1,721,008 research outputs found
Apprendere e lavorare nell'era digitale - On-line collaborative e-learning per le organizzazioni sanitarie e sociali
No full textIl volume introduce all'uso delle tecnologie dell'informazione e della comunicazione sia nell'ambito della formazione a distanza che del Project Management, trovando applicazione in diversi settori sanitari e dell'area sociale. Lo scopo è quello di fornire agli operatori del settore utili indicazioni operative per l'introduzione e l'applicazione pratica di sistemi di E-learning
Synthetic cannabinoid JWH-018 impairs object recognition memory in mice: behavioral and electrophysiological evidence
No full textIntroduction:
JWH-018 (1-pentyl-3-(1-naphthoyl) indole) is a synthetic CB1 and CB2 agonist illegally marketed in 'Spice' and “herbal blend” for its psychoactive effects similar to those produced by Cannabis. In rodents JWH-018 reproduces the typical effects of THC as hypothermia, analgesia, hypolocomotion and akinesia, while its effects on memory functions are still unknowns. Behavioral and in vitro electrophysiological studies were undertaken to investigated the effects of acute JWH-018 administration on novel object recognition memory and hippocampal LTP formation in CD-1 male mice.
Methods and Results:
The novel object recognition task is a one-trial learning paradigm allowing the assessment of acquisition, consolidation or retrieval of (object) information separately. JWH-018 (0.1-1 mg/Kg i.p.) dose-dependently impaired both short (2 hours after training section) and long (24 hours after training section) memory retention in mice by CB1 receptor stimulation, since JWH-018 effect was prevented by the selective CB-1 receptor antagonist AM251 (3 mg/Kg).
Electrically evoked Schaffer area fEPSP has been extracellularly recorded from stratum radiatum of mouse dorsal hippocampal transversal slices. A stimulus–response curve was recorded before and after JWH-018 contact. At this time, an LTP stimulation paradigm was applied. JWH-018 (10-1000 nM) dose-dependently reduced LTP in hippocampal slices and abolished it at higher concentrations (300 and 1000 nM).
Conclusion:
These results show that JWH-018 impairs cognitive function in mice possibly by impairing hippocampal memory formation. This aspect should be carefully investigated since chronic consumption of THC impairs cognitive function not only in animal models but in particular in human consumers by altering brain neurodevelopment (http://www.dronet.org/monografia.php?monografie=93)
Innovative biological matrices and original sample pre-treatments for drugs of abuse analysis
No full textDrugs of abuse analysis has several important applications that can impact both forensic science and basic research. One of the most critical choices in this field is that of a suitable matrix for specimen collection. Urine is very attractive in terms of feasibility, but also not significant for the assessment of actual intoxication. Blood is the most obvious matrix for this purpose, however its sampling is not always possible and is invasive; moreover, blood is subject to degradation and needs to be stored in controlled conditions. Several alternative and innovative matrices are now emerging for drugs of abuse testing: saliva, hair (from different body districts) and dried blood spots (DBS). DBS testing, in particular, is very promising as a possible alternative to blood, being equally significant but much easier to obtain and to store. In the Laboratory of Pharmaco-Toxicological Analysis several methodologies have been implemented for drugs of abuse analysis, with good results, using the DBS technique coupled to LC-F for the monitoring of cocaine intake and of concomitant alcohol consumption. Assays are in progress to apply the DBS testing coupled to LC-MS/MS also to the determination of amphetamines and opioids. Other methods have been developed for the analysis of cocaine and cannabinoids in head, pubic and armpit hairs and to saliva. The sample pre-treatment procedure is also very important, heavily influencing the reliability of analytical data. Very promising results have been obtained by MEPS (microextraction by packed solvent), a procedure that can use significantly lower volumes of sample and solvents than SPE and is also much faster, anyway providing sound results. MEPS procedure coupled to spectrofluorimetric detection has demonstrated to be quite efficient in terms of sample clean-up and extraction yields. Assays are currently in progress, in order to fully validate these methods for application in different environments, such as “on street” for the monitoring of subjects suspected of driving under the influence of psychotropic substances
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
Original HPLC-F method for the simultaneous determination of cocaine and two metabolites in dried blood spots and plasma
No full textIntroduction: Cocaine (methyl (1R,2R,3S,5S)-3-(benzoyloxy)-8-methyl-8-azabicyclo[3.2.1]octane-2-carboxylate) is currently the second most widespread illicit drug in Western countries, after Cannabis. In Europe in particular, its use has been increasing in the past few years, following a pattern similar to that of the USA in the 1980s. This severe trend has attracted much attention from governments and health agencies and is creating much concern regarding its negative impact on people’s and in particular on adolescent’s health. It is evident the need for reliable and easily applied analytical methods for the determination of cocaine in abusers.
Methods: An original chromatographic method coupled to spectrofluorimetric detection (HPLC-F) is presented herein for the simultaneous determination in dried blood spots (DBS) and plasma of cocaine and two important metabolites, namely benzoylecgonine (its main metabolite) and cocaethylene (the active metabolite formed in the presence of ethanol).
Results: The analysis was carried out on a C8 column, using a mobile phase containing phosphate buffer and acetonitrile. Native analyte fluorescence was monitored at 315 nm, while exciting at 230 nm.
For DBS, sample pre-treatment was carried out by solvent extraction; for plasma, by solid phase extraction (SPE) with C8 cartridges. Extraction yields (> 91%) and precision values (RSD < 4.8%) were highly satisfactory on both matrices. The method was successfully applied to DBS and plasma samples collected from some cocaine users, both with and without concomitant ethanol intake.
Conclusions: The method has demonstrated to be suitable for the monitoring of cocaine/ethanol use by means of DBS and plasma testing. Moreover, it represents a significant improvement over existing ones, since it has the fundamental advantage of allowing the simultaneous quantification of cocaine, benzoylecgonine and cocaethylene, thus making it possible to detect the simultaneous intake of both cocaine and ethanol
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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