A method to estimate weight and dimensions of aircraft gas turbine engines. Volume 1: Method of analysis

Weight and envelope dimensions of aircraft gas turbine engines are estimated within plus or minus 5% to 10% using a computer method based on correlations of component weight and design features of 29 data base engines. Rotating components are estimated by a preliminary design procedure where blade geometry, operating conditions, material properties, shaft speed, hub-tip ratio, etc., are the primary independent variables used. The development and justification of the method selected, the various methods of analysis, the use of the program, and a description of the input/output data are discussed

A method to estimate weight and dimensions of aircraft gas turbine engines. Volume 2: User's manual

For abstract, see N77-25171

A method to estimate weight and dimensions of aircraft gas turbine engines. Volume 3: Programmer's manual

For abstract, see N77-25171

Viral Single-Strand DNA Induces p53-Dependent Apoptosis in Human Embryonic Stem Cells

Human embryonic stem cells (hESCs) are primed for rapid apoptosis following mild forms of genotoxic stress. A natural form of such cellular stress occurs in response to recombinant adeno-associated virus (rAAV) single-strand DNA genomes, which exploit the host DNA damage response for replication and genome persistence. Herein, we discovered a unique DNA damage response induced by rAAV transduction specific to pluripotent hESCs. Within hours following rAAV transduction, host DNA damage signaling was elicited as measured by increased gamma-H2AX, ser15-p53 phosphorylation, and subsequent p53-dependent transcriptional activation. Nucleotide incorporation assays demonstrated that rAAV transduced cells accumulated in early S-phase followed by the induction of apoptosis. This lethal signaling sequalae required p53 in a manner independent of transcriptional induction of Puma, Bax and Bcl-2 and was not evident in cells differentiated towards a neural lineage. Consistent with a lethal DNA damage response induced upon rAAV transduction of hESCs, empty AAV protein capsids demonstrated no toxicity. In contrast, DNA microinjections demonstrated that the minimal AAV origin of replication and, in particular, a 40 nucleotide G-rich tetrad repeat sequence, was sufficient for hESC apoptosis. Our data support a model in which rAAV transduction of hESCs induces a p53-dependent lethal response that is elicited by a telomeric sequence within the AAV origin of replication

Comprehensive characterization of molecular interactions based on nanomechanics

Molecular interaction is a key concept in our understanding of the biological mechanisms of life. Two physical properties change when one molecular partner binds to another. Firstly, the masses combine and secondly, the structure of at least one binding partner is altered, mechanically transducing the binding into subsequent biological reactions. Here we present a nanomechanical micro-array technique for bio-medical research, which not only monitors the binding of effector molecules to their target but also the subsequent effect on a biological system in vitro. This label-free and real-time method directly and simultaneously tracks mass and nanomechanical changes at the sensor interface using micro-cantilever technology. To prove the concept we measured lipid vesicle (approximately 748*10(6) Da) adsorption on the sensor interface followed by subsequent binding of the bee venom peptide melittin (2840 Da) to the vesicles. The results show the high dynamic range of the instrument and that measuring the mass and structural changes simultaneously allow a comprehensive discussion of molecular interactions

Value of EUS in Determining Curative Resectability in Reference to CT and FDG-PET: The Optimal Sequence in Preoperative Staging of Esophageal Cancer?

Background: The separate value of endoscopic ultrasonography (EUS), multidetector computed tomography (CT), and18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the optimal sequence in staging esophageal cancer has not been investigated adequately. Methods: The staging records of 216 consecutive operable patients with esophageal cancer were reviewed blindly. Different staging strategies were analyzed, and the likelihood ratio (LR) of each module was calculated conditionally on individual patient characteristics. A logistic regression approach was used to determine the most favorable staging strategy. Results: Initial EUS results were not significantly related to the LRs of initial CT and FDG-PET results. The positive LR (LR+) of EUS-fine-needle aspiration (FNA) was 4, irrespective of CT and FDG-PET outcomes. The LR+ of FDG-PET varied from 13 (negative CT) to 6 (positive CT). The LR+ of CT ranged from 3-4 (negative FDG-PET) to 2-3 (positive FDG-PET). Age, histology, and tumor length had no significant impact on the LRs of the three diagnostic tests. Conclusions: This study argues in favor of PET/CT rather than EUS as a predictor of curative resectability in esophageal cancer. EUS does not correspond with either CT or FDG-PET. LRs of FDG-PET were substantially different between subgroups of negative and positive CT results and vice versa

Trends in esophageal cancer and body mass index by race and gender in the state of Michigan

<p>Abstract</p> <p>Background</p> <p>Adenocarcinoma of the esophagus has been increasing in incidence in the U.S. over the past several decades, particularly among white males. The factors driving the racial disparity in adenocarcinomas rates are not well understood.</p> <p>Methods</p> <p>Here we examine trends in both esophageal cancer incidence and body mass index (BMI) in a geographically defined cohort by gender and race. Age-adjusted esophageal cancer incidence rates from 1985 to 2005 were calculated from data collected by the Michigan state cancer registry. Trends were analyzed along with trends in BMI data obtained from the Behavioral Risk Factor Survey administered by the Centers for Disease Control.</p> <p>Results</p> <p>Overall, age adjusted incidence rates in esophageal carcinoma increased from 4.49 to 4.72 cases/100,000 persons per year in Michigan from 1985 to 2005. Among white males, the rate of adenocarcinomas increased by 0.21 cases/100,000 per year to a maximum of 6.40 cases/100,000 in 1999, after which these rates remained constant. There was a slight but non-significant increase in the rate of adenocarcinomas among African American males, for whom the average incidence rate was 8 times lower than that for white males (0.58 vs 4.72 cases/100,000 person years). While average BMI is rising in Michigan (from 26.68 in 1988 to 30.33 in 2005), average BMI was slightly higher among African Americans on average, and the rates of increase in BMI were not different between African American males and white males.</p> <p>Conclusion</p> <p>The disparity between African American males and white males is not explained by ecological-level trends in BMI. Further research to identify the factors responsible for this disparity, possibly including anatomic fat distribution, are required.</p

An effective serum- and xeno-free chemically defined freezing procedure for human embryonic and induced pluripotent stem cells

Both human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) bear a great potential in regenerative medicine. In addition to optimized clinical grade culture conditions, efficient clinical grade cryopreservation methods for these cells are needed. Obtaining good survival after thawing has been problematic