839 resultados para Aza-Michael Addition
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Carme Serrallonga (Barcelona, 1909-1997) començà a traduir als anys seixanta, en moments de represa de consciència ideològica i literària. Bona coneixedora de diversos idiomes, especialment l’alemany, l’anglès, el francès i l’italià, girà al català unes vint obres del teatre universal dels grans autors. Serrallonga explicava que havia començat a aprendre alemany per poder conèixer a fons l’obra de Brecht, del qual el 1966 traduí La bona persona de Sezuan, a proposta de Ricard Salvat, i cinc obres més. De l’alemany també portà al català autors com Georg Büchner, Heinrich Böll, Friedrich Dürrenmatt, Peter Handke, György Lukács, Goethe, Mozart o Alfred Döblin. A més de l’alta literatura alemanya, Serrallonga féu petites incursions en la literatura anglesa i nord-americana, la italiana i, fins i tot, la sud-africana. El 1983 l’editorial La Galera li encarregà la traducció d’En Jim Botó i en Lluc el maquinista de Michael Ende. En sis anys traduí més de trenta títols de literatura infantil. Ja jubilada, a vuitanta-quatre anys, es posà a estudiar rus pel plaer de poder llegir Anna Akhmàtova i Txèkhov en la seva llengua originària. Abans de morir, treballava en la traducció d’un llibre de poemes de l’autora russa.
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PURPOSE: The purpose of our study was to assess whether a model combining clinical factors, MR imaging features, and genomics would better predict overall survival of patients with glioblastoma (GBM) than either individual data type. METHODS: The study was conducted leveraging The Cancer Genome Atlas (TCGA) effort supported by the National Institutes of Health. Six neuroradiologists reviewed MRI images from The Cancer Imaging Archive (http://cancerimagingarchive.net) of 102 GBM patients using the VASARI scoring system. The patients' clinical and genetic data were obtained from the TCGA website (http://www.cancergenome.nih.gov/). Patient outcome was measured in terms of overall survival time. The association between different categories of biomarkers and survival was evaluated using Cox analysis. RESULTS: The features that were significantly associated with survival were: (1) clinical factors: chemotherapy; (2) imaging: proportion of tumor contrast enhancement on MRI; and (3) genomics: HRAS copy number variation. The combination of these three biomarkers resulted in an incremental increase in the strength of prediction of survival, with the model that included clinical, imaging, and genetic variables having the highest predictive accuracy (area under the curve 0.679±0.068, Akaike's information criterion 566.7, P<0.001). CONCLUSION: A combination of clinical factors, imaging features, and HRAS copy number variation best predicts survival of patients with GBM.
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Objective of this work was to clarify the competitive situation of Russian mobile telecommunications market: who are the main players, are there many regional operators, what is the possibility of new entrants and how intensive is the competition. In the beginning the history of Russian mobile telecommunications sector is described. In the next chapter environmental factors of the market are examined with the help of PESTEL analysis. After that, players of the market are introduced to ease the following of next chapters. The main theory for this work was industry analysis of five competitive forces by Michael Porter, which is presented before the theory related industry analysis of Russian mobile telecommunications industry. Research for the industry analysis is mainly based on up-to-date articles describing Russian market. As a result of the industry analysis, competitive situation of Russian mobile telecommunications industry and the future prospects are described with the help of factors coming from the PESTEL-analysis. Finally development and future prospects for Russian 3G are reported. As a result of this work, it can be said that Russian mobile telecommunications market is not likely to maintain the growth of previous years, because the market is near saturation. According to passive SIM-cards it has already received saturated. The saturation will also make the market share game between operators more volatile. The market is dominated by three national operators that covered 88% of the income in the first half of 2007. In addition to these three, there are also several regional operators. Structure of the market is likely to consolidate.
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Ressenya de: Rafael Feito y Juan Ignacio López (eds.): Construyendo escuelas democráticas. Barcelona: Hipatia, 2008.
