Energy-Filtering Transmission Electron Microscopy of Biological Specimens

By energy-filtering transmission electron microscopy (EFTEM) electrons can be separated by their energy losses. An electron-energy filter, added to the microscope column allows the measurement of the energy distribution of transmitted electrons that have lost energy (\u3c 2,000 eV, with an energy resolution of ~ 1 eV). These filtered electrons, recorded either as a spectrum or as an image, are composed of two parts superimposed on top of each other: (a) the unspecific energy-loss population (= the continuum) and (b) the specific element-related energy-loss population (= the edges). At the edges, electron data in spectra and images are mathematically processed, to obtain the desired element-related net-intensity values or images. These data are related to the total transmitted electron intensity, from the zero-and low-loss spectral region giving the relative spectral-or image intensity ratios (SR*x, IR*x), which can be related to the element concentration. The acquisition of the zero-loss and low-loss data is hampered by the restricted dynamic range of the TV camera. By improvements through the introduction of calibrated attenuation filters in the optical path to the TV-camera, more reliable values for SR*x and IR*x can be acquired. By addition of Bio-standards adjacent to the tissue, a known and unknown concentration of the element present in the same ultrathin section and the bias in the concentration estimation, can be obtained. Some practical examples are given for the estimation of the iron concentration in siderosomes, boron in melanosomes and calcium in calcium oxalate monohydrate crystals

Energy-Filtering Transmission Electron Microscopy as a Tool for Structural and Compositional Analysis of Isolated Ferritin Particles

Structural and compositional analysis of isolated horse-spleen ferritin particles was performed by energy filtering transmission electron microscopy (EFTEM). Ferritin particles were collected in ultrathin (2 nm thick) chromium films and analyzed without any additional stain by electron energy-loss spectroscopy (EELS) for iron and carbon and by electron-spectroscopic imaging (ESI) for carbon. The ultrastructure of the proteinaceous shell of the ferritin particle, as obtained by the carbon net-intensity electron spectroscopical and carbon concentration-distribution images, was qualitatively compared to the structure as acquired by a negative-staining procedure. Quantitative analysis of the number of carbon atoms in the ferritin-shell proteins was carried out through an ESI-acquisition protocol and processing procedure with calibrated attenuation filters in the optical path to the TV camera. This procedure included images acquired with calibrated attenuation filters for the compensation of shading and the non-linear performance of the TV camera used in the analytical part of the procedure. A new ESI-Spectra program is proposed that allows element-related spectra to be generated at any place and with any frame size in a contrast-sensitive or other type of image present on the computer monitor screen

The Consumer Quality Index Hip Knee Questionnaire measuring patients' experiences with quality of care after a total hip or knee arthroplasty

<p>Abstract</p> <p>Background</p> <p>The Dutch Consumer Quality Index Hip Knee Questionnaire (CQI Hip Knee) was used to assess patients' experiences with and evaluations of quality of care after a total hip (THA) or total knee arthroplasty (TKA). The aim of this study is to evaluate the construct validity and internal consistency reliability of this new instrument and to assess its ability to measure differences in quality of care between hospitals.</p> <p>Methods</p> <p>Survey data of 1,675 subjects who underwent a THA or TKA were used to evaluate the psychometric properties. Exploratory factor analyses were performed and item-total correlations and inter-factor correlations were calculated to assess the construct validity of the instrument. Reliability analyses included tests of internal consistency (Cronbach's alpha coefficients). Finally, multilevel analyses were performed to assess the ability of the instrument to discriminate between hospitals in quality of care.</p> <p>Results</p> <p>Exploratory factor analyses indicated that the survey consisted of 21 items measuring five aspects of care (i.e. communication with nurses, communication with doctors, communication with general practitioner, communication about new medication, and pain control). Cronbach's alpha coefficients ranged from 0.76 to 0.90 indicating good internal consistency. The survey's ability to discriminate between hospitals was partly supported by multilevel analysis. Two scales (i.e. communication with nurses and communication with doctors) were able to measure differences between hospitals with respect to patients' experiences with quality of care. Logistic multilevel analyses indicated that hospitals explained part of the variation between patients in receiving information.</p> <p>Conclusion</p> <p>These findings suggest that the CQI Hip Knee is reliable and valid for use in Dutch health care. Health care providers or health plans can use this survey to measure patients' experiences with hospital care and to identify variations in care between hospitals.</p

The role of rewards and demands in burnout among surgical nurses

Job rewards have both, an intrinsic and an extrinsic motivational potential, and lead to employees’ development as well as help them to achieve work goals. Rewards can balance job demands and protect from burnout. Due to changes on the labour market, new studies are needed. The aim of our study was to examine the role of demands and individual rewards (and their absence) in burnout among surgical nurses. Materials and Methods: The study was conducted in 2009 and 2010 with 263 nurses who worked in surgical wards and clinics in hospitals in Southern Poland. The hypotheses were tested by the use of measures of demands and rewards (Effort-Reward Imbalance Questionnaire by Siegrist) and burnout syndrome (Maslach Burnout Inventory). A cross-sectional, correlational study design was applied. Results: Nurses experienced the largest deficiencies in salary and prestige. Exhaustion was explained by stronger demands and lack of respect (large effect). Depersonalization was explained by stronger demands, lack of respect and greater job security (medium effect). Reduced personal achievement was explained by more demands and greater job security (small effect). Conclusions: Excessive demands and lack of esteem are key reasons for burnout among surgical nurses. Job security can increase burnout when too many resources are invested and career opportunities do not appear. These results may help to improve human resource management in the healthcare sector

Colour measurement and white blood cell recognition

As a part of a collaboration with NEMCH aimed at the automation of the differential white blood cell count, studies have been made of the different possibilities for using colour to help in the recognition process. Results are presented comparing data obtained with a microspectrophotometer and with a simulated three-colour scanner