406 research outputs found
Accuracy of Surface Plate Measurements - General Purpose Software for Flatness Measurement
Flatness departures of surface plates are generally obtained from straightness measurements of lines on the surface. A computer program has been developed for on-line measurement and evaluation, based on the simultaneous coupling of measurements in all grid points. Statistical methods are used to determine the accuracy of the measurements. The program runs on standard personal computers and supports different types of measuring instruments like electronic levels, autocollimators, laser interferometers or straight edge based instruments. Apart from the given height map, some meaningful characteristic parameters: sphericity, torsion and waviness are obtained. They have been proven very valuable to record long term effects of surface plates. Reliable measurements with an accuracy of 0.1 μm/m demonstrate the capabilities of the method
The effect of childhood trauma and Five-Factor Model personality traits on exposure to adult life events in patients with psychotic disorders
The effect of childhood trauma and Five-Factor Model personality traits on exposure to adult life events in patients with psychotic disorders
5-Fluorouracil/ leucovorin-induced inhibition of thymidylate synthase in normal tissues of mouse and man
Increased expression of the EZH2 polycomb group gene in BMI-1-positive neoplastic cells during bronchial carcinogenesis.
Increased expression of the EZH2 polycomb group gene in BMI-1-positive neoplastic cells during bronchial carcinogenesis.
Polycomb group (PcG) genes are responsible for maintenance of cellular identity and contribute to regulation of the cell cycle. Recent studies have identified several PcG genes as oncogenes, and a role for PcG proteins in human oncogenesis is suspected. We investigated the expression of BMI-1 and EZH2 PcG oncogenes in human bronchial squamous cell carcinomas (SCCs) and bronchial premalignant precursor lesions (PLs). Whereas normal bronchial epithelium was associated with widespread expression of BMI-1 in resting EZH2-negative cells, neoplastic cells in lung carcinomas displayed altered expression of both BMI-1 and EZH2. Two patterns of abnormal PcG expression were observed: increased expression of BMI-1 in dividing neoplastic cells of PLs and SCCs, and enhanced expression of EZH2 and Ki-67 in BMI-1-positive cells according to severity of the histopathologic stage. We propose that altered expression of BMI1 and EZH2 is an early event that precedes high rates of proliferation in lung cancer. Because PcG complexes are normally involved in the maintenance of cell characteristics, abnormal PcG expression may contribute to loss of cell identity
Complete sequencing of TP53 predicts poor response to systemic therapy of advanced breast cancer
TP53 has been implicated in regulation of the cell cycle, DNA repair, and
apoptosis. We studied, in primary breast tumors through direct cDNA
sequencing of exons 2-11, whether TP53 gene mutations can predict response
in patients with advanced disease to either first-line tamoxifen therapy
(202 patients, of whom 55% responded) or up-front (poly)chemotherapy (41
patients, of whom 46% responded). TP53 mutations were detected in 90 of
243 (37%) tumors, and one-fourth of these mutations resulted in a
premature termination of the protein. The mutations were observed in 32%
(65 of 202) of the primary tumors of tamoxifen-treated patients and in 61%
(25 of 41) of the primary tumors of the chemotherapy patients. TP53
mutation was significantly associated with a poor response to tamoxifen
[31% versu
High pressure diamond-like liquid carbon
We report density-functional based molecular dynamics simulations, that show
that, with increasing pressure, liquid carbon undergoes a gradual
transformation from a liquid with local three-fold coordination to a
'diamond-like' liquid. We demonstrate that this unusual structural change is
well reproduced by an empirical bond order potential with isotropic long range
interactions, supplemented by torsional terms. In contrast, state-of-the-art
short-range bond-order potentials do not reproduce this diamond structure. This
suggests that a correct description of long-range interactions is crucial for a
unified description of the solid and liquid phases of carbon.Comment: 4 pages, 5 figure
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