Biomedical subjects

J S Martins

Publications and source records attributed to J S Martins.

4 recordsLinked to original sources

PubMed2001

Nonlinear network dynamics on earthquake fault systems.

Earthquake faults occur in interacting networks having emergent space-time modes of behavior not displayed by isolated faults. Using simulations of the major faults in southern California, we find that the physics depends on the elastic interactions among the faults defined by network topology, as well as on the nonlinear physics of stress dissipation arising from friction on the faults. Our results have broad applications to other leaky threshold systems such as integrate-and-fire neural networks.

Journal Article↗

PubMed2001

Computer simulations for biological aging and sexual reproduction.

The sexual version of the Penna model of biological aging, simulated since 1996, is compared here with alternative forms of reproduction as well as with models not involving aging. In particular we want to check how sexual forms of life could have evolved and won over earlier asexual forms hundreds of million years ago. This computer model is based on the mutation-accumulation theory of aging, using bits-strings to represent the genome. Its population dynamics is studied by Monte Carlo methods.

Aging↗

PubMedDate not supplied

Exploitation of parasite derived antigen in therapeutic success of human cutaneous leishmaniasis in Brazil.

In a complete study in 25 patients with American cutaneous leishmaniasis, caused by Leishmania braziliensis complex, immunotherapeutic efficacy of parasite derived antigen (94-67 KD) has been compared to antimonial therapy. Additionally, to delineate the mechanism of therapeutic success, microscopical features of immune response in active lesions and healed or non-healed lesions following therapy were analyzed. The results showed that cure rates in immunotherapy and chemotherapy were equal (> 83%). The immunohistochemical changes in two therapeutic groups were also largely similar. The analysis of humoral and cellular immune response suggest that appropriate stimulation of T helper cells in the lesion site, in association with one or more cytokines, play a key role in the healing process.

Adolescent↗

PubMedDate not supplied

[Fractures of the mandibular condyle. Therapeutic controversies].

The condylar mandibular fractures are important because its incidence, possible complications and controversial treatment. The treatment of condylar fractures has generated more controversy and discussion than any other in the field of maxillofacial trauma. The main goal of treatment is restoration of function and not anatomic restoration of parts. Despite several clinical and anatomical studies still lack consensus regarding the best method of treatment. This review article focus on the controversy that surrounds treatment of the condylar fractures, trying to supply consensus about questions like: Should condylar mandibular fractures be managed via a closed or open technique? What is the best surgical approach? Surgical timing? What is the degree and duration of mandibular immobilization? Is or not necessary to treat the ATM disc?

Adolescent↗