A Test Procedure for Simultaneous Determination of Resolving Power and Image Surface of Fluorographic Cameras

Background: Partial least squares (PLS) and principal component regression (PCR) are two well-known chemometric methods based on dimension reduction techniques. They can be very practical analyzing a large data set of multiple correlated predictor variables. Objective: In the presented work, the resolving power of spectrophotometric assisted mathematical techniques was implemented for the simultaneous determination of two active ingredients; ephedrine hydrochloride (EPH) and naphazoline nitrate (NAPH), in a matrix of excipients. Methods: To build the PLS and PCR models, a calibration set was prepared where the two drugs, in combination with the interfering parabens, were modeled by multilevel multifactor design. The proposed models successfully predicted the concentrations of both drugs in validation samples with low root mean squared error of prediction (RMSEP). Results: The results revealed the ability of the mentioned multivariate calibration models to analyze EPH and NAPH in presence of the interfering parabens with high selectivity in the concentration ranges of 4.00-20.00 µg mL-1 and 1.00-9.00 µg mL-1, respectively. Conclusion: A commercially available nasal spray was successfully analyzed using the developed methods without interfering with other dosage form additives.

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A general computer program for the extended plate overlap algorithm

International Astronomical Union Colloquium ◽

10.1017/s0252921100074236 ◽

1978 ◽

Vol 48 ◽

pp. 287-293 ◽

Cited By ~ 1

Author(s):

Chr. de Vegt ◽

E. Ebner ◽

K. von der Heide

Keyword(s):

Computer Program ◽

Simultaneous Determination ◽

General Computer Program ◽

General Computer

In contrast to the adjustment of single plates a block adjustment is a simultaneous determination of all unknowns associated with many overlapping plates (star positions and plate constants etc. ) by one large adjustment. This plate overlap technique was introduced by Eichhorn and reviewed by Googe et. al. The author now has developed a set of computer programmes which allows the adjustment of any set of contemporaneous overlapping plates. There is in principle no limit for the number of plates, the number of stars, the number of individual plate constants for each plate, and for the overlapping factor.

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Transmission Electron Microscopy of Protein Macromolecules

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066176 ◽

1971 ◽

Vol 29 ◽

pp. 424-425

Author(s):

Henry S. Slayter

Keyword(s):

Biological Systems ◽

Metal Vapor ◽

Resolving Power ◽

Electron Microscopic ◽

Chemical Methods ◽

Molecular Weights ◽

The Past ◽

Physical Chemical ◽

Transmission Electron

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

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Experimental Determination of the Effective Resolution Limit in Thick Specimens at High Voltages

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100116942 ◽

1975 ◽

Vol 33 ◽

pp. 664-665

Author(s):

Mircea Fotino

Keyword(s):

Experimental Approach ◽

Chromatic Aberration ◽

Resolving Power ◽

Biological Research ◽

Specimen Thickness ◽

Resolution Limit ◽

High Voltage Electron Microscopy ◽

Voltage Electron ◽

Resolution Level

The use of thick specimens (0.5 μm to 5.0 μm or more) is one of the most resourceful applications of high-voltage electron microscopy in biological research. However, the energy loss experienced by the electron beam in the specimen results in chromatic aberration and thus in a deterioration of the effective resolving power. This sets a limit to the maximum usable specimen thickness when investigating structures requiring a certain resolution level.An experimental approach is here described in which the deterioration of the resolving power as a function of specimen thickness is determined. In a manner similar to the Rayleigh criterion in which two image points are considered resolved at the resolution limit when their profiles overlap such that the minimum of one coincides with the maximum of the other, the resolution attainable in thick sections can be measured by the distance from minimum to maximum (or, equivalently, from 10% to 90% maximum) of the broadened profile of a well-defined step-like object placed on the specimen.

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