97 research outputs found

    Electron stimulated desorption of atomic oxygen from silver

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    The electron stimulated desorption (ESD) of neutral oxygen atoms from polycrystalline silver and of oxygen ions from Ag(110) has been studied. Polycrystalline Ag charged with (16)O2 and (18)O2 and bombarded by low-energy electrons (approx 100 eV) under ultrahigh vacuum (UHV) conditions emitted O atom flux levels of 1 x 10 to the 12th power/sq cm/s at a Ag temperature of 300 C. The flux was detected with a quadrupole mass spectrometer operating in the appearance potential mode. The neutral cross section at about 100 C was determined to be 7 x 10 to the -19 sq cm. Ancillary experiments conducted in a UHV chamber equipped with a cylindrical mirror analyzer and rigged for ion energy distribution and ion angular distribution were used to study O ions desorbed from Ag(110). Two primary O(+) energies of 2.4 and 5.4 eV were detected from the Ag(110) after having been dosed with 2500 L of (16)O2. It also appears that in both experiments there was strong evidence for directionality of the emitted flux. The results of this study serve as a proof of concept for the development of a laboratory atomic oxygen beam generator that simulates the gas flux environment experienced by orbiting vehicles

    Safety assessment of the South oculus, Canterbury catedral (UK)

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    The South Oculus at Canterbury Cathedral is a wrought iron space frame consisting of two layers (Ferramenta and Grille) connected by tie bars (Pins). It is in very good condition despite its almost 850 years of history. The in situ survey of the Cathedral confirmed that the Ferramenta and the external grille are in general in relative good condition with the exception of some local failures. On the contrary, the pins are the most deteriorated part of the structure. Ambient vibration tests were carried out and the modal response of the structure was identified. In order to assess the safety of the oculus with respect to wind load, a model of the structure was built with the finite element software DIANA and calibrated using the results of the experimental campaign. The non-linear analysis of the existing structure resulted in a safety factor of about ten for the wind load. In addition, parametric studies have highlighted the importance of the external grille for the structure and have provided information of the consequences of further deterioration in terms of the load bearing capacity of the Oculus

    Avaliação da estabilidade do oculus sul da catedral de Cantuária

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    Esta publicação tem por objetivos verificar a estabilidade do oculus sul do transepto da Catedral de Cantuária do Reino Unido quando sujeito ação do vento, e estudar a influência da deterioração e da grelha exterior na sua capacidade de carga. O estudo incluiu a inspeção no local, ensaios de vibração ambiental para identificação das propriedades e a análise numérica. A análise não linear estática permitiu concluir que oculus apresenta um fator de segurança igual a dez quando sujeito à ação do vento

    Bosentan and macitentan prevent the endothelial-to-mesenchymal transition (EndoMT) in systemic sclerosis: in vitro study.

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    Background: Systemic sclerosis (SSc) is characterized by early vascular abnormalities and subsequent fibroblast activation to myofibroblasts, leading to fibrosis. Recently, endothelial-to-mesenchymal transition (EndoMT), a complex biological process in which endothelial cells lose their specific markers and acquire a mesenchymal or myofibroblastic phenotype, has been reported in SSc. In the present study, we evaluated the ability of endothelin-1 (ET-1) dual receptor antagonists bosentan (BOS) and macitentan (MAC) to antagonize EndoMT in vitro. Methods: Ten women with limited SSc were enrolled. They underwent double skin biopsy (affected and nonaffected skin). Fibroblasts and microvascular endothelial cells (MVECs) were isolated from biopsies. We performed mono- or coculture of MVECs (isolated from nonaffected skin) with fibroblasts (isolated from affected skin and stimulated with ET-1 and transforming growth factor beta [TGF-\u3b2]). In cocultures, the MVEC layer was left undisturbed or was preincubated with BOS or MAC. After 48 h of coculture, MVECs were analyzed for their tube formation ability and for messenger RNA and protein expression of different vascular (CD31, vascular endothelial growth factor-A [VEGF-A], VEGF-A165b) and profibrotic (alpha-smooth muscle actin [\u3b1-SMA], collagen type I [Col I], TGF-\u3b2) molecules. Results: After 48 h, MVECs showed a reduced tube formation ability when cocultured with SSc fibroblasts. CD31 and VEGF-A resulted in downregulation, while VEGF-A165b, the antiangiogenic isoform, resulted in upregulation. At the same time, mesenchymal markers \u3b1-SMA, Col I, and TGF-\u3b2 resulted in overexpression in MVECs. Tube formation ability was restored when MVECs were preincubated with BOS or MAC, also reducing the expression of mesenchymal markers and restoring CD31 expression and the imbalance between VEGF-A and VEGF-A165b. Conclusions: With this innovative EndoMT in vitro model realized by coculturing nonaffected MVECs with affected SSc fibroblasts, we show that the presence of a myofibroblast phenotype in the fibroblast layer, coupled with an ET-1-TGF-\u3b2 synergic effect, is responsible for EndoMT. BOS and MAC seem able to antagonize this phenomenon in vitro, confirming previous evidence of endothelium-derived fibrosis in SSc and possible pharmacological interferenc

