Human Blood Serum X-Ray Diffraction Patterns of Cancer Patients and Pregnant Women

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

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Examination of Rabbit Fc Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100445 ◽

1968 ◽

Vol 26 ◽

pp. 140-141

Author(s):

J. P. Robinson ◽

P. G. Lenhert

Keyword(s):

Molecular Weight ◽

Flat Plate ◽

Phosphate Buffer ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

X Ray ◽

Neutral Ph ◽

Small Crystals ◽

Carbon Coated ◽

Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

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Human Blood Serum Rich in Factor V

Thrombosis and Haemostasis ◽

10.1055/s-0038-1654241 ◽

1970 ◽

Vol 24 (03/04) ◽

pp. 334-337 ◽

Cited By ~ 1

Author(s):

R Honorato

Keyword(s):

Blood Serum ◽

Human Serum ◽

Human Blood ◽

Human Blood Serum ◽

Factor V ◽

The Stability

Summary1. A technique to obtain human serum rich in factor V is described.2. Calcium increases the stability of factor V in the serum.

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Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

Industrial laboratory Diagnostics of materials ◽

10.26896/1028-6861-2020-86-6-29-35 ◽

2020 ◽

Vol 86 (6) ◽

pp. 29-35

Author(s):

V. P. Sirotinkin ◽

O. V. Baranov ◽

A. Yu. Fedotov ◽

S. M. Barinov

Keyword(s):

Phase Composition ◽

Calcium Phosphates ◽

Position Sensitive Detector ◽

Sensitive Detector ◽

X Ray Diffraction ◽

X Ray ◽

Impurity Phases ◽

Position Sensitive ◽

Diffraction Peaks ◽

Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

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