172,320 research outputs found
H/C, Vivienda y Ciudad: Concurso Internacional de Proyectos
No full textAbbordaggio critico sulla condizione contemporanea del progetto architettonico e lo spazio urbano in relazione al social housing
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
Electrocatalytic CO2 reduction by aminopyridine cobalt complexes: electronic effect of substituents on the pyridyl ring and mechanistic insights
No full textIn the last decade, several earth-abundant metal-based molecular catalysts have been found highly active for the photochemical or electrochemical CO2 reduction. However, despite their efficiency for the light-driven CO2-to-CO process,1 the electrocatalytic performances of Co complexes containing N4 or N5 ligands are still generally affected by catalyst deactivation,2 large overpotentials3 and low faradaic yields, due to either ligand decomposition or a preferential H2 evolution pathway under acidic conditions.4 To overcome these barriers, design of novel Co catalysts should be coupled to a deep understanding of the electrocatalytic mechanism, based on the characterization of key intermediates formed during the process. 5
Herein, we present a series of novel synthesized [CoII(Y,XPyMetacn)(OTf)2] complexes (1R, Scheme 1) containing N4 tetradentate ligands with general formula Y,XPyMetacn (1-[2′-(4-Y-6-X-pyridyl)methyl]-4,7-dialkyl-1,4,7-triazacyclononane),6 employed as catalysts for the electrochemical reduction of CO2. The introduction of different substituents at the - and -positions of the pyridine allowed us to systematically evaluate the effect of the electronic properties of the ligand on the catalytic activity. As highlighted by the electrochemical data, the redox non-innocent character of the Y,XPyMetacn ligand is extremely sensitive to the substitution at the pyridyl ring, and influences not only the E1/2(CoII/I) value, but also the nature of the reduction event itself, thus leading to different reactivity of the electrochemically generated CoI species towards CO2. Moreover, extensive spectroscopic (NMR) and spectroelectrochemical (IR and UV-Vis) studies were carried out to investigate the intermediates produced in the course of the catalytic process. Theoretical modelling provided also key mechanistic details for the CO2 reduction reaction.
Scheme 1. General structures of the 1R complexes under study
References
1 Z. Guo, S. Cheng, C. Cometto, E. Anxolabéhère-Mallart, S.-M. Ng, C.-C. Ko, G. Liu, L. Chen, M. Robert,T.-C. Lau, J. Am. Chem. Soc. 2016, 138, 9413−9416
2 K.-M. Lam, K.-Y. Wong, S.-M. Yang, C.-M. Che, Dalton Trans. 1995, 1103−1107
3 A. Chapovetsky, T. H. Do, R. Haiges, M. K. Takase, S. C. Marinescu, J. Am. Chem. Soc. 2016, 138, 5765−5768
4 D. C. Lacy, C. C. L. McCrory, J. C. Peters, Inorg. Chem. 2014, 53, 4980−4988
5 H. Sheng, H. Frei, J. Am. Chem. Soc. 2016, 138, 9959−9967
6 a) A. Call, F. Franco, S. Fernandez, N. Kandoth, J. M. Lluis J. Lloret-Fillol, Chem. Sci. 2016, submitted; b) A. Call, Z. Codola, F. Acuna-Pares, J. Lloret-Fillol, Chem. Eur. J. 2014, 20, 6171 – 618
La reconstrucción del compás del Duque de Béjar (1677)
No full text[ES] En el manuscrito matemático Observationes diversarum artium (1664-1677) de Fray Ignacio Muñoz, se aborda un capítulo sobre Instrumentos Geometricos que detalla el compás de proporción reducción del Duque de Béjar de 1677. La investigación se enfoca en la reconstrucción del instrumento y el análisis de las 16 operaciones descritas. De las 10 operaciones susceptibles de análisis estadístico, se encuentra una dispersión del 1,574% ±1,509%. Como conclusión, se estable que el error de la construcción del instrumento y sus seis líneas de cálculo es del 1,416%.[EN] In Fray Ignacio Muñoz's mathematical manuscript "Observationes diversarum artium" (1664-1677), a chapter on Geometric Instruments details the 1677 Duque de Béjar's compass of reduction. The study focuses on reconstructing the instrument and analyzing the 16 described operations. Of the 10 operations amenable to statistical analysis, a dispersion of 1.574% ±1.509% is found. In conclusion, the error in the construction of the instrument and its six calculation lines is determined to be 1.416%.Lluis-Teruel, C.;Lluis I Ginovart, J. (2025). The reconstruction of the compass of the Duke of Béjar (1677). EGA Expresión Gráfica Arquitectónica. 30(54):240-255. https://doi.org/10.4995/ega.2025.20906OJS240255305
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
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
More than an adaptor molecule: The emerging role of tRNA in cell signaling and disease
No full textThis FEBS Letters ‘FOCUS ON’ series of short reviews on tRNA captures the essence of the Barcelona BioMed Conference on Gene Translation: Fidelity and Quality Control, which was held at the Institut d’Estudis Catalans in Barcelona on December 2–4, 2013. This meeting was powered by the dramatic resurgence of interest in tRNA biochemistry following the realization that tRNA is much more than a simple adaptor of the genetic code
Immunolocalization of A1 adenosine receptors in mammalian spermatozoa
No full textThe presence of A1 adenosine receptors (A1AR) in mammalian spermatozoa was previously demonstrated by radiochemical and immunochemical detection. This study was performed to investigate the cellular location of the A1AR to determine whether these receptors were somehow connected with ecto-adenosine deaminase and to evaluate their function in calcium uptake. By immunofluorescence staining we showed that in mammalian spermatozoa A1AR were constantly localized in the acrosomal region. This finding was confirmed by immunogold detection. Confocal analyses with anti-A1 and anti-ADA antibodies showed a high degree of colocalization. Calcium loading assay showed that this association was functional and affected calcium accumulation in mammalian spermatozoa. Therefore, we concluded that the acrosomal localization of A1AR was a constant feature in mammalian sperm. Moreover, these A1 receptors were functionally coupled to ecto-ADA and were able to modulate calcium uptake into an IP3-gated store
- …
