131 research outputs found

    El patrón narrativo de la investigación. La Nueva Filosofía de la Historia a la luz del pragmatismo de John Dewey

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    Dewey's thoughts on historical knowledge should be appreciated under the light of the disputes in contemporary philosophy of history, especially in the narrative drift. On the one hand, as he addresses the subject in terms of narration and writing, this chapter appears as a precursor text of narrativist philosophy of history. Furthermore, given that his accounts on history are framed within a general theory of inquiry (narrative writing of the past is a case of judgment), offers us a useful tool to avoid skeptical readings of narrativism. We find in Deweyan text a strong strategy to give good reasons (in terms of pragmatist rationality) to appeal to literary studies when analyzing the processes of construction and acceptance of historical knowledge. Finally, as he presents narrative as the expression of the temporal phase of inquiry in general, on the one hand, he avoids engaging with the methodological dualism that stablishes substantive differences between history and science, and, on the other, he gives arguments against the collapse between history and artistic literature. However, they will not be expressed in Rankean terms (something that Dewey explicitly rejected) but in pragmatist terms, that is, pointing out a functional difference between historical and artistic narrative.Las reflexiones de Dewey sobre el conocimiento histórico deberían apreciarse a la luz de los desarrollos de la filosofía contemporánea de la historia en su deriva narrativista. Por un lado, en tanto aborda el tema en términos de narración y escritura, se manifiesta como un escrito precursor de dichos desarrollos. Además, en tanto se enmarca en una teoría general de la investigación resulta un insumo de sorprendente actualidad para eludir las lecturas escépticas del narrativismo. Encontramos en el escrito deweyano argumentos para dar buenas razones (en los términos de la racionalidad pragmatista) para recurrir a los estudios literarios a la hora de analizar los procesos de construcción y aceptación del conocimiento histórico. Finalmente,  en tanto  presenta a la narración como la expresión de la fase temporal de la investigación en general, por un lado evita comprometerse con el dualismo metodológico que encuentra diferencias sustantivas entre la historia y la ciencia, y, por otro, da argumentos contra el colapso entre historia y literatura artística, solo que no serán formulados en términos rankeanos (algo que Dewey rechazó explícitamente) sino en términos pragmatistas, es decir, de la diferencia funcional entre la narrativa histórica y la artística

    Total endovascular treatment for extent type 1 and 5 thoracoabdominal aortic aneurysms

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    OBJECTIVE: The study objective was to describe the results of thoracic endovascular aortic repair with the intentional coverage of the celiac artery and distal supramesenteric landing zone for extent type 1 and type 5 thoracoabdominal aortic aneurysms. METHODS: Inclusion criteria were thoracic endovascular aortic repair with celiac artery coverage to treat elective or urgent extent type 1 and 5 thoracoabdominal aortic aneurysms. Primary end points were in-hospital and follow-up survival, freedom from aortic-related mortality, and freedom from reintervention. RESULTS: Thoracoabdominal disease extent was type 1 in 12 patients (71%) and type 5 in 5 patients (29%). Urgent repair was performed in 4 patients (23.5%). Primary technical success was 100%. Early mortality and visceral ischemia did not occur. Permanent spinal cord ischemia rate was 6% (n = 1). Follow-up ranged from 3 to 120 months (interquartile range, 12-36.5). Survival estimate was 85% \ub1 9% (95% confidence interval, 67-94) at 1 year and 49% \ub1 17% (95% confidence interval, 21-78) at 5 years. Cumulative freedom from aortic-related mortality was 94%, and estimated freedom from reintervention at 1 and 5 years was 93% \ub1 7% (95% confidence interval, 68-99). Neither type 1 endoleaks nor distal stent-graft migration causing superior mesenteric artery occlusion was detected. CONCLUSIONS: Thoracic endovascular aortic repair with intentional coverage of celiac artery for extent 1 and 5 thoracoabdominal aortic aneurysms had satisfactory results in selected patients at high risk for open repair. Visceral ischemia did not occur, but spinal cord ischemia is still high at 6%. At midterm follow-up, neither endoleak development nor aortic reintervention was related to the inadequate distal landing zone. Follow-up survival is satisfactory and comparable to open repair

    A peculiar association: the skin and the subcutaneus diverticula of the Southern Screamer (Chauna torquata, Anseriformes)

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    The aim of this work is to describe for the first time the skin and the subcutaneous diverticula at histological level (by light microscopy) of the Southern Screamer Chauna torquata. We found that the main distinguishing features of the skin were the presence of deep and branched epidermal invaginations whereas in the dermis abundant elastic fibers were found. These skin features could provide a great stretchability to the skin which, in turn, are related to the change of volume that may experience the subcutaneous diverticula.. Since screamers are flying birds that soar to great heights, the presence of subcutaneous diverticula together with another anatomical features (like a great skeletal pneumaticity) could favor a body mass reduction and an optimization in its mode of locomotion.Fil: Picasso, Mariana Beatriz Julieta. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: Mosto, María Clelia. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; ArgentinaFil: Tozzi, Romina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Ciencias Básicas. Cátedra de Histología y Embriología; ArgentinaFil: Degrange, Federico Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Barbeito, Claudio Gustavo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Departamento de Ciencias Básicas. Cátedra de Histología y Embriología; Argentin

