Cell Adherence as a Serious Source of Error in the Haemacytometer Count of Leucocytes in Artificial Suspensions

2009 ◽  
Vol 14 (5) ◽  
pp. 328-336 ◽  
Author(s):  
Jan F. Sällström
Author(s):  
Fred V. Brock ◽  
Scott J. Richardson

This book treats instrumentation used in meteorological surface systems, both on the synoptic scale and the mesoscale, and the instrumentation used in upper air soundings. The text includes material on first- and second-order differential equations as applied to instrument dynamic performance, and required solutions are developed. Sensor physics are emphasized in order to explain how sensors work and to explore the strengths and weaknesses of each design type. The book is organized according to sensor type and function (temperature, humidity, and wind sensors, for example), though several unifying themes are developed for each sensor. Functional diagrams are used to portray sensors as a set of logical functions, and static sensitivity is derived from a sensor's transfer equation, focusing attention on sensor physics and on ways in which particular designs might be improved. Sensor performance specifications are explored, helping to compare various instruments and to tell users what to expect as a reasonable level of performance. Finally, the text examines the critical area of environmental exposure of instruments. In a well-designed, properly installed, and well-maintained meteorological measurement system, exposure problems are usually the largest source of error, making this chapter one of the most useful sections of the book.


1956 ◽  
Vol 2 (3) ◽  
pp. 145-159 ◽  
Author(s):  
Joseph T Anderson ◽  
Ancel Keys

Abstract 1. Methods are described for the separation, by paper electrophoresis and by cold ethanol, of α- and β-lipoproteins in 0.1 ml. of serum, with subsequent analysis of cholesterol in the separated portions. 2. It is shown that both methods of separation yield separated fractions containing substantially the same amounts of cholesterol. 3. Detailed data are given on the errors of measurement for total cholesterol and for cholesterol in the separated lipoprotein fractions. 4. Studies are reported on the stability of cholesterol in stored serum and on paper electrophoresis strips. It is shown that simple drying on filter paper causes no change in cholesterol content and yields a product that is stable for many weeks at ordinary room temperature. 5. The sources of variability in human serum cholesterol values are examined and it is shown that spontaneous intraindividual variability is a much greater source of error than the errors of measurement with these methods.


Author(s):  
F. Riva ◽  
U. Buck ◽  
K. Buße ◽  
R. Hermsen ◽  
E. J. A. T. Mattijssen ◽  
...  

AbstractThis study explores the magnitude of two sources of error that are introduced when extracorporeal bullet trajectories are based on post-mortem computed tomography (PMCT) and/or surface scanning of a body. The first source of error is caused by an altered gravitational pull on soft tissue, which is introduced when a body is scanned in another position than it had when hit. The second source of error is introduced when scanned images are translated into a virtual representation of the victim’s body. To study the combined magnitude of these errors, virtual shooting trajectories with known vertical angles through five “victims” (live test persons) were simulated. The positions of the simulated wounds on the bodies were marked, with the victims in upright positions. Next, the victims were scanned in supine position, using 3D surface scanning, similar to a body’s position when scanned during a PMCT. Seven experts, used to working with 3D data, were asked to determine the bullet trajectories based on the virtual representations of the bodies. The errors between the known and determined trajectories were analysed and discussed. The results of this study give a feel for the magnitude of the introduced errors and can be used to reconstruct actual shooting incidents using PMCT data.


2021 ◽  
Vol 22 (3) ◽  
pp. 1418
Author(s):  
Elham Shahhoseini ◽  
Masao Nakayama ◽  
Terrence J. Piva ◽  
Moshi Geso

This study examined the effects of gold nanoparticles (AuNPs) and/or ionizing radiation (IR) on the viability and motility of human primary colon epithelial (CCD841) and colorectal adenocarcinoma (SW48) cells as well as human primary epidermal melanocytes (HEM) and melanoma (MM418-C1) cells. AuNPs up to 4 mM had no effect on the viability of these cell lines. The viability of the cancer cells was ~60% following exposure to 5 Gy. Exposure to 5 Gy X-rays or 1 mM AuNPs showed the migration of the cancer cells ~85% that of untreated controls, while co-treatment with AuNPs and IR decreased migration to ~60%. In the non-cancerous cell lines gap closure was enhanced by ~15% following 1 mM AuNPs or 5 Gy treatment, while for co-treatment it was ~22% greater than that for the untreated controls. AuNPs had no effect on cell re-adhesion, while IR enhanced only the re-adhesion of the cancer cell lines but not their non-cancerous counterparts. The addition of AuNPs did not enhance cell adherence. This different reaction to AuNPs and IR in the cancer and normal cells can be attributed to radiation-induced adhesiveness and metabolic differences between tumour cells and their non-cancerous counterparts.


