169,979 research outputs found
Jansen (J. C. G. M.). Landbouw en economische golfoeweging in Zuid-Limburg 1250-1800. Een analyse van de tiendopbrengsten
No full textDaelemans Franck. Jansen (J. C. G. M.). Landbouw en economische golfoeweging in Zuid-Limburg 1250-1800. Een analyse van de tiendopbrengsten. In: Revue belge de philologie et d'histoire, tome 60, fasc. 2, 1982. Histoire médiévale, moderne et contemporaine — Middeleeuwse, moderne en hedendaagse geschiedenis. pp. 499-501
Synthesis and Antitumor Activity of C-7-Alkynylated and Arylated Pyrrolotriazine C-Ribonucleosides
No full textA number of biologically active nucleoside analogues contain the adenine isostere 4-amino-pyrrolo[2,1-f][1,2,4]triazine connected to various sugar moieties through a C-C anomeric linkage. We employed palladium-catalyzed cross-coupling chemistry to promptly functionalize the 7-position of such a heterocyclic scaffold with various alkynyl and aryl groups starting from a common 7-iodo-pyrrolotriazine C-ribonucleoside intermediate. Analogues bearing a 7-cyclopropyl-, 7-propyl-, and 7-butylacetylene moiety displayed potent cytotoxic activity, with the latest being the most selective of this series toward cancer cells. Further insights revealed that such C-nucleosides could exert their antiproliferative action by causing dose-dependent DNA damage.sponsorship: Q.L. thanks the China Scholarship Council (CSC) for funding (grant 201506890014). The authors wish to thank Chantal Biernaux for editorial help. (China Scholarship Council (CSC)|201506890014)status: Publishe
Overview of the author identification task at PAN 2014
No full textThe author identification task at PAN-2014 focuses on author verification. Similar to PAN-2013 we are given a set of documents by the same author along with exactly one document of questioned authorship, and the task is to determine whether the known and the questioned documents are by the same author or not. In comparison to PAN-2013, a significantly larger corpus was built comprising hundreds of documents in four natural languages (Dutch, English, Greek, and Spanish) and four genres (essays, reviews, novels, opinion articles). In addition, more suitable performance measures are used focusing on the accuracy and the confidence of the predictions as well as the ability of the submitted methods to leave some problems unanswered in case there is great uncertainty. To this end, we adopt the c@1 measure, originally proposed for the question answering task. We received 13 software submissions that were evaluated in the TIRA framework. Analytical evaluation results are presented where one language-independent approach serves as a challenging baseline. Moreover, we continue the successful practice of the PAN labs to examine meta-models based on the combination of all submitted systems. Last but not least, we provide statistical significance tests to demonstrate the important differences between the submitted approaches
The role of algorithm bias vs information source in leraning algorithms for morphosyntactic disambiguation
No full textXylo-C-nucleosides with a pyrrolo [2,1-f] [1,2,4]triazin-4-amine heterocyclic base: Synthesis and antiproliferative properties
No full textThe synthesis of a xylo-C-nucleoside containing pyrrolo[2,1-f][1,2,4]triazin-4-amine as nucleobase along with that of its 1'-cyano analogue is described. Among different experimental conditions explored in order to optimize a key debenzylation step in the presented synthetic route, it was found that palladium catalyzed hydrogen transfer allowed for obtaining the target compounds in good yields. The resulting mixture of epimers was separated and each was characterized by NOESY NMR experiments. In vitro antiproliferative assays showed that the 1'-unsubstituted analogue was active against a panel of tumor cell lines such as the human leukemia HL-60 (IC50 = 1.9 µM) and lung cancer NCI-H460 (IC50 = 2.0 µM) cells.sponsorship: P.N. would like to thank the China Scholarship Council (CSC) for funding (grant No. 201506200062). We are grateful to Prof. Jef Rozenski for recording HRMS spectra, Luc Baudemprez for running the 2D NMR experiments, and Leentje Persoons for excellent technical assistance. (China Scholarship Council (CSC)|201506200062)status: Publishe
Synthesis and biological evaluation of pyrrolo[2,1-f][1,2,4]triazine C-nucleosides with a ribose, 2-deoxyribose, and 2,3-dideoxyribose sugar moiety
No full texthe synthesis of hitherto unknown pyrrolo[2,1-f][1,2,4]triazine C-nucleosides is described. Structural variations (chlorine, bromine, iodine, and cyano groups) were introduced at position 7 of 4-aza-7,9-dideazaadenine. In addition, pyrrolo[2,1-f][1,2,4]triazine C-nucleosides bearing a 2'-deoxy-, 2',3'-dideoxy-, and 2',3'-dehydrodideoxyribose moiety were also prepared. Among these analogues, the pyrrolo[2,1-f][1,2,4]triazine C-ribonucleosides with either a hydrogen atom or cyano group at position 7 of the nucleobase displayed potent cytotoxic activity in a panel of various cancer cell lines.sponsorship: Q.L. thanks the China Scholarship Council (CSC) for funding
(grant 201506890014)status: Publishe
Structural investigation of the naphthyridone scaffold: identification of a 1,6-naphthyridone derivative with potent and selective anti-HIV activity
No full textBuilding upon a large, previously reported series of anti-HIV 6-desfluoroquinolones endowed with a peculiar mechanism of action, the inhibition of Tat-mediated transcription, replacement of the quinolone nucleus with a naphthyridone core was shown to be very productive. In this work, the naphthyridone scaffold was investigated in depth by synthesizing various analogues. This led to the identification of NM13 as the most selective derivative obtained in MT-4 cells. It is the result of the successful combination of the 1,6-naphthyridone nucleus and the C7 benzothiazolpiperazine group, which, for the first time, not only grants potent anti-HIV activity but displays very high selectivity. Further studies aimed at a more thorough investigation of the anti-HIV profile of this new derivative are in progress.sponsorship: These studies were supported financially by the MIUR (PRIN 2008, Rome, Italy) and K.U. Leuven (GOA10/14). S.M. is supported by a postdoctoral fellowship from the Fondazione Cassa di Risparmio (Perugia, Italy). We thank Mr. Roberto Bianconi (Department of Chemistry and Technology of Drugs, Perugia), Ms. Kristien Erven, Ms. Cindy Heens, and Mr. Kris Uyttersprot (Rega Institute for Medical Research, Leuven, Belgium) for their excellent technical assistance. (MIUR, Rome, Italy|GOA10/14, Fondazione Cassa di Risparmio (Perugia, Italy))status: Publishe
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
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