125 research outputs found
Surgery of the dilated aortic root and ascending aorta in pediatric patients: techniques and results
Objective: Dilatation of the aortic root is a well-known cardiovascular manifestation in children and adult patients with connective tissue disease (e.g. Marfan syndrome). Dilatation of the ascending aorta is extremely rare and may be associated with bicuspid aortic valve. This report evaluates the incidence of dilatative aortic root and ascending aortic pathology in patients younger than 18 years and analyzes the results obtained after repair and replacement strategies. Methods: Between 1/1995 and 12/2002, a total of 752 operations on the thoracic aorta were performed in adult and pediatric patients. We present our experience with a group of 26 patients <18 years of age, who required isolated surgery of the aortic root and/or ascending aorta because of a dilatative lesion. Fifteen patients had isolated aortic root dilatation (13 of them suffered from Marfan syndrome), eight patients presented with an idiopathic dilatation of the ascending aorta and three patients had dilatation in association with a bicuspid aortic valve. Mean age was 10±4.8 years (4-18 years). Repair of the aortic root with preservation of the aortic valve (Yacoub, David or selective sinus repair) was performed in nine patients, replacement using a homograft was performed in five patients, composite graft with mechanical prosthesis in two patients, with biological prosthesis in one patient and Ross operation was performed in one case. Isolated supracoronary graft replacement was performed in eight patients. Results: Two patients died during hospitalization: a 10-year old girl developed respiratory failure on the 2nd postoperative day and autopsy revealed Ehlers-Danlos syndrome with a massive intrapulmonary emphysema. A 14-year-old Marfan patient with severely depressed preoperative LV function died from low cardiac output following composite-graft, mitral and tricuspid valve repair. One patient required aortic valve replacement 7 days after an aortic valve sparing root repair. There was no additional perioperative morbidity. In the long-term, two patients died from rupture of the thoracic aorta, both following minor non-cardiovascular surgical procedures. Both had normal sized descending and abdominal aorta. Conclusion: Repair of the aortic root and/or ascending aorta in children and adolescent patients can be performed with acceptable early and late results. While the presence of severe comorbidity may adversely affect early outcome, long-term survival was mainly determined by rupture of the descending aort
Surgery of the dilated aortic root and ascending aorta in pediatric patients: techniques and results
Objective: Dilatation of the aortic root is a well-known cardiovascular manifestation in children and adult patients with connective tissue disease (e.g. Marfan syndrome). Dilatation of the ascending aorta is extremely rare and may be associated with bicuspid aortic valve. This report evaluates the incidence of dilatative aortic root and ascending aortic pathology in patients younger than 18 years and analyzes the results obtained after repair and replacement strategies. Methods: Between 1/1995 and 12/2002, a total of 752 operations on the thoracic aorta were performed in adult and pediatric patients. We present our experience with a group of 26 patients <18 years of age, who required isolated surgery of the aortic root and/or ascending aorta because of a dilatative lesion. Fifteen patients had isolated aortic root dilatation (13 of them suffered from Marfan syndrome), eight patients presented with an idiopathic dilatation of the ascending aorta and three patients had dilatation in association with a bicuspid aortic valve. Mean age was 10±4.8 years (4â18 years). Repair of the aortic root with preservation of the aortic valve (Yacoub, David or selective sinus repair) was performed in nine patients, replacement using a homograft was performed in five patients, composite graft with mechanical prosthesis in two patients, with biological prosthesis in one patient and Ross operation was performed in one case. Isolated supracoronary graft replacement was performed in eight patients. Results: Two patients died during hospitalization: a 10-year old girl developed respiratory failure on the 2nd postoperative day and autopsy revealed EhlersâDanlos syndrome with a massive intrapulmonary emphysema. A 14-year-old Marfan patient with severely depressed preoperative LV function died from low cardiac output following composite-graft, mitral and tricuspid valve repair. One patient required aortic valve replacement 7 days after an aortic valve sparing root repair. There was no additional perioperative morbidity. In the long-term, two patients died from rupture of the thoracic aorta, both following minor non-cardiovascular surgical procedures. Both had normal sized descending and abdominal aorta. Conclusion: Repair of the aortic root and/or ascending aorta in children and adolescent patients can be performed with acceptable early and late results. While the presence of severe comorbidity may adversely affect early outcome, long-term survival was mainly determined by rupture of the descending aorta
