893 resultados para tree placement


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This article evaluates the results of portal vein (PV) stent placement in patients with malignant extrinsic lesions stenosing or obstructing the PV and causing symptomatic PV hypertension (PVHT). Fourteen patients with bile duct cancer (n = 7), pancreatic adenocarcinoma (n = 4), or another cancer (n = 3) underwent percutaneous transhepatic portal venous stent placement because of gastroesophageal or jejunal varices (n = 9), ascites (n = 7), and/or thrombocytopenia (n = 2). Concurrent tumoral obstruction of the main bile duct was treated via the transhepatic route in the same session in four patients. Changes in portal venous pressure, complications, stent patency, and survival were evaluated. Mean +/- standard deviation (SD) gradient of portal venous pressure decreased significantly immediately after stent placement from 11.2 mmHg +/- 4.6 to 1.1 mmHg +/- 1.0 (P < 0.00001). Three patients had minor complications, and one developed a liver abscess. During a mean +/- SD follow-up of 134.4 +/- 123.3 days, portal stents remained patent in 11 patients (78.6%); stent occlusion occurred in 3 patients, 2 of whom had undergone previous major hepatectomy. After stent placement, PVHT symptoms were relieved in four (57.1%) of seven patients who died (mean survival, 97 +/- 71.2 days), and relieved in six (85.7%) of seven patients still alive at the end of follow-up (mean follow-up, 171.7 +/- 153.5 days). Stent placement in the PV is feasible and relatively safe. It helped to relieve PVHT symptoms in a single session.

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• Grasses rank among the world's most ecologically and economically important plants. Repeated evolution of the C(4) syndrome has made photosynthesis highly efficient in many grasses, inspiring intensive efforts to engineer the pathway into C(3) crops. However, comparative biology has been of limited use to this endeavor because of uncertainty in the number and phylogenetic placement of C(4) origins. • We built the most comprehensive and robust molecular phylogeny for grasses to date, expanding sampling efforts of a previous working group from 62 to 531 taxa, emphasizing the C(4)-rich PACMAD (Panicoideae, Arundinoideae, Chloridoideae, Micrairoideae, Aristidoideae and Danthonioideae) clade. Our final matrix comprises c. 5700 bp and is > 93% complete. • For the first time, we present strong support for relationships among all the major grass lineages. Several new C(4) lineages are identified, and previously inferred origins confirmed. C(3)/C(4) evolutionary transitions have been highly asymmetrical, with 22-24 inferred origins of the C(4) pathway and only one potential reversal. • Our backbone tree clarifies major outstanding systematic questions and highlights C(3) and C(4) sister taxa for comparative studies. Two lineages have emerged as hotbeds of C(4) evolution. Future work in these lineages will be instrumental in understanding the evolution of this complex trait.

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The Diagnosis and Recommendation System (DRIS) was applied to eucalypt trees (hybrids of Eucalyptus grandis x E. urophylla) with different ages and growing under different environmental conditions for three different clones. The basic data were obtained from 1,986 trees of commercial stands cultivated in the states of Espírito Santo and south Bahia, Brazil. The DRIS indices were calculated using the Beaufils' Range formula and grouped according to the Nutrient Application Potential Response method. The objective of this paper was to evaluate the N, P and Ca status in eucalypt trees, regarding the tree ages and genetic materials. The DRIS indices discriminated differences in the nutritional status of the trees, both in relation to age and the genetic materials (clones). The results indicated that the deficiency of N and Ca tended to decrease with tree age, whereas the P deficiency tended to increase. Furthermore, of the three evaluated clones, those numbered 00014 and 00034 showed opposite trends regarding to N, P, and Ca nutrition, and the clone numbered 00021, in general, presented the highest degree of unbalanced nutrition of N, P and Ca.