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Assisted reproductive technologies (ART) induce vascular dysfunction in humans and mice. In mice, ART-induced vascular dysfunction is related to epigenetic alteration of the endothelial nitric oxide synthase (eNOS) gene, resulting in decreased vascular eNOS expression and nitrite/nitrate synthesis. Melatonin is involved in epigenetic regulation, and its administration to sterile women improves the success rate of ART. We hypothesized that addition of melatonin to culture media may prevent ART-induced epigenetic and cardiovascular alterations in mice. We, therefore, assessed mesenteric-artery responses to acetylcholine and arterial blood pressure, together with DNA methylation of the eNOS gene promoter in vascular tissue and nitric oxide plasma concentration in 12-wk-old ART mice generated with and without addition of melatonin to culture media and in control mice. As expected, acetylcholine-induced mesenteric-artery dilation was impaired (P = 0.008 vs. control) and mean arterial blood pressure increased (109.5 ± 3.8 vs. 104.0 ± 4.7 mmHg, P = 0.002, ART vs. control) in ART compared with control mice. These alterations were associated with altered DNA methylation of the eNOS gene promoter (P < 0.001 vs. control) and decreased plasma nitric oxide concentration (10.1 ± 11.1 vs. 29.5 ± 8.0 μM) (P < 0.001 ART vs. control). Addition of melatonin (10(-6) M) to culture media prevented eNOS dysmethylation (P = 0.005, vs. ART + vehicle), normalized nitric oxide plasma concentration (23.1 ± 14.6 μM, P = 0.002 vs. ART + vehicle) and mesentery-artery responsiveness to acetylcholine (P < 0.008 vs. ART + vehicle), and prevented arterial hypertension (104.6 ± 3.4 mmHg, P < 0.003 vs. ART + vehicle). These findings provide proof of principle that modification of culture media prevents ART-induced vascular dysfunction. We speculate that this approach will also allow preventing ART-induced premature atherosclerosis in humans.
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El treball Ressuscitant a Disney: Rastrejant el sempre present esperit de Walt Disney en els llargmetratges animats de l'era Michael Eisner (1984-2004) pretén definir i analitzar les característiques, tant respecte al procés creatiu com en la definició de contingut, integrades en els clàssics originals de Disney per, a continuació, demostrar que aquestes van ser recuperades i implementades de nou després de la mort de Walt Disney -amb lleus adaptacions- per donar lloc a una segona edat d'or de l'animació
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Les empreses intenten obrir mercats nous constantment, aconseguint atraure nous clients objectiu i augmentar el reconeixement de la marca. Aquest treball investiga el cóm i per què el patrocini d'atletes, per a que aquests representin els productes d'una empresa, ja que és una eina cada vegada més àmplia i popular en el màrqueting mix de les empreses. Michael Jordan, un estel retirada de bàsquet, ha rebut molta atenció dels mitjans publicitaris i ha representat sota patrocini a diversos productes. Especialment el seu contracte de patrocini amb Nike, Inc. s'ha convertit en un excel·lent cas d'estudi per analitzar la tendència actual que suposa patrocinar atletes en el mercat internacional. Els resultats d'aquest cas d'estudi ajuden a entendre els factors que poden influir en èxit de les empreses quan decideixen patrocinar a un atleta com a part de la seva estratègia de màrqueting.
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Purpose: We aimed to determine the impact of SPECT/CT performed in addition to whole-‐body scintigraphy augmented with prone lateral views in patients with well-‐differentiated thyroid carcinoma. Methods and Materials: This retrospective study included 141 patients (87 female, 54 male, mean age 47 years) with well-‐differentiated thyroid carcinoma (105 papillary, 31 follicular, 1 Hürthle cell and 4 poorly differentiated) treated with radioiodine therapy (1000-7400 MBq). Patients were referred for either first postsurgical therapy (n=76) or further treatment (n=65). Two nuclear medicine physicians interpreted the scans in consensus (first whole-‐body scintigraphy with prone lateral view, then SPECT/CT) reporting abnormal iodine uptake in the thyroid bed, lymph nodes and distant metastasis. The corresponding ATA risk score was calculated for each patient before and after SPECT/CT, as well as change in disease extension Results: The analysis showed a difference between scintigraphy and SPECT/CT in n=17 lesions in 14 patients (9.9%): 12 were described as suspicious on scintigraphy and could be considered as benign on SPECT/CT (3 corresponded to local iodine uptake, 6 to lymph nodes metastases and 3 to distant metastases). The others 5 corresponded to metastases (4 lymph nodes and 1 distant) that were not seen on whole-‐body scintigraphy augmented with prone lateral views. In 10 of 141 (7.1%) patients, we observed a change in ATA risk stratification, with a risk increase in 4 of them (2.8%). Conclusion: SPECT/CT allowed detecting 5 focal lesions missed on planar scintigraphy, and to precise benignity of 12 suspicious lesions on planar scintigraphy. Moreover, SPECT/CT improved the risk stratification in 10 patients with a significant change in the patient management
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The advent of simple and affordable tools for molecular identification of novel insect invaders and assessment of population diversity has changed the face of invasion biology in recent years. The widespread application of these tools has brought with it an emerging understanding that patterns in biogeography, introduction history and subsequent movement and spread of many invasive alien insects are far more complex than previously thought. We reviewed the literature and found that for a number of invasive insects, there is strong and growing evidence that multiple introductions, complex global movement, and population admixture in the invaded range are commonplace. Additionally, historical paradigms related to species and strain identities and origins of common invaders are in many cases being challenged. This has major consequences for our understanding of basic biology and ecology of invasive insects and impacts quarantine, management and biocontrol programs. In addition, we found that founder effects rarely limit fitness in invasive insects and may benefit populations (by purging harmful alleles or increasing additive genetic variance). Also, while phenotypic plasticity appears important post-establishment, genetic diversity in invasive insects is often higher than expected and increases over time via multiple introductions. Further, connectivity among disjunct regions of global invasive ranges is generally far higher than expected and is often asymmetric, with some populations contributing disproportionately to global spread. We argue that the role of connectivity in driving the ecology and evolution of introduced species with multiple invasive ranges has been historically underestimated and that such species are often best understood in a global context.