    Diversity of Epichloë in native grasses from Uruguay

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    Studies on endophyte diversity have allowed to describe at least 43 taxa that belong to the genus Epichloë,including distinct species, subspecies, and varieties[1]. Screenings for grasses associated with Epichloë arecontinuously being done worldwide due to the agronomically important beneficial effects they provide to theirhosts. In spite of this, Epichloë presence and diversity in South America has been poorly studied, with most worksfocused in Argentina, although preliminary studies revealed the presence of Epichloë in grasses from Uruguay. Ourobjective was to assess the diversity of Epichloë associated with native grasses from Uruguay, South America.We sampled native grasses from Uruguay and inspected under microscope for typical Epichloë mycelia theparenchymal tissue from within the culm pith or sheaths stained with aniline blue[2]. Fragments of leaves and culmsof endophyte-infected plants were surface-sterilized and plated in Potatoe Dextrose Agar to isolate Epichloë.Subsequently, we obtained single spore cultures for morphological and molecular characterization by phylogeniesof calM gene and detection by PCR multiplex of alkaloid genes[3, 4].Specimens of Bromus auleticus, Bromus brachyanthera, Calamagrostis alba, Festuca fimbriata, Poalanigera and Polypogon elongatus were detected associated with Epichloë. Morphological differences in colony andmicroscopic characteristics were observed among isolates from different host species, but also among isolates fromthe same host species (B. auleticus and P. lanigera). Phylogenetic analyzes based on calmodulin gene (calM)sequences allowed us to infer at least 5 interspecific hybrid lineages. The E. typhina x E. festucae hybrid, Epichloëtembladerae, was detected in all of the studied hosts except in F. fimbriata. Some isolates from B. auleticus and F.fimbriata were also hybrids between E. typhina and E. festucae but clustered in different clades with endophytes ofthese hosts from Argentina, different from any previously described species. A hybrid isolate (E. baconii x E.typhina) was detected in B. auleticus. One isolate from Bromus auleticus presented three copies of calM indicatinga triple hybrid origin (E. festucae x E. typhina x E. elymi) and grouped in a clade that also included isolates fromArgentina. Alkaloid gene profiling indicated that all of the endophytes have perA gene. The endophytes from F.fimbriata and the triple hybrid were dmaW positive. LolC gene was only detected in some endophytes from B.auleticus. Indole di-terpene gene profiling allowed us to detect variability among isolates considered as E.tembladerae, and only some endophytes of B. auleticus were negative for the screened idt genes.These results suggest a great diversity of endophytes in Uruguay and, although most of the endophyteshave been also detected in Argentina, some lineages seem to be endemic to Uruguay. Taking into account thediversity of grasses in this country and that we only studied a small amount of isolates of each host, it is likely thatmore hosts and endophytes will be discovered in Uruguay.Fil: Mc Cargo, Patricia Débora. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Olivero, Laura Maria. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Corallo, Ana B.. Universidad de la Republica. Facultad de Ingeniería; UruguayFil: Lupo, Sandra. Universidad de la Republica. Facultad de Ingeniería; UruguayFil: Novas, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Iannone, Leopoldo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; Argentina10th International Symposium on Fungal Endophytes of GrassesSalamancaEspañaInstitute of Natural Resources and Agrobiology of Salamanc

    The impact of multidisciplinary team management on outcome of hepatic resection in liver-limited colorectal metastases

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    Hepatic resection is the gold standard treatment for patients affected by liver-limited colorectal metastases. Reports addressing the impact of multidisciplinary team (MDT) evaluation on survival are controversial. The aim of this study was to evaluate the benefit of MDT management in these patients in our Institution experience. The objective of the analysis was to compare survivals of patients managed within our MDT (MDT cohort) to those of patients referred to surgery from other hospitals without MDT discussion (non-MDT cohort). Of the 523 patients, 229 were included in the MDT cohort and 294 in the non-MDT cohort. No difference between the two groups was found in terms of median overall survival (52.5 vs 53.6 months; HR 1.13; 95% CI, 0.88–1.45; p = 0.344). In the MDT cohort there was a higher number of metastases (4.5 vs 2.7; p < 0.0001). The median duration of chemotherapy was lower in MDT patients (8 vs 10 cycles; p < 0.001). Post-operative morbidity was lower in the MDT cohort (6.2 vs 21.5%; p < 0.001). One hundred and ninety-seven patients in each group were matched by propensity score and no significant difference was observed between the two groups in terms of OS and DFS. Our study does not demonstrate a survival benefit from MDT management, but it allows surgery to patients with a more advanced disease. MDT assessment reduces the median duration of chemotherapy and post-operative morbidities

