230 research outputs found
Structurally adaptive space crane concept for assembling space systems on orbit
Many future human space exploration missions will probably require large vehicles that must be assembled on orbit. Thus, a device that can move, position, and assemble large and massive spacecraft components on orbit becomes essential for these missions. A concept is described for such a device: a space crane concept that uses erectable truss hardware to achieve high-stiffness and low-mass booms and uses articulating truss joints that can be assembled on orbit. The hardware has been tested and shown to have linear load-deflection response and to be structurally predictable. The hardware also permits the crane to be reconfigured into different geometries to satisfy future assembly requirements. A number of articulating and rotary joint concepts have been sized and analyzed, and the results are discussed. Two strategies were proposed to suppress motion-induced vibration: placing viscous dampers in selected truss struts and preshaping motion commands. Preliminary analyses indicate that these techniques have the potential to greatly enhance structural damping
Structural characterization of a first-generation articulated-truss joint for space crane application
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
Early Results of a Phase II Study Adding Peri-Transplant Rituximab to Nonmyeloablative Conditioning and Allogeneic Hematopoietic Cell Transplantation (HCT) for Patients (PTS) with High-Risk Fludarabine-Refractory Chronic Lymphocytic Leukemia (Cll)
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Donor Lymphocyte Infusion for Relapsed Hematological Malignancies after Allogeneic Hematopoietic Cell Transplantation: Prognostic Relevance of the Initial CD3(+) T Cell Dose.
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
Clubbing masculinities: Gender shifts in gay men's dance floor choreographies
This is an Author's Accepted Manuscript of an article published in Journal of Homosexuality, 58(5), 608-625, 2011 [copyright
Taylor & Francis], available online at: http://www.tandfonline.com/10.1080/00918369.2011.563660This article adopts an interdisciplinary approach to understanding the intersections of gender, sexuality, and dance. It examines the expressions of sexuality among gay males through culturally popular forms of club dancing. Drawing on political and musical history, I outline an account of how gay men's gendered choreographies changed throughout the 1970s, 80s, and 90s. Through a notion of “technologies of the body,” I situate these developments in relation to cultural levels of homophobia, exploring how masculine expressions are entangled with and regulated by musical structures. My driving hypothesis is that as perceptions of cultural homophobia decrease, popular choreographies of gay men's dance have become more feminine in expression. Exploring this idea in the context of the first decade of the new millennium, I present a case study of TigerHeat, one of the largest weekly gay dance club events in the United States
368: Longer follow up of patients (pts) with advanced chronic lymphocytic leukemia (CLL) treated with nonmyeloablative conditioning and allogeneic hematopoietic cell transplantation (HCT)
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Long-term follow up of tandem autologous-allogeneic hematopoietic cell transplantation for multiple myeloma
Treatment of patients (pts) with chemotherapy-refractory chronic lymphocytic leukemia (CLL) with nonmyeloablative (NM) conditioning and hematopoietic cell transplantation (HCT) from HLA-matched related (MRD) or unrelated donors (URD)
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Fludarabine/2 Gy TBI is Superior to 2 Gy TBI as Conditioning for HLA-Matched Related HCT: A Phase III Randomized Trial.
AbstractThe risks and benefits of adding fludarabine to a 2-Gy total body irradiation (TBI) nonmyeloablative regimen are unknown. For this reason, we conducted a prospective randomized trial comparing 2-Gy TBI alone, or in combination with 90 mg/m2 fludarabine (FLU/TBI), before transplantation of peripheral blood stem cells from HLA-matched related donors. Eighty-five patients with hematological malignancies were randomized to be conditioned with TBI alone (n = 44) or FLU/TBI (n = 41). All patients had initial engraftment. Two graft rejections were observed, both in the TBI group. Infection rates, nonrelapse mortality, and graft-versus-host disease (GVHD) were similar between groups. Three-year overall survival was lower in the TBI group (54% versus 65%; hazard ratio [HR], .57; P = .09), with higher incidences of relapse/progression (55% versus 40%; HR, .55; P = .06), relapse-related mortality (37% versus 28%; HR, .53; P = .09), and a lower progression-free survival (36% versus 53%; HR, .56; P = .05). Median donor T cell chimerism levels were significantly lower in the TBI group at days 28 (61% versus 90%; P < .0001) and 84 (68% versus 92%; P < .0001), as was NK cell chimerism on day 28 (75% versus 96%; P = .0005). In conclusion, this randomized trial demonstrates the importance of fludarabine in augmenting the graft-versus-tumor effect by ensuring prompt and durable high-level donor engraftment early after transplantation
A randomized phase II trial of tacrolimus, mycophenolate mofetil and sirolimus after non-myeloablative unrelated donor transplantation
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