed Hematological Malignancies after Allogeneic Hematopoietic Cell Transplantation: Prognostic Relevance of the Initial CD3(+) T Cell Dose.

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    AbstractThe impact of donor lymphocyte infusion (DLI) initial cell dose on its outcome is known in patients with chronic myeloid leukemia but limited in patients with other hematological malignancies. In this retrospective study, we evaluated the effect of initial DLI CD3+ cell dose on graft-versus-host disease (GVHD) and overall survival after DLI given for relapse of any hematological malignancies after allogeneic hematopoietic cell transplantation (HCT) with high- or reduced-intensity conditioning. The cohort included 225 patients. Initial DLI CD3+ cell dose per kilogram of recipient body weight was ≤1 × 107 (n = 84; group A), >1.0 to <10 × 107 (n = 58; group B), and ≥10 × 107 (n = 66; group C). The initial cell dose was unknown for the remaining 17 patients. Cumulative incidence rates of GVHD at 12 months after DLI were 21%, 45%, and 55% for groups A, B, and C, respectively. Multivariate analysis showed that initial DLI CD3+ cell ≥10 × 107 dose per kilogram is associated with an increased risk of GVHD after DLI (P = .03). Moreover, an initial DLI CD3+ cell dose of 10 × 107 or higher did not decrease the risk of relapse and did not improve overall survival. Thus, these results support the use of less than 10 × 107 CD3+ cell per kilogram as the initial cell dose of DLI for treatment of persistent or recurrent hematological malignancy after HCT

    A randomized phase II trial of tacrolimus, mycophenolate mofetil and sirolimus after non-myeloablative unrelated donor transplantation

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    The study is a randomized phase II trial investigating graft-versus-host disease prophylaxis after non-myeloablative (90 mg/m(2) fludarabine and 2 Gy total body irradiation) human leukocyte antigen matched unrelated donor transplantation. Patients were randomized as follows: arm 1 – tacrolimus 180 days and mycophenolate mofetil 95 days (n=69); arm 2 – tacrolimus 150 days and mycophenolate mofetil 180 days (n=71); arm 3 – tacrolimus 150 days, mycophenolate mofetil 180 days and sirolimus 80 days (n=68). All patients had sustained engraftment. Grade II-IV acute graft-versus-host disease rates in the 3 arms were 64%, 48% and 47% at Day 150, respectively (arm 3 vs. arm 1 (hazard ratio 0.62; P=0.04). Owing to the decreased incidence of acute graft-versus-host disease, systemic steroid use was lower at Day 150 in arm 3 (32% vs. 55% in arm 1 and 49% in arm 2; overall P=0.009 by hazard ratio analysis). The Day 150 incidence of cytomegalovirus reactivation was lower in arm 3 (arm 1, 54%; arm 2, 47%; arm 3, 22%; overall P=0.002 by hazard ratio analysis). Non-relapse mortality was comparable in the three arms at two years (arm 1, 26%; arm 2, 23%; arm 3, 18%). Toxicity rates and other outcome measures were similar between the three arms. The addition of sirolimus to tacrolimus and mycophenolate mofetil is safe and associated with lower incidence of acute graft-versus-host disease and cytomegalovirus reactivation. (clinicaltrials.gov identifier: 00105001)
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