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Biomedical subjects

A Stern

Publications and source records attributed to A Stern.

At least 253 records · Page 14Linked to original sources
PubMed1975

[Comparative study of 4 types of polyester arterial prostheses].

The authors report a comparative study of 4 types of arterial prosthesis made of polyester. After implantation in the dog, the superiority of unfolded Rhodergon velvet prostheses was shown. They have excellent qualities for tissue reconstruction owing to presence of histological structures characteristic of large caliber arteries and absence of histological changes and hemorrhagic suffusion after the 12 th month following insertion.

Animals↗
PubMed1970

An approach to conformational analysis of peptides and proteins in solution based on a combination of nuclear magnetic resonance spectroscopy and conformational energy calculations.

Simple criteria, based on the combined use of nmr spectral parameters and potential energy maps, are proposed for the conformational analysis of polypeptides and proteins. Experimentally determined coupling constants (3)J(NC) for the N-C(alpha) bond are consistent with the Karplus-Bystrov relationship. It is proposed therefore that (3)J(NC) can be used to distinguish (a) between right-and left-handed alpha-helices, (b) between alpha-helical, beta-pleated sheet, and randomly coiled forms of peptides. The average (3)J(NC) for the random coil is predicted. The criteria proposed are valid for both L- and D-amino acids. Correlation between the Karplus-Bystrov relationship for (3)J(NC) and the peptide conformational potential energy map limits the possible values of the N-C(alpha) dihedral angle varphi of each amino acid residue in a polypeptide and protein, and therefore presents a method of conformational analysis in solution superior to the use of either nmr or conformational maps alone. Nmr studies of hydrogen bonding or neighboring-group diamagnetic anisotropy reduce the number of possibilities consistent with the above criteria. A suggestion for evaluating the dihedral angle is presented. These criteria are useful provided the coupling constant is not obscured by line broadening.

Amino Acids↗