1,721,231 research outputs found
E se ricominciassimo dalle parole? Considerazioni a margine della riforma del lavoro
No full textBreve analisi critica dei presupposti che hanno portato all'introduzione del "contratto a tempo indeterminato a tutele crescenti"; la riforma del lavoro (cd Jobs act) in itinere suggerisce di indirizzare la ricerca sull'uso delle parole nel diritto del lavoro in trasformazione: termini come flessibilità, sicurezza, solidarietà, tutela, semplificazione, eguaglianza - tutti evocativi di concetti importanti e spesso di principi fondanti - sono sempre più spesso usati in modo ambiguo, improprio, talora mistificante
Effetti collaterali: recesso e consenso nella riforma del lavoro.
No full textIl contributo si sofferma sugli spazi della consensualità nella risoluzione del contratto di lavoro aperti e/o valorizzati nella riforma. In particolare: a) la conciliazione preventiva nel "contratto a tutele crescenti" e b) la prospettiva di una nuova disciplina delle dimissioni e della risoluzione consensuale. Le implicazioni e i rischi della nuova disciplina
Dimissioni in bianco: l’intervento necessario e la semplificazione pericolosa
No full textAnalisi critica del ddl S.1409 di riforma della disciplina delle dimissioni e delle risoluzioni consensuali di lavoratori e lavoratrici. Breve ricognizione dei precedenti normativi; puntualizzazioni sul significato e il ruolo svolto dai controlli mediante convalida delle dimissioni (con particolare riferimento alla disciplina vigente e modificata dalla l. 92/2012), qualche osservazione propositiva sulla riforma in itinere
Le finalità plurime del controllo sulle dimissioni dei lavoratori genitori
No full textSi tratta di uno studio sulla disciplina delle dimissioni e risoluzioni consensuali prevista per i lavoratori genitori e imperniata sul controllo mediante convalida amministrativa: l'evoluzione legislativa dell'istituto e le prassi applicative della convalida - analizzate attraverso una ricerca specifica - mettono in luce le finalità plurime della tutela predisposta, volta a individuare abusi e discriminazioni ma anche a fornire elementi conoscitivi sugli strumenti di conciliazione fra lavoro e compiti di cura
The ampicillin experimental and theoretical SERS spectra
No full textSurface enhanced Raman scattering (SERS) spectroscopy is a powerful tool for the study of structure, symmetry and orientation of molecules adsorbed on metal surfaces. It is a highly
sensitive technique useful to detect species present at a trace level concentrations and to gather information concerning metal–adsorbate interactions. The study of drug molecules adsorbed on
metallic substrate is becoming critical in future applications like drug delivery, bio-active surfaces, bio and chemical nano-sensors, etc. Moreover, the study of interaction of drug molecules with metals in solution can provide useful information on the biological activity of such molecules. Ampicillin or 6-[D(-)α-aminophenylacetamido] penicillanic acid is a wellknown penicillin class antibiotic with betalactamic structure, which is getting new attention for drug resistance problems. In the past we have studied the existing polymorphic and solvate forms by different analytical techniques and by comparing experimental and theoretical data [1].
In this work, ampicillin SERS spectrum at 10-4 M concentration was studied and discussed. The adsorption geometry of the ampicillin molecule on colloidal silver surface was deduced from the SERS selection rules. In addition, Density Functional Theory (DFT) computations on a couple of Ag atoms or AgCl interacting with different ampicillin groups were performed, to obtain theoretical spectra for the interpretation of the SERS experiments. Interactions with Ag colloidal surfaces have been approximated by placing an Ag2 cluster in positions close to electron donor groups of the ampicillin molecule (i.e. the carboxylic group (zwitterion), the sulfur atom (zwitterion), the aromatic ring (zwitterion), the –NH2 group (anion) and the tautomeric –COOH/–NH2 group). For the ampicillin the aug-cc-pVDZ (aug-cc-pV(D+d)Z for Sulfur atom) basis set was used, whereas the Ag atoms were modeled by the lanl2dz basis set. Calculations were performed with an implicit solvent model (CPCM). Computations led to stable optimized geometries with the exception of –NH3+/Ag2 (viz. the ampicillin in zwitterionic form) since such a group has a marked electrophilic character. Interpretation of the theoretical frequency spectra was performed by the Potential Energy Distribution (PED) analysis of the fundamental vibrations modes. According to the theoretical results, SERS experiments demonstrated that ampicillin was adsorbed in tilted orientation on silver colloid; the interaction mainly takes place by means of the benzenic ring and the aminic group
Experimental and theoretical SERS spectra: the case of Ampicillin
No full textSurface enhanced Raman scattering (SERS) spectroscopy is a powerful tool for the study of structure, symmetry and orientation of molecules adsorbed on metal surfaces. It is a highly sensitive technique useful to detect species present at a trace level concentrations and to gather information concerning metal-adsorbate interactions. The study of drug molecules adsorbed on metallic substrate is becoming critical in future applications like drug delivery, bio-active surfaces, bio and chemical nano-sensors, etc. Moreover, the study of interaction of drug molecules with metals in solution can provide useful information on the biological activity of such molecules.
Ampicillin or 6-[D(-)α-aminophenylacetamido] penicillanic acid is a well-known penicillin class antibiotic with betalactamic structure, which is getting new attention for drug resistance problems. In the past we have studied the existing polymorphic and solvate forms by different analytical techniques and by comparing experimental and theoretical data (C. Baraldi, A. Tinti, S. Ottani, M.C. Gamberini, J. Pharm. Biomed. Analysis 100 (2014) 329-340).
In this work, ampicillin SERS spectrum at 10-4 M concentration was studied and discussed. The adsorption geometry of the ampicillin molecule on colloidal silver surface was deduced from the SERS selection rules. In addition, Density Functional Theory (DFT) computations on a couple of Ag atoms or AgCl interacting with different ampicillin groups were performed, to obtain theoretical spectra for the interpretation of the SERS experiments. Interactions with Ag colloidal surfaces have been approximated by placing an Ag2 cluster in positions close to electron donor groups of the ampicillin molecule (i.e. the carboxylic group (zwitterion), the sulfur atom (zwitterion), the aromatic ring (zwitterion), the -NH2 group (anion) and the tautomeric -COOH/-NH2 group). For the ampicillin the aug-cc-pVDZ (aug-cc-pV(D+d)Z for Sulfur atom) basis set was used, whereas the Ag atoms were modeled by the lanl2dz basis set. Calculations were performed with an implicit solvent model (CPCM). Computations led to stable optimized geometries with the exception of -NH3+/Ag2 (viz. the ampicillin in zwitterionic form) since such a group has a marked electrophilic character. Interpretation of the theoretical frequency spectra was performed by the Potential Energy Distribution (PED) analysis of the fundamental vibrations modes.
According to the theoretical results, SERS experiments demonstrated that ampicillin was adsorbed in tilted orientation on silver colloid; the interaction mainly takes place by means of the benzenic ring and the aminic group
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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