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811.
Alfonso Romo de Vivar Carlos Guerrero Eduardo Díaz Eugene A. Bratoeff Leticia Jiménez 《Phytochemistry》1976,15(4):525-527
The structure of budlein-A, the main sesquiterpene lactone of Viguiera buddleiaeformis was established as the 8 angeloyl ester of 1 keto, 8-β, 14-dihydroxy germacra-2,4,11 (13)-trien-3, (10 β) oxido-6 α, 12-olide. Its structure and stereochemistry was determined by chemical and spectroscopic means. Budlein-B, found in the same plant as a minor constituent, is 8 α, 15-dihydroxygermacra-1 (10), 4, 11 (13)-trien-6 α, 12-olide. 相似文献
812.
Martín Martínez-Torres Marta E Hernández-Caballero Juana Alba Luis-Díaz Guadalupe Ortiz-López Mario Cárdenas-León Leticia Moreno-Fierros 《Reproductive biology and endocrinology : RB&E》2010,8(1):19
Background
Several studies have shown that the corpus luteum is the principal source of progesterone during the gravidity period in reptiles; however, its participation in the maintenance of gestation in the viviparous squamata is in dispute. The effects of ovariectomy or luteectomy vary according to the species and the time at which the procedure is performed. In this paper, we describe the effects of luteectomy during early pregnancy on the maintenance of gestation and progesterone concentrations in the temperate Mexican viviparous lizard Barisia imbricata imbricata. 相似文献813.
814.
TMEM16A inhibition impedes capacitation and acquisition of hyperactivated motility in guinea pig sperm 下载免费PDF全文
815.
Leticia Jiménez-González Miriam Álvarez-Corral Manuel Muñoz-Dorado Ignacio Rodríguez-García 《Phytochemistry Reviews》2008,7(1):125-154
Among the phytoalexins with the highest antifungal activity is the isoflavonoid based group of pterocarpans. Here, we present
a comprehensive inventory of the structures and sources of pterocarpans, and summarize some of their most interesting biological
activities. 相似文献
816.
Matthijs van Veelen Julián García Leticia Avilés 《Journal of theoretical biology》2010,264(4):1240-87
Cooperation and grouping are regularly studied as separate traits. The evolution of sociality however requires both that individuals get together in groups and that they cooperate within them. Because the level of cooperation can influence selection for group size, and vice versa, it is worth studying how these traits coevolve. Using a generally applicable two-trait optimization approach, we provide analytical solutions for three specific models. These solutions describe how cooperative associations of non-relatives evolve, and predict how large and how cooperative they will be. The analytical solutions help understand how changes in parameter values, such as the group carrying capacity and the costs of cooperation, affect group size and the level of cooperation in equilibrium. Although the analytical model makes a few simplifying assumptions—populations are assumed to be monomorphic for grouping as well as for cooperative tendencies, and group size is assumed to be deterministic—simulations show that its predictions are matched quite closely by results for settings where these assumptions do not hold. 相似文献
817.
818.
819.
Mexico has two main types of coasts, an Amero-trailing-edge coast along the Gulf of Mexico and a collision coast along the Pacific, each of which determine the characteristics of their coastal lagoons. The lagoons along the Gulf of Mexico are extensive, tropical and rich in seagrass beds and mangroves, and among these Laguna Madre has 84 species of fishes. In contrast, the lagoons along the Pacific are small, closed, mostly oligohaline and usually lack seagrass beds, and among these Laguna Salinas del Padre has 19 species of fishes. This marked difference in species richness, in turn, has a direct effect on the size and value of the fisheries, as these are regional in the first case and local and seasonal in the second. 相似文献
820.
Leticia Quintanilla-Martinez Daphne de Jong Antoine de Mascarel Eric D. Hsi Philip Kluin Yaso Natkunam Marie Parrens Stefano Pileri German Ott 《Journal of Hematopathology》2009,2(4):211-236
The term “gray-zone” lymphoma has been used to denote a group of lymphomas with overlapping histological, biological, and clinical features between various types of lymphomas. It has been used in the context of Hodgkin lymphomas (HL) and non-Hodgkin lymphomas (NHL), including classical HL (CHL), and primary mediastinal large B cell lymphoma, cases with overlapping features between nodular lymphocyte predominant Hodgkin lymphoma and T-cell/histiocyte-rich large B cell lymphoma, CHL, and Epstein–Barr-virus-positive lymphoproliferative disorders, and peripheral T cell lymphomas simulating CHL. A second group of gray-zone lymphomas includes B cell NHL with intermediate features between diffuse large B cell lymphoma and classical Burkitt lymphoma. In order to review controversial issues in gray-zone lymphomas, a joint Workshop of the European Association for Hematopathology and the Society for Hematopathology was held in Bordeaux, France, in September 2008. The panel members reviewed and discussed 145 submitted cases and reached consensus diagnoses. This Workshop summary is focused on the most controversial aspects of gray-zone lymphomas and describes the panel’s proposals regarding diagnostic criteria, terminology, and new prognostic and diagnostic parameters. 相似文献