Shock-formed carbon materials with intergrown sp- and sp-bonded nanostructured units.

Studies of dense carbon materials formed by bolide impacts or produced by laboratory compression provide key information on the high-pressure behavior of carbon and for identifying and designing unique structures for technological applications. However, a major obstacle to studying and designing these materials is an incomplete understanding of their fundamental structures. Here, we report the remarkable structural diversity of cubic/hexagonally (/) stacked diamond and their association with diamond-graphite nanocomposites containing sp-/sp-bonding patterns, i.

Diamond-Graphene Composite Nanostructures.

The search for new nanostructural topologies composed of elemental carbon is driven by technological opportunities as well as the need to understand the structure and evolution of carbon materials formed by planetary shock impact events and in laboratory syntheses. We describe two new families of diamond-graphene (diaphite) phases constructed from layered and bonded sp and sp nanostructural units and provide a framework for classifying the members of this new class of materials. The nanocomposite structures are identified within both natural impact diamonds and laboratory-shocked samples and possess diffraction features that have previously been assigned to lonsdaleite and postgraphite phases.

Quantifying hexagonal stacking in diamond.

Diamond is a material of immense technological importance and an ancient signifier for wealth and societal status. In geology, diamond forms as part of the deep carbon cycle and typically displays a highly ordered cubic crystal structure. Impact diamonds, however, often exhibit structural disorder in the form of complex combinations of cubic and hexagonal stacking motifs.

Duration of action of mepivacaine and lidocaine in equine palmar digital perineural blocks in an experimental lameness model.

Objective: To establish and compare the onset and duration of action of 2 local anesthetics based on objective lameness and skin sensitivity assessment.

Study Design: Interventional crossover experimental trial with balanced randomization.

Animals: Eight horses.

An ex vivo biomechanical study comparing strength characteristics of a new technique with the three-loop pulley for equine tenorrhaphy.

Objective: To test single cycle to failure tensile strength characteristics of 6 suture material-pattern combinations in equine superficial digital flexor (SDF) tenorrhaphy, specifically to compare a 10-strand modification of the Savage core suture technique with the 3-loop pulley technique.

Study Design: Ex vivo mechanical experiment comparing 3 different suture patterns with 2 different materials.

Sample Population: Forelimb and hindlimb SDF tendons (n=48) harvested from adult Thoroughbred and Standardbred horses of mixed age and gender.

Effects of treatment with omeprazole or ranitidine on gastric squamous ulceration in racing Thoroughbreds.

Objective: To compare the effects of oral administration of omeprazole and ranitidine on gastric squamous ulceration in Thoroughbreds in race training.

Design: Modified crossover study.

Animals: 60 Thoroughbreds in race training with gastric squamous mucosal ulceration.