    Humans and Insects Decide in Similar Ways

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    Behavioral ecologists assume that animals use a motivational mechanism for decisions such as action selection and time allocation, allowing the maximization of their fitness. They consider both the proximate and ultimate causes of behavior in order to understand this type of decision-making in animals. Experimental psychologists and neuroeconomists also study how agents make decisions but they consider the proximate causes of the behavior. In the case of patch-leaving, motivation-based decision-making remains simple speculation. In contrast to other animals, human beings can assess and evaluate their own motivation by an introspection process. It is then possible to study the declared motivation of humans during decision-making and discuss the mechanism used as well as its evolutionary significance. In this study, we combine both the proximate and ultimate causes of behavior for a better understanding of the human decision-making process. We show for the first time ever that human subjects use a motivational mechanism similar to small insects such as parasitoids [1] and bumblebees [2] to decide when to leave a patch. This result is relevant for behavioral ecologists as it supports the biological realism of this mechanism. Humans seem to use a motivational mechanism of decision making known to be adaptive to a heterogeneously distributed resource. As hypothesized by Hutchinson et al. [3] and Wilke and Todd [4], our results are consistent with the evolutionary shaping of decision making because hominoids were hunters and gatherers on food patches for more than two million years. We discuss the plausibility of a neural basis for the motivation mechanism highlighted here, bridging the gap between behavioral ecology and neuroeconomy. Thus, both the motivational mechanism observed here and the neuroeconomy findings are most likely adaptations that were selected for during ancestral times

    Optimized EGFR blockade strategies in <i>EGFR</i> addicted gastroesophageal adenocarcinomas

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    Purpose: Gastric and gastroesophageal adenocarcinomas represent the third leading cause of cancer mortality worldwide. Despite significant therapeutic improvement, the outcome of patients with advanced gastroesophageal adenocarcinoma is poor. Randomized clinical trials failed to show a significant survival benefit in molecularly unselected patients with advanced gastroesophageal adenocarcinoma treated with anti-EGFR agents.Experimental Design: We performed analyses on four cohorts: IRCC (570 patients), Foundation Medicine, Inc. (9,397 patients), COG (214 patients), and the Fondazione IRCCS Istituto Nazionale dei Tumori (206 patients). Preclinical trials were conducted in patient-derived xenografts (PDX).Results: The analysis of different gastroesophageal adenocarcinoma patient cohorts suggests that EGFR amplification drives aggressive behavior and poor prognosis. We also observed that EGFR inhibitors are active in patients with EGFR copy-number gain and that coamplification of other receptor tyrosine kinases or KRAS is associated with worse response. Preclinical trials performed on EGFR-amplified gastroesophageal adenocarcinoma PDX models revealed that the combination of an EGFR mAb and an EGFR tyrosine kinase inhibitor (TKI) was more effective than each monotherapy and resulted in a deeper and durable response. In a highly EGFR-amplified nonresponding PDX, where resistance to EGFR drugs was due to inactivation of the TSC2 tumor suppressor, cotreatment with the mTOR inhibitor everolimus restored sensitivity to EGFR inhibition.Conclusions: This study underscores EGFR as a potential therapeutic target in gastric cancer and identifies the combination of an EGFR TKI and a mAb as an effective therapeutic approach. Finally, it recognizes mTOR pathway activation as a novel mechanism of primary resistance that can be overcome by the combination of EGFR and mTOR inhibitors

    reference architecture and framework

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    M. Adorni, F. Arcelli, S. Bandini, L. Baresi, C. Batini, A. Bianchi, D. Bianchini, M. Brioschi, A. Caforio, A. Cali, P. Cappellari, C. Cappiello, T. Catarci, A. Corallo, V. De Antonellis, C. Franza, G. Giunta, A. Limonta, G. Lorenzo, P. Losi, A. Maurino, M. Melideo, D. Micucci, S. Modafferi, E. Mussi, L. Negri, C. Pandolfo, B. Pernici, P. Plebani, D. Ragazzi, C. Raibulet, M. Riva, N. Simeoni, C. Simone, G. Solazzo, F. Tisato, R. Torlone, G. Vizzari, and A. Zill
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