Amplitude–phase calibration of tri-axial accelerometers in the low-frequency range by a LDV

A method for amplitude–phase calibration of tri-axial accelerometers in the low-frequency range (0 to 20&thinsp;Hz) is proposed, based on a linear slide, used to excite all the axes of the accelerometer at the same time, and a laser Doppler vibrometer (LDV) as a reference. For the phase evaluation different methods, like cross-correlation analysis and cross-spectrum analysis, have also been used for validation purposes. The procedure includes many further validation actions in order to verify the correctness of modelling of the systems being tested, of the data processing and to reduce the calibration uncertainty. Results show that the phase is a critical aspect to consider in calibration, more than the amplitude, and the comparison with the theoretical model is useful to verify the hypotheses. Different behaviours result depending on the elements of the measurement chain and not only on the type of accelerometer.</p

Is overexpression of HER-2 a predictor of prognosis in colorectal cancer?

<p>Abstract</p> <p>Background</p> <p>The development of novel chemotherapeutic agents in colorectal cancer has improved survival. Following initial response to chemotherapeutic strategies many patients develop refractory disease. This poses a significant challenge common to many cancer subtypes. Newer agents such as Bevacizumab have successfully targeted the tyrosine kinase receptor epidermal growth factor receptor in metastatic colorectal cancer. Human epidermal growth factor receptor-2 is another member of the tyrosine kinase receptor family which has been successfully targeted in breast cancer. This may play a role in colorectal cancer. We conducted a clinicopathological study to determine if overexpression of human epidermal growth factor receptor-2 is a predictor of outcome in a cohort of patients with colorectal cancer.</p> <p>Methods</p> <p>Clinicopathological data and paraffin-embedded specimens were collected on 132 consecutive patients who underwent colorectal resections over a 24-month period at Mayo General Hospital. Twenty-six contained non-malignant disease. Her-2/neu protein overexpression was detected using immunohistochemistry (IHC). The HER-2 4B5 Ventana monoclonal antibody was used. Fluorescent insitu hybridisation (FISH) was performed using INFORM HER-2/Neu Plus. Results were correlated with established clinical and pathological predictors of outcome including TNM stage. Statistical analysis was performed using SPSS version 11.5.</p> <p>Results</p> <p>114 were HER-2/Neu negative using IHC, 7 showed barely perceptible positivity (1+), 9 showed moderate staining (2+) and 2 were strongly positive (3+). There was no correlation with gender, age, grade, Dukes' stage, TNM stage, time to recurrence and 5-year survival (p > 0.05). FISH was applied to all 2+ and 3+ cases as well as some negative cases selected at random. Three were amplified (2 were 3+ and 1 was 2+). Similarly, HER-2 gene overexpression did not correlate with established prognostic indicators.</p> <p>Conclusion</p> <p>HER-2 protein is over expressed in 11% of colorectal cancer patients. The gene encoding HER-2 is amplified in 3% of cases. Overexpression of HER-2 is not a predictor of outcome. However, patients who over express HER-2 may respond to Herceptin therapy.</p

The population-based oncological health care study OVIS – recruitment of the patients and analysis of the non-participants

<p>Abstract</p> <p>Background</p> <p>The ageing of the population is expected to bring an enormous growth in demand for oncological health care. In order to anticipate and respond to future trends, cancer care needs to be critically evaluated. The present study explores the possibility of conducting representative and population-based research on cancer care on the basis of data drawn from the Cancer Registry.</p> <p>Methods</p> <p>A population-based state-wide cohort study (OVIS) has been carried out in Schleswig-Holstein, Germany. All patients with malignant melanoma, breast, or prostate cancer were identified in the Cancer Registry. Epidemiological data were obtained for all the patients and screened for study eligibility. A postal questionnaire requesting information on diagnosis, therapy, QoL and aftercare was sent to eligible patients.</p> <p>Results</p> <p>A total of 11,489 persons diagnosed with the cancer types of interest in the period from January 2002 to July 2004 were registered in the Cancer Registry. Of the 5,354 (47%) patients who gave consent for research, 4,285 (80% of consenters) completed the questionnaire. In terms of relevant epidemiological variables, participants with melanoma were not found to be different from non-participants with the same diagnosis. However, participants with breast or prostate cancer were slightly younger and had smaller tumours than patients who did not participate in our study.</p> <p>Conclusion</p> <p>Population-based cancer registry data proved to be an invaluable resource for both patient recruitment and non-participant analysis. It can help improve our understanding of the strength and nature of differences between participants and non-respondents. Despite minor differences observed in breast and prostate cancer, the OVIS-sample seems to represent the source population adequately.</p

Metrological characterization of MEMS accelerometers by LDV

In this work two calibration methodologies, able to characterize the digital sensitivity of MEMS accelerometers, are presented and compared, to identify the contributions for the evaluation of the reproducibility in the low frequency range. The methodologies are different from the point of view of test bench, test procedure and data processing method. In particular, different vibration actuators are used, a linear slide and an electro-dynamic shaker, different sensors as a reference for the calibration, piezoelectric accelerometers and a Laser Doppler Vibrometer (LDV). A group of 5 accelerometers is tested for the purpose of developing the calibration techniques and evaluate a first reproducibility estimate. The experimental results provided by the two calibration procedures show significant differences. Some elements that could explain these differences have been identified, and will be further investigated in future work

Metrological traceability of a digital 3-axis MEMS accelerometers sensor network

6noTraceability of digital 3-axis MEMS accelerometer networks is often disregarded by manufacturers and end-users due to the lack of suitable calibration procedures and to the complexity in managing a large number of sensitivities. To overcome these problems, two traceable independent accelerometer calibration systems and methods using inclined planes have been recently developed by a national metrology institute and a calibration laboratory at an uncertainty level of 2 %. In this work, main and transverse magnitude sensitivities of 25 digital 3-axis MEMS accelerometers, part of a sensor network prototype conceived for structural monitoring at low-frequencies, are evaluated at three low-frequencies by the two laboratories. Comparison shows compatible results. Furthermore, a method for decreasing the number of sensitivity and uncertainty data to be managed by sensor network end-users is also proposed. It is shown that its number can be reduced preserving the required traceability at the expense of higher uncertainties up to 4.5 %.nonenonePrato A.; Mazzoleni F.; D'Emilia G.; Gaspari A.; Natale E.; Schiavi A.Prato, A.; Mazzoleni, F.; D'Emilia, G.; Gaspari, A.; Natale, E.; Schiavi, A