Computer controlled stopped-flow studies. Application to simultaneous kinetic analyses

1972 ◽  
Vol 44 (12) ◽  
pp. 1934-1939 ◽  
Author(s):  
Donald. Sanderson ◽  
John A. Bittikofer ◽  
Harry L. Pardue
1977 ◽  
Vol 23 (7) ◽  
pp. 1230-1237 ◽  
Author(s):  
H L Pardue ◽  
H T Gaw ◽  
G E Mieling ◽  
V L Mathews ◽  
D M Fast ◽  
...  

Abstract This paper describes the evaluation of a system for computer-controlled discrete sampling and stopped-flow mixing for equilibrium and kinetic determinations of several sorts of analytes in human serum. The instrumental system features a wash-out sampling system that permits rapid change-over from one sample and (or) reagent type to another, and a mixing-measurement system that can provide reliable data as soon as 10 ms after reagent and sample are mixed. Examples discussed include equilibrium procedures for glucose and cholesterol, slow kinetic procedures for glucose and lactate dehydrogenase, and a fast kinetic method for thiocyanate. The regression equation for all stopped-flow results (n = 114) vs. results by conventional methods is y = (103 +/- 0.01)x - (0.016 +/- 0.019) for numerical values of y between 0.3 and 3.0. The correlation coefficient for these data was 0.991. These results demonstrate that the stopped-flow method is a viable analytical approach for equilibrium, slow kinetic, and fast kinetic determinations that require measurement times shorter than 0.1 s.


1976 ◽  
Vol 48 (12) ◽  
pp. 1686-1693 ◽  
Author(s):  
Glen E. Mieling ◽  
Richard W. Taylor ◽  
Larry G. Hargis ◽  
James. English ◽  
Harry L. Pardue

Author(s):  
M.F. Schmid ◽  
R. Dargahi ◽  
M. W. Tam

Electron crystallography is an emerging field for structure determination as evidenced by a number of membrane proteins that have been solved to near-atomic resolution. Advances in specimen preparation and in data acquisition with a 400kV microscope by computer controlled spot scanning mean that our ability to record electron image data will outstrip our capacity to analyze it. The computed fourier transform of these images must be processed in order to provide a direct measurement of amplitudes and phases needed for 3-D reconstruction.In anticipation of this processing bottleneck, we have written a program that incorporates a menu-and mouse-driven procedure for auto-indexing and refining the reciprocal lattice parameters in the computed transform from an image of a crystal. It is linked to subsequent steps of image processing by a system of data bases and spawned child processes; data transfer between different program modules no longer requires manual data entry. The progress of the reciprocal lattice refinement is monitored visually and quantitatively. If desired, the processing is carried through the lattice distortion correction (unbending) steps automatically.


Author(s):  
R. J. Lee ◽  
J. S. Walker

Electron microscopy (EM), with the advent of computer control and image analysis techniques, is rapidly evolving from an interpretative science into a quantitative technique. Electron microscopy is potentially of value in two general aspects of environmental health: exposure and diagnosis.In diagnosis, electron microscopy is essentially an extension of optical microscopy. The goal is to characterize cellular changes induced by external agents. The external agent could be any foreign material, chemicals, or even stress. The use of electron microscopy as a diagnostic tool is well- developed, but computer-controlled electron microscopy (CCEM) has had only limited impact, mainly because it is fairly new and many institutions lack the resources to acquire the capability. In addition, major contributions to diagnosis will come from CCEM only when image analysis (IA) and processing algorithms are developed which allow the morphological and textural changes recognized by experienced medical practioners to be quantified. The application of IA techniques to compare cellular structure is still in a primitive state.


Author(s):  
Robert W. Mackin

This paper presents two advances towards the automated three-dimensional (3-D) analysis of thick and heavily-overlapped regions in cytological preparations such as cervical/vaginal smears. First, a high speed 3-D brightfield microscope has been developed, allowing the acquisition of image data at speeds approaching 30 optical slices per second. Second, algorithms have been developed to detect and segment nuclei in spite of the extremely high image variability and low contrast typical of such regions. The analysis of such regions is inherently a 3-D problem that cannot be solved reliably with conventional 2-D imaging and image analysis methods.High-Speed 3-D imaging of the specimen is accomplished by moving the specimen axially relative to the objective lens of a standard microscope (Zeiss) at a speed of 30 steps per second, where the stepsize is adjustable from 0.2 - 5μm. The specimen is mounted on a computer-controlled, piezoelectric microstage (Burleigh PZS-100, 68/μm displacement). At each step, an optical slice is acquired using a CCD camera (SONY XC-11/71 IP, Dalsa CA-D1-0256, and CA-D2-0512 have been used) connected to a 4-node array processor system based on the Intel i860 chip.


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