scholarly journals Spiral imaging artifact reduction: A comparison of two k-trajectory measurement methods

2009 ◽  
Vol 29 (6) ◽  
pp. 1485-1492 ◽  
Author(s):  
Silke M. Lechner ◽  
Pekka T. Sipilä ◽  
Florian Wiesinger ◽  
Adam B. Kerr ◽  
Mika W. Vogel
Keyword(s):  
Measurement Methods ◽  
Artifact Reduction ◽  
Spiral Imaging ◽  
Imaging Artifact ◽  
Trajectory Measurement

Bonafide Substructure in the Core of Ferritin

1985 ◽  
Vol 43 ◽  
pp. 322-323
Author(s):  
William H. Massover
Keyword(s):  
Phase Contrast ◽  
Central Cavity ◽  
Amplitude Image ◽  
Ultrastructural Studies ◽  
The Core ◽  
Hydrated Ferric Oxide ◽  
Imaging Artifact ◽  
Contrast Image ◽  
Protein Shell ◽  
Regular Patterns

Each molecule of ferritin (d = 130Å) contains a core of iron surrounded by a 24-subunit protein shell. The amount of iron stored is variable and is present within the central cavity (d = 80Å) as a hydrated ferric oxide equivalent to the mineral, ferrihydrite. Many early ultrastructural studies of ferritin detected regular patterns of a multiparticulate substructure in the iron-rich core [e.g., 3,4], Each small particle was termed a “micelle“; a theory became widely accepted that a core consisted of up to six micelles positioned at the vertices of an octahedron. Other workers recognized that the apparent micelles were smaller or even disappeared if images were recorded closer to exact focus [e.g., 5]. In 1969, Haydon clearly established that the observed substructure was really an imaging artifact; each apparent micelle was only a dot in the underfocused phase contrast image of the supporting film superimposed on the amplitude image of the strongly scattering metal.

A critical comparison of selected implicit measurement methods.

2018 ◽  
Vol 11 (4) ◽  
pp. 249-266 ◽  
Author(s):  
Judith Znanewitz ◽  
Lisa Braun ◽  
David Hensel ◽  
Claudia Fantapié Altobelli ◽  
Fabian Hattke
Keyword(s):  
Measurement Methods ◽  
Critical Comparison ◽  
Implicit Measurement

MR Imaging with Metal Artifact Reduction to Differentiate between Patients with and without Infected Total Hip Arthroplasty

2018 ◽  
Author(s):  
Benedikt Schwaiger ◽  
Alexandra Gersing ◽  
Daniela Muenzel ◽  
Julia Dangelmaier ◽  
Peter Prodinger ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Mr Imaging ◽  
Hip Arthroplasty ◽  
Artifact Reduction ◽  
Metal Artifact ◽  
Metal Artifact Reduction ◽  
Total Hip

Calibration of a Lyophilized Pooled Plasma as Candidate Reference Plasma for Standardization of the Prothrombin Time Ratio

1993 ◽  
Vol 13 (02) ◽  
pp. 96-105 ◽  
Author(s):  
H. Beeser ◽  
U. Becker ◽  
H. J. Kolde ◽  
E. Spanuth ◽  
P. Witt ◽  
...  
Keyword(s):  
Prothrombin Time ◽  
International Study ◽  
International Normalized Ratio ◽  
Measurement Methods ◽  
Factor V ◽  
Diagnostic Instruments ◽  
Plasma Pool ◽  
Normal Plasma ◽  
German Association ◽  
Prothrombin Time Ratio

SummaryThe prothrombin time (PT), obtained from a fresh normal plasma pool (FPP), is the basis both for the establishment of the 100% activity (normal plasma) and for the ratio calculation used in the International Normalized Ratio (INR) according to the recommendations of the ICSH/ICTH (6). Today the PT of lyophilized normal plasma pools are successfully used as reference for the assessment of samples in proficiency studies. However, a lack of comparability is to be recognized. Therefore the Committee of Hematology of the German Association of Diagnostics’ and Diagnostic Instruments’ Manufacturers (VDGH) decided to produce a candidate reference plasma (VDGH Reference Plasma) which was calibrated against fresh normal plasma pools in an international study.The basic calibration was performed by using the same certified BCR thromboplastin (BCT/099) by all participants. The endpoint was determined manually and by using the coagulometer Schnitger-Gross. In additional testings each participant used his own routine thromboplastins and methods. Calculating the ratio [PT VDGH Reference Plasma (sec)/PT fresh normal plasma pool (sec)] the VDGH Reference Plasma showed a deviation from the average fresh normal plasma pool of 1.05 both with the BCT/099 and with all thromboplastins. There were obtained some statistical differences between “plain” and “combined’’ (added factor V and fibrinogen) thromboplastins. No statistical difference was found between the different endpoint measurement methods (manual, mechanical, optical).In spite of these statistical deviations the VDGH Reference Plasma can be used for the standardization of the PT-normal (100%) value with different ratios for plain (1.06) and combined (1.02) thromboplastins. The manufacturers will use this VDGH Reference Plasma for the calibration of their commercially available calibration plasmas, which allows the user of such a material to calculate a calibrated 100% PT value.

Defining and assessing walkability: a concept for an integrated approach using surveys, biosensors and geospatial analysis

2019 ◽  
Vol 62 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Linda Dörrzapf ◽  
Anna Kovács-Győri ◽  
Bernd Resch ◽  
Peter Zeile
Keyword(s):  
Spatial Planning ◽  
Recent Literature ◽  
Integrated Approach ◽  
Measurement Methods ◽  
Transport Mode ◽  
Positive Effects ◽  
Spatial Environment ◽  
Planning Processes ◽  
Valuable Complement ◽  
Definition Of

AbstractWalking as a transport mode is still often underrepresented in the overall transport system. Consequently, pedestrian mobility is usually not recorded statistically in the same manner as it is performed for motorised traffic which leads to an underestimation of its importance and positive effects on people and cities. However, the integration of walkability assessments is potentially a valuable complement in urban planning processes through considering important quantitative and qualitative aspects of walking in cities. Recent literature shows a variety of approaches involving discrepancies in the definition of walkability, the factors which contribute to it, and methods of assessing them. This paper provides a new understanding of the concept of walkability in the European context. Our approach relies on the extension of methodological competence in transportation, spatial planning and geography by linking new measurement methods for evaluating walkability. We propose an integrated approach to assessing walkability in a comprehensive methodology that combines existing qualitative and GIS-based methods with biosensor technologies and thus captures the perceptions and emotions of pedestrians. This results in an increased plausibility and relevance of the results of walkability analysis by considering the spatial environment and its effect on people.

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