Sequences of independent Walsh functions in BMO
Under examination are the sequences of independent Walsh functions in the space of functions of bounded mean oscillation. We study geometric properties of the subspaces spanned by the sequences; in particular, some necessary and sufficient conditions are found for such a subspace to be complementedValiderad; 2013; 20130429 (andbra
Specific antidote therapy in dogs: modern aspects
Current laws of the Russian Federation provide for responsible treatment of animals. Nevertheless, there is an acute problem of the growing number of uncared for dogs. The article addresses issues of dog protection focused on the prevention of dog poisoning by medications illegally used by dog hunters, as well as on dog training aspects and methods of specific antidote therapy. Cytoprotective activity of ubiquinone is studied in view of biochemical profile in dogs
Nordic Forest Energy Solutions in the Republic of Karelia
The situation in Karelia, a region in Northwest Russia, is analyzed in the context of forest energy. The annual potential energy available from wood harvesting is about 7 tera watt hours (TWh) (3.6 million m3), which is equal to the total need of Karelia in energy for municipal heating. We point out that the contribution to the municipal economy, the moderate heating cost, the enhanced energy security in the cold Russian climate, the environmental friendliness, the better access to the forests and the utilization of the proven Nordic forest energy solutions (NFES) might have important consequences for strategy-making processes in forest energy development. For this purpose, connecting Analytic Hierarchy Process (AHP) with SWOT (internal strengths (S) or weaknesses (W) and external opportunities (O) or threats (T)) analysis is proposed to identify local operational strategies and assign priorities. Major threats include lack of government support, an insufficient road network, the dominance of extensive forest management, gasification and financial indiscipline. Analysis indicates that NFES are viewed positively for the Russian conditions. The forest biomass market has virtually unlimited opportunities for growth. Together, with the transition to intensive forest management, favorable policy in terms of forestry development programs can support bioenergy development. The advantageous location of existing power plants next to forests, increasing fossil fuel prices, the improvement of the road network and the availability of new technology are seen as potential opportunities for NFES. However, the results also indicate that there is substantial uncertainty and skepticism concerning how such markets benefit forest leaseholders who would like to adopt forest energy. The lack of bioenergy technology development, high transportation cost, low awareness of NFES, high demands for roads, the requirement for skilled specialists and wood fuel quality are the main weaknesses regarding the transfer of NFES to Karelia
Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron
Tevatron Run II combination of the effective leptonic electroweak mixing angle
International audienceDrell-Yan lepton pairs produced in the process ppÂŻââ+â-+X through an intermediate Îł*/Z boson have an asymmetry in their angular distribution related to the spontaneous symmetry breaking of the electroweak force and the associated mixing of its neutral gauge bosons. The CDF and D0 experiments have measured the effective-leptonic electroweak mixing parameter sin2Ξefflept using electron and muon pairs selected from the full Tevatron proton-antiproton data sets collected in 2001-2011, corresponding to 9â10ââfb-1 of integrated luminosity. The combination of these measurements yields the most precise result from hadron colliders, sin2Ξefflept=0.23148±0.00033. This result is consistent with, and approaches in precision, the best measurements from electron-positron colliders. The standard model inference of the on-shell electroweak mixing parameter sin2ΞW, or equivalently the W-boson mass MW, using the zfitter software package yields sin2ΞW=0.22324±0.00033 or equivalently, MW=80.367±0.017ââGeV/c2
Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element
We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96Â TeV. The data correspond to total integrated luminosities of up to 9.7 fb per experiment. The t-channel cross section is measured to be Ï=2.25 pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s+t channel cross section measurement resulting in Ï=3.30 pb, without assuming the standard model value for the ratio Ï/Ï. The resulting value of the magnitude of the top-to-bottom quark coupling is |V|=1.02, corresponding to |V|>0.92 at the 95%Â C.L
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