conclusions glenohumeral joint reduction with reconstruction of the humeral head seems to be possible even in a neglected locked posterior shoulder fracture-dislocation. if the depressed osteochondral fragment is still spheric, signs of the avascular necrosis are absent on ct, and mal:union: of the fragment has occurred, it is quite possible to reconstruct the head. although results of the case...

By determining the extent of racemization of aspartic acid in a well-dated bone, it is possible to calculate the in situ first-order rate constant for the interconversion of the L and D enantiomers of aspartic acid. Collagen-based radiocarbon-dated bones are shown to be suitable samples for use in "calibrating" the racemization reaction. Once the aspartic-acid racemization reaction has been "ca...

The recent discovery of binary objects in the Kuiper Belt opens an invaluable window into past and present conditions in the trans-Neptunian part of the Solar System. For example, knowledge of how these objects formed can be used to impose constraints on planetary formation theories. We have recently proposed a binary object formation model based on the notion of chaosassisted capture (CAC). In...

The reaction of alpha-chymotrypsin with AcTyr-OEt and with AcTrp-OEt at pH 7.0 and 7.8 was studied over a wide range of substrate concentrations. The reaction with AcTyr-OEt at pH 7.8 was shown to be non-hyperbolic using a variety of criteria whereas those at pH 7.0 with the same substrate and at both pH values with AcTrp-OEt were hyperbolic. The non-hyperbolicity of the reaction with AcTyr-OEt...

Mathematical models of biochemical reaction networks are usually high dimensional, nonlinear, and have many unknown parameters, such as reaction rate constants, or unspecified types of chemical kinetics (such as mass-action, Michaelis-Menten, or Hill kinetics). On the other hand, important properties of these dynamical systems are often determined by the network structure, and do not depend on ...

Ethoxyethyl 3-octylamino-2-cyanoacrylate and related com pounds in which the amino group was replaced by N -C H 3, S, O and CH 2 were synthesized and their activity as inhibitors o f the Hill reaction in isolated pea chloroplasts determined. All com pounds showed moderate to high activity but there was no obvious correlation between activity and the electronic character o f the ester carbonyl g...