ANION EXCHANGE WITH LIQUID AMMONIA: SEPARATION AND IDENTIFICATION OF THE MAIN COMPONENTS OF SULFUR-AMMONIA SOLUTIONS

1990 ◽  
Vol 48 (1-4) ◽  
pp. 275-278 ◽  
Author(s):  
S. Seelert ◽  
U. Schindewolf
Author(s):  
H. Engelhardt ◽  
R. Guckenberger ◽  
W. Baumeister

Bacterial photosynthetic membranes contain, apart from lipids and electron transport components, reaction centre (RC) and light harvesting (LH) polypeptides as the main components. The RC-LH complexes in Rhodopseudomonas viridis membranes are known since quite seme time to form a hexagonal lattice structure in vivo; hence this membrane attracted the particular attention of electron microscopists. Contrary to previous claims in the literature we found, however, that 2-D periodically organized photosynthetic membranes are not a unique feature of Rhodopseudomonas viridis. At least five bacterial species, all bacteriophyll b - containing, possess membranes with the RC-LH complexes regularly arrayed. All these membranes appear to have a similar lattice structure and fine-morphology. The lattice spacings of the Ectothiorhodospira haloohloris, Ectothiorhodospira abdelmalekii and Rhodopseudomonas viridis membranes are close to 13 nm, those of Thiocapsa pfennigii and Rhodopseudomonas sulfoviridis are slightly smaller (∼12.5 nm).


Author(s):  
C. Wolpers ◽  
R. Blaschke

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.


Author(s):  
W. J. Abramson ◽  
H. W. Estry ◽  
L. F. Allard

LaB6 emitters are becoming increasingly popular as direct replacements for tungsten filaments in the electron guns of modern electron-beam instruments. These emitters offer order of magnitude increases in beam brightness, and, with appropriate care in operation, a corresponding increase in source lifetime. They are, however, an order of magnitude more expensive, and may be easily damaged (by improper vacuum conditions and thermal shock) during saturation/desaturation operations. These operations typically require several minutes of an operator's attention, which becomes tedious and subject to error, particularly since the emitter must be cooled during sample exchanges to minimize damage from random vacuum excursions. We have designed a control system for LaBg emitters which relieves the operator of the necessity for manually controlling the emitter power, minimizes the danger of accidental improper operation, and makes the use of these emitters routine on multi-user instruments.Figure 1 is a block schematic of the main components of the control system, and Figure 2 shows the control box.


Author(s):  
Emil Bernstein

An interesting method for examining structures in g. pig skin has been developed. By modifying an existing technique for splitting skin into its two main components—epidermis and dermis—we can in effect create new surfaces which can be examined with the scanning electron microscope (SEM). Although this method is not offered as a complete substitute for sectioning, it provides the investigator with a means for examining certain structures such as hair follicles and glands intact. The great depth of field of the SEM complements the technique so that a very “realistic” picture of the organ is obtained.


1976 ◽  
Vol 73 ◽  
pp. 849-851 ◽  
Author(s):  
Thomas Kottarathil ◽  
Gérard Lepoutre

1994 ◽  
Vol 33 (01) ◽  
pp. 60-63 ◽  
Author(s):  
E. J. Manders ◽  
D. P. Lindstrom ◽  
B. M. Dawant

Abstract:On-line intelligent monitoring, diagnosis, and control of dynamic systems such as patients in intensive care units necessitates the context-dependent acquisition, processing, analysis, and interpretation of large amounts of possibly noisy and incomplete data. The dynamic nature of the process also requires a continuous evaluation and adaptation of the monitoring strategy to respond to changes both in the monitored patient and in the monitoring equipment. Moreover, real-time constraints may imply data losses, the importance of which has to be minimized. This paper presents a computer architecture designed to accomplish these tasks. Its main components are a model and a data abstraction module. The model provides the system with a monitoring context related to the patient status. The data abstraction module relies on that information to adapt the monitoring strategy and provide the model with the necessary information. This paper focuses on the data abstraction module and its interaction with the model.


1979 ◽  
Author(s):  
Takashi Morita ◽  
Craig Jackson

Bovine Factor X is eluted in two forms (X1and X2) from anion exchange chromatographic columns. These two forms have indistinguishable amino acid compositions, molecular weights and specific activities. The amino acid sequences containing the γ-carboxyglutamic acid residues have been shown to be identical in X1 and X2(H. Morris, personal communication). An activation peptide is released from the N-terminal region of the heavy chain of Factor X by an activator from Russell’s viper venom. This peptide can be isolated after activation by gel filtration on Sephadex G-100 under nondenaturing conditions. The activation peptides from a mixture of Factors X1 and X2 were separated into two forms by anion-exchange chromatography. The activation peptide (AP1) which eluted first was shown to be derived from Factor X1. while the activation peptiae (AP2) which eluted second was shown to be derived from X2 on the basis of chromatographic separations carried out on Factors X1 and X2 separately. Factor Xa was eluted as a symmetrical single peak. On the basis of these and other data characterizing these products, we conclude that the difference between X1 and X2 are properties of the structures of the activation peptides. (Supported by a grant HL 12820 from the National Heart, Lung and Blood Institute. C.M.J. is an Established Investigator of the American Heart Association).


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