63 research outputs found
Flight dynamics software in a distributed network environment
As with all NASA facilities, the announcement of reduced budgets, reduced staffing, and the desire to implement smaller/quicker/cheaper missions has required the Agency's organizations to become more efficient in what they do. To accomplish these objectives, the FDD has initiated the development of the Flight Dynamics Distributed System (FDDS). The underlying philosophy of FDDS is to build an integrated system that breaks down the traditional barriers of attitude, mission planning, and navigation support software to provide a uniform approach to flight dynamics applications. Through the application of open systems concepts and state-of-the-art technologies, including object-oriented specification concepts, object-oriented software, and common user interface, communications, data management, and executive services, the FDD will reengineer most of its six million lines of code
Enumeration of leukocyte infiltration in solid tumors by confocal laser scanning microscopy
BACKGROUND: Leukocytes commonly infiltrate solid tumors, and have been implicated in the mechanism of spontaneous regression in some cancers. Conventional techniques for the quantitative estimation of leukocyte infiltrates in tumors rely on light microscopy of immunostained thin tissue sections, in which an arbitrary assessment (based on low, medium or high levels of infiltration) of antigen density is made by the pathologist. These estimates are relatively subjective and often require the opinion of a second pathologist. In addition, since thin tissue sections are cut, no data regarding the three-dimensional distribution of antigen can be obtained. RESULTS: To overcome these problems, we have designed a method to enumerate leukocyte infiltration into tumors, using confocal laser scanning microscopy of fluorescently immunostained leukocytes in thick tissue sections. Using image analysis software, a threshold was applied to eliminate unstained tissue and residual noise. The total antigen volume in the scanned tissue was calculated and divided by the mean cell volume (calculated by "seeding" ten individual cells) to obtain the cell count. Using this method, we compared the calculated leukocyte counts with those obtained manually by ten laboratory personnel. There was no significant difference (P > 0.05) between the cell counts obtained by either method. We then compared leukocyte infiltration into seven tumors and matched non-malignant tissue obtained from the periphery of the resected tissue. There was a significant increase in the infiltration of all leukocyte subsets into the tumors compared to minimal numbers in the non-malignant tissue. CONCLUSION: From these results we conclude that this method may be of considerable use for the enumeration of cells in tissues. Furthermore, since it can be performed by laboratory technical staff, less time input is required by the pathologist in assessing the degree of leukocyte infiltration into tumors
Simultaneous measurements of knee motion using an optical tracking system and radiostereometric analysis (RSA)
A novel circular invasion assay mimics in vivo invasive behavior of cancer cell lines and distinguishes single-cell motility in vitro
Differences in gait patterns, pain, function and quality of life between males and females with knee osteoarthritis: a clinical trial
<p>Abstract</p> <p>Background</p> <p>The aim of this study was to gain a deeper understanding of the gender differences in knee osteoarthritis (OA) by evaluating the differences in gait spatio-temporal parameters and the differences in pain, quality of life and function between males and females suffering from knee OA.</p> <p>Methods</p> <p>49 males and 85 females suffering from bilateral medial compartment knee OA participated in this study. Each patient underwent a computerized gait test and completed the WOMAC questionnaire and the SF-36 health survey. Independent t-tests were performed to examine the differences between males and females in age, BMI, spatio-temporal parameters, the WOMAC questionnaire and the SF-36 health survey.</p> <p>Results</p> <p>Males and females had different gait patterns. Although males and females walked at the same walking speed, cadence and step length, they presented significant differences in the gait cycle phases. Males walked with a smaller stance and double limb support, and with a larger swing and single limb support compared to females. In addition, males walked with a greater toe out angle compared to females. While significant differences were not found in the WOMAC subscales, females consistently reported higher levels of pain and disability.</p> <p>Conclusion</p> <p>The spatio-temporal differences between genders may suggest underlying differences in the gait strategies adopted by males and females in order to reduce pain and cope with the loads acting on their affected joints, two key aspects of knee OA. These gender effects should therefore be taken into consideration when evaluating patients with knee OA.</p> <p>Trial Registration</p> <p>The study is registered in the NIH clinical trial registration, protocol No. NCT00599729.</p
