Biomedical subjects

Chaoming Song

Publications and source records attributed to Chaoming Song.

4 recordsLinked to original sources

PubMed2006

[Treatment of complex acetabular fractures by a modified extended iliofemoral approach].

OBJECTIVE: To evaluate the effect of the modified extended iliofemoral approach on treating complex acetabular fractures. METHODS: Thirty-six cases of complex acetabular fractures were treated by the open reposition and internal fixation by a modified extended iliofemoral approach. RESULTS: Thirty-six cases were followed up for 7-46 months, with an average of 23.8 months. According to the Matta standard, anatomical reposition was performed in 24 cases, perfect reposition in 8 cases, and unsatisfactory reposition in 4 cases. By the modified d'Aubigne-postel score, among the 36 cases, 22 had an excellent result, 9 had a good result, and 5 had a poor result. CONCLUSION: The modified extended iliofemoral approach facilitates the operative exposure of the anterior and posterior walls and both columns of the acetabulum in the surgically-treated acetabular fractures by the open reposition and internal fixation. Because of the reconstruction, the functions of the abductor muscle mass managed by the lag-screw-fixed osteotomies of the iliac crest, and greater trochanter, the patients can achieve a rapid rehabilitation of the joint.

Acetabulum↗

PubMed2005

Granular dynamics in compaction and stress relaxation.

Elastic and dissipative properties of granular assemblies under uniaxial compression are studied both experimentally and by numerical simulations. Following a novel compaction procedure at varying oscillatory pressures, the stress response to a step strain reveals an exponential relaxation followed by a slow logarithmic decay. Simulations indicate that the latter arises from the coupling between damping and collective grain motion predominantly through sliding. We characterize an analogous "glass transition" for packed grains, below which the system shows aging in time-dependent sliding correlation functions.

Journal Article↗

PubMed2005

Experimental measurement of an effective temperature for jammed granular materials.

A densely packed granular system is an example of an out-of-equilibrium system in the jammed state. It has been a longstanding problem to determine whether this class of systems can be described by concepts arising from equilibrium statistical mechanics, such as an effective temperature and compactivity. The measurement of the effective temperature is realized in the laboratory by slowly shearing a closely packed ensemble of spherical beads confined by an external pressure in a Couette geometry. All of the probe particles considered in this study, independent of their characteristic features, equilibrate at the same temperature, given by the packing density of the system.

Journal Article↗

PubMed2005

Self-similarity of complex networks.

Complex networks have been studied extensively owing to their relevance to many real systems such as the world-wide web, the Internet, energy landscapes and biological and social networks. A large number of real networks are referred to as 'scale-free' because they show a power-law distribution of the number of links per node. However, it is widely believed that complex networks are not invariant or self-similar under a length-scale transformation. This conclusion originates from the 'small-world' property of these networks, which implies that the number of nodes increases exponentially with the 'diameter' of the network, rather than the power-law relation expected for a self-similar structure. Here we analyse a variety of real complex networks and find that, on the contrary, they consist of self-repeating patterns on all length scales. This result is achieved by the application of a renormalization procedure that coarse-grains the system into boxes containing nodes within a given 'size'. We identify a power-law relation between the number of boxes needed to cover the network and the size of the box, defining a finite self-similar exponent. These fundamental properties help to explain the scale-free nature of complex networks and suggest a common self-organization dynamics.

Journal Article↗