20,583 research outputs found
High precision cryogenic thermal conductivity standards
New apparatus allows accurate simultaneous measurement of thermal conductivity, electrical resistivity, and thermopower for technically important materials, such as new or uncommon alloys. A list of materials investigated is presented. Sources for obtaining data on these materials, as well as the source giving a description of the apparatus, are cited
Impact of low gravity on water electrolysis operation
Advanced space missions will require oxygen and hydrogen utilities for several important operations including the following: (1) propulsion; (2) electrical power generation and storage; (3) environmental control and life support; (4) extravehicular activity; (5) in-space manufacturing and (6) in-space science activities. An experiment suited to a Space Shuttle standard middeck payload has been designed for the Static Feed Water Electrolysis technology which has been viewed as being capable of efficient, reliable oxygen and hydrogen generation with few subsystem components. The program included: end use design requirements, phenomena to be studied, Space Shuttle Orbiter experiment constraints, experiment design and data requirements, and test hardware requirements. The objectives are to obtain scientific and engineering data for future research and development and to focus on demonstrating and monitoring for safety of a standard middeck payload
Low-speed aerodynamic test of an axisymmetric supersonic inlet with variable cowl slot
The experimental low-speed aerodynamic characteristics of an axisymmetric mixed-compression supersonic inlet with variable cowl slot are described. The model consisted of the NASA P-inlet centerbody and redesigned cowl with variable cowl slot powered by the JT8D single-stage fan simulator and driven by an air turbine. The model was tested in the NASA Lewis Research Center 9- by 15-foot low-speed tunnel at Mach numbers of 0, 0.1, and 0.2 over a range of flows, cowl slot openings, centerbody positions, and angles of attack. The variable cowl slot was effective in minimizing lip separation at high velocity ratios, showed good steady-state and dynamic distortion characteristics, and had good angle-of-attack tolerance
Improved high temperature resistant matrix resins
The objective was to develop organic matrix resins suitable for service at temperatures up to 644 K (700 F) and at air pressures up to 0.4 MPa (60 psia) for time durations of a minimum of 100 hours. Matrix resins capable of withstanding these extreme oxidative environmental conditions would lead to increased use of polymer matrix composites in aircraft engines and provide significant weight and cost savings. Six linear condensation, aromatic/heterocyclic polymers containing fluorinated and/or diphenyl linkages were synthesized. The thermo-oxidative stability of the resins was determined at 644 K and compressed air pressures up to 0.4 MPa. Two formulations, both containing perfluoroisopropylidene linkages in the polymer backbone structure, exhibited potential for 644 K service to meet the program objectives. Two other formulations could not be fabricated into compression molded zero defect specimens
Evaluation of a tumor microenvironment-based prognostic score in primary operable colorectal cancer
Purpose: The tumor microenvironment is recognized as an important determinant of progression and outcome in colorectal cancer. The aim of the present study was to evaluate a novel tumor microenvironment–based prognostic score, based on histopathologic assessment of the tumor inflammatory cell infiltrate and tumor stroma, in patients with primary operable colorectal cancer.
Experimental Design: Using routine pathologic sections, the tumor inflammatory cell infiltrate and stroma were assessed using Klintrup–Mäkinen (KM) grade and tumor stroma percentage (TSP), respectively, in 307 patients who had undergone elective resection for stage I–III colorectal cancer. The clinical utility of a cumulative score based on these characteristics was examined.
Results: On univariate analysis, both weak KM grade and high TSP were associated with reduced survival (HR, 2.42; P = 0.001 and HR, 2.05; P = 0.001, respectively). A cumulative score based on these characteristics, the Glasgow Microenvironment Score (GMS), was associated with survival (HR, 1.93; 95% confidence interval, 1.36–2.73; P < 0.001), independent of TNM stage and venous invasion (both P < 0.05). GMS stratified patients in to three prognostic groups: strong KM (GMS = 0), weak KM/low TSP (GMS = 1), and weak KM/high TSP (GMS = 2), with 5-year survival of 89%, 75%, and 51%, respectively (P < 0.001). Furthermore, GMS in combination with node involvement, venous invasion, and mismatch repair status further stratified 5-year survival (92% to 37%, 93% to 27%, and 100% to 37%, respectively).
Conclusions: The present study further confirms the clinical utility of assessment of the tumor microenvironment in colorectal cancer and introduces a simple, routinely available prognostic score for the risk stratification of patients with primary operable colorectal cancer
Long-term follow-up of patients undergoing resection of tnm stage i colorectal cancer: an analysis of tumour and host determinants of outcome
Background
Screening for colorectal cancer improves cancer-specific survival (CSS) through the detection of early-stage disease; however, its impact on overall survival (OS) is unclear. The present study examined tumour and host determinants of outcome in TNM Stage I disease.
Methods
All patients with pathologically confirmed TNM Stage I disease across 4 hospitals in the North of Glasgow between 2000 and 2008 were included. The preoperative modified Glasgow Prognostic Score (mGPS) was used as a marker of the host systemic inflammatory response (SIR).
Results
There were 191 patients identified, 105 (55 %) were males, 91 (48 %) were over the age of 75 years and 7 (4 %) patients underwent an emergency operation. In those with a preoperative CRP result (n = 150), 35 (24 %) patients had evidence of an elevated mGPS. Median follow-up of survivors was 116 months (minimum 72 months) during which 88 (46 %) patients died; 7 (8 %) had postoperative deaths, 15 (17 %) had cancer-related deaths and 66 (75 %) had non-cancer-related deaths. 5-year CSS was 95 % and OS was 76 %. On univariate analysis, advancing age (p < 0.001), emergency presentation (p = 0.008), and an elevated mGPS (p = 0.012) were associated with reduced OS. On multivariate analysis, only age (HR = 3.611, 95 % CI 2.049–6.365, p < 0.001) and the presence of an elevated mGPS (HR = 2.173, 95 % CI 1.204–3.921, p = 0.010) retained significance.
Conclusions
In patients undergoing resection for TNM Stage I colorectal cancer, an elevated mGPS was an objective independent marker of poorer OS. These patients may benefit from a targeted intervention
MF912
Michael H. Bradshaw & G. Morgan Powell, Understanding your water test report: microbiological, inorganic chemicals and nuisances, Kansas State University, October 2004
MF1142
Michael H. Bradshaw & G. Morgan Powell, Organic chemicals and radionuclides in drinking water, Kansas State University, July 2003
MF1094
Michael H. Bradshaw and G. Morgan Powell, Sodium in drinking water, Kansas State University, October 2002
Multistability in nonlinear left-handed transmission lines
Employing a nonlinear left-handed transmission line as a model system, we
demonstrate experimentally the multi-stability phenomena predicted
theoretically for microstructured left-handed metamaterials with a nonlinear
response. We show that the bistability is associated with the period doubling
which at higher power may result in chaotic dynamics of the transmission line
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