    A peculiar association: the skin and the subcutaneus diverticula of the Southern Screamer (Chauna torquata, Anseriformes)

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    The aim of this work is to describe for the first time the skin and the subcutaneous diverticula at histological level (by light microscopy) of the Southern Screamer Chauna torquata. We found that the main distinguishing features of the skin were the presence of deep and branched epidermal invaginations whereas in the dermis abundant elastic fibers were found. These skin features could provide a great stretchability to the skin which, in turn, are related to the change of volume that may experience the subcutaneous diverticula.. Since screamers are flying birds that soar to great heights, the presence of subcutaneous diverticula together with another anatomical features (like a great skeletal pneumaticity) could favor a body mass reduction and an optimization in its mode of locomotion.Facultad de Ciencias Naturales y MuseoFacultad de Ciencias Veterinaria

    A peculiar association: the skin and the subcutaneus diverticula of the Southern Screamer (Chauna torquata, Anseriformes)

    Get PDF
    The aim of this work is to describe for the first time the skin and the subcutaneous diverticula at histological level (by light microscopy) of the Southern Screamer Chauna torquata. We found that the main distinguishing features of the skin were the presence of deep and branched epidermal invaginations whereas in the dermis abundant elastic fibers were found. These skin features could provide a great stretchability to the skin which, in turn, are related to the change of volume that may experience the subcutaneous diverticula.. Since screamers are flying birds that soar to great heights, the presence of subcutaneous diverticula together with another anatomical features (like a great skeletal pneumaticity) could favor a body mass reduction and an optimization in its mode of locomotion.Facultad de Ciencias Naturales y MuseoFacultad de Ciencias Veterinaria

    Sustainable Valorisation and Efficient Downstream Processing of Giant Reed by High-Pressure Carbon Dioxide Pretreatment

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    This work investigated the catalytic high-pressure CO2 pretreatment of giant reed. CO2 is a renewable resource; its use does not generate chemical wastes and it can be easily removed and recycled. The effect of the addition of low concentrations of FeCl3 (0.16 wt%) and PEG 400 (1.0 wt%) on the hemicellulose hydrolysis to xylose and xylo-oligosaccharides (XOS) is reported for the first time. Under the optimised pretreatment conditions, the xylan conversion of 82 mol% and xylose and XOS yields of 43 and 20 mol% were achieved, respectively. The solid residues obtained from different pretreatments were used as the substrate for the enzymatic hydrolysis to give glucose. The total glucose yield achieved under the optimised two-step process was 67.8 mol% with respect to the glucan units in the biomass. The results demonstrated that PEG-assisted FeCl3-catalysed scCO(2) pretreatment can produce xylose- or XOS-rich hydrolysates and improve the enzymatic hydrolysis of biomass

    Cytosolic 5'-Nucleotidase II Interacts with the Leucin Rich Repeat of NLR Family Member Ipaf

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    IMP/GMP preferring cytosolic 5'-nucleotidase II (cN-II) is a bifunctional enzyme whose activities and expression play crucial roles in nucleotide pool maintenance, nucleotide-dependent pathways and programmed cell death. Alignment of primary amino acid sequences of cN-II from human and other organisms show a strong conservation throughout the entire vertebrata taxon suggesting a fundamental role in eukaryotic cells. With the aim to investigate the potential role of this homology in protein-protein interactions, a two hybrid system screening of cN-II interactors was performed in S. cerevisiae. Among the X positive hits, the Leucin Rich Repeat (LRR) domain of Ipaf was found to interact with cN-II. Recombinant Ipaf isoform B (lacking the Nucleotide Binding Domain) was used in an in vitro affinity chromatography assay confirming the interaction obtained in the screening. Moreover, co-immunoprecipitation with proteins from wild type Human Embryonic Kidney 293 T cells demonstrated that endogenous cN-II co-immunoprecipitated both with wild type Ipaf and its LRR domain after transfection with corresponding expression vectors, but not with Ipaf lacking the LRR domain. These results suggest that the interaction takes place through the LRR domain of Ipaf. In addition, a proximity ligation assay was performed in A549 lung carcinoma cells and in MDA-MB-231 breast cancer cells and showed a positive cytosolic signal, confirming that this interaction occurs in human cells. This is the first report of a protein-protein interaction involving cN-II, suggesting either novel functions or an additional level of regulation of this complex enzym

