tundra alpina

Arctic or subarctic regions where tree growth is limited due to low temperatures, the short growing season, and the permanently frozen subsoil. Dominant vegetation consists of ...

antihelmínticos

Agriculture; General agriculture

Agents destructive to parasitic worms. They are used therapeutically in the treatment of infestation with parasitic worms of the helminth class, in humans and animal.

antígenos de superficie

Agriculture; General agriculture

Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls.

antígenos de neoplasias

Agriculture; General agriculture

Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral ...

antígenos de histocompatibilidad

Agriculture; General agriculture

A group of antigens that includes both the major and minor histocompatibility antigens. The former are genetically determined by the major histocompatibility complex. They ...

antígeno nuclear de célula proliferativa

Agriculture; General agriculture

Nuclear antigen with a role in DNA synthesis, DNA repair, and cell cycle progression. PCNA is required for the coordinated synthesis of both leading and lagging strands at the ...