103 research outputs found

    The carotid and vertebral arteries discovery – initial findings

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    The studies on the vascular system, including the cervicocephalic arteries (carotid and vertebral arteries), present a long trajectory, having their deep roots in the far past, considering the Western authors, having as representatives the Greek sages Alcmaeon, Diogenes, Hippocrates, Aristoteles, Rufus, and Galenus. They produced pivotal knowledge dissecting mainly cadavers of animals, and established solid bases for the later generations of scholars. The information assembled from these six authors makes it possible to build a quite clear picture of the vascular system, here specifically focused on the cervicocephalic arteries, and mainly of the extracranial segments. Thus, the carotid system became fairly well identified, origin, course, and name, as well as the origin of the still unnamed arteries running through the orifices of the transversal processes of the cervical vertebrae, and entering into the cranium. Almost all that was then known about human anatomy, since this period, and then throughout the Middle Ages, was extrapolated from animal dissections. This state of affairs was maintained until the 14th century, when human corpses dissections were again allowed

    The arterial circle described by Willis, and the contribution of his predecessors

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    The description of arteries at the base of the human brain forming an ‘arterial circle’, named after Thomas Willis, has had a long history after the restoration of human dissection, partly due to the studies of many outstanding anatomists that preceded Willis. He provided, with the collaboration of Richard Lower and Christopher Wren, the first incontestable complete description, as recognized nowadays, accompanied by a superb illustration. Additionally, he presented an explanation for its meaning, indicating for the first time the functional significance of this structure, in health and disease. However, it should be recognized that the initial studies of the arteries of the base of the human brain by Willis’ predecessors, as well as those from ancient times, despite their fragmentary descriptions, were certainly pivotal in paving the way for further and more detailed knowledge of this vascular formatio

    Statistical aspects of the TNK-S2B trial of tenecteplase versus alteplase in acute ischemic stroke: an efficient, dose-adaptive, seamless phase II/III design

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    Background TNK-S2B, an innovative, randomized, seamless phase II/III trial of tenecteplase versus rt-PA for acute ischemic stroke, terminated for slow enrollment before regulatory approval of use of phase II patients in phase III

    Estudos preliminares sobre a fertilidade dos solos de sequeiros em algumas zonas de Santiago.

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    A b s t r a c t : D r y l a n d f a r m i n g o n t h e s t e e p s l o p e s o f S a n t i a g o i s c a r a c t e r i z e d a s l o w i n p u t f a r m i n g . E v e r y y e a r t h e f a r m e r s p r e p a r e a n d c u l t i v a t e t h e i r l a n d s , b u t t h e r e h a s n o t b e e n a n y s t u d y t o i d e n t i f y a n d q u a n t i f y t h e l i m i t i n g f a c t o r e s c a u s i n g t h e d e c l i n e i n p r o d u c t i o n e v e n i n y e a r s o f g o o d r a i n f a l l . I n 1 9 8 7 , a y e a r o f g o o d r a i n f a l l , o n e c o u l d i d e n t i f y s m a l l áreas a r o u n d t h e f a r m e r ' s h o u s e s , w h e r e t h e c o r n a n d b e a n s d i d n o t s h o w a n y s i g n o f m i n e - r a l d i f i c i e n c y O n t h e o t h e r h a n d , t h e d i f i c i e n c y s y m p t o m s b e c a m e m o r e s e v e r e w i t h t h e d i s t a n c e f r o m t h e h o u - s e s . T h e o b j e c t i v e s o f t h i s s t u d y w e r e t o d e t e r m i n e n u t r i e n t l e v e i s i n t h e s o i l s a n d p l a n t s , a n d t o i d e n t i f y p o s s i b l e l i m i t i n g f a c t o r s i n t h e d r y l a n d a g r i c u l t u r a T h u s , f i v e r e p r e s e n t a t i v e áreas w e r e c h o s e n i n Ribeira de Faveta a n d Assomada w i t h d i f f e r e n c e s i n c o r n p l a n t v i g o r a n d s t a n d . S o i l a n d p l a n t s a m p l e s w e r e t a k e n a n d a n a l y s e d f o r m a c r o e l e m e n t s a n d m i c r o e l e m e n t s i n t h e l a b o r a t o r y . A l s o , p l a n t h e i g h t , p l a n t d e n s i t y , s l o p e , a s p e c t , a n d t h e d i s - t a n c e a w a y f r o m t h e h o u s e s w e r e m e a s u r e d . R e s u l t s o f s o i l a n d p l a n t a n a l y s i s i d e n t i f i e d P o t a s s i u m a n d P h o s p h o - r o u s t o b e r e l a t e d w i t h p l a n t h e i g h t

    Redução de fósforo em dietas para frangos com base em valores de equivalência da fitase

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    The objective of this work was to evaluate the use of equivalency values of phytase as a basis for reduction of available phosphorus (aP) in broiler diets. Ten nutritional programs were evaluated with six replicates of 15 birds each. The following were evaluated: performance, tibia ash content, and feed costs. From 1 to 7 and 36 to 42 days of age, the birds received basal diet; from 8 to 21 days, diet without phytase containing 3.9 g kg-1 aP and four diets with phytase containing from 1.1 to 2.5 g kg-1 aP; and from 22 to 35 days, diet without phytase containing 3.4 g kg-1 aP plus diet with phytase containing 1.6 g kg-1 aP. The best nutritional plan was formed by the diets: 4.7 g kg-1 aP without phytase (1 to 7 days); 2.0 g kg-1 aP supplemented with phytase (8 to 21 days); 3.4 g kg-1 aP in feed without phytase (22 to 35 days); and 3.0 g kg-1 aP in feed without phytase (36 to 42 days). The reduction of aP occurs in the period from 8 to 21 days of age and corresponds to 2.0 g kg-1 of feed supplemented with phytase.O objetivo deste trabalho foi avaliar o uso de valores de equivalência da fitase como base para redução de fósforo disponível (P-disp) em dietas para frangos. Foram avaliados dez planos nutricionais com seis repetições de 15 aves cada uma. Avaliaram-se: desempenho, teor de cinzas na tíbia e custo da ração. De 1 a 7 e de 36 a 42 dias de idade, as aves receberam dieta basal; de 8 a 21 dias, dieta sem fitase contendo 3,9 g kg-1 de P-disp e quatro dietas com fitase contendo de 1,1 a 2,5 g kg-1 de P-disp; e de 22 a 35 dias, dieta sem fitase contendo 3,4 g kg-1 de P-disp mais dieta com fitase contendo 1,6 g kg-1 de P-disp. O melhor plano nutricional foi composto pelas dietas: 4,7 g kg-1 de P-disp sem fitase (1 a 7 dias); 2,0 g kg-1 de P-disp suplementada com fitase (8 a 21 dias); 3,4 g kg-1 de P-disp em ração sem fitase (22 a 35 dias); e 3,0 g kg-1 de P-disp em ração sem fitase (36 a 42 dias). A redução do P-disp ocorre no período de 8 a 21 dias de idade e corresponde a 2,0 g kg-1 de ração suplementada com fitase
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