Crk and CrkL adaptor proteins: networks for physiological and pathological signaling
The Crk adaptor proteins (Crk and CrkL) constitute an integral part of a network of essential signal transduction pathways in humans and other organisms that act as major convergence points in tyrosine kinase signaling. Crk proteins integrate signals from a wide variety of sources, including growth factors, extracellular matrix molecules, bacterial pathogens, and apoptotic cells. Mounting evidence indicates that dysregulation of Crk proteins is associated with human diseases, including cancer and susceptibility to pathogen infections. Recent structural work has identified new and unusual insights into the regulation of Crk proteins, providing a rationale for how Crk can sense diverse signals and produce a myriad of biological responses
Medial and lateral osteoarthritis of the knee is related to variations of hip and pelvic anatomy
SummaryObjectiveWe evaluated if increased risk of combined hip and lateral knee osteoarthritis (OA) could be attributed to anatomical reasons in the hip region resulting in increased abductor moment over the knee.MethodsWe measured pelvic width, femoral offset, femoral neck length and angle in 29 women with lateral knee OA (13 unilateral, 16 bilateral) and 27 women with bilateral medial OA. Twenty-one of these patients with normal hips (lateral/medial OA of the knee=12/9) and 35 with associated hip OA (lateral/medial OA of the knee=17/18) were evaluated separately. Radiographic examinations in 14 women planned for hip prosthesis because of failures after hip fracture acted as controls.ResultsPatients with lateral OA of the knee had wider pelvis than controls (13.7mm increased distance between the medial borders of the acetabulum, P=0.001). Patients with medial OA had 11.4mm longer distance from the centre of the femoral head to the centre of the proximal part of the femoral shaft (P=0.005), corresponding to a higher offset.The pelvic and hip anatomy also differed between patients with medial and lateral OA of the knee. In the groups without hip OA, presence of lateral knee OA was associated with a wider pelvis (P=0.009), shorter femoral neck (P=0.02) and Head-Shaft distance (P=0.04). In the groups with OA of the hip associated lateral OA of the knee also implied increased Neck Shaft angle (coxa valga, P=0.008), but there was no difference in pelvic width (P=0.15). We found a shorter lever arm over the hip in lateral knee OA compared to medial knee OA (P=0.02), but not when compared to controls.ConclusionOur findings suggest that occurrence of medial or lateral OA has a biomechanical background originating from pelvis and hip anatomy
Cemented carbides based on WC pre-alloyed with Cr or Ta
WC powder pre-alloyed with Ta or Cr was used to produce WC-Co based cemented carbides and these were compared with materials produced from pure WC. Atom probe tomography analysis of the pre-alloyed as-sintered materials showed that a high, non-uniform, concentration of Ta or Cr remained in the WC lattice after sintering. The hexagonal (W,Ta)C partially decomposes during sintering leading to the formation of a fcc MC phase. Similarly, the (W,Cr)C partially decomposes, but no Cr-rich precipitates were observed in either of the Cr containing samples. The hardness of the crystallites of the doped materials was significantly lower than the undoped WC, as measured by nano-indentation. The Young's moduli of the doped crystals were significantly lower than the undoped WC in agreement with the lowering of the elastic constants, from ab initio calculations. The microhardness (HV) reflected what would be expected from the average WC grain size giving that the grain boundary surface area is more important for the material hardness than the hardness of the WC crystals themselves in the investigated grain size range
Oxidation studies of Fe10CrAl-RE alloys exposed to Pb at 550 degrees C for 10,000 h
Five experimental FeCrAl-RE alloys have been exposed up to 10,000 h in stagnant liquid Pb at 550 C. The test matrix consisted of three 10 wt.% Cr alloys, with an Al content ranging from 4 to 8 wt.% (10Cr-4Al, 10Cr-6Al and 10Cr-8Al), one alloy without additions of reactive elements (RE) (10Cr-6Al), and one reference alloy with 21 wt.% Cr and 5 wt.% Al (21Cr-5Al). The evaluation showed a clear difference in oxidation properties, and it was possible to divide the alloys into two distinct groups. A critical Al concentration in the interval of 4-6 wt.% at the given RE content was required to form a thin protective oxide. However, the absence of RE addition in one of the two 10Cr-6Al alloys resulted in a significant reduction in oxidation resistance, comparable with 10Cr-4Al. None of the alloys were severely corroded, however Pb penetrated to a relatively large extent into the porous oxide of the low performing alloys. A 100 nm thick oxide scale, partly consisting of alumina (Al2O3), was observed for the high performing 10Cr-6Al alloy. The Fe10CrAl-RE alloys showed overall very good corrosion resistance and are hence a promising new alloy category for liquid Pb applications. (C) 2013 Elsevier B.V. All rights reserved
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