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Reactions of 2-acetylindole enolate with unsaturated oxazolopiperidones 3, 4 and 10 unexpectedly gives pentacyclic dilactams 6, 7 and 11, respectively, resulting from a domino-type process involving two successive conjugate additions and a final cyclization.
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Conformational constraint is an approach which can be used to restrict the flexibility of peptide molecules and to provide information on the topographical requirements of receptors. The incorporation of conformationally constrained units in a peptide can lead to peptide analogues that present numerous advantages such as the potentialization of the pharmacological activity and the decrease of enzymatic degradation. This review discusses the peptide analogues containing a lactam or azalactam unit in their sequences. Of particular interest has been the replacement of a dipeptide motif in a peptide that simulates a beta-turn.
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Microfibrillated cellulose (MFC) is known to enhance strength properties of paper. Improved strength usually means increased bonding which is strongly connected to dimensional instability of paper. Dimensional instability is due to changes in moisture content of paper; when paper is moistened it expands and when dried, it shrinks. Hygroexpansion is linked to end-use problems and excessive drying shrinkage consumes strength potential. Effective use of materials requires controlling of these phenomena. There isn’t yet data concerning dimensional stability of papers containing MFC which restricts wider use of MFC. Main objective of the work was to evaluate dimensional stability of wood-free paper containing different amounts of MFC. Sheets were dried with different methods to see how drying strains effected on drying shrinkage and hygroexpansion. Also tensile strength was measured to find out the effect of MFC. Results were compared to sheets containing kraft fines and in some test points cationic starch was used alongside with MFC. MFC increased the dimensional instability of freely dried sheets. As the amounts of MFC increased the effects on dimensional stability became more severe. However the fineness of MFC didn’t play any important role. Both hygroexpansion and drying shrinkage were decreased with cationic starch addition. Prevention of drying shrinkage over powered the effects of additives on hygroexpansion. Tensile strength improved up till 7 % addition amount which could be set as the upper limit of MFC addition when paper preparation and tensile strength are concerned.
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The stereoselective addition of the titanium (IV) enolates derived from (S)-4-isopropyl-N-4-chlorobutyryl-1,3-thiazolidine-2-thione (8) and from (S)-4-isopropyl-N-4-chloropentanoyl-1,3-thiazolidine-2-thione (9) to N-Boc-2-methoxypyrrolidine (5b) afforded the addition products (+)-10 and (+)-11 in 84% yield in both cases, as 8.6:1 and 10:1 diastereoisomeric mixtures, respectively. A three-step sequence allowed to convert these adducts to (+)-isoretronecanol (1) and (+)-5-epi-tashiromine (2) in 43% and 49% overall yield, respectively.
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Semi-hydrogenation of alkynes has industrial and academic relevance on a large scale. To increase the activity, selectivity and lifetime of monometallic catalysts, the development of bimetallic catalysts has been investigated. 1-Heptyne hydrogenation over low-loaded Pd and Ni monometallic and PdNi bimetallic catalysts was studied in liquid phase at mild conditions. XPS results suggest that nickel addition to Pd modifies the electronic state of palladium as nickel loading is increased. Low-loaded Pd catalysts showed the highest selectivities (> 95%). The most active prepared catalyst, PdNi(1%), was more selective than the Lindlar catalyst.