    Pure laparoscopic formal right hepatectomy versus anatomical posterosuperior segmental resections : a comparative study

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    Background: To analyze the differences in perioperative outcomes between laparoscopic formal right hepatectomies (RH) and laparoscopic anatomical posterosuperior (PS) resections, including segmentectomies in PS segment SVII and right posterior sectionectomies (segment VI and VII resection). Methods: A retrospective analysis of all patients undergoing laparoscopic formal RHs and anatomical PS resections, including segmentectomies in PS segment SVII and right posterior sectionectomies (segment VI and VII resection), between January 2010 and August 2017 was performed. The two groups were compared in terms of patients’ characteristics, intraoperative parameters, and short-term outcomes. Results: Sixty-eight patients were included of which 32 RHs and 36 anatomical PS resections. In the PS resection group, 18 had a segmentectomy of segment VII and 18 had a bisegmentectomy of both segments VI and VII. Patients’ preoperative data were comparable. The lesion size was higher in the RHs (P<0.001). A significant shorter operative time was found in the PS group: 280 [230–315] vs. 357 [300–463] min in the RH group (P<0.001). Blood loss was comparable: 520 [390–906] in the RHs vs. 560 [370–1,030] in the PS group (P=0.595). The overall morbidity rate was comparable being 25% in the RHs and 22.2% in the PS group (P=1.000). A longer length of stay (LOS) {7 [5–8] vs. 5 [4–7] days, P=0.012} and higher readmission rate (12.5% vs. 0%, P=0.044) was observed in the RHs compared to the PS cohort. Concerning surgical margins, the R0 rate was comparable in the two groups; 90.9% in the RHs vs. 95.2% in the PS group (P=1.000). Conclusions: When deemed feasible based on lesion position and size, the laparoscopic parenchyma-preserving approach using anatomical PS segmental resections is associated with shorter hospital stay and a lower readmission rate in respect to formal RH. Overall, short-term surgical parameters indicated that both procedures are safe and feasible in experienced hands, however both demand a great deal of technical expertise

    Cytosolic 5'-Nucleotidase II Is a Sensor of Energy Charge and Oxidative Stress: A Possible Function as Metabolic Regulator

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    Cytosolic 5'-nucleotidase II (NT5C2) is a highly regulated enzyme involved in the maintenance of intracellular purine and the pyrimidine compound pool. It dephosphorylates mainly IMP and GMP but is also active on AMP. This enzyme is highly expressed in tumors, and its activity correlates with a high rate of proliferation. In this paper, we show that the recombinant purified NT5C2, in the presence of a physiological concentration of the inhibitor inorganic phosphate, is very sensitive to changes in the adenylate energy charge, especially from 0.4 to 0.9. The enzyme appears to be very sensitive to pro-oxidant conditions; in this regard, the possible involvement of a disulphide bridge (C175-C547) was investigated by using a C547A mutant NT5C2. Two cultured cell models were used to further assess the sensitivity of the enzyme to oxidative stress conditions. NT5C2, differently from other enzyme activities, was inactivated and not rescued by dithiothreitol in a astrocytoma cell line (ADF) incubated with hydrogen peroxide. The incubation of a human lung carcinoma cell line (A549) with 2-deoxyglucose lowered the cell energy charge and impaired the interaction of NT5C2 with the ice protease-activating factor (IPAF), a protein involved in innate immunity and inflammation

    Gastrectomy for stage IV gastric cancer. A comparison of different treatment strategies from the SEER database

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    In the West, more than one third of newly diagnosed subjects show metastatic disease in gastric cancer (mGC) with few care options available. Gastrectomy has recently become a subject of debate, with some evidence showing advantages in survival beyond the sole purpose of treatment tumor-related complications. We investigated the survival benefit of different strategies in mGC patients, focusing on the role and timing of gastrectomy. Data were extracted from the SEER database. Groups were determined according to whether patients received gastrectomy, chemotherapy, supportive care. Patients receiving a multimodality treatment were further divided according to timing of surgery, whether performed before (primary gastrectomy, PG) or after chemotherapy (secondary gastrectomy, SG). 16,596 patients were included. Median OS was significantly higher (p&lt;0.001) in the SG (15months) than in the PG (13months), gastrectomy alone (6months), and chemotherapy (7months) groups. In the multivariate analysis, SG showed better OS (HR=0.22, 95%CI=0.18-0.26, p&lt;0.001) than PG (HR=0.25, 95%CI=0.23-0.28, p&lt;0.001), gastrectomy (HR=0.40, 95%CI=0.36-0.44, p&lt;0.001), and chemotherapy (HR=0.42, 95%CI=0.4-0.44, p&lt;0.001). The survival benefits persisted even after the PSM analysis. This study shows survival advantages of gastrectomy as multimodality strategy after chemotherapy. In selected patients, SG can be proposed to improve the management of stage IV disease
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