5,086 research outputs found
Measured and predicted shock shapes for AFE configuration at Mach 6 in air and in CF4
Shock shapes and stand-off distances were obtained for the Aeroassist Flight Experiment configuration from Mach 6 tests in air and in CF4. Results were plotted for an angle-of attack range from -10 to 10 degrees and comparisons were made at selected angles with inviscid-flow predictions. Tests were performed in the Langley Research Center (LaRC) 20 inch Mach 6 Tunnel (air) at unit free-stream Reynolds numbers (N sub Re, infinity) of 2 million/ft and 0.6 million/ft and in the LaRC Hypersonic CF4 Tunnel at N sub Re, infinity = 0.5 million/ft and 0.3 million/ft. Within the range of these tests, N sub Re, infinity did not affect the shock shape or stand off distance, and the predictions were in good agreement with the measurements. The shock stand-off distance in CF4 was approximately half of that in air. This effect resulted from the differences in density ratio across the normal shock, which was approximately 12 in CF4 and 5 in air. In both test gases, the shock lay progressively closer to the body as angle of attack decreased
Ultrastructural tumour differentiation and organ specificity in high and low metastatic lines from a mouse lung carcinoma.
A tissue culture cell line CMT64 was established from a spontaneous alveolar lung carcinoma of a C57BL female mouse (Franks et al., 1976). Subcutaneous inoculation of these cells produced a local tumour and a small number of lung metastases. Four sublines CMT167, 170, 175 and 181 with increased metastatic ability were selected, as described in the accompanying paper (Layton & Franks, 1984). The tissue culture cells and the tumours produced by all the lines are well differentiated and produce laminated surfactant-like bodies as well as basal lamina, even in metastases. No ultrastructural differences were found that might correlate with metastatic behaviour in vivo. Metastases, after subcutaneous inoculation and tumour colonies after intravenous inoculation of all cell lines are only found in the lung, but after inoculation of cells into the arterial system via the left ventricle of the heart, extravascular tumour colonies were found in many organs
Heterogeneity in a spontaneous mouse lung carcinoma: selection and characterisation of stable metastatic variants.
The development and characterisation of a new epithelial model for the experimental investigation of metastasis is described. A tissue culture cell line CMT64 was established from a spontaneous alveolar lung carcinoma of a 17 month old female C57BL/ICRF at mouse (Franks et al., 1976). Subcutaneous inoculation of cells produces local tumours which give rise to a small number of lung metastases within three weeks. Four different tissue culture sublines CMT167, 170, 175 and 181 with increased metastatic ability were selected from pooled lung metastases by culture, mouse inoculation and reselection from lung metastases through four culture/inoculation cycles. These sublines are themselves heterogeneous and clones derived from them display marked differences in metastatic behaviour. Both CMT64 and its sublines have remained relatively stable in morphology and behavior since their origin, are fairly well differentiated, produce basal lamina even in metastases, and metastasise rapidly and preferentially to the lung after subcutaneous and intravenous inoculation in both syngeneic C57 and Nu/Nu mice (Franks & Layton, 1984). The expression of the metastatic potential of these cells is strongly influenced by the age and immune status of the host. The CMT64 system is a particularly useful model for experimental metastasis studies
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