2021 ◽  
Vol 13 (3) ◽  
pp. 409
Author(s):  
Howard Zebker

Atmospheric propagational phase variations are the dominant source of error for InSAR (interferometric synthetic aperture radar) time series analysis, generally exceeding uncertainties from poor signal to noise ratio or signal correlation. The spatial properties of these errors have been well studied, but, to date, their temporal dependence and correction have received much less attention. Here, we present an evaluation of the magnitude of tropospheric artifacts in derived time series after compensation using an algorithm that requires only the InSAR data. The level of artifact reduction equals or exceeds that from many weather model-based methods, while avoiding the need to globally access fine-scale atmosphere parameters at all times. Our method consists of identifying all points in an InSAR stack with consistently high correlation and computing, and then removing, a fit of the phase at each of these points with respect to elevation. A comparison with GPS truth yields a reduction of three, from a rms misfit of 5–6 to ~2 cm over time. This algorithm can be readily incorporated into InSAR processing flows without the need for outside information.


2019 ◽  
Vol 9 (20) ◽  
pp. 4350 ◽  
Author(s):  
Minh Hieu Ho ◽  
Thien Bui-Thuan Do ◽  
Nhi Ngoc-Thao Dang ◽  
An Nguyen-My Le ◽  
Hanh Thi-Kieu Ta ◽  
...  

Green electrospinning has attracted great interest since non-toxic solvents were shown to be applicable in the fabrication of fibrous materials while ensuring health safety and environmental protection. Less harmful reagents such as acetone (AC) and acetic acid (AA) have been employed in this field in recent years. However, research in this area is still rare, yielding only preliminary results. In this study, two different types of solvents (pure AC and an AA/AC mixture) were used to fabricate electrospun polycaprolactone (PCL) membranes. Sample morphology, wettability, tensile strength, and chemical composition were compared between two types of membranes. Cell–scaffold interaction was also examined by cell adhesion and proliferation assays. The results demonstrate that the two types of solvents had significant effects on membrane morphology, physical strength, and cell adherence behaviors, which should be considered for different application purposes.


2014 ◽  
Vol 92 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pradipta Banerjee ◽  
Alka Mehta ◽  
C. Shanthi

Collagen, a major structural protein of the ECM, is known for its high cell adherence capacity. This study was conducted to identify regions in collagen that harbour such bioactivity. Collagen from tendon was hydrolysed and the peptides fractionated using ion-exchange chromatography (IEC). Isolated peptide fractions were coated onto disposable dishes and screened for cell adherence and proliferative abilities. Active IEC fractions were further purified by chromatography, and two peptides, C2 and E1 with cell adhesion ability, were isolated. A cell adhesion assay done with different amounts of C2 coated onto disposable dishes revealed the maximum adhesion to be 94.6%, compared with 80% for collagen coated dishes and an optimum peptide coating density of 0.507 nmoles per cm2 area of the dish. Growth of cells on C2, collagen, and E1 revealed a similar pattern and a reduction in the doubling time compared with cells grown on uncoated dishes. C2 had a mass of 2.046 kDa with 22 residues, and sequence analysis revealed a higher percentage occurrence of hydrophilic residues compared with other regions in collagen. Docking studies revealed GDDGEA in C2 as the probable site of interaction with integrins α2β1 and α1β1, and stability studies proved C2 to be mostly protease-resistant.


1988 ◽  
Vol 158 (1) ◽  
pp. 224-228 ◽  
Author(s):  
M. M. Levine ◽  
V. Prado ◽  
R. Robins-Browne ◽  
H. Lior ◽  
J. B. Kaper ◽  
...  

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